PB98-964510
EPA 541-R98-084
October 1998
EPA Superfimd
Record of Decision:
Mather Air Force Base
Basewide OU Sites
Sacramento, CA
9/28/1998
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SFUND RECORDS CTR
3150-00268
AIR FORCE
INSTALLATION RESTORATION PROGRAM
FINAL COMPREHENSIVE ENVIRONMENTAL
RESPONSE, COMPENSATION, AND LIABILITY ACT OF 1980
RECORD OF DECISION
BASEWIDE OPERABLE UNIT SITES
MATHER AIR FORCE BASE, CALIFORNIA
AIR FORCE CENTER FOR ENVIRONMENTAL EXCELLENCE
BROOKS AIR FORCE BASE, TEXAS
AUGUST 24, 1998
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Comprehensive Environmental Response,
Compensation, and Liability Act of 1980
Record of Decision
Final
Base wide Operable Unit Sites
Mather Air Force Base
Sacramento County, California
August 24, 1998
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Table of Contents.
List of Figures iv
List of Tables v
List of Appendices vii
List of Acronyms viii
Executive Summary ES-1
1.0 Introduction 1-1
1.1 Basewide Operable Unit Background 1-2
1.1.1 Basewide Operable Unit Sites Selected for No Further Action 1-9
1.1.2 Petroleum Only Sites Selected for No Further Action Under
Comprehensive Environmental Response, Compensation, and
Liability Act (which remain to be closed under other
Regulations) 1-10
1.2 Significant Changes from the Focused Feasibility Study and
Proposed Plan 1-11
1.2.1 Sites IOC/68 1-11
1.2.2 Sites 80, 85, and 88 1-11
1.2.3 Site 2 1-12
1.2.4 Site 81 1-12
1.3 Assessment of Comprehensive Risk 1-13
1.4 Signatures 1-15
2.0 Basewide Operable Unit Sites Selected for Remedial Action 2-1
2.1 Declaration for the Basewide Operable Unit Sites Selected
for Remedial Action 2-1
2.1.1 Site Name and Location 2-1
2.1.2 Statement of Basis and Purpose 2-1
2.1.3 Assessment of the Basewide Operable Unit Sites 2-2
2.1.4 Description of the Selected Remedy 2-5
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Table of Contents (Continued).
2.1.5 Statutory Determinations 2-5
2.2 Decision Summary for Basewide Operable Unit Sites Selected for
Remedial Action 2-6
2.2.1 Site Names, Locations, and Descriptions 2-6
2.2.2 Site History and Enforcement Activities 2-6
2.2.3 Highlights of Community Participation 2-6
2.2.4 Scope and Role of Response Action 2-8
2.2.5 Summary of Site Characteristics 2-9
2.2.6 Summary of Site Risks 2-37
2.2.7 Description of Alternatives 2-38
2.2.8 Summary of Comparison Analysis of Alternatives 2-42
2.2.9 The Selected Remedies 2-45
2.2.10 Remedial Action Operation and Maintenance 2-64
3.0 Basewide Operable Unit Sites Selected for No Further Action 3-1
3.1 Declaration for the Basewide Operable Unit Sites Selected for No
Further Action 3-1
3.1.1 Site Name and Location 3-1
3.1.2 Statement of Basis and Purpose 3-1
3.1.3 Description of the No Further Action Decision 3-1
3.1.4 Summary of Site Risks ..: 3-2
3.2 Decision Summary for Basewide Operable Unit Sites Selected for No
Further Action 3-2
3.2.1 Site Name, Location, and Description 3-2
3.2.2 Site History and Enforcement Activities 3-2
3.2.3 Highlights of Community Participation 3-3
3.2.4 Scope and Role of Response Action 3-3
3.2.5 Summary of Site Characteristics .: 3-3
4.0 Basewide Operable Unit "Petroleum Only" Sites Selected for No Action
Under Comprehensive Environmental Response, Compensation, and Liability
Act (but which remain to be closed under other regulations) 4-1
4.1 Declaration for the Basewide Operable Unit Petroleum Only Sites
Selected for No Action 4-1
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Table of Contents (Continued).
4.1.1 Site Name and Location 4-1
4.1.2 Statement of Basis and Purpose 4-1
4.1.3 Description of the Selected Remedy 4-1
4.1.4 Declaration Statement 4-2
4.2 Decision Summary for Basewide Operable Unit "Petroleum Only" Sites
Selected for No Action Under Comprehensive Environmental Response,
Compensation, and Liability Act (but which remain to be closed under
other regulations) 4-2
4.2.1 Site Name, Location, and Description 4-2
4.2.2 Site History and Enforcement Activities 4-2
4.2.3 Highlights of Community Participation 4-4
4.2.4 Scope and Role of Response Action 4-4
4.2.5 Summary of Site Characteristics 4-4
4.2.6 Summary of Site Risks 4-5
4.2.7 Statutory Authority Finding 4-5
5.0 List of Applicable or Relevant and Appropriate Requirements and
Performance Standards 5-1
5.1 Chemical-Specific Applicable or Relevant and Appropriate
Requirements and Performance Standards 5-3
5.1.2 State Chemical-Specific Applicable or Relevant and
Appropriate Requirements and Performance Standards 5-6
5.2 Location-Specific Applicable or Relevant and Appropriate
Requirements and Performance Standards 5-6
5.3 Action-Specific Applicable or Relevant and Appropriate
Requirements Performance Standards 5-7
5.3.1 Federal Action-Specific Applicable or Relevant and
Appropriate Requirements 5-7
6.0 Responsiveness Summary 6-1
7.0 References 7-1
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List of Figures.
Figure Title Page
1-1 Mather Air Force Base Site Vicinity Map 1-3
2-1 Basewicle OU Sites Selected for Remedial Action 2-7
2-2 Site 1OC/68 Former Fire Department Training Area No. 3 Two 2,000
Gallon and Sixteen 50,000 Gallon Underground Storage Tanks at Fuel
Transfer Station Site Plan 2-12
2-3 Site 18 Old Burial Site, Site Plan 2-17
2-4 Site 20 Sewage Treatment Facility Site Plan 2-23
2-5 Site 23 Main Base Area Sanitary Sewer Line System 2-28
2-6 Site 86 Military Firing Range Site Plan 2-32
2-7 Site 87 Skeet/Trap Range Site Plan 2-35
2-8 Selecting a Cleanup Remedy 2-43
2-9 Disposition of Sites 86 and 87 Surface Soils and/or Sediments 2-60
3-1 Basewide OU Sites Selected for No Further Action 3-4
4-1 Basewide OU "Petroleum Only" Sites 4-3
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List of Tables.
Table Title Page
1 -1 Installation Restoration Program Sites and their Corresponding
Records of Decision 1-5
1 -2 Preferred Remedial Alternatives for the Basewide Operable Unit Sites
Selected for Remedial Action 1-10
2-1 Summary of Site Risks for Basewide Operable Unit Sites
Where Remedial Action is Warranted 2-3
2-2 Preferred Remedial Alternatives for the Basewide Operable Unit Sites
Selected for Remedial Action 2-5
2-3 Previous Investigations at the Basewide Operable Unit Sites Selected
for Remedial Action 2-8
2-4 Site IOC - Results of Previous Investigations 2-13
2-5 Site 68 - Results of Previous Investigations 2-15
2-6 Site 18 - Results of Previous Investigations 2-18
2-7 Site 20 - Results of Previous Investigations 2-24
2-8 Site 23 - Results of Previous Investigations 2-29
2-9 Site 86 - Results of Previous Investigations 2-33
2-10 Site 87 - Results of Previous Investigations 2-36
2-11 Sites IOC/68 Remedial Alternatives 2-39
2-12 Site 18 Remedial Alternatives 2-39
2-13 Site 20 Remedial Alternatives 2-40
2-14 Site 23 Remedial Alternatives 2-40
2-15 Site 86 Remedial Alternatives 2-41
2-16 Site 87 Remedial Alternatives 2-41
2-17 Comparative Analysis of Remedial Alternatives for the Basewide
Operable Unit Sites Selected for Remedial Action 2-44
2-18 Sites IOC/68 Cleanup Levels 2-50
2-19 Site 18 Cleanup Levels 2-53
2-20 Site 20 Cleanup Levels 2-55
2-21 Site 23 Cleanup Levels 2-58
2-22 Site 86 Cleanup Levels 2-59
2-23 Site 87 Cleanup Levels 2-62
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List of Tables (Continued).
Table Title Page
3-1 Previous Investigations at the No Further Action Sites 3-3
4-1 Previous Investigations at the Soil Operable Unit "Petroleum
Only" Sites 4-4
5-1 State Chemical-Specific Performance Standards for Surface Soils 5-4
5-2 State Chemical-Specific Performance Standards for Subsurface Soils 5-5
5-3 State and Federal Action-Specific Applicable or Relevant and
Appropriate Requirements 5-8
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List of Appendices.
Appendix Title Page
A Administrative Record Index A-l
B Mather Air Force Base Sites 86 and 87Human Health Risk Assessm B-l
C Ecological Risk Assessment for Mather Air Force Base Sites 86 and 87 ... C-l
D Estimation of Contaminant Concentrations for Waste Disposal at Site 7 .. D-l
E Designated Level Methodology E-1
F Background Distributions of Soil Constituents at Mather Air Force Base .. F-l
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List of Acronyms.
AC&W
AFB
ARAR
bis
BTEX
CBRA
CCR
CERCLA
COC
COPC
CVRWQCB
DCE
DISC
DWR
ESD
FFS
FS
HWCL
ILCR
IRP ,
JP-4
MCL
mg/kg
mg/L
NCP
ng/DSCM
NPL
OU
PAH
POTW
ppm
Aircraft Control and Warning
Air Force Base
applicable or relevant and appropriate requirement
below land surface
benzene, toluene, ethylbenzene, and xylenes
Comprehensive Baseline Risk Assessment
California Code of Regulations
Comprehensive Environmental Response, Compensation, and Liability
Act of 1980
contaminant of concern
contaminant of potential concern
Central Valley Regional Water Quality Control Board
dichloroethene
Department of Toxic Substances Control
Department of Water Resources
Explanation of Significant Difference
Focused Feasibility Study
feasibility study
Hazardous Waste Control Law
incremental lifetime cancer risk
Installation Restoration Program
jet propellant fuel
maximum contaminant level
milligrams per kilogram
milligrams per liter
National Contingency Plan
nanograms per dry square cubic meter
National Priorities List
operable unit
polycyclic aromatic hydrocarbon
publicly owned treatment works
parts per million
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List of Acronyms (Continued).
PQL
RCRA
RI
ROD
RWQCB
SAC
SARA
SIP
SMAQMD
SVE
SWRCB
TBC
TCDD
TCE
TDL
TEQ
TPH
USEPA
UST
VOC
WDR
WQG
practical quantification limit
Resource Conservation and Recovery Act
remedial investigation
Record of Decision
Regional Water Quality Control Board
Strategic Air Command
Superfund Amendments and Reauthorization Act of 1986
State Implementation Plan
Sacramento Metropolitan Air Quality Management District
soil vapor extraction
State Water Resources Control Board
to-be-considered
tetrachlorodibenzo-p-dioxinisomer
trichloroethene
total designated level
toxicity equivalent
total petroleum hydrocarbons
United States Environmental Protection Agency
underground storage tank
volatile organic compound
Waste Discharge Requirement
water quality goal
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Executive Summary
This Record of Decision (ROD) presents the selected remedial actions for the Basewide Operable
Unit (OU) sites, at the formerly active Mather Air Force Base (AFB), Sacramento County,
California. Mather AFB is located in the Central Valley region of northern California in
Sacramento County, approximately ten miles east of downtown Sacramento, California, and due
south of unincorporated Rancho Cordova, California. The base is due south of U.S. Highway 50,
a major highway connecting Sacramento and South Lake Tahoe, and encompassed approximately
5,845 acres at the time of closure (including 129 acres of easements) in an unsurveyed part of
Township 8 North, Ranges 6 East and 7 East. Mather AFB was constructed in 1918 and its
primary mission was as a flight training school. The base was decommissioned under the Base
Realignment and Closure Act on September 30, 1993.
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 and Reauthorization Act of 1986 and, to the extent practicable, in
accordance with the National Oil and Hazardous Substances Pollution Contingency Plan. The
decisions, documented herein, are based on information contained in the Administrative Record
for the subject sites. The Administrative Record Index identifies documents that were considered
or relied upon to make these decisions.
The purpose of this ROD is to document the selection of the appropriate level of remediation
necessary to protect human health, the environment, and groundwater beneficial uses and define
which legal requirements are applicable or relevant and appropriate based on the site-specific
conditions. In addition, this ROD incorporates an assessment of the comprehensive risk from all
the previous operable units.
The Basewide OU was established to facilitate remedial activities associated with Installation
Restoration Program (IRP) sites at Mather AFB that had not been included as part of other
Mather AFB RODs: the Disposal and Reuse ROD [USAF 1993], the Soil OU ROD [IT 1996a],
the Groundwater OU ROD [IT 1996a], the Aircraft Control and Warning OU ROD [IT 1993a],
or the Landfill OU ROD [USAF 1995]. Sites 80, 85, and 88 were included in the Basewide OU;
however, they have been removed from this ROD and will be included in a future ROD, since
proposed cleanup standards were not agreed upon.
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The Basewide OU Focused Feasibility Study (FFS) included a screening-level review of the
cleanup standards established in previous Mather AFB RODs, as well as the Basewide OU
cleanup standards, to determine whether possible cumulative effects from multiple contaminants
exceed acceptable health risk levels (a hazard quotient of 1 or an excess cancer risk of 1 in
10,000). The screening-level review indicated that all but one soil site and the Groundwater OU
had cleanup standards that were not of concern. The cleanup standards from Site 69 (the one soil
site) and the Groundwater OU required more detailed assessment.
The cleanup standards for surface soils at Site 69 could result in an unacceptable risk if each of
the nine categories of dioxins and furans were cleaned up just to the cleanup standard, and
concentrations of all of these chemicals remained at the site at the cleanup level. In fact, the soils
at Site 69 containing dioxins and furans were removed and placed in Mather landfill Site 4 in
1996. Confirmation sampling for dioxins and furans resulted in only one detection, of
octachlorodibenzo-p-dioxin, in ten samples [MW 1998], indicating that there are no longer
concentrations of chemicals remaining in surface soils at Site 69 that pose an unacceptable risk.
The groundwater cleanup standards for the Groundwater OU were acceptable except for the fact
that the cleanup standard for 1,1-dichloroethene (DCE), which is the same as the California
drinking water standard, exceeded the acceptable health risk levels based upon the best estimate
of cancer risk published by U.S. Environmental Protection Agency (USEPA) [USEPA 1994].
However, this estimate contains a great deal of uncertainty and conservatism, and the Remedial
Project Managers agree that the drinking water standard is an appropriate cleanup standard. In
addition, in order to achieve the cleanup standard of the other volatile contaminants in the
groundwater, 1,1-DCE concentrations will be reduced well below the cleanup standard.
The cleanup standard for lead in the groundwater, which is set at the tap-water standard, also
represents a hazard index above one, but lead has only been detected at concentrations above the
cleanup standard in a few locations in the groundwater. As water from many extraction wells is
blended in the groundwater treatment system, any elevated lead concentrations are expected to be
reduced because of the mixing process.
This Basewide OU is comprised of the following IRP sites:
Site 2 - "8150" Area Landfill;
• Site 8 - Fire Department Training Area No. 1;
• Site IOC - Fire Department Training Area No. 3;
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• Site 17 - Weapons Storage Septic Tank;
Site 18-OldBurial Site;
Expanded Site 19 - Jet Propellant Fuel (JP-4) Tanks;
• Site 20 - Sewage Treatment Facility (Digester Tanks Area)
• Site 23 - Sanitary Sewer System (Main Base Area)
• Site 67 - Sanitary Sewer System (Strategic Air Command Area);
• Site 68 - Underground Storage Tanks at Fuel Transfer Station;
• Site 81 - Sewage Oxidation Ponds;
• Site 82 - Golf Course Maintenance Area Yard;
Site 83 - Helicopter Washrack;
• Site 84 - Sanitary Sewer Line (Runway Area);
• Site 86 - Military Firing Range; and
Site 87 - Skeet Range/Trap Range.
Results of the human health and ecological risk assessments and remedial investigations were
evaluated using applicable screening criteria to determine the potential existence of chemicals of
potential concern (COPCs) at each Basewide OU site. The sites with COPCs identified were
evaluated under one of three land-use scenarios, in accordance with the Disposal and Reuse ROD
as amended [USAF 1993], which are dependent upon anticipated future site use or access as
follows:
• Occupational - Sites IOC/68 and 20;
• Recreational - Site 87; and
Residential - Sites 18, 23, and 86.
In addition, those sites that do not have an anticipated residential land-use (per the Disposal and
Reuse ROD [USAF 1993]) were re-evaluated under the more stringent residential scenario in
order to facilitate risk management decisions. Chemicals of concern and cleanup goals have
been developed for all sites to be at levels suitable for residential land-use, except for Site 87
which will be remediated to levels suitable for recreational land-use. Since cleanup is to
non-residential standards at Site 87, institutional controls would be implemented to restrict
activities that may endanger public health.
Contamination exists at Basewide OU sites as a result of past United States Air Force (Air Force)
operations conducted between 1918 and 1993. The Basewide OU is comprised of contaminated
soils associated with waste disposal pits, underground storage tanks, fire training areas, sewage
treatment facility/systems, a gun range, and a skeet/trap range. Sources of contamination at the
Basewide OU sites include equipment maintenance, industrial activities, fire suppression
training, sewage treatment, spent ammunition, and fuels storage and delivery.
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Installation Restoration Program activities (i.e., environmental studies) were initiated at
Mather AFB by the Air Force in 1982 to investigate the extent of soil and groundwater
contamination resulting from past base operations. These previous investigations have
confirmed the presence of volatile organic compounds and other hydrocarbons at several of the
IRP sites. Based on this, the entire base was proposed for listing on the Superfund (CERCLA)
National Priorities List (NPL) in July 1989, and was placed on the NPL on November 21, 1989.
In July 1989, the Air Force, the USEPA, and the State of California signed a Federal Facility
Agreement, 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 human health, welfare, and the environment. The Federal Facility Agreement sets
enforceable deadlines for documents, defines roles and responsibilities of each signatory party,
and provides a vehicle for dispute resolution. The Air Force is the owner of the site, the principal
responsible party, and lead agency for conducting investigative and cleanup activities. There
have been no CERCLA enforcement actions at the Basewide OU sites.
The Final Basewide OU FFS Report [IT 1997a] and Proposed Plan [IT 1997b] became available
to the public in 1997. The FFS identified, screened, and compared alternatives applicable for site
cleanup. The Proposed Plan summarized the cleanup alternatives presented in the FFS,
presented the recommended cleanup actions, explained the reasons for recommending the
actions, and solicited comments from the community on the actions. The Administrative Record
for Mather AFB, which includes copies of the FFS report and supporting site-related documents,
is available for review at the Air Force Base Conversion Agency office at Mather AFB. In
addition, selected major documents are available for review at the Rancho Cordova Community
Library and the Sacramento Central Library.
Formal request for public comment on the Proposed Plan [IT 1997b] and FFS Report [IT 1997a]
was published in the Sacramento Bee on May 22,1997. The public comment period extended
from May 23, 1997 through June 23, 1997, to allow the public a chance to comment on the
Proposed Plan and the supporting remedial investigation and FFS reports. A public meeting was
held at Mather AFB (Denker Hall) on May 29, 1997. Representatives from the Air Force, the
USEPA Region IX, the California Central Valley Regional Water Quality Control Board
(CVRWQCB), and the California Department of Toxic Substances Control were present at the
meeting. Representatives from the Air Force and regulatory agencies answered questions about
the Basewide OU sites and the remedial alternatives under consideration.
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The Air Force, the USEPA Region IX, and the State of California concur with the selected
remedial actions. Cleanup options have been selected for Sites IOC/68, 18, 20, 23, 86, and 87.
Cleanup options were not developed for sites at which no chemicals were identified that would
require the need for remedial action (i.e., no contaminants of concern were identified). Based on
the calculations in the human health risk assessment, excess lifetime cancer risks fall within or
*
below the range of one-in-one million to one-in-ten thousand and non-cancer risks were less than
a hazard index of 1.0 under both the current and future land uses examined for each site.
Additionally, site-specific information was evaluated which determined that cleanup or further
investigative activities are not warranted for these sites. The Basewide OU no further action sites
are: Sites 2, 8, 17, expanded 19, 67, 81, and 84.
The remedial alternatives for Site 2 were presented in the Landfill OU FFS [IT 1993b] and
Proposed Plan [IT 1993c]. Capping was the remedial action proposed in the Proposed Plan and
selected in the ROD [USAF 1995]. However, once cap construction was initiated, it was
apparent that there was less refuse at Site 2 and that there was an opportunity to consolidate the
refuse from Site 2 into Site 4 prior to Site 4 being capped. This was judged more cost-effective
based upon the revised estimate of refuse volume, and additionally would be less restrictive to
future airport development. A Removal Action Memorandum [USAF 1996a] was approved on
September 1996, to document this fundamental change to the Landfill OU ROD [USAF 1995].
All the refuse at Site 2 was excavated and consolidated into Site 4 in 1996, as documented in the
Final Closure Certification Report for Landfill Sites [MW 1997a]. Therefore, this ROD confirms
that the excavation and consolidation of refuse from Site 2 into Site 4 constitutes the final
remedy for Site 2.
No further action under CERCLA is requried for the "petroleum only" sites based on the lack of
statutory authority under CERCLA. The "petroleum only" sites are: Sites 82 and 83. Based on
the calculations in the human health risk assessment, excess lifetime cancer risks fall within or
below the range of one-in-one million to one-in-ten thousand and non-cancer risks are less than a
hazard index of 1.0. However, these sites do not meet criteria for closure under Subtitle I of the
Resource Conservation and Recovery Act or other applicable State of California regulations.
Regulatory oversight will be provided by the CVRWQCB.
There are differences between information presented in the Basewide OU FFS [IT 1997a] and
Proposed Plan [IT 1997b] and this ROD. The main changes effect Sites IOC/68, 80, 81, 85, and
88. For Site IOC, debris existed in an apparent buried disposal pit, with associated lead
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contamination detected in a soil sample. The size of the pit was approximately 20 by 30 feet
with debris found to a depth of six feet below ground surface. A Time-Critical Removal Action
Memorandum for Site IOC was prepared [USAF 1996b] to document the decision to excavate
this waste and consolidate the waste into Site 4. The excavated material was disposed at Landfill
Site 4 after it was determined to meet the acceptance criteria. Confirmation sampling indicated
that lead concentrations remaining in the soil were below the cleanup standard. Based on recent
excavation and confirmation samples at Sites IOC/68, surface soil with lead contamination above
the cleanup standard has been removed. Other contaminants of concern at Site IOC/68 will still
be remediated. This ROD confirms that the removal action at Site 1OC constitutes the final
remedy for lead contamination at this site. Therefore, additional excavation is no longer needed,
and the selected remedy no longer includes excavation, stabilization, and disposal of the
contaminated surface soils. Additionally, Sites 80, 85, and 88, all of which are ditch sites, are
not included in this ROD and will be documented in a future Mather ROD since the extent of
contamination is not fully defined to detection limits consequently consensus has not been
reached on cleanup levels. Site 81 was selected for no further action after reconsideration of
conservative risk assessment assumptions indicated there is not a significant risk to human health
at this site.
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1.0 Introduction
This decision document presents the selected remedial actions for the Basewide Operable Unit
(OU) sites, at the formerly active Mather Air Force Base (AFB), 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 and Reauthorization Act of 1986 (SARA) and, to the extent
practicable, in accordance with the National Oil and Hazardous Substances Pollution
Contingency Plan (NCP). The decisions, documented herein, are based on information contained
in the Administrative Record for the subject sites. The Administrative Record Index
(Appendix A) identifies documents that were considered or relied upon to make these decisions.
The purpose of this Record of Decision (ROD) is to document the selection of the appropriate
level of remediation necessary to protect human health, the environment, and
groundwater/surface water beneficial uses, and define which legal requirements are applicable or
relevant and appropriate requirements (ARARs) based on site-specific conditions.
This ROD has been divided into six sections which specifically address the selected remedial
actions for the Basewide OU sites. These six sections are:
Section l.O - Introduction
This section presents a summary of the selected remedial alternatives, as
well as signatures of concurrence by the United States Air Force (Air
Force), United States Environmental Protection Agency (USEPA), and the
State of California.
Section 2.0 - Basewide OU Sites Selected for Remedial Action
This section documents the remedial actions selected for soil sites where
cleanup is warranted.
Section 3.0 - Basewide OU Sites Selected for No Further Action
This section documents the decision that no action is warranted at
specified soil sites because conditions pose no current or potential future
threat to human health or the environment.
Section 4.0 - Basewide OU "Petroleum Only" Sites Selected for No Action Under
CERCLA (but which remain to be closed under other regulations')
This section documents the decision that no action is warranted under
CERCLA. Comprehensive Environmental Response, Compensation, and
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Liability Act of 1980 does not provide the appropriate legal authority to
undertake a remedial action at petroleum only soil sites. The no action
decision does not constitute a finding that adequate protection has been
achieved at the sites. Cleanup alternatives have been developed and will
be implemented under the Resource Conservation and Recovery Act
(RCRA) Subtitle I, other appropriate State of California regulations, and
the Defense Environmental Restoration Program.
• Section 5.0 - Listing of ARARs and Performance Standards
This section describes all federal and state ARARs and performance
standards that must be addressed under this ROD.
• Section 6.0 - Responsiveness Summary
This section contains comments received during the public comment
period and public meeting and responses to those comments.
The Basewide OU sites selected for remedial action (Section 2.0) are the main focus of this
ROD.
1.1 Basewide Operable Unit Background
The formerly active Mather AFB is located in the Central Valley region of northern California in
Sacramento County, approximately ten miles east of downtown Sacramento, California, and due
south of unincorporated Rancho Cordova, California, as shown on Figure l-l. Mather AFB is
due south of U.S. Highway 50, a major highway connecting Sacramento and South Lake Tahoe
and encompassed approximately 5,845 acres at time of closure (including 129 acres of
easements) in an unsurveyed part of Township 8 North, Ranges 6 East and 7 East. Mather AFB
was constructed in 1918 and its primary mission was as a flight training school. The base was
decommissioned under the Base Realignment and Closure Act on September 30, 1993.
The Basewide OU addresses sites which had not been included as part of the Soil OU [IT 1996a],
the Groundwater OU [IT 1996a], the Aircraft Control and Warning (AC&W) OU [IT 1993a], or
the Landfill OU [USAF 1995]. Sites 80, 85, and 88 were included in the Basewide OU;
however, they have been removed from this ROD and will be included in a future ROD.
Contamination exists at Basewide OU sites as a result of past Air Force operations conducted
between 1918 and 1993. The Basewide OU is comprised of contaminated soils associated with
waste disposal pits, underground storage tanks (USTs), fire training areas, sewage treatment
facility/systems, a gun range, and a skeet/trap range. Sources of contamination at the
1-2
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Me CLELLAN
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Basewide OU sites include equipment maintenance, industrial activities, fire suppression
training, sewage treatment, spent ammunition, and fuels storage and delivery. Table 1-1 presents
a list of the Installation Restoration Program (IRP) sites and the corresponding ROD in which
they are documented.
Installation Restoration Program activities (i.e., environmental studies) were initiated at
Mather AFB by the Air Force in 1982 to investigate the extent of soil and groundwater
contamination resulting from past base operations. These previous investigations have
confirmed the presence of volatile organic compounds (VOCs) and other hydrocarbons at several
of the IRP sites. Based on this, the entire base was proposed for listing on the Superfund
(CERCLA) National Priorities List (NPL) in July 1989, and was placed on the NPL on
November 21, 1989. In July 1989, the Air Force, the USEPA, and the State of California signed
a Federal Facility Agreement, 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 human health, welfare, and the environment. The Federal Facility Agreement
sets enforceable deadlines for documents, defines roles and responsibilities of each signatory
party, and provides a vehicle for dispute resolution. The Air Force is the owner of the site, the
principal responsible party, and lead agency for conducting investigative and cleanup activities.
There have been no CERCLA enforcement actions at the Basewide OU sites.
The Final Basewide OU FFS Report [IT 1997a] and Proposed Plan [IT 1997b] became available
to the public in 1997. The FFS identified, screened, and compared alternatives applicable for site
cleanup. The Proposed Plan summarized the cleanup alternatives presented in the FFS,
presented the recommended cleanup actions, explained the reasons for recommending the
actions, and solicited comments from the community on the actions. The Administrative Record
for Mather AFB, which includes copies of the FFS report and supporting site-related documents,
is available for review at the Air Force Base Conversion Agency office at Mather AFB. In
addition, selected major documents are available for review at the Rancho Cordova Community
Library and the Sacramento Central Library.
Formal request for public comment on the Proposed Plan [IT 1997b] and FFS Report [IT 1997a]
was published in the Sacramento Bee on May 22, 1997.
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1-4
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Table 1-1. Installation Restoration Program Sites and their Corresponding
Records of Decision
IRP Site Number
1
2 (a)
3
4
5
6
7/11
8
9
10
IOC
12
13
14
15
16
17
18
19
expanded 19
20 (b)
21
22
AC&W
OU
X
Landfill OU
X
X
X
X
X
X
GW OU/Soil
OU
X
X
X
•
X
X
X
X
X
X
X
X
Basewide
OU
X
X
X
X
X
X
X
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Table 1-1. Installation Restoration Program Sites and their Corresponding
Records of Decision (Continued)
IRP Site Number
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
39
40
41
42
43
44
45
46
AC&W
OU
X
X
Landfill OU
GW OU/Soil
OU
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Basewide
OU
X
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Table 1-1. Installation Restoration Program Sites and their Corresponding
Records of Decision (Continued)
IRP Site Number
47
48
49
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70 (formerly Site A)
AC&W
OU
X
Landfill OU
GW OU/Soil
OU
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
X
Basewide
OU
X
X
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Table 1-1. Installation Restoration Program Sites and their Corresponding
Records of Decision (Continued)
IRP Site Number
71 (formerly Site B)
72 (formerly Site C)
73 (formerly Site E)
74 (formerly Site F)
75 (formerly Site G)
76 (formerly Site H)
77 (formerly Site I)
78 (c)
79 (c)
81
82
83
84
86
87
AC&W
OU
Landfill OU
GW OU/Soil
OU
X
X
X
X
X
X
X
Basewide
OU
1
X
X
X
X
X
X
Note: Sites 80, 85, 88, and 89 were removed from the Basewide Operable Unit and will be addressed in a future
ROD.
(a) Site 2 was originally a Landfill Operable Unit site and was remediated under a Removal Action Memorandum
[USAF 1996a]. (b) The site has been documented in the Soil OU and Groundwater OU ROD [IT 1996a];
however, the digester tank area associated with the site was investigated further during the Additional Site
Characterization Investigation [IT 1996b] and Final Comprehensive Baseline Risk Assessment [IT 1996c] and was
referenced as the Sewage Treatment Facility.
(c) This site was not included in any operable unit; however, it is designated as a non-Comprehensive
Environmental Response, Compensation, and Liability Act petroleum site.
OU = operable unit
AC&W = Aircraft Control and Warning
GW = Groundwater
IRP = Installation Restoration Program
ROD = Record of Decision
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The public comment period extended from May 23,1997 through June 23, 1997, to allow the
public a chance to comment on the Proposed Plan and the supporting remedial investigation (RI)
and FFS reports. A public meeting was held at Mather AFB (Denker Hall) on May 29, 1997.
Representatives from the Air Force, the USEPA Region IX, the California Central Valley
Regional Water Quality Control Board (CVRWQCB), and the California Department of Toxic
Substances Control (DTSC) were present at the meeting. Representatives from the Air Force and
regulatory agencies answered questions about the Basewide OU sites and the remedial
alternatives under consideration. The Responsiveness Summary (Section 6.0) contains
comments received during the public meeting and public comment period and the Air Force
responses to these comments.
The Air Force, the USEPA Region IX, and the State of California concur with the selected
remedial actions (which are presented in Table 1-2) and statutory determinations for each of the
separate sections of this ROD. Concurrence by the parties is indicated by the signatures in
Section 1.3.
1.1.1 Basewide Operable Unit Sites Selected for No Further Action
Cleanup options were not developed for sites at which no chemicals were identified that would
require the need for remedial action (i.e., no contaminants of concern [COCs] were identified).
Based on the calculations in the human health risk assessment, excess lifetime cancer risks fall
within or below the range of one-in-one million to one-in-ten thousand and non-cancer risks are
less than a hazard index of 1.0 under both the current and future land uses examined for each site.
Additionally, site-specific information was evaluated which determined that cleanup or further
investigative activities are not warranted for these sites. These no further action sites are:
Sites 2, 8, 17, expanded 19, 67, 81, and 84.
The remedial alternatives for Site 2 were presented in the Landfill OU FFS [IT 1993b] and
Proposed Plan [IT 1993c]. Capping was the remedial action proposed in the Proposed Plan
[IT 1993c] and selected in the Landfill OU ROD [USAF 1995]. However, once cap construction
was initiated, it was apparent that there was less refuse at Site 2 and that there was an opportunity
to consolidate the refuse from Site 2 into Site 4 prior to Site 4 being capped. This was judged
more cost-effective based upon the revised estimate of refuse volume, and additionally would be
less restrictive to future airport development. A Removal Action Memorandum [USAF 1996a]
was approved on September 1996, to document this change. All the refuse at Site 2 was
excavated and consolidated into Site 4 in 1996, as documented in the Final Closure Certification
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Table 1-2. Preferred Remedial Alternatives for the Basewide Operable Unit Sites
Selected for Remedial Action
Selected Remedial
Alternative
IOC/68.4
18.2
20.4
23.2
86.2
87.2
Description
In situ treatment (i.e., soil vapor extraction and/or bioremediation) of fuel-contaminated
subsurface soils.
Soil vapor extraction of the contaminated shallow and deep subsurface soils, as appropriate.
Excavation, stabilization (if needed for disposal), and transportation and placement of those
soils at Site 7 for onbase treatment and use as foundation material in the construction of a cap
(assuming Site 7 acceptance criteria are met) or to an appropriate off-base disposal facility.
Ex situ bioremediation of the excavated soils until treatment standards are achieved. In
addition, a groundwater monitoring well will be installed and monitored.
Soil vapor extraction of the contaminated shallow and deep subsurface soils, as appropriate.
Excavation, stabilization (if needed for disposal), and transportation of the contaminated
surface soils to either Site 7 for use as foundation material in the construction of a cap if the
soils meet Site 7 acceptance criteria or to an appropriate off-base disposal facility.
Excavation, stabilization (if needed for disposal), and transportation of the contaminated
surface soils and sediments to either Site 7 for use as foundation material in the construction
of a cap if the materials meet Site 7 acceptance criteria or to an appropriate off-base disposal
facility. In addition, since cleanup at this site is to non-residential standards, institutional
controls will be implemented to restrict activities that may endanger public health.
Note: At Sites 1OC/68 installation and pilot testing of a soil vapor extraction system was conducted in August 1997. However.
following consistently low influent concentrations the system was shut down in December 1997. The system is currently shut
down to evaluate the rebound of contaminant concentrations in the vadose zone and to determine if in situ bioremediation is
more appropriate for this site. As part of a removal action performed by Montgomery Watson in 1996 [USAF 1996b], the debris
identified in the surface soils at the Site IOC burn pit was excavated, transported to, and disposed into Site 4 under authority of a
Removal Action Memorandum [USAF I996b]. The disposal pit was then backfilled with clean soil.
Report for Landfill Sites [MW 1997a]. Therefore, this ROD confirms that the removal action at
Site 2 constitutes the final remedy for Site 2.
1.1,2 Petroleum Only Sites Selected for No Further Action Under Comprehensive
Environmental Response; Compensation, and Liability Act (which remain
to be closed under other regulations)
A "no action" decision is the selected remedy for the "petroleum only" sites based on the lack of
statutory authority under CERCLA. The "petroleum only" sites are Sites 82 and 83. Based on
the calculations in the human health risk assessment, excess lifetime cancer risks fall within or
below the range of one-in-one million to one-in-ten thousand and non-cancer risks are less than a
hazard index of 1.0. However, these sites do not meet criteria for closure under RCRA Subtitle I
or other applicable State of California regulations. Regulatory oversight will be provided by the
CVRWQCB.
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1.2 Significant Changes from the Focused Feasibility Study and Proposed
Plan
There have been a number of differences between the FFS [IT I997a], Proposed Plan [IT I997b],
and this document. The following subsections briefly describe the changes and reasons for the
changes.
1.2.1 Sites 10C/68
The FFS [IT I997a] identified COCs at Sites IOC/68 as lead, oil and grease, total petroleum
hydrocarbons (TPH) measured as diesel, TPH measured as gasoline, and volatile organic
compounds (benzene, toluene, ethylbenzene, and xylene [BTEX] and carbon tetrachloride) all of
which were identified based on protection of groundwater quality.
The preferred alternative as presented in the Proposed Plan [IT I997b] consisted of the following
components:
• excavate the lead-contaminated surface soils, stabilize the soils (if appropriate),
and dispose onbase at Site 7; and
• treat remaining in-place soils using a combination of soil vapor extraction (SVE)
and/or bioremediation.
Since these documents have been issued, Montgomery Watson has performed activities at the
site which include soil excavation activities and installation and testing of an SVE pilot system.
Debris existed in an apparent buried disposal pit at Site IOC, with associated lead contamination
detected in a soil sample. The size of the pit was approximately 20 by 30 feet with debris found
to a depth of six feet below ground surface. A Time-Critical Removal Action Memorandum for
Site IOC was prepared [USAF I996b] to document the decision to excavate this material and
consolidate the material into Site 4. The excavated material was disposed at Landfill Site 4 after
it was determined to meet the acceptance criteria. Confirmation sampling indicated that
concentrations remaining in the surface soil were below the cleanup standard and were deleted as
COCs. Therefore, since excavation activities abated the problem with the surface soils, the only
remaining component of the preferred alternative is in situ treatment of the subsurface soils
(i.e., for TPH and VOCs).
1.2.2 Sites 80, 85, and 88
Sites 80, 85, and 88, all of which are ditch sites, were initially evaluated and proposed for
remedial action. However, based on recent conversations with the regulators it was noted that
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the extent of contamination is not well defined, toxicity tests are not conclusive, and consensus
has not been reached on cleanup levels. Therefore, it is premature to include these sites in this
Basewide OU ROD; however, the sites will be addressed in a future Mather ROD.
1.2.3 Site 2
The Site 2 landfill was documented in the Landfill OU ROD [USAF 1995]. Subsequent to the
ROD, a Removal Action Memorandum [USAF I996a] documented a change in remedy from
capping (selected in the ROD) to excavation of the refuse and consolidation in the Site 4 landfill.
This Basewide OU ROD confirms that the removal action at Site 2 constitutes the final remedy
for Site 2.
1.2.4 Site 81
The FFS [IT I997a] and Proposed Plan [IT I997b] identified the need for remediation based on
TPH measured as diesel in the soils/sediments and an unacceptable human health risk from
inhalation of dust (i.e., cadmium). However, additional sampling was conducted by
Montgomery Watson to measure soluble levels for TPH [MW 1998]. Based on the TPH results
and subsequent conversations with the RWQCB, it was determined that the TPH does not pose a
threat to groundwater quality; therefore, TPH is not a COC. The only COC identified in the
sediments/surface soils (e.g., maximum of three feet deep) was cadmium which was based on
protection of human health (i.e., inhalation of dust). The estimate of total residential ILCR at the
Sewage Oxidation Ponds was 1.6 x 10'5, with cadmium contributing all of the risk through the
inhalation of dust pathway. This ILCR is below the USEPA upper bound limit of 1 x 10'4
(therefore the site as a whole does not pose significant carcinogenic risk, but is still within the
range of concern of 1 x 10'6 to 1 x 10"4. However, there were numerous conservative
assumptions built into the calculation of risk at the Sewage Oxidation Pond. The following is a
brief description of these assumptions and a more realistic inhalation of dust risk calculation for
the Sewage Oxidation Ponds.
The initial ILCR estimate presented in the CBRA [IT 1996c] for dust inhalation included the
following assumptions;
• the cadmium was present at the 95 percent upper confidence limit over the entire
site (1.5 x 105 square meters);
• there was no vegetation at the site;
1-1?
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• the California Environmental Protection Agency slope factor ([15 mg/kg-day]"1)
was used in the calculation of risk instead of the less conservative USEPA value
found in Integrated Risk Information System ([6.3 mg/kg-day]"1);
• the wind was assumed to prevail in the direction of the receptor 100 percent of the
time; and
• the wind speed was assumed to be strong enough to carry dust 100 percent of the
time.
Upon further examination the majority of the cadmium above background is limited to the
western portion of the northern most oxidation pond (pond No. 4) and is a small fraction of the
site area (approximately one quarter). When this new area (approximately 30,000 square meters)
was used in the ILCR calculation and using a 50 percent vegetative cover assumption, the site
falls near the 1 x 10"6 threshold (i.e., 1.3 x 10"*). Under these conditions and without examining
the remaining conservative assumptions above, this site does not pose a significant threat to
human health. Therefore, this site was selected for no further action.
1.3 Assessment of Comprehensive Risk
In addition, this ROD incorporates an assessment of the comprehensive risk from all the previous
operable units. The Basewide OU Focused Feasibility Study (FFS) included a screening-level
review of the cleanup standards established in previous Mather AFB RODs, as well as the
Basewide OU cleanup standards, to determine whether possible cumulative effects from multiple
contaminants exceed acceptable health risk levels (a hazard quotient of I or an excess cancer risk
of I in 10,000). The screening-level review indicated that all but one soil site and the
Groundwater OU had cleanup standards that were not of concern. The cleanup standards from
Site 69 (the one soil site) and the Groundwater OU required more detailed assessment.
The cleanup standards for surface soils at Site 69 could result in an unacceptable risk if each of
the nine categories of dioxins and furans were cleaned up just to the cleanup standard, and
concentrations of all of these chemicals remained at the site at the cleanup level. In fact, the soils
at Site 69 containing dioxins and furans were removed and placed in Mather landfill Site 4 in
1996. Confirmation sampling for dioxins and furans resulted in only one detection, of
octachlorodibenzo-p-dioxin (OCCD), in ten samples [MW 1998], indicating that there are no
longer concentrations of chemicals remaining in surface soils at Site 69 that pose an unacceptable
risk.
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The groundwater cleanup standards for the Groundwater OU were acceptable except for the fact
that the cleanup standard for 1,1-dichloroethene (DCE), which is the same as the California
drinking water standard, exceeded the acceptable health risk levels based upon the best estimate
of cancer risk published by USEPA [USEPA 1994]. However, this estimate contains a great deal
of uncertainty and conservatism, and the Remedial Project Managers agree that the drinking
water standard is an appropriate cleanup standard. In addition, in order to achieve the cleanup
standard of the other volatile contaminant in the groundwater, 1,1-DCE concentrations will be
reduced well below the cleanup standard.
The cleanup standard for lead in the groundwater, which is set at the tap-water standard, also
represents a hazard index above one, but lead has only been detected at concentrations above the
cleanup standard in a few locations in the groundwater. As water from many extraction wells is
blended in the groundwater treatment system, any elevated lead concentrations are expected to be
reduced because of the mixing process.
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1.4 Signatures
Albert F. Lowas, Jfy
Director, Air Force Base C
U.S. Air Force
'ersion Agency
Janiel D.
Chief, Federal Facilities Cleanup Branch
U.S. Environmental Protection Agency Region IX
Date
Anthony J. Larj0is, P.E.
Chief, Northern California Operations
Office of Military Facilities
Department of Toxic Substances Control
California Environmental Protection Agency
Date
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2.0 Basewide Operable Unit Sites Selected for Remedial
Action
2.1 Declaration for the Basewide Operable Unit Sites Selected for Remedial
Action
Statutory Preference for Treatment as a
Principal Element is Met
and a Five-Year Review is Required at those Basewide OU
Sites Selected for Remedial Action Under CERCLA
2.1.1 Site Name and Location
Basewide OU Sites (IRP Sites) Selected for Remedial Action
Mather AFB (a NPL Site)
Sacramento County, California
2.1.2 Statement of Basis and Purpose
The Basewide OU sites were investigated under the Mather AFB IRP and are described and
evaluated in the remedial investigation/feasibility study (RJ/FS) documents [IT 1996b and
IT I997a]. This ROD has the following purposes:
• certify that the remedy selection process was carried out in accordance with the
requirements of CERCLA;
• outline the engineering components and cleanup goals of the selected remedies;
• provide the public with a consolidated source of information for the site, as well as
a summary of cleanup alternatives considered, evaluated, and reason(s) selected;
and
• assess risk from all previously documented operable units.
This section presents the selected remedial actions for Basewide OU sites at which remedial
action is warranted. These sites include:
Sites IOC/68 - Former Fire Department Training Area No. 3/Two 2,000 Gallon
and Sixteen 50,000 Gallon USTs at Fuel Transfer Station;
Site 18-Old Burial Site;
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• Site 20 - Sewage Treatment Facility;
• Site 23 - Sanitary Sewer Line (Main Base Area);
• Site 86 - Military Firing Range; and
Site 87 - Skeet/Trap Range.
Remedial actions were chosen in accordance with CERCLA, as amended by SARA, and, to the
extent practicable, in accordance with the NCP. All remedial decisions are based on the
Administrative Record for these sites.
The USEPA Region IX and the State of California concur with the selection of remedial
alternatives for each of the Basewide OU sites.
2.1.3 Assessment of the Basewide Operable Unit Sites
Contamination exists at these Basewide OU sites as a result of past Air Force operations
conducted between 1918 and 1993. The main sources of contamination include industrial
activities, fire suppression training, sewage treatment, spent ammunition, and fuels storage and
delivery. Results of the human health and ecological risk assessments and RIs were evaluated
using applicable screening criteria to determine the potential existence of COCs at each
Basewide OU site. A formal Comprehensive Baseline Risk Assessment (CBRA) was conducted
at all Basewide OU sites, except Sites 86 and 87, with results documented in the CBRA Report
[IT 1996c], However, a screening level risk assessment for Sites 86 and 87 was conducted with
details presented in Appendices B and C, respectively. The screening level risk assessment
consisted of evaluating the ecological and human health risks posed by the identified COCs.
Table 2-1 presents a summary of site risks for the Basewide OU sites.
Based on the human health risk assessment, all cancer risks are within or below the acceptable
range of 1 x 10"4 to 1 x 10"6 and all non-cancer risks have a hazard index of less than 1.0 in their
current state, except for Site 87, which has an estimated future total non-carcinogenic risk greater
than 1.0 (however, no individual risk is greater than 1.0).
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Table 2-1. Summary of Site Risks for Basewide Operable Unit Sites
Where Remedial Action is Warranted
Installation
Restoration Site
Number
IOC/68 (c)
I8(c)
20 (c)
23 (c)
86 (c)
87 (e)
Maximum
Carcinogenic Risk
(ILCR)
3. Ox 10^(0
None
1.2xlO-$
None
2.5x1 0'3
4.9x1 0's
Non-Carcinogenic Risk
(HQ)
<1.0
<1.0
<1.0
None
-------
and plants were analyzed for chemical concentrations. This information, in addition to field
observations and professional judgement, was used to validate earlier screening assessment
results obtained from the use of literature obtained values, model parameter values, and
conservative exposure concentrations. Based on this information, an ecological risk exists only
(medium or higher) at Site 87. The selected remedies at the Basewide OU sites will be instituted
to reduce risk to human health, and/or reduce the risk to ecological receptors, and/or for the
protection of groundwater and surface water quality.
Chemicals were classified as COCs if assessment efforts determined that they could adversely
impact groundwater/surface water or pose unacceptable ecological or human health risks. In
accordance with the Disposal and Reuse ROD as amended [USAF 1993] issued by the Air Force,
the Basewide OU sites (where COCs were identified) were evaluated in the FFS Report
[IT I997a] under one of three land-use scenarios which were dependent upon anticipated future
site use or access:
Occupational - Sites IOC/68 and 20;
• Recreational - Site 87; and
Residential - Sites 18,23, and 86.
However, implementation of the selected remedy for sites evaluated under occupational and
recreational land-use scenarios would achieve cleanup compatible with residential development
with a minimal increase in cost, except for Site 87. The minimal cost increase is due to the fact
that cleanup to residential-use levels versus occupational- or recreational-use does not
significantly increase the volume of soil to be remediated. Therefore, due to minimal cost
increases, all sites will be remediated to levels suitable for residential land-use, excluding Site 87
which will be remediated to levels suitable for recreational land-use.
Actual or threatened releases of hazardous substances from these sites, if not addressed by
implementing the response actions selected in this section of the ROD, may present an imminent
and substantial endangerment to human health, welfare, and/or the environment.
A summary of site characteristics for each of the Basewide OU sites is provided in Section 2.2.5.
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2.1.4 Description of the Selected Remedy
This section summarizes the major components of the preferred remedies for contamination at
Sites IOC/68, 18, 20, 23, 86, and 87. Table 2-2 provides the major components of the selected
remedy for each of the Basewide OU sites selected for remedial action.
Table 2-2. Preferred Remedial Alternatives for the Basewide Operable Unit Sites
Selected for Remedial Action
Selected Remedial
Alternative
IOC/68.4
18.2
20.4
23.2
86.2
87.2
Description
In situ treatment (i.e., soil vapor extraction and/or biorcmcdiation) of fuel-contaminated
subsurface soils.
Soil vapor extraction of the contaminated shallow and deep subsurface soils, as appropriate.
Excavation, stabilization (if needed for disposal), and transportation and placement of those
surface soils at Site 7 for onbase treatment and use as foundation material in the construction
of a cap (assuming Site 7 acceptance criteria are met) or to an appropriate off-base disposal
facility. Ex situ bioremcdiation of the excavated surface soils until treatment standards are
achieved. In addition, a groundwater monitoring well will be installed and monitored.
Soil vapor extraction of the contaminated shallow and deep subsurface soils, as appropriate.
Excavation, stabilization (if needed for disposal), and transportation of the contaminated
surface soils to either Site 7 for use as foundation material in the construction of a cap if the
soils meet Site 7 acceptance criteria or to an appropriate off-base disposal facility.
Excavation, stabilization (if needed for disposal), and transportation of the contaminated
surface soils and sediments to either Site 7 for use as foundation material in the construction
of a cap if the materials meet Site 7 acceptance criteria or to an appropriate off-base disposal
facility. In addition, since cleanup at this site is to non-residential standards, institutional
controls will be implemented to restrict activities that may endanger public health.
Note: At Sites IOC/68 installation and pilot testing of a soil vapor extraction system was conducted in August 1997. However,
following consistently low influent concentrations the system was shut down in December 1997. The system is currently shut
down to evaluate the rebound of contaminant concentrations in the vadose zone and to determine if in situ bioremcdiation is
more appropriate for this site. A:> pan of a removal action performed by Montgomery Watson in 1996 [USAF I996b), the debris
identified in the surface soils at the Site IOC bum pit was excavated, transported to, and disposed into Site 4 under authority of a
Removal Action Memorandum [USAF 1996b). The disposal pit was then backfilled with clean soil.
2.1.5 Statutory Determinations
The selected remedies satisfy the statutory requirements of Section I2l(b) of CERCLA, as
amended by SARA, in that the following mandates are attained:
• selected remedies are protective of human health, the environment, and/or
groundwater/surface water quality;
• selected remedies comply with federal and state requirements that are legally
applicable or relevant and appropriate to the remedial actions;
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• selected remedies are cost-effective; and
• selected remedies use permanent solutions and alternative treatment technologies,
or resource recovery technologies, to the maximum extent practicable.
A review will be conducted within five years after commencement of the remedial actions to
ensure that the remedies continue to provide adequate protection of human health and the
environment, and protect water quality for its beneficial uses.
2.2 Decision Summary for Basewide Operable Unit Sites Selected for Remedial
Action
The Decision Summary provides an overview of the site characteristics, the alternatives
evaluated, and the analysis of those options. The Decision Summary also identifies the selected
remedy and explains how the remedy fulfills statutory requirements.
2.2.1 Site Names, Locations, and Descriptions
The Basewide OU sites selected for remedial action at Mather AFB are presented in Figure 2-1
and include: Sites IOC/68 - Former Fire Department Training Area No. 3/Two 2,000 Gallon and
Sixteen 50,000 Gallon USTs at Fuel Transfer Station, Site 18 - Old Burial Site, Site 20 - Sewage
Treatment Facility, Site 23 - Sanitary Sewer Line Main Base Area, Site 86 - Military Firing
Range, and Site 87 - Skeet/Trap Range. More detailed site maps are presented in the Basewide
OU FFS Report [IT 1997a] and in Section 2.2.5 below.
2.2.2 Site History and Enforcement Activities
Previous investigations have been conducted at the sites listed in Section 2.2.1 as part of the Air
Force IRP. No enforcement activities have been conducted for the Basewide OU sites. A listing
of the investigations conducted at each of these sites is summarized in Table 2-3.
2.2.3 Highlights of Community Participation
The public participation requirements of CERCLA Sections 113(k)(2)(B)(i-v) and 117 were met
through a public comment period (held May 23 through June 23,1997) and public meeting (held
May 29, 1997) to address the Proposed Plan [IT 1997b] and content of supporting RI/FS
documents.
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2-6
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SANITARY SEWCH LINE LOO I ION
RECREATKMWL L*NO-US£ Slit
R£SIDCMIVM. LAND-USE SITES
-------
Table 2-3. Previous Investigations at the Basewide Operable Unit Sites Selected
for Remedial Action
Site Number
IOC/68
18
20
23
86
87
Applicable Investigation
6, 10, 14, 15, 17
1,2,3,4,5,6,7,8,9, 11, 12, 14, 15,
1,2,4,6,8,9, 11, 12, 13, 14, 15, 1
1,6,9, 14, 15, 17
16, 17
16, 17
17
7
I. Installation Restoration Program (IRP) Records Search for Mather Air Force Base, Phase I [CH2M-Hill,
Inc. 1982);
2. IRP Phase II, Stage 2 Investigation [AeroVironment 1987J;
3. IRP Phase II, Stage 3 Investigation [AeroVironment 1988];
4. Well Redevelopment and Sampling Plan [IT I988a];
5. Solid Waste Assessment Test Report [IT 1993d];
6. Quarterly Routine Groundwater Sampling (IT 1995a] and [EA I990a-c];
7. Landfill Gas Testing Report [IT 1 988b];
8. Site Inspection Report [IT 1990a];
9. Group 2 Sites Remedial Investigation Report [IT 1992];
10. Group 3 Sites Technical Memorandum [IT 1993e];
1 1 . Final Soils and Groundwater Operable Unit (OU) Additional Field Investigation Report [IT 1 994a];
1 2. Groundwater OU and Soil OU Focused Feasibility Study (FFS) Report [IT 1 995b];
13. Mather Baseline Risk Assessment Report [IT 1 995cJ;
14. Additional Site Characterization Remedial Investigation Report [IT 1996b];
1 5. Comprehensive Baseline Risk Assessment Report [IT I996c];
16. Site Characterization for IRP Sites 86 and 87 (IT I997c]; and
1 7. Basewide OU FFS Report [IT 1997aJ.
2.2.4 Scope and Role of Response Action
Environmental studies were initiated by the Air Force in 1982 to investigate contamination
resulting from past operations at the base. The USEPA placed Mather AFB on the NPL (or
"Superfund" list) in 1989. To administer cleanup efforts, sites at Mather AFB were organized
into five operable units, such that sites with similar sources of contamination and site conditions
could be grouped together. Previous RODs presented cleanup options for the AC&W OU
[IT 1 993a] (where contaminated groundwater is currently being extracted and treated by air
stripping), the Landfill OU [USAF 1995] (where landfill caps are in-place or where refuse and
debris have been removed), the Soil OU [IT 1996a], and the Groundwater OU [IT 1996a]. The
Basewide OU addresses sites not included as part of the previous RODs and assesses the
comprehensive risk from all operable units. The Basewide OU FFS conducted a screening-level
review of the cleanup standards established in previous Mather AFB RODs, as well as the
RL/8-98/ES/392000I.AWS
-------
Basewide OU cleanup standards, to determine whether or not cumulative effects from multiple
contaminants exceed acceptable levels. The results indicated that all sites had appropriate
cleanup standards which provide adequate protection of human health and the environment, with
the exception of the surface soils at Site 69 and 1,1-DCE in the groundwater. The risk of
exposure to 1,1 -DCE is uncertain. The federal drinking water standard (maximum contaminant
level or MCL) of 7 micrograms per liter, is the cleanup standard, but is estimated to represent an
incremental lifetime cancer risk of IxlO"6. Additionally, the majority of surface soils at Site 69,
which posed the unacceptable risk, have been removed from the site. The remaining soils are
planned for remediation (i.e., excavation) in 1999.
2.2.5 Summary of Site Characteristics
Contamination exists at the Basewide OU sites as a result of past Air Force operations conducted
between 1918 and 1993. The Basewide OU is comprised of contaminated soils and sediments
associated with site drainages, disposal pits, USTs, a gun range, a skeet/trap range, fire training
areas, a waste burial site, a golf course maintenance area, a sewage treatment facility, and sewage
treatment systems.
Previous RJs have been conducted at Basewide OU sites as part of the Air Force IRP. A brief
description of each of the Basewide OU sites recommended for remedial action, including
summaries of hazardous material releases and the nature and extent of contamination, is provided
in the following sections.
2.2.5.1 Site 10C/68 - Former Fire Department Training Area No. 3/Two
2,000 Gallon and Sixteen 50,000 Gallon Underground Storage Tanks
at Fuel Transfer Station
For purposes of remediation, Sites IOC and 68 were grouped together based on proximity and
common contaminants. A pilot treatment system was installed in 1997 by the Air Force to
evaluate the effectiveness of in situ remediation technologies at these combined sites.
Sites IOC/68 (Figure 2-2) is located adjacent to the northwestern border of the "Charlie" Ramp
(Strategic Air Command [SAC] Refueling Apron). Petroleum, oil, and lubricant waste were
ignited and extinguished during training exercises conducted at the site. The combined site also
included two 2,000 gallon waste fuel USTs and sixteen 50,000 gallon USTs as part of the Fuel
Transfer Station, to the area of the former SAC refueling apron. The Fuel Transfer Station
consisted of pumps, filters, USTs, and valving which integrated the jet propellant fuel (JP-4)
pipeline delivery and storage system with individual fuel lines located beneath the SAC refueling
RU8.98/ES/392000I .AWS
2-9
-------
apron. In 1994, all USTs and ancillary valves and piping were removed. A summary of the
results of previous investigations conducted at Sites IOC/68 are presented in Tables 2-4 and 2-5,
respectively.
Additionally, the Air Force conducted a pilot SVE test in 1997 at Sites IOC/68 to determine the
extent of subsurface VOC and petroleum hydrocarbon contamination and evaluate the
effectiveness of using in situ treatment technologies. The data on contaminant distribution
acquired during the pilot test is reported in the Site Investigation and SVE System Installation
Report for Site IOC/68 [EA 1997]. Approximately 33 borings were drilled at the sites for use as
remediation SVE or bioventing wells, or soil gas monitoring wells. Most of the borings were
drilled to depths of about 40 feet, although several extended to near the water table at about
85 feet below ground surface. The data from this report indicates that gasoline contamination
extends no further than 30 feet below ground surface, leaving a separation of about 50 feet
between the deepest detection and groundwater. The system was installed in August 1997, and
an initial compliance source test of the SVE system was conducted on August 15, 1997. After
the compliance source test was conducted, the system was shut down while awaiting analytical
results. The analytical results indicated that the unit was operating in accordance with the
Sacramento Metropolitan Air Quality Management District (SMAQMD) requirements, and the
SVE system was restarted and became fully operational on August 21, 1997. The system was
operating at approximately 400 cubic feet per minute and was treating an influent vapor stream
with contaminant concentrations at approximately 50 parts per million volume. The SVE system
was shut down December 3, 1997, following consistently low influent concentrations. The
system is currently shut down to examine the rebound of contaminant concentration in the
vadose zone, and to determine if in situ bioremediation is more appropriate for this site.
Debris identified in an apparent buried disposal pit at Site IOC (along with lead-impacted surface
soil) was excavated, transported to, and disposed into Site 4 [MW 1998] by Montgomery Watson
under authority of a Removal Action Memorandum [USAF 1996b]. A Time-Critical Removal
Action Memorandum was prepared [USAF 1996b] to document the decision to excavate this
waste and consolidate the waste into Site 4. The size of the pit was approximately 20 feet by
30 feet, with debris found to a depth of six feet below ground surface. Eight confirmation
samples were collected and analyzed. Lead, motor oil, and oil and grease were detected in the
samples. Lead detections ranged from 4.7 to 99 milligrams per kilogram (mg/kg) and oil and
grease was detected at levels from 11 to 150 mg/kg, both of which were below the soil cleanup
standard. Motor oils were detected at levels ranging from 30 to 200 mg/kg (no cleanup level has
been established). The excavation was then backfilled with clean soil. Through these excavation
RL/8-98/ES/3920001. A WS
2-10
-------
activities, the impacted surface soils (previously identified in the FFS [IT 1997a] and Proposed
Plan [IT 1997b]) are no longer a concern at this site.
Contamination therefore only exists in the subsurface soils at both Site IOC and Site 68. The
COCs identified at Sites IOC/68 under a residential future land-use scenario include: petroleum
hydrocarbons (measured as diesel and gasoline) and VOCs. The basis for cleanup is protection
of groundwater quality. The impacted volumes are estimated at 24,000 cubic yards of subsurface
soils at Site IOC and 4,100 cubic yards of subsurface soils at Site 68.
RL/8-98/ES/3920001 .A WS
2-11
-------
I
1 (
10
H^
K)
105
210 FEET
-AREA SHOWN
\
SITE LAYOUT
LEGEND
OUSTING MONITORING WELL
'*
TIRE HYDRANT
SITE BOUNDARY
UST - UNDERGROUND STORAGE TANK
NOTES
I.) SITE IOC- NEW SITE ASSOCIATED WITH THE
rORMER FIRE DEPARTMENT TRAINING AREA NO.J
2.) SITE 68- OSTt AT fUQ. TRANSfER STATION
ncunc 2-2
9TE IOC/88
romiCR FWE OCPAMTUENT TRAMINC AAEA NO.
TWO 2.000 GMUON A*0> StXTIEN 50.000 GALLON
UKXRGROUMD STDMCC TANKS AT FUEL TWKSFtR STATUM
STTE PUN
MATHER AIR FORCE BASE
SACRAMENTO. CAUFORNIA
-------
Table 2-4. Site IOC - Results of Previous Investigations
Investigation and
Investigator
ASC Investigation -
IT Corporation
Air Investigation and
Significant Analytical
Results
None
Soil Investigation and Significant Analytical
Results
Five surface soil samples collected and analyzed.
Maximum concentrations detected were: TPH-D
(660 ppm), oil and grease (4,400 ppm). barium
(1,150 ppm), chrom ium ( 1 43 ppm), copper
(61 1 ppm), manganese ( 1 ,730 ppm), zinc
(1,980 ppm), lead (2,600 ppm), arsenic
(10.5 ppm), cadmium (66.4 ppm), mercury
(0.36 ppm), silver (6.3 ppm), and Aroclor-1260
(0.0-15 ppm).
Collected and analyzed twenty-two soil vapor
samples. Maximum concentrations detected
were: TPH-G (390 mg/L). benzene (3,300 MB/L).
toluene (150 Mg/L), ethylbenzene (130 Mg/L), and
total xylenes (360 Mg/L).
Six borings were drilled and sampled. Maximum
concentrations detected were: TPH-D
(3,200 ppm), oil and grease (970 ppm). TPH-G
(310 ppm), cadmium (1.6 ppm), thallium
(0.55 ppm), and total xylenes (880 ppb).
Benzene, toluene, ethylbenzene, and xylenes
otherwise delected (18 ppb).
Forty-two trench soil samples were collected and
analyzed. Maximum concentrations detected
were: oil and grease (10.600 ppm), TPH-D
(3,500 ppm), TPH-G (2,700 ppm). copper
(3,030 ppm), lead (1,830 ppm). benzene
(37,000 ppb), ethylbenzenc (37,000 ppb), toluene
(23,000 ppb), total xylenes (66,000 ppb),
naphthalene ( 1 ,000 ppb), and dioxins and furans
(40 pg/g).
Groundwaler Investigation
and Significant Analytical
Results
None
Other Activities
NA
References
[IT I996b)
K)
RL/J-9S/ES/392000I .AWS
-------
Table 2-4. Site IOC - Results of Previous Investigations (Continued)
Investigation and
Investigator
Sites IOC/68 SVE
Bioventing System Design -
Montgomery Watson
Draft Project Definition -
Montgomery Watson
Air Investigation and
Significant Analytical
Results
None
None
Soil Investigation and Significant Analytical
Results
Collected and analyzed 49 soil vapor samples
from 25 soil borings at Site IOC in October,
1996. Maximum concentrations detected were:
TPH-G (15,000 ppm), benzene (39 ppm), toluene
(28 ppm), elhylbenzene (40 ppm), xylenes
(46 ppm), and carbon leuachloride (6.8 ppm).
Collected and analyzed 109 soil samples from
33 soil borings at Sites IOC/68 in January, 1997.
Maximum concentrations detected were: TPH-D
(720 ppm), TPH-G (31 ppm), benzene (22 ppb).
toluene (12 ppb), ethylbenzehe (180 ppb), and
xylenes (2 10 ppb).
Collected and analyzed eight soil samples for
lead, motor oil, and oil and grease following
excavation activities. Maximum concentrations
delected were: lead (99 ppm), motor oil
(200 ppm), and oil and grease (150 ppm).
Groundwalcr Investigation
and Significant Analytical
Results
None
None
Other Activities
Excavated and
removed
approximately
570CYofrefuse
from the refuse pit
at Site IOC.
Excavation pits
7080 and 7090 were
de watered, lined
with 20 mil
polyethylene
sheeting and
backfilled.
NA
References
[MW I997b)
[MW 1998]
S)
ASC = Additional Site Characterization
TPH-D = total petroleum hydrocarbons as diesel
ppm = parts per million
TPH-G = total petroleum hydrocarbons as gasoline
mg/L - milligrams per liter
ug/L " micrograms per liter
ppb = parts per billion
pg/g = picograms per gram
SVE = soil vapor extraction
CY = cubic yard
NA = not applicable
RJJ^pES/3920001 .A WS
-------
Table 2-5. Site 68 - Results of Previous Investigations
Investigation and
Investigator
Quarterly Routine
Groundwater Sampling -
IT Corporation
Group 3 Sites RI -
IT Corporation
Final Comprehensive
Baseline Risk Assessment -
IT Corporation
Sites IOC/68 SVE
Bioventing System Design
- Montgomery Watson
Air Investigation and
Significant Analytical
Results
None
None
None
None
Soil Investigation and Significant Analytical
Results
None
Drilled and sampled Tour soil borings.
Maximum concentrations delected were: oil
and grease (833 ppm); TPH-G (1 .300 ppm);
TPH-D (67 ppm); ethylbenzene (1.5 ppm);
toluene (0.002(J) ppm); total xylenes (0.43
ppm); lead (0.57 ppm): 4.4'-DDD (0.003 1(J)
ppm); 4.4'-DDE (0.01 1(J) ppm): and
benzo(g,h.i)perylene (0.05{J) ppm).
None
Collected and analyzed 109 soil samples from
33 soil borings at Sites IOC/68 in January,
1997. Maximum concentrations delected were:
TPH-D (720 ppm); TPH-G (31 ppm). benzene
(22 ppm), toluene (12 ppm). ethylbenzene
(180 ppm). and xylenes (210 ppm).
Groundwater Investigation
and Significant Analytical
Results
Data for selected constituents
were summarized most
recently in the 3rd Quarter,
Quarterly Groundwaler
Monitoring Report
[IT, 19930.
Installed and sampled Well
MAFB-208. No significant
levels of contaminants were
detected.
None
None
Other Activities
NA
NA
No ILCR > 10*
No HQ > 1
NA
References
(IT I993f]
[IT 1993g]
(IT I993h)
[IT 1993e]
[IT 1996c]
[MW 1997b]
TPH-D = total petroleum hydrocarbons as diesel
TPH-G = tout petroleum hydrocarbons as gasoline
RI = remedial investigation
ODD = dichlorodiphenyldichloroethane
ILCR = incremental lifetime cancer risk
ppm = parts per million
NA = not applicable
HQ = hazard quotient
DDE • dichlorodiphenyldichloroelhylene
SVE " soil vapor extraction
RLrt-9S/ES/J92000I.AWS
-------
2.2.5.2 Site 18 • Old Burial Site
Site 18 (Figure 2-3) is located in the northwest portion of Mather AFB and is currently covered
by the paved fuel tanker yard north of Building 4120 and a smaller parking lot west of the
building. The site was reportedly used in the late 1940s for disposal of general refuse and
various stock items, however, drilling in this area has not revealed any debris. A summary of the
results of previous investigations conducted at Site 18 is presented in Table 2-6.
Contamination has been identified in soil vapor samples collected from the subsurface soils.
Volatile organic compounds have been identified as COCs based on VLEACH modeling. The
basis for cleanup is protection of groundwater quality.
RL/8-98/ES/3920001 .AWS
2-16
-------
owe
NAME:
9888A6p
DRAWN
BY
BAG.
1/27/98
CHECKED BY
APPROVED BY
409888-A6pp
MAFB-90
K)
>—*
-4
MAFB-33
MAFB-101
MAFB-89 50 ft..
(FROM ARROWHEAD)
SITE LAYOUT
MAFB-160 125 ft.,
(FROM ARROWHEAD)
LEGEND
EXISTING MONITORING WELL
PAVED
AREA
POSSIBLE TRENCH
BOUNDARY
90
180 FEET
FIGURE 2-3
SITE 18
OLD BURIAL SITE
SITE PLAN
PREPARED TOR
MATHER AIR FORCE BASE
SACRAMENTO. CALIFORNIA
INTERNATIONAL
TECHNOLOGY
CORPORATION
-------
Table 2-6. Site 18 - Results of Previous Investigations
Investigation and
Investigator
IRP Phase 1. Records
Search - CH2M Hill
IRP Phase II. Stage 2
Investigation -
AeroVironment, Inc
IRP Phase II. Stage 3
Investigation -
AeroVironment. Inc
Well Redevelopment and
Sampling -
IT Corporation
Quarterly Routine
Groundwater Sampling -
IT Corporation and EA
Engineering, Science and
Technology. Inc.
Landfill Gas Testing -
IT Corporation
Air Investigation and
Significant Analytical
Results
None
None
None
None
None
None
Soil Investigation and Significant
Analytical Results
None
None
None
None
None
Installed and sampled three wells
(CW-46. MW-47 and MW-48).
Maximum concentrations detected in
the CW were: TCE (2.000 ppb);
PCE (380 ppb); trichloromethane
(71 ppb): tetrachloromelhane
(100 ppb) and methane
(<2 percent).
Groundwaler Investigation and
Significant Analytical Results
None
Installed and sampled Wells
MAFB-33. 34. and 35. Maximum
concentrations detected were: TCE
(67 ppb). PCE (2.1 ppb).
Sampled three wells (MAFB-33
through 35). Maximum
concentrations detected were: TCE
(67 ppb) and PCE (2. 1 ppb).
Sampled Wells MAFB-33, 34. and
35. Maximum concentrations
detected were: TCE (24 ppb) and
lead (11 ppb).
Data for selected constituents were
summarized most recently in the
3rd Quarter 1993. Quarterly
Groundwater Monitoring Report
[IT 1993f).
None
Other Activities
Base Records
Search
NA
NA
NA
NA
NA
References
[CH2M Hill. Inc. 1982]
[AeroVironment 1987]
[AeroVironment 1988]
JIT 1990b]
[IT 1989]
[IT 1990c]
[IT 1990d]
IEA 1990a)
(EA 1990b]
[EA 1990c]
[IT 1993f]
[IT I993g]
[IT I993h]
[IT 1988b]
to
CO
1920001 .A WS
-------
Table 2-6. Site 18 - Results of Previous Investigations (Continued)
Investigation and
Investigator
IRP Site Inspection -
IT Corporation
Group 2 Sites RI -
IT Corporation
Air Investigation ami
Significant Analytical
Results
None
Collected integrated
surface air samples.
Maximum
concentrations detected
were: methylene
chloride (0.64 ppb);
l.l.l-TCA(0.65ppb):
benzene (1.2 ppb) and
PCE (0.5 ppb).
Soil Investigation and Significant
Analytical Results
Evaluated all geologic and chemical
data relating to environmental
contamination at Mather AFB. No
sampling or analysis conducted.
A SOV survey was conducted to
screen potential contaminant
sources. Maximum concentrations
detected were: total petroleum
hydrocarbon compounds
(40.000 ppm); TCE ( > 1 ,000 ppm);
PCE ( < 50 ppm): DCE ( <25 ppm);
TCA (760 ppm) and benzene
(22.3 ppm).
Sampled three landfill gas wells
(CW-46. MW-47 and MW-48).
Maximum concentrations detected
were: TCE (3.200 ppb) and PCE
(1,000 ppb).
Eleven soil borings, including three
redrills. (DSB-I8A through
DSB-I8F) were drilled and
sampled. Maximum concentrations
found were: TCE (50 ppb): oil and
grease (6.600 ppm); 1.2-DCE
(13 ppb); PCE(l5ppb);TPH-D
(50 ppm); TPH-G (19 ppm); and
alpha-benzene hexachjoride
(10 ppb). All delected inorganics
were below established background
concentrations, except cadmium.
silver, and thallium.
Ground water Investigation and
Significant Analytical Results
Evaluated all geologic anil chemical
data relating to environmental
contamination at Mather AFB.
Data from 1988 ground water
sampling included. Two rounds of
water level measurements
conducted for all on-base
monitoring wells. No sampling or
analysis conducted.
Installed and sampled four new
wells (MAFB-89. 90. 101. and
160). Maximum concentrations
detected were: TCE (21 ppb): PCE
(170 ppb): lead (5.740 ppb): and
carbon tetrachloride (3.3 ppb).
Other Activities
NA
NA
References
[IT 1990a]
(IT 1993i]
H^
VO
Myg-9J/ES/392000I.AWS
-------
Table 2-6. Site 18 • Results of Previous Investigations (Continued)
Investigation and
Investigator
Air Investigation and
Significant Analytical
Results
Soil Investigation and Significant
Analytical Results
Groundwater Investigation and
Significant Analytical Results
Other Activities
References
Solid Waste Assessment
Report - IT Corporation
None
None
Sampled and analyzed four existing
wells (MAFB-33.90,101. and 160).
Maximum concentrations delected
were: TCE (15 ppb); PCE
(180 ppb); and carbon lelrachloride
(7.9 ppb).
NA
[IT 1993d)
Soils and Groundwater OU
API Report •
IT Corporation
None
Drilled and sampled two soil
borings (SB-18-OI and SB-18-02).
The only contaminant detected was
TCE (0.005(J) ppm).
KJ
tb
O
Drilled and logged five straiigraphic
borings to evaluate site subsurface
stratigraphy.
A groundwater sample was
collected at the bottom of each
boring and analyzed. One sample
was analyzed at the field screening
lab while the other was analyzed at
a contract laboratory. Detectable
concentrations were not found in
either sample.
Installed and sampled seven
groundwater monitoring wells
(MAFB-251. 264. 265. 272. 273.
291. and 292). Maximum
concentrations detected were:
carbon letrachloride (2.3 ppb);
chloroform (0.88 ppb); PCE
(4.0 ppb); and TCE (26 ppb).
Slug tests were conducted in each
well to evaluate aquifer
characteristics.
NA
[IT I994a]
-------
Table 2-6. Site 18 - Results of Previous Investigations (Continued)
Investigation and
Investigator
Groundwater OU and Soil
OU FFS -
IT Corporation
Comprehensive Baseline
Risk Assessment -
IT Corporation
ASC Investigation -
IT Corporation
Air Investigation and
Significant Analytical
Results
None
None
None
Soil Investigation and Significant
Analytical Results
Installed and sampled two soil vapor
extraction wells (SVE-18S and
SVE-I8D). Maximum vapor
concentrations delected were: total
petroleum hydrocarbon (270 ppm);
TCE (250 ppm); PCE (32 ppm);
and total lead (0.24 /ig/nr1).
Additionally, soil samples were
collected during drilling and were
analyzed for geolechnical and
biological parameters.
None
Sampled existing soil vapor
extraction well SVE-I8S.
Maximum vapor concentrations
delected were: TCE (310 ppmv),
PCE(180ppmv). TPH-G
(280ppmv),cis-l.2-DCE
(220 ppmv), methylene chloride
(2.7 ppmv), and toluene
(2.2 ppmv).
Groundwater Investigation and
Significant Analytical Results
None
None
None
Other Activities
NA
ILCR > 10" for
Benzene
No HQ > 1
NA
References
[IT 1995b)
[IT I996c]
[IT I996b]
RU8-98/ES/3920001 .A WS
-------
2.2.5.3 Site 20 • Sewage Treatment Facility
Site 20 (Figure 2-4) is located in the southwest portion of Mather AFB, near the southwest end of
the main runway. Site 20 was originally defined to consist of sludge drying beds and a diesel
spill associated with the facility's 150-gallon UST. The original Site 20 was included in a
Non-Time Critical Removal Action Memorandum [IT 1994b], to document the decision to
remove sludge and soil associated with the sludge drying beds and digester tanks at the former
sewage treatment facility. The material was excavated between September 1996 and
January 1997, with most of the excavated material being disposed onbase at Site 4 (which was
closed in 1997). Some of the material exceeded hazardous waste criteria and was transported to
the Class I Hazardous Waste Disposal Facility at Kettleman Hills. The removal action was
successful in achieving performance standards found in the final Soil OU and Groundwater OU
ROD [IT 1996a]. The Sewage Treatment Facility was further investigated in the area of the
sedimentation and digester tanks during the Additional Site Characterization Investigation to
determine whether the facility had contributed contaminants, particularly chlorinated VOCs and
metals, to groundwater. These additional portions were investigated as part of the Basewide OU
and are addressed in this ROD. A summary of the results of previous investigations conducted at
Site 20 is presented in Table 2-7.
Contamination has been identified in the surface soils and subsurface soils. Risks due to
contamination associated with this site were evaluated and presented under an occupational
future land-use scenario in the FFS [IT 1997a] and Proposed Plan [IT 1997b] documents.
However, due to the fact that cleanup compatible with residential development can be achieved
at this site with a minimal increase in cost, it was decided to set cleanup standards commensurate
with residential land use for this ROD. Contaminants of concern identified at the site are lead
and polycyclic aromatic hydrocarbons (PAH). The basis for cleanup is protection of human
health and groundwater quality. The impacted volume to be excavated is estimated to be
500 cubic yards of surface soils. Even though sporadic detections of phthalates and diesel were
detected in the subsurface soils no remediation is planned. One groundwater well will be
installed and monitored for phthalates and diesel.
RL/8-98/ES/392000I .AWS
2-22
-------
io STVACE o»o*noN PONDS (sue ai)
•AWSW-'V-,' i\.A X \ \
Wfm^
SITE 20 (APPROKIUATT)-
RESUIT1NC fROU PRCVKXJS INVtSTCATIONS.
SITE HAS 8CCN RCUCOUTCO UNOCR A RAM.
\ N\
IFCFVD
DllSlWC UOMrORINC WELL
MATHER AIR FORCE BASE
SACRAMENTO, CAtfORNIA
(OCST) ABANOONCO UONITOR1NC WtU.
-------
Table 2-7. Site 20 - Results of Previous Investigations
Investigation and
Investigator
IRP Phase 1, Records
Search - CH2M Hill
IRP Phase II, Stage 2
Investigation -
AeroVironment, Inc
Well Redevelopment and
Sampling -
IT Corporation
Quarterly Routine
Groundwater Sampling -
IT Corporation and EA
Engineering. Science and
Technology, Inc.
IRP Site Inspection -
IT Corporation
Air Investigation
and Significant
Analytical Results
None
None
None
None
None
Soil Investigation and Significant
Analytical Results
None
None
None
None
Evaluated all geologic and chemical data
relating to environmental contamination
at Mather AFO. No sampling or analysis
conducted.
Groundwater Investigation and
Significant Analytical Results
None
Installed and sampled one well
(MAFD-38). No significant
contamination was detected.
Sampled Well MAFB-38. No
significant contamination was
delected.
Data for selected constituents
were summarized most recently
in the 3rd Quarter 1993,
Quarterly Groundwater
Monitoring Report [IT I993f).
Evaluated all geologic and
chemical data relating to
environmental contamination at
Mather AFB. Data from 1988
groundwater sampling was
included. Conducted two
rounds of water level
measurements Tor all on-base
monitoring wells.
Other Activities
Base Records Search
Conducted a terrain
conductivity and GPR
geophysical survey.
None
NA
NA
References
[CH2M Hill 1982]
[AeroVironment 1987]
[IT !990b]
[IT 1989]
[IT 1990c]
[IT I990d]
[EA I990a]
[EA I990b]
[EA I990c)
[IT 19931]
[IT I993g|
[IT I993h|
[IT I990a)
RL^^S/3920001.A WS
-------
Table 2-7. Site 20 - Results of Previous Investigations (Continued)
Investigation and
Investigator
Group 2 Sites RJ -
IT Corporation
Comprehensive Baseline
Risk Assessment •
IT Corporation
Air Investigation
and Significant
Analytical Results
None
None
Soil Investigation and Significant
Analytical Results
Conducted a SOV survey to screen
potential source areas. Maximum
concentrations detected were: TPHC
(2,049 ppm); TCE (20 ppm); benzene
(41 ppm); toluene (2.2 ppm); and
cthyibenzene (2.S ppm).
One shallow (SSD-20A) and four deep
(DSD-A-20A through DSB-A-20D) soil
borings were drilled and sampled.
Maximum concentrations found were:
diesel (1,400 ppm); gasoline (IO*
NoHQ>l
References
[IT I993i]
(IT I996c]
to
RL/8-98/ES/3920001 _A WS
-------
Table 2-7. Site 20 - Results of Previous Investigations (Continued)
Investigation and
Investigator
ASC Investigation -
IT Corporation
Air Investigation
and Significant
Analytical Results
None
Soil Investigation and Significant
Analytical Results
Three surface soil samples were collected
and analyzed. Contaminants delected
include: metals, PAHs, pesticides, and
petroleum hydrocarbons. Analytical
results may be found in the ASC FU
Report [IT 1996cJ.
Six soil borings were drilled and sampled.
Maximum concentrations detected were:
lead (186 mg/kg),
1,1,2,2-tclrachloroelhanc (1 ug/kg),
acetone (13 ug/kg),
bis(2-ethylhexyl)phthalate (1,200 ug/kg).
butyl benzyl phthalate (35 ug/kg), dicthyl
phthalate (42 ug/kg), pyrene (20 ug/kg),
and TPH-D (360 mgAg).
One surface soil and four subsurface soil
samples were analyzed with a waste
extraction test. Analytical results may be
found in the ASC Rl Report [IT I996b).
Groundwater Investigation and
Significant Analytical Results
Groundwater sampling was
conducted from two existing
wells. Maximum concentrations
delected were: calcium
(10,500 ug/L). magnesium
(5,8 10 ug/L), sodium
(8,860 ug/L), and vanadium
(15.4 ug/L).
Other Activities
Five sludge samples were
collected from the Digester
Tanks. The only contaminant
to exceed California Total
Threshold Limit Concentration
standard was mercury
(20 mg/kg)
Two surface water samples
were collected from the
Digester Tanks. No detections
exceeded standards.
References
[IT 1996bJ
N>
K)
O\
IRP » Installation Restoration Program
AFB = Air Force Base
GPR = ground penetrating radar
NA e not applicable
Rl = remedial investigation
SOV = soil organic vapor
TPHC - total petroleum hydrocarbon compounds
ppm • parts per million
TCE = trichloroethene
ppb « parts per billion
ILCR - incremental lifetime cancer risk
HQ - hazard quotient
ASC " Additional Site Characterization
PAH = polycyclic aromatic hydrocarbons
TPH-D = total petroleum hydrocarbon as diesel
mg/kg » milligrams per kilogram
ug/kg • micrograms per kilogram
ug/L =• micrograms per liter
p92000.«AWS
-------
2.2.5.4 Site 23 • Sanitary Sewer Line Main Base Area
Site 23 (Figure 2-5) consists of portions of the Main Base sanitary sewer line totaling
approximately 13,000 feet in length. The primary section is in the Main Base area and extends
eastward along the entire length of Superfortress Avenue with several north-trending laterals. A
summary of the results of the previous investigations conducted at Site 23 is presented in
Table 2-8. As a result of previous investigations, four main areas of concern (23 A, 23B, 23C,
and 23D) have been identified. These areas of concern are where significant contamination was
identified in the immediate vicinity of the sanitary sewer line. However, this contamination may
or may not be attributed to contamination from other known IRP sites (e.g., Site 18 or 39).
Volatile organic compounds have been identified as COCs based on VLEACH modeling. The
basis for cleanup is protection of groundwater quality.
RU8-9S/ES/392000I .AWS
2-27
-------
NJ
K)
OO
Ifc i "T, — V. \
VW,-\ \ \ \
<• \\ * ,--"-">i i -•' y-".:-.---,^-
V % v ••• ':, • ••••'• h if
,--•"•••. .sjWi • i' Hi /
V-'M^M;
xOxy/r-ifHl r'^1 ^-^ L--^--,
^
• ^/.J^^MbF^f^! myw
4 KJH i« :«
i_i.JL9.V;^ I ---•-
-------
Table 2-8. Site 23 - Results of Previous Investigations
Investigation and
Investigator
1RP Phase 1, Records
Search - CH2M Hill
Quarterly Routine
Groundwater Sampling -
!T Corporation and EA
Engineering, Science and
Technology, Inc.
Group 2 Sites RJ -
IT Corporation
Comprehensive Baseline
Risk Assessment -
IT Corporation
Air Investigation and
Significant Analytical
Results
None
None
None
None
Soil Investigation and Significant
Analytical Results
None
None
Ten shallow (SSB-23A through
SSB-23J) soil borings were drilled
and sampled. Maximum
concentrations found were: diesel
(10 ppm); gasoline (12 ppm); total
xylcnes (<5 ppb); 2-butanone
(12 ppb); toluene (<5 ppb):
ethylbenzene (<5 ppb); lead (0.5 ppb)
and oil and grease (59 ppm).
None
Groundwater Investigation and
Significant Analytical Results
None
Data Tor selected constituents were
summarized most recently in the 3rd
Quarter 1993, Quarterly
Groundwater Monitoring Report [IT
I993J1.
Installed and sampled seven wells
(MAFB-94 through 99. and
MAFB-105). Maximum
concentrations detected were: TCE
(19 ppb); PCE (60 ppb) and carbon
(etrachloride(l.6ppb).
None
Other Activities
Base Records
Search
NA
NA
NolLCR>IO<
NoHQ>l
References
[C1I2M Hill 1982]
(IT 1989]
(IT I990cl
[IT I990d]
[EA I990a]
[EA I990bj
[EA I990c]
[IT 19931]
[IT 1993g]
[IT I993h]
[IT 1993i]
[ITI996c]
I-J
RL/J.98/ES/392000I AWS
-------
Table 2-8. Site 23 - Results of Previous Investigations (Continued)
Investigation and
Investigator
ASC Investigation -
IT Corporation
Air Investigation and
Significant Analytical
Results
None
.
Soil Investigation and Significant
Analytical Results
Eight deep soil borings were drilled
and sampled. Maximum
concentrations delected were:
1,2-dichloroelhcnc (3 ug/kg),
2-butanonc (28 ug/kg), acetone
(190 ug/kg). ethylbcnzene
(56 ug/kg), toluene (3 ug/kg),
trichloroethene (25 ug/kg), and total
xylenes (8 ug/kg).
Forty-four locations were sampled for
SOVs. Shallow SOV screening
detections of less than 10 ug/L
occurred in 43 of the samples. One
sample detected PCE at 32 ug/L.
Eight deep soil boring locations were
sampled for SOVs. Up to
approximately 1 30,000 ppb of TCE
was detected.
Groundwater Investigation and
Significant Analytical Results
None
Other Activities
One hundred twenty
grab samples of
flush water from the
sanitary sexver line
xvere collected and
analyzed. The flush
samples confirmed
that chlorinated
VOCs are not
present in
significant amounts
within the sewer
lines.
References
[IT I996b]
N>
U>
O
IRP = Installation Restoration Program
Rl = remedial investigation
ppm = pans per million
ppb - parts per billion
TCE - trichloroelhene
PCE = tctrachloroethene
NA = not applicable
ILCR = incremental lifetime cancer risk
HQ = hazard quotient
ASC = Additional Site Characterization
ug/kg = micrograms per kilogram
SOV = soil organic vapor
ug/L = micrograms per liter
VOC = volatile organic compound
92000I.AWS
-------
2.2.5.5 S/te 86 - Military Firing Range
Site 86 (Figure 2-6) is located in the southeastern portion of Mather AFB. The site was operated
by the military as a small arms firing range. A summary of the results of previous investigations
conducted at Site 86 is presented in Table 2-9.
Contamination has been identified in the surface soils. The only COC identified at the site under
a residential future land-use scenario is lead. The bases for this cleanup is protection of human
health, groundwater quality, and ecological receptors. The volume of impacted soils associated
with Site 86 is estimated at 6,100 cubic yards (1,900 cubic yards to excavate from the bullet
flight path and 4,200 cubic yards stockpiled at the site).
RU8-9S/ES/3920001 AWS
2-31
-------
5!
to
u>
KJ
APPROXIMATE CONTOUR A8OVE
EXISTING SURFACE (FTD)
-------
Table 2-9. Site 86 - Results of Previous Investigations
Investigation and
Investigator
Air Investigation and
Significant Analytical
Results
Soil Investigation and Significant
Analytical Results
Groundwater Investigation and
Significant Analytical Results
Other Activities
References
Site Characterization for
IRP Sites 86 and 87-
IT Corporation
None
Forty-three soil samples were
collected from the bullet flight line
area and four discrete soil stockpiles
and analyzed for bullet fragment
counts. A total of 113 lead bullets
and five brass casings were found in
the soil samples. Of the samples.
five were analyzed at a laboratory
with the maximum concentration of
lead found in the soil being
l,660mg/kg. This sample was also
analyzed by waste extraction lest
methodology, and lead was detected
at 16 mg/L.
None
NA
[IT I997c)
N)
IRP = Installation Restoration Program
mg/kg = milligrams per kilogram
mg/L = milligrams per liter
NA = not applicable
RL/8-98/ES/392000I -AWS
-------
2.2.5.6 Site 87 • Skeet/Trap Range
Site 87 (Figure 2-7) is located in the eastern portion of Mather AFB. The site was operated by a
local shooting club as a skeet/trap shooting range. Morrison Creek traverses the site in front of
the firing positions. A summary of the results of previous investigations conducted at Site 87 is
presented in Table 2-10.
Contamination has been identified in the surface soils and sediments. If water is encountered
during excavation of the sediments, it will be diverted around the impacted area (only during
remediation) or discharged to the publicly owned treatment works (POTW) (if acceptable to
Sacramento County). The COCs identified at the site under a recreational future land-use
scenario are arsenic, lead, and PAHs. The bases for cleanup are protection of human health,
groundwater and surface water quality, and ecological receptors. The volume of impacted
sediments and surface soils associated with Site 87 is estimated at 28,000 cubic yards.
RL/8-98/ES/392000I.AWS
2-34
-------
I
ro
u>
LA
-------
Table 2-10. Site 87 - Results of Previous Investigations
Investigation and
Investigator
Site Characterization for
IRP Sites 86 and 87 -
IT Corporation
Air Investigation and
Significant Analytical
Results
None
Soil Investigation and Significant
Analytical Results
A total of 137 surface soil and
sediment samples were collected for
fragment count. Of these samples,
24 were chemically analyzed.
Surface soil samples detected a
maximum lead concentration of
1,330 mg/kg along with nine
different PAHs. Waste extraction
test analysis on six of the soil
samples delected lead concentrations
ranging from 0.5 mg/L to
1 .7 mg/L. Waste extraction lest
analysis on four surface soil samples
did not delect any PAHs above the
method detection limit.
Sediment samples detected a
maximum lead concentration of
6,800 mg/kg along with eight
different PAHs. Waste extraction
test analysis on two samples did not
detect any PAHs above the method
detection limit.
Groundwater Investigation and
Significant Analytical Results
None
Other Activities
One surface water sample and
one duplicate were collected
from the pond located on the
range. The only parameter
detected was barium at 87 and
89 Mg/L.
References
[IT 1997cJ
K>
U)
ON
IRP = Installation Restoration Program
PAH = polycyclic aromatic hydrocarbons
mg/kg = milligrams per kilogram
mg/L = milligrams per liter
/>g/L = micrograms per liter
-------
2.2.6 Summary of Site Risks
Remedial investigation activities at Mather AFB have included detailed assessments of potential
human health and ecological risks, and assessments of potential impacts to ground water and/or
surface water quality, associated with the subject sites (Section 2.1.3). Results of the human
health and ecological risk assessments for all subject sites at Mather AFB, with the exception of
Sites 86 and 87, are presented in the Final CBRA [IT 1996c]. A screening level risk assessment
was conducted for Sites 86 and 87 as part of this ROD with results presented in Appendices B
and C of this document. Results of the assessments of potential threat to groundwater and/or
surface water quality, and other details of the COC selection process, are documented in the
Basewide OU FFS Report [IT 1997a]. The data collected and used in the RIs and the FFSs were
of USEPA Level III, IV, V, or equivalent [USEPA 1987]. Formal data validation of the RI- and
FFS-generated data was performed to ensure that data were of quality commensurate with their
intended use. The potential human health and ecological risks, and potential threats to
groundwater and/or surface water associated with the subject sites are summarized below.
Estimates of potential risks/hazards to human and ecological receptors were obtained from the
CBRA [IT 1996c]. Revisions from the previous risk assessment [IT 1995c] included the use of
surrogate toxicity values, an updated dermal exposure model, revised dermal absorption values,
additional ecological risk assessment activities, and an aggregate mining scenario. The initial list
of contaminants of potential concern (COPCs) (presented in the FFS Report [IT 1995b]) which
were identified on the basis of potential ecological risk/hazard have not changed appreciably due
to these additional activities.
From an ecological perspective, COPCs for which concentrations exceed background screening
values, or for which associated estimates of potential ecological hazard index exceed 1.0, were
also identified as COCs. Site 87 was rated as medium for ecological risk. Therefore, the
selected remedies at this site will be instituted for the protection of ecological receptors.
From a human health perspective, COPCs with estimated incremental lifetime cancer risk (ILCR)
exceeding 1 x 10"6, or the hazard quotient exceeding 1.0 (on an individual pathway basis), were
identified as COCs.
Based on the calculations in the human health risk assessment, excess lifetime cancer risks were
within or below the range of one-in-one million to one-in-ten thousand. However, the
non-cancer risk at Site 87 exceeded the hazard quotient of 1.0. The selected remedies at Sites 20,
86, and 87 will be implemented to reduce potential human health risks.
RL/8-98/ES/J92000 LAWS
2-37
-------
Contaminants of concern have been identified on the basis of potential impact to groundwater
quality at Sites IOC/68, 18,20,23, 86, and 87. Potential impacts to surface water quality have
also been identified at Site 87. Accordingly, the selected remedies for these sites will also be
initiated to ensure protection of groundwater and/or surface water quality, as applicable.
Actual or threatened releases of hazardous substances, if not addressed by implementing the
response actions selected in this ROD, may present an imminent and substantial endangerment to
public health, welfare, or the environment.
2.2.7 Description of Alternatives
Remedial alternatives (including the no action alternative) were developed for each of the sites
for detailed analysis in the FFS Report [IT 1997a]. These remedial alternatives address
contaminants in soil, soil vapor, surface water, and sediments as appropriate. Groundwater
contamination beneath these sites, if present, was previously addressed in the Soil OU and
Groundwater OU ROD [IT 1996a].
In developing the alternatives, it was assumed that the sediments (maximum two feet deep based
on sediment sampling procedures), surface soils (a maximum of three feet below land surface
[bis] depending upon contamination extent and site physical characteristics), and shallow soils
(base of the surface soils to 30 feet bis) are capable of being excavated without specialized
equipment. Excavation of the deep soils (30 feet bis to the water table) is not considered feasible
or appropriate. The no action alternative, as required by CERCLA, has been included for each
site to provide a baseline for comparison purposes.
2.2.7.1 Sites 10C/68 Remedial Alternative
Table 2-11 summarizes four remedial alternatives that were developed for possible application at
Sites IOC/68 and presented in the FFS [IT I997a]. The selected remedy is shown in bold, italic
text.
RL/8-98/ES/392000I.AWS
2-38
-------
Table 2-11. Sites IOC/68 Remedial Alternatives
ALTERNATIVE
IOC/68.1
IOC/68.2
IOC/68.3
IOC/68.4*
DESCRIPTION
No Action
Excavation (lead-contaminated surface soils) with off-base disposal; and in situ
treatment (consisting of bioremediation and soil vapor extraction) of the remaining
contaminated surface soils and shallow and deep subsurface soils.
Excavation (lead-contaminated surface soils) with off-base disposal; excavation
(remaining contaminated surface soils) with ex situ bioremediation and on-base
disposal at Site 7; and in situ treatment (consisting of bioremediation and soil vapor
extraction) of the contaminated shallow and deep subsurface soils.
In situ treatment (consisting of bioremediation and soil vapor extraction) of the
remaining contaminated surface soils and shallow and deep subsurface soils.
The surface soils at the Site IOC Bum Pit have been removed and transported to Site 4 under authority of a
Removal Action Memorandum [USAF 1996b]. Eight confirmation samples were collected and analyzed.
Risks from the lead-contaminated soils have been reduced to acceptable levels and are protective of
groundwater quality as a result of the excavation activities. Therefore, in situ treatment (i.e., shallow and
deep subsurface soils) is the only portion of the remedy that would remain. Installation and pilot testing of
a soil vapor extraction system was conducted in August 1997. However, following consistently low
influent concentrations the system was shut down in December 1997 to evaluate the rebound of
contaminant concentrations in the vadose zone and to determine if in situ bioremediation is more
appropriate for this site.
2.2.7.2 Site 18 Remedial Alternatives
Table 2-12 summarizes two remedial alternatives that were developed and evaluated for possible
application at Site 18 in the FFS [IT 1997a]. The selected remedy is shown in bold, italic text.
Table 2-12. Site 18 Remedial Alternatives
ALTERNATIVE
18.1
18.2
DESCRIPTION
No Action
In situ soil vapor extraction (shallow and deep subsurface soils).
RU8-98/ES/3920001 AWS
2-39
-------
2.2.7.3 Site 20 Remedial Alternatives
Table 2-13 summarizes four alternatives that were developed and evaluated for possible
application at Site 20 in the FFS [IT 1997a]. The selected remedy is shown in bold, italic text.
Table 2-13. Site 20 Remedial Alternatives
ALTERNATIVE
20.1
20.2
20.3
20. 4
DESCRIPTION
No Action
Excavation (surface soils) with off-base disposal; and groundwater well installation and
monitoring. Institutional controls will be implemented to restrict activities that may
endanger public health.
Excavation (surface soils) with stabilization, ex situ bioremediation, and on-base
disposal at Site 7 (however, if lead levels are below acceptance criteria for Site 7, the
soils will not be stabilized prior to on base disposal at Site 7); and in situ bioremediation
(shallow and deep subsurface soils). Institutional controls will be implemented to restrict
activities that may endanger public health.
Excavation (surface soils) with stabilization, ex situ bioremediation (as necessary),
and on-base disposal at Site 7; and groundwater well installation and monitoring.
2.2.7.4 Site 23 Remedial A Iternatives
Table 2-14 summarizes two alternatives that were developed and evaluated for possible
application at Site 23 in the FFS [IT 1997a]. The selected remedy is shown in bold, italic text.
Table 2-14. Site 23 Remedial Alternatives
ALTERNATIVE
23.1
23.2
DESCRIPTION 1
No Action
In situ soil vapor extraction (shallow and deep subsurface soils). j
RU8-98/ES/3920001 .AWS
2-40
-------
2.2.7.5 Site 86 Remedial Alternatives
Table 2-15 summarizes three remedial alternatives that were developed and evaluated for
possible application at Site 86 in the FFS [IT 1997a]. The selected remedy is shown in bold,
italic text.
Table 2-15. Site 86 Remedial Alternatives
ALTERNATIVE
86.1
86.2
86.3
DESCRIPTION
No Action
Excavation (surface soils) with treatment (Le., stabilization) and on-base disposal at
Site 7 (however, if lead levels are below acceptance criteria for Site 7, the soils will
not be stabilized prior to onbase disposal at Site 7) or off-base disposal if the
excavated material exceeds Site 7 acceptance criteria.
Excavation (surface soils) with on-base disposal at Site 7 (or off-base disposal if the
excavated material exceeds Site 7 acceptance criteria).
2.2.7.6 Site 87 Remedial Alternatives
Table 2-16 summarizes three remedial alternatives that were developed and evaluated for
possible application at Site 87 in the FFS [IT 1997a]. The selected remedy is shown in bold,
italic text.
Table 2-16. Site 87 Remedial Alternatives
ALTERNATIVE
DESCRIPTION
87.1
No Action
87.2
Excavation (sediments and surface soils) with treatment (Le., stabilization) and
on-base disposal at Site 7 (or off-base disposal if the excavated material exceeds
Site 7 acceptance criteria). Institutional controls will be implemented to restrict
activities that may endanger human health. Institutional controls will be
implemented to restrict activities that may endanger public health, unless cleanup
does reduce risk to a level compatible with unrestricted land use.
87.3
Excavation (sediments and surface soils) with on-base disposal at Site 7 (or off-base
disposal if the excavated material exceeds Site 7 acceptance criteria). Institutional
controls will be implemented to restrict activities that may endanger human health.
Since cleanup at this site is to non-residential standards. Institutional controls will be
implemented to restrict activities that may endanger public health, since cleanup at this
site is to non-residential standards.
Rtyg-98/ES/3920001 .AWS
2-41
-------
2.2.8 Summary of Comparison Analysis of Alternatives
The remedial alternatives developed in the FFS Report [IT 1997a] were analyzed in detail using
the first seven evaluation criteria required by the NCP (Section 300.430(e)(7)). These criteria are
classified as either threshold or primary balancing criteria.
Threshold criteria must be met for a remedial alternative to be selected and include:
• overall protection of human health and the environment; and
• compliance with ARARs.
Primary balancing criteria are designed to identify trade-offs between those alternatives which
meet the threshold criteria and include:
• long-term effectiveness and permanence;
• reduction of toxicity, mobility, or volume through treatment;
• short-term effectiveness;
• implementability; and
• cost.
Two additional criteria, referred to as modifying criteria, are evaluated during the public
comment period and development of this document. The modifying criteria include:
• state/support agency acceptance; and
• community acceptance.
The relative ability of each alternative to meet each of the nine criteria (Figure 2-8) were weighed
to identify the alternative providing the best tradeoffs for each site. The following sections
summarize the nine criteria. Table 2-17 summarizes the results of the comparative analysis.
2.2.8.1 State/Support Agency Acceptance
This indicates whether, based on review of the RI Report [IT I996c], FFS Report [IT I997a], and
Proposed Plan [IT I997b], the state concurs with, opposes, or has no comment on the preferred
cleanup options. The State of California is represented by the California Environmental
Protection Agency, DTSC as a support agency under the Federal Facility Agreement for
Mather AFB; DTSC coordinates review comments from other state agencies, such as the
CVRWQCB and the Integrated Waste Management Board. Section 1.3 of this ROD presents
signature of state acceptance of the selected remedies.
RL«-98/ES/392000l .AWS
2-42
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THRESHOLD! CRITERIA
Overall Protection of Human Health and the
Environment. Addresses whether or not a cleanup option
provides adequate protection and describes how risks,
posed through each pathway, are eliminated, reduced, or
controlled through treatment, engineering controls, or
institutional controls.
Compliance with Applicable or Relevant and
Appropriate Requirements. Addresses whether a
cleanup option will meet all applicable or relevant and
appropriate requirements or federal and state
environmental statutes and/or provide grounds for
invoicing a waiver. Applicable or relevant and appropriate
requirements include cleanup and protection of
groundwater/surface water quality for its beneficial uses.
BALANCING CRITERIA
Long-Term Effectiveness of Permanence. Refers to the
ability of a cleanup option to maintain reliable protection
of human health and the environment over lime, once
cleanup goals (i.e.. cleanup standards) have been met.
Reduction of Toxicity, Mobility, and Volume through
Treatment. Refers to the anticipated ability of a cleanup
option to reduce the toxicity, mobility, and volume of the
hazardous components present at the site.
Snort-Term Effectiveness. Addresses the period of time
needed to complete the cleanup option, and any adverse
impacts on human health and the environment that may be
posed during the construction and implementation period,
until the cleanup goals (i.e., cleanup standards) are
achieved.
Implementability. Refers to the technical and
administrative feasibility of a cleanup option, including the
availability of materials and services needed to carry out
a particular option.
Cost. Refers to the estimated capital and operation and
maintenance costs of each cleanup option. For comparison
purposes, a present worth value was calculated using a 5
percent discount factor so that each option could be equally
compared in 1996 dollars.
MODIFYING CRITERIA
State Acceptance. Indicates whether, based on its review
of the information, the state concurs with, opposes, or has
no comment on the preferred cleanup options.
Community Acceptance. Indicates whether community
concerns are addressed by the cleanup option and whether
or not the community has a preference for a cleanup
option.
Figure 2-8. Selecting a Cleanup Remedy
RL/8-98/ES/3920001 .A WS
2-43
-------
Table 2-17. Comparative Analysis of Remedial Alternatives for the Basewide Operable Unit Sites Selected
for Remedial Action
Evaluation
Criteria
Site
Number
Alternative
-ong-Term Effectiveness and
Permanence
Reduction of Toxicity,
vtobility, and Volume
Short-Term Effectiveness
mplementability
Community Acceptance
Slate Acceptance
Present Worth Cost
$ millions)
IOC/68
IOC/
68.1
P
P
P
B
No
No
0.030
IOC/
68.2
B
F
F
G
No
No
0.608
10O
68.3
B
G
G
G
No
No
0.693
IOC/
68,4
fc
B
6
G
Ye*
Ye*
0.5*7
18
18.1
F
P
F
B
No
No
0.017
18.2
B
B
B
a
Yes
Y«
I.039/
acre
20
20.1
F
P
F
B
No
No
0.040
20.2
G
G
G
G
No
No
0.191
20J
B
B
B
G
No
No
0.731
204
<3
<3
G
6
Yes
Yte
0,108
23
23.1
G
P
G
B
No
No
0
23.2
8
A
a
<3
Ye*
Ye*
1.04 1/
acre
86
86.1
P
P
P
B
No
No
0
86.2
B
B
B
a
Ye*
Y«s
0.5464
•1073
86.3
G
B
G
G
No
No
0.147-
5.223
87
87.1
P
P
P
B
No
No
0
87J
&
B
8
G
Ye?
y«*
2,«0
-------
2.2.8.2 Community Acceptance
This is an assessment of the general public's response to the Proposed Plan [IT 1997b] following
review of the public comments received during the public comment period (from May 23 through
June 23, 1997) and open community meeting (held on May 29, 1997). It indicates whether
community concerns are addressed by the cleanup option and whether or not the community has
a preference for a cleanup option. Section 6.0 of this ROD documents the community acceptance
of the selected remedies, as presented in the Responsiveness Summary.
2.2.9 The Selected Remedies
This section presents the remedies selected by the Air Force, with concurrence by the USEPA
and the State of California, for each of the Basewide OU sites which warrant cleanup. The
selected remedies were chosen based on the results of the comparative analysis of the alternatives
presented in Table 2-17 and are optimized in terms of the nine evaluation criteria. Design and
construction of the selected remedial actions will be conducted by certified professionals or
under the supervision of certified professionals, as appropriate.
2.2.9.1 Sites 10C/68 - Former Fire Department Training Area No. 3/Two
2,000 Gallon and Sixteen 50,000 Gallon Underground Storage Tanks
at Fuel Transfer Station
Alternative IOC/68.4 was selected by the Air Force, with concurrence by the USEPA and the
State of California, as the remedy for Sites IOC/68. The major components of this remedy
include:
• in situ treatment of the fuel contaminated subsurface soils at Sites IOC and 68; and
• treatment of the offgas (if applicable) will be conducted using granular activated
carbon or more cost-effective means of best available control technology as
necessary to comply with ARARs.
The in situ treatment system could be used as a bioremediation system or converted to an SVE
system, depending on the contaminants measured. Compliance with cleanup standards will be
demonstrated before system operation is terminated. Thermal destruction of chlorinated
hydrocarbons may generate dioxins. Therefore, if thermal destruction technology is used as part
of the in situ remediation selected for this Basewide Operable Unit site and the influent gas
contains chlorinated chemicals the emissions from the thermal treatment unit will be monitored
(which will consist of at least three sampling events) for dioxin/rurans during the first month of
operation, and again if significant changes are made to the influent vapor or the operation of the
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thermal treatment unit that could reasonably be expected to result in increased dioxin/furan
emissions. If the emissions exceed the value of 0.2 nanograms per dry square cubic meter
(ng/DSCM), calculated as the sum of toxicity equivalent (TEQ) (values to the
2,3,7,8-tetrachlorodibenzo-p-dioxin [TCDD] isomer) currently proposed as an emissions
standard for RCRA incinerators, then a risk calculation will be performed. Risks exceeding the
10"6 to 10"4 threshold range will require mitigation; risks within the threshold range will be
subject to further consideration by the Air Force, USEPA, and the State of California under the
Federal Facility Agreement.
The Air Force will conduct further soil gas sampling at this site to define the extent of VOC
contamination, as part of the remedial design work. Interim actions have been initiated at
Sites IOC/68 which involved the installation and pilot testing of an SVE system. Details of the
pilot test are described in Section 2.2.5.1. The feasibility of SVE will be evaluated when it is
demonstrated that soil contaminants may cause concentrations in the leachate to exceed the
aquifer cleanup levels, based on an interpretation of soil gas data using VLEACH or another
appropriate vadose zone model.
The actual decision on whether to build and operate an SVE system will depend on the degree to
which the contamination presents a threat to groundwater and whether site characteristics are
suitable for the SVE technology. It is generally preferable from a technical and cost perspective
to clean up contamination in the vadose zone before it reaches the groundwater. The feasibility
analysis will be prepared by the Air Force as a primary document. The decision will be made by
the signatory parties to the Federal Facility Agreement and will be based, at a minimum, on the
following factors:
• the cost and time associated with the predicted additional groundwater remediation
if no SVE is implemented;
• the cost of implementing the SVE system to meet the SVE soil cleanup standard;
• the incremental cost over time of vadose zone remediation compared to the
incremental cost of ground water remediation, on the basis of a common unit
(e.g., cost to remove a pound of trichloroethene [TCE]), provided that the
underlying groundwater has not reached aquifer cleanup levels;
• the results of VLEACH or another appropriate vadose zone model, in conjunction
with a groundwater fate and transport model to predict the resulting concentration
from the vadose zone contamination in the nearest groundwater wells monitoring
the site; and
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• the results of VLEACH or another appropriate vadose zone model, that interprets
soil gas data, to predict the mass and concentration of discharges from the vadose
zone to the groundwater.
This demonstration is to be made prior to operation of the bioventing system in areas considered
for SVE (to prevent interference from bioventing). Once SVE is initiated, it will be terminated in
accordance with the demonstration described in the following paragraphs. The need to
implement the bioventing remedy will be reevaluated when SVE is terminated.
The goal of cleaning up the vadose zone is to minimize further degradation of the groundwater
by the contaminants in the soil. It is generally preferable from a technical and cost perspective to
clean up contamination in the vadose zone before it reaches the groundwater. The soil cleanup
standard will be achieved when the residual vadose zone contaminants will not cause the
groundwater cleanup standard, as measured in groundwater wells monitoring the plume, to be
exceeded after the cessation of the groundwater remediation. The Air Force will make the
demonstration that the standard has been met through contaminant fate and transport modeling,
trend analysis, mass balance, and/or other means. This demonstration will include examination
of the effects of the residual vadose zone contamination in the groundwater using VLEACH or
another appropriate vadose zone model, in conjunction with a groundwater fate and transport
model, to predict the resulting concentration from this residual vadose zone contamination in the
nearest groundwater wells monitoring the site. This demonstration can be made prior to the
cessation of groundwater remediation. The Air Force shall provide verification, through actual
data, that the above standard has been met. The signatory parties to this ROD will jointly make
the decision that the soil cleanup standard has been met.
The Air Force shall operate the SVE system until it makes the demonstration that the cleanup
standard, set forth above, has been met. The Air Force shall continue to operate the SVE system
if appropriate, after considering the following factors:
• whether the mass removal rate is approaching asymptotic levels after temporary
shutdown periods and appropriate optimization of the SVE system;
• the additional cost of continuing to operate SVE system at concentrations
approaching asymptotic mass levels;
• whether the predicted concentration of the leachate from the vadose zone using
VLEACH or another appropriate vadose zone model that interprets soil gas data
will exceed the groundwater cleanup standard;
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• the predicted effectiveness and cost of further enhancements to the SVE system
(e.g., additional vapor extraction wells);
whether the cost of groundwater remediation will be significantly more if the
residual vadose zone contamination is not addressed;
whether the residual mass in the vadose zone will significantly prolong the time to
attain the groundwater cleanup standard; and
• the incremental cost over time of vadose zone remediation compared to the
incremental cost over time for groundwater remediation on the basis of a common
unit (e.g., cost of a pound of TCE removed) provided that the underlying
groundwater has not reached aquifer cleanup levels.
The signatory parties agree that the Air Force may cycle the SVE system on and off in order to
optimize the SVE operation and/or evaluate the factors listed above.
The signatory parties to this ROD will jointly make the decision that the SVE system may be shut
off. If the parties cannot reach a joint resolution, any party may invoke dispute resolution. This
ROD does not resolve the ARAR status of state requirements regarding the establishment of soil
cleanup levels. The parties agree that in the event of a dispute regarding SVE shutoff, the state
may argue its authority to require soil cleanup (including soil cleanup standards) as the basis for
continuing operation of the SVE system, based on the above factors.
Alternative IOC/68.4 was chosen as the preferred alternative since in situ SVE/bioremediation
reduces the toxicity and mobility associated with the fuel-contaminated subsurface soils.
Capital cost estimates for this remedy are estimated at approximately $155,000, operation and
maintenance costs are estimated at $506,000. Total cost, represented as a net present worth using
a five percent discount rate, is estimated at $597,000.
This site was evaluated using a residential land-use scenario. The risk assessment concluded that
acceptable human health risks exist at this site. The basis for cleanup at Sites IOC/68 is
protection of groundwater quality. Therefore, this site will be cleaned up to levels commensurate
with residential land-use.
A cleanup level of 1 milligram per liter (mg/L) for gasoline in the subsurface soil at Site 68 was
identified in the Basewide OU FFS [IT 1997a]. The cleanup level is the practical quantitation
limit (PQL) for the available analytical method. The FFS calculated a Total Designated Level
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(TDL) of 0.05 ppm based on a water quality goal (WQG) of 0.005 mg/L, an attenuation factor of
1.0, and a teachability factor of 10 (0.005 ppm x 1 x 10 = 0.05 ppm). An attenuation factor of
1.0 is typically used when the distance from the deepest contaminant detection to groundwater is
equal to or less than ten feet. Since information on the distance from the deepest contaminant
detection to groundwater was not available when the FFS was prepared, an attenuation factor of
1.0 was apparently chosen to be conservative. The TDL in the FFS [IT 1997a] is less than the
PQL, so the preliminary remediation goal and hence the cleanup level was proposed at the PQL.
Regional Water Quality Control Board (RWQCB) guidance suggests an attenuation factor of 100
is suitable for the case when the distance from the deepest contaminant detection to groundwater
is greater than 30 feet, as is now understood to be the case at Site 68. Therefore, an attenuation
factor of 100 has been used to re-calculate the TDL for Site 68, resulting in a cleanup level of
5 ppm for TPH measured as gasoline. This is also the cleanup level for Site IOC which has
distribution of contaminants very similar to Site 68.
Oil and grease was apparently selected as a COC in the subsurface soil at Site IOC because of its
potential to impact groundwater quality. A TDL was calculated at 100 ppm using a WQG of
1 ppm, an attenuation factor of 10, and a teachability factor of 10 (1 ppm x 10 x 10 = 100 ppm).
This level is less than the established background level of 430 ppm, so the background level was
selected as a cleanup level in the draft version of this ROD. However, data from the Site
Investigation and SVE System Installation Report for Site IOC/68 [EA 1997] indicates that an
attenuation factor of 100 is appropriate based on the distance from the deepest contaminant
detection to groundwater. Use of a higher attenuation factor is also supported by the relative
immobility of oil and grease in most soil types. With an attenuation factor of 100 the TDL for oil
and grease is 1,000 ppm. Only one sample obtained during drilling of the pilot test wells had a
detection of oil and grease above 1,000 ppm (MATHER-SO-10C-SB30-15 at 3,340 ppm). One
other sample had a detection at 530 ppm (same boring as MATHER-SO-10C-SB30-15 but at a
depth of 25 feet), but all other samples were less than the background level. The Air Force, the
USEPA, and the State of California decided not to require cleanup for oil and grease since the
site data indicates that it is not widely distributed above the revised cleanup level. Only an
alternate remedy such as excavation could ensure cleanup that will meet the oil and grease
cleanup standard. This alternative was not considered when the FFS was prepared, but would be
considerably more costly than the selected remedy, and the benefit of removing such a limited
amount of oil and grease is not considered to warrant the additional cost to remove it. Therefore,
it is thereby determined that oil and grease is no! a COC at this site. Table 2-18 presents the
Sites IOC/68 cleanup levels.
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Table 2-18. Sites IOC/68 Cleanup Levels
Contaminant of Concern
COC Basis
Cleanup Level
Cleanup Basis
Subsurface Soils - Site IOC
Benzene
Toluene
Ethylbenzene
Xylenes
Carbon Tetrachloride
TPH measured as Diesel
TPH measured as Gasoline
Subsurface Soils - Site 68
TPH measured as Gasoline
VLEACH
VLEACH
VLEACH
VLEACH
VLEACH
DLM
DLM
DLM
Total (ppm)
See text in
Section 2.2.9. 1
See text in
Section 2.2.9. 1
See text in
Section 2.2.9. 1
See text in
Section 2.2.9. 1
See text in
Section 2.2.9.1
100
5
Total
5
Soluble (mg/L)
NA
NA
NA
NA
NA
10
NA
Soluble
NA
(a)
(a)
(a)
(a)
(a)
TDL/SDL
TDL/NA
TDL/NA
(a) Potential threat to groundwater quality
ppm = parts per million
VLEACH = VLEACH model results
mg/L = milligrams per liter
COC = chemical of concern
TPH = total petroleum hydrocarbon
TDL = total designated level
SDL = soluble designated level
NA = not applicable
DLM = Designated Level Methodology (i.e., protection of groundwater quality)
2.2.9.2 Site 18 - Old Burial Site
Alternative 18.2 was selected by the Air Force, with concurrence by the USEPA and State of
California as the remedy for Site 18. The major components of this remedy include:
• installing an in situ SVE system comprised of extraction wells and possibly
passive injection wells; and
treatment of offgas by granular activated carbon or more cost-effective means of
best available control technology as necessary to comply with ARARs.
Thermal destruction of chlorinated hydrocarbons may generate dioxins. Therefore, if thermal
destruction technology is used as part of the in situ remediation selected for this Basewide
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Operable Unit site and the influent gas contains chlorinated chemicals the emissions from the
thermal treatment unit will be monitored (which will consist of at least three sampling events) for
dioxin/furans during the first month of operation, and again if significant changes are made to the
influent vapor or the operation of the thermal treatment unit that could reasonably be expected to
result in increased dioxin/furan emissions. If the emissions exceed the value of 0.2 ng/DSCM,
calculated as the sum of TEQ (values to the 2,3,7,8-TCDD isomer) currently proposed as an
emissions standard for RCRA incinerators, then a risk calculation will be performed. Risks
exceeding the 10"6 to 10"4 threshold range will require mitigation; risks within the threshold range
will be subject to further consideration by the Air Force, USEPA, and the State of California
under the Federal Facility Agreement. Once SVE is initiated, it will be terminated in accordance
with the demonstration described in the following paragraphs.
The goal of cleaning up the vadose zone is to minimize further degradation of the groundwater
by the contaminants in the soil. It is generally preferable from a technical and cost perspective to
clean up contamination in the vadose zone before it reaches the groundwater. The soil cleanup
standard will be achieved when the residual vadose zone contaminants will not cause the
groundwater cleanup standard, as measured in groundwater wells monitoring the plume, to be
exceeded after the cessation of the groundwater remediation. The Air Force will make the
demonstration that the standard has been met through contaminant fate and transport modeling,
trend analysis, mass balance, and/or other means. This demonstration will include examination
of the effects of the residual vadose zone contamination in the groundwater using VLEACH or
another appropriate vadose zone model, in conjunction with a groundwater fate and transport
model, to predict the resulting concentration from this residual vadose zone contamination in the
nearest groundwater remediation. The Air Force shall provide verification, through actual data,
that the above standard has been met. The signatory parties to this ROD will jointly make the
decision that the soil cleanup standard has been met.
The Air Force shall operate the SVE system until it makes the demonstration that the cleanup
standard, set forth above, has been met. The Air Force shall continue to operate the SVE system
if appropriate, after considering the following factors:
• whether the mass removal rate is approaching asymptotic levels after temporary
shutdown periods and appropriate optimization of the SVE system;
• the additional cost of continuing to operate SVE system at concentrations
approaching asymptotic mass levels;
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• whether the predicted concentration of the leachate from the vadose zone (using
VLEACH or another appropriate vadose zone model that interprets soil gas data)
will exceed the groundwater cleanup standard;
• the predicted effectiveness and cost of further enhancements to the SVE system
(e.g., additional vapor extraction wells);
• whether the cost of groundwater remediation will be significantly more if the
residual vadose zone contamination is not addressed;
• whether residual mass in the vadose zone will significantly prolong the time to
attain the groundwater cleanup standard; and
• the incremental cost over time of the vadose zone remediation compared to the
incremental cost over time for groundwater remediation on the basis of a common
unit (e.g., cost of a pound of TCE removed) provided that the underlying
groundwater has not reached aquifer cleanup levels.
The signatory parties agree that the Air Force may cycle the SVE system on and off in order to
optimize the SVE operation and/or evaluate the factors listed above.
The signatory parties to this ROD will jointly make the decision that the SVE system may be shut
off. If the parties cannot reach a joint resolution, any party may invoke dispute resolution. This
ROD does not resolve the ARAR status of state requirements regarding the establishment of soil
cleanup levels. The parties agree that in the event of a dispute regarding SVE shutoff, the state
may argue its authority to require soil cleanup (including soil cleanup standards) as the basis for
continuing operation of the SVE system, based on the above factors.
Alternative 18.2 was chosen as the preferred alternative for the following reasons:
• significant mass of VOCs removed during the 1993 and 1995 pilot tests
demonstrates technical feasibility;
• potential to expand system to mitigate contamination at Site 23A; and
• the site would be actively remediated through SVE thereby reducing mass and
potentially reducing the duration of groundwater remediation.
It is anticipated that the system would be installed in a phased approach in conjunction with
additional sampling during the Remedial Design/Remedial Action phase to delineate the extent
of contamination. Therefore, this alternative is conceptual in nature with costs presented in a
unit (per acre) basis. Capital cost estimates for this remedy are estimated to be approximately
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$736,000 per acre, operation and maintenance costs are estimated at $319,000 per acre. Total
cost, represented as a net present worth using a five percent discount rate, is estimated to be
$1,039,000 per acre.
This site was evaluated using a residential land-use scenario. The risk assessment concluded that
human health and ecological risks at this site are acceptable. The basis for cleanup at Site 18 is
protection of groundwater quality. Therefore, this site will be cleaned up to levels commensurate
with residential land-use. Table 2-19 presents the Site 18 cleanup levels.
Table 2-19. Site 18 Cleanup Levels
Contaminant of
Concern
COC Basis
Cleanup Level
Cleanup Basis
Soil Vapor
TCE
I.2-DCE
VLEACH
VLEACH
see text in
Section 2.2.9.2
see text in
Section 2.2.9.2
(a)
(a)
(a) Potential threat to groundwater quality
TCE = trichloroethene
DCE = dichloroethene
COC = chemical of concern
VLEACH = VLEACH model results
2.2.9.3 Site 20 - Sewage Treatment Facility
Alternative 20.4 was selected by the Air Force, with concurrence by the USEPA and State of
California as the remedy for Site 20. The major components of this remedy include:
• Excavating and transporting approximately 500 cubic yards of contaminated
surface soils to the Mather Soil Bioremediation Facility.
• Ex situ bioremediation of excavated surface soils if necessary until Site 7
acceptance criteria for PAHs are achieved. Compliance with the acceptance
criteria will be verified with post treatment confirmation soil sampling and
analysis.
• Transporting the treated Site 20 soils from the Mather Soil Bioremedtation Facility
to Site 7 for use as foundation material in construction of a cap if the soils meet
Site 7 acceptance criteria or to an appropriate off-base disposal facility.
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• Installing one additional groundwater monitoring well at the site. Compliance
with cleanup standards will be verified with groundwater monitoring.
• Groundwater monitoring for phthalates and diesel would be conducted for four
quarters, if non-detect, monitoring would be discontinued.
Alternative 20.4 was chosen as the preferred alternative for the following reasons:
• Excavation provides an immediate reduction of the toxicity and mobility
associated with the lead contaminated surface soils.
• Stabilization will be done if it can allow the lead-contaminated soils to be suitable
for disposal at Site 7 which results in a cost savings over off-base disposal.
The TPH measured as diesel analytical results were all (J) qualified (estimated)
and at relatively low concentrations in the subsurface soils; therefore, groundwater
monitoring is appropriate to evaluate future potential impacts.
Capital cost estimates for this remedy are estimated to be approximately $73,000, operation and
maintenance costs are estimated at $38,000. Total cost, represented as a net present worth using
a five percent discount rate, is estimated to be $108,000.
This site was evaluated using a residential land-use scenario. The risk assessment concluded an
unacceptable human health risk exists at this site. The bases for cleanup is protection of human
health and groundwater quality. Therefore, this site will be cleaned up to levels commensurate
with residential land-use. Table 2-20 presents the Site 20 cleanup levels.
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Table 2-20. Site 20 Cleanup Levels
Contaminant of Concern
COC Basis
Cleanup Level
(ppm)
Cleanup Basis
Surface Soils
Lead
Benzo(b)fluoranthene
Benzo(k)flouranlhene
Benzo(a)pyrene
Phenanthrene
Benzo(a)anthracene
DLM, HH
DLM, HH
DLM
HH
DLM
DLM
130
0.33
0.33
0.33
0.33
0.33
CAL EPA
PQL
PQL
PQL
PQL
PQL
ppm = parts per million COC = chemical of concern
PQL = practical quantitation limit HH = human health risk
DLM = Designated Level Methodology (i.e., protection of ground water quality)
CAL EPA = California Environmental Protection Agency screening level (i.e., LEADSPREAD model)
2.2.9.4 Site 23 - Sanitary Sewer Line Main Base Area
Alternative 23.2 was selected by the Air Force, with concurrence by the USEPA and the State of
California as the remedy for Site 23. The major components of this remedy include:
• installing an in situ SVE system comprised of extraction wells and passive
injection wells; and
• treatment of offgas by granular activated carbon or more cost-effective means of
best available control technology.
Thermal destruction of chlorinated hydrocarbons may generate dioxins. Therefore, if thermal
destruction technology is used as part of the in situ remediation selected for this Basewide
Operable Unit site and the influent gas contains chlorinated chemicals the emissions from the
thermal treatment unit will be monitored (which will consist of at least three sampling events) for
dioxin/furans during the first month of operation, and again if significant changes are made to the
influent vapor or the operation of the thermal treatment unit that could reasonably be expected to
result in increased dioxin/furan emissions. If the emissions exceed the value of 0.2 ng/DSCM,
calculated as the sum of TEQ (values to the 2,3,7,8-TCDD isomer) currently proposed as an
emissions standard for RCRA incinerators, then a risk calculation will be performed. Risks
exceeding the 10"6 to 10"* threshold range will require mitigation; risks within the threshold range
will be subject to further consideration by the Air Force, USEPA, and the State of California
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under the Federal Facility Agreement. Once SVE is initiated, it will be terminated in accordance
with the demonstration described in the following paragraphs.
The goal of cleaning up the vadose zone is to minimize further degradation of the groundwater
by the contaminants in the soil. It is generally preferable from a technical and cost perspective to
clean up contamination in the vadose zone before it reaches the groundwater. The soil cleanup
standard will be achieved when the residual vadose zone contaminants will not cause the
groundwater cleanup standard, as measured in groundwater wells monitoring the plume, to be
exceeded after the cessation of the groundwater remediation. The Air Force will make the
demonstration that the standard has been met through contaminant fate and transport modeling,
trend analysis, mass balance, and/or other means. This demonstration will include examination
of the effects of the residual vadose zone contamination in the groundwater using VLEACH or
another appropriate vadose zone model, in conjunction with a groundwater fate and transport
model, to predict the resulting concentration from this residual vadose zone contamination in the
nearest groundwater remediation. The Air Force shall provide verification, through actual data,
that the above standard has been met. The signatory parties to this ROD will jointly make the
decision that the soil cleanup standard has been met.
The Air Force shall operate the SVE system until it makes the demonstration that the cleanup
standard, set forth above, has been met. The Air Force shall continue to operate the SVE system
if appropriate, after considering the following factors:
• whether the mass removal rate is approaching asymptotic levels after temporary
shutdown periods and appropriate optimization of the SVE system;
the additional cost of continuing to operate SVE system at concentrations
approaching asymptotic mass levels;
• whether the predicted concentration of the leachate from the vadose zone (using
VLEACH or another appropriate vadose zone model that interprets soil gas data)
will exceed the groundwater cleanup standard;
• the predicted effectiveness and cost of further enhancements to the SVE system
(e.g., additional vapor extraction wells);
• whether the cost of groundwater remediation will be significantly more if the
residual vadose zone contamination is not addressed;
• whether residual mass in the vadose zone will significantly prolong the time to
attain the groundwater cleanup standard; and
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• the incremental cost over time of the vadose zone remediation compared to the
incremental cost over time for groundwater remediation on the basis of a common
unit (e.g., cost of pound of TCE removed) provided that the underlying
groundwater has not reached aquifer cleanup levels.
The signatory parties agree that the Air Force may cycle the SVE system on and off in order to
optimize the SVE operation and/or evaluate the factors listed above.
The signatory parties to this ROD will jointly make the decision that the SVE system may be shut
off. If the parties cannot reach a joint resolution, any party may invoke dispute resolution. This
ROD does not resolve the ARAR status of state requirements regarding the establishment of soil
cleanup levels. The parties agree that in the event of a dispute regarding SVE shutoff, the state
may argue its authority to require soil cleanup (including soil cleanup standards) as the basis for
continuing operation of the SVE system, based on the above factors.
Alternative 23.2 was chosen as the preferred alternative for the following reasons:
• SVE has been successfully applied at other on-base sites with similar
contaminants; and
• potential to expand remedial action from other sites (i.e., Sites 18, 39, and 59) to
encompass Site 23 areas of concern (e.g., 23 A, 23B, 23C, and/or 23D).
It is anticipated that the system would be installed in a phased approach in conjunction with
additional sampling during the Remedial Design/Remedial Action phase to delineate the extent
of contamination. Therefore, this alternative is conceptual in nature with costs presented in a
unit (per acre) basis. Capital cost estimates for this remedy are estimated to be approximately
$738,000 per acre, operation and maintenance costs are estimated at $319,000 per acre. Total
cost, represented as a net present worth using a five percent discount rate, is estimated to be
$1,041,000 per acre.
This site was evaluated using a residential land-use scenario. The risk assessment concluded that
the human health and ecological risks were acceptable. The basis for cleanup is protection of
groundwater quality. Therefore, the site will be cleaned up to levels commensurate with
residential land use. Table 2-21 presents the Site 23 cleanup levels.
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Table 2-21. Site 23 Cleanup Levels
Contaminant of
Concern
COC Basis
Cleanup Level
Cleanup Basis
Soil Vapor - Site 23 A
TCE
VLEACH
see text in
Section 2.2.9.4
(a)
Soil Vapor -Site 23 B
TCE
1,2-DCE
VLEACH
VLEACH
see text in
Section 2.2.9.4
see text in
Section 2.2.9.4
(a)
(a)
Soil Vapor - Site 23C
PCE
VLEACH
see text in
Section 2.2.9.4
(a)
Soil Vapor - Site 23 D
Xylenes
VLEACH
see text in
Section 2.2.9.4
(a)
(a) Potential threat to groundwater quality
TCE = trichloroethene
DCE = dichloroethene
COC = contaminant of concern
PCE = tetrachloroethene (perch loroethene)
VLEACH = VLEACH model results
2.2.9.5 Site 86- Military Firing Range
Alternative 86.2 was selected by the Air Force, with concurrence by the USEPA and the State of
California as the remedy for Site 86. The major components of this remedy include:
• excavating approximately 1,900 cubic yards of lead-contaminated surface soils
from the bullet flight path;
• stabilizing (if needed for disposal) approximately 6,100 cubic yards of
contaminated surface soil (e.g., the excavated soils and lead-contaminated soils
stockpiled at the site);
• transporting the soils stabilized as needed, to Site 7 for use as foundation material
in construction of a cap, or to an off-base facility if sample screening (Figure 2-9)
indicates that Site 7 acceptance criteria are not met; and
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• backfilling the excavated areas with uncontaminated soils and/or recontouring to
create effective drainage.
Alternative 86.2 was chosen as the preferred alternative for the following reasons:
• treatment of soil reduces the mobility of the contaminants; and
• stabilization results in the soils to be potentially disposed on-base.
Capital costs, assuming disposal at Site 7, for this remedy are estimated to be approximately
$564,000, while no operation and maintenance costs are anticipated. Total cost, as net present
worth using a five percent discount rate, is estimated to be $564,000. Should the soils not meet
Site 7 acceptance criteria, off-base disposal will be required.
Capital costs assuming all soils are disposed off-site are estimated to be $2,073,000. No
operation and maintenance costs are associated with this alternative. Total cost, represented as a
net present worth using a five percent discount rate, is estimated to be $2,073,000.
This site was evaluated using a residential land-use scenario. The risk assessment concluded that
an unacceptable human health and ecological risk exists at the site. The bases for cleanup is
protection of human health, groundwater quality, and ecological receptors. Therefore, this site
will be cleaned up to levels commensurate with residential land use. Table 2-22 presents the
Site 86 cleanup levels.
Table 2-22. Site 86 Cleanup Levels
Contaminant of
Concern
COC Basic
Cleanup Level
(ppm)
Cleanup Basis
Surface Soil
Lead
DLM, ECO Risk, HH
130
CAL EPA
ppm = pans per million
CAL EPA = California Environmental Protection Agency screening level (i.e., LEADSPREAD model)
COC = chemical of concern
HH = human health risk
DLM = Designated Level Methodology (i.e., protection of groundwater quality)
ECO Risk = ecological risk
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to
6\
o
Excavate Soil and
Sediment
Does Material
Meet Site 7
Acceptance
Criteria?
Does Material
Meet Site 7
Acceptance
Criteria?
Dispose at Site 7
Dispose at Site 7
Off-Base Disposal
Figure 2-9. Disposition of Sites 86 and 87 Surface Soils and/or Sediments
Off-Base
Disposal
920001 .A WS
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2.2.9.6 Site 87 - Skeet/Trap Range
Alternative 87.2 was selected by the Air Force, with concurrence by the USEPA and the State of
California as the remedy for Site 87. The major components of this remedy include:
• excavating approximately 28,000 cubic yards of contaminated sediments and
surface soils to a 6 inch depth through the fall zone of the lead shot;
• stabilizing (if needed for disposal) approximately 28,000 cubic yards of
contaminated sediments and surface soils;
• if surface water is present, constructing diversion dams to channel the water flow
away from the areas to be excavated. These dams would be removed following
completion of the excavation activities. If diversion dams are not appropriate, the
water will be discharged to the POTW, if approved by Sacramento County;
• transporting the soil, stabilized as necessary, to Site 7 for use as foundation
material in construction of a cap, or an off-base facility if sample screening
(see Figure 2-9) indicates that Site 7 acceptance criteria are not met;
• backfilling the excavated areas with uncontaminated soils and/or recontouring to
create effective drainage; and
• institutional controls will be implemented with the goal of protecting human
health.
Alternative 87.2 was chosen as the preferred alternative for the following reasons:
• treatment of soil reduces the mobility of the contaminants;
• stabilization results in the soils to be potentially disposed on-base; and
• institutional controls provide further protection of human health and the
environment.
Capital costs, assuming disposal at Site 7, for this remedy are estimated to be approximately
$2,800,000, while no operation and maintenance costs are anticipated. Total cost, as net present
worth using a five percent discount rate, is estimated to be $2,800,000. Should the soils not meet
Site 7 acceptance criteria, off-base disposal will be required.
Capital costs, assuming all soils are disposed off-site, are estimated to be $9,026,000. No
operation and maintenance costs are associated with this alternative. Total cost, represented as a
net present worth using a five percent discount rate, is estimated to be $9,026,000.
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This site was evaluated using a recreational land-use scenario. The risk assessment concluded
unacceptable human health and ecological risks exist at the site. The basis for cleanup is
protection of human health, groundwater and surface water quality, and ecological receptors.
This site will be cleaned up to levels commensurate with recreational land use. Table 2-23
presents the Site 87 cleanup levels. However, since cleanup is not planned to achieve residential
standards, institutional controls will be implemented to restrict activities that could endanger
public health unless the cleanup does reduce risk to a level compatible with unrestricted land use.
Table 2-23. Site 87 Cleanup Levels
Contaminant of
Concern
COC Basis
Cleanup Level (ppm)
Cleanup Basis
Sediments
Arsenic
Lead
Surface Soil
Lead
Benzo(a)pyrene
Dibenz(a,h)anthracene
Benzo(g,h,i)perylene
Fluoranthene
Phenanthrene
DLM, ECO Risk, HH
DLM, ECO Risk, HH
ECO Risk, HH
HH
DLM, HH
DLM
DLM
DLM
9.6
15.5 (a)
700
0.33
0.33
0.33
0.33
0.33
BKGRD
DLM
ECO
PQL
PQL
PQL
PQL
PQL
(a) Additionally, lead pellets in the stream bed will be removed to the extent practicable in order to reduce the
risk of ingestion by water fowl and prevent further leaching from the sediments.
ppm = parts per million COC = chemical of concern
PQL = practical quantitation limit HH = human health risk
ECO Risk = ecological risk ECO = ecological risk-based cleanup
BKGRD = Inorganic Background (Aerojet and Mather Air Force Base [see Appendix F])
DLM = Designated Level Methodology (protection of groundwater/surface water quality)
Institutional controls are warranted under the CERCLA remedial action at Site 87 in order to
assure the protection of human health when contaminants posing a significant health threat
remain in the environment. The cleanup standard for lead in the soil at Site 87 is 700 ppm
(Table 2-23); this is a higher concentration than that acceptable for unrestricted or residential use.
Institutional controls are necessary to prevent humans from significant exposure to contaminated
soil at Site 87. Therefore, institutional controls will be implemented with the goal of limiting
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unacceptable exposure where contamination remains in place during or after cleanup such that
the site is not compatible with residential (or unrestricted) use. Such institutional controls could
consist of lease restrictions and/or "deed restrictions" or other controls mutually agreed to by the
Air Force, the USEPA, and the State of California. These institutional controls will be
implemented in accordance with relevant Air Force, DOD, USEPA, and state guidance with
respect to such implementation. The restrictions will prohibit land use that presents unacceptable
risk to human health due to the residual contamination.
In addition to these controls, the terms and conditions of property leases or transfers include the
right of the Air Force, the USEPA, and the State of California to access the property as necessary
to accomplish and oversee required remediation.
The proposed ecological cleanup goal for lead in terrestrial habitats at Site 87 is 700 mg/kg. This
was based on site-specific data from another terrestrial site at Mather. In the Phase II Detailed
Ecological Risk Assessment for Mather AFB, IRP Site 20 and a reference location were selected
to represent grassland habitats associated with the base [IT 1996c - Appendix L]. As part of this
effort, soil, plants, and small mammals were collected and analyzed for a suite of metals which
included lead. In addition, toxicity tests were performed using rye grass to assay for potential
phytotoxic effects associated with metals in the soil. Statistical analysis of data from Site 20 and
Reference Site 2 did not indicate significant differences in lead concentrations in plant tissues
from the two sites. Lead concentrations in small mammals were, however, significantly different
as were concentrations of lead in surface soils from the two sites. With regard to the lead
concentrations measured in the small mammals from Site 20, they are not believed to be
hazardous to small mammals as supported by Eisler [1998] who reported whole body lead
concentrations in small mammals collected from uncontaminated sites to range from 1 to
7 mg/kg (dry weight). The maximum lead concentration in animals collected from Site 20 was
5.1 mg/kg (dry weight) and the mean was 2.2 mg/kg (dry weight).
A 28-day rye grass shoot length and biomass assay (a modification of the early seedling growth
test) was conducted to assess toxicological impacts on vegetation at Site 20. (Biomass was
selected as the toxicological endpoint as recommended by Clarence Callahan, USEPA Region 9.)
Rye grass was used as a test species in the bioassay study because it is common to the grasslands
of Mather AFB and is found at both Site 20 and Reference Site 2. Statistically significant
differences in biomass and shoot length were not found between the two test groups.
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Development of ecological cleanup goals for terrestrial sites at Mather AFB incorporated
information on special status species within the area and data from the Phase II investigation. No
special status or protected species are associated with Site 87. Because the Phase II investigation
at Site 20 did not indicate ecological risks to terrestrial receptors when compared to a reference
site, the 95 percent upper confidence limit of the mean concentration of lead in surface soil at
Site 20 (700 mg/kg) was used as an ecological cleanup goal for lead in Mather AFB surface soils.
As a final note, surface soil lead concentrations for Site 20 (Phase II investigation) ranged from
151 to 703 mg/kg with a 95 percent upper confidence limit of the mean concentration of
700 mg/kg. Site 87 had a 95 percent upper confidence limit of the mean concentration of
718 mg/kg for lead. This indicates that lead exposure concentrations at the two sites are similar
on a site-wide basis.
The Air Force will perform monitoring to insure that the residual levels of lead left in place at
Site 87 do not represent a hazard to small mammals and waterfowl. To accomplish this,
monitoring of lead levels in small mammal tissue will be required on an annual basis for three
years, with the results evaluated in an annual monitoring report to the regulatory agencies. In
addition, any dead waterfowl found in the area of Site 87 must be reported to the regulatory
agencies, and necropsied by a certified laboratory for signs of lead toxicity. The details of the
monitoring program will be worked out cooperatively between the Air Force and the regulatory
agencies.
If small mammal tissue lead levels are lower than those reported to cause adverse effects
[Eisler 1998] after a minimum of two years of monitoring, then monitoring will be discontinued
upon agreement by the regulatory agencies. If small mammal tissue lead levels are higher than
those reported to cause adverse effects [Eisler 1998] after a minimum of two years of monitoring,
then further ecological investigation and re-evaluation of the lead cleanup level will be
conducted. The Air Force may have to undertake additional remedial action to reduce lead levels
at Site 87.
If necropsied waterfowl show evidence of adverse effects due to ingestion of lead, then further
ecological investigation and re-evaluation of the lead cleanup level will be conducted. The
Air Force may have to undertake additional remedial action to reduce lead levels at Site 87.
2.2.10 Remedial Action Operation and Maintenance
The CERCLA program at Mather AFB has identified 88 sites organized into six operable units.
As of this ROD, 83 of those sites have been selected either for remedial action or no further
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action under CERCLA. Each of the sites selected for remedial action has or will have remedial
action plans describing in detail the design and the operation, maintenance, and monitoring of the
remedial action, as required by the federal facility agreement for Mather AFB.
In order to assist the Air Force, the USEPA, the State of California, and the public to understand
how the CERCLA program is implemented and documented, the BRAC Cleanup Plan will be
periodically updated to summarize the current status of environmental restoration at Mather, and
present a comprehensive strategy for implementing the response actions necessary to protect
human health and the environment. The Air Force and regulatory agencies will determine the
appropriate level of detail in this plan.
The BRAC Cleanup Plan will address both engineered remedial actions (i.e., groundwater
treatment systems and landfill caps), as well as non-engineered remedial actions
(i.e., institutional controls). The Air Force will revise the BRAC Cleanup Plan to describe the
operation and maintenance of each remedial action, briefly explaining each remedial action,
provide a list of all pertinent documents used to complete each remedial action, including the
remedial action work plans (operation and maintenance plans, health and safety plans, and the
performance and environmental monitoring requirements), and any institutional controls required
to accomplish the remedies.
The objectives of this plan are to:
• provide a comprehensive guide to the management of each long-term remedial
action;
• provide a single reference point for all ROD cleanup goals;
• provide text and tables graphing the status and schedule of completion for each
remedial action;
• reference and briefly describe the purpose of each document developed for a
particular remedial action;
• evaluate project progress; and
streamline the management of all long-term remedial actions at Mather.
The plan should be reviewed annually and be revised as necessary.
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3.0 Basewide Operable Unit Sites Selected for No Further
Action
3.1 Declaration for the Basewide Operable Unit Sites Selected for No Further
Action
No Further Action is Necessary to Ensure
Protection of Human Health and the Environment
3.1.1 Site Name and Location
Basewide OU Sites (IRP Sites) Selected for No Further Action
Mather AFB (a NPL Site),
Sacramento County, California.
3.1.2 Statement of Basis and Purpose
The Basewide OU sites for which no further action was chosen at the formerly active
Mather AFB were investigated under the Mather AFB IRP and are described and evaluated in the
RJ/FS documents. These sites include:
Site 2-"8150" Area Landfill;
• Site 8 - Fire Training Area No. I;
• Site 17 - Weapons Storage Septic Tank Leach Field;
Site 19 (Expanded) - Bulk Fuel Storage Facility;
• Site 67 - SAC Area Shop Drainage Systems;
• Site 81 - Sewage Oxidation Ponds; and
• Site 84 - Sanitary Sewer Line Runway Investigation.
These decisions are based on the Administrative Record for these sites.
The USEPA Region IX and the State of California concur that no action is appropriate at these
sites and that no action ensures protection of human health and the environment.
3.1.3 Description of the No Further Action Decision
Cleanup options were not developed for sites which no COCs were identified. Based on the
calculations in the human health risk assessment, excess lifetime cancer risks fall within or below
the range of one-in-one million to one-in-ten thousand, or do not exist at all, and all non-cancer
risks have a hazard index of less than 1.0 . Therefore, the Air Force is not proposing cleanup or
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further investigative activities. Additionally, no threats to water quality or ecological risks are
associated with these sites.
3.1.4 Summary of Site Risks
Remedial investigation activities at Mather AFB have included a CBRA which consisted of a
baseline risk assessment which evaluated the potential human health and ecological risks
associated with exposures to contaminated soils that would result if no cleanup actions are taken
at a site [IT I996c], and assessments of potential impacts to ground water and/or surface water
quality [IT I997aj. The data collected and used in the RIs and FFS were of USEPA quality
Level III, IV or V, or equivalent [USEPA 1987]. Formal data validation of the RI- and
FFS-generated data was performed to ensure that data were of the quality commensurate with
their intended use.
Based on the calculations in the human health risk assessment, excess lifetime cancer risks for
the sites described in this section fall within or below the range of one-in-one million to
one-in-ten thousand, and non-cancer risks had a hazard index less than 1.0 in their current state.
The sites selected for no further action do not present a threat to groundwater or surface water
quality and do not present an ecological risk.
3.2 Decision Summary for Basewide Operable Unit Sites Selected for No
Further Action
The Decision Summary provides a brief overview of the site characteristics, the alternatives
evaluated, and the analysis of those options.
3.2.1 Site Name, Location, and Description
The Basewide OU sites selected for no further action at the formerly active base are presented in
Figure 3-1 and in Section 3.1.2.
3.2.2 Site History and Enforcement Activities
Previous investigations have been conducted at the Basewide OU sites selected for no further
action as part of the Air Force IRP. A listing of the investigations conducted at each of these
sites is summarized in Table 3-1.
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Table 3-1. Previous Investigations at the No Further Action Sites
SITE NUMBER
2
8
17
19 (expanded)
67
81
84
APPLICABLE INVESTIGATION
1,5,6,7,8
1,3.4, 5, 9. 10, 1 1
1,2,4,5, 10, II
1,2,3,4,5,6,8,9, 10,
11
4,7,8.9, 10, II
9, 10, II
9, 11
I. Installation Restoration Program (IRP) Records Search for Mather Air Force Base, Phase I [CH2M-HJII, Inc. 1982);
2. IRP Phase II, Stage 1 Investigation [Weston 1986];
3. IRP Phase II, Stage 3 Investigation [AeroVironmcnt 1988];
4. Well Redevelopment and Sampling Plan [IT 1988a];
5. Solid Waste Assessment Test Report [IT 1993d];
6. Quarterly Routine Groundwater Sampling [IT I995a) and [EA I990a-c];
7. Landfill Gas Testing Report [IT I988b);
8. Group 2 Sites Remedial Investigation Report [IT 1992);
9. Additional Site Characterization Remedial Investigation Report [IT I996b];
10. Comprehensive Baseline Risk Assessment Report [IT I996c|;
11. Basewide Operable Unit Focused Feasibility Study Report [IT 1997a].
3.2.3 Highlights of Community Participation
The public participation requirement of CERCLA Sections 113(k)(2)(B)(i-v) and 117 were met
through a public comment period (held May 23 through June 23, 1997) and a public meeting
(held on May 29, 1997) to address the Proposed Plan [IT 1997b] and content of supporting RI/FS
documents in the selection of the no further action sites.
3.2.4 Scope and Role of Response Action
Because no COCs were identified at these sites, the no further action alternative is chosen as the
planned response action. No unacceptable risk to human health or the environment exists at
these sites.
3.2.5 Summary of Site Characteristics
A brief description of each of the no further action sites is provided in the following sections.
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I
•^
If
BASC BOUNOWfT
o
OICM M SAMTAftY SCWER
DUE LOCATION
NO ACTION Slit
ncu«
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3.2.5.1 Site 2 - "8150" Area Landfill
The remedial alternatives for Site 2 were presented in the Landfill OU FFS [IT I993b] and
Proposed Plan [IT 1993c]. Capping was the remedial action proposed in the Proposed Plan and
selected in the ROD [USAF 1995]. However, once cap construction was initiated, it was
apparent that there was less refuse at Site 2 and that there was an opportunity to consolidate the
refuse from Site 2 into Site 4 prior to Site 4 being capped. This was judged more cost-effective
based upon the revised estimate of refuse volume, and additionally would be less restrictive to
future airport development. A Removal Action Memorandum [USAF 1996a] was approved on
September 1996, to document this change. All the refuse at Site 2 was excavated and
consolidated into Site 4 in 1996, as documented in the Final Closure Certification Report for
Landfill Sites [MW 1997a). Therefore, this ROD confirms that the removal action at Site 2
constitutes the final remedy for Site 2.
3.2.5.2 S/te 8 - Fire Training Area Number 1
Fire Training Area No. I was the original fire-training area at Mather AFB and was in use until
1945. The site was located by historical aerial photographs; however, the Air Force found no
evidence of a bum pit during the RI. Petroleum, oil, and lubricant wastes were used during
weekly training exercises. Cleaning solvents such as TCE and carbon tetrachloride were possibly
commingled with the wastes. Investigations at Site 8 found no evidence to suggest that the
Former Fire Training Area No. I has been a source for contamination. Investigations have
revealed no COCs; therefore, no threat to human health or the environment exists.
3.2.5.3 Site 17 - Weapons Storage Septic Tank Leach Field
The Weapons Storage Septic Tank Leach Field is located in the SAC Weapons Storage Area and
was used for sewage disposal until 1978. In addition, solvents and petroleum hydrocarbons may
have been disposed in small amounts. Investigations at Site 17 have revealed no COCs;
therefore, no threat to human health or the environment exists.
3.2.5.4 Site 19 (Expanded) - Bulk Fuel Storage Facility
The Bulk Fuel Storage Facility is located in the northwest portion of the base, inside a bermed
area containing two main aboveground JP-4 storage tanks. Expanded site work took place
outside the bermed area. Contamination at Site 19 (inside the bermed areas) has been addressed
in the Groundwater OU and Soil OU FFS [IT 1995b] and Soil OU and Groundwater OU ROD
[IT 1996a]. In these documents, the selected remedy has been identified as in situ
bioremediation of the shallow subsurface soils. Since the time these decisions were made,
expanded investigations have been conducted in the immediate vicinity of the site (i.e., expanded
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Site 19). These investigations were focused in an area northwest of the bulk storage tanks near
the excavated tank site, pumphouses, and truck fill stands. Investigations of the expanded area
have revealed no COCs; therefore, no threat to human health or the environment exists.
3.2.5.5 Site 67 - Strategic Air Command Area Shop Drainage Systems
The SAC Area Shop Drainage System consists of storm drains, sanitary sewers (approximately
14,200 feet of sewer line), and an open ditch (approximately 1,200 feet in length) near
Building 7008. Waste solvents (tetrachloroethene, trichloroethane, and TCE), fuels, and oils
were generated in the SAC Area facilities and may have been disposed into the sewer system.
Leaks in the drainage system might have provided possible pathways for migration of solvents or
hydrocarbon wastes produced in the SAC Area shops. Investigations at Site 67 found no
evidence to suggest that the SAC Area Shop Drainage System has been a source for soil or
groundwater contamination. Investigations have revealed no COCs; therefore, no threat to
human health or the environment exists.
3.2.5.6 Site 81 - Sewage Oxidation Ponds
Site 81, the sewage oxidation ponds, is located in the southwestern portion of the Mather AFB,
south of the Sewage Treatment Facility (Site 20) and east of the "7100" Area Disposal (Site 7).
The sewage oxidation ponds were constructed to indirectly increase the capacity of the sewage
treatment facility by providing additional retention time. The base sewage system was connected
to the municipal system approximately one year prior to its deactivation in 1983.
However, during heavy periods of rainfall, the conveyance system overloads and the southern
most ponds (1 and 2) serve as emergency retention until such time as the water can be metered
back through the base system and into the municipal system.
It is not feasible to distinguish between the sediments and surface soils; therefore, COCs of one
medium were considered as likely for the other medium. Risks due to contamination associated
with this site were evaluated and presented under an occupational future land-use scenario in the
FFS [IT 1997a] and Proposed Plan [IT 1997b] documents. Additional sampling was conducted
by Montgomery Watson to measure soluble levels for TPH [MW 1998]. Based on the TPH
results and subsequent conversations with the RWQCB, it was determined that the TPH does not
pose a threat to groundwater quality; therefore, TPH is not a COC. The only COC identified in
the sediments/surface soils (e.g., maximum of three feet deep) was cadmium which was based on
protection of human health (i.e., inhalation of dust). The estimate of total residential ILCR at the
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Sewage Oxidation Ponds was 1.6 x 10'5, with cadmium contributing all of the risk through the
inhalation of dust pathway. This ILCR is below the USEPA upper bound limit of 1 x 10"4
(therefore the site as a whole does not pose significant carcinogenic risk, but is still within the
range of concern of 1 x 10"6 to 1 x 10"4. However, there where numerous conservative
assumptions built into the calculation of risk at the Sewage Oxidation Pond. The following is a
brief description of these assumptions and a more realistic inhalation of dust risk calculation for
the Sewage Oxidation Ponds.
The initial ILCR estimate presented in the CBRA [IT 1996c] for dust inhalation included the
following assumptions;
• the cadmium was present at the 95 percent upper confidence limit over the entire
site (1.5 x 105 square meters);
• there was no vegetation at the site;
• the California Environmental Protection Agency slope factor ([15 mg/kg-day]"1)
was used in the calculation of risk instead of the less conservative USEPA value
found in Integrated Risk Information System ([6.3 mg/kg-day]'1);
• the wind was assumed to prevail in the direction of the receptor 100 percent of the
time; and
• the wind speed was assumed to be strong enough to carry dust 100 percent of the
time.
Upon further examination the majority of the cadmium above background is limited to the
western portion of the northern most oxidation pond (pond No. 4) and is a small fraction of the
site area (approximately one quarter). When this new area (approximately 30,000 square meters)
was used in the ILCR calculation and using a 50 percent vegetative cover assumption, the site
falls near the 1 x 10"6 threshold (i.e., 1.3 x 10"6). Under these conditions and without examining
the remaining conservative assumptions above, this site does not pose a significant threat to
human health. Therefore, this site was selected for no further action.
3.2.5.7 Site 84 - Sanitary Sewer Line Runway Investigation
The Sanitary Sewer Line Runway Investigation was conducted from the SAC Area to the Sewage
Treatment Facility, approximately 4,200 feet of sewer line. The sewer line was identified as a
possible source of various potential COCs to the vadose zone and a potential threat to
groundwater. Investigations at Site 84 found no evidence to suggest that the sanitary sewer line
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in the runway area has been a source for soil or groundwater contamination. Investigations have
revealed no COCs; therefore, no threat to human health or the environment exists.
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4.0 Basewide Operable Unit "Petroleum Only" Sites
Selected for No Action Under Comprehensive
Environmental Response, Compensation, and Liability
Act (but which remain to be closed under other
regulations)
4.1 Declaration for the Basewide Operable Unit Petroleum Only Sites Selected
for No Action
No Action is Necessary Based
on the Lack of Statutory Authority under CERCLA
4.1.1 Site Name and Location
Site 82 - Golf Course Maintenance Yard and Site 83 - Helicopter Wash Rack
Mather AFB (a NPL Site),
Sacramento County, California
4.1.2 Statement of Basis and Purpose
The "petroleum only" sites were investigated under the Mather AFB IRP and are described and
evaluated in previous RJ/FS documents. However, there is no CERCLA authority to take action
at these sites; therefore, they will be cleaned up under RCRA Subtitle I and other applicable State
of California regulations. Regulatory oversight will be provided by the CVRWQCB, and
Sacramento County as appropriate. These decisions are based on the Administrative Record File
for these sites.
The USEPA Region IX and the State of California concur on the lack of statutory authority under
CERCLA to examine remedial actions for the "petroleum only" sites; therefore, those sites will
be addressed further under the Defense Environmental Restoration Program, RCRA Subtitle I,
and other applicable State of California regulations.
4.1.3 Description of the Selected Remedy
The COCs at the "petroleum only" sites are exempt from remedial action under CERCLA.
Therefore, no further action is required under CERCLA for the "petroleum only" sites based on
the lack of statutory authority under CERCLA. The "petroleum only" sites include: Sites 82
and 83.
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4.1.4 Declaration Statement
The USEPA does not have authority under CERCLA Section 104 to address the "petroleum
only" sites. However, the "no action" decision does not constitute a rinding that adequate
protection has been achieved at the sites. Cleanup alternatives have been developed and
documented in the FFS Report [IT I997a] and these sites will be addressed under RCRA
Subtitle I and other applicable State of California regulations, with regulatory oversight by the
CVRWQCB and Sacramento County as appropriate. Cleanup activities at the "petroleum only"
sites are not subject to the same requirements as the CERCLA sites, i.e., "petroleum only" sites,
do not require a CERCLA five-year review and are not subject to the 15 month requirement to
begin remedial activities.
4.2 Decision Summary for Basewide Operable Unit "Petroleum Only" Sites
Selected for No Action Under Comprehensive Environmental Response,
Compensation, and Liability Act (but which remain to be closed under
other regulations)
The Decision Summary provides an overview of the site characteristics, the alternatives
evaluated, and the analysis of those options. The Decision Summary also identifies the selected
remedy and explains how the remedy fulfills statutory requirements.
4.2.1 Site Name, Location, and Description
Locations of the Basewide OU "petroleum only" sites at the formerly active Mather AFB are
presented in Figure 4-1 and include: Site 82 - Golf Course Maintenance Yard and Site 83
Helicopter Wash Rack.
4.2.2 Site History and Enforcement Activities
Cleanup options were developed for the "petroleum only" sites and are presented in the FFS
Report [IT 1997a]; however, the USEPA does not have authority under CERCLA to address
these sites. Therefore, the no action decision is documented as the selected remedy.
Previous investigations have been conducted at the Basewide OU "petroleum only" sites as part
of the Air Force IRP. A listing of the investigations conducted at each of these sites is
summarized in Table 4-1.
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. i ' \:_~-v
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Table 4-1. Previous Investigations at the Soil Operable Unit "Petroleum Only" Sites
Site Number
82
83
Applicable Investigation
1,2,3
1,2,3
I. Additional Site Characterization Remedial Investigation Report [IT 19966J;
2. Final Comprehensive Baseline Risk Assessment Report [IT I996c];
3. Basewide Operable Unit Focused Feasibility Study Report [IT 1997a).
4.2.3 Highlights of Community Participation
The public participation requirement of CERCLA Sections 113(k)(2)(B)(i-v) and 117 do not
apply to these sites; however, these sites were included in the Proposed Plan [IT 1997b], and the
public comment period (held from May 23 through June 23, 1997) and public meeting (held
May 29, 1997) to address the Proposed Plan and content of supporting RJ/FS documents.
4.2.4 Scope and Role of Response Action
Because there is no CERCLA authority to take action at these sites, the no action alternative was
selected as the planned response action. No risk to human health or the environment exist at
these sites from CERCLA (i.e., non-petroleum) constituents. Petroleum-only COCs were
identified based on protection of groundwater quality.
4.2.5 Summary of Site Characteristics
The Basewide OU "petroleum only" sites are comprised of contaminated soils associated with a
fuel washrack and a golf course maintenance area. The sources of contamination are equipment
maintenance and fuels storage and delivery. The objective of this section of the ROD is to
address the primary concerns at the Basewide OU "petroleum only" sites posed by soil
contamination.
Environmental studies were initiated by the Air Force in 1982 to investigate soil contamination
resulting from past base operations. Previous RJs have been conducted at the Basewide OU
"petroleum only" sites as part of the Air Force IRP. A brief description of the nature and extent
of contamination at each of the Basewide OU "petroleum only" sites is provided in the following
sections.
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4.2.5.1 Site 82 - Golf Course Maintenance Yard
Site 82 is located in the eastern portion of Mather AFB, along Eagles Nest Road. Activities at
the site, include equipment washing, pesticide mixing and storage, and fuel and oil refilling and
storage. Contamination was identified in the subsurface soils. Petroleum only hydrocarbons
measured as diesel have been identified as a COC based on protection of groundwater quality.
4.2.5.2 Site 83 • Helicopter Washrack
Site 83 is located in the southeastern portion of the Main Base Area. During repair of the storm
drain near the washrack, fuel contamination was detected in the shallow soils. Contamination
was identified in the subsurface soils. Petroleum only hydrocarbons measured as diesel have
been identified as a COC based on protection of groundwater quality.
4.2.6 Summary of Site Risks
Remedial investigation activities at Mather AFB included a CBRA [IT 1996c] (which include an
ecological and human health assessment) and assessments of potential impacts to groundwater
and surface water quality [IT I996c]. The data collected and used in the RJs and FFS were of
USEPA quality Level III, IV, or V, or equivalent [USEPA 1987]. Formal data validation of the
RI- and FFS-generated data was performed to ensure that data were of the quality commensurate
with their intended use.
Based on the calculations in the human health risk assessment, excess lifetime cancer risks fall
within or below the range of one-in-one million to one-in-ten thousand or no cancer risk existed.
Additionally, all non-cancer risks had a hazard index of less than 1.0. However, petroleum
hydrocarbons in soils at Sites 82 and 83 may pose a threat to groundwater quality. Accordingly,
although the sites have been designated for no further action under CERCLA, corrective actions
pursuant to RCRA Subtitle I and applicable State of California regulations will be performed to
ensure protection of groundwater quality.
4.2.7 Statutory Authority Finding
The no action finding is selected based on the petroleum exclusion in CERCLA. However, the
"no action" decision does not constitute a finding that adequate protection has been achieved at
the sites. Cleanup alternatives have been developed and documented in the FFS Report
[IT I997a] and these sites will be addressed under RCRA Subtitle I and other applicable State of
California regulations, with regulatory oversight by the CVRWQCB and Sacramento County as
appropriate.
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5.0 List of Applicable or Relevant and Appropriate
Requirements and Performance Standards
Pursuant to Section 121(d)(l) of CERCLA, 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 onsite must meet standards,
requirements, limitations, or criteria that are applicable or relevant and appropriate requirements.
Federal ARARs include requirements under federal environmental laws, while state ARARs
include promulgated requirements under state environmental or facility-siting laws that are more
stringent than federal ARARs, and have been identified to USEPA by the State of California in a
timely manner.
Applicable requirements are those cleanup 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 circumstance at a CERCLA site. Under CERCLA regulation, onsite actions
need comply only with the substantive aspects of ARARs, not with corresponding administrative
requirements (such as, but not limited to, permits, recordkeeping, and reporting). However,
substantive components of apparently administrative requirements, such as recordkeeping, are
potential ARARs. For example, a regulation that describes required reports can include specific
measures of remediation performance that must be made. The report is not a potential ARAR
but the specific measures needed to document remediation performance are substantive
requirements and may be ARARs.
Relevant and appropriate requirements include those that, while not "applicable" to a hazardous
substance, pollutant, contaminant, remedial action, location, or other circumstance at a CERCLA
site, nevertheless address problems or situations sufficiently similar to those encountered at the
CERCLA site to indicate their use. 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 nonpromul gated standards, criteria, guidance,
and to-be-considered (TBC) advisories may be used to develop a protective remedy. Where a
TBC was used to develop a remedy or cleanup goal, it becomes a performance standard that must
be met for the remediation project.
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Applicable or relevant and appropriate requirements are identified on a site-specific basis from
information about site-specific chemicals, specific actions that are being considered, and specific
features of the site location. There are three categories of ARARs:
• Chemical-specific ARARs are numerical values or methods which, when applied
to site-specific conditions, result in 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, or may
affect, a special location, such as a wetland or floodplain.
• Action-specific ARARs are technology- or activity-based requirements or
limitations on actions taken with respect to hazardous waste.
The ARARs and performance standards were developed using the following guidelines and
documents:
CERCLA Compliance with Other Laws Manual, Part I: Interim Final
[USEPA 1988];
"CERCLA Compliance with Other Laws Manual, Part II: Clean Water Act and
Other Environmental Statutes and State Requirements" [USEPA 1989]; and
"California State Water Resources Control Board ARARs Under CERCLA"
[SWRCB 1992].
The following sections outline the ARARs and other information considered for the
Basewide OU sites where remedial actions will be initiated (see Section 2.0). These sections
present the federal and state regulations and guidance under each appropriate ARAR category
(i.e., chemical-, location-, and action-specific). Chemical-specific ARARs and performance
standards are listed in Section 5.1, location-specific ARARs and performance standards are listed
in Section 5.2, and action-specific ARARs and performance standards are listed in Section 5.3.
It should be noted that the California State Water Resources Control Board (SWRCB)
regulations governing disposal to land, Title 23 California Code of Regulations (CCR),
Chapter 15, were recodified in Title 27. Due to the timing of these events, the Chapter 15
regulations have been retained in this ROD, however, any enforcement actions of Chapter 15
RL/8-98/ES/392000I .AWS
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regulations identified as ARARs in this ROD are likely to be done under the authorities provided
to the SWRCB and RWQCB under Title 27.
5.1 Chemical-Specific Applicable or Relevant and Appropriate Requirements
and Performance Standards
Contaminants of concern for the Basewide OU sites are listed in the following subsections.
These COCs were identified for soils (i.e., sediments, surface soils, and subsurface soils), and
surface water. The chemical-specific ARARs and performance standards for these COCs are
presented based on whether they are ARARs or performance standards, the type of
contamination, and applicable medium.
5.1.1 Federal Chemical-Specific Applicable or Relevant and Appropriate
Requirements and Performance Standards
The following federal chemical-specific ARARs and performance standards have been identified
for the Basewide OU sites.
5.1.1.1 Soils
There are no federal chemical-specific ARARs for COCs identified in the soils (i.e., surface soils
and subsurface soils) for the Basewide OU sites. Certain sites in the Basewide OU may impact
or threaten to impact surface water (Site 87) or groundwater (Sites IOC/68, 18, 20, 23, 86, and
87). For these sites, chemical-specific performance standards were developed from the WQGs
using the Designated Level Methodology (for inorganic and semi-volatile organic chemicals) or
VLEACH modeling (for volatile organic chemicals). The numeric WQG was used as the
regulatory factor for each COC identified at a site. The performance standards established for
surface soils and subsurface soils are presented in Tables 5-1 and 5-2, respectively.
5.1.1.2 Surface Waters
Contaminants of concern were presented in the FFS [IT I997a] for surface water at Site 87.
Site 87 includes part of Morrison Creek, a tributary of the Sacramento River, which has
beneficial use designation including municipal, domestic, and agricultural supply; water contact
and non-contact recreation; esthetic enjoyment; navigation; groundwater recharge; freshwater
replenishment; and preservation and enhancement offish, wildlife, and other aquatic resources.
Protection of surface waters will be achieved through remediation of the sediments, because they
are a potential source of surface water pollution. If present during remediation, the water would
be diverted around the contaminated area in order for the source to be removed and then returned
Riyg-98/ES/392000 LAWS
5-3
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Table 5-1. State Chemical-Specific
Performance Standards for Surface Soils
Chemical
Total Concentration (mg/kg |ppm|)
Total Designated Level
Associated Sites
Metals
Lead
1500 (a)
20, 86, 87
Organic Chemicals
Benzo(a)pyrene
Benzo(b)fluoranthene
Benzo(k)fluoranthene
Benzo(g,h,i)perylene
Benzo(a)anthracene
Dibenz(a,h)anthracene
Fluoranthene
Phenanthrene
20
0.029
0.029
0.28
0.029
30
(b)
(b)
87
20
20
87
20
87
87
20,87
mg/kg = milligrams per kilogram
ppm = parts per million
(a) Even though the total designated level is 1,500 ppm; a more stringent standard does exist (the soluble
threshold limit concentration of 1,000 ppm).
(b) No Water Quality Goal currently available. Will be based on an evaluation if detected in the future.
Note: Surface soil cleanup goals were developed using the Designated Level Methodology (DLM) for metals and
semi volatile organic chemicals. Designated Level Methodology parameter values vary with site conditions
(e.g., depth to groundwater) and appropriate water quality objective (see Appendix E for an explanation of
the DLM).
There are no federal performance standards.
RL/8-9S/ES/392000I .AWS
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Table 5-2. State Chemical-Specific
Performance Standards for Subsurface Soils
Chemical
-*/
Total Concentration (rag/kg (ppm))
Total Designated Level
Associated Sites
Organic Chemicals .
Benzene
Bis(2-ethylhexyl)phthalate
Carbon Tetrachloride
Xylenes
TPH measured as gasoline
TPH measured as diesel
Toluene
Ethylbenzene
Oil and Grease
TCE
1.2-DCE
NA(1)
4
NA(I)
NA(1)
5
100
NA(1)
NA(1)
100
NA(1)
NA(I)
IOC/68
20
IOC/68
IOC/68, 23
IOC/68
IOC/68
IOC/68
IOC/68
IOC/68
18,23
18,23
NA = not applicable
ppm = parts per million
mg/kg = milligrams per kilogram
COC = contaminant of concern
PRO = preliminary remediation goal
TCE = trichloroethene
DCE = dichloroethene
TPH-D = total petroleum hydrocarbons as diesel
TPH-G = total petroleum hydrocarbons as gasoline
(1) COC identified through VLEACH modeling, PRGs have not been established.
Note: Subsurface soil cleanup goals were developed using VLEACH modeling for volatile organic chemicals and
the Designated Level Methodology (DLM) for metals and semivolatile organic chemicals. Designated
Level Methodology parameter values vary with site conditions (e.g., depth to groundwater) and appropriate
water quality objective (see Appendix E for an explanation of the DLM).
There are no federal performance standards.
RU8-98/ES/392000I .AWS
5-5
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to its channel. If diversion dams are not appropriate, the water will be discharged to the POTW,
if approved by Sacramento County.
5.1.2 State Chemical-Specific Applicable or Relevant and Appropriate
Requirements and Performance Standards
The following State of California chemical-specific ARARs and performance standards have
been identified for the Basewide OU sites.
5.1.2.1 Soils
There are no state chemical-specific ARARs for COCs identified in the soils (i.e., surface soils
and subsurface soils) for the Basewide OU sites. The performance standards established for
surface soils and subsurface soils are presented in Tables 5-1 and 5-2.
5.1.2.2 Surface Waters
Contaminants of concern were presented in the FFS [IT I997a] for surface water at Site 87.
Site 87 includes a portion of Morrison Creek, a tributary of the Sacramento River, which has
beneficial use designation including municipal, domestic, and agricultural supply; water contact
and non-contact recreation; esthetic enjoyment; navigation; groundwater recharge; freshwater
replenishment; and preservation and enhancement offish, wildlife, and other aquatic resources.
However, since the surface water at this site is seasonal and may or may not be present during
remedial actions, no cleanup goals for surface water were established. A potential source of
surface water contamination, i.e., contaminated sediments, will be remediated through
excavation. If present, the water would be diverted around the contaminated area in order for the
source to be removed and then returned to its channel. If diversion dams are not appropriate, the
water will be discharged to the POTW, if approved by Sacramento County.
5.2 Location-Specific Applicable or Relevant and Appropriate Requirements
and Performance Standards
Location-specific ARARs and performance standards are requirements that place restrictions on
the concentration of a COC or the conduct of activities due to the presence of unique site features
such as surface waters and wetlands. The location of the Basewide OU sites were analyzed for
unique site features to identify location-specific ARARs. The unique site features considered
were:
• surface water;
• floodplain and wetlands;
• habitats of rare, threatened, endangered, and special status species;
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5-6
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• earthquake faults;
• historically or culturally significant properties;
• wilderness areas;
• wild and scenic rivers; and
• coastal zones.
Of these unique site features, flood plains and/or surface water occurs at or near Site 87. No
other unique site features were identified.
The surface waters associated with this site is seasonal and builds up during the winter and spring
as a result of heavy rains. Site 87 has natural drainage which conveys stormwater. Stormwater
ARARs are listed as action-specific ARARs in Section 5.3 below.
5.3 Action-Specific Applicable or Relevant and Appropriate Requirements
Performance Standards
Action-specific ARARs are technology- or activity-based requirements or limitations on actions
taken with respect to the hazardous waste. The following sections describe the state and federal
action-specific ARARs and performance standards. All action-specific ARARs are listed in
Table 5-3 with each substantive requirement identified as either applicable or relevant and
appropriate. Several of the requirements are marked with a footnote providing clarification to
either their ARAR status or the legal interpretation of why they are considered ARARs for a
particular site or remedial action. Sections 5.3.1 and 5.3.2 include a description of the sources of
the action-specific ARAR regulations and the authorization the state regulatory agencies have to
enforce these requirements. In addition, the Air Force position on substantive requirements of
ARARs and how they apply to the selected remedial actions is described.
5.3.1 Federal Action-Specific Applicable or Relevant and Appropriate
Requirements
The following federal action-specific ARARs and performance standards have been identified.
The federal (and state) action-specific ARARs are listed in Table 5-3.
RLy8-9g/ES/M2000I.AWS
5-7
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Table 5-3. State and Federal Action-Specific Applicable or Relevant and Appropriate Requirements
Source
Standard, Requirement, Criterion, or
Limitation
ARAR Status
Description of Applicable or Relevant and Appropriate
Requirements
Associated Sile(s)
Federal ARARs
Federal Clean Walcr
Act
40 CFR 122 - USEPA Administered
Permit Programs: The National Discharge
Elimination System
40 CFR 122.26
40 CFR 122.4 l(d)
40CFR I22.4l(c)
40 CFR I22.44(d)
Subscclion(s) as
Listed Below
Applicable
Applicable
Applicable
Applicable
Requirements to ensure storm water discharges from Mather AFB
remedial action activities do not contribute to a violation of surface
water quality standards.
A!! reasonable steps must be taken to minimize or prevent discharges
which have a reasonable likelihood of causing adverse impacts on
surface water quality (40 CFR I22.4l(d)). Discharges into surface
water must achieve federal and state water quality standards (40 CFR
I22.44(d)).
87
State of California Hazardous Waste ARARi (Federal ARARs)
California
Hazardous Waste
Control Law
Title 22, Division 4.5 (Environmental
Health Standards Tor Management of
Hazardous Waste), Chapter 1 1 (Standards
Applicable to Generators of Hazardous
Waste), Article 1 (Applicability)
22 CCR 6626 I.I
22 CCR 6626 1.2
22 CCR 6626 1.3
22 CCR 6626 1.4
22 CCR 6626 1.5
22 CCR 6626 1.6
22 CCR 6626 1.7
Subsection(s) as
Listed Below
Applicable
Applicable
Applicable
Applicable
Applicable
Applicable
Applicable
Identifies whether the wastes are hazardous or non-hazardous for the
purposes of being able to dispose onsilc or dispose at an offsilc landfill.
IOC/68, 18,23
oo
RL/8-9&/ES/3920001 .A WS
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Table 5-3. State and Federal Action-Specific Applicable
or Relevant and Appropriate Requirements (Continued)
Source
Slindird, Requirement, Criterion, or
Limitation
ARAR Status
Description of Appliciblt or Relevant and Appropriate
Requirements
Associated Site(s)
California
Hazardous Waste
Control Law
Title 22, Division 4.5 (Environmental
Health Standards Tor Management of
Hazardous Waste), Chapter 14 (Standards
for Owners and Operators of Hazardous
Waste Transfer, Treatment, Storage, and
Disposal Facilities), Article 9 (Use and
Management of Containers)
Subscclion(s) as
Listed Below
22 CCR 66264.171
Applicable
22 CCR 66264.172
Applicable
22 CCR 66264.173
Applicable
22 CCR 66264.174
Applicable
22 CCR 66264.175
Applicable
22 CCR 66264.176
Applicable
22 CCR 66264.177
Applicable
22 CCR 66264.178
Applicable
The chemicals recovered from the sediments, surface soils, or
subsurface soils, may need to be managed as either a RCRA or
non-RCRA hazardous waste. The treatment, storage, and disposal
requirements for these wastes are either applicable or relevant and
appropriate (depending upon the classification of the waste material)
and they include: using containers to store the recovered product that
are compatible with this material (22 CCR 66264.172); using
containers that are in good condition (22 CCR 66264.171); segregating
the waste from incompatible wastes (22 CCR 66264.177); inspecting
the containers (22 CCR 66264.176); and providing adequate secondary
containment for the water stored (22 CCR 66264.175); containers
must be closed during transfer (22 CCR 66264.173); and all hazardous
material must be removed at closure (22 CCR 66264.178).
If during excavation, treatment processes, or cleanup activities
hazardous waste is identified throughout the waste characterization
process, the hazardous waste will be managed in accordance with what
the standards slates in these sections of the regulations.
20,86
2000*1
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Table 5-3. State and Federal Action-Specific Applicable
or Relevant and Appropriate Requirements (Continued)
Source
California
Hazardous Waste
Control Law
Standard, Requirement, Criterion, or
Limitation
Title 22, Division 4.5 (Environmental
Health Standards Tor Management of
Hazardous Waste), Chapter 14 (Standards
for Owners and Operators of Hazardous
Waste Transfer, Treatment, Storage, and
Disposal Facilities), Article 12 (Waste
Piles)
22 CCR 66264.251
22 CCR 66264.254
22 CCR 66264.256
22 CCR 66264.257
22 CCR 66264.258
22 CCR 66264.259
AKAK Stilus
Subsection(s) as
Listed below
Applicable
Applicable
Applicable
Applicable
Applicable
Applicable
Description of Applicable or Relevant and Appropriate
Requirements
Delineates requirements for the management of waste piles for
hazardous waste. This regulation is applicable to sites where
excavated materials are classified as hazardous wastes and managed in
waste piles. The titles of the regulations arc 22 CCR 66264.25 1 -
Design and Operating Requirements; 22 CCR 66264.254 - Monitoring
and Inspection; 22 CCR 66264.256 - Special Requirements for
Ignitable or Reactive Waste; 22 CCR 66264.257 - Special
Requirements for Incompatible Wastes; 22 CCR 66264.258 - Closure
and Post-Closure Care; and 22 CCR 66264.259 - Special
Requirements for Hazardous Wastes F020, F02I, F022, F023,
F026, and F027.
If during excavation, treatment processes, or cleanup activities,
hazardous waste is identified through the proper characterization
process, and land disposed within the meaning of the LDRs. the
hazardous waste will be managed in accordance with the standards
stated in these sections of the regulation.
Associated Sile(s)
IOC/68.20,86,87
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Table 5-3. State and Federal Action-Specific Applicable
or Relevant and Appropriate Requirements (Continued)
Source
Standard, Requirement, Criltrion, or
Limitation
ARAR Status
Description ofApplicable or Relevant and Appropriate
Requirement]
Associated Site(s)
California
Hazardous Waste
Control Laxv
Title 22, Division 4.5 (Environmental
Health Standards Tor Management of
Hazardous Waste), Chapter 14 (Standards
for Owners and Operators of Hazardous
Waste Transfer, Treatment, Storage, and
Disposal Facilities), Article 19 (Corrective
Action for Waste Management Units)
Subsection(s) as
Listed Below
22 CCR 66264.5J2
Relevant and
Appropriate
22 CCR 66264.553
Relevant and
Appropriate
CAMU: Placement, consolidation, and treatment of soils and wastes
being generated as pan of a corrective action under RCRA will not be
considered a new disposal to land as long as the materials arc handled
in designated CAMUs. Land disposal restrictions (22 CCR 66268)
arc not invoked when remediation wastes arc managed at a CAMU.
A CAMU can only be used for the management of remediation
wastes pursuant to implementing corrective actions at the facility.
USCPA intended that the Federal CAMU rule be considered for the
management of wastes generated at CERCLA sites. Excavation of
wastes from the discharge and disposal sites might be managed at a
CAMU for on-base disposal, or ex situ bioremediation.
A CAMU is an area within a facility for the purpose of implementing
corrective actions. Uncontaminaled areas are allowed to be
designated as part of a CAMU when they are necessary to achieve
the overall goals for the facility and will enhance the prolccliveness
of the remedial action. The CAMU rule allows consolidation and
treatment of wastes in a single unit, from other a/cas of the facility,
without triggering minimum technology requirements and LDR found
in other provisions of RCRA and HWCL: that is, placement of
wastes into a CAMU is not considered land disposal and redeposition
of treated wastes into the CAMU does not trigger the LDRs.
Groundwater must be monitored at the CAMU in order to detect and
characterize a release.
As of May 1998 a
CAMU is not being
proposed for the
Oasewide OU, thus
there are no applicable
sites.
However, this
regulation has been
identified as an ARAR
to allow flexibility in
the event a CAMU is
needed in the future.
California
Hazardous Waste
Control Law
Title 22, Division 4.5 (Environmental
Health Standards for Management of
Hazardous Waste), Chapter 18 (Land
Disposal Restrictions), Article I (General)
Subsection(s) as
Listed Iklow
22 CCR 66268.3
Applicable
Relevant and
Appropriate
22 CCR 66268.7(a) & (b)
Applicable
22 CCR 66268.9
Applicable
Provides the purpose, scope, and applicability of LDRs. The title of the
sections of the regulations are; 22 CCR 66268.3 - Dilution Prohibited
As a Substitute for Treatment; 22 CCR 66268.7 - Waste Analysis and
Recordkccping; and 22 CCR 66268.9 • Special Rules Regarding
Wastes That Exhibit a Characteristic.
If during excavation, treatment processes, or cleanup activities
hazardous waste is identified through the proper characterization
process, and will be land disposed within the meaning of the LDRs, the
hazardous waste will be managed in accordance with the standards
stated in these sections of the regulation. Only applicable if hazardous
wastes are disposed of or treated in an area not designated as a CAMU
or disposed of or treated beyond the area of contamination.
20, 86. 87
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Table 5-3. State and Federal Action-Specific Applicable
or Relevant and Appropriate Requirements (Continued)
Source
Sundird, Requirement, Criterion, or
Limitation
ARAR Status
Description of Applicable or Relevant and Appropriate
Requirements
Associated Site(s)
California
Hazardous Waste
Control Law
o
Tille 22, Division 4.5 (Environmental
Health Standards for Management of
Hazardous Waste), Chapter 18 (Land
Disposal Restrictions), Article 3
(Prohibitions on Land Disposal)
Subsection (s) as
Listed Below
22 CCR 66268.30
Applicable
22 CCR 66268.31
Applicable
22 CCR 66268.32
Applicable
22 CCR 66268.33
Applicable
22 CCR 66268.34
Applicable
These standards are applicable to sites where excavated material is
classified as hazardous waste and is disposed of or treated in an area
not designated as a CAMU. Provides waste-specific LDRs Tor
22 CCR 66268.30 - Waste Specific Prohibitions-Solvent Wastes;
22 CCR 66268.31 • Waste Specific Prohibitions-Dioxin-Containing
Wastes; 22 CCR 66263.32 - Waste Specific Prohibitions-California
List Wastes; 22 CCR 66268.33 - Waste Specific Prohibitions-First
Third Wastes; 22 CCR 66268.34 • Waste Specific Prohibitions-Second
Third Waste; and 22 CCR 66268.35 - Waste Specific
Prohibitions-Third Waste.
If during excavation, treatment processes, or cleanup activities
hazardous xvaste is identified through the proper characterization
process, and will be land disposed within the meaning of the LDRs, the
hazardous waste will be managed in accordance with the standards
staled in these sections of the regulation.
20, 86. 87
22 CCR 66268.35
Applicable
California
Hazardous Waste
Control Law
Title 22, Division 4.5 (Environmental
Health Standards for Management of
Hazardous Waste), Chapter 18 (Land
Disposal Restrictions), Article 5
(Prohibitions on Storage)
Subsection(s) as
Lisicd Uclow
22 CCR 66268.50
Applicable
This standard is applicable to sites where excavated material is
classified as hazardous waste. The standard provides prohibitions on
storage of restricted wastes.
If during excavation, treatment processes, or cleanup activities
hazardous waste is identified through the proper characterization
process, and will be land disposed within the meaning of the LDRs,
the hazardous waste will be managed in accordance with the standards
stated in these sections of the regulation.
20, 86. 87
RL/8-9S/EV392000I.AWS
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Table 5-3. State and Federal Action-Specific Applicable
or Relevant and Appropriate Requirements (Continued)
Source
Standard, Requirement, Criterion, or
Limitation
ARAIt Status
Description of Applicable or Relevant and Appropriate
Requirements
Associated Sile(s)
Stale of California AtrARARi
California Clean Air
Act
OJ
SMAQMO, Rule 202, Section 301
Applicable
This section of the rule requires the installation of DACT to a new
emissions unit or modification of an existing emissions unit that will
result in an emission of ROG, NOx, SOx, PMIO, CO, lead, or mercury.
Dest Available Control Technology for any emission unit is the most
stringent of the following:
The most effective emission control device, emission limit, or
technique, singly or in combination, which has been required or used
for the type of equipment comprising such an emissions unit unless the
applicant demonstrates to the satisfaction of the SMAQMO that such
limitations required on other sources have not been demonstrated to be
achievable.
For remediation processes, a control efficiency (effluent/influent) of
95 percent is considered BACT. Sacramento Metropolitan Air Quality
Management District will determine BACT for the technologies used
under the remedial alternatives for each site.
Top-down analysis process is the selection of any alternative basic
equipment, fuel, process, emission control device, or technique, singly
or in combination, determined to be technically feasible and
cost-effective by the SMAQMD.
In making a BACT determination for each affected pollutant the
district may consider the overall effect on other affected pollutants.
This regulation will apply to the treatment processes that release or
cause to be released the pollutants listed in the regulation. The remedia
alternatives utilizing air strippers, soil vapor extraction, and ex situ
bioremcdiation (at the Mather bioremediation facility) must ensure
BACT is used to control emissions in excess of levels specified in the
rule.
IOC/68, 18.23
I92000I.AWS
-------
Table 5-3. State and Federal Action-Specific Applicable
or Relevant and Appropriate Requirements (Continued)
Source
California Clean Air
Act
California Clean Air
Act
California Clean Air
Act
Standard, Requirement, Criterion, or
Limitation
SMAQMO, Rule 202, Section 302
SMAQMD. Rule 401
SMAQMO, Rule 402
ARAR Status
Applicable
Applicable
Applicable
Description of Applicable or Relevant and Appropriate
Requirements
This section of the rule requires an applicant to provide offsets for any
stationary source with the potential to emit any pollutant in excess of
the levels shown below.
ROG I50lbs/day
NO.x i50ibs/day
SOx 150lbs/day
PMI0....80lbs/day
CO 550 Ibs/day
Offsets for CO shall not be required if the applicant can demonstrate
that ambient air quality standards will not be violated in the affected
areas, and will not cause or contribute to a violation of the ambient
air quality standard. All emissions increases in excess of the levels
specified above need to be offset for the same calendar quarter.
Emissions are determined by using actual slack lest data, emission
factors, engineering calculations, or other methods approved by the
district in accordance with Section 4 1 1 of Rule 202.
This regulation will apply to the treatment processes that release or
cause lo be released the pollutants listed in the regulation. The
remedial alternatives utilizing air strippers, soil vapor extraction, and
ex situ bioremediation must ensure offsets are used for emissions in
excess of levels specified in the rule.
This rule prohibits the discharge of air contaminants which obscure
visibility by more than 20 percent for a period of more than three
minutes in any one hour.
This regulation is applicable to any remedial action activity, which
may cause a visible emission.
This rule prohibits the discharge of air contaminants in quantities
which cause injury, detriment, nuisance, or annoyance to any
considerable number of persons or which endangers the comfort,
response, health, or safety of any such person or which causes or
has natural tendency to cause injury or damage lo business or property.
This regulation is applicable (o any remedial action activity, which
may discharge air contaminants as defined by the rule.
Associated Site(s)
IOC/68, 18.23
IOC/68, 18.23
IOC/68, 18,23
RI/8-98/ES/392000 LAWS
-------
Table 5-3. State and Federal Action-Specific Applicable
or Relevant and Appropriate Requirements (Continued)
Source
Standard, Requirement, Criterion, or
Limitation
ARAR Status
Description of Applicable or Relevant and Appropriate
Requirements
Associated Site(s)
California Clean Air
Act
SMAQMD, Rule 403
Applicable
This rule requires a person to lake every reasonable precaution not to
cause or allow emissions of fugitive dusts from being airborne beyond
the property line from which the emissions originated.
This regulation is applicable to any remedial action activity, which
may cause (he release of fugitive dust.
All sites
California Clean Air
Act
SMAQMD. Rule 404
Applicable
This rule prohibits the discharge of paniculate matter from any source
in excess of O.I grains per standard cubic foot.
This regulation is applicable to any remedial action activity, which
may cause the release of paniculate matter.
All sites
California Clean Air
Act
SMAQMD, Rule 405
Applicable
This rule controls the discharge ofdust and condensed fumes into (he
atmosphere by establishing emission rates based on process weight.
This regulation is applicable lo any remedial action activity, which
may cause the release of dust or condensed fumes.
All sites
Stale of California Croundwaler and Soil ARARt1
California Water
Code
Stale Water Resources Control Board
Order 92-08-DWQ
(General order for storm water
management at construction sites)
Relevant and
Appropriate
Must identify (he sources of sediment and other pollutants (hat affect
the quality of storm water discharges and implement practices to
reduce these discharges.
Storm water discharges from construction sites must meet pollutant
limits and standards. The narrative effluent standard includes the
requirements to implement DMPs and/or appropriate pollution
prevention control practices.
Inspections of the construction site prior lo anticipated storm events
and after actual storm events need to be conducted lo identify areas
contributing lo storm water discharge and evaluated for (he
effectiveness of BMPs and other control practices.
Applies to construction sites five acres or greater in size. It also
applies to smaller sites that are part of a larger common plan of
development or sale.
Administrative portions of this permit are not applicable in accordance
with CERCLA.
Site 87
'J92000I.AWS
-------
Table 5-3. State and Federal Action-Specific Applicable
or Relevant and Appropriate Requirements (Continued)
Souret
Standard, Requirement, Criterion, or
Limitation
ARAR Status
Description of Applicable or Relevant and Appropriate
Requirements
Associated Site(s)
California Water
Code
Stale Water Resources Control Board
Order (Waste Discharge Requirements
[WDRs] for Discharges of Storm Water
Associated with Industrial Activities
Excluding Construction Activities)
97-03-DWQ
Applicable
Storm water discharges must meet the narrative standard of the
permit, this standard includes implementing BMPs and prohibits the
discharge of non-storm xvaier. Discharges should identify the sources
of pollutants to the storm water. Best Management Practices for these
sources can include treatment of storm water discharge and source
reduction. Non-stnrm water sources ofpoilutants include improper
dumping, spills, and leaks.
Monitoring must be conducted to demonstrate compliance and
measure the effectiveness of BMPs. Monitoring includes
performing visual inspections during the dry and wet seasons,
conducting annual inspections, and sampling and analysis for specific
analytical parameters.
Administrative portions of this permit arc not applicable in accordance
with CERCLA.
20. 86, 87
Porter-Cologne
Water Quality
Control Act
'California Water
Code Sections
13000. 13140,
13240)
Central Valley Region Basin Plan
Applicable
Establishes water quality objectives, including narrative and numerical
standards, that protect the beneficial uses of surface waters and
groundwaters in the region. The uses are municipal, domestic,
agricultural, and industrial service supply.
Specific applicable portions of the Basin Plan include beneficial uses
of affected water bodies water quality objectives to protect those uses.
The slate believes that several additional provisions of the CVR Basin
Plan, including the cleanup and water quality objective policies are
also ARARs. The stale will not dispute their omission in the ROD;
however, as the Air Force is complying with the substance of these
provisions.
All Sites
Riyg.98/ES/392000I.AWS
-------
Table 5-3. State and Federal Action-Specific Applicable
or Relevant and Appropriate Requirements (Continued)
Source
Porter-Cologne
Water Quality
Control Act
(California Water
Code Sections
13000. 13 HO,
13240)
Porter-Cologne
Water Quality
Control Act
(California Water
Code Sections
13000. 13140.
13240)
Standard, Requirement, Criterion, or
Limitation
SWRCB Resolution 68-16
SWRCB Resolution 88-63
ARAK Status
Applicable
Applicable
Description of Applicable or Relevant and Appropriate
Requirements
The resolution establishes requirements for activities involving
discharges of contamination directly into surface waters or groundwater
(e.g., quality of pump and treat diluent into surface waters or
groundwater).
Substantive requirements established by the resolution include use of
"best practicable treatment of control" for discharging the effluent.
This regulation applies to remedial action activities that cause active
discharges to surface waters or groundwater. The state believes that
several additional provisions of the CVR Basin Plan, including the
cleanup and water quality objective policies are also ARARs. The state
will not dispute their omission in the ROD; however, as the Air Force is
complying with substance of these provisions.
Specifies that, with certain exceptions, all ground and surface waters
have the beneficial use of municipal or domestic water supply.
Applies in determining beneficial uses for waters that may be
affected by discharges of waste.
State Water Resources Control Board Resolution 88-63 applies to all
sites that may be affected by discharges of waste to groundwaier or
surface water. The resolution specifies that, with certain exceptions,
all groundwater and surface waters have beneficial use of municipal
or domestic water supply. Consequently the more stringent of the
Federal and California Stale primary MCLs are relevant and
appropriate and are the ARAR for the remedial action. California
Safe Drinking Water Act standards which may be ARARs for the
site(s) are found in 22 CCR 66435. 22 CCR 64444.5. and
22 CCR 64473.
AssociatedSite(s)
All Sites
All sites
'392009J.AWS
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Table 5-3. State and Federal Action-Specific Applicable
or Relevant and Appropriate Requirements (Continued)
Source
SUndtrd, Requirement, Criterion, or
Limililion
ARAR Status
Description of Applicable or Relevant and Appropriate
Requirements
Associated Site(s)
oo
Porter-Cologne
Water Quality
Control Act
(California Water
Code Sections
13140, 13240,
13260, 13263,
13267, 13300,
13304.13307)
SWRCB Resolution 92-49 (as amended
April 12. 1994) Subparagraph IIIG
Relevant and
Appropriate
Section IIIG directs the Water Boards to ensure dischargers clean up
and abate the "effects" of discharges in a manner promoting
attainment of either background water quality or the best reasonable
water quality if background quality is not feasible. (Feasibility is
determined by the factors listed in Section IIIG and 23 CCR,
Chapter 15, Section 2550.4.) Minimum waicr siandards must be
protective of the beneficial use(s).
Section IIIG directs the Water Boards to apply 23 CCR, Chapter 15,
Section 2550.4 in approving any alternative cleanup levels less
stringent than background quality. The requirement lo obtain the
Water Board's approval is not a substantive requirement (ARAR);
however, the Air Force will consult with (he Water Board and
USEPA in applying the State's criteria to establish alternative cleanup
level(s).
Subject lo the limitations described above, this requirement is relevant
and appropriate for establishing levels for effect to surface and
groundwalcr quality caused by releases contaminants.
All sites
Porter-Cologne
Water Quality
Control Act
(California Water
Code Sections
I3I40-I3I47,
13172. 13260,
13263, 13267,
13304)
Title 23 (Waters), Division 3 (State Water
Resources Control Board), Chapter IS
(Discharges of Waste to Land), Article I
(General)
Subsection(s) as
Listed Delow
23CCR25ll(d)
Relevant and
Appropriate1
23 CCR 2511 (d) stales actions taken by or at the direction of public
agencies lo cleanup or abate conditions of pollution or nuisance
resulting from unintentional or unauthorized releases of waste or
pollutants lo the environment; provided that wastes, pollutants, or
contaminated materials removed from the immediate place of release
shall be discharged according lo Article 2 of this Chapter; and further
provided that remedial actions intended to contain such wastes at the
place of release shall implement applicable provisions of this
subchapier to the extent feasible.
It should be noted thai the California SWRCB regulations governing
disposal lo land, Title 23 CCR, Chapter 15, were recodified in Title 27.
Due lo the timing of these events, the Chapter 15 regulations have been
retained in this ROD, however any enforcement actions of Chapter 15
regulations identified as ARARs in this ROD are likely to be done
under the authorities provided to the SWRCB and RWQCB under
Tille 27.
All Sites
R17S-98/ES/392000I.AWS
-------
Table 5-3. State and Federal Action-Specific Applicable
or Relevant and Appropriate Requirements (Continued)
Source
Standard, Requirement, Criterion, or
Limitation
ARAR Status
Description of Applicable or Relevant and Appropriate
Requirements
Associated Site(s)
Porter-Cologne
Water Quality
Control Act
(California Water
Code Sections
13140-13147,
13172.13260,
13263, 13267,
13304)
Title 23 (Waters), Division 3 (Stale Water
Resources Control Board), Chapter 15
(Discharges of Waste to Land), Article 2
(Waste Classification and Management)
23CCR252I
23 CCR 2522
23 CCR 2523
23 CCR 2524
Applicable or
Relevant and
Appropriate1'4
Applicable or
Relevant and
Appropriate1''1
Applicable or
Relevant and
Appropriate1''1
Applicable or
Relevant and
Appropriate1'4
Applicable or
Relevant and
Appropriate1'4
Waste Classification: Wastes must be classified as either: Hazardous
waste (23 CCR 2521). designated waste (23 CCR 2522), nonhazaidous
solid waste (23 CCR 2523). or inert waste (23 CCR 2524). A
hazardous waste can only be discharged to a Class I facility (unless a
variance is applicable under Title 22 regulations). A designated waste
can be discharged to a Class I or Class II facility. A nonhazardous
solid waste can be discharged to a Class I, II, or III facility. Inert
wastes do not need to be sent to a classified facility.
Some of the sites have alternatives that involve excavation of the
contaminated soil. At the conclusion of on-base treatment, the soils
are proposed for use in the foundation layer of the landfill cap at Site 7.
It is expected, based on engineering judgement, that most of the sites
excavated will yield designated and not yield hazardous waste.
I lowever, until sampling is performed on the material at time of
excavation, a final determination cannot be made. The excavated waste
must be discharged to the appropriate facility pursuant to Article 2.
All Sites
920001.
AWS
-------
Table 5-3. State and Federal Action-Specific Applicable
or Relevant and Appropriate Requirements (Continued)
Source
Standard, Requirement, Criterion, or
Limitation
ARAR Status
Description of Applicable or Relevant and Appropriate
Requirements
Associated Site(s)
Porter-Cologne
Water Quality
Control Act
(California Water
Code Sections
13140-13147,
13172, 13260.
13263. 13267,
13304)
Title 23 (Waters), Division 3 (State Water
Resources Control Board), Chapter 15
(Discharges of Waste to Land), Article 2
(Waste Classification and Management)
Subscction(s) as
Listed Below
23 CCR 2530 (c)
Applicable
3.-I
23 CCR 2530 (d)
Applicable3-*
K)
O
23 CCR 2532
Applicable" and
Relevant and
Appropriate
Classification and Siting Criteria (23 CCR 2530 (c & d): New waste
piles shall be designed, constructed, and operated to ensure that wastes
will be a minimum of five feet above the highest ground water
elevation. All containment structures at the unit shall have a foundation
or base capable of supporting the structures and capable of
withstanding hydraulic pressure gradients. The unit needs to be able to
withstand flooding without washout, ground rupture, and rapid
geological change.
Class II (23 CCR 2532): Waste Management Units for Designated
Waste: Waste management units will be isolated from the waters of
the state through cither natural or engineered barriers. Relevant to
the waste being treated at the ex tint bioremediation facility.
Excavated wastes from various sites will be spread in lifts in the Mather
biorcmedialion cell. Treatment might include nutrient addition,
irrigation, and aeration. This treatment is considered similar to a
waste pile.
Soils containing petroleum hydrocarbons are not anticipated to be
classified as hazardous, but may be classified as designated wastes.
Thus Class II requirements are considered most relevant.
20 (Applicable)
86 and 87 (Relevant
and Appropriate)
RIVS-98/ES/3920001.AWS
-------
Table 5-3. State and Federal Action-Specific Applicable
or Relevant and Appropriate Requirements (Continued)
Souret
Porter-Cologne
Water Quality
Control Act
(California Water
Code Sections
I3I40-I3I47.
13172, 13260.
13263. 13267.
13304)
Standard, Requirement, Criterion, or
Limitation
Title 23 (Waters), Division 3 (Slate Water
Resources Control Board). Chapter 15
(Discharges of Waste to Land), Article 5
(Water Quality Monitoring and Response
Programs for Waste Management Units)
23 CCR 2550.1
ARAR Status
Subscclion(s) as
Listed Below1
Relevant and
Appropriate
Description of Applicable or Relevant ind Appropriate
Requirements
These provisions of Chapter 15 address remediation of contamination
at waste management units and monitoring of groundwalcr quality
during the remedial action. The corrective action program requires
that the cleanup objectives be met at the designated monitoring points
and that they be met throughout the zone that is affected. Further,
demonstration of the effectiveness of the remediation requires
showing (he concentrations at each monitoring point are at or below
the cleanup levels for one year following completion of the corrective
aclion(s). The evaluation monitoring program provides further
substantive requirements regarding the designation of monitoring
parameters and monitoring frequency.
Section 23 CCR Part 2550.1 describes the three types of groundwater
monitoring programs; detection, statistical evajuation, and physical
evaluation monitoring. Section 23 CCR Part 2*550.10 (Corrective
Action Program) requires that a groundwaler monitoring program be
implemented in conjunction with a corrective action to demonstrate
the effectiveness of the remedial technologies.
Associated Site(s)
IOC/68, 18.20,23
I/I
K)
920001 .A WS
-------
Table 5-3. State and Federal Action-Specific Applicable
or Relevant and Appropriate Requirements (Continued)
Source
Stindtrd, Requirement, Criterion, or
Limitation
A KAR Status
Description of Applicable or Relevinl and Appropriate
Requirements
Associated Site(s)
23 CCR 2550.4
Relevant and
Appropriate5
Cleanup levels must be set at background concentration levels or. if
background levels are not technologically and economically feasible,
then at the lowest levels that are economically and technologically
feasible. Specific factors must be considered in setting cleanup levels
above background levels. Cleanup levels above background levels
shall be evaluated every five years, if the actual concentration of a
constituent is lower than its associated cleanup level, the cleanup level
shall be lowered to reflect existing water quality (23 CCR 2550.4). It
has been determined that cleanup to background is not economically
feasible and; therefore, not relevant and appropriate to aquifer cleanup
standards.
IOC/68. 18,23
23 CCR 2550.6
Relevant and
Appropriate
Requires monitoring for compliance with cleanup standards for three
years from the date of achieving cleanup levels (23 CCR 2550.6) at
waste management units.
IOC/68. 18,20,23
23 CCR 2550.7
NJ
to
Relevant and
Appropriate
Requires general soil, surface water, and groundwater monitoring
(23 CCR 2550.7) which stales:
there is a sufficient number of monitoring points, including
background points; and
the monitoring points should be located at appropriate
locations and screened in the zones of concern.
IOC/68. 18,20,23
23 CCR 2550.9
Relevant and
Appropriate
Requires an assessment of the nature and extent of the release,
including a determination of the spatial distribution and concentration
ofeach constituent (23 CCR 2550.9).
IOC/68, 18,20.23
23 CCR 2550.10
Relevant and
Appropriate
Requires implementation of corrective action measures that ensure that
cleanup levels are achieved throughout the zone affected by the release
by removing the waste constituents or treating them in-place. Source
control may be required. Also requires monitoring to determine the
effectiveness of corrective actions. To demonstrate cleanup, the
concentration of each COC in the groundwaler must be equal to, or less
than, the cleanup goal for at least one year following suspension of the
corrective action (23 CCR 2550.10).
All Sites
RL/8-98/ES/3920001 .A WS
-------
Table 5-3. State and Federal Action-Specific Applicable
or Relevant and Appropriate Requirements (Continued)
Source
Standard, Requirement, Criterion, or
Limitation
A KAK Status
Description of Applicable or Relevant and Appropriate
Requirements
Associated Site(s)
Other State of California ARARs
Fish and Game Code Section 1603
California Water Code, Chapters 1 1 52,
1373, and 13801 (California Well
Standards. DWR Bulletin 74-90. and
Sacramento County Code, Title 6,
Chapter 6.28)
Relevant and
Appropriate
Performance
Standards
It is unlawful for any person to substantially direct or obstruct the
natural flow or substantially change the bed, channel, or bank of any
river, stream, or lake designated by the department, or use any material
from the strcambeds, without first notifying the department of the
activity.
These provisions establish standards for the construction, operation,
and abandonment of monitoring wells.
87
20
CCR = California Code of Regulation
CFR = Code of Federal Regulations
ROG = reactive organic gas
PMIO » particular matter
MCL ~ maximum contaminant level
AFB = Air Force Base
USAF = U.S. Air Force
RWQCB = Regional Water Quality Control Board
CAMU = Corrective Action Management Unit
District
CERCLA = Comprehensive Environmental Response, Compensation, and Liability Act
IIWCL = Hazardous Waste Control Law
Ibs/day = pounds per day
NOx = nitrogen oxide
CO = carbon monoxide
DWQ = Department of Water Quality
SWRCB = Slate Water Resource Control Board
BACT = Best Available Control Technology
ARAR = applicable or relevant and appropriate requirement
USEPA = United States Environmental Protection Agency
BMP = Best Management Practice
LOR » land disposal restrictions
SOx - sulfur oxide
ROD - Record of Decision
COC ° contaminant of concern
OU = operable unit
CVR = Central Valley Region
RCRA = Resource Conservation and Recovery Act
SMAQMD = Sacramento Metropolitan Air Quality Management
1. The Stale does not agree on the characterization of certain ARARs in this table to be "Relevant and Appropriate" instead of "Applicable." However, since these requirements are included in the
ROD as ARARs, the Stale will not dispute this ROD.
2. 23 CCR 251 l(d) is applicable to waste management units in operation alter November 27, 1984, and relevant and appropriate for units whose operations ceased prior to November 27, 1984.
3. Only as invoked by 23 CCR 2511 (d).
4. Only as invoked through 23 CCR 2511 (d).
5. Only as invoked by 92-49 IIIG.
'3920001.AWS
-------
The California DISC regulations promulgated under the Hazardous Waste Control Law
(HWCL) are applicable to ensure proper characterization of hazardous waste, and storage and
disposal of such waste. Specific federal environmental programs allow authorized states to
administer state regulations in lieu of parallel federal regulations. For a program to become
authorized, each state requirement must be at least as stringent as its parallel federal requirement.
Under authorized state programs, state requirements are federal ARARs. California has been
authorized to administer state programs in lieu of the hazardous waste (Subtitle C) and UST
(Subtitle I) portions of the RCRA. If any hazardous waste is identified, it will be managed under
the permit by rule provisions of HWCL with treatment to render non-hazardous or disposed
offsite. Other HWCL provisions are relevant and appropriate to treatment systems, such as
ex situ bioremediation treatment cells, where soils with hazardous substances are managed.
Many of the HWCL provisions are both relevant and appropriate because they describe
requirements for the safe handling of contaminated materials and precautions for preventing
further contamination.
The following chapters of Title 22, Division 4.5 Environmental Health Standards for
Management of Hazardous Waste, have been identified as ARARs for remedial action sites at
Mather AFB:
• Chapter 12 - Standards Applicable to Generators of Hazardous Waste,
Article 1 - Applicability;
• Chapter 14 - Standards for Owners and Operators of Hazardous Waste Transfer,
Treatment, Storage, and Disposal Facilities; Article 9 - Use and Management of
Containers; Article 12 - Waste Piles; Article 19 - Corrective Action for Waste
Management Units;
• Chapter 18 - Land Disposal Restrictions, Article 1 - General; Article 3 -
Prohibitions on Land Disposal; and Article 5 - Prohibitions on Storage.
5.3.2 State Action-Specific Applicable or Relevant and Appropriate
Requirements and Performance Standards
The following California statutes, laws, and regulations have been identified as ARARs and
performance standards. The following subsections list the ARARs and performance standards in
the following order: air, water, waste, and other state regulations.
The state action-specific ARARs are listed in Table 5-3, performance standards are listed in the
text under other regulations and a brief description of the source of the ARARs are listed along
RL/8-98/ES/392000 LAWS
5-24
-------
with the regulations derived under the source. Also presented is the Air Force position on
substantive requirements of these ARARs and how they apply to the selected remedial actions.
5.3.2.1 State Air Applicable or Relevant and Appropriate Requirements
The California Clean Air Act, under the Federal Clean Air Act and 1990 Amendments,
authorizes the State of California to develop a State Implementation Plan (SIP) to enforce clean
air regulations and laws. The SIP, developed through state legislation, divided the state into local
air control districts and allowed each district to enforce the requirements of the federal and state
Clean Air Acts. Mather AFB is located in the SMAQMD; local air regulations are the most
stringent ARARs. The SMAQMD applicable regulations are: Rule 202, Section 301 - Best
Available Control Technology; Section 302 - Offsets; Rule 401 - Visible Emissions; Rule 402 -
Nuisance; Rule 403 - Fugitive Dust; Rule 404 - Particular Matter; and Rule 405 - Dust and
Condensed Fumes. Table 5-3 contains the applicable or relevant and appropriate sections of
these regulations identifying the ARAR status and a brief description of the substantive
requirements and applicability to either the site, remedial action, or technology used to cleanup
the site and contaminated material.
5.3.2.2 State Water and Soil Applicable or Relevant and Appropriate
Requirements
The Federal Clean Water Act regulates discharge to surface waters. Under this statute is the
40 Code of Federal Regulations 122 - USEPA Administrative Permit Program: National
Discharge Elimination System regulation for storm water and other discharges to surface waters.
This program is delegated to the state under the statute and therefore is considered a state ARAR.
The SWRCB has issued two general orders under the federal statute, Clean Water Act, that
provides the substantive requirements for storm water management at industrial sites
(SWRCB Order 92-13-DWQ) and construction sites (SWRCB Order 97-03-DWQ). The
substantive requirements for industrial sites are meeting the narrative water quality standards,
implementing best management practices, identifying and monitoring sources of storm water
pollutants, and eliminating non-storm water sources of pollutants. The substantive requirements
associated with construction activities such as excavation and grading include application of
engineering measures and best management practices to control storm water runoff.
The Porter-Cologne Water Quality Control Act is one of the statutory bases for regulation of
discharges of waste to land that could impair either surface water or groundwater quality in
California. It establishes the authority of the SWRCB and the CVRWQCB to protect the quality
RLK-9S/ES/392000 LAWS
5-25
-------
of surface water and groundwater. The California Water Code sections used as a source for
action-specific ARARs and performance standards are presented in Table 5-3 along with the
associated regulatory citations. Under the Porter-Cologne Act, the following regulations or
resolutions regulating and protecting the waters of the state are considered ARARs: Central
Valley Region Basin Plan (specifically the water quality objectives and the beneficial uses
enumerated in this plan); SWRCB Resolution 88-63; SWRCB Resolution 92-49; California
Title 23, Division 3, SWRCB, Subchapter 15 - Discharges of Waste to Land, Article 1 - General;
Article 2 - Waste Classification and Management; Article 3 - Waste Management Unit
Classification and Siting (substantive requirements only); and Article 5 - Water Quality
Monitoring and Response Programs for Waste Management Units. The State does not agree on
the characterization of certain ARARs in this table to be "Relevant and Appropriate" instead of
"Applicable." However, since these requirements are included in the ROD as ARARs, the State
will not dispute this ROD.
Table 5-3 contains the applicable or relevant and appropriate sections of these regulations
identifying the ARAR status and a brief description of the substantive requirements and
applicability to either the site, remedial action, or technology used to clean up the site and
contaminated material.
State Water Resources Control Board Resolution 68-16 has been identified as an applicable
requirement for the protection of surface waters and groundwater of the state. The Air Force and
the state do not agree on the full substantive requirements of this resolution and the impacts on
the remedial action activities needed to cleanup Mather AFB. The state believes that this
resolution also applies to in-situ migration of pollutants and in setting in-situ cleanup levels. The
state will not dispute the above description; however, as the Air Force is complying with the
substance of these provisions. The Air Force disagrees with the state's contention that the
narrative language establishes chemical-specific ARARs for both soils and groundwater, and that
discharges subject to the resolution include post-1968 migration of in situ contamination from
the vadose zone to groundwater. The Air Force believes that discharges only encompass
remedial activities that actively discharge to surface water and groundwater of the state and
Resolution 68-16 is not included in this ROD since there are no sites which would "actively
discharge.".
Section IIIG of SWRCB Resolution 92-49 contains substantive requirements that are ARARs.
Section IIIG is the only provision of SWRCB Resolution 92-49 that arguably is relevant and
appropriate in establishing water-related cleanup levels under limited circumstances yet to be
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determined. The portion of Section IIIG, through incorporation of certain provisions in Titles 22
and 23 CCR, that creates a presumption of media cleanup resulting in background ground water
concentration levels is not generally a relevant and appropriate requirement for vadose zone
cleanup levels. The Air Force hopes to eventually resolve the ARAR status of SWRCB
Resolution 92-49 through ongoing discussions with its U.S. Department of Defense counterparts,
USEPA, and the state. For purposes of this ROD, the Air Force believes that if vadose zone
contamination overlies a groundwater plume, that remediation of the COCs in the groundwater
satisfies the requirement of Section IIIG to abate the effects of discharge. In that situation,
Section IIIG is not a relevant and appropriate requirement for the remediation of the vadose zone,
even though technical considerations, risk, cost-effectiveness, and other remedy-selection factors
may warrant concurrent remediation of the vadose zone to promote the groundwater remediation.
If these factors warrant concurrent vadose zone remediation, the Air Force will conduct such
remediation but not based on the premise that Section IIIG requires such action.
The state's position is that SWRCB Resolution 92-49 is an applicable requirement for remedial
actions in the vadose zone where there is an impact, or a threat of an impact, to the beneficial
uses of the groundwater or surface waters. In such a case the state contends, SWRCB
Resolution 92-49 requires remediation of the vadose zone to the lowest concentration levels of
constituents technically and economically feasible, which must at least protect the beneficial uses
of groundwater and surface waters, but need not be more stringent than is necessary to achieve
background levels of the constituents in surface water and groundwater.
Many of the requirements for the proper handling and disposal of designated waste (23 CCR,
Division 3, Chapter 15) have been incorporated through the use of the on-base ex situ
bioremediation facility. This facility will first handle RCRA and/or designated waste from
petroleum-only contaminated sites. These sites are, by definition, excluded from CERCLA but
included within the Defense Environmental Restoration Program conducted pursuant to ten
U.S. Code Section 2701 et. seq. These provisions require that Defense Environmental
Restoration Program response actions be conducted consistent with CERCLA Section 120 and
guidelines, rules, and regulations (e.g., NCP), and criteria established by the USEPA. The
"petroleum only" contaminated sites were included in the RI, FFS [IT 1997a], and Proposed Plan
[IT 1997b] in a manner consistent with the Federal Facility Agreement and Defense
Environmental Restoration Program. The SWRCB identified Waste Discharge Requirements
(WDRs) for the operation of the ex situ bioremediation site due to the use of the site for treatment
of contaminated medium from the "petroleum only" contaminated sites. Substantive WDRs have
been developed in order to implement the portions of WDRs that are substantive requirements
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for treating CERCLA wastes at the ex situ bioremediation facility. Under these circumstances,
the WDRs served as a means of identifying the RWQCBs substantive requirements for the ex situ
bioremediation facility. This expedient reference to the WDRs to identify substantive
requirements is not intended to suggest that WDRs or any other form of permit are requirements
for this ROD or any other CERCLA on-site response actions. The substantive WDRs for wastes
being sent to and treated wastes removed from the ex-sites bioremediation facility are listed in
Section 5.3.2.5. Operations at the ex-situ bioremediation facility and Site 7, the anticipated
location that treated wastes will be disposed of, are addressed in the Mather Soils OU and
Groundwater OU ROD [IT 1996a] and this document provides the ARARs associated with these
operations.
5.3.2.3 Other State Regulations and Guidance
The State Fish and Game Code regulates to protect aquatic life living in the waters of the state. It
is unlawful to substantially direct or obstruct the natural flow or substantially change the bed,
channel, or bank of any river, stream, or lake. This requirement applies to remediation activities
at Site 87.
California Well Standards (California Department of Water Resources [DWR], Bulletin 74-90,
June 1991) and Sacramento County Code, Title 6, Chapter 6.28 - The California Water Code
(Chapters 1152, 1373, and 13801) requires the DWR to establish standards for the construction,
operation, and abandonment of water wells, monitoring wells, and cathodic protection wells.
Sacramento County has developed well construction regulations based on authority granted to the
county through enforcement of the state standards. These standards should be considered as
performance standards for construction of monitoring wells at Site 20.
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
professional or under the supervision of certified professionals as appropriate.
5.3.2.4 State Requirements for Ex Situ Soil Bioremediation Facility
The Air Force is currently operating the Mather Soil Bioremediation Facility onsite to treat
excavated soils from Soil OU sites. Several of the remedial alternatives subsequently developed
for the Basewide OU sites include using an existing on-base ex situ bioremediation component.
Basewide OU sites for which excavation with on-base ex situ bioremediation is chosen as the
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preferred alternative are expected to also be treated at this bioremediation facility. This
bioremediation facility consists of a single lined bioremediation cell and soil processing area.
During operation of the bioremediation facility for CERCLA-related response actions
(e.g., treatment and disposal of treated soils from the sites discussed in this ROD), the Air Force
will continue to comply with the substantive operational and closure requirements for Class II
Waste Piles found in or derived from Chapter 15 of Title 23 CCR. These ARARs for the ex-situ
bioremediation treatment facility are listed in the Soils OU and Groundwater OU ROD
[IT 1996a]. The ARARs that have been used to define waste acceptance criteria for this facility
(that are part of the Soil OU and Groundwater OU ROD [IT 1996a]), are ARARs for wastes from
Basewide OU sites that will be treated at the ex-situ bioremediation facility. The Air Force
agrees to comply with the following requirements for the wastes generated from the
Basewide OU sites and treated at the Mather Soil Bioremediation Facility.
• Only soils that are not classified as "hazardous waste," using the criteria in Title 22
CCR, Division 4.5, Chapter 11, will be discharged to the bioremediation facility,
subject to variances from hazardous waste management requirements established
by the DTSC. Additionally, wastes that could potentially impair the integrity of
containment structures, require a higher level of containment than provided by the
unit, or which are restricted hazardous wastes will not be discharged to the
bioremediation facility.
• The discharge of designated solid or liquid waste or leachate to surface water,
surface water drainage courses, ponded water, or groundwater that would cause
impairment to water quality is prohibited.
• Treated soils may be disposed of as "inert waste" if the following criteria are met:
the treated soil is not a hazardous waste as determined by criteria in
22 CCR Division 4, Chapter 11, including toxicity, ignitability, reactivity,
and corrosivity;
TPH measure as gasoline and aromatic volatile organics (BTEX) are not
detectable in representative samples of treated soil;
the leachable TPH measured as diesel concentration is less than
10 micrograms per liter;
the metal concentrations are less than the maximum area inorganic
background concentrations (Aerojet and Mather [see Appendix Fj); and
PAHs will not be discharged where they will be subject to erosion and
transport to surface waters.
• Treated soil that originated from the Basewide OU (and Soil OU sites) and is taken
from the bioremediation facility that is intended to be used as fill material at Site 7
will have total or leachable constituent concentrations equal to or less than those
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presented in Table 5-4. (Table 5-4 is provided in this ROD solely for convenience
of the reader. The governing waste acceptance criteria for Site 7 are found in the
final Explanation of Significant Difference (ESD) Site 7 which became final on
December 14, 1997. The ESD is the primary and governing document.)
Appendix D summarizes the approach for estimating the maximum contaminant
concentration that can be delivered as backfill to Site 7 without adversely
impacting groundwater quality. The acceptance criteria is the greater of the
background concentration and the soluble concentration (from the waste extraction
test). Soil not achieving these levels will be disposed at an offsite Class II waste
disposal facility or treated and disposed in an appropriate manner.
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Table 5-4. Site 7 Acceptance Criteria
Site 7 Acceptance Criteria
Contaminant of Concern
Arsenic (24)
Barium (5)
Cadmium (1)
Chromium (5)
Cobalt (13)
Copper (17)
Lead(l)
Manganese (2)
Mercury (1)
Nickel (1)
Selenium (1 7)
Silver (2)
Vanadium (22)
Zinc (17)
Aroclor- 1248(6)
Aroclor- 1254(1)
Aroclor- 1260(7)
4,4-DDD(7)
4.4-DDE (7)
4,4-DDT (7)
Chlordane (7)
Dieldrin (7)
Water Quality
Coal (me/L)
0.005
1.0
0.005
0.05
0.05
0.2
0.015
0.05
0.002
O.I
0.02
O.I
O.I
2.0
0.0000045
0.0000045
0.0000045
0.00015
0.0001
0.0001
0.000029
0.0000022
Soil Quanlilation
Limit (ing/kg)
2.0
40.0
1.0
2.0
10.0
5.0
0.6
3.0
0.2
8.0
1.0
2.0
10.0
4.0
0033
0033
0.033
0.0033
0.0033
0.0033
0.0017
0.0033
Environmental
Attenuation
Factor
100
100
100
100
too
1000
1000
100
100
100
100
100
100
1000
100
100
100
1000
1000
1000
8620
364.000
Soluble Designated
Level (DI-WET)
(mg/L)
0.05
10.0
0.05
0.5
0.5
20.0
1.5
0.5
0.02
1.0
0.2
1.0
0.5
200.0
0.001 (0)
0.001 (B)
0.001 (B)
0.015
0.01
0.01
0.25
0.8
WET
Dilution
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
Background
Concentration
(ppm)
16
1300
1
92
35
93
81
5720
ND
81
ND
5
139
116
NA
NA
NA
NA
NA
NA
NA
NA
Recommended
Level (A)
(nig/kg)
500
10000
100
2500
1000
20
2000
2.5
8
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Table 5-4. Site 7 Acceptance Criteria (Continued)
Site 7 Acccplanct Criteria
Contaminant of Concern
Dioxin & associated congeners (25)
Oil & Grease (21)
TPH measured as Diesel ( 1 0)
TP! ! measured as Gasoline (10)
Benzene (5)
Carbon Telrachloride (5)
Ethylbenzene(l)
Toluene (1)
Xylene(l)
Acenaphthene (21)
Acenaphihylene (22)
Qenzo(a)Anthracene (7)
Benzo(b)Flouranlhene (7)
Oenzo(k)Flouranthene (7)
Benzo(g,h,i)Perylcne (25)
Chrysene(l)
Dibenz(a,h)Anthracene (7)
Flouranthcne (25)
Fluorene (22)
lndeno(l,2.3-CD)Pyrene (7)
Naphthalene (22)
Water Quality
(_io»l (nig/L)
2.2xlO'10
NA
O.I
NA
NA
NA
NA
NA
NA
0.02
0.42
0.000029
0.000029
0.000029
No WQG
0.0002
0.0000085
No WQG
0.28
0.000029
0.02
Soil Quanlilalion
Limit (nig/kg)
0.0000055
50.0
10.0
10
0.01
0.01
0.01
0.01
0.01
0.33
0.33
0.33
0.33
0.33
0.33
033
0.33
0.33
0.33
0.33
0.33
Environmental
Attenuation
Factor
100
NA
100
NA
NA
NA
NA
NA
NA
100
100
100
100
100
100
100
100
100
100
100
100
Soluble Designated
Level (DI-WE11
(mg/L)
0001 (C)
NA
1.0
NA
NA
NA
NA
NA
NA
0.2
4.2
0.00029
0.00029
0.00029
No WQG
0.002
0.0003 (B)
No WQG
2.8
0 000-43 (B)
0.2
WET
Dilution
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
10
Background
Concentration
(ppm)
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA .
NA
NA
NA
NA
Recommended
Level (A)
(mg/kg)
0.01 (U)
570
300
ND
ND
ND
ND
ND
Ul
K)
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Table 5-4. Site 7 Acceptance Criteria (Continued)
Site 7 Acceptance Criterii
Contaminant of Concern
Phenanlhrcne (25)
Pyrene (22)
Water Quality
Goal (mg/L)
NoWQG
0.21
Soil Quantitation
Limit (nig/kg)
0.33
0.33
Environmental
Attenuation
Factor
too
too
Soluble Designated
Level (DI-WET)
(mg/L)
NoWQG
2.1
WET
Dilution
10
10
Background
Concentration
(ppm)
NA
NA
Recommended
Level (A)
(mg/kg)
(A) Total concentration criteria were developed from vadose zone modeling and negotiations with the RWQCB (September 1997).
(B) The soluble designated level is below the practical quantilalion limit; therefore, the practical quanlitation limit will be used.
(C) The soluble designated level has been established for Site 7 by the RWQCB as (he hazardous level expressed as 2,3,7,8 - TCDD equivalent
(I) EPA Primary Drinking Water Standard
(2) EPA Secondary Drinking Water Standard
(5) California Primary MCL
(6) Taste and Odor Threshold (USEPA)
(7) Cal/EPA Cancer Potency Factor as Water Quality Criteria
(10) USEPA Health Advisory
(13) No promulgated standard for cobalt. Value obtained from "Water Quality for Agriculture" Food and Agriculture Organization of the United Nations - Irrigation and Drainage Paper No. 29.
(17) Agriculture WQG
^ (21) Taste and Odor Threshold (S WRCB)
^, (22) USEPA IRIS Reference Dose as a Water Quality Criterion
u> (24) California Proposition 65
(25) No WQG currently available. Will be based on an evaluation ifdeteclcd in the future.
DDD = dichlorodiphcnyldichloroelhane
DDE = dichlorodiphenyldichlorocihylene
DDT = dichlorodiphenyltrichloroethane
TPII = total petroleum hydrocarbon
WQG = water quality goal
RWQCB = Regional Water Quality Control Board
SWRCB = State Water Resources Control Board
TCDD = letrachlorodibenzo-p-dtoxin
IRIS = Integrated Risk Management System
USEPA = U.S. Environmental Protection Agency
NA = not applicable
EPA = Environmental Protection Agency
ND = non-delect
MCL = Maximum contaminant level
DI-WET •= Dcionized Waste Extraction Test
mg/L - milligrams per liter
mg/kg = milligrams per kilogram
ppm = pans per million
3920001 A WS
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6.0 Responsiveness Summary
The public comment period for the "Proposed Plan for Environmental Cleanup at the Basewide
Operable Unit Sites" [IT 1997b] at Mather AFB, began on May 23, 1997 and ended on
June 23, 1997. A public meeting was held on May 29, 1997, at which the Proposed Plan was
summarized, and questions and public comments solicited. The transcript from the public
meeting is included in the Administrative Record File and reproduced here. Six members of the
public asked questions at the public meeting, and two members of the public submitted letters
with formal written comments on the Proposed Plan. The written comments are reproduced
herein and are included in the Administrative Record. No other comments were received during
the public comment period.
Note: Sites 82 and 83 are sites with only petroleum contamination and are excluded from
regulation under CERCLA. No comments were received by the USAF on these sites; however,
any public comments received on "petroleum only" sites will be considered by the CVRWQCB
in approving cleanup activities at these sites.
The first seven comments consist of questions and comments from members of the public at the
public meeting held on May 29, 1997. These questions and comments along with responses
provided at the meeting are excerpted from the transcript of the meeting, and any additional
responses are added immediately following the excerpt.
Comment 1 (see pages 21 - 23 of the public meeting transcript) and Response:
2 MS. VON ECKERT: Eloise Von Eckert.
3 I got lost in the residential sections. And I
4 wasn't able to track, but what would be the housing area
5 right in the middle near where we are?
6 SITE MANAGER WONG: Down here?
7 MS. VON ECKERT: Yeah, which sites are we there?
8 SITE MANAGER WONG: There's actually this ditch
9 site. This one right here.
10 MS. VON ECKERT: 18 and 20 and 23?
11 SITE MANAGER WONG: 18 is up here.
12 MR. HUGHES: The only sites in this proposed plan
13 that are, nearby are what's called the Morrison Creek
14 Reference Site. This drainage had three samples collected
15 and right near the roadway there were some pesticides
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16 detected. And it might have been from mosquito abatement in
17 the past or something of that nature.
18 But two samples downstream didn't have any
19 significant contaminants of concern, but we need to do a
20 little more sampling to be really — to well define the area
21 that will need to be excavated. We don't believe that
22 contamination extends near the housing here.
23 The second ditch that drains to the golf course
24 maintenance area, again, pesticides in the ditch nearby where
25 pesticides were mixed and stored for use on the golf course.
1 Again, the sample here had pesticides. Two more
2 samples were collected that were very widely spaced. And
3 additional samples need to be taken after being collected
4 very soon to try to better define the actual length of the
5 ditch that would require some remediation.
6 There's two other sites that were discussed in a
7 past public meeting, and for which a Record of Decision has
8 already been signed, that are in the housing area. One was
9 an underground storage tank near the water tank. It was a --
10 I believe it was a generator fuel for a backup generator for
11 the pumping of the water system. That site where--the tank
12 was removed and it's been remediated.
13 The second site is a former military gas station or
14 actually military -- or actually -- yes, a military gas
15 station that has fuel tanks. And that remediation is also
16 underway. It was part of a past Record of Decision. That
17 site is a petroleum-only site. That's been regulated by the
18 Regional Water Quality Control Board.
19 So by and large there are not a lot of contaminated
20 sites near the housing.
21 MS. VON ECKERT: Okay.
Additional response: The two ditch sites mentioned above are Installation Restoration Program
(IRP) Sites assigned to the Basewide Operable Unit, and for which decisions are presented in
this Record of Decision. The Morrison Creek Reference Site is IRP Site 88 and the Golf Course
Maintenance Area Ditch is IRP Site 80. The underground storage tank near the water tank in the
Mather Family Housing area is Installation Restoration Program Site 28 Installation Restoration
Program Site 28. The tank was removed in 1988, and the site was determined to present no
further risk to human health or the environment, as documented in the Superfund Record of
Decision for Soil Operable Unit Sites and Groundwater Operable Unit Plumes, dated April 1996.
The former military gas station at the Mather Family Housing area is Installation Restoration
Program Site 34. The five underground storage tanks were removed in 1993. The soil at the site
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requires additional remediation, as documented in the Superfund Record of Decision for Soil
Operable Unit Sites and Groundwater Operable Unit Plumes, dated April 1996. This cleanup is
planned to begin in summer of 1997, under the oversight of the Regional Water Quality Control
Board.
Comment 2 (see pages 23 - 24 of the public meeting transcript) and Response:
23 MR. VERDON: My name is Scott Verdon. I'm also a
24 student. My question is the employment opportunities. What
25 kind of thing is that?
1 Will there be employment generated from the work
2 that's going to be brought in cleaning it up on the outside?
3 Is that going to be mostly outside contractors or things of
4 the nature where there are possible opportunities to employ
5 myself?
6 SITE MANAGER WONG: The situation with environmental
7 work here is that our agency who's headquartered out of
8 Washington D.C. has a contracting agency out of Brooks Air
9 Force Base in Texas. And what they do is they contract, you
10 know, all the different environmental works at all the
11 various bases that we control. And part of that contract
12 that they have, is that whoever it is awarded to, a certain
13 portion of it needs to be done locally.
14 They have to go out locally and get subcontractors.
15 Our current contractor is Montgomery Watson. Their building
16 is right over there. And they're our prime contractor for
17 all remediation work. And they have a team of, you know,
18 other contractors that they use. And they also go out
19 locally.
20 So I can pass that information along in terms of,
21 you know, for anything local that they might be able to do,
22 but that's the way our process is.
Comment 3 (see pages 24 - 29 of the public meeting transcript) and Response:
23 MS. WALKER: My name is Annette Walker. And I would
24 like to know what do the experts feel is the worst thing that
25 can happen? And what preventative measures have you in place
1 for the worst thing that can happen?
2 SITE MANAGER WONG: Is this specifically to the site
3 here at Mather?
4 MS. WALKER: Yes. I mean, any of the contamination
5 or whatever you may know from Aerojet or any information,
6 because contamination is just contamination without a label.
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7 SITE MANAGER WONG: Right. Well, in terms of
8 Mather's contamination and specifically in terms of our
9 proposed plan on these 18 sites, most of the contaminations
10 are either, what we call VOCs or Volatile Organic Compounds
11 or fuel constituents, or lead. Again, we do have treatment
12 options available to us to take care of it. We are in the
13 process through this Record of Decision to take care of that
14 contamination, and prevent it from going anywhere. Sol
15 would hope the potential impact is very low. We have
16 identified as much as we can, and we're moving forward.
17 We're trying to get it cleaned up.
18 MS. WALKER: But I'm saying what has been identified
19 as the worst thing that can happen? What has been
20 identified?
21 SITE MANAGER WONG: In terms of the worst thing?
22 MS. WALKER: Yes.
23 SITE MANAGER WONG: Again, when we go through our
24 risk assessment for human health and the ecology, we come up
25 with numbers that tell us, you know, what levels that could
1 potentially be out there and these risk assessments are
2 associated with the one-in-a-million cancer risk. And
3 anything that is above the one-in-a-million cancer risk, we
4 have to deal with in terms of taking care of it.
5 So we feel we're at the low enough level right now
6 where there is no risk as long as we take action.
7 MS. WALKER: I'm saying for the future generations.
8 Do you understand? What I'm saying is right now, right, I
9 understand that. But I'm just saying say for the next five
10 years, ten years, what is probably the worst thing may/could
11 happen if we do not clear this up within the allotted time?
12 SITE MANAGER WONG: Well, I can't answer that right
13 now.
14 MS. WALKER: I'm saying have the experts said this
15 is the worst scenario or not? They haven't looked at the
16 worst thing that can happen?
17 SITE MANAGER WONG: Again, they look at it in terms
18 of risk, and what the potential risk is. And if it falls
19 into a certain category where action needs to be taken, we
20 are taking action. I don't think they project out five
21 years, ten years down the line.
22 MS. WALKER: Okay. And one other thing too that I
23 would like to elaborate on what he just said. Since this is
24 at a level of federal dollars, state dollars, county, city,
25 dollars — this is more of a comment — I think that more of
1 the monies and the dollars should be invested in our
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2 communities with some of the people here and employ them more
3 so that maybe some of the contractors who are getting some of
4 the governmental contracts and more so, we should probably
5 invest in people.
6 SITE MANAGER WONG: Right. And again the government
7 contract is going through AFCEE, which is in Texas, but that
8 does not exclude them from hiring people locally. There is a
9 process where packages describing what needs to be done is
10 sent out to all the various contractors including the local
11 ones, so they are usually at the same level as everyone else
12 in terms of getting those contracts awarded.
13 In addition to that, there is also language in the
14 contracts that requires, whoever gets the award, to hire
15 locally a certain percentage. So those provisions are in
16 there and they are government contract laws.
17 MS. WALKER: Does this include the plan - does it
18 include education to the public? How to better be able to
19 live with the contaminate ~ well, the possibility?
20 SITE MANAGER WONG: In addition to what we have
21 here, is we have quarterly news letters, fact sheets, that,
22 you know, we — and again we can discuss this later in terms
23 of, you know, all the water stuff we're doing, but we do have
24 an ongoing community relations plan that we try to get
25 information out to the public. We also have a Restoration
1 Advisory Board here at Mather that we get public comment on,
2 public input on in our whole process, which is something
3 that's been just started recently within the last couple
4 years.
5 We're looking at all the different avenues to get
6 information out, to get the public aware of what's happening
7 here. And again, you know, we're trying with our mailings,
8 and we've done several mailings in terms of what's happening
9 here. We've got a mailing list that is growing and will
10 continue to grow as long as there's interest.
11 MS. WALKER: Okay. And just one other thing. Due
12 to the environment, and like you say, the paper flow, I would
13 like to suggest centrally located bulletin boards to update
14 the community, such as maybe at the Franchise Tax Board,
15 that's right off from the 50 freeway along with the movie
16 goers and I would like to see more of being environmental
17 friendly.
18 And also offering those kind of products -- I'm
19 concerned too, as a citizen of the community who uses water
20 -- some of the products that I'm using if they are
21 environmentally safe. And then once they're mixed with the
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22 water while we're cleaning the bath tub when the children are
23 getting in, are we doing more harm than we are good? So I
24 really want to stress the education as to the people who are
25 living here and some kind of solutions for future generations
1 as well.
2 SITE MANAGER WONG: I appreciate the comment. And
3 we will take the comment in terms of trying to get that
4 information out there. We can work on getting our news
5 letters and fact sheets out and posted like you said. And,
6 you know, we have a couple of our RAB members here and our
7 community relations specialists here, that you can -- you
8 know, I'm sure they'll take those suggestions down and we'll
9 see what we can do.
10 MS. WALKER: Thank you.
Additional response: The worst-case scenario based upon the contamination identified at IRP
sites at Mather is that the sites that require cleanup to protect human health and the environment
would not be cleaned up. However, all sites requiring cleanup are either in the process of being
cleaned up or are proposed for cleanup in the Basewide Operable Unit Proposed Plan. Some of
the sites have cleanup proposed to protect human health, based upon conservative estimates of
human exposure to contamination at any time in the future. Other sites have cleanup proposed
to protect the ecosystem or to protect water quality, even though the contamination at these sites
may not pose a threat to human health.
Comment 1 (see pages 29 - 30 of the public meeting transcript) and Response:
13 MR. ALEXANDER: My name is K. Alexander here in
14 Sacramento.
15 I see we have general information. Can we define
16 it, the whole can of work in, you know, critical, highly
17 critical, average, something like, you know, something like
18 different phases? Sometimes you ask for more money, we can
19 put which one into which phases, phase 1, 2, 3,4, you
20 address this situation here.
21 SITE MANAGER WONG: Right. And that boils down to
22 risk. When we look at the information that we get through
23 our investigations, we get numbers that tell us what kind of
24 risk is out there. If there's anything that's a high risk,
25 we'll go after it immediately and try to do anything we can
1 to take care of it, you know, right away.
2 Based on what risk levels show up —
3 MR. ALEXANDER: It's here in the -- do you have the
RL/8-98/ES/392000I.AWS
6-6
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4 risk values in this figure here?
5 SITE MANAGER WONG: The actual risk values are in
6 the Feasibility Study.
7 MR. ALEXANDER: Well, if it's a high risk, you
8 better do it now to show those people we have a higher risk.
9 Sometimes we do it later on, you know, because it costs a lot
10 of more money. We justify it as a different risk, different
11 critical, highly critical, something. I wish we included
12 something in the report.
13 SITE MANAGER WONG: It's in our Feasibility Study --
14 MR. ALEXANDER: Here? Thank you.
15 SITE MANAGER WONG: --where you can see the risk
16 numbers.
17 Thank you.
Additional response: Although different sites have different levels of risk associated with them,
the law (Comprehensive Environmental Response, Compensation, and Liability Act) requires
that significant continuous work toward cleanup begin within 15 months of completion of the
investigation and study, which is interpreted as the issuance of a Record of Decision for that site.
Therefore, the USAF plans to accomplish all cleanup as required by law.
Comment 5 (see pages 30 - 31 of the public meeting transcript) and Response:
18 MS. MAKOWSKI: My name is Claudette Makowski. And I
19 have a question about the plume back there. It's very close
20 to the Citizen's Utilities wells.
21 Have those wells been affected, and what is in that
22 plume?
23 SITE MANAGER WONG: That plume primarily consists of
24 solvents, TCE.
25 MS. MAKOWSKI: What kind of solvents, TCE?
1 SITE MANAGER WONG: TCE, PCE and
2 carbon tetrachloride. It has affected two wells with
3 Citizen's wells. One well is shut down. The other well has
4 a treatment system on it. And there's a picture of it in the
5 lower right-hand corner there. It's an activated carbon
6 unit, that is treating water right now. I think it's been
7 operating for the last month.
8 MS. MAKOWSKI: When were those wells shut down?
9 SITE MANAGER WONG: The Explorer Well was shut down
10 in 1994, September of 1994, and the Moonbeam Well was shut
11 down in April of last year. The unit has been operating for
12 the last month and it's been shut down between that time.
RI/8-98/ES/392000I .AWS
6-7
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13 MS. MAKOWSKI: And you say that's TCE and
14 carbon tetrachloride in there?
15 SITE MANAGER WONG: And PCE.
16 MS. MAKOWSKI: PCE.
Comment 6 (see pages 31 - 32 of the public meeting transcript) and Response:
17 MR. SEMBACH: My name is Erik Sembach. Have you
18 guys — has there been a projected target date for the
19 completion of all the remedial actions?
20 SITE MANAGER WONG: Our intention is to get all
21 remediation up and going in the year 1999. Now, what that
22 means is, our systems will be in place. There is a prove-out
23 period where we need to operate it and satisfy the regulation
24 in terms of making sure it's operating correctly.
25 Once we get to that phase, it goes into the
1 long-term phase, where we just operate the system. I think
2 there's five-year review cycles to verify it's working
3 correctly. And then maybe re-evaluate what needs to be done.
Comment 7 (see page 32 of the public meeting transcript) and Response:
7 MS. VON ECKERT: I have a comment, not so much
8 formal, but what Annette Walker mentioned was what I look at.
9 I know that because we play with so many technological toys
10 that something is going to kick back and we're going to have
11 to leam what we're dealing with. And Mather being brave
12 enough to do this on an open forum, highly commendable. And
13 it also should make us look at how we operate on a daily
14 basis with pesticides and other cleaning products and fuels,
15 gas tanks and so forth.
16 And rather than attack Mather or the program and use
17 it as a fear tactic of what's going to happen to us or our
18 children even, even though that is a concern of ours, to
19 understand how we ourselves our responsible for the health of
20 our environment, and to know that we run off of consumerism
21 and how we're going to impact our economy and everybody who
22 has jobs making whatever widgets are out there. There's no
23 blame here as far as I see. It's just a learning process.
24 And I thank you.
RL/B-98/ES/3920001 .A WS
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The following comments were received in writing during the 30-day comment period ending
June 23, 1997.
Comment 8 (comment from Annette Walker) and response:
Community Plans
We would like to see the United States of America s the example of "Humanity." We have been
exposed to deadly chemicals that have taken our loved ones; caused our children to be constantly
ill; women with an alarming rate of breast lumps; and even I have suffered the loss of our unborn
child. There must be IMMEDIATE ATTENTION in the best interest of the health and well
being of mankind, the environment, and our future generations to come.
We would like ALL levels of government, local businesses, and our communities to work
together in a joint effort for solutions. We know how important it is to teach people 'how to
FISH' than to 'give them FISH'...but we recognize we must have the tool box.
This disaster was not something that was planned by the United States Armed Forces, however,
we can take a BAD situation to utilize our talents, skills, and knowledge to be solutions for a new
global economy, reconstruction of deadly environmental habits, and most
IMPORTANT...health-conscious society!
I. Health
1 .a. IMMEDIATELY - RELOCATE FAMILIES OUT
OF CONTAMINATED AREAS
There should not be any reason humans are made to eat and drunk deadly chemicals the United
States has caused, because of economic finances. The Armed Forces are the most organized
movers in the world, we should utilize our military to help AMERICANS: NOT ONLY TO
HELP OTHER COUNTRIES, OR KILL OTHER HUMANS! (This will be an option for those
who choose).
2.a. WATER TREATMENT SYSTEMS - FOR ALL SCHOOLS -
BUSINESSES - RESIDENCES
RU8-98/ES/392000 LAWS
6-9
-------
Health needs to be the top priority! If we do noj focus on health NOW, it will cost us more later.
It is a fact, that water-treatment systems will give added security to the working taxpayer -
property owner (who has seen our value depreciated 30% to 50%) and we do not feel the
government is spending our money wisely. Furthermore, it will create jobs for our community -
NOT RICH INVESTORS!! CAPITALIZING ON OUR LIVES.
The mass quantity of systems will also make the cost very affordable, and can be used as a
community investment. There are multi-level marketing companies such as Amway, Equinox,
etc. who have various products and systems that will benefit the entire community.
3. HEALTHCARE
The most important element is Quality Family Health Care! After we lost our unborn child in
the fifth month of pregnancy, I went to Kaiser, Morse Avenue, where a routine D&C procedure
was improperly performed; I almost lost my life...returned back to the same facility, where I was
RAPED by the MEDICAL STAFF! We cannot allow this to continue. Again, we must give
people the tools to fish...we as a community can pay the same premiums and co-payments, but
we must have QUALITY FAMILY CARE, and the funding for rats can be used for humans to
complete accurate studies for research for other areas, future generations, and education how to
live with the contamination. We suggest the New Shriners and U.C. Davis Medical Centers as
the project. We can use the multi-level marketing concept for vitamins to help supplement
nutrition; AGAIN, the IMPORTANCE OF HEALTH - QUALITY FAMILY CARE, IS THE
TOP PRIORITY!
4. TRANSPORTATION:
Transportation will be one of the major solutions to our problems:
1 .a.) Efficient Transportation with buses
Mandatory & Incentives
b.) Community Owned and Operated
Transportation will be the new global industry of America. We can utilize not only Mather,
which is one of our country's most beautiful air facilities in the Western U.S. We should build
on the dream with our technology and vision for the future. It is cheaper now that the year 4050!
RL/8-98/ES/3920001. A WS
6-10
-------
Sacramento has four airports...Let's go from the horse & buggy; to automobile; to the
JETSONS! We cannot afford to ignore the problems of TOO MANY AUTOMOBILES!!
A.) FATALITIES
B.) DRINKING & DRIVING
C.) ECONOMICS - PAYMENTS, INSURANCE, REGISTRATION,
VIOLATIONS, GASOLINE, REPAIRS.
D.) ENVIRONMENT
E.) HEALTH - RESPIRATORY PROBLEMS
F.) TIME FACTOR-FASTER TO FLY
G.) RECYCLING - ETC.
Utilizing our technology and the airports that are in operation, we can start the groundwork for
the aerospace age. Vision transporting people by rails that are in place - the monorail system;
buses to connect; and ALL air stations as commuter/ commercial/ domestic/ international means
of future travel.
As a community we would like to have the quality of life. We would like to see creative,
innovative ideas that include a UNI-VERSE community; NOT DI-VERSE community. UNI-
means "one, united, together." DI- means "divide, separate, ununified."
• Other government programs - such as HUD to target areas that have been affected
to help WORKING PEOPLE who have invested in America, with depreciated
property.
• President Clinton to declare "Disaster Prevention" for tax breaks to help in areas.
NOT WAIT FOR DISASTER TO HAPPEN - THE FOCUS IS PREVENTION!
• Community Investing - Residents use 401-K, retirement plans, Businesses
(Local); Multi-Level Marketing with water treatment systems;
telecommunications - utilities, vitamins, environmentally safe products,
community gardens & farming .buses, mass media, school sites for education and
central information centers, community bulletin boards (reduce paper to save trees
& recycling).
• All plans can be duplicated in ALL communities all over the country, with a
NEW AMERICAN AGENDA.
RU8-98/ES/392000I.AWS
6-11
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Responses to Comment #8:
Much or all of the comment addresses concerns other than the Basewide Operable Unit Proposed
Plan. However, several statements are about contamination and health effects in general. These
are repeated and responded to below.
Comment: "We have been exposed to deadly chemicals that have taken our loved ones; caused
our children to be constantly ill; women with an alarming rate of breast lumps; and even I have
suffered the loss of our unborn child."
Response: There is no evidence indicating that anyone has been exposed to chemical
contaminants from any of the Basewide Operable Unit sites nor any other contamination from
Mather at unsafe levels. The independent federal Agency for Toxic Substances and Disease
Registry is performing a Public Health Assessment of Mather Air Force Base, as is required for
all sites on the Superfund, or National Priorities List. This assessment includes the evaluation of
any past exposure history, current, and future risks, and determines whether follow-up studies are
needed to determine if there are any health effects associated with past exposures.
Comment: "There should not be any reason humans are made to eat and drunk deadly chemicals
the United States has caused, because of economic finances."
Response: The USAF is committed to protecting human health and the environment according to
law. The law considers cost as one criteria in comparing cleanup alternatives, but a cleanup
alternative must be protective of human health and the environment to be selected. In other
words, the law requires the USAF to protect human health as a criteria under the Superfund law
(the Comprehensive Environmental Response, Compensation, and Liability Act of 1980).
Comment:
"2.a. WATER TREATMENT SYSTEMS - FOR ALL SCHOOLS -
BUSINESSES - RESIDENCES
Health needs to be the top priority! If we do not focus on health NOW, it will cost us more later.
It is a fact, that water-treatment systems will give added security to the working taxpayer -
property owner (who has seen our value depreciated 30% to 50%) and we do not feel the
RL/8-98/ES/392000I .AWS
6-12
-------
government is spending our money wisely. Furthermore, it will create jobs for our community -
NOT RICH INVESTORS!! CAPITALIZING ON OUR LIVES.
The mass quantity of systems will also make the cost very affordable, and can be used as a
community investment. There are multi-level marketing companies such as Amway, Equinox,
etc. who have various products and systems that will benefit the entire community."
Response: Although this comment does not pertain to the Basewide Operable Unit, this
response is offered. The USAF is committed to providing water treatment or an alternative water
supply whenever contamination enters a drinking water supply at concentrations that are unsafe.
The USAF has placed well-head treatment on the Moonbeam Drive well and is in the process of
installing well-head treatment on the water system serving the Sacramento County facilities
along Branch Center Drive.
Placing water treatment at the water source ensures that every user receives treated water, and
only these central treatment systems need monitoring and maintaining. The total amount of
activated carbon required is much less than would be required to treat water at each tap or
household. In addition, if water treatment systems were placed in each household or place of
water use, each treatment system would require periodic water testing to ensure that the carbon
capacity was not used up. Monitoring water at each household would be prohibitively expensive
when compared to monitoring at each well that provides drinking water, because there are
hundreds of households or taps for each well in a large community water system.
Comment 9 (comment #1 from Sandra Lunceford) and response:
Carbon tetrachloride has presented a remediation problem for Mather Field in that its detection
limit and cleanup level have been the same. It appears that one site on base has been pinpointed
as the source area for this chemical, Site 1OC. It does not seem reasonable that this could be the
sole-source area for this contamination given its effects on off-base wells. My recommendation
would be to further pursue investigation at the oil water separators, Site 18, and other appropriate
sites to determine other source areas for this particular problem chemical, and perhaps other
sources for PCE and TCE will also be uncovered.
Response to Comment #9: Several potential areas on Mather have been identified as potential
sources in soil of carbon tetrachloride, TCE, or PCE contamination found in underlying
RiyS-98/ES/.192000I.AWS
6-13
-------
groundwater. The Additional Site Characterization and Final Basewide Operable Unit Remedial
Investigation Report provides details of the investigation for such sources at Site 23, 67, and 84.
In addition, the Basewide Operable Unit Focused Feasibility Study Report explains the USAF
plan to treat carbon tetrachloride, TCE, and PCE at Site 18 because they were successfully
removed during pilot testing of a soil vapor extraction system at that site.
Comment 10 (comment #2 from Sandra Lunceford) and response:
I will look forward to Basewide ROD documentation discussing the UXO area on Mather
Field.
Response to Comment #10: As the USAF has committed to the U.S. EPA, the Basewide
Record of Decision will contain an explanation of how the USAF is investigating the site of
reported ordnance disposal in the former weapons storage area. This location is not an
Installation Restoration Program site, but could be added to the IRP if contamination is found at
the site.
Comment 11 (comment #3 from Sandra Lunceford) and response:
I encourage, again, designated federal funding cites that are made available to guarantee that
new, unaddressed contamination encountered on Mather Field and other closed bases be
promptly remediated to forestall economic impacts to local communities.
Response to Comment #11: This comment is beyond the scope of the Basewide Operable Unit.
Comment 12 (comment #4 from Sandra Lunceford) and response:
Presumably Site 81 will be accepting contamination from other sites, as it is to be used as a land
farm. I hope to see that the Basewide ROD documents acceptance criteria and restrictions in
nontechnical language.
Response to Comment #12: There are no plans to accept any contamination from other sites at
Site 81. The remedial alternative proposed in the Proposed Plan and selected in the Draft Record
of Decision consists of land farming only contamination found at Site 81.
RU8-98/ES/392000I.AWS
6-14
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Comment 13 (comment #5 from Sandra Lunceford) and response:
Hopefully the Basewide ROD will briefly discuss the other sites comprising Mather and how
they are being addressed.
Response to Comment #13: The Basewide Operable Unit Record of Decision provides an
overview of all the Installation Restoration Program sites at Mather, and refers the reader to
documents where more detail can be found for sites in other operable units.
Comments received from Annette Walker 6/23/97
Community Plans
We would like to see the United States of America s the example of "Humanity." We have been
exposed to deadly chemicals that have taken our loved ones; caused our children to be constantly
ill; women with an alarming rate of breast lumps; and even I have suffered the loss of our unborn
child. There must be IMMEDIATE ATTENTION in the best interest of the health and well
being of mankind, the environment, and our future generations to come.
We would like ALL levels of government, local businesses, and our communities to work
together in a joint effort for solutions. We know how important it is to teach people 'how to
FISH' than to 'give them FISH'...but we recognize we must have the tool box.
This disaster was not something that was planned by the United States Armed Forces, however,
we can take a BAD situation to utilize our talents, skills, and knowledge to be solutions for a new
global economy, reconstruction of deadly environmental habits, and most
IMPORTANT.. .health-conscious society!
I. Health
1 .a. IMMEDIATELY - RELOCATE FAMILIES OUT
OF CONTAMINATED AREAS
There should not be any reason humans are made to eat and drunk deadly chemicals the United
States has caused, because of economic finances. The Armed Forces are the most organized
RLft-98/ES/392000 LAWS 6-15
-------
movers in the world, we should utilize our military to help AMERICANS: NOT ONLY TO
HELP OTHER COUNTRIES, OR KILL OTHER HUMANS! (This will be an option for those
who choose).
2.a. WATER TREATMENT SYSTEMS - FOR ALL SCHOOLS -
BUSINESSES - RESIDENCES
Health needs to be the top priority! If we do not focus on health NOW, it will cost us more later.
It is a fact, that water-treatment systems will give added security to the working taxpayer -
property owner (who has seen our value depreciated 30% to 50%) and we do not feel the
government is spending our money wisely. Furthermore, it will create jobs for our community -
NOT RICH INVESTORS!! CAPITALIZING ON OUR LIVES.
The mass quantity of systems will also make the cost very affordable, and can be used as a
community investment. There are multi-level marketing companies such as Amway, Equinox,
etc. Who have various products and systems that will benefit the entire community.
3. HEALTHCARE
The most important element is Quality Family Health Care! After we lost our unborn child in
the fifth month of pregnancy, I went to Kaiser, Morse Avenue, where a routine D&C procedure
was improperly performed; I almost lost my life...returned back to the same facility, where I was
RAPED by the MEDICAL STAFF! We cannot allow this to continue. Again, we must give
people the tools to fish...we as a community can pay the same premiums and co-payments, but
we must have QUALITY FAMILY CARE, and the funding for rats can be used for humans to
complete accurate studies for research for other areas, future generations, and education how to
live with the contamination. We suggest the New Shriners and U.C. Davis Medical Centers as
the project. We can use the multi-level marketing concept for vitamins to help supplement
nutrition; AGAIN, the IMPORTANCE OF HEALTH - QUALITY FAMILY CARE, IS THE
TOP PRIORITY!
4. TRANSPORTATION:
RL/8-98/ES/3920001 .A WS
6-16
-------
Transportation will be one of the major solutions to our problems:
1 .a.) Efficient Transportation with buses
Mandatory & Incentives
b.) Community Owned and Operated
Transportation will be the new global industry of America. We can utilize not only Mather,
which is one of our country's most beautiful air facilities in the Western U.S. We should build
on the dream with our technology and vision for the future. It is cheaper now that the year 4050!
Sacramento has four airports...Let's go from the horse & buggy; to automobile; to the
JETSONS! We cannot afford to ignore the problems of TOO MANY AUTOMOBILES!!
A.) FATALITIES
B.) DRINKING & DRIVING
C.) ECONOMICS - PAYMENTS, INSURANCE, REGISTRATION,
VIOLATIONS, GASOLINE, REPAIRS.
D.) ENVIRONMENT
E.) HEALTH - RESPIRATORY PROBLEMS
F.) TIME FACTOR - FASTER TO FLY
G.) RECYCLING - ETC.
Utilizing our technology and the airports that are in operation, we can start the groundwork for
the aerospace age. Vision transporting people by rails that are in place - the monorail system;
buses to connect; and ALL air stations as commuter/ commercial/ domestic/ international means
of future travel.
As a community we would like to have the quality of life. We would like to see creative,
innovative ideas that include a UNI-VERSE community; NOT DI-VERSE community. UNI-
means "one, united, together." DI- means "divide, separate, ununified."
• Other government programs - such as HUD to target areas that have been affected
to help WORKING PEOPLE who have invested in America, with depreciated
property.
• President Clinton to declare "Disaster Prevention" for tax breaks to help in areas.
NOT WAIT FOR DISASTER TO HAPPEN - THE FOCUS IS PREVENTION!
RL/8-98/ES/392000 LAWS 6-17
-------
• Community Investing - Residents use 401-K, retirement plans, Businesses
(Local); Multi-Level Marketing with water treatment systems;
telecommunications - utilities, vitamins, environmentally safe products,
community gardens & farming,buses, mass media, school sites for education and
central information centers, community bulletin boards (reduce paper to save trees
& recycling).
• All plans can be duplicated in ALL communities all over the country, with a
NEW AMERICAN AGENDA.
Comment received from Sandra Lunceford, 6/23/97:
Sandra Lunceford
121 KennarWay
Folsom.CA 95630
23 June 1997
Anthony C. Wong
Mather Field Site Manager
Dear Tony:
Enclosed are my comments on the Final Basewide OU FFS.
GENERAL COMMENTS:
I) Carbon tetrachloride has presented a remediation problem for Mather Field in that its detection
limit and cleanup level have been the same. It appears that one site on base has been pinpointed
as the source area for this chemical, Site IOC. It does not seem reasonable that this could be the
sole-source area for this contamination given its effects on off-base wells. My recommendation
would be to further pursue investigation at the oil water separators, Site 18, and other appropriate
sites to determine other source areas for this particular problem chemical, and perhaps other
sources for PCE and TCE will also be uncovered.
2) I will look forward to Basewide ROD documentation discussing the UXO area on Mather Field.
3) I encourage, again, designated federal funding cites that are made available to guarantee that
new, unaddressed contamination encountered on Mather Field and other closed bases be
promptly remediated to forestall economic impacts to local communities.
4) Presumably Site 81 will be accepting contamination from other sites, as it is to be used as a land
farm. I hope to see that the Basewide ROD documents acceptance criteria and restrictions in
nontechnical language.
5) Hopefully the Basewide ROD will briefly discuss the other sites comprising Mather and how
they are being addressed.
There is a void at this time between the Basewide ROD and off-base groundwater remediation If there is
RL/8-98/ES/392000I.AWS 6-18
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some way the USAF would or could address the events that are simultaneously occurring, it may go a
long way towards producing a degree of closure to this process.
Once again, thank-you for allowing me to comment on documentation for Mather Field.
Sincerely,
(signed, Sandra Lunceford)
RL/8-9S/ES/3920001. AWS 6-19
-------
PUBLIC HEARING
DEPARTMENT OF THE AIR FORCE
MATHER AIR FORCE BASE
—oOo-
In the Matter of: )
)
THE PROPOSED PLAN FOR ENVIRONMENTAL )
CLEANUP AT THE BASEWIDE OPERABLE )
UNIT SITES )
Denker Hall
10460 Armstrong Avenue
Mather, California
Thursday, May 29, 1997
7:00 p.m.
JAMES F. PETERS, CSR, RPR
Certified Shorthand Reporter
License No. 10063
APPEARANCES
Anthony Wong, Air Force Site Manager, Environmental
Coordinator
Kathleen Salyer, U.S. Environmental Protection Agency,
Region 9
PETERS SHORTHAND REPORTING CORPORATION (916) 362-2345
Kent Strong, California Department of Toxic Substances
Control
James Taylor, Central California Regional Water Quality
Control Board
RL«-98/ES/3920001 .A WS
6-20
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INDEX
Page
Opening remarks by Site Manager Wong 1
Questions by
Ms. VonEckert 21,31
Mr. Verdon 23
Ms. Walker 24
Mr. Alexander 28
Ms. Makowski 30
Mr. Sembach 31
Reporter's Certificate 34
RU8-98/ES/392000 LAWS
6-21
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22
1 PROCEEDINGS
2 SITE MANAGER WONG: Let's go ahead and get started.
3 It's scheduled to start at 7:00. So we'll try to get as
4 close as possible to it as we can.
5 (Thereupon an overhead presentation
6 was presented.)
7 SITE MANAGER WONG: I'd like to welcome everyone to
8 our proposed plan public meeting for our basewide operable
9 unit here at Mather Field.
10 My name is Tony Wong. I'm with the Air Force and I
11 work for the Air Force Base Conversion Agency here at
12 Mather.
13 Some other people in our crowd that may be of
14 interest to you. We have our Region 9 EPA representative,
15 Kathleen Salyer. She's right there. We have Kent Strong our
16 Department of Toxic Substances Control representative. And
17 we have James Taylor our Central California Regional Water
18 Quality Control Board representative.
19 These are some of the regulators that help us come
20 to these decisions and help guide us in terms of how we go
21 about cleaning up the Base.
22 I hope everyone one picked up a handout with these
RL/8-98/ES/392000I.AWS
6-22
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23
23 slides on them on the front desk. If you don't have one,
24 we'll have someone get you one. It might help facilitate
25 following along. I don't know if this is bright enough or
1 not.
2 -oOo--
3 SITE MANAGER WONG: Again, basically, we're here to
4 present to the public for public comment our proposed plan
5 for our basewide operable unit. We'll also propose those
6 sites that we consider no further action at. We have
7 documentation available to the public, both at the Rancho
8 Cordova Library, which is on Folsom Boulevard not far from
9 the Base here, and also our wing headquarters building which
10 is that building with the flag poles in front. You probably
11 passed it on the way in. Those are both information
12 repositories that we have all the supporting documentation to
13 help us come to our decisions on how we clean up the Base.
14 We have some of the documentation here that supports
15 this proposed plan, the basewide operable unit — it's at the
16 table right there - that includes the focus Feasibility
17 Study and some other ones.
18 Just a reminder. The public comment period is May
19 23rd through June 23rd 1997. So we are in that public
Riy8-98/ES/392000l .AWS
6-23
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24
20 comment period right now. You can submit comments several
21 ways. You can do it tonight, both orally and in writing or
22 you can submit more comments in writing to my office and the
23 address is on the back of the proposed plan on where to send
24 it to, or you can stop by and make written comments.
25 Again, the end date on that is June 23rd 1997.
1 What I want to try to do tonight is go through a
2 formal presentation. I'll go through the slides and I'll
3 have some overheads to help clarify the situation. And we
4 also have a picture of the base map here that we can help
5 orient you to where we're at and where these sites are.
6 Just to help you out. We're up in this area here.
7 This building right there. And this building right there by
8 the circle. There's the runway. Here's the Base housing.
9 The golf course. And north is up.
10 After the presentation we'll have a
11 question-and-answer period, where I'll accept questions from
12 the audience. And I would prefer that if there were any
13 questions and the follow-on comments, that the person would
14 come up here and make those questions or comments available
15 so our court reporter can clearly put them down.
16 And before you state your question, state your name
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17 and then he can keep a record of it.
18 --oOo~
19 SITE MANAGER WONG: Just a little background in
20 terms of where we are in our cleanup process. What we have
21 going on here at Mather is that we're following what's called
22 the Superfund process. That was a name that's given to a
23 longer name called the Comprehensive Environmental Response
24 Compensation and Liability Act, which was adopted in 1980.
25 They shortened that to Superfund Act.
1 And what that entails is a process where you go
2 through a couple of phases, an investigation phase. That
3 includes remedial investigation. And then with that
4 information, it gets rolled into the document and that's
5 called the Feasibility Study. And that Feasibility Study
6 takes that data that was gathered during our investigation
7 phase, looks at the local or the regulators of the A-wires is
8 what we call them, the applicable or relevant and appropriate
9 requirements.
10 We try to match our cleanup options with those
11 requirements to come up with something that will satisfy
12 them. And that's presented in the Feasibility Study. And
13 that Feasibility Study is then condensed or at least the
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14 major points in the options are proposed in the proposed
15 plan, which is this document that was mailed to most of you.
16 And if you don't have a copy of this, it's available in the
17 back desk.
18 It's about 20 pages. And it briefly goes over all
19 the options that we have available to us that are various
20 sites. And in our process, as you can see right here in the
21 middle, it stays right here where we've done the
22 investigation. And we've come up with a Feasibility Study
23 and again that's available on the table over there.
24 That's condensed and summarized into a proposed
25 plan. It gives us our options. Once we accept public
1 comment on those options, we roll those into a decision
2 document, that's called a Record of Decision. In that
3 document we pick our alternative or our option that we're
4 going to use for clean up.
5 And from there on that document required a
6 regulator's signature. So we have — here at Mather we have
7 what's called a Federal Facilities Agreement. And that's an
8 agreement between the Air Force, the State and the USEPA. So
9 as this document is finalized, we need all three concurrences
10 on our remediation and our option that we are deciding to
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11 use.
12 So at that point, once the Record of Decision is
13 signed, we'll go forward with our remediation, both the
14 design and then the action.
15 Once the Record of Decision is signed, we're
16 required by law to implement or start remedial action within
17 15 months. And just a little background in terms of Record
18 of Decisions here at Mather. We have five Record of
19 Decisions. What we did is we broke up this process into five
20 units. We call them Operable Units.
21 --oOo»
22 SITE MANAGER WONG: Our first unit is called the
23 Aircraft Control and Warning site. And basically that's a
24 groundwater plume emanating from our FAA — the golf ball
25 that you see out by the golf course, that area that comes
1 down into the housing.
2 It's a groundwater plume, a TCE plume, and that
3 Record of Decision was signed in 1993. We have remediation
4 in place. And there's a picture of an air stripping tower
5 back there on one of these tables. And that system is now
6 pumping and treating that water and has been working for the
7 last couple of years.
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8 Our landfill operable unit Record of Decision was
9 signed in 1995. And that included all our landfills on the
10 Base. That's Site 3 and 4. That's Site 6, Site 2. And that
11 Record of Decision allowed us to consolidate three of our
12 landfills into landfill 4. Landfill 6, landfill 2 and
13 landfill 5 were all excavated and moved to landfill 4.
14 So currently we have landfill 3 and 4 with caps on
15 them. And the only thing left on that remedial action is to
16 get a vegetative cap to grow on landfill 4, and then the
17 fencing to go up around those landfills.
18 Our soils and groundwater operable units had a
19 Record of Decision that was signed back in 1996. We are
20 currently in the field implementing those remedial actions.
21 We are putting in a pump and treat system in the main base
22 area. And that's hoped to go in this summer or this
23 construction season and start pumping by the fall.
24 And our last operable unit is our basewide operable
25 unit. And that's come about because of the investigations.
1 And these sites have kind of filtered through these other
2 operable units and this is basically our catch-all Record of
3 Decision. There's 18 sites associated with this Record of
4 Decision. They're all soil sites. And I'll get into some
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5 further detail on what that is.
6 ~oOo~
7 SITE MANAGER WONG: Some of the sites that are
8 included in this Record of Decision are a disposal site, some
9 underground storage tank sites, fire training areas, sewage
10 treatment facility, both the facility and the system, and
11 some of the pipe work. There's a golf course maintenance
12 area. There are some ditches, a gun range, and the skeet and
13 trap range.
14 And what's done in terms of coming up with these
15 options is that these sites are looked at. They're looked at
16 to find out what chemicals are present in the ground and they
17 look at three things. They look at the chemical and its
18 protection or trying to protect the groundwater quality and
19 its impact on the groundwater. They look at the human health
20 risk and the ecological risk.
21 So based on those three factors, if the compound
22 comes up as a concern, then that compound is tracked and that
23 site needs to be cleaned up accordingly.
24 -oOo--
25 SITE MANAGER WONG: Another thing we'll be getting
1 into is what we're cleaning up to. There are three
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2 categories that we're looking at, residential, occupational
3 and recreational. And that is more geared towards reuse, in
4 terms of what the intended use of that land is going to be.
5 A simple breakdown is the residential use would have
6 exposure or someone living there 3 50 days of the year. An
7 occupational situation is someone being there 250 days a
8 year, and the recreational situation is about 150 days a
9 year. So that's some of the criteria that we look at for how
10 we clean up the sites.
11 ~oOo~
12 SITE MANAGER WONG: Some of the cleanup technologies
13 that are available to us are access restrictions, air
14 monitoring, bioremediation, excavation, and groundwater
15 monitoring.
16 Access restriction can be physical or
17 institutional. Physical restrictions can be fence, as an
18 example. Institutional restrictions can be something written
19 in the deed that restricts any wells to be drilled or any
20 certain type of activity based on the environmental
21 condition.
22 Air monitoring includes instruments that detect any
23 contamination in the air during any cleanup activities such
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24 as excavation or for example that air stripping tower is
25 taking contamination out to a low enough level that it can be
1 dispersed into the air. But we do have instrumentation to
2 verify that.
3 --oOo-
4 SITE MANAGER WONG: Bioremediation, if you want to
5 look at that slide over there, is a process where you use the
6 natural occurring organisms in the soil and then convert
7 organic matter, primarily fuel constituents, gasoline and
8 diesel and break them down into harmless components.
9 Excavation is what it says. You go in there and you
10 take your back-hoe or your front-loader and just dig out
11 everything you can to get rid of the contamination.
12 And groundwater monitoring is, our wells that we
13 have several of, that we have put into the ground to pull up
14 samples quarterly or monthly depending on where it's at and
15 analyzed for several constituents based on what we're trying
16 to look for, what we think is in the area. And that's an
17 ongoing process.
18 --oOO"
19 SITE MANAGER WONG: Some other technologies
20 available to us are off-base disposal, where a lot of— or
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21 some of the excavation that we pull up out of the ground may
22 contain hazardous wastes or California designated waste,
23 which is soil that is contaminated that could potentially
24 impact the groundwater. Those type of materials we have to
25 take off base to dispose of. And that's usually at a
1 classified landfill in the area.
2 On-base disposal usually entails areas on the Base
3 where, with regulated concurrence we have acceptance criteria
4 with that. At certain levels that material can be used for
5 foundation material, like in landfill caps or fill material.
6 So we've got a site, Site 7, that we'll be talking about
7 later that needs some of that soil. And we already have
8 acceptance criteria that's agreed upon with the regulators
9 that will allow us to test the soil as it comes up. And as
10 long as it meets those criteria, we can take it there and
11 dispose of it. And usually that's a lot cheaper alternative
12 for us to get rid of that soil.
13 Another process we have available to us is called
14 soil vapor extraction. There's a schematic of it over there
15 on the overhead.
16 -oOo~
17 SITE MANAGER WONG: And what that entails is
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18 basically a vacuum effect, where we have a pump that will
19 pull air into the soil that has contamination in it, and then
20 that air is pulled up into a unit that will take out the
21 contamination and then vent off the rest of the air.
22 And that just deals with constituents or
23 contamination that's in the soil between the ground and the
24 groundwater because it's in the vapor there.
25 That's a very effective method and we have a site
1 here that we're using it on that we're pulling up a lot of
2 constituent.
3 Stabilization is another method that we have
4 available to us. And what that entails is an additive that
5 we add to the soil, that will bind the constituent to the
6 soil and not allow water to filter through it and move that
7 contamination around.
8 «oOo~
9 SITE MANAGER WONG: An example of what we're going
10 to see both in the post plan and also in our Feasibility
11 Study is tables that are site specific. And these tables are
12 basically laid out like this, where you'll have the site name
13 and various options. And no action is always an option for
14 us at each site.
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15 Sometimes there's a cost associated with no action
16 and that usually is associated with some kind of monitoring
17 program, where we have to take samples of the groundwater and
18 analyze it to verify what's there or not. In this case,
19 there is no cost associated with no action.
20 This talks about in situ bioremediation, excavation
21 of groundwater. And there's also an estimated dollar value
22 associated with that. We have to come up with estimates on
23 the various cleanup options that we have. And we use those
24 estimates as sort of a working number to help us come to some
25 decision and also just for programming purposes or getting
1 money to clean up the site.
2 But every site does have various options. What I
3 intend to do is go through the sites and show you the
4 preferred alternative that we're looking at and explain
5 that.
6 But before I get into that, I want to go through
7 some of the criteria that needs to be discussed, and used in
8 terms of coming to these decisions on what alternative, what
9 option that we're pursuing.
10 -oOo-
11 ' SITE MANAGER WONG: Threshold criteria consist of
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12 these two parts. And these criteria both have to be met to
13 pick an option. And they are overall protection of human
14 health and compliance with applicable or relevant and
15 appropriate requirements. And that's what I had mentioned
16 before in the regulations that the regulators are governed by
17 and that we have to comply with. So whatever option that we
18 consider, we have to meet these two criteria.
19 -oOo--
20 SITE MANAGER WONG: Next, we have the, what's called
21 the balancing criteria. These are used primarily to compare
22 the different options. It's to come up with a solution to
23 look at the long-term effectiveness of the option; how
24 effective it is at reducing the toxicity, mobility and volume
25 of the contamination; the short-term effectiveness, and how
1 soon can it be put in place; and what risk is there involved
2 during that time period; can we wait or do we have to do
3 something more immediate.
4 Implementability, that's if something is feasible or
5 not. And there's certain situations where it may not be
6 technically feasible to go after that contamination. And we
7 have to look at alternate methods. And there's costs. Is it
8 worth the cost to go after it? Is it that much more or is it
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9 almost the same?
10 -oOo--
11 SITE MANAGER WONG: And finally, there's the
12 modifying criteria. These are state acceptance and community
13 acceptance. And the community acceptance is the public being
14 aware of our options. And again at this time in our process,
15 this public comment period is when we accept those comments
16 from the public and we need to respond to those comments.
17 And in one case here at Mather we had a community
18 concern with our landfill. And at our landfill proposed plan
19 meeting we had someone — actually, it was the County of
20 Sacramento — but they expressed a concern on leaving that
21 landfill, landfill 6 in that area. They had plans to develop
22 that area. So their comment was that they would prefer to
23 have that moved.
24 We went through some, I think a month or so of
25 looking at the numbers and coming up with costs associated
1 with that and trying to justify moving it from that point of
2 view. And we ended up moving it, moving it all the way to
3 landfill 4.
4 So community input is important. It does affect,
5 you know, what is done here. And it's again very important
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6 that we get some comment. And it does and can modify the
7 remedy that we have chosen.
8 -oOo-
9 SITE MANAGER WONG: I'm going to start off with
10 certain sites that, after investigation, that we found that
11 there was no chemical of concern, that we feel there is no
12 impact, both human health and the environment. So we call
13 these No Further Action Sites. They include Site 8, the fire
14 training area, Site 17 the weapons storage septic tank leach
15 field, Site 19 the bulk fuel storage facility, Site 67
16 strategic air command area shop drainage system, and Site 84
17 the sanitary sewer line runway investigation. That's the
18 sanitary line that ran underneath the runway.
19 So again, based on our investigation and analysis of
20 the data, we felt there's no contamination of concern there,
21 so we feel these sites will be proposed for no further
22 action.
23 -oOo-
24 SITE MANAGER WONG: Our next site is what we call
25 the petroleum-only sites. As part of CERCLA or Superfund
1 there is an exclusion for petroleum-only sites. Those sites
2 that have only fuel contamination are not included in that
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3 process. And that has been delegated or that authority goes
4 to the State, and in our case the State Water Board. So
5 these two sites are being — is under their jurisdiction and
6 we are working closely with them to take care of these
7 sites.
8 One of the sites we have is Site 83, the helicopter
9 wash rack, is we feel no action. And Site 82, which is the
10 golf course maintenance area, we have proposed that we will
11 install three groundwater monitoring wells in that area to
12 verify if there's any problem in terms of fuel. We intend to
13 do that, and basically monitor it. And if there's anything
14 that comes up in terms of contamination, we'll have to deal
15 with it.
16 But the initial plan is to go ahead and put in the
17 monitoring well and see what the data shows.
18 -oOo--
19 SITE MANAGER WONG: Now, we start getting into the
20 sites where we have categorized for residential use. There
21 are several sites that we have identified with that criteria
22 for evaluation. And I'll explain a little later what we mean
23 by -- you'll see right here evaluation for occupational
24 standards. First, we'll get into the Site 18, the old burial
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25 site.
1 MS. CORTENBACH: Burial of what?
2 SITE MANAGER WONG: Usually, it's--
3 MR. HUGHES: It was reported when the sites were
4 first identified (hat this site had toolboxes and Ethel
5 mercaptain, which is the chemical that you put in natural gas
6 that you can smell it. And it was investigated for any
7 debris or landfill material and nothing was found.
8 However, there were some petroleum fuels and some
9 solvents found. And so it started out being investigated as
10 a burial site, but ended up that we chose to remediate
11 because it apparently received run off from aircraft washing
12 operations.
13 One of the air photographs shows ponding of water.
14 So it's called a burial site still, but it's really an area
15 for wash water. It carried contamination in it and soaked
16 into the soil.
17 SITE MANAGER WONG: Right. So as a result of the
18 investigation, and we found solvents, the proposed
19 remediation would be soil vapor extraction. And that's where
20 we go in -- like I explained earlier, where we go in and
21 start drawing the vapors off the soil and removing
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22 contamination that way.
23 Our site 20, the sewage treatment facility, is found
24 south of the runway. What we have for our option is
25 excavation and stabilization with ex situ bioremediation.
1 And what that is", we'll go in and we'll dig the dirt up and
2 move it to our bioremediation facility, which is located in
3 that area, where they'll treat the soil and bring it down to
4 levels acceptable to put it in our Site 7 area, the landfill
5 foundation and fill.
6 In addition to that, we'll also put in groundwater
7 monitoring wells and monitor the water there to verify what
8 is or is not going into the groundwater.
9 And this is one of the sites that we evaluated for
10 occupational standards. And as I explained earlier, there's
11 standards based on exposure. And one of the things that we
12 were looking at as part of the cleanup is, you know, what's
13 the intended use there? Is there going to be light
14 industrial or is it going to be residential or occupational?
15 And each one of those, because they're differential
16 exposure ranges, you know, the number of days has slightly
17 different cleanup standards. So when we go in and start
18 evaluating our options for these sites, we kind of look at
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19 the intended reuse or the intended plan for that area and
20 look at the options, occupational versus residential. And in
21 this case, it came up, you know, the same, that if we went
22 after occupational standards we would also look at the
23 residential in terms of the constituents that we're cleaning
24 up. So that's why we're categorizing this as residential.
25 ~oOo~
1 SITE MANAGER WONG: Some additional sites is Site
2 23. That's a sanitary sewer line in the main base area. It
3 runs parallel to the -- not the runway but the ramp area.
4 And our plan there is to put in in situ - I mean —
5 yeah, in situ soil vapor extraction. Again, the compound
6 that we're concerned about is Volatile Organic Compounds,
7 those constituents that we can pull out of the vapor and
8 clean.
9 Our Site 80, the golf course maintenance ditch is
10 over parallel to the golf course. And some of the
11 constituents that we found there were pesticides and metals
12 identified in the surface water that pose an ecological risk
13 and a possible impact to surface water quality.
14 So our plan is to excavate, again with on-base
15 disposal. That's our, hopefully, our Site 7 area, as long as
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16 it meets the acceptance criteria. And this one was one of
17 the sites that we looked at in terms of recreational
18 standards. It's in the area that is currently under lease
19 with the County Parks. And they have a plan to develop that
20 area with various recreational activities. So again, when we
21 looked at that versus residential, it came up about the same.
22 So we're looking at residential standards.
23 Site 8 is the sewage oxidation ponds located in the
24 southern portion of the Base. Those ponds had metals found
25 in them and some petroleum products. The plan there is,
1 because the area is so large and there's such a large volume
2 of soil that needs to be taken care of, any options in terms
3 of digging it up and moving it to both on-base or off-base
4 for remediation is just too costly.
5 So we came up with the option of what we call
6 land-farming and that's remediation in place. We're going to
7 go in and fix the area up so we won't get any more water
8 coming in there and treat it in place until it gets to a low
9 enough level. And again this is another one of the sites
10 that was looked at for an occupational standard.
11 -oOo-
12 SITE MANAGER WONG: Our next site is Site 85, the
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13 south ditch area. It's a ditch that runs parallel to the
14 runway on the southern portion of it. It gets water from the
15 northern area from underneath the runway and drains out to
16 the south to Morrison Creek.
17 Some of the chemicals of concern there are metals
18 and pesticides and some petroleum products. There is a
19 potential risk to human health and the ecology. And there's
20 a potential problem with getting into the groundwater. So
21 the option we have there is excavation. And again, we hope
22 to meet the acceptance criteria at Site 7 to put that soil
23 there.
24 Site 86 is our military firing range. It's located
25 in one of the southern-most portions of our base. There's a
1 small arms firing range. And one of the compounds there is
2 lead. And it was in the soil. So one of the -- our option
3 that we prefer is to excavate it and treat it, and then
4 dispose of it on base, again, as long as we meet the
5 acceptance criteria.
6 Site 88, our Morrison Creek area, it had metals
7 identified as a chemical of concern. Our plan there is to
8 excavate it and use it for on-base disposal.
9 -oOo-
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10 SITE MANAGER WONG: One of the sites that we did
11 meet the recreational criteria for was our Site 87, the skeet
12 and trap range. It's located close to the golf ball out
13 there by the golf course. It was a skeet range. And we
14 found metals there, shell fragments. And there's also some
15 problems. There's a petroleum by-product from the clay
16 pigeons that were used out there. They need to be cleaned
17 up. So our preferred alternative is to excavate it and
18 dispose of it on base.
19 It's a pretty large area in the overhead there.
20 It's a large volume of soil that needs to be taken care of.
21 -oOo-
22 SITE MANAGER WONG: And the last site is our Site
23 1OC/68. One of the sites that we identified as an
24 occupational standard. It's in the — it's just off the ramp
25 there off the runway. And that area is being developed for
1 the air cargo facility that the County has plans for. So we
2 felt that it fits the occupational standards.
3 The plan there is to excavate. And there is lead
4 found in the soil and metals, and again disposal on base.
5 And some of the soil that we can't excavate and dispose of,
6 we're going to treat in place with in situ treatment.
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7 That concludes the presentation portion of this
8 meeting.
9 What I'd like to do is answer any questions that you
10 might have concerning the presentation. If you could, could
11 you come over here and state your name and ask your question
12 and we'll answer it. That helps our court reporter in terms
13 of getting the information down clearly and correctly.
14 And once we finish with that portion of our meeting
15 tonight, we'll go into our formal comment period. Again, I
16 would ask that you come over here and make your comments so
17 he can record it accurately. And again, we'll try to answer
18 as best we can right now. And if we can't, we will have
19 those comments answered in writing as part of our Record of
20 Decision, which is the next phase that we need to go into in
21 our process.
22 So at this time, are there any questions on the
23 presentation?
24 MS. VON ECKJERT: I have one.
25 SITE MANAGER WONG: Would you state your name for
1 the reporter.
2 MS. VON ECKERT: Eloise Von Eckert.
3 I got lost in the residential sections. And I
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4 wasn't able to track, but what would be the housing area
5 right in the middle near where we are?
6 SITE MANAGER WONG: Down here?
7 MS. VON ECKERT: Yeah, which sites are we there?
8 SITE MANAGER WONG: There's actually this ditch
9 site. This one right here.
10 MS. VON ECKERT: 18 and 20 and 23?
11 SITE MANAGER WONG: 18 is up here.
12 MR. HUGHES: The only sites in this proposed plan
13 that are nearby are what's called the Morrison Creek
14 Reference Site. This drainage had three samples collected
15 and right near the roadway there were some pesticides
16 detected. And it might have been from mosquito abatement in
17 the past or something of that nature.
18 But two samples downstream didn't have any
19 significant contaminants of concern, but we need to do a
20 little more sampling to be really -- to well define the area
21 that will need to be excavated. We don't believe that that
22 contamination extends near the housing here.
23 The second ditch that drains to the golf course
24 maintenance area, again, pesticides in the ditch nearby where
25 pesticides were mixed and stored for use on the golf course.
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1 Again, the sample here had pesticides. Two more
2 samples were collected that were very widely spaced. And
3 additional samples need to be taken after being collected
4 very soon to try to better define the actual length of the
5 ditch that would require some remediation.
6 There's two other sites that were discussed in a
7 past public meeting, and for which a Record of Decision has
8 already been signed, that are in the housing area. One was
9 an underground storage tank near the water tank. It was a ~
10 I believe it was a generator fuel for a backup generator for
11 the pumping of the water system. That site where -- the tank
12 was removed and it's been remediated.
13 The second site is a former military gas station or
14 actually military -- or actually — yes, a military gas
15 station that has fuel tanks. And that remediation is also
16 under way. It was part of a past Record of Decision. That
17 site is a petroleum-only site. That's been regulated by the
18 Regional Water Quality Control Board.
19 So by and large there are not a lot of contaminated
20 sites near the housing.
21 MS. VON ECKERT: Okay.
22 SITE MANAGER WONG: Any other questions?
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23 MR. VERDON: My name is Scott Verdon. I'm also a
24 student. My question is the employment opportunities. What
25 kind of thing is that?
1 Will there be employment generated from the work
2 that's going to be brought in cleaning it up on the outside?
3 Is that going to be mostly outside contractors or things of
4 the nature where there are possible opportunities to employ
5 myself?
6 SITE MANAGER WONG: The situation with environmental
7 work here is that our agency who's headquartered out of
8 Washington D.C. has a contracting agency out of Brooks Air
9 Force Base in Texas. And what they do is they contract, you
10 know, all the different environmental works at all the
11 various bases that we control. And part of that contract
12 that they have, is that whoever it is awarded to, a certain
13 portion of it needs to be done locally.
14 They have to go out locally and get subcontractors.
15 Our current contractor is Montgomery Watson. Their building
16 is right over there. And they're our prime contractor for
17 all remediation work. And they have a team of, you know,
18 other contractors that they use. And they also go out
19 locally.
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20 So I can pass that information along in terms of,
21 you know, for anything local that they might be able to do,
22 but that's the way our process is.
23 MS. WALKER: My name is Annette Walker. And I would
24 like to know what do the experts feel is the worst thing that
25 can happen? And what preventative measures have you in place
1 for the worst thing that can happen?
2 SITE MANAGER WONG: Is this specifically to the site
3 here at Mather?
4 MS. WALKER: Yes. I mean, any of the contamination
5 or whatever you may know from Aerojet or any information,
6 because contamination is just contamination without a label.
7 SITE MANAGER WONG: Right. Well, in terms of
8 Mather's contamination and specifically in terms of our
9 proposed plan on these 18 sites, most of the contaminations
10 are either, what we call VOCs or Volatile Organic Compounds
11 or fuel constituents, or lead. Again, we do have treatment
12 options available to us to take care of it. We are in the
13 process through this Record of Decision to take care of that
14 contamination, and prevent it from going anywhere. Sol
15 would hope the potential impact is very low. We have
16 identified as much as we can, and we're moving forward.
RU8-98/ES/392000I.AWS
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50
17 We're trying to get it cleaned up.
18 MS. WALKER: But I'm saying what has been identified
19 as the worst thing that can happen? What has been
20 identified?
21 SITE MANAGER WONG: In terms of the worst thing?
22 MS. WALKER: Yes.
23 SITE MANAGER WONG: Again, when we go through our
24 risk assessment for human health and the ecology, we come up
25 with numbers that tell us, you know, what levels that could
1 potentially be out there and these risk assessments are
2 associated with the one-in-a-million cancer risk. And
3 anything that is above the one-in-a-million cancer risk, we
4 have to deal with in terms of taking care of it.
5 So we feel we're at the low enough level right now
6 where there is no risk as long as we take action.
7 MS. WALKER: I'm saying for the future generations.
8 Do you understand? What I'm saying is right now, right, I
9 understand that. But I'm just saying say for the next five
10 years, ten years, what is probably the worst thing may/could
11 happen if we do not clear this up within the allotted time?
12 SITE MANAGER WONG: Well, I can't answer that right
13 now.
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51
14 MS. WALKER: I'm saying have the experts said this
15 is the worst scenario or not? They haven't looked at the
16 worst thing that can happen?
17 SITE MANAGER WONG: Again, they look at it in terms
18 of risk, and what the potential risk is. And if it falls
19 into a certain category where action needs to be taken, we
20 are taking action. I don't think they project out five
21 years, ten years down the line.
22 MS. WALKER: Okay. And one other thing too that I
23 would like to elaborate on what he just said. Since this is
24 at a level of federal dollars, state dollars, county, city,
25 dollars -- this is more of a comment --1 think that more of
1 the monies and the dollars should be invested in our
2 communities with some of the people here and employ them more
3 so that maybe some of the contractors who are getting some of
4 the governmental contracts and more so, we should probably
5 invest in people.
6 SITE MANAGER WONG: Right. And again the government
7 contract is going through AFCEE, which is in Texas, but that
8 does not exclude them from hiring people locally. There is a
9 process where packages describing what needs to be done is
10 sent out to all the various contractors including the local
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52
11 ones, so they are usually at the same level as everyone else
12 in terms of getting those contracts awarded.
13 In addition to that, there is also language in the
14 contracts that requires, whoever gets the award, to hire
15 locally a certain percentage. So those provisions are in
16 there and they are government contract laws.
17 MS. WALKER: Does this include the plan « does it
18 include education to the public? How to better be able to
19 live with the contaminate — well, the possibility?
20 SITE MANAGER WONG: In addition to what we have
21 here, is we have quarterly news letters, fact sheets, that,
22 you know, we -- and again we can discuss this later in terms
23 of, you know, all the water stuff we're doing, but we do have
24 an ongoing community relations plan that we try to get
25 information out to the public. We also have a Restoration
1 Advisory Board here at Mather that we get public comment on,
2 public input on in our whole process, which is something
3 that's been just started recently within the last couple
4 years.
5 We're looking at all the different avenues to get
6 information out, to get the public aware of what's happening
7 here. And again, you know, we're trying with our mailings,
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8 and we've done several mailings in terms of what's happening
9 here. We've got a mailing list that is growing and will
10 continue to grow as long as there's interest.
11 MS. WALKER: Okay. And just one other thing. Due
12 to the environment, and like you say, the paper flow, I would
13 like to suggest centrally located bulletin boards to update
14 the community, such as maybe at the Franchise Tax Board,
15 that's right off from the 50 freeway along with the movie
16 goers and I would like to see more of being environmental
17 friendly.
18 And also offering those kind of products -- I'm
19 concerned too, as a citizen of the community who uses water
20 — some of the products that I'm using if they are
21 environmentally safe. And then once they're mixed with the
22 water while we're cleaning the bath tub when the children are
23 getting in, are we doing more harm than we are good? So I
24 really want to stress the education as to the people who are
25 living here and some kind of solutions for future generations
1 as well.
2 SITE MANAGER WONG: I appreciate the comment. And
3 we will take the comment in terms of trying to get that
4 information out there. We can work on getting our news
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54
5 letters and fact sheets out and posted like you said. And,
6 you know, we have a couple of our RAB members here and our
7 community relations specialists here, that you can -- you
8 know, I'm sure they'll take those suggestions down and we'll
9 see what we can do.
10 MS. WALKER: Thank you.
11 SITE MANAGER WONG: State your name for the
12 reporter. It makes it easier for him to report.
13 MR. ALEXANDER: My name is K. Alexander here in
14 Sacramento.
15 I see we have general information. Can we define
16 it, the whole can of work in, you know, critical, highly
17 critical, average, something like, you know, something like
18 different phases? Sometimes you ask for more money, we can
19 put which one into which phases, phase 1,2, 3, 4, you
20 address this situation here.
21 SITE MANAGER WONG: Right. And that boils down to
22 risk. When we look at the information that we get through
23 our investigations, we get numbers that tell us what kind of
24 risk is out there. If there's anything that's a high risk,
25 we'll go after it immediately and try to do anything we can
1 to take care of it, you know, right away.
R1V8-98/ES/392000I.AWS
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55
2 Based on what risk levels show up —
3 MR. ALEXANDER: It's here in the--do you have the
4 risk values in this figure here?
5 SITE MANAGER WONG: The actual risk values are in
6 the Feasibility Study.
7 MR. ALEXANDER: Well, if it's a high risk, you
8 better do it now to show those people we have a higher risk.
9 Sometimes we do it later on, you know, because it costs a lot
10 of more money. We justify it as a different risk, different
11 critical, highly critical, something. I wish we included
12 something in the report.
13 SITE MANAGER WONG: It's in our Feasibility Study -
14 MR. ALEXANDER: Here? Thank you.
15 SITE MANAGER WONG: - where you can see the risk
16 numbers.
17 Thank you.
18 MS. MAKOWSKJ: My name is Claudette Makowski. And I
19 have a question about the plume back there. It's very close
20 to the Citizen's Utilities wells.
21 Have those wells been affected, and what is in that
22 plume?
23 SITE MANAGER WONG: That plume primarily consists of
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56
24 solvents, TCE.
25 MS. MAKOWSKI: What kind of solvents, TCE?
1 SITE MANAGER WONG: TCE, PCE and
2 Carbon tetrachloride. It has affected two wells with
3 Citizen's wells. One well is shut down. The other well has
4 a treatment system on it. And there's a picture of it in the
5 lower right-hand comer there. It's an activated carbon
6 unit, that is treating water right now. I think it's been
7 operating for the last month.
8 MS. MAKOWSKI: When were those wells shut down?
9 SITE MANAGER WONG: The explorer well was shut down
10 in 1994, September of 1.994, and the moonbeam well was shut
11 down in April of last year. The unit has been operating for
12 the last month and it's been shut down between that time.
13 MS. MAKOWSKI: And you say that's TCE and
14 Carbon tetrachloride in there?
15 SITE MANAGER WONG: And PCE.
16 MS. MAKOWSKI: PCE.
17 MR. SEMBACH: My name is Erik Sembach. Have you
18 guys — has there been a projected target date for the
19 completion of all the remedial actions?
20 SITE MANAGER WONG: Our intention is to get all
RU8-9S/ES/3920001 .AWS
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57
21 remediation up and going in the year 1999. Now, what that
22 means is, our systems will be in place. There is a prove-out
23 period where we need to operate it and satisfy the regulation
24 in terms of making sure it's operating correctly.
25 Once we get to that phase, it goes into the
1 long-term phase, where we just operate the system. I think
2 there's five-year review cycles to verify it's working
3 correctly. And then maybe re-evaluate what needs to be done.
4 Any other questions?
5 Do we have any formal comments that we need to
6 address here or address in writing that we'll take down?
7 MS. VON ECKERT: I have a comment, not so much
8 formal, but what Annette Walker mentioned was what I look at.
9 I know that because we play with so many technological toys
10 that something is going to kick back and we're going to have
11 to learn what we're dealing with. And Mather being brave
12 enough to do this on an open forum, highly commendable. And
13 it also should make us look at how we operate on a daily
14 basis with pesticides and other cleaning products and fuels,
15 gas tanks and so forth.
16 And rather than attack Mather or the program and use
17 it as a fear tactic of what's going to happen to us or our
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58
18 children even, even though that is a concern of ours, to
19 understand how we ourselves our responsible for the health of
20 our environment, and to know that we run off of consumerism
21 and how we're going to impact our economy and everybody who
22 has jobs making whatever widgets are out there. There's no
23 blame here as far as I see. It's just a learning process.
24 And I thank you.
25 SITE MANAGER WONG: You're welcome.
1 Any other comments?
2 All right. Then we'll conclude this portion of the
3 meeting. And if anyone wants to ask any more questions or
4 wants any more information, we'll be available here and you
5 can ask us.
6 Again, my office is the Wing headquarters building
7 over there. If you have any other concerns, you have my
8 address and the phone number. Stop by any time and we can
9 discuss your concerns, let you know what our information is,
10 our data is, and help you alleviate those concerns.
11 (Thereupon the Public Hearing on the Proposed
12 Plan for Environmental Cleanup at the Basewide
13 Operable Unit Sites was concluded at 7:50 p.m.)
14
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59
15
16
17
18
19
20
21
22
23
24
25
1 CERTIFICATE OF REPORTER
2 I, James F. Peters, a Certified Shorthand Reporter
3 of the State of California, and a Registered Professional
4 Reporter do hereby certify:
5 That I am a disinterested person herein; that the
6 foregoing Public Hearing on the Proposed Plan for
7 Environmental Cleanup at the Basewide Operable Unit Sites,
8 was reported by me, James F. Peters, and thereafter
9 transcribed into typewriting.
10 I further certify that I am not of counsel or
11 attorney for any of the parties to said hearing, nor in any
RL/8-98/ES/392000 LAWS
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60
12 way interested in the outcome of said hearing.
13 IN WITNESS WHEREOF, I have hereunto set my hand this
14 9th day of June, 1997.
15
16
17
18
19
20
(Signed)
21
22 James F. Peters, CSR, RPR
23 Certified Shorthand Reporter
24 License Number 10063
25
RU8-98/ES/3920001 .AWS
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7.0 References
t
AeroVironment, Inc., 1987, "Installation Restoration Program Phase II -
Confirmation/Quantification Stage 2 Final Report, September 1985 to June 1987," Volumes 1
and 2, AeroVironment, Inc., Monrovia, California.
AeroVironment, Inc., 1988, "Installation Restoration Program Phase II -
Confirmation/Quantification Stage 3 Final Report, July 1986 to March 1987," Volumes 1 and 2,
AeroVironment, Inc., Monrovia, California.
CH2M-HJ11, Inc., 1982, "Installation Restoration Program Records Search (Phase 1),"
CH2M-HH1, Inc., Gainesville, Florida.
EA Engineering, Science, and Technology (EA), 1990a, "Quarterly Groundwater Sampling at
Mather Air Force Base, May-June 1990," Volume 1-Report; Volume 2-Appendix A,
Appendix B, Appendix C, Pt. 1; Volume 3-Appendix C, Pt. 2; EA Engineering, Science, and
Technology Corporation, Lafayette, California.
EA Engineering, Science, and Technology (EA), 1990b, "Quarterly Groundwater Sampling at
Mather Air Force Base, August 1990," Volume 1-Report; Volume 2-Appendix A, Appendix B,
Appendix C, Pt. 1; Volume 3-Appendix C, Pt. 2; EA Engineering, Science, and Technology
Corporation, Lafayette, California.
EA Engineering, Science, and Technology (EA), 1990c, "Quarterly Groundwater Sampling at
Mather Air Force Base, November-December 1990," Volume 1-Report; Volume 2-Appendix A,
Appendix B, Appendix C, Pt. 1; Volume 3-Appendix C, Pt. 2; EA Engineering, Science, and
Technology Corporation, Lafayette, California.
EA Engineering, Science, and Technology (EA), 1997, "Site Investigation and SVE System
Installation Report Site IOC/68, Former Mather Air Force Base, Sacramento County, California,"
Sacramento, California, December 1997.
Eisler, R., 1998, "Lead Hazards to Fish, Wildlife, and Invertebrates: A Synoptic Review,"
U.S. Fish and Wildlife Service Contaminant Hazard Review, Report No. 14, U.S. Department of
the Interior, Washington, D.C.
Riy8-98/ES/392000 LAWS ' " 1
-------
IT Corporation (IT), 1988a, "Well Redevelopment and Sampling Plan for Mather Air Force Base,
California," Prepared by IT Corporation for HAZWRAP, July 1988.
IT Corporation (IT), 1988b, "U.S. Air Force Installation Restoration Program, Phase IV-A
Activities at Mather Air Force Base, California, Landfill Gas Testing Report for Eight Sites at
Mather Air Force Base, California", Prepared by IT Corporation for Hazardous Waste Remedial
Actions Program.
IT Corporation (IT), 1989, "Quarterly Groundwater Monitoring Reports - First through Fourth
Quarters 1989 for Mather Air Force Base, California," IT Corporation, Martinez, California.
IT Corporation (IT), 1990a, "U.S. Air Force Installation Restoration Program, Phase IV-A
Activities at Mather Air Force Base, California, Final Site Inspection Report", IT Corporation,
Knoxville, Tennessee.
IT Corporation (IT), 1990b, "Underground Storage Tank Closure Report, Mather Air Force Base,
California," Martinez, California.
IT Corporation (IT), 1990c, "U.S. Air Force Installation Restoration Program, Phase IV-A
Activities at Mather Air Force Base, California, Sampling and Analysis Report for Site Monitor
Wells," prepared by IT Corporation for Hazardous Waste Remedial Actions Program.
IT Corporation (IT), 1990d, "Quarterly Groundwater Monitoring Reports - First through Fourth
Quarters 1990 for Mather Air Force Base, California," IT Corporation, Martinez, California.
IT Corporation (IT), 1992, "Final Remedial Investigation for Group 2 Sites, Mather Air Force
Base, California", Prepared by IT Corporation for Environmental Management Operations.
IT Corporation (IT), I993a, "Super-fund Record of Decision: Aircraft Control and Warning Site,
Mather Air Force Base, Sacramento County, California", December 1993, Prepared by IT
Corporation for Environmental Management Operations.
IT Corporation (IT), 1993b, "Final Focused Feasibility Study Report of the Landfill OU Sites for
Mather Air Force Base, California," prepared by IT Corporation for Environmental Management
Operations.
RL/8-98/ES/392000 LAWS
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IT Corporation (IT), 1993c, "Proposed Plan for Environmental Cleanup at the Mather Air Force
Base Landfill Operable Unit Sites," December 1993, Prepared by IT Corporation for Air Force
Center for Environmental Excellence.
IT Corporation (IT), 1993d, "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.
IT Corporation (IT), 1993e, "U.S. Air Force Installation Restoration Program, Final Technical
Memorandum for Group 3 Sites for Mather Air Force Base, California", Prepared by IT
Corporation for Environmental Management Operations.
IT Corporation (IT), 1993f, "Quarterly Groundwater Monitoring Report - Third Quarter 1993 for
Mather Air Force Base, California," IT Corporation, Martinez, California.
IT Corporation (IT), 1993g, "Quarterly Groundwater Monitoring Report - First Quarter 1993 for
Mather Air Force Base, California," IT Corporation, Martinez, California.
IT Corporation (IT), 1993h, "Quarterly Groundwater Monitoring Report - Second Quarter 1993
for Mather Air Force Base, California," IT Corporation, Martinez, California.
IT Corporation (IT), 1993i, "Final Remedial Investigation for Group 2 Sites, Mather Air Force
Base, California," Prepared by IT Corporation for Environmental Excellence Management
Operations.
IT Corporation (IT), 1994a, "Final Soils and Groundwater Operable Unit Additional Field
Investigation Remedial Investigation Report for Mather Air Force Base, California," Prepared by
IT Corporation for Air Force Center for Environmental Excellence, Brooks Air Force Base,
Texas.
IT Corporation (IT), 1994b, "Removal Action Memorandum for Sites 20,29, and 32, Mather Air
Force Base, California," prepared by IT Corporation for Battelle Environmental Services
Organization, Richland, Washington, September 1994.
IT Corporation (IT), 1995a, "Quarterly Monitoring Report - Third Quarter 1995 for Mather Air
Force Base, California," IT Corporation, Martinez, California.
RL/8-98/ES/392000I.AWS '"-*
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IT Corporation (IT), 1995b, "Groundwater Operable Unit and Soil Operable Unit Focused
Feasibility Study Report for Mather Air Force Base, California," Prepared by IT Corporation for
Air Force Center for Environmental Excellence, Brooks Air Force Base, Texas.
IT Corporation (IT), 1995c, "Final Mather Baseline Risk Assessment (MBRA) Mather Air Force
Base, California," Prepared by IT Corporation for Air Force Center for Environmental
Excellence, Brooks Air Force Base, Texas, December 19, 1995.
IT Corporation (IT), 1996a, "Soil Operable Unit and Groundwater Operable Unit Record of
Decision," prepared by IT Corporation, Richland, Washington for Air Force Center for
Environmental Excellence.
IT Corporation (IT), 1996b, "Final Additional Site Characterization and Basewide Operable Unit
Remedial Investigation Report for Mather Air Force Base, California," Prepared by
IT Corporation for Air Force Center for Environmental Excellence, Brooks Air Force Base,
Texas, September 6, 1996.
IT Corporation (IT), 1996c, "Final Comprehensive Baseline Risk Assessment for Mather Air
Force Base, California," Prepared by IT Corporation for Air Force Center for Environmental
Excellence, Brooks Air Force Base, Texas, May 1996.
IT Corporation (IT), 1997a, "Final Basewide Operable Unit Focused Feasibility Study Report for
Mather Air Force Base, California," Prepared by IT Corporation, Richland, Washington for Air
Force Center for Environmental Excellence, Brooks Air Force Base, Texas, April 1997.
IT Corporation (IT), 1997b, "Proposed Plan for Environmental Cleanup at the Basewide
Operable Unit Site," Prepared by IT Corporation for Air Force Center for Environmental
Excellence, Brooks Air Force Base, Texas, May 1997.
IT Corporation (IT), 1997c, "Final Site Characterization Report for Sites 86 and 87 for Mather
Air Force Base, California," Prepared by IT Corporation for Air Force Center for Environmental
Excellence, Brooks Air Force Base, Texas, February 20, 1997.
Montgomery Watson (MW), 1997a, "Final Closure Certification Report for Landfill Sites LF02,
LF03, LF04, LF05, and LF06," Prepared by Montgomery Watson for Air Force Center for
Environmental Excellence, Brooks AFB, Texas, August 1997.
RU8-98/ES/392000 I .A WS
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Montgomery Watson (MW), 1997b, "Draft Final Technical Plans and Quality Program Remedial
Action Pilot at Site 57 and Remedial Action Pilot Test at Sites IOC/68," Prepared by
Montgomery Watson for Air Force Center for Environmental Excellence, Brooks Air Force
Base, Texas, January 1997.
Montgomery Watson (MW), 1998, "Draft Final Project Definition Investigation Report for
Surface Soil Sites IOC, 69, 80, 81, and 88," prepared by Montgomery Watson for the Air Force
Center for Environmental Excellence, Brooks Air Force Base, Texas, June 1998.
State Water Resources Control Board (SWRCB), 1992, "California State Water Resources
Control Board ARARs Under CERCLA," California State Water Resources Control Board,
Sacramento, California, 1992.
United States Air Force (USAF), 1993, "Final Record of Decision, Disposal and Reuse of Mather
Air Force Base, Environmental Impact Statement, Sacramento County, California," Department
of the Air Force, March 31,1993.
United States Air Force (USAF), 1995, "Superfund Final Record of Decision, Landfill Operable
Unit Sites, Mather Air Force Base, Sacramento County California," Department of the Air Force,
1995.
United States Air Force (USAF), 1996a, "Removal Action Memorandum, Mather AFB IRP
Landfill Operable Unit, Site 2: the '8150' Area Landfill, Time-Critical Removal," prepared by
William T. Hughes, Operational Technologies Corporation for AFBCA/DBM, Mather,
California, September 1996.
United States Air Force (USAF), 1996b, "Removal Action Memorandum, Mather AFB IRP
Basewide Operable Unit, Site IOC: Fire Training Area Number 3, Time-Critical Removal,"
prepared by AFBCA/DBM, Mather, California, September 16, 1996.
U.S. Environmental Protection Agency (USEPA), 1987, "Data Quality Objectives for Remedial
Response Activities: Development Process, March 1987," EPA/540/G-87/003, Washington, D.C.
U.S. Environmental Protection Agency (USEPA), 1988, "CERCLA Compliance with Other
Laws Manual, Part I: Interim Final, August 1988," EPA/540/G-89/006, Washington, D.C.
RL/8-98/ES/392000 LAWS
7-5
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U.S. Environmental Protection Agency (USEPA), 1989, "CERCLA Compliance with Other
Laws Manual, Part II: Clean Water Act and Other Environmental Statutes and State
Requirements," Washington, D.C.
U.S. Environmental Protection Agency (USEPA), 1994, "Health Effects Assessment Summary
Tables (HEAST), Annual FY 1993," OERR 9200.6-303 (92-1), U.S. Environmental Protection
Agency, Office of Emergency and Remedial Response, Washington, D.C.
Weston, Roy F., Inc.(Weston), 1986, "Installation Restoration Program Phase II -
Confirmation/Quantification Stage 1 Final Report," Volumes 1 and 2, Roy F. Weston, Inc., West
Chester.
RU8-98/ES/3 92000 LAWS
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Appendix A
Administrative Record Index, Basewide Operable Unit,
Mather AFB, California
Riy8-98/ES/392000l .AWS
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
ARFILE
NUMBER
Jun82
Phase I, Records Search Report
CH2M Hill
04 Oct 82 CVRWQCB Letter to Air Force
Transmitting Comments on Records
Search Report
20 Oct 82 CDHS Letter to Base Transmitting
Interim Status Inspection Report
18 Jan 83 Phase IIA, Presurvey Report
10 Aug 83 Phase IIB Field Evaluation SOW
Johnson, William S
California Regional
Water Quality
Control Board
Stahler, James L
California Department
of Health Services
Engineering-Science Inc.
US Army Corps of
Engineers - Omaha
District
7
654
12 Aug 83 Waste Discharge Requirements for Mather Crooks, William
AFB, Sacramento County California Regional
Water Quality
Control Board
911
03 Oct 83 CVRWQCB Letter to Base Concurring
with Phase IIB SOW
Pinkos, Thomas R
California Regional
Water Quality
Control Board
20 Dec 83 CVRWQCB Letter to Base Transmitting
Summary of 6 Dec 83 Meeting
Pinkos, Thomas R
California Regional
Water Quality
Control Board
11
15 Feb 84 USAF OEHL Letter to MAJCOM
Transmitting Proposed Modification to
Phase II SOW
01 Aug 84 CDHS Letter to Base Outlining State
Requirements
Sanders, Dee Ann 12
USAF OEHL/CVT
Allen, James T 14
California Department
of Health Services
RU8-98/ES/3920001. AWS
A-l
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DOC. AUTHOR or AR FILE
DATE SUBJECT OR TITLE CORP. AUTHOR NUMBER
17Aug84 Minutes of 2 Aug 84 IRP Meeting Slaughter, John T, Col 15
323 ABG/CC
17 Aug 84 Minutes of 6 Aug 84 TWO Meeting Curran, James P, Capt 450
USAF Hosp/SGPB
20 Aug 84 Minutes of 20 Aug 84 TWO Meeting Slaughter, John T, Col 16
323 ABG/CC
24 Oct 84 Minutes of 1 Oct 84 TWG Meeting Slaughter, John T, Col 17
323 ABG/CC
04 Dec 84 EPA Letter to Base Providing Comments Seraydarian, Harry 18
on Phase I and II Documents EPA Region IX
05 Dec 84 Minutes of 26 Oct 84 IRP Meeting Slaughter, John T, Col 19
323 ABG/CC
April 1985 Phase II Stage 2, SOW, USAFOEHLATSS 380
Confirmation/Quantification
18 Apr 85 Minutes of 18 Apr 85 IRP Work Group Bost, Thomas D, LtCol 24
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 EPA Region IX
21 May 85 CDHS Letter to Base Transmitting Landis, Anthony J 29
Comments on Proposed Phase II, Stage 2 California Department
SOW of Health Services
29 May 85 County Letter to Base Providing Knight, K Kenneth 28
Comments on Draft Phase II Stage 2 Sacramento County
SOW Health Department
RL/8-98/ES/392000I .AWS
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
ARFILE
NUMBER
04 Jun 85 Base Letter to MAJCOM Transmitting
Review Comments for Draft Phase II
Stage 2 SOW
21 Jun 85 MAJCOM Letter to OEHL Transmitting
Consolidated Comments on Draft
Phase II Stage 2 SOW
12 Jul 85 Phase II Stage 2, Confirmation/
Quantification SOW
02 Jan 86 Base Letter to CDHS Concerning
Progression of Phase II
Jun 86 Phase II Stage 2, Draft
Confirmation/Quantification Report
27 Jun 86 Memorandum for Record Concerning
Technical Advisory Group Meeting
Held 25 Jun 86
19 Jan 87 AFRCE Letter to Base Providing
Comments on Phase II Stage 2 Report
05 Feb 87 CVRWQCB Letter to Base Providing
Review Comments on Phase II
Stage 2 Report
Curran, James P, Capt 30
USAF Hosp/SGPB
Schiller, Ronald L, LtCol 31
HQ ATC/SGPB
USAF Hosp/SGPB 32
Johnson, Bruce R, Col 41
323 ABG/CC
Aerovironment Inc. 51
Curran, James P, Capt 54
USAF Hosp/SGPB
Lammi, Phillip E 60
AFRCE-WR/ROV
Matteoli, Robert J 61
California Regional Water
Quality Control Board
06 Feb 87
10 Feb 87
11 Feb 87
MAJCOM Letter to Base Concerning Schiller, Ronald L, LtCol
State Requirement for Landfill Gas Testing HQ ATC/SGPB
CDHS Letter to Base Transmitting
Comments on Draft Phase II Stage 2
Report
EPA Letter to Base Transmitting
Comments on Draft Phase II Stage 2
Report
Wang, David
California Department
of Health Services
Zimpfer, Amy K
EPA Region IX
62
63
64
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A-3
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
AR FILE
NUMBER
17 Feb 87 CDHS Letter to Base Providing
Comments on Draft Phase II Stage 2
Confirmation/Quantification Report
05 Mar 87 Base Letter to USAF OEHL/ECQ on
Landfill Gas Testing
21 Apr 87 SCAPCD Letter to Base on Screening
Questionnaires for Inactive Solid Waste
Disposal Sites
Jun 87 Phase II Stage 2, Final Confirmation/
Quantification Report, Vol I of II
Jun 87 Phase II Stage 2, Final Confirmation/
Quantification Report, Vol II of II
03 Jun 87 Assembly California Legislature Letter
to Base on Subjects Discussed at Toxic
Contamination Cleanup Meeting
12 Jun 87 Base Letter to Technical Advisory
Committee Members on Initial
Coordination Meeting
24 Jun 87 EPA Letter to Base on AC&W Site and
Questions Raised at the Technical
Advisory Group Meeting
27 Jun 87 Memo for Record on Technical Advisory
Group Meeting
30 Jun 87 Base Letter to USAF OEHL/ECQ on
Landfill Gas Testing
17 Jul 87 Base Letter to County Air Pollution
Control District on Proposed Gas
Testing Plan
Karoly, B T 65
California Department of
Health Services
Curran, James P, Capt 70
USAF Hosp/SGPB
Skelton, Eric P 72
Sacramento County
Air Pollution
Control District
Aerovironment Inc. 73
Aerovironment Inc. 74
Connelly, Lloyd G 75
California
Legislative Assembly
Johnson, Bruce R, Col 76
323 ABG/CC
Martyn, Kathleen 78
EPA Region IX
Curran, James P, Capt 79
USAF Hosp/SGPB
Curran, James P, Capt 80
USAF Hosp/SGPB
Johnson, Bruce R, 81
323 ABG/CC
RLTC-98/ES/392000I.AWS
A-4
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or AR FILE
CORP. AUTHOR NUMBER
22 Jul 87
06 Aug 87
01 Sep87
14 Sep 87
06 Nov 87
06 Nov 87
IT Letter to HAZWRAP on Coordination Bradley, A Allen
Meeting Minutes IT Corp.
RI/FS, SOW
Base Letter HQ ATC/DEEV on
Approved Gas Testing Plan
EPA Letter to Base on Phase II Stage 2,
Final Confirmation/Quantification
Report
IT Letter to Martin Marietta on Meeting
with SCAPCD to Discuss Landfill Gas
Testing Program
Plan for Conducting a Geologic
Investigation
22 Dec 87 Minutes of 15 Dec 87 TRC Meeting
HAZWRAP
Thomas, Chester L
323 CES/DEEV
Zimpfer, Amy K
EPA Region IX
Bradley, A Allen
IT Corp.
HAZWRAP
Kosovac, Don E, Col
323 FTW/EM
06 Jan 88 Phase IVA, Draft Landfill Gas Testing IT Corp.
Work Plan
13 Jan 88 County Letter to Contractor Approving Skelton, Eric P
Draft Landfill Gas Testing Work Plan Sacramento County Air
Pollution Control District
27 Jan 88 Contractor Letter to County Providing Bradley, A Allen
Copy of Final Landfill Gas Testing Work IT Corp.
Plan
27 Jan 88 Final Landfill Gas Testing Work Plan IT Corp.
09Feb88 Minutes of 27 Jan 88 Mini TRC Meeting Kosovac, Don E, Col
323 FTW/EM
04 Apr 88 Draft IAG
EPA Region IX
84
86
89
92
95
96
98
100
101
102
103
104
133
RL/8-98/ES/392000I.AWS
A-5
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or AR FILE
CORP. AUTHOR NUMBER
14 Apr 88 Minutes of 22 Mar 88 TRC Meeting
30 Jun 88 Minutes of 30 Jun 88 TRC Meeting
Kosovac, Don E, Col
323 FTW/EM
135
Blank, Richard A, LtCol 142
323 FTW/EM
Jul 88 Landfill Gas Testing Report for Eight IT Corp.
Sites
26 Jul 88 Draft FFA
Nov 88 RI/FS, Draft Site Inspection Report
30 Nov 88 Minutes of 6 Oct 88 TRC Meeting
06 Mar 89 Minutes of 12 Jan 89 TRC Meeting
20 Mar 89 Internal Base Letter Concerning Public
Review Committee Meeting
Apr 89 Mather AFB Community Relations Plan
01 May 89 Minutes of 6 Apr 89 TRC Meeting
10 Jul 89 Transcript of 10 Jul 89 TRC Meeting
20 Jul 89 Minutes of 10 Jul 89 TRC Meeting
Oct 89 RI/FS, Draft Site Inspection Report
03 Oct 89 Transcript of 3 Oct 89 TRC Meeting
EPA Region IX
IT Corp.
Blank, Richard A, LtCol
323 FTW/EM
143
465
155
156
Blank, Richard A, LtCol 163
323 FTW/EM
Wimberly, M Cathryn 164
323 FTW/PA
Wimberly, Cathryn 903
323rd Flying Training
Wing, Public Affairs
Blank, Richard A, LtCol 170
323 FTW/EM
Parks, Nadine J 177
Peters Shorthand
Reporting Corp.
Blank, Richard A, LtCol 178
323 FTW/EM
IT Corp. 187
Peters, Ronald J 188
Peters Shorthand
Reporting Corp.
RL/8-98/ES/.192000 LAWS
A-6
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or AR FILE
CORP. AUTHOR NUMBER
18 Oct 89 CVRWQCB Letter to Base Providing
Comments on SWAT Report
Nov 89 RJ/FS, Draft Work Plan for
Investigations at Identified Sites, Vol
I of IV
Matteoli, Robert J 189
California Regional Water
Quality Control Board
IT Corp. 190
Nov 89
Nov 89
Nov 89
RI/FS, Draft Sampling and Analysis Plan IT Corp.
for Investigations at Identified Sites,
Vol II of IV
RI/FS, Draft Quality Assurance Project
Plan for Investigations at Identified
Sites, Vol III of IV
RI/FS, Draft Health and Safety Plan for
Investigations at Identified Sites, Vol
IV of IV
13 Nov 89 Minutes of 3 Oct 89 TRC Meeting
IT Corp.
IT Corp.
Blank, Richard A, LtCol
323 FTW/EM
191
192
193
195
29 Nov 89 CVRWQCB Letter to CDHS Providing
Review Comments on RI/FS Draft Site
Inspection Report
30 Nov 89 Transcript of 30 Nov 89 TRC Meeting
Dec 89 Mather AFB Community Relations Plan
01 Dec 89 CDHS Letter to Base Providing Comments
on RI/FS Draft Site Inspection Report
Matteoli, Robert J 198
California Regional Water
Quality Control Board
Parks, Nadine J 199
Peters Shorthand
Reporting Corp.
Wimberly, Cathryn 913
323 Flying Training
Wing, Public Affairs
Landis, Anthony J 200
California Department
of Health Services
R178-98/ES/392000I .AWS
A-7
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
ARFILE
NUMBER
03 Jan 90 CVRWQCB Letter with Review
Comments to DTSC on Draft RJ/FS
Work Plan
12 Jan 90 EPA Letter to MAJCOM Transmitting
Review Comments on the Nov 89 RI/FS
Draft Work Plans
16 Jan 90 Dept. of Health Services review
comments on Draft Workplan for RI/FS
at the Group 2 Sites
16 Jan 90 CDHS Letter to Base Transmitting
Comments on Nov 89 RI/FS Draft Work
Plans for Identified Sites (Group 2
Sites)
16 Jan 90 Internal CVRWQCB Memo Providing
Review Comments on RI/FS Draft
Sampling and Analysis Plan for
Identified Sites
18 Jan 90 Dept. of Health Services' additional
comments on Draft Workplan for RI/FS
for Group 2 Sites
30 Jan 90 Transcript of 30 Jan 90 TRC Meeting
14 Feb 90 EPA Letter to Base Transmitting
Comments on Draft Final CRP
07 Mar 90 Minutes of 30 Jan 90 TRC Meeting
08 Mar 90 Transcript of 8 Mar 90 TRC Meeting
Matteoli, Robert J 655
California Regional Water
Quality Control Board
Chesnutt, John D 202
EPA Region IX
Landis, Anthony J 1068
California Department
of Health Services
Landis, Anthony J 203
California Department
of Health Services
Mosbacher, Michael H 204
California Regional Water
Quality Control Board
Billington, Tracie L 1067
California Department
of Health Services
Parks, Nadine J 206
Peters Shorthand
Reporting Corp.
Chesnutt, John D 207
EPA Region IX
Blank, Richard A, LtCol 212
323 FTW/EM
Peters, Ronald J 213
Peters Shorthand
Reporting Corp.
RL/8-98/ES/392000I.AWS
A-8
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or AR FILE
CORP. AUTHOR NUMBER
23 Mar 90 Minutes of 8 Mar 90 Project
Managers Meeting
Apr 90 RI/FS, Draft Final Work Plan, Vol I of
IV, Group 2 Sites
Apr 90 RI/FS, Draft Final Sampling and
Analysis Plan, Vol II of IV, Group 2
Sites
Apr 90 RI/FS, Draft Final Quality Assurance
Project Plan, Vol III of IV, Group 2
Sites
Apr 90 RI/FS, Draft Final Health and Safety
Plan, Vol IV of IV, Group 2 Sites
18 Apr 90 CDHS Letter to Base Concerning
Recommendation for Stipulated Penalties
for Group 2 Sites Work Plan
25 Apr 90 MAJCOM Letter to Regulators
Transmitting Background Data on No
Further Action Decision Documents,
LF-01, FT-08, FT-09, FT-10, RW-16,
WP-17,OT-21,OT-22
10 May 90 Transcript of 10 May 90 TRC Meeting
17 May 90 CDHS Letter to Base Concerning
Finalization of RI/FS Draft Final Work
Plans, Group 2 Sites
21 May 90 EPA Letter to Base Concerning RI/FS
Draft Final Work Plans, Group 2 Sites
25 May 90 Minutes of 10 May 90 TRC Meeting
Blank, Richard A, LtCol
323 FTW/EM
IT Corp.
IT Corp.
IT Corp.
IT Corp.
Diebert, Donn
California Department
of Health Services
Wentz, George
HQ ATC/DEEV
McNulty, Bernadette
Peters Shorthand
Reporting Corp.
Landis, Anthony J
California Department
of Health Services
Chesnutt, John D
EPA Region IX
Blank, Richard A, LtCol
323 FTW/EM
214
215
216
217
218
221
222
223
224
225
451
FU78-98/ES/392000I .AWS
A-9
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
AR FILE
NUMBER
01 Jun90
20 Jun 90
22 Jun 90
Jul90
Jul90
Aug90
Aug90
02 Aug 90
31 Aug 90
06 Sep 90
!9Sep90
CVRWQCB Letter to CDHS Providing
Comments on No Further Action Decision
Documents, LF-01, FT-08, FT-09, FT-10,
RW-16, WP-17, OT-21, OT-22
CDHS Letter to Base Providing Comments
on No Further Action Decision
Documents, LF-01, FT-08, FT-09, FT-10,
RW-16, WP-17, OT-21, OT-22
EPA Letter to Base Providing Comments
on No Further Action Decision
Documents, LF-01, FT-08, FT-09, FT-10,
RW-16, WP-17, OT-21, OT-22
No Further Action Decision Document,
FT-08
No Further Action Decision Document,
FT-10
No Further Action Decision Document,
WP-17
RJ/FS, Final Site Inspection Report
Transcript of 2 Aug 90 TRC Meeting
Mosbacher, Michael H 226
California Regional Water
Quality Control Board
Billington, Trade L 227
California Department of
Health Services
Chesnutt, John D
EPA Region IX
323 FTW/EM
323 FTW/EM
323 FTW/EM
IT Corp.
Parks, Nadine J
Peters Shorthand
Reporting Corp.
CDHS Letter to Base Providing Comments Diebert, Donn
on FS Draft Work Plan, AC&W Site, and California Department of
RJ/FS QAPP Addendum, Group 2 and Health Services
AC&W Sites
Minutes of 2 Aug 90 TRC Meeting
Blank, Richard A, LtCol
323 FTW/EM
CDHS Letter to Base Providing Comments Wang, David
on RI/FS Solid Waste Water Quality California Department
Assessment Test, Draft Project Plans of Health Services
Addendum, Group 2 Sites
228
233
234
249
253
254
256
257
258
RL/8-98/ES/392000 LAWS
A-10
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or AR FILE
CORP. AUTHOR NUMBER
19 Sep 90 EPA Letter to Base Providing Comments
on RI Draft Work Plan Addendum,
Group 2 Sites
23 Oct 90 Transcript of 23 Oct 90 TRC Meeting
25 Oct 90 Base Memo to MAJCOM Concerning
Regulatory Comments on IRP Decision
Documents
Nov 90 RI/FS, Solid Waste Water Quality
Assessment Test, Draft Final Project
Plans Addendum, Group 2 Sites
08 Nov 90 Memorandum Summarizing Regulators
Review Comments on RI/FS Work Plan,
Group 2 Sites
09 Nov 90 MAJCOM Letter to EPA Transmitting No
Further Action Decision Documents and
Response to Regulatory Comments
09 Nov 90 MAJCOM Letter to CDHS Transmitting
No Further Action Decision Documents
and Response to Regulatory Comments
15 Nov 90 Transcript of 15 Nov 90 TRC Meeting
19 Nov 90 Minutes of 23 Oct 90 TRC Project
Managers Meeting
28 Nov 90 CDHS Letter to Base Concerning Final
Site Inspection Report and FS Draft
Final Work Plan, AC&W Site
29 Nov 90 Minutes of 15 Nov 90 TRC Meeting
Chesnutt, John D 259
EPA Region IX
Parks, Nadine J 264
Peters Shorthand
Reporting Corp.
Hughes, William T 266
OpTech c/o 323 FTW/EM
IT Corp. 268
323 FTW/EM 364
Sizemore, Daniel L, LtCol 270
HQ ATC/DEEV
Sizemore, Daniel L, LtCol 271
HQ ATC/DEEV
Parks, Nadine J 272
Peters Shorthand
Reporting Corp.
Blank, Richard A, LtCol 274
323 FTW/EM
Wang, David 275
California Department
of Health Services
Blank, Richard A, LtCol 276
323 FTW/EM
RL/8-98/ES/392000I.AWS
A-ll
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or AR FILE
CORP. AUTHOR NUMBER
19 Dec 90 EPA Letter to Base Providing
Conditional Approval of Draft Final
Project Plans Addendum for Group 2
. Sites
Chesnutt, John D
EPA Region IX
279
26 Dec 90 CDHS Letter to Base Approving Draft Wang, David 280
Final Project Plans Addendum for Group California Department
2 Sites of Health Services
.30 Jan 91 Transcript of 30 Jan 91 TRC Meeting
14 Feb 91 Minutes of 30 Jan 91 TRC Project
Managers Meeting
15 Feb 91 CVRWQCB Letter to Base Transmitting
Comments on Draft Final Project Plans
Addendum, Group 2 Sites
28 Mar 91 Transcript of 28 Mar 91 TRC Meeting
15 Apr 91 Minutes of 28 Mar 91 TRC Meeting
21 May 91 Transcript of 21 May 91 TRC Meeting
18 Jun 91 Minutes of 21 May 91 TRC Meeting
25 Jun 91 Transcript of 25 Jun 91 Project
Managers' Meeting
25 Jul 91 Minutes of 25 Jul 91 Project Managers
Meeting
Parks, Nadine J 286
Peters Shorthand
Reporting Corp.
Blank, Richard A, LtCol 288
323 FTW/EM
Mosbacher, Michael H 289
California Regional Water
Quality Control Board
Parks, Nadine J 296
Peters Shorthand
Reporting Corp.
Blank, Richard A, LtCol 299
323 ABG/EM
Parks, Nadine J 306
Peters Shorthand
Reporting Corp.
Blank, Richard A, LtCol 314
323 ABG/EM
Parks, Nadine J 315
Peters Shorthand
Reporting Corp.
Blank, Richard A, LtCol 324
323 ABG/EM
RU8-98/ES/392000I .AWS
A-12
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or AR FILE
CORP. AUTHOR NUMBER
20 Aug 91 Transcript of 20 Aug 91 TRC Meeting
Sep91
Sep91
Sep91
Sep91
17Sep91
17Sep91
24Oct91
06Nov91
12Nov91
20Nov91
20Nov91
RI, Draft Work Plan, Vol I of IV, Group
3 Sites
RI, Draft Sampling and Analysis Plan,
Vol II of IV, Group 3 Sites
RI, Draft Quality Assurance Plan, Vol
III of IV, Group 3 Sites
RI, Draft Health and Safety Plan, Vol
IV of IV, Group 3 Sites
Minutes of 20 Aug 91 TRC Meeting
DTSC Letter to Base Transmitting
Summary of State and Local ARARs
Minutes of 25-26 Sep 91 Project
Managers Meeting
DTSC Letter to Base Providing
Comments on Draft CRP
Parks, Nadine J
Peters Shorthand
Reporting Corp.
IT Corp.
IT Corp.
IT Corp.
IT Corp.
Billington, Trade L
California Department of
Toxic Substances Control
Blank, Richard A, LtCol
323 FTW/EM
Billington, Tracie L
California Department of
Toxic Substances Control
EPA Letter to Base Providing Comments Moore, Katherine L
on QAPP, Group III Sites EPA Region IX
DTSC Letter to Base Transmitting Billington, Tracie L
Comments on RI/FS Project Plans, Group California Department of
3 Sites Toxic Substances Control
CVRWQCB Letter to Base Providing
Comments on Draft Work Plan and
Sampling and Analysis Plan for Group 3
Sites
330
332
333
334
335
Blank, Richard A, LtCol 341
323 FTW/EM
342
350
353
354
355
Mosbacher, Michael H 356
California Regional Water
Quality Control Board
RU8-98/ES/392000I.AWS
A-13
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or AR FILE
CORP. AUTHOR NUMBER
21 Nov 91 Minutes of 21 Nov 91 TRC Meeting
03 Dec 91 Minutes of 21 Nov 91 TRC Meeting
Jan 92 Community Relations Plan
08 Jan 92 EPA Letter to Base on Review of
Background Soils Sampling Strategy
08 Jan 92 U.S. EPA's comments on Background
Soils Sampling Strategy
23 Jan 92 Minutes of 9 Jan 92 RPM Meeting
20 Feb 92 EPA Letter to Base on Review of Draft
Final Group 3 Work Plan and Sample and
Analysis Plan
02 Mar 92 CVRWQCB Letter to Base Concerning
of Final Work Plan for Group 3 Sites
11 Mar 92 Transcript of 11 Mar 92 TRC Meeting
27 Mar 92 Minutes of 11 Mar 92 RPM Meeting
27 Mar 92 Minutes of 11 Mar 92 TRC Meeting
06 May 92
27 May 92
Bailey, Doris M 351
Peters Shorthand
Reporting Corp.
Blank, Richard A, LtCol 360
323 FTW/EM
IT Corp. 368
Moore, Katherine L 374
EPA Region IX
Moore, Katherine L 890
EPA Region IX
Blank, Richard A, LtCol 377
323 FTW/EM
Moore, Katherine L 382
EPA Region IX
Vorster, Antonia K J 390
California Regional Water
Quality Control Board
Nicol, Janet H 395
Peters Shorthand
Reporting Corp.
Blank, Richard A, LtCol 399
323 FTW/EM
Blank, Richard A, LtCol 400
323 FTW/EM
EPA Letter to Base on Review of RI,
Draft Group 2 Report
Moore, Katherine L
EPA Region IX
413
California Integrated Waste Management Zielinski, Tamara 855
Board comments on Group 2 RI California Integrated Waste
Management Board
RU8-98/ES/392000I .AWS
A-14
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or AR FILE
CORP. AUTHOR NUMBER
Jun 92 Draft Work Plan, Additional Field
Investigation, Soils and Groundwater
OU,VolIofIV
Jun 92 Draft SAP, QAPP, and Health and Safety
Plan for Additional Field Investigation
at Soils and Groundwater OU, Vol II,
III, and IV of IV
03 Jun 92 Minutes of 3 Jun 92 TRC Meeting
Battelle
Environmental
Management Operations
Battelle
Environmental
Management Operations
Blank, Richard A, LtCol
323 FTW/EM
421
422
15 Jun 92 DTSC Letter to Base with Comments on Billington, Tracie L
RI, Group 2 Report California Department
of Toxic Substances Control
06 Jul 92 Minutes of 3 Jun 91 TRC Meeting
20 Jul 92 EPA Letter to Base on Review of
Additional Field Investigation Plan,
OU-2 and OU-3
28 Jul 92 Transcript of 28 Jul 92 TRC Meeting
10 Aug 92 DTSC Letter to Base on Additional
Field Investigation Work Plan
Blank, Richard A, LtCol
323 FTW/EM
Moore, Katherine L
EPA Region IX
Medeiros, Vicki L
Peters Shorthand
Reporting Corp.
Billington, Tracie L
California Department of
Toxic Substances Control
423
432
434
439
444
449
28 Aug 92 CVRWQCB Letter to Base on Draft
Additional Field Investigation Work
Plan for Soil and Groundwater OUs
28 Sep 92 HQ ATC/DEEV Letter to DTSC on TRC
Meeting
28 Sep 92 HQ ATC/DEEV Letter to EPA on TRC
Meeting
Mosbacher, Michael H 452
California Regional Water
Quality Control Board
Pehlivanian, William 466
HQ ATC/DEEV
Pehlivanian, William 467
HQ ATC/DEEV
R178-98/ES/392000I .AWS
A-15
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
AR FILE
NUMBER
29 Sep 92
30 Sep 92
Oct92
Oct92
IT Letter to Battelle on Draft Work
Plan, Additional Field Investigation,
Soils and Groundwater OUs, Vol I, II,
and III
Robinson, Dennis M
IT Corp.
469
Additional Field Investigation, SAP;
QAPP; Health and Safety Plan,
Vol II, HI, and IV of IV, OU-2 and OU-3
Base Letter to TRC Members on Agenda Blank, Richard A, LtCol
for the 8 Oct Meeting 323 FTW/EM
Additional Field Investigation, Work Plan, IT Corp.
Vol I of IV, OU-2 and
IT Corp.
Nicol, Janet H
Peters Shorthand
Reporting Corp.
Moore, Katherine L
EPA Region IX
IT Corp.
Moore, Katherine L
EPA Region IX
Pearson, J Lawrence
California Regional Water
Quality Control Board
Moore, Katherine L
EPA Region IX
IT Corp.
08 Oct 92 Transcript of 8 Oct 92 TRC Meeting
09 Oct 92 EPA Letter to Base Transmitting
Comments on RJ Report, Group 2 Sites
14 Oct 92 Contractor Response to Regulators
Comments on Field Investigation Project
Plans
12 Nov 92 EPA Letter to Base Transmitting
Comments on Chapter 6 and Missing
Appendices, RI Report, Group 2 Sites
18 Nov 92 CVRWQCB Notice of Public Hearing
Concerning Invoking A Formal Dispute
Over Soil Cleanup
18 Nov 92 EPA Letter to Base Transmitting
Comments on Draft Final Soils and
Groundwater OU Additional Field
Investigation Work Plan, SAP, and QAPP
18 Nov 92 Focused FS, Work Plan, OU-2
and OU-3
470
472
473
474
476
477
484
485
486
488
RU8-98/ES/392000 LAWS
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or AR FILE
CORP. AUTHOR NUMBER
24 Nov 92 Base Letter to CVRWQCB Transmitting
Statement to be Entered into Hearing
Minutes
Blank, Richard A, LtCol
323 FTW/EM
489
24 Nov 92 DTSC Letter to MAJCOM Invoking Wang, David
Dispute Resolution on Draft Final "...Soils California Department of
and Groundwater OU Additional Field Toxic Substances Control
Investigation..."
27 Nov 92 Minutes of 8 Oct 92 TRC Meeting
Blank, Richard A, LtCol
323 FTW/EM
490
491
27 Nov 92 Minutes of 8/9 Oct 92 RPM Meeting
30 Nov 92 DTSC Letter to Base Transmitting
Comments on Comprehensive Baseline
Risk Assessment, Draft Work Plan,
Sep92
01 Dec 92 Base Letter to RPMs and TRC Members
Providing Agenda for 9 and 10 Dec 92
Meetings
09 Dec 92 Minutes of 1 Dec 92 Meeting to Resolve
the Additional Field Investigation Work
Plan Dispute
10 Dec 92 Transcript of 10 Dec 92 TRC Meeting
17 Dec 92 Notification of invocation of
Resolution 92-236 by RWQCB and
initiating formal dispute concerning
soil cleanup levels
24 Dec 92 DTSC Comments on Background Soils
Sampling Strategy
Blank, Richard A, LtCol
323 FTW/EM
492
Billington, Tracie L 493
California Regional Water
Quality Control Board
Blank, Richard A, LtCol
323 FTW/EM
494
Mosbacher, Michael H 496
California Regional Water
Quality Control Board
Medeiros, Vicki L 499
Peters Shorthand
Reporting Corp.
Crooks, William 1101
California Regional Water
Quality Control Board
Billington, Tracie L 891
California Department of
Toxic Substances Control
RL/8-98/ES/392000I.AWS
A-17
-------
DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
AR FILE
NUMBER
30 Dec 92 CVRWQCB comments on Background
Soil Sampling Strategy
Jan 93 Work Plan, Comprehensive Baseline
Risk Assessment
Jan 93 Draft No Further Action Decision
Document, OT-23
19 Jan 93 IT Letter with Comments to Base on
Draft Final Work PJan, Comprehensive
Baseline Risk Assessment
26 Jan 93 SAF/MIQ Letter to EPA on Dispute
Resolution Under the Federal Facility
Agreement
25 Mar 93 Transcript of 25 Mar 93 RPM Meeting
26 Mar 93 Transcript of 26 Mar 93 TRC Meeting
Apr 93 RJ Report, Volume 1 of 12,
Group 2 Sites
Apr 93 RI Report, Volume 2 of 12,
Group 2 Sites
Apr 93 RI Report, Volume 3 of 12,
Group 2 Sites
Apr 93 RI Report, Volume 4 of 12,
Group 2 Sites
Apr 93 RI Report, Volume 5 of 12,
Group 2 Sites
Mosbacher, Michael H 892
California Regional Water
Quality Control Board
IT Corp. 506
IT Corp. 507
Dove, F Harvey 514
IT Corp.
Vest, Gary D 515
Deputy Assistant
Secretary of the Air Force
Bailey, Doris M 534
Peters Shorthand
Reporting Corp.
Nicol, Janet H 535
Peters Shorthand
Reporting Corp.
Battelle Environmental 1624
Management Operations
Battelle Environmental 1625
Management Operations
Battelle Environmental 1626
Management Operations
Battelle Environmental 1627
Management Operations
Battelle Environmental 1628
Management Operations
RU8-98/ES/392000I .AWS
A-18
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
AR FILE
NUMBER
Apr 93 RI Report, Volume 6 of 12,
Group 2 Sites
Apr 93 RI Report, Volume 7 of 12,
Group 2 Sites
Apr 93 RI Report, Volume 8 of 12,
Group 2 Sites
Apr 93 RI Report, Volume 9 of 12,
Group 2 Sites
Apr 93 RI Report, Volume 10 of 12,
Group 2 Sites
Apr 93 RI Report, Volume 11 of 12,
Group 2 Sites
Apr 93 RI Report, Volume 12 of 12,
Group 2 Sites
16 Apr 93 CVRWQCB Letter to Base Concerning
Additional Field Investigation
Consensus Statement
03 May 93 Request for Historical Data on use of
Pesticides and Herbicides
16 May 93 U.S.-EPA's review of Comprehensive
Baseline Risk Assessment's 1) Human
Health Risk Assessment and 2)
Ecological Risk Assessment
16 May 93 EPA Draft Comments on Human Health
Risk Assessment of CBRA
18 May 93 Draft Comments on Draft Comprehensive
Baseline Risk Assessment
Battelle Environmental 1629
Management Operations
Battelle Environmental 1630
Management Operations
Battelle Environmental 1631
Management Operations
Battelle Environmental 1632
Management Operations
Battelle Environmental 1633
Management Operations
Battelle Environmental 1634
Management Operations
Battelle Environmental 1635
Management Operations
Williams, Camilla 543
California Regional Water
Quality Control Board
Blank, Richard A, LtCol 873
323rd Flying Training Wing
Lowe, Debbie 1047
EPA Region IX
Serda, Sophia 546
EPA Region IX
Christopher, John P 547
California Department of
Toxic Substances Control
RU8-98/ES/3920001 .AWS
A-19
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
AR FILE
NUMBER
07 Jun 93 CVRWQCB Letter to Base Providing
Comments on Draft Final Work Plan,
Appendix A: Background Soils and
Groundwater Sampling Strategy
07 Jun 93 EPA Letter to Base Transmitting
Comments on Appendix A of Draft Final
Comprehensive Baseline Risk Assessment
Work Plan and Background Soils Sampling
Strategy
15 Jun 93 21 May 1993 Remedial Project Manager's
Meeting Minutes
28 Jun 93 Proposed Revision to Appendix D to
Federal Facility Agreement
30 Jun 93 EPA Letter to Base Concerning Extension
for Submittal of Focused FS Reports for
Groundwater/Comprehensive and
Soils OUs
Jul 93 Final Installation Restoration Program
Data Summary
Jul 93 Draft EE/CA Report, ST-20, ST-29, and
ST-32
07 Jul 93 DTSC Letter to Base on Draft Technical
Memorandum Group 3 Sites
09 Jul 93 EPA Letter with Comments to Base on
Draft Technical Memorandum Group 3
Sites
09 Jul 93 CVRWQCB Letter with Comments to
Base on Draft Technical Memorandum
Group 3 Sites
Taylor, James D
California Regional Water
Quality Control Board
Swarthout, Brian
EPA Region IX
553
AFBCA/OL-D
Smith, Charles H
AFBCA/OL-D
Swarthout, Brian
EPA Region IX
IT Corp.
IT Corp.
Strong, Kent
California Department of
Toxic Substances Control
Swarthout, Brian
EPA Region IX
Williams, Camilla
California Regional Water
Quality Control Board
554
958
875
561
915
563
564
567
568
RU8-98/ES/392000 LAWS
A-20
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
ARFILE
NUMBER
16Jul93
22 Jul 93
30 Jul 93
30 Jul 93
Aug93
10Aug93
16 Aug93
20 Aug 93
31 Aug 93
03 Sep 93
DTSC Letter to Base on Draft Final
Work Plan, Appendix A, Groundwater
and Soil Sampling
Strong, Kent
California Department of
Toxic Substances Control
RWQCB's letter regarding Draft Proposed Williams, Camilla
Plan for Landfill OU California Regional Water
Quality Control Board
CVRWQCB Letter to Base on Draft
Technical Memorandum Group 3 Sites
EPA Letter to Base on Draft Technical
Memorandum Group 3 Sites
Draft Final Work Plan, Comprehensive
Baseline Risk Assessment
DTSC Letter to Base on Draft Technical
Memorandum Group 3 Sites
DTSC Letter to Base on Draft Technical
Memorandum Group 3 Sites
27 July 1993 Remedial Project Manager
(BCT) Meeting Minutes
IT Letter to AFCEE/ESB on RPM and
TRC Meeting Minutes
IT Letter to Battelle on Response to
Regulator Comments on Technical
Memorandum for Group 3 Sites and
Addendum
Swarthout, Brian
EPA Region IX
IT Corp.
Strong, Kent
California Department of
Toxic Substances Control
Strong, Kent
California Department of
Toxic Substances Control
AFBCA/OL-D
Shafer, William C
IT Corp.
Robinson, Dennis M
IT Corp.
572
1079
Williams, Camilla 574
California Regional Water
Quality Control Board
575
580
576
577
957
579
581
22 Sep 93
CVRWQCB Letter to Base on Draft Final Williams, Camilla
Work Plan, Comprehensive Baseline Risk California Regional Water
Assessment Quality Control Board
582
RL/&-98/ES/392000 LAWS
A-21
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
ARFILE
NUMBER
24 Sep 93 EPA Letter to Base on Draft Final Work
Plan, Comprehensive Baseline Risk
Assessment
01 Oct 93 RWQCB's review comments on Draft
Engineering Evaluation/Cost Analysis
for Site 20,29, and 32
01 Oct 93 DTSC Letter with Comments to Base on
Draft EE/CA Report, ST-20, ST-29, and
ST-32
Swarthout, Brian 583
EPA Region IX
Williams, Camilla 586
California Regional Water
Quality Control Board
Strong, Kent 587
California Department of
Toxic Substances Control
04 Oct 93 DTSC Memorandum with Comments on Vest, Mark D
Draft EE/CA Report, ST-20, ST-29, and California Department of
ST-32 Toxic Substances Control
13 Oct 93 Transcript of 13 Oct 93 TRC Meeting
26 Oct 93 Management Action Plan
28 Oct 93 RWQCB's review of Draft Technical
Memorandum for Group 3 Sites
28 Oct 93 EPA Letter to Base on Draft Final
Technical Memorandum for Group 3 Sites
29 Oct 93 Investigation of Disposal Site East of
Facility 7080 and 7090, Site IOC
04 Nov 93 DTSC Letter to Base on Draft Technical
Memorandum Group 3 Sites
Nicol, Janet H
Peters Shorthand
Reporting Corp.
Radian Corp.
Williams, Camilla
California Regional Water
Quality Control Board
Swarthout, Brian
EPA Region IX
AFBCA/OL-D
Strong, Kent
California Department of
Toxic Substances Control
588
589
392
1066
664
1081
595
23 Nov 93 DTSC Letter to Base on Establishment
of Restoration Advisory Board
29 Nov 93 SOW for Contaminated Soil Removal,
ST-20
Wang, David
California Department of
Toxic Substances Control
599
US Army Corps of 666
Engineers - Omaha District
RL«-98/ES/392000l .AWS
A-22
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
AR FILE
NUMBER
Dec 93 Basewide Environmental Baseline Survey Department of the
Air Force
Dec 93 Final EE/CA Report, ST-20, ST-29, and IT Corp.
ST-32
955
603
01 Dec 93 EPA Letter to AFCEE Providing
Comments on Preliminary Final
Environmental Baseline Survey
06 Dec 93 DTSC Letter to Base Providing
Comments on the Background
Inorganic Soils Report
08 Dec 93 CVRWQCB Letter to Base Providing
Comments on the Background Inorganic
Soils Report
Swarthout, Brian 606
EPA Region IX
Strong, Kent 609
California Department of
Toxic Substances Control
Williams, Camilla 611
California Regional
Water Quality
Control Board
29 Dec 93
06 Jan 94
10 Jan 94
U.S. EPA's review comments on Draft
Final Engineering Evaluation/Cost
Analysis for Site 20, 29, and 32
Earth Technology's Giant Garter Snake
Survey
Swarthout, Brian
EPA Region IX
Hildreth, Jane
Earth Technology Corp.
DTSC Letter to Base Transmitting Strong, Kent
Comments on Draft Final EE/CA, ST-20, California
ST-29, ST-32 Department of Toxic
Substances Control
12 Jan 94 Removal of Hydrant Fueling System
18 Jan 94 EPA Letter with Review Comments to
AFBDA/NW-D on EE/CA, ST-20,
ST-29 and ST-32
Erikson, Susan
Sacramento County
Environmental
Management Department
Lowe, Debbie
EPA Region IX
1053
1052
618
1096
671
RU8-98/ES/392000 LAWS
A-23
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
AR FILE
NUMBER
19 Jan 94
24 Jan 94
Feb94
State's concurrence with Final
Engineering Evaluation and Cost
Analysis (EE/CA)
13 January 1994 Restoration Advisory
Board (RAB) Meeting Minutes
Strong, Kent
California
Department of Toxic
Substances Control
Smith, Charles H
AFBCA/OL-D
1051
Proposed Plan for Environmental Cleanup AFBCA/OL-D
at Three Sites on Mather Air Force Base
01 Feb 94 State's comments on Draft Proposed Plan
for Environmental Cleanup at Three
Sites (20,29, and 32)
01 Feb 94 Public Notice for 1) Remediation of
Landfill Sites 1-6, 2) Interim Actions
at Sites 20, 29, and 32, and 3) Use of
treated groundwater for irrigation
01 Feb 94 DTSC Letter to Base on Draft Proposed
Plan for Environmental Cleanup, ST-20,
ST-29 and ST-32
Strong, Kent
California
Department of Toxic
Substances Control
AFBCA/OL-D
Strong, Kent
California
Department of Toxic
Substances Control
619
620
1050
1093
672
01 Feb 94 DTSC Letter to Base on Environmental
Baseline Survey
15 Feb 94 Department of Health Services comments
on Basewide Environmental Baseline
Survey
15 Feb 94 Transcript of 15 Feb 94 Public Hearing
Strong, Kent
California
Department of Toxic
Substances Control
Williams, Camilla
California Regional
Water Quality
Control Board
Nicol, Janet H
Peters Shorthand
Reporting Corp.
673
1048
623
RL/8-98/ES/392000I .AWS
A-24
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or AR FILE
CORP. AUTHOR NUMBER
15Feb94
04 Mar 94
23 Mar 94
16 May 94
CVRWQCB Letter with Comments to
DTSC on Environmental Baseline
Survey
IT Corp Letter to Battelle on
Preliminary Draft Removal Action
Memorandum, ST-20, ST-29 and ST-32
Williams, Camilla
California Regional
Water Quality
Control Board
Robinson, Dennis M
IT Corp.
674
CVRWQCB Letter to Base Concerning No Williams, Camilla
Further Action Sites, and Additional California Regional Water
Field Investigation Dispute Quality Control Board
State's request for Federal Facility Strong, Kent
Agreement Extension to Draft California
Comprehensive Baseline Risk Assessment Department of Toxic
Substances Control
18 May 94 State's comments on Draft Comprehensive Strong, Kent
Baseline Risk Assessment California
Department of Toxic
Substances Control
676
629
1046
1045
19 May 94 EPA Letter to Base on Draft Removal Lowe, Debbie
Action Memorandum, ST-20, ST-29 and EPA Region IX
ST-32
20 May 94 State's comments on the Preliminary
Draft Removal Action Memorandum
14 Jun 94 IT Corp.'s surrogate toxicity values
for Comprehensive Baseline Risk
Assessment (COBRA)
16 Jun 94 IT Corp.'s Strawman Outline for
Additional Ecological Risk Assessment
sampling
17 Jun 94 U.S.-EPA's summary of Comprehensive
Baseline Risk Assessment revisions
Strong, Kent
California
Department of Toxic
Substances Control
Dove, Harvey
IT Corp.
Dove, Harvey
IT Corp.
Lowe, Debbie
EPA Region IX
679
1044
1043
1042
1041
RU8-98/ES/392000I.AWS
A-25
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
AR FILE
NUMBER
23 Jun 94 CVRWQCB Letter to DTSC Providing
Comments on Draft Additional Field
Investigation Report
23 Jun 94 Draft Groundwater and Soil Operable
(OU-2, OU-3) Units Additional Field
Investigation Remedial Investigation
Report
24 Jun 94 DTSC Letter to Base Providing
Comments on Draft RI Additional Field
Investigation Report
24 Jun 94 EPA Letter to Base Providing Comments
on Draft RI Additional Field
Investigation Report
29 Jun 94 U.S. EPA's comments on the Strawperson
Outline for Additional Ecological
Sampling
Jul 1994 RAB comments on Proposed Plan for
Landfill ROD, RAM, Draft
Comprehensive Baseline Risk Assessment
14 Jul 94 U.S. EPA's suggested inclusions to
program strategies of Additional Field
Investigation, Focused Feasibility
Study, and Risk Assessment reports
18 Jul 94 Air Force's request for extension of
Draft Final Comprehensive Baseline
Risk Assessment Report
18 Jul 94 Note on U.S. EPA's program strategy
letter involving Additional Field
Investigation, Focused Feasibility
Study, and Risk Assessment Reports
Taylor, James D
California Regional
Water Quality
Control Board
Taylor, James
California Regional
Water Quality
Control Board
Strong, Kent
California
Department of Toxic
Substances Control
Lowe, Debbie
EPA Region IX
Lowe, Debbie
EPA Region IX
RAB members
Lowe, Debbie
EPA Region IX
Wong, Anthony
AFBCA/OL-D
Hughes, William
Operational
Technologies Corp
129
714
139
281
1040
995
1038
1032
1039
RU8-98/ES/392000I .AWS
A-26
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
ARFILE
NUMBER
19 Jul 94 Request for Extension for Draft Final
Removal Action Memorandum
26 Jul 94 IT Corp Memo Transmitting Comments
and Responses to the Draft Additional
Field Investigation
Aug 94 RI, Final Additional Field
Investigation Report, Vol I of VI, Text
and Appendices A-B
Aug 94 RI, Final Additional Field
Investigation Report, Vol II of VI,
Appendix C
Aug 94 RI, Final Additional Field
Investigation Report, Vol III of VI,
Appendices D-F
Aug 94 RI, Final Additional Field
Investigation Report, Vol IV of VI,
Appendices G-L
Aug 94 RI, Final Additional Field
Investigation Report, Vol V of VI,
Appendix M
Aug 94 RI, Final Additional Field
Investigation Report, Vol VI of VI,
Appendix M (Cont'd)
18 Aug 94 Draft Final Mather Baseline Risk
Assessment Consensus Statement for
Delivery of Draft Final Report and
evolution of name from Comprehensive
Baseline Risk Assessment
Wong, Anthony 1036
AFBCA/OL-D
IT Corp. 681
IT Corp. 632
IT Corp. 633
IT Corp. 634
IT Corp. 635
IT Corp. 636
IT Corp. 637
Smith, Charles H., 1035
AFBCA/OL-D;
Lowe, Debbie,
EPA Region IX;
Strong, Kent,
California Department of
Toxic Substances Control
RL/8-98/ES/392000 LAWS
A-27
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
AR FILE
NUMBER
18Aug94
19 Aug 94
23 Aug 94
23 Aug 94
29 Aug 94
31 Aug 94
Sep94
Sep94
Sep94
Sep94
Sep94
AFBCA submits proposed revision to Wong, Anthony
Appendix D to accommodate Request for AFBCA/OL-D
Extension, Draft Final Comprehensive
Baseline Risk Assessment Report
981
Preliminary Summary Tables for
Comprehensive Baseline Risk
Assessment Revised Risk Estimates
Proposed Scope for Additional Field
Investigation
EPA Letter to DTSC on Removal Action
Memorandum, ST-20, ST-29 and ST-32
Course of Action to Finalize Removal
Action Memorandum for Sites 20,29,
and 32
EPA Letter to SWRCB on Proposed
ARARs, ST-20
Removal Action Memorandum, ST-20,
ST-29 and ST-32
Draft Final UST Removal and Fuel
Hydrant System Decommissioning
Report, Vol I of II
Draft Final UST Removal and Fuel
Hydrant System Decommissioning
Report, Vol II of II
IT Corp.
Wong, Anthony
AFBCA/OL-D
Lowe, Debbie
EPA Region IX
Wong, Anthony
AFBCA/OL-D
Estrada, Thelma K
EPA Region IX
IT Corp.
OGDEN
Environmental
and Energy Services
OGDEN
Environmental
and Energy Services
Draft Final UST Removal and Fuel OGDEN
Hydrant System Decommissioning Report, Environmental
Appendix A and B and Energy Services
Draft Final UST Removal and Fuel
Hydrant System Decommissioning
Report, Appendix C
OGDEN
Environmental
and Energy Services
794
1034
690
1033
692
703
704
705
706
707
R1V8-98/ES/3920001 .A WS
A-28
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
AR FILE
NUMBER
Sep94
02 Sep 94
09 Sep 94
12 Sep 94
28 Sep 94
28 Sep 94
04 Oct 94
21 Oct 94
Draft Final UST Removal and Fuel
Hydrant System Decommissioning
Report, Appendix D
OGDEN
Environmental
and Energy Services
DTSC Letter to EPA on Proposed ARARs, Small, Suzanne
ST-20 California
Department of Toxic
Substances Control
Sacramento Metropolitan Air Quality
Management District's Regulatory
Oversight of Remedial Activities at
Military Bases
Response to Agency Comments and
Revised Response to Comments on
the Removal Action Memorandum
23 Sep 94 Mather Baseline Risk Assessment
(MBRA) suggested changes and effects
on the Groundwater and Soil Operable
Unit Focused Feasibility Study
26 Sep 94 Camilla Williams replacement by James
Taylor, CVRWQCB
DeGuzman, Jorge
Sacramento County
Air Pollution
Control District
Marks, Barbara
IT Corp.
Lowe, Debbie
EPA Region IX
Vorster, Antonia
California Regional
Water Quality
Control Board
IT Corp Letter to AFCEE Transmitting Dove, F Harvey
Comments on Appendix J of Draft Mather IT Corp.
Baseline Risk Assessment
Draft Mather Baseline Risk Assessment
revised comment resolution
October 1994 BCT Meeting Minutes
Transmirtal of Revised Scope of Work
for Upcoming Additional Field
Investigation
Dove, F. Harvey,
Ph.D., P.H.
IT Corp.
AFBCA/OL-D
Smith, Charles H
AFBCA/OL-D
708
696
977
829
715
976
701
716
922
867
RL/8-98/ES/3920001 .AWS
A-29
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
AR FILE
NUMBER
17 Nov 94 Review Comments on Draft Quality
Project Plan for Mather Pipeline
Removal Projects
17 Nov 94 State's announcement of applicability
of Resolution 92-49
21 Nov 94 Mather Phase II Detailed Ecological
Risk Assessment: Proposed Tasks
Dec 94 Final Quality Project Plans for Fuel
Distribution System Pipeline Removal
and Abandonment-In-Place
07 Dec 94 Proposed Tasks for the Mather Phase II
Ecological Risk Assessments
21 Dec 94 Draft Petroleum Exclusion Language for
the Soil and Groundwater Operable Units
Focused Feasibility Study
21 Dec 94 Identification of ARARs
Jan 95
Jan 95
17 Jan 95
10 January 1995 BCT Meeting Minutes
Draft Health and Safety Plan for the
Mather Soils Management Area (OU-3)
Ogden 904
Environmental
and Energy Services
Strong, Kent 1060
California
Department of Toxic
Substances Control
Meyers-Schone, 1031
Linda
IT Corp.
OGDEN 693
Environmental
and Energy Services
Meyers-Schone, 1030
Linda
IT Corp.
Lowe, Debbie 1058
EPA Region IX
Strong, Kent 917
California Department
of Toxic Substances Control
AFBCA/OL-D 924
Montgomery Watson 720
U.S. EPA's comments on Draft Lowe, Debbie
Environmental Operation and Maintenance EPA Region IX
Plan for the Soil Bioremediation at the
Old RV Storage Area
1026
RL/8-98/ES/392000I .AWS
A-30
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
AR FILE
NUMBER
23 Jan 95
23 Jan 95
24 Jan 95
25 Jan 95
30 Jan 95
31 Jan 95
07 Feb 95
07 Feb 95
U.S. EPA's comments on the Quality
Program Plan, Vol. IV: Sampling and
Analysis Plan for Mather AFB Remedial
Action Contract
ARARs Identified by the Sacramento
Metropolitan Air Quality Management
District for the Groundwater Operable
Unit and Soil Operable Unit Focused
Feasibility Study
U.S. EPA's comments on the Draft
Quality Program Plan for Soil Treatment
at the Old RV Storage Area, Section 3,
Sampling and Analysis Plan
Lowe, Debbie
EPA Region IX
DeGuzman, Jorge
Sacramento
Metropolitan Air
Quality Management
District
Lowe, Debbie
EPA Region IX
1025
15 November 1994 BCT Meeting Minutes AFBCA/OL-D
30 November 1994 Restoration Advisory
Board (RAB) Meeting Minutes
Montgomery Watson's Meeting Notes for
10-11 January BCT Meeting
State's comments on Draft Technical
Plans for Site 20
Groundwater and Soils Operable Unit
(OU-2, OU-3) Focused Feasibility Study
State ARARs
10 Feb 95 Cover letter for State's comments on
Draft Technical Plans and Sampling and
Analysis Plan for Site 20
14 Feb 95 U.S. EPA's comments on Draft Technical
Plans and Quality Program Plans for
Site 20
Byrne, Ruth
AFBCA/OL-D
Scott, John
Montgomery Watson
Americas, Inc
Strong, Kent
California
Department of Toxic
Substances Control
Strong, Kent
California
Department of Toxic
Substances Control
Bernheisel, Paul
AFCEE/ERB
Lowe, Debbie
EPA Region IX
807
1024
724
937
1011
1010
732
1007
1009
RU8-98/ES/392000I.AWS
A-31
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
AR FILE
NUMBER
22 Feb 95 State's comments on Draft Environmental
Operation and Maintenance Plan for Soil
Bioremediation at the Old RV Storage
Area
23 Feb 95
24 Feb 95
08 Mar 95
14 Mar 95
17 Mar 95
20 Mar 95
27 Mar 95
30 Mar 95
12 Apr 95
U.S. EPA's comments on Draft Phase II
Ecological Risk Assessment Work Plan
Thelma Estrada, U.S. EPA's, comment
responses on the revised ARARs Table
for the Soil and Groundwater
Feasibility Study
Proposed Revisions to Site 20 Sample
Analysis Plan
08 February 1995 Restoration Advisory
Board (RAB) Meeting Minutes
Cleanup Criteria and Monitoring for
VOC's Discussion Paper for Draft
Groundwater and Soils Operable Unit
(OU-2, OU-3) Focused Feasibility Study
"White Paper" for Groundwater and Soil
Operable Units (OU-2, OU-3) Focused
Feasibility Study
Strong, Kent
California
Department of Toxic
Substances Control
Lowe, Debbie
EPA Region IX
Estrada, Thelma
EPA Region IX
Scott, John
Montgomery Watson
Americas, Inc
Byrne, Ruth
AFBCA/OL-D
Taylor, James
California Regional
Water Quality
Control Board
Wong, Tony
AFBCA/OL-D
1004
28 February 1995 BCT Meeting Minutes AFBCA/OL-D
State's comments on Soil Gas "White
Paper"
Solicitation of Applicable or Relevant
and Appropriate Requirements (ARARs)
for the Groundwater and Soil Operable
Units (OU-2, OU-3) Focused Feasibility
Study
Strong, Kent
California
Department of Toxic
Substances Control
Wong, Anthony
AFBCA/OL-D
1002
719
1000
938
741
742
925
1055
731
RL/8-98/ES/392000I.AWS
A-32
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
ARFILE
NUMBER
18 Apr 95 Draft Final Phase II Detailed
Ecological Risk Assessment Work Plan
for Groundwater and Soils OU
18 Apr 95 Draft Health and Safety Plan for the
Mather Soils Management Area (OU-3),
comments from AFBCA
16 May 95 U.S. EPA suggestions regarding Special
Status Plant, Wildlife, and Species
Assessment
26 May 95 Quality Program Plan for Mather AFB
Jun 95 Draft Final Technical Plan and Quality
Program Plan for Site 20
07 Jun 95 DTSC ARARs for the Groundwater and
Soil Operable Units (OU-2, OU-3)
Record of Decision
14 Jun 95 31 May - 01 June 1995 BCT Meeting
25 July 95 Minutes, and corrections to same
27 Jun 95 Air Force review of ARARs on Draft
Mather Groundwater and Soil Operable
Units (OU-2, OU-3) ROD
10 Jul 95 26 April 1995 Restoration Advisory
Board Meeting Minutes
12 Jul 95 Cal-EPA's and Regional Water Quality
Control Board's comments on the Draft
Remedial Investigation, Additional Site
Characterization for the Soil and
Groundwater Operable Units
IT Corp. 723
Smith, Charles H 764
AFBCA/OL-D
Lowe, Debbie 850
EPA Region IX
Montgomery Watson 923
Americas, Inc.
Montgomery Watson 781
Americas, Inc.
Strong, Kent 743
AFBCA/OL-D
Wong, Anthony C. 926
Smith, Charles H., Phd, P.E.
AFBCA
Rupe, Sam C., LtCol 751
Department of the
Air Force, Office of
the Regional Counsel/
Western Region
Byrne, Ruth 939
AFBCA/OL-D
Taylor, James 749
Regional Water
Quality Control Board
A-33
WTH, May 29, 1998
-------
DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
ARFILE
NUMBER
14 Jul 95 US-EPA request for extended review of
Remedial Investigation, Additional Site
Characterization, and Remedial Design
Support Draft Work Plan
21 Jul 95 US-EPA's comments on Draft Remedial
Investigation, Additional Site
Characterization and Remedial Design
Support Work for Soil and Groundwater
Operable Units
21 Jul 95 Dioxin and Furan Sampling Request in
the Draft Remedial Investigation,
Additional Site Characterization, and
Remedial Design Work Plan
24 Jul 95 19 July 1995 Restoration Advisory Board
Meeting Minutes
25 Jul 95 12-13 July 1995 BCT Meeting Minutes
28 Jul 95 EPA Request for Extension for Review
and Comment on Mather Baseline Risk
Assessment
28 Aug 95 RWQCB's Waste Discharge Requirements
for Soil Bioremediation at the Old RV
Storage Area
30 Aug 95 U.S. EPA's request for extension for
review and comment of Draft Final
Mather Baseline Risk Assessment
31 Aug 95 Approval of Extension for Review of
Draft Final Mather Baseline Risk
Assessment to 15 Sep 1995
05 Sep 95 Special-Status Plant and Wildlife
Species Assessment for Landfill Areas
Lowe, Debbie
EPA Region IX
Lowe, Debbie
EPA Region IX
748
Strong, Kent
California
Department of Toxic
Substances Control
Smith, Charles H.
AFBCA
Smith, Charles H.
AFBCA
Lowe, Debbie
EPA Region IX
Crooks, William
Regional Water Quality
Control Board
Lowe, Debbie
EPA Region IX
Smith, Charles H
AFBCA/OL-D
Sugnet & Associates
746
813
940
927
758
1072
836
771
849
A-34
WTH, May 29. 1998
-------
DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
ARFILE
NUMBER
07 Sep 95
07 Sep 95
12 Sep 95
29-30 August 1995 BCT Meeting Minutes Smith, Charles H.
AFBCA
14 Sep 95
18 Sep 95
19 Sep 95
29 Sep 95
Oct95
05 Oct 95
06 Oct 95
30 August 1995 Restoration Advisory
Board Meeting Minutes
State's request for extension for
review of the Draft Final Mather
Baseline Risk Assessment
AFCEE requests extension for delivery
of MBRA from HSC/PKVA
Revised Proposed Waste Discharge
Requirements (WDRs) for Soil
Bioremediation Unit
U.S. EPA approves extension request for
Draft Final Mather Baseline Risk
Assessment (MBRA)
27-28 September 1995 BCT Meeting
Minutes
Additional Site Characterization and
Remedial Design Support Work (vol 1
Work Plan; vol 2-4 SAP, QAPP, and HSP)
Draft Final Mather Baseline Risk
Assessment, comments from EPA
Region IX
Smith, Charles H.
AFBCA
Strong, Kent
California
Department of Toxic
Substances Control
Loudon, Fred
AFCEE/ERB
Rupe, Sam, Lt Col
Dept. of Air Force,
Office of the Regional
Counsel/Western Region
Lowe, Debbie
EPA Region IX
Smith, Charles H.
AFBCA
IT Corp.
Lowe, Debbie
EPA Region IX
Mather Baseline Risk Assessment Strong, Kent
comments from California Department of California
Toxic Substances Control Department of Toxic
Substances Control
928
941
827
1115
1106
935
929
1118
768
767
A-35
WTH, May 29, 1998
-------
DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
ARFILE
NUMBER
16 Oct 95 11 October 1995 Amended Restoration
Advisory Board Meeting Minutes
19 Oct 95 Contractor Response to Regulators'
Comments on the Draft Final Mather
Baseline Risk Assessment
Hovander, Brian, P.E. 943
AFBCA
Meyers-Schone, Linda 1099
IT Corp.
27 Oct 95 State's review comments on Additional
Site Characterization Contract
Modification, Draft Work Plan Addendum
Christopher, John
California
Department of Toxic
Substances Control
1069
14 Nov 95 07-08 November 1995 BCT Meeting
Minutes
16 Nov 95 15 November 1995 Restoration Advisory
Board Meeting Minutes
20 Nov 95 State's request for delivery extension
for Draft Final Mather Baseline Risk
Assessment and Draft Final Soils OU
and Groundwater OU Record of Decision
Smith, Charles H.
AFBCA
Smith, Charles H.
AFBCA
Strong, Kent
California
Department of Toxic
Substances Control
930
942
936
21 Nov 95 State's Request for Additional
Extensions on Revised Draft Final
Mather Baseline Risk Assessment and
Draft Final Soil and Groundwater ROD
22 Nov 95 Comments from the State on Additional
Site Characterization Contract
*= Modification, Draft Workplan Addendum
22 Nov 95 U.S. EPA's Request for Extended Review
of Additional Site Characterization
Work Plan Addendum
Dec 1995 Draft Report of Analytical Results Site
20 Characterization Investigation
Smith, Charles H 971
AFBCA/OL-D
Strong, Kent 818
California Department of
Toxic Substances Control
Lowe, Debbie 825
EPA Region K
Montgomery Watson 786
Americas, Inc.
A-36
WTH, May 29,1998
-------
DOC.
DATE
SUBJECT OR TITLE
AUTHOR or AR FILE
CORP. AUTHOR NUMBER
01 Dec 95 US-EPA Request for Extension for
Review of Additional Site
Characterization Work Plan Addendum
19 Dec 95
Jan 96
Jan 96
10 Jan %
Lowe, Debbie
EPA Region IX
05 Dec 95 U.S. EPA's review comments on the Lowe, Debbie
Comprehensive and Final Baseline Risk EPA Region DC
Assessment Workplan
05 Dec 95 U.S. EPA's comments on Draft Additional Lowe, Debbie
Site Characterization Addendum Work EPA Region IX
Plan
13 Dec 95 Request for Extension for Community
Relations Plan
Smith, Charles H
AFBCA/OL-D
18 Dec 95 Estimate of Constraints to Reuse Posed Smith, Charles H
by Contamination and Remediation at AFBCA/OL-D
Mather AFB
Draft Final Mather Baseline Risk
Assessment, vol. 1-4
Additional Site Characterization for
Groundwater, Soil, and Basewide
Operable Units, vol. 1-4 (Final Work
Plan, SAP, QAPP, and Health and Safety
Plan)
January 1996 Draft Final Community
Relations Plan
IT Corp.
IT Corp.
Gutierrez-
Palmenberg, Inc.
09-10 January 1996 BCT Meeting Minutes Dennis, Randall E.
AFBCA
17 Jan 96 Mather RAB Meeting Minutes,
10 January, 1996
07 Feb 96 Work Plan Addendum,
Additional Site Characterization
Contract Modification Plan Addendum
AFBCA/DBM
IT Corp.
A-37
820
1098
822
803
816
762
765
805
931
944
761
WTH, May 29,1998
-------
DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
ARFILE
NUMBER
16 Feb 96 State's comments on Draft Report of
Analytical Results Site 20
Characterization Investigation
Strong, Kent
California
Department of Toxic
Substances Control
961
Lowe, Debbie
EPA Region IX
20 Feb 96 U.S. EPA requests a two week extension
for review of the Draft Landfill
Closure Plan and a seven day extension
to review the Report of Analytical
Results, Site 20, and an additional
three days to review the Draft
Technical Plans and Quality Program
Plan for Removal Actions for Soil
Operable Unit Sites 56, 59,60,62, and 65
21 Feb 96 State's comments and ARARs from IWMB Strong, Kent
regarding disposal of treated soils California
from Mather bioremediation unit into Department of Toxic
Site 7 Substances Control
948
985
23 Feb 96 U.S. EPA's comments on Draft Technical
Plans and Draft Quality Program Plan
for Removal Actions for Soils Operable
Units, Sites 56,59,60,62, and 65 and
Draft Report of Analytical Results,
Site 20 Characterization Investigation
Report
18 Mar 96 Mather RAB Meeting Minutes,
13 March, 1996
12 Mar 96 Draff Technical Information Report on
Soil Vapor Extraction Pilot Testing at
Sites 18,39, and 57
18 Mar 96 13 March 1996 RAB Meeting Minutes
Lowe, Debbie
EPA Region IX
986
AFBCA/DBM
Loy, Ken
IT Corp.
Wong, Anthony C.
AFBCA
1598
1014
1076
20 Mar 96 13-14 March 1996 BCT Meeting
Summary
A-38
WTH, May 29.1998
Wong, Anthony C.
AFBCA
1077
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
AR FILE
NUMBER
26 Mar 96
29 Apr 96
08 May 96
09 May 96
17 May 96
19Jun96
24 Jun 96
25 Jun 96
01 Jul 96
25 Jul 96
31 Jul 96
Sep96
Air Force's solicitation from State of
potential ARARs pertaining to Final OU
Final Record of Decision for Soil
Operable Unit Sites and Groundwater
Operable Unit Plumes
Mather RAB Meeting Minutes,
May 1, 1996
Minutes of the BRAC Cleanup Team
Meeting, 1 and 2 May, 1996
Final Technical Report, Pipeline
Removal and Abandonment-in Place, for
Delivery Order 21
Minutes of the BRAC Cleanup Team
Meeting and Reuse Meeting, 18 - 20
June, 1996
Mather RAB Meeting Minutes,
18 June, 1996
Draft Final Technical Information
Report on Soil Vapor Extraction Pilot
Testing At Installation Restoration
Program Sites 18, 39, and 57
Wong, Anthony
AFBCA/OL-D
AFBCA/OL-D
AFBCA/DBM
AFBCA/DBM
Scher, Patrick
OGDEN
AFBCA/DBM
AFBCA/DBM
IT Corp.
Mather AFB Federal Facility Agreement Wong, Anthony C.
Appendix D Document Deliverable Dates AFBCA/OL-D
Mather BCT and Reuse Meeting Minutes AFBCA/DBM
23-24 July 1996
Mather RAB Meeting Minutes,
23 July, 1996
AFBCA/DBM
1086
945
1599
1580
1219
1581
1600
1130
Additional Site Characterization and IT Corp.
Final Basewide OU Remedial Investigation
Report, vol 1 of 6
1140
1582
1601
1636
RL/8-98/ES/3920001 .A WS
A-39
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
AR FILE
NUMBER
Sep96
Sep96
Sep96
Sep96
Sep96
10 Sept 96
17Sep96
19Sep96
22 Sep 96
22 Sep 96
Additional Site Characterization and IT Corp.
Final Basewide OU Remedial Investigation
Report, vol 2 of 6
Additional Site Characterization and IT Corp.
Final Basewide OU Remedial Investigation
Report, vol 3 of 6
Additional Site Characterization and IT Corp.
Final Basewide OU Remedial Investigation
Report, vol 4 of 6
Additional Site Characterization and IT Corp.
Final Basewide OU Remedial Investigation
Report, vol 5 of 6
Additional Site Characterization and IT Corp.
Final Basewide OU Remedial Investigation
Report, vol 6 of 6
Memorandum for IT, Review of Watts, Debra, Major
Contractor's Response to Comments on HQ AFCEE/ERB
the Revised Draft of the Comprehensive
Baseline Risk
Transmirtal of Removal Action
Memorandum (RAM) for Site IOC
Transmittal of the Draft Technical
Plans and Quality Program Plans for
Remedial Action at Site 57 and Remedial
Action Pilot Test at Site IOC/68
Mather BCT and Reuse Meeting Minutes
11 - 12 September, 1996
Mather RAB Meeting Minutes,
11 September, 1996
Wong, Anthony C.
AFBCA/OL-D
Wong, Anthony C.
AFBCA/OL-D
AFBCA/DBM
AFBCA/DBM
1637
1638
1639
1640
1641
173
1150
1153
1583
1602
RU8-98/ES/392000I.AWS
A-40
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
AR FILE
NUMBER
23 Sep 96 Submission of the Draft Final Work Plan
for Remediation and Closure of
Petroleum Sites 19,20 (facility) 2595
and (facility) 18015, Contract
F41624-94-D-8090, Delivery Order 06
01 Oct 96 Request for FFA Schedule Adjustments,
Final CBRA and Draft Proposed Plan
15 Oct 96 Mem for IT: Review of Draft Additional
Site Characterization and Final Basewide
Operable Unit Work Plan Addendum
17 Oct 96 Comprehensive Baseline Risk
Assessment, Vol I of III
17 Oct 96 Comprehensive Baseline Risk
Assessment, Vol II of III,
Appendices A-I
17 Oct 96 Comprehensive Baseline Risk
Assessment, Vol III of III,
Appendices J-L
17 Oct 96 Final Comprehensive Baseline Risk
Assessment (transmittal of replacement
pages)
18 Oct 96 Memorandum for HQ AFCEE/ERB,
Comments on Draft Site Characterization
and Basewide Operable Unit Work Plan
Addendum: IRP sites 86 and 87
Scott, John
Montgomery Watson
Americas, Inc.
Wong, Anthony C.
AFBCA/DBM
Watts, Debra, Major
HQ AFCEE/ERB
IT Corp.
IT Corp.
IT Corp.
Dove, F. Harvey
IT Corp.
Wong, Anthony C.
AFBCA/DBM
1152
1162
1172
626
627
628
1175
1174
21 Oct 96 Review of Draft Basewide Operable Unit Watts, Debra, Major
Focused Feasibility Study, Mather AFB, HQ AFBCA/EV
CA
1183
21 Oct 96 Request for Addition to Administrative
Record Comprehensive Baseline Risk
Assessment (CBRA)
Watts, Debra, Major
HQ AFCEE/ERB
1191
RU8-98/ES/3920001 .A WS
A-41
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
AR FILE
NUMBER
22 Oct 96 Draft Basewide Operable Unit Focused
Feasibility Study Report, Mather
(Review extension)
31 Oct 96 Comments for Draft Basewide Operable
Unit Focused Feasibility Study Report
for MAFB
Strong, Kent
California
Department of Toxic
Substances Control
Lowe, Debbie
U.S. EPA Region IX
1176
1198
01 Nov 96 Mather BCT and Reuse Meeting
Minutes, 23-24 October, 1996
01 Nov 96 Amended Summary, Mather RAB
Meeting, 23 October 1996
08 Nov 96 Draft Basewide Operable Unit Focused
Feasibility Study Report for Mather Air
Force Base
AFBCA/DBM
AFBCA/DBM
Strong, Kent
California
Department of Toxic
Substances Control
1584
1603
1197
12 Nov 96
18 Nov 96
19 Nov 96
Lunceford comments to Draft Basewide
Focused Feasibility Study
Lunceford, Sandra
(Comments on) Draft Final Work Plans Taylor, James
for Remediation and Closure of Petroleum California Regional
Sites 19, 20, 2595 and 18015, Mather Air Water Quality
Force Base(MAFB) Sacramento County Control Board
EPA comments to Draft Technical Plans
and Quality Program for Remedial Action
at Site 57 and Remedial Action Test at
Site IOC/68 for Mather AFB
20 Dec 96 Transmittal of Draft Final Additional Site
Characterization and Basewide Operable
Unit Work Plan Addendum: IRP Sites 86
and 87
23 Dec 96 Mather BCT and Reuse Meeting
Minutes, 11-12 December, 1996
Lowe, Debbie
U.S. EPA Region IX
Wong, Anthony C.
AFBCA/DBM
AFBCA/DBM
1199
1207
1206
1220
1585
RU8-98/ES/392000I .AWS
A-42
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or AR FILE
CORP. AUTHOR NUMBER
23 Dec 96 Mather RAB Meeting Minutes,
II Dec, 1996
06 Jan 97 FFA Schedule Adjustments, Draft Final
Mather AFB Off-Base Water Supply
Contingency Plan, Draft Final Basewide
Operable Unit Focused Feasibility
Study, and Draft Basewide Operable Unit
Proposed Plan
10 Jan 97 Review of Draft Site Characterization
Report for IRP Sites 86 and 87, Mather
AFB, CA
13 Jan 97 Transmittal of Final Work Plans for
Remediation and Closure of Petroleum
Sites 19,20, 2595, and 18015.
13 Jan 97 Transmittal of Draft Final Technical
Plans, Quality Program, and
Construction Package for Remedial
Action at Site 57 and Remedial Action
Pilot Test at Site IOC/68
AFBCA/DBM
Wong, Anthony C.
AFBCA/DBM
Watts, Debra, Major
AFCEE/ERB
Wong, Anthony C.
AFBCA/DBM
Wong, Anthony C.
AFBCA/DBM
1604
1224
1246
1227
1228
13 Jan 97 Transmittal of Draft Final Site
Characterization Report for IRP Sites
86 and 87
Wong, Anthony C.
AFBCA/DBM
1231
21 Jan 97 Transmittal of Consensus Statement for
FFA Schedule Adjustments, Draft Final
Basewide Operable Unit Focused
Feasibility Study
27 Jan 97 Mather BCT and Reuse Meeting
Minutes, 15-16 January 1997
27 Jan 97 Mather Restoration Advisory Board
Meeting Minutes, 15 January, 1997
Wong, Anthony C.
AFBCA/DBM
AFBCA/DBM
AFBCA/DBM
1229
1586
1605
RU8-98/ES/3920001 .A WS
A-43
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or AR FILE
CORP. AUTHOR NUMBER
04 Feb 97 FFA Schedule Extension Request for the
Draft Final Basewide Operable Unit
Focused Feasibility Study, and Draft
Basewide Operable Unit Proposed Plan
11 Mar 97 Mather BCT and Reuse Meeting Minutes,
26-27 February, 1997
11 Mar 97 Mather Restoration Advisory Board
Meeting Minutes, 26 February, 1997
08 Apr 97 AFCEE Draft Basewide OU FFS
Comments
17 Apr 97 EPA comments to the [Draft] Proposed
Plan for Environmental Cleanup at the
Basewide Operable Unit Sites, May 1997
18 Apr 97 Mather Restoration Advisory Board
Meeting Minutes, 09 April 1997
19 Apr 97 Transmittal of the Final Basewide
Operable Unit Focused Feasibility Study
21 Apr 97 Site 7 Acceptance Criteria Table
Wong, Anthony C.
AFBCA/DBM
AFBCA/DBM
AFBCA/DBM
Loy, Ken
IT Corp.
Salyer, Kathleen
U.S. EPA Region IX
AFBCA/DBM
Wong, Anthony C.
AFBCA/DBM
Taylor, James
Regional Water Quality
Control Board
1239
21 Apr 97 Air Force Center for Environmental Loy, Ken
Excellence (AFCEE) Final Basewide OU HQ AFCEE/ERB
FFS Comments
22 Apr 97 RWQCB comments to Draft Basewide Taylor, James
Operable Unit Proposed Plan, Mather Air California Regional
Force Base (MAFB), Sacramento County Water Quality Control
Board
23 Apr 97 Mather BCT and Reuse Meeting Minutes, AFBCA/DBM
09-10 April, 1997
1587
1606
1271
1288
1607
1312
1283
1337
1285
1588
RL«.98/ES/3920001. A WS
A-44
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
ARFILE
NUMBER
24 Apr 97 Basewide OU comments
29 Apr 97 Transmittal of the Draft Closure Report
for Soil Operable Unit Site 20
12 May 97 Wetlands/Endangered or Threatened
Species Issues at Sites 13, 15 and 85
13 May 97 IT Responses to Proposed Plan Basewide
OU
13 May 97 EPA review of Draft Annual 1996
Basewide Groundwater Monitoring
Report, Mather AFB, March, 1997
16 May 96 Quarterly Groundwater Monitoring
Report, Second Quarter 1995
19 May 97 Transmittal of the Final Basewide
Operable Unit Proposed Plan
20 May 97 First Quarter 1997 Basewide Groundwater
Monitoring Report
28 May 97 EPA review of Draft Closure Report for
Soil Operable Unit Site 20, April 1997
29 May 97 (Corrected 9/23/97) Public Hearing
The Proposed Plan for Environmental
Cleanup at the Basewide Operable Unit
Sites
02 Jun 97 EPA review of U.S. Air Force
Installation Restoration Program
Community Relations Plan
03 Jun 97 Mather Restoration Advisory Board
Meeting Minutes, 21 May 1997
Vorster, Ton 1339
California Regional Water
Quality Control Board
Wong, Anthony C. 1292
AFBCA/DBM
Cummings, John R. 1317
Montgomery Watson
Americas, Inc.
SiIva,Mike . 1338
IT Corp.
Salyer, Kathleen 1309
U.S. EPA Region IX
Ramage, Joseph 1404
IT Corp.
Wong, Anthony C. 1310
AFBCA/DBM
Wong, Anthony C. 1307
AFBCA/DBM
Salyer, Kathleen 1334
U.S. EPA Region IX
Peters, James F. 1327
CSR, RPR
Peters Shorthand
Reporting Corporation
Salyer, Kathleen 1336
U.S. EPA Region IX
AFBCA/DBM 1608
RU8-98/ES/3920001 .A WS
A-45
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
AR FILE
NUMBER
06 Jun 97 Mather BCT and Reuse Meeting
Minutes, 21-22 May, 1997
12 Jun 97 Basewide Operable Unit Focused
Feasibility Study, Mather (IWMB)
19 Jun 97 Meeting Agenda
23 Jun 97
23 Jun 97
30 Jun 97
01 Jul97
10Jul97
21 Jul97
Aug97
05 Aug 97
Community Plan (Comments on
Basewide OU Proposed Plan)
Comments to Final Basewide OU FFS
Basewide Operable Unit Focused
Feasibility Study (DTSC comments were
addressed)
Transmittal of the Draft Superfund
Record of Decision for the Basewide
Operable Unit Sites
Draft Final Annual 1996 Basewide
Groundwater Monitoring Report
Cal/EPA review of Draft Operation and
Maintenance Manual for Site 19
Bioventing System, Mather AFB
AFBCA/DBM
Strong, Kent
California
Department of Toxic
Substances Control
California Regional
Water Quality
Control Board
Walker, Annette
Lunceford, Sandra
Strong, Kent
California
Department of Toxic
Substances Control
Wong, Anthony C.
AFBCA/DBM
Wong, Anthony C.
AFBCA/DBM
Taylor, James
California Regional Water
Quality Control Board
Second Quarter 1997 Wong, Anthony C.
Basewide Groundwater Monitoring Report AFBCA/DBM
1589
1340
1341
1325
1326
1342
Revised Appendix D: Proposed FFA
Deadlines for Draft Primary Documents
Wong, Anthony C.
AFBCA/DBM
1350
1356
1357
1436
1366
RL/8-98/ES/J920001 .A WS
A-46
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or AR FILE
CORP. AUTHOR NUMBER
05 Aug 97
Substantive Requirements for Site 57
and Site IOC/68 at Mather AFB
14 Aug 97
18 Aug 97
20 Aug 97
20 Aug 97
21 Aug 97
26 Aug 97
26 Aug 97
08 Sept 97
12Sep97
16Sep97
Mather BCT and Reuse Meeting
Minutes, 30-31 July, 1997
Mather Restoration Advisory Board
Board Meeting Minutes, 31 July 1997
EPA request for 30 day extension for
the Draft Superftmd Record of Decision
Basewide Operable Unit Sites, Mather
Air Force Base, California, July 1, 1997.
(Comments on) Draft Superfund Record
of Decision for Basewide Operable Units
Transmittal of the Draft Explanation of
Significant Differences (ESD) from the
ROD for the Soils Operable Unit Sites
and Groundwater Operable Unit Plumes
Final Basewide Groundwater Monitoring
Sampling and Analysis Plan
Draft Final Closure Report for Soil
Operable Unit Site 20
Mather AFB Quality Program Plan,
Volume IV, Sampling and Analysis Plan
BCT and Reuse Meeting Minutes,
04 February 1997
Mather Restoration Advisory Board
Meeting Minutes, 03 September, 1997
DeGuzman, Jorge
Sacramento
Metropolitan Air
Quality Management
District
AFBCA/DBM
AFBCA/DBM
Salyer, Kathleen
U.S. EPA Region IX
Rak, Andrew
HQ AFCEE/ERB
Wong, Anthony C.
AFBCA/DBM
Wong, Anthony C.
AFBCA/DBM
Wong, Anthony C.
AFBCA/DBM
Montgomery Watson
Americas, Inc.
AFBCA/DBM
AFBCA/DBM
1376
1590
1609
1387
1406
1379
1388
1389
1390
1591
1610
RL/8-98/ES/392000I .AWS
A-47
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
AR FILE
NUMBER
19 Sept 97 Compliance source tests for 1000 cfrn
thermal oxidizer system at Site IOC/68,
Mather
19 Sept 97 Draft Final Operations and Maintenance
Manual for Site 19 Bioventing System
(Also Manufacturer Literature Book)
22 Sept 97 Draft Explanation of Site 7 Acceptance
Criteria, Informal Technical
Information Report, September 1997,
Mather Air Force Base
26 Sept 97 (Comments on) Draft Superfund Record
of Decision for the Basewide Operable
Unit Sites
30 Sept 97 Submission of EPA Region IX
Questionnaire for Federal Facility
Cleanup Sites, Mather Air Force Base,
California
30 Sept 97 Comments on the Basewide OU ROD
(Submitted through the RAB)
01 Oct 97 (Comments on) Draft Record of
Decision, Basewide Operable Unit
Sites, Mather Field
02 Oct 97 EPA Comments on the Draft Superfund
Record of Decision, Basewide Operable
Unit Sites
Scott, John
Montgomery Watson
Americas, Inc.
Wong, Anthony C.
AFBCA/DBM
Hogg, Linda D.
California
Department of Toxic
Substances Control
1478
1426
1400
1402
Truszkowski, Thomas
County of Sacramento,
Dept. of Economic Development
Scott, John 1427
Montgomery Watson
Americas, Inc.
Lunceford, Sandra 1403
Taylor, James 1414
California Regional
Water Quality Control Board
Salyer, Kathleen 1423
U.S. EPA Region IX
02 Oct 97 (Comments on) Draft Record of
Decision for the Basewide Operable
Unit Sites
Strong, Kent
California
Department of Toxic
Substances Control
1416
RU8-98/ES/392000I .AWS
A-48
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
AR FILE
NUMBER
08 Oct 97 EPA review of Soil Operable Unit Draft
Explanation of Significant Differences
(ESD) from the Record of Decision,
Disposal of Contaminated Soil at Site
7/11, Mather Air Force Base, 22 August
1997
Salyer, Kathleen
U.S. EPA Region IX
1430
14 Oct 97 Submission of the Third Quarter 1997
Basewide Groundwater Monitoring Report
15 Oct 97 Draft Explanation of Significant
Differences from the Record of Decision
for the Soil Operable Unit/Disposal of
Contaminated Soil, at Site 7/11, Mather
16 Oct 97 EPA Additional Comments on the Draft
Superfund Record of Decision, Basewide
Operable Unit Sites
12 Nov 97 Comments on Draft Superfund Record of
Decision, Basewide Operable Unit Sites
13 Nov 97 CVRWQCB Meeting
Wong, Anthony C.
AFBCA/DBM
Taylor, James
California Regional
Water Quality
Control Board
Salyer, Kathleen
U.S. EPA Region IX
Wong, Anthony C.
AFBCA/DBM
Taylor, James
California Regional
Water Quality
Control Board
1422
1424
1616
1437
1442
14 Nov 97 Transmittal of the Draft Final
Explanation of Significant Differences
(ESD) from the ROD for the Soils
Operable Unit Sites and Groundwater
Operable Unit Plumes
17 Nov 97 Investigation of Bombing Activities on
Mather Field, Mather, California
Wong, Anthony C.
AFBCA/DBM
Strong, Kent
California
Department of Toxic
Substances Control
1438
1439
18 Nov 97 BRAC Cleanup Team (BCT) and Reuse
Meeting Minutes, 04 November, 1997
AFBCA/DBM
1592
RL/8-98/ES/392000 LAWS
A-49
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
AR FILE
NUMBER
18 Nov 97 Mather Restoration Advisory Board
Meeting Minutes, 05 November, 1997
18 Nov 97 Proposed Institutional Control Language
for Basewide Record of Decision, Mather
AFBCA/DBM
Hogg, Linda D.
California
Department of Toxic
Substances Control
1611
1444
20 Nov 97 Preliminary Analytical Results of Site
81 Surface Soil Sampling Contract
F41624-94-D-6090
21 Nov 97 EPA requests 14 day extension on
comment period for Draft Technical
Plans and Quality Program Plan for
Remedial Action at Sites 56 and 60 and
Monitoring Wells Installation at Site
82, Sept 1997 and Draft Remedial Action
Work Plan and Quality Program Plan
Phase II Groundwater Remediation at
Mather AFB
Scott, John
Montgomery Watson
Americas, Inc.
Salyer, Kathleen
U.S. EPA Region IX
1479
1445
24 Nov 97 Review of Draft Technical Plans and
Quality Program Plan for Remedial Action
at Sites 56 and 60 and Monitoring Well
Installation at Site 82, Mather Air
Force Base, Sacramento
26 Nov 97 Final Operations and Maintenance Manual
and Manufacturer Literature for Site 19
Bioventing System
26 Nov 97 FFA Schedule Extension Request for the
Draft Final Basewide Operable Unit
Record of Decision
Taylor, James
California Regional
Water Quality
Control Board
Wong, Anthony C.
AFBCA/DBM
Wong, Anthony C.
AFBCA/DBM
1458
1451
1452
Dec 97 Volume I, Underground Storage Tank
Removal Reports Sites 20,2527, 2527B,
4540, and 10052
EA Engineering,
Science, and
Technology, Inc.
1558
R1V8-98/ES/392000I .AWS
A-50
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or AR FILE
CORP. AUTHOR NUMBER
Dec 97 Volume II, Underground Storage Tank
Removal Reports Sites 20,2527, 2527B,
4540, and 10052
Dec 97 Volume I Bioventing System Installation
Report Sites 19,2595 and 18015
Dec 97 Volume III Bioventing System
Installation Report Sites 19, 2595, and
18015 (Site 19(Appendix B)(Continued))
Dec 97 Volume IV Bioventing System
Installation Report Sites 19,2595, and
18015 (Site 2595 and 18015(Appendix B))
Dec 97 Site Investigation and SVE System
Installation Report Site IOC/68
03 Dec 97 Mather BCT and Reuse Meeting Minutes,
03-04 December, 1997
15 Dec 97 Mather Restoration Advisory Board
Meeting Minutes, 03 December, 1997
17 Dec 97 Project Definition Investigation
Sampling Plan for Surface Soil Sampling
Sites 86 and 87
19 Dec 97 EPA review of the proposed disclosure
notices for contaminated soil in
Parcels A, F and G, dated September 30,
1997. At Sites 80, 81, 82 and 85.
30 Dec 97 Draft Technical Plans and
Quality Program Plan for Remedial
Action At Sites 56 and 60 and
Monitoring Well Installation at Site
82, Mather Air Force Base, Sacramento
County
EA Engineering,
Science, and
Technology, Inc.
EA Engineering,
Science, and
Technology, Inc.
EA Engineering,
Science, and
Technology, Inc.
EA Engineering,
Science, and
Technology, Inc.
Montgomery Watson
Americas, Inc.
AFBCA/DBM
AFBCA/DBM
Scott, John
Montgomery Watson
Americas, Inc.
Salyer, Kathleen
U.S. EPA Region IX
AFBCA
1559
1565
1567
1568
1575
1593
1612
1550
1469
1463
RU8-98/ES/3920001. AWS
A-51
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
ARFILE
NUMBER
16 Jan 98 Basewide Operable Unit Record of
Decision Consensus Statement
22 Jan 98 Draft Final Technical Plan and Quality
Program Plan for Remedial Action At
Sites 56 and 60 and Monitoring Well
Installation at Site 82, Mather Field
22 Jan 98 Draft Site Investigation and SVE System
Installation Report Site IOC/68, Mather
Field
27 Jan 98 Transmittal of the red-line revised
Draft Superfund Record of Decision for
the Basewide Operable Unit Sites
29 Jan 98 Draft Project Definition Investigation
Report for Surface Soil Sites IOC, 69,
80,81, and 88
30 Jan 98 Soil Vapor Extraction Systems Sites 29,
57, and IOC/68 Quarterly Emissions
Monitoring Report Fourth Quarter 1997
30 Jan 98 Draft Technical Plans and Quality
Program Plan for Sites 20, 86, and 87
02 Feb 98 BRAC Cleanup Team (BCT) and Reuse
Meeting Minutes, 28-29 January, 1998
02 Feb 98 Mather Restoration Advisory
Meeting Minutes, 28 January, 1998
Wong, Anthony C.
1687
Taylor, James 1498
California Regional
Water Quality
Control Board
Taylor, James 1506
California Regional Water
Quality Control Board
Wong, Anthony C. 1517
AFBCA/DBM
Wong, Anthony C. 1509
AFBCA/DBM
Wong, Anthony C. 1508
AFBCA/DBM
Wong, Anthony C. 1513
AFBCA/DBM
AFBCA/DBM 1594
AFBCA/DBM 1613
20 Feb 98 Status Report for Site 1OC/68, Mather
Field, Sacramento County
Taylor, James
California Regional
Water Quality
Control Board
1520
A-52
WTH, May 29, 1998
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DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
ARFILE
NUMBER
27 Feb 98 Quarterly Emissions Monitoring Report
Fourth Quarter 1997
03 Mar 98 Phase II Project Definition
Investigation Sampling Plan for Soil
Sampling Sites 86 and 87, Former Small
Anns Range and Skeet Range Mather Air
Force Base, California
12 Mar 98 Basewide Operable Unit Record of
Decision Consensus Statement, 3/12/98
17 Mar 98 Revised Draft Explanation of
Significant Difference from the
Landfill Operable Unit Record of
Decision and Modification to Site 7/11
Acceptance Criteria Former Mather Air
Force Base, Sacramento County
17 Mar 98 Draft Explanation of Significant
Difference (BSD), Landfill Operable
Unit Record of Decision, and
Modification to Site 7/11 Acceptance
Criteria, Mather Field, Sacramento
County
23 Mar 98 Mather Restoration Advisory Board
Meeting Minutes, 16 March, 1998
24 Mar 98 Base Cleanup Team (BCT) and Reuse
Meeting Minutes, 11 March, 1998
•«:
24 Mar 98 RCRA ARARs for Vadose Zone Cleanup
25 Mar 98 Additional Applicable or Relevant and
Appropriate Requirements (ARARs) for
the Draft Basewide Record of Decision
Wong, Anthony C. 1556
AFBCA/DBM
Scott, John 1530
Montgomery Watson
Americas, Inc.
Wong, Anthony C. 1537
AFBCA/DBM
Taylor, James 1543
California Regional
Water Quality
Control Board
Hogg, Linda D. 1544
California
Department of Toxic
Substances Control
AFBCA/DBM 1614
AFBCA/DBM 1595
Kathleen Salyer 1710
U.S. EPA, Region IX
Hogg, Linda D. 1554
California
Department of Toxic
Substances Control
A-53
WTH, May 29, 1998
-------
DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
ARFILE
NUMBER
07 Apr 98 DTSC request for extension on Draft
Document Review of Technical Plan for
Sites 20, 86 and 97; and Draft Project
Definition Investigation Report for
Sites IOC, 69, 80, 81, and 88
20 Apr 98 Request for Review and Comment -
Resolution of Remaining Issues for
Basewide Operable Unit Record of
Decision
20 Apr 98
21 Apr 98
30 Apr 98
1 May 98
05 May 98
05 May 98
07 May 98
Hogg, Linda D.
California
Department of Toxic
Substances Control
Wong, Anthony C.
AFBCA/DBM
1571
DTSC Comments on Interim Draft Final
Basewide Record of Decision (ROD),
Mather Air Force Base, Sacramento
County
Transmittal of Adopted Resolution No.
98-105, Former Mather Air Force Base,
Sacramento County
Interim Draft Final Record of Decision Taylor, James
for Basewide Operable Unit Sites, Former California Regional Water
Mather Air Force Base, Sacramento County Quality Control Board
EPA review of Interim Draft Final Record
of Decision for Basewide Operable Unit
Sites, Mather AFB, March 30, 1998
Draft Technical Plans and Quality
Program Plan for Remedial Actions for
Sites 20, 86 and 87, January 1998,
Mather
Base Cleanup Team (BCT) and Reuse
Meeting Minutes, April 22, 1998
EPA review of Draft Technical Plans and
Quality Program Plan for Remedial
Actions Sites 20, 86, and 87, Mather
AFB, January 1998
Salyer, Kathleen
U.S. EPA Region EX
Hogg, Linda D.
California
Department of Toxic
Substances Control
AFBCA/DBM
Salyer, Kathleen
U.S. EPA Region IX
1577
Hogg, Linda D. 1578
California
Department of Toxic
Substances Control
Vorster, Antonia K. J. 1618
California Regional Water
Quality Control Board
1619
1660
1620
1596
1621
A-54
WTH, May 29, 1998
-------
DOC.
DATE
SUBJECT OR TITLE
AUTHOR or ARFILE
CORP. AUTHOR NUMBER
08 May 98 EPA review of Draft Project Definition
Investigation Report for Surface Soil
Sites IOC, 69,80,81, and 88, Mather
AFB, January 1998
08 May 98 Draft Project Definition Investigation
Report for Surface Soil Sites IOC, 69,
80, 81, and 88, Former Mather Air Force
Base, Sacramento County
11 May 98 Comments on Interim Draft Final
Basewide Record of Decision (ROD),
Mather Air Force Base, Sacramento
County
11 May 98 Draft Project Definition Investigation
Report for Soil Sites IOC, 69, 80, 81
and 88, January 1998, Mather Air Force
Base, Sacramento County
12 May 98 Review of Report on Mather Field Range
Activities
19 May 98 Basewide Operable Unit Record of
Decision Consensus Statement
21 May 98
29 May 98
June 98
9 June 98
Evaluation of Cleanup Standards for
Basewide Operable Unit Soils
Salyer, Kathleen
U.S. EPA Region EX
Taylor, James
California Regional
Water Quality
Control Board
Hogg, Linda D.
California
Department of Toxic
Substances Control
Hogg, Linda D.
California
Department of Toxic
Substances Control
Wong, Anthony C.
AFBCA/DBM
Wong, Anthony C.
Wong, Anthony C.
AFBCA/DA Mather
1622
Draft Final Superrund Record of Decision, HQ AFCEE/ERB
Basewide Operable Unit Sites, Mather
Air Force Base, California
Draft Final Technical Plans and Quality
Program Plan for Remedial Actions
Sites 20, 86, and 87
Applicability of RCRA Regulations to
Vadose Zone Cleanup at Mather
(reference your letter of 24 March 1998)
A-55
Montgomery Watson
Wong, Anthony C.
AFBCA/DA Mather
1623
1617
1616
1642
1682
1054
1661
1678
1670
WTH, May 29, 1998
-------
DOC.
DATE
SUBJECT OR TITLE
AUTHOR or ARFILE
CORP. AUTHOR NUMBER
9 Jun 98 Applicability of RCRA Regulations to
Vadose Zone Cleanup at Mather
(reference your letter of 25 March, 1998)
19 June 98 Basewide Operable Unit Record of
Decision Consensus Statement
Wong, Anthony C.
Wong, Anthony C.
AFBCA/DBM
1702
1669
29 June 98 Review of Ecological Risk Assessment
for Mather Firing Range Sites
29 Jun 98 Transcription of Comments on Draft
Final Basewide Operable Unit Record
of Decision
Wong, Anthony C.
AFBCA/DA Mather
Hughes, Bill
WPI
1673
1711
30 June 98 Final Site Investigation and SVE System Montgomery Watson
Installation Report for Site IOC/68
1676
7 July 98 Mather Draft Final Basewide ROD
14 July 98
15Jul98
17Jul98
23 July 98
Draft Final Record of Decision for the
Basewide Operable Unit Sites, Former
Mather Air Force Base, Sacramento
County
EPA review of Draft Final Superfund
Record of Decision for Basewide
Operable Unit Sites, Mather AFB
dated May 29,1998
Taylor, James
Regional Water Quality
Control Board
Taylor, James
Regional Water Quality
Control Board
Salyer, Kathleen
U.S. EPA Region EX
Comments on Draft Final Basewide Hogg, Linda D.
Record of Decision (ROD) May 1998, CA DTSC
Mather Air Force Base, Sacramento County
Mather Air Force Base Site 87
Ecological Risk Assessment
Chernoff, Gerald F., PhD
CA Dept. Fish & Game
1712
1688
1695
1696
1713
A-56
WTH, May 29.1998
-------
DOC.
DATE
SUBJECT OR TITLE
AUTHOR or
CORP. AUTHOR
ARFILE
NUMBER
24Jul98
31 July 98
Aug98
13Aug98
Basewide Operable Unit ROD: Proposed
Text for Institutional Controls at Site 87
and for Emissions Monitoring for Dioxin
Transmittal of the Revised Draft Final
CERCLA Record of Decision for the
Basewide Operable Unit Sites
Wong, Anthony C.
AFBCA DA Mather
Wong, Anthony C.
AFBCA/DAM
Revised Draft Final Comprehensive
Environmental Response, Compensation,
and Liability Act of 1980, Record of Decision
HQ AFCEE/ERB
Basewide Operable Unit Record of
Decision Consensus Statement
Wong, Anthony C.
AFBCA/DBM
1698
1714
1704
1716
13 Aug 98 Mather Air Force Base Site 87 Ecological
Risk Assessment and Record of Decision
19 Aug 98 Changes to Revised Draft Final
Basewide Operable Unit Record of
Decision
Chernoff, Gerald F., PhD 1717
CA Dept of Fish & Game
Wong, Anthony C. 1715
AFBCA/DAM
A-57
WTH, May 29, 1998
-------
Appendix B
Mather Air force Base Sites 86 and 87
Human Health Risk Assessment
RL/8-98/ES/392000 LAWS
-------
Table of Contents.
List of Tables B-ii
List of Acronyms B-iii
B. 1 Introduction B-l
B.2 Identification of Chemicals of Potential Concern B-l
B.2.1 Site Descriptions B-l
B.2.1.1 Site 86 - Former Military Firing Range B-2
B.2.1.2 Site 87 - Former Skeet /Trap Range B-2
B.2.2 Methodology for Selection of Chemicals of Potential Concern B-2
B.2.3 Chemicals of Potential Concern B-3
B.3 Exposure Assessment B-8
B.3.1 Exposure Pathways B-8
B.3.2 Quantification of Exposure B-9
B.3.2.1 Exposure Models B-9
B.3.2.2 Exposure Parameters B-10
B.3.2.3 Intakes for Chemicals of Potential Concern B-10
•
B.4 Toxicity Assessment B-l 1
B.5 Risk Characterization B-l 1
B.5.1 Estimation of Carcinogenic Risk B-l 1
B.5.2 Estimation of Noncarcinogenic Risk B-14
B.5.3 Department of Toxic Control Leadspread VI B-l 5
B.5.4 Risks Due to Chronic Exposure to Largely Intact Lead Shot or Slugs B-l6
B.5.5 Results of the Human Health Risk Characterization B-16
B.5.6 General Uncertainties B-27
B.6 References B-28
RU8-WES/392000I.AWS
-------
List of Tables.
Table Title Page
B-l Statistical Summary for Chemicals of Potential Concern for Site 86 Soils
at Mather Air Force Base(a) B-4
B-2 Statistical Summary for Chemicals of Potential Concern for Site 87 Soils
at Mather Air Force Base(a) B-5
B-3 Statistical Summary for Chemicals of Potential Concern for Site 87
Sediment at Mather Air Force Base(a) B-6
B-4 Statistical Summary for Chemicals of Potential Concern for Site 87
Surface Water at Mather Air Force Base(a) B-7
B-5 Human Toxicity Factors Used for Calculation of Incremental Lifetime
Cancer Risk and Hazard Index from Exposure to Chemicals of Potential
Concern at IRP Site 86 and 87(a) B-12
B-6 Estimated Daily Intakes and Incremental Lifetime Cancer Risks at Site 86
for Mather Air Force Base B-l7
B-7 Estimated Daily Intakes and Hazard Quotients at Site 86 for Mather Air
Force Base B-l8
B-8 Estimated Daily Intakes and Incremental Lifetime Cancer Risks at Site 87
for Mather Air Force Base B-19
B-9 Estimated Daily Intakes and Hazard Quotients at Site 87 for Mather Air
Force Base B-22
RU8-98/ES/3'32000 LAWS
B-ii
-------
List of Acronyms.
ug/L micrograms per Liter
AFB Air Force Base
CBRA Comprehensive Baseline Risk Assessment
COPC chemicals of potential concern
DTSC Department of Toxic Control
FS feasibility study
HI hazard index
HQ hazard quotient
ILCR incremental lifetime cancer risk
IRIS Integrated Risk Information System
IRP Installation Restoration Program
mg/L milligrams per Liter
NCP National Oil and Hazardous Substances Pollution Contingency Plan
ppm parts per million
RAGS Risk Assessment Guidance for Superfund
RfD reference dose
RI remedial investigation
RME reasonable maximum exposure
SF slope factor
USEPA United States Environmental Protection Agency
RU8-98/ES/3920001 .AWS
B-iii
-------
B. 1 Introduction.
This appendix addresses the overall human health effects of exposure to chemicals of potential
concern (COPC) in soil, sediment, and surface water at Installation Restoration Program (IRP)
Site 86 (the Former Military Firing Range) and Site 87 (the Former Skeet/Trap Range) for
Mather Air Force Base (AFB). The methodology for conducting the risk assessment will be
summarized below. For complete methodology, refer to the Final Comprehensive Baseline Risk
Assessment (CBRA) for Mather AFB [IT 1996].
A risk assessment is an interpretive link between a remedial investigation (RJ) and a feasibility
study (FS). It is designed to use data generated by a RI to evaluate potential health effects at a
site and to formulate the goals to be used in selecting remedial actions in the FS. This risk
assessment was performed in accordance with the Risk Assessment Guidance for Superfund
(RAGS) [USEPA 1989] and with guidance provided by the U.S. Environmental Protection
Agency (USEPA), Region IX, and the California Department of Toxic Control (DTSC).
This appendix presents discussions on major risk assessment elements including identification of
COPC (Section B.2), exposure assessment (Section B.3), toxicity assessment (Section B.4) and
risk characterization (Section B.5).
B.2 Identification of Chemicals of Potential Concern
This section identifies the COPC for Sites 86 and 87 at Mather AFB. Pertinent data collection
considerations are discussed, and the data evaluation process is presented.
Data collected during the IRP Sites 86 and 87 investigations were evaluated for use in this risk
assessment in accordance with USEPA guidance [USEPA 1989]. This process included
evaluating the sample collection and analytical methods used, evaluating the quality of the data,
and selection of the COPC. The COPC selection process was three-fold: (1) to identify those
chemicals that are likely to be site-related, (2) to determine the acceptability of the analytical data
for use in the risk assessment, and (3) to focus the risk assessment on those constituents that
represent the dominant potential risks at these sites. The analytical data are summarized in the
"Final Site Characterization Report for IRP Sites 86 and 87" [IT 1997].
B.2. 7 Site Descriptions
This section briefly describes the historical activities at Sites 86 and 87. For additional
information refer to the "Final Site Characterization Report for IRP Sites 86 and 87" [IT 1997].
RU8-98/ES/3920001.AWS
B-l
-------
B. 2.1.1 Site 86 - Former Military Firing Range
The Former Military Firing Range is located on the southeast portion of Mather AFB. The range
was opened in the late 1950s when the Strategic Air Command wing moved to Mather AFB.
The firing range was operated by the military until closure in 1993. The site consisted of the rifle
and pistol range which covered an area of approximately 112,900 square feet. Recently, portions
of the firing range have been dismantled or altered. Soil on the interior target faces of the berm
have been removed and stockpiled at the site. The outer portions of the berms were used as
construction material in a landfill under construction at IRP Site 4.
B.2.1.2 Site 87 - Former Skeet /Trap Range
The Former Skeet/Trap Range is located on the eastern portion of Mather AFB and consists of an
open grassy area. The skeet/trap range was operated by a local shooting club. The range was
constructed in phases. The eastern-most two sets of the skeet/trap range were built sometime
between 1968 and 1972. A third set of firing stations was added to the west of the other two sets
between 1974 and 1976. A fourth set was added between 1988 and 1989. Prior to being used as
a skeet/trap range, the site was a parasail course.
B.2.2 Methodology for Selection of Chemicals of Potential Concern
This section presents the procedure used to identify the COPC for Sites 86 and 87. The
analytical data were organized by IRP site and medium into individual data sets (e.g., Site 86
surface soil). For individual data sets that contained nondetects (i.e., data which were "U" or
"UJ" qualified), the detection limit of the nondetected result was divided by two before any
statistical calculation were performed. Samples with duplicates were averaged and treated as a
single result for any statistical calculations. Both of these steps are in accordance with USEPA
guidance [USEPA 1989]. All statistical calculations were performed using STATISTICA for
Windows Version 5 [StatSoft, Inc. 1996]. The following statistical manipulations were
performed on each of the individual data sets:
Frequency Sampled - Number of samples that were collected and analyzed for a
particular chemical in a specific medium. Field duplicate samples for the same
sample locations were averaged and counted as a single sample.
• Number of Detections - Number of detections of a particular chemical in a
specific medium.
• Maximum Concentration - Highest concentration of a particular chemical in a
specific medium.
R178-98/ES/3920001 .AWS
B-2
-------
• Minimum Concentration - Lowest concentration of a particular chemical in a
specific medium. This value may be one half of the detection limit for data sets
which contain nondetects.
• Mean Concentration - Arithmetic mean of a particular chemical in a specific
medium.
• Standard Deviation - Sample standard deviation of a particular chemical in a
specific medium.
• Upper 95-Percent Confidence Limit of the Mean - Upper 95-percent confidence
limit of the mean was calculated for a chemical in a specific medium using the
Student's / statistic and assuming that the analytical data are normally distributed.
Refer to the CBRA [IT 1996] for additional information on the summary statistics calculation
methodology outlined above.
Subsequent to the statistical calculations, analytical results were screened using criteria from
USEPA guidance [USEPA 1989] to focus the risk assessment process onto those constituents
that were COPC. The screening criteria included the following:
• Chemicals of potential concern which were 100 percent nondetects for a given
medium were eliminated from consideration.
If inorganic chemicals were present in soil at naturally occurring background
levels (the maximum detected concentration were evaluated for comparison), they
were eliminated from consideration.
• All metals which are considered essential nutrients were eliminated from
consideration.
The remaining COPC were carried through the risk assessment process. For further information
on the screening criteria outlined above, refer to the CBRA [IT 1996].
B.2.3 Chemicals of Potential Concern
The analytical data for Sites 86 and 87 are summarized in Tables B-l through B-4. Included in
this summary are the number of samples, the number of detections, the maximum and minimum
values, the mean, the standard deviation, the 95 percent upper confidence limit of the mean, if the
analyte is a COPC, and the reason for exclusion if the analyte is not a COPC.
R178-98/ES/392000I .AWS
B-3
-------
Table B-l. Statistical Summary for Chemicals of Potential Concern
for Site 86 Soils at Mather Air Force Base(a)
Chemical
Antimony
Arsenic
Barium
Copper
Lead
Tin
Zinc
Units
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
Background
12
8
375
93
14
NA
116
Number
Sampled
5
5
5
5
5
5
5
Number
Detected
4
5
5
5
5
0
5
Minimum
Value
O.I
9
96
34
86
NA
53
Maximum
Value
5.2
II
258
118
1660
NA
72
Mean
1.4
10
196
57
467
NA
59
Standard
Deviation
2.1
1
61
35
675
NA
8
95% Confidence
Limit on the Mean
4.1
11
27!
113
1305
NA
68
Chemical of
Concern
No
Yes
No
Yes
Yes
No
No
Reason for
Exclusion
(b)
-------
Table B-2. Statistical Summary for Chemicals of Potential Concern for Site 87 Soils at Mather Air Force Base(a)
Chemical
Antimony
Arsenic
Barium
Copper
Lead
Tin
Zinc
Acenaphthene
Acenaphthylene
Anthracene
Benzo(a)anthracene
Benzo{a)Pyrene
Benzo(b)Fluoranlhene
Benzo(g,h,i)perylene
3enzo(k)Fluoranthene
Chrysene
Dibenz(a,h)anthracene
Huoranlhene
rluorene
lndeno( 1 ,2,3-cd)Pyrene
Naphthalene
'henanlhrene
Pyrene
Units
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
Mg/kg
Mg/kg
Mg/kg
Mg/kg
Mg/kg
Mg/kg
Mg/kg
Mg/kg
Mg/kg
Mg/kg
Mg/kg
Mg/kg
Mg/kg
Mg/kg
Mg/kg
Mg/kg
Background
12
8
375
93
14
NA
116
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Number
Sampled
II
II
II
II
II
II
II
13
13
13
13
13
13
13
13
13
13
13
13
13
13
13
13
Number
Detected
6
II
II
II
II
1
II
0
0
0
9
9
9
9
9
9
8
6
0
9
0
6
8
Minimum
Value
O.I
5
92
14
9
37
28
NA
NA
NA
1
1
1
1
1
1
2.6
1
NA
1
NA
1
1
Maximum
Value
4.9
18
270
53
1330
105
81
NA
NA
NA
2390
3670
2800
3380
1110
3750
970
2720
NA
2540
NA
603
4900
Mean
1.3
8
152
22
390
43
43
NA
NA
NA
506
819
603
737
242
817
282
704
NA
526
NA
208
1075
Standard
Deviation
1.9
4
48
II
488
21
14
NA
NA
NA
771
1152
868
1033
342
1203
334
993
NA
771
NA
217
1666
95% Confidence
Limit on the Mean
2.6
II
185
30
718
57
53
NA
NA
NA
972
1515
1127
1361
449
1544
484
1304
NA
992
NA
339
2082
Chemical of
Concern
No
Yes
No
No
Yes
Yes
No
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
Yes
No
Yes
Yes
Reason Tor
Exclusion
(b)
(b)
(b)
(b)
(c)
(c)
(c)
(c)
(c)
to
(a) One half of the detection limit reported for nondetects, and duplicate samples were averaged.
(b) Chemical not of concern based on comparison to background.
(c) Chemical not of concern, all samples nondetects.
mg/kg = milligram per kilogram.
ug/kg = microgram per kilogram.
NA = Not applicable.
-------
Table B-3. Statistical Summary for Chemicals of Potential Concern for Site 87 Sediment at Mather Air Force Base(a)
Chemical
Antimony
Arsenic
Barium
Copper
Lead
Tin
Zinc
Acenaphihene
Acenaphthylene
Anthracene
3enzo(a)anthracene
3enzo(a)Pyrene
3enzo(b)Fluoranthene
3enzo(g,h,i)perylene
3enzo(k)Fluoranlhene
Chryscne
3ibenz(a,h)anthracene
rluoranthene
rluorene
lndeno(l,2.3-cd)Pyrene
Naphthalene
'henanthrene
'yrene
Units
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
mg/kg
Mg/kg
Mg/kg
Mg^g
Mg/kg
Mg/kg
Mg/kg
Mg/kg
Mg/kg
Mg/kg
Mg/kg
Mg/kg
Mg/kg
Mg/kg
Mg/kg
Mg/kg
Mg/kg
Background
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Number
Sampled
4
4
4
4
4
4
4
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
Number
Delected
2
4
4
4
4
0
4
0
0
0
1
1
1
1
1
1
1
0
0
1
0
0
1
Minimum
Value
O.I
6
131
18
29
NA
34
NA
NA
NA
4.8
8
6.5
16.5
6
33.5
10.5
NA
NA
13.8
NA
NA
53.5
Maximum
Value
21.0
49
302
58
6305
NA
93
NA
NA
NA
9.4
18
66
27
7
55
13
NA
NA
16
NA
NA
95
Mean
6.7
19
189
31
1966
NA
55
NA
NA
NA
7.1
13
36
22
6.5
44
12
NA
NA
15
NA
NA
74
Standard
Deviation
9.9
20
76
18
2973
NA
27 _,
NA
NA
NA
3.25
6.7
42
7.1
0.71
15
1.6
NA
NA
1.6
NA
NA
29
95% Confidence
Limit on the Mean
22.4
51
311
60
6697
NA
97
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Chemical of
Concern
Yes
Yes
Yes
Yes
Yes
No
Yes
No
No
No
Yes
Yes
Yes
Yes
Yes
Yes
Yes
No
No
Yes
No
No
Yes
Reason for
Exclusion
(b)
(b)
(b)
(b)
(b)
(b)
(b)
(b)
w
(a) One half of the detection limit reported for nondetects, and duplicate samples were averaged.
(b) Chemical not of concern, all samples nondetects.
mg/kg = milligram per kilogram.
Mg/kg = microgram per kilogram.
NA = Not applicable.
RJVI-9S/ES/392000I.AWS
-------
Table B-4. Statistical Summary for Chemicals of Potential Concern for Site 87 Surface Water at Mather Air Force Base(a)
Chemical
Antimony
Arsenic
Barium
Copper
Lead
Tin
Zinc
Acenaphlhene
Acenaphlhylene
Anthracene
Benzo(a)anthracene
Benzo(a)Pyrene
Benzo(b)Fluoranthene
3enzo(g,h,i)perylene
Uenzo(k)Fluoranthene
Chrysene
Dibenz(a,h)anthracene
Fluoranthene
Fluorene
lndcno(l,2,3-cd)Pyrene
Naphthalene
Phenanthrene
Pyrene
Units
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Mg/L
Background
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Number
Sampled
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
2
Number
Delected
1
0
2
0
1
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
0
Minimum
Value
0.8
NA
87
NA
0.6
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Maximum
Value
2
NA
89
NA
1
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Mean
1.4
NA
88
NA
0.8
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Standard
Deviation
0.9
NA
1.4
NA
0.3
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
95% Confidence
Limit on the Mean
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
NA
Chemical of
Concern
Yes
No
Yes
No
Yes
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
No
Reason for
Exclusion
(b)
(b)
(b)
(b)
(b)
(b)
(b)
(b)
(b)
(b)
(b)
(b)
(b)
(b)
(b)
(b)
(b)
(b)
(b)
(b)
w
(a) One half of the detection limit reported For nondetects, and duplicate samples were averaged.
(b) Chemical not of concern, all samples nondetects.
mg/L = milligram per liter.
Hg/L = microgram per liter.
NA = Not applicable.
1920001.AWS
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B.3 Exposure Assessment
This chapter identifies exposure pathways and quantifies chemical intakes. The purpose of this
exposure assessment is to estimate the type and magnitude of exposure to humans.
B.3.1 Exposure Pathways
For exposure and potential risks to occur, complete exposure pathways must exist. A complete
pathway requires the following elements [USEPA 1989]:
• a source and mechanism for release of contamination;
• a transport or retention medium;
• a point of potential human contact (exposure point); and
• an exposure route at the exposure point.
If any one of these elements is missing, the pathway is not considered complete. The following
is a brief discussion of the exposure pathway elements.
Exposure points are locations of human contact with contaminated media. Exposure points
consider human activity patterns and the location of potentially exposed individuals relative to
the location of contaminated media. There are two scenarios for the metals (primarily lead)
where potential contact may occur. The first assumes the potential receptor ingests intact lead
shot or slugs in soil, and the second assumes that the lead shot has decomposed and dispersed
throughout the soil. The analytical data summarized in Section B.2.3 assumes that the lead has
decomposed and is dispersed throughout the soil. Risks due to ingestion of intact lead shot are
discussed in Section B.5.4 below. Risks due to the decomposition of lead are summarized in
Section B.5.5.
For this risk assessment, contact with potentially contaminated media takes place as a result of
occupational, residential, and recreational receptors. To maintain the conservative methodology
of RAGS [USEPA 1989], the contact point for soil contamination with all exposure scenarios is
assumed to be located at the contaminant source.
An exposure route is a way in which a chemical enters or comes into contact with the human
body. The following three exposure routes may be parts of exposure pathways:
• Ingestion;
• Inhalation;
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B-8
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• Dermal Contact; and
• Ingestion of Secondary Pathways.
Because of the current conditions at Mather AFB (i.e., the base is closed), there is no exposure
point (point of human contact) for the contamination considered in this risk assessment under
current conditions. The only complete exposure pathways occur under potential future land-use
scenarios. Refer to the CBRA [IT 1996] for additional information on the selection of potential
exposure pathways at Mather AFB. The complete exposure pathways are residential ingestion,
dermal contact, and ingestion of home grown produce for soil and sediment; residential ingestion
of surface water; occupational ingestion and dermal contact with soil and sediment; occupational
ingestion of surface water; recreational ingestion and dermal contact with soil and sediment; and
recreational ingestion of surface water.
B.3.2 Quantification of Exposure
This section describes the estimation of exposure (intake) for the COPC that may come in to
contact with human receptors. The process involves the following:
• Identification of applicable human exposure models and input parameters.
Determination of the concentration of each chemical in environmental media at
the point of human exposure.
• Estimation of human intakes.
For each potentially complete future exposure pathway identified in Section B.3.1, a reasonable
maximum exposure (RME) scenario has been developed. The RME is the highest exposure that
is reasonably expected to occur at a site [USEPA 1989]. The intent of the RME, as defined by
the USEPA, is to estimate a conservative exposure case (i.e., well above the average case) that is
still within the possible range of exposures. The RME is both protective and reasonable but not
the worst possible case [USEPA 199la].
B. 3.2.1 Exposure Models
The primary source for the exposure models used in this baseline risk assessment is RAGS
[USEPA 1989]. Shown below is the generalized equation for calculating chemical intakes:
; = c CREFD
BW AT
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B-9
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where:
I = Intsike; the amount of chemical at the exchange boundary (milligrams [mg]
per kilogram [kg] body weight - day).
C = Chemical concentration at the exposure point; the concentration contacted
over the exposure period (e.g., mg per liter water or mg per kg soil).
CR = Contact rate; the amount of contaminated medium contacted per unit time
or event (e.g., mg per day soil ingestion rate or cubic meters per hour air
inhalation rate).
EFD = Exposure frequency and duration; describes how often and how long
exposure occurs. Often calculated using two terms (EF times ED).
EF = Exposure frequency (days/year).
ED = Exposure duration (years).
BW = Body weight; the average body weight over the exposure period (kg).
AT = Averaging time; period over which exposure is averaged (days).
The exposure models used in the calculation of intakes for Site 86 and 87 were identical to the
exposure models presented in the CBRA [IT 1996].
B. 3.2.2 Exposure Parameters
Three types of parameters are used in exposure models to estimate intake [USEPA 1989]:
• Chemical-related parameters (e.g., exposure point concentrations).
• Parameters that describe the exposed population (e.g., contact rate, exposure
frequency and duration, and body weight).
• Toxicity-related parameters (i.e., slope factors and reference doses).
The exposed population and exposure-related parameters are summarized in Table 3-13 of the
CBRA [IT 1996]. Please refer to the CBRA for a complete summary of the exposure parameters
used. The exposure parameters were taken from USEPA guidance [USEPA 1989] and are based
on best professional judgement using site-specific information where available. Upper-bound
values are generally 90th or 95th percentile values, depending on the data available for each
parameter. A combination of upper-bound and average exposure parameters were used to
estimate the RME for each scenario.
B.3.2.3 Intakes for Chemicals of Potential Concern
Noncarcinogenic and carcinogenic intakes at Sites 86 and 87 are tabulated and presented in
Section B.5.
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B-10
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B. 4 Toxicity Assessment.
The primary source for toxicity values, both reference doses (RfD) and slope factors (SF), is the
Integrated Risk Information System (IRIS) [USEPA 1997]. If a toxicity value for a given
chemical is not available in IRIS, the secondary sources included the Health Effects Assessment
Summary Tables [USEPA 1996], and the Region IX Cancer Potency Factors [CEPA 1994]. If
the SFs in the Region IX Cancer Potency Factors were more stringent, these toxicity value were
used in the calculation of risk. No surrogate values were developed for chemicals for which no
toxicity information existed in either of the above references for IRP Sites 86 and 87. The
CBRA [IT 1996] provides detailed information, including toxicity profiles, for all of the COPC
summarized below. Table B-5 summarizes the COPC toxicity information, including the RfDs,
SFs, and cancer classes.
B.5 Risk Characterization
This section provides a characterization of the potential health risks associated with the intake of
chemicals at Site 86 and 87. Risk characterization compares estimated potential cancer risks
with reasonable levels of risk for carcinogens and compares estimated daily intake (rate) with
reference levels for noncarcinogens. Carcinogens may also pose a systemic (noncarcinogenic)
hazard, and these potential hazards are characterized in the same manner as other
noncarcinogens.
Estimation of potential risk from exposure to the site contaminants is based on RAGS
[USEPA 1989]. This assessment employs a health-protective bias that leads to the
overestimation of the risk. Individuals are exposed to an RME in Section B.3.1 and evaluated in
Section B.3.2 to provide estimates of daily intakes. These estimated intakes (rates) are combined
with the individual chemical toxicological values (Section B.4.1) to determine the potential
carcinogenic risks and the potential systemic impacts on human health.
B. 5.1 Estimation of Carcinogenic Risk
In weighing occupational exposure to potentially carcinogenic compounds, a reasonable level of
risk must be selected. The USEPA used an incremental lifetime cancer risk (ILCR) (also referred
to as excess cancer risk) of one-in-one-million (I x I0~6) as the lower bound of an acceptable
range for developing drinking water standards. The upper bound of an acceptable ILCR
recommended by the USEPA for drinking water is one-in-ten-thousand (I x 10"*)
[USEPA 1987]. In addition, the USEPA specifies a risk range of 10"6 to I0'4 associated with the
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B-ll
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Table B-5. Human Toxicity Factors Used for Calculation of Incremental Lifetime
Cancer Risk and Hazard Index from Exposure to Chemicals of Potential Concern
at IRP Site 86 and 87(a)
Contaminant of Concern
Antimony
Arsenic
Barium
Copper
Lead
Tin
Zinc
Benzo(a)anthracene
Benzo(a)Pyrene
Benzo(b)Fluoranthene
Benzo(g,h,i)perylene
Benzo(k)Fluoranthene
Chrysene
Dibenz(a,h)anthracene
Fluoranthene
Indeno( 1 ,2,3-cd)Pyrene
Phenanthrene
Pyrene
Reference Doses
Oral
(mg/kg-day)
4.0 x ID"04
3.0 x lO"04
7.0 x 10-02
3.7 x lO*2
ND
6.0 x 10-°'
3.0 x 10-*'
ND
ND
ND
ND
ND
ND
ND
4.0 x ID"02
ND
3.0 x 10-°'
3.0 x 10-02
Inhalation
(mg/kg-day)
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
ND
Slope Factors
Oral
(mg/kg-day)-'
ND
1.5
ND
NA
ND
ND
NA
7.3 x IO-01
l.2x 10*°'
7.3 x JO-01
NA
7.3 x 10-*'
7.3 x IO-03
7.3
NA
7.3 x lO*1
NA
NA
Inhalation
(mg/kg-day)-1
ND
1.5x 10"'
ND
NA
ND
ND
NA
ND
ND
ND
NA
ND
ND
ND
NA
ND
NA
NA
Cancer Class
ND
A
ND
D
ND
ND
D
B2
B2
B2
D
B2
B2
B2
D
B2
D
D
Note: The U.S. Environmental Protection Agency definition of cancer class is: Class A - definite human
carcinogen; Class B2 - probable human carcinogen based on sufficient evidence of animal data; and Class D
- non carcinogenic.
(a) All toxicity values from Integrated Risk Information System [USEPA 1997], unless otherwise stated.
ND = No data available to establish toxicity factor
NA = Not considered to be carcinogenic to humans [USEPA 1997]
mg/kg = milligrams per kilogram
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B-12
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consideration and selection of remedial alternatives for contaminated land in the "National Oil
and Hazardous Substances Pollution Contingency Plan" (NCP) [USEPA 1990].
Based on the regulatory precedents cited above, a reasonable and appropriate ILCR range would
be from 10"6 to 10~4. As implemented under the NCP, pathway ILCR greater than 10"6 must
receive risk management consideration [USEPA 1990]. The quantitative risk assessment is one
of many factors that is considered in the decision-making process for remediation. Therefore,
there is no single risk value that defines "acceptable" and "unacceptable" risk. The purpose of
this risk assessment is to present quantitative and qualitative estimates of potential risk, and thus,
all pathway risk greater than the lower bound of 10"6 will be examined.
For IRP Sites 86 and 87, cumulative site ILCRs were developed. These cumulative ILCRs
included all media and pathways that were appropriate to combine. These pathways occur when
there is potential for an individual to be exposed to multiple pathways at the same given instant
in time. Where the cumulative site ILCR to an individual based on the RME for both current and
future land use is less than 10"4, action generally is not warranted unless there is adverse
environmental impacts [USEPA 1991b].
Carcinogenic risk is estimated as the probability of an additional incidence of cancer above
background. This risk is:
ILCR = SF Intake
where:
ILCR = ILCR (unitless)
SF = Carcinogenic SF [(mg/kg-day)"1]
Intake = Chronic daily intake averaged over a 70-year lifetime (mg/kg-day).
The carcinogenic SFs for the COPC were presented in Table B-5.
For a given pathway and medium with exposure to several carcinogens, the following equation
was used to sum the cancer risk:
/
M = £
i = I
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B-13
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where:
Risk, p = Total cancer risk for pathway p (unitless)
= Individual cancer risk for constituent i through exposure pathway p
(unitless).
Estimates of ILCRs are provided for each exposure pathway in Section B.5.5.
B. 5.2 Estimation of Noncarcinogenic Risk
Chemicals that pose a health threat other than cancer were evaluated by comparing an exposure
level or intake to an acceptable level or RfD. The ratio of estimated daily intake to the RfD is
termed the hazard quotient (HQ) and is defined as:
HQ. = —ii-
'•" RfD(
where:
HQj p = Individual HQ for exposure to constituent i through exposure pathway p
(unitless)
Ii p = Daily intake via a specific pathway p for constituent i (mg/kg-day)
RfDj = RfD for exposure by the specific pathway (limited to oral and inhalation
values) for constituent i (mg/kg-day).
The RfD is an estimate of the intake level to which a human population, including sensitive
subpopulations, may be chronically exposed without a significant risk of adverse health effects
[USEPA 1989]. The RfDs for the COPC are listed in Table B-5. Because the HQ does not
define intake response relationships, its numerical value should not be construed as a direct
estimate of risk, but it does suggest that a given situation should be more closely scrutinized.
The concept of the HQ implies the existence of a threshold for systemic health effects. It is a
numerical indication of the fraction of acceptable limits of exposure or the degree to which
acceptable exposure levels are exceeded. As this quotient increases toward unity, concern for the
potential hazard of the constituent increases. A value above unity is an indication of risk,
although a direct correlation to the magnitude of the risk cannot be drawn.
In the case of simultaneous exposure to several chemicals, the hazard index (HI) is calculated to
evaluate the potential risk from exposure to the mixture by summing the HQs for each chemical,
media, and pathway. The total HI incorporates the assumption of additive effects when dealing
RL/&-98/ES/392000I .AWS
B-14
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with a mixture of components. The HI formula is as follows [USEPA 1989]:
HI =
where:
HI = Hazard index (unitless)
HQ, = Hazard quotient for exposure to constituent i (unitless).
Summation of the individual HQs could result in an HI that exceeds 1.0, even if no single
chemical exceeds its acceptable level. Mechanistically, it is not appropriate to sum HQs unless
the constituents that make up the mixture have similar modes of action on an identical organ.
Consequently, the summing of HQs for a mixture of compounds that is not expected to include
the same type of effects could overestimate the potential risk. The USEPA recommends that if
the total HI is greater than unity, the components of the mixture should be grouped by critical
effect, and separate hazard indices should be calculated for each effect.
Estimates of noncarcinogenic risks for each occupational exposure pathway are provided in the
following section.
B. 5.3 Department of Toxic Control Leadspread VI
Risk for inorganic lead in soil was calculated using the DTSC LEADSPREAD model Version VI
[DTSC 1992]. LEADSPREAD was run for both Sites 86 and 87, due to the fact that lead
concentrations for both sites were above 130 parts per million (ppm). This level was established
as an "action level". Lead concentrations below 130 ppm do not pose significant risk
[DTSC 1992].
Four different LEADSPREAD runs were completed for each IRP site considered; one with plant
uptake on and one with plant uptake off, for both the 95 percent upper confidence limit
concentration and the maximum concentration. Therefore, the potential worst case scenario of
on-site gardening at the maximum concentrations has been considered. Lead in dissolved water
at a concentration of 15 micrograms per liter (ug/L) (the LEADSPREAD default) was not
changed. This default is based on the federal action level concentration of lead in tap water. The
highest concentration for lead in groundwater on Mather AFB to date is 1.6 ug/L. There are no
regional or site specific data for lead in air, therefore, the LEADSPREAD default value of
0.15 micrograms per cubic meter was used.
RU8-98/ES/392000I .AWS
B-15
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B.5.4 Risks Due to Chronic Exposure to Largely Intact Lead Shot or Slugs
Risks due to the chronic ingestion of largely intact lead shot, are difficult to evaluate because of
the numerous factors that influence ingestion rates which are unknown or hard to quantify.
These factors include:
• surface area of soil to which the child is exposed;
• probability of a locating lead shot in the given exposure area;
• probability of ingesting a single lead shot;
• probability of locating and ingesting multiple lead shot; and
• percentage of lead shot which is biologically available.
The above factors in combination with the uncertainties already built into the LEADSPREAD
model make it difficult to quantify the risk due to total lead shot. However, with some simple
assumptions it may be possible to quantify the number of shot per a given area which would
exceed allowable lead soil concentrations. These assumption would include:
• the amount (or percentage) of lead shot which has decomposed;
the mass of the remaining lead shot in soil including any crust material which may
have built up on the shot; and
• the percentage of lead in shot which is bioavailable.
B. 5.5 Results of the Human Health Risk Characterization
Tables B-6 through B-9 summarize the risks for the each exposure pathway for IRP Sites 86
and 87 at Mather AFB. Included in this summary is the carcinogenic and noncarcinogenic
intakes; ILCR and HQ for each COPC and pathway; and pathway total ILCR and HQ.
Table B-10 summarizes the LEADSPREAD run for Sites 86 and 87. This output summarizes the
blood lead level concentrations for three potential receptors: adult, child, and occupational.
Children are the most sensitive subpopulation, and represent the greatest potential for risk due to
exposure to lead. The whole-blood level of concern for children is 10 ug/deciliter of whole
blood. The point of departure for risk management is a 0.01 (99 percent confidence) risk of
exceeding this value [DTSC 1992].
The human health risk assessment suggests that the level of soil contamination found at both of
these sites does pose a potential significant risk. Both sites had soil lead levels above the
acceptable residential soil lead level of 130 ppm. Site 86 had a total cumulative site residential
RU8-98/ES/392000I .AWS
B-16
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Table B-6. Estimated Daily Intakes and Incremental Lifetime Cancer
Risks at Site 86 for Mather Air Force Base
Potentially Exposed
Population
Residential
Residential
Occupational
Occupational
Recreational
Recreational
Exposure Pathway
Incidental Ingestion of
Soil
Dermal Contact with Soil
Incidental Ingestion of
Soil
Dermal Contact with Soil
Incidental Ingestion of
Soil
Dermal Contact with Soil
Constituent
Arsenic
Arsenic
Arsenic
Arsenic
Arsenic
Arsenic
Estimated
Intake
(mg/kg-day)
I.7E-05
5.7E-06
I.9E-06
3.5E-06
7.3E-06
3.7E-06
ILCR
2.5E-05
8.6E-06
2.8E-06
5.3E-06
I.IE-05
5.5E-06
ILCR - incremental lifetime cancer risk
mg/kg = milligrams per kilogram
RL/8-98/ES/392000I .AWS
B-17
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Table B-7. Estimated Daily Intakes and Hazard Quotients
at Site 86 for Mather Air Force Base
Potentially Exposed
Population
Residential
Residential
Occupational
Occupational
Recreational
Recreational
Exposure Pathway
Incidental Ingestion of
Soil
Dermal Contact with Soil
incidental Ingestion of
Soil
Dermal Contact with Soil
Incidental Ingestion of
Soil
Dermal Contact with Soil
Constituent
Arsenic
Copper
Total
Arsenic
Copper
Total
Arsenic
Copper
Total
Arsenic
Copper
Total
Arsenic
Copper
Total
Arsenic
Copper
Total
Estimated
Intake
(mg/kg-day)
1.5E-04
I.6E-03
4.1E-05
1.4E-04
5.3E-06
5.5E-05
9.9E-06
3.4E-05
6.6E-05
6.8E-04
I.8E-05
6.2E-05
HQ
5.IE-01
4.3E-02
5.5E-OI
1.4E-01
3.9E-03
I.4E-OI
1.8E-02
I.5E-03
I.9E-02
3.3E-02
9.3E-04
3.4E-02
2.2E-OI
1.8E-02
2.4E-01
5.9E-02
I.7E-03
6.IE-02
mg/kg = milligrams per kilogram
HQ = hazard quotient
RU8-98/ES/392000 LAWS
B-18
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Table B-8. Estimated Daily Intakes and Incremental Lifetime Cancer
Risks at Site 87 for Mather Air Force Base
Potentially Exposed
Population
Residential
Residential
Residential
Occupational
Occupational
Exposure Pathway
Incidental Ingestion of
Soil
Dermal Contact with Soil
Ingestion of Home Grown
Produce (soils)
Incidental Ingestion of
Soil
Dermal Contact with Soil
Constituent
Arsenic
Benzo(a)Pyrene
3enzo(b)Fluoranthene
Benzo(k)Fluoranthene
Chrysene
Dibenz(a,h)anthracene
lndeno( 1 ,2,3-cd)Pyrene
Total
Arsenic
3enzo(a)Pyrene
3enzo(b)Fluoranthene
3enzo(k)Fiuoranthene
Chrysene
Dibenz(a,h)anthracene
Indeno( 1 ,2,3-cd)Pyrene
Total
Benzo(a)Pyrene
Benzo(b)Fluoranthene
Benzo(k)Fluoranthene
Chrysene
Dibenz(a,h)anthracene
Indeno( 1 ,2,3-cd)Pyrene
Total
Arsenic
Benzo(a)Pyrene
Benzo(b)Fluoranthene
Benzo(k)Fluoranthene
Chrysene
Dibenz(a,h)anthracene
lndeno( 1 ,2,3-cd)Pyrene
Total
Arsenic
Benzo(a)Pyrene
Benzo(b)Fluoranthene
Benzo(k)Fluoranthene
Chrysene
Dibenz(a,h)anthracene
lndeno( 1 ,2,3-cd)Pyrene
Total
Estimated
Intake
(mg/kg-day)
I.7E-05
2.4E-06
1.8E-06
7.0E-07
2.4E-06
7.6E-07
1.6E-06
5.6E-06
4.0E-06
3.0E-06
I.2E-06
4.IE-06
1.3E-06
1.8E-06
2.0E-06
I.4E-06
4.3E-07
2.2E-06
5.2E-07
1 .OE-06
I.9E-06
2.6E-07
2.0E-07
7.8E-08
2.7E-07
8.5E-08
1.7E-07
3.5E-06
2.5E-06
1.8E-06
7.3E-07
2.5E-06
7.9E-07
I.IE-06
ILCR
2.5E-05
2.8E-05
I.3E-06
5.IE-07
I.8E-08
5.5E-06
I.IE-06
6.2E-05
8.4E-06
4.8E-05
2.2E-06
8.7E-07
3.0E-08
9.4E-06
1.3E-06
7.0E-05
2.4E-05
1. OE-06
3.2E-07
1.6E-08
3.8E-06
7.5E-07
3.0E-05
2.8E-06
3.2E-06
I.4E-07
5.7E-08
2.0E-09
6.2E-07
I.3E-07
6.9E-06
5.2E-06
3.0E-05
I.3E-06
5.4E-07
I.8E-08
5.8E-06
7.9E-07
4.3E-05
RL/8-98/ES/392000 LAWS
B-19
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Table B-8. Estimated Daily Intakes and Incremental Lifetime Cancer
Risks at Site 87 for Mather Air Force Base (Continued)
Potentially Exposed
Population
Recreational
Recreational
Residential
Residential
Residential
Exposure Pathway
Incidental Ingestion of
Soil
Dermal Contact with Soil
Incidental Ingestion of
Sediment
Dermal Contact with
Sediment
Ingestion of Home Grown
Produce (Sediment)
Constituent
Arsenic
Benzo(a)Pyrene
8enzo(b)FI uoranthene
Bcnzo(k)Fluoranthene
Chrysene
Dibenz(a,h)anthracene
lndeno( 1 ,2,3-cd)Pyrene
Total
Arsenic
Benzo(a)Pyrene
Benzo(b)Fluoranthene
Benzo(k)Fluoranthene
Chrysene
Dibenz(a,h)anthracene
Indeno(I,2,3-cd)Pyrene
Total
Arsenic
Benzo(a)Pyrene
Benzo(b)Fluoranthene
Bcnzo(k)Fluoranthene
Chrysene
Dibenz(a,h)anthracene
lndeno( 1 ,2,3-cd)Pyrene
Total
Arsenic
Benzo(a)Pyrene
Benzo(b)Fluoranthenc
Benzo(k)Fluoranthene
Chrysene
Dibenz(a,h)anthracene
Indeno( 1 ,2,3-cd)Pyrene
Total
Benzo(a)Pyrene
Benzo(b)Fluoranthene
Benzo(k)Fluoranthene
Chrysene
Dibenz(a,h)anthracene
lndeno(l,2,3-cd)Pyrene
Total
Estimated
Intake
(mg/kg-day)
7.1E-06
l.OE-06
7.6E-07
3.0E-07
l.OE-06
3.2E-07
6.7E-07
3.6E-06
2.6E-06
I.9E-06
7.7E-07
2.6E-06
8.3E-07
1.1E-06
7.6E-05
2.7E-08
I.OE-07
I.1E-08
8.6E-08
2.0E-08
2.5E-08
2.6E-05
4.6E-08
I.7E-07
1 .9E-08
1.5E-07
3.4E-08
2.8E-08
2.3E-08
8.3E-08
6.7E-09
7.8E-08
I.4E-08
1 .7E-08
1LCR
I.1E-05
1.2E-05
5.5E-07
2.2E-07
7.6E-09
2.4E-06
4.9E-07
2.6E-05
5.4E-06
3.1E-05
I.4E-06
5.6E-07
1.9E-08
6.0E-06
8.3E-07
4.5E-05
1.1E-04
3.3E-07
7.5E-08
8.0E-09
6.3E-IO
I.5E-07
I.8E-08
I.IE-04
3.9E-05
5.6E-07
I.3E-07
I.4E-08
I.1E-09
2.5E-07
2.IE-08
4.0E-05
2.8E-07
6.0E-08
4.9E-09
5.7E-10
I.OE-07
I.2E-08
4.6E-07
RLft-9S/ES/3920001 .A WS
B-20
-------
Table B-8. Estimated Daily Intakes and Incremental Lifetime Cancer
Risks at Site 87 for Mather Air Force Base (Continued)
Potentially Exposed
Population
Occupational
,
Occupational
Recreational
Recreational
Residential
Occupational
Exposure Pathway
Incidental ingestion of
Sediment
Dermal Contact with
Sediment
Incidental Ingestion of
Sediment
Dermal Contact with
Sediment
Incidental Ingestion of
Surface Water
Incidental Ingestion of
Surface Water
Constituent
Arsenic
Benzo(a)Pyrene
Benzo(b)Fluoranthene
Benzo(k)Fluoranthene
Chrysene
Dibenz(a,h)anthracene
lndeno( 1 ,2,3-cd)Pyrene
Total
Arsenic
Benzo(a)Pyrene
Benzo(b)Fluoranthene
Benzo(k)Fluoranthene
Chrysene
Dibenz(a,h)anthracene
Indeno( 1 ,2,3-cd)Pyrene
Total
Arsenic
Benzo(a)Pyrene
Benzo(b)Fluoranthene
Benzo(k)Fluoranthene
Chrysene
Dibenz(a,h)anthracene
lndeno( 1 ,2,3-cd)Pyrene
Total
Arsenic
Benzo(a)Pyrene
Benzo(b)Fluoranthene
Benzo(k)Fluoranthene
Chrysene
Dibenz(a,h)anthracene
lndeno(I,2,3-cd)Pyrene
Total
Estimated
Intake
(mg/kg-day)
8.5E-06
3.1E-09
1.IE-08
I.2E-09
9.6E-09
2.2E-09
2.8E-09
1.6E-05
2.9E-08
1.1E-07
I.IE-08
9.0E-08
2.IE-08
1.7E-08
3.3E-05
I.2E-08
4.4E-08
4.7E-09
3.7E-08
8.6E-09
I.IE-08
I.7E-05
3.0E-08
I.IE-07
I.2E-08
9.4E-08
2.2E-08
I.8E-08
ILCR
1.3E-05
3.7E-08
8.4E-09
8.9E-10
7.0E-I1
I.6E-08
2.0E-09
I.3E-05
2.4E-05
3.4E-07
7.8E-08
8.4E-09
6.6E-10
1.5E-07
I.3E-08
2.4E-05
4.9E-05
I.4E-07
3.2E-08
3.4E-09
2.7E-IO
6.3E-08
7.8E-09
4.9E-05
2.5E-05
3.6E-07
8.2E-08
8.7E-09
6.9E-IO
1.6E-07
I.3E-08
2.6E-05
No carcinogenic chemicals of potential concern
No carcinogenic chemicals of potential concern
JLCR = incremental lifetime cancer risk
mg/kg = milligrams per kilogram
RL/8-98/ES/392000I .AWS
B-21
-------
Table B-9. Estimated Daily Intakes and Hazard Quotients
at Site 87 for Mather Air Force Base
Potentially Exposed
Population
Residential
Residential
Residential
Occupational
Occupational
Recreational
Exposure Pathway
Incidental Ingestion of
Soil
Dermal Contact with Soil
Ingestion of Home Grown
Produce (soils)
Incidental Ingestion of
Soil
Dermal Contact with Soil
Incidental Ingestion of
Soil
Constituent
Arsenic
Tin
Benzo(a)anthracene
Fluorantfiene
Phenanthrene
Pyrene
Total
Arsenic
Tin
Benzo(a)anthracene
Fluoranthene
Phenanthrene
Pyrene
Total
Benzo(a)anthracene
Fluoranthene
Phenanthrene
Pyrene
Total
Arsenic
Tin
Benzo(a)anthracene
Fluoranthene
Phenanthrene
Pyrene
Total
Arsenic
Tin
Benzo(a)anthracene
Fluoranthene
Phenanthrene
Pyrene
Total
Arsenic
Tin
Benzo(a)anthracene
Fluoranthene
Phenanthrene
Pyrene
Total
Estimated
Intake
(mg/kg-day)
1.5E-04
8.IE-04
1.4E-05
1.8E-05
4.8E-06
2.9E-05
4.IE-05
7.3E-05
1.2E-06
2.5E-05
6.5E-06
4.0E-05
2.9E-06
l.OE-05
3.7E-06
I.6E-05
5.2E-06
2.8E-05
4.8E-07
6.4E-07
I.7E-07
I.OE-06
9.7E-06
I.7E-05
3.0E-07
6.0E-06
I.6E-06
9.5E-06
6.4E-05
3.5E-04
5.9E-06
7.9E-06
2.IE-06
I.3E-05
HQ
5.0E-01
1.3E-03
2.0E-04
4.6E-04
1.6E-05
9.8E-04
5.0E-OI
1.4E-01
1.2E-04
I.8E-05
6.3E-04
2.2E-05
1.3E-03
I.4E-01
4.IE-05
2.5E-04
I.2E-05
5.4E-04
8.5E-04
I.7E-02
4.6E-05
6.8E-06
I.6E-05
5.5E-07
3.4E-05
1.7E-02
3.2E-02
2.9E-05
4.2E-06
I.5E-04
5.2E-06
3.2E-04
3.3E-02
2.IE-OI
5.8E-04
8.4E-05
2.0E-04
6.9E-06
4.2E-04
2.2E-OI
RL/8-98/ES/3920001 .AWS
B-22
-------
Table B-9. Estimated Daily Intakes and Hazard Quotients
at Site 87 for Mather Air Force Base (Continued)
Potentially Exposed
Population
Recreational
Residential
Residential
Residential
Occupational
Occupational
Exposure Pathway
Dermal Contact with Soil
Incidental Ingestion of
Sediment
Dermal Contact with
Sediment
Ingestion of Home Grown
Produce (Sediment)
Incidental Ingestion of
Sediment
Dermal Contact with
Sediment
Constituent
Arsenic
Tin
3enzo(a)anthracene
•luoranthene
*henanthrene
Pyrene
Total
Antimony
Arsenic
Barium
Copper
Zinc
3enzo(a)anthracene
*yrene
Total
Antimony
Arsenic
Barium
Copper
Zinc
3enzo(a)anthracene
Pyrene
Total
Benzo(a)anthracene
Pyrene
Total
Antimony
Arsenic
Barium
Copper
Zinc
Benzo(a)anthracene
Pyrene
Total
Antimony
Arsenic
Barium
Copper
Zinc
Benzo(a)anthracene
Pyrene
Total
Estimated
Intake
(mg/kg-day)
I.7E-05
3.IE-05
5.3E-07
I.IE-05
2.8E-06
I.7E-05
3.0E-04
6.9E-04
4.3E-03
8.2E-04
I.3E-03
1.3E-07
1.3E-06
2.7E-05
1.9E-04
3.9E-04
7.4E-05
I.2E-04
I.2E-08
I.8E-06
2.8E-08
7.4E-07
I.OE-05
2.4E-05
1.5E-04
2.8E-05
4.5E-05
4.6E-09
4.6E-08
6.4E-06
4.4E-05
9.2E-05
I.8E-05
2.8E-05
2.9E-09
4.4E-07
HQ
5.8E-02
5.2E-05
7.6E-06
2.7E-04
9.3E-06
5.7E-04
5.9E-02
7.4E-OI
2.3E+00
6.1E-02
2.2E-02
4.4E-03
1.9E-06
4.5E-05
3.1E+00
6.7E-02
6.2E-OI
5.5E-03
2.0E-03
4.0E-04
I.7E-07
6.IE-05
7.0E-OI
4.0E-07
2.5E-05
2.5E-05
2.6E-02
7.9E-02
2.1E-03
7.6E-04
1.5E-04
6.6E-08
1.5E-06
1.IE-OI
1 .6E-02
I.5E-OI
1.3E-03
4.8E-04
9.5E-05
4.IE-08
1.5E-05
1.7E-01
RU8-98/ES/392000I.AWS
B-23
-------
Table B-9. Estimated Daily Intakes and Hazard Quotients
at Site 87 for Mather Air Force Base (Continued)
Potentially Exposed
Population
Recreational
Recreational
Residential
Occupational
Exposure Pathway
Incidental Ingestion of
Sediment
Dermal Contact with
Sediment
Incidental Ingestion of
Surface Water
Incidental Ingestion of
Surface Water
Constituent
Antimony
Arsenic
Barium
Copper
Zinc
Benzo(a)anthracene
Pyrene
Total
Antimony
Arsenic
Barium
Copper
Zinc
Benzo(a)anthracene
Pyrene
Total
Antimony
Barium
Total
Antimony
Barium
Total
Estimated
Intake
(mg/kg-day)
1.3E-04
2.9E-04
I.8E-03
3.5E-04
5.6E-04
5.7E-08
5.8E-07
1.2E-05
8.0E-05
I.7E-04
3.2E-05
5.IE-05
5.2E-09
7.8E-07
I.2E-07
5.IE-06
3.8E-08
I.7E-06
HQ
3.2E-OI
9.8E-OI
2.6E-02
9.5E-03
1.9E-03
8.1E-07
1.9E-05
I.3E+00
2.9E-02
2.7E-OI
2.4E-03
8.6E-04
1.7E-04
7.4E-08
2.6E-05
3.0E-01
2.9E-04
7.3E-05
3.6E-04
9.4E-05
2.4E-05
1.2E-04
HQ = hazard quotient
mg/kg = milligrams per kilogram
RL/8-98/ES/392000I .AWS
B-24
-------
Table B-10. Lead Blood Level Summary
Site
Media
95 % UCL Soil
Concentration
(ppm)
Maximum Soil
Concentration
(ppm)
Receptor
95% Blood Level
at UCL
Concentration
(Mg/dL)
99% Blood Level
at UCL
Concentration
(Mg/dL)
95% Blood Level
at Maximum
Concentration
(Mg/dL)
99% Blood Level
at Maximum
Concentration
(Mg/dL)
With Plant Uptake
86
87
87
Soil
Soil
Sediment
1305
718
6305
1660
1330
6305
Adult
Child
Industrial Adult
Adult
Child
Industrial Adult
Adult
Child
Industrial Adult
10.1
27.2
4.7
7.1
17.5
4.1
35.9
109.5
10.0
12.9
34.6
6.0
9.0
22.3
5.3
45.7
139.5
12.7
With No Plant Uptake
86
87
Soil
Soil
1305
718
1660
1330
Adult
Child
Industrial Adult
Adult
Child
Industrial Adult
5.2
15.5
4.7
4.4
11.2
4.1
6.6
19.7
6.0
5.6
14.2
5.3
12.0
33.0
5.1
10.3
27.6
4.8
35.9
109.5
10.0
5.6
18.1
5.1
5.2
15.6
4.8
15.2
42.1
6.5
13.1
35.2
6.1
45.7
139.5
12.7
7.1
23.0
6.5
6.6
19.9
6.1
32000 ffAWS
-------
Table B-10. Lead Blood Level Summary (Continued)
Site
87
Media
Sediment
95 % UCL Soil
Concentration
(ppm)
6305
Maximum Soil
Concentration
(ppm)
6305
Receptor
Adult
Child
Industrial Adult
95% Blood Level
at UCL
Concentration
(Mg/dL)
11.5
52.0
10.0
99% Blood Level
at UCL
Concentration
(ug/dL)
14.7
66.3
12.7
95% Blood Level
at Maximum
Concentration
(Mg/dL)
11.5
52.0
10.0
99% Blood Level
at Maximum
Concentration
(Mg/dL)
14.7
66.3
12.7
UCL = upper confidence limit
ppm = parts per million
= micrograms per deciliter
to
RL/8-98/ES/3920001 .AWS
-------
ILCR of 3.4 x \Q~5 with arsenic contributing all of the risk. However, the cumulative ILCR is
less than 1 x 10"4 and therefore, the site as a whole does not pose significant carcinogenic risk.
None of the COPC at Site 86 exceeded a HQ of 1.0. Site 87 had a total cumulative site
residential ILCR of 1.6 x 10"4 for soils and 1.5 x 10"4 for sediment with arsenic and polycyclic
aromatic hydrocarbons contributing all of the risk. Arsenic also exceeded a HQ of 1.0 for
residential incidental ingestion of sediment.
B. 5.6 Genera/ Uncertainties
The overriding uncertainties associated with the risk characterization are as follows:
• The extrapolation of toxic effects observed at the high doses necessary to conduct
animal studies to effects that might occur at much lower, more realistic doses.
• The extrapolation from toxic effects in laboratory animals to toxic effects in
humans (i.e., responses of animals may be different from responses of humans).
• Pathway analyses have been conservative and generally do not include fate and
transport considerations (such as dispersion, adsorption, etc.) in the estimates.
Extrapolations from laboratory animal studies form the basis for the derivation of factors used to
estimate risks. Uncertainties are taken into account when deriving RfDs and SFs. The risk
assessment utilized USEPA guidance in minimizing the uncertainties through the use of
published standards and criteria to evaluate risks posed by chemicals measured at George AFB.
In addition to the general uncertainties listed above, the sources of uncertainty in characterizing
risk at Sites 86 and 87 include the following paragraph
Risk assessment is ultimately an integrated evaluation of historical, chemical, analytical,
environmental, demographic, and toxicological data that are as site-specific as possible. To safe
guard against the effects of uncertainty in the evaluation, each step is biased toward health
protective estimations. Because each step builds on the previous one, this biased approach
should more than compensate for risk assessment uncertainties. In addition, the calculations
presented in this risk assessment do not necessarily accurately represent currently existing or
expected future exposure or health risks. Rather, they are estimates of potential risk only if all
the conservative assumptions are realized.
RU8-98/ES/3920001 .AWS
B-27
-------
B.6 References.
California Department of Toxic Substances Control (DISC), 1992, "Guidance for Site
Characterizations and Multimedia Risk Assessment for Hazardous Substances Release Sites,"
draft, Vol. 7, California Department of Toxic Substances Control, Sacramento, California.
California Environmental Protection Agency (CEPA), 1994, "California Cancer Potency
Factors," California Environmental Protection Agency, Office of Environmental Health Hazard
Assessment, Sacramento, California.
CEPA, see California Environmental Protection Agency.
DTSC, see California Department of Toxic Substances Control.
USEPA, see U.S. Environmental Protection Agency.
IT Corporation (IT), 1997, "Final Site Characterization Report for IRP Sites 86 and 87", IT
Corporation, Richland, Washington.
IT Corporation (IT), 1996, "Final Comprehensive Baseline Risk Assessment for Mather Air
Force Base, California", IT Corporation, Richland, Washington.
StatSoft, Inc. (1996), STATISTICA for Windows [Computer program manual], Tulsa, OK:
StatSoft, Inc., 2300 East 14th Street, Tulsa, OK 74104,
U.S. Environmental Protection Agency (USEPA), 1997, "Integrated Risk Information System
(IRIS)," on-line database, maintained by the U.S. Environmental Protection Agency,
Washington, D.C.
U.S. Environmental Protection Agency (USEPA), 1996, "Health Effects Assessment Summary
Tables (HEAST), Annual FY 1994," OERR 9200.6-303(92-1), Office of Emergency and
Remedial Response, Washington, D.C.
U.S. Environmental Protection Agency (USEPA), 1992a, "Supplemental Guidance to RAGS:
Calculating the Concentration Term,"Publication 9285.7-081, Office of Solid Waste and
Emergency Response, Washington, D.C., May 1992.
RL/8-98/ES/392000I .AWS
B-28
-------
U.S. Environmental Protection Agency (USEPA), 1992b, "Dermal Exposure Assessment:
Principles and Applications," Interim Report, USEPA/600/8-91/01 IB, Exposure Assessment
Group, Office of Health and Environmental Assessment, Washington, D.C.
U.S. Environmental Protection Agency (USEPA), 1991a, "Human Health Evaluation Manual,
Supplemental Guidance: Standard Default Exposure Factors," Memorandum, OSWER
Directive 9285.6-03, Office of Solid Waste and Emergency Response, Washington, D.C.
U.S. Environmental Protection Agency (USEPA), 1991b, "Role of the Baseline Risk Assessment
in Superrund Remedy Selection Decisions," OSWER Directive 9355.0-30, Office of Solid Waste
and Emergency Response, Washington, D.C.
U.S. Environmental Protection Agency (USEPA), 1990, "National Oil and Hazardous Substances
Pollution Contingency Plan (NCP)," Title 40, Code of Federal Regulations, Part 300, (40 CFR
300), U.S. Environmental Protection Agency, Washington, D.C.
U.S. Environmental Protection Agency (USEPA), 1989, "Risk Assessment Guidance for
Superfund" (RAGS), Vol. I, Human Health Evaluation Manual (Part A), OSWER
Directive 9285.7-0JA, Office of Emergency and Remedial Response, Washington, D.C.
U.S. Environmental Protection Agency (USEPA), 1987, "National Primary Drinking Water
Regulations Synthetic Organic Chemicals' Monitoring for Unregulated Contaminants," Federal
Register, Vol. 52, Washington, D.C., pp. 25690-25734.
RL/8-98/ES/3920001 .A WS
B-29
-------
Appendix C
Ecological Risk Assessment
for Mather Air Force Base
Sites 86 and 87
RU8-98/ES/392000I. AWS
-------
Table of Contents.
List of Figures C-iii
List of Tables C-iv
List of Acronyms • C-vi
C.I Introduction C-l
C.2 Problem Formulation C-l
C.2.1 Study Site Identification C-2
C.2.1.1 Site 86 - Former Military Firing Range C-2
C.2.1.2 Site 87 - Former Skeet/Trap Range C-2
C.2.2 Ecosystems Potentially at Risk C-2
C.2.2.1 Sites 86 - The Former Military Firing Range C-2
C.2.2.2 Site 87 - The Former Skeet/Trap Range C-3
C.2.3 Endpoint Selection C-5
C.2.4 Conceptual Model C-7
C.2.5 Chemicals of Potential Ecological Concern C-7
C.3 Analysis Phase C-7
C.3.1 Quantification of Exposure C-12
C.3.1.1 Terrestrial Exposure Models C-12
C.3.1.1.1 Vegetation C-12
C.3.1.1.2 Wildlife C-13
C.3.1.2 Aquatic Exposure Models C-18
C.3.1.2.1 Vegetation C-18
C.3.1.2.2 Wildlife C-19
C.3.1.2.3 Aquatic Macroinvertebrates C-19
C.3.2 Effects Characterization C-20
C.3.2.1 Plants C-20
C.3.2.2 Wildlife C-21
C.3.2.3 Aquatic Life C-21
RL/8-98/ES/392000 LAWS
C-i
-------
Table of Contents (Continued).
C.4 Risk Characterization C-24
C.4.1 Risk Estimation C-24
C.4.2 Risk Characterization C-25
C.4.2.1 Risk Assessment with Contaminants of Potential Ecological
Concern C-25
C.4.2.1.2 Site 86 C-25
C.4.2.1.3 Site 87 C-27
C.4.2.2.1 Site 86 C-33
C.4.2.2.2 Site 87 C-33
C.4.3 Identification of Uncertainties C-33
C.5 Summary and Conclusions C-34
RL/8-98/ES/3920001 .A WS
C-ii
-------
List of Figures.
Figure Title Page
C-l Generalized Food Web for the Grassland Communities at Mather
IRP Sites 86 and 87 C-4
C-2 Generalized Food Web for the Surface Water Drainage System
Communities at Mather IRP Site 87 C-5
C-3 Conceptual Model Grasslands C-7
C-4 Conceptual Model Surface Water Drainage Systems C-8
RL/8-98/ES/392000I.AWS
-------
List of Tables.
Table Title Page
C-1 Summary of Habitat-Specific Pathways Evaluated for
Mather Sites 86 and 87 C-3
C-2 Environmental Media of Potential Ecological Concern Present
at Mather Installation Restoration Program Sites 86 and 87 C-3
C-3 Chemicals of Potential Ecological Concern Associated with
Site 86 C-10
C-4 Chemicals of Potential Ecological Concern Associated with
Site 87 C-l 1
C-5 Soil-to-Plant and Soil-to-Insect Transfer Factors for Inorganic
Analytes in Vegetative Plant Parts C-13
C-6 Home Range Factors for Mather Air Force Base Indicator
Species C-14
C-7 Ecological Toxicity Summary Table: Plant Screening and
Toxicity Values C-20
C-8 Ecological Toxicity Summary Table: Mammalian Wildlife
Screening and Toxicity Values C-22
C-9 Ecological Toxicity Summary Table: Avian Screening and
Toxicity Values C-22
C-10 Ecological Toxicity Summary Table: Freshwater Aquatic
Screening and Toxicity Values C-23
C-11 Comparison of Concentrations of Chemicals of Potential
Ecological Concern in Soils and Plants to Phytotoxicity
Benchmark Values: Mather Air Force Base Site 86 C-26
C-l2 Ecological Hazard Quotients for Terrestrial Wildlife Indicator
Species Exposed to Contaminants Associated with Surface Soils:
Mather Air Force Base Site 86 C-26
C-13 Comparison of Concentrations of Chemicals of Potential
Ecological Concern in Soils and Plants to Phytotoxicity
Benchmark Values: Mather Air Force Base Site 87 C-28
RL/8-98/ES/392000I .AWS
C-iv
-------
List of Tables (Continued).
Table Title Page
C-14 Ecological Hazard Quotients for Terrestrial Wildlife Indicator
Species Exposed to Contaminants Associated with Surface Soils:
Mather Air Force Base Site 87 C-29
C-15 Potential Hazards to Wildlife Following Ingestion of Surface
Water: Mather Air Force Base Site 87 C-29
C-16 Comparison of Surface Water Concentrations to Water Quality
Objectives/Criteria for the Protection of Freshwater Aquatic
Life: Mather Air Force Base Site 87 C-30
C-17 Comparison of Sediment Concentrations with Sediment
Benchmark: Mather Air Force Base Site 87 C-30
C-18 Comparison of Concentrations of Chemicals of Potential
Ecological Concern in Sediments and Plants to Phytotoxicity
Benchmarks Values: Mather Air Force Base Site 87 C-31
C-19 Ecological Hazard Quotients for the Mallard and Great Blue
Heron Exposed to Contaminants Associated with Sediments and
Surface Waters: Mather Air Force Base Site 87(a) C-32
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C-v
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List of Acronyms.
AFB Air Force Base
CBRA Comprehensive Baseline Risk Assessment
CEPA California Environmental Protection Agency
COPEC chemicals of potential ecological concern
DTSC Department of Toxic Substances Control
IRP Installation Restoration Program
mg/kg milligrams per kilogram
NOAEL no-observed-adverse-effect levels
PAH polycyclic aromatic hydrocarbons
USEPA U.S. Environmental Protection Agency
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C. 1 Introduction.
This appendix addresses the overall ecological risks associated with exposure to chemicals of
potential ecological concern (COPECs) in surface soil, sediment, and surface water associated
with Installation Restoration Program (IRP) Site 86 (former Military Firing Range) and Site 87
(former Skeet/Trap Range) at Mather Air Force Base (AFB) in Sacramento, California. The
ecological risk assessment process performed for these sites follows the methodology used in the
Final Comprehensive Baseline Risk Assessment (CBRA) for Mather, AFB, California [IT 1996].
The methodology is consistent with a phased approach in the evaluation of ecological risks as
recommended in the updated USEPA guidance "Proposed Guidelines for Ecological Risk
Assessment" [USEPA 1996a] and in the guidance for Ecological Risk Assessment at Hazardous
Waste Sites and Permitted Facilities, part A: Overview" [DTSC 1996]. The ecological risk
assessment performed for Sites 86 and 87, as presented here, is a screening level evaluation.
This appendix presents discussion on major risk assessment elements including problem
formulation, analysis, and risk characterization.
C.2 Problem Formulation
Problem formulation the first step of an ecological risk assessment process. It can be defined as
a systematic planning step that identifies the major factors to be considered in a particular
assessment [USEPA 1992a]. In short, it establishes the goals, breadth, and focus of the
assessment and is linked to the regulatory and policy context of the assessment. The problem
formulation process begins with the initial stages of characterizing exposure and ecological
effects expected and observed. It describes the relationships among assessment and
measurement endpoints, data required, and methodology that will be used to analyze the data.
Because Sites 86 and 87 were formerly used as firing ranges, environmental media from these
sites are expected to contain elevated concentrations of constituents found in lead shot, clay
pigeons, and bullet slugs. Ways in which ecological receptors may come into contact with these
agents and their chemical contents will be evaluated in the risk assessment. Points of contact
were eliminated from further consideration where an element necessary to complete an exposure
pathway was determined to be lacking.
r i
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C.2.1 Study Site Identification
This section briefly describes previous land use activities and identifies COPECs at Sites 86
and 87. For additional information refer to the Site Characterization Report for IRP Sites 86
and 87 [IT 1997].
C.2.1.1 Site 86 - Former Military Firing Range
The Former Military Firing Range (Site 86) is located on the southeastern portion of
Mather AFB. The site formerly consisted of the rifle and pistol range (approximately 380 feet
long and 215 feet wide) and the former pistol range (approximately 240 feet long and 130 feet
wide) which covered an area approximately 112,900 square feet. The source of contamination is
small arms ammunition. Chemicals of potential ecological concern include antimony, copper,
and lead from bullets; copper, tin, and zinc from the bullet jackets; and antimony and barium
from the primers.
C.2.1.2 Site 87 - Former Skeet/Trap Range
The Former Skeet/Trap Range (Site 87) is located on the eastern portion of Mather AFB and
consists of an open grassland area. The skeet/trap range, which is currently closed, was operated
by a local shooting club since the early 1970s and covers an area approximately 1,271,700 square
feet. The source of suspected contamination at the site is predominately lead shot resulting from
the discharge of shotgun shells. In addition to lead, other COPECs associated with lead shot
include antimony, arsenic, and copper. Asphalt or coal tar pitch and limestone may also be
present from the manufacturer of the "clay pigeons" (small airborne targets).
C.2.2 Ecosystems Potentially at Risk
This section briefly describes the ecological conditions and potentially complete pathways at
both Sites 86 and 87. Tables C-l and C-2 identify habitat specific pathways and environmental
media of potential ecological concern for each sites, respectively.
C.2.2.1 Sites 86 - The Former Military Firing Range
Site 86 primarily consists of semi-disturbed grassland. The principal terrestrial wildlife species
consist of small mammals, such as house mice (Mus musculus), deer mice (Peromyscuc
maniculatus), and California voles (Microtus calif or nicus). Larger herbivores include blacktail
jackrabbits (Lepus californicus) and desert cottontails (Sylvilagus auduboni). Common
terrestrial predators include the gopher snake (Pituophis melanoleucus) and the coyote
RL/8-98/ES/392000 LAWS
C-2
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Table C-l. Summary of Habitat-Specific Pathways Evaluated for Mather
Sites 86 and 87
Site No.
86
87
Grassland
X
X
Surface Water
Drainage System
NA
X
Seasonal Surface
Water/Vernal Pools
NA
NA
No Pathways
NA
NA
NA = not applicable
Table C-2. Environmental Media of Potential Ecological Concern Present at
Mather Installation Restoration Program Sites 86 and 87
Site No.
86
87
Surface Soil
X
X
Surface Water
NA
X
Sediment
NA
X
Air
NA
NA
NA = not applicable
(Canis latrans). Common birds within this habitat are western meadowlarks (Sturnella
neglecta), house finches (Carpodacus mexicanus), northern mocking birds (Mimus polyglottos),
and American crows (Corvus brachyrhynchos). Raptors are also common, with red-tailed hawks
(Buteojamaicensis) and northern harriers (Cirus cyaneus), being the most common hawks.
Contaminant migration from the site to the ecologically accessible environment is most likely to
occur through the direct uptake or exposure through the food chain in contaminants associated
with surface soils. Surface water is nor readily accessible at this site and is not considered as a
media of potential ecological concern. As shown in Figure C-l and Table C-l, only grassland
receptors are of potential ecological concern at Site 86.
C.2.2.2 Site 87 - The Former Skeet/Trap Range
Site 87 is similar in habitat and species composition to Site 86 with the exception of Morrison
Creek. Morrison Creek is an ephemeral stream that runs from the northeast to the southwest
corners of the site. The water level within this creek fluctuates with seasonal precipitation and is
commonly dry in summer and early fall. Damming of the creek has created a small pond which
covers approximately one-tenth of an acre on the western edge of the site [IT 1997].
This man made pond attracts waterfowl, shore birds, and wading birds, particularly mallards
(Anas platyrhynchos), which breed in and around these habitats, killdeer (Charadrius
RL/8-98/ES/392000I.AWS
C-3
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Coyole
o
.U
Blockloil Jockrobbil
Red-Toiled Howk
Vegelolion
House Mouse
Invertebrates
tyre C-l
Generolized Food Web for (he Grosslond Communities ol
Mother IRP Siles 86 ond 87
-------
vociferus), and great egrets (Casmerodius albus). Wildlife species that are more dependent upon
permanent surface water are also attracted to this habitat type including muskrats (Ondatra
zibethica\ red-winged blackbirds (Agelaiusphoenceus), tadpoles (e.g., western spadefoots
[Scaphiopus hammondii], Pacific treefrogs [Hyla regilla]), and bullfrogs (Rana catesbeiand)
which provide a food source to great blue herons (Ardea herodias), green-backed herons
(Butorides striatus), and raccoons (Procyon lotor) that feed around the permanent water bodies
on the base.
As illustrated in Table C-l and Figure C-2, terrestrial and semi-aquatic receptors are likely to be
exposed to contaminants through the ingestion of water or through the direct uptake or exposure
through the food chain in contaminants associated with sediment. The potential for food-chain
transfers from aquatic biota to the terrestrial receptors is also possible.
C.2.3 Endpoint Selection
The endpoint selected estimation of risk associated with Sites 86 and 87 are similar to those
listed in the CBRA [IT 1996]. As in the CBRA, emphasis is placed on habitat type. The
endpoints and associated management goals for the grassland habitats are:
• Management Goal - Protection of the natural plant diversity of the grasslands
associated with Sites 86 and 87
Assessment Endpoint - Toxicity of surface soil to plants.
Measurement Endpoints - Comparison of surface soil chemistry data with
phytotoxicity benchmark values.
• Management Goal - Protection of the natural animal diversity of the grasslands
associated with Sites 86 and 87.
Assessment Endpoint - Toxicity of surface soil to terrestrial wildlife.
Measurement Endpoints - Use of the quotient method with hazard
quotients greater than 1.0 as indicative of potential risk.
The endpoints and associated measurement goals for the surface water drainage system habitat
are:
• Management Goal - Protection of the wetland ecosystems of the surface water
drainage system associated with Site 87.
Assessment Endpoints - Toxicity of surface water and sediments to
freshwater biota, benthic invertebrates, emergent plants, and semiaquatic
and terrestrial wildlife populations.
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C-5
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fiju-eC-2
Generated Food Web for the Surface Water Drainage System Communities
at Mother IRP Site 87
-------
Measurement Endpoints - Comparison of surface water chemistry data to
water quality criteria, comparison of sediment chemistry data to sediment
quality criteria and phytotoxicity benchmark values, and use of the
quotient method to predict potential risk to vertebrates.
C.2.4 Conceptual Model
Conceptual models for the two habitat types are presented in Figures C-3 and C-4. Primary
routes of exposure within the grassland habitats of Sites 86 and 87 are expected to occur through
ingestion and direct uptake of soil, and through consumption of surface water, major routes of
exposure of ecological receptors to contaminants within the surface water drainage system of
Site 87 are through ingestion and direct uptake. For both habitat types ingestion includes food
chain related pathways.
C.2.5 Chemicals of Potential Ecological Concern
Chemicals of potential ecological concern for the two sites were determined as stated in the
CBRA [IT 1996]. The selection process is also discussed in Appendix B - the Human Health
Risk Assessment for Sites 86 and 87. The process used for human health was identical to that
used for this ecological risk assessment. The COPECs.for Sites 86 and 87 are presented in
Tables C-3 and C-4. The COPECs at IRP Site 86 occur in surface soil and consist of arsenic,
copper, and lead. The COPEC at IRP Site 87 occur in surface soil, sediment, and surface water.
Arsenic, benzo(a)anthracene, benzo(a)pyrene, benzo(b)fluoranthene, benzo(g,h,i)perylene,
benzo(k)fiuoranthene, chrysene, dibenz(a,h)anthracene, fluoranthene, indeno(l,2,3-cd)pyrene,
lead, phenanthrene, pyrene, and tin are COPECs in surface soil. Antimony, barium, and lead
occur in surface water. Antimony, arsenic, barium, benzo(a)anthracene, benzo(a)pyrene,
benzo(b)fluoranthene, benzo(g,h,i)perylene, benzo(k)fluoranthene, chrysene, copper,
dibenz(a,h)anthracene, indeno(l,2,3-cd)pyrene, lead, pyrene, and zinc in sediment.
C.3 Analysis Phase
The analysis phase of an ecological risk assessment is basically the exposure section of a risk
assessment. Based on information provided in the Problem Formulation and site-specific data
exposure to ecological receptors are assessed. This section specifically addressed the
quantification of exposure and characterization of potential toxicological effects. Methods used
in this screening level assessment are identical to those presented in the CBRA [IT 1996].
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C-7
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PRUIART
SOURCES
PRIUAOT
HHAS
UECHANISU
SECOIIDWf
SOURCES
SECOWMW
REUASE
UECIIANISU
PATHWAY
Exposure
Route
RECEPTOR
BIOTA
Terrestrial
O
oo
Silt
Specific
Chemlcd
Migration
O Minor Ejposuft Polhtoy
ojof Dposurt Palhtoy
-J
Concepluol Model
Grosslonds
-------
PfllUART
SOURCES
KLUS
UECHANISU
sccaowr
SOURCES
o
Stt
Specific
SECOWWW
RELEASE
UtDWJKU
PATHWAY
RECEPTOR
Exposure
Route
BIOTA
Terminal
Aqualk
VoloUGiotion/
WodDosion
^
Air
^-
hhololion
O
khablion
Inqeslkwi
Uptake
Inqeslion
iloct
O
O
O
O
O
O Uinor Exposuie Polhvay
O Uojor Eiposute Polhvay
Figure C-<
Conceptual Model
Surface Waler Uroinoge Syslems
-------
Table C-3. Chemicals of Potential Ecological Concern Associated with Site 86
Chemical of Potential Ecological Concern(a)
Surface Soil Concentration (mg/kg)
Inorganic
Arsenic
Copper
Lead
10.81
112.86
1304.62
(a) Surface soil concentrations are either the 95 percent upper confidence limit of the mean or the maximum
concentration, whichever is lowest.
mg/kg = milligrams per kilogram
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C-10
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Table C-4. Chemicals of Potential Ecological Concern Associated with Site 87
Chemical of Potential
Ecological Concern(a)
Surface Soil
Concentration
Sediment Concentration
Surface Water
Concentration
Inorganic(b)
Antimony
Arsenic
Barium
Copper
Lead
Tin
Zinc
"(C)
10.59
-
-
717.71
56.89
--
21
48.5
301.5
58
6305
~
93
0.002
-
0.089
~
0.001
-
«
Organic(tl)
Benzo(a)anthracene
Benzo(a)pyrene
Benzo(b)fluoranthene
Benzo(g,h,i)perylene
Benzo(k)fluoranthene
Chrysene
Dibenz(a,h)anthracene
Fluoranthene
lndeno( 1 ,2,3-cd)pyrene
Phenanthrene
Pyrene
971.74
1515.42
1127.19
1361.20
448.79
1543.84
483.82
1304.15
991.79
339.11
2082.40
9.4
17.5
65.5
26.5
7
55
12.8
--
16
-
95
«
--
"
-
--
"
'
-
--
-
--
(a) All values are either the 95 percent upper confidence limit of the mean or the maximum concentration.
whichever is lowest.
(b) Inorganic values are in milligrams per kilogram
(c) Dash indicates value could not be determined
(d) Organic values are in micrograms per kilogram
RlV8-9«/ES/3<)20001 .AWS
C-ll
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C.3.1 Quantification of Exposure
The concentrations of COPEC in plants and animals were modeled in order to assess the
potential hazards associated with organic and inorganic contaminants in surface soils, surface
waters, and sediment Sites 86 and 87 biota. Models used to quantify ecological exposure in both
terrestrial and aquatic environments were developed as part of the CBRA [IT 1996] and are
addressed in the following subsections.
C.3.1.1 Terrestrial Exposure Models
Potential risks to terrestrial biota were assessed following direct and indirect exposure to COPEC
in soil and surface water. Exposure concentrations used for the evaluation of potential effects on
terrestrial indicator species were the lowest of either the 95 percent upper confidence limit of the
arithmetic mean concentrations or the maximum concentration measured [USEPA I989aj.
Indicator species considered in terrestrial exposure pathways include a generic annual plant,
house mouse, blacktail jackrabbit, coyote, and red-tailed hawk.
C. 3.1.1.1 Vegetation
Estimates of the concentrations of COPEC in Mather AFB terrestrial plants were made using the
chemical-specific concentration in surface soil from the particular site of interest. Direct uptake
of contaminants from soil was assumed to be the major route of exposure of plants to
contaminants, with exposure of plants to wind-blown soil and associated contaminants and
uptake of contaminants in surface water assumed to be minor routes of exposure. As mentioned
above, the indicator plant species selected was assumed to be a generic annual plant.
Soil-to-plant transfer factors for metals in vegetative plant parts (a mixture of pasture grass, hay,
leafy vegetables, and mixed silages) were obtained from Baes et al. [1984] [IT 1996]. Those for
antimony and tin, COPECs not previously addressed in the CBRA, are presented in Table C-5.
Soil-to-plant (vegetative plant parts only) transfer coefficients for organic compounds of
potential concern were estimated using the equation derived by Travis and Arms [1988] based on
the linear regression of the log of the Kow for 29 organic compounds ranging from 1.15 to 9.35
and the log of analytically derived soil-to-plant bioconcentration factors [IT 1996]. These
transfer factors are conservative and do not consider such factors as the bioavailability of a
chemical in soil, the biodegradation rate of a compound in soil or the metabolic transformation of
compounds in plants. Concentrations in the aboveground vegetative part of plants were
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Table C-5. Soil-to-Plant and Soil-to-insect Transfer Factors for Inorganic Analytes in
Vegetative Plant Parts
Element
Antimony
Tin
Soil-to-Plant Transfer Factor(a)
2.0E-01
3.0E-02
Soil-to-Insect Transfer Factor(b)
l(c)
l(c)
(a) Transfer factors from Baes, et al. 1984, are all based on dry soil and dry plant weights.
(b) Transfer factors based on dry soil and dry invertebrate weight.
(c) Default value
Baes, C.F., III, R.D. Sharp, A.L. Sjoreen, and R.W. Shor, 1984, "A Review and Analysis of Parameters for
Assessing Transport of Environmentally Release Radionuclides through Agriculture," ORNL-5786, Oak Ridge
National Laboratory, Oak Ridge, Tennessee.
estimated using the following equation from Baes et al. [1984]:
Cv = (
where:
Cv = Concentration of the chemical of potential concern in vegetation (milligrams per
kilogram [mg/kg], dry weight).
Cs = Concentration of the chemical of potential concern in soil (mg/kg, dry weight).
Bv = Soil-to-plant transfer factor for the specific chemical (mg/kg dry weight plant per
mg/kg dry weight soil).
All concentrations are in mg/kg dry weight.
C. 3.1.1.2 Wildlife
Exposure of each of the terrestrial wildlife indicator species to soil COPEC was estimated using
exposure models adapted from the USEPA [1989]. As mentioned earlier, the wildlife indicator
species were assumed to be exposed to contaminants through ingestion. Ingestion-related
pathways included one or more of the following: soil, vegetation, insects, or other wildlife
species, and water. All other potential pathways were considered to be of minor importance.
Total intake values include intake rates for all dietary components, including soil. Water intake
was treated separately.
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Ingestion of Plant Matter: Intake of contaminants in vegetation was estimated using a
modification of an equation from USEPA's Human Health Evaluation Manual [USEPA 1989], in
which:
/ =
(AO
where:
I
Dv
F
M
Intake rate of chemical in vegetation (mg/kg-day).
Concentration of chemical of potential concern in vegetation (mg/kg) (dry
weight).
Ingestion rate (kilograms per day [kg/day]) (dry weight).
Dietary fraction consisting of vegetation (unitless).
Fraction ingested from contaminated source (unitless).
Body weight (kg) (wet weight).
This equation was used to predict the intake of contaminants in vegetation by blacktail
jackrabbits and omnivorous house mice. Because all modeled individuals were assumed to
spend their entire lives at each site, the exposure duration times the exposure frequency divided
by the averaging time (from the USEPA intake equation) was assumed to equal one.
Species-specific values for parameters such as ingestion rate and body weight are presented in
the CBRA [IT 1996]. The fraction ingested from a contaminated source was based on the
animal's typical home range. The amount of food and water expected to be consumed from
contaminated areas is assumed to be proportional to the fraction of the home range occupied by
the particular site. This value is therefore both species-specific and site-specific (Table C-6).
Table C-6. Home Range Factors for Mather Air Force Base Indicator Species
Mather
AFB
Location
Site 86
Site 87
Area
(Ha)
1.05
11.81
Blacktail
Jackrabbit(a)
6.99E-03
7.88E-02
House
Mouse(b)
l.OOE+00
l.OOE+00
Coyote(a)
9.60E-04
I.09E-02
Mallard(a)
3.75E-03
4.22E-02
Red-Taile
d Hawk(a)
1.84E-03
2.07E-02
Great Blue
Heron(a)
NA
1 .OOE+02
AFB = Air Force Base
Ha = hectare
NA = not applicable
(a) One range factor is defined as the area of the Mather AFB location divided by the home range of the
indicator species.
(b) The home range factor for the house mouse is 1.0 for all Mather AFB locations.
(c) The home range factor for the great blue heron at IRP Site 87 is 1.0.
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For each chemical, site-specific intake rates for vegetation were summed with those obtained for
soil ingestion to obtain the total intake values for the omnivorous mouse and rabbit. Total intake
rates for the omnivorous mouse and coyote were a summation of intake rates for vegetation and
animal matter.
Ingestion of Insects: Because the feeding habits of the house mouse are opportunistic in nature,
the omnivorous mouse was assumed to ingest 48 percent plant matter, 50 percent insects, and
two percent soil in its diet. When soil-to-terrestrial insect transfer factors were available in the
literature, such values were used to estimate concentrations of specific chemicals in insects.
When such information was not available, concentrations in insects were estimated using the
methodology presented below.
Very little information exists on the estimation of chemical concentrations in terrestrial
invertebrates. As a consequence, a conservative approach was taken in the estimation of such
concentrations. The terrestrial insects used in the models were assumed to be a subterranean
invertebrate (specifically, an earthworm). Because earthworms can absorb chemicals across their
moist epidermis more readily than insects can across their cutaneous exoskeleton, it was assumed
that the use earthworm models would provide a conservative estimate of contaminant
concentrations in subsurface insects.
Concentrations of COPEC in invertebrates living below the ground surface were estimated using
transfer factors obtained from the literature or derived for earthworms (depurated) [IT 1996].
Preference was given to information specific to insects. Soil-to-earthworm concentration factors
for the inorganic contaminants were obtained from references such as Ma [1982]. For those
inorganic analytes where no soil-to-insect or soil-to-earthworm transfer factor could be found,
either the transfer factor for an analogous metal or a value of one was used as a default value. As
shown in Table C-5, default values of one were used for both antimony and tin.
When necessary, concentration factors for subterranean insect larvae exposed to organic
compounds were estimated using one of two models selected according to the lipophilic
properties of the compound. The criterion for defining a compound as being strongly lipophilic
was based on the same criterion used in the Great Lakes study reported by USEPA [1993 a] to
identify organic compounds as capable of biomagnification. Specifically, compounds with log
Kow values equal to or greater than four are capable of biomagnification and are, therefore,
considered here as strongly lipophilic.
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C-15
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According to Menzie et aJ. [1992], critical components to consider in the bioaccumulation of
highly lipophilic compounds by earthworms are the organic carbon content of the soil and the
lipid content of the organism. For this reason, the following equation was used to estimate the
bioaccumulation of organic compounds with log K^ values equal to or greater than four:
BAF =
0.66 /
•* at
The bioaccumulation factors were assumed to be equivalent to bioconcentration factors and were
based on a transfer from a soil dry-weight concentration to fresh-weight insect values.
Ingestion of Animal Matter: In order to evaluate the potential exposure of predators such as
the resident coyote and the red-tailed hawk to COPECs, estimates were made of the amount of a
chemical assimilated into prey tissues. Intake values for predators were estimated using the
following equation:
-
Mi .
where:
F
M
s
Intake rate of chemical of potential concern by the predator (mg/kg-day,
wet weight).
Concentration of chemical of potential concern in prey species (mg/kg,
wet weight, assumes Q = intake rate of chemical of potential concern by
the prey [mg/kg-day, wet weight] x assimilation coefficient for the
chemical [unitless]).
Ingestion rate of the predator (kg/day) (wet weight).
Dietary fraction consisting of the particular prey species (unitless).
Fraction ingested from contaminated source (unitless).
Body weight of the predator (kg).
Number of prey species.
The ingestion rate was converted from dry weight to wet weight with a conversion factor of
3.125 [Morrison 1959].
Assimilation coefficients were obtained from Owen [1990]. Eleven of the inorganic analytes of
potential ecological concern have specific absorption coefficients listed in the Owen [1990]
document. Absorption coefficients for inorganics not listed by Owen [1990] were assumed to be
RLW-98/ES/3920001. A WS
C-16
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equal to 0.5. This applies specifically to antimony and tim. Absorption coefficients for the
organics of potential ecological concern are listed in Owen [1990]. These values range from 0.5
to 1.0. Because of this wide range, the conservative approach was used, and a default value of
1.0 was used for all organics not listed in the CBRA [IT 1996].
The biomagnification of specific chemicals in the terrestrial foodwebs at Sites 86 and 87 was
assumed to be insignificant. Although some polycyclic aromatic hydrocarbons (PAHs) may
biomagnify, this process was not considered significant to the pathways examined. The organic
compounds mentioned above all have log Kow values less than 5.4. According to the USEPA
[1993], such compounds are estimated to have food-chain multiplier values of less than or equal
to eight for the mammalian and avian predators of interest. Taking into consideration the
generally herbivorous nature of the prey species used in the exposure models, the relatively low
food-chain multiplier values, and the inherent uncertainties associated with the exposure models,
it was assumed that, if biomagnification of the organic compounds were to occur, it would be
minimal.
Ingestion of Soil: Ingestion of contaminated soil was considered a viable pathway for
evaluation for the house mouse and the blacktail jackrabbit. Soil intake for both the blacktail
jackrabbit and the house mouse was assumed to be two percent of the total dietary consumption
rate (dry weight) for each species [IT 1996].
Soil intake was estimated using an equation similar to that used to estimate the intake of plant
matter. The concentration of a chemical in soil was substituted for the vegetation concentration
and 0.02 was used as the dietary fraction.
Water Consumption: Wildlife indicator species from Sites 86 and 87 were assumed to
consume water from Site 87. As with the other terrestrial pathways, intake of water by each
species was estimated by utilizing either the 95 percent upper confidence limit of the mean
concentration or the maximum concentration of a given contaminant measured in Site 87 surface
water, whichever value was lowest. The following equation was used to estimate intake of a
contaminant in water:
(M)
RL/8-98/ES/392000I .AWS C- 1 7
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where:
Iw = Intake rate of chemical of potential concern in surface water (mg/kg-day).
Cw = Concentration of chemical of potential concern in surface water
(milligrams per liter [mg/L]).
Qw = Ingestion rate (liters per day [L/day]).
F = Fraction ingested from contaminated source (unitless).
M = Body weight (kg) (wet weight).
As in the plant ingestion model, all modeled organisms were assumed to spend their entire lives
at each site, the exposure duration times the exposure frequency divided by the averaging time
was assumed to be one in the intake equation. Species-specific parameters used in the equation
are presented in the CBRA [IT 1996].
C.3.1.2 Aquatic Exposure Models
Risks to aquatic species were evaluated for exposure to contaminants in surface water at Site 87.
Exposure of aquatic organisms to COPECs was assumed to occur through direct uptake or
ingestion of contaminated water and sediment or by indirect exposure through uptake through the
food chain. Chronic exposures of aquatic biota to contaminants in surface water and sediments
were estimated using the lowest value of either the 95 percent upper confidence limit of the
arithmetic mean concentrations of a contaminant or the maximum concentration of a specific
contaminant measured in Site 87 surface waters or sediments. Surface water and sediment were
considered environmental media of concern in the aquatic exposure pathways. Total intake
values were determined for each chemical based on the sum of dietary and sediment-ingestion
intake values for a given species. Consumption of contaminated surface water was considered
independently. Indicator species with aquatic related exposure pathways were the generic
emergent aquatic plant, the mallard, the great blue heron, and generic aquatic macroinvertebrates.
C. 3.1.2.1 Vegetation
The uptake of contaminants in sediment was evaluated for wetland emergent plants using the
same method outlined for terrestrial vegetation. Exposure of emergent plants to aquatic
contaminants was assumed to occur primarily from the uptake of chemicals from sediments and
not from the water column. This is expected to be the major route of exposure for emergent
vegetation.
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C-18
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C.3.1.2.2 Wildlife
Two species were selected as wildlife indicator species for the aquatic environments associated
with Site 87. These are the mallard and great blue heron. The quantification of exposure to
COPEC for each of these species is discussed in the following paragraphs.
Ingestion of Animal Matter: Both mallards and great blue herons were assumed to ingest
animal matter. With regard to the mallard, concentrations in nonbenthic macroinvertebrates
(i.e., amphipods) were estimated using bioconcentration factors reported in the literature. Herons
were assumed to ingest crayfish and house mice from Site 87. Concentrations of chemicals in
crayfish were also estimated using bioconcentration factors reported in the literature. The
bioconcentration factors used represented the upper range of values and were therefore assumed
conservative. Exposure of these invertebrates to contaminants within the aquatic environments
was assumed to occur through surface water only. The model that was used to estimate exposure
of the mallard and heron to contaminants in macroinvertebrates and crayfish was similar to that
presented for ingestion of vegetation. The concentration of a chemical in the invertebrates,
however, was substituted for the concentration of the chemical in vegetation.
Exposure of great blue herons to contaminants in house mice occupying drainage ditch areas was
estimated utilizing the model discussed earlier for terrestrial wildlife. The model included the
intake of contaminated wetland vegetation, insects, and sediment by the house mouse followed
by the subsequent ingestion of the mice by the heron.
Water Consumption: Mallards and great blue heron were assumed to drink water from
contaminated surface-water sources. The exposure model used to estimate intake of
contaminants in surface water via this route was similar to that presented for terrestrial wildlife.
Mallards, herons, and mice were assumed to be exposed to surface water contaminants within the
areas from which they feed.
C.3.1.2.3 Aquatic Macroinvertebrates
Aquatic macroinvertebrates were exposed to chemical contaminants in surface water and to
contaminants. Because risk was evaluated by direct comparison of either surface water
concentrations to water quality criteria or sediment concentrations to sediment quality benchmark
values, it was not necessary to utilize exposure models. Exposure concentrations used in the
models are either the 95 percent upper confidence limit of the arithmetic mean or the maximum
measure concentration, whichever is lower.
RU8-98/ES/392000 LAWS
C-19
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C.3.2 Effects Characterization
A part of the analysis phase of an ecological risk assessment is the documentation of
stressor-response characteristics [USEPA 1996a]. This includes a discussion of the chemical
stressors of concern and adverse ecological effects that may be associated with them. In this
document, Section C.3.2 will summarize benchmark toxicity values for terrestrial plants,
wildlife, and aquatic biota. These values were obtained from the literature and are summarized
in the CBRA [IT 1996]. Although synergetic and antagonistic effects may occur following
exposure to a mixture of chemicals, only chemical-specific responses will be discussed in this
section.
C.3.2.1 Plants
General information on the chronic toxicity of inorganic analytes and organic compounds to
vascular plants was primarily obtained in the CBRA [IT 1996]. Phytotoxicity benchmark
screening values based on soil concentrations have been proposed for a variety of inorganic
chemicals and a few organic compounds. The threshold for significant effects is based on a
20 percent reduction in growth or plant yield. In addition, tissue concentrations of specific
elements that are known to elicit toxic responses in vascular plants, with the exclusion of very
sensitive or highly tolerant species, have also been compiled. Values obtained for antimony and
tin, chemicals not previously considered as COPECs in the CBRA [IT 1996] are listed in
Table C-7. The phytotoxicity benchmark screening values presented in the CBRA [IT 1996]
were used to screen those constituents likely to adversely affect plants.
Table C-7. Ecological Toxicity Summary Table: Plant Screening and Toxicity Values
Chemical
Phytotoxicity
Benchmark Screening
Value for Soil mg/kg
(dry weigh t)(a)
Excessive or Toxic Plant
Tissue Concentration
mg/kg (dry weight)(b)
Plant Tissue
Concentration Resulting
in 10% Loss in Crop
Yield (dry weight)(c)
Inorganics
Antimony
Tin
5
50
60
150
-
-------
C.3.2.2 Wildlife
The toxicities of contaminants in Mather AFB surface soils, sediment, and surface waters to the
wildlife receptors were primarily evaluated based on chronic no-observed-adverse-effect levels
(NOAEL). Wildlife-specific NOAELs were either obtained from the literature or derived from
laboratory toxicity data and are presented in the CBRA [IT 2996]. Emphasis was placed on
toxicity data-specific to reproduction, development, and survival whenever possible. Estimations
of wildlife-specific NOAEL values were made using a body-weight-based allometric equation
presented in Opresko et al. [1994]. In addition, laboratory toxicity data were modified with
uncertainty factors to adjust lowest-observed-adverse-effect level to NOAELs and to adjust
subchronic data to chronic data. In each case, an uncertainty factor or less than or equal to ten
was used [Opresko et al. 1994]. An uncertainty factor often was also used to adjust for
phylogenetic differences, specifically between mammals and birds, when avian toxicity data were
not available. In cases where only an LD50 value (lethal dose that will result in the death of
50 percent of the test animals) could be found for a particular chemical, the NOAEL was
estimated using the ratio between the LDJO and NOAEL values of a closely related chemical
[Opresko et al. 1994]. Tables C-8 and C-9 present the NOAELs for mammalian and avian
wildlife indicator species not previously determined in the CBRA [IT 1996].
C. 3.2.3 Aquatic Life
Several sources of published information were utilized to evaluate the toxicity of surface-water
and sediment contaminants to freshwater biota such as fish, macroinvertebrates, and submergent
aquatic plants. Ambient water quality criteria for the protection of freshwater aquatic life were
derived by the USEPA [USEPA 1996b; USEPA 1992b] for a number of the inorganic and
organic COPEC. In all cases, California water quality objectives for the protection of freshwater
aquatic life [CEPA 1993] are in agreement with the federal criteria. Advisory values have been
calculated by Suter and Mabrey [1994] for many chemicals not listed by the USEPA
[USEPA 1996b; USEPA 1992b] or the California Environmental Protection Agency (CEPA)
[IT 1993]. These values are presented in the CBRA [IT 1993]. Table C-10 presents toxicity
data-specific to antimony, barium, and lead not previously addressed in the CBRA [IT 1996].
Direct comparisons of measured concentrations in water with freshwater aquatic screening and
toxicity values should be made with caution. A number of both biotic and abiotic factors can
influence the toxicity of chemicals to aquatic life. Exposure and toxicity to a particular chemical
can be affected by the age, growth stage, and food habits of an organism.
f-91
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Table C-8. Ecological Toxicity Summary Table: Mammalian Wildlife Screening and Toxicity Values
Chemical
House Mouse
Estimated
Dietary
NOAEL(a)
(mg/kg/d)
Estimated
Drinking
Water
NOAEL(a)
(mg/L)
Estimated
Inhalation
NOAEL(b)
(mg/mj/d)
Blacktailed Jackrabbit
Estimated
Dietary
NOAEL(a)
(mg/kg/d)
Estimated
Drinking
Water
NOAEL(a)
(mg/L)
Estimated
Inhalation
NOAEL(b)
(mg/mVd)
Coyote
Estimated
Dietary
NOAEL(a)
(mg/kg/d)
Estimated
Drinking
Water
NOAEL(a)
(mg/L)
Inorganics
Antimony
Tin
I.54E-OI
2.88E+OI
1.03E+00
1 .92E+02
3.08E-02
5.77E+00
3.33E-01
6.24E+01
I.54E-02
2.88E+00
2.05E-OI
3.84E+01
o
K)
to
(a) Chronic no-observed-adverse-efTect level (NOAEL) values were adapted from Opresko et al. 1994. Body weights and water consumption rates used are
those presented in Section 4.1.2 of the CBRA [IT 1996].
(b) NOAEL values were estimated using published laboratory toxicity data [USEPA 1996; NLM 1996].
mg/kg/d = milligrams per kilogram per day mg/L = milligrams per liter mg/mVd = milligrams per cubic meter per day
Table C-9. Ecological Toxicity Summary Table: Avian Screening and Toxicity Values
Chemical
Red-Tailed Hawk
Estimated Dietary
NOAEL(a)
(mg/kg/d)
Estimated
Drinking Water
NOAEL(a)(mg/L)
Mallard
Estimated Dietary
NOAEL(a)
(mg/kg/d)
Estimated
Drinking Water
NOAEL(a) (mg/L)
Great Blue Heron
Estimated Dietary
NOAEL(a)
(mg/kg/d)
Estimated
Drinking Water
NOAEL(a) (mg/L)
Inorganics
Antimony
Tin
3.72E-03
3.47E-HX)
6.57E-02
6.I1E+01
3.78E-03
3.52E+00
6.57E-02
6.I2E+01
2.90E-03
2.70E+00
6.54E-02
6.09E+01
(a) Chronic no-observed-adverse-effect level (NOAEL) values were adapted from Opresko et al. 1994. Body weights and water consumption rates used are
those presented in Section 4.1.2.
mg/kg/d = milligrams per kilogram per day mg/L = milligrams per liter
RL/8-98/ES/3920001 .AWS
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Table C-10. Ecological Toxicity Summary Table: Freshwater Aquatic Screening and Toxicity Values
Chemical
Ambient Water Quality Criteria(a) (ug/L)
Acute
Chronic
Tier II Value(b) (ug/L)
Acute
Chronic
Lowest Chronic Value(b) (ug/L)
Acute
Chronic
Inorganics
Antimony
Barium
Lead
8.20E+OI
3.20E+00
I.80E+02
6.9IE+OI
3.00E+OI
3.80E+00
I.60E+03
1.89E+01
5.40E+03
5.80E+03
1.23E+01
o
Ni
OJ
(a) Values obtained from U.S. Environmental Protection Agency (USEPA), 1996a, and USEPA, 1986b, with water hardness of 100 milligrams per liter
assumed.
(b) Information obtained fro Suter and Tsao, 1996.
|ig/L = micrograms per liter
920001.A WS
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Water-chemistry parameters such as hardness, total suspended solids, dissolved oxygen
concentration, and pH can have a significant impact on the availability and subsequent toxicity of
inorganic chemicals to aquatic biota. For example, as water hardness increases, the toxicity of
most heavy metals decreases. Such factors as these should be considered in evaluating potential
toxic effects associated with contaminated aquatic environments.
The toxicity of organic COPEC to sediment associated benthic macroinvertebrates was evaluated
utilizing sediment quality benchmark criteria. Benthic macroinvertebrates were assumed to be
exposed to nonionic organic compounds within the interstitial water of sediments. The
partitioning of these compounds into interstitial waters was estimated utilizing an assumed
fraction of organic carbon of 0.01 and K^ (organic carbon adsorption coefficient) based on K^
values [Hull and Suter 1994; Lyman 1982]. Sediment quality benchmark criteria were also based
on water quality benchmark values such as USEPA ambient water quality criteria for the
protection of freshwater aquatic life [USEPA 1996b; USEPA 1992b] were used as screening
values in this risk assessment. The value used for antimony, a chemical not previously discussed
in the CBRA [IT 1996] was 2 mg/kg.
C.4 Risk Characterization
Risk characterization is the final stage of an ecological risk assessment which involves the
estimation of risk and the description of predicted risk. Potential risk at Sites 86 and 87 as
addressed in the following subsections, includes exposure to chemical elements compounds and
lead shot and bullet slugs.
C.4.1 Risk Estimation
Risk estimation methods used in this assessment are identical to that used in the CBRA
[IT 1996]. Risk to ecological receptors associated with the grassland and aquatic habitats of
Sites 86 and 87 were addressed for each of the COPECs discussed earlier. Risks to vegetation
were assessed by comparison of the exposure concentration in soil/sediment (refer to Section
C.3) to benchmark screening values and comparison to estimated plant tissue concentrations to
plant tissue benchmark values. If both benchmarks were exceeded, the COPEC was predicted to
be potentially hazardous to plant life. For aquatic life, exposure concentrations were compared
to water quality criteria or sediment quality criteria as appropriate. For wildlife receptors,
estimated daily exposures/intake were compared with benchmark screening values. In each case,
if the quotient of the site value divided by the benchmark exceeded unity, the COPEC was
predicted to be potentially hazardous.
RL/8-98/ES/3920001. AWS
C-24
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Risk estimates associated with exposure of ecological receptors to lead shot and bullet slugs was
more qualitative. This estimate was based on the likelihood of exposure and potential oral
toxicity associated with lead in shot and slugs.
C.4.2 Risk Characterization
Because this is a screening level assessment, potential risks to biota associated with Sites 86
and 87 were estimated based on comparisons to toxicity based benchmark screening values and
the likelihood of exposure to lead shot and slugs. Risks predicted for each of these sites are
summarized below.
C.4.2.1 Risk Assessment with Contaminants of Potential Ecological Concern
Risks associated with exposure to each of the COPECs at Sites 86 and 87 are presented below.
The final characterization of ecological risks at each site was based on screening assessment
results and comparison of existing media concentrations to those found at other Mather sites
where Phase II detailed ecological risk evaluations were performed.
C.4.2.1.2 Site 86
Site 86 was evaluated for potential ecological risks to receptors within a grassland habitat.
Specifically, this site was evaluated for potential risks to terrestrial species following exposure to
surface-soil contaminants. Risks to terrestrial plants and house mice were predicted through
modeling to be exposed to hazardous chemical concentrations (Tables C-l 1 and C-12). Only
copper and lead were predicted to be at levels potentially toxic to plant life. The jackrabbit,
coyote, and red-tailed hawk were not predicted to be exposed to hazardous chemical
concentrations at this site. Based on modeling results, arsenic was predicted to be potentially
hazardous to the omnivorous house mouse via food-related pathways associated with soil.
Comparisons with other IRP locations on Mather AFB with a similar habitat type (i.e., grassland)
show that soil concentrations for arsenic at this site were similar to those identified at IRP Site 3
(10.7 mg/kg and 10.81 mg/kg, respectively) [IT 1996]. Previous field surveys did not indicate
differences in small mammal populations between Site 3 and reference locations. Field surveys
showed that both the density and diversity of small mammals at Site 3 fall within the range of the
reference sites. Although small mammal surveys were not conducted at Site 86, the similarity of
habitat conditions, as with Site 3, suggest that the modeling estimates may have over predicted
hazards to the mouse. Based on the modeling results and comparison to data from Site 3,
ecological risks associated with Site 86 were designated as low.
RU8-98/ES/392000 LAWS
C-25
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Table C-ll. Comparison of Concentrations of Chemicals of Potential Ecological Concern in Soils and Plants
to Phytotoxicity Benchmark Values: Mather Air Force Base Site 86
Chemical
Arsenic
Copper
Lead
Concentration
in Surface Soil
(mg/kg) (dry
weight)(a)
10.81
112.86
1304.62
Benchmark
Concentration
in Soil (mg/kg)
(dry weight)(b)
10
100
50
Exceeds Soil
Benchmark
Value
Yes
Yes
Yes
Predicted Plant
Tissue
Concentration
(mg/kg) (dry
weight)(c)
0.432
45.1
58.7
Excessive or
Toxic Plant
Concentration
(mg/kg) (dry
weight)(d)
5-20
20-100
30-300
Exceeds Plant
Tissue
Benchmark
Value
No
Yes
Yes
Exceeds Both
Soil and Plant
Tissue
Benchmark
Value
No
Yes
Yes
n
K)
OS
mg/kg = milligrams per kilogram
(a) Concentration in soil is the lowest of either the 95 percent upper confidence limit of the mean or maximum soil concentration.
(b)
(c)
(d)
Benchmark values reported in Will and Suter 1994.
Predicted plant concentration based on the lowest of either the 95 percent upper confidence limit of the mean or maximum soil concentration and soil to
plant transfer factors reported in Baes et al. 1984, for metals or derived transfer factors organics as recommended in Travis and Arms 1988.
Information from Kabata-Pendias and Pendias 1992.
Table C-12. Ecological Hazard Quotients for Terrestrial Wildlife Indicator Species Exposed to Contaminants
Associated with Surface Soils: Mather Air Force Base Site 86
Chemical
House Mouse
Blacktail Jackrabbits
Coyote
Red-Tailed Hawk
Inorganic
Arsenic
Copper
Lead
6.98E+00(a)
1.52E-01
6.66E-OI
I.04E-02
2.54E-03
9.48E-03
3.67E-03
I.17E-04
2.45E-04
3.35E-05
I.54E-05
I.33E-04
(a)
Values in bold are greater than 1.0.
RL/8-98/ES/3920001 .A WS
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C.4.2.1.3 Site 87
Site 87 was evaluated for potential ecological risk to receptors associated with grassland and
surface water habitats. Ecological receptors at Site 87 were exposed to contaminants in surface
soil, surface water, and sediment. With regard to surface soil, only lead exceeded soil quality
criteria and was predicted to be potentially hazardous to terrestrial plants (Table C-l 3). Based on
modeling results, arsenic, and the sum total of PAHs were predicted to be hazardous to house
mice via food-related pathways associated with soil (Table C-l4). Individual analytes within this
organic group of chemicals predicted to be hazardous to the dibenz(a,h)antnracene, fluoranthene,
and indeno(l,2,3-cd)pyrene. The sum total of PAHs were also predicted to be hazardous to the
hawk; however, no one individual analyte had a hazard quotient greater than l.O.
With reference to the aquatic habitat, modeling results indicated direct consumption and sole
utilization of Site 87 surface water (i.e., Morrison Creek) as not hazardous to the mammalian or
avian receptors at this site (Table C-l 5). Concentrations of antimony, barium, and lead were
detected in surface water, however, none were found to exceed USEPA or CEPA water quality
criteria for the protection of freshwater aquatic life (Table C-l 6). Sediment quality criteria that
were exceeded for benthic invertebrates were for antimony, arsenic, copper, and lead
(Table C-l7). No additional chemicals were predicted to be potentially hazardous to terrestrial
wildlife following the summation of food and water exposure pathways.
With reference to aquatic and semiaquatic receptors, concentrations of antimony, arsenic, lead,
and zinc in sediment exceeded sediment quality criteria. In addition, concentrations of lead and
zinc in sediment were predicted to be at levels toxic to emergent plant life (Table C-l 8).
Modeling results indicate antimony may be potentially hazardous to the mallard and heron via
food-related pathways (Table C-l 9). The sum total of PAHs were also predicted to be hazardous
to the heron; however, no one individual analyte had a hazard quotient bigger than 1.0. Based on
all available information ecological risks associated with Site 87 were designated as
low-medium.
C.4.2.2 Risk Associated with Lead Shot and Bullet Slugs
Studies have shown that certain wildlife species, especially waterfowl, can ingest lead shot
[e.g., Kendall et al. 1996]. Ingestion can occur as a result of birds mistaking shot for grit
[e.g., Pain 1991] or mistaking shot for food [e.g., Bellrose 1951]. Furthermore, ingested lead
shot has been shown to be toxic [e.g., Kendall et al. 1996, Whitehead and Tschirner 1991, and
Anderson 1975]. Based on this information it is possible that exposure of ecological receptors to
lead shot may occur and prove toxic. Although this is true for lead shot, it is not likely to be true
RL/8-98/ES/392000I .AWS
C-27
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Table C-13. Comparison of Concentrations of Chemicals of Potential Ecological Concern in Soils and Plants
to Phytotoxicity Benchmark Values: Mather Air Force Base Site 87
Chemical
Arsenic
Copper
Lead
PAHs (totall
Concentration
in Surface Soil
(mg/kg) (dry
weigh t)(a)
10.59
717.71
56.89
10.3
Benchmark
Concentration
in Soil (mg/kg)
(dry weigh t)(b)
10
50
50
18
Exceeds Soil
Benchmark
Value
Yes
Yes
Yes
No
Predicted Plant
Tissue
Concentration
(mg/kg) (dry
weight)(c)
0.424
32.3
1.71
0.216
Excessive or
Toxic Plant
Concentration
(mg/kg) (dry
weight)(d)
5-20
30-300
150
~(e)
Exceeds Plant
Tissue
Benchmark
Value
No
Yes
No
~
Exceeds Both
Soil and Plant
Tissue
Benchmark
Value
No
Yes
No
No
(a) Concentration in soil is the lowest of either the 95 percent upper confidence limit of the mean or maximum soil concentration.
f) (b) Benchmark values reported in Will and Suter 1994.
to (c) Predicted plant concentration based on the lowest of either the 95 percent upper confidence limit of the mean or maximum soil concentration and soil to
"*J plant transfer factors reported in Baes et al. 1984, for metals or derived transfer factors organics as recommended in Travis and Arms 1988.
(d) Information from Kabata-Pendias and Pendias 1992.
(e) Dash indicates value could not be determined.
mg/kg = milligrams per kilogram
PAHs = polycyclic aromatic hydrocarbons
RL/8-98/ES/392000I .AWS
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Table C-14. Ecological Hazard Quotients for Terrestrial Wildlife Indicator Species Exposed to Contaminants Associated
with Surface Soils: Mather Air Force Base Site 87
Chemical
House Mouse
Blacktail Jackrabbit
Coyote
Red-Tailed Hawk
Inorganics
Arsenic
Lead
Tin
6.84E+00(a)
3.66E-OI
I.96E-OI
I.I5E-OI
5.88E-02
2.78E-03
4.08E-02
I.53E-03
6.13E-04
3.7IE-04
8.50E-04
I.47E-03
Organics
PAHs (total)
2.I3E+01
9.66E-03
1.22E-01
1.59E+00
n
N)
00
n
i
to
(a) Values in bold are greater than 1.0.
PAHs = polycyclic aromatic hydrocarbons
Table C-15. Potential Hazards to Wildlife Following Ingestion of Surface Water: Mather Air Force Base Site 87
Chemical
Antimony
Barium
Lead
Concentration
in Water
(mg/L)(a)
2.00E-03
8.90E-02
I.OOE-03
Ecological Hazard Quotient(b)
House Mouse
I.94E-03
9.44E-04
6.7IE-06
Blacktail
Jackrabbit
6.0IE-03
2.9IE-03
2.07E-05
Coyote
9.76E-03
4.7IE-03
3.36E-05
Red-Tailed
Hawk
3.04E-02
2.I8E-04
3.I4E-05
Mallard
3.04E-02
2.18E-04
3.14E-05
Great Blue
Heron
3.06E-02
2.I9E-04
3.I5E-05
(a) Concentration in water (milligrams per liter [mg/L]) is the maximum surface water concentration.
(b) Ecological hazard quotients based on estimated no-observed-adverse-effect levels.
,92000 LAWS
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Table C-16. Comparison of Surface Water Concentrations to Water Quality
Objectives/Criteria for the Protection of Freshwater Aquatic Life:
Mather Air Force Base Site 87
Constituent
Antimony
Barium
Lead
Concentration
Measured in
Water(a)Oig/L)
2
89
1
California
Chronic Exposure
Objective(b)
(ug/L)
1.6(0
USEPA Chronic
Continuous
Exposure
Criterion(c) (ug/L)
50,000(e)
1.6(g)
Other Chronic
Benchmark
Advisory Values
(ug/L)
30(d)
3.9(d)
2.5(h)
(a) Surface water concentration is either the 95 percent upper confidence limit of the mean or the maximum
concentration, whichever is lowest. Values in bold exceed water quality criteria.
(b) Four-day average values reported in CEPA 1993.
(c) USEPA 1992b and 1996.
(d) . Value is not a USEPA criterion. The value reported is a tolerance value obtained fro USEPA 1986b.
(e) Tier II values calculated in Suter Marbery 1994, as reported in USEPA 1996, Ecotox thresholds (Ambient
Water Quality Criteria).
(f) Value is a four-day average concentration, based on a water hardness of 58.33 milligrams per liter (mg/L)
formula reported in CEPA 1993.
(g) Value is calculated and based on a total water hardness of 58.33 mg/L and a water effect ratio of 1.0 for
USEPA 1992b.
(h) USEPA 1996, Ecotox thresholds (Ambient Water Quality Criteria).
Table C-17. Comparison of Sediment Concentrations with Sediment Benchmark:
Mather Air Force Base Site 87
Chemical
Antimony
Barium
Concentration in
Sediment (mg/kg)
21
301.5
Concentration in
Sediment (mg/kg)
2(a)
--(b)
Exceeds Sediment
Benchmark Value
Yes
-
(a) NOAA; Long and Morgan 1991
(b) Dash indicates value could not be determined
mg/kg = milligrams per kilogram
RL/8-98/ES/3920001. A WS
C-30
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Table C-18. Comparison of Concentrations of Chemicals of Potential Ecological Concern in Sediments and Plants
to Phytotoxicity Benchmarks Values: Mather Air Force Base Site 87
Chemical
Antimony
Arsenic
Barium
Copper
Lead
Zinc
PAHs (total)
Concentration
in Sediment
(mg/kg) (dry
weight)(a)
21
48.5
301.5
58
6305
93
0.305
Benchmark
Concentration
in Soil (mg/kg)
(dry weight)(b)
5
10
500
100
50
50
18
Exceeds Soil
Benchmark
Value
Yes
Yes
No
No
Yes
Yes
No
Predicted Plant
Tissue
Concentration
(mg/kg) (dry
weigh t)(c)
4.20
1.94
45.2
23.2
284
140
0.00791
Excessive or
Toxic Plant
Concentration
(mg/kg) (dry
weight)(d)
60
5-20
~(e)
20-100
30-300
100-400
--
Exceeds Plant
Tissue
Benchmark
Vale
No
No
-
Yes
Yes
Yes
--
Exceeds Both
Soil and Plant
Tissue
Benchmark
Values
No
No
No
No
Yes
Yes
No
n
U)
(a) Concentration in sediment is the lowest of either the 95 percent upper confidence limit of the mean or maximum sediment concentration.
(b) Benchmark values reported in Will and Suter 1994.
(c) Predicted plant concentration based on the lowest of either the 95 percent upper confidence limit of the mean or maximum sediment concentration and
soil-to-plant transfer factors reported in Baes et al. 1984, for metals and derived transfer factors for organics as recommended in Travis and Arms 1988.
(d) Information from Kabata-Pendias and Pendias 1992.
(e) Dash indicates value could not be determined
mg/kg = milligrams per kilogram
PAHs = polycyclic aromatic hydrocarbons
392(X)!fl.AWS
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Table C-19. Ecological Hazard Quotients for the Mallard and Great Blue Heron
Exposed to Contaminants Associated with Sediments and Surface Waters:
Mather Air Force Base Site 87(a)
Chemical
Mallard
Heron(b)
Inorganics
Antimony
Arsenic
Barium
Copper
Lead
Zinc
2.54E-K)0(c)
8.11E-04
4.13E-03
1.33E-03
3.30E-OI
9.99E-02
4.73E+01
8.13E-02
1.24E-02
4.26E-03
3.80E-01
2.25E-01
Organic*
PAHs (total)
5.57E-04
2.25E+00
(a) Hazard quotients consider food related pathways only. Maximum concentrations detected in sediments and
surface water from a given site were used in the estimation of risk.
(b) The heron was assumed to consume 50 percent omnivorous mice and 50 percent crayfish.
(c) Values in bold are greater than 1.0.
PAHs = polycyclic aromatic hydrocarbons
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for bullet slugs. This is because slugs are much larger in size that shot and consumption of bullet
slugs by wildlife is deemed an unlikely exposure scenario.
C.4.2.2.7 Site 86
Although Site 86 has a history of use as a skeet/trap and pistol range, exposure of wildlife to shot
within this area is unlikely because of more current remediation practices. According to
IT [1997], the grounds of Site 86 have been scraped and removed. Dirt and associated lead shot
and slugs have either been used elsewhere as fill or stockpiled on Site 86. Current exposure of
wildlife to shot is unlikely. Because these stockpiles are scheduled for removal, future exposure
is not expected to occur.
C.4.2.2.2 Site 87
Lead shot associated with Site 87 is likely to be hazardous to wildlife within the area. Surveys of
lead shot within the area revealed concentrations of greater than 100 shots/sample as occurring
directly over Morrison Creek [IT 1997]. Adjacent grasslands have also been found to contain
high densities of the shot. This distribution correlates with lead concentrations recently
measured in soils at the site [IT 1997]. Because mallards and other wildlife have been observed
utilizing the creek and associated grassland areas of Site 87, it is possible that ecological
receptors may currently be at risk to lead from ingestion of lead shot within this area. As for
future risks, the top six inch to one foot of soil at Site 87 is scheduled to be remediated. Such an
action would result in the removal of shot and associated risk from the area.
C.4.3 Identification of Uncertainties
The approach used to quantify exposure to the ecological receptors involved both modeling with
conservative default values and the validation of these models through toxicity tests and residue
analyses. As mentioned in the CBRA work plan [IT 1993], modeling was conducted as a
screening assessment.
With reference to the models, the use of either the 95 percent upper confidence limit of the
arithmetic mean or the measured maximum concentration of a specific chemical in the exposure
medium contributes significantly to the uncertainty associated with the estimation of risk. This
may greatly overestimate the chemical concentration to which the plant or animal is actually
exposed. Uncertainties are also associated with the use of non-site-specific data in the exposure
models. Because site-specific soil-to-pant transfer factors for the COPEC were not available at
the time the screening assessment was performed, transfer factors for inorganic chemicals were
RL/8-98/ES/392000 LAWS
C-33
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obtained from the literature and those for organic compounds were derived from log K^ values
as recommended by Travis and Arms [1988]. Other examples of the utilization of
non-site-specific data in this ecological risk assessment include the use of literature obtained
bioconcentration factors for the aquatic invertebrates in the diets of the mallard and heron and the
use of wet weight to dry weight conversion values reported in the literature. Dietary intake
values were estimated with allometric equations and the time spent at a given site by each species
was based on home range information in the literature or were estimated from soil-to-earthworm
data or bioaccumulation models. In addition, estimates were made of the transfer of chemicals
through food webs. This involved the use of a default absorption coefficients of one for all
chemicals with a gastrointestinal adsorption coefficient that could not be located in the literature.
Once again, this a very conservative assumption. Lastly, potential risk associated with exposure
to lead shot is extremely difficult to predict due to lack of information associated with the
likelihood of exposure and the percentage of lead from ingested shot that is actually toxic. Each
of these factors and assumptions contribute substantially to the overall uncertainty in the
estimation of exposure of the indicator species to contaminants at Sites 86 and 87.
C. 5 Summary and Conclusions .
Ecological risks are predicted for Sites 86 and 87 through a screening level risk assessment. Risk
to ecological receptors associated with the grassland habitats at Site 86 was predicted to be low.
Chemicals that remain of concern in soil are possibly arsenic to the mouse, and copper and lead
to plants. Lead shot and bullet slugs do not appear to be an issue because of previously
conducted activities at the site which have resulted in the removal and relocation of surface soils
from the area. Some of this soil remains on site as stockpiles which are scheduled for removal.
Risks predicted at Site 87 are greater than those predicted at Site 86. Screening predictions
indicate lead may be hazardous to grassland plants and PAHs to small mammals associated with
the grassland habitats of Site 87. Surface water does not appear to be hazardous. With reference
to sediment, sediment quality criteria were exceeded for antimony, arsenic, copper, and lead and
could therefore be potentially toxic to benthic invertebrates. Lead and zinc in sediment may also
be hazardous to emergent plants. Polycyclic aromatic hydrocarbons and antimony were also
predicted to be potentially hazardous to heron and mallard, respectively, associated with the
surface water habitat. Because lead shot is present in relatively high concentrations at Site 87, it
is possible that species such as the mallard, which utilize the creek, may be at risk. Overall
ecological risk associated with Site 87 are currently rated as medium.
RU8-98/ES/392000I.AWS
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C.6 References.
Anderson, W.L., 1975, "Lead Poisoning in Waterfowl at Rice Lake, Illinois," Journal of Wildlife
Management, Vol. 39, No. 2, pp. 264-270.
Baes, C.F., II, R.D. Sharp, A.L. Sjoreen, and R.W. Shor, 1984, "A Review and Analysis of
Parameters for Assessing Transport of Environmentally Released Radionuclides through
Agriculture," ORNL-5786, Oak Ridge National Laboratory, Oak Ridge, Tennessee.
Bellrose, F.C., 1951, "Effects of Ingested Lead Shot upon Waterfowl Populations," North
American Wildlife Conference Transaction 16, pp. 125-133.
California Department of Toxic Substances Control (DTSC), 1996, "Guidance for Ecological
Risk Assessment at Hazardous Waste Sites and Permitted Facilities, Part A: Overview," State of
California, California Department of Toxic Substances Control, Human and Ecological Risk
Division, Sacramento, California.
California Environmental Protection Agency (CEPA), 1993, "Functional Equivalent Document,
Amendments of the Water Quality Control Plan for Inland Surface Waters of California," State
Water Resources Control Board, California Environmental Protection Agency.
CEPA, see California Environmental Protection Agency.
DTSC, see California Department of Toxic Substances Control.
IT, see IT Corporation.
IT Corporation (IT), 1997, "Air Force Installation Restoration Program Draft Final Site
Characterization Report for IRP Sites 86 and 87, Mather Air Force Base, California," Air Force
Center for Environmental Excellence, Brooks Air Force Base, Texas.
IT Corporation (IT), 1996, "Final Comprehensive Baseline Risk Assessment for Mather Air
Force Base, California," IT Corporation, Albuquerque, New Mexico.
IT Corporation (IT), 1993, "Comprehensive Baseline Risk Assessment Final Work Plan for
Mather Air Force Base, California," IT Corporation, Richland, Washington.
RL/8-98/ES/3920001 .AWS
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Hull, R.N. and G.W. Suter, II, 1984, "lexicological Benchmarks for Screening Contaminants of
Potential Concern for Effects on Sediment Associated Biota: 1994 Revision," ES/ER/TM-95/RI,
Oak Ridge National Laboratory ^ Oak Ridge, Tennessee.
Kabata-Pendias, A. and H. Pendias, 1992, Trace Elements in Soil and Plants, 2nd ed.,
CRC Press, Boca Raton, Louisiana.
Kendall, R.J., I.E. Lacher, Jr., C. Bunck, B. Daniel, C. Driver, C.E. Cure, F. Leighton,
W. Stansley, P.O. Watanabe, and M. Whitworth, 1996, "An Ecological Risk Assessment of Lead
Shot Exposure in Non-Waterfowl Avian Species: Upland Game Birds and Raptors,"
Environmental Toxicology and Chemistry, Vol 15, No. 1, pp. 4-20.
Long, E.R. and L.G. Morgan, 1991, "The Potential for Biological Effects of Sediment-Sorbed
Contaminants Tested in National Status and Trends Program," NOAA Technical Memorandum
NOS OMA 52, National Oceanic and Atmospheric Administration.
Lyman, W.J., 1992, "Adsorption Coefficients for Soil and Sediments," in W.J. Lyman, W.F.
Reehl, and D.H. Rosenblatt (eds.), Handbook of Chemical Estimation Methods: Environmental
Behavior of Organic Compounds, McGraw-Hill Book Company, New York, pp. 4-1 to 4-33.
Ma, W.C., 1982, "The Influence of Soil Properties and Worm-Related Factors on the
Concentration of Heavy Metals in Earthworms," Pedobiologia, Vol. 24, pp. 109-119.
Menzie, C.A., D.E. Bummaster, J.S. Freshman, and C.A. Callahan, 1992, "Assessment of
Methods for Estimating Ecological Risk in the Terrestrial Component: A Case Study at The
Baird & McGuire Superfund Site in Holbrook, Massachusetts," Journal of Environmental
Toxicology and Chemistry, Vol. 11, pp. 245-260.
Morrison, F.B., 1959, Feed and Feeding: A Handbook for the Student and Stockman, The
Morrison Publishing Company, Clinton, Iowa.
Opresko, D.M., B.E. Sample, and G.W. Suter, II, 1994, "Toxicological Benchmarks for Wildlife:
1994 Revision," ES/ER/TM-86/R1, Oak Ridge National Laboratory, Oak Ridge, Tennessee.
Owen, B.A., 1990, "Literature-Derived Absorption Coefficients for 39 Chemicals via Oral and
Inhalation Routes of Exposure," Regulatory Toxicology and Pharmacology, 11, pp. 237-252.
RL/8-98/ES/392000 LAWS
C-36
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Pain, D.J., 1991, "Lead Shot Densities and Settlements Rates in Camargue Marshes, France,"
Biological Conservation, Vol. 57, pp. 273-286.
Suter, G.W., II and J.B. Mabrey, 1994, "Toxicological Benchmarks for Screening Potential
Contaminants of Concern for Effects on Aquatic Biota: 1994 Revision," ES/ER/TM-96/R1, Oak
Ridge National Laboratory, Oak Ridge, Tennessee.
Taylor, R.L., 1975, Butterflies in My Stomach, Woodbridge Press Publishing Co., Santa Barbara,
California.
Travis, C.C. and A.D. Arms, 1988, "Bioconcentration of Organics in Beef, Milk, and
Vegetation," Environmental Science and Technology. Vol. 22, pp. 271-274.
U.S. Environmental Protection Agency (USEPA), 1996a, "Proposed Guidelines for Ecological
Risk Assessment," EPA/630/R-95/002B, U.S. Environmental Protection Agency,
Washington, D.C.
U.S. Environmental Protection Agency (USEPA), 1996b, "Integrated Risk Information System
(IRIS)," on-line database, maintained by the U.S. Environmental Protection Agency,
Washington, D.C.
U.S. Environmental Protection Agency (USEPA), 1993, "Wildlife Criteria Portions of the
Proposed Water Quality Guidance for the Great Lakes System," EPA/822/R-93-006,
U.S. Environmental Protection Agency, Office of Water, Washington, D.C.
U.S. Environmental Protection Agency (USEPA), 1992a, "Framework for Ecological Risk
Assessment," EPA/63O/R-92/001, U.S. Environmental Protection Agency, Washington, D.C.
U.S. Environmental Protection Agency (USEPA), 1992b, "Water Quality Standards:
Establishment of Numeric Criteria for Priority Toxic Pollutants; State's Compliance; Final Rule,"
Federal Register, Title 40, Code of Federal Regulations, Part 131, U.S. Environmental
Protection Agency, Washington, D.C.
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U.S. Environmental Protection Agency (USEPA), 1989, "Risk Assessment Guidance for
Superfund," (RAGS), Vol. I, Human Health Evaluation Manual (Part A), OSWER
Directive 9285.7-01'A, U.S. Environmental Protection Agency, Office of Emergency and
Remedial Response, Washington, D.C.
U.S. Environmental Protection Agency (USEPA), 1986, "Quality Criteria for Water, 1986,"
PB87-226759, U.S. Environmental Protection Agency, Office of Water, Regulations and
Standards, Washington, D.C.
USEPA see U.S. Environmental Protection Agency
Whitehead, P.J. and K. Tschimer, 1991, "Lead Shot Ingestion and Lead Poisoning of Magpie
Geese Anseranas Semipalmata Foraging in a Northern Australian Hunting Reserve," Biological
Conservation, Vol. 58, pp. 99-118.
Will, M.E. and G.W. Suter, II, 1994, "Toxicological Benchmarks for Screening Potential
Contaminants of Concern for Effects on Terrestrial Plants: 1994 Revision," ES/ER/TM-85/R1,
Oak Ridge National Laboratory, Oak Ridge, Tennessee.
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Appendix D
Estimation of Contaminant Concentrations for
Waste Disposal at Site 7
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Table of Contents.
List of Tables D-ii
List of Acronyms D-iii
D. 1 Water Quality Goals D-l
D.2 Leachability Factors D-l
D.3 Designated Level Methodology Calculations D-3
D.4 Further Evaluations D-3
D.5 References D-6
RL/8-98/ES/3920001 .AWS
D-i
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List of Tables.
Table Title Page
D-l Site 7 Acceptance Criteria for Selected Contaminants of
Concern Designated Level Methodology Mather Air Force
Base, California D-2
D-2 Leachability Factors for Selected Metals Sites 86 and 87
Mather Air Force Base, California D-4
D-3 Analytical Comparison Total TPH-D vs. DI-WET
Concentrations D-5
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D-ii
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List of Acronyms.
COC chemical of concern
DLM designated level methodology
MCL maximum contaminant level
MSMA Mather Soils Management Facility
SAC Strategic Air Command
TPH-D total petroleum hydrocarbon measured as diesel
USEPA U.S. Environmental Protection Agency
WQG water quality goal
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D-iii
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The following summarizes Montgomery Watson's approach for estimating the maximum
contaminant concentrations that can be delivered to Site 7 as backfill without adversely
impacting groundwater quality. The chemicals of concern (COCs) include arsenic, barium,
cadmium, chromium, lead, nickel, mercury, diesel, and oil and grease. This list was selected
from known COCs at Sites 13,15, 86, and 87, which will be excavated as part of future remedial
actions. The excavated soils at these sites represent major potential sources of backfill to regrade
the large depression at Site 7.
The initial estimations were made using the designated level methodology (DLM) as
recommended by the California Regional Water Quality Control Board. One parameter in the
DLM (i.e., the leachability factor) was updated to include data and statistical information specific
to the soils that will represent major contributions to the backfill at Site 7. In addition, the water
quality goals (WQG) were updated to conform with those being proposed in the Final Focused
Feasibility Study for the Basewide Operable Unit [IT 1997a].
D. 1 Water Quality Goals
The WQGs shown on Table D-l were obtained from the California maximum contaminant levels
(MCLs) with the following exceptions:
• Total petroleum hydrocarbon measured as diesel (TPH-D) was based on the
cleanup levels adopted in the Final Superfund Record of Decision for Soil
Operable Unit Sites and Groundwater Operable Unit Plume [IT 1996].
• Arsenic was based on concentrations identified in the California Proposition 65
regulatory level and used as a water quality criterion.
• Lead was based on the primary MCL according to the Federal drinking water
standard by the U.S. Environmental Protection Agency (USEPA).
D.2 Leachability Factors
The leachability factor used in the DLM for inorganic constituents was 100, as recommended by
the Regional Water Quality Control Board, except for sites where site-specific or base-specific
leaching data was available. This data included analytical results form paired soils samples (i.e.,
samples having both total and soluble analyses) where the soluble samples were analyzed with
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D-l
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Table D-l. Site 7 Acceptance Criteria for evaluated Contaminants of Concern
Designated Level Methodology
Mather Air Force Base, California
Analyte
TPH-diesel [a]
Arsenic [c]
Barium [e]
Cadmium [e]
Q Chromium [e]
Lead [g]
Mercury [e]
Nickel [e]
Water Quality Environmental WET
Goal Attenuation Factor Dilution
lOOug/L
5»g/L
1000 i/ g/L
5 i/ g/L
50 i/g/L
15//g/L
2 i/g/L
100 u g/L
100
100
100
100
100
1000
100
100
10
10
10
10
10
10
10
10
Soluble
Designated Level
1 ,000 H g/L
50 i/g/L
10,000 wg/L
50i
-------
the waste extraction test using deionized water. The teachability factors used in the DLM were
derived from the following investigations:
• Arsenic, barium, and lead were based on nine samples that were analyzed for total
and soluble concentrations at Sites 86 and 87, the small arms range and skeet
range, respectively. These results reported by IT Corporation in the Draft Final
Site Characterization Report for Installation Restoration Program Sites 86 and 87
[IT 1997b].
The teachability factors for TPH-D was based on fifteen soil samples that were
analyzed for total and soluble concentrations at a number of underground storage
tank stockpiles location at the Mather Soils Management Facility (MSMA), the
Old RV Storage Area, and Strategic Air Command (SAC) Service areas. These
results reported by Montgomery Watson in the Final Report of Analytical Results
of Soil Stockpiles at MSMA, ORVSA, and SAC Service areas, June 1996.
Table D-2 includes the supporting data and compilation of leaching factors statistics for arsenic,
barium, and lead. Table D-3 includes the data regression analysis establishing the relationship
between total and soluble TPH-D concentrations.
D.3 Designated Level Methodology Calculations
Table D-l shows the results of the DLM in terms of the calculated and recommended total and
soluble designated levels for the selected list of constituents. The calculated results of the total
designated levels for arsenic, barium, and lead exceed the regulatory levels for classification as a
hazardous waste. As a result, the recommended concentrations for these metals were limited to
their respective Total Threshold Limit Concentrations. Total designated levels are the preferred
criteria for evaluating acceptance for backfill at Site 7 due to the lower analytical cost of the total
concentrations and the more rapid turn around times from the analytical laboratories.
D.4 Further Evaluations
To further evaluate and demonstrate the conservatism of the DLM calculations, additional
estimations are being made with the aid of fate and transport models that simulate the vadose
zone and saturated zone. Vadose zone simulations will be performed to estimate contaminant
concentrations (mass) reaching the water table. The estimated mass reaching the water table will
then be applied to the saturated zone model to estimate groundwater concentrations. The
allowable soil concentrations will then be estimated using the simulation results.
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D-3
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Table D-2. Leachability Factors for Selected Metals
Sites 86 and 87
Mather Air Force Base, California
Site 86
Analyte
Arsenic
Barium
Copper
Lead
Zinc
Mather Inorganic
Background
(mg/kg)
8
375
93.2
13.5
116
Sample SSA-086-A02
Total
(mg/kg)
9.2
199
34
98
56
Soluble
(ug/L)
2.1
992
26
113
28
LF
4.381
201
1,308
867
2,000
Sample SSA-086-D 12
Total
(mg/kg)
9.1
96
118
1.660
72
Soluble
(ug/L)
2.1
703
780
16.000
180
LF
4.333
137
151
104
400
Sample SSA-086-R02
Total
(mg/kg)
10
258
46
340
57
Soluble
(ug/L)
2.1
2.350
180
892
110
LF
4.762
110
256
381
518
Leachability Factors
Sites 86 and 87
Mean
3.735
230
1.208
719
2.008
Deviation
2.170
115
733
363
1,092
Site 87
Analyte
Arsenic
Barium
Copper
Lead
Zinc
Mather Inorganic
Background
(mg/kg)
8
375
93.2
13.5
116
Sample SSA-087-05B
Total
(mg/kg)
7.7
165
21
690
42
Soluble
(ug/L)
5.7
390
10.9
562
17
LF
1.351
423
1,927
1,228
2471
Sample SSA-087-OBD
Total
(mg/kg)
8.5
157
18
1.330
38
Soluble
(ug/L)
4.4
403
9.2
1,660
17
LF
1.932
390
1.957
801
2,235
Sample SSA-087-10C
Total
(mg/kg)
5.2
139
16
340
37
Soluble
(ug/L)
2.1
492
10
281
17
LF
2.476
283
1.600
1,210
2,176
Sample SSA-087-12E
Total
(mg/kg)
5
116
18
8.5
33
Soluble
(ug/L)
2.1
843
19
8.5
8.9
LF
2,381
138
947
690
3.708
Sample SSA-087-13B
Total
(mg/kg)
18
270
53
690
81
Soluble
(ug/L)
2.1
1.090
26
1,120
26
LF
8.571
248
2,038
616
3.115
Sample SSA-087-04D
Total
(mg/kg)
7.2
156
22
38
39
Soluble
(ug/L)
2.1
1.090
32
66.2
27
LF
3,429
143
688
574
1.444
Note: Where soluble concentrations were less than the reporting limit, the reporting limit was used (or the teachability factor calculation.
LF (Leachability Factor) is the total concentration divided by the soluble concentration.
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Table D-3. Analytical Comparision
Total Petroluem Hydrocarbons as Diesel vs.
Deionized Waste Extration Test Concentration
Sample
USTE-R-9-C
USTA-R-8-1
USTE-R-1-C
USTB-R-8-2
USTD-R-1-C
AFIG3-R-3-C
MSMA-SCRN-3
RVI-R-4-C
i
MSMA-SCRN-2
AFIG3-R-1-C
USTG-R-2-C
RVH-R-6-C
USTG-R-1-C
MSMA-SCRN-1
RVH-R-1-2
RVI-R-2-C
RVI-R-3-C
RVI-R-9-C
RVH-R-9-4
RVI-R-6-C
RVH-R-5-4
TPH-D
(mg/kg)
8.9
9.4
9.5
16
28
28
30
82
86
94
110
160
190
210
240
480
570
620
710
720
3900
TPH-D WET (a)
(mg/L)
0.26
0.33
0.35
0.19
0.38
0.23
0.32
0.62
0.27
0.58
1.3
4.2
1.2
0.88
1.4
4.3
5.2
10
77
13
89
(a) Dl water
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D-5
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Vadose zone simulations will be conducted with the Vadose Zone Leaching Model (VLEACH
Version 2.2). VLEACH is a one-dimensional finite-difference computer code for estimating the
impact of contamination in the vadose zone on groundwater quality. It was originally developed
by CH2M Hill in 1990 for the USEPA Region IX. Wherever possible, site-specific data will be
used to represent model parameters. In the absence of site data, conservative estimates of model
parameters will be used.
Saturated zone simulations will be performed with MODFLOW (for flow simulations) and
MT3D96 (for transport simulations).
D.5 References
IT Corporation (IT), 1997a, "Final Basewide Operable Unit Focused Feasibility Study Report for
Mather Air Force Base, California," Prepared by IT Corporation, Richland, Washington for Air
Force Center for Environmental Excellence, Brooks Air Force Base, Texas, April 997.
IT Corporation (IT), 1997b, "Final Site Characterization Report for Sites 86 and 87 for Mather
Air Force Base, California," Prepared by IT Corporation for Air Force Center for Environmental
Excellence, Brooks Air Force Base, Texas, February 20, 1997.
IT Corporation (IT), 1996, "Soil Operable Unit and Groundwater Operable Unit Record of
Decision," prepared by IT Corporation, Richland, Washington for Air Force Center for
Environmental Excellence.
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Appendix E
Designated Level Methodology
RL/8-98/ES/392000 LAWS
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Table of Contents.
List of Tables E-ii
List of Acronyms E-iii
E.I Designated Level Methodology E-l
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E-i
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List of Tables.
Table Title Page
E-1 Environmental Attenuation Factors E-1
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E-ii
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List of Acronyms.
COPC chemicals of potential concern
WQG water quality goal
MCL maximum contaminant level
EAF environmental attenuation factor
FFS Focused Feasibility Factor
LF leachability factor
TDL total designated level
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E. 1 Designated Level Methodology
The California Regional Water Quality Control Board - Central Valley Region's Designated
Level Methodology [CVRWQCB 1989] was used to evaluate or estimate potential impact to the
groundwater from chemicals of potential concern (COPCs) in surface and subsurface soils. The
application of this methodology consisted of the following steps:
• Determined the desired water quality goal (WOGt for each constituent:
Promulgated regulations and standards were used where available (primary
Maximum Contaminant Levels (MCLs) were used as WQGs for surface soil and
subsurface soil evaluations. In the absence of promulgated regulations,
contaminant goals, health advisories, or risk-based values were used as WQGs.
• Detepniped the environmental attenuation factor (EAH for each constituent:
This factor was used to transform WQGs into site-specific designated levels
(concentrations of constituents in the soils that have the potential to degrade water
quality at the site of discharge). For purposes of determining COPCs in the
Focused Feasibility Study (FFS) [IT 1997] and consistency with DLM guidance
[CVRWQCB 1989], the EAFs presented in Table E-l were used.
Table E-l. Environmental Attenuation Factors
Depth to Groundwater
(from deepest constituent
detection)
>30 feet
29-11 feet
< 10 feet
Environmental Attenuation Factor
Subsurface and Surface Soils
100(a)
10(b)
l(c)
(a) 1000 for copper, zinc and dichlorodiphenyldichloroethane (ODD), dichlorodiphenyldichloroethylene
(DDD), and dichlorodiphenyltrichloroethane (DDT) since these constituents have a greater than average
degree of environmental attenuation.
(b) 100 for copper, zinc, DDD, DDE, and DDT.
(c) 10 for copper, zinc, DDD, DDE, and DDT.
(d) Sediments assumed in contact with surface water; therefore, 10 for copper, zinc, DDD, DDE, and DDT.
• Determined a Leachability Factor (LF): This factor was used to determine the
fraction of the total constituent concentration available for leaching from the
waste. The remaining portion of the constituent is immobile or unavailable for
leaching due to encapsulation in the waste matrix or chemical bonding. When
available, site-specific waste extraction test analysis results were used to establish
LFS for each constituent. In the absence of site-specific Waste Extraction Test
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E-l
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results (or extrapolation from the Waste Extraction Test data), a LF of 100 was
used for inorganic constituents and ten for organic constituents as prescribed in
the DLM guidance [CVRWQCB 1989].
• Determined a Total Designated Level (TDL): This level represents the
concentration of a constituent in the soils which, if exceeded, may threaten the
water quality. The TDL was calculated using the following equation:
Total Designated Level = Water Quality x Environmental x Leachability
Goal Attenuation Factor
Factor
The COPCs for which the 95 percent upper confidence level (or in some cases the maximum
concentration) was less than the associated TDL were eliminated from further consideration.
As mentioned above, the DLM analysis established COPCs for inorganic and semi-volatile
constituents. Volatile constituents were analyzed using VLEACH modeling to determine
whether or not the volatile contaminants are to be considered a COPCs as presented in
Appendix D of the FFS [IT 1997].
E. 2 References
Central Valley Regional Water Quality Control Board (CVRWQCB), 1989, "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).
IT Corporation (IT), 1997, "Final Basewide Operable Unit Focused Feasibility Study Report for
Mather Air Force Base, California," Prepared by IT Corporation, Richland, Washington for Air
Force Center for Environmental Excellence, Brooks Air Force Base, Texas, April 1997.
RU8-98/ES/392000I.AWS E-2
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Appendix F
Background Distributions of Soil Constituents at
Mather Air Force Base
R178-98/ES/392000I .AWS
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Table of Contents.
List of Tables F-ii
List of Acronyms F-iii
F.I Background Distributions of Soil Constituents at Mather Air Force Base F-l
F.I.I Handling of Nondetections F-l
F. 1.2 Calculation of Summary Statistics, Upper Tolerance Limit Values, and
Upper Confidence Limits F-2
F.2 Results F-3
F.3 References F-3
RU8-98/ES/3920001 .A WS
F-i
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List of Tables.
Table Title
F-l Summary Statistics For Mather Air Force Base Background Soils F-4
F-2 Summary Statistics For Aerojet Background Soils F-5
F-3 Summary Statistics For Combined Background Soils F-6
RL/8-98/ES/392000I.AWS
F-ii
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List of Acronyms.
AFB Air Force Base
UCL upper confidence limit
UTLV upper tolerance limit value
USEPA U.S. Environmental Protection Agency
RL«-9g/ES/392000I.AWS
F-iii
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F. 1 Background Distributions of Soil Constituents at Mather
Air Force Base
Background distributions of naturally occurring constituents at Mather Air Force Base (AFB)
were recalculated using appropriate methodology in response to comments received on the Draft
Basewide Operable Unit Record of Decision. The following provides a description of the
methodology used to establish background distributions (Section F. I), followed by descriptions
of the background distributions (Section F.2).
A set of background values were identified in the Basewide Operable Unit Focused Feasibility
Study which were comprised of data sets from McCellan AFB, Mather AFB, and the local
Sacramento area. The maximum value for each constituent was used as the "background" to be
used for site comparisons and for setting cleanup goals. However, comments were received from
the regulatory agencies that the "background" data set was not appropriate and that a revised data
set be compiled by combining data sets from Mather AFB and Aerojet. The following
subsections describe the processes followed to statistically combine and evaluate the data sets in
order to arrive at one representative "background" data set.
F. 1.1 Handling of Nondetections
A proportion of nondetections are common in background data sets for anthropogenic
constituents and naturally occurring trace metals. A variety of methods to deal with
nondetections have been proposed, each of which has advantages and disadvantages with respect
to introducing unwanted bias into the description of background.
In the case of naturally occurring constituents, the U.S. Environmental Protection Agency
(USEPA) guidance of replacing nondetections with a value equal to one-half of the practical
quantitation limit for that analyte [USEPA 1989] was used. Data sets were screened for "high
nondetects" which are defined as a nondetect with a detection limit that is two times higher than
the median of the detected values. These nondetections are rejected from the data sets because
they contain very little information, and assigning a value of one-half the detection limit to these
data points will introduce large uncertainties in the calculated summary statistics. However,
none of the background distributions contained high detections limits.
RU8-98/ES/392000 LAWS
F-l
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F.1.2 Calculation of Summary Statistics, Upper Tolerance Limit Values, and
Upper Confidence Limits
A complete description of the background distributions of each detectable constituent is provided
based on the Mather background data set, the Aerojet background data set, and the combined
Mather and Aerojet data sets. This description includes the number of samples, minimum,
maximum, median, mean, standard deviation, 95th upper confidence limit (UCL), and 95th upper
tolerance limit value (UTLV). As with the Mather background statistics, all of the distributions
were assumed to be normally distributed [IT 1993]. All of the summary statistics were calculated
using the Statistical Version 5.0 for Windows software package.
The UCL is defined as:
UCL9J=X +(Wn.. •S/A)
where:
UCL9J = Upper 95-percent confidence limit
X = Arithmetic mean of the data set
IOQJ „., = Student's t statistic for a one-sided, 95-percent confidence interval with
n-1 degrees of freedom
S = Standard deviation of the data set
n = Number of samples.
The 95 percent UCL of the mean provides reasonable confidence that the true average will not be
underestimated. That is, there is a 95 percent confidence that the average concentration is below
the 95 percent UCL.
The UTLV is defined as:
UTLV95 = X + (K • S)
where:
UTLV95 = 95th Upper tolerance limit value
X - Arithmetic mean of the data set
S = Standard deviation of the data set
K = One-sided normal tolerance factor.
The UTLV establishes a concentration range that is constructed to contain a specified proportion
of the population with a specified confidence. The proportion of the population included is
referred to as the coverage, and the probability with which the tolerance interval included the
proportion is referred to as the tolerance coefficient. The one-sided normal tolerance factor (K)
RU8-98/ES/392000 LAWS
¥-2
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in the above equation is a function of the desired percent coverage, the desired tolerance
coefficient, and the number of samples. The USEPA-recommended coverage value of 95 percent
and tolerance coefficient value of 95 percent [USEPA 1989] are used in this report to calculate
the UTLVs. This 95th UTLV implies that five percent, or one in 20 of the values from
subsequent sampling rounds would be expected to be above the 95th UTLV or 95th percentile
and do not necessarily represent contamination.
F.2 Results
Tables F-l through F-3 describe the background distributions for metals at Mather, Aerojet, and
the combined data sets. It is recommended that the combined data set, based on the 95th UTLV,
is representative of the site and will be used in the evaluation of sample data and setting of
cleanup criteria.
F.3 References.
IT Corporation (IT), 1993, "Background Inorganic Soils for Mather Air Force Base,"
IT Corporation, Albuquerque, New Mexico and Richland, Washington.
U. S. Environmental Protection Agency (USEPA), 1989, Statistical Analysis of Ground-Water
Monitoring Data at RCRA Facilities, Interim Final Guidance," EPA/530-SW-89-026,
U.S. Environmental Protection Agency, Office Of Solid Waste, Waste Management Division,
Washington, D.C.
RL/8-98/ES/392000I .AWS
F-3
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Table F-l
Summary Statistics For Mather Air Force Base Background Soils
Metal
Silver
Aluminum
Arsenic
Barium
Beryllium
Calcium
Cadmium
Cobalt
Chromium
Copper
Iron
Mercury
Potassium
Magnesium
Manganese
Molybdenum
Nickel
Lead
Selenium
Thallium
Vanadium
Zinc
Valid N
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
64
Minimum
1
7060
0.46
43.2
0.44
555
0.5
6
6.2
7.8
11600
0.1
475
780
110
20
8
2.7
6
0.48
31.7
29
Maximum
1
41200
8
375
3
6580
0.5
25.6
176
104
43700
0.1
5670
8260
2350
20
68.9
13.5
6
1
153
116
Median
1
16250
2.35
117.5
0.875
2970
0.5
14.1
34.95
34.3
24050
0.1
1755
3845
428.5
20
26.35
6.4
6
1
67.9
59.25
Mean
1.000
18667
2.90
140
1.04
2949
0.5
14.0
39.4
37.5
24659
0.1
1805
4323
513
20.0
28.6
6.7
6.0
1.0
67.9
61.6
95 % UCL
—
20918
3.33
158
1.19
3302
«
15.3
46.5
42.8
26761
—
2027
4785
606
—
32.4
7.5
—
1.0
74.2
66.2
95 % UTLV
—
36714
6.36
286
2.22
5779
—
23.9
96.3
80
41515
—
3867
8028
1253
—
58.4
12.8
«
1.14
119
98.6
Note: all constituent concentrations are in parts per million
N = number of samples
UCL = upper confidence limit
UTLV = upper tolerance limit value
RU8-98/ES/3920001. AWS
F-4
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Table F-2
Summary Statistics For Aerojet Background Soils
Metals
Silver
Aluminum
Arsenic
Barium
Beryllium
Calcium
Cadmium
Cobalt
Chromium
Copper
Iron
Mercury
Potassium
Magnesium
Manganese
Molybdenum
Sodium
Nickel
Potassium
Lead
Selenium
Thallium
Vanadium
Zinc
Valid
N
60
0
60
60
60
0
60
60
60
60
0
60
0
60
60
60
0
60
60
60
60
60
60
60
Minimum
0.01
—
0.2
140
0.25
—
0.05
7
20
5.8
--
0.01
~
0.13
140
0.1
—
7
--
4.5
0.1
0.05
69
18
Maximum
0.16
—
15.6
980
1.5
—
0.3
36
161
218.2
—
0.12
—
1.72
1760
2
—
106
630
19
0.8
0.5
306
112
Median
0.02
—
4.4
630
0.5
«
0.05
18.5
98.5
20.4
—
0.02
—
0.355
922.5
0.6
—
40
380
11
0.2
0.3
132.5
41
Mean
0.032
~
4.567
612
0.446
—
0.072
18.58
99.0
27.510
~
0.024
«
0.521
868
0.690
—
41.40
373.2
10.79
0.22
0.27
138.2
47.63
95 % UCL
0.039
—
5.413
648
0.512
—
0.085
20.16
107.3
34.806
—
0.029
—
0.612
964
0.783
—
46.74
409.5
11.53
0.26
0.30
148.3
53.46
95 % UTLV
0.087
--
11.2
891
0.963
—
0.179
30.9
164
84.5
~
0.061
—
1.23
1616
1.42
--
83.1
657
16.6
0.521
0.5
217
93.1
Note: All constituent concentrations are in Parts per million
N = number of samples
UCL = upper confidence limit
UTLV = upper tolerance limit value
RL/8-98/ES/392000I.AWS
F-5
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Table F-3
Summary Statistics For Combined Background Soils
Metal
Silver
Aluminum
Arsenic
Barium
Beryllium
Calcium
Cadmium
Cobalt
Chromium
Copper
Iron
Mercury
Potassium
Magnesium
Manganese
Molybdenum
Nickel
Lead
Selenium
Thallium
Vanadium
Zinc
Valid N
124
64
124
124
124
64
124
124
124
124
64
124
64
124
124
124
124
124
124
124
124
124
Minimum
0.01
7060
0.2
43.2
0.25
555
0.05
6
6.2
5.8
11600
0.01
475
0.13
110
0.1
7 j
2.7
0.1
0.05
31.7
18
Maximum
1
41200
15.6
980
3
6580
0.5
36
176
218.2
43700
0.12
5670
8260
2350
20
106
19
6
1
306
116
Median
1
16250
3.4
292.5
0.5
2970
0.5
16
60.65
25.95
24050
0.1
1755
1670
604
20
32.1
9
6
0.83
100.5
49
Mean
0.531
18667
3.705
369
0.751
2949
0.293
16.24
68.27
32.68
24659
0.063
1805
2231
685.10
10.66
34.81
8.70
3.20
0.64
101.9
54.85
95 % UCL
0.618
20918
4.188
415
0.848
3302
0.332
17.30
75.81
37.17
26761
0.070
2027
2683
757.90
12.38
38.18
9.33
3.72
0.71
110.4
58.70
95 % UTLV
1.6
36714
9.6
942
1.95
5779
0.705
27.5
149
80.4
41515
0.151
3867
7821
1460
28.90
70.7
15.5
8.69
1.34
193
96
Note: All constituent concentrations are in parts per million
N = number of samples
UCL = upper confidence limit
UTLV = upper tolerance limit value
RL/8-98/ES/392000 LAWS
F-6
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