PB95-964510
EPA/ROD/R09-95/140
September 1995
EPA Superfund
Record of Decision:
Mather Air Force Base, Landfill OU
Sacramento County, CA
8/3/95
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SUPERFUND
RECORD OF DECISION
FINAL
LANDFILL OPERABLE UNIT SITES
MATHER AIR FORCE BASE
SACRAMENTO COUNTY, CALIFORNIA
July 1995
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Table of Contents
List of Figures. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . VI
List of Tables
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . Vll
List of Acronyms. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. x
1.0
2.0
Declaration. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I-I
1.1 Site Name and Location. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.2 Statement of Basis and Purpose. . . . . . . . . . . . . . . . . . . . . . . . . . . 1-1
1.3 Assessment of the Site. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-2
1.3.1 Site 1: Runway Overrun Landfill. . . . . . . . . . . . . . . . . . . . . 1-2
1.3.2 Site 2: "8150" Area Landfill. . . . . . . . . . . . . . . . . . . . . . . 1-3
1.3.3 Site 3: Northeast Perimeter Landfill No.1. . . . . . . . . . . . . . . 1-5
1.3.4 Site 4: Northeast Perimeter Landfill No.2. . . . . . . . . . . . . . .1-8
1.3.5 Site 5: Northeast Perimeter Landfill No.3. . . . . . . . . . . . . . 1-10
1.3.6 Site 6: Firing Range Landfill Site. . . . . . . . . . . . . . . . . . . 1-12
1.4 Description of the Selected Remedy. . . . . . . . . . . . . . . . . . . . . . . 1-14
1.4.1 Site 1 - Runway Overrun Landfill. . . . . . . . . . . . . . . . . . . . 1-15
1.4.2 Site 2 - "8150" Area Landfill. . . . . . . . . . . . . . . . . . . . . . 1-15
1.4.3 Site 3 - Northeast Perimeter Landfill No.1. . . . . . . . . . . . . . 1-15
1.4.4 Site 4 - Northeast Perimeter Landfill No.2. . . . . . . . . . . . . . 1-15
1.4.5 Site 5 - Northeast Perimeter Landfill No.3. . . . . . . . . . . . . . 1-16
1.4.6 Site 6 - Firing Range Landfill Sites. . . . . . . . . . . . . . . . . . . 1-16
1.5 Statutory Determinations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-16
1.6 Signatures.... . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1-18
Decision Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .2-1
2.1 Site Name, Location, and Description. . . . . . . . . . . . . . . . . . . . . . .2-1
2.2 Site History and Enforcement Activities. . . . . . . . . . . . . . . . . . . . . . 2-1
2.3 . Highlights of Community Participation. . . . . . . . . . . . . . . . . . . . . 2-36
2.4 Scope and Role of Response Action. . . . . . . . . . . . . . . . . . . . . . . 2-37
2.5 Summary of Site Characteristics. . . . . . . . . . . . ..... . . . . . . . . . . . 2-37
2.5.1 Summary of Hazardous Material Releases. . . . . . . . . . . . . . . 2-37
2.5.2 Nature and Extent of Contamination. . . . . . . . . . . . . . . . . . 2-37
RUI2-94/ES/I26000I.A WS
I
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2.6
2.5.1 Summary of Hazardous Material Releases. . . . . . . . . . . . . . . 2-37
2.5.2 Nature and Extent of Contamination. . . . . . . . . . . . . . . . . . 2-37
Summary of Site Risks. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-38
2.6.1 Human Health Risks. . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-38
2.6.1.1 Contaminant Identification. . . . . . . . . . . . . . . 2-38
2.6.1.2 Exposure Assessment. . . . . . . . . . . . . . . . . . 2-57
2.6.1.3 Toxicity Assessment. . . . . . . . . . . . . . . . . . . 2-57
2.6.1.4 Risk Characterization. . . . . . . . . . . . . . . . . . 2-61
2.6.2 Environmental Risks 0. . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-78
2.7 Description of Alternatives. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-78
2.7.1 Site 1 Remedial Alternative. . . . . . . . . . . . . . . . . . . . . . . . 2-79
2.7.1.1 Alternative L 1 ...................... 2-79
2.7.2 Site 2 Remedial Alternatives. . . . . . . . . . . . . . . . . . . . . . . 2-79
2.7.2.1 Alternative 2.1 - No-Action. . . . . . . . . . . . . . . 2-79
2.7.2.2 Alternative 2.2 - Landfill Capping. . . . . . . . . . . 2-79
2.7.2.3 Alternative 2.3 - Landfill Excavation and
Consolidation. . . . . . . . . . . . . . . . . . . . . . . 2-81
2.7.3 Site 3 Remedial Alternatives.. .. . . . . . . . . . . . . .. . . .. .2-81
2.7.3.1 Alternative 3.1 - No-Action. . . . . . . . . . . . . . . 2-81
2.7.3.2 Alternative 3.2 - Landfill Capping. . . . . . . . . . . 2-82
2.7.3.3 Alternative 3.3 - Landfill Excavation and
Consolidation. . . . . . . . . . . . . . . . . . . . . . . 2-82
2.7.4 Site 4 Remedial Alternatives. . . . . . . . . . . . . . . . . . . . . . . 2-82
2.7.4.1 Alternative 4.1 - No-Action. . . . . . . . . . . . . . . 2-83
2.7.4.2 Alternative 4.2 - Landfill Capping and
Embankment. . . . . . . . . . . . . . . . . . . . . . . . 2-83
Alternative 4.3 - Landfill Excavation,
Consolidation, and Capping. . . . . . . . . . . . . . . 2-83
2.7.5 Site 5 Remedial Alternatives. . . . . . . . . . . . . . . . . . . . . . . 2-84
2.7.5.1 Alternative 5.1 - No-Action. . . . . . . . . . . . . . . 2-84
2.7.5.2 Alternative 5.2 - Landfill Excavation and
Consolidation. . . . . . . . . . . . . . . . . . . . . . . 2-84
...
Alternative 5.3 - Landfill Excavation,
Consolidation, Embankment and Capping. . . . . . 2-86
2.7.4.3
2.7.5.3
RU 12-94fESf1260001.A WS
11
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2.8
Alternative 6.2 - Landfill Capping. . . . . . . . . . . 2-87
Alternative 6.3 - Landfill Excavation and
Consolidation. . . . . . . . . . . . . . . . . . . . . . . 2-87
Summary of the Comparative Analysis of Alternatives. . . . . . . . . . . . 2-88
2.8.1 Overall Protection of Human Health and the Environment. . . . . 2-89
2.8.1.1 Site 1 - Runway Overrun Landfill. . . . . . . . . . . 2-89
2.8.1.2 Site 2 - "8150" Area Landfill . . . . . . . . . . . . . . 2-89
2.8.1.3 Site 3 - Northeast Perimeter Landfill No.1. . . . . 2-89
2.8.1.4 Site 4 - Northeast Perimeter Landfill No.2. . . . 2-90
2.8.1.5 Site 5 - Northeast Perimeter Landfill No.3. . . . 2-90
2.8.1.6 Site 6 - Firing Range Landfill Sites. . . . . . . . . 2-90
2.8.2 Compliance with ARARs ....... . . . . . . . . . . . . . . . . . . 2-91
2.8.2.2 Applicability of California Code of Regulations
Title 23, Chapter 15 ..... . . . . . . . . . . . . . 2-123
2.8.2.3 Chemical-Specific ARARs for Soils. . . . . . . . . 2-124
2.8.2.4 Location-Specific ARARs . . . . . . . . . . . . . . . 2-127
2.8.2.5 Action-Specific ARARs ... . .. . . . . . . . . . . 2-128
2.8.2.6 Site 1 - Runway Overrun Landfill. . . . . . . .. 2-133
2.8.2.7 Site 2 - "8150" Area Landfill. . . . . . . . . . . . . 2-133
2.8.2.8 Site 3 - Northeast Perimeter Landfill No.1. . .. 2-134
2.8.2.9 Site 4 - Northeast Perimeter Landfill No.2. . .. 2-134
2.8.2.10 Site 5 - Northeast Perimeter Landf1ll No.3. .. 2-135
2.8.2.11 Site 6 - Firing Range Landfill Sites. . . . . . .. 2-135
2.8.3 Long-Term Effectiveness and Permanence. . . . . . . . . . . . . . 2-135
2.8.3.1 Site 1 - Runway Overrun Landfill. . . . . . . .. 2-135
2.8.3.2 Site 2 - "8150" Area Landfill. . . . . . . . . . . .. 2-135
2.8.3.3 Site 3 - Northeast Perimeter Landfill No.1. . .. 2-135
2.8.3.4 Site 4 - Northeast Perimeter Landfill No.2. . .. 2-135
2.8.3.5 Site 5 - Northeast Perimeter Landfill No.3. .. 2-136
2.8.3.6 Site 6 - Firing Range Landf1ll Sites. . . . . . .. 2-136
2.8.4 Reduction of Toxicity, Mobility, or Volume. . . . . . .. 2-136
2.8.4.1 Site 1 - Runway Overrun Landf1ll ......... 2-136
2.8.4.2 Site 2 - "8150" Area Landfill. . . . . . . . . . . .. 2-136
2.8.4.3 Site 3 - Northeast Perimeter Landfill No.1. . .. 2-136
.
2.8.4.4 Site 4 - Northeast Perimeter Landfill No.2. . .. 2-137
2.8.4.5 Site 5 - Northeast Perimeter Landfill No.3. .. 2-137
2.7.6.2
2.7.6.3
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2.9
2.8.4.3 Site 3 - Northeast Perimeter Landfill No.1. . .. 2-136
. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-136
2.8.4.4 Site 4 - Northeast Perimeter Landfill No.2. . .. 2-137
2.8.4.5 Site 5 - Northeast Perimeter Landfill No.3. .. 2-137
2.8.4.6 Site 6 - Firing Range Landfill Sites. . . . . . .. 2-137
2.8.5 Short-Term Effectiveness. . . . . . . . . . . . . . . . . . . . . . . . 2-137
2.8.5.1 Site 1 - Runway Overrun Landfill. . . . . . . .. 2-137
2.8.5.2 Site 2 - "8150" Area Landfill. . . . . . . . . . . . . 2-138
2.8.5.3 Site 3 - Northeast Perimeter Landfill No.1. . .. 2-138
2.8.5.4 Site 4 - Northeast Perimeter Landfill No.2. . .. 2-138
2.8.5.5 Site 5 - Northeast Perimeter Landfill No.3. .. 2-138
2.8.5.6 Site 6 - Firing Range Landfill Sites. . . . . . .. 2-138
2.8.6 Implementability ............................. 2-139
2.8.6.1 Site 1 - Runway Overrun Landfill. . . . . . . .. 2-139
2.8.6.2 Site 2 - "8150" Area Landfill. . . . . . . . . . . . . 2-139
2.8.6.3 Site 3 - Northeast Perimeter Landfill No.1. . .. 2-139
2.8.6.4 Site 4 - Northeast Perimeter Landfill No.2. . .. 2-139
2.8.6.5 Site 5 - Northeast Perimeter Landfill No.3. .. 2-139
2.8.6.6 Site 6 - Firing Range Landfill Sites. . . . . . .. 2-139
2.8.7 Cost..................................... 2-140
2.8.7.1 Site 1 - Runway Overrun Landfill. . . . . . . .. 2-140
2.8.7.2 Site 2 - "8150" Area Landfill. . . . . . . . . . . . . 2-140
2.8.7.3 Site 3 - Northeast Perimeter Landfill No.1. . .. 2-140
2.8.7.4 Site 4 - Northeast Perimeter Landfill No.2. . .. 2-140
2.8.7.5 Site 5 - Northeast Perimeter Landfill No.3. .. 2-141
2.8.7.6 Site 6 - Firing Range Landfill Sites. . . . . . .. 2-141
2.8.8 State/Support Agency Acceptance. . . . . . . . . . . . . . . . . . . 2-142
2.8.8.1 Site 1 - Runway Overrun Landfill. . . . . . . . .. 2-142
2.8.8.2 Site 2 - "8150" Area Landfill. . . . . . . . . . . .. 2-142
2.8.8.3 Site 3 - Northeast Perimeter Landfill No.1. . .. 2-142
2.8.8.4 Site 4 - Northeast Perimeter Landfill No.2. . .. 2-142
2.8.8.5 Site 5 - Northeast Perimeter Landfill No.3. .. 2-142
2.8.8.6 Site 6 - Firing Range Landfill Sites. . . . . . .. 2-142
2.8.9 Community Acceptance. . . . . . . . . . . . . .... . . . . . . . . . . 2-143
The Selected Remedies. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-143
2.9.1 Site 1 - Runway Overrun Landfill. . . . . . . . . . . . . . . . . . . 2-143
RUI2-94/ES/1260001.A WS
IV
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2.9.6 Site 6 - Firing Range Landfill Sites. . . . . . . . . . . . . . . . . . 2-145
2.10 Estimated Costs. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-146
2.11 Statutory Determinations. . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2-146
2.11.1 Protection of Human Health and the Environment. . . . . 2-158
2.11.2 Compliance with Applicable or Relevant and Appropriate
Requirements. . . . . . . . . . . . . . . . . . . . . . . . . . . 2-158
2.11.2.1 Site 1 - Runway Overrun Landfill. . . . . . . . . . 2-158
2.11.2.2 Site 2 - "8150" Area Landfill. . . . . . . . . . . . . 2-158
2.11.2.3 Site 3 - Northeast Perimeter Landfill No.1. . .. 2-158
2.11.2.4 Site 4 - Northeast Perimeter Landfill No.2. . .. 2-159
2.11.2.5 Site 5 - Northeast Perimeter Landfill No.3. . .. 2-160
2.11.2.6 Site 6 - Firing Range Landfill Sites. . . . . . . . . 2-160
2.11.3 Cost Effectiveness. . . . . . . . . . . . . . . . . . . . . . . . 2-161
2.11.3.1 Site 1 - Runway Overrun Landfill. . . . . . . . . . 2-161
2.11.3.2 Site 2 - "8150" Area Landfill. . . . . . . . . . . . . 2-161
2.11.3.3 Site 3 - Northeast Perimeter Landfill No.1. . .. 2-161
2.11.3.4 Site 4 - Northeast Perimeter Landfill No.2. . .. 2-161
2.11.3.5 Site 5 - Northeast Perimeter Landfill No.3. . .. 2-161
2.11.3.6 Site 6 - Firing Range Landfill Sites. . . . . . . .. 2-162
2.11.4 Utilization of Permanent Solutions and Alternative
Treatment (or Resource Recovery) Technologies to the
Maximum Extent Practicable. . . . . . . . . . . . . . . . . 2-162
Preference for Treatment as a Principal Element. . . .. 2-162
2.12 References..................................... 2-163
2.11.5
3.0
Responsiveness Summary. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3-1
APPENDIX:
A - Administrative Record
...
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v
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List of Figures
Figure
1.1
1.2
1.3
1.4
1.5
2.1
2.2
RU12-94/ES/126000I.A WS
Title
"8150" Area Landfill Site 2
Northeast Perimeter Landfill No.1 - Site 3
Northeast Perimeter Landfill No.2 - Site 4
Northeast Perimeter Landfill No.3 - Site 5
Firing Range Landfill Sites - Site 6
Site Vicinity Map
Locations of Landfill Sites
.
vi
Paae
1-4
1-6
1-8
1-11
1-13
2-2
2-3
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List of Tables
Table
Table 2.1
Table 2.2
Table 2.3
Table 2.4
Table 2.5
Table 2.6
Table 2.7
Table 2.8
Table 2.9
Table 2.10
Table 2.11
Table 2.12
Table 2.13
Table 2.14
Table 2.15
Table 2.16
Table 2.17
Table 2.18
Table 2.19
Table 2.20
Table 2.21
Table 2.22
Table 2.23
Table 2.24
Table 2.25
Title
Site 1 - Results of Previous Investigations
Site 2 - Results of Previous Investigations
Site 3 - Results of Previous Investigations
Site 4 - Results of Previous Investigations
Site 5 - Results of Previous Investigations
Site 6 - Results of Previous Investigations
Site 1 - Quarterly Sampling
Results for Sel~ted Analytes
Site 2 - Quarterly Sampling
Results for Selected Analytes
Site 3 - Quarterly Sampling
Results for Selected Analytes
Site 4 - Quarterly Sampling
Results for Selected Analytes
Site 5 - Quarterly Sampling
Results for Selected Analytes
Site 6 - Quarterly Sampling
Results for Selected Analytes
Refined List of Chemicals of Potential Concern and Affected Media
at Landfill au Sites from RI Baseline Risk Assessment
Site 2 - Designated Level Methodology
Site 3 - Designated Level Methodology
Site 4 - Designated Level ¥ethodology
Site 5 - Designated Level Methodology
Site 6 - Designated Level Methodology
Surface Water ARARs
Groundwater Constituents Above ARARs
Site 2 - Chemicals of Potential Concern
Site 3 - Chemicals of Potential Concern
Site 4 - Chemicals of Potential Concern
Site 5 - Chemicals of Potential Concern
Site 6 - Chemicals of Potential Concern
...
RU12-94/ES/1260001.A WS
Vll
Page
2-9
2-11
2-14
2-18
2-21
2-24
2-27
2-28
2-29
2-32
2-34
2-35
2-39
2-43
2-44
2-45
2-47
2-49
2-50
2-51
2-52
2-53
2-54
2-55
2-56
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Table 2.26 Final Landfill OU FFS Chemicals of Potential Concern
Table 2.27 Current Potential Exposure Scenarios and Chemicals of Potential Concern
Table 2.28 Future Potential Exposure Scenarios and Chemicals of Potential Concern
Table 2.29 Toxicity Summary for Chemicals of Potential Concern Mather AFB Sites
2, 3, 4, 5, and 6: Carcinogenic Effects
Table 2.30 Toxicity Summary for Chemicals of Potential Concern Mather AFB Sites
2, 3, 4, 5, and 6: Noncarcinogenic Effects
Table 2.31 Estimated Daily Intakes and Incremental Lifetime Cancer Risks
for Carcinogens - Site 2
Table 2.32 Estimated Daily Intakes and Hazard Quotients
for Noncarcinogens - Site 2
Table 2.33 Estimated Daily Intakes and Incremental Lifetime Cancer Risks
for Carcinogens - Site 3
Table 2.34 Estimated Daily Intakes and Hazard Quotients
for Noncarcinogens - Site 3
Table 2.35 Estimated Daily Intakes and Incremental Lifetime Cancer Risks
for Carcinogens - Site 4
Table 2.36 Estimated Daily Intakes and Hazard Quotients
for Noncarcinogens - Site 4
Table 2.37 Estimated Daily Intakes and Incremental Lifetime Cancer Risks
for Carcinogens - Site 5
Table 2.38 Estimated Daily Intakes and Hazard Quotients
for Noncarcinogens - Site 5
Table 2.39 Estimated Daily Intakes and Incremental Lifetime
Cancer Risks for Carcinogens - Site 6
Table 2.40 Estimated Daily Intakes and Hazard Quotients
for Noncarcinogens - Site 6
Mather AFB Remedial Alternatives
Water Quality Standards
Costs for the Selected Remedies
Site 2 Estimated Cost Summary
S~te 2 Estimated Cost Summary, Present Worth Calculation
Site 3 Estimated Cost Summary
Site 3 Estimated Cost Summary, Present Worth Calculation
...
Site 4 Estimated Cost Summary
Site 4 Estimated Cost Summary, Present Worth Calculation
Table 2.41
Table 2.44
Table 2.45
Table 2.46
Table 2.47
Table 2.48
Table 2.49
Table 2.50
Table 2.51
RU12-94/ES/1260001.A ws
Vlll
2-57
2-58
2-59
2-62
2-63
2-64
2-65
2-66
2-67
2-69
2-70
2-72
2-73
2-75
2-76
2-80
2-126
2-147
2-148
2-149
2-150
2-151
2-152
2-153
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Table 2.52
Table 2.53
Table 2.54
Table 2.55
Site 5 Estimated Cost Summary
Site 5 Estimated Cost Summary, Present Worth Calculation
Site 6 Estimated Cost Summary
Site 6 Estimated Cost Summary, Present Worth Calculation
2-154
2-155
2-156
. 2-157
""
RUI2-94/ES/1260001.A WS
IX
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List of Acronyms
AC&W
AFB
ARAR
BACT
BCRA
CCR
CERCLA
cOPC
CPR
CSF
CVRWQCB
CW
DCA
DCB
DCE
DCP
DDD
DDE
DDT
DLM
DFG
DSB
DTSC
ECR
EPA
FEMA
FFA
FFS
HEAST
HI
HQ
IRP
IRIS
Aircraft Control and Warning
Air Force Base
Applicable or Relevant and Appropriate Requirement
Best Available Control Technology
Base Closure and Realignment Act
California Code of Regulations
Comprehensive Environmental Response, Compensation, and Liability Act of
1980
Chemicals of Potential Concern
Code of Federal Regulations
cancer slope factor
Central Valley Region Water Quality Control Board
gas characterization well
dichloroethane
dichlorobenzene
dichloroethylene
dichloropropane
dichlorodiphenyldichloroethane
dichlorodiphenyldichloroethylene
dichlorodiphenyltrichloroethane
Designated Level Methodology
Department of Fish and Game
deep soil boring
Department of Toxic Substances Control
excess cancer risk
Environmental Protection Agency
Federal Emergency Management Agency
Federal Facility Agreement
Focused Feasibility Study
. Health Effects Assessment Summary Tables
Hazard Index
Hazard Quotient
Installation Restoration Program
Integrated Risk Information System
...
RU12-94/ES/1260001.A ws
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List of Acronyms (Continued)
IWMB
LOAEL
lMCB
MCL
MCLG
MSWLF
MW
NCP
NOAEL
NPL
O&M
OU
PAH
PCB
PCE
PDI
PM 10
POL
POTW
PRP
RID
RI
ROC
ROD
RWQCB
SAC
SARA
SDWA
SMAQMD
STLC
SWAT
SWRCB
TBC
TCA
Integrated Waste Management Board
Lowest-Observable-Adverse-Effect- Level
monbchlorobenzene
Maximum Contaminant Level
Maximum Contaminant Level Goal
Municipal Solid Waste Landfill
gas migration well
National Pollution Contingency Plan
No-Observed- Adverse- Effect-Level
National Priorities List
Operation and Maintenance
operable unit
polyaromatic hydrocarbon
polychlorinated biphenyls
tetrachloroethylene
preliminary design investigation
particulate matter less than 10 microns in size
petroleum, oil and lubricant
Publicly Owned Treatment Works
principal responsible party
reference dose
remedial investigation
reactive organic chemicals
Record of Decision
Regional Water Quality Control Board
Strategic Air Command
Superfund Amendments Reauthorization Act of 1986
Safe Drinking Water Act
Sacramento Metropolitan Air Quality Management District
. Soluble Threshold Limit Concentration
Solid Waste Assessment Test
State Water Resources Control Board
To-Be-Considered
trichloroethane
...
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L~tofAcronyms~on6nue~
TCE
THC
TILC
TPH
UCL
u.s.
USAF
VOC
WET
trichloroethylene
total hydrocarbon content
total threshold limit concentration
total petroleum hydrocarbon
upper confidence level
United States
United States Air Force
volatile organic compound
Waste Extraction Test
RU 12-94fES/126000 I.A WS
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XlI
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1.0 Declaration
Statutory Preference for Treatment as a
Principal Element is Not Met
and a Five-year Review is Required
1. 1 Site Name and Location
Landfill Operable Unit (aU) Sites
Mather Air Force Base (AFB),
Sacramento County, California
1.2 Statement of Basis and Purpose
This decision document presents the selected remedial actions for the LandfIll au Sites,
at the inactive Mather APB, Sacramento County, California. The selected remedial
actions were developed in accordance with the Comprehensive Environmental Response,
Compensation, and Liability Act of 1980 (CERCLA), as amended by the Superfund
Amendments Reauthorization Act of 1986 (SARA) and, to the extent practicable, the
National Oil and Hazardous Substance Pollution Contingency Plan (NCP). The
Installation Restoration Program (IRP) sites which comprise the Landfill au at the
inactive Mather AFB include: Site 1 - Runway Overrun Landfill; Site 2 - "8150" Area
Landfill; Site 3 - Northeast Perimeter Landfill No.1; Site 4 - Northeast Perimeter
Landfill No.2; Site 5 - Northeast Perimeter Landfill No.3; and Site 6 - Firing Range
Landfill Sites. This decision is based on the Administrative Record for these sites. The
content of this Record of Decision (ROD) is based on recommendations in the
Environmental Protection Agency's (EPA) Interim Final Guidance on Preparing
Superfund Decision Documents rEP A 1989a). The Administrative Record Index
(Appendix A) identifies documents that were considered or relied upon to make these
decisions.
The purpose of this ROD is to set forth the remedial actions to be conducted at the
Landfill au Sites to eliminate contact with the landfill contents and comply with
regulations governing the closure of landfills.
FUl/12-94/~/1260001J\VVS
1-1
-------
The United States (U.S.) EPA Region IX and the State of California concur with the
following selected remedial alternatives:
.
Site 1:
Site 2:
Site 3:
Site 4:
Site 5:
Site 6:
Alternative 1.1 - No-Action
Alternative 2.2 - Capping (Vegetative Cover)
Alternative 3.2 - Capping (Engineered Cap)
Alternative 4.2 - Capping (Engineered Cap) and Embankment
Alternative 5.2 - Excavation and Consolidation
Alternative 6.3 - Excavation and Consolidation.
.
.
.
.
.
This ROD reflects substantial disagreement between the U.S. Air Force (USAF), the
U.S. EP A, and the State regarding the applicability of State environmental requirements.
However, the State has detennined that the proposed actions will comply with the
substance of those requirements. Therefore, in the interest of promoting expedient
remediation and reuse, the State has not disputed this ROD.
1.3 Assessment of the Site
Contamination exists at the Landfill OU sites as a result of past Air Force operations
conducted between 1918 and 1974. The landfills were mainly used for the disposal of
general and sanitary refuse. In addition to garbage and household trash, it was reported
that petroleum, oil, and lubricant (POL) wastes, as well as waste solvents, primarily
trichloroethylene (TCE), may have been disposed in the landfills. It has also been
reported that daily burning of the refuse occurred at two of the landfills (Sites 3 and 4).
A brief description of each of the Landfill OU sites is provided in the following sections.
1.3.1 Site 1: Runway Overrun Landfill
Site 1 is . located southeast of the formerly active Main Base Area and is partially covered
by the overrun of Runway 22R. The site was the original Base landfill and received
general refuse from Base operations prior to 1942. Records are not available describing
the materials buried at this site. No evidence of refuse has been found during previous
investigations. Therefore, it appears that all refuse was removed from Site 1 during the
construction" of the runway overrun in the 1950s.
Investigations at Site 1 consisted of landfill gas characterization and monitoring,
geophysical surveying, soil sampling, and groundwater monitoring. Table 2.1 presents a
RL/12-94 /ES/l2BXXJIA WS
1-2
-------
chronologie summary of the investigation results. Two landfill gas characterization wells
(CW) (CW-2 and CW-3) and five gas migration wells (MW) (MW-4 through MW-8)
were installed and sampled. Methane was not detected in either CW, but hydrocarbons
were found in the MWs. No refuse or debris were encountered in the CWs drilled in
the suspected landfill trench location or perimeter MWs.
Five deep soil borings (DSB) (DSB-T-1A through DSB-T-IE) were drilled and sampled.
Diesel, oil and grease, and methylene chloride were detected. Inorganics were detected
below total threshold limit concentrations (TfLC).
Two shallow groundwater wells, i.e., MAFB-14 and MAFB-15 were installed and
sampled. Dichloroethylene (DCE), TCE, tetrachloroethylene (PCE), and 1,2-
dichloropropane (DCP) were detected. Wells MAFB-14 and 15 were abandoned and
replaced with Well MAFB-l25. Additionally, Wells MAFB-1l5 and 126 were installed.
Four quarters (1991) of sampling for Solid Waste Assessment Test (SWAT) metals and
volatile organic compounds (VOC) was conducted in Wells MAFB-1l5, 125, and 126.
Tetrachloroethylene (PCE), TCE, and DCE were detected.
Since no refuse or contaminants were found at Site 1 in the subsurface soils, no potential
source for contamination exists. Therefore, there is no threat to public health, welfare,
or the environment.
1.3.2 Site 2: "8150" Area Landfill
Site 2 is located northwest of the Aircraft Control and Warning (AC&W) OU Site Area
and is partially covered by the now inactive Strategic Air Command (SAC) alert apron
(see Figure 1.1). The site was the main sanitary landfill for the Base from 1942 to 1950.
Limited information is available concerning past operations conducted at the landfill.
However, common practice of this era would suggest that some POL wastes may have
been disposed with the refuse.
Investigations at Site 2 consisted of landfill gas characterization and monitoring,
geophysical sUIveying, soil sampling and trenching, and groundwater monitoring.
Table 2.2 presents a chronologie summary of the investigation results. Three landfill
CWs (CW-9 through CW-ll) and four landfill MWs (MW-12 through MW-15) were
installed and sampled. In Wells CW-9 and CW-ll carbon dioxide and methane were not
~etected. Detected compounds were trichloromethane, carbon tetrachloride, 1,1,1-
RL/12-94/ES/1260001AWS .
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FIGURE 1.1
.8150" MfA LANDFILL
SITE 2
PREPARED FOR
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I
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-------
trichloroethane (TCA), TCE, and PCE. A vapor sample could not be collected from
Well CW-lO because the well contained water. Migration well samples were analyzed
only for total hydrocarbon content (TIlC); Wells MW-12, MW-13, MW-14, and MW-15
contained TIlC. No refuse or debris was encountered. Original landfill gas migration
wells (MW-12 through MW-15) were later resampled for methane; methane was
detected in Well MW -12.
Five deep soil borings (DSB-A-2A through DSB-A-2E) were drilled and sampled.
1,4-dichlorobenzene (DCB), diesel, and total oil and grease were detected. All detected
inorganics were below TfLCs. The presence of refuse (mainly glass, bottles, and metal
debris) was confirmed in three of five trenches (IWMB-l, 4, and 5 of IWMB-1 through
IWMB-5) excavated by the Base Civil Engineering in coordination with the Integrated
Waste Management Board (IWMB). Eight additional trenches (TR2-1 through TR2-8)
were excavated to assess the lateral extent of refuse in the landfills. Trenches 1R2-4 and
TR2-8 encountered refuse. Trench 1R2-4 showed evidence of burned refuse.
Three shallow wells were installed and sampled (MAFB-16, MAFB-17, MAFB-18). No
significant levels of VOCS were detected. Total oil and grease and lead were detected.
Well MAFB-16 was not redeveloped or sampled due to well damage. No significant
levels of contamination were detected in Wells MAFB-17 or -18. Wells MAFB-16 and
MAFB-17 were abandoned and replaced with MAFB-127 and 128. Groundwater was
sampled from one landfill CW, Well CW-10. Only total lead was detected. Initial/first,
second, and third quarter 1991 sampling of Wells MAFB-127, 128, and 129 detected total
lead. No other constituents were detected. Well MAFB-129 was installed for the SWAT
monitoring network. Four quarters (1991) of sampling for SWAT metals and VOCs was
conducted in Wells MAFB-18, 127, 128, and 129. All values detected were below
established Soluble Threshold limit Concentrations (STLC) and maximum contaminant
levels (MCL). No pesticides or polycholorinated biphenyls (PCB) were detected.
Actual or threatened releases of hazardous substances from Site 2, if not addressed by
implementing the response actions selected in this ROD, may present a current or
potential threat to public health, welfare, or the environment.
1.3.3 Site 3: Northeast Perimeter Landfill No.1
Site 3 is located in the northeast comer of the now inactive Base (see Figure 1.2). Site 3
was the main sanitary landfill for the Base from 1950 through 1967. Refuse was
RL/12-94fES/1260001.A WS
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reportedly placed in trenches, burned, and covered daily. The backfilled trenches are
discernable at the surface of the site where settlement of the refuse and surface cover
cracking has occurred. In addition to refuse, the following items were also reportedly
disposed at this site: drummed POL wastes; hospital wastes; waste paint and thinners;
and empty pesticide containers.
Investigations at Site 3 consisted of landfill gas characterization and monitoring,
geophysical surveying, soil sampling and trenching, and groundwater monitoring.
Table 2.3 presents a chronologie summary of the investigation results. Three CWs
(CW-16, 17, and 18) and four MWs (MW-19, 20, 22, and 23) were installed and sampled.
Hydrocarbons as mc, vinyl chloride, TCE, and PCE were detected. Methane was not
detected in any of the perimeter MWs. Methane and refuse were detected in
Well CW-18. Additionally, two CWs (CW-301 and 302) and eight MWs (MW-301
through MW-308) were installed and sampled for methane; Wells CW-18 and MW-19
were resampled for methane. None of the perimeter MWs detected methane. Methane
was detected in both Wells CW-301 and CW-302.
Ten DSBs (DSB-A-3A through 3J) were drilled and sampled. Trichlorotluoromethane,
diesel, methylene chloride, and oil and grease were detected. Detected inorganic
constituents were below TI1..Cs. Four surface soil samples (SS-3A to SS-3D) were
collected and sampled. Toluene, xylene, oil and grease, diesel, acenaphthene,
anthracene, benzo( a )pyrene, pyrene, phenanthrene, benzo( a )anthracene,
benzo(b )tluoranthene, benzo(g,h,i)perylene, benzo(k)tluoranthene, chrysene,
tluoranthene, ideno(1,2,3-cd)pyrene, and acenaphthylene were detected. All detected
inorganics were below TI1..Cs. Nine soil samples were collected during drilling of the
CWs and analyzed for geotechnical parameters. Additionally, three surface bulk samples
were collected for geotechnical analyses. Four trenches (1R3-1 through TR3-4) were
excavated to assess the lateral extent of refuse in the landfills. All four trenches
encountered refuse with little or no evidence of burning.
Groundwater monitoring wells MAFB-24, 25, and 26 were installed and sampled.
Dichloroethylene, TCE, and 1,2-DCP were detected in Well MAFB-26. No significant
levels of contamination were detected in Wells MAFB-24 or 25. Wells MAFB-ll1, 112,
130, 131, 132, and 133 were installed and sampled. Trichloroethylene, PCE, and DCE
were detected. A perched water sample from Well CW-30l was collected and analyzed.
Vinyl chloride, DCE, and DCB were detected.
RL{12-94 fJ3{l2fJX1JIA WS
1-7
-------
Actual or threatened releases of hazardous substances from Site 3, if not addressed by
implementing the response actions selected in this ROD, may present a current or
potential threat to public health, welfare, or the environment.
1.3.4 Site 4: Northeast Perimeter Landfill No.2
Site 4 is adjacent to and east of Site 3, and was the main sanitary landfill site for the
entire Base from 1967 through 1971 (see Figure 1.3). Operations were reportedly similar
to those conducted at Site 3, and included daily filling, burning, and covering operations.
The trenches are discemable across the surface due to settling and extensive surface
cracking. A POL waste disposal pit was reportedly located at the northeast comer of the
site and was in operation for approximately two years during the late 1960s.
Trichloroethylene may have been present in the POL waste.
Investigations at Site 4 consisted of landfill gas characterization and monitoring,
geophysical surveying, soil sampling and trenching, and groundwater monitoring.
Table 2.4 presents a chronologic summary of the investigation results. Two CWs (CW-24
and 25) and four MWs (MW-26 through MW-29) were installed and sampled.
Trichloroethylene, PCE, and mc were detected. Methane was detected in both Wells
CW-24 and CW-25. Refuse was encountered during drilling of the CWs. Two additional
CWs (CW-401 and 402) and three MWs (MW-401, 402 and 403) were installed and
sampled for methane. Six other wells (MW-26 through MW-29 and CW-24 and 25) were
also resampled for methane. None of the perimeter MWs detected methane. Methane
was detected in both Wells CW-401 and CW-402.
Eight DSBs (DSB-A-4A through DSB-A-4H) were drilled and sampled. Chlorobenzene,
diesel, gasoline, ethylbenzene, and oil and grease were detected. All metals were below
TTLCs. Four surface soil samples (SS-4A through SS-4D) were collected and analyzed.
Toluene, gasoline, diesel, 2-butanone, and oil and grease were detected. Six sediment
samples (SD-4A through SD-4D) were collected and analyzed. Toluene, ethylbenzene,
diesel, 2-butanone, and gasoline were detected. Ten soil samples were collected during
drilling of Wells CW-401 and CW-402 and analyzed for geotechnical parameters. Also,
three surface bulk samples were collected for geotechnical analyses. Ten trenches
(TR4-1 through TR4-10) were excavated to assess the lateral extent of refuse in the
landfill. Four of the trenches (TR4-1 through TR4-4) encountered refuse. Trench
TR4-3 showed evidence of burned refuse.
RL/12-94/ES/1260001A WS
1-8
-------
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NORTHEAST PERIMETER lANDFlLL NO.2
SITE 4
PREPARED FOR
MATHER AIR FORCE BASE
SACRAMENTO. CALIFORNIA
m INTERNATIONAL
TECHNOlDGY
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WATER MONITORING WELL
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1R4-1 TRENCH LOCATION
MA-L2S4R(MA183)
FU/2-94/~/1260001~VVS.
1-9
-------
[-
Three shallow groundwater monitoring wells, i.e., Wells MAFB-19 through MAFB-21,
were installed and sampled. Dichloroethylene, TCE, and PCE were detected mainly in
Well MAFB-21. Well MAFB-19 was not redeveloped or sampled due to well damage.
No significant contamination was detected in Well MAFB-20. Groundwater samples
were collected from perimeter Well MAFB-5 and analyzed for target analytes.
Trichloroethylene, PCE, toluene, xylenes, benzene, and DCE were detected. Three
surface water samples (SW-4A, SW-4B, and SW-4F) were collected and analyzed. Diesel
and total lead were detected; All inorganics were below MCLs. Wells MAFB-19 and 20
were dry in 1990 and wex:e replaced by MAFB-136 and 132, respectively.
Actual or threatened releases of hazardous substances from Site 4, if not addressed by
implementing the response actions selected in this ROD, may present a current or
potential threat to public health, welfare, or the environment.
1.3.5 Site 5: Northeast Perimeter Landfill No.3
Site 5, which is located south of Site 4, was the main sanitary landfill during 1971 (see
Figure 1.4). This site consists of two major east-west trending trenches and an
apparently narrower trench which extends further to the east. The location of the major
trenches is visible due to extensive cracking and settling of the surface soils. Following
disposal in the landfill, the wastes were covered without being burned. Small quantities
of drummed POL wastes may have been disposed at this site.
Investigations at Site 5 consisted of landfill gas characterization and monitoring,
geophysical surveying, soil sampling and trenching, and groundwater monitoring.
Table 2.5 presents a chronologie summary of the investigation results. One CW (CW-30)
and two MWs (MW-31 and MW-32) were installed. Trichloroethylene, PCE, and
benzene were detected. Methane was detected in Well CW-30. An additional CW
(CW-501) and four MWs (MW-501 through MW-504) were installed and sampled for
methane. The existing wells (MW-31, MW-32, and CW-30) were also resampled for
methane. None of the perimeter MWs detected methane. The maximum detected
methane concentration was in Well CW-30.
Three DSBs (DSB-A-5A through DSB-A-5C) were drilled and sampled. Gasoline and
oil and grease were detected. Detected inorganics were below lTLCs. Two surface soil
samples (SS-A-5A and SS-A-5B) were collected and analyzed. Toluene, diesel, and oil
and grease were detected. Inorganic constituents were detected at levels below TI1£s.
RL/12-94/ES/1260001.A ws
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FIGURE 1.4
NORTHEAST PERIMETER LANDFILL NO. J
SITE 5
PREPARED FOR
MATHER AIR FORCE BASE
SACRAMENTO, CAUFORNIA
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-------
One sediment sample (SD-5A) was collected and analyzed. Toluene and gasoline were
detected. Inorganic constituents were detected at levels below TTLCs. Six soil samples
were collected during drilling of Well CW-501 and analyzed for geotechnical parameters.
Also, three surface bulk samples were collected for geotechnical analyses. Twelve
trenches (TRS-l through TRS-4 and TRS-2A through TR5-2H) were excavated to assess
the lateral extent of refuse in the landfills. All trenches, except trenches TRS-2G
and 2H, encountered refuse with little or no evidence of burning. Trenches showed the
eastward extent of refuse extent was greater than expected.
Groundwater monitoring wells MAFB-22 and MAFB-23 were installed and sampled. N?
significant contaminants were detected in Well MAFB-22. Samples from Well MAFB-23
contained DCE, PCE, 1,2-DCP, and dichloroethane (DCA). Well MAFB-23 was not
redeveloped or sampled due to well damage. Groundwater samples were collected from
Wells MAFB-139 and MAFB-141 and analyzed for target analytes. Chloromethane,
1,I-DCA, TCE, and 1,2-DCP were detected. One surface water sample (SW-5A) was
collected and analyzed. Diesel and total lead were detected. Inorganic constituents
were detected at levels below MCLs. Four quarters (1991) of sampling for SWAT
metals and VOCs were conducted in Wells MAFB-139, 140, and 141. The compounds
1,1-DCA, 1,2-DCP, chloroform, chloromethane, methylene chloride, PCE, TCE, and
DCE were detected. All detected inorganic constituents were below established STLCs
and MCLs.
Actual or threatened releases of hazardous substances from Site 5, if not addressed by
implementing the response actions selected in this ROD, may present a current or
potential threat to public health, welfare, or the environment.
1.3.6 Site 6: Firing Range Landfill Site
Site 6 is located in the southeastern portion of the now inactive Mather AFB and was
the main sanitary landfill site for the Base from 1972 through 1974 (see Figure 1.5).
Site 6 consists of two soil-covered landfills, one north and one south of an intermittent
stream channel. Refuse (primarily garbage and household trash) was dumped into the
landfill trenches. Small quantities of drummed used and unused paint thinners, and POL
wastes were "reportedly disposed at this site. Extensive settling and surface cracking of
the surface soil is evident at both landfills.
FUL/12-94/~/1260001J\VVS
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FIGURE 1.5
fiRING RANGE LANDfiLL SITES
SITE 6
PREPARED fOR
MATHER AIR fORCE BASE
SACRAMENTO, CALIFORNIA
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Investigations at Site 6 consisted of landfill gas characterization and monitoring, soil
sampling and trenching, and groundwater monitoring. Table 2.6 presents a chronologie
summary of the investigation results. Two CWs (CW-33 and CW-34) and four MWs
(MW-35 through MW-38) were installed and sampled. Vinyl chloride, TCE, PCE,
benzene, l,l,l-TCA, and mc were detected. Methane was detected in Wells CW-33
and CW-34. Four wells CW-33, CW-34, MW-35, and MW-36 were resampled; vinyl
chloride, benzene, and TCE were detected. Two additional CWs (CW-601 and 602) and
ten MWs (MW-601 through MW-610) were installed and sampled for methane; Wells
CW-33 and 34 were also resampled for methane. None of the perimeter MWs detected
methane. The maximum methane concentration detected was in Well CW-33.
Eight DSBs (DSB-A-6A through DSB-A-6H) were drilled and sampled.
1,2-dichlorobenzene, gasoline, 1,4-DCB, 4,4-dichlorodiphenyldichloroethane (DDD),
4,4-dichlorodiphenyldichloroethylene (DDE), monochlorobenzene (MCB), ethylbenzene,
xylenes, 4,4-dichlorodiphenyltrichloroethane (DDT), oil and grease, heptachlor epoxide,
gamma-Chlordane, and diesel were detected. All detected inorganics were below
TILCs. Four surface soil samples (SS-6A through SS-6D) were collected and analyzed.
Diesel and oil and grease were detected. All detected inorganics were below TILes.
Sediment samples SD-6A, SD-6B, and SD-6C were collected and analyzed. Only
inorganic constituents were detected, all of which were below TILes. Eight soil samples
were collected during drilling of wells CW-601 and CW-602 and analyzed for
geotechnical parameters. Also, three bulk soil samples were collected for geotechnical
analyses. Ten trenches were excavated (TR6-1 through 1R6-10) to assess the lateral
extent of the refuse in the landfills. Seven of the ten trenches encountered refuse with
little or no evidence of burning.
Three shallow groundwater monitoring wells were installed and sampled (MAFB-28, 29,
and 30). No significant contamination was detected. Groundwater monitoring wells
MAFB-142, 143 and 144 were installed. Groundwater samples were collected from
Wells MAFB-28, 142, 143, and 144 and analyzed. There were no detections in Well
MAFB-28. Total petroleum hydrocarbons (TPH) as diesel, oil and grease, total lead,
and benzyl chloride were detected in Wells MAFB-142, 143, and 144. Three surface
water samples (SW-6A through SW-6C) were collected and analyzed. Diesel and total
lead were detected. All detected inorganics were below drinking water MCLs.
RL/12-94/ES/1260001.A ws
1-14
-------
Actual or threatened releases of hazardous substances from Site 6, if not addressed by
implementing the response actions selected in this ROD, may present a current or
potential threat to public health, welfare, or the environment.
1.4 Description of the Selected Remedy
This OU addresses only remedies related to contamination of the soils at
Sites 1 through 6. Any contamination of the groundwater underlying these sites will be
addressed as part of a separate Groundwater OU ROD.
Based on the human health risk assessment, all risks are within the acceptable range of
1 x 10-4 to 1 x 10-6 in their current state. Therefore, the selected remedies will be
instituted to prevent contact with the landfill contents and comply with landfill closure
regulations.
The following sections provide the major components of the selected remedy for each of
the Landfill OU sites.
1.4. 1 Site 1 - Runway Overrun Landfill
No refuse or contaminants were found during investigative activities. Therefore, it is
believed that all refuse was removed prior to construction of the runway overrun. Since
there is no refuse or soil contamination, no potential source for contamination exists.
Therefore, no further action is the selected remedy. .
1.4.2 Site 2 - "8150" Area Landfill
The selected remedy for Site 2 is a vegetative cover. The major components of this
remedy include:
.
installing a vegetative cover;
installing passive gas vent wells;
monitoring of groundwater and landfill gas; and
invoking access restrictions.
.
.
.
1.4.3 Site 3 - Northeast Perimeter Landfill No.1
The selected remedy for Site 3 is an engineered cap.
remedy include:
The major components of this
.
installing an engineered cap;
RL/12-94/ES/1260001AWS .
1-15
-------
.
installing passive gas vent wells;
monitoring of groundwater and landfill gas; and
invoking access restrictions.
.
.
7.4.4 Site 4 - Northeast Perimeter Landfill No.2
The selected remedy for Site 4 is an engineered cap and embankment.
components of this remedy include:
The major
.
installing an engineered cap;
installing flood control measures (e.g., embankment);
installing passive gas vent wells;
monitoring of groundwater and landfIll gas; and
invoking access restrictions.
.
.
.
.
1.4.5 Site 5 - Northeast Perimeter Landfill No.3
The selected remedy for Site 5 is excavation and consolidation.
of this remedy include:
The major components
.
excavating the landfIll materials;
transporting the material to, and consolidating it with the landfill materials
at Site 4; and
monitoring the groundwater.
.
.
7.4.6 Site 6 - Firing Range Landfill Sites
The selected remedy for Site 6 is excavation and consolidation.
of this remedy include:
The major components
.
excavating the landfill materials;
transporting the material to, and consolidating it with the landfill materials
at Site 4; and
monitoring the groundwater.
.
.
1.5 Statutory Determinations
The selected remedies satisfy the statutory requirements of Section 121(b) of CERCLA,
as amended by SARA, in that the following four mandates are attained:
.
The selected remedies are protective of human health and the
environment.
RL/12-94/ES/1260001.A WS
1-16
-------
.
The selected remedies comply with federal and state requirements that are
legally applicable or relevant and appropriate to the remedial actions.
.
The selected remedies are cost-effective.
.
The selected remedies utilize permanent solutions and alternative
treatment technologies, or resource recovery technologies, to the maximum
extent praCticable.
However, because treatment of the principal threats at the sites was not found to be
practicable, these remedies do not satisfy the statutory preference for treatment as a
principal element of the remedies. The facts that no onsite "hot spots" exist that
represent continuing major sources of contamination, and no unacceptable risk exists
from the landfills in their current state, preclude remedies in which contaminants would
be excavated and treated in a cost-effective manner. The remedy for Landfill au Sites
2, 3, and 4 will result in hazardous substances remaining onsite above health-based levels
during the remedial action. Therefore, a review will be conducted within five years after
commencement of the remedial action to ensure that the remedy continues to provide
adequate protection of human health and the environment.
RL/12-94/'ES/11fIXXJ1A WS
1-17
-------
1.6
Signatures
;;J~'~
Director, Federal Facilities Cleanup Office, Region IX
U.S. Environmental Protection Agency
?!~ /fS-
/ ,Date
Alan K. Olsen
Director Air Force Base Conversion Agency
U.S. Air Force
!l~~ O-~
Anthony J.liInd~ P.E...
Chief, Northern California Operations
Office of Military Facilities
Department of Toxic Substances Control
California Environmental Protection Agency
6-7-9<;
Date
RL/IZ-94/ES/1260001A WS
1-18
-------
2.0 Decision Summary
2. 1 Site Name, Location, and Description
The now inactive Mather AFB is located in the Central Valley region of northern
California in Sacramento County, approximately 12 miles east of downtown Sacramento,
C~ornia and due south of unincorporated Rancho Cordova, California, as shown on
Figure 2.1. The now inactive Base is due south of U.S. Highway 50, a major highway
connecting Sacramento and South Lake Tahoe. Mather AFB was constructed in 1918
and its primary mission was as a flight training school. The now inactive Base
encompassed at the time of closure approximately 5,845 acres (129 acres of easements)
in an unsurveyed part of Township 8 North, Ranges 6 East and 7 East. The Base was
decommissioned under the Base Closure and Realignment Act (BCRA) on
September 30, 1993.
The sites which comprise the Landfill au at the now inactive Mather AFB includ~:
Site 1 - Runway Overrun Landfill; Site 2 - "8150" Area Landfill; Site 3 - Northeast
Perimeter Landfill No.1; Site 4 - Northeast Perimeter Landfill No.2; Site 5 - Northeast
Perimeter Landfill No.3; and Site 6 - Firing Range Landfill Sites. Figure 2.2 presents a
location map of the Landfill au sites.
Topography at the sites is nearly flat and vegetation consists of annual grasses. At
Sites 3, 4, 5, and 6, the landfill trenches are visible across the surface due to settling and
extensive surface cracking. Surface features at the sites include wetlands near Sites 3, 4,
and 6, portions of Sites 4, 5, and 6 that are within the 1000year floodplain of Morrison
Creek and its tributaries, and an intermittent tributary of Morrison Creek between the
two landfills at Site 6.
There is no present onbase residential area near any of the Landfill au sites. Before
the Base was decommissioned, the nearest onbase residential area was near Sites 1
and 2. The nearest offbase residential area was, and remains, near Site 6.
2.2 Site H/story and Enforcement Activities
Mather AFB was constructed in 1918 and its primary mission was as a flight training
school. The Base was decommissioned on September 30, 1993.
RL/12-94/ES/1260001A WS
2-1
-------
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FIGURE 2.1
SITE VICINITY MAP
PREPARED FOR
MA THER AIR FORCE BASE
SACRAMENTO. CALIFORNIA
m INTERNATIONAL
TECHNOIDGY
CORPORATION
1,26A311
RI/2-94/ES/126(XX)lA WS
2-2
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VI
LANDFIll SITES
1. RUNWAY OVERRUN lANDF1U.
2. 88150" AREA lANDF1LL
3. NE PERIMETER lANDF1LL NO.1
4. NE PERIMETER lANDF1ll NO.2
5. NE PERIMETER lANDF1LL NO.3
8. F1RING RANGE lANDF1LL SfT£S
rz::z:J
IRP SITE
MA-lOUS(MA 183)
CHECKED BY
APPROVED BY
I
o
SCALE
I
3000
I
6000 FEET
MATHER AIR FORCE BASE
SACRAMENTO, CALIFORNIA
[j] INTDNAnONAL
TBCBNOlA)Gy
CORPOBAnON
DRAWING 199817-A493
NUMBER
t
fiGURE 2.2
LOCATIONS Of
LANDFILL SITES
PREPARED FOR
-------
Contamination exists at the landfill sites as a result of past Air Force operations
conducted between 1918 and 1974. The landfills were mainly used for the disposal of
general and sanitary refuse. In addition to garbage and household trash, it was reported
that POL wastes, as well as waste solvents, primarily TCE, may have been disposed in
the landfills. It has also been reported that daily burning of the refuse occurred at two
of the landfill sites (Sites 3 and 4).
i
I"
I
Remedial investigation (RI) activities at the now inactive Base have been conducted
since 1982. These previous investigations have confirmed the presence of VOCS and
other hydrocarbons at several of the U.S. Air Force IRP sites. Based on this, the entire
Base was proposed for listing on the Superfund (CERCLA) National Priorities Ust
(NPL) in July 1989. Mather AFB was placed on the CERCLA NPL list on November
21, 1989. In July 1989, the U.S. Air Force, the U.S. EPA, and the State of California
signed a Federal Facility Agreement (FF A) under CERCLA Section 120 to ensure that
environmental impacts from past and present operations are thoroughly investigated and
appropriate cleanup actions are taken to protect health, welfare, and the environment.
The U.S. Air Force is the owner of the site, the principal responsible party (PRP), and
lead agency for conducting investigative and cleanup activities. There have been no
CERCLA enforcement actions at the Landfill OU sites.
Previous RIs have been conducted at the Landfill OU sites as part of the Air Force IRP.
The dates, type of studies, and organization conducting the studies, are summarized in
Tables 2.1 through 2.6 and include:
.
IRP Records Search for Mather AFB, Phase I, June 1982 [CH2M-Hill,
Inc. 1982];
.
IRP Phase II, Stage 2 Investigation, June 1987 [AeroVironment 1987];
.
Well Redevelopment and Sampling Plan, July 1988 [IT 1988a];
.
Quarterly Routine Groundwater Sampling, October 1988 to present
[IT 1993a-b] and [EA 1990a-c];
. Landfill Gas Testing Report, July 1988 [IT 1988b];
.
.
Site Inspection Report, August 1990 [IT 1990b];
Group 2 Sites Remedial Investigation Report, April 1993 [IT 1993c];
.
RL/12-94/ES/J.26OCX)l.A WS
2-4
-------
.
Solid Waste Assessment Test Repon, March 1993 [IT 1993d]; and
.
Landfill OU Focused Feasibility Study (FFS) Repon, October 1993
[IT 1993e].
In 1982 the Air Force Engineering and Services Center retained CH2M-Hill, Inc., to
conduct a Phase I onbase records search [CH2M-Hill1982]. The primary obje,ctive was
to evaluate waste disposal sites and disposal practices at Mather AFB. Major findings
included:
.
identifying and prioritizing for additional investigations a total of -
23 disposal or spill sites; and
.
determining that TCE was a commonly used solvent on the Base from 1958
through 1974.
The Phase I records search was followed by the Phase II, Stage 1 Investigation by Roy F.
Weston, Inc. However, this investigation did not address the landfill sites. A Phase II,
Stage 2 Investigation was conducted in 1985 and early 1986 by AeroVironment, Inc.,
[AeroVironment 1987]. Activities included:
.
installing and sampling of 16 shallow monitoring wells, Wells MAFB-14
through MAFB-26 and Wells MAFB-28 through MAFB-30, at Sites 1
through 6; and
. '
conducting ground penetrating radar and terrain conductivity surveys at
Sites 1, 3, 4, and 5.
AeroVironment, Inc., conducted a Phase II, Stage 3 Investigation [Aerovironment 1988]
at essentially the same sites included in the Phase II, Stage 1 Investigation. However,
the landfill sites were not addressed.
In the Fall of 1988, IT Corporation conducted a redevelopment and groundwater
sampling program for all useable groundwater monitoring wells at Mather AFB,
including those at the Landfill OU sites [IT 1988a]. Redevelopment began in
August 1988 and was completed in October 1988. Well sampling began in October 1988
and was completed in November 1988.
RLfI2-94fESfl260001AWS '
2-5
-------
The quarterly sampling and analysis program of Mather AFB groundwater monitoring
wells began in the 4th quarter of 1989 and continues through the present.
IT Corporation performed quarterly sampling and analysis for the 3rd quarter of 1989
and the 1st quarter of 1990. EA Engineering, Science and Technology, Inc. [EA 1990a-c]
performed quarterly sampling and analysis for the 2nd, 3rd, and 4th quarters of 1990.
IT Corporation has been performing quarterly sampling and analysis since the 1st
quarter of 1991. Analytical results for selected analytes are presented in Tables 2.7
through 2.12.
In 1988, IT Corporation installed and sampled 17 shallow CWs and 29 shallow MWs in
order to identify the composition of the vapor or gas immediately above or adjacent to
confirmed or suspected solid waste disposal sites. Thirteen of the CWs and 23 of the
MWs were located at Sites 1 through 6. The remaining gas wells were installed at
Sites 7 and 18. Results are presented in Tables 2.1 through 2.6.
In 1987 and 1988 a variety of tasks were performed as part of the Site Inspection Report
[IT 1990a] to develop a comprehensive base-wide evaluation of existing geologic and
chemical data related to potential environmental contamination at Mather AFB. Tasks
conducted in order to complete the Site Inspection Report included:
.
collecting two rounds of water level measurements from all onbase
monitoring wells to establish hydraulic conditions;
.
reviewing for accuracy available well location, well construction, and
groundwater analytical data;
.
evaluating and listing Applicable or Relevant and Appropriate
Requirements (ARAR) of the federal, State of California, and local
regulations to be utilized and considered in the IRP investigations at
Mather AFB; and
.
developing recommendations for future work to more clearly define
contaminant migration pathways.
Investigations were conducted at the inactive landfill sites during the Group 2 Sites RI
(field work implemented from August 1990 through November 1991). The primary
objectives of the RI were to:
RL/12-94 /ES/1260001.A ws
2-6
-------
.
determine whether environmental contaminants existed at each site, and if
so, aid in determining their lateral and venical extent in the soil;
.
identify the transpon pathways and fate of any chemical constituents
present; and
.
provide data for, and conduct a baseline health risk assessment of, current
and projected risks to public health and the environment posed by
chemical constituents.
Activities were conducted as part of the SWAT work scope in conjunction with the
Group 2 Sites RI. The purpose of the SWAT activities was to implement guidelines
from the Technical Guidance Manual, SWAT [SWRCB 1988a], which would characterize
the landfill sites. Activities included:
.
drilling soil borings, and collecting and analyzing soil samples for SWAT
parameters;
.
drilling and installing groundwater monitoring wells;
.
collecting quarterly groundwater samples and analyzing for SWAT
parameters; and
.
drilling and logging stratigraphic borings.
In 1992, as part of the FFS, field activities were conducted at each of the landfill sites.
Activities were performed to provide additional information on the character or extent of
refuse within each Landfill au site; determine the extent of gas migration in and around
the landfill sites; define the area of impact for closure; and determine the adequacy of
surface materials for use as landfill cover. Primary field activities and their objectives
included:
.
Conducting area-wide surface geophysics to aid in the delineation of the
areal extent of buried refuse;
.
Drilling and sampling of the soils during well installation to assess lithology
and waste characteristics in and around the landfills. Collecting surface
bulk samples to provide information regarding the adequacy of surficial
. soils for use as landfill cover materials;
.
Installing and sampling CWs and MWs to determine the magnitude and
extent of methane generation and migration;
FUL/12-94/~/1260001J\VVS
2-7
-------
.
Excavating trenches to confirm or establish landfill limits and boundaries;
and
Surveying and locating all soil borings, trenches, and wells.
.
RL/12-94 /ES/1260001.A WS
2-8
-------
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Table 2.1
Site 1 . Results of Previous Investigations
Investigation and Air Investigation Bnd Soil Investigation and Groundwater Investigation and Significant Other References
Investigator Significant Analytical Significant Analytical Analytical Results Activities
Results Results
IRP Phase I, Records None None None Base (CH2M-llill
Search - CU2M-llill Records 1982J
Sea rch
IRP Phase II, Stage 2 None Conducted GPR and terrain Installed and sampled two shallow wells: None IAeroVironment
Investigation - conductivity surveys. MAFB-14 and MAFB-1S. Maximum 1981(
AeroVironment, Inc. contaminants detected were: DCI! (11 ppb);
TCE (2.4 ppb); PCE (9.7 ppb); and 1.2-
dichloropropane (0.32 ppb).
Well Redevelopment None None Wells MAFB-14 and MAI'l]-IS were not None lIT 1990bl
and Sampling - redeveloped or sampled due to well damage.
rr Corporation
Quarterly Routine None None Data for selected constituents were summarized None lEA 1mal
Groundwater in the Quarterly GroundW'dter Monitoring lEA 1990bl
Sampling - Reports. See Table 2.7 for a summary of lEA I 'J'Jllc I
IT Corporation a",1 quarterly data for selected analytes. lIT 19')3al
EA Engineering, Irr 1993bl
Science and
Technology, Inc.
Landfill Gas None Installed and sampled two CWs (CW.2 None None (IT 1988bl
Testing - IT and CW-3) and five MWs (MW-4
Corporation through MW-8). Detected TIIC (1.2 to
13 ppm). Methane was not detected in
either CWo No refuse or debris was
encountered in the CWs drilled in the
suspected landCilitrench location or
perimeter MWs.
IRP. Site Inspection - None Evaluated all geologic and chemical Evaluated all geologic and chemical data relating None 11'1' I'J'JllaJ
IT Corporation data relating to environmental to environmental contamination at Mather AI"8.
contamination at Mather AFB. No Data Crom 1988 groundwater sampling was
sampling or analysis conducted. included. Conducted two rounds oC W'dter level
measurements for all onbase monitoring wells.
tV
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Table 2.1 Site 1 . Results of Previous Investigations (continued)
Investigation and Air Investigation and Soil Investigation and Groundwater Investigation and Significant Other References
Investigator Significant Analytical Significant Analytical Analytical Results Activities
Results Results
Group 2 Sites None None None None lIT 19')3c1
Remedial
Investigation -
IT Corporation
Solid Waste None Five DSBs (DSB-T-IA through Wells MAFB-14 and 15 were abandoned and None Irr 1!J'J3d1
Assessment Report - DSB-T-1E) were drilled and sampled. replaced with MAFB-I2S. Installed wells
IT Corporation Maximum contaminant concentrations MAFB-1l5 and 126. four quarters (1991) of
detected: diesel « 10 ppm); oil and sampling for SWAT metals and VOCs was
grease (75 ppm); and methylene conducted in wells MAFB-1l5. 125. and 126.
chloride (0.02 ppm). Inorganics were Maximum concentrations detected 'were: PCE
detected below lTtCs. (4.9 ppb); TCE (2.3 ppb); DCE (4.4 ppb).
Landfill OU Focused None None None None lIT 1993eJ
Feasibility Siudy -
rr Corporation
tV
I
-
o
Note: An Air Force NFAD was filed and stated that the refu5C appeared to have been removed.
None -
TILC -
NFAD -
MW-
TCE-
PCE.
DCE-
TIIC-
OU-
media nol investigated
total threshold limit concentration
no further action decision
migration well
trichloroethylene
tetrachloroethylene
dichloroethylene
tOlal hydrocarbon content
operable unit
AFU -
GPR -
CWo
ppm -
SWAT.
DSB.
VOC-
IRP -
ppb -
Air Force Base
ground penetrating radar
characterization well
parts per million
Solid Waste Assessment Test
deep soil boring
volatile organic compound
Installation Restoration Program
parts per billion
-------
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Table 2.2 Site 2 - Results of Previous Investigations
Investigation and Air Investigation and Soil Investigation and Groundwater Investigation and Other Activities References
Investigalor Significant Analytical Significant Analytical Significant Analytical Results
Results Results
IRP Phase I, Records None None None Base Records ICII2M-Hill
Search - CII2M-lIiII Search 19821
I RP Phase II, Stage 2 None None Three shallow wells were installed None IAemVimllmenl
Investigation .. and sampled' (MAFU-16, 1~11
AeroVironmcnt, Inc. MAFU-17, MAFB-18). No
significant levels of vor..s
detected. Maximum contaminant
concentrations detected were:
total oil and grease (3.4 ppm) and
lead (72 "pb).
Well Redevelopment None None Well MAFB-16 was not None lIT 1990bJ
and Sampling - redeveloped or sampled due 10
IT Corporation well damage. No significant
levels of contamination detected
in Wells MAFB-11 or -18.
Quarterly Routine None None Data for selected constituents None lEA 1990al
Groundwater were summaril.ed in the Quarterly lEA 199Ob1
Sampling - Groundwater Monitoring lEA 199Oc1
IT Corporation and Reports. See Table 2.8 for a lIT 1993al
EA Engineering, summary of quarterly data for lIT 1993bl
Science and selected analytes.
Technolol!V, Inc.
Landfill Gas None TlIree landfill gas characterization wells Sampled groundwater from None lIT 1988bl
Testing.. IT (CW-9 through CW-l1) and four landfill landfill vapor Well CW-10. The
Corporation gas migration wells (MW-12 through only compound detected was total
MW-IS) were installed and sampled. In lead (18.8 pph).
CW-') and CW-l1 carbon dioxide and
methane were not detected. Maximum
detected concentrations of other
compounds were: trichloromethane
(6.4 ppb); tetrachloromethane (20 ppb);
1,ltl-TCA (100 ppb); TCE (27 ppb)j and
PCE (67 ppb). A vapor sample could
not he collected from CW-IO because the
well contained water. Migration well
samples were analyzed only for TIIC;
MW-IJ, MW-14, and MW-1S contained
< l~m TIIC- MW-12 contained
100, ppm me. No refuse or debris
encountered.
-------
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Table 2.2 Site 2 - Results of Previous Investigations (continued)
Investigation and Air Investigation and Soil Investigation and Groundwater Investigation and Other Activities References
Investigator Significant Analytical Significant Analytical Significant Analytical Results
Results Results
IRP, Site Inspection. None Evaluated all geologic and chemical data Evaluated all geologic and None lIT 1990a)
IT Corporation relating to envil'Qnmental contamination chemical data relating to
at Mather AFB. No sampling or analysis environmental contamination at
conducted. Mather AFB. Data from 1988
groundwater sampling .was
included. Conducted two rounds
of wate r level measurements for
all on base monitorin2 wells.
Group 2 Sites Integrated surface air Original landfill gas migration wells Initial/1sl, 2nd, and 3rd quarter None In'I993cJ
Remedial samples collected (MW-12 through MW-1S) were 1991 sampling of Wells
Invesligation - from two grid resampled for methane. Maximum MAFD-127, 128, and 129 detected
IT Corporation locations. Maximum methane detected was 1.7% in MW-12. tOlal lead (3.2 to 9.4, ND, and
contaminant detected ND). All other constituents were
was: benzene (0.33 Five deep soil borings (DSn-A-2A below detection limits.
ppb) at only one of through DSB-A-2E) were drilled and
the grids. sampled (SO samples). Maximum
detected contaminant levels: 1,4-DCB
(0.18 ppm); diesel « 101'1'01); and total
oil and grease (94 ppm). All detected
inorganics were below TfLCs.
Solid Waste None None Wells MAFD-16 and 17 were None lIT 1993dJ
Assessment Report - abandoned and replaced with
IT Corporation MAFB-127 and 128. Installed
well MAFB-129 for SWAT
monitoring network. Four
quarters (1')91) or umpling ror
SWAT metals and VOCS W'dS
conducted in Wells MAFIJ..18,
127, 128, and 129. All values
delected below established STLCs
and MCI.s. No pesticides or
1'(;lIs detel.ted.
-------
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~
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Table 2.2 Site 2 - Results of Previous Investigations (continued)
Invesligalion and Air Investigation and Soil Investigation and Gmundwaler Investigalion and Olher Activities References
Invesligalor Significant Analytical Significant Analytical Significant Analytical Results
Resulls Resulls
Landfill au Focused None Five trenches (IWMB-l through IWMB- None An area-wide (IT 199Jc:1
Feasibility Study - S) were excavated by Base Civil geophysical
IT Corporation Engineering"in coordination with the survey was
IWMB. Confirmed the presence of conducted to
refuse (mainly glass, bottles, and metal identify the
debris) in three of five trenches (IWMB- extent of
I, 4, and S). refuse.
Identified
Original landfill gas well (MW-12) was anomalies were
sampled and analyzed for methane. investigaled
Methane was detected at 16% wilh trenches
TRl-lthrough
Eight trenches (fRl-lthmugh TRl-8) TRl.8.
were excavated to assess the lateral
extent or re"fuse in the landfills. Two of
the Irenches (fRl-4 and TRl-8)
encountered rerusc:. Trench TRl-4
showed evidence or burned reruse:.
None -
STI.C -
MW-
TCE-
PCE -
TCA-
l11C -
MCL-
TII.C-
IWMB-
media not investigated
soluble threshold limit concenlralion
landfill gas migration well
t richloroc:thylene
tetrachloroc:lhylene
lrichloroc:thane
total hydrocarbon content
maximum contaminant level
total threshold limit concentration
Integrated Waste Management Board
AFB -
CWo
ppm -
SWAT-
DCB.
VOC-
IRP -
rCB -
OU-
Air Force Base:
landfill gas eharacterizalion well
pacts per million
Solid Waste Assessment Test
dichlorobenzene
volatile organic compound
Installalion Resloration Program
polychlorinated biphenyl
operable unit
ppb.
parts per billion
-------
t
N
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....
C!
....
N
~
>-
~
tV
I
-
~
Table 2.3 Site 3 . Results of Previous Investigations
Invesligation and Air Investigation and Soil Investigation and Significant Groundwater Investigation and Other Activities Rderences
Invesligator Significant Analytical Analytical Results Significant Analytical Results
Results
IRP Phase I, Records None None None Base Records ICIIZM-Ilill
Search - CH2M-lIiII Search 19821
IRP Phase II, Siage 2 None Conducted GPR and terrain Installed and sampled Wells None (AeroVironment
Invcsligaliun - conductivity surveys. MAFIJ-24, 25, and 26. 19811
AeroVironmenl, Inc. Maximum detecled conlaminant
concentralions: DCE (12 ppb);
TCE (1.9 ppb); and
1,2-dichloropropane (2.1 ppb).
Well Redevelopment None None No significanl levels of None (IT 199Ob1
and Sampling - conlamination were delected at
IT Corporation Wells MAF()-24 or -25.
Maximum delecled contaminant
concentrations: I'CH (13 ppb)
and DCE (15 pph) in well
MAFH-26.
Quarterly Routine None None Data for selected conslituents None lEA 1990al
Groundwater were summarized in Ihe lEA 1990bl
Sampling - Quarterly Groundwater lEA 199Oc1
rr Corporation and Monitoring Reports. See Table Ill' 1993al
EA Engineering, 2.9 for a summary of quarterly Irr 1993bl
Science and data for selected analytes.
Technology, Inc.
-------
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I
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0-
~
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-
VI
i i
Table 2.3 Site 3 . Results of Previous Investigations (continued)
Investigation and Air Investigation and Soil Investigation and Significant Groundwater Investigation and Other Activities References
Investigator Significant Analytical Analytical Results Significant Analytical Results
Results
landfill Gas None Installed and &led three CWs None None lIT 1988b}
Testing - IT (CW-16, 11, and 18) and four MWs
Corporation (MW-19, 20, 22, and 23). Maximum
concentrations detected were: 111C
(2 ppm); vinyl chloride (220 ppb); TCI!
(5.5 ppb); and PCI! (3.3 ppb).
Methane was not detected in any or the
perimeter MWs. Methane was
detected at 4.2% in well CW-18.
Refuse: was only encountered in Well
CW-18.
IRP, Site Inspection - None Evaluated all geologic and chemical Evaluated all geologic and None lIT 1990al
IT Corporation data relating to environmental chemical data relating to
contamination at Mather AfD. No environmental contamination at
&ling or analysis conducted. Mather AFB. Data from 1988
groundwater sampling was
included. Conducted two
rounds of water level
measurements for all on base:
monitoring wells.
-------
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....
~
~
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......
0\
Table 2.3 Site 3 - Results of Previous Investigations (continued)
Investigation and Air Investigation and Soil Investigation and Significant Groundwater Investigation and Other Activities Rererences
Investigator Significant Analytical Analytical Results Significant Analytical Resulls
Results
Group 2 Sites Integrated sunace air Ten DSBs (DSB-A-3A through 3J) Installed and sampled Wells None (IT 1993cJ
Remedial samples collected rrom were drilled and sampled (103 MAFB-lll, 112, 130, 131, 132,
Investigation - five grid locations. samples). Maximum detected and 133. Maximum detected
IT Corporation Maximum detected contaminant concentrations were: concentrations were: TCE
contaminant trichloronuoromethane (0.02 ppm); (3 ppb)i I'CE (6.2 ppb); and
concentrations were: diesel « 10 ppm)i methylene chloride DCI! (18 ppb).
benzene (0.81 ppb); (0.02 ppm); and oil and grease
methylene chloride (830 ppm). Detected inorganic
(29 ppb)i I'CE (2.4 conslituents were below 111,(".$.
ppb)i and I,I,I-TCA (10
ppb). Four sunace soil samples (SS-3A to
S5-3D) were collected and sampled.
Maximum contaminant concentrations
detected were: toluene (12 ppb)i xylene
(5 ppb)i oil and grease (3400 ppm)i
diesel « 10 ppm); acenaphthene
(40 ppb)i anthracene (90 ppb)i
benzo(a)pyrene (570 ppb); pyrene
(1130 ppb)i phenanthrene (680 ppb);
benzo(a)anthracene (S50 ppb);
benzo(b )nuoranthene (560 ppb);
benzo(g,h,i)perylene «J)250 ppb);
benzo(k)nuoranthene (470 ppb);
chrysene (620 ppb); nuoranthene
(111 0 ppb); ideno(1 ,2,J..cd)pyrene
«1)250 ppb)i and acenaphthylene
(40 ppb). All detected inorganics were
below 'ITLCs.
-------
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10
.,.
~
~
~
III
N
I
-
-J
Table 2.3 Site 3 - Results of Previous Investigations (continued)
Investigation and Air Investigation and Soil Investigation and Significant Groundwater Investigation and Other Activities References
Investigator Significant Analytical Analytical Results Significant Analytical Results
Results
Landfill OU Pocused None Two CWs (CW-301 and 302) and eight A perched water sample from None lIT 1993e)
feasibility Study - MWs (MW-301 through MW-308) were Well CW-301 was collected and
IT Corporation installed and sampled for methane. analyzed. Vinyl chloride
Two existing wells (CW-18 and MW- (140 ppb); nCE (25 ppb)j and
19) were also sampled for methane. DCB (11 ppb) were delected in
None of the perimeter MWs detected the sample.
methane. Methane was detected at a
maKimum of 9.7% (CW-302).
Nine soil samples were collected during
drilling of the CWs and analyzed for
geotechnical parameteB. Additionally,
three surrace bulk samples were
collecled for geotechnical analyses.
Four Irenches (rR3-1 through TR3-4)
were excavated tu assess the lateral
extent of refuse in the landfills. All
four trenches encountered refuse with
little or no evidence of burning.
None -
S11..C -
ppb -
TCE-
DCE-
TCA-
PCE-
TIIC -
MCL-
DCB-
OU-
ppm -
media not investigated
soluble threshold limit concentration
parts per billion
trichloroethylene
dichloroethylene
trichloroethane
tetrachloroethylene
total hydrocarbon conlent
maximum contaminant level
dichlorobenzene
operable unit
parts per million
AFB-
CW-
MW-
SWAT-
DSB.
VOC-
TTI.C -
lit.. .
1'<:11-
OPR-
J-
Air force Base
landfill gas characterization well
landfill gas migration well
Solid Waste Assessment Test
deep soil boring
volatile organic compound
total threshold limit concentration
Installation Restoration Program
polychlorinated biphenyl
ground penetrating radar
estimated value
-------
s
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...
~
~
~
~
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I-"
00
Table 2.4 Site 4 - Results of Previous Investigations
Investigation and Air Investigation and Soil Investigation and Groundwater Investigation and Other Activities References
Investigator Significant Analytical Significant Analytical Significant Analytical Results
Results Results
IRP Phase I, Records None None None Base Records ICII2M-llill
Search - CII2M-llill Sea rch 1982)
IRP Phase II, Stage 2 None Conducted GPR and temin Installed and sampled three shallow None IAeroVironment
Investigation - conductivity surveys. wells: MAFB-19 thmugh MArB-2t. )91171
AeroVironment, Inc. Maximum detected contaminant
concentrations were: DCE (JS ppb)j
TCE (4.5 ppb); and I'CE (J5 ppb).
Well Redevelopment None None Well MAFB-19 was not redeveloped or None I IT 19')(}b I
and Sampling - sampled due to well damage. No
rr Corporation significant contamination was detected
at well MAFB-20. Detected TCE (6
ppb)j I'CE (28 pph)j and DCE (JS
ppb) in Well MA1'8-21.
Quarterly Routine None None Data for selected constituents were None lEA 1990a\
Groundwater summarized in the Quarterly lEA 1990bl
Sampling. Groundwater Monitoring Reports. See lEA 19')()C I
rr Corporation and Table 2.10 for a summary of quarterly (n' 19')3al
EA Engineering, data for seleete~ analytes. liT 19'J3bl
Science and
Technology, Inc.
I.andfill Gas None Installed and sampled two CWs None None (1'1' 1988h(
Testing - IT (CW-24 and 25) and lour MWs
Corporation (MW-26 through MW-29). Maximum
detected contaminant concentrations
were: TCE (4.8 ppb); PCE (4.6 ppb)j
and THC (23 ppm). Methane was
detected at a maximum or 8.7% in
Well CW-1S. Refuse was
encountered during drilling of the
CWs.
-------
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....
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Table 2.4 Site 4 . Results of Previous Investigations (continued)
Investigation and Air Investigation and Soil Investigation and Groundwater Investigation and Other Activities Rderences
Investigator Significant Analytical Significant Analytical Significant Analytical Results
Results Results
IRP, Site Inspection - None Evaluated all geologic and chemical Evaluated all geologic and chemical None lIT 1990aJ
IT Corporation data relating to environmental data relating to environmental
contamination at Mather AFB. No contamination at Mather AFB. Data
sampling or analysis conducted. from 1988 groundwater sampling was
included. Conducted two rounds or
water level measurements ror all on-
base monitoring wells.
Group 2 Sites Integrated surface air Eight OSBs (DSB-A-4A through Groundwater samples were collected None lIT 19')31:1
Remedial samples collected DSB-A-4I1) were drilled and rrom well MAFD-5 and analyzed ror
Investigation - r rom five grid sampled (83 samples). Maximum target analytes. Contaminant
IT Corporation locations. Maximum contaminant concentration round concentrations detected were: TCE
detected contaminant were: chlorobenzene (0.18 ppm); (1.9 ppb); PCE (7.5 ppb); toluene
concentration were: diesel (10 ppm); gasoline « 10 (1.8 ppb); xylenes (1.8 ppb); benzene
benzene (1.5 ppb); ppm); ethylbenzene (0.14 ppm); and (1.3 ppb); and DCE (7.8 ppb).
methylene chloride oil and grease (480 ppm). All metals
(2.6 ppb); and were below TIl...Cs. Three surface water samples (SW-4A,
I,I,I-TCA (0.89 ppb). SW-4D, and SW-4F) were collected and
Four surface soil samples (SS-4A analyzed. Maximum contaminant
through SS-4D) were collected and concentrations detected were: diesel
analyzed. Maximum contaminant (SO ppb); and total lead (3.6 ppb). All
concentrations round were: toluene inorganics were below MCu.
(0.005 ppm); gasoline « 10 ppm);
diesel « 10 ppm); 2-butanone
«J)OJ)) ppm); and oil and grease:
(ISO ppm).
Six sediment samples (SD-4A
through SD-4D) were collected and
analyzed. Maximum contaminant
concentrations detected were:
toluene (0.008 ppm); ethylbenzene
«0.005 ppm); dicsc:1 « 10 ppm); 2-
bu.tanone «J)0.013 ppm); and
gasoline ( < 10 ppm).
-------
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o
Table 1.4 Site 4 - Results or Previous Investigations (continued)
Investigation and Air Investigation and Soil Investigation and Groundwater Investigation and Other Activities References
Investigator Significant Analytical S.ignificant Analytical Significant Analytical Results
Results Results
Landfill QU Focused None Two CWs (CW401 and 402) and None An area-wide [IT 1993e)
Feasibility Study - three MWs (MW-401, 402 and 403) geophysical
IT Corporation were installed and sampled Cor survey was
methane. Six existing wells (MW-26 conducted to
through MW-29 and CW-24 and 25) identify the
were also sampled for methane. extent of
None of the perimeter MWs refuse.
detected methane. The maximum Detected
detected methane concentration was anomalies were
46% in l.W-401. investigated
with trenches
Ten soil samples were colleCled TR4-1, and
during drilling of Wells CW401 and TR4-3 through
CW-402 and analyzed for TR4-10.
geotechnical parameters.
Additionally, three surface bulk
samples were collected for
geotechnical analyses.
Ten trenches (TR4-1through TR4-
10) were excavated to assess the
lateral extent of reCuse in the landfill.
Four of the trenches (TR4-1 through
TR4-4) encountered reCuse. TR4-3
showed evidence of burned reCuse.
None -
S'n.c -
MW-
TCE-
DCE-
TCA-
pcn -
TIIC -
MCl-
DCB-
QU-
J-
media not investigated
soluble threshold limit ("()ncentratiun
landfill gas migration well
trichloroethylene
diehloroethylene
trichloroethane
tetrachloroethylene
total hydrocarbon content
maximum conlaminanl level
dichlorobenzene
operable unit
estimated value
AFB-
CWo
ppm -
SWAT-
DSB -
VOC-
T11X -
IRP -
GI'R-
PCB -
ppb -
Air Force Base
landfill gas characlerization well
pans per million
Solid Waste Assessment Test
deep soil boring
volatile organic compound
total threshold limit concentration
Installation Restoration Program
ground penelrating radar
polychlorinated biphenyl
parts per billion
-------
t
~
.0
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~
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~
)-
~
1/1
Table 2.5 Site 5 . Results of Previous Investigations
Investigation and Air Investigation and Soil Investigation and Groundwater Investigation and Other Activities References
Investigator Signiricant Analytical Significant Analytical Significant Analytical Results
Results Results
IRP Phase I, Records None None None Base Records (CII2M-llill
Search - CHZM-Hill Search 19821
IRP Phase II, Siage 2 None Conducted GPR and terrain conductivity Installed and sampled two wells: None (AeroVironment
Investigation - surveys. MAFB-22 and MAFB-23. No 19871
AeroVironment, Inc. signilicant contaminants were detected
in Well MAFB-22. Maximum
contaminant concentrations detected
were: DCE (0.9 ppb); PCB (1.3 ppb);
1,2-DCP (6.1 ppb); and DCA (0.75
ppb) in well MAFB-23.
Well Redevelopment None None No significant contamination detected None (IT 19901>1
and Sampling - in Well MAFlI-22. WeJl MAfB-23 was
rr Corporation not redeveloped or sampled due to well
damage.
Quarterly Routine None None Data ror selected constituents were None (FA 1990al
Groundwater summarized in the Quarterly (EA 1990bl
Sampling - Groundwater Monitoring Reports. See 11!A I 9')(Jc I
rr Corporation and Table 2.11 for a summary of quarterly lIT 1993al
EA Engineering, data ror selecled analytes. Irr 1993bl
Science and
Technolo2Y, Inc.
Landfill Gas None Installed and sampled one CW (CW-JO) and None None (IT 1988bl
Testing - IT two MWs (MW-31 and MW-32). Detected
Corporation TCB (18 ppb); PCB (6.1 ppb); and benzene
(240 ppb). Methane was detected in Well
CW.JO at 37%
IRP, Site Inspection - None Bvaluated all geologic and chemical data Bvaluated all geologic and chemical None (IT 1990al
IT Corporation relating to environmental contamination at data relating to environmental
Mather AFD. No sampling or analysis contamination at Mather AFB. Data
conducted. from 1988 groundwater sampling was
included. Conducted two rounds of
water level measurements for all on-
base moniloring wells.
N
I
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......
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.
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)-
~
Table 2.5 Site 5 . Results of Previous Investigations (continued)
Investigation and Air Investigation and Soil Investigation and Groundwater Investigation and Other Activities References
Investigator Significant Analytical Significant Analytical Significant Analytical Results
Results Results
Group 2 Sites Integrated surface air Three DSBs (DSB-A-5A through Groundwater samples were collected None (IT 1993c)
Remedial samples collected DSB-A-5C) were drilled and sampled (30 hom Wells MAFB-13? and MAFB-141
Investigation - from two grid samples). Maximum contaminant and analyzed for target analytes.
IT Corporation locations. Maximum concentrations found were: gasoline Maximum concentrations detected
detected contaminant « 10 ppm) and oil and grease (66 ppm). were: 1,I-IJCA «0.5 ppb); TCE (0.6
concentrations were: Detected inorganics were below Tn..es. ppb); chloromethane (0.9 ppb); and
benzene (0.45 ppb) 1,2-DCP (4.2 ppb).
and methylene Two surface soil samples (SS-A-SA and
chloride (1.0 ppb). SS-A-5B) were collected and analyzed. One surface waler sample
Maximum contaminant concentrations found (SW-5A) was collected and analyzed.
were: toluene «O.ooS ppm); diesel Contaminant concentrations found
« 10 ppm); and oil and grease (94 ppm). were: diesel (60 ppb) and total lead
Inorganic constituents were detected at levels (4.3 ppb). Inorganic constituents were
below TI1..Cs. detected at levels below MCLs.
One sediment sample (SD-SA) was collected
and analyzed. Contaminant concentrations
found were: toluene «0.005 ppm) and
gasoline « 10 ppm). Inorganic constituents
were detected at levels below Tn..Cs.
Solid Waste None None Four quarters (1991) of sampling for None lIT 1993d)
Assessment Report - SWAT metals and VOCs were
IT Corporation conducted in Wells MAFD-139, 140,
and 141. Maximum contaminant levels
were: I,I-DCA (0.7 ppb); 1,2-DCP (S.8
ppb); chloroform «0.5 ppb);
chloromethane (0.9 ppb); methylene
chloride (O.S ppb); PCE (05 ppb);
TCE! (1.1 ppb); and DCB «05 ppb).
All detected inorganic constituents
were below established SJ1.es and
MCI..s.
tV
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~
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....
~
~
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~
Table 2.5 Site 5 - Results of Previous Investigations (continued)
Investigation and Air Investigation and Soil Investigation and Groundwater Investigation and Other Activities References
Investigator Significant Analytical Significant Analytical Significant Analytical Results
Results Results
Landfill OU Focused None One CW (CW-SOl) and four MWs (MW-SOI None An area-wide lIT 199Je)
Feasibility Study - through MW-S04) were installed and sampled geophysical
IT Corporation for methane. Three existing wells (MW-31. survey was
MW-32, and CW-30) were also sampled for conducted 10
methane. Nllne of the perimeter MWs idenlify the
detected methane. The maximum detected. extent "'
methane concentration was 29% (CW-30). refuse.
Detected
Six soil samples were collected during drilling anomalies were
of Well CW-SOI and analyzed for investigated
geotechnical parameters. Additionally, three with trenches
surface bulk samples were collected for TRS-lthrough
geotechnical analyses. TRS-4.
Twelve trenches (fRS-l through TRS-4 and
TRS-2A through TRS-2H) were excavated to
assess the lateral extent of the refuse in the
landfills. All trenches, except trenches
TRS-2G and 211, encountered refuse with
lillie or no evidence of burning. Trenches
showed the eastward extent of refuse extent
was greater than expected.
N
I
N
UJ
None -
STI.C -
MW-
TCE -
DCE-
TCA -
PCE.
THC-
MCL-
DCA-
OU-
media not investigated
soluble threshold limit concentration
landfill gas migration well
trichloroethylene
dichloroethylene
trichloroethane
tetrachloroethylene
total hydrocarbon content
maximum contaminant level
dichloroethane
operable unit
AFB-
CW-
ppm -
SWAT -
DSB -
VOC-
TI1.C -
IRP -
I>CI' -
GPR -
ppb -
Air Force Base
landfill gas characterization well
parts per million
Solid Waste Assessment Test.
deep soil boring
volatile organic compound
total threshold limit concentration
Installation Restoration Program
dichloropropane
ground penetrating radar
parts per billion
-------
t
i;;
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..
~
~
~
:.-
~
Table 2.6 Site 6 . Results of Previous Investigations
Investigation and Air Investigation and Soil Investigation and Significant Groundwater Investigation and Other Activities Rderences
Investigator Significant Analytical Analytical Results Significant Analytical Results
Results
IRP Phase I, Records None None None Base Reoords ICH2M.HiII
Search. CII2M-lIiII Search 19821
IRP Phase II, Stage 2 None None Three shallow wells were installed and None IAeroVironment
Investigation - sampled (MAFB-28, 29, and 30). No 1987)
AeroVironmenl, Inc. significant contaminants detected.
Well Redevelopment None None No significant contamination was None liT IlJ90bl
and Sampling - delected in Wells MAFB-28, -29, or .30.
fr Corporation
Quarterly Routine None None Data for sclech:d constituents were None lEA 199Oa)
Groundwaler summarized in the Quarterly 1M 199Ob)
Sampling - Groundwater Monitoring Repor1s. See 1M 1 9')(Jc I
fr Corporation and Table 2.12 for a summary of quarterly In' 1993al
EA Engineering, data for selected analytes. Iff' 1993bl
Science and
Technolol!Y. Inc.
Landfill Gas None Two CWs (CW-33 and CW.34) and None None Ifr 1988bl
Testing - IT four MWs (MW.]S through MW-38)
Corpol"dtion were installed and sampled. Maximum
contaminant concentrations found were:
vinyl chloride (1500 ppb), TCE
(3400 ppb); PCE (140 ppb)j benzene
(1300 ppb); I,I,I-TCA (S.s ppb); and
TIIC (2800 ppm). Methane was
detected in Wells CW-33 and CW-34 8t
SO% and 49%, respectively.
IRP, Site Inspection - None Evaluated all geologic and chemical Evaluated all geologic and chemical data None lIT 1990al
IT Corporation data relating to environmental relating to environmental contamination
contamination at Mather AFB. No at Mather AFD. Uata from 1988
sampling (lr analysis conducted. groundwaler sampling was indudcd.
Conducted Iwo rounds of water level
measurements for all on-base monitoring
wells.
N
I
N
~
-------
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..
~
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)-
~
Table 2.6 Site 6 - Results of Previous Investigations (continued)
Investigation and Air Investigation and Soil Investigation and Significant Groundwater Investigation and Other Activities Rderences
Investigator Significant Analytical Analytical Results Significant Analytical Results
Results
Group 2 Sites Remedial Integrated surface air Eight DSBs (DSB-A~ through Groundwater samples were collected None lIT 1993c)
Investigation - samples collected from D58-A-6" were drilled and sampled from Wells MAFB-28, 142, 143, and \44
IT Corporation five grid locations. (100 samples). Maximum contaminant and analyzed. Maximum contaminant
Maximum contaminant concentrations Cound: 1,2-DCB (1 concentrations detected were: TPH
concentrations found: ppm)i gasoline (10 ppm); 1,4-DC8 (0.15 diesel «SOO ppb)i oil and grease
benzene (t.4/ND ppb)j ppm)i 4,4-DDD (54 ppb)i 4,4-DDE «SOOO ppb); total lead (22.4 ppb); and
methylene chloride (\S27 ppb); MCa (0.05 ppm)i benzyl chloride (05 ppb). No detectable
(3.2/44 ppb)i PCB ethylbenzene (0.18 ppm)i xylenes (0.28 constituents were detected in Well
(0.49/2.0 ppb)j and ppm); 4,4-DDT (615 ppb); oil and MAFB-28.
1,1,I-TCA (1.3/10 grease (4900 ppm)i heptachlor epoxide
ppb). (29 ppb)i gamma-Chlordane (148 ppb)i Three surfacc walcr samples (SW-6A
and diesel (4440 ppm). All detected through SW-6C) were collected and
inorganics were below lTLCs. analyzed. Maximum contaminant
concentralions were: diesel (SO ppb) and
Four surCace soil samples (SS.(jA total lead (9.3 pph). All detected
through SS-60) were collected and inorgani~ wCle helllw drinking waler
analyzed. Maximum contaminant MCu.
concentrations found were: diesel
«J)120 ppm) and oil and grease (2300
ppm). All detected inorganics were
below 'm.Cs.
Original landfill gas wells (CW-33,
CW.34, MW.3S, and MW-36) were
sampled. Wells MW-37 and 38 were
not sampled due to missing well caps.
Maximum detected contaminant
concentrations were: vinyl chloride
(1200 ppb)i benzene (1200 ppb)j TCE
(250 ppb); and methane (61 percent).
Sediment samples 5D-6A, SD-6B, and
5D-6C were collected and analyzed.
Only inorganic constituents were
detected; all of which were below
TI1.Cs.
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~
Table 2.6 Site 6 . Results or Previous Investigations (continued)
Investigation and Air Investigation and Soil Investigation and Significant Groundwater Investigation and Other Activities References
Investigator Significant Analytical Analytical ResuJls Significant Analytical ResuJls
Results
Landfill OU focused None Two CWs (CW'()()I and 6(2) and ten None An area-wide (IT J993eJ
Feasibility Siudy - MWs (MW-601through MW-6JO) were geophysical
IT Corporation installed and sampled for methane. survey was
Two existing wells (CW-33 and 34) conducted 10
were also sampled lor methane. None identify the
of the perimeter MWs detected extentuf
methane. l1\e maximum methane reCuse.
concentration detected was 53% (CW- Detecled
33). anomalies were
invesligated
Eighl soil samples were collected during with trenches
drilling of wells CW-601 and CW-602 TR6-1
and analyzed for geotechnical through
parameters. Additionally, three bulk TR6- 10.
soil samples were collected for
geolechnical analyses.
Ten trenches were excavated (fR6-1
through Tll6-10) to assess the lateral
extent of the refuse in the landfills.
Seven of the trenches encountered
refuse wilh lillie or no evidence of
burning.
None -
STl.C -
MW-
SWAT.
TCA-
TIl-C -
MCL-
001'-
TPII -
pcn -
media not investigated
soluble threshold limit concentration
landfill gas migration well
Solid Waste Assessment Test
trichloroethane
total threshold limit concentration
maximum contaminant level
dichlorodi phenylt richloroethane
total petroleum hydrocarbon
polychlorinated biphenyl
xx/yy -
ppb -
TCE-
DSn -
I'CI! -
IRP-
DDE-
DCB-
MCD-
J-
sample original/OC field duplicate
parts per billion
trichloroethylene
deep soil boring
telrachloroethylene
Installation Restoration Program
dichlorodiphenyldichloroethylene
dichlorobenzene
monochlorobenzene
estimated value
AFIJ-
CW-
ppm -
DCE-
VOC-
TIIC -
000-
GPR-
ND-
QU-
Air Force Base
landfill gas characterization well
pans per million
dichloroethylene
volatile organic compound
total hydrocarbon content
dichlorodiphenyldichlorocthane
ground penetrating radar
not detected
operable unit
-------
Table 2.7 Site 1 - Quarterly Sampling
Results for Selected Analytes
WeD NlIIDber Date Total TCE PeE Carboo Lead
Sampled Petnleam (ppb) (ppb) Tetr8chloride (ppb)
Hydroearboas (ppb)
(ppb)
MAFB-12S 5/91 ND 3.2 0.9 ND ND
7/91 ND 1.8 0.9 ND 4.9
10/91 ND ND 0.8 ND 3.2
2/92 ND 2.2 1.0 ND ND
4/92 ND 2.6 1.3 ND ND
7/92 ND 2.0 0.7 ND ND
10/92 ND 1.9 0.7 ND ND
2/93 NS NS NS NS NS
5/93 NP 2.1 0.7 ND ND
7/93 NS NS NS NS NS
10/93 NP 1.5 ND ND ND
1/94 NS NS NS NS NS
4/94 NP 2.4 0.74 ND NP
MAFB-126 5/91 ND 1.0 3.0 ND ND
7/91 ND 0.8 3.0 ND ND
10/91 ND ND 3.4 ND ND
2/92 ND 1.6 6.2 ND 2.3
4/92 ND 0.6 2.7 ND 2.2
7/92 ND ND 2.2 ND ND
10/92 ND 1.0 4.7 ND NO
2/93 NS NS NS NS NS
5/93 NP 0.8 4.6 ND ND
7/93 NS NS NS NS 'NS
10/93 NS NS NS NS NS
1/94 NS NS NS NS NS
4/94 NP 0.99 4.8 ND NP
ND-
NP-
N/A-
NS-
ppb -
TCE-
PCE-
not detected
not analyzed for parameter
not applicable
not sampled
pans per billion
trichloroethylene
tetrachloroethylene
FUL/12-94/~/1260001~WS
2-27
-------
Table 2.8 Site 2 . Quarterly Sampling
Results for Selected Analytes
Well Number Date ToaJ TCE PeE Carboa Lead
Sampled Petroleum (ppb) (ppb) TetnIchIoride (ppb)
Hydrocarboas (ppb)
(ppb)
MAf'B..18 10/89 ND ND ND ND 18.9
2/90 ND ND ND ND 3.2
6/90 ND ND ND ND 4.0
8/90 ND ND ND ND ND
11/90 ND ND ND ND 5.8
3/91 - 10/91 ND ~'D ND ND ND
2/92 ND ND ND ND 1.0
4/92 ND ND ND ND 1.6
7/92 ND ND ND ND ND
10/92 N/A N/A N/A N/A N/A
2/93 NS NS NS NS NS
4/93 NP NP NP NP ND
7/93 NS NS NS NS NS
10/93 NP NP NP NP NP
1/94 NS NS NS NS NS
5/94 NP ND ND ND ND
MAf'B..127 5/91 60.0 (diesel) ND ND ND ND
8/91 - 2/92 ND ND ND ND ND
4/92 ND ND ND ND 5.7
8/92 11/92 ND ND ND ND ND
2/93 NS NS NS NS NS
5/93 NP ND ND ND NP
7/93 NS NS NS NS NS
10/93 NS NS NS NS NS
1/94 NS NS NS NS NS
5/94 NP ND ND ND NP
MAf'B..128 5/91 - 10/91 ND ND ND ND ND
2/92 ND ND ND ND 1.6
4/92 - 11/92 ND ND ND ND ND
2/93 NS NS NS NS NS
4/93 NP NP NP NP ND
7/93 NS NS NS NS NS
10/93 NP NP NP NP ND
1/94 NS NS NS NS NS
5/94 NP ND ND ND NP
MAf'B..129 6/91 - 2/92 ND ND ND ND ND
4/92 ND ND ND ND 1.2
8/92 - 11/92 ND ND ND ND ND
2/93 NS NS NS NS NS
5/93 NP NO ND NO NP
7/93 NS NS NS NS NS
10/93 NP NO ND NO NP
1/94 NS NS NS NS NS
5/94 NP NO ND NO NP
. ND-
NP-
N/A-
NS-
ppb -
TCE-
PCE-
not detected
not analyzed for parameter
not applicable
not sampled
parts per billion
trichloroethylene
tettachloroethylene
RL/12-94/ES/1260001.A WS
2-28
-------
Table 2.9 Site 3 - Quarterly Sampling
Results for Selected Analytes
Well Number Date Total TCE PeE Cubon Lead
Sampled Petroleum (ppb) (ppb) Tetrachloride (ppb)
Hyclro&:amom (ppb)
(ppb)
MAFB-24 10/89 ND 1.0 3.0 NO 51.9
2/90 ND ND 2.9 ND 2.9
5/90 ND ND 22 NO 4.0
8/90 ~/93 N/A N/A N/A N/A N/A
7/93 N/A N/A N/A N/A N/A
10/93 N/A N/A N/A N/A N/A
2/94 N/A N/A N/A N/A N/A
4/94 N/A N/A N/A N/A N/A
MAFB-26 10/89 ND 1.4 5.4 ND 2.4
2/90 ND ND ND NO 3.8
5/90 . 11/90 ND ND ND ND ND
3/91 - 11/92 N/A N/A N/A N/A N/A
2/93 NS NS NS NS NS
5/93 N/A N/A N/A N/A N/A
7/93 N/A N/A N/A N/A N/A
10/93 N/A N/A N/A N/A N/A
2/94 N/A N/A N/A N/A N/A
4/94 N/A N/A N/A N/A N/A
MAFB-loo 5/91 100 (diesel) ND ND NO NO
8/91 . 3/92 ND ND ND ND ND
4/92 ND ND ND NO 1.3
8/92 - 10/92 ND ND ND ND ND
2/93 NS NS NS NS NS
5/93 NP ND ND ND NP
7/93 NS NS NS NS NS
10/93 NS NS NS NS NS
1/94 NS NS NS NS NS
5/94 NP ND ND ND NP
MAFB-l11 6/91 ND 0.6 4.7 ND ND
8/91 ND 7.5 4.0 NO ND
10/91 ND ND 3.1 ND ND
2/92 ND ND 4.2 ND 11.9
4/92 ND ND 4.3 ND 1.5
7/92 ND ND 35 ND ND
10/92 ND ND 2.4 ND ND
2/93 NS NS NS NS NS
5/93 NP ND 3.5 ND ND
7/93 NS NS NS NS NS
10/93 NS NS NS NS NS
1/94 NS NS NS NS NS
5/94 NP 1.1 9.7 ND NP
RL/12-94 /ES/126lJOOIA WS .
2-29
-------
Table 2.9 Site 3 - Quarterly Sampling
Results for Selected Analytes (continued)
WeD Number Date Total TCE PeE Carbon Lead
Sampled Petroleum (ppb) (ppb) T etI'8I:bIoride (ppb)
Hydroc:arboas (ppb)
(ppb)
MAFB-1l2 5/91 ND ND 1.8 ND ND
8/91 ND ND 1.8 ND ND
10/91 ND ND 2.4 ND ND
2/92 ND 0.5 3.9 ND ND
4/92 ND 0.6 3.8 ND ND
7/92 1330 (diesel) ND 3.0 ND ND
10/92 ND 0.6 3.7 ND ND
2/93 NS NS NS NS NS
4/93 NP ND 3.8 ND NP
7/93 NS NS NS NS NS
10/93 NP ND 3.5J ND NP
1/94 NS NS NS NS NS
5/94 ND 0.52 3.8 ND NP
MAFB-1l3 5/91 - 8/91 ND ND ND ND ND
10/91 N/A N/A N/A N/A N/A
2/92 ND ND ND ND ND
4/92 ND ND ND ND 1.8
7/92-4/93 N/A N/A N/A N/A N/A
7/93 N/A N/A N/A N/A N/A
10/93 N/A N/A N/A N/A N/A
1/94 NS NS NS NS NS
4/94 N/A N/A N/A N/A N/A
MAFB-1l4 5/91 - 4/94 N/A N/A N/A N/A N/A
RL/12-94 /F5/12fHYJl.A WS
2-30
-------
Table 2.9 Site 3 . Quarterly Sampling
Results for Selected Analytes (continued)
Wt'JI Number Date Total TeE PeE Carbou Lead
Sampled PeuaIeam (Pllb) (ppb) Tetr8cbloride (Pllb)
HyclrocariJoas (Pllb)
(plIb)
MAFB-130 5/91 NO NO 1.4 NO NO
8/91 NO NO 1.1 NO NO
10/91 NO NO 1.3 NO NO
2/92 NO NO 1.7 NO NO
4/92 NO NO 2.0 NO 2.0
7/92 NO NO 2.9 NO NO
10/92 NO NO 2.1 NO NO
2/93 NS NS NS NS NS
4/93 NP NO 3.9 NO NP
7/93 NS NS NS NS NS
10/93 NP 0.5 4.5 NO NP
1/94 NS NS NS NS NS
4/94 NP 1.2 8.3 NO NP
MAFB-131 5/91 NO NO NO NO NO
8/91 NO NO 1.5 NO NO
10/91 NO NO 1.2. NO NO
2/92 NO NO 1.0 NO 8.6 .
4/92 NO NO 0.7 NO 2.3
7/92 NO NO 0.8 NO 3.0
10/92 NO NO 0.6 NO NO
2/93 NS NS NS NS NS
4/93 NP NO ND NO NO
7/93 NS NS NS NS NS
10/93 NP NO NO NO 3.0
1/94 NS NS NS NS NS
4/94 NP NO NO NO NO
MAFB-133 5/91 NO NO 2.4 NO NO
8/91 NO 0.5 2.6 NO ND
10/91 NO NO 4.7 NO ND
2/92 NO 1.6 11.0 NO ND
4/92 NO 1.5 8.8 NO 1.8
7/fJ2 NO 2.4 16.0 NO NO
10/92 NO 3.0 11.0 NO NO
2/93 NS NS NS NS NS
4/93 NP NP NP NP NO
7/93 NO 1.9J 101 NO NO
10/93 NO 1.7J 9.1 NO NO
1/94 NS NS NS NS NS
4/94 NP 2.S 13 NO NP
NO-
NP-
N/A-
NS-
ppb -
. J-
TCE-
PCE-
not detected
not analyzed for parameter
not applicable
not sampled
parts per billion
estimated value
trichloroethylene
tettac:hloroethylene
RL/12-94/ES/1260001.A WS
2-31
-------
Table 2.10 Site 4 . Quarterly Sampling
Results for Selected Analytes
Well Number Date Total TeE PeE Carboo Lead
Sampled Petroleum (ppb) (ppb) TetnchIoride (ppb)
Hydrocarbons (ppb)
(ppb)
MAFB-5 10/89 ND NO 1.2 NO 3.9
2/90 ND NO 1.8 NO 4.4
6/90 N/A 1.1 0.9 NO 9.0
8/90 ND NO 0.8 NO 23.0
11/90 NO NO 0.6 NO 4.1
3/91 ND NO 1.1 NO NO
5/91 ND NO 1.1 ND NO
8/91 NO NO 0.6 NO NO
11/91 NO NO 1.0 NO NO
3/92 ND NO 0.6 ND NO
5/92 ND NO NO NO 1.0
8/92 NO NO NO /1.'0 NO
11/92 NO NO 1.1 NO NO
2/93 NS NS NS NS NS
4/93 NP NO NO NO NO
7/93 NS NS NS NS NS
10/93 NP NO NO NO NO
1/94 NS NS NS NS NS
4/94 NP NO 0.61 NO NP
MAFB-75 10/89 ND NO 05 NO 25
2/90 ND NO NO NO 3.4
5/90 ND NO 1.6 NO ND
8/90 NO NO NO NO 15.0
11/90 ND NO NO NO 13.6
3/91 . 11/91 ND NO NO NO NO
3/92 ND NO NO NO 1.0
4/92 ND NO NO NO 25
8/92 ND NO ND ND NO
11/92 ND NO NO NO 2.9
2/93 NS NS NS NS NS
.4/93 NP NP NP NP NP
7/93 NS NS NS NS NS
10/93 NS NS NS NS NS
1/94 NS NS NS NS NS
4/94 NP NP NP NP NO
MAFB-76 10/89 NO NO NO NO 25.2
2/90 ND NO NO NO 45
5/90 ND NO NO NO 12.0
8/90 NO NO NO NO 71.0
11/90 - 11/91 NO NO ND NO NO
3/92 NO NO ND NO 2.0
4/92 NO NO NO NO 2.0
8/92 NO NO NO NO NO
11/92 N/A N/A N/A N/A N/A
2/93 NS NS NS NS NS
4/93 N/A N/A N/A N/A N/A
7/93 NS NS NS NS NS
10/93 NS NS NS NS NS
1/94 NS NS NS NS NS
4/94 NS NS NS NS NS
RL/12-94/ES/I260001A WS
2-32
-------
i --
Table 2.10 Site 4 . Quarterly Sampling
Results for Selected Analytes (continued)
WeD Number Date Total TCE PeE Carboa Lead
Sampled Petroleum (ppb) (ppb) T etrIIcbIoride (ppb)
HydnJc:arboos (ppb)
(ppb)
MAFB-135 5/91 - 11/91 NO NO NO NO NO
2/92 NO NO ND ND 1.0
4/92 NO NO ND NO 1.0
8/92 -10/92 NO NO ND NO ND
2/93 NS NS NS NS NS
4/93 NP NP NP NP ND
7/93 NS NS NS NS NS
10/93 NS NS NS NS NS
1/94 NS NS NS NS NS
4/94 NP ND NO ND NP
MAFB-136 5/91 ND 1.9 7.5 ND ND
8/91 NO 0.8 3.8 NO ND
11/91 ND ND 1.6 ND ND
3/92 ND ND 2.2 ND 1.5
4/92 ND ND 2.3 ND NO
8/92 ND ND 1.4 ND NO
10/92 ND 0.6 2.2 ND NO
2/93 NS NS NS NS NS
4/93 NP 0.6 4.3 NO ND
7/93 NS NS NS NS NS
10/93 NP 0.6 27 ND 4.4
1/94 NS NS NS NS NS
4/94 NP 1.2 5.9 ND ND
MAFB-137 5/91 60 (diesel) ND ND ND ND
8/91 - 11/91 ND ND ND ND ND
3/92 ND NO ND ND 1.3
5/92 ND NO ND ND 2.2
8/92 - 10/92 ND ND ND ND ND
2/93 NS NS NS NS NS
4/93 NP ND ND ND 3.5
7/93 NS NS NS NS NS
10/93 NS NS NS NS NS
1/94 NS NS NS NS NS
4/94 NP ND ND ND ND
ND-
NP-
N/A-
NS -
ppb -
TCE-
PCE-
not detected
not analyzed for parameter
not applicable
not sampled
parts per billion
trichloroethylene
tetrachloroethylene
RL/12-94 /ES/I260001A WS
2-33
-------
Table 2.11 Site 5 - Quarterly Sampling
Results for Selected Analytes
WeD Number Date Total TCE PeE Carbon Lead
Sampled Petroleum (ppb) (ppb) Tetracbloride (ppb)
Hyclroc.arlMJas (ppb)
(ppb)
MAFB-22 10/89 NO NO NO NO 24.0
2/90 NO NO NO NO 9.2
5/90 NO NO NO NO 85.0
8/90 - 11/90 N/A N/A N/A N/A N/A
3/91 90.0 (diesel) NO NO NO 3.7
5/91 - 11/92 N/A N/A N/A N/A N/A
2/93 NS NS NS NS NS
4/93 N/A N/A N/A N/A N/A
7/93 NS NS NS NS NS
10/93 N/A N/A N/A .N/A N/A
1/94 NS NS NS NS NS
4/94 N/A N/A N/A N/A N/A
MAFB-138 5/91 NO NO NO NO 2.0
8/91 - 2/92 NO NO NO NO NO
4/92 NO NO NO NO 3.2
8/92 - 10/92 NO NO NO NO NO
2/93 4/93 NS NS NS NS NS
7/93 NS NS NS NS NS
10/93 NS NS NS NS NS
1/94 NS NS NS NS NS
4/94 NS NS NS NS NS
MAFB-139 5/91 NO 0.6 NO NO NO
8/91 - 2/92 NO NO NO NO NO
4/92 NO 0.5 NO NO 1.4
8/92 - 10/92 NO NO NO NO NO
2/93 NS NS NS NS NS
4/93 NP NO NO NO NP
7/93 NS NS NS NS NS
10/93 NP NO NO NO NP
1/94 NS NS NS NS NS
4/94 NP. NO NO NO NP
MAFB-140 5/91 NO NO NO NO NO
8/91 NO NO NO NO 24.6
11/91 - 2/92 NO NO NO NO NO
4/92 NO NO NO NO 2.3
8/92 - 10/92 NO NO NO NO NO
2/93 - 4/93 NS NS NS NS NS
7/93 NS NS NS NS NS
10/93 NS NS NS NS NS
1/94 NS NS NS NS NS
4/94 NP NO NO NO NP
MAFB-141 5/91 - 2/92 NO NO NO NO NO
4/92 NO NO NO NO 2.2
8/92 - 10/92 NO NO NO NO NO
2/93 NS NS NS NS NS
4/93 NP NO NO NO NP
7/93 NS NS NS NS NS
10/93 NP NO NO NO NP
1/94 NS NS NS NS NS
4/94 NP NO NO NO NP
ND - not detected NfA - not applicable NS - not sampled NP - not analyzed for parameter
ppb -
parts per billion
TCE-
trichloroethylene
PCE-
tetrachloroethylene
RL/12-94/ES/I260001A WS
2-34
-------
Table 2.12 Site 6 - Quarterly Sampling
Results for Selected Analytes
WeD Number Date Total TCE PeE Carbon Lead
Sampled Petroleum . (ppiJ) (ppiJ) TetndIJoride (ppiJ)
Hydrotarboos (ppiJ)
(ppiJ)
MAFB-28 10/89 NO NO NO NO 1.2
2/90.8/90 NO NO NO NO NO
11/90 NO NO NO NO 10.0
3/91 . 10/91 NO NO NO NO NO
2/92 NO NO NO NO 1.0
4/92 NO NO NO NO 1.2
7/92 . 10/92 NO NO NO NO NO
2/93 NS NS NS NS NS
4/93 NP NP NP NP 6.6
7/93 NS NS NS NS NS
10/93 NP NP NP NP NO
1/94 NS NS NS NS NS
4/94 NP NP NP NP ND
MAFB-142 5/91 NO ND ND NO 7.0
8/91 . 11/91 NO NO NO NO ND
2/92 NO NO NO NO 1.6
4/92 - 10/92 NO NO NO NO NO
2/93 NS NS NS NS NS
5/93 NP NP NP NP NO
7/93 NS NS NS NS NS
10/93 NS NS NS NS NS
1/94 NS NS NS NS NS
4/94 NS NS NS NS NS
MAFB-143 5/91 - 4/92 NO NO NO NO NO
7/92 NO NO NO NO 8.2
10/92 NO NO NO NO NO.
2/93 - 4/93 NS NS NS NS NS
7/93 NS NS NS NS NS
10/93 NS NS NS NS NS
1/94 NS NS NS NS NS
4/94 NP NP NP NP NO
MAFB-144 5/91 - 11/91 NO NO NO NO NO
3/92 NO NO NO NO 4.3
4/92 NO NO NO NO 1.3
7/92 NO NO NO NO 5.3
10/92 NO NO NO NO NO
2/93 NS NS NS NS NS
4/93 NP NP NP NP NO
7/93 NS NS NS NS NS
10/93 NS NS NS . NS NS
1/94 NS NS NS NS NS
4/94 NS NS NS NS NS
NO-
NP- .
N/A-
NS.
ppb .
TCE-
PCE-
not dctectcd
not analyzcd for paramctcr
not applicablc
not samplcd
parts per billion
trichloroethylcnc
tctrachloroethylcnc
RL/12-94/ES/1260001A WS.
2-35
-------
2.3 Highlights of Community Participation
The Group 2 Sites RI Repon which addresses the Landfill OU sites became available to
. the public at the Mather Environmental Management Office in April 1993 [IT 1993c].
TheFFS for the Landfill OU Sites became available to the public at the Mather
Environmental Management Office in December 1993 [IT 1993e]. The Group 2 Sites RI
Repon, FFS for the Landfill OU Sites, and Proposed Plan for the Landfill OU Sites.
were made available to the public in January. 1994 in both the Administrative Record file
and the information repositories maintained at the following locations:
.
the Environmental Management Office, Mather AFB;
the Sacramento Central Library;
the Rancho Cordova Community Library; and
the U.S. EP A Region IX Docket Room, San Francisco.
.
.
.
The notice of availability for the RI Repon [IT 1993c], FFS Report [IT 1993e], and the
Proposed Plan was published in the Sacramento Bee on the 17th and 27th of
January 1994.
A public comment period was held from February 1, 1994 to March 3, 1994, to address
the Proposed Plan and the content of the supporting RIfFS reports. A public meeting
was held at the now inactive Mather AFB (Building 2460) on February 15, 1994. The
public comment period and public meeting addressed the Proposed Plan.
Representatives from the USAF, U.S. EP A-Region IX, the California Regional Water
Quality Control Board (RWQCB), the California Depanment of Toxic Substances
Control (DTSC), and the California IWMB were present at the meeting.
Representatives from the USAF and regulatory agencies answered questions about the
Landfill au sites and the remedial alternatives under consideration. The
Responsiveness Summary, Section 3.0 of this ROD, contains responses to questions from
the public meeting and also documents comments received during the public comment
period.
The public panicipation requirement of CERCLA Sections 113(k)(2)(B)(i-v) and 117
were met in. the remedial alternative selections. This ROD presents the selected
remedial actions for the Landfill OU Sites, Mather AFB, California, chosen in
accordance with CERCLA (as amended by SARA) and to the extent practicable, the
NCP. The decisions for these sites are based on the Administrative Record.
RL/12-94 /ES/1260001.A ws
2-36
-------
2.4 Scope and Role of Response Action
This ROD presents the planned response actions to address the primary concerns at the
Landfill au Sites posed by landfill contents. . The purpose of the response actions is to
prevent contact' with the landfill contents and to comply with landfill closure
requirements.
2.5
Summary of Site Characteristics
2.5. 7 Summary of Hazardous Material Releases
In addition to garbage and household trash, it was reported that POL wastes, as well as
waste solvents, primarily TCE, may have been disposed in the landfills. It has also been
reported that daily burning of the refuse occurred at two of the landfills (Sites 3 and 4).
The Landfill OU sites have been impacted by past waste disposal practices and
consequently the soils are the affected medium at the sites. The objective of this ROD
is to address the primary concerns at the Landfill au sites posed by refuse, soil, and air
(landfill gas) contamination. Any impact to the groundwater underlying the landfills will
be addressed in a separate Groundwater OU ROD.
2.5.2 Nature and Extent of Contamination
Contamination exists at the Landfill OU sites as a result of past Air Force operations
conducted between 1918 and 1974. The landfills were mainly used for the disposal of
general and sanitary refuse. In addition to garbage and household trash, it was reported
that POL wastes, 'as well as waste solvents, primarily TCE, may have been disposed in
the landfills. It has also been reported that daily burning of the refuse occurred at two
of the landfIlls (Sites 3 and 4).
Previous remedial investigations have been conducted at the Landfill OU sites as part of
the Air Force IRP. The date, type of study, organization conducting the study, and
results of the study are summarized and presented in Tables 2.1 through 2.6 for each of
the Landfill au sites.
2.6 Summary of Site Risks
The RI for "Group 2 Sites [IT 1993c] included fate and transport modeling and a baseline
risk assessment. The data collected and utilized in the RI and FFS were of U.S. EPA
quality level In, IV, or V, or equivalent [EPA 1987]. Formal data validation of the
RL/12-94 /ES/1260001.A WS
2-37
-------
RI- and FFS-generated data was performed to ensure that data were of the quality
commensurate with their intended use.
Although the sites are currently controlled by the Air Force, Mather AFB was
decommissioned on September 30, 1993. Future land use is currently undecided.
2.6. 1 Human Health Risks
2.6. 1. 1 Contaminant Identification
Remedial investigation data collected at the Landfill OU sites were used to identify the
initial chemicals of potential concern (COPC). The list of initial COPCS was reduced
using the following methods as prescribed by U.S. EPA guidance [EPA 1989b]:
.
Quality Control Blank Contamination - As part of the data validation
process, a chemical was not considered further if the maximum sample
concentration did not exceed ten times the highest blank for all common
laboratory contaminants (acetone, 2-butanone, methylene chloride, toluene,
and phthalates) or five times the highest blank for other chemicals. This
screening action reduces the inclusion of chemicals that are most likely
sampling or analytical artifacts.
.
Comparison with Background - Inorganic constituents present at naturally
occurring background levels were eliminated. Specifically, a chemical was
not considered further if the 95% upper confidence level (UCL)
concentration was within the range of background sample concentrations.
.
Frequency of Detection - Chemicals were eliminated if they were detected
. in 5 % or less of the samples for the site. Infrequently detected chemicals
may be artifacts of sampling, analytical, or other problems.
.
Essential Nutrients - Iron, magnesium, calcium, sodium, potassium,
phosphorus, sulfates, and carbonates are essential nutrients. These
constituents are generally toxic only at very high doses and were eliminated
because they were detected at levels below toxic concentrations.
RL/12-94/ES/1260001A WS
2-38
-------
Table 2.13 Refined List of Chemicals of Potential Concern
and Affected Media at Landfill OU Sites from RI Baseline Risk Assessment [IT 1993c]
Constituent Site 2 Media Site 3 Media Site 4 Media Site 5 Media Site 6 Media
Acenapthylene 0 SS 0 0 0
Benzene A A A A A
2-Butanone 0 0 SS, Sed 0 0
Ethylbenz.ene 0 0 Sed 0 0
Methylene chloride 0 A, SuS A A A, SUS
Tetrachloroethylene 0 A 0 0 A
Toluene 0 SS SS, Sed SS, Sed 0
1,1, I-Trichloroethane 0 A A 0 A
4,4-DDE 0 SS 0 0 0
4,4-DDT 0 SS 0 0 0
Total Xylenes 0 SS 0 0 0
Aluminum 0 SuS 0 0 0
Antimony 0 0 0 0 SuS
Arsenic 0 SS 0 0 0
Barium SuS SS SS, SuS, Sw SS, SuS, Sw SS, SUS, Sed,
SW
Cadmium SuS 0 0 SuS SS, SUS
Chromium 0 SS 0 0 0
Chromium VI 0 SS, SuS SS, Sed SS, SUS, Sed SS, Sed
Cobalt SUS 0 SuS SS, SuS SUS, Sed
Copper SuS SS, SuS SS, SUS, Sed SS, SUS, Sed SS, SuS, Sed
Lead 0 SS SW SW SS, Sed, SW
Manganese 0 SS SS, SuS, SW SS, SuS, SW Sed, SW
Molybdenum 0 SuS SuS Sed
Mercury 0 0 Sed SUS 0
Nickel SUS SS, SuS SS, SUS, Sed SS, SUS, Sed SS, Sed
Silver 0 SuS SuS, Sed SUS, Sed SUS
Vanadium 0 o. 0 SS 0
Zinc SUS SS, SuS SS, SUS, Sed, SS, SUS, Sed, SS, SuS, Sed,
SW SW SW
o = Not a chemical of potential concern in media at site
A = Air
SS = Surface soil
SUS = SubsUrface soil
Sed = Sediment
SW = Surface water
RI = remedial investigation
au = operable unit
RL/12-94/ES/1260001A WS
2-39
-------
The COPCs remaining after this initial screening were further refined during the
baseline health risk assessment. Table 2.13 presents this refined list of COPCs. Based
upon the results of the baseline health risk assessment, the media of interest included:
.
surface soils at Sites 3 and 6;
.
air above Sites 2, 3, 4, 5, and 6 which may be impacted by the migration of
VOCs; and
.
groundwater beneath Sites 3 and 4 which was likely impacted by the
migration of contaminants through the landfill.
As discussed in Section 2.1.5, all media except groundwater were evaluated in the FFS.
During the FFS, the refined list of COPCs from the baseline risk assessment was
evaluated and further refined utilizing the following screening factors.
.
Central Valley Regional Water Quality Board's (CVRWCQB) Designated
Level Methodology (DLM) [CVRWCQB 1989];
.
comparison to ARARs;
.
process/ disposal knowledge of the landfills; and
.
risk assessment results.
2.6. ,. ,. 1 Designated Level Methodology
The DLM was developed by the CVRWQCB [CVRWQCB 1989] and served as a
screening of chemicals in the landfill soils and sediments to evaluate or estimate
potential for impact to the groundwater. The application of this methodology consisted
of the following steps.
.
Determine the desired water quality goal for each constituent -
Promulgated regulations and standards were used where available. In the
absence of promulgated regulations, contaminant goals, health advisories,
or risk-based dose rates were used as water quality goals.
.
Determine an environmental attenuation factor for each constituent - This
factor is used to transform water quality goals into site-specific designated
levels (concentrations of constituents in the waste that have the potential to
degrade water quality at the site of discharge). For purposes of
RL/12-94lES/12HXXJIA WS
2-40
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determining COPCS for this FFS, an environmental attenuation factor of
100 was used for most constituents as prescribed in the DLM guidance
[CVRWQCB 1989]. A factor of 1000 was used for copper and zinc
because these constituents tend to have a much greater than average
degree of environmental attenuation.
.
Determine a Soluble Designated Level - This level represents the
concentration of a soluble constituent in the waste above which leachate
would be able to carry them to ground or surface waters in amounts that
would cause water quality goals to be exceeded in those waters. . The
soluble designated level is calculated by the following equation:
Soluble
Designated =
Level
Environmental Attenuation Factor
10
Water
Quality x
Goal
The above divisor of 10 accounts for the ten-fold dilution of the waste
extraction test (WET) results.
.
Determine a LeachabilitY Factor - This factor is used to determine the
fraction of the total constituent concentration available for leaching from
the waste and for uptake by organisms upon which the constituent would
have a toxic or deleterious effect. For purposes of determining COPCs for
this FFS, a leachability factor of 100 was used for inorganic constituents
and 10 for organic constituents as prescribed in the DLM guidance
[CVRWQCB 1989].
.
Compare the Soluble Designated Level with WET Results - If a
constituent's WET level is below the soluble designated level, the potential
threat to groundwater is minimal. In addition, if the total concentration of
a constituent in the waste is less than 10 times the soluble designated level,
it would be impossible for the extractable constituent concentration from
the WET to equal or exceed the soluble designated level. Constituents
which met either of these conditions were eliminated from the list of
COPCs.
.
Determine a Total Designated Level - This level represents total
concentration of a constituent in a solid waste or total or dissolved
concentration of a constituent in a liquid waste which may threaten to
degrade water quality if equalled or exceeded. The total designated level
is calculated by the following equation:
Total
Designated =
Level
Water
Quality x
Goal
Leachability
Factor
x
10
RL/12-94/ES/126(XX)1.A WS .
2-41
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The application of the DLM to the refined list of inorganic COPCS, resulting from the
baseline health risk assessment, is presented in Tables 2.14 through 2.18.
2.6. 1. 1.2 Comparison to ARARs
No chemical-specific ARARs were identified for soils or sediments. Federal and State
primary MCl.s were compared to surface water and groundwater concentrations in the
au. While groundwater will be addressed as part of the Groundwater au FFS, it was
considered in ibis FFS as an indicator of contamination.
2.6.1.1.2.1 Surface Water
Table 2.19 presents the ARARs comparison for surface water. Manganese was the only
chemical which exceeded the MCl.s of 40 Code of Federal Regulations (CFR) Part 141
or the corresponding State of California requirements. This chemical is marked with an
asterisk based on the probability of higher natural background concentrations in the
area.
2.6. ,. 1.2.2 Groundwater
Table 2.20 presents the constituent concentrations in the groundwater underlying the
landfills which exceed the ARARs. Two constituents at Site 3, cis-1,2-DCE and PCE,
were elevated only slightly above their ARARs. Neither of these constituents were
detected in the soil samples. Cis-1,2-dichloroethene was detected in 8 of 14 groundwater
samples. However, the detection limit for those samples that did not detect cis-1,2-DCE
was higher than those that did detect it. This tended to bias the statistical analysis for
this constituent, resulting in an inflated 95% UCL concentration. The maximum
detected level of cis-1,2-dichloroethene was 0.6 p.g/ t, well below the MCL of 6 p.g/ t.
2.6.1.1.2.3 Air
The Sacramento Metropolitan Air Quality Management District (SMAQMD)
chemical-specific limits for emissions of reactive organic chemicals (ROC) is the relevant and
appropriate chemical-specific requirement for air. Most organic gases are classified as
ROCs; however, the definition of ROC specifically excludes methane, most inorganic carbon
gases, and halogenated hydrocarbons. Under Regulation 2, Rule 202, Paragraph 301.1 of
the SMAQMD sets the maximum allowable emission of ROC as 0 pounds per day.
Tables 2.1 through 2.6 summarize the analytical results for the integrated surface air
sampling for each Landfill au site. Benzene was the only ROC detected in the air and it
RL/12-94 /F15/126OC1JIA WS
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was found in levels between 0.33 and 1.5 ppbv. Because these are trace levels, it is not
believed that the landfills exceed the ARAR.
Table 2.14 Site 2 - Designated Level Methodology
/c~ ,::W8ter .~ .. H SOIiiIiIe. .. ...:.Total".. :.' COa&:8Itr'IdioD ~,... CbemiI:aI or
,
"".. :"":Qa8IiIy :"-';.~".. .:::~.... ::.~...... ..., ...:(95~UCLl.. . .: Resiibs."... : :Coa:ena1
..::.. H:.. .;:::'GoaI. F8dDr.:,.,:' .:H . LeY",,: :.:tent, (95~UCL)
:..,:::,..:
SUBSURFACE SOILS
Cadmium (1) 0.005 100 O.OS 50 2.51 0.0171 No (A)
Cobalt (2) 50 100 soo 500000 29.68 0.579 No (A)(B)
Copper (3) 1 1000 100 100000 663 1.287 No (A)(B)
Nidcel (1)" 0.1 100 1 1000 69.87 0.499 No (A)
Zinc (3) 5 1000 500 500000 104.99 1.55 No (A)(B)
NOTES:
All units in ppm
. = Propo&cd at time Focused Feasibility Study was conducted, value was finalized and effective in January 1994
Water Quality Goal Sources:
(1) U.s. Primary Drinking Water Standards (40 Code of Federal Regulations Part 141) or California Primary
Drinking Water Standards (22 California Code of Regulations 64473)
No promulgated standards identified for cobalt. Value obtained from .Water Quality for Agriculture", Food and
Agriculture Organization of the United Nations - Irrigation and Drainage Papcr No. 29, Rev. 1 [Rome 1985) and
may be considered as a To-Be-Considered.
U.s. Environmental Protection Agency Secondary Drinking Water Standards (40 Code of Federal Regulations
Part 143); proposed value from Central Valley Regional Water Quality Control Board [CVRWQCB 1993].
(2)
(3)
Reasons for removal from list of OIemicals of Potential Concern:
(A) Waste Extraction Tests Results < Soluble Designated Level
(8) Concentration of Constituent < 10 x Soluble Designated Level
Ua. =
WET =
upper confidence level
waste extnlction test
RL/12-94/ES/1260001A WS
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Table 2.15 Site 3 . Designated Level Methodology
CODStiiumt . . . .<' :Water EaviromDeataI.. SoIuIaIe, . . Totalu COaceatratioa WETReiu1ts CbemicaI of
.<:. .4",",",,,600" . Desipated ~u (9S~ VCL) (9S~ VCL) CouI:em? .
F8dor LeftI... LeY8..
SURF ACE SOILS
Acenaphthytene (1) 0.0000028 100 0.000028 0.0028 0.27 NR Yes
4,4-DDE (2) 0.001 100 0.01 1 0.018 NR No (A)
4,4-DDT (2) 0.001 100 0.01 1 0.044 NR No (A)
Toluene (3)" 0.04 100 0.4 40 0.013 NR No (A)
Total Xytenes (3)" 0.02 100 0.2 20 0.0033 NR No (A)
Arsenic (2) O.DOS 100 0.05 SO 11.3 NO No (8)
Barium (5) 1 100 10 10000 1386 8.025 No (8)
Chromium (5) 0.05 100 0.5 SOD 12754 0.143 No (8)
Chromium VI (5) 0.05 100 0.5 SOD 1.97 NR No (8)(C)
Copper (3) 1 1000 100 100000 63.76 0.763 No (8)(C)
Lead (2) 0.0002S 100 0.0025 2.5 500.35 1.795 Yes"
Manganese (3) 0.05 100 0.5 SOD 1036.76 58.8 Yes"
Nickel (4) 0.1 100 1 1000 45.23 0.34 No (8)
Zinc (3) 5 1000 SOD 500000 410.28 2.533 No (8)(C)
SUBSURFACE SOILS
Methytene chloride (4)" O.DOS 100 0.05 5 0.03 NR No (A)
Aluminum (5) 1 100 100 100000 6510754 NR No (A)
Chromium VI (5) 0.05 100 0.5 SOD 0.35 0.0109 No (8)(C)
Copper (3) 1 1000 100 100000 61.05 1.726 No (8)(C)
Molybdenum (1) 0.05 100 0.5 SOD 2.79 NR No (A)
Nickel (4) 0.1 100 1 1000 50.18 0.458 No (8)
Silver (5) 0.05 100 0.5 500 1.39 NO No (8)(C)
Zinc (3) 5 1000 SOD 500000 97.09 1.408 No (8)(C)
NOTES:
All units in ppm
NR = Not recorded
DDT = dichlorodiphenyttrichloroethane
Ua. = upper confidence level
Water Quality Goal Sources:
(1) Risk Based
(2) Proposition 65
(3) U.S. Environmental Protection Agency Secondary Drinking Water Standards (40 Code of Federal Regulations Part 143)
(4) U.S. Environmental Protection Agency Primary Drinking Water Standards (40 Code of Federal Regulations Part 141)
(5) California Primary Maximum Contaminant Level
Reasons for removal from list of Chemicals of Potential Concern:
(A) Total Designated Level > Constituent Concentrations
(8) Waste Extraction Test Results < Soluble Designated Level
(C) Concentration of Constituent < 10 x Soluble Designated Level
. Proposed value from Central Valley Regional Water Quality Control Board [CVRWQC8 1993)
.. Determination based on limited background data. Additional data may eliminate contaminant from list of chemicals of potential concern.
DDE =
WET =
NO=
dichlorodiphenytdichloroethytenc
waste extraction test
Not detected
RL/12-94/ES/I260001.A WS
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Table 2.16 Site 4 . Designated Level Methodology
COllSlitueat ,:'::"Water" "ED'riroumeatal', Soluble Total', COaceatracioa WET'ResuIts ClIemicaI,of
Quidity , '" ;A.H...n..fion, Desipa!ed ~..t""" (95"VCL) (95" VCL) C'?
0DCeI1I.
..GOal, ':,:' 'Fador.. Left) Level
SURFACE sou.s
2-Butanone (1) 0.2 100 2 200 0.01 NR No (A)
Toluene (2)" 0.04 100 0.4 40 0.00539 NR No (A)
Barium (4) 1 100 10 10000 248.69 10.003 No (B)
01lomium VI (4) 0.05 100 0.5 SOO 1.95 0.0113 No (B)(q
Copper (2) 1 1000 100 100000 91.61 1.435 No (B)(q
Manganese (2) 0.05 100 0.5 SOO 1110.21 42.38 Yes"
Nickel (3) 0.1 100 1 1000 60.05 0.445 No (B)
Zinc (2) 5 1000 500 500000 88.47 2.499 No (B)(q
SUBSURFACE SOILS
Barium (4) 1 100 10 10000 279.12 10 No (B)
Chromium VI (4) 0.05 100 0.5 500 0.42 0.0113 No (B)(q
Cobalt (5) SO 100 SOO 500000 32.45 0.58 No (B)(q
Copper (2) 1 1000 100 100000 69.96 1.435 No (B)(q
Manganese (2) 0.05 100 0.5 SOO 1217.14 42.38 Yes"
Molybdenum (1) 0.05 100 0.5 500 3.33 0.0312 No (B)(q
Nickel (3) 0.1 100 1 1000 61.46 0.445 No (B)
SiJvcr (4) 0.05 100 0.5 SOO 4.08 0.0068 No (B)(q
Zinc (2) 5 1000 SOO SOOOOO 131.02 2.499 No (B)(q
SEDIMENTS
2-Butanone (1) 0.2 100 2 200 0.01054 NR No (A)
Elhylbenzene (2) 0.03 100 0.3 30 0.0028 I NR I No (A)
Toluene (2)" 0.04 100 0.4 40 0.00582 NR No (A)
Ctromium VI (4) 0.05 100 0.5 500 1.25 0.0113 No (B)(q
RL/12-94/ES/1260001.A WS
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Table 2.16 Site 4. Designated Level Methodology (continued)
C~ . water " . ta;,.u,..meat8i... . Soluble '. Total ' Coaaatratioo WETResaits CIKmic.aI or
Quality . ;Att-nAUooo " Desipated DesigDated (95" VCL) (95'1> VCL) Coacem?
.' Goal ""i Fiidor.' . .. :LeftI. LeYeI ... .
SEDIMENTS (cootiDued)
Copper (2) 1 1000 100 100000 77.2 1.435 No (B)(C)
Mercury (3) 0.002 100 0.02 20 0.19 ND No (B)(C)
Nickel (3) 0.1 100 1 1000 50.28 0.455 No (B)
Silver (3) O.OS 100 0.5 SOO 2.07 0.0068 No (B)(C)
Zinc (2) 5 1000 SOO SOOOOO 116.91 2.499 No (B)(C)
NOTES:
NR = not recorded
Ua. = upper confidence level
All unitS in ppm
ND = not detected
WE!' = waste extraction test
Water Quality Goal SoUR:CS:
(1) U.S. Environmental Protection Agency Health Advisory
(2) U.S. Environmental Protection Agency Secondary Drinking Water Standards (40 Code of Federal Regulations Part 143)
(3) U.s. Environmental Protection Agency Primary Drinking Water Standards (40 Code of Federal Regulations Part 141)
(4) California Primary Maximum Contaminant Level
(5) No promulgated standards identified for cobalt. Value obtained from "Water Quality for Agriculture", Food and Agriculture Organization of
the United Nations - Irrigation and Drainage Paper No. 29, Rev. 1 [Rome 1985J and may be considered as a To-Be-Considered. .
Reasons for removal from list of OIemicals of Potential Concern:
(A) Total Designated Level > Total Constituent Concentration
(8) Waste Extraction Test Results < Soluble Designated Level
(C) Concentration of Constituent < 10 x Soluble Designated Level
. Proposed yaluc reference is Central Valley Regional Water Quality Control Board [CVRWQCB 1993]
.. Determination based on limited background data. Additional data may eliminate contaminant from list of chemicals of potential concern.
RL/12-94/ES/1260001.A WS
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Table 2017 Site 5 - Designated Level Methodology
c;,~ Water ED~eataI... Soluble:.:.. TOtal.. CoactmratioB .... WETResaits CIieiDicaI or
...: QaaJity . ~H"".Qh"'" ' . D-9'AfM . Desipated (95" UCL) (95~ UCL) . Coacena?
Goal . :..FIICtOr... LeftI.. . LeYeJ.
SURFACE SOILS
Toluene (1)0 0.04 100 0.4 40 0.00543 NR No (A)
Barium (4) 1 100 10 10000 11207.13 11.604 Ycs"
QlIomium VI (4) O.OS 100 0.5 SOO 1.05 0.0239 No (B)(C)
Cobalt (3) SO 100 SOO SOOOOO 103.49 0.936 No (B)(C)
Copper (1) 1 1000 100 100000 16278 1.335 No (B)(C)
Manganese (1) O.OS 100 0.5 SOO 2487.9 &5.5 Ycs"
Nickel (2) 0.1 100 1 1000 2035.56 0.393 No (B)
Vanadium (5) 0.02 100 0.2 200 664.75 0.958 Ycs"
Zinc (1) 5 1000 SOO 500000 130.35 4.208 No (B)(C)
SUBSURFACE SOILS
Barium (4) 1 100 10 10000 281.94 11.604 Ycs"
Cadmium (2) 0.005 100 O.OS SO 1.38 0.0106 No (B)
Cobalt (3) 50 100 SOO SOOOOO 31.13 0.936 No (B)(C)
Copper (1) 1 1000 100 100000 61.9 1.335 No (B)(C)
Manganese (1) O.OS 100 0.5 SOO 1429.7 &5.5 Ycs"
MercuIY (2) 0.002 100 0.02 20 O.OS NO No (B)(C)
Nickel (2) 0.1 100 1 1000 48.76 0.393 No (8)
Silver (4) O.OS 100 0.5 500 3.24 0.0131 No (B)(C)
Zinc (1) 5 1000 SOO SOOOOO 116.3 4.208 No (8)(C)
SEDIMENTS
Toluene (1)0 0.04 100 0.4 40 0.004 NR No (A)
Quomium VI (4) O.OS 100 0.5 SOO 0.82 0.0239 No (B)(C)
Copper (1) 1 1 ()()() 100 100000 111 1.335 No (B)(C)
FUl/12-94/~/1260001J\VVS.
2-47
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,-
Table 2.17 Site 5 - Designated Level Methodology (continued)
" c~:..,......,.....:. Wliter EaiYinlmDeatal Soluble., H Total.. .....COaamraDoa.. WET ReSults ..., ,. ('10-...... of,
,:.,".<>> ' /Qilality. ...,.:,4"-"000>. Desipiated.. ~..tM. ' (95" UCL) (95"'UCL) H Cciacem? H.
.'.'. H
:..'.):Gci8I'.. ' Factor . Le.eI H :,.LeYei .,. . H:. .
SEDIMENTS (C....I:",....".I)
Nickel (2) 0.1 100 1 1000 46.9 0.393 No (B)
Silver (4) 0.05 100 0.5 500 3 0.0131 No (B)(C)
Zinc (1) 5 1000 500 500000 181 4.208 No (B)(C)
NOTES:
All units in ppm
ND = not detcc:ted
NR = not n:cordcd
WEI' = waste extraction test
Ua. = upper confidence level
Water Quality Goal Sources:
(1) U.S. Environmental Protc:ction Agency Secondary Drinking Water Standards (40 Code of Federal Register Pan 143)
(2) U.s. Environmental Protc:ction Agency Primary Drinking Water Standards (40 Code of Federal Register Pan 141)
(3) No promulgated standards identified for cobalt. Value obtained from .Water Quality for Agricullure", Food and Agriculture Organization of
the United Nations - Irrigation and Drainage Paper No. 29, Rev. 1 (Rome 1985) and may be considered as a To-Bc-Considered.
(4) California Primary Maximum Contaminant Level
(5) U.s. Environmental Protc:ction Agency Health Advisory
Reasons for removal from list of QlemicaJs of Potential Concern:
(A) Total Designated I..cvI:I > Total Constituent Concentration
(B) Waste Extraction Test Results < Soluble Designated Level
(C) Concentration of Constituent < 10 x Soluble Designated Level
. Proposed values from Central Valley Regional Water Quality Control Board (CVRWQCB 1993)
.. Determination based on limited background data. Additional data may eliminate contaminant from list of chemicals of potential concern.
RL/12-94/ES/I260001.A WS
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C,."i'j_.. :"'W~::". . EDmoamflltaJ. : WET Results Cbemic:aI of
Soluble Total::. .. ~....
. QiWitY. .:...~. .. .Desipated. ~oad.. ..(95" UCL) (95" UCL) . Coacera?
I::}. ;.}(;o8i.....:' .,
::Fador Lefti ~eI !i::, :.: .d
Surface Soils
Barium (2) 1 100 10 10000 304.15 8.521 No (A)
Cadmium (1) 0.005 100 0.05 50 3.51 0.0533 No (A)
CIromium VI (2) 0.05 100 0.5 500 3.25 0.2399 No (A)(B)
Copper (3) 1 1000 100 100000 85.71 0.951 No (A)(B)
Lead (4) 0.0002S 100 0.0025 2.5 82.17 1.091 Ycs.
Nickel (1) 0.1 100 1 1000 41.47 0.2402 No (A)
Zinc (3) 5 1000 SOO SOOOOO 102.64 2.581 No (A)(B)
Sabsarface Soib
Methylene chloride (1)" 0.005 100 0.05 5 0.03 No (B)(q
Antimony (7) 0.003 100 0.03 30 8.56 0.0852 Ycs.
Barium (2) 1 100 10 10000 222.53 9.353 No (A)
Cadmium (1) 0.005 100 0.05 50 2.99 0.0116 No (A)(B)
Cobalt (5) 50 100 SOO 500000 39.26 0.408 No (A) (B)
Copper (3) 1 1000 100 100000 82.56 0.936 No (A)(B)
Silver (2) 0.05 100 0.5 SOO 5.14 0.0101 No (A)
Zinc (3) 5 1000 SOl) 500000 148.61 1.969 No (A)(B)
Sedimems
Barium (2) 1 100 10 10000 526.5 9.353 No (A)
Chromium VI (2) 0.05 100 0.5 500 1.19 0.0167 No (A) (B)
Cobalt (5) 50 100 SOl) 500000 29.25 0.408 No (A)(B)
Copper (3) 1 10000 100 100000 229.39 0.936 No (A)(B)
Lead (4) 0.0002S 100 0.0025 2.5 50.29 0.053 Ycs'
Manganese (3) 0.05 100 0.5 500 1367.65 27.205 Ycs'
Molybdenum (6) 0.05 100 0.5 SOO 4.7 0.0334 No (A)(B)
Nickel (1) 0.1 100 1 1000 75.73 0.325 No (A)
Zinc (3) 5 1000 SOl) 500000 313.93 1.969 No (A)(B)
Table 2.18 Site 6 - Designated Level Methodology
NOTES:
WET = waste extraction tcst UCL = upper confidence level
All units in ppm
Water Quality Goal Sources:
(I) U.S. Environmental Protection Agency Primary Drinking Water Standards (40 Code of Federal Register Part 141)
(2) California Primary Maximum Contaminant Level
(3) U.s. Environmental Protection Agency Secondary Drinking Water Standards (40 Code of Federal Register Part 143)
(4) Proposition 65
(5) No promulgated standards identified for cobalt. Value obtained from .Water Quality for Agriculture., Food and Agriculture Organization of
the United Nations -Irrigation and Drainage Paper No. 29, Rev. 1 [Rome 1985J and may be considered as a T~Bc-Considered.
(6) U.S. Environmental Protection Agency Health Advisory
(7) Maximum Contaminant, Level Goals (proposed)
Reasons for removal from list of Chemicals of Potential Concern:
(A) Waste Extraction Tcst Results < Soluble Designated Level
(B) Concentration of Constituent < 10 timcs Soluble Designated Level
(q Total Designated Level > Total Constituent Concentration
. Determination based on limited background data. Additional data may eliminate contaminant from list of chemicals of potential concern.
RL/12-94/F..5/1260001A WS
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Table 2.19 Surface Water ARARs
Site Constituent Concentration Federal Standards (poh) Chemical of
= Primary MCL Ambient Potential
Concern
Water Quality
Criteria
4 Barium 47.6 - 76.1 2000 1000 No
Lead (Total) 2(ND) - 3.6 50" -- No
~, 4\4\ - Q7 'i0" SOb yp,,*
Zinc 12.7 - 50 5000" 5000 b No
5 Barium 69.5 2000 1000 No
T p.ad (Tntal\ 4~ ~ -- No
M::tnu::tnpcp ~~ 4\0" SOb Nn
Zinc 11.1 5000" 5000 b No
6 Barium 130.79 2000 1000 No
Lead 7.81 50" -- No
Manuan~ce 262-S7 'i0" <;0" y PC *
Zinc 18.79 5000 . 5000 b No
* -
Secondary MCL
Taste & Odor or Welfare criteria
Federal MCL was 50 ppb at the time of the FFS was prepared; since that
time the MCL has been lowered to 15 ppb. The change in the MCL has not
resulted in lead being identified as a chemical of potential concern.
Determination based pn limited background data. Additional data may
eliminate contaminant from list of chemicals of potential concern
Not detected
parts per billion
Applicable or Relevant and Appropriate Requirements
Maximum Contaminant Levels
Focused Feasibility Study
. -
b -
c -
ND -
ppb -
ARAR -
MCLo-
FFS -
RL/12-94/ES/1260001A ws
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Table 2.20 Groundwater Constituents Above ARARs
Site Constituent Frequency 95% UCL Water
of Concentration Quality
Detection Goal
(ppb)
3 - Groundwater cis-1,2-dichloroethene 8/14 6.961 6
Unit B (max. detection = 0.6)
Tetrachloroethylene 18/20 5.09 5
Manganese 3/3 417.88 50
Nickel 1/3 894.09 100
4 - Groundwater Manganese 2/5 11739 50
Unit B
6 - GroundwCiter Manganese 6/6 81.38 50
Unit C
ARAR =
95% UCL =
ppb =
Applicable or Relevant and Appropriate Requirements
95% Upper Confidence Level
parts per billion
The detection limit of the non-detected samples was higher than the detected sample levels.
This tended to bias the statistical analysis for this constituent, resulting in an inflated 95%
UCL concentration.
The other constituents associated with the Landfill au ground waters were manganese
and nickel. These constituents may be within background. However, groundwater
background data for these constituents are currently unavailable. Other metal
concentrations were below MCLs.
2.6.1.1.2.4 Process/Disposal Knowledge
No constituents were removed from the list of COPCs based solely on process/disposal
knowledge.
2.6. ,. 1.2.5 Risk Assessment Results
This step in the screening process assured that each constituent which posed a
carcinogenic risk greater than 1 x 1O~ or a hazard quotient (HQ) greater than 1.0 would
be retained' as a COpc.
Tables 2.21 through 2.25 present the justification for including or excluding each
constituent from the final COPC list based on the above-described screening factors.
RL/12-94 /ES/1260001A WS
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The fina1list of COPCS for the Landfill au sites, resulting from application of the
screening processes, is presented in Table 2.26.
Table 2.21 Site 2 - Chemicals of Potential Concern
Media Constituent COPe Justification
Air Benzene Yes Cancer risk due to inhalation> 1 x 1~
Subsurface soils Cadmium No DLM, no impact to ~undwater, HQ < 1. likely within background
Cobalt concentration, lack 0 process knowledge for release of constItuent
~r
Zinc
DLM =
HQ =
COPC =
Designated Level Methodology
Hazard Quotient, noncarcinogenic risk
Chemicals of Potential Concern
RL/U-94 /ES/1260001A WS
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Table 2.22 Site 3 . Chemicals of Potential Concern
I Media I Constituent I COPC I Justification I
Air Benzene Yes Risk due to inhalation> 1 x 1()'6
Methylene chloride
Temchlorocthylene
Vinyl chloride Yes"
l,l,l-Trichloroethane No Not found in soil samples, risk < 1 x 1()"4
Surface soil Acenaphthylene No High affmity to bond to soil, only 1 detection in 4 samples, Class 0
carcinogen, low risk. no impact to groundwater
4,4-DDE No DLM. risk < 1 x 1()'6, concentration in soils below water quality goal
4,4-DDT (impacts impoliSible)
Toluene No DLM. very low concentration, concentration in soils below water
Total Xylenes quality goal (impacts impossible), risk < 1 x 1()"4
Arsenic Yes Risk due to ingestion of surface soils> 1 x 10'"
Barium No DLM, no impact to ~undwater, HQ < I, likely within baclcground
Chromium concentration, lack 0 process knowledge for release of constlruent
Quomium VI
~r
Lead Yes HQ > 1 for surface soil ingestion
Manganese Yes" HQ < I, lack of process knowledge for release of constituent,
concentration is probably within baC~und because constituent
concentration exceeds background by css than 3% (also 'Z only a
fraction of the standard deviation), available bac:kground ta arc
limited. essential nutrient, water quality goal is SeCondary Drinking
Water Standard for taste and odor, not a sufficient driver for
remedial action
Nickel No OLM, detected in 1 poundwatersample in Site 3 (> Ma.l'
h~r, not found 10 groundwater in Sites 4 or S, HQ <
subsUrface soils Methylene chloride No OLM, vecr..IOW concentration, concentration in soils below drinking
water M risk < 1 x 1()"4.
Aluminum No DLM. EPA considers aluminum an essential nutrient, lack of
process Icnowlcd&; for release of constituent, concentration is
probably within ckground. no reference dose or SIO~ factor
available. only water quality standard is California M L no federal
Ma. or health based adviSories
Chromium VI No DLM. no impact to groundwater, HQ < I, likely within background
Co~r concentration, lack of process knowledge for release of constituent
Nic el
Silver
Zinc
COPC = Chemicals of Potential Concern
DDE = dichlorodiphenyldichloroethylene
DDT = dichlorodiphenyltrichloroethane
DLM = Designated Level Methodology
HQ = Hazard Quotient, noncarcinogenic risk
EPA = U.S. Environmental Protection Agency
MCL = Maximum Contaminant Levels
Yes* = Determination based on limited background data. Additional data may eliminate contaminant
from list of COPCs
Yes.. = Vinyl chloride was detected in landfill gas characterization well vapor samples but not in the
integrated surface air samples. Vinyl chloride will be likely entrained in the vented gas.
RL/12-94 /ES/I260001A WS
2-53
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Table 2.23 Site 4 - Chemicals of Potential Concern
Media Constituent COPC Justification
Air Benzene Ycs Risk due to inhalation> 1 x 1~
Methylene chloride No 1 dctcction/6 analyses, common laboratory chemical. risk < 1 x 10"
l,l,l-Trichloroethane No Not found in soil samples, 1 detection/6 analyses, HQ < 1
Surface soil 2-Butanone No DLM. concentration in soilless than groundwater MCL, HQ < 1
Toluene No DLM, concentration in soilless than groundwater MCL, common
laboratory contaminant, HQ < 1
Barium No DLM. no impaCt to ~undwater, HQ < 1, likely within background
Chromium VI concentration, lack 0 process knowledge for release of constituent
~r
Zinc
Manganese Ycs. HQ < 1, Lack of process knowledge for release of constituent.
concentration is probably within background, available background
data are limited. essential nutrient, water quality goal is SecOndary
Drinking Water Standard for taste and odor, not a sufficient driver
for remedial aCtion
Subsurface soils Barium No DLM. no impaCt to ~undwater, HQ < I, likely within background
Chromium VI concentration, lack 0 process knowledge for release of constituent
~~~enum
Nickel
Silver
Zinc
Cobalt No DLM. no im~Ct to fcf,undwater. no water quality ARAR or health
advisory aval able, Ii ely within bac\cgrl?und concentration, laclt of
process knowledge for release of constituent
Manganese Ycs. HQ < I, LacIt of process knowledge for release of constituent,
concentration is probably within background, available background
data are limited, essential nutrient, water quality goal is SecOndary
Drinking Water Standard for taste and odor. not a sufficient driver
for remedial aCtion
Sediments 2-Butanone No DLM. concentration in soilless than groundwater MCL, HQ < 1
~benzene
Toluene
Chromium VI No DLM, no impact to ~undwater, HQ < I, likely wilhin background
~r concentration, lack 0 process knowledge for release of constituent
Mercury
Nickel
Silver
Zinc
Surface Water Manganese Ycs. HQ < 1, Laclt of process knowledge for release of constituent,
concentration is probably within background, available background
data are limited, essential nutrient, water quality goal is SecOndary
Drinking Water Standard for taste and odor, not a sufficient driver
for remedial aCtion
DLM =
HQ =
MCL.=
ARAR =
cOPc =
Yes. =
Designated Level Methodology
Hazard Quotient, noncarcinogenic risk
Maximum Contaminant Levels
Applicable or Relevant and Appropriate Requirements
Chemicals of Potential Concern
Determination based on limited background data. Additional data may eliminate
contaminant from list of cOPCs
RL/12-94/ES/1260001A WS
2-54
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Table 2.24 Site 5 - Chemicals of Potential Concern
I Media I Constituent I COPe I Justification I
Air Benzene Yes Risk due to inhalation> 1 x 1~
Methylene chloride No Not found in soil samples, Risk < 1 x 1~
Surface soil Toluene No DLM, concennation in soilless than groundwater MCL, common
laboratory contaminant, HO < 1
Barium Yes WET results O~ight1lr elc:wted OYer soluble designated level, no
im:: to groun tcr, Q < I, likely within background concentration,
la of process knowledge for release: of COIIStituent
Ouomium VI No DLM, no impact to ~undwater. HQ < I, likely within background
Cobalt concentration, lack 0 process knowledge for release: of constituent
~r
Zinc
Manganese No HO < 1, Lack of ~rocess knowledge for release: of constituent, only 2
samples analyzed, ighest concentration within ba~und, essential
nutnent, water quality goal is Secondary Drinking ater Standard for
taste and odor, not a sufficient driver for remedial action
Subsurface soils
Ouomium VI No DLM, no impact to groundwater, HQ < 1, likely within background
Cobalt concentration, lack of process knowledge for release: of constituent
Copper
MolYbdenum
Nickel
Silver
Zinc
Manganese Yes. HO < 1, Lack ofllOCCSS knowled~ for release: of constituent, likely
witbin bacltgroun concentration, ck of process knowledge for release:
of constituent, essential nutrient, water quality goal is SecOndary
Drinki;:5 Water Standard for taste and Odor, not a sufficient dnvcr for
remed. action
Sediments
Ouomium VI No DLM, no impact to ~undwater. HQ < 1, likely within background
~r concentration, lack 0 process knowledge for release: of constituent
Silver
Zinc
DLM = Designated Level Methodology
COPC = Chemicals of Potential Concern
HQ = Hazard Quotient, noncarcinogenic risk
MCL = Maximum Contaminant Levels
WET = Waste Extraction Test
Yes* = . Determination based on limited background data.
contaminant from list of Copcs
Additional data may eliminate
RL/12-94/ES/I260001A ws
2-55
-------
Table 2.25 Site 6 . Chemicals of Potential Concern
Media Constituent COPC Justification
Air Benzene Ycs Risk due to inhalation> 1 x 10'"
Methylene chloride
Tetrachloroethylene Ycs"
Vinyl OlIoridc
1,I,I-Trichlol'OCthane No Not found in soil samples, risk < 1 x 10'"
Surface soil Barium No DLM, no impact to ~undwater, HQ < I, likely within background
Cadmium concentration, lack 0 process knowledge for release of constituent
Cuomium VI
~r
Zinc
Lead Ycs HQ > 1, potential risk to juvenilcs through soil ingestion
Subsurface soils Methylene chloride No DLM, no impact to ~undwater. common laboratog contaminant,
detected 3 timcs in samplcs. ILCR < 1 x 10"', H < 1
Antimony Ycs. HQ < 1. Lack of process knowledge for release of constituent.
concentration is probably within background. available background
data are limited
Barium No DLM, no impact to ~undwater. HQ < 1. likely within background
Cadmium concentration, lack 0 process knowledge for release of constituent
~r
Zinc
Cobalt No DLM, no impact to ~undwater, lik~ within background
concentration, lack 0 process knowl ge for release of constituent
Sediments Barium No DLM, no impact to ~undwater, HQ < I, likely within background
Clromium VI concentration, lack 0 process knowledge for release of constituent
~r
Molybdenum
Nickel
Zinc
Cobalt No DLM, no impact to ~undwater, like~ within background
concentration, lack 0 process knowle ge for release of constituent
Manganese No HQ < 1, Lack of ~rocess knowledge for release of constituent,
detected 3/3 samp es, highest concentration within bac~und,
essential nutrient, watc~uality goal is Secondary Drinking Water
Standard for taste and or. not a sufficient driver for remedial action
Surface Water Manganese Ycs. HQ < I, Lack of process knowledge for release of constituent,
concentration is probably within background, available background
data are limited, essential nutrient, water quality goal is SecOndary
Drinking Water Standard for taste and odor, not a sufficient driver
for remedial action
DLM = Designated Level Methodology
COPC = Chemicals of Potential Concern
HQ = Hazard Quotient, noncarcinogenic risk
ILCR = Incremental Lifetime Cancer Risks
Yes. = Determination based on limited background data.
contaminant from list of COPCs
Additional data may eliminate
Yes.. = Vinyl chloride was detected in gas characterization well vapor samples but not in the
integrated surface air samples. Vinyl chloride will likely be entrained in the vented gas.
FUL/12.94/~/1260001~WS
2-56
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Table 2.26 Final Landfill OU FFS Chemicals of Potential Concern
I Media I Site I
2 I 3 I 4 I 5 I 6
Air Benzenc' Benzenc' Benzenc' Benzenc' Benzenc'
Methylenc chloridc' Methylene chloride'
Tetrachloroethylene' T ctrachloroethylene'
Vinyl chloride .. Vinyl Olloride"
Surface Soil AJsenic:' Manganese . Barium . Lead'..
Done
Lead'
Manganese .
Subsurface Soil Done none Manganese . Barium . Antimony.
Manganese .
Sediments none none none none Lead.
Surface Water Manganese . nonc Manganese .
Done none
FFS = Focused Feasibility Study
OU = operable unit
, ILCR > 1 x 10" and < 1 x 10" per baseline risk assessment [IT 1993c]
, Hazard quotient> 1.0 per baseline risk assessmeDt [IT 1993c]
. Determination based on limited background information. Additional data may eliminate from list of COPCs.
.. Vinyl chloride was dctected in gas charactcrization well vapor samples but not iD thc intcgrated surface air samples.
Vmyl chloride willlikcly be cntraincd in the vented gas.
2.6. 1.2 Exposu,e Assessment
Although there are no residents currently in base housing, the area was used to house
base workers and their families until September 30, 1993, and is planned to be used
again after redevelopment. The RI baseline risk assessment included an exposure
assessment for Sites 2, 3, 4, 5, and 6, for residential, trespasser, and occupational
receptors [IT 1993c]. Trespassers are the principal potential current receptors now that
Mather AFB is closed. Table 2.27 presents the current potential exposure scenarios and
COPCs at Sites 2, 3, 4, 5, and 6. The baseline risk assessment included exposure
assessments for future potential residential and occupational receptors [IT 1993c].
Table 2.28 presents the future potential exposure scenarios and COPCs at Sites 2, 3, 4, 5,
and 6. The COPCs were established during the FFS [IT 1993e] and are presented in
Table 2.26.
2.6.1.3 Toxicity Assessment
To underst~d the potential health risks associated with the chemicals of potential
concern at the Mather AFB Landfill au sites, information on chemical-specific chronic
toxicity is required. This toxicity information is used in conjunction with results of the
exposure assessment to characterize the potential health risks at Mather AFB Sites 2, 3,
RL/12-94/ES/I260001.A WS
2-57
-------
I~
4, 5, and 6, and is summarized from the Group 2 Sites RI baseline risk assessment [IT
1993c].
Table 2:27 Current Potential Exposure Scenarios and Chemicals of Potential Concern
I Poteatially Exposed Populatioa I Exposure Patlnwy I n.-ir"h 0' PoteDtiaI Coocera I
Site 2
Base WorlcelS Inhalation of landfiU gas emissions Benzene
Site 3
Base Residents{frespasselS Inhalation landfill gas emissions Benzene, Methylene chloride, Tetrachloroethylene,
Vinyl chloride'
Base Residents{frespasselS Incidental ingestion of surface soil Alsenic, Lead. Manganese
Site 4
Base Residentsrrn:spas&C1S Inhalation of landfill gas emissions Benzene
Base Residents{frespasselS Incidental ingestion of surface soil Manganese
Base Residents{frespllS5ClS Incidental ingestion of surface water Manganese
Site 5
Base Residents{frespasselS Inhalation of landfill gas emissions Benzene
Base Residents{frespassen; Incidental ingestion of surface soil Barium
Site 6
Base Residents{frespasselS Inhalation of landfill gas emissions Benzene, Methylene chloride, Tetrachloroethylene,
Vinyl Otloride8
Base Residents{frespasselS Incidental ingestion of surface soil Manganese
Base Residents{frespasselS Incidental ingestion of surface water Manganese
Source IT 1993c and IT 1993e
Vinyl chloride was detected in gas characterization well vapor samples but not in the integrated surface air samples. Vinyl
chloride will likely be entrained in the vented gas. .
RI./12-94/ES/1260001.A WS
2-58
-------
Table 2.28 Future Potential Exposure Scenarios and Chemicals of Potential Concern
I Poteati8Dy Exposed PopuiatioD I Exposure Pathway I Ch&aK:aIs or PotmtiaI Coocem I
Site 2
WorlcelS Inhalation of landfill gas emissions Benzene
Site 3
ResidencsfWoritelS Inhalation landfill gas emissions Benzene, Methylene chloride, Tetrachloroethylene,
Vinyl chloride.
ResidencsfWoritelS Incidental ingestion of surface soil AJsenic, Lead, Manganese
Site 4
ResidencsfWorlcelS Inhalation of landfill gas emissions Benzene
ResidencsfWoritelS Incidental ingestion of surface soil Manganese
ResidencsfWoritelS Incidental ingestion of surface water Manganese
WorlcelS Incidental ingestion of subsurface soil Manganese
Site 5
ResidencsfWoritelS Inhalation of landfill gas emissions Benzene
ResidencsfWorlcelS Incidental ingestion of surface soil Barium
WoritelS Incidental ingestion of subsurface soil Barium, Manganese
Site 6
Residcncs Inhalation of landfill gas emissions Benzene, Mcthylene chloride, Tetrachloroethylene,
Vinyl CIIoridc.
ResidencsfWorkelS Incidental ingestion of surface soil Lead
ResidencsfWorkelS Incidental ingestion of sedimencs Lead
ResidencsfWorkclS Incidental ingestion of surface water Manganese
WorlcelS Incidental ingestion of subsurface soil Manganese
Source IT 1993c and IT 1993e .
Vinyl chloride was detected in gas characterization well vapor samples but not in the integrated surface air samples. Vinyl
chloride will likely be entrained in the vented gas.
The U.S. EP A evaluates available chemical-specific toxicity information and presents this
data in the Integrated Risk Information System (IRIS) data base [EPA 1992] and the
Health Effects Assessment Summary Tables (HEAST) [EPA 1991]. The IRIS and HEAST
toxicity information includes chemical-specific cancer slope factor (CSF) and reference
dose (RID) values. A CSF describes the dose-response relationship of a cancer causing
chemical, Le., a carcinogen. A RID, which is also called a threshold dose, describes the
dose above which adverse health effects other than cancer may result. The CSF and
RID values are often derived from animal studies. Two fundamental uncertainties
RL/12-94 /ES/1260001A WS
2-59
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associated with the use of laboratory animal studies for calculation the eSF and RID
values are:
.
The extrapolation of toxic effects observed at high doses necessary to
conduct animal studies to effects that might occur at much lower,
environmentally relevant doses.
.
The extrapolation from toxic effects in animals to toxic effects in humans
(i.e., responses of animals may be different from responses of humans).
The U.S. EPA has devised eSFs using weight-of-evidence approach to studies in the
scientific literature. The eSFs represent the 95 percent UCL on the slope of the dose
response curve for carcinogenic responses. Because the eSFs represent the upper limits
of the slope of the line, the use of eSF is more likely to overestimate the actual risk
than underestimate it.
The RID values have associated uncertainty factors. In addition to the two overriding
uncertainties noted above, there are additional uncertainties because animal studies
often are used to establish the lowest-observable-adverse-effect-Ievel (LOAEL). The
LOAEL is then used to calculate the no-observed-adverse-effect-Ievel (NOAEL). Either
the LOAEL or NOAEL is used in calculation of the RID. The uncertainty factor is used
to account for five types of uncertainty that are applicable to noncarcinogenic toxological
values:
.
sensitive subpopulations in the general population;
extrapolation from animals to humans;
extrapolation from a sub chronic study to a chronic estimate;
extrapolation from a LOAEL to a NOAEL, and;
additional uncertainties in the critical study used to set the RID.
.
.
.
.
The RID is the total acceptable daily intake of a chemical. The RID does not assume
that the receptor is exposed to the chemical from other unidentified sources.
Table 2.29 summarizes the toxicity information for the carcinogenic cope for Sites 2, 3, .
4, 5, and 6. Table 2.30 summarizes the toxicity information for the noncarcinogenic
COPC for Sites 2, 3, 4, 5, and 6. For many chemicals the route of exposure is a
significant factor in the toxicity, and as a result CSF and RID values are provided for the
different routes of exposure, i.e., oral (ingestion), inhalation, and dermal routes.
RL/12-94 /ES/I26OCXJl.A WS
2-60
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However, none of the COPC at Sites 2, 3, 4, 5, and 6 ~ave any known toxic effects that
are different for oral versus dermal exposure, so only oral and inhalation data are
presented in Tables 2.29 and 2.30.
The U.S. EP A has not established an oral RID for lead, because its toxicity is not
thought to demonstrate a threshold. An estimated RID was calculated in the Group 2
Sites RI baseline risk assessment [IT 1993c] using the approach of Marcus
[Marcus 1986]. The estimated oral RID is 0.0005 mgjkgj day for adults and
0.0007 mgjkgjday for children [IT 1993c]. In the baseline risk assessment [IT 1993c] a
RID of 0.0007 mgjkgj day was adopted for both children and adult oral lead exposure.
2.6.7.4 Risk Characterization
Excess lifetime cancer risks are calculated using the assumed contaminant intake level,
other exposure correction factors, and the CSF. The excess lifetime cancer risk for a
probable human carcinogen was obtained by multiplying the intake for the contaminant
by the contaminant's CSF. These risks are probabilities that are generally expressed in
scientific notation (e.g., 1 x 10-6). An excess lifetime cancer risk of 1 x 10-6 indicates that,
as a plausible upper bound, an individual has a one in one million chance of developing
cancer as a result of site-related exposure to a carcinogen over a 70-year lifetime under
specific exposure conditions at a site.
Potential concern for noncarcinogenic effects of a single contaminant in a single medium
is expressed as the HQ (or the ratio of the estimated intake derived from the
contaminant concentration in a given medium to the contaminant's reference dose). By
adding the HQs for all contaminants within a medium or across all media to which a
given population may reasonably be exposed, the Hazard Index (HI) can be generated.
The HI provides a useful reference point for gauging the potential significance of
RL/12-94/ES/1260001AWS .
2-61
-------
t
;::;
.Q
~
~
;::;
0\
~
~
N
I
~
Table 2.29 Toxicity Summary for Chemicals or Potential Concern Mather AFB Sites 2, 3, 4, 5, and 6:
Carcinogenic Effects
Chemical of Oral CSF Carcinogen Target Species Inhalation Can:inogen Target Species
Potential (mg/kg/day)"1 Class Organ or CSF Class Organ or
Concern Type of (mg/kg/day)"1 Type of
Cancer Cancer
Arsenic 1.75 A Skin Human 50 A Respiratory Human
Tract
Benzene 0.029 A Leukemia Human 0.029 A Leukemia Human
.
Methylene 0.0075 B2 Liver Mouse 0,0016 B2 Lung, Liver Mouse
chloride
Tetrachloroethene 0.051 B2 Liver Mouse 0.0018 B2 Leukemia, Rat,
Liver Mouse
AFB - Air Force Base
CSF - Cancer Slope Factor
Carcinogen Class A - Known human carcinogen
Carcinogen Class B2 - Probable human carcinogen; no human data
mglkg/day - milligram per kilogram per day
Source - IT 1993c
-------
t
;:;
~
~
.....
~
~
~
Table 2.30 Toxicity Summary for Chemicals of Potential Concern Mather AFB Sites 2, 3, 4, 5, and 6:
Noncarcinogenic Effects
Chemical or . Oral RID Critical Effect Species Uncertainty Inhalation Critical Effect Species Uncertainty
Potential (mg/kg/day) Factor RID Factor
Concern (mg/kg/day)
Antimony 0.0004 Reduced lifespan. Rat 1000 ND' NA NA NA
altered blood
chemistry
Ars~nic 0.001 K~ratosis Human 1 ND NA NA NA
and
byperpigm~ntation
Barium 0.05 Increased Rat 100 0.0004 Fetotoxicity Rat 1000
blood pressllr~
Lead 0.0007 Central nervous Human NA 0.0007 Central Human NA
system nervous system
Manganese 0.1 No effect Human 1 0.0004 Respiratory Human 900
symptoms,
psychomotor
disturbances
Tetrachloroethene 0.01 Hepatotoxicity Mouse 1000 ND NA NA NA
tV
I
~
RID - R~f~rence Dose
ND - not detennined
NA - not available or not applicable
mg/kg/day - milligram per kilogram per day
Source - IT 1993c
-------
multiple contaminant exposures within a single medium or across media. The HI
provides a numerical indicator of the nearness to acceptable limits of exposure or the
degree to which acceptable exposure levels are exceeded. As the HI increases toward
unity (Le., 1.0), so does concern for the potential hazard posed by the constituent.
For the Group 2 Sites baseline risk assessment, a residential unrestricted land use,
maximum exposure scenario was assumed. The potential risk posed by exposure to
contaminants was estimated by quantifying potential human intake and identifying
toxicity characteristics for the COPCS in the exposure pathways. The baseline risk
assessment considered risk from groundwater. However, because groundwater is not
addressed in this ROD, the groundwater risk values were not included in this document.
The results of the risk characterization process for the Landfill OU sites are summarized
in Tables 2.31 through 2.40.
Table 2.31 Estimated Daily Intakes and Incremental Lifetime Cancer Risks
for Carcinogens - Site 2
Estimated
Potentially Exposed Intake
Populations Exposure Pathway Constituent (mg/kgjday) [LeR
.,::... .:,.,.....:.. .':. :. ... ..'/'....'., . .~entl~ndU~ ../) ... ......:'.::'.::....: ...'../
.'. ".:'..:.}{:":: .'..'."':.:<:
.... 'c.
Base Workers I~~tion of landfill gas Benzene 7.3 x 10.3 2.1 x 10~
emISSIons
Future Land Use
Workers Inhalation of landfill gas Benzene 4.4 x 10.3 13 x 1~
emissions
ILCR =
mg/kg/ day =
Incremental Lifetime Cancer Risk
milligram per kilogram per day
RL/12-94 /ES/l2£iXXJIA WS
2-64
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Table 2.32 Estimated Daily Intakes and Hazard Quotients
for Noncarcinogens - Site 2
Estimated
Potentially Exposed Intake Hazard
Populations Exposure Pathway Constituent (mg/kg/ day) Quotient
. ..
,i . Future Land Use .
Residents Ingestion of Drinking l~-DjclUorobenzene 2.7 x 10-<1 3.0 X 10.5
Water (Unit C) Methylene chloride 2.2 x 10"5 3.7 x 10~
1,1,1- Trichloroethane 8.0 x 10-<1 8.8 X 10-5
Arsenic 8.9 x 10-5 8.9 X 10-2
Barium 4.1 x 10~ 82 X 10-3
Lead 1.7 x 1~ 3.5 X 10-1
Manganese 5.5 x 10~ 5.5 X 1003
Vanadium 4.0 x 1~ 5.7 X 10-2
Xylene (Total) 1.4 x 10-<1 6.9 X 1007
Zinc 4.1 x 10~ 2.0 X 1003
Total 52 x 1001
mg/kg/ day -
milligram per kilogram per day
RL/12-94 /ES/1260001.A ws
2-65
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r-
i
Table 2.33 Estimated Daily Intakes and Incremental Lifetime Cancer Risks
for Carcinogens - Site 3
Estimated
Potentially Exposed Intake
POPUlatiODS Exposure Pathway Constituent (mg/kgJday) ILCR
..,( '.L::., ....'.'..:. Cwot Land Use. .
Base Residents{ Inhalation of landfill gas Benzene 2.9 x 10" 8.6 x 1O~
Trespassers emissions Methylene chloride 8.9 x 10-3 1.5 x 10-5
T etrachloroethene 1.5 x 10-3 2.7 x 1O~
Total 2.6 x 10-5
Base Residents{ Incidental ingestion of surface 4,4'-DDE 33 x 10-10 1.1 X 10-10
Trespassers soil 4,4'-DDT 8.0 x 10-10 2.7 X 10-10
Arsenic 3.9 x 10-7 6_8 X 10-7
Total 6.8 x 10-7
Base Residents{ Dermal contact with surface ;4,4'-DDE 2.7 x 10-10 93 X 10-11
Trespassers soil 4,4'-DDT 6.7 x 10-10 23 X 10-10
Total 32 x 10-10
Future Land Use .
Workers Incidental ingestion of Methylene chloride 1.5 x 10-41 1.1 X 10-10 .
subsurface soil
Workers Dermal contact with Methylene chloride 1.1 x 11)-9 8.5 X 10-12
subsurface soil
Residents Dermal contact with surface 4,4'-DDE 2.7 x 10-10 93 X 10-11
soil 4,4'-DDT 6.7 x 10-10 2.3 X 10-10
Total 3.2 x 10-10
Residents Incidental ingestion of 4,4'-DDE 4.2 x 10-9 1.4 X 10-9
(Adult and Juvenile) surface soil 4,4'-DDT 1.0 x 10-41 3.5 x 1~
Arsenic 5.0 x 10~ 8.8 x 1~
Total 8.8 x 10~
Workers Inhalation of landfill gas Benzene 1.1 x 10" 3.1 x 1~
emissions Methylene chloride 3.2 x 10-3 53 x 1~
T etrachloroethene 5.4 x 10" 9.8 X 10-7
Total 93 x 1~
ILCR =
mg{kg{ day =
DDE =
DDT =
Incremental Lifetime Cancer Risk
milligram per kilogram per day
dichlorodiphenyldichloroethylene
dichlorodiphenyltrichloroethane
RL/12-94/ES/1260001.A WS
2-66
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Table 2.34 Estimated Daily Intakes and Hazard Quotients
for Noncarcinogens - Site 3
Estimated
Potentially Intake Hazard
Exposed Exposure Pathway Constituent (mgJkg/day) Quotient
Populations
.:.,. .'. . '..
.". . Current .wdUse.>
Base Residents/ Incidental ingestion of 4,4-DDT 2.2 x 1~ 4.5 x 1~
Trespassers surface soil Toluene 6.1 x 10..10 3.0 x 1~
XyJenes (Total) 5.1 x 10011 2.5 X 10011
Arsenic 1.1 x 10-6 1.1 X 1003 .
Barium 1.4 x 10-4 2.7 X 1003
Chromium 1.2 x 10,5 1.2 X 10.5
Chromium VI 1.8 x 1007 3.7 X 10-5
Copper 5.2 x 10-6 1.4 X 10-4
Lead 4.9 x 10..5 7.1 X 1002
Manganese 1.0 x 10-4 1.0 X 1003
Nickel 4.0 x 10-6 2.0 x 1~
Zinc 4.0 X 1005 2.0 x 1~
Total 7.6 x 10-2
Base Residents/ Dermal contact with 4,4-DDT 1.9 x 1009 3.7 x 1~
Trespassers surface soil Toluene 5.1 x 10-10 2.5 X 1009
Xylenes (Total) 4.2 x 10011 2.1 XlO-Il
Total 3.7 x 10-6
Base Residents/ Inhalation of landfill gas Methylene chloride 2.1 x l(r2 2.4 x 10-2
Trespassers emissions Tetrachloroethene 3.5 x 10.3 3.5 X 10-1
1,1,1- Trichloroethane 1.1 x 10-2 3.8 X 10-2
Total 4.1 x 10-1
.. . \
. ''''. .
Future..LandUSe '.'
Residents Incidental ingestion of 4,4-DDT 3.0 x 10-& 6.0 x 10-5
(Adult) surface soil Arsenic 1.5 x 1005 1.5 X 10.2
Barium 1.8 x 1003 3.6 X 10.2
Chromium 1.7 x 1~ 1.7 x 1cr
Chromium VI 2.5 x 1~ 4.9 x 1cr
Copper 7.0 x 1005 1.9 X 10-3
Lead 6,6 x 1~ 9.5 X 10-1
Manganese 13 x 1003 13 X 10-2
Nickel 504 x 1005 2.7 X 10-3
Toluene 8.2 x 1~ 4.1 x 10-&
Xylenes (Total) 6.8 x 10-10 3.4 X 10,10
Zinc 5.4 X 10-4 2.7 X 1003
Total 1.0 x 1(1'
RL/12..94/ES/1260001AWS .
2-67
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Table 2.34 Estimated Daily Intakes and Hazard Quotients
for Noncarcinogens . Site 3 (continued)
Estimated
Potentially Intake Hazard
Exposed Exposure Pathway Constituent (mg/kgjday) Quotient
Populations
Residents Incidental ingestion of 4,4-DDT 53 x 10-7 1.1 X 10""3
(Juvenile) surface soil Arsenic 13 x 10" 13 X 10-1
Barium 1.6 x 10-2 3.2 X 10-1
Chromium 1.5 x 10-3 1.5 X 10-3
Chromium VI 2.2 x 10-5 43 X 10-3
Copper 6.2 x 10" 1.7 X 10-2
Lead 5.7 x 10.3 83 x 100
Manganese. 1.2 x 10.2 1.2 X 10-1
Nickel 4.8 x 10" 2.4 X 10-2
Toluene 1.4 x 10.7 7.2 X 10-7
Xylenes (Total) 1.2 x 10-11 6.0 X 10-9
Zinc 4_7 X 10"3 2.4 X 10-2
Total 9.0 x 100
Residents Dermal contact with 4,4-DDT 1.6 x 10.9 3.1 x 1O~
surface soil Toluene 43 x 10-10 2.1 X 10-9
Xylenes (Total) 3.6 x 10-11 1.8 X 10-11
Total 3.1 x 1O~
Workers Incidental ingestion of Chromium VI 1.6 x 1
-------
Table 2.35 Estimated Daily Intakes and Incremental Lifetime Cancer Risks
for Carcinogens - Site 4
Estimated
Potentially Exposed Intake
Populations Exposure Pathway Constituent (mg/kgfday) ILCR
.. ..
: :: '. CUiTentLand Use ."
Base Residents/ Inhalation of landfill Benzene 1.0 x lO-5 3.0 X 10-7
Trespasser gas emissions Methylene chloride 1.4 x lO"5 23 X 10-8
Total 3.2 x 10-7
. .." .
'. :.' >..:,.,...,',:,,:.,::,. Fufure'.LandUSc'
Workers Inhalation of landfill Benzene 1.8 x lQ-4 5.2 x 10-6
gas emissions Methylene chloride 2.4 x lO~ 3.9 X 10-7
T otaI 5.6 x 10-6
n.CR =
mg/kg/ day =
Incremental Lifetime Cancer Risk
milligram per kilogram per day
RL/12-94 /ES/1260001.A ws
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Table 2.36 Estimated Daily Intakes and Hazard Quotients
for Noncarcinogens . Site 4
Potentially Estimated
Exposed Intake Hazard
Populations Exposure Pathway Constituent (mg/kgfday) Quotient
.CuirentUuid Use
Base Incidental ingestion of 2-Butanone 5.1 x 10.10 1.0 x 10-i
Residentsf surface soil Toluene 2.5 x 10-10 13 X 10-9
Trespasser Barium 2.2 x 10-5 4.5 X 10-4
Chromium VI 1.8 x 10-7 3.7 X 10.5
Copper 8.7 x 1~ 2.4 X 10-4
Manganese 1.1 x 1~ 1.1 X 10.3
Nickel 5.8 x 1cr 2.9 X 10-4
Zinc 8.5 X 10.() 4.2 X 10.5
Total 2.1 x 10-3
Base Dermal contact with 2-Butanone 4.2 x 10-10 8.5 X 10-9
Residentsf surface soil Toluene 2.1 x 10-10 1.1 X 10.9
Trespasser Total 9.6 x 10-9
Base Inhalation of landfill gas Methylene chloride 3.9 x 10-5 4.6 X 10-5
Residentsf emissions 1,1,1- Trichloroethane 24 x 10-5 7.9 x l(r5
Trespasser Total 1.2 x 1~
?. .. ..i . .. ... .
. .. .
..FutureLaDdUse
Residents Incidental ingestion of 2-Butanone 6.9 x 10-9 1.4 X 10-7
(Adult) surface soil Toluene 3.4 x 10-9 1.7 x 10-i
Barium 3.0 x 10-4 6.0 X 10-3
Chromium VI 2.5 x 10-6 4.9 x 1~
Copper 1.2 x 1~ 3.2 X 10-3
Manganese 1.5 x 10.3 1.5 X 10-2
Nickel 7.8 x 10-5 3.9 X 10.3
Zinc 1.1 X 10-4 5.7 X 10-4
Total 2.9 X 10.2
Residents Incidental ingestion of 2-Butanone 6.0 x 10-a 1.2 X 10.()
(Juvenile) surface soil Toluene 3.0 x 1o-a 1.5 X 10-7
Barium 13 x 10-3 2.6 x l(r2
Chromium VI 1.1 x 10-5 2.2 X 10-3
Copper 5.1 x 10-4 1.4 X 10-2
Manganese 6.4 x 10.3 6.4 X 10-2
Nickel 3.4 x 1~ 1.7 X 10.2
Zinc 5.0 x 1~ 2.5 X 10-3
Total 13 x 10-1
Residents Dermal contact with 2-Butanone 3.5 x 10-10 7.1 X 10"9
surface soil Toluene 1.8 x 10.10 8.9 X 10.10
Total 8.0 x 10-9
RL/12-94/ES/1260001.A WS
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Table 2.36 Estimated Dajly Intakes and Hazard Quotients
for Noncarcinogens . Site 4 (continued)
PoteotiaJly Estimated
Exposed Intake Hazard
Populations Exposure Pathway Constituent (mg/kg/day) Quotient
Workers Incidental ingestion of Barium 13 x 1003 2.6 X 1002
subsurface soil Chromium VI 2.0 x 10-6 4.0 X 10-4
Copper 33 x 10-4 8.9 X 1003
Manganese 5.7 x 1003 5.7 X 1002
Molybdenum 1.6 x 100j 3.9 X 10.3
Nickel 2.9 x 10-4 1.4 X 10.2
Silver 1.9 x 1O.j 6.4 X 10.3
Zinc 6.2 X 10-4 3.1 X 1003
Total 1.2 x 1001
Workers Inhalation of landfill gas Methylene chloride 1.1 x 10.3 13 X 10.3
emissions 1,1,1- Trichloroethane 6.9 x 10-4 2.3 X 10.3
Total 3.6 x 1003
mg/kg/ day -
milligram per kilogram per day
RL/12-94/ES/1260001A WS
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Table 2.37 Estimated Daily Intakes and Incremental Lifetime Cancer Risks
for Carcinogens. Site 5
Estimated
Potentially Exposed Intake
Populations Exposure Pathway Constituent (mg/kgf- ILCR
daY»
Current Land Use ...
Base Residentsf Inhalation of landfill gas Benzene 3.4 x 1«r 9.8 x 10-8
Trespassers emissions Methylene chloride 85 x 10-6 1.4 X 10-8
Total 1.1 x 10,,7
..<.... . >?/...... ...i.................> <....... ... iFuture 1~~dU~U ..
>. .
Workers Inhalation of landfill gas Benzene 5.9 x 10"~ 1.7 X 10-6
emissions Methylene chloride 15 x 10-4 23 X 10.7
Total 1.9 x 10-6
ILCR =
mg/kg/ day =
Incremental Lifetime Cancer Risk
milligram per kilogram per day
RL/12-94/ES/1260001.A WS
2-72
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Table 2.38 Estimated Daily Intakes and Hazard Quotients
for Noncarcinogens . Site 5
Estimated
Potentially Exposed Intake Hazard
Populations Exposure Pathway Constituent (mgJkg/day) Quotient
cUrrent Land Use
Base Residents/ Incidental ingestion of Toluene 1.0 x 10-10 5.1 X 10,10
Trespassers surface soil Barium 1.8 x 1~ 3.5 x l(r3
Chromium VI 7.7 x 10-8 1.5 x l(r5
Copper 7.6 x 10-6 2.0 X 10-4
Manganese 7.5 x 10-5 7.4 x 1~
Nickel 3.4 x l(r5 1.7 x 10-3
Vanadium 1.7 x 10,5 2.5 X 10-3
Zinc 8.6 X 10-6 43 X 10-5
Total 8.6 x 10"3
Base Residents/ Dermal contact with Toluene 8.5 x 10-11 4.2 X 10-10
Trespassers surface soil
Base Residents/ Inhalation of landfill gas Methylene chloride 2.4 x lO-s 2.7 x 1O-s
Trespassers emissions
)i .. i... ' . .. .
. . ....
...:.. .... < Fut\UeL8nd uSe
Residents Incidental ingestion of Toluene 1.4 x 1~ 6.8 X 10"
(Adult) surface soil Barium 2.4 x 10-3 4.7 X 10-2
Chromium VI 1.0 x 1~ 2.1 X 10-4
Copper 1.0 x 10-4 2.7 X 10-3
Manganese 1.0 x 10-3 1.0 X 10,2
Nickel 4.5 x 1~ 23 X 10-2
Vanadium 23 x 1~ 33 X 10-2
Zinc 1.2 X 10-4 5.8 X 10-4
Total 1.2 x 10-1
Residents Incidental ingestion of Toluene 1.2 x 10-8 6.0 x 1
-------
Table 2.38 Estimated Daily Intakes and Hazard Quotients
for Noncarcinogens - Site 5 (continued)
Estimated
Potentially Exposed Intake Hazard
Populations Exposure Pathway Constituent (mg/kgfday) Quotient
Workers Incidental ingestion of Barium 13 x 10') 2.6 X 10'2
subsurface soil Cadmium 6.5 x 10-' 6.5 x 10')
Copper 2.9 x 1O~ 7.9 X 10')
Manganese 6.7 x l(r) 6.7 x 10,2
Mercury 2.4 x 10'7 7.8 x 10~
Nickel 23 x 1~ 1.1 X 10'2
Silver 1.5 x 10,5 5.1 X 10')
Zinc 5.5 x 10~ 2.7 x 10')
Total 13 x 10'.
mg/kg/day -
milligram per kilogram per day
RL/12-94/ES/1260001A WS
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Table 2.39 Estimated Daily Intakes and Incremental Lifetime
Cancer Risks for Carcinogens - Site 6
Estimated
Potentially Exposed Intake
Populations Exposure Pathway Constituent (mg/kg/day) ILCR
Current" Land. Use
Base Inhalation of landfill gas Benzene 9.9 x 10~ 2.9 X 1007
Residents/Trespassers emissions Methylene chloride 22 x 10-4 3.7 X 10..7
Tetrachloroethene 23 x 10-.5 43 x 10"
Total 7.0 x 10..7
. ...Hi:/
-------
Table 2.40 Estimated Daily Intakes and Hazard Quotients
for Noncarcinogens - Site 6
Estimated
Potentially Exposed Intake Hazard
Populations Exposure Pathway Constituent (mg/kg/day) Quotient
. . CUrrent Land Use
Base Residents/ Incidental ingestion Cadmium 6.7 x 10,7 6.7 x 10"
Trespassers of surface soil Barium 5.9 x 10,5 1.2 X 10'3
Chromium VI 6.1 x 10.7 1.2 x 10"
Copper 1.6 x 10,5 4.4 x 1~
Lead 1.4 x 1(}"5 2.0 x lCr2
Nickel 8.1 x 10045 4.1 x 1~
Zinc 1.9 x 10,5 9.6 x 10,5
Total 23 x 10'2
Base Residents/ Inhalation of landfill Methylene chloride 6.3 x 1~ 73 x 10"
Trespassers gas emissions 1,1,1- Trichloroethane 23 x 10" 7.7 x 1~
Tetrachloroethene 6.6 x 10,5 6.6 X 10,3
Total 8.0 x 1(}'3
.. Future Land Use.. :..:0
00" 0..,,00:
Residents (Adult) Incidental ingestion Barium 4.0 x 1~ 8.0 X 10.3
of surface soil Cadmium 4.5 x 10045 4.5 X 10-3
Chromium VI 4.1 x 1~ 8.2 x 1~
Copper 1.1 x 1~ 2.9 X 10.3
Lead 9.1 x 10,5 13 X 10-1
Nickel 5.5 x 10,5 2.7 X 10'3
Zinc 13 x 10" 6.5 x 10"
Total 1.5 x 10'1
Residents (Juvenile) Incidental ingestion Barium 3.5 x 1003 7.0 X 10'2
of surface soil Cadmium 4.0 x 1005 4.0 X 10'2
Chromium VI 3.6 x 10'5 7.2 X 10,3
Copper 9.5 x 10" 2.6 X 10-2
Lead 8.0 x 10" 1.2 x 100
Nickel 4.8 x 1~ 2.4 X 10,2
Zinc 1.1 X 10'3 5.7 X 10,3
Total 1.3 x 100
Residents Inhalation of landfill Methylene chloride 2.6 x 10'2 3.0 X 10'2
gas emissions 1,1,1- Trichloroethane 93 x 10'3 3.1 X 10.2
T etrachloroethene 2.7 x 10'3 2.7 X 10'1
Total 3.3 x 10-1
RL/12-94/ES/12SXXJl.A WS
2-76
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Table 2.40 Estimated Daily Intakes and Hazard Quotients
for Noncarcinogens . Site 6 (continued)
Estimated
Potentially Exposed Intake Hazard
Populations Exposure Pathway Constituent (mg/kgfday) Quotient
Workers Incidental ingestion Methylene chloride 7.4 x 10-& 1.2 x 10-<1
of subsurface soil Antimony 4.2 x 10-5 1.0 X 10-.
Barium 1.1 x 10-3 2.2 X 10.2
Cadmium 1.5 x 10-5 1.5 X 10-2
Copper 4.0 x 10-4 1.1 X 10-2
Silver 2.5 x 10-5 8.4 X 10-3
Zinc 7:3 x 1~ 3.6 X 10-3
Total 1.6 x 10-1
Workers Dermal contact with Methylene chloride 5.5 x 10.9 9.2 x 10"
subsurface soil
mgjkgjday -
milligram per kilogram per day
RL/I2-94 /ES/I260001A ws
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1-
2.6.2 Environmental Risks
There are few environmental risks associated with contaminants at Sites 2, 3, 4, 5, and 6
as reported in the RIjFeasibility Study Site Inspection Report [IT 1990a], the Group 2
Sites RI Report [IT 1993c], and Landfill OU FFS Report [IT 1993e] because there are
no:
.
critical habitats affected by contamination at Sites 2, 3, 4, 5, or 6;
.
endangered species or habitats of endangered species affected by
contamination at Sites 2, 3, 4, 5, or 6; and
.
indications that vernal pools located near Sites 3 and 4 are currently under
stress [IT 1993c].
Some environmental risk may be associated with future remedial actions taken at Sites 3,
4, and 6. The remedial actions taken at Sites 3 and 6 must protect and prevent
degradation of the nearby vernal pools. Remedial actions taken at Site 4 must protect
and prevent degradation of the nearby vernal pools as well as fish and wildlife habitat
associated with the nearby floodplain.
However, actual or threatened releases of the COPCS in the landfills, surface soil,
subsurface soil, sediment, water, and landfill gas emissions, if not addressed by
implementing the response action selected in this ROD, may present potential threat to
public health, welfare, or the environment.
These conclusions are based on Section 8.4 "FLORA and FAUNA" of the Site Inspection
Report [IT 1990a] and Section 6.3.1.2 "Receptor Assessment" of the Group 2 Sites RI
Report [IT 1993c]. Site-specific ecological risk assessments have not been performed;
however, a basewide comprehensive risk assessment, which will include an ecological risk
assessment, will be completed before issuance of the final Mather AFB ROD.
2.7 Description 01 Alternatives
A total of 16 remedial alternatives for the six Landfill OU sites were developed for
detailed analysis in the FFS Report for the Landfill OU sites [IT 1993e]. Soils and air
are the affected media at the Landfill OU sites that were addressed in the FFS. Any
groundwater contamination, which may be present beneath the landfill sites, will be
addressed as part of the Groundwater and Soil OU FFS. Because no unacceptable risk
RL/12-94/ES/1260001,AWS
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exists from the landfills in their current state, cleanup alternatives were developed which
focused on:
.
eliminating contact with the landfill contents; and
complying with regulations governing the closure of landfills.
.
Table 2.41 summarizes the alternatives considered for the landfill sites. A brief summary
of the remedial alternatives follows below.
2.7. 1 Site 1 Remedial Alternative
One alternative was developed for application at Site 1.
2. 7. 1. 1 Alternative 1. 1
Alternative 1.1 is the "no-action" alternative as required by the NCP [40 CFR Part 300].
The no-action alternative se~es as a baseline for evaluating remedial action measures
and is defined as the current site conditions. It was the only alternative developed for
Site 1 because the contents of this landfill were removed prior to construction of the
runway overrun.
2.7.2 Site 2 Remedial Alternatives
Three alternatives were developed for possible application at Site 2.
2.7.2. 1 Alternative 2.1 - No-Action
Alternative 2.1 is the "no-action" alternative and is defined as the current site conditions
with semi-annual groundwater monitoring for 5 years under the existing Base
groundwater monitoring program. At the end of the 5-year period, an evaluation would
be performed to determine if continued groundwater monitoring would be necessary.
2.7.2.2 Alternative 2.2 - Landfill Capping
Under this alternative, a vegetative cover would be installed over the landfill. However,
if groundwater impairment is identified through additional groundwater sampling an
engineered cap will be installed over the landfill. Passive gas vent wefls would be
installed to . prevent pressure buildup of gases beneath the cover surface and to abate
potential lateral migration of gases.
FUL/12-94/~/1260001J\WS
2-79
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t
i::.i
:f
~
i::.i
0-
~
)-
~
Table 2.41 Mather AFB Remedial Alternatives
Site I Site 2 Site 3 Site 4 Site S Site 6
Technology All Ait All All Alt All Ait Ait All Ait Ait Alt Alt All Ait Ait
1.1 2.1 2.2 2.3 3.1 3.2 3.3 4.1 4.2 4.3 5.1 5.2 5.3 6.1 6.2 6.3
No Action 8 8 8 8 8 8
Access Restrictions 8 8 8 8 8 8
Landfill Monitoring 8 8 8 . 8 8 8 8 8 8 8 8 8 8 8
Capping 8 8 . . . .
Gas Venting I . 8 8 8 8 .
Excavation 8 8 . 8 8 .
Embankments 8 8
Compaction 2
Di sposal/Consolidation 8 8 8 8 . .
Thennal Treatment)
N
I
00
o
Ait = Alternative
II
Best Available Control Technology for offgas is applicable to gas venting technology if there is an increase in daily reactive organic chemical
emissions.
21
Compaction was not evaluated as a remedial alternative for the purpose of specifically reduciug soil and refuse volumes. lIowever, moderate
compaction would be achieved from heavy equipment operation during excavation/consolidation or cap/cover construction.
)1
Thermal Irealmenl of solid wasle was judged as very cosily and difficult 10 implement. Thermal treatment of the off-gas was determined as
unnecessary based on modeling projections.
-------
Alternative 2.2 assumed gas monitoring would occur quarterly for five years, then semi-
annually through year 30; in practice, gas monitoring will be conducted quarterly until a
frequency adjustment is proposed and approved by the ROD signatories. Alternative 2.2
assumed groundwater monitoring would occur semi-annually for five years, then annually
through year 30; in practice, groundwater monitoring will be conducted quarterly until
frequency adjustment is proposed and approved by representatives of the ROD signatory
agencies. A review of monitoring frequency will be conducted no less than every five years.
Access restrictions would involve fencing and deed restrictions to maintain the integrity of
the vegetative cover. Deed restrictions would be imposed to prevent excavations and certain
types of land use, such as farming, that would be considered inappropriate.
2.7.2.3 Alternative 2.3 - Landfill Excavation and Consolidation
Under this alternative, landfill refuse and associated soils would be excavated,
transported to, and placed at the consolidation site (Le., Site 4) with commercially
available equipment. Prior to excavation, the site would undergo a preliminary design
investigation (PDI) to define the vertical extent of soils affected by landfill leachate.
Once excavation had been started, it would continue until post-excavation "verification"
samples indicated that underlying soils were clean. The site would then be recontoured
to eliminate topographic depressions and it would then be clean-closed.
Alternative 2.3 assumed groundwater monitoring would occur quarterly for three years;
in practice, groundwater monitoring will be conducted quarterly until a frequency
adjustment is proposed and approved by representatives of the ROD signatory agencies.
2.7.3 Site 3 Remedial Alternatives
Three alternatives were developed for possible application at Site 3.
2.7.3. 1 Alternative 3. 1 - No-Action
This is the "no-action" alternative and is defined as the current site conditions with
semi-annual groundwater monitoring for five years under the existing Base groundwater
monitoring 'program. At the end of the five-year period, an evaluation would be
performed to determine if continued monitoring would be necessary.
RL/12-94 /F15/12f:l:XXJ1A ws
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2.7.3.2 Alternative 3.2 - Landfill Capping
Under this alternative, an engineered cap would be installed over the landfill. Passive
gas vent wells would be installed to prevent pressure buildup of gases beneath the cap
surface and to abate potential lateral migration of gases.
Alternative 3.2 assumed gas monitoring would occur quarterly for five years, then semi-
annually through year 30; in practice, gas monitoring would occur quarterly for five years,
then semi-annually through year 30; in practice, groundwater monitoring will be
conducted quarterly until a frequency adjustment is proposed and approved by
representatives of the ROD signatory agencies. A review of monitoring frequency will
be conducted no less than every five years.
Access restrictions would involve fencing and deed restrictions to preserve the integrity
of the engineered cap. Deed restrictions would be imposed to prevent excavations and
cenain types of land use, such as farming, that are deemed inappropriate.
2.7.3.3 Alternative 3.3 - Landfill Excavation and Consolidation
Under this alternative, landfIll refuse and associated soils would be excavated,
transponed to, and placed at the consolidation site (i.e., Site 4) with commercially
available equipment. Prior to excavation, the site would undergo a PDI to define the
vertical extent of soils affected by landfill leachate. Once excavation had been started, it
would continue until post-excavation "verification" samples indicated that underlying soils
were clean. The site would then be recontoured to eliminate topographic depressions
and clean-closed.
Alternative 3.3 assumed groundwater monitoring would occur quarterly for three years,
then semi-annually through year 10; in practice, groundwater monitoring will be
conducted quarterly until a frequency adjustment is proposed and approved by
representatives of ROD signatory agencies. A review of monitoring frequency will be
conducted no less than every five years.
2.7.4 Site 4 Remedial Alternatives
Three alternatives were developed for possible application at Site 4.
FUL/12-94/~/1260001J\VVS
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-------
2.7.4. 1 Alternative 4. 1 - No-Action
This is the "no-action" alternative and is defined as the current site conditions with
semi-annual groundwater monitoring for 5 years under the existing Base groundwater
monitoring program. At the end of the 5-year period, an evaluation would be performed
to determine if continued monitoring would be necessary.
2.7.4.2 Alternative 4.2 - Landfill Capping and Embankment
Under this alternative, an engineered cap would be installed over the landfill. In order
to protect the southeastern portion of the cap from an intermittent stream and its
floodwaters, flood control measures, such as an embankment, would be installed. Passive
gas vent wells would be installed to prevent pressure buildup of gases beneath the cap
surface and to abate potential lateral migration of gases. The foundation layer may
consist of soil, contaminated soil, or other waste material of suitable engineering
properties, compacted to a maximum density.
Alternative 4.2 assumed gas monitoring would occur quarterly for five years, then semi-
annually through year 30; in practice, gas monitoring will be conducted quarterly until a
frequency adjustment is proposed by the ROD signatories. Alternative 4.2 assumed
groundwater monitoring will be conducted quarterly for five years, then semi-annually
through year 30; in practice, groundwater monitoring would be conducted quarterly until
a frequency adjustment is proposed and approved by representatives of the ROD
signatory agencies. A review of monitoring frequencies would be conducted no less than
every five years.
Access restrictions would involve fencing and deed restrictions to preserve the integrity
of the engineered cap. Deed restrictions would be imposed to prevent excavations and
certain types of land use, such as farming, that are deemed inappropriate.
2.7.4.3 Alternative 4.3 - Landfill Excavation, Consolidation, and Capping
The eastern portion of the landfill, the portion that is bordered by a drainage area,
would be excavated and combined with the remaining refuse and associated soils. The
excavated area would be recontoured to eliminate topographic depressions. Removing
. .
the eastern portion of the landfill would eliminate the need for flood control and would
reduce the area of the landfill. An engineered cap would then be installed over the
reduced landfill area. The foundation layer may consist of soil, contaminated soil, or
other waste material of suitable engineering properties, compacted to maximum density.
RL/12-94/ES/1260001A WS
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Passive gas vent wells would be installed to prevent pressure buildup of gases beneath the
cap surface and to abate potential lateral migration of gases. Prior to excavation, the site
would undergo a PDI to define the vertical extent of soils affected by landfill leachate. Once
excavation had been started, it would continue until post-excavation "verification" samples
indicated that underlying soils were clean. The site would then be recontoured to eliminate
topographic depressions and it would then be c1ean-closed.
Alternative 4.3 assumed gas monitoring would occur quarterly for five years, then semi-
annually through year 30; in practice, gas monitoring will be conducted quarterly until a
frequency adjustment is proposed and approved by the ROD signatories. Alternative 4.3
assumed groundwater monitoring would occur quarterly for five years, then semi-annually
through year 30; in practice, groundwater monitoring will be conducted quarterly until a
frequency adjustment is proposed and approved by representatives of the ROD signatory
agencies. A review of monitoring frequency will be conducted no less than every five years. .
Access restrictions would involve fencing and deed restrictions to preserve the integrity of
the engineered cap. Deed restrictions would be imposed to prevent excavations and certain
types of land use, such as farming, that are deemed inappropriate.
2.7.5 Site 5 Remedial Alternatives
Three alternatives were developed for possible application at Site 5.
2.7.5.1
Alternative 5.1 - No-Action
This alternative is the "no-action" alternative and is defined as the current site conditions
with semi-annual groundwater monitoring for 5 years under the existing Base groundwater
monitoring program. At the end of the 5-year period, an evaluation would be performed to
determine if continued monitoring would be necessary.
2.7.5.2 Alternative 5.2 - Landfill Excavation and Consolidation
Under this alternative, landf1l1 refuse and associated soils would be excavated, transported to,
and placed at the consolidation site (i.e., Site 4) with commercially available equipment.
Prior to excavation, the site would undergo a PDI to define the verti~ extent of soils
affected by landfill leachate. No contaminated soil will be left in place with concentrations
RUI2-94/ES/126000 I.A WS
2-84
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of constituents that threaten water quality unless it is technically or economically infeasible to
remove this soil. Technical or economic feasibility will be determined by the Air Force, in
consultation with U.S. EPA and the State, based on the factors described in Porter Collogne
~ 13304 and 23 CCR ~ 2550.4, and subject to the signatory parties' authority in the Federal
Facility Agreement and CERCLA ~121. A Water Quality Assessment will be conducted
using the Designated Level Methodology and V-LEACH, depending on the constituent, or
other equivalent appropriate method to determine whether a threat to groundwater quality
remains. If a threat to groundwater quality remains, it will be addressed by consideration of
alternative remedial actions. The site would then be recontoured to eliminate topographic
depressions and clean-closed.
The discharge to Site 4 of hazardous waste, designated waste, containerized liquids (intact
liquid containers of five-gallons or greater), solid waste containing free liquid or moisture in
excess of the waste's moisture holding capacity, and liquid or semi-solid waste (i.e., waste
containing less than 50% solids), is prohibited. During consolidation of refuse from Sites 5
and 6 into 4, intact containers of 5-gallons or larger and any significant quantities of
apparently prohibited waste will be segregated for characterization and appropriate disposal.
Alternative 5.2 assumed groundwater monitoring would occur quarterly for five years then
semi-annually through year 30; in practice, following the removal of refuse and underlying
soil at Site 5, groundwater monitoring continue for a period of at least three years to
demonstrate the success of the remedial action. The monitoring will be accomplished
quarterly in the existing monitoring wells at Site 5. The suite of analytes will consist at a
minimum of those constituents identified at elevated concentrations in waste characterization,
and/or sampling of the soil beneath the sites, and taking into consideration constituents
detected at elevated concentrations in other media (landfill gas, soil adjacent to the sites,
sediment, and surface water). The monitoring data will be evaluated against the groundwater
quality performance measure described below using a statistical method from among those
described in 40 CFR 258.53 or 23 CCR 2550.7(e)(8). The performance measure is the
water quality .that corresponds to any concentration of contamination remaining in the soil. If
groundwater quality impairment above the performance measure is detected, and determined
to be caused by release from Site 5, the need for further remedial action will be evaluated to
address this impairment.
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Alternative 5.3 - Landfill Excavation, Consolidation, Embankment and
Capping
Under this alternative, a portion of the landfill contents, that portion which currently
occupies an intermittent stream channel and lOO-year floodplain, would be excavated.
Due to the limited extent of refuse within the stream channel and floodplain, no
provisions were made for a PDI. Excavated materials would be consolidated onto the
remaining landfill areas to the west and east of the stream channel. Once excavation
had been started, it would continue until post-excavation ''verification'' soil samples
indicated underlying soils are clean. Excavated areas would be recontoured to eliminate
topographic depressions and then would be clean-closed. Engineered caps would be
installed at the two remaining refuse areas. In order to protect the engineered caps from
the intermittent stream's tOO-year floodwaters, flood control measures, such as an
embankment, would be installed. Passive gas vent wells would be installed to prevent
pressure buildup of gases beneath the cap surface and to abate potential lateral
migration of gases.
2.7.5.3
Alternative 53 assumed gas monitoring would occur quarterly for five years, then semi-
annually through year 30; in practice, gas monitoring will be conducted quarterly until a
frequency adjustment is proposed and approved by the ROD signatories. Alternative 5.3
assumed groundwater monitoring will be conducted quarterly for five years, then semi-
annually through year 30; in practice, groundwater monitoring will be conducted
quarterly until a frequency adjustment is proposed and approved by representatives of
the ROD signatory agencies. A review of the monitoring frequency will be conducted no
less than every five years.
Access restrictions would involve fencing and deed restrictions to preserve the integrity
of the engineered cap. Deed restrictions would be imposed to prevent excavations and
cenain types of land use, such as farming, that are deemed inappropriate.
2.7.6 Site 6 Remedial Alternatives.
Three alternatives were developed for possible application at Site 6.
2.7.6. 1 Alternative 6. 1 - No-Action
This alternative is the "no-action" alternative and is defined as the current site conditions
with semi-annual groundwater monitoring for 5 years under the existing Base
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groundwater monitoring program. At the end of the 5-year period, an evaluation would be
performed to determine if continued groundwater monitoring would be necessary.
2.7.6.2 Alternative 6.2 - Landfill Capping
Under this alternative, a vegetative cover would be installed over the "north" and "south"
landfills. Passive gas vent wells would be installed to prevent pressure buildup of gases
beneath the cover surface and to abate potential lateral migration of gases.
Alternative 6.2 assumed gas monitoring would occur quarterly for five years, then semi-
annually throiIgh year 30; in practice, gas monitoring will be conducted quarterly until a
frequency adjustment is proposed and approved by the ROD signatories. Alternative 6.2
assumed groundwater monitoring will be conducted quarterly for five years, then semi-
annually through year 30; in practice, groundwater monitoring would be conducted quarterly
until a frequency adjustment is proposed and approved by representatives of the ROD
signatory agencies. A review of monitoring frequency will be conducted no less than every
five years.
Access restrictions would involve fencing and deed restrictions to preserve the integrity of
the engineered cap. Deed restrictions would be imposed to prevent excavations and certain
types of land use, such as farming, that are deemed inappropriate.
2.7.6.3 Alternative 6.3 - Landfill Excavation and Consolidation
Under this alternative, landfill refuse and associated soils would be excavated, transported to,
and placed at the consolidation site (i.e., Site 4) with commercially available equipment.
Prior to excavation, the site would undergo a PDI to define the vertical extent of soils
affected by landfill leachate. No contaminated soil will be left in place with concentrations
of constituents that threaten water quality unless it is technically or economically infeasible to
remove this soil. Technical or economic feasibility will be determined by the Air Force, in
consultation with U.S. EPA and the State, based on the factors described in Porter Collogne
~ 13304 and 23 CCR ~ 2550.4, and subject to the signatory parties' authority in the Federal
Facility Agreement and CERCLA ~121. A Water Quality Assessment will be conducted
using the Designated Level Methodology and V-LEACH, depending on the constituent, or
other equivalent appropriate method to determine whether a threat to..groundwater quality
2-87
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remains. If a threat to groundwater quality remains, it will be addressed by consideration of
alternative remedial actions. The site would then be recontoured to eliminate topographic
depressions and clean-closed.
Following the removal of refuse and underlying soil at Site 6, groundwater monitoring
continue for a period of at least three years to demonstrate the success of the remedial action.
Alternative 6.3 assumed groundwater monitoring would occur quarterly for five years, then
semi-annually through year 30; in practice, groundwater monitoring will be conducted
quarterly until a performance measure is demonstrated to have been met for three consecutive
years. The monitoring will be accomplished using the existing monitoring wells at Site 6 and
in one additional well to be installed near the down gradient margin of the northern part of
Site 6. The suite of analytes will consist at a minimum of those. constituents identified at
elevated concentrations in waste characterization, and/or sampling of the soil beneath the
sites, and taking into consideration constituents detected at elevated concentrations in other
media (landfill gas, soil adjacent to the sites, sediment, and surface water). The monitoring
data will be evaluated against the groundwater quality performance measure described below
using a statistical method from among those described in 40 CFR 258.53 or 23 CCR
2550.7(e)(8). The performance measure is the water quality that corresponds to any
concentration of contamination remaining in the soil. If groundwater quality impairment
above the performance measure is detected, and determined to be caused by release from Site
6, the need for further remedial action will be evaluated to address this impairment.
2.8 Summary of the Comparative Analysis of Alternatives
The remedial alternatives developed in the FFS were analyzed in detail using the nine
evaluation criteria required by the NCP (Section 300.430(e)(7». These criteria are classified
as threshold criteria, primary balancing criteria, and modifying criteria. Threshold criteria
are:
.
overall protection of human health and the environment; and
compliance with ARARs.
.
Primary balancing criteria are:
.
long-term effectiveness and permanence;
reduction of toxicity, mobility, or volume through treatment;
short-term effectiveness;
.
.
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.
implementability; and
cost.
.
Modifying criteria are:
.
state/support agency acceptance; and
community acceptance.
.
The resulting strengths and weaknesses of the alternatives were weighed to identify the
alternative providing the best balance among the nine criteria for each landfill site. The
nine criteria are summarized in the following sections.
2.8.1 Overall Protection of Human Health and the Environment
Overall protection of human health and the environment addresses whether or not a
remedy provides adequate protection and describes how risks posed through each
exposure route are eliminated, reduced, or controlled through treatment, engineering
controls, or institutional controls.
2.8. 1. 1 Site 1 - Runway Overrun Landfill
Alternative 1.1 is the only alternative developed for this site. No refuse or contaminants
were found during remedial activities. Therefore, no comparative analysis is necessary.
2.8. 1.2 Site 2 - .8150. Area Landfill
The baseline risk assessment determined that current and future risk are within
acceptable limits (i.e., between 104 and 10-6) [IT 1993c]. Either Alternative 2.2 or 2.3
would provide protection of human health and the environment and therefore could be
implemented. Alternative 2.2 reduces risk through controlling exposure pathways and
natural degradation. Alternative 2.3 eliminates risk at Site 2 by removing the source.
However, a higher potential exists for worker exposure to the refuse and associated soils
during excavation and consolidation. This exposure can be controlled through
development and implementation of appropriate health and safety procedures.
2.8.1.3 . Site 3 - Northeast Perimeter Landfill No.1
The baseline risk assessment determined that current and future risk are within
acceptable limits (Le., between 10-4 and 10-6) [IT 1993c]. Therefore, either
Alternative 3.2 or 3.3 could be implemented. Alternative 3.2 offers a higher degree of
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protection of human health and the environment than Alternative 3.3 since there is no
excavation which results in potential contact with refuse. Alternative 3.2 reduces risk
through controlling exposure pathways and natural degradation. Alternative 3.3
eliminates risk at Site 3 by removing the source. However, a higher potential exists for
worker exposure to the refuse and associated soils during excavation and consolidation.
This exposure can be controlled through development and implementation of
appropriate health and safety procedures.
2.8.1.4 Site 4 - Northeast Perimeter Landfill No.2
The baseline risk assessment determined that current and future risk are within
acceptable limits (i.e., between 10-4 and 10-6) [IT 1993c]. Either Alternative 4.2 or 4.3
would provide protection of human health and the environment and therefore could be
implemented. Alternatives 4.2 offers a higher degree of protection of human health and
the environment than Alternative 4.3 since there is no excavation which results in
potential contact with refuse. Alternative 4.3 potentially exposes workers to refuse and
associated soils during excavation and consolidation. However, this exposure can be
controlled through development and implementation of appropriate health and safety
procedures. .
2.8.1.5 Site 5 - Northeast Perimeter Landfill No.3
The baseline risk assessment determined that current and future risk are within
acceptable limits (i.e., between lQ-4 and lQ-6) [IT 1993c]. Either Alternative 5.2 or 5.3
would provide protection of human health and the environment and therefore could be
implemented. Alternative 5.3 offers a higher degree of protection of human health and
the environment than Alternative 5.2 since less refuse is excavated and risk is reduced
through control of exposure pathways and natural degradation. Alternative 5.2
eliminates risk at Site 5 by removing the source. Both Alternatives 5.2 and 5.3
potentially expose workers to refuse and associated soils during excavation and
consolidation. However, this exposure can be controlled through development and
implementation of appropriate health and safety procedures.
2.8. 1.6 Site 6 - Firing Range Landfill Sites
The baseline risk assessment determined that current and future risk are within
acceptable limits (i.e., between 10-4 and 10-6) [IT 1993c]. Either Alternative 6.2 or 6.3
would provide protection of human health and the environment and therefore could be
implemented. Alternative 6.2 offers a higher degree of protection of human health and
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the environment than Alternative 6.3 since no refuse is excavated and risk is reduced
through control of exposure pathways and natural degradation. Alternative 6.3
eliminates risk at Site 6 by removing the source. The potential exists for worker
exposure to the refuse and associated soils during excavation and consolidation.
However, exposure can be controlled through development and implementation of
appropriate health and safety procedures.
2.8.2 Compliance with ARARs
2.8.2.1 ARAR Definitions
Pursuant to Section 121(d)(l) of CERCLA [42 USC Section 9621(d)], remedial actions
must attain a degree of cleanup which assures protection of human health and the
environment. Additionally, remedial actions that leave hazardous substances, pollutants,
or contaminants on site must meet standards, requirements, limitations, or criteria that
are ARARs. Federal ARARs may include requirements under any federal
environmental laws. State ARARs include promulgated requirements under State
environmental or facility-siting laws that are more stringent than federal ARARs and
that have been identified to U.S. EPA by the State in a timely manner.
Applicable requirements are those clean-up standards, control standards, 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 circumstances at a CERCLA site.
Relevant and appropriate requirements include those that, while not "applicable" to a
hazardous substance, pollutant, contaminant, remedial action, location, or other
circumstances at a CERCLA site, nevertheless address problems or situations sufficiently
similar to those encountered at the CERCLA site to indicate their use is well-suited to
the particular site. A requirement must be both relevant and appropriate to be
designated an ARAR. If no ARAR addresses a particular situation, or if an ARAR is
insufficient to protect human health or the environment, then nonpromulgated standards,
criteria, gui~ance, and to-be-considered (TBC) advisories may be used to provide a
protective remedy.
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ARARs are identified on a site-specific basis from information about specific chemicals
at the site, specific actions that are being considered as remedies, and specific features of
the site location. There are three categories of ARARs:
.
Chemical-specific ARARs are numerical values or methodologies which,
when applied to site-specific conditions, result in the establishment of
numerical values. They are used to determine acceptable concentrations of
specific hazardous substances, pollutants, and contaminants in the
environment;
.
Location-specific ARARs are restrictions placed on the concentration of
hazardous substances or the conduct of activities solely because the site
occurs in a special location, such as a wetland or floodplain; and
.
Action-specific ARARs are technology- or activity-based requirements or
limitations on actions taken with respect to hazardous waste.
The ARARs and TBCs were developed using the following guidelines and documents:
CERCLA Compliance with Other Laws Manual, Part I (Interim Final) [EPA 1988);
CERCLA Compliance with Other Laws Manual, Part n: Clean Water Act and Other
Environmental Statutes and State Requirements [EPA 1989c); and California State
Water Resources Control Board ARARs Under CERCLA [SWRCB 1992). The
following sections outline the ARARs and other information considered for the Landfill
au sites.
The Federal ARARs are summarized in Table 2.42. The State ARARs are summarized
in Table 2.43.
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IV
I
\0
W
Table 2.42 Mather AFB Landfil~ Operable Unit Federal ARARs(a)
Standard,
Requirement, Criterion, Associated
Source or Limitadon ARAR Status Description Comment Site(s)
Resource Conservation 40 Code of Federal Relevant and Appropriate (if Airport Safety: Municipal Solid Waste Applies to new, existing, or 3,4
and Recovery Act, Regulation (CFR) 258.10 definition of sirport is met) Landfills (MWSLF) units thst are located lateral expansion MSWLF.
Subtitle D within 10,000 feet of the end of a The operation at Site 4 does
runway used by turbojet aircraft must be not fit the definitions of
designed and operated so that the unit "New," "Existing," or
does not pose a bird hazard to the "Lateral Expansion," thus
aircraft the regulations that
specifically apply to new,
existing, or lateral
expansion MSWLF are not
applicable to Site 4.
However aIrport aafety Is
relevant and appropriate
becauIC the consolidation of
wastes at Site 4 is
sufficIently similar to
MSWLP operations 10 cause
a potential bird aafety Issue.
Further Site 4 Is
approximately 4,000 feet
northeast of the end of the
runway.
Resource Conservation 40 CFR 258.12 Relevant and Appropriate Wetlands: The construction of a new This regulation is relevant 4
and Recovery Act, MSWLF or lateral expansion of an and appropriate because
Subtitle D existing MSWLF will not cause or there are three vernal pools
~ contribute to the degradation of a west of Site 4.
wetland as a result of erosion, stability,
or migration of materials; cause or
contribute to a violation of a waler
quality standard, violate the toxic emuent ..
standard under the Clean Water Act,
I jeopardize the existence of endangered or
threatened species or their habitats
(a)
The requirements of the Federal Resource Conservation and Recovery Act Subtitle D program in 40 CFR Part 258 et. seq. are the ARARa for the Sites 2, 3, and 4, unless the requirement
in tho State, Subtitle D regulations in Title 23, California Code of Regulations, Division 3, Chapter IS, and Title 14 California Code of Regulstions, Division 7, Chapter 3 is more stringent,
and in that event, the State requirement is the ARAR.
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Table 2.42 Mather AFB Landfill Operable Unit Federal ARARs(8)
tV
~
.J>o.
Standard,
Requirement, Criterion, Associated
Source or Limitation ARAR Status Description Comment Slte(s)
Resource Conservation 40 CFR 258.20 Applicable Procedures for Excluding the Receipt of The wastes from Sites 5 and 4
and Recovery Act, Hazardous Waste: All MSWLF 6 are not expected to
Subtitle 0 receiving waste after October 9, 1991 contain hazardous wastes
(herein referred to as .operating based on analysis of the
MSWLP") must have a program to umpling resulta and
exclude hazardous waste and histories of these sites.
Polychlorinated Biphenyls from disposal However, the p099ibllity of
at the lite. Thil program must include hazardoul Waltel being
random inspections or another method to encountered in the
ensure incoming loads do not contain excavated wastes can not be
these w89tes. This requirement is excluded.
applicable to Site 4 because it will be
receiving waste from landfill sites 5 and
6
Resource Conservation 40 CFR 258.21 Applicable Cover Material Requirements: To Wastes from Sites 5 and 6 4
and Recovery Act, control disease vectora, fire., odora, are expected to be
Subtitle 0 blowing litter, and scavenging, all comparable to municipal
operating MSWLFs must be covered wastes. Thus cover
with .ix inche. of earthen material (or material. at Site 4, the .ite
equivalent) at the end of the day or more where consolidation will
frequently if necessary occur, would need to limit
disease vectora, fire., odora,
blowing litter and
.cavenging that are
89sociated with uncontrolled
municipal waste dispoul.
f
Resource Conservation 40 CFR 258.22 Applicable Oi.ease Vector Control: Rodents, flies, Consolidation of wastes at 4
and Recovery Act, mosquitoes, and other animals thst are Site 4 might attract disease
Subtitle 0 capable of transmiUing diseases to vectors unle99 they are
humans must be prevented or populations controlled.
controlled at all MSWLP.
(a)
The requirement. of the Federal Resource Conservation and Recovery Act Subtitle D program in 40 CFR Part 258 et. seq. are the ARARs for the Site. 2, 3, and 4, unles. the requirement
in the State, Subtitle D regulations in Title 23, California Code of Regulation., Divi.ion 3, Chapter IS, and Title 14 California Code of Regulations, Division 7, Chapter 3 is more stringent,
and in that event, the State requirement is the ARAR.
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Table 2.42 Mather AFB Landfill Operable Unit Federal ARARs(a)
IV
I
\0
VI
Standard,
Requirement, Criterion, Associated
Source or Limitation ARAR Status Description Comment Sile(s)
Resource Conservation 40 CFR 258.23 Applicable Explosive Oas Control: Monitoring and Methane has been measured 4
and Recovery Act, control of methane is required at all in the landfill gases
Subtitle D MSWLF. The concentration of methane generated at Site 4. The
must not exceed 25 % of the lower materials to be excavated
explosive limit (LEL) in facility from Sites 5 and 6 may also
structures and must be at or below the generated methane when
LEL at the facility property boundary. consolidated at Site 4.
Resource Conservation 40 CFR 258.24 Applicable Air Criteria: Oas emissions from the 4
and Recovery Act, landfill must not result in a violation of
Subtitle D an air quality .tandard developed under a
State Implementation Plan for the Federal
Clean Air Acl. Applies to all MSWLFs.
Resource Conservation 40 CFR 258.25 Applicable Access Requirements: Natural or Site 4 is located in a portion 4
and Recovery Act, artificial barriera must be used to prevent of the Base that is near an
Subtitle D unauthorized vehicle traffic and illegal area that has been
dumping and to control public aCcess to designated for public access
all MSWLFs. as a regional park.
Resource Conservation 40 CFR 258.26 Applicable Run-onlRun-OfTControl Systems: A run- 4
and Recovery Act, on and run-ofT 'ystem must be designed
Subtitle D to handlo tho potential flow from a 24.
hour, 2S-year .torm
Resource Conservation 40 CFR 2S8.28(a) Applicable Liquid Restrictions: Bulk and 4
and Recovery Act, noncontainerized wastes can nol be added
Subtitle D to any MSWLF except septic waste from
f a household. Leachate and condensato
derived from tho MSWLF can be placed
in the unit if tho unit has a composite
linear and leachate collection system.
(a)
The requirements of the Federal Resource Conservation and Recovery Act Subtitle D program in 40 CFR Part 258 ct. seq. are the ARARs for the Sites 2, 3, and 4, unleu the requirement
in the State, Subtitle D regulations in Title 23, California Code of Regulations, Divi.ion 3, Chapter IS, and Title 14 California Code of Regulations, Division 7, Chapter 3 i. more stringent,
and in that event, the State requirement is the ARAR.
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Table 2.42 Mather AFB Landfill Operable Unit Federal ARARs(a)
t-.)
~
0\.
Standard,
Requirement, Criterion, Associated
Sourc:e or Limitation ARAR Status Description Comment Site(s)
Resource Conservation 40 CFR 258.28(b) Applicable. A waiver may be Liquid Restrictions: Containerized 4
and Recovery Act, needed because you can not liquids placed into a MSWLP must met
Subtitle D tell If the origin was three restrictions: I) the containera must
"household waste" be similar in size to that normally found
in household wastej 2) the container is
designed to hold liquids for use other
than storagej 3) or the waste is
housebold waste
Resource Conservation 40 CFR 258.SI Applicable Groundwater Monitoring Systems: A 4
and Recovery Act, groundwater monitoring system must be
Subtitle D Installed that characterizes the upper
aquifer. More than one unit may be
monitored by the same system if the
hydrogeological setting Is appropriate.
The system must include a sufficient
number of wells positioned in locations
to characterize the quality of
groundwater in unaffected area (i.e.,
background) and at either a point of
compliance or at the unit boundary.
Monitoring wells must be constructed to
provide representative samples and
prevent contamination from surface
sources of chemicals.
f
(a)
The requirements of the Federal Resource Conservation and Recovery Act Subtitle D program in 40 CFR Part 258 et. seq. are the ARARs for the Sites 2, 3, and 4, unless the requirement
in the State, Subtitle D regulations in Tille 23, California Code of Regulations, Division 3, Chspter IS, and Title 14 California Code of Regulations, Division 7, Chapter 3 is more stringent,
and in that event, the State requirement is the ARAR.
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Table 2.42 Mather AFB Landfill Operable Unit Federal ARARs(a)
N
I
\0
--.)
Standard,
Requirement, Criterion, Associated
Soun:e or Limitation ARAR Status Description Comment Site!!)
Resource Conservation 40 CFR 258.60(a) and (b) Applicable Closure Criteria: All MSWLF must 4
and Recovery Act, install a final cover to minimize
Subtitle D infiltration and erosion. The cover must:
have a permeability of permeability of
0.00001 em/see or less; have an
infiltration layer containing a minimum
of 18-inches of earthen materials; and
have an erosion layer with a minimum of
6-inches of earthen materials that is
capable of sustaining native plant growth.
Alternative designs may be approved if
they meet the performance standards for
minimization of Infiltration, wind
erosion, and water erosion.
Resource Conservation 40 CFR 258.60(1) and (g) Applicable Closure Criteria: All MWSLF must 4
and Recovery Act, begin closure 30-days after the receipt of
Subtitle D the final load of waste. The closure
activities must be complete within 180
days unless an exemption has been
granted and all steps are taken to prevent
threats to human health and the
environment.
Resource Conservation 40 CFR 258.60(i) Applicable (for Site 4) and <;Iosure Criteria: Following closure a As of 1994 there are no 4: Applicable
and Recovery Act, Relevant and Appropriate (for notification muat be added to the deed or deeds to the Mather Air
Subtitle D Sites 2 and 3) equivalent instrument to notify a Force Base (AFB) property. 2 and 3:
f purchaser that the property was used 88 a Notification of the property Relevant and
landfill. use is planned to be added Appropriate
to the transfer records.
(a)
The requirements of the Federal Resource Conservation and Recovery Act Subtitle D program in 40 CFR Part 258 ct. seq. are the ARARs for the Sites 2, 3, and 4, unless the requirement
in the State, Subtitle D regulations in Title 23, California Code of Regulations, Division 3, Chapler 15, and Tille 14 California Code of Regulations, Division 7, Chapler 3 ia more stringent,
and in that event, the Stale requiremenlls the ARAR.
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Table 2.42 Mather AFB Landfill Operable Unit Federal ARARs(a)
N
~
00
Standard,
Requirement, Criterion, Associated
Source or Limitation ARAR Status Description Comment Site(s)
R~sourc~ Cons~rvation 40 CFR 258.6I(a)(I), Applicable (for Site 4) and Post-Closu~ Ca~ R~qui~m~nts: For a Waste will be add~d to Site 4: Applicable
and R~cov~ry Act, 40 CFR 258.6I(a)(3), & R~levant and Appropriate (for p~riod of 30 years (unl~ss det~rmined 4 following the applicabl~
Subtitl~ D 40 CFR 258.6I(a)(4) Sit~s 2 and 3) that another p~riod is appropriat~), th~ date for Subtitle D (i.~., 2 and 3:
final cover and gas collection syst~m Oc:tob~r 9, 1991), thus it i8 R~I~vant and
must be maintain~d. Further applicable. Appropriate
groundwater must b~ monitor~d pursuant
to the groundwat~r monitoring The post-closu~
~qul~m~nts id~ntified in 40 CFR ~qui~m~nts a~ conside~d
258.50 - 258.58. ~Ievant and appropriate for
Sitel 2 and 3 because they
we~ used for the disposal
of municipal solid waste
prior to the passage of
RCRA Subtitle D. Further,
the ~quirementa for post-
closure addrels systems
(final covers, gas venting
w~lIs, and groundwater
monitoring n~tworka) that
are being plaM~d as part of
the closure of th~se sites.
Maint~nancc of a leachate
col1~ction syst~m (40 CFR
258.6 I (a) (2) haa not bc~n
Identified as an applicable or
relevant and appropriate
f requi~ment (ARAR) for
Sites 2, 3, or 4. Because
there are no Icachate
coll~tion systems in the
final remedial alternative.
(a)
The requi~m~nts of the Federal Resource Conservation and Recovery Act Subtitle D program in 40 CFR Part 258 et. I~q. are the ARARs for the Sites 2,3, and 4, untelS the requirement
in the State, Subtitle D regulations in Title 23, California Code of Regulations, Division 3, Chapt~r 15, and Title 14 California Code of Regulations, Division 7, Chaptcr 3 is more stringent,
and in that event, the State requirement Is the ARAR.
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Table 2.42 Mather AFB Landfill Operable Unit Federal ARARs(8)
N
t
\0
\0
Standard,
Requlremeat, CriterioD, Associated
Soun:e or Llmltadon ARAR Status Description Commeat Slte(s)
Clean Water Act, Subsection B, Applicable Nationwide Pennit No. 38, Cleanup of Hazardous waste may be 3,4, Sand 6
Section 404 Appendix A to Part 330, Hazardous and Toxic Wastes present in the landfills at
33 CFR 330 (Nationwide Pennit from the U.S. Anny Mather AFB. Vernal pools,
Corps of Engineers for work in wetlands a type of wetland, are
and other water): Cleanup activities that located between sites 3 and
may involve containment, stabilization, 4. The extent of these pools
or removal of hazardous or toxic wastes have been mapped. Some
would need to delineate wetlands prior to refuse to be excavated at
field operations. Site S lies beneath an
Intermittent drainage. Site 6
is adjacent to a drainage.
Clean Water Act, Subsection C, Applicable Nationwide Pennit Conditions: The Vernal pools are located 3,4, Sand 6
Section 404 Appendix A to Part 330, following conditions/practices must be between sites 3 and 4 and
33 CFR 330 followed: any structure or fill shall be poaaibly near Site 6; site 5
maintained. including maintenance to and 6 are near drainage
ensure public safety; erosion and siltation channels. In addition, the
controls must be used and maintained tadpoles of the western
during construction and all fills must be spadefoot frog, a species of
permanently stabilized at the earliest concern in California,
practicable date; heavy equipment although not either an
working in wetlands must be placed on endangered or threatened
mala or other measures must be taken to species, have been seen near
minimize soil distUrbances; no activity Site 6.
conducted under a nationwide pennit
must jeopardize the continued existence
of a threatened or endangered species or
f a species proposed for designation
Clean Water Act, 40 CFR 230.10(a) to Applicable Restrictions on Discharge: If there is a Vernal pools are located 3, 4, 5 and 6
Section 404 230.10(c) practicable alternative that would have a between sites 3 and 4. and
lesser impact on the wetlands, fill possibly near Site 6. Site S
materials should not be discharged at the intersects a drainage
wetland. Any discharge that occura channel, and Site 6 is
should not cause a violation of a state adjacent to a drainage
water quality objective or a significant channel
degradation of water quality.
(a)
The requirements of the Federal Resource Conservation and Recovery Act Subtitle D program in 40 CPR Part 258 et. seq. are the ARARs for the Sites 2, 3. and 4, unless the requirement
in the State, Subtitle D regulations In Title 23. California Code of Regulations, Division 3, Chapter 15, and Title 14 California Code of Regulations, Division 7, Chapter 3 is more stringent,
and in that event, the State requirement Is the ARAR.
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Table 2.42 Mather AFB Landfill Operable Unit Fecleni ARARs(8)
N
.
-
8
Staudard,
Requiremeut, Criterion, AssodIIted
Source or Umltation ARAR Status Description Commeut Site(s)
Clean Water Act, 40 CFR 230.70 . 230.77 Applicable The project should be d~igDcd '8) VemsJ pools occur betWeen 3, 4, 5, and 6
Section 404 (Subpart H: Actions to minimize potential adverse eff~ sites 3 and 4, and possibly
Minimize Adverse considering the following issues: near Site 6. Site 5
Impacts) 1) DischaIJe Location intersects a drainage clwmcl
2) Material to Be Discharged and Sile 6 is adjacent to .
3) CODlroI of DischaIJcd MatcDa! If8::r drainage channel. Eat1h
Discharge moving and recontouring
4) Technologies Used will occur at all sites.
5) Plant and Animal Populations
6) Other potential adverse effcas
EDdangercd SJ?Ccies Acl 50 CFR 222, 226. 227, Applicable The remedial actions al the Landfill au 2, 3, 4. 5, and
, and 402 'ttj sites may impact endangered spccics.. 6
All procedures must ensure that
substantive regulatory requirerneas IIJe
followed to avoid or mitigate iqIIcu.
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Table 2.43 Mather AFB Landfill Operable Unit State ARARsI
N
I
.....
o
.....
Source Standard, ARAR Slam Destripdon Comment Assoclated Site(s)
Requirement,
Criterion, or
Limitation
California Integrated 14 CCR 17766 Applicable for Emergency Response Plan (ERP): potential emergency Closure or Postclosure 2 &. 3': Relevant
Waste Management Site 4 conditions that may exceed the design of the site and Maintenance Standard of and Appropriate
Act of 1989 Title 14, CCR, Division could endanger the public health or environment must Title 14, CCR, Division 7,
Public 7, Chapter 3, Article Relevant and be anticipated. Response procedures for these Chapter 3, Article 7.8. Scope 4: Applicable
Resource Code 7.8 Disposal Site Clo- Appropriate for conditions must be addressed in the RDIRA plans. and Applicability purauant to
Section 40502 sure and Postclosure Sites 2 &. 3' 14 CCR 17760.
Section 43020 Maintenance
California Integrated 14 CCR 177672 Applicable for Security at Closed Sites: all points of access to the site Closure or Postclosure 2 &. 3': Relevant
Waste Management Site 4 must be restricted, except pennitted entry points. All Maintenance Standard of and Appropriate
Act of 1989 Title 14, CCR, Division monitoring, control, and recovery systems shsll be Title 14, CCR, division 7,
Public 7, Chapter 3, Article Relevant and protected from unauthorized access Chapter 3, Article 7.8. Scope 4: Applicable
Resource Code 7.8 Disposal Site Appropriate for and Applicability purauant to
Section 40502 Closure and Postclosure Sites 2 &. J' 14 CCR 17760.
Section 43020 Maintenance
#
1: The State does not agree on the characterizations of certain ARARs in this table to be "Relevant and Appropriate" instead of
"Applicable." However since these requirements are included in the ROD as ARAR, the State will not dispute this ROD.
2: The requirements of the Federal RCRA Subtitle D program in 40 CFR Part 258 et seq. are the ARARs for landfills 2,3, and
4, unless the requirement in the State Subtitle D regulations in 23 CCR, Div. 3, Ch. 15, or 14 CCR, Div. 7, Ch. 3 is more
stringent, and in that event, the state requirement is the ARAR. .
3: Identification of provisions of Title 14 CCR, Chapter 3, Article 7.8 as "Relevant and Appropriate" to Sites 2 & 3 is subject to
consistency with the selected remedial alternative for each site.
4: U.S. EPA believes this requirement of Chapter 15 is applicable only because Site 4 is now subject to the state Subtitle D
Regulations in Chapter 15.
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Table 2.43 Mather AFB Landfill Operable Unit State ARARsI
tV
I
-
S
Source Standard, ARAR Status Description Comment Associated Slte(s)
Requirement,
Criterion, or
Limitation
California Integrated 14 CCR 17773(b) to Applicable for Final Cover: the design and construction of the final Closure or Postclosure 2 &. 3 I: Relevant
Waste Management 17773{e) 2 Site 4 cover must meet specific prescriptive standards. These Maintenance Standard of and Appropriate
Act of 1989 include minimum thickness and quality of the Title 14, CCR, Division 7,
Public Title 14, CCR, Division Relevant and construction material (14 CCR 17173 (b) and (e» Chapter 3, Article 7.8. Scope 4: Applicable
Resource Code 7, Chapter 3, Article Appropriate for and Applicability pursuant to
Section 40502 7.8 Disposal Site CIa- Sites 2 &. 3 1 14 CCR 17760.
Section 43020 sure and Postclosure
Maintenance
California Integrated 14 CCR 17774{a) &. Applicable for Site Construction Quality Auurance (CQA): a CQA Closure or Postclosure 2 &. 3 I: Relevant
Waate Management 17774(c) to 17774(11) 2 4 program must be designed and implemented. It must Maintenance Standard of and Appropriate
Act of 1989 include specific parameten (and for some components Title 14, CCR, Division 7,
Public Title 14, CCR, Division Relevant and specific testing melhods) for each component of the final Chapter 3, Article 7.8. Scope
Resource Code 7, Chapter 3, Article Appropriate for cover. and Applicability purauant to 4: Applicable
Section 40502 7.8 Disposal Site CIa- Sites 2 &. 3 1 14 CCR 17760.
Section 43020 sure and Postclosure
Maintenance
California Integrated 14 CCR 17776(a); (c); Applicable for Site Final Grades: the final grades for the covered landfill Closure or Postclosure 2 &. 3 ': Relevant
Waste Management substantive requirements 4 mult meet grading standards provided in 23 CCR 2581, Maintenance Standard of and Appropriate
Act of 1989 of (d); (e) &. (I) 2 they must be appropriate to control runoff and erosion. Title 14, CCR, Division 7,
Public Relevant and Chapter 3, Article 7.&. Scope 4: Applicable
Resource Code Title 14, CCR, Division Appropriate for and Applicability purauant to
Section 40502 7, Chapter 3, Article Sites 2 &. 3 1 14 CCR 17760.
Section 43020 7.8 Disposal Site
Closure and Postclosure
f Maintenance
California Integrated 14 CCR 17777(a) &. Applicable for Site Final Site Face: the design of the final site face must Closure or Poltclosure 2 &. 3 I: Relevant
Waate Management 17777(b), and 4 provide for the integrity of the final cover both under Maintenance Standard of and Appropriate
Act of 1989 substantive content of static and dynamic conditions. Title 14, CCR, Division 7,
Public 17777{c) 2 Relevant and Chapter 3, Article 7.8. Scope 4: Applicable
Resource Code Appropriate for and Applicability purauant to
Section 40502 Title 14, CCR, Division Sitea 2 &. 3' 14 CCR 11760.
Section 43020 7, Chapter 3, Article
7.8 Di8posal Site
Closure and Postclosure
Maintenance
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Table 2.43 Mather AFB Landfill Operable Unit State ARARsI
tV
I
....
o
w
Source Standard, ARAR Status Description Comment Assodated Slte(s)
RequJrement,
Criterion, or
Limitation
California Integrated 14 CCR 17778(a), &. Applicable for Site Final Drainage: the design of the final cover must Closure or Postclosure 2 &; 3 ': Relevant
Waste Management 17778(c) to 17778(j)2 4 control runon and runoff produced by a 100 year Maintenance Standard of and Appropriate
Act of 1989 24 hour storm event and must be prepared according to Title 14, CCR, Division 7,
Public Title 14, CCR, Division Relevant and CQA requirements Chapter 3, Article 7.8. Scope 4: Applicable
Resource Code 7, Chapter 3, Article Appropriate for and Applicability pursuant to
Section 40502 7.8 Disposal Site Sites 2 &; 3 ' 14 CCR 17760.
Section 43020 Closure and Postclosure
Maintenance
California Integrated 14 CCR 17779(a), &. Applicable for Site Slope Protection and Erosion Control: the design and Closure or Postclosure 2 &. 3 ': Relevant
Waste Management 17779(c) to 17779(i) 2 4 construction of the slopes must protect the integrity of Maintenance Standard of and Appropriate
Act of 1989 the final cover and minimize soil erosion Title 14, CCR, Division 7,
Public Title 14, CCR, Division Relevant and Chspter 3, Article 7.8. Scope 4: Applicable
Resource Code 7, Chapter 3, Article Appropriate for and Applicability pursuant to
Section 40502 7.8 Disposal Site Sites 2 &. 3' 14 CCR 17760.
Section 43020 Closure and Postclosure
Maintenance
California Integrated 14 CCR 17781 2 Applicable for Site Leachate Control During Closure and Post Closure: The slate docs not intend that 2 &; 3 ': Relevant
Waste Management 4 leachate must be monitored, collected, treated, and subsurface leachate monitoring and Appropriate
Act of 1989 Title 14, CCR, Division discarded appropriately and collecting systems need to
Public 7, Chapter 3, Article Relevant and be added to existing landfills 4: Applicable
Resource Code 7.8 Disposal Site Appropriate for unless leachate production
Section 40502 Closure and Postclosure Sites 2 &. 3 ' and/or accumulation is
Section 43020 Maintenance evident.
Californit Integrated 14 CCR 17783' Applicable for Site Gu Monitoring and Control During Closure and Post Monitoring should be 2 &; 3 ': Relevant
Waste Management 4 Closure: landfill gases must be collected and analyzed; conducted for 30 yeara or until and Appropriate
Act of 1989 Title 14, CCR, Diviaion the concentration of combustible gas at the landfill authorized to be discontinued
Public 7, Chapter 3, Article Relevant and boundary must be 5 % or le88, trace gases must be by showing that there is no 4: Applicable
Resource Code 7.8 Disposal Site Appropriate for 2 controlled to prevent adverse acute and chronic exposure potential for gal migration
Section 40502 Closure and Postclosure &. 3' to toxic and/or carcinogenic compounds beyond the propeny boundary
Section 43020 Maintenance or into onsite structures, and
that landfill gases do not pose
a thrcat to public health and
safety or a threat to the
environment.
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N
I
-
~
Table 2.43 Mather AFB Landfill Operable Unit State ARARsI
Source Standard, ARAR Status Description Comment Assoclated Slte(s)
Requirement,
Criterion, or
Limitation
California Integrated 14 CCR 11788 ' Applicable for Site Poat Closure Maintenance: the landfill must be Monitoring Is continued for 30 2 &: 3 ': Relevant
Waete Management 4 maintained and monitored for no less than 30 yeara years following closure unless and Appropriate
Act of 1989 Title 14, CCR, Division following closure it can be demonstrated that the
Public 7, Chapter 3, Article Relevant and landfill does not pose a threat 4: Applicable
Resource Code 7.8 Disposal Site Appropriate for 2 to public health and safety or
Section 40502 Closure and Postclosure &: 3' a threat to the environment. If
Section 43020 Maintenance the threat has been eliminated,
post~losure maintenance can
be discontinued.
California Integrated 14 CCR 11796' Applicable for Site Post Closure Land Use: Site Closure Design shall show Closure or Poatclosure 2, 3, 5, &: 6 ':
Waete Management 4 one or more proposed uses of the closed site or show Maintenance Standard of Relevant and
Act of 1989 Title 14, CCR, Division development that is compatible with open space Title 14, CCR, Division 7, Appropriate
Public 7, Chapter 3, Article Relevant and Chapter 3, Article 7.8. Scope
Resource Code 7.8 Dispoaal Site Appropriate for 2, and Applicability pursuant to 4: Applicable
Section 40502 Closure and Postclosure 3, 5 & 6 ' 14 CCR 1'7760.
Section 43020 Maintenance
California Integrated 14 CCR 18262.3 2 Applicable for Site Provides the content requirements for closure plans for Applies to solid waate disposal 2 &: 3': Relevant
Waste Management 4 solid waete disposal sites. sites that received waste after and Appropriate
Act of 1989 Title 14, CCR, January I, 1988.
Public Resources Chapter 5, Article 3.4 Relevant and 4: Applicable
Code Sections Closure and Postclosure Appropriate for 2
40502 and 43509 Maintenance Plans and 3
California Integrated 14 CCR 18265.32 Applicable for Site Provides the content requirements for postclosure plans Applies to solid waste disposal 2 and 3: Relevant
Waate Mlnagement 4 for solid waate disposal sites. sites that received waste after and Appropriate
Act of 1989 Title 14, CCR, January I, 1988.
Public Resources Chapter 5, Article 3.4 Relevant and 4: Applicable
Code Sections Closure and Postclosure Appropriate for
40502 and 43509 Maintenance Plans Sites 2 and 3
California Integrated 14 CCR 176362 Applicable WeightNolume Records: the weight or volume of Applies to solid waste disposal 4
Waste Management waste accepted must be determined to an accuracy of sites as defined by Public
Act of 1989 Title 14, CCR, Division :t:10% Resources Code Section
Public Resources 7, Chapter 3, Article 40122.
Code Sections 1.3 Disposal Site
40502, 43020, Records
43021 and 43030
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N
I
..-
o
VI
Table 2.43 Mather AFB Landfill Operable Unit State ARARsI
Source Standard, ARAR Status Description Comment Associated Site(s)
Requirement,
Criterion, or
Limitation
California Integrated 14 CCR 17637 Applicable Subsurface Records: the length and depth of any cut(s) Applies to solid waite diapo881 4
Waste Management made In natural temin where fill will be placed and the sites as defined by Public
Act of 1989 Title 14, CCR, Division depth to groundwater must be determined and Resources Code Section
Public Resources 7, Chapter 3, Article documented 40122. While it i. not
Code Sections 7.3 Diapo881 Site planned that solid wRIte will
40502, 43020, Records be placed in cuts in native
43021 and 43030 soil, clean fill will be used
where refuse or contaminated
soil haa been excavated.
California Integrated 14 CCR 176582 Applicable to Site Site Security: the perimeter of the landfill muat be Applies to solid waste diapo881 4: Applicable
Waste Management 4 ICCUred either through barrien or topographic con- sltea as defined by Public
Act of 1989 Title 14, CCR, Division straints to diacourage unauthorized entry Resources Code Section 5 and 6: Relevant
Public Resources 7, Chapter 3, Article Relevant and 40122. and Appropriate
Code Sections 7.4 Dispo881 Site Appropriate for
40502,43020, Improvements Sites 5 &. 6
43021 and 43030
California Integrated 14 CCR 176592 Applicable to Site Accel8 Roads: landfill roads must be reasonably Applies to solid waite diapoaal 4: Applicable
Waste Management 4 smooth to minimize dust and tracking of materials onto sites aa defined by Public
Act of 1989 Title 14, CCR, Division public roads Resources Code Section 5 and 6: Relevant
Public Resources 7, Chapter 3, Article Relevant and 40122. and Appropriate
Code Sections 7.4 Dispo881 Site Appropriate for
40502, 43020, Improvements Sites 5 &. 6
43021 and 43030
Califom& Integrated 14 CCR 17676 Applicable Confined Unloading: Require. limiting unloading area, Applies to solid waste dlapo881 4
Waste Management controlling windblown materials, and deposition at toe sites aa defined by Public
Act of 1989 Title 14, CCR, Division of fill Resources Code Section
Public Resources 7, Chapter 3, 40122.
Code Sectiona Article 7.5 Disposal Site
40502, 43020, Operations
43021 and 43030
California Integrated 14 CCR 176772 Applicable Spreading and Compacting: Require.s spreading and Applies to solid waate diaposal 4
Waste Management compacting of refuse in layen sites as defined by Public
Act of 1989 Title 14, CCR, Division Resources Code Section
Public Resources 7, Chapter 3, 40122.
Code Sections Article 7.5 Disposal Site
40502, 43020, Operations
43021 and 43030
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N
I
-
o
0'\
Table 2.43 Mather AFB LandfiU Operable Unit State ARARsI
Soun:e Standard, ARAR Status Description CommEllt Assoclated Site(s)
Requh-emEllt,
Criterion, or
Limitation
California Integrated 14 CCR 176782 Applicable Slope. and CUll: The slope of the working face shall be Applies to solid wallO disposal 4
Waste Management maintained at a ratio which will allow effective compac- sitea as defined by Public
Act of 1989 Title 14, CCR, Division tlon of the wastes. The depth of cull and slopes of Resources Code Section
Public Resources 7, Chapter 3, trench sides shall not exceed specified horizontal to 40122.
Code Sections Article 7.5 Disposal Site vertical ratios
40502, 43020, Operations
43021 and 43030
California Integrated 14CCR 176802 Applicable Stockpiling: Requires stockpiled cover material and Applies to solid waste disposal 4
Waste Management unacceptable native materials to be placed so 88 not to sites as defined by Public
Act of 1989 Title 14, CCR, Division cause problems or interference with operations Resources Code Section
Public Resources 7, Chapter 3, 40122.
Code Sections Article 7.5 Disposal Site
40502, 43020, Operations
43021 and 43030
California Integrated 14 CCR 176842 Applicable Intermediate Cover: Requires cover on fill where no Applies to solid W88te disposal 4
Waste Management additional refuse will be deposited within 180 days. sites 88 defined by Public
Act of 1989 Title 14, CCR, Division Resources Code Section
Public Resources 7, Chapter 3, 40122.
Code Sections Article 7.5 Disposal Site
40502, 43020, Operations
43021 and 43030
California Integrated 14 CCR 176862 Applicable to Site Scavenging: Scavenging is prohibited. Appliea to solid waste disposal 4: Applicable
Waste Management 4 sites as defined by Public
Act of lt89 Title 14, CCR, Division Resources Code Section 5 '" 6: Relevant
Public Resources 7, Chapter 3, Relevant '" 40122. '" Appropriate
Code Sections Article 7.5 Disposal Site Appropriate to
40502, 43020, Operations Sites 5 '" 6
43021 and 43030
California Integrated 14CCR 176872 Applicable to Site Salvaging Permitted: Salvaging Is permitted in a No salvage is currently 4: Applicable
Waste Management 4 planned and controlled maMer. foreseen as a part of the
Act of 1989 Title 14, CCR, Division selected action, but it may be 5'" 6: Relevant
Public Resources 7, Chapter 3, Relevant '" proposed depending on '" Appropriate
Code Sections Article 7.5 Disposal Site Appropriate to character of refuse exposed.
40502, 43020, Operations Sites 5 '" 6
43021 and 43030 Applies to solid wsste disposal
sites as defined by Public
Resources Code Section
40122.
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Table 2.43 Mather AFB Landfill Operable Unit State ARARs'
IV
I
-
o
-J
Source Standard, ARAR Status Description Comment Associated Site(s)
Requirement,
Criterion, or
Limitation
California Integrated 14 CCR 176882 Applicable to Site Volume Reduction and Energy Recovery: Volume Applies to solid waste disposal 4: Applicable
Waste Management 4 reduction and energy recovery sre permitted in planned sites as defined by Public
Act of 1989 Title 14, CCR, Division and controlled mannera. Resources Code Section 5 &. 6: Relevant
Public Resources 7, Chapter 3, Relevant & 40122. & Appropriate
Code Sections Article 7.5 Disposal Site Appropriate to
40502, 43020, Operations Sites 5 & 6
43021 and 43030
California Integrated 14 CCR 176892 Applicable to Site Proceuing Area: Proceuing area shall be confined to Applies to solid waste disposal 4: Applicable
Waste Management 4 greatest degree practicable. litel al defined by Public
Act of 1989 Title 14, CCR, Divilion Resourcel Code Section 5 &. 6: Relevant
Public Resourcea 7, Chapter 3, Relevant &. 40122. &; Appropriate
Code Sections Article 7.5 Disposal Site Appropriate to
40502, 43020, Operations Sitel 5 &. 6
43021 and 43030
California Integrated 14 CCR 17690 ill Applicable to Site Storage of Salvage: Salvage material must be safely No salvage Is currently 4: Applicable
Waste Management 4 isolated for storage. foreleen as . part of the
Act of 1989 Title 14, CCR, Division selected action, but it may be 5 &; 6: Relevant
Public Resources 7, Chapter 3, Relevant &. proposed depending on &; Appropriate
Code Sections Article 7.5 Disposal Site Appropriate to character of refuse exposed.
40502, 43020, Operations Sitea 5 &. 6
430211nd 43030 Applies to solid waste disposal
sitel al defined by Public
Resourcel Code Section
40122.
California Integrated 14 CCR 17691 2 Applicable to Site Removal: Storage time for salvage materials shill be No salvage is currently 4: Applicable
Waste Management 4 limited to a 88fe duration. foresecn al a part of thc
Act of 1989 Title 14, CCR, Division selected action, but it may be 5 &; 6: Relevant
Public Resourcel 7, Chapter3, Relevant &. proposed depending on &; Appropriate
Code Sections Article 7.5 Dilposal Site Appropriate to character of refuse expoaed.
40502, 43020, Operations Sites 5 &. 6
43021 and 43030 Appliel to solid waste disposal
lite! as defined by Public
Resourcel Code Section
40122.
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Table 2.43 Mather AFB Landfill Operable Unit State ARARsI
tV
I
....
o
00
Soun:e Standard, ARAR Status Description Comment Associated Site(s)
Requirement,
Criterion, or
Limitation
California Integrated 14 CCR 176921 Applicable to Site Non-Salvageable Items: Items capable of impairing No 88lvage Is cUITCmtly 4: Applicable
Waste Management 4 public health shall not be 88lvaged without approval by foreseen as a part of the
Act of 1989 Title 14, CCR, Division Enforcement Agency and local health entity. selected action, but it may be 5 &; 6: Relevant
Public Resources 7, Chapter 3, Relevant & proposed depending on &; Appropriate
Code Sections Article 7.5 Disposal Site Appropriate to character of refuse exposed.
40502, 43020, Operations Sites 5 & 6
43021 and 43030 Applies to solid waele dispo881
sites 88 defined by Public
Resources Code
Section 40122.
California Integrated 14 CCR 17696 ill Applicable to Site Operating Site Maintenance: The operator shan monitor Applies to solid waste disposal 4: Applicable
Waste Management 4 and promptly repair deteriorated or defective conditions sites 88 defined by Public
Act of 1989 Title 14, CCR, Division with respect to requirements of these standards. Reaources Code Section 5 &; 6: Relevant
Public Resources 7, Chapter 3, Relevant &; 40122. &; Appropriate
Code Sections Article 7.5 Dispo881 Site Appropriate to
40502, 43020, Operations Sites 5 & 6
43021 and 43030
California Integrated 14 CCR 177011 Applicable to Site Nui88nce Control: Each site shan be operated and Applies to solid waele disposal 4: Applicable
Waste Management 4 maintained so as not to create a public nuillnce. sitea as detined by Public
Act of 1989 Title 14, CCR, Division Resources Code Section 5 &; 6: Relevant
Public Resources 7, Chapter 3, Article Relevant & 40122. &; Appropriate
Code Sections 7.6 Dispolll Site . Appropriate to
40502, 43020, Controls Sites 5, and 6
43021 am! 43030
California Integrated 14 CCR 177031 Applicable to Site Fire Control: Operator shall take adequate measures for Applies to solid waele dispoaal 4: Applicable
Waste Management 4 prompt tire control as required by local fire authorities. sites 88 detined by Public
Act of 1989 Title 14, CCR, Division Resources Code Section 5 &; 6: Relevant
Public Resources 7, Chapter 3, Relevant & 40122. &; Appropriate
Code Sections Article 7.6 Dispoaal Site Appropriate to
40502, 43020, Controls Sites 5, and 6
43021 and 43030
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Table 2.43 Mather AFB Landfill Operable Unit State ARARsI
I'-)
I
-
f6
Source Standard, ARAR Status Description Comment. AssocIated Site(!)
Requirement,
Criterion, or
Limitadon
California Integrated 14 CCR 17704' Applicable to Site Leachate Control: The operator mall take adequate steps The state docs not intend that 4: Applicable
Waste Management 4 to monitor, collect, treat, and effectively diapose of subsurface leachate monitoring
Act of 1989 Title 14, CCR, Diviaion leachates and collection systems need to 5 &. 6: Relevant
Public Resources 7, Chapter 3, Relevant &. be installed at existing sites &. Appropriate
Code Sections Article 7.6 Disposal Site Appropriate to unless there Is evidence of
40502, 43020, Controls Sites 5, and 6 leachate production and/or
43021 and 43030 accumulation.
Applies to solid waste disposal
sites as defined by Public
Resources Code Section
40122.
California Integrated 14 CCR 11705' Applicable to Site Oal Control: Landfill gas control may be required baaed Applies to solid waste disposal 4: Applicable
Waste Management 4 on the monitoring resultl site I IS defined by Public
Act of 1989 Title 14, CCR, Division Resources Code Section 5 &. 6: Relevant
Public Resources 7, Chapter 3, Relevant &. 40122. &. Appropriate
Code Sections Article 7.6 Disposal Site Appropriate to
40502, 43020, Controls Sites 5, and 6
43021 and 43030
California Integrated 14 CCR 11706' Applicable to Site Dult Control: The operator mall take adequate meaaures Applies to IOlid waste disposal 4: Applicable
Waate Management 4 to minimize the creation of dust. sites as defined by Public
Act of 1989 Title 14, CCR, Division RelOurces Code Section 5 &. 6: Relevant
Public Re80urcea 7, Chapter 3, Relevant &. 40122. &. Appropriate
Code Sections Article 7.6 Disposal Site Appropriate to
40502, .3020, Controls Sites 5, and 6
43021 and 43030
California Integrated 14 CCR 17707' Applicable to Site Vector and Bird Control: The operator shall take Applies to IOlid waite disposal 4: Applicable
Waste Management 4 adequate measurel to control or prevent the propagation, sites as defined by Public
Act of 1989 Title 14, CCR, Division harborage, or attraction of Oies, rodents, or other Resources Code Seotion 5 &. 6: Relevant
Public Resources 7, Chapter 3, Relevant &. vectora, and to minimize bird problems. 40122. &. Appropriate
Code Sections Article 7.6 Disposal Site Appropriate to
40502, 43020, Controls Sites 5, and 6
43021 and 43030
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Table 2.43 Mather AFB Landfill Operable Unit State ARARsI
N
I
-
-
o
Source Standard, ARAR Status Description Commeot AssocIated Site(s)
Requiremeot,
Criterion, or
Limitation
California Integnlted 14 CCR 177082 Applicable to Site Dnlinage And Erosion Control: Adequate dnlinage shall Applie8 to solid waste disposal 4: Applicable
Wa8te Management 4 be provided. Effects of erosion 8hall be promptly 81108 a8 defined by Public
Act of 1989 Title 14, CCR, Divi8ion repaired and 8tep8 taken to prevent further occurrence. Resource8 Code Section S &. 6: Relevant
Public Resourcca 7, Chapter 3, Relevant &. 40122. &. Appropriate
Code Section8 Article 7.6 Dispoul Site Appropri8te to
40502,43020, Control8 Site8 Sand 6
43021 and 43030
California Integrated 14 CCR 17709 2 Applicable to Site Contact with Water: No 80lid waste 8hall be deposited in Applies to solid waBle disposal 4: Applicable
Waste Management 4 direct contact with surface water. 8ites 88 defined by Public
Act of 1989 Title 14, CCR, Divi8ion Resource8 Code Section S &. 6: Relevant
Public Resource8 7, Chapter 3, Relevant &. 40122. &. Appropriate
Code Section8 Article 7.6 Di8posal Site Appropriate 10
40502, 43020, Control8 Site8 5 &. 6
43021 and 43030
California Integrated 14 CCR 177102 Applicable to Site Grading of Fill Surface: Covered 8urfacea of the Applie8 10 solid Was\C disposal 4: Applicable
Wa8te Management 4 disposal area mall be graded to promote run-off and 8ilo8 18 defined by Public
Act of 1989 Title 14, CCR, Division prevent ponding, accounting for future settlement. Resource8 Code Section S &. 6: Relevant
Public Resource8 7, Chapter 3, Relevant &. 40122. &. Appropriate
Code Section8 Article 7.6 Disposal Site Appropriate to
40502, 43020, Control8 Site8 5 and 6
43021 and 43030
California Integrated 14CCR 177112 Applicable to Site Litter Control: Liller and loose malorial8 mall be Applies 10 solid was\C disposal 4: Applicable
Waste Management 4 routinely collected and disposed of properly. 81te8 88 denned by Public
Act of 1989 Title 14, CCR, Division Resource8 Code Section S &. 6: Relevant
Public Resources 7, Chapter 3, Relevant &. 40122. &. Appropri8te
Code Sections Article 7.6 Disposal Site Appropriate to
40502, 43020, Controls Site8 Sand 6
43021 and 43030
California Integrated 14 CCR 177122 Applicable to Site Noise Control: Noise 8hall be controlled to prevent Applie8 to solid waBle disposal 4: Applicable
Waste Management 4 health hazard8 to person8 using the site. 8ite8 a8 defined by Public
Act of 1989 Title 14, CCR, Division Resources Code Section S &. 6: Relevant
Public Resource8 7, Chapter 3, Relevant &. 40122. &. Appropriate
Code Sections Article 7.6 Disposal Site Appropriate to
40502, 43020, Control8 Site8 S, and 6
43021 and 43030
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Table 2.43 Mather AFB Landfill Operable Unit State ARARs'
IV
t
-
-
....
Source Standard, ARAR Status Descnption Comment Associated Site(s)
Requirement,
Cntenon, or
Limitation
California Integrated 14 CCR 177132 Applicable to Site Odor Control: The disposal site shall not be a source of Applies to solid waste disposal 4: Applicable
Waste Management 4 odor nuisances. sites as defined by Public
Act of 1989 Title 14, CCR, Division Resources Code Section 5 & 6: Relevant
Public Resources 7, Chapter 3, Relevant & 40122. & Appropriate
Code Sections Article 7.6 Disposal Site Appropriate to
40502, 43020, Controls Sites 5, and 6
43021 and 43030
California Integrated 14 CCR 17741 2 Applicable Burning Wastes: Burning wastes shall be extinguished. Applies to solid waste disposal 4: Applicable
Waste Management sites as defined by Public
Act of 1989 Title 14, CCR, Division Relevant & Resources Code Section 5 & 6: Relevant
Public Resources 7, Chapter 3, Appropriate to 40122. & Appropriate
Code Sections Article 7.6 Disposal Site Sites 5 and 6
40502,43020, Controls
43021 and 43030
California Integrated 14 CCR 18222 Applicable to Site Report of Disposal Site Information: The planning and Applies to operating solid 4: Applicable
Waste Management 4 procedural requirements necessary to ensure that IOlid waste disposal sites as defined
Act of 1989 Title 14, CCR, Division waste Is handled and disposed In mannera that protect by Public RelOurces Code 5 & 6: Relevant
Public Resources 7, Chapter 5, Article Relevant & public heallh and safety and the environment must be Section 40122. and Appropriate
Code Sections 3.2 Reports of Facility Appropriate for conducted.
40502, 43020, Information Sites 5& 6
43021 and 43030
Porter-Cologne Water Quality Control Applicable Establishes water quality objectives, including narrative Specific applicable portions of 2, 3, 4, 5, & 6
Water Quality Plan (Basin Plan) for the and numerical standards, that protect the beneficial uses the Basin Plan Include
Control Act CVRWQCB. of surface and ground watera in the region. The beneficial uses of affected
(California Water designated beneficial uses are municipal and domestic; water bodie. and water quality
Code Section. agricultural; and industrial supply. objectives to protect those
13240,13241, 132- uses. Any activity, Including,
42, 13243) for example, a new discharge
of contaminated lOils or Insitu
treatment or containment of
contaminated soils, that may
affect water quality must not
result in water quality
exceeding water quality
objectives.
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tV
Table 2.43 Mather AFB Landfill Operable Unit State ARARst
Source Standard, ARAR Status ~ription Comment Associated Site(!)
Requirement,
Criterion, or
Limitation
Porter-Cologne State Water Resources Applicable Speclfiea that, with certain exceptions, all ground and Applies in detennining 2, 3, 4, S, & 6
Water Quality Control Board surface waters have the beneficial use of municipal or beneficial uses for waten that
Control Act Resolution No. 88-63 domestic water supply. may be affected by discharges
(California Water ("Sources of Drinking of waste.
Code Sections Water Policy.) (as
13000, 13140, contained in the
13240) RWQCB's Water
Quality Control Plan)
Porter-Cologne State Water Resources Applicable Policy for regulation of discharges of municipal solid Applies to solid waste disposal 4
Water Quality Control Board waste. sites.
Control Act Resolution No. 93-62
(California Water
Code Sections
13140,13142,
13 172)
Porter-Cologne Regional Water Quality Relevant & Promulgated order of the State Water Resources Control Applies to solid waste disposal 4
Water Quality Control Board Order Appropriate Board regulating opention and closure of solid waste sites.
Control Act 93-200 disposal sites. Only substantive portions of this order
(California Water that arc consistent with the selective alternative are
Code Sections relevant and appropriate.
13140, 13172)
porter-Cologne Titte 23, CCR, Section Applicable Actions taken by or at the direction of public agencies to Applies to all actions taken by 2, 3, 4, S, &I 6
Water Quality 2S 11 (d) cleanup or abate conditions or nuisance resulting from or at the direction of public
Control A~t unintentional or unauthorized releases of waste or agencies to clean up
(California Water pollutanta to the environment are exempt from the unintentional or unauthorized
Code Sections provision. of Chapter IS of Titte 23 of the California discharges of waste to the
13140-13147,131- Code of Regulations with the following provisions: environment.
72, 13260, 13263,
13267, 13304) 1) Wastes removed from the immediate place of release
must be discharged in accordance with the classification
and siting requirements of Chapter IS; and,
2) Remedial actions intended to contain wastes at the
place of release shall Implement applicable provisions of
Chapter IS to the extent feasible.
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Table 2.43 Mather AFB Landlfill Operable Unit State ARARsI
IV
I
-
-
~
Source Standard, ARAR Status Description Comment Associated Site(s)
Requirement,
Criterion, or
Limltadon
Porter-Cologne Title 23, CCR, Seclion Applicable Requiree thaI wlBlca identified IB hlZlrdoue, deeignaled, Appliee 10 diaciluICI of WIBle Site 4. and the
Water Quality 2520(a)21 or nonhlZlrdoue eo lid waste (eeclions 2521, 2522 and to IOlid wsste disposal sites, wastee excavated
Control Act 2523 of Article 2) t.e allowed only at waste management and storage sites. from Sites 5 &. 6
(California Water unlt8 which have been approved and cllBsified.
Code Sections
13140-13147,
13172,13260,
13263,13267,
13304)
Porter-Cologne Title 23, CCR, Section Applicable Prohibita the discharge of wlBtea which have the Applies to diacharges of wlBte 4.
Water Quality 2520(b) 1 potential to reduce 0 r impair the integrity of containment to IOlid waste disposal sites.
Control Act etructure8 or which, if commingled with other wastes in
(California Water the unit, could produce violent reaction, heat or
Code Sections pressure, fire or explosion, toxic by-products, or
13140-13147, reaction products which in turn:
13172,13260, a. require a higher I,:vel of containment than provided
13263, 13267, by the unit;
13304) b. are restricted 'hazardous waste8'; or
c. impair the integrity of containment structures.
Porter-Cologne Title 23, CCR Section Applicable to Site Requiree accurate characterization of waste. Applie8 to diacharge8 of waste Sltee 4 . and
Water Quality 2520(c) 1 4 and wIBte8 from to IOlid wlBte dispoaal eitee. waste8 from Sites
Control Act Sites 5, &. 6 S &. 6: Applicable
(California Water Site 4 will be accepting waste8
Code Sections Relevant &. from Site8 5 &. 6, 10 thie Site 3: Relevant
13140-13147, Appropriate to Site provi8ion is considered and Appropriate
13172, 13260, 3 applicable to the waste8 from
13263, 13267, the latter landfill8.
13304)
Excavated lOil8 from other
IRP sltee on Mather may be
used for the foundation layer
at Site 3. Thele wlBtes must
be appropriate for site
conditlon8.
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.po.
Table 2.43 Mather AFB Landfill Operable Unit State ARARst
Source StaIIdard, ARAR Status Description Comment Associated Site(s)
Requirement,
Criterion, or
Limitation
Porter-Cologne Title 23, CCR, Section Applicable to Site Requires management of liquids at classified waste man- Applies to discharges of waste Sites 4. and
Water Quality 2520(d) 2 4 and wastes from agement units. to solid waste dispoaal sites. wastes from Sites
Control Act Sites 5, &: 6 5 &: 6: Applicable
(California Water
Code Sections
13140-13147,
13172, 13260,
13263, 13267,
13304)
Porter-Cologne Title 23, CCR, Section Applicable to Site Requires that hszardous waste be discharged to Class 1 Applies to discharges of Sites 4. and
Water Quality 2521 2 4 and wastes from waste management units. hazardous waste to land for wastes from Sites
Control Act Sites 5, &: 6 treatment, storage, or 5 &. 6: Applicable
(California Water dispoaal.
Code Sections
13140-13147,
13172, 13260,
13263, 13267,
13304)
Porter-Cologne Title 23, CCR, Section Applicable to Site Requires that designated waste be discharged to Class 1 Applies to discharges of Sites 4. and
Water Quality 2522 2 4 and wastes from or Class II waste management units. designated waste wastes from Site.
Control Act Situ 5, &. 6 (nonhazardous waste that 5 &. 6: Applicable
(California Water could cause degradation of
Code Sections surface or ground watera) to
13140-13147, land for treatment, storage, or
13172, 11260, diapollli.
13263, 13267,
13304)
Porter-Cologne Title 23, CCR, Section Applicable to Site Requires that nonhazardous solid waste be discharged to Applies to discharges of Sites 4. and
Water Quality 2523 2 4 and wastes from a clauified waste management unit. nonhazardou'lOlid waste to waste. from Site.
Control Act Sites 5, &: 6 land for treatment, storage, or 5 &. 6: Applicable
(California Water diapoaal.
Code Sections
13140-13147,
13172, 13260,
13263, 13267,
13304)
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IV
I
.....
.....
VI
Table 2.43 Mather AFB Landfill Operable Unit State ARARst
Source Standard, ARAR Status Description Comment Assoclated Slte(s)
Requirement,
Criterion, or
Limitation
Porter-Cologne Title 23, CCR, Section Relevant &. Requires that new lanllfills be designed, conltrocted, Applies to the design, 2,3,4
Water Quality 2533(c) 2 Appropriate operated, and maintained to prevent inundation or constroction, operation, and
Control Act washout due to floods with a l00-year return period. maintenance of new solid
(California Water waite disposal sites.
Code Sections
13140-13147, Site 4 may be within the
13172, 13260, l00-year floodplain of an
13263, 13267, unnamed tributary of
13304) MorrilOn Creek.
Porter-Cologne Title 23, CCR, Section Applicable to Site Requires hydraulic conductivities determined through Applies to the conltroctlon of Applicable to
Water Quality 2541(c) 2 4 laboratory methods be ,)onfirmed by appropriate field engineered caps at solid waste Site 4 4
Control Act testing. disposal sites. Relevant and
(California Water Relevant &. Appropriate to Site 2 if 23 Relevant and
Code Sections Appropriate to Site CCR, Div. 3, Ch 15, Article Appropriate to
13140-13147, 3 8 cap later required. Site 3
13172,13260,
13263, 13267,
13304)
Porter-Cologne Title 23, CCR, Section Applicable to Site Requires earthen materi!ls used in containment Applies to discharges of waste Applicable to
Water Quality 2541(d) 2 4 stroctures consist of a mixture of clay and other suitable to IOlid waste disposal sites. Site 44
Control Act fine-grained lOils which have specified characteristics, Relevant and Appropriate to
(California Water Relevant &. and which can be comp"cted to attain the required Site 2 i£23 CCR, Div. 3, Ch Relevant and
Code Sections Appropriate to Site permeability when installed. 15, Article 8 cap later Appropriate to
13140-13r7, 3 required. Site 3
13172, 1 260,
13263, 13267,
13304)
Porter-Cologne Title 23, CCR, Section Applicable to Site Requires management of precipitation and drainage Applies to all areas at which Applicable to
Water Quality 2546(a) &. 4 control waste has been discharged to Site 44
Control Act 2546(c) to (I) 2 land.
(California Water Relevant &. Relevant and
Code Sections Appropriate to Appropriate to
13140-13147, Sites 1 and 3 Sites 2, 3
13172, 13260,
13263, 13267,
13304)
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Table 2.43 Mather AFB Landfill Operable Unit State ARARsI
N
I
-
-
0\
Source Standard, ARAR Status Description Comment Assoclated Site(s)
Requirement,
CriterioD, or
LimitatioD
Porter-Cologne Title 23, CCR, Relevant and May require water quality monitoring and response Applies to solid waste disposal 2, 3, and 4
Water Quality Article 5 Appropriate programs for waste management units. sites.
Control Act
(California Water
CodCJ Sections
13140-13147,
13172, 13260,
13263, 13267,
13304)
Porter-Cologne Title 23, CCR, Section Applicable, Site 4 Requires maintenance of waste contaminant facilities and Applies to thCJ closure and Applicable to
Water Quality 2580(a) 2 precipitation and drainage controls, and contaminated pollt-closure maintenance of Site 4 "
Control Act Relevant &. groundwater monitoring throughout the post-closure solid waste disposal sites.
(California Water Appropriate, Sites maintenance period. The post-closure maintenance Relevant and
Code Sections 2,3 period will extend as long 88 wastes pose a threat to Appropriate to
13140-13147, water quality. Sites 2, 3
13172,13260,
13263, 13267,
13304)
Porter-Cologne Title 23, CCR, Section Applicable, Site 4 Requires that closed landfills be provided with at le88t Applies to closing solid waste Applicable to
Water Quality 2580(d) 2 two permanent monuments installed from which the disposal sites. Site 4"
Control Act Relevant &. location and elevation of wastes, contaminant structures,
(California Water Appropriate, Sites and monitoring facilities can be determined throughout Relevant and
Code Sections 2,3 the post-closure maintenance period. Appropriate to
13140-pI47, Sites 2, 3
13172, 13260,
13263, 13267,
13304)
Porter-Cologne Title 23, CCR, Section Applicable, Site 4 Require. that vegetation for closed waste management Applies to the closure of solid Applicable to
Water Quality 2580(e) 2 units ba selected to require minimum irrigation and waste dlsp08l1 sites Ind other Site 4 "
Control Act Relevant &: maintenance, and not impair the integrity of containment areas where wastes have been.
(California Water Appropriate, Sites structures including the finll cover. discharged to land. Relevant and
Code Sections 2,3 Appropriate to
13140-13147, Sites 2, 3
13112, 13260,
13263, 13267,
13304)
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Table 2.43 Mather AFB Landfill Operable Unit State ARARst
Source Standard, ARAR Status Description Comment Assoclated Slte(.)
Requirement,
Criterion, or
Limitation
Porter-Cologne Title 23, CCR, Section Applicable to Site Require. 8 final covnr constNcted in accordance with If water quality ia threatened, Applicable to
Water Quality 2581 2 4 epeclfic preacriptive standard., to be maintained as long thi. aection Is relevant and Site 44
Control Act as wastes pose a thre st to water quality. appropriate for wastes
(California Water Relevant &; contained or left in plsce 'at Relevant and
Code Sections Appropriate to Site the end of remedial actions Appropriate to
13140-13147, 3 that could affect water quality. Site 3
13172,13260, Include. closure of landfills
13263, 13267, and other area. where wastes
(3304) have been dlacharged to land.
Would be relevant and
appropriate to Site 2 if a 23
CCR, Div. 3, Ch. 15, Art. 8
cap were later required.
Porter-Cologne Title 23, CCR, Section Applicable to Site Procedures related to routine operations and emergency Applies to existing solid waste Applicable to
Water Quality 2596(b) 2 4 conditions must be de'veloped for the waste disposal disposal sites. Site 44
Control Act activitiel.
(California Water
Code Sections
13140-13147,
13172,13260,
13263, 13267,
13304)
Porter-Cologne Title 23, CCR, Section applicable to Site Procedurel for closure and pOlt-clo.ure maintenance Applies to cloling solid waste Applicable to
Water
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Table 2.43 Mather AFB Landfill Operable Unit State ARARsI
N
I
-
-
00
Source Standard, ARAR Status Description Comment Associated Site(!)
Requirement,
Criterion, or
Limitation
Sacl'8mento Rule 2M, Section 301, Applicable Requires the application of Best Available Control Applies to any new emissions 2,3, &4
Metropolitan Air Beat Available Technology unit or modification to an
Quality Technology existing emi88iona unit which
Management resull8 in an increalO in daily
District ROC emi88lons
SMAQMD determined that the
passive venting of landfill
galOs is BACT for aites 2, 3,
&4
Sacl'8mento Rule 402, Nuisance Applicable Limil8 emissions of odol'8 and other nuisance material to 2, 3, 4, 5, & 6
Metropolitan Air Standard the air
Quality
Management
District
Sacl'8mento Rule 403, Fugitive Applicable Limita visible particulate emiasions to the property line 2, 3, 4, 5, & 6
Metropolitan Air Dusts
Quality
Management
District
Hazardous Waste Title 22. Social Applicable Article 1 Identities thOIO wastes which are subject to The wastes excavated from Waste from Sites
Control Law Security, (22 CCR) regulation as hazardous wastes under this division and Sites 5 & 6 must be cla88ified 5 and 6
(HWCL) Division 4.5. which are subject to the notification requirements of using either genel'8tor
f Environmental Health Health and Safety Code section 25153.6. Article 1 knowledge or waste analysis
Standards for the defines the terms "waste" and "hazardous waste" ,
Management of identifies thOIO wastes which are excluded from
Hazardous Wastes, regulation under this division, and establishes special
Chapter II., management requirementa for hazardous waste which is
Identification and recycled and establishes rules for clusifying and
Listing of Hazardous managing contaminated containers.
Waste, Article I.
Oenel'8l.
HWCL 22 CCR., Applicable Article 2 IOta forth the criteria to identify chal'8cteristics Waste from Sites
Division 4.5., of hazardous wute. 5 and 6
Chapter II., Article 2.
Criteria for Identifying
the Chal'8cteriatics of
Hazardous Waste.
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Table 2.43 Mather AFB Landfilll Operable Unit State ARARsI
N
I
....
....
\0
Source Standard, ARAR Status Description Comment Assodated Site!s)
RequJrement,
Criterion, or
Limitation
HWCL 22 CCR., Applicable Article 3 identifie8 chllracteri8tic8 of hazardou8 waste. Waste from Site8
Divi8ion 4.5., 5 and 6
Chapter 11., Article 3.
Characteri8tic8 of
Hazardou8 Wa8te.
HWCL 22 CCR., Applicable Article 4 lim particular hazardou8 waste8. Waste from Site8
Divi8ion 4.5., 5 and 6
Chapter 11., Article 4.
LI81a of RCRA
Hazardous Waste8.
HWCL 22 CCR., Applicable Article 5 Identifie8 cate,gorie8 of hazardou8 wa8te Waste from Sites
Divi8ion 4.5., including RCRA hazan:lou8 waste, non-RCRA hazardou8 5 and 6
Chapter 11., Article 5. waste, extremely hazardou8 wa8te, and 8pecial wa8te,
Categorie8 of and e8tabli8hes criteria IInd management 8tandard8 for
Hazardou8 Waste. 8pecial waste and extremely hazardou8 waste.
HWCL 22 CCR., Applicable Article 1 e8tabli8hes 8tandsrds for generaton of Only applicable if the wastes Wa8le from Site8
Divi8ion 4.5., hazardou8 waste located in California. from Site 5 & 6 are clal8lfiecJ 5 and 6
Chapter 12. 81 hazardous or non-RCRA
Standards Applicable to hazardous waste
Oeneraton of
Hazardou8 Waste
Article I.
Applicability.
HWCL 22 CCR., Applicable Article 1 emblishes minimum standard8 which define Only applicable If the wastes Waste from Site8
Divi8ion 4.5., the acceptable managemc.nt of hazardou8 waste. from Site 5 & 6 are cla88ified 5 and 6
Chapter 14., a8 hazardous waste.
Article I.
I Oeneral. I
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Table 2.43 Mather AFB Landfill Operable Unit State ARARs'
~
I
-
~
Source Standard, ARAR Status Description Comment Assoclated Site(s)
Requirement,
Criterion, or
Limitation
HWCL 22 CCR., Applicable Article 2 requires that before any hllZ8rdous waste is Only applicable If wutes from Waite from Sites
Divilion 4.5., transferred, treated, Itored, or dispoled of a detailed Sites 5 &. 6 are cluillied 18 5 and 6
Chapter 14., Article 2. chemical and physical analysis of a representative hazardous
General Facility Ample of the waste will be obtained. Furthermore, it
Standards. requires security to prevent the unknowing entry, snd
minimize the possibility for the unauthorized entry, or
persons or livestock onto the area of hazardous wute
storage. The inspection of the hazardous wute storage
facility for malfunctions and deterioration, operator
errors, and discharges is required.
HWCL 22 CCR., Applicsble Article 3 requires the proper design, operation, Only applicable if wutes from Waite from Sites
Division 4.5., equipment procurement, for hazardoua stonge facilities. Sites 5 &. 6 are cla8sified a8 Sand 6
Chapter 14., Article 3. hazardous
Preparedness and
Prevention.
"WCL 22 CCR., Applicable Article 4 requires the development of a contingency and Only applicable if wastes from Waste from Sites
Division 4.5., emergency procedures planning. Sites 5 &. 6 are clusified as Sand 6
Chapter 14., Article 4. hllZ8rdous
Contingency Plan and
Emergency Procedures.
HWCL 22 CCR., Applicable Article 7 requires that the hazardous waste Itorage Only applicable if wutes from Waste from Sites
Division 4.5., facility shall minimize the need for further maintenance; Sites 5 &. 6 are classilied as 5 and 6
Chapter 14., Article 7. and controls, minimizes or eliminates, to the extent hllZ8rdous
f Closure and Post- necClAry to protect human health and the environment,
Closure. post-closure capture of hazardous wute, hllZ8rdous
conltituents, leachate, contaminated rainfall or runoff,
or waite decomposition products to the ground or
surface waters or to the atmosphere.
HWCL 22 CCR., Applicable Article 9 requires the proper management of hazardous Only applicable if wutes from Waste from Sites
Division 4.5., wute containers. Sites 5 &. 6 are clusified as 5 and 6
Chapter 14., Article 9. hazardous and stored in
Use and Management of containers maintained on-site.
Containers.
HWCL 11 CCR., Applicable Article 11 applies to the management of Surface Im- Only applicable if wlltes from Wllte from Sites
Divilion 4.5., pound menta for hllZ8rdous wute. Sites 5 &. 6 are classified 18 5 and 6
Chapter 14., Article 11. hllZ8rdous and are managed in
Surface Impoundments. a surface impoundment
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Table 2.43 Mather AFB Landfilll Operable Unit State ARARs.
tV
I
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tV
-
Source Standard, ARAR Status Description Commeut Associated Slte(s)
Requlremeut,
Criterion, or
Limitation
HWCL 22 CCR., Applicable Article 12 applies to the management of Waste Piles. Only applicable if wastes from Waste from Sites
Division 4.5., Sites 5 &. 6 are classified as 5 and 6
Chapter 14., Article 12. hazardous and are managed in
Waste Piles. waste piles
HWCL 22 CCR., Applicable Article 1S.5 allows for the designation of an area at a This provision would allow Waste from Sites
Division 4.5., facility as a corrective action management unit for the consolidation and/or 5 and 6
Chapter 14., (CAMU). management of hazardous
Article 15.5. wastes from Sites 5 and 6 at
Correction Action for an onsite, land-based storage
Waste Management or treatment unit without
Units triggering land disposal
restrictions.
HWCL 22 CCR., Applicable Article 1 provides the purpose, scope, and applicability Only applicable if wastes from Waste from Sites
Division 4.5., of Land Disposal Restrictions. Sites 5 &. 6 are clauified as 5 and 6
Chapter 18., hazardous and are disposed or
Article 1. treated in an area not
General. designated as a CAMU
HWCL 22 CCR., Applicable Article 2 provides a list of wastes subject to landfill Only applicable if wastes from Waste from Sites
Division 4.5., disposal restrictions. Sites 5 &. 6 are cla..lfied as 5 and 6
Chapter 18., Article 2. hazardous and are disposed or
Schedule for Land treated in an area not
Disposal Prohibition and designated as a CAMU
Establishment of
f Treatment Standards.
HWCL 22 CCR., Applicable Article 3 provides waste specific land dispolll Only applicable if wastes from Waste from Sites
Division 4.5., prohibitions for Solvent 'Nastes, Dioxin-<:ontaining Sites 5 &. 6 are clal8ified as 5 and 6
Chapter 18., Article 3. Wastes, and California Listed Wastes. hazardous and are disposed or
Prohibitions on Land treated in an area not
Dispolli. designated as a CAMU
HWCL 22CCR., Applicable Article 4 provides treatment standards expressed as Only applicable if wastes from Waste from Sites
Division 4.5., concentrations in Waste Bxtract, Specified Technologies, Sites 5 &. 6 are cla..ified as 5 and 6
Chapter 18., Article 4. and Waste Concentration!. hazardous
Treatment Standards.
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Table 2.43 Mather AFB Landfill Operable Unit State ARARst
tV
I
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tV
tV
Source Standard, ARAR Status Description Comment Assoclated Site(s)
Requirement.
Criterion, or
Limitation
HWCL 22 CCR., Applicable Article 5 providea prohibitiona on Itorage of Reltricted Only applicable if waltea from Wa818 from Sites
Diviaion 4.5., Wutes. Sitea 5 &; 6 are cluaified u 5 and 6
Chapter 18., Article 5. hazardoua
Prohibitiona on Storage.
Fiah &; Game Code Applicable Work within the rOO-year flood plain, conaisting of but Site 5 ia located within the 4&5
Section 1600 et aeq. not limited to divenion or obstruction of the natural rOO-year floodplain of an
flow or changea in the channel, bed, or bank of any unnamed tributary of
river, stream, or lake will involve mitigation meuurea Morrison Creek.
to avoid or minimize impacta on natunl resourcea.
Site 4 may be located within a
rOO-yur floodprain of
unnamed tributary of
Morrison Creek
Fish &; Game Code Applicable It is unlawful to deposit in, permit to pus into, or place Site 5 ia located within the 4&5
Sectiona 5650 & where it can paas into the waten of thia atate any rOO-year floodplain of an
5652 material Ii lied in Fish & Game Code Section 5650 & unnamed tributary of
5652. Morrison Creek.
Site 4 may be located within a
1000year floodplain of
unnamed tributary of
Morrison Creek
CCR - Qlllifornia Code of Regulationa
U.S. EPA - United State a Environmental Protection Agency
CFR . Code of Federal Regulationa
RDIRA - remedial deaign/remedial action
ARAR - applicable or relevant and appropriate requirement
ROD - Record of Deciaion
RWQCB - Regional Water Quality Control Board
CAMU - Corrective Action Management Unit
-------
2.8.2.2 Applicability of California Code of Regulations Title 23, Chapter 15
The U.S. EPA believes that Title 23 (Waters), Division 3 (State Water Resources Control
Board), Chapter 15 (Discharge of Waste to Land) has limited applicability to those remedial
actions. The Air Force concurs with this interpretation. Pursuant to Section 2511 (d) of
Chapter 15, remedial actions undertaken by or at the direction of public agencies are exempt
from the provisions of Chapter 15, with two exceptions: 1) waste that is removed from the
immediate place of release shall be discharged according to Article 2 of Chapter 15; and 2)
waste that is contained at the place of release shall implement applicable provisions of
Chapter 15 to the extent feasible.
Applying this exemption in Section 2511(d) to the remedial actions at the landfills, since the
waste at Sites 2, 3, and 4 are being contained at the place of release, the second exception to
the general exemption requires the Air Force to implement the applicable provisions of
Chapter 15 to the extent feasible in its remedial actions for these three landfills. Because
these three landfills are closed, abandoned, or inactive landfills, the only applicable provision
of Chapter 15 to these landfills is Section 251O(g). Since the waste at Sites 5 and 6 are
being removed from the place of release, the first exception to the general exemption in
Section 25 i 1 (d) requires that Air Force to discharge the waste being removed from these two
landfills in accordance with Article 2 of Chapter 15.
However, U.S. EPA also believes that Chapter 15 has special applicability to Site 4 under
the State's Subtitle D program (Section 4005 of the Solid Waste Disposal Act, as amended by
the Resource Conservation and Recovery Act of 1976). Since the Air Force has decided to
consolidate wastes from Sites 5 and 6 into Site 4, the landfill at Site 4 now becomes a
municipal solid waste landfill ("MSWLF") subject to the federal and State Subtitle D
regulations, with the State requirements becoming ARARs only if they are more stringent
than the federal requirements. The State's Subtitle D Program, approved by U.S. EPA on
February 1, 1993, includes the State Water Resources Control Board's regulations in Chapter
15 and the Integrated Waste Management Board's regulations in Title 14, as amended on
April 19, 1994.
The State disagrees with portions of U.S. EPAts position. The State believes that the
consolidation of wastes from Sites 5 and 6 into Site 4 constitutes a new discharge of waste to
land, which is subject to the Chapter 15 regulations independent of SJ,ibtitle D. In
accordance with Section 2511(d), the wastes must be discharged according to Article 2 of
RUI2-94/ESf1260001.A WS
2-123
-------
Chapter 15. Article 3 provides that the discharge of nonhazardous solid wastes shall be
permitted only at waste management units that meet Chapter 15 requirements.
The State believes that, pursuant to Section 25lO(g), Sites 2, 3, 5, and 6 must be monitored
in accordance with Article 5. If there is a threat to water quality, Article 5 corrective action
is also applicable. Article 8 closure requirements would then be relevant and appropriate.
The State also believes that Chapter 15 applies to any wastes remaining in place at Sites 5
and 6 after the excavation actions. It may be necessary to contain the remaining wastes to
prevent impacts to waters of the state. Actions to contain the wastes must implement
applicable provisions of Chapter 15 to the extent feasible.
The U.S. EPA and the State have agreed to disagree on the applicability of Chapter 15 to
these landfills. Notwithstanding this disagreement on the applicability of Chapter 15, U.S.
EP A believes that there are substantive requirements in Chapter 15 that the Air Force must
comply with in these remedial actions, either because of the exception to the general
exemption in Section 2511(d), or because of the special applicability of Chapter 15 under the
State's Subtitle D regulations to Site 4, or, in the case of the landfills at Sites 2, 3, 5 and 6,
because EPA .concludes that these Chapter 15 requirements are relevant and appropriate.
These substantive requirements are identified in the Table 2.43.
2.8.2.3 Chemical-Specific ARARs for Soils
Chemicals of potential concern were identified primarily from the chemical characterizations
of the surface and subsurface fill materials and an evaluation of the potential for each
contaminant to impact groundwater. Table 2.26 summarizes the COPCs for the landfill sites.
Chemical-specific ARARs and TBCs for these constituents have been identified for both soil
and water and are described below.
2.8.2.1.2 Chemical-Specific ARARs and TSCs for Soil
There are currently no chemical-specific ARARs identified for the site soils. The cleanup
levels proposed by the U.S. EPA proposed for soils under the Corrective Action for Solid
Waste ManagC?ment Units at Hazardous Waste Management Facilities in 1990 [55 Federal
Register (FR) 30798-30884] were considered as potential TBCs. While these proposed
cleanup levels are not ARARs, since they have not been promulgated., they were evaluated as
potential TBCs. The proposed cleanup levels are relevant but not appropriate since they are
for the management of hazardous waste. The fill materials at the landfills are not hazardous
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wastes under the Resource Conservation and Recovery Act or Hazardous Waste Control Act.
Also, the methodology in the proposed rule uses several exposure assumptions that do not
accurately describe the situations at the Mather AFB landfills. Consequently, the proposed
regulation was considered inappropriate.
Soil levels of chemicals developed using the DLM guideline [CVRWQCB 1989] have been
identified as TBCs for establishing cleanup levels or evaluating the ability of an alternative to
protect groundwater quality by changing the leachability of the fill materials. The DLM-
derived TBC values for each site are provided in Tables 2.14 to 2.18. If contaminants are
identifed in soil beneath sites 5 and 6, a Water Quality Assessment will be conducted using
the DLM and V -LEACH, depending on the constituent, or other equivalent appropriate
method to determine whether the soil contaminant poses a threat to groundwater quality.
2.8.2. 1.2 Chemical-Specific ARARs and TSCs for Water
Because the groundwater beneath the landfills will be addressed in the Mather AFB Soil and
Groundwater Operable Unit ROD, it is not necessary to address ARARs for groundwater in
this ROD. However, because the landfills have the potential to impact groundwater quality,
chemi~1-specific ARARs and TCEs for water have been considered in the evaluation of the
alternatives. Specifically, each alternative was evaluated for its ability to either reduce the
soil concentrations or leachability of the COPCs, such that leachate formed from the waste
material will not result in the conceittrations of COPCs in the groundwater exceeding
ARARs. The DLM guideline [CVRWQCB 1989] was the TBC methodology utilized to
assess the ability of each alternative to protect groundwater quality.
The regulatory framework associated with cleanup at the landfill is driven in part by the
potential use of the local groundwater. Drinking water is considered to be the highest
beneficial use and remediation to drinking water standards or prevention of degradation of
water beyond drinking water use affords the greatest level of protection and cleanup. As
required by the California Porter-Cologne Water Quality Act, the Regional Water Quality
Control Board-Central Valley Region defines the beneficial uses of various water bodies for
the Sacramento River Basin. Water bodies and their beneficial uses are presented in the
Central Valley Basin Plan. The Basin Plan classifies aquifers in the Mather AFB area to
have, "existing or potential ~neficial uses as sources of drinking water."
....
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Groundwater beneath the landfill sites is a potential source of drinking water. Consequently,
the following have been identified as ARARs for remedial actions at the landfill sites, which
include groundwater monitoring,:
.
u.s. Primary MCLs [40 CFR Part 141];
..
California State Primary MCLs [22 California Code of Regulations 64435];
and
.
California State Secondary MCLs [22 CCR 64473].
The water quality goals for each contaminant of concern at the landfill sites are provided in
Table 2.44.
If more than one potential standard or criterion was established for a single chemical, the
most stringent generally was identified as the ARAR. Compliance with Resolution 68-16
requires that the quality of the underlying groundwater must be maintained following
implementation of the selected remedies for the landfills. Water is not extracted from the
aquifers directly below the landfills, and groundwater beneath the landfills will be addressed
as part of the Mather AFB Soil and Groundwater OU ROD, as noted above.
Table 2.44 Water Quality Standards
Concentration (p.g/ t)
Constituent Relevant and Appropriate Requirements
U.S. Calif. Calif.
Primary Primary Secondary
MCL MCL MCL
Antimony 6 -- -
Arsenic 50 - --
Barium -- 1000 --
Lead 15 - -
Manganese -- -- 50
p.g/ t = microgram per liter
MCL = maximum contaminant level
summarized from the CVRWQCBs Water Quality Goals
[CVRWQCB 1993]
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2.8.2.4 Location-Specific ARARs
For each of the landfills, the site and the surrounding area (Le., within 0.25 mile of the
landfill perimeter) were reviewed to identify and locate special features. Only floodplains
and wetlands occur at or near the landfill sites.
Based on review and extrapolations of Federal Emergency Management Agency (FEMA)
flood insurance rate maps for Sacramento County, California [FEMA 1989] and floodplain
calculations performed by the U.S. Army Corp of Engineers, it is believed that portions of
Sites 4 and 5 may be within the l00-year floodplain of Morrison Creek and its tributaries.
The California Department of Fish and Game (DFG) regulations [14 CCR 1600] establish
applicable requirements for any construction work within l00-year floodplains for the
protection and continuance of fish or wildlife resources.
Vernal pools are classified as wetlands under U.S. Army Corps of Engineers criteria. A
large vernal pool occurs about midway between Site 3 and Site 4, three small vernal pools
are known to occur near the western side of Site 4 [IT 1993c], and seasonal ponding occurs
north of the southern landfill at Site 6. As of December 1992 there has been no obvious
:;igii5 uf disiurbance or stress of the vernal pools or areas of ponding near Sites 3, 4, and 6
[IT 1993c]. The U.S. EPA regulations (40 CFR 230.10(a) to 230.10 (c» and U.S. Army
Corps of Engineers regulations (33 CFR 330 and its associated Appendix) promulgated under
Section 404 of the Clean Water Act [33 USC Section 1344] are location-specific ARARs for
Sites 3, 4, and 6 due to the nearby vernal pools. These regulations require that impacts to an
existing wetland from a contaminated site and potential impacts from a remediation project
be considered and any adverse impacts be minimized to the extent possible. For a remedial
action, the potential for degradation or destruction of a functioning wetland needs to be
considered. Activities that might come under this provision include diversion of either
surface or groundwater from or into a wetland, silting of a wetland, and construction of
roads or other facilities within the wetland, removing vegetation where the root system
seriously disturbs the substrate, and any excavation, including dredging that is designed to
minimized spillage of dredged material. The substantive requirements of 33 CFR 330 for
construction work in wetlands are: use of erosion and siltation controls, heavy construction
equipment wQrking in wetlands must be placed on mats or other measures must be taken to
minimize soil disturbances, and activity must jeopardize the continual existence of an no
endangered or threatened species. Executive Order 11990 is location.-specific TBC guidance.
The Executive Order requires federal agencies to limit adverse impacts to wetland areas, both
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in the short and long term, by avoidance of "direct or indirect support of new construction in
wetlands whenever there is a practicable alternative. "
2.8.2.5 Action-Specific ARARs
Action-specific ARARs are technology-based or activity-based requirements or limitations on
actions taken with respect to the waste. For the landf1l1s, the major governing action-specific
ARARs are those regulations and guidelines developed for the operation and closure of
MSWLFs.
At the Federal level, MSWLFs are regulated under Subtitle D of the Resource Conservation
and Recovery Act. The Subtitle D regulations are found at Title 40, Part 258 of the CFR.
Under Subtitle D, states were required to adopt solid waste permit programs that met the
Federal requirements. Within California, the MSWLF regulations are found in Chapter 15,
Division 3, Title 23 of the CCR and Chapter 3, Division 7, Title 14 of the CCR. The
California State program has been approved by U.S. EPA, but it is not authorized: that is,
U.S. EPA has not permitted the state to administer and enforce Subtitle D in lieu of the
Federal regulations. The Federal regulations are applicable to any MSWLF that accepts
household waste. However, within approved states, such as California, the state regulations
may be enforced in addition to the Federal Subtitle D regulations.
Specific provisions of the Federal Subtitle D and state MSWLF regulations have been
identified as either applicable or relevant and appropriate for the remediation activities at the
landfills. When specific state and Federal MSWLF regulations are the same, the Federal
regulation is the ARAR. If the State and Federal standards address the same issue but are
not identical, the most stringent requirement is the ARAR. For the Landfill OU, the
determination of whether the State MSWLF requirement is more stringent than the federal
MSWLF requirement has been deferred to the remedial design phase. The Federal and State
requirements are not always directly comparable and sufficient information is not available to
determine the stringency of the differing requirements. Tables 2.42 and 2.43 list both the
State and Federal MSWLF regulations and a summary of requirements.
Resource Conservation and Recovery Act Subtitle D is applicable only to sites that accept
municipal solid wastes after October 1993. Site 4 will be receiving waste from sites 5 and 6
after October 9, 1993. The wastes from sites 5 and 6 are expected te be comparable to
municipal solid waste. Consequently, the provisions of Subtitle D (federal or state
requirements, whichever are more stringent) are applicable to Site 4.
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Disposal Site Operation regulations [14 CCR, Division 7, Chapter 3, Article 7.5] and
Federal Subtitle D operating criteria [40 CFR 258.20 to 40 CPR 258.28] have been identified
as action-specific ARARs. These regulations define appropriate parameters for the
following:
. conf1l1ed unloading;
. spreading and compaction;
. slopes and cut angles;
. stockpiling;
. availability of cover material;
. daily covers;
. liquid restrictions;
. runon/runoff controls;
. surface water requirements;
. access requirements;
. air emissions;
. explosive gas controls;
. disease vector controls; and
. exclusion of hazardous waste.
In addition, Dispo~ Site Control regulatiuns [14 CCR, Division 3, Chapter 3, Article 7.6]
are considered applicable to Site 4 and relevant and appropriate to sites 5 and 6. These
include requirements for controlling:
.
nuisances;
fire.
,
leachate;
landfill gases;
dust;
drainage and erosion; and
waste contact with water, litter, noise, odor, traffic, and ponding water.
.
.
.
.
.
.
Based on disposal histories and remedial investigation results, the wastes at Sites 5 and 6 are
not expected to be hazardous. However, the potential to excavate hazardous wastes from
these landfills can not be excluded. If hazardous wastes are found, portions of the DTSC
regulations governing the generation (22 CCR 66261) and transfer, treatment, storage, and
disposal of hazardous wastes (22 CCR 66264) would be applicable to onsite activities. Any
suspected waste would be classified based on the characteristics of hazardous waste (22 CCR
66261) (and also as designated waste under 23 CCR 2522). Any hamrdous waste managed
on site needs to be handled according to the substantive requirements, including:
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.
packaging prior to transport (22 CCR 66262.30);
labeling prior to transport (22 CCR 66262.31); and
marking prior to transport (22 CCR 66262.32).
.
.
Federal regulations that implement the Solid Waste Disposal Act (SWDA) Subtitle D [40
CPR Part 258.60 to 258.61], and State regulations governing closure and post-closure of
solid waste disposal sites promulgated by the California Integrated Waste Management Board
[14 CCR Division 7, Chapter 3, Article 7.8] were identified as applicable to Site 4 and
relevant and appropriate to sites 2 and 3. The State Water Resources Control Board
(SWRCB) regulations found at 23 CCR Division 3, Chapter 15, regulations are considered
applicable to Site 4 and relevant and appropriate to sites 2 and 3. These regulation are:
.
23 CCR 2546 (a) for final drainage;
23 CCR 2546 (c) for run-off controls;
23 CCR 2546 (d) for collection and holding of surface water drainage;
23 CCR 2558 for groundwater monitoring;
23 CCR 2580 (d) for final grading;
23 CCR 2581 (a) for final cover design criteria;
23 CCR 2596 (b) for an elevation survey.
.
.
.
.
.
.
Substantive Solid Waste Disposal Act Subtitle D closure and post-closure care requirements
include:
.
designing and installing a final cover system that minimizes infiltration and
erOSIOn;
.
providing an estimate of the largest area of the landfill requiring a final cover;
.
providing an estimate of the maximum inventory of wastes ever onsite over the
active life of the facility;
.
developing a closure schedule;
.
complying with substantive requirements for obtaining certification of closure;
.
recording a notation on the deed to the landfill property to notify the any
potential purchasers that the site was used for landfilling; and
.
conducting post-closure care for the length of time sufficient to protect human
health and the environment, including: maintaining the integrity of the final
cover, maintaining and operating the leachate collectiobsystem (if applicable);
monitoring the groundwater; and maintaining and operating the gas monitoring
system.
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State Water Resources Control Board regulations established criteria for closure and post-
closure care of landfill facilities [23 CCR, Division 3, Chapter 15, Article 8]. The action-
specific requirements address the following:
.
waste containment;
precipitation and drainage controls;
final cover construction;
grading requirements; and
protection and maintenance of sUIveyed monuments.
.
.
.
.
Additional requirements establish groundwater and vadose zone monitoring requirements for
the post-closure period [23 CCR, Division 3, Chapter 15, Article 5].
The IWMB requirements for closure [14 CCR, Division 3, Chapter 3, Article 7.8] address:
.
development of an emergency response plan;
security of the landfill site;
final cover, grading, site face and drainage designs;
slope protection and erosion ('.l)otrol;
leachate control;
groundwater monitoring and perimeter monitoring networks;
landfill gas monitoring and control; and
structural monitoring.
.
.
.
.
.
.
.
The IWMB requirements for closure include restrictions on the concentration of methane in
air, i.e., 5 percent by volume, that is allowed at the facility property boundary [14 CCR,
Division 3, Chapter 3, Article 7.8, Section 17783 (2)]. They also require control of trace
gasses to prevent chronic exposure to toxic and/or carcinogenic compounds [14 CCR,
Division 3, Chapter 3, Article 7.8, Section 17783 (3)].
The following SMAQMD requirements are ARARs for the covering and
removal/consolidation alternatives:
.
Rule 403 - Fugitive Dusts: Limits visible particulate emissions at the property
-line.
.
Rule 202 - New Source Review: Requires that any ne~ source meet emission
limitations for criteria air pollutants, including use of Best Available Control
Technology (BACT) to any new emissions unit. The SMAQMD has
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determined that no controls is BACT for .passive gas venting at site 2, 3, and
4.
.
Rule 402 - Nuisance Standard: Limits emissions of odors and other nuisance
material to the air.
The State has asserted that State Water Resources Control Board Resolution 92-49,
specifically Paragraphs ill F and ill G, is an applicable requirement for all of the proposed
remedial actions. No determination is made in this document that Resolution 92-49 is an
ARAR for the selected remedial actions. However, the State has determined that the
substantive requirements of Resolution No. 92-49 are being met by the remedial actions.
Therefore, the State has decided not to dispute the ROD on these grounds.
A number of regulatory requirements in Title 14, CCR, Division 7, Chapter 3, Article 7.5
(Disposal Site Operations) were not considered ARARs because they are do not directly
address protection of public health and the environment, but rather address worker health and
safety or good work and management practices. However, the landfill sites will be
remedi.ated under approved health and safety plans to ensure that work is accomplished
according to applicable health and safety requirements. In addition, the work will be planned
and conducted to meet the ARARs identified for the remedial actions, incorporating these
practices as appropriate. The requirements in these categories contained in the Title 14
regulations that were not considered ARARs include:
.
Sanitary Facilities: Adequate sanitary facilities for site personnel shall be
available on-site or in the immediate vicinity
.
Water Supply: Safe and adequate drinking water shall be available for site
personnel
.
Communications Facilities: Communications facilities will be available to site
personnel to allow quick response to emergencies
.
. Lighting: Lighting will be used for operations conducted during hours of
darkness
~
.
Personnel Health and Safety: Operating and maintenance personnel shall be
required to wear and use approved safety equipment
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.
Availability: Adequate staffing will be provided by operator to deal effectively
and promptly with operations, maintenance, environmental controls, emergen-
cies, and health and safety
.
Training: Personnel assigned to the site will be adequately trained.
.
Supervision: Adequate supervision of site operations will be provided, as well
as notification to authorities of responsible operator, station manager, and
supervisor
.
General: Equipment will be adequate in type, capacity, number and maintained
in order to consistently perform work to comply with regulatory standards
.
Standby Equipment: Standby equipment is not required providing a source of
replacement equipment is maintained adequately.
.
General: Preventative maintenance procedures and programs for equipment and
site facilities will be developed and used for operating and completed sites.
.
Traffic Control: Traffic will be managed to minimize traffic safety problems
on adjacent public roads.
Several of the California regulations require certification by a professional geologist or
engineer, registered or certified by the State of California. These portions of the regulations
are considered procedural rather than substantive requirements. However, to the degree that
federal contractors perform and/or supervise the engineering and geotechnical work, they
will be certified professionals or under the supervision of certified professionals as
appropriate.
2.8.2.6 Site 1 - Runway Overrun Landfill
Alternative 1.1 is the only alternative developed for this site. No refuse or contaminants
were found d1;1ring remedial activities. Therefore, no comparative analysis is necessary.
2.8.2. 7 Site 2 - "8150" Area Landfill ...
Both Alternatives 2.2 and 2.3 would meet ARARs in approximately the same timeframe.
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2.8.2.8 Site 3 - Northeast Perimeter Landfill No.1
Alternatives 3.2 and 3.3 would meet ARAR requirements in approximately the same
timeframe.
2.8.2.9 Site 4 - Northeast Perimeter Landfill No.2
Alternatives 4.2 and 4.3 both meet ARAR requirements in approximately the same
timeframe.
...
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2.8.2.10 Site 5 - Northeast Perimeter Landfill No.3
Alternatives 5.2 and 5.3 would both meet ARAR requirements in approximately the same
timeframe.
2.8.2. 11 Site 6 - Firing Range Landfill Sites
Alternatives 6.2 and 6.3 would both meet ARAR requirements in approximately the same
timeframe.
2.8.3 Long-Term Effectiveness and Permanence
Long-term effectiveness and permanence refers to the ability of a remedy to maintain reliable
protection of human health and the environment after clean-up goals have been met. The
criterion includes the consideration of residual risk and the adequacy and reliability of
controls.
2.8.3.1 Site 1 - Runway Overrun Landfill
Alternative 1.1 is the only alternative developed for this site. No refuse or contaminants
were found during remedial activities. Therefore, no comparative analysis is necessary.
2.8.3.2 Site 2 - "8150" Area Landfill
Alternative 2.3 is judged to offer a higher level of long-term effectiveness than Alternative
2.2 because all the refuse is removed and the site is c1ean-closed. Under Alternative 2.2 the
refuse would remain in place and be covered with a vegetative cover.
2.8.3.3 Site 3 - Northeast Perimeter Landfill No.1
Alternative 3.3 is judged to offer a higher level of long-term effectiveness than Alternative
3.2, since all the refuse is removed from Site 3, thereby reducing the volume of solid waste
to zero and the site is clean-closed. Under Alternative 3.2 the refuse would remain in place
and covered with an engineered cap.
2.8.3.4 Site 4 - Northeast Perimeter Landfill No.2
Alternatives 4.2 and 4.3 are judged to offer a high level of long-term effectiveness. Under
both alternatives, refuse would remain in place and be covered with an engineered cap.
...
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2.8.3.5 Site 5 - Northeast Perimeter Landfill No.3
Alternative 5.2 is judged to offer a higher level of long-term effectiveness than Alternative
5.3 since all the refuse is removed and the site is clean-closed. Under Alternative 5.3 the
refuse remains in place and is covered by an engineered cap.
2.8.3.6 Site 6 - Firing Range Landfill Sites.
Alternative 6.3 is judged to offer a higher level of long-term effectiveness than Alternative
6.2 since all the refuse is removed and the site is clean-closed. Solid waste remains in place
under Alternatives 6.2 and is covered with a vegetative cover.
2.8.4 Reduction of Toxicity, Mobility, or Volume
Reduction of toxicity, mobility, or volume refers to the preference for a remedy that uses
treatment to reduce health hazards, contaminant migration, or quantity of contaminants at the
site. Treatment was not used for any of the landfill sites because it was not considered
practicable or cost-effective.
2.8.4.1 Site 1 - Runway Overrun Landfill
Alternative 1.1 is the only alternative developed for this site. No refuse or contaminants
were found during remedial activities. Therefore, no comparative analysis is necessary.
2.8.4.2 Site 2 - "8150" Area Landfill
Alternative 2.3 is judged to be more effective at this site than Alternative 2.2 since all the
refuse is removed from Site 2, thereby reducing the volume of solid waste at Site 2 to zero.
The volume_of waste at Mather AFB is not reduced, merely consolidated. However, the risk
of contaminated exposure is localized. Solid waste is left in place under Alternative 2.2.
However, landfill cap infiltration modeling suggests that precipitation infiltration and
potential corresponding leachate generation is decreased by up to 85 percent.
2.8.4.3 Site 3 - Northeast Perimeter Landfill No.1
Alternative 3.3 is judged to be more effective at this site than Alternative 3.2 since all the
refuse is removed from Site 3, thereby reducing the volume of solid waste at Site 3 to zero.
The volume ()f waste at Mather AFB is not reduced, merely consolidated. However, the risk
of contaminated exposure is localized. All refuse would remain in place under Alternative
3.2. However, landfill cap infiltration modeling shows that precipitation infiltration and
corresponding potential leachate generation is decreased by up to 82 percent with installation
of an engineered cap.
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2.8.4.4 Site 4 - Northeast Perimeter Landfill No.2
Volumes of solid waste remain the same under both Alternative 4.2 and 4.3. Alternative 4.3
is judged to be more effective than Alternative 4.2 since the landfill area is reduced by
approximately 20 percent, which would reduce the corresponding potential for leachate
generation. Landfill cap infiltration modeling shows that precipitation infiltration, and
corresponding potential leachate generation is decreased by up to 83 percent (Alternative 4.2)
and up to 87 percent (Alternative 4.3) with installation of an engineered cap.
2.8.4.5 Site 5 - Northeast Perimeter Landfill No.3
Alternative 5.2 is judged to be more effective at this site than Alternative 5.3 since the
volume of refuse at Site 5 is reduced to zero through excavation. The volume of waste at
Mather AFB is not reduced, merely consolidated. However, the risk of contaminated
exposure is localized. Alternative 5.3 consolidates refuse from the stream channel to the
remaining landfills. No waste reduction is realized; however, the landfIll area would be
reduced and it will lessen the impact on the stream as well as the potential for leachate
generation. Landfill cap infIltration modeling shows that precipitation infiltration, and
corresponding potential leachate generation is decreased by up to 83 percent for Alternative
5.3 with installation of an engineered cap.
2.8.4.6 Site 6 - Firing Range Landfill Sites
Alternative 6.3 is judged to be more effective at this site than Alternative 6.2 since the
volume of refuse at Site 6 is reduced to zero through excavation. The volume of waste at
Mather AFB is not reduced, merely consolidated. However, the risk of contaminated
exposure is localized. Solid waste remains in place under Alternative 6.2. However, landfill
cap infiltration modeling shows that precipitation infiltration, and corresponding potential
leachate generation is decreased by up to 87 percent with installation of a vegetative cover.
2.8.5 Short- Term Effectiveness
Short-term effectiveness refers to the period of time in which the remedy achieves protection,
as well as the remedy's potential to create adverse impacts on human health and the
environment that may result during the excavation, construction, or implementation period.
2.8.5. 1 Site 1 - Runway Overrun Landfill
Alternative 1.1 is the only alternative developed for this site. No ret;use or contaminants
were found during remedial activities. Therefore, no comparative analysis is necessary.
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2.8.5.2 Site 2 - "8150" Area Landfill
Alternatives 2.2 and 2.3 are judged to offer a high degree of short-term effectiveness. No
adverse effects to community, workers, or the environment are anticipated. Appropriate
health and safety procedures would be developed and implemented to assist in worker
protection during construction of a vegetative cover or excavation and consolidation of the
refuse.
2.8.5.3 Site 3 - Northeast Perimeter Landfill No.1
Alternatives 3.2 and 3.3 are judged to offer a high degree of short-term effectiveness and no
adverse effects to community, workers, or the environment are anticipated. Appropriate
health and safety procedures would be developed and implemented to assist in worker
protection to minimize hazards during construction of an engineered cap or excavation and
consolidation of the refuse.
2.8.5.4 Site 4 - Northeast Perimeter Landfill No.2
Alternatives 4.2 and 4.3 are judged to offer a high degree of short-term effectiveness and no
adverse effects to community, workers, or the environment are anticipated. Appropriate
health and safety procedures would be developed and implemented to assist in worker
protection during construction of an engineered cap or excavation and consolidation of the
refuse. Potential impacts to the stream channel at the eastern border of the landfill are
anticipated to be minimal.
2.8.5.5 Site 5 - Northeast Perimeter Landfill No.3
Alternatives 5.2 and 5.3 are judged to offer a high degree of short-term effectiveness and no
adverse effects to community, workers, or the environment are anticipated. Appropriate
health and safety procedures would be developed and implemented to assist in worker
protection during construction of an engineered cap or excavation and consolidation of the
refuse. Potential impacts to the stream channel, due to excavation are anticipated to be
minimal.
2.8.5.6 Site 6 - Firing Range Landfill Sites
Alternatives 6.2 and 6.3 are judged to offer a high degree of short-term effectiveness and no
adverse effects to community, workers, or the environment are anticipated. Appropriate
health and safety procedures would be developed and implemented tQ. assist in worker
protection during construction of a vegetative cover or excavation and consolidation of the
refuse.
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2.8.6 Implementability
Implementability refers to the technical and administrative feasibility of a remedy, including
the availability of materials and services needed to implement the selected remedy. It also
includes coordination of federal, State, and local governments in cleanup of the site.
2.8.6.1 Site 1 - Runway Overrun Landfill
Alternative 1.1 is the only alternative developed for this site. No refuse or contaminants
were found during remedial activities. Therefore, no comparative analysis is necessary.
2.8.6.2 Site 2 - .8150" Area Landfill
Both Alternatives 2.2 and 2.3 are considered to be readily implementable utilizing existing
resources and technologies. Buildings and an asphalt road represent potential complications
for remedial activities at Site 2. Alternative 2.3 has been judged to be more difficult to
implement than Alternative 2.2 based on the premise that removing refuse from near roads
and buildings could not be accomplished with great certainty and ease as compared to the
construction of a vegetative cover.
2.8.6.3 Site ;$ - Northeast Perimeter Landfill No.1
Alternatives 3.2 and 3.3 are considered to be readily implementable using existing resources
and technologies. However, Alternative 3.3 is judged to be more complicated to implement
due to potential exposure to contaminants during excavation. Under both alternatives, an
existing dirt road would most likely need to.be rerouted or replaced.
2.8.6.4 Site 4 - Northeast Perimeter Landfill No.2
Both Alternatives 4.2 and 4.3 are considered to be readily implementable using existing
resources and technologies. Alternative 4.2 offers a higher degree of implementability since
it does not introduce the complexities associated with excavation of the refuse as under
Alternative 4.3.
2.8.6.5 Site 5 - Northeast Perimeter Landfill No.3
Alternative 5.3 offers a higher degree of implementability using existing resources and
technologies ~ince only the stream channel is excavated (1 percent of refuse and associated
soils volume) compared to excavation of the entire site under Alternative 5.2.
...
2.8.6.6
Site 6 - Firing Range Landfill Sites
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Both Alternatives 6.2 and 6.3 are considered to be readily implementable using existing
resources and technologies. Alternative 6.2 offers a higher degree of implementability since
it does not introduce the complexities associated with excavation (i.e., exposure to
contaminants) as under Alternative 6.3.
2.8.7 Cost
This criteria examines the estimated cost for each remedial alternative. For comparison,
capital costs and annual operation and maintenance (O&M) costs were used to calculate a
present worth cost for each alternative. A detailed cost analysis was performed for each of
the alternatives proposed in the FFS Report [IT 1993e]. The present worth cost estimates
assume zero equipment salvage value, zero percent inflation, and a five percent discount rate.
2.8.7. 1 Site 1 - Runway Overrun Landfill
Alternative 1.1 is the only alternative developed for this site. No refuse or contaminants
were found during remedial activities. Therefore, no comparative analysis is necessary.
2.8.7.2 Site 2 - -8150" Area Landfill
The present worth costs to implement Alternatives 2.1, 2.2, and 2.3 are estimated in the
Focused Feasibility Study at $140,718, $978,213, and $1,536,068, respectively. Alternative
2.1 includes costs associated with semi-annual groundwater monitoring for 5 years.
Alternative 2.2 includes costs associated with semi-annual groundwater monitoring and
quarterly landfill monitoring for at least 5 years. Alternative 2.3 includes costs for quarterly
groundwater monitoring for 3 years. Also included in Alternative 2.3 is the prorated cost to
accommodate Site 2 refuse and associated soils at the consolidation site (i.e., Site 4).
2.8.7.3 Site 3 - Northeast Perimeter Landfill No.1
The present worth costs to implement Alternatives 3.1, 3.2, and 3.3 are estimated in the
Focused Feasibility Study at $338,336, $2,189,438, and $2,729,088, respectively.
Alternative 3.1 includes costs associated with semi-annual groundwater monitoring for 5
years. Alternative 3.2 includes costs associated with quarterly groundwater monitoring and
quarterly landfill monitoring for at least 5 years. Alternative 3.3 includes costs for quarterly
groundwater monitoring for at least 3 years. Also included in Alternative 3.3 is the prorated
cost to accommodate Site 3 refuse and associated soils at the consolidation site (Le., Site 4).
...
2.8.7.4
Site 4 - Northeast Perimeter Landfill No.2
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The present worth costs to implement Alternatives 4.1,4.2 and 4.3 are estimated in the
Focused Feasibility Study at $288,931, $2,803,778, and $3,352,373, respectively.
Alternative 4.1 includes costs associated with semi-annual groundwater monitoring for 5
years. Alternatives 4.2 and 4.3 include costs associated with quarterly groundwater
monitoring and quarterly landfill monitoring for at least 5 years.
2.8.7.5 Site 5 - Northeast Perimeter Landfill No.3
The present worth costs to implement Alternatives 5.1, 5.2 and 5.3 are estimated in the
Focused Feasibility Study at $214,824, $1,015,793, and $1,364,542, respectively.
Alternative 5.1 includes costs associated with semi-annual groundwater monitoring for 5
years. Alternative 5.2 includes costs associated with quarterly groundwater monitoring for at
least 5 years. Alternatives 5.3 includes costs associated with quarterly groundwater
monitoring and quarterly landfill monitoring for at least 5 years. Also included in
Alternative 5.2 is the prorated cost to accommodate Site 5 refuse and associated soils at the
consolidation site (Le., Site 4).
2.8.7.6 Site 6 - Firing Range Landfill Sites
The present worth costs to implement Alternatives 6.1, 6.2 and 6.3 are estimated in the
Focused Feasibility Study at $140,718, $1,048,008, and $2,361,121, respectively.
Alternative 6.1 includes costs associated with semi-annual groundwater monitoring for 5
years. Alternative 6.2 includes costs associated with semi-annual groundwater monitoring
and quarterly landfill monitoring for at least 5 years. Alternatives 6.3 includes costs
associated with quarterly groundwater monitoring for 3 years. Also included in Alternative
6.3 is the prorated cost to accommodate Site 6 refuse and associated soils at the consolidation
site (Le., Site 4).
...
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2.8.8 State/Support Agency Acceptance
This indicates whether, based on its review of the RI Report, FFS Report, and Proposed
Plan, the State in which the site resides agrees with the preferred alternative. The Air Force,
as the lead agency, has involved the State of California Department of Toxic Substances
Control, State of California Regional Water Quality Control Board, and the State of
California Integrated Waste Management Board.
2.8.8.1 Site 1 - Runway Overrun Landfill
The Air Force has responded to all State regulatory agency comments during their reviews of
the FFS Report and the Proposed Plan. The State regulators support the selection of
Alternative 1.1 as the preferred remedy.
2.8.8.2 Site 2 - "8150" Area Landfill
The Air Force has responded to all State regulatory agency comments during their reviews of
the FFS Report and the Proposed Plan. The State regulators support the selection of
Alternative 2.2 as the preferred remedy.
2.8.8.3 Site 3 - Northeast Perimeter Landfill No.1
The Air Force has responded to all State regulatory agency comments during their reviews of
the FFS Report and the Proposed Plan. The State regulators support the selection of
Alternative 3.2 as the preferred remedy.
2.8.8.4 Site 4 - Northeast Perimeter Landfill No.2
The Air For~ has responded to all State regulatory agency comments during their reviews of
the FFS Report and the Proposed Plan. The State regulators support the selection of
Alternative 4.2 as the preferred remedy.
2.8.8.5 Site 5 - Northeast Perimeter Landfill No.3
The Air Force has responded to all State regulatory agency comments during their reviews of
the FFS Report and the Proposed Plan. The State regulators support the selection of
Alternative 5.2 as the preferred remedy.
2.8.8.6 Site 6 - Firing Range Landfill Sites
The Air Force has responded to all State regulatory agency comments during their reviews of
the FFS Report and the Proposed Plan. The State regulators support the selection of
Alternative 6.3 as the preferred remedy.
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2.8.9 Community Acceptance
This is an assessment of the general public response to the Proposed Plan following a review
of the public comments received on the RI Report, FFS Report, and Proposed Plan during
the public comment period and open community meeting(s). Section 3.0 of this ROD
documents the community acceptance of the selected remedy, as presented in the
Responsiveness Summary.
2.9 The Selected Remedies
This section presents the remedies selected by the Air Force, with concurrence by the U.S.
EPA and the State for each of the landfill sites. The selected remedies were chosen based on
the results of the comparative analysis of the alternatives presented in Sections 2.8.1 through
2.8.9 and provide the best of trade-offs with respect to the nine evaluation criteria. All
design and construction of the selected remedial actions conducted or supervised by a
contractor of the Air Force (other than an agency of the federal government) will be designed
or supervised as appropriate by a registered geologist licensed in the State of California, a
licensed professional engineer, or other licensed professional, with experience appropriate to
the type of work or document required.
2.9.1 Site 1 - Runway Overrun Landfill
Alternative 1.1 (No Action) was the only alternative developed for Site 1, hence it is the
selected remedy. No refuse or contaminants were found during investigative activities.
Therefore, it is believed that all refuse was removed prior to construction of the runway
overrun. Since there is no refuse and no soil contamination at Site 1, no potential source for
contamination to the groundwater exists.
2.9.2 Site 2 - "8150" Area Landfill
Alternative 2.2 (Capping) was selected by the Air Force, with concurrence by the U.S. BPA
and the State as the remedy for Site 2. The selected remedy consists of installing a
vegetative cover, monitoring of groundwater and landfill gas for at least 5 years, and
invoking access restrictions (i.e., fencing and deed restrictions). Alternative 2.2 was chosen
as the selected remedy for the following reasons:
.
access restrictions and a vegetative cover prevent contact with the refuse and
provide erosion control;
...
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.
the vegetative cover reduces precipitation infiltration and corresponding
potential leachate generation at this site by up to 85 percent compared to
existing site conditions;
.
a vegetative cover is considered to be readily implementable utilizing existing
resources and technologies; and
.
costs associated with Alternative 2.2 are 36 percent less than Alternative 2.3.
2.9.3 Site 3 - Northeast Perimeter Landfill No.1
Alternative 3.2 (Capping) was selected by the Air Force, with concurrence by the U.S. EPA
and the State as the remedy for Site 3. The selected remedy consists of installing an
engineered cap, monitoring of groundwater and landfill gas for at least 5 years, and invoking
access restrictions (i.e., fencing and deed restrictions). Alternative 3.2 was chosen as the
selected remedy for the following reasons:
.
access restrictions and an engineered cap prevent contact with the refuse and
provide erosion control;
.
an engineered cap reduces precipitation infiltration and corresponding potential
leachate generation at this site by up to 82 percent compared to current site
conditions;
.
an engineered cap is considered to be readily implementable utilizing existing
resources and technologies; and
.
costs associated with Alternative 3.2 are 20 percent less than Alternative 3.3.
2.9.4 Site 4 - Northeast Perimeter Landfill No.2
Alternative 4.2 (Capping and Embankment) was selected by the Air Force, with concurrence
by the U.S. EPA and the State as the remedy for Site 4. The selected remedy consists of
installing an engineered cap, installing flood control measures (i.e., an embankment),
monitoring of groundwater and landfill gas for at least 5 years, and invoking access
restrictions (i.e., fencing and deed restrictions). Alternative 4.2 was chosen as the selected
remedy for the following reasons:
.
access restrictions and an engineered cap prevent contact with the refuse and
provide erosion control; ...
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.
an engineered cap reduces precipitation infiltration and corresponding potential
leachate generation at this site by up to 83 percent compared to existing site
conditions;
.
an engineered cap and flood controls are considered to be readily
implementable utilizing existing resources and technologies; and
.
costs associated with Alternative 4.2 are 16 percent less than Alternative 4.3.
2.9.5 Site 5 - Northeast Perimeter Landfill No.3
Alternative 5.2 (Excavation and Consolidation) was selected by the Air Force, with
concurrence by the U.S. EPA and the State as the remedy for Site 5. The selected remedy
consists of excavating the landfill refuse, transporting it to, and consolidating it with refuse at
the consolidation site (i.e., Site 4) and monitoring the groundwater for at least 5 years.
Alternative 5.2 was chosen as the selected remedy for the following reasons:
.
exposure to the refuse at Site 5 is eliminated/reduced once the refuse is
excavated;
.
precipitation !nf1ltraticn ~d cvITQpOnding potemialleachate generation is
eliminated once the source is removed;
.
the area made available by excavation will be available for other land uses;
and
.
costs associated with Alternative 5.2 are 26 percent less than Alternative 5.3.
2.9.6 Site 6 - Firing Range Landfill Sites
Alternative 6.3 (Excavation and Consolidation) was selected by the Air Force, with
concurrence by the U.S. EPA and the State as the remedy for Site 6. The selected remedy
consists of excavating the landfill refuse, transporting it to, and consolidating it with refuse at
the consolidation site (i.e., Site 4) and monitoring the groundwater for at least 5 years.
Alternative 6.3 was chosen as the selected remedy for the following reasons:
.
exposure to the refuse at Site 6 is eliminated/reduced once the refuse is
-excavated;
.
precipitation infiltration and corresponding potential ldchate generation is
eliminated once the source is removed; and
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.
the area made available by excavation will be available for other land uses.
2. 10 Estimated Costs
Major costs associated with the selected remedies were estimated during the FFS and
presented in the FFS Report [IT 1993e]. Costs are summarized in Tables 2.43 through 2.53.
Cost estimates will be refined and finalized during the remedial design phase. On subsequent
cost analyses (wholistic approach) savings were reali7.ed at Site 4 by excavating and
consolidating Sites 5 and 6 to Site 4.
2. 11 Statutory Determinations
The selected remedies satisfy the statutory requirements in CERCLA Section 121(b), as
amended by SARA, in that the following mandates are attained:
.
the selected remedies are protective of human health and the environment, will
decrease site risks, and will not create short-term risks nor have cross-media
consequences;
.
the selected remedies comply with federal and State requirements that are
applicable, or relevant and appropriate, to the remedial actions such as
chemical-specific ARARs, location-specific clean-up standards, and
action-specific ARARs for closure of the landfills;
.
the selected remedies are cost-effective in their fulfillment of the nine
CERCLA evaluation criteria through eliminating contact with the landfill
contents; and
.
the selected remedies utilize permanent solutions to the maximum extent
practicable.
""
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Table 2.45 Costs for the Selected Remedies
Selected Remedy Cost Component Total Dollars Present W ortba
Alternative 1.1 Capital $0 $0
Operation and Maintenance $0 $0
Total Costs $0 $0
Alternative 2.2 Capital $543,233 $511,189
Operation and Maintenance $829,675 $467,024
Total Costs $1,372;908 $978,213
Alternative 3.2 Capital $642,428 $964,931
Operation and Maintenance $2,885,960 $1,624,507
Total Costs $3,528,388 $2,189,438
Alternative 4.2 Capital $1,512,173 $1,382,684
Operation and Maintenance $2,524,918 $1,421,094
Total Costs $4,037,091 $2,803,778
Alternative 5.2 Capital $500,188 $497,523
Operation and Maintenance $645,059 $518,270
Total Costs $1,145,247 $1,015,793
Alternative 6.3 Capital $2,184,098 $2,184,098
Operation and Maintenance $195,017 $177,023
Total Costs $2,379,115 $2,361,121
.
Discount rate equals 5 percent
...
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Table 2.46 Site 2 Estimated Cost Summary
.selected Remedy:
Alternative 2.2 - Vegetative Cover
Capital Costs:
Access Restrictions
Vegetative Cover
Maintenance of Cover
Cover Repairs
Installation of Gas Vent and Monitoring Wells
Replacement of Dedicated Pumps
Replacement/Construction of Asphalt Road
Sub Total of Capital Costs
Bid Contingency of 15 %
Scope Contingency of 15 %
Permitting Costs of 5 %
Total Capital Costs
Operation and Maintenance Costs:
Sampling of Existing Groundwater Wells
Year 1-5
Year 6-30
Sampling of Landfill Gas Vent and Monitoring Wells
Year 1-5
. Year 6-30
Labor for Writing Reports
Year 1-5
Year 6-30
Miscellaneous O&M
Year 1-5
Year 6-30
. Total O&M Cost/Year
Year 1-5
Year 6-30
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. .
$70,000
$140,536
$21,000
$8,104
$14,400
$30,000
$118,356
$402,395
$60,359
$60,359
$20,120
$543,233
$25,148
$12,574
$13,552
$6,776
$4,400
$2,200
$4,310
$2,155
...
$47,410
$23,705
-------
Table 2.47 Site 2 Estimated Cost Summary, Present Worth Calculation
...
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Table 2.48 Site 3 Fstimated Cost Summary
Selected Remedy:
Alternative 3.2 - Engineered Cap
Capital Costs:
Sub Total of Capital Costs
$65,000
$257,239
$36,000
$16,533
$8,400
$90,000
$2,700
$475,873
Access Restrictions
Engineered Cap
Maintenance of Cap
Cap Repairs
Installation of Gas Vent and Monitoring Wells
Replacement of Dedicated Pumps
Replacement/Construction of Unpaved Road
Bid Contingency of 15 %
Scope Contingency of 15 %
Permitting Costs of 5%
$71 ,381
$71,381
$23,794
Total Capital Costs
$642,428
Operation and Maintenance Costs:
Sampling of Existing Groundwater Wells
Year 1-5
Year 6-30
$133,288
$66,644
Sampling of LandfIll Gas Vent and Monitoring Wells
Year 1-5
Year 6-30
$7,832
$3,916
Labor for Writing Reports
Year 1-5
Year 6-30
$8,800
$4,400
Miscellaneous O&M
Year 1-5
Year 6-30
$14,992
$7,496
. Total O&M CostlY ear
Year 1-5
Year 6-30
...
$164,912
$82,456
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Table 2.49 Site 3 Estimated Cost Summary, Present Worth Calculation
...
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Table 2.50 Site 4 Estimated Cost Summary
Selected Remedy:
Alternative 4.2 - Engineered Cap and Embankment
Capital Costs:
Access Restrictions
Engineered Cap
Maintenance of Cap
Cap Repairs
Installation of Gas Vent and Monitoring Wells
Replacement of Dedicated Pumps
Embankment
Maintenance/Repair of Embankment
Sub Total of Capital Costs
$100,000
$682,968
$96,000
$44,089
$9,300
$75,000
$88,046
$24,726
$1,120,129
Bid Contingency of 15 %
Scope Contingency of 15 %
Permitting Costs of 5 %
Total Capital Costs
$168,019
$168,019
$56,006
$1,5U,173
Operation and Maintenance Costs:
Sampling of Existing Groundwater Wells
Year 1-5
Year 6-30
$112,540
$56,270
Sampling of Landfill Gas Vent and Monitoring Wells
Year 1-5
Year 6-30
$9,636
$4,818
Inspection of Embankment
Year 1-5
Year 6-30
$110
$110
Labor for Writing Reports
Year 1-5
Year 6-30
Total O&M CostlY ear
Year 1-5
Year 6-30
$8,800
$4,400
$13,109
$6,560
... $144,195
$72,158
Miscellaneous O&M
Year 1-5
Year 6-30
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Table 2.51 Site 4 Fstimated Cost Summary, Present Worth Calculation
...
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Table 2.52 Site 5 E8timated Cost Summary
Selected Remedy:
Alternative 5.2 - Excavation and Consolidation
Capital Costs:
Sub Total of Capital Costs
$17,961
$8,035
$220,076
$106,738
$10 ,500
$7,200
$370,510
Preliminary Design Investigation
Post-Excavation Verification Sampling Program
Excavation/Consolidation
Prorated Cost to Cap Consolidation Site
Replacement of Dedicated Pumps
Replacement/Construction of Unpaved Road
Bid Contingency of 15 %
. Scope Contingency of 15 %
Permitting Costs of 5 %
$55,576
$55,576
$18,525
Total Capital Costs
$500,188
Operation and Maintenance Costs:
Sampling of Existing Groundwater Wells
Year 1-5
Year 6-30
$81,418
$40,709
Labor for Writing Reports
Year 1-5
- Year 6-30
$8,800
$4,400
Miscellaneous O&M
Year 1-5
Year 6-30
$9,022
$4,511
Total O&M Cost/Year
Year 1-5
Year 6-30
$99,240
$49,620
...
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Table 2.53 Site 5 Estimated Cost Summary, Present Worth Calculation
...
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Table 2.54 Site 6 Fstimated Cost Summary
Selected Remedy:
Alternative 6.3 - Excavation and Consolidation
Capital Costs:
Sub Total of Capital Costs
Bid Contingency of 15 %
Scope Contingency of 15 %
Permitting Costs of 5 %
$80,297
$35,487
$927,489
$560,177
$14,400
$1,617,800
$242,678
$242,678
$80,893
Preliminary Design Investigation
Post-Excavation Verification Sampling Program
Excavation/Consolidation
Prorated Cost to Cap Consolidation Site
Replacement/Construction of Unpaved Road
Total Capital Costs
$2,184,098
Operation and Maintenance Costs:
Sampling of Existing Groundwater Wells
Year 1-3
$50,296
Labor for Writing Reports
Year 1-3
$8,800
I.
Miscellaneous O&M
Year 1-3
$5,910
Total O&M CostlY ear
Year 1-3
$65,006
...
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Table 2.55 Site 6 Estimated Cost Summary, Present Worth Calculation
...
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2. ". 1 Protection of Human Health and the Environment
As reported in the Group 2 Sites RI Report [IT 1993c] and the Landfill au FFS Report [IT
1993e], current onsite cancer risks are calculated to be within the range considered to be
acceptable by the U.S. EPA (Le., 104 to 1()"6 carcinogenic risk). Installation of a vegetative
cover at Site 2 will reduce risk through controlling exposure pathways and natural
degradation. Installation of engineered caps at Sites 3 and 4 will reduce risk through
controlling exposure pathways and facilitating natural degradation. Both the vegetative
covers and engineered caps will prevent contact with the landfill contents, provide erosion
control, and comply with landfill closure regulations. At Sites 5 and 6, risk will be
eliminated by removing the source through excavation and consolidation of the refuse and
associated soils. Five- Year Site Reviews will apply to the selected remedies [55 FR 8730]
since during the period of remediation, hazardous substances will remain on site possibly in
concentrations above health-based levels.
The selected remedies do not pose unacceptable short-term risks to human health or the
environment during implementation. Appropriate health and safety procedures would be
developed and implemented to assist in worker protection particularly when the selected
remedy requires the refuse to be excavated and consolidated.
2. 11.2
Compliance with Applicable or Relevant and Appropriate Requirements
2. 11.2. 1 Site 1 - Runway Overrun Landfill
No remedial action was necessary for Site 1 because all refuse has been removed and there is
no soil contamination and no potential for groundwater contamination.
2.11.2.2 Site 2 - "8150" Area Landfill
The selected remedy, when complete, will satisfy federal and State ARARs and TBCs.
Installation of a vegetative cover will reduce infiltration into the refuse, thereby reducing the
potential for leachate generation and migration of contaminants to the groundwater.
The vegetative cover for Site 2 incorporates the appropriate substantive requirements of
federal and state ARARs. Monitoring of groundwater (under the established Base
groundwater monitoring program) and landfill gases will be conducted. The integrity of the
vegetative cover will be preserved through proper construction and maintenance. A
summary of ARARs are presented in Tables 2.42 and 2.43. ...
2.11.2.3
Site 3 - Northeast Perimeter Landfill No.1
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The selected remedy, when complete, will satisfy federal and State ARARs and TBCs.
Installation of an engineered cap will reduce infiltration into the refuse, thereby reducing the
potential for leachate generation and migration of contaminants to the groundwater.
The engineered cap at Site 3 incorporates the appropriate substantive requirements of federal
and State ARARs. Monitoring of groundwater (under the established Base groundwater
monitoring program) and landfill gases will be conducted. The integrity of the engineered
cap will be preserved through proper construction and maintenance. A summary of ARARs
are presented in Tables 2.42 and 2.43.
The selected remedy, when complete, will also satisfy the DLM TBC, since the chemicals
present at Site 3 do not pose an appreciable risk to the groundwater. Maximum
concentrations of manganese and lead exceeded the limits determined by DLM. The
concentration of manganese is most likely within the range of background concentration.
The concentration of lead appears to exceed background. Acenaphthalene also exceeded the
DLM limit; however, the water quality goal established for this was based on risk
calculations using the polycyclic aromatic hydrocarbons category for carcinogens.
Acenaphthalene is a Class D carcinogen and the risk-based goal is overconservative. The
chemical also tends to bind in the soils and the potential for impact to the groundwater is
limited.
Construction of an engineered cap at Site 3 will not impact the wetlands which have been
identified near the site, and thus will comply with the substantive requirements of the
location-specific ARARs and TBCs.
2.11.2.4 Site 4 - Northeast Perimeter Landfill No.2
The selected remedy, when complete, will satisfy federal and State ARARs and TBCs.
Installation of an engineered cap will reduce infiltration into the refuse, thereby reducing the
potential for leachate generation and migration of contaminants to the groundwater.
The engineered cap at Site 4 incorporates the appropriate substantive requirements of federal
and State ARARs. Monitoring of groundwater (under the established Base groundwater
monitoring program) and landfill gases will be conducted. The integrity of the engineered
cap will be preserved through proper construction and maintenance. A summary of ARARs
are presented in Tables 2.42 and 2.43.
...
The selected remedy, when complete, will also satisfy the DLM TBC, since the chemicals
present at Site 4 do not pose an appreciable risk to the groundwater. Manganese and
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exceeded the limits as determined by DLM; however, the manganese concentration is most
.likely within the range of background concentration.
2.11.2.5 Site 5 - Northeast Perimeter Landfill No.3
The selected remedy, when complete, will satisfy federal and State ARARs and TBCs.
Removal of refuse from the site will eliminate any potential for contaminant migration to the
groundwater. Additionally, excavation and consolidation, in lieu of installation of a cap,
complies with Chapter 15 requirements. A summary of ARARs are presented in Tables 2.42
and 2.43.
The selected remedy, when complete, will also satisfy the DLM TBC, since the chemicals
present at Site 5 do not pose an appreciable risk to the groundwater. Maximum
concentrations of manganese, barium, and vanadium exceeded the limits as determined by
DLM. The concentrations of manganese and barium are most likely within the range of
background concentration. The concentration of vanadium does not constitute a HQ > 1, so
vanadium is not a COPC. Excavation of the refuse and associated soils containing these
constituents will remove them from the pathway to the groundwater.
2. 11.2.6 Site 6 - Firing Range Landfill Sites
The selected remedy, when complete, will satisfy federal and state ARARs and TBCs.
Removal of refuse from the site will eliminate any potential for contaminant migration to the
groundwater. Additionally, excavation and consolidation, in lieu of installation of a cap,
complies with Chapter 15 requirements. A summary of ARARs are presented in Tables 2.42
and 2.43.
The selected remedy, when complete, will also satisfy the DLM, TBC. Manganese, lead,
and antimony exceeded the limits as determined by DLM. The potential impacts from
manganese include taste and odor considerations and not potential human health
considerations. Antimony WET results were the same order of magnitude as the calculated
soluble designated level as detailed in the DLM guidance.
...
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2.11.3
Cost Effectiveness
2.11.3.1 Site 1 - Runway Overrun Landfill
No-action, which is defined as current site conditions, was the selected remedy for Site 1.
No costs are associated with this remedy.
2. 11.3.2 Site 2 - "8150" Area Landfill
The FFS determined that either Alternative 2.2 or 2.3 is effective in preventing contact with
the landfill contents and complying with regulations governing the closure of landfills.
Alternative 2.2 reduces risk through controlling exposure pathways (Le., vegetative cover),
while Alternative 2.3 eliminates risk at the site by removing the source (Le., excavation and
consolidation). As shown in Section 2.8.7.2, Alternative 2.2 (the selected remedy) is less
costly than Alternative 2.3.
2.11.3.3 Site 3 - Northeast Perimeter Landfill No.1
The FFS determined that either Alternative 3.2 or 3.3 is effective in preventing contact with
the landfill contents and complying with regulations governing the closure of landfills.
Alternative 3.2 reduces risk through controlling exposure pathways (i.e., engineered cap),
while Alternative 3.3 eliminates risk at the site by removing the source (Le., excavation and
consolidation). As shown in Section 2.8.7.3, Alternative 3.2 (the selected remedy) is less
costly than Alternative 3.3.
2.11.3.4' Site 4 - Northeast Perimeter Landfill No.2
The FFS determined that Alternative 4.2 and 4.3 are equally effective in preventing contact
with the landfill contents and complying with regulations governing the closure of landfills.
Both alternatives reduce risk through controlling exposure pathways (Le., engineered cap).
However, Alternative 4.2 requires construction of flood controls. As shown in Section
2.8.7.4, Alternative 4.2 (the selected remedy) is less costly than Alternative 4.3.
2.11.3.5 Site 5 - Northeast Perimeter Landfill No.3
The FFS determined that either Alternative 5.2 or 5.3 is effective in preventing contact with
the landfill contents and complying with regulations governing the closure of landfIlls.
Alternative 5.2 eliminates risk at the site by removing the source (Le., excavation and
consolidation), while Alternative 5.3 reduces risk through controllin~exposure pathways
(Le., engineered cap). Additionally, it is necessary to excavate and consolidate a portion of
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the landfill that occupies an intermittent stream. As shown in Section 2.8.7.5, Alternative
5.2 (the selected remedy) is less costly than Alternative 5.3.
2. 11.3.6 Site 6 - Firing Range Landfill Sites
The FFS determined that either Alternative 6.2 or 6.3 is effective in preventing contact with
the landfill contents and complying with regulations governing the closure of landfills.
Alternative 6.2 reduces risk through controlling exposure pathways (i.e., vegetative covers),
while Alternative 6.3 eliminates risk at the site by removing the source (i.e., excavation and
consolidation) Alternative 6.3 (the selected remedy) was estimated in the FFS to be more
costly than Alternative 6.2 but cost savings are expected at Site 4 due to consolidation.
2.11.4
Utilization of Permanent Solutions and Alternative Treatment (or
Resource Recovery) Technologies to the Maximum Extent Practicable
The selected remedies at the Landfill au Sites utilize permanent solutions to the maximum
extent practicable. The selected remedy for Site 1 is the no-action alternative, since no
refuse or contamination exists there is no risk. The selected remedy for Sites 2, 3, and 4 is
the containment remedy (i.e., vegetative cover or engineered cap). The selected remedy for
Sites 5 and 6 is excavation, transportation to, and consolidation of the refuse at the
consolidation site (i.e., Site 4). These remedies were chosen because no onsite hot spots
exist that represent major sources of contamination, and no unacceptable risk exists from the
landfills in their current state. These characteristics excluded remedies in which
contaminants could be excavated and treated in a cost-effective manner.
2. 11.5 Preference for Treatment as a Principal Element
Treatment of the principal threats of the sites was not found to be practicable. Therefore,
the selected remedies do not satisfy the statutory preference for treatment as a principal
element of the remedies. Remedies in which contaminants could be excavated and treated in
a cost-effective manner are precluded because no onsite "hot spots" exist that represent major
sources of contamination, and no unacceptable risk exists from the landfills in their current
state,
...
RUI2-94/ES/1260001.A WS
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2. 12 References
Aero Vironment
1987
Aero Vironment
1988
CH2M-Hill Inc.
1982
CVRWCQB 1989
CVRWQCB 1990
CVRWQCB 1991
CVRWQCB 1993
RU12-94/ES11260001.A WS
"Installation Restoration Program Phase II, Stage 2 Final Report,
September 1985 to June 1987, Volumes 1 and 2," Prepared by
Aero Vironment Inc., Monrovia, California.
"Installation Restoration Program Phase II, Stage 3 Final Report,
July 1986 to March 1987, Volumes 1 and 2," Prepared by
AeroVironment Inc., Monrovia, California.
"Installation Restoration Program Records Search for Mather Air
Force Base, California, Phase I, June 1982," Contract No.
F0863780-GOO 1 0-00 13, Gainesville, Florida.
"The Designated Level Methodology for Waste Characterization and
Cleanup Level Determination," California Regional Water Quality
Control Board, Central Valley Region Staff Report~ October 1986
(Updated June 1989).
"The Water Control Plan (Basin Plan) for the Central Valley Regional
Water Quality Control Board (Region 5): The Sacramento River Basin
(Basin 5A), The Sacramento-San Joaquin Delta Basin (Basin 5B), and
The San Joaquin River Basin (Basin 5C), Second Edition, March
1990," California Regional Water Quality Control Board - Central
Valley Region, Sacramento, California.
"A Compilation of Water Quality Goals," Staff Report of the California
Regional Water Quality Control Board, Central Valley Region,
Prepared by Jon B. Marshack, September 1991.
"A Compilation of Water Quality Goals," Staff Report of the California
Regional Water Quality Control Board, Central Valley Region,
Prepared by Jon B. Marshack, May 1993.
...
2-163
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EA 1990a
EA 1990b
EA 1990c
EP A 1987
EPA 1988
EPA 1989a
EPA 1989b
EPA 1989c
RU12-94/ES/1260001.A WS
"Quarterly Ground Water Sampling at Mather Air Force Base, May,
June 1990," Prepared by EA Engineering, Science and Technology
Corporation, Lafayette, California.
"Quarterly Ground Water Sampling at Mather Air Force Base, August
1990," Prepared by EA Engineering, Science and Technology
Corporation, Lafayette, California.
"Quarterly Ground Water Sampling at Mather Air Force Base,
November, December 1990," Prepared by EA Engineering, Science
and Technology Corporation, Lafayette, California.
"Data Quality Objectives for Remedial Response Activities:
Development Process, March 1987," EPA/540/G-87/oo3, U.S.
Environmental Protection Agency, Washington, D.C.
"CERCLA Compliance with Other Laws Manual: Interim Final,
August 1988, tI EPA/540/G-89/oo6, U.S. Environmental Protection
Agency, Washington, D.C.
"Interim Final Guidance On Preparing Superfund Decision Documents:
The Proposed Plan, The Record of Decision, Explanation of Significant
Differences, The Record of Decision Amendment, June 1989, tI
OSWER Directive 9355.3-02, Office of Emergency and Remedial
Response, U.S. Environmental Protection Agency, Washington, D.C.
"Risk Assessment Guidance for Superfund, Volume I, Human Health
Evaluation Manual, Interim Final, December, 1989," EPA/540/1-
89/002, U.S.. Environmental Protection Agency, Washington, D.C.
"CERCLA Compliance with Other Laws Manual, Part II: Clean Air
Act and Other Environmental Statues and State Requirements, tI U.S.
Environmental Protection Agency, EPA/540/G-89/009, Washington,
D.C., August 1989. ..
2-164
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EPA 1991
EPA 1992
Executive Order
11990
FEMA 1989
IT 1988a
IT 1988b
IT 1990a
IT 1990b
IT 1993a
RU12-94/ES/1260001.A WS
"Health Effects Assessment Summary Tables; Annual FY-1991, II
January 1991.
"Integrated Risk Information System (IRIS)," February 1992.
"Protection of Wetlands," Federal Register, Volume 42, page 26961
and Code of Federal Regulations, Title 3.
"Federal Emergency Management Agency Floodplain Insurance Map
for Rancho Cordova, California," Federal Emergency Management
Agency, 1989.
"Well Redevelopment and Sampling Plan for Mather Air Force Base,
California, II Prepared by IT Corporation for HAZWRAP, July 1988.
"U.S. Air Force Installation Restoration Program, Phase IV-A,
Activities for Mather Air Force Base, California, Landfill Testing
Report fOr Eighty Sites at Mather Air Force Base, California, II
Prepared by IT Corporation for HAZWRAP, January 6, 1988.
"U.S. Air Force Installation Restoration Program, RIlFS Activities for
Mather Air Force Base, California, Final Site Inspection Report,
August 1990," Prepared by IT Corporation for HAZWRAP.
"Sampling and Analysis Report for Site Monitor Wells October!
November 1988, Mather Air Force Base, California," Prepared by IT
Corporation for HAZWRAP.
"U.S. Air Force Installation Restoration Program, Quarterly
Groundwater Monitoring Report, Fourth Quarter 1992, Mather Air
Force Base, California, February 1993," Prepared by IT Corporation
for Battelle Environmental Management Operations (EMO).
....
2-165
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IT 1993b
IT 1993c
IT 1993d
IT 1993e
Marcus, W.L.
1986
Rome 1985
SWRCB 1988a
SWRCB 1988b
RU12-94/ES/1260001.A WS
"U.S. Air Force Installation Restoration Program, Quanerly
Groundwater Monitoring Report, First Quarter 1993, Mather Air Force
Base, California, June 1993," Prepared by IT Corporation for Battelle
Environmental Management Operations (EMO).
"U.S. Air Force Installation Restoration Program, Final Remedial
Investigation for Group 2 Sites, Mather Air Force Base, California, "
Prepared by IT Corporation for Environmental Management
Operations, April 1993.
"U.S. Air Force Installation Restoration Program, Final Solid Waste
Assessment Test Report for Mather Air Force Base, California,"
Prepared by IT Corporation for Environmental Management
Operations, March 1993.
"U.S. Air Force Installation Restoration Program, Final Landfill
Operable Unit Focused Feasibility Study for Mather Air Force Base,
California," Prepared by IT Corporation for Environmental
Management Operations, October 1993.
"Lead Health Effects in Drinking Water," Toxicology and Industrial
Health, Volume 4, pp. 363 - 407.
"Water Quality for Agriculture," Food and Agriculture Organization of
the United Nations - Irrigation Drainage Paper No. 29, Rev 1.
"Technical Guidance Manual, Solid Waste Water Quality Assessment
Test (SW AT) Proposals and Reports," State Water Resources Control
Board, Solid Waste Disposal Program, Hydrogeology Section, Land
Disposal Branch, Division of Water Quality.
"Sources of Drinking Water Policy," State Water Resources Control
Board, Resolution No. 88-63, 1988.
...
2-166
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SWRCB 1991
SWRCB 1992
14 CCR, Division
3, Chapter 3,
Article 7.5
14 CCR, Division
3, Chapter 3,
Article 7.6
14 CCR, Division
,., "'L__....-- ""
J, \....Ili:1VLCl J,
Article 7.8
14 CCR
1600
22 CCR 64444.5
22 CCR 64435 -
64445
22 CCR
64473
22 CCR
12703 - 12711
RUI2-941ES1l260001.A WS
"California Inland Surface Waters Plan: Water Quality Control Plan for
Inland Surface Waters of California, It 1991, California State Water
Resources Control Board, Sacramento, California.
"California State Water Resources Control Board ARARs Under
CERCLA," California State Water Resources Control Board,
Sacramento, California.
California Code of Regulations, Title 14, Division 7, Chapter 3,
Article 7.5
California Code of Regulations, Title 14, Division 7, Chapter 3,
Article 7.6
California Code of Regulations, Title 14, Division 7, Chapter 3,
Article 7.8
California Code of Regulations, Title 14, Section 1600
"Maximum Contaminant Levels," California Code of Regulations,
Title 22, Section 64444.5.
California Code of Regulations, Title 22, Sections 64435 -
664445.
California Code of Regulations, Title 22, Section 64473.
California Code 'of Regulations, Title 22, Sections 12703-12711.
...
2-167
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23 CCR, Division
3, Chapter 15
Article 5
23 CCR, Division
3, Chapter 15
Article 8
33 USC
Section 1344
40 CFR Part 141
40 CFR Part 143
40 CFR Part 230
California Code of Regulations, Title 23, Division 3, Chapter 15,
Article 5.
California Code of Regulations, Title 23, Division 3, Chapter 15,
Article 8.
"Federal Water Pollution Control Act as amended by the Clean
Water Act of 1977," Title 33 United States Code, Section 1344.
Code of Federal Regulations, Title 40, Part 141, U.S. Environmental
Protection Agency, Government Printing Office, Washington, D.C.
Code of Federal Regulations, Title 40, Part 143, U.S. Environmental
Protection Agency, Government Printing Office, Washington, D.C.
Code of Federal Regulations, Title 40, Part 230, Section 404, U.S.
Environmental Protection Agency, Government Printing Office,
Washington, D.C.
40 CFR Part 258.60 Code of Federal Regulations, Title 40, Parts 258.60 - 258.61,
- 258.61 U.S. Environmental Protection Agency, Government Printing Office,
Washington, D.C.
40 CFR Part 260
- 264
40 CFR Part 261
40 CFR Part 265
RU12-94/ES/126000I.A WS
Code of Federal Regulations, Title 40, Parts 260 - 264, U.S.
Environmental Protection Agency, Government Printing Office,
Washington, D.C.
Code of Federal Regulations, Title 40, Part 261, U.S. Environmental
Protection Agency, Government Printing Office, Washington, D.C.
Code of Federal Regulations, Title 40, Part 265, U.S. Environmental
Protection Agency, Government Printing Office, Washington, D.C.
2-168
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40 CFR Part 300
42 USC
Section 9621 (d)
53 FR 53194
55 FR 8666
55 FR 30798
-30884
58 FR 8658
- 8685
RUI2-94/ES/1260001.A WS
"National Oil and Hazardous Substances Pollution Contingency Plan,"
Code of Federal Regulations, Title 40, Part 300, u.s. Environmental
Protection Agency, Government Printing Office, Washington, D.C.
"Comprehensive Environmental Response, Compensation, and
Liability Act of 1980 as amended by the Superfund Amendments and
Reauthorization Act of 1986," Title 42 United States Code, Section
9621(d).
"Federal Register," Volume 53, December 21, 1988, page 51394 et
~, EPA's Preamble to the Proposed Rule of the "National Oil and
Hazardous Substances Pollution Contingency Plan," 40 CFR Part 300,
u.s. Environmental Protection Agency, Government Printing Office,
Washington D.C.
"Federal Register," Volume 55, March 8, 1990, page 8666 et seq.,
EPA's Preamble to the Final Rule of the "National Oil and Hazardous
Substances Pollution Contingency Plan," 40 CFR Part 300, u.S.
Environmental Protection Agency, Government Printing Office,
Washington D.C.
"Federal Register," Volume 55, July 27, 1990, pages 30798 - 30884,
EPA's Preamble and Proposed Rule for "Corrective Action for Solid
Waste Management Units (SWMUs) at Hazardous Waste Management
Facilities," 40 CPR Parts 264, 265, 270, and 271, U.S. Environmental
Protection Agency, Government Printing Office, Washington, D.C.
"Federal Register," Volume 58, February 16, 1993, page 8658 - 8685,
Preamble and Final Rule for "Corrective Action Management
Units and Temporary Units; Corrective Action Provisions under
Subtitle C," 40 CPR Parts 260, 264, 265, 268, 270, and 271,
U.S. Environmental Protection Agency, Government Printing
Office, Washington, D.C.
...
2-169
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3.0 Responsiveness Summary
The public comment period for the Proposed Plan for the Landfill Operable Unit at Mather
AFB, began on February 1, 1994, and ended on March 3, 1994. A public meeting was held
on the evening of February 15, at which the Landfill Proposed Plan was summarized, and
questions and public comments solicited. The transcript from the public meeting is included
in the Administrative Record. . The public asked 3 questions and made two comments on the
Landf1l1 Proposed Plan at the public meeting; these are recorded in the transcript and
repeated below. The comment by the County of Sacramento was presented verbally and also
submitted in writing. The written comment from the County of Sacramento is also included
in the Administrative record. No other comments were received during the public comment
period. Questions as well as comments are addressed in this responsiveness summary.
1. Question #1, from Mr. Coughran, on the presence of intermittent streams at sites 5 and 6
(pp. 35-40 of transcript):
Excerpt from public meeting transcript, page 35:
13
MR. COUGHRAN: I'm a little confused by this
14 document.
15
The description of the sites, Site 6 cites an
16 intermittent stream. Site 5 is not. But in the discussion
17 of the alternatives, Alternative 5.3 refers to an
18 intermittent stream. And then the discussion of the
19 alternatives for Site 6 there's no reference to the stream.
20
So I'm confused about which site the stream is on
RU12-94/ESf1260001.AWS
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21 or are there two or --
22
DR. SMI11I: There is a stream at 5, yes, and there
23 is a stream at 6 also. And the stream at 6 goes right
24 between the north and south landfills. The stream is down
25 at the lowest part and you come up and over here. 50 the
Excerpt from public meeting transcript, page 36:
1 two landfills are over here. They are not in the stream.
2 The stream actually goes through them, but the landfills
3 themselves are not.
4
MR. COUGHRAN: The stream does not go through the
5 landfills?
6
DR. SMITII: No. The landfills are to the side on
7 6.
8
Our contractor here has something. You want to
9 say something, Bryant?
10
MR. KROUTCR: Sure. My name is Bryant Kroutch and
11 I'm with IT Corporation, as an environmental consultant to
12 the Air Force.
RUI2-94/ES/126000l.AWS .
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13
To help answer your question and clear up the
14 discrepancy about the streams and where exactly they exist
15 and what impacts they mayor may not have.
16
This is very quick schematic that we used in a
17 previous life or a previous presentation of Site 6, which
18 again is down in that southeastern comer of the base.
19
And you can see they refer to the northern lobe of
20 the contamination and the southern lobes of contamination or
21 landfill material.
22
Here is the intermittent stream channel that flows
23 between them.
24
The reason why this intermittent stream channel is
25 not really addressed during the remedial alternatives is
Excerpt from public meeting transcript, page 37:
1 that they have done the calculations to show the extreme
2 latitudes of the hundred-year floods or exactly during a
3
lOO-year storm event how much of the surrounding area would
4 be inundated with the floodwaters. Those floodwaters do not
R.LJ12-94/ES/1260001.A WS
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5 impact either the north or the southern lobe at Site 6.
6
And because the fact that there are no impactS
7 from the lOO-year flood engineering controls to circumvent
8 any floodwater hitting the landfill were not necessary and a
9 moot point.
10
MR. COUGHRAN: That's fine. I have no problem
11 with that.
12
But the document implies that in the one case that
13 there is a intermittent stream there that apparently is of
14 some significance because it's mentioned and it's not
15 mentioned in the proposed solution.
16
I'm just suggesting that the document itself,
17 okay, appears to have an inconsistency in it.
18
MR. KROUTCH: What I'm hoping to do here or
19 provide solutions to those inconsistencies so that it's
20 clear in your mind for you at this meeting today.
21
And here's a schematic of Site 5 and I can show
22 you very quickly there is essentially an intermittent stream
RU12-94/ES/1260001.A ws
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23 channel that's dry 11 and a half months out of the year,
24 essentially, that runs down through this area down in
25 through here.
Excerpt from public meeting transcript, page 38:
1
And the reason why it's necessary to be evaluated
2 in the remedial alternatives evaluation is because again
3 those hundred-year storm waters show that this little stream
4 actually has some water in it during that storm event and
5 because this intermittent stream flows or at least goes
6 across an area that contains landfill refuse, okay, remedial
7 alternatives had to be developed to take the potential for
8 that 100-year storm into account.
9
. And the two alternatives were to excavate the
10 portion of refuse that was occupied in this intermittent
11 stream channel that could potentially be flooded and get it
12 out of there and put it back with refuse that would not be
13 inundated by floodwaters, or simply excavate all of it at
14 Site 5 and take it to the consolidation site at Site 4.
RU12-94/ES/1260001.A WS
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15
In either scenario the intermittent stream channel
16 no longer contains refuse.
17
MR. COUGHRAN: I understand.
18
But I don't think you understand my point.
19
MR. KROUTCH: I think I do and I can't speak for
20 that document without having it here. It very well may have
21 an inconsistency. I have to look at it.
22
MODERATOR WHITTEN: I think what you see is an
23 inconsistency is the reason the stream channel was mentioned
24 in Site 6 is because there are two landfills that are
25 physically separated by this stream. The stream doesn't
Excerpt from public meeting transcript, page 39:
1 have anything to do with the remedial action.
2
So, yes, it's a physical geological ponion of the
3 site but that stream does not affect what we do as a
4 remedial action because both of these landfills are actually
5 up on a little hill. You got a hill here and a hill here
6 with a stream going between them.
RUI2-94fES/126000I.A WS
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7
$0 no matter what the stream does it doesn't
8 impact the site.
9
MR. COUGHRAN: I'm not suggesting it does. I'm
10 simply suggesting that the lay reader like myself who reads
11 this document doesn't see that, all of this .background
12 information.
13
MODERATOR WHITIEN: I think your point is well
14 taken. You see a stream line once, you don't see it
15 another, there maybe isn't enough background.
16
One of the things that I'll put in a plug now for
17 the RAB, the Restoration Advisory Board, there are
18 bookshelves of documents backing up the action.
19
MR. COUGHRAN: I'm sure.
20
MODERATOR WHITTEN: And members of the RAB are
21 more than welcome to come in and investigate those.
22
This is a summary. In a summary sometimes you're
23 going to maybe leave out details and maybe make an error of
24 omission and if it's misled you here that's probably an
RU12-94/ES/1260001.A WS
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25 error or omission.
Excerpt from public meeting transcript, page 40:
1
MR. COUGHRAN: It doesn't mislead me, it just
2 raised a question in my mind and I assumed that it might
3 raise the same question in somebody else's mind. .
4
MODERATOR WHITTEN: Yes.
5
MR. KROUTCH: Is that the reference on page 4,
6 sir, that you're giving of the intermittent stream channel?
7
MR. COUGHRAN: Right.
8
MR. KROUTCH: That is a geographic reference to
9 allow people to understand that there is northern lobe and a
10 southern lobe and I can see --
11
MR. COUGHRAN: I have no problem with that. I'm
12 just suggesting that in the description of Site 5 it might
13 be well to mention the fact that there is a stream there
14 since it's addressed in the alternative. Okay.
15
MR. HUGHES: I will propose that we include that
16 in the Record of Decision to reflect your comment and make
RUI2-94/ES/1260001.A WS
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17 it more clear in the final document.
18
MR. COUGHRAN: That's all I'm suggesting.
19
MODERATOR WHfITEN: And it will be.
Air Force ResDonse to auestion number 1: There are intermittent streams at both landfill
sites 5 and 6. The stream channel at Site 5 passes over buried refuse, while the stream
channel at Site 6 passes between the two refuse burial areas. The text of the Record of
Decision will clarify that intermittent streams exist at both sites.
2. Question #2, from Mr. Coughran, on why fencing is needed if the remedial control
technologies are effective (pp. 40-43 of transcript):
Excerpt from public meeting transcript, page 40:
20
MR. COUGHRAN: And I had one other question.
21
Under the proposed actions for Sites 2, 3, 4 and 6
22 the statement is used that says controlled technologies,
23 which is passive gas vents, fencing and land use
24 restrictions would be imposed.
25
And those are either caps or you have the
Excerpt from public meeting transcript, page 41:
1 vegetative cover and I think the difference is kind of
2 academic as far as I'm concerned.
3
I assume from the fact that hypothetical future
RU12-94/ES/1260001.A WS
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4 uses are considered that we don't really know what the
5 future uses of the sites are going to be, which makes me
6 wonder why if the controls are effective we're going to put
7 a fence around it.
8
DR. SMI1H: Okay. It is basically consistent.
9
For example, if we go to Landfill 6 why did we put
10 a fence around it? It's passive recreation. Okay.
11
If you want to build a golf course there, which I
12 think the County is planning on, that is passive recreation.
13 You have limited access to a golf course.
14
John Q. Bagadonuts cannot bring his dirt bike on
15 there and tear up your cap.
16
Well, the fence is until it is fixed, and at this
17 stage we don't know.
18
But let us say you come in, whoever has this, they
19 come in and say we want to build a golf course. You're
20 going to put a fence around that golf course, you're going
21 to have limited access. This fence around the landfill is
RU12-94/ESfl260001.A ws
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22 no longer needed unless there is a health risk. Then we
23 have other problems.
24
But basically that fence at this stage of the game
25 is to tell you you want controlled access even if it is
Excerpt from public meeting transcript, page 42:
1 passive recreation and until you tell us specifically what
2 it is, that's why the fence there. That is not concrete.
3 That's just what we're proposing.
4
Now, if you come in and say, oh, God, we're going
5 to build a golf course, then we don't need that fence around
6 the landfill or you can control it. We just want to keep
7 dirt bike -- because these caps are to keep the water from
8 getting down and taking any contaminant that might be there
9 to there.
10
If you tear up the cap, why put it on there? And
11 this is what it is, this is part of the cap protection.
12
MR. COUGHRAN: Makes sense to me.
13
I would suggest --
RU12-94/ES/1260001.A WS
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14
DR. SMITH: If you put a parking lot there that
15 would protect it.
16
MR. COUGHRAN: In your document you indicate that
17 this is some kind of an interim solution pending a decision
18 about how the property is going to be used or something.
19
DR. SMITH: All of the remedial actions are
20 usually that way until it is fIxed exactly what it's going
21 to be there. We--
22
MR. COUGHRAN: But this document doesn't say that,
. 23 is what I'm saying.
24
DR. SMITH: We've probably fallen short on that.
25
MR. COUGHRAN: I read this document and it sounds
Excerpt from public meeting transcript, page 43:
1 to me -- someone less charitable than I could say that what
2 you're talking about doing is throw some dirt and some weed
3 seed on it and putting barbed wire around it and say the
4 problem is gone away. And I don't think that's what you're
5 saying.
RU12-941ES/1260001.A WS
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6
DR. SMITH: No. You're right.
7
MR. COUGHRAN: But the impression is we put a
8 fence around it so everything is okay.
9
DR. SMITH: Okay.
Air Force reSDonse to ouest ion number 2: The remedial alternatives that consist of
capping protect public health and the environment by constructing vegetative cover(s) or
engineered caps over the landfill refuse, and allowing the venting of gases formed as the
refuse decomposes. The cover will be designed to prevent exposure to the refuse, and to
reduce the amount of rainwater and surface runoff that can come into contact with the
refuse and possibly carry dissolved contaminants down to the groundwater. Fencing will
likely be needed to restrict unauthorized access in order to protect the landfill covers. In
addition, if it is determined that there is an unacceptable health threat associated with
exposure to the vented landfill gases, access will also be restricted to prevent such an
exposure. The actual placement of fences will be determined during the detailed
remedial design, and would likely be based upon more detailed gas dispersion modeling
and risk assessment, and confirmed by air monitoring. The fence will be placed in order
to achieve the least constraints on the use of surrounding land consistent with the
protection of human health and the environment.
The gas dispersion modeling performed as a part of the Focused Feasibility Study
predicts that the landfill gases can be vented without treatment, but there could be a risk
from long-term exposure of gases near the vent locations. The assumptions used in
modeling are conservative; the true distance from each vent over which the gases present
an unacceptable health threat (if any) will only be known after designing and
constructing the landfill caps or covers; and passive gas control systems. When
measurements are made of the actual gases vented from each capped or covered landfill,
a determination of any access restrictions necessary can be made.
3. Question #3, from Mr. Richard Anders, on whether Site 5 is being consolidated
within its own boundaries or with another site (p. 43 of transcript):
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Excerpt from public meeting transcript, page 43:
11
MR. ANDERS: Richard Anders.
12
Site 5, your alternative is excavation and
13 consolidation. Is that you're going to excavate at the end
14 where the 100-year stream is and consolidate it at the other
15 end where it is or be consolidated with some other site?
16
DR. SMITH: Actually our action we're taking all
17 of 5 out and that's going to 4, because it's such a small
18 amount there that if you bring in your heavy equipment to do
19 all of this, to do this little bit, the cost to do the rest
20 of it is basically insignificant. The cost of -- some of
21 this equipment is very expensive, the earth movers. Once
22 it's there, the operators are there you might as well just
23 finish the whole job.
24
Obviously the best remedial thing you could do is
25 get everything out so everything is pristine, but this is a
Excerpt from public meeting transcript page 44:
1 real world and a lot of times we can't.
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Air Force reSDonse to auestion number 3: Alternative 5.2 consists of removing all the
refuse at Site 5 and consolidating it with the Site 4 landfill. This is the alternative
proposed in the Proposed Plan and presented in the public meeting on February 15,
1994. Alternative 5.3 consists of excavating ponions of Site 5 subject to flooding by the
100-year storm event, and consolidating this material in other ponions of Site 5.
Alternative 5.2 has been selected in this Record of Decision.
4. Comment #1, from the County of Sacramento, presented by Mr. Randall Yim,
opposing the proposed action for Site 6. The comment is repeated below as it appears
on pages 44-53 of the public meeting transcript, with additions from the written comment
insened in brackets. The written comment is included as an attachment to this
responsIveness summary.
Excerpt from public meeting transcript, page 44:
4
MR. YIM: We have extensive public testimony on
5 behalf of the County.
6
My name is Randall Yim. I'm an independent
7 environmental counsel for the County of Sacramento,
8 providing this testimony on behalf of the County of
9 Sacramento.
10
We're also providing a copy of our testimony in
11 writing for purposes of this forum, so that we may receive
12 written responses to the testimony that's being provided
13 tonight. So let me summarize it briefly for the people that
14 are here.
R1.J12-94/ES/1260001.AWS
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15
The County of Sacramento is the single designated
16 local reuse entity for Mather.
17
The County objects to the Air Force's proposed
18 remedial alternative for Landfill Site No.6, which proposes
19 that the landfill be capped [with a vegetative cover,] and fenced in place, passively
20 vented for hazardous landfill gases [emissions].
21
As currently modeled by the Air Force the fence
22 that would encircle that landfill would have a radius of
23 approximately 420 feet, be [extend] in excess of 4300 lineal feet, be
24 eight feet high in chain link with one access point. [This would be security fence,
with only one access allowed.]
25
The passive gas venting stack is modeled to reduce
Excerpt from public meeting transcript, page 45:
1 the health risk to acceptable limits to be about 25 feet
2 high.
3
A buffer zone must be created around any passive
4 gas venting stacks to comply with the air dispersion models
5 to mitigate health risks created by the Air Resources Board,
6 and primarily to mitigate the impacts of vinyl chloride or
RU 1 2-94/ES/l 26000 1 .A WS
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7 benzene, known carcinogens [as potential health threats] that may be generated in
this
8 landfill. The threat may extend beyond the boundaries of
9 the Mather Air Force Base property.
10
The County, as I said, objects to this particular
11 proposed remedy and instead insists that the Landfill No.6
12 be excavated and consolidated with existing landfills on
13 base.
14
And it's only in this way that we believe that
15 President Clinton's five-point plan for productive reuse of
16 [closing] military bases be implemented.
17
And in addition it's only by selection of the
18 excavation remedy do we believe that the Air Force complies
19 with the Department of Defense policy articulated in
20 testimony provided before the Senate's Armed Services
21 Committee on May 20, 1993 from Deputy Undersecretary of
22 Defense for Environmental Security, Ms. Sherry Wasserman-
23 Goodman, who stated, quote, "that one of the most important
24 changes we can make to accelerate cleanup is to match future
RU12-94/ES/1260001.A WS
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25 land use plans to cleanup standards."
Excerpt from public meeting transcript, page 46:
1
That's the bulk of our concerns that we have
2 raised in previous correspondence provided to the Air Force
3 through the Department of Toxic Substances Control,
4 principally our correspondence dated November 30th, 1993,
5 which is incorporated into our written version of this
6 public testimony.
7
And to review briefly, to summarize our
8 objections, we do not believe that the Air Force has
9 adequately considered several of the evaluation criteria
10 mandated by U.S. EPA in evaluating remedies in CERCLA or
11 Superfund sites, of which Mather is.
12
First, the selected remedy in comparison to the
13 excavation alternative does not enhance overall protection
14 of human health and the environment.
15
Secondly, the selected remedy does not ensure
16 long-term effectiveness and permanence.
RUI2-94/ES/126000I.A WS
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17
Third, the selected remedy does nothing to reduce
18 toxicity, mobility and volume of the problem.
19
Fourth, we believe and dispute the Air Force
20 figures that the cost of excavation, we believe, compares
21 very favorably to the cost of capping and fencing in place.
22
Indeed, the Integrated Waste Management Board, a
23 California agency, in its November 15th correspondence to
24 DTSC, estimates that the present wonh cost, if you reduce
25 to present dollars, 1994 dollars, the cost of capping and
Excerpt from public meeting transcript, page 47:
1 fencing with the long-term monitoring that would be
2 required, even without considering the loss of the value of
3 property or the loss of the utility of the property by the
4 restricted access, would be either equivalent to or even
5 less than the cost of excavation and consolidation of the
6 property.
7
. In addition the Air Force has failed to consider
8 the hidden costs by the selection of this remedy. It shifts
RU12-94/ES/1260001.A WS
3-19
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9 many of the enforcement, liability concerns, maintenance
10 responsibilities to the County of Sacramento or whatever
11 entity is going to have ownership and control of that
12 particular property.
13
And finally one of the most important criteria
14 that EPA uses in selecting remedies is the community
15 acceptability of a particular remedy.
16
And here Sacramento County as a community does not
17 accept remediation' alternatives which severely restrict
18 productive use of the property, regardless of whether
19 [the County of] Sacramento has ownership of that property or not.
20
A remedial alternative which is selected which
21 . creates the potential for short- and long-term health
22 exposures is also not acceptable.
23
It is not -- the County has already developed a
24 regional land use plan that designates active and passive
25 recreadon for this particular area.
Excerpt from public meeting transcript, page 48:
RU12-94/ES/1260001.AWS .
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1
It is not acceptable to this community to allow
2 the Air Force to select a remedy, particularly of Landfill
3 6, which imposes significant land use restrictions and
4 frustrates that [comprehensive] regional [land use] plan.
5
The Air Force itself has stated in its own policy
6 documents, one entitled "'The United States Air Force
7 Environmental Restoration Program Future Use Considerations
8 in the Cleanup of Air Force Installations," as long ago as
9 October '92 that "We should not as a nation write off parcels
10 of land to restrictive uses..." And that we feel very strongly
11 about in the County of Sacramento.
12
Again, summarizing some of our concerns, we
13 believe that the cost of excavation of Landfill 6 compares
14 very favorably to the cost of capping and fencing when you
15 reduce it to present value and consider the long-term
16 monitoring responsibilities if that landfill was left in
17 place.
18
And that analysis does not take into consideration
RU12-94/ES/1260001.A WS
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19 a loss of productivity of that property nor the increased
20 construction costs that would be incurred by whoever
21 controls that property if they wish to build any structure
22 or make any productive use upon that.
23
The land use restrictions are unacceptable to the
24 County.
25
These land use restrictions are attached to our
Excerpt from public meeting transcript, page 49:
1 testimony and detailed quite a bit. It's about this much of
2 our testimony, our packet, in Title 14 of California's
3 administrative regulations.
4
And these restrictions can be divided into two
5 categories, direct land use restriction and future land use
6 disincentives, such as increased construction costs and
7 maintenance responsibilities.
8
In addition, we believe that the fair market value
9 of the landfill property itself and the surrounding property
10 is substantially reduced as a result of leaving that
RU12-94/ES/1260001.AWS
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11 landfill in place.
12
What we did is summarize some of the land use
13 restrictions in the material that we will be submitting to
14 the Air Force. These include restrictions set out in the
15 regulations which require prior approval of any construction
16 improvements, significant additional construction costs, for
17 example in the setting of a foundation for structures that
18 penetrate into a landfill by the placing of utilities to
19 prevent the migration of landfill gas with a leaching of
20 material into the groundwater of surrounding areas,
21 significant addition of utility construction costs, creation
22 of a 1,OOO-foot buffer zone around the waste holding area
23 such that any structures constructed within that buffer area
24 must meet and contain significant additional gas mitigation
25 measures.
Excerpt from public meeting transcript, page 51:
1
. And we believe that demonstrates that's another
2 reason why the County is opposed to capping and leaving that
RU12-94/ES/1260001.A WS
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3 landfill in place and why U.S. EPA in developing its
4 selection criteria stressed overall protection of human
5 health and the environment, long-term effectiveness and
6 permanence, not an interim solution, and emphasis on
7 reduction of toxicity and mobility.
8
So again we in the County oppose the imposition of
9 arbitrary land use restriction on redevelopment plans when
10 reasonable alternatives exist that do not create such land
11 use restrictions.
12
As a summary, in our testimony we provided a
13 matrix listing some of the possible land uses and possible
14 land use restrictions given the various scenarios that could
15 be created with the capping and fencing in place.
16
And some of the variables would be the nature of
17 the cap, either a vegetative cap or a Chapter 15 cap, a hard
18 cap as people have been talking about, or gas control
19 measures that are either active or passive, more aggressive
20 or less aggressive.
RU12-941ES/1260001.AWS
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21
The types of land uses that we anticipate need to
22 be evaluated and suitability would be. For example, we just
23 listed ten different land uses that can be conceived of for
24 any piece of property, residential low-density, residential
25 high-density, schools, recreation passive, recreation
Excerpt from public meeting transcript, page 52:
1
active. These are not what are being planned, we're listing
2 all of the possible land uses. Commercial high-density,
3 commercial low-density, industrial or manufacturing,
4 roadways or utilities.
5
We believe the consensus among the regulatory
6 agencies in the county is that none of those land uses could
7 be allowed on this property as presently proposed without
8 significant additional mitigation, significant additional
9 construction costs, significant additional measures being
10 taken to mitigate the health impacts, the health risks where
11 the larid use restrictions that would be imposed by leaving
12 that landfill in place.
RL/12-94/ES/1260001.A WS
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13
And let's talk about some of those land use
14 restrictions just in summary.
15
We listed about ten. Controlled access, a
16
1,DOO-foot buffer zone outside the landfill area, prior
17 approval of any construction, increased construction costs,
18 special utility worker protection, special foundation
19 requirements, special gas collection systems, special gas
20 monitoring, and annual maintenance because landfills settle
21 and the ground slumps. And the unequal settling, the need
22 to continuing to fill.
23
As we went through our matrix we believe all of
24 the land use restrictions would apply, again without
25 significant mitigation measures.
Excerpt from public meeting transcript, page 53:
1
So you're looking at a situation where uses would
2 be restricted significantly. Land use restrictions would be
3 imposed as a condition of this remedy. That's unacceptable
4 to the County of Sacramento. We think that's unacceptable
RU12-94/ES/1260001.AWS.
3-26
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. -
5 to the nation because we're writing off pieces of property.
6
We'd ask the Air Force to consider our proposals
7 and responding to the Remedial Investigation Feasibility
8 Studies.
Air Force reSDonse to comment number 1: The several points in the commentary will be
addressed individually.
a. Pages 44 - 45 of transcript, concerning fence, stack, and buffer zone:
Excerpt from public meeting transcript, page 44:
21
As currently modeled by the Air Force the fence
22 that would encircle that landfill would have a radius of
23 approximately 420 feet, be in excess of 4300 lineal feet, be
24 eight feet high in chain link with one access point.
25
The passive gas venting stack is modeled to reduce
Excerpt from public meeting transcript, page 45:
1 the health risk to acceptable limits to be about 25 feet
2 high.
3
A buffer zone must be created around any passive
4 gas venting stacks to comply with the air dispersion models
5 to mitigate health risks created by the Air Resources Board,
RU12-94/ES/1260001.A WS
3-27
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6 and primarily to mitigate the impacts of vinyl chloride or
7 benzene, known carcinogens that may be generated in this
8 landfill. The threat may extend beyond the boundaries of
9 the Mather Air Force Base property.
Air Force response to above comment: The gas dispersion modeling performed as a part
of the Focused Feasibility Study predicts that the landfill gases can be vented without
treatment, but there could be a risk from long-term exposure of gases near the vent
locations. The gas control system configuration modeled consisted of a single vent stack.
The assumptions used in modeling are conservative; the true distance from each vent
over which the gases present an unacceptable health threat (if any) will only be known
after designing and constructing the landfill caps or covers, and passive gas control
systems. When measurements are made of the actual gases vented from each capped or
covered landfill, a determination of any access restrictions necessary can be made. The
size, location, and number of access points of a perimeter fence will be based upon more
detailed site-specific modeling conducted. during the remedial design of the gas control
system for landfill Site 6.
b. (p. 46 of transcript) 'The selected remedy in comparison to the excavation
alternative does not enhance overall protection of human health and the environment."
Air Force response to above comment: EP A Guidance for evaluating remedial
alternatives against the nine evaluation criteria is contained in "Conducting Remedial
Investigations/Feasibility Studies for CERClA Municipal landfill Sites," document
EPA/540-P-91/001, dated February 1991. The assessment of overall protection of
human health and the environment is based on evaluating how each of the following
potential threats has been addressed in terms of a composite of factors assessed under
the other evaluation criteria, especially long-term effectiveness and permanence, short-
term effectiveness, and compliance with ARARs. The excavation and consolidation
alternative is considered to have the same long-term effectiveness as a cover in place,
with many of the same short-term concerns of exposure to workers, and exposure to
community of dust, noise, traffic, etc., and also potential community exposure through
volatilization of waste. Both alternatives comply with ARARs. Therefore both the
RUI2-94/ES/126000I.AWS
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vegetative cover and the excavation and consolidation alternatives are considered to be
similarly protective of buman bealth and the environment.
c. (p. 46 of transcript) "Secondly, the selected remedy does not ensure long-term
effectiveness and permanence."
Air Force reSDonse to above comment: The balancing criteria of 'long-term effectiveness
and permanence' is evaluated based on tbe degree of certainty tbat the alternatives will
be successful over the long term. Factors considered include (i) the residual risk posed
by untreated waste remaining at the conclusion of remedial activities, and (ii) tbe
adequacy and reliability of controls necessary to manage any untreated waste or
treatment residuals.
Alternatives 6.2 and 6.3 are judged equally effective and permanent. These tWo
alternatives both include long-term maintenance of tbe landfill cover and monitoring of
landfill gas and groundwater. Alternative 6.1 is judged less permanent because tbe
current cover allows water to pond and infiltrate into tbe refuse, thereby causing a long-
term threat to tbe underlying groundwater.
d.. (p. 46 of transcript) "Third, the selected remedy does nothing to reduce toxicity,
mobility and volume of the problem." .
Air Force reSDonse to above comment: Remedial technologies that satisfy this criteria,
such as incineration, were considered during the development of alternatives in the
Focused Feasibility Study. An alternative incorporating a technology to reduce toxicity,
mobility or volume would be significantly more costly and would present a higher short-
term risk of exposure during handling of tbe landfill contents.
Alternatives 6.1, 6.2, and 6.3 all fail to reduce toxicity, mobility and volume of the landfill
waste. However, alternatives 6.2 and 6.3 significantly restrict infiltration of water into
the waste, thereby reducing the degree of leachate formation and reducing the threat of
future groundwater contamination.
e. Excerpt from public meeting transcript (pp. 46-47):
RU12-94/ES/1260001.A WS
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"Fourth, we believe and dispute the Air Force figures that the cost of excavation, we
believe, compares very favorably to the cost of capping and fencing in place.
Indeed, the Integrated Waste Management Board, a California agency, in its
November 15th correspondence to DTSC, estimates that the present worth cost, if you
reduce to present dollars, 1994 dollars, the cost of capping and fencing with the
long-term monitoring that would be required, even without considering the loss of the
value of property or the loss of the utility of the property by the restricted access, would
be either equivalent to or even less than the cost of excavation and consolidation of the
property.
In addition the Air Force has failed to consider the hidden costs by the selection
of this remedy. It shifts many of the enforcement, liability concerns, maintenance
responsibilities to the County of Sacramento or whatever entity is going to have
ownership and control of that particular property."
From written comment submitted by County of Sacramento:
"As stated by the California Integrated Waste Management board, in its
comments to the proposed remedy selection dated November 15. 1993:
'The [cost comparison between excavation and capping in place] showed
capital costs of the excavation alternative 6.3, exceed the capping alternative 6.2.
However, the long term operation and maintenance of the landfill cap and the
associated environmental monitoring and control systems showed an overall cost
savings of as much as 53% for the excavation alternatives.'
The Waste Board's analysis did not even consider the additional costs of capping
and fencing, both direct and indirect, such as reduced property values, increased
construction costs, increased maintenance and security costs, and threats to human health
and the environment. If the costs for two alternative remedial alternatives are
equivalent, the Air Force is obligated to choose that alternative which best enhances
reuse plans, and does not limit or restrict future land uses."
Air Force resDonse to above comment: The Air Force cost estimates are based upon the
remedial alternatives as described in the Focused Feasibility Study. The cost estimates
presented in the Focused Feasibility Study are estimated for a 3D-year period for each
alternative, and are discounted to present value for purposes of comparison. These cost
RUI2-94/ES/I26000I.A ws
3-30
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estimates show a present value of $1,048,008 for Alternative 6.2, and a present value of
$2,361,121 for Alternative 63.
These cost estimates assume continued Air Force responsibility for long-term operation
and maintenance of the landfill covers, gas control systems, monitoring wells, and all
other components of the remedial action. Therefore there is not a shift of hidden costs
to future land users.
The cost estimates presented in the Integrated Waste Management Board's (IWMB)
letter of November 15, 1994, were based upon different assumptions. Four assumptions
differed in the IWMB analysis. The IWMB estimated costs for Alternative 6.2 with the
addition of an active gas treatment system added. Screening models presented in the
Focused Feasibility Study indicate that an active gas treatment system is not necessary to
control landfill gas emissions. The IWMB estimate for Alternative 6.3 omitted three
components of the alternative developed in the Focused Feasibility Study. These
components are (i) the conduct of a pre-excavation sampling program to estimate the
volume of any soil underlying the waste that might need to be excavated, (ii) the
incorporation of the waste at the consolidation site, and (iii) the cost of replacing
unpaved roads at the excavation site.
The remedial project mangers from the U.S. EPA, California EPA, and the Air Force
have held discussions on comparative cost subsequent to public comment period, in
which they considered the inclusion of a more rigorous landfill gas monitoring program
under Alternative 6.2, and reassessed the cost of consolidating refuse at Si~e 4 under
Alternative 6.3. The Air Force estimated a present value for alternative 6.2 with the
more rigorous monitoring program to be about 1.35 million dollars, and believed a
reasonable estimate for Alternative 6.3 is about 2 million dollars. Additional cost savings
are expected at Site 4 by consolidation of waste therefore making the cost more equal at
Site 6.
f. "And finally one of the most important criteria that EP A uses in selecting remedies is
the community acceptability of a particular remedy. And here Sacramento County as a
community' does not accept remediation alternatives which severely restrict productive
use of the property, regardless of whether Sacramento has ownership of that property or
not. A remedial alternative which is selected which creates the potential for short- and
long-term health exposures is also not acceptable. It is not -- the County has already
RU12-94/ES/1260001.A WS
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-------
developed a regional land use plan that designates active and passive recreation for this particular
area. It is not acceptable to this community to allow the Air Force to select a remedy,
particularly of Landfill 6, which imposes significant land use restrictions and frustrates that
regional plan. The Air Force itself has stated in its own policy documents, one entitled "The
United States Air Force Environmental Restoration Program Future Use Considerations and
Cleanup of Air Force Installations, " as long ago as October '92 that we should not as a nation
write off parcels of land to restrictive uses. And that we feel very strongly about in the County
of Sacramento. "
Air Force response to above comment: The Final Supplemental Record of Decision for the
Disposal and Reuse of Mather AFB, dated November 21, 1994, documents that the Air Force
will offer parcel C, containing landfill Site 6, for negotiated/public sale. At the time of the
public comment meeting on February 15, 1994, the landfill was part of Parcel G, which was to
have been conveyed through the National Park Service to Sacramento County to use as parkland.
Some productive uses of portions of these parcels may need to be restricted. The 5.3
acres containing refuse at Site 6 will have the most severe restriction: a radius estimated to be
no greater than 420 feet radius around a central vent stack may require access restrictions to
limit exposure to landfill gases: and construction on-site within 1000 feet of the la...T1dfills must
incorporate protection against the possible sub-surface migration of landfill gases.
f. "The land use restrictions are unacceptable to the County.
These land use restrictions are attached to our testimony and detailed quite a bit. It's about this
much of our testimony, our packet, in Title 14 of California's administrative regulations. And
these restrictions can be divided into two categories, direct land use restriction and future land
use disincentives, such as increased construction costs and maintenance responsibilities. In
addition, we believe that the fair market value of the landfill property itself and the surrounding
property is substantially reduced as a result of leaving that landfill in place. What we did is
summarize some of the land use restrictions in the material that we will be submitting to the Air
Force. These include restrictions set out in the regulations which require prior approval of any
construction improvements, significant additional construction costs, for example in the setting
of a foundation for structures that penetrate into a landfill by the placing of utilities to prevent
the migration. of landfill gas with a leaching of material into the groundwater of surrounding
areas, significant addition of utility construction costs, creation of a 1,000-foot buffer zone
around the waste holding area such that any structures constructed ...
3-32
-------
within that buffer area must meet and contain significant additional gas mitigation
measures.
And we believe that demonstrates that's another reason why the County is
opposed to capping and leaving that landfill in place and why U.S. EPA in developing its
selection criteria stressed overall protection of human health and the environment,
long-term effectiveness and permanence, not an interim solution, and emphasis on
reduction of toxicity and mobility.
So again we in the County oppose the imposition of arbitrary land use restriction
on redevelopment plans when reasonable alternatives exist that do not create such land
use restrictions.
As a summary, in our testimony we provided a matrix listing some of the possible
land uses and possible land use restrictions given the various scenarios that could be
created with the capping and fencing in place. And some of the variables would be the
nature of the cap, either a vegetative cap or a Chapter 15 cap, a hard cap as people have
been talking about, or gas control measures that are either active or passive, more
aggressive or less aggressive.
The types of land uses that we anticipate need to be evaluated and suitability
would be. For example, we just listed ten different land uses that can be conceived of
for any piece of property, residential low-density, residential high-density, schools,
recreation passive, recreation active. These are not what are being planned, we're listing
all of the possible land uses. Commercial high-density, commercial low-density,
industrial or manufacturing, roadways or utilities.
We believe the consensus among the regulatory agencies in the county is that
none of those land uses could be allowed on this property as presently proposed without
significant additional mitigation, significant additional construction costs, significant
additional measures being taken to mitigate the health impacts, the health risks where
the land use restrictions that would be imposed by leaving that landfill in place.
And let's talk about some of those land use restrictions just in summary.
We listed about ten. Controlled access, a 1,OOO-foot buffer zone outside the
landfill area, p~or approval of any construction, increased construction costs, special
utility worker protection, special foundation requirements, special gas collection systems,
special gas monitoring, and annual maintenance because landfills settle and the ground
slumps. And the unequal settling, the need
to continuing to fill.
As we went through our matrix we believe all of the land use restrictions would
apply, again without significant mitigation measures. So you're looking at a situation
RU12-941ES/126000I.AWS
3-33
-------
where uses would be restricted significantly. Land use restrictions would be imposed as
a condition of this remedy. That's unacceptable to the County of Sacramento. We think
that's unacceptable to the nation because we're writing off pieces of property.
We'd ask the Air Force to consider our proposals and responding to the Remedial
Investigation Feasibility Studies.
Air Force reSDonse to above comment: The implementation of Alternative 6.3 will result
in no long term land use restrictions at Site 6.
4. Comment #2, from Joe Shackelford, (p. 53 of transcript):
Excerpt from public meeting transcript, page 53:
4
MR. SHACKELFORD: I'm Joe Shackelford.
5
I have a comment.
6
The delay of the use of the land and the
7 forfeiture of the government having an income from the land,
8 is that a considering factor that we factored into all these
9 things?
10
For an example, by delaying the landfills for that
11 particular area, would that be profitable if they did a
12 temporary and later redid certain portions for Landfill 6
13 for an example?
14
If this is going to take several years to do and
15 hold up the land itself, maybe it would be more economical
RU12-94/ES/1260001.A WS
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16 for the American people to say we will accept a more logical
17 solution that cost us less money keeping that off the
18 market.
Air Force response comment number 2: The timeframe for implementing alternatives 6.2
(construction of a vegetative cap) and 6.3 (excavation and consolidation) are similar. As
estimated in the Focused Feasibility Study for the Landfill Operable Unit, the cost for
excavation exceeds the cost for capping in place. However, the conveyance and/or sale
of surrounding land need not be held up by the implementation of the remedial actions
at the landfill sites.
All remedial actions selected in the Record of Decision (ROD) are required by law to
be implemented within 15 months of the completion of the Remedial Investigation/
Feasibility Study, considered by the Air Force to be the date the ROD is signed.
RU12-94/ES/126000I.A WS
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APPENDIX A
Administrative Record Index
RU12-94/ES/1260001.A WS
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ADMINISTRATIVE RECORD
MATHER Am FORCE BASE, CALIFORNIA
DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
FILE
NUMBER
Jun 82 Phase I, Records Search Report CH2M Hill 4
04 Oct 82 CRWQCB Letter to AFRCE Transmitting Johnson, William S 5
Comments on Records Search Report California Regional
Water Quality
Control Board
18 Ian 83 Phase IIA, Presurvey Report Engineering-Science 7
Inc.
03 Oct 83 CRWQCB Letter to Base Concurring Pinkos, Thomas R 9
with Phase liB SOW California Regional
Water Quality
Control Board
06 Dec 83 Memorandum of Record, Coordination Korvcinski - Dennis- 10
~ J - - ---I - -------7
Meeting With State Regulatory Agencies Capt
USAF Hosp/SGPB
20 Dec 83 CRWQCB Letter to Base Transmitting Pinkos, Thomas R 11
Summary of 6 Dec 83 Meeting California Regional
Water Quality
Control Board
15 Feb 84 USAF OEHL Letter to MAlCOM Sanders, Dee Ann 12
Transmitting Proposed Modification USAF OEHUCVT
to Phase II SOW
01 Aug 84 CDHS Letter to Base Outlining State Allen, James T 14
Requirements California
Department of Health
Services
17 Aug 84 Minutes of 2 Aug 84 IRP Meeting Slaughter, John T, 15
Col
323 ABG/CC
20 Aug 84 Minutes of 20 Aug 84 TWG Meeting Slal,lghter, John T, 16
Col
323 ABG/CC
A-2
-------
DOC. AUTHOR or FILE
DATE SUBJECT OR TITLE CORP. AUTHOR NUMBER
24 Oct 84 Minutes of 1 Oct 84 TWG Meeting Slaughter, John T, 17
Col
323 ABG/CC
04 Dee 84 EP A Letter to Base Providing Comments Seraydarian, Harry 18
on Phase I and II Documents EP A Region IX
05 Dee 84 Minutes of 26 Oct 84 IRP Meeting Slaughter, John T, 19
Col
323 ABG/CC
Jan 85 Phase II Stage 1, Draft Final Report Roy F. Weston, Inc. 20
10 Feb 85 CDHS Letter to Base Concerning Allen, James T 21
Drilling Technique for Phase II California
Stage 3 Department of Health
Services
18 Apr 85 Minutes of 18 Apr 85 IRP Work Group Bost, Thomas D, 24
LtCol
323 ABG/CC
23 Apr 85 CDHS Letter to Base Providing Karoly, B T 25
Comments on Phase II Stage 2 SOW California
Department of Health
Services
25 Apr 85 EPA Letter to Base Providing Comments Clifford, Jerry 27
on Proposed Phase II Stage 2 SOW EP A Region IX
29 May 85 County Letter to Base Providing Knight, K Kenneth 28
Comments on Draft Phase II Stage 2 Sacramento County
SOW Health Department
21 May 85 CDHS Letter to Base Transmitting Landis, Anthony J 29
Comments on Proposed Phase II, California
Stage 2 SOW Department of Health
Services
...
12 Jul 85 Phase II Stage 2, USAF Hosp/SGPB 32
Confirmation/Quantification SOW
A-3
-------
. DOC. AUTHOR or FILE
DATE SUBJECT OR TITLE CORP. AUTHOR NUMBER
11 Sep 85 Base Letter to MAlCOM Transmitting Curran, James P, 33
Review Comments on Second Draft of Capt
Phase II Stage 1 Report USAF Hosp/SGPB
01 Oct 85 CRWQCB Letter to Base Transmitting Matteoli, Robert J 34
Comments on Draft Phase II Stage 3 California Regional
SOW Water Quality
Control Board
23 Oct 85 EP A Letter to Base Transmitting Clifford, Jerry 35
Comments on Draft Phase II Stage 3 EP A Region IX
SOW
Dee 85 Phase II Stage I, Draft Roy F. Weston, Inc. 36
Confirmation/Quantification Report,
Vol I of II
Dee 85 Phase II Stage 1, Draft Roy F. Weston, Inc. 37
Confirmation/Quantification Report.
Vol II of II
19 Dee 85 CDHS Letter to Base Providing Review Allen, James T 38
Comments on Phase II Stage 3 SOW California
Department of Health
Services
02 Jan 86 Base Letter to CDHS Concerning Johnson, Bruce R, 41
Progression of Phase II Col
323 ABG/CC
06 Feb 86 CRWQCB Letter to Base Transmitting Pinkos, Thomas R 43
Review Comments on Phase II Stage 1 California Regional
Report, Off-Base Monitoring Results, Water Quality
and Monitoring Results on Phase II Control Board
Stage 2 Wells
06 Mar 86 CDHS Letter to Base Transmitting Jones, Jeanine 45
Comments on Phase II Stage I Draft California
Report Department of Health
Se~ices
A-4
-------
DOC. AUTHOR or FILE
DATE SUBJECT OR TITLE CORP. AUTHOR NUMBER
13 Mar 86 EP A Letter to Base Providing Review Clifford, Jerry 46
Comments on Draft Phase II Stage 1 EP A Region IX
Report
26 Mar 86 County Letter to Base Providing Review Knight, K Kenneth 47
Comments on Draft Phase II Stage 1 . Sacramento County
Report Health Department
Jun 86 Phase II Stage 1, Final Roy F. Weston, Inc. 49
Confmnation/Quantification Report,
Vol I of II
Jun 86 Phase II Stage 1, Final Roy F. Weston, Inc. 50
Confirmation/Quantification Report,
Vol II of II, Appendices
Jun 86 Phase II Stage 2, Draft Aerovironment Inc. 51
Confmnation/Quantification Report
19 Jun 86 Base Letter to Assemblyman Providing Johnson, Bruce R, 52
Status of Clean-up Program Col
323 ABG/CC
27 Jun 86 Memorandum for Record Concerning Curran, James P, 54
Technical Advisory Group Meeting Held Capt
25 Jun 86 USAF Hosp/SGPB
25 Jul 86 News Release, "Groundwater Report 323 FfW /P A 55
Released"
01 Aug 86 CRWQCB Letter to Base Transmitting Matteali, Robert J 57
Comments on Phase II Stage I Report California Regional
Water Quality
Control Board
08 Aug 86 CDHS Letter to Base Advising of McLaughlin, 58
Deficiencies of Phase II Stage 3 QAP Charles A.
California
Department of Health
Se~ices
A-5
-------
DOC. AUTHOR or FILE
DATE SUBJECT OR TITLE CORP. AUTHOR NUMBER
05 Feb 87 CRWQCB Letter to Base Providing Matteoli, Robert J 61
Review Comments on Phase II Stage 2 California Regional
Report Water Quality
Control Board
06 Feb 87 MAlCOM Letter to Base Concerning Schiller, Ronald L, 62
State Requirement for Landfill Gas LtCol
Testing HQ A TC/SGPB
10 Feb 87 CDHS Letter to Base Transmitting Wang, David 63
Comments on Draft Phase II Stage 2 California
Report Department of Health
Services
11 Feb 87 . EPA Letter to Base Transmitting Zimpfer, Amy K 64
Comments on Draft Phase II Stage 2 EP A Region IX
Report
17 Feb 87 CDHS Letter to Base Providing K~mlv R T 65
----- --.I 1 - -
Comments on Draft Phase II Stage 2 California
Confirmation/Quantification Report Department of Health
Services
25 Feb 87 CRWQCB Letter to Base Advising of Matteoli, Robert J 67
Requirement to Perform a Solid Waste California Regional
Water Quality Assessment Test Water Quality
Control Board
Mar 87 Phase II Stage 3, Draft Aerovironment Inc. 68
Confirmation/Quantification Report,
Vol. I of II
Mar 87 Phase II Stage 3, Draft Aerovironment Inc. 69
Confumation/Quantification Report,
Vol II of II
21 Apr 87 SCAPCD Letter to Base on Screening Skelton, Eric P 72
Questionnaires for Inactive Solid Waste Sacramento County
Disposal Sites Air Pollution
CoruroI District
A-6
-------
DOC. AUTHOR or FILE
DATE SUBJECT OR TITLE CORP. AUTHOR NUMBER
Iun 87 Phase II Stage 2, Final Aerovironment Inc. 73
Confirmation/Quantification Report,
Vol I of II
Iun 87 Phase II Stage 2, Final Aerovironment Inc. 74
Confirmation/Quantification Report,
Vol II of II
27 Iun 87 Memo for Record on Technical Advisory Curran, James P, 79
Group Meeting Capt
USAF Hosp/SGPB
.
17 Iul 87 Base Letter to County Air Pollution Johnson, Bruce R, 81
Control District on Proposed Gas Col
Testing Plan 323 ABG/CC
12 Aug 87 CDHS Letter to Base on Phase II Karoly, B T 85
Stage 3, Draft Confirmation/Quantification California
Report Department of Health
Services
27 Aug 87 CRWQCB Letter to Base 00 Phase II Matteoli, Robert J 87
Stage 3 Groundwater Investigation Report California Regional
Water Quality
Control Board
28 Aug 87 EP A Letter to Base on Phase II Stage 3 Zimpfer, Amy K 88
Draft Report EP A Region IX
02 Sep 87 Base Hydrogeologist Comments on Phase Shaffer, James D 90
II Stage 3, Second Final Draft Report 323 CES/DEEV
02 Sep 87 CDHS Letter to Base on Phase II Stage Wang, pavid 91
3, Confmnation/Quantification Report California
Department of Health
Services
14 Sep'87 EP A Letter to Base on Phase II Stage 2, Zimpfer, Amy K 92
Final Confirmation/Quantification EPA Region IX
Report ...
18 Sep 87 RIlFS, Technical Proposal, Part A IT Corp. 93
A-7
-------
DOC. AUTHOR or FILE
DATE SUBJECT OR TITLE CORP. AUTHOR NUMBER
15 Oct 87 CRWQCB Letter to Base on Solid Waste Matteoli, Robert J 94
Assessment Test Waiver Denial California Regional
Water Quality
Control Board
22 Dee 87 Minutes of 15 Dee 87 TRC Meeting Kosovac, Don E, 98
Col
323 FTW /EM
Ian 88 Phase II Stage 3, Aerovironment Inc. 99
Confirmation/Quantification Report
06 Ian 88 Phase IV A, Draft Landfill Gas Testing IT Corp. 100
Work Plan
13 Ian 88 County Letter to Contractor Approving Skelton, Eric P 101
Draft Landfill Gas Testing Work Plan Sacramento County
Air Pollution
Control District
27 Ian 88 Contractor Letter to County Providing Bradley, A Allen 102
Copy of Final Landfill Gas Testing IT Corp.
Work Plan
27 Ian 88 Final Landfill Gas Testing Work Plan IT Corp. 103
09 Feb 88 Minutes of 27 Jan 88 Mini TRC Meeting Kosovac, Don E, 104
Col
323 FTW IEM
23 Mar 88 OEHL Letter to Base Providing Response Gibson, 129
to Comments on Phase II Stage 3 Report David P, Jr.
Capt
USAF OEHLlTSS
01 Apr 88 Base News Release, "Groundwater 323 FTW/PA 130
Report Released"
02 Apr 88 Newspaper Article, "Unsafe Toxic Gibson, Steve 131
Levels Found At Mather" Saqpmento Bee
A-8
-------
DOC. AUTHOR or FILE
DATE SUBJECT OR TITLE CORP. AUTHOR NUMBER
11 Apr 88 Declaration for Proof of Publication, Graham, Barbara L 134
Notice of Release of Phase II Stage 3 Sacramento Union
Report and 20 Apr 88 Public Meeting
May 88 Base IRP Newsletter 323 FIW IEM 137
13 May 88 EP A Letter to Base Transmitting Anderson, Iulie 138
Comments on Phase II Stage 3 Final EP A Region IX
Confmnation/Quantification Report
14 Iun 88 MAJCOM Letter to EP A Providing Saenz, 141
Responses to EPA Comments on Phase II Jose L, LtCol
Stage 3 Final Report HQ ATC/DEEV
30 Iun 88 Minutes of 30 Iun 88 TRC Meeting Blank, Richard A, 142
LtCol
323 FIW IEM
Jul 88 Landfill Gas Testing Report for Eight IT Corp. 143
Sites
29 Jul 88 Phase IV A, Well Redevelopment and IT Corp. 144
Sampling Plan
15 Aug 88 CRWQCB Letter to Base Providing Guadagnino, 146
Comments on Well Redevelopment and Philip G
Sampling Plan California Regional Water
Quality Control Board
17 Aug 88 CDHS Letter to Base Wang, David 147
Transmitting Review Comments on California
Revised Well Redevelopment and Department of Health
Sampling Plan, 29 July 88 Services
18 Aug 88 EPA Letter to MAlCOM Transmitting Seid, Raymond 148
Comments on Well Redevelopment and EP A Region IX
Sampling Plan, 29 Jul 88
Sep 88 RIIFS, Draft Work Plan, Vol I of V IT Corp. 149
...
Sep 88 RIIFS, Draft Sampling and Analysis IT Corp. 151
Plan, Vol III of V
A-9
-------
DOC. AUTHOR or FILE
DATE SUBJECT OR TITLE CORP. AUTHOR NUMBER
Sep 88 RIfFS, Draft Quality Assurance Project IT Corp. 152
Plan, Vol IV of V
Sep 88 RIlFS, Draft Health and Safety Plan, IT Corp. 153
Vol V of V
Nov 88 RIlFS, Draft Site Inspection Report IT Corp. 155
30 Nov 88 Minutes of 6 Oct 88 TRC Meeting Blank, Richard A, 156
LtCol
323 FTW IEM
07 Dee 88 CRWQCB Letter to MAlCOM Providing Matteoli, Robert J 157
Comments on Draft RIIFS Work Plan California Regional
Documents Water Quality
Control Board
08 Dee 88 EPA Letter to MAlCOM Transmitting Chesnutt, John D 158
Review Comments on RIIFS Draft Work EP A Region IX
Plans
29 Dee 88 CDHS Letter to MAlCOM Transmitting Wang, David 159
Review Comments on RIfFS Draft Work California
Plans Department of Health
Services
Feb 89 Base IRP Newsletter 323 FTW IEM 160
06 Mar 89 Minutes of 12 Jan 89 TRC Meeting Blank, Richard A, 163
LtCol
323 FTW/EM
26 Apr 89 CDHS Letter to Base Concerning Wang, David 166
Monitoring Well Sampling California
Department of Health
Services
01 May 89 Minutes of 6 Apr 89 TRC Meeting Blank, Richard A, 170
LtCol
323.,.FTW IEM
A-10
-------
DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
FILE
NUMBER
10 Iul 89
Transcript of 10 Jul 89 TRC Meeting
Parks, Nadine J
Peters Shorthand
Reporting Corp.
177
20 Iul 89
Minutes of 10 Jul 89 TRC Meeting
Blank, Richard A,
LtCol
323 F1W/EM
178
Oct 89 RIlFS, Draft Site Inspection Report IT Corp. 187
03 Oct 89 Transcript of 3 Oct 89 TRC Meeting Peters, Ronald J 188
Peters Shorthand
Reporting Corp.
18 Oct 89 CRWQCB Letter to Base Matteali, Robert J 181
Providing Review Comments California Regional
on SWAT Report Water Quality
Control Board
Nov 89 RI/FS, Draft Work Plan for IT Corp. 190
Investigations at Identified Sites, Vol
I of IV
Nov 89 RIlFS, Draft Sampling and Analysis Plan IT Corp. 191
for Investigations at Identified Sites,
Vol II of IV
Nov 89 RI/FS, Draft Quality Assurance Project IT Corp. 192
Plan for Investigations at Identified
Sites, Vol III of IV
Nov 89 RIlFS, Draft Health and Safety Plan for IT Corp. 193
Investigations at Identified Sites, Vol
IV of IV
29 Nov 89 CRWQCB Letter to CDHS Matteoli, Robert J 198
-Providing Review Comments on RI/FS California Regional
Draft Site Inspection Report Water Quality
Control Board
...
A-ll
-------
DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
FILE
NUMBER
30 Nov 89
01 Dee 89
12 Jan 90
Transcript of 30 Nov 89 TRC Meeting
CDHS Letter to Base Providing
Comments on RIfFS Draft Site Inspection
Report
EPA Letter to MAJCOM Transmitting
Review Comments on the Nov 89 RI/FS
Draft Work Plans
. Parks, Nadine J
Peters Shorthand
Reporting Corp.
199
Landis, Anthony J
California
Department of Health
Services
200
Chesnutt, John D
EP A Region IX
202
203
16 Jan 90 CDHS Letter to Base Transmitting
Comments on Nov 89 RI/FS Draft Work
Plans for Identified Sites (Group 2
Sites)
Landis, Anthony J
California
Department of Health
Services
16 Jan 90
30 Jan 90
20 Feb 90
Mar 90
07 Mar 90
Internal CRWQCB Memo Providing
Review Comments on RI/FS Draft
Sampling and Analysis
Plan for Identified Sites
Transcript of 30 Jan 90 TRC Meeting
Sampling and Analysis Report for Site
Monitoring Wells, October/November
1988
Base Newsletter, "IRP
Community Update"
Minutes of 30 Jan 90 TRC Meeting
A-12
Mosbacher,
Michael H
California Regional
Water Quality
Control Board
204
Parks, Nadine J
Peters Shorthand
Reporting Corp.
206
IT Corp.
209
323 FTW/EM
210
Blank, Richard A,
LtCol
323 FTW/EM
212
...
-------
DOC. AUTHOR or FILE
DATE SUBJECT OR TITLE CORP. AUTHOR NUMBER
08 Mar 90 Transcript of 8 Mar 90 TRC Meeting Peters, Ronald J 213
Peters Shorthand
Reporting Corp.
23 Mar 90 Minutes of FF A 8 Mar 90 Project Blank, Richard A, 214
Managers Meeting LtCol
323 FrW/EM
Apr 90 RIlFS, Draft Final Work Plan, Vol I of IT Corp. 215
IV, Group 2 Sites
Apr 90 RIIFS, Draft Final Sampling and IT Corp. 216
Analysis Plan, Vol II of IV,
Group 2 Sites
Apr 90 RIIFS, Draft Final Quality Assurance IT Corp. 217
Project Plan, Vol III of IV, Group 2
Sites
Apr 90 RIlFS, Draft Final Health and Safety IT Corp. 218
Plan, Vol IV of IV, Group 2 Sites
Apr 90 Draft Sampling and Analysis Plan for EA Engineering, 219
Quarterly Groundwater Sampling Science, and
Technology
18 Apr 90 CDHS Letter to Base Concerning Diebert, Donn 221
Recommendation for Stipulated Penalties California
for Group 2 Sites Work Plan Department of Health
Services
25 Apr 90 MAlCOM Letter to Regulators Wentz, George 222
Transmitting Background Data on No HQ A TCIDEEV
Further Action Decision Documents,
LF-Ol, FT-08, FT-09, FT-lO, RW-16,
WP-17, OT-21, OT-22
10 May 90 Transcript of 10 May 90 TRC Meeting McNulty, Bernadette 223
Peters Shorthand
ReRPrting Corp.
A-13
-------
DOC. AUTHOR or FILE
DATE SUBJECT OR TITLE CORP. AUTHOR NUMBER
17 May 90 CDHS Letter to Base Concerning Landis, Anthony J 224
Finalization of RIfFS Draft Final Work California
Plans, Group 2 Sites Department of Health
Services
21 May 90 EP A Letter to Base Concerning RIfFS Chesnutt, John D 225
Draft Final Work Plans, Group 2 Sites EP A Region IX
01 Jun 90 CRWQCB Letter to CDHS Providing Mosbacher, 226
Comments on No Further Action Michael H
Decision Documents, LF-Ol, Ff-08, California Regional
Ff-09, Ff-lO, RW-16, WP-17, Water Quality Control
OT-21, OT-22 Board
20 Jun 90 CDHS Letter to Base Billington, Tracie L 227
Providing Comments on No California
Further Action Decision Documents, Department of Health
LF-Ol, Ff-08, Ff-09, FT-lO, Services
RW-16, WP-17, OT-21, OT-22
22 Jun 90 EP A Letter to Base Providing Comments Chesnutt, John D 228
on No Further Action Decision EP A Region IX
Documents, LF-Ol, Ff-08, Ff-09,
Ff-lO, RW-16, WP-17, OT-21, OT-22
Jul 90 RIIFS, Solid Waste Water Quality IT Corp. 230
Assessment Test, Draft Project Plans
Addendum, Group 2 Sites
25 Jul 90 RIfFS, Quality Assurance Project Plan IT Corp. 248
Addendum
Aug 90 RIIFS, Final Site Inspection Report IT Corp. 253
02 Aug 90 Transcript of 2 Aug 90 TRC Meeting Parks, Nadine J 254
Peters Shorthand
Reporting Corp.
06 Sep 90 Minutes of 2 Aug 90 TRC Meeting Blank, Richard A, 257
LtCol
...
323 FTW/EM
A-14
-------
DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
FILE
NUMBER
19 Sep 90
19 Sep 90
_.- -
23 Oct 90
23 Oct 90
Nov 90
07 Nov 90
09 Nov 90
09 Nov 90
15 Nov 90
CDHS Letter to Base Providing
Comments on RIIFS Solid Waste
Water Quality Assessment Test, Draft
Project Plans Addendum, Group 2 Sites
Wang, David
California
Department of Health
Services
258
259
EPA Letter to Base Providing Comments Chesnutt, John D
on ~ Draf~ Work Pial! Adde~dum, EPA Region IX
Group 2 Sites
County Letter to Base Amending Sewer
Use Permit for Disposal of Groundwater
Well Development Water
Transcript of 23 Oct 90 TRC Meeting
RIfFS, Solid Waste Water Quality
Assessment Test, Draft Final Project
Plans Addendum, Group 2 Sites
CDHS Letter to Base Approving Dual
Completion Groundwater
Monitoring Wells
MAJCOM Letter to EPA
Transmitting No Further Action
Decision Documents and Response
to Regulatory Comments
MAJCOM Letter to CDHS
Transmitting No Further
Action Decision Documents
and Response to Regulatory Comments
Transcript of 15 Nov 90 TRC Meeting
A-15
Del Sarto, Glen
Sacramento County
Department of Public
Works
263
Parks, Nadine J
Peters Shorthand
Reporting Corp.
264
IT Corp.
268
Billington, Tracie L 269
California
Department of Health
Services
Sizemore, Daniel L, 270
LtCol
HQ ATCfDEEV
Sizemore, Daniel L, 271
LtCol
HQ A TCfDEEV
Parks, Nadine J
Peters Shorthand
ReR.0rting Corp.
272
-------
DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
FILE
NUMBER
19 Nov 90
28 Nov 90
29 Nov 90
19 Dec 90
26 Dec 90
Ian 91
Feb 91
15 Feb 91
28 Mar 91
Minutes of 23 Oct 90 TRC Project
Managers Meeting
CDHS Letter to Base Concerning Final
Site Inspection Report and FS Draft
Final Work Plan, AC&W Site
Minutes of 15 Nov 90 TRC Meeting
EP A Letter to Base Providing
Conditional Approval of Draft Final
Project Plans Addendum for Group 2
Sites
CDHS Letter to Base Approving Draft
Final Project Plans Addendum for Group
2 Sites
Routine Groundwater Monitoring Draft
Project Plans: Quality Assurance
Project Plan, and Sampling and Analysis
Plan
Blank, Richard A,
LtCol
323 FTW/EM
274
Wang, David
California
Department of Health
Services
275
Blank, Richard A,
LtCol
323 FTW/EM
276
Chesnutt, John D
EP A Region IX
279
280
Wang, David
California
Department of Health
Services
IT Corp.
282
287
Routine Groundwater Monitoring Project IT Corp.
Plans: Quality Assurance Project Plan,
and Sampling and Analysis Plan
CRWQCB Letter to Base Transmitting
Comments on Draft Final Project Plans
Addendum, Group 2 Sites
Transcript of 28 Mar 91 TRC Meeting
A-16
Mosbacher,
Michael H
California
Department of Health
Services
289
Par~s, Nadine J
Peters Shorthand
Reporting Corp.
296
-------
DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
FILE
NUMBER
15 Apr 91 Minutes of 28 Mar 91 TRC Meeting Blank, Richard A, 299
LtCol
323 ABG/EM
May 91 Quarterly Groundwater Monitoring IT Corp. 301
Report, Mar 1991
01 May 91 CDHS Letter to Base Wang, David 302
Providing Comments on Draft Routine California
Groundwater Monitoring Project Plan Department of Health
Services
15 May 91 EPA Letter to Base Providing Comments Moore, Katherine L 305
on 31 Mar 91 Routine Groundwater EP A Region IX
Monitoring Program Project Plans
23 May 91 CRWQCB Letter to Base Providing Mosbacher, 309
Comments on Routine Groundwatet Michael H
Monitoring Program Project Plans Cali fornia Regional Water
Quality Control Board
29 May 91 EP A Letter to Base Concerning Proposed Moore, Katherine L 310
Schedule of Primary Documents in the EP A Region IX
FFA
18 Jun 91 Minutes of 21 May 91 TRC Meeting Blank, Richard A, 314
LtCol
323 ABG/EM
Iul 91 Quarterly Groundwater Monitoring IT Corp. 317
Report, May 1991
02 Iul 91
EPA Letter to Base Providing Comments Moore, Katherine L 318
on Quarterly Groundwater Monitoring EP A Region IX
Report, Mar 91
25 Iul 91
Minutes of 25 J ul 91 Project Managers
Meeting
Blank, Richard A,
LtCol
323 ABG/EM
324
...
A-17
-------
DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
FILE
NUMBER
20 Aug 91 Transcript of 20 Aug 91 TRC Meeting Parks, Nadine J 330
Peters Shorthand
Reporting Corp.
Sep 91 Quarterly Groundwater Monitoring IT Corp. 336
Report, Third Quarter 1991
11 Apr 88 Public Meeting Notice on Phase II 323 FTW IP A 337
Stage 3
17 Sep 91 Minutes of 20 Aug 91 TRC Meeting Blank, Richard A, 341
LtCol
323 FTW IEM
18 Sep 92 EPA Letter to Base Transmitting Moore, Katherine L 343
Comments on Draft Groundwater
Operable Unit and Soil Operable
Unit Focused Feasibility Study
Work Plan
16 Oct 91 EP A Letter to Base Providing Comments Moore, Katherine L 349
on Jul 91 Quarterly Groundwater EP A Region IX
Monitoring Report
03 Dee 91 EP A Letter to Base Transmitting Moore, Katherine L 359
Comments on Third Quarter 1991 EP A Region IX
Groundwater Monitoring Report
05 Dee 91 Northern Trust Co. Letter to Base Carlisle, Kurt A 361
Transmitting A License Agreement Northern Trust Co.
Between RMC Lonestar, and United
States of America
Jan 92
Quarterly Groundwater Monitoring
Report, Fourth Quarter 1991
IT Corp.
366
08 Jan '92
EP A Letter to Base on Review of
Background Soils Sampling Strategy
Moore, Katherine L 374
EP A Region IX
...
A-18
-------
DOC. AUTHOR or FILE
DATE SUBJECT OR TITLE CORP. AUTHOR NUMBER
23 Ian 92 Minutes of 9 Ian 92 RPM Meeting Blank, Richard A, 377
LtCol
323 FfW fEM
Mar 92 RI, Draft Report, Vol I of II, Group 2 Battelle 386
Sites Environmental
Management
Operations
Mar 92 RI, Draft Report, Vol II of II, Group 2 Battelle 387
Sites Environmental
Management
Operations
12 May 88 Base Letter to HAZWRAP on RIfFS Saenz, Jose L, 389
SOW, Amendment 2 LtCol
HQ A TCfDEEV
10 Mar 92 EP A Letter to Base Commenting Moore, Katherine L 394
on Fourth Quarter 91 Groundwater EP A Region IX
Monitoring Report
27 Mar 92 Minutes of 11 Mar 92 RPM Meeting Blank, Richard A, 399
LtCol
323 FfW fEM
Apr 92 Draft Groundwater Monitoring Project IT Corp. 401
Plans, Vol I: Sampling and Analysis
Plan; Vol II: Quality Assurance
Project Plan; Vol III: Health and
Safety Plan
03 Apr 92 FS, Draft Work Plan, OU-4 IT Corp. 404
22 Apr 92 Base Letter to MAlCOM Transmitting Blank, Richard A, 407
Comments on Internal Draft Landfill OU LtCol
FS Work Plan 323 FfW fEM
...
A-19
-------
DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
FILE
NUMBER
May 92 Field Investigation, Draft Sampling and IT Corp. 410
Analysis Plan; Draft Quality Assurance
Project Plan; Draft Health and Safety
Plan, Vol II, III, and IV of IV, OU-2
and OU-3
06 May 92 EPA Letter to Base on Review of RI, Moore, Katherine L 413
Draft Group 2 Report EP A Region IX
12 May 92 FS, Draft Work Plan, Landfill au Battelle 415
Environmental
Management
Operations
20 May 92 Base Letter to HQ ATC/DEVR with Blank, Richard A, 417
Comments on Internal Draft Work Plan of LtCol
Additional Field Activities for the 323 FTW /EM
Groundwater and Soils Operable Units
Iun 92 Draft Work Plan, Additional Field Battelle 421
Investigation, Soils and Groundwater Environmental
OU, Vol I of IV Management
Operations
Iun 92 Draft Sampling and Analysis Plan, Battelle 422
Quality Assurance Project Plan, and Environmental
Health and Safety Plan for Additional Management
Field Investigation at Soils and Operations
Groundwater OU, Vol II, III and, IV, of
IV
03 Iun 92 Minutes of 3 J un 92 TRC Meeting Blank, Richard A, 423
LtCol
323 FTW/EM
04 Iun 92 First Quarter Groundwater Monitoring Battelle 425
Report Environmental
Management
Operations
....
A-20
-------
DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
-FILE
NUMBER
15 Iun 92
06 Iul 92
06 Iul 92
13 Iul 92
20 Iul 92
20 Iul 92
27 Iul 92
28 Iul 92
28 Iul 92
07 Aug 92
CDTSC Letter to Base with
Comments on RI, Group 2 Report
Minutes of 3 Iun 91 TRC Meeting
EPA Letter to Base on FS, Draft Work
Plan for Landfill au
CDTSC Letter to Base on FS, Draft
Final Preliminary Design Report,
Landfill OU
EP A Letter to Base on Review of Field
Investigation Plan, OU-2 and OU-3
EP A Letter to Base on Review of First
Quarter Groundwater Monitoring Report
CDTSC Letter to Base on Groundwater
Monitoring Program
CRWQCB Letter to Base on FS,
Draft Work Plan for Landfill OU
Transcript of 28 J ul 92 TRC Meeting
Quarterly Groundwater Monitoring
Report, Second Quarter 1992
A-21
Billington, Tracie L 432
California
Department of Toxic
Substances Control
Blank, Richard A,
LtCol
323 FTW IEM
434
Moore, Katherine L 435
EP A Region IX
Billington, Tracie L 436
California
Department of Toxic
Substances Control
Moore, Katherine L 439
EP A Region IX
Moore, Katherine L 440
EP A Region IX
Billington, Tracie L 442
California
Department of Toxic
Substances Control
Mosbacher,
Michael H
California Regional
Water Quality
Control Board
443
Medeiros, Vicki L
Peters Shorthand
Reporting Corp.
444
IT Corp.
448
...
-------
DOC. AUTHOR or FILE
DATE SUBJECT OR TITLE CORP. AUTHOR NUMBER
10 Aug 92 CDTSC Letter to Base on Additional Billington, Tracie L 449
Field Investigation Work Plan California
Department of Toxic
Substances Control
25 May 90 Minutes of 10 May 90 TRC Meeting Blank, Richard A, 451
LtCol
323 FIW/EM
28 Aug 92 CRWQCB Letter to Base on Draft Mosbacher, 452
Additional Field Investigation Work Michael H
Plan for Soil and Groundwater OUs California Regional
Water Quality
Control Board
Sep 92 RI, Draft Final Report, Vol I of II, Battelle 453
Group 2 Sites Environmental
Management
Operations
Sep 92 RI, Draft Final Report, Vol II of II, Battelle 454
Group 2 Sites Environmental
Management
Operations
Sep 92 Draft Solid Waste Assessment Test IT Corp. 455
Report, Vol I of II
Sep 92 Draft Solid Waste Assessment Test IT Corp. 456
Report, Vol IT of II
Sep 92 Draft Work Plan, Comprehensive IT Corp. 457
Baseline Risk Assessment
12 Sep 92 FS, Draft Final Work Plan, Landfill OU IT Corp. 459
28 Sep 92 Base Letter HQ ATC/DEVR on Blank, Richard A, 465
Review of Base Soils Management Plan LtCol
323 FIW /EM
...
A-22
-------
DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
FILE
NUMBER
29 Sep 92
30 Sep 92
May 92
May 92
09 Oct 92
09 Oct 92
29 Oct 92
06 Nov 92
12 Nov 92
18 Nov 92
IT Letter to Battelle on Draft Work
Plan, Additional Field Investigation,
Soils and Groundwater OUs, Vol I, II,
and III
EP A Letter to Base on Second Quarter
1992 Groundwater Monitoring Report
Field Investigation, Final Work Plan,
Vol I of IV, OU-2 and OU-3
Field Investigation, Sampling and
Analysis Plan; Quality Assurance
Project Plan; Health and Safety Plan,
Vol II, III, and IV of IV, OU-2 and
OU-3
Robinson,
Dennis M
IT Corp.
469
Moore, Katherine L 471
EP A Region IX
IT Corp.
472
IT Corp.
473
EPA Letter to Base Providing Comments Moore, Katherine L 475
on FS, Draft Final Work Plan, OU-4 EPA Region IX
EP A Letter to Base Transmitting
Comments on RI Report, Group 2 Sites
Moore, Katherine L 476
EP A Region IX
EP A Letter to Base Providing Comments Moore, Katherine L 480
on Draft Groundwater Monitoring EPA Region IX
Program Evaluation
Quarterly Groundwater Monitoring
Report, Third Quarter 1992
EPA Letter to Base Transmitting
Comments on Chapter 6 and Missing
Appendices, RI Report, Group 2 Sites
CRWQCB Notice of Public Hearing
Concerning Invoking A Formal Dispute
Over Soil Cleanup
A-23
IT Corp.
483
Moore, Katherine L 484
EP A Region IX
Pearson, J Lawrence 485
California Regional
Water Quality
Control Board
...
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
FILE
NUMBER
18 Nov 92 EP A Letter to Base Transmitting Moore, Katherine L 486
Comments on Draft Final Soils and EP A Region IX
Groundwater OU Additional Field
Investigation Work Plan, Sampling and
Analysis Plan, and Quality Assurance
Project Plan
24 Nov 92 CDTSC Letter to MAlCOM Invoking Wang, David 490
Dispute Resolution on Draft Final California
"...Soils and Groundwater OU Department of Toxic
Additional Field Investigation..." Substances Control
30 Nov 92 CDTSC Letter to Base Transmitting Billington, Tracie L 493
Comments on Comprehensive Baseline California Regional
Risk Assessment, Draft Work Plan, Water Quality
Sep 92 Control Board
07 Dee 92 Draft Soils Management Plan IT Corp. 495
09 Dee 92 Minutes of 1 Dee 92 Meeting to Resolve Mosbacher, 496
the Additional Field Investigation Work Michael H
Plan Dispute California Regional
Water Quality
Control Board
09 Dee 92 CDTSC Letter to Base Providing Billington, Tracie L 497
Summary of State and Local ARARs California
for Abandoned Landfills Department of Toxic
Substances Control
09 Dee 92 CRWQCB Letter to Base Providing Mosbacher, 498
Comments on Draft Final FS Work Plan, Michael H
OU-4 California Regional
Water Quality
Control Board
22 Dee 92 CRWQCB Letter to Base Providing Mosbacher, 503
Comments on Draft Groundwater Michael H
Monitoring Program Evaluation California Regional
W~r Quality
Control Board
A-24
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DOC. AUTHOR or FILE
DATE SUBJECT OR TITLE CORP. AUTHOR NUMBER
23 Dee 92 Base Letter to MAlCOM on Base Draft Blank, Richard A, 504
Soils Management Plan LtCol
323 FIW IEM
Ian 93 Draft Final Work Plan, Comprehensive IT Corp. 506
Baseline Risk Assessment
19 Ian 93 IT Letter with Comments to Base on Dove, F Harvey 514
Draft Final Work Plan, Comprehensive IT Corp.
Baseline Risk Assessment
Feb 93 Draft Final Solid Waste Assessment Test IT Corp. 516
Report, Vol I of II
Feb 93 Draft Final Solid Waste Assessment Test IT Corp. 517
Report, Vol II of II
08 Feb 93 Quarterly Groundwater Monitoring IT Corp. 519
Report, Fourth Quarter 1992
26 Feb 93 CDTSC Letter to Base on Extension to Billington, Tracie L 524
FFA Enforceable Schedule California
Department of Toxic
Substances Control
Mar 93 Final Solid Waste Assessment Test, Vol IT Corp. 526
I of II
Mar 93 Final Solid Waste Assessment Test, Vol IT Corp. 527
II of II
Mar 93 Draft Background Groundwater Sampling IT Corp. 529
Strategy
08 Mar 93 EP A Letter with Comments to Base on Moore, Katherine L 531
Quarterly Groundwater Monitoring EP A Region IX
Report, Fourth Quarter
19 Mar 93 CRWQCB Letter with Comments to Williams, Camilla 533
Base on Quarterly Groundwater CalU"ornia Regional
Monitoring Report, Fourth Quarter Water Quality
Control Board
A-25
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
FILE
NUMBER
16 Apr 93
16 Apr 93
16 Apr 93
16 May 93
18 May 93
02 Jun 93
07 Jun 93
07 Jun 93
18 Jun 93
18 Jun 93
,"
Focused FS, Draft Report, OU-4
CRWQCB Letter to Base Concerning
Additional Field Investigation
Consensus Statement
IT Letter to Battelle EMO Transmitting
Draft Final Soil Management Plan
EP A Draft Comments on Human Health
Risk Assessment of CBRA
IT Corp.
Williams, Camilla
California Regional
Water Quality
Control Board
Kroutch, G Bryant
IT Corp.
Serda, Sophia
EP A Region IX
541
543
544
546
EPA Draft Comments on Draft Christopher, John P 547
Comprehensive Baseline Risk Assessment EP A Region IX
Quarterly Groundwater Monitoring
Report, First Quarter 1993
CRWQCB Letter to Base Providing
Comments on Draft Final Work Plan,
Appendix A: Background Soils and
Groundwater Sampling Strategy
EPA Letter to Base Transmitting
Comments on Appendix A of Draft Final
Comprehensive Baseline Risk Assessment
Work Plan and Background Soils Sampling
Strategy
IT Corp.
Taylor, James D
California Regional
Water Quality
Control Board
Swarthout, Brian
EP A Region IX
EPA Letter to Base Transmitting Swarthout, Brian
Comments on Draft Landfill OU Focused EPA Region IX
Feasibility Study
CDTSC Letter to Base Providing
Comments on the Focused Feasibility
Study, Landfill au
A-26
Strong, Kent
California
Department of Toxic
Substances Control
...
552
553
554
555
557
-------
DOC. AUTHOR or FILE
DATE SUBJECT OR TITLE CORP. AUTHOR NUMBER
18 Iun 93 CRWQCB Letter to Base Transmitting Williams, Camilla 558
Comments on Draft Focused FS Report, California Regional
OU-4 Water Quality
Control Board
18 Iun 93 Base Letter to Regulators Transmitting Smith, Charles H 559
Draft Proposed Plan, OU-4 AFBDA/NW-D
Iul 93 Final Base Soils Management Plan IT Corp. 562
08 Iul 93 Base Letter to CRWQCB on Landfill Smith, Charles H 566
Closure Cover AFBDA/NW-D
16 Jul 93 CDTSC Letter to Base on Draft Final Strong, Kent 572
Work Plan, Appendix A, Groundwater California
and Soil Sampling Department of Toxic
Substances Control
Aug 93 Draft Final Work Plan, IT Corp. 580
Comprehensive Baseline Risk Assessment
22 Sep 93 CRWQCB Letter to Base on Draft Williams, 582
Final Work Plan, Comprehensive Camilla
Baseline Risk Assessment California
Regional
Water Quality
Control Board
24 Sep 93 EP A Letter to Base on Draft Final Swarthout, 583
Work Plan, Comprehensive Baseline Brian
Risk Assessmen t . EP A Region IX
15 Oct 93 Focused FS, Draft Final Work Battelle 590
Plan for Landfill au Environmental
Management
Operations
....
A-27
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DOC. AUTHOR or FILE
DATE SUBJECT OR TITLE CORP. AUTHOR NUMBER
15 Nov 93 CIWMB Letter to the Base on Focused Zielinski, 596
FS for Landfill OU Tamara
Cali fornia
Integrated Waste
Management
Board
15 Nov 93 CRWQCB Letter to CDTSC on Williams, 597
Focused FS, Draft Final Landfill OU Camilla
California
Regional
Water Quality
Control Board
30 Nov 93 Attorney Letter to CDTSC on Focused Vim, Randall 601
FS for Landfill OU Attorney at Law
Dee 93 Fact Sheet, "Proposed Plan for AFCEE 604
Environmental Cleanup at... Landfill
OU Sites;;
01 Dee 93 EP A Letter to AFCEE Providing Swarthout, Brian 606
Comments on Preliminary Final EP A Region IX
Environmental Baseline Survey
06 Dee 93 CDTSC Letter to Base Providing Strong, Kent 609
Comments on the Background California
Inorganics Soils Report Department of
Toxic Substances
Control
08 Dee 93 CDTSC Letter to Base Strong, Kent 610
Commenting on Draft Final California
Focused FS Report, OU-4 Department of
Toxic Substances
Control
'"
A-28
-------
DOC. AUTHOR or FILE
DATE SUBJECT OR TITLE CORP. AUTHOR NUMBER
08 Dee 93 CRWQCB Letter to Base Williams, 611
Providing Comments on the Background Camilla
Inorganic Soils Report California
Regional
Water Quality
Control Board
08 Dee 93 Base Letter to Contractor Concerning Smith, Charles H 613
Concerning Revision to Draft Final AFBCA/OL-D
Landfill Focused FS Report
28 Dee 93 CDTSC Letter to Base Transmitting Strong, Kent 616
Comments on Draft Final Proposed Plan, California
OU-4 Department of Toxic
Substances Control
11 Feb 94 Draft Record of Decision, OU-4 IT Corp. 622
15 Feb 94 Transcript of 15 Feb 94 Public Hearing Nicol, Janet H 623
Peters Shorthand
Reporting Corp.
16 Mar 94 Draft Comprehensive Baseline Risk IT Corp. 626
Assessment, Vol I of III
16 Mar 94 Draft Comprehensive Baseline Risk IT Corp. 627
Assessment, Vol II of III, Appendices
A-F
16 Mar 94 Draft Comprehensive Baseline Risk IT Corp. 628
Assessment, Vol III of III, Appendices
G-I
23 Mar 94 CRWQCB Letter to Base Concerning No Williams, Camilla 629
Further Action Sites, and Additional California Regional
Field Investigation Dispute Water Quality
Control Board
22 Apr 94 RI, Draft Additional Field IT Corp. 632
Investigation Report, OU-2 and OU-3, ...
Vol I of VI, Text and Appendices A-B
A-29
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DOC. AUTHOR or FILE
DATE SUBJECT OR TITLE CORP. AUTHOR NUMBER
22 Apr 94 RI, Draft Additional Field IT Corp. 633
Investigation Report, OU-2 and OU-3,
Vol IT of VI, Appendix C
22 Apr 94 RI, Draft Additional Field IT Corp. 634
Investigation Report, OU-2 and OU-3,
Vol III of VI, Appendices D-F
22 Apr 94 RI, Draft Additional Field IT Corp. 635
Investigation Report, OU-2 and OU-3,
Vol IV of VI, Appendices G-L
22 Apr 94 RI, Draft Additional Field IT Corp. 636
Investigation Report, OU-2 and OU-3,
Vol V of VI, Appendix M
22 Apr 94 RI, Draft Additional Field IT Corp. 637
Investigation Report, OU-2 and OU-3,
Vol VI of VI, Appendix M (Cont'd)
May 94 Additional Field Investigation, Soil IT Corp. 639
Management Report
Iun 94 Interim Soil Management Report, UST, IT Corp. 661
Vol I of III
Iun 94 Interim Soil Management Report, UST, IT Corp. 662
Vol II of III
IUD 94 Interim Soil Management Report, UST, IT Corp. 663
Vol III of III
23 Iun 94 CRWQCB Letter to CDTSC Providing Taylor, James D 671
Comments on Draft Additional Field California Regional
Investigation Report, OU-2 and OU-3 Water Quality
Control Board
24 Jun "94 CDTSC Letter to Base Providing Strong, Kent 672
Comments on Draft RI Additional Field California
Investigation Report, OU-2 and OU-3 Dep~ment of Toxic
Substances Control
A-30
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DOC. AUTHOR or FILE
DATE SUBJECT OR TITLE CORP. AUTHOR NUMBER
24 Iun 94 EP A Letter to Base Providing Comments Lowe, Debbie 673
on Draft RI Additional Field EP A Region IX
Investigation Report, OU-2 and OU-3
Dee 90 SOW, Quarterly Monitoring Program HSD/Y AQE 677
13 Iul 89 Phase II Stage 2, SOW, USAF OEHUTSS 678
Confirmation/Quanti fication
10 Aug 82 Base News Release, "Completion of Fagan, Clarence L 687
Phase I Records Search" 323 FTW/PA
17 Aug 84 Minutes of 6 Aug 84 TWG Meeting Curran, James P, 689
Capt
USAF Hosp/SGPB
15 Ian 86 CDHS Letter to Base on Review of Phase Karoly, B T 691
II, Stage 1 Draft Report California
Department of Health
Services
Sep 86 Newspaper Article, "Mather Wants to Sacramento Union 692
Explain but no One Shows Up"
11 Sep 86 Newspaper Article, "Mather to Discuss Sacramento Bee 693
Water Contamination"
12 Sep 86 Newspaper Article, "IRP Meeting" Wing Tips 694
12 Iu! 94 Request for FF A Extension to Draft Strong, Kent 696
Landfill OU ROD California
Department of Toxic
Substances Control
10 Aug 94 Review of Draft Landfill OU Sites Zielinski, Tamara 699
Superfund ROD Dated 23 May 94 California
Integrated Waste
Management Board
11 Aug 94 Draft Landfill OU ROD Taylor, James 700
California Regional
Water Quality
Control Board
A-31
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
FILE
NUMBER
11 Aug 94
11 Aug 94
7 Sep 94
21 Sep 94
7 Oct 94
11 Oct 94
29 Apr 94
31 May 94
21 Jun 94
EP A Review of Draft Landfill OU
ROD, 13 May 93
Draft Superfund ROD, Landfill OU Sites
EP A Review of Sacramento Metropolitan
Air Quality Management District Letter
of 27 Iul 94 RE: Air Requirements for
Landfill ROD
Lowe, Debbie
EP A Region IX
Strong, Kent
California
Department of Toxic
Substances Control
Lowe, Debbie
EP A Region IX
EPA Additional Comments on ARARs for Lowe, Debbie
Draft Landfill ROD EP A Region IX
Consensus Statement for Extending FF A
Delivery Date for Draft Final ROD for
the Landfill OU
Consolidation of Landfills 4, 5, and 6
Reassessment of Remedial Action Cost
Estimate for Landfill 6
Lowe, Debbie
Strong, Kent
Wong, Anthony C
EP A Region IX
California
Department of Toxic
Substances Control
AFBCA/OL-D
DeGuzman, Jorge
Sacramento
Metropolitan Air
Quality Management
District
IT Corp.
701
702
703
704
706
707
Review of Draft Landfill OU ROD Dated Williams, Camilla
14 February 94 California Regional Water
Quality Control Board
Reassessment of Remedial Action Costs
for Landfill Site 6
A-32
Strong, Kent
Ca1lfornia Department of
Toxic Substances Control
-------
DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
FILE
NUMBER
12 Sept 94
17 Oct 94
08 Nov 94
14 Nov 94
12 Dec 94
US EP A Letter Concerning ARARs for
the Draft Landfill OU ROD
Comments on Draft Landfill OU ROD
Notice to Extend Delievery Date of
the Draft Final Landfill OU ROD
BACT for Landfill Sites 2 and 3
Superfund Record of Decision,
Draft Final, Landfill OU Sites
A-33
Lowe, Debbie
US EP A Region IX
McChesney, Frances
California Regional
Water Quality Control
Board
Wong, Tony
AFBCA/OL-D
DeGuzman, Jorge
Sacramento Metropolitan
Air Quality Management
District
US Air Force
...
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