Section 9 Lease Mines
Western Abandoned Uranium Mine Region
Coconino County, Arizona
Final
Section 9 Lease Mines
Engineering Evaluation/Cost Analysis
November 2024
TETRA TECH
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Section 9 Lease Mines
Western Abandoned Uranium Mine Region
Coconino County, Arizona
Final
Section 9 Lease Mines
Engineering Evaluation/Cost Analysis
Response, Assessment, and Evaluation Services 2
Contract No. 68HE0923D0002
Task Order 020
November 2024
Submitted to
U.S. Environmental Protection Agency
Submitted by
Tetra Tech, Inc.
1999 Harrison Street, Suite 500
Oakland, CA 94612
TETRA TECH
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Section 9 Lease Mines EE/CA
TABLE OF CONTENTS
Section Page
ACRONYMS AM) ABBREVIATIONS vi
1.0 INTRODUCTION 1
1.1 SITE CHARACTERIZATION 1
1.2 REMOVAL ACTION OBJECTIVES 2
1.3 IDENTIFICATION OF REMOVAL ACTION ALTERNATIVES 3
1.4 ANALYSIS OF REMOVAL ACTION ALTERNATIVES 3
2.0 SITE CHARACTERIZATION 5
2.1 SITE DESCRIPTION AND BACKGROUND 5
2.1.1 Site Location 5
2.1.2 Type of Mine and Operational Status 5
2.1.3 Regulatory Hi story 6
2.1.4 Site Features and Landscape 6
2.1.5 Geology 7
2.1.6 Hydrology 8
2.1.7 Land Use and Populations 8
2.1.8 Sensitive Ecosystems and Habitat 8
2.1.9 Meteorology and Climate 9
2.2 PREVIOUS RECLAMATION AND REMOVAL ACTIONS 9
2.3 PREVIOUS SITE INVESTIGATIONS 9
2.4 SOURCE, NATURE, AND EXTENT OF CONTAMINATION 10
2.4.1 Western Abandoned Uranium Mine Regional Background and Site-
Specific Background 11
2.4.2 Site Contaminants 11
2.4.3 Source and Nature of Contamination 11
2.4.4 Extent of Contamination 13
2.5 RISK ASSESSMENT 14
2.5.1 Purpose 14
2.5.2 Exposure Unit 14
2.5.3 Human Health Risk Evaluation 15
2.5.4 Ecological Risk Evaluation 16
2.5.5 Risk Assessment Results Summary 16
2.6 RISK MANAGEMENT ANALYSIS 18
2.6.1 Comparison of Site Concentrations of Candidate Contaminant of Concern
and Candidate Contaminants of Ecological Concern to Background
Concentrations 19
2.6.2 Consideration of Natural Forms of Chromium 20
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2.6.3 Comparison of Maximum Detected Concentrations to Preliminary Removal
Goals for Human Health and Ecological Health 22
2.6.4 Co-Location Assessment 24
2.6.5 Risk Management Summary and Conclusions 25
2.7 REMOVAL ACTION EXTENT 26
2.7.1 Identification of Removal Action Goals 26
2.7.2 Removal Action Extent Development 26
3.0 IDENTIFICATION OF REMOVAL ACTION OBJECTIVES 28
3.1 REMOVAL ACTION OBJECTIVES 28
3.2 STATUTORY LIMITS ON REMOVAL ACTIONS 28
3.3 REMOVAL SCOPE 29
3.4 REMOVAL SCHEDULE 29
4.0 IDENTIFICATION AND ANALYSIS OF REMOVAL ACTION ALTERNATIVES .. 30
4.1 DEVELOPMENT AND SCREENING OF ALTERNATIVES 30
4.1.1 Summary of Technology Identification and Screening 30
4.1.2 Summary of Alternative Development 33
4.1.3 Applicable or Relevant and Appropriate Requirements 34
4.2 DESCRIPTION OI ALTERNATIVES 36
4.2.1 Common Elements 36
4.2.2 Description of Removal Action Alternatives 43
4.3 ANALYSIS OF ALTERNATIVES 50
4.3.1 Alternative 1: No Action 53
4.3.2 Alternative 2: Consolidate and Cap All Waste Onsite 54
4.3.3 Alternative 3: Disposal of All Mine Waste at aWestern AUM Regional
Repository 60
4.3.4 Alternative 4: Disposal of All Mine Waste in Offsite Resource
Conservation and Recovery Act-Licensed Facility 65
5.0 COMPARATIVE ANALYSIS OF ALTERNATIVES 71
5.1 COMPARATIVE ANALYSIS APPROACH 71
5.2 SUMMARY OF ANALYSIS 71
5.2.1 Effectiveness 71
5.2.2 Implementability 76
5.2.3 Projected Costs 77
6.0 REFERENCES 79
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EXHIBITS
Exhibit 1. Summary of Alternative Ratings 4
Exhibit 2. Site-Wide Candidate COECs 17
Exhibit 3. Candidate COCs and Candidate COECs Recommended for Further Evaluation 17
Exhibit 4. Background Comparison Results Summary 21
Exhibit 5. Human Health Preliminary Removal Goals and NAUM PERGs for Candidate COCs
and COECs in Soil Above Background 23
Exhibit 6. Radium-226 Removal Action Goal Development 24
Exhibit 7. COCs and COECs Recommended for Removal Action 25
Exhibit 8. Removal Action Goal 26
Exhibit 9. Existing Conditions at Consolidation Area 1 (AUM 458) 45
Exhibit 10. Existing Conditions at Consolidation Area 2 (AUM 457) 46
Exhibit 11. Alternative 2 Cost Breakdown 59
Exhibit 12. Alternative 3 Cost Breakdown 65
Exhibit 13. Alternative 4 Cost Breakdown 69
Exhibit 14. Analysis of Alternatives for the Section 9 Lease Mines 72
Exhibit 15. Summary of Quantities for Resource Use and Greener Cleanups 75
Exhibit 16. Construction Completion Time for Alternatives 76
Exhibit 17. Alternative Costs and Ratings 78
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Section 9 Lease Mines EE/CA
FIGURES
Figure 1 Section 9 Lease Mines Regional Location
Figure 2 Section 9 Lease Mines Abandoned Uranium Mine Locations
Figure 3 Section 9 Lease Mines Site Inspection and Removal Site Evaluation Features
Figure 4 Section 9 Lease Mines AUM 457 Site Inspection and Removal Site Evaluation
Features
Figure 5 Section 9 Lease Mines AUM 458 Site Inspection and Removal Site Evaluation
Features
Figure 6 Section 9 Lease Mines Geology
Figure 7 Section 9 Lease Mines AUM 457 Hydrology
Figure 8 Section 9 Lease Mines AUM 458 Hydrology
Figure 9 Section 9 Lease Mines TENORM Areas
Figure 10 Section 9 Lease Mines Gamma Radiation Survey
Figure 11 Section 9 Lease Mines Measured and Estimated Radium-226 Surface Soil
Concentrations
Figure 12 Section 9 Lease Mines Conceptual Site Model Wire Diagram
Figure 13 Section 9 Lease Mines Proposed Excavation Area
Figure 14 Section 9 Lease Mines Removal Volumes
Figure 15 Section 9 Lease Mines Alternative 2 Consolidate and Cap All Waste Onsite
Figure 16 Section 9 Lease Mines Alternative 3 Disposal of All Mine Waste at aWestern
AUM Regional Repository
Figure 17 Section 9 Lease Mines Alternative 4 Disposal of All Mine Waste in Offsite
Resource Conservation and Recovery Act (RCRA)-Licensed Facility
Figure 18 Section 9 Lease Mines Alternative 2 Proposed Surficial Restoration Activities
Figure 19 Section 9 Lease Mines Alternative 3 Proposed Surficial Restoration Activities
Figure 20 Section 9 Lease Mines Alternative 4 Proposed Surficial Restoration Activities
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Section 9 Lease Mines EE/CA
TABLES
Table 1. Cameron, Arizona Summary of Climate and Meteorology
Table 2. Western AUM Region Regional BTVs
Table 3. Background Comparison
Table 4. Risk Management Summary
Table 5. Selected Soil RAG for Each COC and COEC
Table 6. General Response Actions, Technologies, and Process Options Screening Summary
Table 7. Applicable or Relevant and Appropriate Requirements and To Be Considered
Requirements for Section 9 Lease Mines
APPENDICES
Appendix A. Scoping Investigation Summary Memorandum
Appendix B. Risk Assessment
Appendix C. Contaminant Distribution
Appendix D. Cost Analysis
Appendix E. Post-Removal Visualization
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Section 9 Lease Mines EE/CA
§ Section
[xR/hr Microroentgen per hour
APE Area of potential effect
ARAR Applicable or relevant and appropriate requirement
AUM Abandoned uranium mine
Babbitt Ranches Babbitt Ranches, LLC
bgs Below ground surface
BLM Bureau of Land Management
BTV Background threshold value
CERCLA Comprehensive Environmental Response, Compensation, and Liability Act
CFR Code of Federal Regulations
COC Contaminant of concern
COEC Contaminant of ecological concern
COPC Contaminant of potential concern
COPEC Contaminant of potential ecological concern
EA Engineering Analytics, Inc.
EE/CA Engineering evaluation/cost analysis
ERA Ecological risk assessment
ET Evapotranspiration
EU Exposure unit
HDPE High-density polyethylene
HHRA Human health risk assessment
HPIC High-pressure ionization chamber
IC Institutional control
IL Investigation level
LCR Little Colorado River
LiDAR Light detection and ranging
LLRW Low-level radioactive waste
LUC Land use control
mg/kg Milligram per kilogram
Murchison Ventures Murchison Ventures, Inc.
NAUM Navajo abandoned uranium mine
NCP National Contingency Plan
NORM Naturally occurring radioactive material
NPV Net present value
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ACRONYMS AND ABBREVIATIONS (CONTINUED)
PA
Preliminary assessment
pCi/g
Picocurie per gram
PERG
Preliminary ecological removal goal
PRG
Preliminary removal goal
Ra-226
Radium-226
RAG
Removal action goal
RAO
Removal action objective
Rare Metals
Rare Metals Corporation of America
RCRA
Resource Conservation and Recovery Act
RSE
Removal site evaluation
SE
Secular equilibrium
SI
Site inspection
SLERA
Screening-level risk assessment
SWCA
SWCA Environmental Consultants
TBC
To be considered
TENORM
Technologically enhanced naturally occurring radioactive material
Tetra Tech
Tetra Tech, Inc.
U-238
Uranium-238
UMTRCA
Uranium Mill Tailings Radiation Control Act
UPL95
95 percent upper prediction limit
USEPA
U.S. Environmental Protection Agency
UTL95-95
95 percent upper tolerance limit with 95 percent coverage
Weston
Weston Solutions, Inc.
WRS
Wilcoxon rank sum
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Section 9 Lease Mines EE/CA
1.0 INTRODUCTION
J
This engineering evaluation/cost assessment (EE/CA) develops and evaluates alternatives for
addressing the risks to human health and the environment associated with mine waste and
contaminated soils remaining at the Section 9 Lease Mines. The alternatives presented in this
EE/CA were developed and evaluated in accordance with the Comprehensive Environmental
Response, Compensation, and Liability Act (CERCLA). The U.S. Environmental Protection
Agency (USEPA) will solicit input from stakeholders before selecting an alternative.
1.1 SITE CHARACTERIZATION
The Section 9 Lease Mines is located along the west side of the Little Colorado River (LCR)
approximately 40 air miles north of Flagstaff, Arizona. The Navajo Nation surrounds the site
from the north and east, and the abandoned uranium mines (AUM) on the site are classified as
part of the Western AUM Region of the Navajo Nation (Figure 1). The Section 9 Lease Mines
contains AUM 457, AUM 458, a small portion of AUM 459, and small portions of the adjacent
property in Section 10 owned by the United States on which hazardous substances have come to
be located (Figure 2). The full extent of AUM 459, which is primarily in Section 16 (State of
Arizona land) to the south of Section 9, is not included in the scope of this EE/CA. AUMs 458
and 459 produced an estimated 386 tons of ore between 1957 and 1962. AUM 457 has no mine
production features within its boundary. AUM features include pit areas, a former drainage pond,
the foundation of an upgrader, and unreclaimed waste piles (Figure 3).
Gray Mountain, Arizona, is the nearest population center to the site and is 8 miles west of
Section 9. The agricultural and residential community of Cameron, Arizona, is 10 miles north of
the site. The nearest residential structure is on private land outside the Section 9 Lease Mine
boundary and at approximately 2 miles northeast of AUM 458 and AUM 457. The Section 9
Lease Mines is not used for human, livestock, agricultural, or other purposes, and no structures
are in use on the site. The likely future land uses at the Section 9 Lease Mines are:
• Recreational (Trespasser) - The easternmost portion of the site includes a small portion
of AUM 457, which is on Section 10 land managed by the Bureau of Land Management
(BLM). BLM staff, as well as recreators, have access to this portion of the site. However,
the mines are largely on private land owned by Babbitt Ranches, LLC (Babbitt Ranches)
and CO Bar, Inc. with a land use easement prohibiting residential use. Currently, Babbitt
Ranches does not allow access in Section 9 and any recreational users are considered
trespassers.
• Periodic Work - Employees of Babbitt Ranches visit the site periodically to complete
inspections and maintenance. Users within Section 9 completing periodic inspections and
maintenance are considered Periodic Workers.
The nature and extent of surface soil contamination at the site were assessed with various
technologies during the preliminary assessment (PA), the site inspection (SI), Phase II and
Phase III investigations, the removal site evaluation (RSE) completed in March 2021, and the
data gaps investigation completed in February 2024. Most of the contaminated soil at the site is
within the unreclaimed waste piles throughout the site and in the drainage downslope of the
former upgrader at AUM 457. Areas with contamination outside the waste rock piles and AUM
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Section 9 Lease Mines EE/CA
boundaries are present because of migration of alluvial material in drainage channels and debris
from mining-related transportation along haul roads. In addition, mining activities exposed
naturally occurring radioactive material (NORM) from bedrock and ore on the edges of the mine
pits.
As part of this EE/CA, risk evaluations were completed at the Section 9 Lease Mines in
accordance with Navajo Abandoned Uranium Mines (NAUM) program risk assessment
methodology (USEPA 2024a). The results of the human health risk assessment (HHRA) indicate
that risks are estimated at 8x 10"4 for adult and child trespassers for surface soil and 5x 10"4 for
subsurface soil attributable to radium-226 (Ra-226). The noncancer hazard is below the target
hazard index of 1 for all areas and all trespasser/periodic worker receptors. Ra-226 is a
contaminant of concern (COC) for human health receptors. The ecological risk assessment
(ERA) identified ecological risk at the site. Ra-226 is the only contaminant of ecological concern
(COEC) recommended for removal action.
Removal action goals (RAG) were derived for COCs and COECs. The selected RAGs are the
lesser of the human health preliminary removal goal (PRG) and the preliminary ecological
removal goal (PERG) unless one of these values is less than background. For purposes of the
final EE/CA, the Ra-226 RAG of 12 picocuries per gram (pCi/g) based on the human health
PRG is used for delineating contaminated areas. Removal of contaminated soil above the Ra-226
RAG will mitigate the risks associated with the COCs and COECs. Protecting human health and
the environment is the purpose of removal action activities at the Section 9 Lease Mines.
The removal action extent covers 6.5 acres based on the surficial extent of surficial Ra-226
above the RAG based on the site-specific gamma-radium correlation. An estimated total of
14,711 cubic yards of mine waste and contaminated soil will be addressed by removal action.
1.2 REMOVAL ACTION OBJECTIVES
The first step in developing removal alternatives is to establish removal action objectives (RAO).
CERCLA does not allow removal action alternatives to require remediation of NORM or to
remediate soil to concentrations below background levels. Taking current and potential future
land uses into account at the site, the RAOs are to:
• Prevent exposure to soil with contaminants associated with past mining activities that
would pose an unacceptable risk to human health with the reasonably anticipated future
land use
• Prevent exposure to soil with contaminants associated with past mining activities that
would pose an unacceptable risk to plants, animals, and other ecological receptors
• Prevent offsite migration of contaminants associated with past mining activities that
would pose an unacceptable risk to human or ecologic health by soil, surface water,
groundwater, or air
The anticipated current and future use will be by periodic workers and trespassing recreators
because of the deed restricted designation of Section 9 and the open space recreation at Section
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10. The scope of the removal action will be to address soil and sediment contamination within
the site and to be the final action for solid media at the site.
1.3 IDENTIFICATION OF REMOVAL ACTION ALTERNATIVES
The following removal action alternatives were developed and evaluated as part of this EE/CA:
• Alternative 1: No Action (this alternative must always be evaluated) - No treatment
or removal action would occur at the site. In this case, all threats would remain
unchanged. Mine waste and contaminated soils would continue to threaten human and
ecological receptors. Gamma radiation and physical hazards would still be present.
• Alternative 2: Consolidate and Cap All Waste Onsite - Reaches RAOs by excavating
the waste rock piles, residual waste rock, and contaminated soils; and consolidating and
capping the waste in the pit areas. The cap will require long-term maintenance. A
protective evapotranspiration (ET) cap would be used that would control contaminant
migration.
• Alternative 3: Disposal of All Mine Waste at a Western AUM Regional Repository -
Reaches RAOs by excavating the waste rock piles, residual waste rock, and contaminated
soils; and consolidating and capping the waste in a regional repository located on Section
9. The regional repository is located approximately 1 mile from AUM 457 and 0.6 mile
from AUM 458. This location would provide for increased distance from drainages and
floodplains. The cap and exposed bedrock areas will require long-term maintenance. A
protective ET cap would be used that would control contaminant migration.
• Alternative 4: Disposal of All Mine Waste in Offsite Resource Conservation and
Recovery Act (RCRA)-Licensed Facility - Reaches RAOs by excavating the waste
rock piles, residual waste rock, and contaminated soils; hauling the waste 515 miles (one
way) to the Energy Solutions LLRW facility in Clive, Utah; and disposing of the waste in
the facility.
For the applicable removal action alternatives, plant life that matches the natural landscape
would be planted on the installed covers of excavated material. All temporary roads built for
construction would also be removed, and the site will be restored. The surface of excavation
areas would be recontoured and revegetated to match the natural landscape.
1.4 ANALYSIS OF REMOVAL ACTION ALTERNATIVES
The removal action alternatives were evaluated individually and in relation to each other using
three broad criteria: effectiveness, implementability, and cost. An overview of the comparative
analysis is presented in Exhibit 1.
The draft final EE/CA was prepared without a recommended removal action alternative to
provide an opportunity for public input on the removal action alternatives development and
evaluation process. Following stakeholder and public input, the final EE/CA was prepared,
including the recommended removal action alternative. A formal public comment period on the
final EE/CA will follow.
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Section 9 Lease Mines EE/CA
It
Exhibit 1. Summary of Alternative Ratings
Alternative
Protective of
Human
Health and
Environment
Effectiveness
Implementability
Cost Rating
(2024
Million)3
Alternative 1:
No Action
Poor
Short-Term: Average
Long-Term: Very Poor
Tech: Very
Good
Admin: Very
Good
Very Good
($0)
Alternative 2:
Consolidate and Cap
All Waste Onsite
Pass
Short-Term: Good
Long-Term: Average
Tech: Good
Admin: Good
Good
($3.6)
Alternative 3:
Disposal of All Mine
Waste at a Western
AUM Regional
Repository
Pass
Short-Term: Good
Long-Term: Very Good
Tech: Good
Admin: Good
Good
($4.0)
Alternative 4:
Disposal of All Mine
Waste in Offsite RCRA-
Licensed Facility
Pass
Short-Term: Poor
Long-Term: Very Good
Tech: Good
Admin: Good
Very Poor
($12.8)
Notes:
Bold indicates the highest rating in the category.
a Estimated costs are net present value.
Admin Administrative feasibility
N/A Not applicable
RCRA Resource Conservation and Recovery Act
Tech Technical feasibility
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2.0 SITE CHARACTERIZATIO
J
This section presents a description and background of the Section 9 Lease Mines; previous
reclamation and removal actions; previous site investigations; source, nature, and extent of
contamination; and the risk assessment for AUMs 457 and 458.
2.1 SITE DESCRIPTION AND BACKGROUND
The Section 9 Lease Mines contains AUM 457, AUM 458, and a small northern portion of
AUM 459. The following subsections describe the site location, type of mines and operational
status, regulatory history, features and landscape, geology and hydrology, land use and
populations, sensitive ecosystems and habitat, and meteorology and climate.
2.1.1 Site Location
The Section 9 Lease Mines is in the LCR valley in Coconino County, Arizona, on the west side
of the LCR at 35.734 degrees latitude and -111.328 degrees longitude. A regional map is
provided on Figure 1. The Navajo Nation surrounds the site from the north and east, and the site
is classified as part of the Western AUM Region of the Navajo Nation. The boundaries for
AUMs 457, 458, and 459 are based on historical documents and remnants from mining
operations observed at the site (Weston Solutions, Inc. [Weston] 2012). The site is largely on
land owned by Babbitt Ranches and CO Bar, Inc. in Section 9 with a small portion on federal
land managed by BLM in Section 10. Land ownership and locations of mine boundaries
established from historical records and observations during the PA are shown on Figure 4. These
figures show the site location generally. Site features across Section 9 are shown in Figure 3 and
subsequent sections in this EE/CA describe site features in more detail. In total, the APE (EA
2018) includes an area of 464 acres of Section 9 for which a total of 26 acres are covered by
AUM 457, AUM 458, and AUM 459.
2.1.2 Type of Mine and Operational Status
Former open pit mining operation facilities are located on AUMs 457 and 458. Figure 4 and
Figure 5 provide the locations of major site features for AUMs 457 and 458 as documented in
the RSE report (Engineering Analytics, Inc. [EA] 2021) and field-verified during the data gaps
investigation in 2024 (Appendix A).
A history of AUMs 457, 458, and 459 is summarized below from USEPA (2016a) and EA
(2021). Uranium was first reported in the Cameron area in 1950, and mining ceased by 1963.
Mining occurred on Section 9 from 1957 to 1962. In 1957, Arrowhead Uranium, a subsidiary
of Rare Metals Corporation of America (Rare Metals), leased the rights to Section 9 from
CO Bar Livestock Company (currently called CO Bar, Inc.) and began an open pit mining
operation. In the first year, Rare Metals shipped 17.95 tons of low-grade ore from the site to
the Rare Metals Mill in Tuba City and paid royalties to CO Bar Livestock Company. By 1958,
Rare Metals ceased mining operations, and C.L. Rankin acquired the lease from CO Bar
Livestock Company. C.L. Rankin shipped 87.21 tons of low-grade ore in 1958 and 234.32 tons
of low-grade ore in 1959.
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In 1959, Murchison Ventures, Inc. (Murchison Ventures), owned by John Milton Addison and
others, acquired the lease of Section 9. Murchison Ventures built a small processing plant known
as the Benson Upgrader in the northeast part of Section 9 near one of the former pits
(AUM 457). Murchison Ventures claimed that the Benson Upgrader would separate the waste
rock from previous mining activities into a "sellable" higher-grade slime fraction and a
lower-grade sand fraction. Murchison Ventures sent a shipment of 10.76 tons of upgraded ore to
the Tuba City Mill in 1959. In 1960, Murchison Ventures modified the plant and sent another
shipment of 11.31 tons of ore to the mill. John Milton Addison was adjudicated bankrupt on
June 27, 1960. On this date, all funds and assets—including the mining lease for the east half of
Section 9—of John Milton Addison and various corporate entities with which he was affiliated
came under the jurisdiction of the United States District Court for the Northern District of Texas
(Dallas). The lease to Section 9 was conveyed to Arizona Title and Trust Company in June 1960.
In 1961, John Milton Addison, along with six associates, were convicted of fraud, conspiracy,
and federal security violations related to the upgrading operation.
In October 1960, a group of John Milton Addison's investors incorporated as Milestone Hawaii
assumed control over the Murchison Ventures operation on Section 9. During the summer of
1961, Milestone Hawaii demolished the original Benson Upgrader on Section 9 and replaced it
with a larger upgrader. In March 1962, 23.9 tons of low-grade material was shipped to the Tuba
City Mill. Mining operations ceased in 1961, and no known mining activities have occurred
since that time. While operational, the Atomic Energy Commission estimated the uranium ore
production volume at the site, including all three AUMs, as 386 tons. No uranium processing
through chemical extraction (which would generate uranium tailings) is thought to have been
performed at the Benson Upgrader or the larger upgrader installed in 1961.
2.1.3 Regulatory History
The primary landowners of the Section 9 Lease Mines Babbitt Ranches and CO Bar, Inc. entered
an administrative settlement agreement and order on consent with USEPA in 2016. This
agreement stipulates that the respondents conduct an RSE and removal action based on RSE
findings (that is, removal of waste volumes above a specified concentration for a listed
hazardous substance).
2.1.4 Site Features and Landscape
AUM 457 is 16.5 acres and is contained within Section 9 except for the easternmost boundary on
the banks of the LCR, which is in Section 10 on federal land managed by BLM. As shown in
Figure 4, AUM 457 includes a former borrow pit and pond. Concrete foundations and two 30-
foot-tall walls from the Benson Upgrader (the ore processing plant demolished in 1961) are near
the center of the AUM (Weston 2011). The main foundation covers a footprint of approximately
100 feet by 50 feet, and a smaller foundation south of the larger concrete pad measures 20 feet
by 20 feet.
AUM 458 is 9.3 acres and is contained entirely within Section 9. As shown in Figure 5, AUM
458 is 0.25 mile west of the LCR and includes uranium waste rock, mining debris, and a recessed
pit near the center of the AUM (Weston 2011). A regional drainage, Mays Wash, is east and
south of the AUM boundary.
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AUM 459 is not included in the scope of this EE/CA because it is mostly in Section 16 on
State of Arizona land. However, a small area (0.42 acre) of this AUM is a part of the site in
Section 9 and included in the revised technologically enhanced naturally occurring radioactive
material (TENORM) extent for the Section 9 Lease Mines. AUM 459 includes an open pit area
and piles of uranium waste rock (Weston 2011). Waste from AUM 459 appears to have migrated
onto the Section 9 Lease Mines based on predicted surface Ra-226 from the site gamma-radium
correlation (Tetra Tech, Inc. [Tetra Tech] 2022).
Outside of AUM 457, AUM 458, and AUM 459, the APE established during the Phase II RSE
(EA 2018) consists of areas that have been disturbed by mining exploration and the creation of
haul and access roads across the site.
2.1.5 Geology
The geology of the Cameron area is characterized by layered sedimentary units typical of the
Colorado Plateau. The complex geologic history and long-term stability of the Colorado Plateau
allowed for the mineralization of uranium, and the Cameron area contains abundant uranium ore
deposits that are found primarily in the upper Triassic Chinle Formation. Quaternary-age
materials, comprising sedimentary alluvium, sand, and gravel deposits, overlay the Triassic
Chinle Formation. Fluvial sandstones in the lower part of the Petrified Forest Member of the
Chinle Formation contain most of the uranium deposits around Cameron with lesser amounts
found in the Shinarump Member of the Chinle Formation. The Moenkopi Formation underlies
the Chinle Formation and is exposed in areas near the LCR and other washes where overlying
deposits have been eroded (Chenoweth 1993). Ore bodies occur at the surface to a depth of
130 feet below ground surface (bgs) and vary in size from a single mineralized fossil log to
hundreds of feet in length (Chenoweth and Malan 1973). General descriptions of the
three relevant geological units are presented below in descending stratigraphic order (Bollin and
Kerr 1958; Dubiel and others 1991):
• Quaternary Alluvium (Holocene, 11,700 years ago to current): Includes dune and
fluvial sand/gravel deposits commonly found within washes (fluvial deposits) and on top
(terrace gravel) of and along hill slopes (dunes).
• Petrified Forest Member of the Chinle Formation (Late Triassic, 237 to 201 million
years ago): Red and brown fluvial sandstones and floodplain mudstone deposits. Also
contains volcanic ash and carbonaceous material.
• Shinarump Member of the Chinle Formation (Late Triassic, 237 to 201 million
years ago): White to yellow and gray sandstone and conglomerate with minor
gray mudstone. Fluvial channel and valley fill deposits incised into underlying
Moenkopi Formation. Sediments were deposited as lenticular beds that contain
carbonaceous material.
• Moenkopi Formation (Middle and Early Triassic, 252 to 237 million years ago):
Marine to marginal marine sediments, including red sandstones, shales, silts,
mudstones, and limestones, that unconformably lie below the Shinarump Member of
the Chinle Formation.
A map showing the geologic units for the site and vicinity are presented on Figure 6.
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2.1.6 Hydrology
The Section 9 Lease Mines is in the Lower Little Colorado Watershed and adjacent to the LCR.
The LCR is perennial between its headwaters and the Lyman Dam. Below the Lyman Dam,
including the segment next to the site, the LCR is intermittent because of impoundments,
diversions, and falling groundwater levels from well pumping (Arizona Department of Water
Resources 2009).
Mays Wash, an ephemeral drainage, runs through the site near AUM 458 and drains to the LCR.
Ephemeral drainage pathways out of AUMs 457 and 458 were documented in the RSE (EA
2021) based on the light detection and ranging (LiDAR) survey performed for the site, but flow
directions were mapped differently than reported in the SI (Weston 2014). A desktop evaluation
of the RSE LiDAR survey and the U.S. Geological Survey elevation data available for the site
was performed to identify potential transport pathways leading out of the AUM areas at the site
(Tetra Tech 2022). Drainages flowing through the site near and within the Atlas boundaries for
AUMs 457 and 458 were field-verified with disturbance mapping during the 2024 data gaps
investigation (Appendix A). Figure 7 and Figure 8 show the locations and flow directions of the
drainages for AUM 457 and AUM 458, respectively, on Section 9.
Groundwater conditions within Section 9 are unknown because no monitoring wells are on or
near the site.
2.1.7 Land Use and Populations
A land easement prohibiting residential use of Babbitt Ranches' land within Section 9 was
established in 2019 (EA 2021). Accessing the site outside of maintenance of the main access
road and inspection of the property is prohibited, and trespassing is in violation of State of
Arizona law. The site is not currently used for human, livestock, agricultural, or other purposes.
No structures are in use on the site, and no structures will be built on the site in the future.
The populations most likely to access the site in the future after removal actions are periodic
workers, including employees of Babbitt Ranches and CO Bar, Inc., and possible trespassers.
Recreators on BLM land, as well as BLM staff, can access the portion of the site on Section 10.
Signage is installed along the Section 9 and 10 boundary. However, no physical barriers limit
movement between Sections 9 and 10; thus, a person legally accessing BLM-managed land on
Section 10 could also trespass on Section 9.
The nearest population center to the site is the community of Gray Mountain, Arizona, 8 miles
west of Section 9. The PA by Weston (2012) determined no active drinking water wells are
within 4 miles of the site.
2.1.8 Sensitive Ecosystems and Habitat
The U.S Fish and Wildlife Service determined that no federally listed or proposed endangered or
threatened species are present at or near the site and no critical habitats for such species exist at
the site (SWCA Environmental Consultants [SWCA] 2016).
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The biological resources survey assessed other special status plant and animal species identified
by the State of Arizona and Navajo Nation as potentially relevant to the site and found a low
likelihood of occurrence of these species at the site (SWCA 2016). Sparse vegetation at the site
is not ideal for many ecological receptors and, thus, the potential for occurrence of Navajo
endangered species and State of Arizona species of greatest conservation need at the site is low.
At the time of the biological survey, no aquatic vegetation in the dry channel of the LCR and no
aquatic life in standing pools from recent rain events in the channel bed were observed. Further,
wetland features previously identified by USEPA (2013) were not observed and are not present
at the site (SWCA 2016).
2.1.9 Meteorology and Climate
The Section 9 Lease Mines is in a semi-arid region at high elevation (Arizona Department of
Water Resources 2009). A summary of relevant climate and meteorological conditions for the
site is presented in Table 1.
2.2 PREVIOUS RECLAMATION AND REMOVAL ACTIONS
No removal or reclamation actions have been completed at the site since mining operations
ended in 1962. As observed in previous site investigations, waste rock piles at all three AUMs
are unreclaimed and wood and metal mining debris remain throughout the site (Weston 2011).
2.3 PREVIOUS SITE INVESTIGATIONS
Previous environmental investigations for the site and the larger portion of AUM 459 that is not
part of the site include:
• Weston (2011) performed a site screen of AUMs 457, 458, and 459 in 2011. An initial
gamma radiation survey of the site was completed, and site features were documented.
• Weston (2012) completed a PA in 2012 that reviewed features and hazards for
AUMs 457, 458 and 459.
• USEPA (2013) performed a wetlands evaluation at AUMs 457, 458, and 459 in 2013 that
identified two potential wetland areas at the site, including within the boundaries of
AUM 458 and partially within the riparian zone of the LCR that overlaps with the eastern
boundary of AUM 457.
• Weston (2014) completed an SI in 2014 that included an initial background study, soil
and sediment sampling, and a transect gamma radiation survey.
• SWCA (2016, 2017) performed biological and cultural resources surveys during Phase I
of the RSE:
o Completed a biological resources survey in 2016 that found no wetlands hydrology,
hydric soils, obligate wetland vegetation, or other wetland species at AUMs 457 and
458, including at locations previously identified as potential wetland areas by USEPA
in 2013 (SWCA 2016)
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o Completed a cultural resources survey of the site in 2016 that identified two
archeological sites adjacent to background study areas outside of the site boundaries
(SWCA 2017)
• EA (2018) performed multiple tasks during Phase II of the RSE in 2018:
o Established the area of potential effect (APE) as the primary study area at the site,
including the full extents of AUM 457, AUM 458, and a small northern fraction of
AUM 459
o Performed a gamma radiation survey
o Conducted a gamma correlation study that established a relationship between the
gamma exposure rate and contaminant of potential concern (COPC) and contaminant
of potential ecological concern (COPEC) concentrations
o Performed a background characterization study
o Delineated NORM and TENORM areas across the site
• EA (2020) performed additional tasks to characterize the site during Phase III of the RSE
in 2020:
o Excavated and sampled test pits at 21 locations across the site
o Obtained high-resolution LiDAR topographic data to develop mine waste capacity
estimates
o Performed the HHRA and ERA to assess risks for human and ecological receptors
based on environmental data collected during the Phase II and Phase III studies
• Tetra Tech (2024) performed site mapping and soil sampling in 2024 to update the risk
assessment for the site to meet NAUM program requirements and improve development
of removal action alternatives for onsite management of waste material. The activities
and results of this data gaps investigation are summarized in Appendix A.
2.4 SOURCE, NATURE, AND EXTENT OF CONTAMINATION
The APE for the site, has a total surface area of 464 acres and encompasses all TENORM
identified during the RSE (EA 2021). The extent of soil contamination within the APE was
characterized during Phase II and Phase III of the RSE with high-density mobile gamma
radiation surveys, surface soil and sediment sampling, and subsurface excavation and sampling
(EA 2018, 2020). The TENORM boundary for the site was revised in 2024 following additional
site mapping by Tetra Tech. The following subsections describe the methods used to characterize
contamination at the site for the purpose of determining preliminary removal action extents for
the EE/CA.
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2.4.1 Western Abandoned Uranium Mine Regional Background and Site-Specific
Background
Geology-specific background concentrations for major soil contaminants at AUMs in the
Western AUM Region have been evaluated at regional scale for five of the geologic units present
in the region: Quaternary Alluvium, Dunes, Terrace Gravels, Shinarump Member of the Chinle
Formation, and Petrified Forest Member of the Chinle Formation (Tetra Tech 2024). Provisional
regional statistics including background threshold values (BTV) based on the 95 percent upper
tolerance limit with 95 percent coverage (UTL95-95) of each COPC or COPEC for each
geologic unit were calculated using the Western AUM Region background dataset provided in
Table 2 (Tetra Tech 2024). The UTL95-95 represents a 95 percent probability (or confidence)
that 95 percent of samples from background are below that value.
Background radiation at the site was characterized through gamma radiation surveys at
designated background study areas, including pooled background study area groups for three
different land areas within the APE: LCR, drainage, and alluvial. The UTL95-95 for each
grouping was calculated for Ra-226 based on the gamma-radium correlation developed for the
site. The UTL95-95s for Ra-226 as calculated for the three different grouped landforms within
the APE (EA 2020) are as follows:
• LCR: 1.52 pCi/g
• Drainage: 4.83 pCi/g
• Alluvial: 5.35 pCi/g
Site-specific BTVs for the metals COPCs and COPECs were not established in the RSE
investigation.
2.4.2 Site Contaminants
The updated risk assessment (Section 2.5) and risk management analysis (Section 2.6) used soil
data from the SI, RSE, and data gaps investigation to establish a comprehensive list of
constituents of interest for the site. The metals assessed as soil constituents of interest in the risk
assessment (Appendix B) are aluminum, antimony, arsenic, barium, beryllium, cadmium,
chromium, cobalt, copper, iron, lead, manganese, mercury, molybdenum, nickel, selenium,
silver, thallium, uranium, vanadium, and zinc.
2.4.3 Source and Nature of Contamination
Elevated gamma radiation was identified by Weston (2011) at the site during a site screen in
2011. During the SI, the occurrence of elevated concentrations of radionuclides and metals in
soil at the site were observed by Weston (2014). Waste rock across the site from historical
mining activities is the primary source of radiological and metals contamination. Excavation of
mining-related ore and waste rock from near-surface uranium deposits have dispersed metals and
radionuclides into the local environment. The nature and extent of contamination at the site were
assessed by EA (2021) during the RSE completed in March 2021.
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Supplemental site mapping, including disturbance mapping, was completed at the site during the
data gaps investigation. Disturbance mapping results included delineation of waste transport
pathways, identification of site features, and waste pile mapping. Using this information, the
Section 9 TENORM boundary was revised. The TENORM boundary includes all waste at the
site within the boundaries of AUMs 457 and 458 and the unreclaimed waste piles in exploration
areas across the APE. The revised TENORM boundary is shown on Figure 9.
2.4.3.1 Radiological Impacts
To evaluate radionuclide concentrations and metals and to assess risk to human health and
ecological receptors at the site, the following activities were performed within the APE:
1. Gamma radiation surveys
2. Surface soil and sediment sampling (0 to 6 inches bgs)
3. Subsurface soil sampling (greater than 6 inches up to a maximum of 5 feet bgs)
Results from gamma radiation survey measurements within the APE are provided on Figure 10.
Gamma radiation surveys allow for a more comprehensive site characterization compared to
traditional soil sampling and laboratory analysis alone. Because of greater surface coverage and
higher density of data points achievable compared to soil sampling and analysis, gamma
radiation survey data were used to evaluate the extent of Ra-226 contamination at the site. A
correlation between gamma exposure rate in microroentgen per hour (|iR/hr) and Ra-226 activity
in pCi/g (based on a high-pressure ionization chamber [HPIC] study completed during Phase II
of the RSE) was developed to use existing gamma count readings to estimate the surficial extent
of Ra-226 contamination. Ra-226 surface soil concentrations are shown with the interpolated
Ra-226 surface based on gamma survey results on Figure 11. The gamma-radium correlation
equation for the site is (EA 2021):
Equation 1 Exposure rate = 4.5400457 + 0.0002339 * [Gamma count (cpm)]
Once converted to the gamma exposure rate, the data were converted again to predicted Ra-226
in pCi/g based on a linear regression and graphical analysis of soil Ra-226 concentrations (pCi/g)
and HPIC measurements ([xR/hr) as follows (EA 2021):
Where:
|iR = Microroentgen
hr = Hour
cpm = Counts per minute
Equation 2 22^Ra = -4.206274 + 0.459266 * [Exp
osure rate
Where:
pCi
g
Picocurie
Gram
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An alternative approach to converting gamma radiation measurements to soil Ra-226 is the
95 percent upper prediction limit (UPL95) of the radium-gamma exposure rate correlation. This
approach is commonly applied to attain a desired confidence level at which the surficial
contamination is adequately contained based on a cutoff level (that is, the RAG or cleanup goal
for Ra-226) (Johnson, Meyer, and Vidyasagar 2006). Applying a UPL95 model to Equation 2,
the linear regression of soil Ra-226 measurements and HPIC measurements, the resulting
model is:
Equation 3 22^Ra = -1.317193 + 0.476373 * [Exposure rate
In the APE, elevated radiological contamination as exhibited through the mobile gamma
radiation survey results is mostly concentrated within the boundaries of AUMs 457 and 458.
Elevated gamma radiation is present outside the mine boundaries within the TENORM boundary
near roads and in the exploratory drilling area south of AUM 457 and with material that has
migrated out of AUMs 457 and 458 and into the APE from AUM 459 as shown on Figure 10.
2.4.3.2 Metals Impacts
The COPCs carried through the HHRA are aluminum, arsenic, cadmium, chromium, cobalt, iron,
manganese, mercury, molybdenum, thallium, uranium, and vanadium. The COPECs carried
through the ERA are arsenic, barium, cadmium, chromium, cobalt, lead, manganese, mercury,
molybdenum, nickel, selenium, thallium, uranium, vanadium, and zinc.
2.4.4 Extent of Contamination
Data characterizing the extent of contamination (collected through the measurement of radiation
through walkover gamma scanning surveys and total metals and radionuclides soil
concentrations in soil samples collected during the SI, RSE, and data gaps investigation) are used
to identify contamination migration pathways, excluding groundwater and surface water, and
support the risk assessment and removal decisions for the site. The waste at the site is the result
of mining activities and is covered under the Bevill Amendment exemption to hazardous waste
classification.
Site disturbance observations during the SI (Weston 2014), RSE (EA 2021), and 2024 data gaps
investigation (Appendix A) were used to identify the extent of mining-related disturbance at the
site, potential for transport of contaminated material, and transport pathways from the site. Areas
of the site with remnants from mining operations, exploratory boring locations south of
AUM 457, other visible ground disturbance, and roads buffered to 50 feet were categorized as
TENORM areas in addition to the Atlas survey mine boundaries (EA 2021). Gamma scanning
results and site mapping were reviewed to differentiate NORM from TENORM (defined as
NORM that has been disturbed by human activity in a way that increases exposure or transport).
The TENORM boundaries for the site were updated following field verification of site features
during the data gaps investigation (Appendix A) and are shown on Figure 9.
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Areas undisturbed by mining activity are considered NORM and may include land upslope of
mining-disturbed areas, mineralized bedrock outcrops outside the area of mining activity,
mineralized bedrock outcrops within an area otherwise disturbed by mining activity, and areas
impacted by transport of material from undisturbed areas. Downwind transport or erosion and
mass wasting from these NORM areas may contribute to elevated gamma levels and Ra-226 and
metals concentrations downslope of these outcrops. USEPA does not consider NORM to be
contamination and, thus, NORM areas are not considered for removal action.
2.5 RISK ASSESSMENT
The complete risk assessment is presented in Appendix B. The risk assessment uses laboratory
sampling data from the Section 9 Lease Mines to identify the candidate COCs and COECs,
provide an estimate of how and to what extent human and ecological receptors might be exposed
to these contaminants, and describe whether the exposures pose unacceptable risk to the
receptors. A conceptual site model is presented in Figure 12. Candidate COCs and COECs are
those contaminants that contribute to unacceptable risk and are recommended for further
evaluation in the risk management analysis (See Section 2.6). In Appendix B, Table B-l
provides a summary of the analytical data used in the risk assessment the Section 9 Lease Mines,
Figure B-2 through Figure B-5 present the locations of the soil samples used in the risk
assessment, and Attachment B-l provides the full dataset used in the risk assessment. The
following subsections present the purpose of the risk assessment, describe the exposure risk
evaluations, and summarize the risk assessment methodology and results.
2.5.1 Purpose
The purpose of the risk assessment is to estimate current and future human health risk under
appropriate reasonable maximum exposure scenarios and ecological risk focused on the known
ecosystems for the region. This risk assessment was performed using procedures in the NAUM
program risk assessment methodology (USEPA 2024a). The results of the risk assessment are
used to assist in removal action decisions for a site. The HHRA estimates the risk posed to
human health by contaminants at the site and identifies human health candidate COCs in each
exposure unit (EU). The ERA identifies the risks posed to ecological receptors by contaminants
at the site and candidate COECs on a site-wide basis.
2.5.2 Exposure Unit
An EU is a geographic area where receptors (a person or animal) may reasonably be assumed to
move at random and where contact across the EU is equally likely over the course of an exposure
duration. The risk assessment boundary was established via soil sampling and augmented
through examination of gamma survey data. Areas of NORM, such as natural mineralized
outcrops and nonimpacted areas, although not included in the TENORM boundary, were also
included within the risk assessment boundary because a receptor would also be exposed to
NORM areas when at the site.
The Section 9 Lease Mines risk assessment boundary is a 406-acre area that encompasses
AUM 457, AUM 458, the small portion of AUM 459 within Section 9, and the portion of
Section 10 between Section 9 and the LCR. Only the reasonable maximum exposed receptor is
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evaluated in NAUM HHRAs; for the Section 9 Lease Mines a trespasser was identified as the
RME receptor. A single EU was used to evaluate the trespasser receptor at the Section 9 Lease
Mines. In Appendix B, Table B-2 and Figure B-2 through Figure B-5 present the areas and
samples at the site that were evaluated. Section 2.1.7 describes the land uses at the site.
2.5.3 Human Health Risk Evaluation
This subsection describes the key elements of the HHRA methodology. An HHRA is the process
for evaluating how people are impacted by exposure to one or more environmental stressors,
such as metals or radiation. Exposure is how a contaminant can enter a body, for example, by
eating produce that absorbed contaminants, by breathing contaminated dust, by touching
contaminated materials, or from radiation emanating from soil.
The HHRA evaluates whether site-related COPCs pose unacceptable risks to potential current
and future people at a site under conditions at the time the EE/CA is prepared (unremediated
conditions) (USEPA 1989, 1993). The HHRA includes the following components: data
evaluation and selection of COPCs, exposure assessment, toxicity assessment, and risk
characterization.
Any contaminant with a maximum detected value exceeding its COPC screening level is retained
as a COPC for the HHRA risk calculations. The COPC screening levels are based on a lxlO"6
cancer risk and a hazard index of 0.1 for a default (non-Navajo) resident. In Appendix B,
Table B-l provides the COPC screening. Based on the screening, the following contaminants
were identified as COPCs at the Section 9 Lease Mines and are included in the risk estimates in
the HHRA: uranium-23 8 (U-238) in secular equilibrium (SE), aluminum, arsenic, cadmium,
chromium, cobalt, iron, manganese, mercury, molybdenum, thallium, uranium, and vanadium.
The exposure assessment is the process of measuring or estimating the intensity, frequency, and
duration of human exposure to a contaminant in the environment. The conceptual site model
describes the exposure setting and identifies potentially complete exposure pathways by which
receptors (both people and ecological) could contact site-related contaminants. Figure 7 and
Figure 8 present the hydrologic transport pathways for the Section 9 Lease Mines.
For the HHRA, human health cancer risk and noncancer hazard were calculated for the receptor
with the reasonable maximum exposure at the site for both current and future conditions.
Trespassers were identified as the reasonable maximum exposure receptor for the Section 9
Lease Mines. The HHRA focuses on soil and sediment contamination only and does not include
ingestion of surface water or groundwater by humans or animals. The specific exposure
pathways and inputs for the receptors evaluated in the HHRA are provided in Appendix B,
Table B-3.
The toxicity assessment identifies the toxicity parameters needed for the risk assessment. The
toxicity values used in the HHRA are all standard values provided by USEPA. Risk
characterization proceeds by combining the results of the exposure and toxicity assessments. For
the NAUM HHRAs, the risk characterization process as described in Appendix B was used.
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The intake factors used in the HHRA were calculated using the NAUM Risk Calculator (USEPA
2023b). The cumulative cancer risk for the age-adjusted adult and child, and noncancer hazard
for the child receptor for each soil interval are provided in Appendix B, Table B-7.
Risks for combined adult and child trespassers (combined 26 years of exposure) exceeded the
acceptable USEPA cancer risk range (defined as less than or equal to 1 x 10"6 to 1 x 10"4 risk). The
cancer risk at the Section 9 Lease Mines is estimated to be 8x 10"4 for surface soil and 5x 10"4 for
subsurface soil for the adult and child trespasser. The noncancer hazard is below the target
hazard index of 1 for all areas for both the adult and child receptors. U-238 in SE is a candidate
COC for the trespasser at the Section 9 Lease Mines in surface and subsurface soils.
2.5.4 Ecological Risk Evaluation
An ERA is the process for evaluating how likely the environment will be impacted from
exposure to one or more environmental stressors, such as radionuclides or metals. The objective
of the ERA is to evaluate whether ecological receptors may be adversely affected by exposure to
contaminants. The ERA is intended to provide input for risk management decision-making at a
site while maintaining a conservative approach protective of ecological populations and
communities. This ERA follows the guidelines in the NAUM program risk assessment
methodology (USEPA 2024a).
As described in USEPA (1993) EE/CA guidance, a risk assessment is used to help justify a
removal action, identify what current or potential exposures should be prevented, and focus on
the specific problem that the removal action is intended to address. NAUM ERAs include a
screening-level risk assessment (SLERA) and SLERA refinement. The SLERA includes Steps 1
and 2 of USEPA's eight-step ERA process (USEPA 1997) and is intended to provide a
conservative estimate using maximum site concentrations of potential ecological risks and
compensate for uncertainty in a precautionary manner by incorporating conservative
assumptions. The SLERA refinement includes a refinement of Steps 1 and 2 and is intended to
provide additional information for risk managers. Candidate COECs are identified based on the
results of the SLERA refinement for soil.
The ERA evaluated the Section 9 Lease Mines as a single site-wide EU. The SLERA COPECs
for soil at the Section 9 Lease Mines are presented in Appendix B, Table B-8. Contaminants in
soil for which the hazard quotient was greater than or equal to 1.0 were U-238 in SE (adjusted
Ra-226), arsenic, barium, cadmium, chromium, cobalt, lead, manganese, mercury, molybdenum,
nickel, selenium, thallium, uranium, vanadium, and zinc.
In Appendix B, the candidate COECs and the calculated hazard quotient risk estimates are listed
in Table B-10 for plants and invertebrates, Table B-l 1 for birds, and Table B-12 for mammals.
The candidate COECs are summarized in Exhibit 2.
2.5.5 Risk Assessment Results Summary
Candidate COCs and COECs were identified based on available laboratory data. The HHRA and
ERA results for the Section 9 Lease Mines indicate risk is above a level of concern for the
contaminants listed in Exhibit 3.
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It
Exhibit 2. Site-Wide Candidate COECs
Candidate COEC
Receptor
Soil
Interval
Uranium-238 in SE
Arsenic
Barium
Chromium
Cobalt
Lead
Manganese
Mercury
Molybdenum
Selenium
Thallium
Uranium
Vanadium
Plants
Surface Soil
X
X
X
X
X
X
X
X
X
X
X
X
X
Subsurface Soil
X
X
X
X
X
-
X
X
X
X
-
X
-
Invertebrates
Surface Soil
X
X
X
X
-
-
X
X
-
X
Birds
Surface Soil
X
-
-
-
-
X
-
X
X
X
X
-
X
Mammals
Surface Soil
X
-
X
X
X
-
-
Subsurface Soil
X
-
X
X
X
-
-
Notes:
Not a candidate COEC
X Candidate COEC
COEC Contaminant of ecological concern
SE Secular equilibrium
Exhibit 3. Candidate COCs and Candidate COECs Recommended for Further Evaluation
Contaminant
LLI
<0
C
Receptor
Media
00
fO
CSI
E
3
'E
5
3
Arsenic
Barium
Chromium
Cobalt
Lead
Manganese
Mercury
Molybdenum
Selenium
Thallium
Uranium
Vanadium
Trespasser
Surface/
Subsurface Soil
X
Ecological
Surface Soil
X
X
X
X
X
X
X
X
X
X
X
X
X
Subsurface Soil
X
X
X
X
X
-
X
X
X
X
X
X
-
Notes:
—
Not a candidate COC or COEC; not recommended for further evaluation in this EE/CA.
X
Candidate COC and/or COEC. Recommended for further evaluation in this EE/CA.
coc
Contaminant of concern
COEC
Contaminant of ecological concern
EE/CA
Engineering evaluation/cost analysis
SE
Secular equilibrium
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2.6 RISK MANAGEMENT ANALYSIS
Risk management is a different process from risk assessment. The risk assessment establishes
whether a risk is present and defines the magnitude of the risk. In risk management, the results of
the risk assessment are integrated with other considerations to make and justify risk management
decisions. Risk managers must understand the risk assessment, including its uncertainties and
assumptions to evaluate the overall protectiveness of any response action (USEPA 1997). By
understanding the potential adverse effects posed by candidate COCs and COECs and the
removal actions themselves, risk managers can balance the costs and benefits of the available
removal alternatives.
U-238 (and its decay products) is the only COC at the Section 9 Lease Mines. For risk
management, site data for Ra-226 are used to represent the soil concentration of U-238; however,
the human health PRGs and the NAUM PERG use toxicity values that include toxicity from the
entire U-238 decay chain. Use of Ra-226 for risk management reduces the number of
radionuclides evaluated when establishing the extent of radiological contamination.
The risk assessment for the Section 9 Lease Mines identified one candidate COC and several
candidate COECs. Radiological contamination is the predominant risk driver at the Section 9
Lease Mines; thus, the extent of Ra-226 above the selected RAG will primarily be used to
establish the extent of the removal action. In addition to Ra-226, candidate COECs are arsenic,
barium, chromium, cobalt, lead, manganese, mercury, molybdenum, selenium, thallium,
uranium, and vanadium. The risk management analysis is focused on understanding the excess
risk from the metals identified as candidate COECs in soil.
The NAUM risk management process involves assessment of various lines of evidence
for candidate COCs and COECs including:
• Refinement of candidate COCs and COECs:
o Comparison of site concentrations to background concentrations (Table 3)—
candidate COCs and COECs below background are removed from further analysis
o Consideration of natural forms of chromium
o Comparison of maximum detected concentrations with human health PRGs and
NAUM PERGs (USEPA 2024c)
o Assessment of co-location via a comparison of the metals distribution to the Ra-226
preliminary removal action extent—metal candidate COECs with concentrations
above NAUM PERGs that are fully co-located with the Ra-226 preliminary removal
action extent are removed from further analysis
• Refinement of candidate COECs only (if needed):
o Potential impacts of site risks for candidate COECs based on a comparison of site-
wide exposure point concentrations to NAUM PERGs (USEPA 2024c)
o Analysis of contaminant distribution
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o Assessment of other uncertainties
Refinement of the exposures, inputs, and uncertainties for the ERA is warranted because the
ERA was completed using literature-based assumptions and inputs. Section 2.6.1 presents the
background comparison, Section 2.6.2 presents a discussion on chromium, Section 2.6.3 presents
and describes the NAUM PERGs, and Section 2.6.4 presents the co-location analysis. For the
Section 9 Lease Mines, the refinement of candidate COECs was unnecessary because all
candidate COECs were determined to not warrant removal action. Section 2.6.5 presents a
summary of risk management conclusions and decisions.
Table 4 presents the results of the risk management analysis and identifies the final analytes
recommended for removal action, as well as the rationale for refinement of each candidate
COEC not considered for removal action.
2.6.1 Comparison of Site Concentrations of Candidate Contaminant of Concern and
Candidate Contaminants of Ecological Concern to Background Concentrations
The candidate COCs and COECs were compared to background concentrations to identify any
contaminants present at background levels. For the Section 9 Lease Mines, the background
comparison used the Quaternary Alluvium, Shinarump Member of the Chinle Formation, and
Petrified Forest Member of the Chinle Formation results per the discussion in Section 2.4.1.
Two-population statistical tests were performed to compare concentrations in soil at the site for
candidate COCs and COECs. All methods followed USEPA (2002, 2010, 2022) statistical
guidance for evaluating background concentrations of chemicals in soil. The background
comparison results are presented in Table 3.
A tiered approach employing one or more statistical methods was used to conduct
two-population tests. The first tier in this approach compares the median concentrations between
the site and background populations using the Wilcoxon-Mann-Whitney test for datasets having
all detected data. For datasets with nondetect results, Gehan's modification to the Wilcoxon
rank-sum (WRS) test (Gehan test) and the Tarone-Ware test were used. These two-population
tests are available in ProUCL (USEPA 2022a).
If the first-tier tests indicated site concentrations were greater than background concentrations,
no further testing was conducted. If the first-tier tests indicated site concentrations were less than
or equivalent to background concentrations, a second-tier test was used to compare the right-
hand tails or upper quantiles of the site and background populations using the Quantile test
(USEPA 1994, 2010). Two-sided statistical tests were used in all cases and employed a Type I
error rate of 0.05 (5 percent).
The following null and alternative hypotheses were tested:
• Null hypothesis: The median metal concentration for the site is less than or equal to the
median concentration in the background population.
• Alternative hypothesis: The median metal concentration for the site is greater than the
median concentration in the background population.
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The Quantile test (USEPA 1994, 2010) was conducted for all metals where the Gehan,
Tarone-Ware, and Wilcoxon-Mann-Whitney tests did not reject the null hypothesis (that is,
when the median site and background concentrations were not significantly different).
The Quantile test is a nonparametric two-population test developed for comparing the right-hand
tails or upper quantiles of two distributions. The Quantile test can be used when some proportion
of high-value measurements (rather than the entire distribution) of one population has shifted
relative to a second population. The Quantile test is not as powerful as the WRS test when the
distribution of site concentrations is shifted in its entirety to the right of the background
distribution. However, the Quantile test is more powerful than the WRS test for detecting cases
where only a small number of high-value measurements are present in the upper quantile of the
site distribution. For this reason, USEPA (1994, 2002, 2010) guidance recommends the Quantile
test be used in conjunction with the WRS test. When applied together, these tests have more
power to detect true differences between two population distributions.
Exhibit 4 presents the background comparison results for the Section 9 Lease Mines. In addition
to Ra-226, candidate COECs (arsenic, molybdenum, selenium, uranium, and vanadium) were
found at concentrations greater than background at the Section 9 Lease Mines and are
recommended for further evaluation. Additionally, two-population tests could not be conducted
for barium, chromium, cobalt, lead, manganese, mercury, and thallium; therefore, these COECs
are also recommended for further evaluation.
2.6.2 Consideration of Natural Forms of Chromium
The assumption used in the HHRA and ERA was that the measured chromium at the site is
entirely hexavalent chromium. Trivalent chromium is the most common oxidation state and is an
essential dietary element that aids normal glucose, protein, and fat metabolisms (Agency for
Toxic Substances and Disease Registry 2012). Hexavalent chromium is the most toxic chromium
ion and is a known human carcinogen.
Hexavalent chromium is almost exclusively produced from industrial processes and is not
expected from natural sources atNAUM sites. Sources of compounds containing hexavalent
chromium in the environment are discharged dye and paint pigments, wood preservatives, and
chrome-plating liquid wastes. Prominent uses of hexavalent chromium are in processes for
production of metal alloys such as stainless steel, protective coatings on metal, magnetic tapes,
pigments for paints, cement, paper, rubber, and composition floor covering (Agency for Toxic
Substances and Disease Registry 2012). These industrial processes or commercial products are
not associated with NAUM sites. Hexavalent chromium is not expected to be elevated above
naturally occurring levels at NAUM sites without an industrial process that created
hexavalent chromium.
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Exhibit 4. Background Comparison Results Summary
Exposure Unit
Candidate COC or COEC Background Comparison Result
Radium-226
Arsenic
Barium
Chromium
Cobalt
Lead
Manganese
Mercury
Molybdenum
Selenium
Thallium
Uranium
Vanadium
Western AUM Region Background Quaternary Alluvium
Site-Wide (Trespasser)
>BG
Site-Wide (Ecological Risk)
>BG
>BG
NA
NA
NA
NA
NA
NA
>BG
>BG
NA
>BG
>BG
Western AUM Region Background Petrified Forest Member
Site-Wide (Trespasser)
>BG
Site-Wide (Ecological Risk)
>BG
>BG
NA
NA
NA
NA
NA
NA
>BG
>BG
NA
>BG
BG
Site-Wide (Ecological Risk)
>BG
>BG
NA
NA
NA
NA
NA
NA
>BG
BG
BG Site concentrations are greater than background concentrations. Candidate COC or COEC is
recommended for further evaluation in the EE/CA.
AUM Abandoned uranium mine
COC Contaminant of concern
COEC Contaminant of ecological concern
EE/CA Engineering evaluation/cost analysis
NA Identified as a candidate COEC, but background comparison results are not available.
Mineral forms of hexavalent chromium are rare in nature (Greenwood and Earnshaw 2012).
Based on the documented mineralogy within the NAUM regions, these minerals are not present
at NAUM sites. Oxidation of natural sources of trivalent chromium to hexavalent chromium in
soil at NAUM sites is unlikely given typical site conditions—the sites do not contain ultramafic
rock and serpentine soils, which are the most likely natural source of hexavalent chromium.
Furthermore, weather conditions on the Navajo Nation are arid and ionic compounds containing
chromium typically are not detected in the desert sandy loam soils present in the area. Trivalent
chromium is typically found in soils with higher pH (more basic), aerobic conditions, low
amounts of organic matter, and manganese and iron oxides. In contrast to hexavalent chromium,
which does not interact significantly with clay or organic matter, trivalent chromium is cationic
and adsorbs onto clay particles, organic matter, metal oxyhydroxides, and other negatively
charged particles. Finally, desert sandy loam soils typically contain low amounts of organic
matter. According to the Bureau of Indian Affairs (2020), pHs of the different soil types on the
Navajo Nation range from 6 to 9.
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The lines of evidence presented above suggest total chromium concentrations measured at the
Section 9 Lease Mines is the less toxic trivalent form and, therefore, should be evaluated as
trivalent chromium. From a risk management perspective for uranium mines, the presence of
hexavalent chromium is expected to be minimal and the assumption that the chromium measured
at the site is trivalent chromium is reasonable and supported by site conditions.
The maximum detected result for total chromium at the Section 9 Lease Mines is 17 milligrams
per kilogram (mg/kg), which is below both the default residential regional screening level for
trivalent chromium (8,500 mg/kg) (USEPA 2024d) and the lowest trivalent chromium no
observed effect concentration in the ERA (26 mg/kg) (based on the avian ground insectivore).
Thus, trivalent chromium would not be identified as either a COPC or COPEC and would not be
included in the human health risk calculations or the SLERA refinement. Therefore, chromium is
not recommended for removal action at the Section 9 Lease Mines.
2.6.3 Comparison of Maximum Detected Concentrations to Preliminary Removal
Goals for Human Health and Ecological Health
Human health PRGs and NAUM PERGs were developed for use in risk management decision-
making and determination of RAGs.
Human health PRGs are land-use specific and calculated using the NAUM Risk Calculator
(USEPA 2024b) with the same target cancer and noncancer risk levels used to identify candidate
COCs. PRGs for carcinogenic metals and radionuclides are based on a target cancer risk of
lxlO"4, and PRGs for noncarcinogenic metals are based on a target noncancer hazard quotient
of 1.0.
PERGs for radionuclides and metals were developed for NAUM sites by USEPA (2024c).
USEPA (1999) guidance recommends designing remedial actions to protect local populations
and communities of biota rather than protect organisms on an individual basis except for
threatened and endangered species. NAUM PERGs establish analyte-specific thresholds that
correspond to minimal disruption on wildlife communities and populations. Reducing or
maintaining site concentrations to levels below the PERG will support the recovery and
maintenance of healthy local populations and communities of biota.
NAUM PERGs for radionuclides were based on dose assessments using the ERICA Tool
(Brown and others 2008) for terrestrial animals and plants (USEPA 2024a, 2024c). NAUM
PERGs for radionuclides were identified based on the radionuclide concentration corresponding
to a dose rate where individuals have a higher probability to be adversely affected, but the
population is still protected (USEPA 2024c). NAUM PERGs for metals were developed using
average exposure parameters for food ingestion rates, toxicity reference values, soil intake
factors, and body weights (USEPA 2024c).
To identify if candidate COCs or COECs should be considered for removal action at the
Section 9 Lease Mines, the maximum detected concentrations of the candidate COCs and
COECs remaining after the background comparison were compared to the human health PRGs
and NAUM PERGs.
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Exhibit 5 presents the Section 9 Lease Mines human health PRGs and NAUM PERGs for soil for
candidate COCs and COECs greater than background and provides the maximum detected
comparison to the PRGs and PERGs to establish whether the contaminant requires further risk
management evaluation.
Exhibit 5. Human Health Preliminary Removal Goals and NAUM PERGs for Candidate
COCs and COECs in Soil Above Background
Candidate
COC/COEC
Unit
Human Health
PRG
Trespasser1
NAUM PERG2
Maximum Detected
Concentration
Maximum Detected
Concentration
Exceeds
PRG or PERG
Radium-2263
pCi/g
12
40
945
Yes
Arsenic
mg/kg
--
68
230
Yes
Barium
mg/kg
--
1,400
1,100
No
Cobalt
mg/kg
--
130
47
No
Lead
mg/kg
570
150
No
Manganese
mg/kg
--
1,100
540
No
Mercury
mg/kg
—
0.5
8.7
Yes
Molybdenum
mg/kg
—
430
2,000
Yes
Selenium
mg/kg
--
3.4
37
Yes
Thallium
mg/kg
--
0.5
26
Yes
Uranium
mg/kg
--
250
970
Yes
Vanadium
mg/kg
--
80
390
Yes
Notes:
Bold values exceed the human health PRG and/or the NAUM PERG for the contaminant.
1 The human health PRG was calculated using the NAUM Risk Calculator (USEPA 2024b) and is based on a
target cancer risk of 1x10 4. The human health PRG for radium-226 is based on uranium-238 in SE to
include doses from all progeny of uranium-238 in SE as described in Appendix C of the NAUM risk
assessment methodology (USEPA 2024a).
2 The radium-226 NAUM PERG is the minimum PERG for uranium-238 in SE for all feeding guilds (USEPA
2024c). The NAUM PERGs are applicable site-wide. The NAUM PERG for radium-226 is based on
uranium-238 in SE to include doses from all progeny of uranium-238 in SE as described in Appendix F of
the NAUM risk assessment methodology (USEPA 2024a).
3 Site data for radium-226 are used to evaluate the extent of radionuclides above the human health PRG and
NAUM PERG.
Not a candidate COC
COC Contaminant of concern
COEC Contaminant of ecological concern
mg/kg Milligram per kilogram
NAUM Navajo abandoned uranium mine
pCi/g Picocurie per gram
PERG Preliminary ecological removal goal
PRG Preliminary removal goal
SE Secular equilibrium
USEPA U.S. Environmental Protection Agency
As shown in Exhibit 5, the maximum detected results for barium, cobalt, lead, and manganese do
not exceed their NAUM PERGs. Thus, these candidate COECs are not recommended for
removal action and are not discussed further in the risk management analysis.
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2.6.4 Co-Location Assessment
The Ra-226 removal action extent encompasses a large portion of the TENORM areas in the
Section 9 Lease Mines (see Figure 9). The source of the contamination is from historical
uranium mining activities, and the mining waste and contaminated soil are expected to exhibit
similar characteristics in all areas of contamination. Areas where estimated Ra-226 levels
exceed BTVs is a strong indicator of areas with mine waste, and concentrations of other elevated
metals are expected to be co-located in those areas. Section 2.6.4.1 defines the Ra-226 removal
action extent, and Section 2.6.4.2 assesses whether candidate COCs and COECs are co-located
with Ra-226 via a comparison of the metals distribution to the Ra-226 preliminary removal
action extent.
2.6.4.1 Development of Radium-226 Removal Action Extent
The Ra-226 RAG is the lesser of the human health PRG and NAUM PERG unless either of the
preliminary goals is less than the BTV. For all areas at the Section 9 Lease Mines, the Ra-226
RAG is based on the human health PRG for a trespasser and is 12 pCi/g. Table 4 provides the
comparison of the human health PRG, NAUM PERG, and geology-specific BTVs for Ra-226
considered to establish the RAG. Exhibit 6 lists the RAG for each geologic unit present at
the site.
Exhibit 6. Radium-226 Removal Action Goal Development
Geologic Unit
Radium-226 RAG1
[pCi/g]
Basis for RAG
Quaternary Alluvium
12
Human health PRG
Petrified Forest Member of the Chinle Formation
12
Human health PRG
Shinarump Member of the Chinle Formation
12
Human health PRG
Notes:
1 Site data for radium-226 are used to evaluate the extent of radionuclides above PRGs.
pCi/g Picocurie per gram
PRG Preliminary removal goal
RAG Removal action goal
The estimated Ra-226 interpolated surface was generated using gamma survey data from the
Section 9 Lease Mines as discussed in Section 2.4.3.1. Gamma survey results were converted
from counts per minute to estimated Ra-226 concentrations in pCi/g. The Ra-226 preliminary
removal action extent for the site was developed using geospatial tools based on the area
estimated to exceed the RAG within the TENORM boundary. The proposed excavation areas for
Ra-226 based on a RAG of 12 pCi/g is provided on Figure 13.
2.6.4.2 Assessment of Metals Co-Location with the Radium-226 Preliminary
Removal Action Extent
The distributions of the remaining metal candidate COECs (arsenic, mercury, molybdenum,
selenium, thallium, uranium, and vanadium) were compared with the Ra-226 preliminary
removal action extent to identify whether concentrations of the remaining metal candidate
COECs are co-located with the Ra-226 preliminary removal action extent. In Appendix C,
Figure C-2 through Figure C-8 present the soil sample results for each metal candidate COEC
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above background overlain with the Ra-226 preliminary removal action extent with results
screened against relevant BTVs and NAUM PERGs.
At the Section 9 Lease Mines, the extents of arsenic, mercury, molybdenum, selenium, thallium,
uranium, and vanadium are all co-located within the preliminary Ra-226 removal action extent
that is planned for removal. Further assessment of the extents of arsenic, mercury, molybdenum,
selenium, thallium, uranium, and vanadium will not result in a change in the removal action
extent and, therefore, arsenic, mercury, molybdenum, selenium, thallium, uranium, and
vanadium will not be considered for further evaluation and are not identified as COECs
recommended for removal action.
2.6.5 Risk Management Summary and Conclusions
Based on the HHRA and ERA for the Section 9 Lease Mines, the candidate COC for soil is
Ra-226 and candidate COECs for soil are Ra-226, arsenic, barium, chromium, cobalt, lead,
manganese, mercury, molybdenum, selenium, thallium, uranium, and vanadium. Following the
lines of evidence considered in the risk management analysis in the previous subsections, the
recommended removal action objective is:
• To address excess human health and ecological risk from Ra-226 contamination at the
Section 9 Lease Mines by removal of Ra-226 above the applicable RAG
The conclusions for the candidate COC are based on the results of the risk assessment and
background comparison. The conclusions for candidate COECs also include consideration of
whether the maximum concentration of the COEC exceeds the NAUM PERG. In addition, the
results of the co-location analysis comparing metal COEC concentrations exceeding their
NAUM PERGs with the preliminary Ra-226 contamination extent to be addressed during the
removal action. Table 5 presents the results of the risk management analysis and identifies the
final COC and COEC recommended for removal action, as well as the rationale for refinement of
each candidate COC or COEC not considered for removal action. Exhibit 7 lists the COCs and
COECs recommended for removal action at the site.
Exhibit 7. COCs and COECs Recommended for Removal Action
Exposure Unit
Receptor
Surface Soil
COC/COEC
Subsurface Soil
COC/COEC
Site-Wide (Human Health Risk)
Trespasser
Radium-226
Radium-226
Site-Wide (Ecological Risk)
Plants, Invertebrates,
Birds, and Mammals
Radium-226
Radium-226
Notes:
COC Contaminant of concern
COEC Contaminant of ecological concern
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2.7 REMOVAL ACTION EXTENT
Multiple lines of evidence were used to develop the removal action extent at the site, including
the extent of Ra-226 in surface soil based on soil and sediment samples and gamma-radium
correlation, extent of contamination of other COCs and COECs, subsurface soil investigations,
NORM and TENORM mapping, and risk management considerations.
2.7.1 Identification of Removal Action Goals
Based on the HHRA and ERA results, cleanup is recommended for surface and subsurface soils
for Ra-226 at the Section 9 Lease Mines. RAGs were derived for each applicable receptor for
each geologic unit. RAGs were not developed for surface water because removal actions at
AUM sites are focused on removing soil as the source of contamination. Removal of
contaminated soil should remove the source of contamination to surface water, including
waterways such as the intermittent LCR and ephemeral Mays Wash.
Table 4 presents the human health PRGs, NAUM PERGs, BTVs for each geologic unit at the
site, and the selected soil RAG for each COC and COEC recommended for removal action in the
TENORM areas. The RAG is the lower value of the human health PRG and NAUM PERG
unless either value is less than the BTV. If the human health PRG or NAUM PERG is less than
the BTV, the cleanup goal is the concentration representative of background conditions. Exhibit
8 lists the RAG for each COC and COEC recommended for removal action.
Exhibit 8. Removal Action Goal
Exposure Unit
COC/COEC
Surface and
Subsurface Soils
Basis for RAG
Site-Wide
Radium-226
12 pCi/g
Human Health PRG for
Trespasser
Notes:
COC Contaminant of concern
COEC Contaminant of ecological concern
pCi/g Picocurie per gram
PRG Preliminary removal goal
RAG Removal action goal
2.7.2 Removal Action Extent Development
Because of greater coverage and density, gamma scan data are used as a surrogate to evaluate the
extent of Ra-226 contamination within the APE. Gamma survey data (Figure 10) were evaluated
and converted to estimated Ra-226 concentrations to calculate the Ra-226 removal action extent.
Areas of the site with concentrations above the Ra-226 RAG of 12 pCi/g based on the UPL95
gamma-radium correlation model were included as part of the removal action extent. The
removal action extent covers approximately 6.5 acres based on the extent of surficial Ra-226
above the RAG based on the site-specific gamma-radium correlation. An estimated total of
14,711 cubic yards of mine waste and contaminated soil would be addressed by the
removal action. Figure 13 provides the estimated excavation area for the Ra-226 removal action
extent.
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Surficial contamination requiring a removal action was established for the site using Equation 3
in Section 2.4.3.1 and creating an interpolated surface using results from the gamma radiation
survey and geostatistical analysis following methods in the NAUM program removal action
extent development standard operating procedure (USEPA 2024e). The interpolated Ra-226
concentrations were assigned to a 10- by 10-foot grid system spanning the site, and grids within
the revised TENORM boundary with estimated Ra-226 in surface soil exceeding the RAG were
included in the removal action extent. In addition, 10- by 10-foot grids including soil samples
measuring above the Ra-226 RAG but containing interpolated estimated Ra-226 concentrations
below the RAG were added to the grid footprint to generate the complete removal action extent
for the site. The removal action extent was also checked against the disturbance mapping results
from the data gaps investigation to verify locations of waste piles, concrete structures, and other
site features included in the resulting surface. The grid footprint was converted to 64 discrete,
contiguous areas—areas within Section 9 and Section 10 are differentiated. The proposed
excavation areas for the removal action extent based on the gamma-radium correlation, site soil
samples, and field-verified site features within the TENORM boundaries are provided on Figure
13.
The method applied to generate the removal action extent, consistent with the NAUM program
methodology, refines the methods previously used to characterize Ra-226 contamination at the
site (Tetra Tech 2022). The original method included applying a 5-meter buffer to the surface
raster of the same UPL95 model. However, the buffer is not applied to the updated removal
action extent because of field verification of site features and improved NORM-TENORM
delineation from the data gaps investigation (Appendix A).
Estimated volumes for the removal action extent were generated from the LiDAR survey
contours, and the estimated depth of TENORM above the site investigation level was recorded in
the RSE (EA 2021). The difference between the LiDAR survey contours and the TENORM
depth contours was interpolated across each of the 64 discrete areas. In the RSE report, the
TENORM depth contours used a minimum depth of TENORM of 1 inch. Because of the
feasibility for future excavation under each of the removal action alternatives, the minimum
excavation thickness was set at 6 inches as the minimum estimated depth of TENORM to
estimate volumes in this analysis. For areas of the site included in the removal action extent not
co-located with the LiDAR survey contours, the excavation thickness was based on the minimum
excavation depth of 6 inches except where waste pile descriptions from disturbance mapping
estimated waste pile heights.
At the Section 9 Lease Mines, the locations of waste piles, open pits, and former structures
consistently have the highest Ra-226 and metals concentrations and exceed the RAG. These
areas cover primary drainage pathways to the LCR and off site at AUMs 457 and 458 as shown
on Figure 7 and Figure 8. The data collected indicate that metals and Ra-226 contamination in
the soil and sediment is present and offsite migration is likely until the removal action is
completed. However, based on the available data from the RSE, neither increased radiation nor
elevated Ra-226 or metals COPCs and COPECs in soil and sediment samples have been
observed in the APE adjacent to the LCR (Tetra Tech 2022). Removal action at the site would
minimize the source of potential soil contamination migration to the LCR and regional drainages.
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3.0 IDENTIFICATION OF REMOVAL ACTION OBJECTIVES
J
This section presents the site RAOs, statutory limits on removal actions, removal scope, and
removal schedule.
3.1 REMOVAL ACTION OBJECTIVES
An early step in developing removal action alternatives is to establish RAOs. RAOs are a general
description of what the removal action will accomplish. RAGs are separate numerical cleanup
goal concentrations. CERCLA does not allow removal action alternatives to require remediation
of NORM or to remediate soil to concentrations below background levels. Based on current and
potential future land use at the site, the site RAOs are to:
• Prevent exposure to soil with contaminants associated with past mining activities that
would pose an unacceptable risk to human health with the reasonably anticipated future
land use.
• Prevent exposure to soil with contaminants associated with past mining activities that
would pose an unacceptable risk to plants, animals, and other ecological receptors.
• Prevent offsite migration of contaminants associated with past mining activities that
would pose an unacceptable risk to human or ecologic health by soil, surface water,
groundwater, or air.
The anticipated current and future use of the site is deed restricted. While legal land use
restrictions exist on Section 9, no physical barriers limit trespassing onto Section 9 from BLM
land in Section 10. The cleanup goals are also protective for potential future migration of
material from Section 9 onto public land.
The human health receptors evaluated were agreed to by Babbitt Ranches, BLM, and USEPA
with acceptance of the "Babbitt Ranches, LLC - Milestone Hawaii Stewardship Project
(Section 9 Lease Abandoned Uranium Mine) RSE Phase III Work Plan" (Engineering Analytics,
Inc. and Integral Consulting, Inc. 2019). USEPA will update the document to describe the human
health receptor as trespasser and clarify that the human receptor is not a recreator but a trespasser
on Section 9 land. The scope of the removal action will be to address soil contamination within
the site and to be the final action for solid media at the site. The COCs and the numeric RAGs at
the site are listed in Table 5.
3.2 STATUTORY LIMITS ON REMOVAL ACTIONS
Pursuant to CERCLA Section (§) 104(c)(1), the normal statutory limits for CERCLA removal
actions of $2 million and 12 months do not apply since the selected action will be funded by a
responsible party and not by Superfund.
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3.3 REMOVAL SCOPE
The scope of the removal action will be to address solid media contamination at the site under
the assumption that this will be the final action regarding solid media at the site. Post-removal
action site controls will be included under alternatives that do not specify complete removal of
contaminants to an offsite location. Post-construction monitoring requirements will be defined in
the post-closure plan.
3.4 REMOVAL SCHEDULE
The National Contingency Plan (NCP) requires a minimum public comment period of 30 days
following release of the proposed final EE/CA by USEPA. USEPA will respond to comments
received during the public comment period with the action memo. USEPA will provide public
notification of the removal action schedule upon issuance of the action memorandum.
During implementation of the selected removal action alternative, several factors may affect the
removal action schedule, including removal action planning and design, cultural and biological
clearances and mitigation, seasonal weather-related restrictions, and access for construction
equipment. Depending on the removal action alternative selected in the final EE/CA, design and
implementation of the construction activities will likely require between 2 to 4 months, which
are limited to March through November, depending on schedule-limiting factors such as truck
availability, monsoon rains, and snowfall. Annual post-removal site controls (termed
maintenance within this EE/CA for brevity) include 10 years of annual inspections and
maintenance of graded and revegetated site surfaces. Annual inspections and maintenance of an
onsite consolidation area cap, if selected, will occur as specified in a site-specific long-term
surveillance plan with inspection frequencies adjusted based on cover or cap stability and
inspection findings.
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This section identifies and analyzes the removal action alternatives for the site. Section 4.1
summarizes the process of screening potential technologies and identifies the removal action
alternatives that may be effective and implementable at the site, Section 4.2 describes in detail
the retained removal action alternatives, and Section 4.3 provides a detailed analysis of the
removal action alternatives based on the NCP evaluation criteria of effectiveness,
implementability, and cost.
4.1 DEVELOPMENT AND SCREENING OF ALTERNATIVES
This subsection identifies general response actions, identifies and screens technologies, develops
and describes potential removal action alternatives, and identifies applicable or relevant and
appropriate requirements (ARAR).
4.1.1 Summary of Technology Identification and Screening
The removal action alternative development process involves identification of general
response actions, technology types, and process options that may satisfy RAOs. General
response actions were considered for all AUMs and include institutional controls (IC),
engineering controls, disposal, and ex situ and in situ treatment. The initial screening below
eliminates infeasible technologies and process options and retains potentially feasible
technologies and process options.
A technology or process option can be eliminated from further consideration if it does not meet
the effectiveness threshold criteria (protectiveness and compliance with ARARs) or substantive
implementability criteria (technical, administrative, availability, and local acceptance), details of
which are conveyed in Section 4.3. In addition, a technology or process option can be eliminated
if its cost is substantially higher than other technologies or process options and at least one other
technology or process option is retained that offers equal protectiveness.
Treatment technologies and process options considered for AUMs on the Navajo Nation have
been identified, described, and initially screened in the following subsections. The initial
screening eliminates infeasible technologies and process options and retains potentially feasible
technologies and process options. Table 6 presents a summary of the detailed screening
discussion below.
Land Use Controls. Land use controls (LUC) include the implementation of access restrictions
to control current and future land use. LUCs would not reduce waste migration from a site but
could be used to protect human health and the environment by administratively restricting access
to affected areas. In addition, these restrictions may be used in conjunction with other
technologies to protect an implemented action. Potentially applicable LUCs consist of land use
and access restrictions are described below.
• Zoning - Zoning is a LUC that would be implemented to control current and future land
uses on or around waste and source areas consistent with the potential hazards present,
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the nature of removal action implemented, and future land-use patterns. Zoning is not an
effective control since zoning rules can be changed and exemptions can be granted.
• Deed restrictions - Deed restrictions are another form of LUC that could be used to
prevent the transfer of property without notification of limitations on the use of the
property or requirements related to preservation and protection of the effectiveness of the
implemented removal action alternative. Deed restrictions only regulate future
development of properties.
• Environmental control easements - Environmental control easements are a legal
mechanism that could be used to restrict different land uses at a site. Such easements
could be used to restrict access or development and land uses such as residential.
Engineering Controls. Engineering controls are used primarily to reduce exposure to
contaminants. These goals are accomplished by removal of contaminants and offsite disposal or
by creating a barrier that prevents direct exposure to or transport of waste from the contaminated
sources to the surrounding lands. Engineering controls include surface controls, physical barriers,
soil sorting, containment, consolidation and capping, onsite backfilling of pits and highwalls,
backfilling of underground voids, and offsite disposal.
• Surface Controls - Surface control measures are used primarily to reduce contaminant
mobility, direct exposure, and overall exposure area. Surface controls could be
appropriate in more remote areas where direct human contact is not a primary concern or
as a component of a containment alternative. Surface control process options include
consolidation, grading, revegetation, and erosion controls. These process options are
usually integrated with other technologies to various degrees based on site characteristics
and are usually not effective as a standalone technology.
• Physical Barriers - Physical barriers may include installing site access controls such as
earthen berms, fencing, and signage. These process options will usually be integrated
with other technologies to various degrees based on site characteristics and are usually
not effective as a standalone technology.
• Sorting - Soil and waste sorting is a standard process applied as an intermediate step
between soil or waste excavation and onsite or offsite treatment or disposal methods. The
process goal is to segregate highly contaminated material from less contaminated
material, allowing for different treatment or disposal options. Sorting reduces waste
volume requiring treatment or disposal, increases the volume of material that can remain
on site with limited or no treatment or containment, and allows classification of waste to
reduce volume requiring more costly treatment or disposal options.
• Onsite Containment, Consolidation, and Capping - Mine waste can be
consolidated and capped on site to reduce leaching and erosion. Waste from all areas of a
site is gathered together or consolidated and then capped. Typically, the cap is an ET
cover designed to minimize waste infiltration and leaching of contaminants, control
erosion, control radon emissions, and prevent exposure to contaminants.
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• Offsite Disposal at a Radiological Waste Accepting Facility - This standard
disposal method involves the transport and disposal of waste at a RCRA C licensed
hazardous waste landfill or low-level radioactive waste (LLRW) facility. Licensed or
permitted facilities are constructed to prevent release of hazardous or radioactive
materials and include engineered cells and liners that exceed the typical requirements for
mine waste. Mine waste would be hauled to the offsite facility using off-road and
on-highway haul trucks to transfer waste. The long trucking distances (approximately
600 miles) from the mines to the licensed disposal facilities in Clive, Utah, or Andrews,
Texas is the primary drawback.
Treatment. CERCLA and the NCP express a preference for treatment that significantly and
permanently reduces the toxicity, mobility, or volume of contaminants in selecting remedial
actions where such treatments are practicable. See CERCLA § 121(b) and 40 Code of Federal
Regulations (CFR) § 300.430(a)(l)(iii). See also USEPA (1991) guidance describing how to
identify wastes that may be appropriate for treatment. Principal threat wastes are those source
materials considered to be highly toxic or mobile that generally cannot be contained in a
reliable manner or would present a significant risk to human health or the environment should
exposure occur.
USEPA considered whether the site contains any principal threat waste, whether the waste could
safely be contained using engineering controls, and what treatment options could be practicable
for the waste at the site. As a result of its investigation and analysis, USEPA concluded that,
while some individual samples at the site contain higher levels of contaminants, the waste at the
site is variable and heterogeneous and no distinct areas of waste rock were distinguishable as
meeting the definitions of principal threat waste in USEPA (1991) guidance. However, to be
consistent with USEPA's preference for treatment, USEPA did evaluate a complete range of
treatment options. A summary of the treatment evaluation is discussed below.
Ex Situ Treatment. Excavation and treatment involve removal of waste from a source area and
subsequent treatment using processes that chemically, physically, or thermally reduce
contaminant mobility or volume. Treatment processes have the primary objective of either
(1) removing contaminants from the soil for separate disposal or additional treatment, or
(2) reducing the mobility of the chemicals. A short summary of different ex situ treatment classes
is described below. A short summary of different ex situ treatment options is presented in Table
6. Ex situ treatments are not considered as viable alternatives because the treatments will not
reduce the amount of radiation, treated materials will still require containment, volumes may be
increase, and treatments will require significant amounts of water to implement.
• Physical and Chemical Treatments - Physical treatment processes use physical
characteristics of materials to concentrate constituents into a relatively smaller volume
for disposal or further treatment. Chemical treatment processes act by adding a
chemical reagent that either removes contaminants from the material or fixates
contaminants within the material matrix. Different types of physical and chemical
treatments include milling or reprocessing, soil washing or acid extraction, ablation, and
stabilization or solidification.
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• Thermal Treatments - Thermal treatment technologies apply very high levels of heat to
the excavated soil in a reactor to oxidize contaminants and render them amenable to
additional processing. Thermal treatment is typically used for organic contaminants and
is not effective for the radionuclides and metals at the site.
In Situ Treatment. In situ treatment involves treating the contaminated medium where it is
located. In situ technologies remove the contaminants or reduce the mobility of the contaminated
medium and may reduce exposure to the contaminated materials; however, they allow a lesser
degree of control, in general, in comparison to ex situ treatment options. In situ treatments can
include physical, chemical, thermal, and vegetative uptake methods. A short summary of
different in situ treatment options is presented in Table 6. In situ treatments are not considered as
viable alternatives because the treatments will not reduce the amount of radiation, treated
materials will still require containment, volumes may be increased, treatments will require
significant amounts of water to implement, and maintenance may be significant.
If the treatments discussed in Table 6 or any other treatment methods are shown to be effective
and practicable before selection of a response action, USEPA will amend this analysis and
consider such treatments.
4.1.2 Summary of Alternative Development
After an initial screening of general response actions and technologies, containment,
consolidation, and capping along with various disposal process options were the only
technologies identified as being fully protective, effective, and implementable for the site. ICs,
surface controls, and access controls are feasible but not effective as standalone responses and
may be combined with containment and disposal options. A list of analyzed but excluded
disposal process options for the site is included below and is followed by a list of retained
alternatives comprising excavation and other disposal process options.
The following site-specific disposal alternatives were removed from consideration as infeasible
during development of this EE/CA:
• Excavation and Disposal at Uranium Mill Tailings Radiation Control Act
(UMTRCA) Sites. Several UMTRCA sites, including the nearby Shiprock Mill, were
assessed for disposal of the waste, but considered infeasible because those sites were
closed and transferred to the U.S. Department of Energy legacy management program,
had insufficient capacity to receive the waste, or had groundwater contamination issues
that could prohibit disposal under the CERCLA Off-Site Rule. The United Nuclear
Corporation Church Rock Mill was also considered, but the property owner and the
U.S. Nuclear Regulatory Commission objected to receiving any waste from mine sites
other than the Northeast Church Rock Mine. This option was eliminated because the
many legal, administrative, and implementation hurdles would likely add years to the
process.
• Excavation and Disposal at the White Mesa Mill. The White Mesa Mill facility was
considered for extraction of uranium from waste rock and subsequent disposal in the
adjacent tailings facility. However, disposal at the tailings facility was determined to be
currently infeasible because of potential groundwater contamination issues that would
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prohibit disposal under the CERCLA Off-Site Rule. This may be an option in the future if
compliance with the CERCLA Off-Site Rule can be documented and concurrence is
obtained from USEPA.
• Disposal at a Local Municipal Solid Waste Landfill. The closest municipal solid waste
landfill is in Flagstaff, Arizona. The landfill will not accept uranium mine waste.
Retained Removal Action Alternatives. Removal action alternatives for AUMs on the Navajo
Nation were developed as described in the "NAUM Program Navajo Nation AUM Technology
Evaluation and Alternative Development Technical Memorandum" (USEPA 2022b). The
memorandum is also valid for the AUMs at the site. Retained removal action alternatives for the
site also considered site-specific conditions and other local requirements. The following
alternatives were retained for further evaluation in this EE/CA and have been tailored to address
site-specific conditions and other local requirements:
• Alternative 1: No Action (this alternative must always be evaluated) - No treatment
or removal action would occur at the site. In this case, all threats would remain
unchanged. Mine waste and contaminated soils would continue to threaten human and
ecological receptors. Gamma radiation and physical hazards would remain.
• Alternative 2: Consolidate and Cap All Waste Onsite - Achieves RAOs by excavating
the waste rock piles, residual waste rock, and contaminated soils; and consolidating and
capping the waste in the onsite pit areas. A protective ET cap would be used that would
control contaminant migration and require long-term maintenance. Details of Alternative
2 are shown in Figure 15.
• Alternative 3: Disposal of All Mine Waste at a Western AUM Regional Repository -
Achieves RAOs by excavating the waste rock piles, residual waste rock, and
contaminated soils; and consolidating and capping the waste in a regional repository.
This location would provide for increased distance from major drainage pathways and
floodplains. A protective ET cap would be used to control contaminant migration and
along with the exposed bedrock require long-term maintenance. Details of Alternative 3
are shown in Figure 16.
• Alternative 4: Disposal of All Mine Waste in Offsite RCRA-Licensed Facility -
Achieves RAOs by excavating the waste rock piles, residual waste rock, and
contaminated soils; hauling the waste 515 miles (one way) for disposal at the Energy
Solutions LLRW facility in Clive, Utah. Details of Alternative 2 are shown in Figure 17.
The retained removal action alternatives listed above are described in Section 4.2.2 and carried
through a detailed analysis in Section 4.3.
4.1.3 Applicable or Relevant and Appropriate Requirements
Pursuant to NCP at 40 CFR § 300.415(j), USEPA has promulgated a requirement that removal
actions attain federal and state ARARs to the extent practicable considering the exigencies of the
situation. The ARARs evaluation completed for the site was comprehensive, and no ARARs
were rejected based on the exigencies of the situation. The site mines are located on land within
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Arizona. The identification of ARARs is an iterative process; therefore, ARARs are referred to
as potential until the final determination is made by USEPA in the action memorandum.
NCP at 40 CFR § 300.5 identifies ARARs and "to be considered" (TBC) requirements
as follows:
• Applicable requirements are defined as "those cleanup standards, standards of control,
and other substantive requirements, criteria, or limitations promulgated under federal
environmental or state environmental facility siting laws that specifically address a
hazardous substance, pollutant, contaminant, remedial action, location or other
circumstance found at a CERCLA site."
• Relevant and appropriate requirements are defined as "those cleanup standards,
standards of control, and other substantive requirements, criteria, or limitation
promulgated under federal or state environmental facility siting laws that, while not
'applicable' address problems or situations sufficiently similar to those encountered at the
CERCLA site and that is well suited to the particular site."
• TBC criteria consist of advisories, criteria, or guidance that were developed by USEPA,
other federal agencies, or states that may be useful in developing CERCLA remedies and
include non-promulgated guidance or advisories that are not legally binding and that do
not have the status of potential ARARs. TBCs generally fall within three categories:
health effects information with a high degree of credibility, technical information on how
to perform or evaluate site investigations or response actions, and policy.
ARARs apply to onsite actions completed as part of a removal action. Compliance with ARARs
requires compliance only with the substantive requirements contained within the statute or
regulation and, pursuant to CERCLA § 1211(1), does not require compliance with procedural
requirements, such as permitting or recordkeeping. ARARs do not apply to offsite response
actions. Instead, offsite response actions must comply with independently applicable
requirements (not relevant and appropriate) and must comply with both substantive and
procedural components of the requirements.
USEPA, as the lead agency, is responsible for identifying potential federal ARARs and
evaluating potential Arizona ARARs. For a state of Arizona requirement to be identified as a
potential ARAR, the requirement must be more stringent than federal ARARs.
USEPA has divided ARARs into three categories: chemical specific, location specific, and action
specific. The three categories are described below:
• Chemical-Specific ARARs are usually health- or risk-based numerical values or
methodologies that, when applied to site-specific conditions, result in the establishment
of numerical values. These values establish the acceptable amount or concentration of a
chemical that may be found in, or discharged to, the ambient environment.
• Location-Specific ARARs apply to the geographical or physical location of a site. These
requirements limit where and how the response action can be implemented.
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• Action-Specific ARARs include performance, design, or other controls on the specific
activities to be performed as part of the response action for a site.
The potential ARARs for all alternatives are presented and analyzed in Table 7.
4.2 DESCRIPTION OF ALTERNATIVES
This subsection describes the retained removal action alternatives for the site. Section 4.2.1
provides a summary of common site construction and restoration elements applicable to all
alternatives. A detailed description of removal action alternatives and associated costs, which
focuses on the different waste disposal options, is presented in Section 4.2.2.
4.2.1 Common Elements
To reduce repetitive discussion in the detailed alternative analyses, common removal action
elements for Alternatives 2, 3, and 4 are provided in the following subsections.
4.2.1.1 Common Elements for Construction and Restoration
Common removal action elements at the site for construction and restoration for Alternatives 2,
3, and 4 are described below.
Site Preparation. Laydown areas would be established on the site after biological and cultural
resource clearances. Laydown areas may include port-a-potties, wash water, refuse pickup,
decontamination station, temporary offices, radiation scanning equipment, personal protective
equipment, first aid supplies, temporary Wi-Fi and radio, and potentially a construction water
well and tank stand. The laydown areas would also include security personnel and temporary
security fencing and signage for access controls. Laydown areas would remain until completion
of the removal action.
A sufficient water supply is not available for construction near the site. Purchase of water from
Flagstaff, Arizona, or construction of a new construction supply well would be needed for the
project. If an onsite water supply were developed, well depths would likely range from 500 to
1,000 feet bgs. Diesel generators would be used to run the well pumps and provide power for the
temporary work site (laydown area), and well site location (if constructed). The diesel generators
would require bulk fuel storage at the laydown area. A secondary containment area would be
constructed around generators, storage tanks, and the fueling area. A water storage tank for the
water trucks would also be required.
Cultural and Biological Exclusion and Timing. Cultural resource investigations may be
conducted at the site. The results of these surveys would be reviewed and used where possible
for planning and removal design. Additional surveys would be performed after design, and
USEPA would specify compliance requirements for cultural resources. For the purposes of this
EE/CA and consistent with other CERCLA actions in this area, cultural resources would be
avoided or protected during site work activities and no special status plant or animal species
would be identified that would limit site work activities.
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Natural resource surveys (for example, biological and botanical) for special status species would
be required to verify the current land use for each area, mapped habitat and vegetation cover
types, and recorded locations of potential special status species resources. No threatened or
endangered species have been identified at the site.
Previous site surveys would be consulted where possible, and new surveys would be conducted
if necessary. Furthermore, if new action areas are identified as part of the selected removal
action, these areas would be surveyed before earthmoving activities. If any natural resources are
found, ARARs would be identified.
The removal actions would involve widening access roads for haul roads and establishing an
overall larger work area than the previous investigations. Therefore, additional field surveys and
reports of both natural and cultural resources in the proposed work areas may be required. The
surveys must conclude the proposed removal action project area would not affect natural and
cultural resources before design and construction can proceed.
An environmental protection plan would be developed for monitoring protocols during the work
activities and include a review and evaluation of potential impacts to historic properties and
locations. Natural resource (for example, biological and botanical) inspections would be
conducted at the site, and information from these inspections would be included in the
environmental protection plan. Environmental protection would include a review and evaluation
of potential impacts on government-protected species and critical habitats.
Site Access. The site is accessed by taking Indian Route 6728 from U.S. Route 89 approximately
40 miles north of Flagstaff, Arizona. Indian Route 6728 leads to Section 9 approximately 8 miles
to the east.
During the response and restoration activities, site access would be restricted by signage,
temporary fencing at access points, and security maintained during all non-working hours while
site work is occurring. The laydown area will be completely fenced. The site foreperson and the
health and safety officer would be responsible for personnel while on the site. USEPA and its
authorized representatives, including its contractors, and representatives of Babbitt Ranches;
CO Bar, Inc.; BLM; and the State of Arizona would have access to the site at all times. A site
access and security plan would describe the activities used to monitor and control access to the
site during implementation of the response actions and the period of work performance.
The alternatives being considered require hauling soil and water over the construction period and
may require widening, grading, and installation of culverts along the 8-mile Indian Route 6728.
During transport of waste off site, traffic controls would be necessary. A traffic control plan
would be developed and followed throughout operations. Even with precautions, nearby roads
would require maintenance to protect the roadway and road users. To maintain road load limits,
temporary scales would be used to weigh the trucks that navigate Arizona roadways.
Observing road load limits would help reduce roadway wear and maintain the local roadways
in a safe operating condition. Equipment and materials would be available to restore the
roadways as needed.
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Air Monitoring. A sampling and analysis plan would be prepared that describes the methods
and procedures for collecting, analyzing, and evaluating air samples within and at the perimeter
of work zones. Air monitoring stations would be positioned and operated to monitor dust and
airborne contaminant concentrations during excavation, stockpiling, loading of trucks, hauling,
waste compaction, and site restoration. Air monitoring would be used to document that offsite
migration of contaminants at unacceptable concentrations does not occur, maintain compliant air
quality conditions and a safe working environment, and protect the health of workers, the general
public, and the environment. Water spraying would be used during soil-moving activities at all
work zones and for dust suppression. Alternate engineering controls may be used on haul roads
to limit water application needs. Water would be sourced as described under Site preparation.
Dust Control. Off-road haul routes and site excavation, waste transfer, waste compaction, and
restoration areas would be wetted to minimize dust generation. Water spraying would be used
during soil-moving activities for dust suppression. Rock fields and grating would be used to
reduce the track out of dirt onto paved surfaces. To maintain the haul routes as laid out, signs and
barriers would be provided, as necessary, to contain traffic along the designated route. Water
used for dust control and cleaning of paved surfaces would be imported as described under site
preparation. Alternate methods of dust control, such as chemical polymers, gravel cover,
recycled asphalt, and paving of access and haul roads, will be considered to reduce the water
required. Dust control would be used to maintain compliant air quality conditions and a safe
working environment and to protect the health of nearby residents, workers, the general public,
and the environment.
Stormwater Control. Excavated areas would be graded to pre-mining contours when possible
and oriented to reduce scouring with low-energy flow rates and patterns. The drainage system
would be integrated with the topography and existing geomorphology to the extent possible.
Activities at the site must be evaluated for potential impacts on federally listed species and
critical habitat and for certification to meet the substantive requirements of the National Pollutant
Discharge Elimination System Multi-Sector General Permit. Once the site has been stabilized,
post-removal action site controls would be initiated.
Excavation Approach. Waste rock piles and contaminated soils containing metals and
radionuclides above RAGs are within 64 identified removal areas of concern within the
TENORM boundary (Figure 13). An estimated 14,711 cubic yards of contaminated soil exceed
the Ra-226 RAG (12 pCi/g) in Sections 9 and 10. Although land ownership may differ between
Section 9 and Section 10, the identification and screening of the response action and the
conclusions are independently evaluated. Section 16, including AUM 459, has been excluded
from the APE.
Figure 14 summarizes the locations, average estimated depth, and average estimated volume for
each of the 64 removal areas by 7 individual TENORM boundary areas. The excavation volumes
were estimated using limited depth contours corresponding to soil exceeding 12 pCi/g Ra-226.
The contours and extent of each area were used to create a computer-generated surface and
estimated excavation volume. Depths shown on Figure 14 are the area-weighted average depth
that approximates the computer-generated estimated excavation volume. Detailed excavation
cross-sections for each of the 64 excavation areas will be prepared in the remedial design.
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Site removal areas include:
• The removal area within Section 9 has an estimated volume of 13,478 cubic yards
(Figure 14).
• The removal area within Section 10 has an estimated volume of 1,233 cubic yards
(Figure 14).
• The removal areas attributable to mining activities at AUM 459 are included in the
Section 9 estimated removal volume (Figure 14).
The waste is accessible with standard construction equipment, including excavators and
bulldozers. Waste rock and contaminated soils would be loaded into 16.7-cubic-yard articulated
haul trucks for hauling to onsite consolidation locations or loaded into 25-ton trucks for hauling
to the offsite RCRA-licensed facility.
Waste would be removed to a native soil interface and excavation would proceed in lifts using
field screening techniques such as gamma scanning and X-ray fluorescence measurements until
RAGs are attained. Confirmation sampling and a final status gamma survey would be conducted
to verify attainment of RAGs. Borrow material would first be obtained on site and then
additional borrow material would be imported from nearby.
Waste Handling and Transfer. For cost-estimating purposes, 16.7-cubic-yard articulated dump
trucks were assumed for onsite transport (Alternatives 2 and 3) and 25-ton covered on-highway
trucks were assumed for offsite transport to the offsite RCRA-licensed facility (Alternative 4).
Controls would be used to ensure contamination is not released from the site and may include
radiological scanning of tires and equipment, dry brushing truck beds and wheels, and power
spraying equipment.
Cap Design Assessment. Consolidation and capping on site (Alternatives 2 and 3) would
involve the construction of an engineered cap over the consolidated mine waste. Two types of
engineered caps were evaluated through infiltration and radon flux modeling: (1) a soil ET
cap and (2) a soil cap containing an integral high-density polyethylene (HDPE) layer (Tetra
Tech 2021).
Approximately 36 inches of cover would be required for an ET cap to limit infiltration of
precipitation and snowmelt, control radon gas flux, and reduce gamma activity to background. A
cap with an HDPE liner would require less soil cover; however, at least 24 inches of cover would
still be needed to protect the liner from frost heave, burrowing animals, and plant roots.
Biodegradable matting and wattles would be placed on the cover top and side slopes to limit
erosion. Surface controls would involve directing run-on water around the capped area using
berms and ditches.
Both engineered cap types would minimize the vertical migration of precipitation and snowmelt
to the underlying mine waste. However, an ET cap would be stable on slopes less than 3:1 while
the smooth surface of an HDPE liner can create a slip plane, which carries risks such as
instability during seismic or heavy precipitation events. An ET cap would allow for slow
dissemination of radon gas while a soil cap with an HDPE liner would tend to trap radon gas,
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which may find preferential pathways for a point of release at higher concentrations. A bottom
liner under the waste would not be needed because the evaporation rate far exceeds the
precipitation rate and volume in the region and an ET cap is sufficient to limit infiltration into the
waste. A bottom liner would not provide any additional protectiveness. Ventilation would not be
required for radon-222 as the modeled flux within the waste is below 20 picocuries per meter
squared per second. ET covers are widely used throughout the United States and have been
shown to be especially effective in the Southwest (Tetra Tech 2021). The average annual
precipitation in Cameron, Arizona, is 5.57 inches while the pan evaporation rate is 80.57 inches
(Table 1). Thus, given that ET covers work with nature to provide similar or better
protectiveness than a cap with an HDPE liner, the ET cover with no liners would be used for the
alternatives analysis.
Waste would be placed and consolidated to mimic surrounding topography and blend into the
landscape. Nearby sources of borrow soil for cap construction would be identified, as well as the
potential import of clayey soil from the Chinle Formation and gravel for including in the cap to
improve erosion resistance. Sandstone rock would be excavated from local bluffs to face the
terrace slopes of a cap.
CERCLA Off-Site Rule. Alternatives that involve transportation off site for disposal would
require compliance with the CERCLA Off-Site Rule. In general, the CERCLA Off-Site Rule
requires facilities accepting contaminated or hazardous wastes from a CERCLA site must follow
all applicable regulations and laws (that is, they must be approved to take those wastes and
comply with the applicable federal, state, and local requirements). The licensed disposal facilities
considered for any alternatives involving offsite disposal would be required to have existing
approval under the CERCLA Off-Site Rule.
Site Restoration Activities. Details regarding site features are shown on Figure 18, Figure 19
and Figure 20, and areas requiring surficial restoration are described below:
• Main Haul Roads. Haul roads from Section 9 to U.S. Route 89 (8 miles) would be
improved to facilitate construction and removal of the waste. Water control bars and
rolling dips would be used on portions of the road that have an extended length and a
slope greater than 5 percent. Drainage swales would be covered with rock to reduce
erosion. The road would be maintained as needed for at least 10 years to provide access
to the mine sites during restoration. If an onsite cap is selected as a removal action
alternative, the haul road would be maintained as needed for at least 30 years to provide
access for monitoring and maintenance.
• Temporary Access Roads to Mine Pits and Waste Piles. To facilitate construction, haul
roads may be constructed between Indian Route 6728 and AUMs 457 and 458 (Figure 15
and Figure 16). The route of road construction would be monitored to minimize the
production of TENORM. When work is complete, the temporary access roads would be
obliterated. Those portions of the road pathway on benches below highwalls would be
covered with rock. The road pathways would be restored by pulling overbank materials
back onto the road surface, contour grading to match surrounding grade, covering with
biodegradable matting and coir logs, and seeding using local grasses and forbs. Upslope
berms and drainage ditches would be constructed to divert water away from the
disturbed road pathway. Drainage swales would be covered with rock to reduce erosion.
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Soil berms would be used to block vehicular access to the temporary access roads from
the haul road.
• Stabilizing Pits. Pits would be backfilled with waste or clean fill (depending on the
alternative) to provide positive drainage through waste consolidation or backfill. Soil and
rock berms and drainage ditches would be constructed upslope to divert run-on water
away from unstable areas. Rock outfalls would be constructed at the end of ditch systems
and benches to reduce the erosive force of water that could impact restored areas further
downslope.
• Run-on and Runoff Controls. Rock berms, rock-lined drainage ditches, biodegradable
matting and coir logs, and rock fields and covers are discussed within the respective
surficial restoration area type above.
• Slope Downhill from Upgrader at AUM 457. The area of waste removal downhill from
the upgrader would be covered with 1 foot of soil and revegetated (Figure 15 and Figure
16). Following construction, the drainage would be restored. The drainage would be
graded to restore a natural energy grade line, boulders and gabion weirs may be placed
strategically in the drainage for energy dissipation, and biodegradable matting and coir
logs would be added along with planting shrubs and forbs within the riparian zone.
• Access Roads toAUMs 457 and 458. To facilitate equipment access and removal of
waste from AUMs 457 and 458, temporary access roads may be constructed (Figure 15
and Figure 16) between Indian Route 6728 and the mine and consolidation sites. A
0.4-mile-long temporary haul road from Indian Route 6728 to AUM 457 and a
0.35-mile-long temporary haul road from Indian Route 6728 to AUM 458 would be
constructed and maintained for 10 years.
• Waste Consolidation or Removal Areas. The disturbed areas would be backfilled with
waste, cap soil, or clean fill; contour graded; and revegetated. Rock-lined channels may
be constructed where slopes are greatest with rock selected to best match the natural
colors in the area. Cover soil and rock may be imported from existing and future local
quarries while rock required to meet engineering specifications would be imported from
outside the region. Capped areas would be fenced.
4.2.1.2 Common Elements for Maintenance
Common elements for the maintenance of site and restoration features are described below.
Short-Term Maintenance of Site and Restoration Features. Maintenance would be performed
for up to 10 years for the restored areas of the site outlined in Section 4.2.1.1. Annual
maintenance will include:
• Vegetation surveying in late spring
• Erosion control inspection and maintenance surveying after the monsoon season(s)
• Vegetation maintenance, including reseedings, replanting, and removing weeds
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• Access road maintenance prior to site visits and until vegetation and restored areas
have stabilized
• Repairs to fences, erosional features, rock outfalls, and water control berms
• Erosion control maintenance on the caps including removing decayed biodegradable
matting and wattles to minimize rills and gullies and clearing sediment from berms and
ditches to direct run-on and runoff water around the onsite consolidation area cap
• Temporary range fencing maintenance including repairing damaged fencing installed
around the onsite cap areas during the revegetation period to stop recreational vehicles or
livestock from disturbing the soil cover and revegetation efforts
Onsite Cap Long-Term Maintenance. Activities for Alternatives 2 and 3 include:
• Final grading, surface erosion controls, and revegetation of the onsite caps would be
needed to limit the visual impact by mimicking local terrain and using local soils and
vegetation (Appendix E). Maintenance would include repairing erosional features and
ongoing establishment of vegetative cover. Maintenance would include repairing
erosional features and ongoing establishment of vegetative cover.
• LUCs would be required to restrict activities that could damage the cap. The form of the
LUCs would likely be an environmental covenant, such as the land easement currently in
place for Babbitt Ranches' land within Section 9 that restricts future residential use (EA
2021) or activities that would disturb the cap.
Inspection and maintenance of the onsite caps would be conducted as specified in a long-term
surveillance plan with inspection frequencies adjusted based on the cover stability and inspection
findings. Maintenance would consist of repairing eroded surfaces or damages to caps, clearing
accumulated erosion materials, replanting vegetation, and repairing access roads. Periodic,
10-year maintenance costs were developed based on a 30-year period for cost estimate
comparisons. Additional maintenance costs may be incurred beyond 30 years depending on
inspection results and updates to the long-term surveillance plan.
4.2.1.3 Potential Unavoidable Impacts
Except for Alternative 1 (no action), each of the removal action alternatives would result in an
overall improvement to the local environment. However, for Alternatives 2, 3, and 4,
unavoidable impacts are expected and include:
• Vegetation coverage on the site currently includes scrub brush and grasses.
Mining-disturbed areas are generally devoid of vegetation or are covered with grasses.
Construction activities would generally be limited to areas of mining disturbance.
Disturbed areas would be reclaimed, but existing grasses and forbs would take up to
10 years to reestablish. Areas with shallow slopes would be contour-graded and
revegetated. Areas with moderate to steep slopes would be covered with rock where
accessible. Areas with exposed bedrock may not be covered at all.
• New temporary access and haul roads to the site would be constructed to provide access
for construction equipment and to haul out waste. Construction of the new roads may
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disturb mineralized rock and generate additional TENORM that must be addressed.
When work is complete, the roads would be removed and the disturbed slopes and
drainages would be restored to the extent possible.
• Local populations using U.S. Route 89 would be inconvenienced for the duration of the
construction period by increased truck traffic. Generation of dust on access and haul
roads would be minimized through spraying with water or other engineering controls
during construction and hauling activities.
• While no sensitive species and habitat are known present on the site, any later found may
be disturbed during construction activities.
• While no cultural resources have been identified at the site (SWCA 2017), cultural
resource monitors would be on site during construction activities to clear any work areas
beyond those already cleared.
• Range fencing would be used at entry points for up to 10 years after completion of site
work to help establish vegetation.
• Risk of traffic accidents, fatalities, and greenhouse gas emissions would increase because
of the trucking of fill, cover material, and waste. As the offsite haul distance increases,
the potential risks also increase.
• Water and other engineering controls would be used for dust control during excavation,
waste compaction, and restoration, and on roads during waste hauling.
4.2.2 Description of Removal Action Alternatives
The following subsections present descriptions of the three removal action alternatives identified
in Section 4.1.2. All haul roads, laydown areas, and truck and access roads needed for the
removal actions are shown on Figure 15 and Figure 16.
4.2.2.1 Alternative 1: No Action
Under Alternative 1, radionuclide and metal COCs and COECs in the waste piles and
surrounding contaminated soils would not be addressed. No LUCs, signage, range fencing, or
barriers would be used to limit access to the site. No removal or site stabilization activities
would occur.
4.2.2.2 Alternative 2: Consolidate and Cap All Waste Onsite
Under Alternative 2, RAOs would be accomplished through excavation, hauling, sorting, and
consolidation of waste on the site; containment of waste under an ET cap; and implementation
and short-term maintenance of site restoration measures and land use and access controls to
protect the cap and site restoration process (Figure 15 and Figure 18). Site excavation and
restoration elements common to alternatives are described in Section 4.2.1.1.
An estimated 1,233 of 14,711 cubic yards (about 8.6 percent) of all contaminated soils in
Sections 9 and 10 are in Section 10. An estimated 14,711 cubic yards of waste from the AUMs
would be consolidated and capped on site (Figure 15). The proposed consolidation areas were
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previously disturbed by mining. The consolidation area for AUM 457 is south and west of the
former concentrator. The topography is gently sloping to the west with steeper slopes to the
east. No headwater areas exist that could direct surface water to the capped area. The
consolidation area for AUM 458 is the location of the excavated area. The consolidation areas
have year-round access for maintenance. Design considerations to limit visual impact include
reduced height, grading and contouring into an existing hillslope, and use of local soils and small
rocks within the cap to better blend in with the surroundings. Criteria used in the design phase
may limit the amount of material placed near the steeper slopes to the east but would likely fill
any west-to-east depressions. The cap would comprise native soil and a gravel admixture and be
revegetated using native plants to blend in with the landscape. Post-removal visualizations of the
onsite consolidation are included in Appendix E.
Site restoration activities include access roads; backfilling and grading of waste excavation areas;
controlling runoff from above the mine sites; covering slopes with rocks where possible;
covering mining-disturbed areas with soil, rock, or gravel where possible; and restoring the
minor drainage channels within and below the excavation sites (Figure 18). Roads required for
maintenance activities would be reclaimed once the site has stabilized (after 10 years). Site
restoration activities are described further in Section 4.2.1.1. Post-removal visualizations of the
restored site are included in Appendix E.
Multiple Repository Conceptual Design
The repositories and surface treatments would be designed to blend in with the surrounding
landscape as much as possible. Exhibit 9 shows the existing conditions where Repository 1 in
AUM 458 would be placed. Exhibit 10 shows the existing conditions where Repository 2 in
AUM 457 would be placed. These locations partially comprise existing topographical
depressions. These existing topographical depressions would be used to the greatest extent
possible to accommodate consolidated waste. The existing site conditions are sparse grasses and
shrubs with an undulating topography.
The onsite consolidation areas are moderately steep with bedrock at more than 6 feet bgs.
Outcrops and bedrock encountered during placement of consolidated waste and construction
of the repository would be covered along with the waste and repository ET cap system.
Any remaining outcrops and bedrock at the surface would not be disturbed and not
considered TENORM.
The onsite capped consolidation areas would be constructed by rough grading the base of the
consolidation area to allow for vehicular traffic and waste placement. An average of 3 feet of
waste would be placed in Consolidation Area 1 and an average of 9 feet of waste would be
placed in Consolidation Area 2. For the repository, the immediate slope(s) of surrounding grade
would govern first. Where the repository is higher in elevation than surrounding grades, the
repository slopes would have no more than 10:1 slope. The final 6 inches of cap material would
be furrowed along contours at 6- to 12-inch intervals to promote capture of water and growth of
native grasses. Polyacrylamide crystals would be mixed in with the final 6 inches of soil to
enhance water retention and slow release. The site would be seeded with a mixture of native
grasses. Native shrub species would be seeded at discrete locations across the site. Coir rolls
would be installed along contours and would degrade in 5 to 10 years. Bonded fiber matrix
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lb
(hydroseeded) or crimped straw may also be used to increase germination rates. These features
will increase the likelihood the finished repository will blend in with the natural landscape as
much as possible while limiting erosion of the repository cap.
Exhibit 9. Existing Conditions at Consolidation Area 1 (AUM 458)
Source: Photo 31 in Appendix B of the preiiminary assessment report by Weston Solutions,
Inc. (2012).
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Exhibit 10. Existing Conditions at Consolidation Area 2 (AUM 457)
Source: Photo 14 in Appendix C of the site inspection report by Weston Solutions, Inc. (2014).
The 36-inch-thick ET cap, requiring approximately 11,900 cubic yards of borrow soil for
Consolidation Area 1 and 2,300 cubic yards of borrow soil for Consolidation Area 2, would be
constructed on top of the waste. Borrow and cover soil are expected to be obtained within
0.5 mile of the repository. Borrow areas will be located outside TENORM boundaries, and any
outcrops or bedrock exposed as a result of borrow excavation will still be considered NORM.
Cover soil will be selected from the top 6 inches of borrow areas.
Removal Action Components
Additional information regarding common construction elements is provided in Section 4.2.1.1.
• Excavation of waste and contaminated soil from the 64 excavation areas on the north and
south side of Indian Route 6728; rework in situ (and not excavation) of excavation areas
co-located with the consolidation area locations
• Excavation of borrow soil for caps and surficial and site restoration
• Construction of the waste consolidation areas, transport of waste to the consolidation
area, and placement of waste in the consolidation area
• Closure of the consolidation area with ET caps
• Installation of short-term erosion and stormwater controls, grading, and revegetation
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• Implementation of access controls, such as range fencing and signage to allow for
successful revegetation on the ET caps and installation of gates to allow rotational
grazing once vegetation becomes established
• Surficial and site restoration of excavation locations and laydown areas
• Implementation of access controls, such as temporary fencing and signage, berms, or
barricades on temporary access roads to reduce ease of access for livestock over the short
term, to allow for successful revegetation on the site
• Long-term maintenance of the consolidation area cap as described in Section 4.2.1.2
• Maintenance of surficial and site restoration areas as described in Section 4.2.1.2
4.2.2.3 Alternative 3: Disposal of All Mine Waste at a Western AUM Regional
Repository
Under Alternative 3, RAOs would be accomplished through excavation, hauling, sorting, and
consolidation of waste at a regional repository; containment of waste under an ET cap; and
implementation and short-term maintenance of site restoration measures and land use and access
controls to protect the cap and site restoration process (Figure 16 and Figure 19). Site excavation
and restoration elements common to alternatives are described in Section 4.2.1.1.
An estimated 13,478 cubic yards (about 92 percent) of all contaminated soils are in Section 9 and
1,233 cubic yards (about 8 percent) are in Section 10. An estimated 14,711 cubic yards of waste
from the AUMs would be consolidated and capped in the Western AUM Region repository. The
proposed consolidation area for AUMs 457 and 458 is in the northwest corner of Section 9 on
top of a low mesa (Figure 16). The topography is flat with nearby drainage sloping to the east.
No headwater areas exist that could direct surface water to the capped area. The consolidation
area has year-round access for maintenance. Design considerations to limit visual impact include
reduced height, grading and contouring into an existing hillslope, and use of local soils and small
rocks within the cap to better blend in with the surroundings. Criteria used in the design phase
may limit the amount of material placed near the steeper slopes to the east but would likely fill
any west-to-east depressions. The cap will comprise native soil and a gravel admixture and will
be revegetated using native plants to blend in with the landscape. Post-removal visualizations of
the onsite consolidation are included in Appendix E.
Regional Repository Conceptual Design
The repository and surface treatments are designed to blend in with the surrounding landscape as
much as possible. Design and environmental considerations will be evaluated to determine the
location, elevation, and topography of the repository.
The onsite repository would be constructed by rough grading the base of the consolidation area
to allow for vehicular traffic and waste placement. An average of 8 feet of waste will be placed
in the consolidation area. For the repository, the immediate slope(s) of surrounding grade will
govern first. Where the repository is higher in elevation than surrounding grades, the repository
slopes will have no more than 10:1 slope. The final 6 inches of cap material will be furrowed
along contours at 6- to 12-inch intervals to promote capture of water and growth of native
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grasses. Polyacrylamide crystals will be mixed in with the final 6 inches of soil to enhance water
retention and slow release. The site will be seeded with a mixture of native grasses. Native shrub
species will be seeded at discrete locations across the site. Coir rolls will be installed along
contours and will degrade in 5 to 10 years. Bonded fiber matrix (hydroseeded) or crimped straw
may also be used to increase germination rates. These features will increase the likelihood that
the finished repository will blend in with the natural landscape while limiting erosion of the
repository cap.
The 36-inch-thick ET cap, requiring approximately 7,400 cubic yards of borrow soil, would be
constructed on top of the waste. Borrow and cover soil are expected to be selected from adjacent
land. No TENROM or NORM have been identified at the location. Cover soil will be selected
from the top 6 inches of borrow area.
Removal Action Components
Additional information regarding common construction elements is provided in Section 4.2.1.1.
• Construction of a 0.35-mile-long haul road from Indian Route 6728 to the consolidation
area (Figure 16)
• Excavation of waste and contaminated soil from the 64 excavation areas on the north and
south side of Indian Route 6728
• Excavation of borrow soil for caps and surficial and site restoration
• Construction of the waste consolidation area, transport of waste to the consolidation area,
and placement of waste in the consolidation area
• Closure of the consolidation area with ET caps
• Installation of short-term erosion and stormwater controls, grading, and revegetation
• Implementation of access controls on ET caps, such as the installation of range fencing
and signage to allow for revegetation and the installation of gates to allow rotational
grazing once vegetation becomes established
• Surficial and site restoration of excavation locations, backfill sites, and laydown areas
• Implementation of access controls on temporary access roads, such as the installation of
temporary fencing and signage, berms, or barricades to reduce ease of access for
livestock over the short term to allow for revegetation on the site
• Long-term maintenance of the consolidation area cap as described in Section 4.2.1.2
• Maintenance of backfill, surficial, and site restoration areas as described in
Section 4.2.1.2
4.2.2 A Alternative 4: Disposal of All Mine Waste in Offsite Resource Conservation
and Recovery Act-Licensed Facility
Under Alternative 4, RAOs would be accomplished through excavation, transport, and offsite
disposal of mine waste and contaminated soil at a RCRA facility licensed to accept LLRW
(Figure 17). Although land ownership may differ between Section 9 and Section 10, the
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identification and screening of the response action is not affected and the conclusions were
independently evaluated. Section 16 has been excluded from the APE. The site would be
reclaimed through implementation of site restoration measures followed by the short-term
maintenance of restored features and use of access controls to protect the site restoration process.
Site excavation and restoration elements common to alternatives are described in Section 4.2.1.1.
An estimated 14,711 cubic yards of waste from the site would be hauled approximately 9 miles
via an unpaved road to Indian Route 6728 and then to one of the facilities with the necessary
permits and CERCLA Off-Site Rule approvals listed below. Indian Route 6728 is assumed
passable for 25-ton on-highway haul trucks so waste transfer is not included. The hauling of
waste would comply with applicable Navajo and state permitting requirements for the transport
of radioactive materials.
The following facilities have licenses or permits that allow for acceptance of uranium
mine waste:
• US Ecology, Grand View, Idaho: RCRA C hazardous waste disposal facility located
800 miles from the site
• Clean Harbors, Deer Trail, Colorado: RCRA C hazardous waste disposal facility located
690 miles from the site
• Energy Solutions, Inc. (Clive Operations), Clive, Utah: LLRW facility located 515 miles
from the site.
• Waste Control Specialists, Andrews, Texas: LLRW facility located 730 miles from
the site
The Clive Operations LLRW facility was identified as the most cost-effective disposal facility
and is located near Clive, Utah, approximately 515 miles from the site (Figure 17). The disposal
facility could be changed in the action memorandum stage if necessary.
Disposal at a licensed LLRW or RCRA C hazardous waste facility is a standard disposal method
involving transport to and disposal at the applicable waste disposal facility. Licensed or
permitted facilities are generally constructed to prevent the release of hazardous or radioactive
materials and include engineered cells and liners that exceed requirements for municipal or
commercial solid waste disposal facilities.
Site restoration activities include obliterating access roads on the site; backfilling and grading
waste excavation areas; controlling runoff from above the mine sites; covering slopes with rocks
where possible; covering mining-disturbed areas with soil, rock, or gravel where possible; and
restoring the minor drainage channels within and below the excavation sites (Figure 20). Roads
required for maintenance activities will be reclaimed once the site has stabilized (after 10 years).
Site restoration activities are described further in Section 4.2.1.1. Post-removal visualizations of
the restored site are included in Appendix E.
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Removal Action Components
Additional information regarding common construction elements is provided in Section 4.2.1.1.
• Improvement of segments of the existing 9-mile-long Indian Route 6728 to access the
laydown areas
• Excavation of waste and contaminated soil from the 64 excavation areas
• Excavation and stockpiling of borrow soil for surficial and site restoration
• Backfill of excavated areas and exposed bedrock with clean fill
• Hauling and offsite disposal of waste by 25-ton on-highway haul trucks to the Clive
Operations LLRW disposal facility near Clive, Utah
• Restoration of each excavation area, certain haul roads, and all laydown areas with short-
term erosion and stormwater controls, grading, and revegetation
• Implementation of access controls, such as temporary fencing and signage, berms, or
barricades on temporary access roads to reduce ease of access for livestock over the short
term to allow for revegetation
• Maintenance of surficial and site restoration areas as described in Section 4.2.1.2
4.3 ANALYSIS OF ALTERNATIVES
As required by NCP and described in the "Guidance on Conducting Non-Time Critical Removal
Actions under CERCLA" (USEPA 1993), retained removal action alternatives are evaluated
individually against three broad criteria: effectiveness, implementability, and cost. The
individual alternative analysis ranks the three criteria of each alternative qualitatively as
Very Poor, Poor, Average, Good, or Very Good.
In addition, based on USEPA (2016b) guidance, five key elements in greener cleanup activities
should be considered throughout the response action selection process:
• Minimize total energy use and maximize renewable energy use
• Minimize air pollutants and carbon dioxide equivalent emissions
• Minimize water use and negative impacts to water resources
• Improve materials management and waste reduction efforts by reducing, reusing, or
recycling whenever feasible
• Protect ecosystem services
The evaluation criteria and qualitative rating ranges are described below.
Effectiveness Criterion
This criterion evaluates protectiveness, compliance with ARARs, short-term effectiveness,
long-term effectiveness and permanence, and reduction in toxicity, mobility, or volume of waste.
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• Overall Protection of Human Health and the Environment - This threshold criterion
evaluates whether each alternative provides adequate protection of human health and the
environment. The assessment of overall protection focuses on whether a specific
alternative achieves adequate protection and how site risks posed through each pathway
addressed by the EE/CA are eliminated, reduced, or controlled through treatment,
engineering, or LUCs. Alternatives are either considered protective or not protective.
• Compliance with ARARs - This threshold criterion evaluates whether each alternative
would meet the identified ARARs. Alternatives are either in compliance with ARARs or
not in compliance.
• Short-Term Effectiveness (during Removal Action) - This criterion evaluates the
effects that the alternative would have on human health and the environment under
current conditions prior to the action and during its construction and implementation
phase. The evaluation includes both radiation risks from exposure to the contaminated
soils and risks to the workers and communities under current conditions and from
construction work, pollution, and traffic during implementation, and also takes into
account the time necessary to complete the action. A qualitative greener cleanups
analysis was completed for each alternative to evaluate energy requirements, emissions,
water resources, materials management, land management, and ecosystem protection.
Short-term effectiveness was rated from very poor to very good.
• Long-Term Effectiveness and Permanence (after Removal Action) - This criterion
evaluates the results of the removal action in terms of the risk remaining at the site after
response objectives have been met. The primary focus of this evaluation is on the extent
and effectiveness of the controls used to manage the risk posed by wastes remaining at
the site. Long-term effectiveness and permanence was rated from very poor to very good.
• Reduction of Toxicity, Mobility, or Volume through Treatment - This criterion
addresses the statutory preference for remedies that employ treatment as a principal
element by assessing the relative performances of treatment technologies for reducing
toxicity, mobility, or volume of the contaminated media. Specifically, the analysis should
examine the magnitude, significance, and irreversibility of each estimated reduction.
None of the retained alternatives include treatment, so this is not applicable.
Implementability Criterion
This criterion evaluates the technical and administrative feasibility of implementing an
alternative and the availability of required services and materials.
• Technical Feasibility - This criterion takes into account construction considerations,
demonstrated performance, adaptability to environmental conditions, and timing.
Technical feasibility was rated from very poor to very good.
• Availability of Required Services and Materials - This criterion evaluates whether
staff, equipment services, disposal locations, and any other required services and
materials are available in the necessary time frames for construction and maintenance
activities. This criterion was combined with technical feasibility for this EE/CA.
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• Administrative Feasibility - This criterion considers regulatory approval and scheduling
constraints. Administrative feasibility was rated from very poor to very good.
• Supporting Agency and Community Acceptance - This criterion will be addressed in
the final EE/CA after initial input from Babbitt Ranches; CO Bar, Inc.; BLM; and
supporting agencies. Community acceptance will be addressed in the action
memorandum after the public review and comment period on the final EE/CA.
Cost Criterion
The types of costs assessed include the following:
• Capital costs, including both direct and indirect costs
• Annual post-removal site control costs (termed maintenance within this EE/CA
for brevity)
• Net present value (NPV) of capital and maintenance costs
In accordance with USEPA (1993, 2000) guidance, engineering costs are estimates within
plus 50 to minus 30 percent of the actual project cost (based on year 2024 dollars).
Cost Estimating Process
Cost estimates were prepared in accordance with USEPA (2000) guidelines using engineer's
estimates, RSMeans 2024 cost-estimating software (Gordian 2024), and vendor quotes. Flagstaff,
Arizona, was used as the reference city in the RSMeans software to estimate costs for labor,
equipment, and supplies where applicable. Only the rolled-up construction and capital costs,
short-term maintenance costs for site restoration, long-term maintenance costs for repositories,
and NPVs are presented for each alternative. Cost details and assumptions are presented in
Appendix D. Cost estimating was conducted using a crew time and materials approach, which
uses the time required for a crew to accomplish an activity based on a realistic production rate
for site conditions. A unit cost approach uses RSMeans unit costs for construction based on cubic
yard, linear feet, and square foot quantities, which would not be realistic because of the specific
equipment needs and low production rates in remote, steep slope work areas.
Other construction-related costs were identified and included in the cost approach,
including mobilization and demobilization, contractor site overhead, travel and lodging,
third-party oversight, 5.6 percent Arizona state sales tax, and a 20 percent contingency.
Non-construction-related costs required before and during construction activities were also
identified and included in the cost approach, including design, planning, resource surveys,
confirmation sampling, and reporting.
Contingency costs for construction are based on the extra time, equipment, and personnel
required to safely work with radioactive materials; remote location of the site; differences in
labor pool costs between RSMeans estimating software reference cities and the project area; and
potential for changes in material and transportation costs. Changes in the cost elements are likely
as commodity prices change and new information and data are collected during the engineering
design and construction pre-bid and walk-through meetings.
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The need for short- and long-term maintenance costs were identified, including the short-term
need for site restoration for a period of 10 years to address any erosion and revegetation efforts
and the long-term need for cap maintenance for a period of 30 years for the onsite consolidation
alternatives. Project duration varies depending on the alternative (10 years versus 30 years) and
will be addressed in the cost discussion for each alternative.
Common capital and maintenance costs for each removal action alternative include access road
construction, access road reclamation, site restoration, and annual site restoration over 10 years.
The NPV of each removal action alternative provides the basis for the cost comparison. The
NPV represents the amount of money that, if invested in the initial year of the removal action at
a given interest rate, would provide the funds required to make future payments to cover all
maintenance costs associated with the removal action over its planned life.
To assess the required funds to be set aside for implementing maintenance activities in the future,
this EE/CA uses a 3.5 percent discount rate, which is the 30-year rolling average of the annual
discount rates for varying streams of payments as provided by the Office of Management and
Budget (2022). The 3.5 percent discount rate would require more money to be set aside for future
maintenance costs than the historic average of 7 percent referenced in USEPA (1993) guidance.
4.3.1 Alternative 1: No Action
Under Alternative 1, no actions would be performed at the site. The conditions currently found at
the site would remain unchanged. Alternative 1 would not achieve RAOs. This alternative would
not minimize potential exposure to or transport of COCs or COECs from the site or control
radiation and physical hazards at the site. This alternative would not reduce risk to human health
or the environment. Therefore, overall protection of human health and the environment would
not be achieved under Alternative 1. Since the overall protection of public health and the
environment is a threshold criterion that is not met, evaluation of effectiveness,
implementability, and cost are not applicable but presented here for comparison purposes.
4.3.1.1 Effectiveness
Effectiveness for Alternative 1 is based on the following discussion.
Overall Protection of Public Health and the Environment - Alternative 1 would not achieve
RAOs. This alternative would not minimize potential exposure to or transport of COCs or
COECs from the site or control radiation and physical hazards at the site. This alternative would
not reduce risk to human health or the environment. Therefore, protection of human health and
the environment would not be achieved under Alternative 1.
Compliance with ARARs - Under Alternative 1, no ARARs would exist with which to comply
per CERCLA § 121(d). ARARs are triggered by an action and are, therefore, not pertinent if no
cleanup occurs.
Short-Term Effectiveness (Rating: Average) - Alternative 1 has no action, so no short-term
risks would exist for the community or workers from construction activities. However, threats to
human and ecological receptors would persist in the short term. Because no construction
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activities would occur, no additional energy use, air pollution, water use, waste and materials
management, and ecosystem protection requirements would be triggered. No additional traffic
volume or potential accidents and fatalities associated with construction would occur.
Long-Term Effectiveness and Permanence (Rating: Very Poor) - No controls or long-term
measures would be implemented to control COCs or COECs at the site under Alternative 1.
Under this alternative, waste would continue to be accessible by humans and animals and subject
to potential migration to uncontaminated or less contaminated areas. Risks at the site are
currently unacceptable and would continue to be unacceptable under Alternative 1. Over time,
the site risks may increase, decrease, or remain the same as exposure to and migration of waste
would not be controlled.
Reduction of Toxicity, Mobility, or Volume through Treatment - Alternative 1 employs
no treatment, so no reductions in toxicity, mobility, or volume through active treatment
would occur.
4.3.1.2 Implementability
Alternative 1 is implementable based on the following discussion.
Technical Feasibility and Availability of Services and Materials (Rating: Very Good) -
Alternative 1 is readily implementable because no construction is involved. This alternative
would not impact the ability to conduct removal or remedial actions in the future. No services or
materials would be needed to implement Alternative 1.
Administrative Feasibility (Rating: Very Good) - Alternative 1 is administratively feasible as
taking no action is always feasible.
State Acceptance - Acceptance by Arizona, BLM, and supporting agencies is an additional
criterion that will be addressed in the final EE/CA report and action memorandum after
stakeholder comments have been received on the draft EE/CA.
Community Acceptance - Acceptance by any interested nearby communities is an additional
criterion that will be addressed in an action memorandum after public comments have been
received on the final EE/CA.
4.3.1.3 Costs
The cost for Alternative 1 is Very Good as it involves no removal activities and no legal or
administrative activities.
4.3.2 Alternative 2: Consolidate and Cap All Waste Onsite
Alternative 2 involves the excavation and consolidation of mine waste and contaminated soil into
capped, onsite waste repositories.
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4.3.2.1 Effectiveness
The effectiveness rating for Alternative 2 is Good based on the following discussion.
Overall Protection of Public Health and the Environment (Rating: Protective) -
Alternative 2 is protective because soil and mine waste containing radionuclide and metal COCs
and COECs will be excavated and consolidated and capped on site. The potential for direct
contact, ingestion, inhalation, and external irradiation of human and ecological receptors will be
eliminated where waste has been contained. Maintenance of the cap will prevent long-term risk
to human and ecological receptors. Alternative 2 will be protective of public health and the
environment.
Compliance with ARARs (Rating: In Compliance) - Federal and state ARARs identified in
Table 7 would be met for the site under Alternative 2.
Short-Term Effectiveness (Rating: Good) - The short-term impacts to the community,
workers, and environment under Alternative 2 are described below.
• Protection of the Community during Removal Action - No communities exist at or
near the site and excavation, waste consolidation, waste compaction, and capping of the
waste would occur on site and be away from the nearest potentially affected communities
of Cameron (10 miles) and Gray Mountain (8 miles). Trucks hauling equipment and
supplies would add incremental noise. However, the access roads and Indian Route 6728
do not pass through populated areas. U.S. Route 89 passes through the communities of
Cameron, Grey Mountain, and Flagstaff, but the anticipated truck volume and cycle time
would not be detected over normal traffic. Alternative 2 does not include offsite disposal,
so no waste would be hauled on public roads.
Alternative 2, therefore, has low potential impact to the community from construction
activity or traffic. Statistically, the incremental on-highway construction traffic
related to the project would result in 0.001 deaths and 0.033 accidents (based on
68,500 miles). Risks to the community remain low because waste hauling between the
mine sites and onsite waste consolidation areas is only on unpaved haul roads rather
than on the highway.
• Protection of Workers - Short-term risks of physical injury would exist for site workers
under Alternative 2 during construction primarily related to operating equipment during
access road construction, waste excavation, site restoration, and waste consolidation area
and cap construction. Worker commuter miles are estimated at 47,600 miles.
Short-term impacts to air quality in the surrounding environment may occur during
excavation and loading of waste for transfer to the onsite consolidation area. However,
exposures to workers would be within acceptable safe limits because of dust suppression
and air monitoring.
Worker exposure to radiation and contaminants would be maintained within allowable
levels with health and safety measures described in Section 4.2.1.
• Environmental Impacts - Short-term environmental impacts that could occur from the
excavation and consolidation and capping of waste on site are estimated to be low. These
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environmental impacts may include sedimentation of local drainages, residual track-in
and track-out effects of soil and mud, noise, disturbed vegetation, and dust generation.
Disturbance of the potential riparian area in the eastern portion of AUM 457 could
adversely impact the ecosystem, but the size of the riparian area is small and, therefore,
the impact of its potential loss to the surrounding ecosystem is also small. Fuel use and
resultant emissions and climate impacts would be relatively low because no offsite
hauling would be required. The overall threat to the environment is low because the
waste rock could be consolidated and capped on site within one to two field seasons. In
addition, revegetation would expedite the return of native flora once cleanup actions are
complete. However, revegetation may not occur immediately.
The short-term threat posed by ecological exposure to uranium and radionuclides would
be minimal and result in reduced long-term impacts through waste consolidation and
isolation. Green remediation considerations are discussed below.
• Greener Cleanups Analysis - This analysis determined the mass of different emissions,
including greenhouse gases, nitrogen oxides, sulfur oxides, particulate matter, and listed
air pollutants, generated by different construction activities. For all categories,
Alternative 2 was assessed as having a small environmental footprint.
o Energy and Emissions - Alternative 2 has a small energy and emissions footprint
because all waste hauling would be on site for consolidation.
o Water Resources - Alternative 2 requires use of imported water or installation of a
water supply well for waste compaction and dust control during excavation, loading,
backfilling, and grading on local access roads. Overall, because of the small
construction area and minimal waste hauling, Alternative 2 would have a small water
resource footprint. The amount of water required during the construction phase of the
project is estimated at 643,000 gallons.
o Materials Management - Alternative 2 requires import of rock for onsite drainage
stabilization and sediment detention basin construction, as well as import of clayey
soil and gravel for cap construction. Borrow soil for site restoration and most of the
cap construction will be from nearby the mine sites. No waste would leave the site.
Alternative 2 would have a small material management footprint because of the short
transport distance, small onsite waste consolidation areas, and limited quantity of
imported materials.
o Land Management and Ecosystems Protection - Alternative 2 has a small footprint
because future land use would be only partially limited by the capped waste area and
the capped waste area is only 5 acres out of 26 acres in AUM 457 and AUM 458 and
the APE comprises 464 acres. Minimizing the capped waste aerial extent could be
considered to reduce land use impacts. Land use at the site would not likely be limited
in the long term after restoration. Use of geomorphic grading for the waste
consolidation areas and cap and site restoration would minimize visual impacts.
Disturbance of the potential riparian area in the eastern portion of AUM 457 could
adversely impact the ecosystem, but the size, health, and contribution of the potential
riparian area to the ecosystem is low. Waste removal and drainage channel restoration
will provide a positive ecosystem impact.
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• Time Until Removal Action Objectives Are Achieved - Excavation, consolidation, and
containment of waste on site would meet preliminary RAOs in the short term. The
construction time required to achieve preliminary RAOs for Alternative 2 would be
several months at the site with intermittent maintenance afterwards. Construction may be
extended depending on schedule-limiting factors such as monsoon rains and snowfall.
Long-Term Effectiveness and Permanence (after Removal Action) (Rating: Average) -
Alternative 2 would safely and reliably contain all waste on site under an ET cap, and RAOs
would be achieved at all contaminated areas at the site. Although the onsite consolidated waste
with ET cap is expected to be fully protective in the short and long term, the caps will require
long-term inspection and maintenance.
Over the long term, accidents and fatalities could result from Sis and long-term maintenance of
the onsite capped waste but would be consistent with typical inspection and maintenance crews
anywhere. Although the cost estimate is limited to 30 years of activities, long-term maintenance
for Alternative 2 would be in perpetuity. However, the intensity of the maintenance regime is
expected to have low long-term energy and greenhouse gas footprints from fuel consumption and
emissions. Statistically, the incremental on-highway construction traffic related to long-term
maintenance of the project would result in 0.001 deaths and 0.033 accidents (based on 68,500
miles).
LUCs would be necessary to limit access to and disturbance of capped waste during restoration.
A long-term surveillance plan would be implemented after construction to ensure compliance
with LUCs and cover integrity.
Alternative 2 would not require replacement of components because their lifespan is indefinite
under an inspection and maintenance regime as described above. Force majeure events, such as
earthquakes, climate change, or large floods, could impact the response action or waste left in
place, but design criteria for the removal action would take these into account to the extent
practicable. The capped wastes location near the LCR decreases the overall resilience to force
majeure events and reduces design flexibility, which contributes to a long-term effectiveness
rating of average.
Finally, the uncertainties of capping waste onsite under Alternative 2 are considered low and the
effectiveness good because of the stable nature of the waste, design of waste consolidation areas
and ET caps, use of conventional materials and methods, and long track record of capped waste
consolidation areas as an accepted response action. Capping waste is standard practice for
landfills and mine sites.
Reduction of Toxicity, Mobility, or Volume through Treatment (Rating: Not Applicable) -
Alternative 2 employs no treatment, so no reductions in toxicity, mobility, or volume through
active treatment would occur.
4.3.2.2 Implementability
The implementability rating for Alternative 2 is Good based on the following discussion.
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Technical Feasibility and Availability of Services and Materials (Rating: Good) -
Alternative 2 consists of earthwork and material consolidation and capping. The equipment
required for the work is readily available and consists of conventional and specialty excavators,
scrapers, loaders, crushing and screening plants for borrow materials, and articulated haul trucks.
Construction and environmental monitoring equipment and services are all readily available.
Although somewhat distant, labor and equipment would be available in the regional Cameron
and Flagstaff markets. A sufficient volume of water for onsite dust suppression and waste
and cap compaction may be obtained by importing from the Flagstaff area. Drought
considerations may require alternate methods of dust control such as binders, gravel cover,
or pavement.
Sources of local borrow material can easily be developed to meet the needs for fill, topsoil,
clayey soil, and gravel for capping options under all potential cap designs and for site restoration
after excavation. Riprap would be imported from Flagstaff, Arizona, to meet engineering
specifications for armoring drainage channels. Alternate materials such as local volcanic
materials would be evaluated to potentially reduce delivered riprap pricing.
The expertise and equipment needed for long-term monitoring and maintenance of the onsite
cap, erosional features and controls, and revegetation are and will be available. Alternative 2
would not require replacement of components because their lifespan is indefinite (at least
200 years per design requirements) under an inspection and maintenance regime as
described above.
Administrative Feasibility (Rating: Good) - Alternative 2 is administratively implementable
and would require coordination between USEPA; Arizona; Babbitt Ranches; CO Bar, Inc.; and
BLM. While such coordination and agreements take time, no difficulties are expected.
Federal and state permits for onsite actions under CERCLA and the proposed onsite waste
consolidation areas and cap are not required because this is an onsite location in a
mining-disturbed area. Environmental reviews may be required from Arizona, which is a
standard practice and would be included in removal action planning. Negotiations are not
expected to be difficult with Babbitt Ranches or other landowners concerning potential offsite
soil borrow sources.
The entity responsible for the long-term surveillance plan would maintain various plans and
conduct periodic inspections and reviews, including:
• A stormwater pollution prevention plan implemented by Babbitt Ranches (to verify that
site restoration is protective of surface water quality)
• A long-term surveillance plan implemented after waste consolidation area cap
construction and overseen by Babbitt Ranches; CO Bar, Inc.; BLM; and USEPA
LUCs for waste placed in the waste consolidation areas would require coordination with Babbitt
Ranches; CO Bar, Inc.; and BLM.
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State and Community Acceptance - Acceptance by Babbitt Ranches; CO Bar, Inc.; BLM;
the State of Arizona; the community; and other stakeholders will be addressed in the final
EE/CA report and action memorandum after stakeholder comments have been received on the
draft EE/CA.
4.3.2.3 Costs
The cost rating for Alternative 2 is Good. Overall, Alternative 2 has the lowest costs of all the
alternatives (besides Alternative 1) primarily because of lower transportation and disposal costs
than offsite disposal (Alternative 4).
The total NPV for consolidating and capping on site of 14,711 cubic yards of waste is
$3.6 million. This includes capital costs of $3.5 million, NPV 10-year SI and maintenance of
$78,000, and NPV 30-year onsite cap maintenance of $95,000. Site operation and maintenance
costs reflect annual activities for the first 10 years and then one maintenance operation every 10
years for 30 years thereafter. Activities include:
• SI
• Travel and lodging for inspection and maintenance crews
• Mobilization and demobilization of crew and equipment
• Rental and labor for excavators, front-end loaders, and articulated dump trucks
• Hydroseed and mulch materials
• Range fencing repair
• Riprap material and hauling
A breakdown of the major cost categories associated with implementing Alternative 2 is
presented in Exhibit 11. Detailed cost estimates are provided in Appendix D in Table D-7 with
underlying assumptions shown in detail in Table D-5.
Exhibit 11. Alternative 2 Cost Breakdown
Component
Section 9 Lease Mines Totals
Excavated Surface Area (SF)
283,000
Excavated Volume (LCY)
15,000
Capital Costs
Access Road Construction
$
74,000
Waste Excavation and Hauling
$
258,000
Site and Road Restoration
$
315,000
Onsite Consolidation and Cap Construction
$
1,467,000
Subtotal Construction
$
2,113,000
Non-Construction
$
1,338,000
Total Capital Costs
$
3,451,000
NPV Costs (3.5% discount rate)1
Capital Costs
$
3,451,000
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It
Component
Section 9 Lease Mines Totals
10-Year Site Inspection
$
28,000
10-Year Maintenance
$
50,000
30-Year Onsite Cap
$
95,000
Total NPV Costs
$
3,623,000
Notes:
1 Present worth analysis produces a single figure representing the amount of money that, if invested in the
base year and disbursed as needed, would be sufficient to cover all costs associated with the alternative.
For projects of less than 1 year (generally, projects that do not require O&M), the present worth is simply the
one-time cost of performing the action.
LCY Loose cubic yard
NPV Net present value
O&M Operation and maintenance
SF Square foot
4.3.3 Alternative 3: Disposal of All Mine Waste at a Western AUM Regional
Repository
Alternative 3 involves the excavation and consolidation of mine waste and contaminated soil into
a regional waste repository.
4.3.3.1 Effectiveness
The effectiveness rating for Alternative 3 is Good based on the following discussion.
Overall Protection of Public Health and the Environment (Rating: Protective) -
Alternative 3 is protective because soil and mine waste containing radionuclide and metal COCs
and COECs will be excavated, transported, and consolidated and capped at the regional
repository. The potential for direct contact, ingestion, inhalation, and external irradiation of
human and ecological receptors will be eliminated where waste has been contained. Maintenance
of the cap will prevent long-term risk to human and ecological receptors. Alternative 3 will be
protective of public health and the environment.
Compliance with ARARs (Rating: In Compliance) - Federal and state ARARs identified in
Table 7 would be met under Alternative 3.
Short-Term Effectiveness (Rating: Good) - The short-term impacts to the community,
workers, and environment under Alternative 3 are described below.
• Protection of the Community during Removal Action - No communities exist at or
near the site and excavation, waste consolidation, waste compaction, and capping of the
waste would occur at the regional repository and away from the nearest potentially
affected communities of Cameron (10 miles) and Gray Mountain (8 miles). Trucks
hauling equipment and supplies would add incremental noise. However, the access roads
and Indian Route 6728 do not pass through populated areas. U.S. Route 89 passes
through the communities of Cameron, Grey Mountain, and Flagstaff, but the anticipated
truck volume and cycle time would not be detected over normal traffic. The regional
repository is located adjacent to the site; therefore, no waste would be hauled on public
roads.
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Alternative 3, therefore, has low potential impact to the community from construction
activity or traffic. Statistically, the incremental on-highway construction traffic
related to the project would result in 0.001 deaths and 0.033 accidents (based on
68,500 miles). Risks to the community remain low because waste hauling between the
mine sites and regional repository is only on unpaved haul roads rather than on the
highway.
• Protection of Workers - Short-term risks of physical injury would exist for site workers
under Alternative 3 during construction primarily related to operating equipment during
access road construction, waste excavation, site restoration, and waste consolidation area
and cap construction. Worker commuter miles are estimated at 47,600 miles.
Short-term impacts to air quality in the surrounding environment may occur during
excavation and loading of waste for transfer to the onsite consolidation area. However,
exposures to workers would be within acceptable safe limits because of dust suppression
and air monitoring.
Worker exposure to radiation and contaminants would be maintained within allowable
levels with health and safety measures described in Section 4.2.1.
• Environmental Impacts - Short-term environmental impacts that could occur from the
excavation and consolidation and capping of waste on site are estimated to be low. These
environmental impacts may include sedimentation of local drainages, residual track-in
and track-out effects of soil and mud, noise, disturbed vegetation, and dust generation.
Disturbance of the potential riparian area in the eastern portion of AUM 457 could
adversely impact the ecosystem, but the size of the riparian area is small and, therefore,
the impact of its potential loss to the surrounding ecosystem is also small. Fuel use and
resultant emissions and climate impacts would be relatively low because no offsite
hauling would be required. The overall threat to the environment is low because the
waste rock could be consolidated and capped on site within one to two field seasons. In
addition, revegetation would expedite the return of native flora once cleanup actions are
complete. However, revegetation may not occur immediately.
The short-term threat posed by ecological exposure to uranium and radionuclides would
be minimal and result in reduced long-term impacts through waste consolidation and
isolation. Green remediation considerations are discussed below.
• Greener Cleanups Analysis - This analysis determined the mass of different emissions,
including greenhouse gases, nitrogen oxides, sulfur oxides, particulate matter, and listed
air pollutants, generated by different construction activities. For all categories,
Alternative 3 was assessed as having a small environmental footprint.
o Energy and Emissions - Alternative 3 has a medium energy and emissions footprint
because all waste hauling would occur locally for consolidation.
o Water Resources - Alternative 3 requires use of imported water or installation of a
water supply well for waste compaction and dust control during excavation, loading,
backfilling, and grading on local access roads. Overall, because of the small
construction area and minimal waste hauling, Alternative 3 would have a small water
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resource footprint. The amount of water required during the construction phase of the
project is estimated at 643,000 gallons.
o Materials Management - Alternative 3 requires import of rock for onsite drainage
stabilization and sediment detention basin construction, as well as import of clayey
soil and gravel for cap construction. Borrow soil for site restoration and the cap
construction will be from a nearby repository location. No waste would leave the site.
Alternative 3 would have a medium material management footprint because of the
longer transport distance, medium regional repository waste consolidation area, and
limited quantity of imported materials.
o Land Management and Ecosystems Protection - Alternative 3 has a small footprint
because future land use would be only partially limited by the areas where the
removal of waste will occur. Land use at the site would not likely be limited in the
long term after restoration. Use of geomorphic grading for the waste removal areas
and site restoration would minimize visual impacts. Disturbance of the potential
riparian area in the eastern portion of AUM 457 could adversely impact the
ecosystem, but the size, health, and contribution of the potential riparian area to the
ecosystem is low. Waste removal and drainage channel restoration will provide a
positive ecosystem impact.
• Time Until Removal Action Objectives Are Achieved - Waste excavation,
transportation, and consolidation at the regional repository would meet preliminary
RAOs in the short term. The construction time required to achieve preliminary RAOs for
Alternative 3 would be several months at the site with intermittent maintenance
afterwards. Construction may be extended depending on schedule-limiting factors such as
monsoon rains and snowfall.
Long-Term Effectiveness and Permanence (after Removal Action) (Rating: Very Good) -
Alternative 3 would safely and reliably contain all waste at the regional repository under an ET
cap, and RAOs would be achieved at all contaminated areas at the site. Although the regional
repository with ET cap is expected to be fully protective in the short and long term, the cap
would require long-term inspection and maintenance.
Over the long term, accidents and fatalities could result from Sis and long-term maintenance of
the capped waste at the regional repository but would be consistent with typical inspection and
maintenance crews anywhere. Although the cost estimate is limited to 30 years of activities,
long-term maintenance for Alternative 3 would be in perpetuity. However, the intensity of the
maintenance regime is expected to have low long-term energy and greenhouse gas footprints
from fuel consumption and emissions. Statistically, the incremental on-highway construction
traffic related to long-term maintenance of the project would result in 0.001 deaths and
0.033 accidents (based on 68,500 miles).
LUCs would be necessary to limit access to and disturbance of waste removal footprints during
restoration. A long-term surveillance plan would be implemented after construction to ensure
compliance with LUCs and cover integrity.
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Alternative 3 would not require replacement of components because their lifespan is indefinite
under an inspection and maintenance regime as described above. Force majeure events, such as
earthquakes, climate change, or large floods, could impact the response action, but design criteria
for the removal action would take these into account to the extent practicable. Alternative 3
provides protection from force majeure events by capping the waste 1.0 mile away from the LCR
(compared with 0.10 mile away for AUM 457 and 0.5 mile away for AUM 458 under
Alternative 2).
The Alternative 3 waste consolidation location has abundant space for the storage volume of
waste with abundant nearby borrow, which would increase long-term effectiveness and
design flexibility.
Finally, the uncertainties of capping waste at the regional repository under Alternative 3 are
considered low and the effectiveness good because of the stable nature of the waste, design of
waste consolidation areas and ET caps, use of conventional materials and methods, and long
track record of capped waste consolidation areas as an accepted response action. Capping waste
is standard practice for landfills and mine sites.
Reduction of Toxicity, Mobility, or Volume through Treatment (Rating: Not Applicable) -
Alternative 3 employs no treatment, so no reductions in toxicity, mobility, or volume through
active treatment would occur.
4.3.3.2 Implementability
The implementability rating for Alternative 3 is Good based on the following discussion.
Technical Feasibility and Availability of Services and Materials (Rating: Good) -
Alternative 3 consists of earthwork and material consolidation and capping. The equipment
required for the work is readily available and consists of conventional and specialty excavators,
scrapers, loaders, crushing and screening plants for borrow materials, and articulated haul trucks.
Construction and environmental monitoring equipment and services are all readily available.
Although somewhat distant, labor and equipment would be available in the regional Cameron
and Flagstaff markets. A sufficient volume of water for onsite dust suppression and waste
and cap compaction may be obtained by importing from the Flagstaff area. Drought
considerations may require alternate methods of dust control such as binders, gravel cover,
or pavement.
Sources of local borrow material can easily be developed to meet the needs for fill, topsoil,
clayey soil, and gravel for capping options under all potential cap designs and for site restoration
after excavation. Riprap would be imported from Flagstaff to meet engineering specifications for
armoring drainage channels. Alternate materials such as local volcanic materials would be
evaluated to potentially reduce delivered riprap pricing.
The expertise and equipment needed for long-term monitoring and maintenance of the regional
repository, erosional features and controls, and revegetation are and will be available.
Alternative 3 would not require replacement of components because their lifespan is indefinite
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(at least 200 years per design requirements) under an inspection and maintenance regime as
described above.
Administrative Feasibility (Rating: Good) - Alternative 3 is administratively implementable
and would require coordination between USEPA; State of Arizona; Babbitt Ranches; CO Bar,
Inc.; and BLM. While such coordination and agreements take time, no difficulties are expected.
Federal and state permits for onsite actions under CERCLA and the proposed onsite waste
consolidation area and cap are not required because this is an onsite location in a
mining-disturbed area. Environmental reviews may be required from Arizona, which is a
standard practice and would be included in removal action planning. Negotiations are not
expected to be difficult with Babbitt Ranches or other landowners concerning potential offsite
soil borrow sources.
The entity responsible for the long-term surveillance plan would maintain various plans and
conduct periodic inspections and reviews, including:
• A stormwater pollution prevention plan implemented by Babbitt Ranches (to verify that
site restoration is protective of surface water quality)
• A long-term surveillance plan implemented after waste consolidation area cap
construction and overseen by Babbitt Ranches; CO Bar, Inc.; BLM; and USEPA
LUCs for waste placed in the waste consolidation areas would require coordination with Babbitt
Ranches; CO Bar, Inc.; and BLM.
State Acceptance and Community Acceptance - Acceptance by Babbitt Ranches; CO Bar,
Inc.; BLM; the State of Arizona; the community; and other stakeholders will be addressed in the
final EE/CA report and action memorandum after stakeholder comments have been received on
the draft EE/CA.
4.3.3.3 Costs
The cost rating for Alternative 3 is Good. Overall, Alternative 3 has the third lowest costs of all
the alternatives (besides Alternative 1) primarily because of lower transportation and disposal
costs than offsite disposal (Alternative 4).
The total NPV for consolidating and capping on site of 14,711 cubic yards of waste is
$4.0 million. This includes capital costs of $3.8 million, NPV 10-year SI and maintenance of
$101,000, and NPV 30-year onsite cap maintenance of $95,000. Site operation and maintenance
costs reflect annual activities for the first 10 years and then one maintenance operation every
10 years for 30 years thereafter. Activities include:
• SI
• Travel and lodging for inspection and maintenance crews
• Mobilization and demobilization of crew and equipment
• Rental and labor for excavators, front-end loaders, and articulated dump trucks
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It
• Hydroseed and mulch materials
• Range fencing repair
• Riprap material and hauling
A breakdown of the major cost categories associated with implementing Alternative 3 is
presented in Exhibit 12. Detailed cost estimates are provided in Appendix D in Table D-13 with
underlying assumptions shown in detail in Table D-l 1.
4.3.4 Alternative 4: Disposal of All Mine Waste in Offsite Resource Conservation and
Recovery Act-Licensed Facility
Alternative 4 involves the excavation of mine waste and contaminated soil and transport and
disposal of waste at an LLRW-licensed or RCRA C-licensed facility. Clive Operations currently
has the appropriate licensing, bonding, and CERCLA Off-Site Rule approvals.
4.3.4.1 Effectiveness
The effectiveness rating for Alternative 4 is Average based on the following discussion.
Overall Protection of Public Health and the Environment (Rating: Protective) - Under
Alternative 4, overall protectiveness is achieved because soil and mine waste that contain
radionuclide and metal COCs and COECs would be disposed of at an offsite hazardous waste
disposal facility. Therefore, potential direct contact, ingestion, inhalation, and external irradiation
by human and ecological receptors would be eliminated where waste has been removed.
Alternative 4 would be protective of public health and the environment.
Compliance with ARARs (Rating: In Compliance) - Federal and state ARARs identified in
Table 7 would be met under Alternative 4.
Exhibit 12. Alternative 3 Cost Breakdown
Component
Section 9 Lease Mines Totals
Excavated Surface Area (SF)
268,000
Excavated Volume (LCY)
15,000
Capital Costs
Access Road Construction
$
109,000
Waste Excavation and Hauling
$
347,000
Site and Road Restoration
$
415,000
Onsite Consolidation and Cap Construction
$
1,466,000
Subtotal Construction
$
2,337,000
Non-Construction
$
1,484,000
Total Capital Costs
$
3,821,000
NPV Costs (3.5% discount rate)1
Capital Costs
$
3,821,000
10-Year Site Inspection
$
37,000
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It
Component
Section 9 Lease Mines Totals
10-Year Maintenance
$ 65,000
30-Year Onsite Cap
$ 95,000
Total NPV Costs
$ 4,018,000
Notes:
1 Present worth analysis produces a single figure representing the amount of money that, if invested in the
base year and disbursed as needed, would be sufficient to cover all costs associated with the alternative.
For projects less than 1 year (generally, projects that do not require O&M), the present worth is simply the
one-time cost of performing the action.
LCY Loose cubic yard
NPV Net present value
O&M Operation and maintenance
SF Square foot
Short-Term Effectiveness (Rating: Poor) - Alternative 4 involves excavation of all waste for
offsite disposal at a RCRA-licensed facility. The short-term impacts to the community, workers,
and environment under Alternative 4 are described below.
• Protection of the Community - The increased truck traffic required to haul waste offsite
to the Clive Operations LLRW disposal facility would have a minimal impact on traffic
safety. Trucks transporting waste material from the site on U.S. Route 89 would be
indistinguishable from regular truck traffic. No communities are between the site and
U.S. Route 89. The total number of round trips for trucks transporting waste to Clive,
Utah, is about 2,660.
Alternative 4 also has a low potential impact to the community from construction activity
and traffic. Statistically, the incremental on-highway construction traffic related to the
project would result in 0.032 deaths and 1.054 accidents (based on 2,170,000 million
miles), stemming from the 515-mile on-highway travel distance between the site and the
Clive Operations LLRW disposal facility. Most of the miles traveled will occur outside of
the immediate community; therefore, impacts to the community are considered low.
Off-road hauling between U.S. Route 89 and the site are not included in the traffic safety
analysis as the public would not be impacted.
• Protection of Workers - Short-term risks of physical injury would exist for site workers
under Alternative 4 during construction primarily related to operating equipment during
access road construction, waste excavation, site restoration, loading waste into
on-highway haul trucks, and long-distance transport of waste to the Clive Operations
LLRW disposal facility. Short-term impacts to air quality in the surrounding environment
may occur during excavation and loading of waste for transfer to the onsite consolidation
area. However, exposures to workers would be within acceptable safe limits because of
dust suppression and air monitoring. Because at least half of the statistical risk of injury
or death from on-highway truck traffic would be experienced by the truck drivers, the
short-term risk to workers from on-highway hauling would be medium when compared to
Alternatives 2 and 3. However, when compared to the routine risks of truck drivers,
workers experience no incremental additional risk. Worker commuter miles are estimated
at 60,000 miles.
• Environmental Impacts - Short-term environmental impacts that could occur from the
excavation, hauling, and offsite disposal of waste are estimated to be medium. Under
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Alternative 4, the impacts would be similar to Alternatives 2 and 3 (consolidate and
cap on site) but with significant fuel use, noise, and emissions from haul truck traffic
off site. Fuel consumption and greenhouse gas emissions would be large. Disturbance
of the potential riparian area in the eastern portion of AUM 457 could adversely impact
the ecosystem, but the size, health, and contribution of the potential riparian area to the
ecosystem is low. Similar to Alternatives 2 and 3, the threat to the local environment
is moderate because of the longer project duration (11 months) associated with
offsite hauling.
• Greener Cleanups Analysis - This analysis determined the mass of different emissions,
including greenhouse gases, nitrogen oxides, sulfur oxides, particulate matter, and listed
air pollutants, generated by different construction activities. For all categories,
Alternative 4 was assessed as having a very large environmental footprint.
o Energy and Emissions - Alternative 4 has a very large short-term energy and
emissions footprint because all waste will be hauled 515 miles to the LLRW facility
in Clive, Utah, for disposal.
o Water Resources - Alternative 4 does not involve consolidation area construction and
would not require water for waste compaction. Alternative 4 requires use of imported
water or installation of a water supply well for dust control during excavation,
loading, backfilling, grading, and hauling on haul roads. Overall, because of the
volume of waste, Alternative 4 would have a medium water resource footprint. The
estimated amount of water for the project construction phase is estimated at
1,296,000 gallons.
o Materials Management - Alternative 4 requires hauling waste from the site and
import of rock for onsite drainage stabilization. Borrow soil for site restoration will be
from nearby the mine sites. Alternative 4 would have a large material management
footprint from both onsite waste removal and offsite waste hauling.
o Land Management and Ecosystems Protection - Alternative 4 has a small footprint
because of negative ecosystem impacts. Excavation of contaminated material,
including disturbance of the potential small riparian area in the eastern portion of
AUM 457, is not likely to adversely impact the ecosystem. Use of geomorphic
grading for site restoration would minimize visual impacts. Land use would not be
limited in the long term after has been restored under CERCLA LUCs. However,
elevated concentrations of NORM will remain on site. Waste removal and drainage
channel restoration will provide a positive ecosystem impact.
• Time Until Removal Action Objectives Are Achieved - Excavation, offsite hauling,
and disposal of waste at the Clive Operations LLRW disposal facility would meet
preliminary RAOs in the short term. The construction time required to achieve
preliminary RAOs for Alternative 4 would be two to three field seasons because of the
3-day truck cycle time between the site and the waste disposal facility. Construction may
be extended depending on schedule-limiting factors such as truck availability, monsoon
rains, and snowfall.
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Long-Term Effectiveness and Permanence (after Removal Action) (Rating: Very Good) -
Alternative 4 would safely and reliably contain all waste off site in a RCRA-licensed disposal
facility, and RAOs would likely be achieved at all areas at the site. Although the RCRA-licensed
disposal facility is expected to be fully protective in the short and long term, the facility will
require long-term inspection and maintenance by the operators.
Minimal maintenance of restored areas is required for Alternative 4. Therefore, Alternative 4
has a substantial advantage over onsite actions, which would require cap inspections
and maintenance.
LUCs would be necessary to limit access to and disturbance of during restoration. For the areas
at where all waste will be removed, short-term monitoring and repair of revegetation and erosion
controls would also be required for up to 10 years.
Because no waste would remain on site, force majeure events, such as earthquakes, climate
change, or large floods, that could impact waste left in place do not need to be considered.
Finally, the uncertainties of disposing of waste off site under Alternative 4 are considered low
because of the use of conventional materials and methods and the long track record of hazardous
waste disposal facilities as an accepted response action.
Reduction of Toxicity, Mobility, or Volume through Treatment (Rating: Not Applicable) -
Alternative 4 employs no treatment, so no reductions in toxicity, mobility, or volume through
active treatment would occur.
4.3.4.2 Implementability
The implementability rating for Alternative 4 is Good based on the following discussion.
Technical Feasibility and Availability of Services and Materials (Rating: Good) - Similar to
Alternatives 2 and 3, this alternative consists of earthwork and material consolidation. Offsite
and on-highway hauling are also required. Construction equipment requirements are the same.
Offsite disposal is less complicated than consolidation and capping onsite.
Equipment, services, and labor market availability are the same as Alternatives 2 and 3. Sources
and availability of borrow materials, including riprap, are the same as Alternatives 2 and 3.
Alternate materials such as local volcanic materials should be evaluated to potentially reduce
delivered riprap pricing. The local trucking market is difficult to predict. This EE/CA estimates a
fleet of 20 trucks servicing the site with a 1,030-mile round-trip distance. Each truck can
complete the round trip in about 3 days.
Long-term monitoring and maintenance would not be required; however, short-term maintenance
of erosional controls and revegetation efforts for removal area restorations would be required.
Administrative Feasibility (Rating: Good) - Similar to Alternatives 2 and 3, this alternative is
administratively implementable and would require coordination between USEPA; Babbitt
Ranches; CO Bar, Inc.; and BLM. While such coordination and agreements take time,
no difficulties are expected.
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As previously discussed, federal and state permits for onsite actions under CERCLA are not
required. Environmental reviews may be required from Arizona, which would be included in
removal action planning. Since waste would be disposed of offsite, Arizona and Utah
Department of Transportation requirements and permits for hauling radioactive waste would be
applicable but easily attainable and complied with. The Clive Operations LLRW disposal facility
is currently in compliance with its operating permit and the CERCLA Off-Site Rule.
Long-term surveillance would not be required as no waste would remain on site. No LUCs
would be required. Babbitt Ranches and CO Bar, Inc. would oversee stormwater pollution
prevention plan periodic inspections during site restoration.
State Acceptance - Acceptance by Arizona and supporting agencies is an additional criterion
that will be addressed in the final EE/CA report and action memorandum after stakeholder
comments have been received on the draft EE/CA.
State and Community Acceptance -Acceptance by Babbitt Ranches; CO Bar, Inc.; BLM;
the State of Arizona; the community; and other stakeholders will be addressed in the final
EE/CA report and action memorandum after stakeholder comments have been received on the
draft EE/CA.
4.3.4.3 Costs
The cost rating for Alternative 4 is Very Poor. Overall, Alternative 4 has the highest costs of all
the alternatives because of the high cost of hauling waste long distance off site to the Clive
Operations LLRW disposal facility in Clive, Utah. Transportation and tipping costs for the Clive
Operations LLRW disposal facility are based on costs of $424 per ton and $636 per band cubic
yard. Cost use conversion factors of 1.5 tons per bank cubic yard and 1.25 loose cubic yards per
bank cubic yard were used in the costs determination.
The total NPV for the transportation and offsite disposal of approximately 18,500 cubic yards of
waste at the Clive Operations LLRW disposal facility in Clive, Utah, is $12.8 million. This
includes a capital cost of $12.7 million and NPV 10-year Sis and maintenance of $78,000. A
breakdown of the major cost categories associated with implementing Alternative 4 is presented
in Exhibit 13. Detailed cost estimates are provided in Appendix D in Table D-19 with detailed
underlying assumptions shown in Table D-17.
Exhibit 13. Alternative 4 Cost Breakdown
Cost Component
Section 9 Lease Mines Totals
Excavated Surface Area (SF)
283,000
Excavated Volume (LCY)
15,000
Capital Costs
Access Road Construction
$ 74,000
Waste Excavation and Loading
$ 1,049,000
Site and Road Restoration
$ 249,000
Waste Hauling to LLRW Facility
$ 2,975,000
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Cost Component
Section 9 Lease Mines Totals
Disposal at LLRW Facility
$
6,431,000
Subtotal Construction
$
10,779,000
Non-Construction
$
1,898,000
Total Capital Costs
$
12,676,000
NPV Costs (3.5% discount rate)1
Capital Costs
$
12,676,000
10-Year Site Inspection
$
28,000
10-Year Maintenance
$
50,000
Total NPV Costs
$
12,754,000
Notes:
1 Present worth analysis produces a single figure representing the amount of money that, if invested in the
base year and disbursed as needed, would be sufficient to cover all costs associated with the alternative.
For projects less than 1 year (generally, projects that do not require O&M), the present worth is simply the
one-time cost of performing the action.
LCY Loose cubic yard
LLRW Low-level radioactive waste
NPV Net present value
O&M Operation and maintenance
SF Square foot
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5.0 COMPARATIVE ANALYSIS OF ALTERNATIVE
J
This section presents the approach for the comparative analysis of alternatives and a summary of
the analysis. The comparative analysis includes evaluation of the relative effectiveness,
implementability, and cost between alternatives.
5.1 COMPARATIVE ANALYSIS APPROACH
The final step of the EE/CA is to conduct a comparative analysis of the removal action
alternatives. This analysis discusses each alternative's strengths and weaknesses relative to the
other alternatives with respect to the three criteria and in achieving RAOs. An explanation of the
evaluation and ranking criteria is presented in Section 4.3.
5.2 SUMMARY OF ANALYSIS
All alternatives except Alternative 1 meet the threshold criterion of protectiveness of public
health and the environment. Exhibit 14 summarizes the comparative rating of alternatives.
5.2.1 Effectiveness
Effectiveness comprises two threshold criteria—protectiveness and compliance with ARARs—
and includes short-term effectiveness (during removal action) and long-term effectiveness
and permanence (after removal action). Overall effectiveness ratings are shown in Exhibit 14.
Individual criteria and ratings contributing to the overall ratings are discussed in the following
subsections.
5.2.1.1 Overall Protectiveness of Human Health and the Environment
All alternatives except Alternative 1 are protective of public health and the environment.
5.2.1.2 Compliance with ARARs
All action alternatives would be performed in compliance with the federal and state ARARs
identified in Table 7.
5.2.1.3 Short-Term Effectiveness (during Removal Action)
Short-term effectiveness comprises four criteria: protection of the community, protection of
workers, environmental impacts, and time to meet RAOs. Overall short-term effectiveness is
rated higher for Alternative 2 and 3, than for Alternative 4.
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lb
Exhibit 14. Analysis of Alternatives for the Section 9 Lease Mines
Alternative
Threshold Criteria
Effectiveness
Implementability
Cost Rating3
Protective of
Human
Health and
the
Environment
Compliance
with ARARs
Short Term
(during
Action)
Long Term
(after
Action)
Technical
Feasibility/
Availability
of Services
and
Materials
Administrative
Feasibility
2024 Million
Dollars
1
No Action
Not
Protective
Not Compliant
Not
Compliant
Not Compliant
Not
Compliant
Not Compliant
Not
Compliant
2
Consolidate and Cap
All Waste Onsite
Protective
In Compliance
Good
Average
Good
Good
Good
$3.6 M
3
Disposal of All Mine
Waste at a Western
AUM Regional
Repository
Protective
In Compliance
Good
Very Good
Good
Good
Good
$4 M
4
Disposal of All Mine
Waste in Offsite
RCRA-Licensed
Facility
Protective
In Compliance
Poor
Very Good
Good
Good
Very Poor
$12.8 M
Notes:
Bold indicates the highest rating in the category.
a Estimated costs are net present value.
ARAR Applicable or relevant and appropriate requirement
RCRA Resource Conservation and Recovery Act
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Protection of the Community
Alternatives 2 and 3 create the least traffic and dust impacts to the community as truck traffic
would only be increased on the main access road to transport equipment and construction
materials for onsite area construction. Alternatives 2 and 3 would require about 630 truck trips.
No excavated waste would be hauled through the community. Dust impacts would be limited to
site construction and the dirt haul road to the onsite waste consolidation areas with no impacts to
the community.
Alternative 4 (offsite RCRA-licensed facility disposal) has the highest impact on local and
regional traffic, largest increase in haul truck emissions, and largest increase in potential traffic
accidents and fatalities. Excavated waste would be hauled on local and state highways to an
offsite disposal facility located 515 miles away, resulting in the highest miles traveled.
Alternative 4 has much higher impacts to the community than Alternatives 2 and 3 because of
the 2,660 truck trips to haul waste.
Protection of Workers
Worker protection primarily involves radiation exposure, dust inhalation hazards, physical
injury, and traffic accidents. All action alternatives would involve the same degree of excavation
work; therefore, all action alternatives have equal amounts of potential radiation exposure,
potential dust inhalation hazards, and potential for injury to workers. However, Alternatives 2
and 3 involve construction of waste consolidation areas, which introduces an additional level of
threat to workers because of additional handling activities and duration of exposure during
consolidation and capping. Alternative 4 involves higher volumes because of the intermediate
steps to load haul trucks from consolidation stockpiles; under Alternative 2 and 3, this step is
unnecessary. Also, an additional 5 acres (comprising the repository sites in AUMs 457 and 458)
are excavated and restored under Alternatives 3 and 4, but not under Alternative 2.
Even though Alternatives 2 and 3 pose an additional hazard associated with the handling of and
exposure to waste during consolidation and capping on site, the long-haul distances for offsite
disposal (presented in Alternative 4) pose the greatest accident threat to truck drivers. Therefore,
Alternative 4 with a 515-mile haul distance poses a much higher risk to workers than
Alternatives 2 or 3. Alternative 1 poses no risk to workers as no removal activities would occur
that could impact workers.
Environmental Impacts
All alternatives involve the excavation of waste and substantial site disturbance. Shorter haul
distances and construction durations for Alternatives 2 and 3 minimize the potential for
construction-related environmental impacts to both on public roads and off road and in the
construction areas that would require mitigation compared to Alternative 4. These impacts may
include residual track-out effects of soil and mud, noise, nuisance, and soil spills during waste
hauling; excavation in and sedimentation of local drainages; and harmful emissions. However,
construction of onsite capped areas or repositories (Alternatives 2 and 3) would increase the
amount of construction activities and, therefore, increase environmental impacts. Offsite disposal
(Alternative 4) would increase fuel consumption and greenhouse gas emissions. The long-term
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maintenance required for cap maintenance is expected to have an increased environmental
impact on the Alternative 2 and 3 footprints. Long-term maintenance of closure systems now or
in the future at Clive Operations (Alternative 4) are external to this EE/CA.
Water import or installation of a water supply well would also have an environmental impact
depending on the water source, import distance, and volume required for dust control and waste
compaction. Onsite consolidation and capping under Alternatives 2 and 3 would use less water
than offsite hauling because of less frequent haul road watering and shorter project duration
compared to Alternative 4. An environmental footprint analysis is summarized below under
greener cleanups analysis.
In summary, the short-term environmental impacts of the large haul distance under Alternative 4
are significantly larger than the impacts of waste consolidation, onsite repository construction,
and 30-year repository maintenance under Alternatives 2 and 3.
Greener Cleanups Analysis. A qualitative environmental footprint analysis was conducted for
the removal action elements common to all action alternatives. The analysis focused on the
environmental footprint associated with five main categories: energy use, air pollutants and
greenhouse gas emissions, water use and impacts to water resources, materials management and
waste reduction, and land management and ecosystems protection.
• Energy and Emissions. Among the common elements applicable to all action alternatives,
road construction, waste excavation, and site restoration activities resulted in a moderate
amount of energy use and generated emissions. Alternative 4 has a very large footprint
because of the longest offsite haul distance even after the relatively short (10-year)
inspection visits for site restoration are considered. Alternatives 2 and 3 have a small
energy and emissions footprint because of the short distances to the onsite waste
consolidation area.
• Water Resources. Among the common elements applicable to all alternatives, water use
is required for dust control during road work, waste excavation and loading, backfilling,
and site restoration. Alternatives 2 and 3 require water for waste compaction and
restoring removal areas while Alternative 4 requires water for restoring removal areas
and for dust control on haul roads within the APE. Alternatives 2 and 3 require water for
waste compaction and dust control. Alternatives 2,3, and 4 would require use of
imported water.
• Materials Management. Alternative 2 has a small materials management footprint,
requiring hauling of waste locally to the onsite repository locations and import of gravel
and clayey soil and use of nearby borrow soil for cap construction. Alternative 3 has a
medium materials management footprint, requiring hauling of waste locally to a single
location and import of gravel and clayey soil and use of nearby borrow soil for cap
construction. Alternative 4 has a large materials management footprint because of the
required hauling of waste off site for disposal.
• Land Management and Ecosystems Protection. All alternatives have a small footprint
because of disturbance in drainage channels, and adjacent riparian habitat and noise and
activity disturbance of potential sensitive biological species during construction.
Alternative 2 and 3 have a small footprint because of the small size of the repositories
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compared to the size of the AUMs and APE. Minimal loss of grazing land is expected
over the long term if vegetation of the cap becomes established. Alternative 4 has a small
land management and ecosystems protection footprint because all waste would be hauled
off site and no land uses would be impacted.
Greener Cleanups Summary. Under all action alternatives, restoration of any disturbed
drainage channels and adjacent riparian habitat could result in better ecosystem quality than
exists currently. Onsite disposal and capping of waste under Alternatives 2 and 3 would not limit
land uses significantly. Alternatives 2 and 3 use less water than Alternative 4. Fuel consumption
and emissions generation are the driving factors when evaluating an energy and greenhouse gas
footprint. Though not evaluated, Alternative 4 may have higher greenhouse gas and pollution
emissions than Alternatives 2 and 3 because of higher resource use. Alternative 4 has the largest
footprint of the alternatives because of the long-haul distance to the offsite disposal facility in
Clive, Utah. Alternative 1 has no footprint as no removal action would be performed.
Annual inspections and maintenance of the onsite waste consolidation areas under Alternatives 2
and 3 would also result in increased cumulative fuel consumption and emissions over the long
term (30 years). However, because the inspection and maintenance activities would only occur
over 1 month each year, the annual environmental footprint would be small. Furthermore, these
cumulative impacts would be dwarfed by the fuel consumption and emission footprint of
long-distance hauling to Clive, Utah, under Alternative 4.
A summary of resource use and greener cleanups quantities is summarized in Exhibit 15.
Exhibit 15. Summary of Quantities for Resource Use and Greener Cleanups
Item
Quantity
Alternative 2
Quantity
Alternative 3
Quantity
Alternative 4
On-highway truck travel, trips
630
630
2,660
On-highway travel (includes worker
commutes), miles
67,500
(46,600)
69,000
(47,600)
2,170,000
(60,000)
Transportation-related diesel fuel, gallons
6,700
8,000
356,400
Dust control water, gallons
643,000
675,000
1,296,000
On-highway injuries
0.033
0.034
1.054
On-highway fatalities
0.001
0.001
0.032
Time until Removal Action Objectives Are Achieved
A summary of the construction completion time for each alternative is presented in Exhibit 16.
The action alternatives would be completed in two or three field seasons, depending on the
alternative selected and schedule-limiting factors such as truck availability, monsoon rains,
and snowfall.
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Exhibit 16. Construction Completion Time for Alternatives
Alternative
Construction Completion Time
Alternative 1: No Action
0 month (baseline)
Alternative 2: Consolidate and Cap All Waste Onsite
2 months
Alternative 3: Disposal of All Mine Waste at a Western AUM
Regional Repository
2 months
Alternative 4: Disposal of All Mine Waste in Offsite RCRA-
Licensed Facility
15 months
Note:
RCRA Resource Conservation and Recovery Act
5.2.1.4 Long-Term Effectiveness and Permanence (after Removal Action)
For all action alternatives, waste removal from or containment at source areas would reduce the
magnitude of residual risk to background levels for radionuclides. Noncancer hazards would be
reduced or removed, and risk to ecological receptors would be reduced or removed to levels
below known effects concentrations or background levels. None of the alternatives reduce the
toxicity, mobility, or volume through treatment.
Alternative 4 is effective in the long term and permanent as sources of risk would be removed
and waste would be disposed of off site. The cap at the LLRW facility would eliminate exposure
pathways. Alternative 4 would also allow for future use of for recreation and onsite workers.
Removing waste eliminates the long-term surveillance requirements associated with onsite
consolidated and capped waste under Alternatives 2 and 3.
Permanence of risk reduction for Alternatives 2 and 3 would rely on the cap and consolidation
area design, construction, and maintenance to prevent future risk at the site. Replacement of
consolidation area components would not be required because their lifespan is indefinite,
especially under a monitoring and maintenance regime. Alternatives 2 and 3 are permanent
because the capped waste would be located on flat, gentle slopes and permanence would be
attained.
Alternative 3 provides greater protection against force majeure events and reduced design costs
because of its location away from the LCR and its associated floodplains and drainage areas.
Additionally, Alternative 3 provides increased design flexibility compared to Alternative 2
because of a larger area for capping design and repository depths.
5.2.2 Implementability
Implementability comprises two criteria: technical feasibility and availability of services
and materials, and administrative feasibility. Overall implementability ratings are shown in
Exhibit 14. Individual criteria and ratings contributing to the overall ratings are discussed in the
following subsections.
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5.2.2.1 Technical Feasibility and Availability of Services and Materials
Action alternatives consist mainly of earthwork and material hauling. The alternatives are
technically feasible with labor available through the local and regional markets, as well as
equipment and materials.
The action alternatives would be completed as a single phase, and no future remedial actions are
anticipated. Short-term monitoring (10 years) of site restoration features will occur under all
action alternatives while long-term monitoring and maintenance, particularly the inspection and
repair of erosional features and controls and revegetation, would be required for the caps in
Alternative 2 and the single cap in Alternative 3. Experienced contractors, construction
equipment, and materials are available within the region.
Alternative 4 is technically feasible to implement as all waste is removed from the site. However,
the long-distance hauling of waste in Alternative 4 involves greater effort than that in
Alternative 2 or 3.
Alternatives 2 and 3 are technically feasible to implement as waste is consolidated and capped on
site. Design methods, construction practices, and engineering requirements are well documented
and understood. Under Alternatives 2 and 3, maintenance of the caps involves greater effort than
that in Alternative 4.
In summary, no significant difference in the technical feasibility and availability of materials
exists between Alternatives 2,3, and 4.
5.2.2.2 Administrative Feasibility
Alternatives 2,3, and 4 are comparable administratively to implement, and differences are
unremarkable. The alternatives have no significant barriers.
5.2.2.3 State, Tribal, and Community Acceptance
Acceptance by the State of Arizona, BLM, communities, and other stakeholders will be
addressed in the final EE/CA report after stakeholder comments have been received on the
draft EE/CA.
5.2.3 Projected Costs
A summary of the NPV cost for each alternative is presented in Exhibit 17. Although the cost
estimate is limited to 30 years of activities, long-term maintenance would be in perpetuity. Costs
are presented as NPV, including capital, periodic maintenance costs at 10-year intervals, and
periodic maintenance costs at 1-year intervals for the first 10 years. The 30-year rolling average
discount rate is 3.5 percent (Office of Management and Budget 2022).
Alternative 2 and 3 costs are based on the overall costs for construction and 30-year maintenance
of the onsite caps. Alternative 4 has a NPV of $11.7 million, which is 3.3 times that of
Alternative 2. Alternative 4 has the highest cost because of the long hauling distance
(1,030 miles round trip).
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Exhibit 17. Alternative Costs and Ratings
Alternative
Cost Rating
Total Estimated NPV
Cost
(2024 Million Dollars)
Alternative 1: No Action
N/A
$0.0
Alternative 2: Consolidate and Cap All Waste Onsite
Good
$3.6
Alternative 3: Disposal of All Mine Waste at a Western
AUM Regional Repository
Good
$4.0
Alternative 4: Disposal of All Mine Waste in Offsite RCRA-
Licensed Facility
Very Poor
$12.8
Notes:
Higher cost alternatives rate lower in cost ratings, which is consistent with the rating scheme where higher is less
desirable.
N/A Not applicable
NPV Net present value
RCRA Resource Conservation and Recovery Act
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6.0 REFERENC
J
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2008. "The ERICA Tool." Journal of Environmental Radioactivity. Volume 99, Issue 9.
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Bureau of Indian Affairs. 2020. "Programmatic Environmental Impact Statement, Navajo Nation
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Chenoweth, W.L., and R.C. Malan. 1973. "The Uranium Deposits of Northeastern Arizona."
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Chenoweth, W.L. 1993. "Geology and Production History of the Uranium Ore Deposits in the
Cameron Area, Coconino County, Arizona." Arizona Geological Survey Report 93-B.
Dubiel, R.F., J.T. Parrish, J.M. Parrish, and S.C. Good. 1991. "The Pangean Megamonsoon:
Evidence from the Upper Triassic Chinle Formation, Colorado Plateau." PALAIOS.
Volume 6. Number 4. Pages 347 through 370.Engineering Analytics, Inc. (EA). 2017.
"Phase II Work Plan, Babbitt Ranches, LLC - Milestone Hawaii Stewardship Project
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EA. 2018. "Summary Report for Phase II Work, Babbitt Ranches, LLC - Milestone Hawaii
Stewardship Project (Section 9 Lease Abandoned Uranium Mine)." Revision 2.1.
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EA. 2020. "Summary Report for Phase III, Babbitt Ranches, LLC - Milestone Hawaii
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EA. 2021. "Removal Site Evaluation Report, Babbitt Ranches, LLC - Milestone Hawaii
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Engineering Analytics, Inc. and Integral Consulting, Inc. 2019. "Babbitt Ranches, LLC -
Milestone Hawaii Stewardship Project (Section 9 Lease Abandoned Uranium Mine)
Removal Site Evaluation Phase III Work Plan." CERCLA Docket No. 2016-13. Prepared
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Gordian. 2022. "RSMeans Data." Version 2022.
Greenwood. N.N., and A. Earnshaw. 2012. Chemistry of the Elements. Elsevier. Leeds. United
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Johnson, J.A., H.R. Meyer, and M. Vidyasagar. 2006. "Characterization of Surface Soils at a
Former Uranium Mill." Health Physics. Volume 90, Number 2. Pages S29 through S32.
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March 15.
SWCA Environmental Consultants (SWCA). 2016. "Biological Resources Survey, Babbitt
Ranches Milestone Hawaii Reclamation Project (Section 9 Lease AUM Removal
Action), Coconino County, Arizona." Prepared for Babbitt Ranches, LLC. December.
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Stewardship Project, Coconino County, Arizona." Prepared for Babbitt Ranches, LLC.
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Tetra Tech (Tetra Tech). 2021. "Application of Evapotranspiration Cover in the Southwest."
February.
Tetra Tech. 2022. "Summary and Evaluation of Previous Investigations at Section 9 Lease
Mines." December 15.
Tetra Tech. 2024. "Navajo Abandoned Uranium Mines Regional Background Methodology."
Interim Final. May 13.
U.S. Climate Data. 2023. "Climate Cameron - Arizona and Weather Averages Cameron."
Accessed May 9. https://www.usclimatedata.com/climate/cameron/arizona/united-
states/usaz0025.
U.S. Environmental Protection Agency (USEPA). 1991. "A Guide to Principal Threat and Low
Level Threat Wastes." Office of Solid Waste and Emergency Response (OSWER).
9380.3-06FS. November.
USEPA. 1993. "Guidance on Conducting Non-Time Critical Removal Actions under CERCLA."
OSWER. EPA/540-R-93-057. August. https://semspub.epa.gov/work/HQ/122068.pdf.
USEPA. 1997. "Ecological Risk Assessment Guidance for Superfund: Process for Designing and
Conducting Ecological Risk Assessments." EPA/540-R-97-006. June.
www.epa.gov/oswer/riskassessment/ecorisk/ecorisk.htm.
USEPA. 1999. "Issuance of Final Guidance: Ecological Risk Assessment and Risk Management
Principles for Superfund Sites." Office of Solid Waste and Emergency Response.
Directive 9285.7-28P. October 7.
Contract No. 68HE0923D0002, Task Order 020
80
-------
Section 9 Lease Mines EE/CA
USEPA. 2000. "A Guide to Developing and Documenting Cost Estimates during the Feasibility
Study." EPA 540-R-00-002. July.
USEPA. 2002. "Calculating Exposure Point Concentrations at Hazardous Waste Sites." OSWER
Directive 9285.6-10. December.
USEPA. 2010. "ProUCL Statistical Software for Environmental Applications for Data Sets with
and without Nondetect Observation." Version 4.1.01. Prepared by A. Singh and A.K.
Singh. EPA/600/R-07/041. May.
USEPA. 2013. "Site Visit to Determine the Presence of Wetlands, Section 9 Lease Mine Site."
September.
USEPA. 2016a. "Administrative Settlement Agreement and Order on Consent in the Matter of
Section 9 Lease Mine Site, Arizona, Entered into between the EPA Region IX and
Babbitt Ranches, LLC." October 25.
USEPA. 2016b. Memorandum Regarding Consideration of Greener Cleanups Activities in the
Superfund Cleanup Process. August 2.
https:// semspub. epa.gov/work/HQ/100000160.pdf.
USEPA. 2022a. "ProUCL Statistical Software for Environmental Applications for Data Sets with
and without Nondetect Observations." Version 5.2. June 14.
USEPA. 2022b. "Navajo Abandoned Uranium Mines Program, Navajo Nation Abandoned
Mines Technology Evaluation and Alternative Development Technical Memorandum."
Internal Draft. September 23.
USEPA. 2024a. "Navajo Abandoned Uranium Mine Risk Assessment Methodology." Draft
Final. March.
USEPA. 2024b. "Navajo Abandoned Uranium Mine Risk Calculator." Version 1.03. March.
USEPA. 2024c. "Navajo Abandoned Uranium Mines Program Preliminary Ecological Removal
Goals for Metals and Radionuclides in Soil for Navajo Abandoned Uranium Mine Sites."
Draft. March.
USEPA. 2024d. "Regional Screening Levels (RSLs)." May 14. https://epa-prgs.ornl.gov/cgi-
bin / chemical s/csl_search.
USEPA. 2024e. "Removal Action Extent Development Standard Operating Procedure." Navajo
Abandoned Uranium Mines Program. September.
U.S. Geological Survey. 2007. "Geologic Map of the Cameron 30' x 60' Quadrangle, Coconino
County, Northern Arizona." https://pubs.usgs.gov/sim/2007/2977/.
Western Regional Climate Center. 2023a. "Average Wind Speeds - MPH." Accessed May 9.
https://wrcc.dri.edu/Climate/comp_table_show.php?stype=wind_speed_avg.
Contract No. 68HE0923D0002, Task Order 020
81
-------
Section 9 Lease Mines EE/CA
Western Regional Climate Center. 2023b. "Evaporation Stations." Accessed May 9.
https://wrcc.dri. edu/Climate/comp_table_show.php? stype=pan_evap_avg.
Western Regional Climate Center. 2023c. "Prevailing Wind Direction." Accessed May 9.
https://wrcc.dri. edu/Climate/comp_table_show.php? stype=wind_dir_avg.
Weston Solutions, Inc. (Weston). 2011. "Navajo Abandoned Uranium Mine Site Screen Report."
January.
Weston. 2012. "Preliminary Assessment, Section 9 Lease Abandoned Uranium Mine, Coconino
County, Arizona." Report prepared for USEPA Region 9. November.
Weston. 2014. "Site Inspection Report, Section 9 Lease Abandoned Uranium Mine, Coconino
County, Arizona." Report prepared for USEPA Region 9. June.
Contract No. 68HE0923D0002, Task Order 020
82
-------
FIGURES
-------
North Central
Region
Northern
Region
Western
Region
Central
Region
XHopiOy
Reservation
Eastern
Region
Section 9 Inset
Southern
¦ Region]
llittleieolorado River
Cameron Chapter
Little Colorado
River
Colorado
A Section 9 Lease Mines
Little Colorado River
f^j Chapter Boundaries
r 1 Navajo Nation
KX3 Hopi Reservation
Navajo Nation AUM Regions
B Western Region
Northern Region
North Central Region
Central Region
Eastern Region
Southern Region
Reference:
NAD 1983 State Plane Arizona Central FIRS 0202 Feet Transverse Mercator
Note:
AUM
Abandoned uranium mine
Prepared for: U.S. EPA Region 9
PRo^°
Oakland, CA 94612
SECTION 9 LEASE M
REGIONAL LOCATI
INES
ON
AUM 459
Coconino County
Arizona
Prepared By:
"It
TETRA TECH
1999 Harrison Street, Suite 500
Location.
COCONINO COUNTY, AZ
Contract No.:
68HE0923D0002
Date:
10/8/2024
Figure No.:
Coalmine Canyon
Chapter
1.8
Ji Miles
/ Arizona
, ^
1
'Navajo Nation 1
rlHH 1 1
*
I
I
New Mexico S
1
Task Order No.:
,VAUM457
-------
Section 03
Section 04
Section 05
AUM 457
Section 09,^
Section 08
AUM 458
AUM 459
Section 16
Section 17
!•_ I AUM Boundary
"S*!i APE Boundary
~ PLSS Section Boundary
Land Ownership Types
Bureau of Indian Affairs
Navajo Nation Land
Bureau of Land Management
Arizona State Land
Navajo Nation Boundary
Road
— Little Colorado River
Drainage
Notes:
APE Area of potential effect
AUM Abandoned uranium mine
PLSS Public Land Survey System
1 inch = 900 Feet
1:10,800
N
W E
S
900 450 0 900
Feet
SECTION 9 LEASE MINES
ABANDONED URANIUM
MINE LOCATIONS
Prepared For: U.S. EPA Region 9
Pr
spared
It
iy:
TETRA TECH
1999 Harrison Street, Suite 500
Oakland, CA 94612
Task Order No.:
020
Contract No.:
68HE0923D0002
Location:
COCONINO COUNTY, AZ
Date:
1 0/8/2024
Coordinate System:
NAD 1983 State Plane Arizona East
FIRS 0201 Feet Transverse Mercator
Figure No.:
2
-------
AUM-^457
AUM-458
Section 10
Section 09
AUM-459
Site Features
= Berm
~ Concrete Pad
Dozer Cut
Pit
Shallow Mine Waste
pj: » 1 Waste Pile
™"I AUM Boundary
3 APE Boundary
PLSS Section Boundary
— Road
Drainage
Little Colorado River
Notes:
APE
AUM
PLSS
Area of potential effect
Abandoned uranium mine
Public Land Survey System
1 inch = 700 Feet
1:8,400
700 350 0
w
700
13 Feet
SECTION 9 LEASE MINES
SITE INSPECTION AND
REMOVAL SITE EVALUATION
FEATURES
Prepared For: U.S. EPA Region 9
Prepared By:
It
TETRA TECH
1999 Harrison Street, Suite 500
Oakland, CA 94612
Task Order No.:
020
Contract No.:
68HE0923D0002
Location:
COCONINO COUNTY, AZ
1 1/3/2024
Coordinate System:
NAD 1983 State Plane Arizona East
FIPS 0201 Feet Transverse Mercator
Figure No.:
3
-------
Section
Former Pond
Concrete Pad
Upgrader
Foundation
Concrete Pad
Site Features
Berm
Surface Water Drainage Pathway
Concrete Pad
Dozer cuts
Shallow Mine Waste
Waste Pile
AUM Boundary
APE Boundary
PLSS Section Boundary
Roads
Little Colorado River
Notes:
APE
AUM
PLSS
Area of potential effect
Abandoned uranium mine
Public Land Survey System
1 inch = 200 Feet
1:2,400
200 100 0
W
200
13 Feet
SECTION 9 LEASE MINES
AUM 457 SITE INSPECTION
AND REMOVAL SITE
EVALUATION FEATURES
Prepared For: U.S. EPA Region 9
5®
Prepared By:
It
TETRA TECH
1999 Harrison Street, Suite 500
Oakland, CA 94612
Task Order No.:
020
Contract No.:
68HE0923D0002
Location:
COCONINO COUNTY, AZ
1 0/1 4/2024
Coordinate System:
NAD 1983 State Plane Arizona East
FIRS 0201 Feet Transverse Mercator
Figure No.:
4
-------
Section 09
Site Features
Surface Water Drainage Pathway
Dozer Cut
fe*» a Excavated Area
K'jiM Shallow Mine Waste
1V.&1 Waste Pile
n AUM Boundary
^3 APE Boundary
li ] PLSS Section Boundary
Road
Drainage
Notes:
APE
AUM
PLSS
Area of potential effect
Abandoned uranium mine
Public Land Survey System
1 inch = 200 Feet
1:2,400
200 100 0
w
200
13 Feet
SECTION 9 LEASE MINES
AUM 458 SITE INSPECTION
AND REMOVAL SITE
EVALUATION FEATURES
Prepared For: U.S. EPA Region 9
SEz
Prepared By:
It
TETRA TECH
1999 Harrison Street, Suite 500
Oakland, CA 94612
Task Order No.:
020
Contract No.:
68HE0923D0002
Location:
COCONINO COUNTY, AZ
1 1/8/2024
Coordinate System:
NAD 1983 State Plane Arizona East
FIRS 0201 Feet Transverse Mercator
Figure No.:
5
-------
Geologic Units1
Qay - Quaternary Alluvium
TRcp - Chinle Formation (Petrified Forest)
TRcs - Shinarump Member
3 APE Boundary
AUM Boundary
PLSS Section Boundary
— Little Colorado River
Drainage
Notes:
'Geologic unit map from USGS (2007).
APE Area of potential effect
Abandoned uranium mine
PLSS Public Land Survey System
USGS U.S. Geological Survey
-------
Section
Former Pond
Concrete Pad
Upgrader
Foundation
Concrete Pad
Site Features
= Berm
~ Concrete Pad
Dozer cuts
Kf I Shallow Mine Waste
Waste Pile
I APE Boundary
Abandoned Uranium Mine
^3 APE Boundary
1 I PLSS Section Boundary
Roads
Drainage
Little Colorado River
Notes:
APE
AUM
PLSS
Area of potential effect
Abandoned uranium mine
Public Land Survey System
1 inch = 200 Feet
1:2,400
200 100 0
N
S
200
I Feet
SECTION 9 LEASE MINES
AUM 457 HYDROLOGY
Prepared For: U.S. EPA Region 9
5®
Prepared By:
It
TETRA TECH
1999 Harrison Street, Suite 500
Oakland, CA 94612
Task Order No.:
020
Contract No.:
68HE0923D0002
Location:
COCONINO COUNTY, AZ
1 0/1 4/2024
Coordinate System:
NAD 1983 State Plane Arizona East
FIRS 0201 Feet Transverse Mercator
Figure No.:
-------
Site Features
= Berm
~ Concrete Pad
Dozer Cut
E3 Pit
Shallow Mine Waste
E5S] Waste Pile
| J AUM Boundary
|_J APE Boundary
~ PLSS Section Boundary
Road
Drainage
Little Colorado River
Notes:
APE
AUM
PLSS
Area of potential effect
Abandoned uranium mine
Public Land Survey System
1 inch = 200 Feet
1:2,400
200 100 0
W
200
13 Feet
SECTION 9 LEASE MINES
AUM 458 HYDROLOGY
Prepared For: U.S. EPA Region 9
Task Order No.:
020
Location:
COCONINO COUNTY, AZ
Prepared By:
It
TETRA TECH
1999 Harrison Street, Suite 500
Oakland, CA 94612
Contract No.:
68HE0923D0002
1 1/3/2024
Coordinate System:
NAD 1983 State Plane Arizona East
FIRS 0201 Feet Transverse Mercator
Figure No.:
8
% •
it- V
-------
Section 10
TENQRM-7
AUM-457
TENORM-5
TENORM-3
TENORM-2
TENORM^
x •v; ¦
I .VH _ I
TENORM Area
Description of Disturbances
TENORM-1
Exploratory dozer cuts into theTriassic Petrified Forest
member with lateral and terminal berms.
AUM458 pit in the Petrified Forest and Shinarump members.
Primary disturbances related to exploratory and production
mining activities resulting on dozer push piles, waste rock
piles, and a mine pit.
TENORM-3
Exploratory dozer cuts into theTriassic Petrified Forest
member with lateral and terminal berms.
Ro ads from AUM459 through the Shinarump member cutting
through the Shinarump including some near-surface
exploration. Elevated gamma in area outside of the western
boundary is documented (mineralized outcrop) as NORM
TENORM-5
Large exploration area south of AUM457 in the Petrified Forest
and Shinarump members consisting of numerous drill trails
and exploratory dozer cuts.
TENORM-6
Exploration area in theNW corner of Section 9 in the Petrified
Forest consistingof dozer cuts and berms.
TENORM-7
AUM457 production mine area consisting of multiple
unreclaimed waste piles, haul roads, drill trails, dozer push
areas, structures from milling facility, and drainage channels.
Section 09
TENORM-6
TENORM Area
APE Boundary
AUM Boundary
PLSS Section Boundary
Little Colorado River
Notes:
APE
AUM
PLSS
TENORM
Area of potential effect
Abandoned uranium mine
Public Land Survey System
Technologically enhanced naturally
occurring radioactive material
1 inch = 700 Feet
1:8,400
700 350 0
N
S
700
1 Feet
SECTION 9 LEASE MINES
TENORM AREA
Prepared For: U.S. EPA Region 9
SEz
Prepared By:
It
TETRA TECH
1999 Harrison Street, Suite 500
Oakland, CA 94612
Task Order No.:
020
Contract No.:
68HE0923D0002
Location:
COCONINO COUNTY, AZ
1 1/3/2024
Coordinate System:
NAD 1983 State Plane Arizona East
FIRS 0201 Feet Transverse Mercator
Figure No.:
-------
Section 10
,5AU M-457
Gamma Reading (cpm)1
• < 38,364
• 38,364-66,291
66,291 -299,018
• 299,018-578,289
• > 578,289
D TENORMArea
®=] APE Boundary
[ ~] AUM Boundary
l~~l PLSS Section Boundary
Little Colorado River
Drainage
Notes:
1The mobile gamma radiation survey was
performed using 3-inch by 3-inch sodium
iodide detectors (Ludlum 44-20) (EA2018).
APE Area of potential effect
AUM Abandoned uranium mine
cpm Counts per minute
EA Engineering Analytics, Inc.
PLSS Public Land Survey System
1 inch = 700 Feet
1:8,400
700 350 0
W
700
I Feet
SECTION 9 LEASE MINES
GAMMA RADIATION
SURVEY
Prepared For: U.S. EPA Region 9
V
v
Prepared By:
It
TETRA TECH
1999 Harrison Street, Suite 500
Oakland, CA 94612
Task Order No.:
020
Contract No.:
68HE0923D0002
Location:
COCONINO COUNTY, AZ
1 1/3/2024
Coordinate System:
NAD 1983 State Plane Arizona East
FIRS 0201 Feet Transverse Mercator
Figure No.:
10
-------
Radium-226 Surface Soil Concentration (pCi/g)
1,2
•
< 2
•
LO
CM
•
C\J
LO
•
12-30
•
30-60
•
> 60
| Interpolated Estimated Radium-226 (pCi/g)
<2
2-5
5-12
12-30
30-60
HI >60
3 TENORMArea
3 APE Boundary
^ AUM Boundary
PLSS Section Boundary
Little Colorado River
Notes:
%
m
1Only non-background surface soil samples within the
m
APE from the SI and Phase III of the RSE are shown.
\
2Radium-226 rbAL = 12 pCi/g
m
%
3Radium-226 concentrations were estimated from the
UPL95 of the gamma-radium correlation model (EA
2021),
and the surface was interpolated using an
ordinary Kriging method.
APE
Area of potential effect
AUM
Abandoned uranium mine
EA
Engineering Analytics, Inc.
pCi/g
PLSS
Picocurie per gram
Public Land Survey System
rbAI
Risk-based action level
' ••
RSE
Removal site evaluation
SI
Site inspection
UPL95
95 percent upper prediction limit
¦"i¦ * 'l *
1 inch = 700 Feet
1:8,400
700 350 0
N
S
700
1 Feet
SECTION 9 LEASE MINES
MEASURED AND ESTIMATED
RADIUM-226 SURFACE SOIL
CONCENTRATIONS
Prepared For: U.S. EPA Region 9
J***.
Task Order No.:
020
Location:
COCONINO COUNTY, AZ
Prepared By:
It
TETRA TECH
1999 Harrison Street, Suite 500
Oakland, CA 94612
Contract No.:
68HE0923D0002
1 1/3/2024
Coordinate System:
NAD 1983 State Plane Arizona East
FIRS 0201 Feet Transverse Mercator
Figure No.:
11
-------
APPLICABLE HUMAN EXPOSURE SCENARIOS
ECOLOGICAL EXPOSURE SCENARIOS
PRIMARY SOURCES OF
CONTAMINATION
SOURCE MEDIA
PRIMARY RELEASE
MECHANISMS
SECONDARY SOURCES
OF CONTAMINATION
SECONDARY RELEASE
MECHANISMS
EXPOSURE MEDIA
EXPOSURE
ROUTES
TRESPASSER
EXPOSURE
ROUTES
PLANTS AND
INVERTEBRATES
BIRDS AND
MAMMALS
Rock, Soil
-~ Radioactive Decay
Radon Gas
Emanation
Wind Erosion
Erosion via
-> Storm or
Snowmelt Runoff
Mass Wasting
Ambient Air
Soil
_ Onsite Drainages —
Surface Water
I
Sediment
in
Alluvial
Groundwater
Stormwater/
Snowmelt Runoff
Leaching/
Dissolution
Plant
Uptake/Uptake
through Food
Entrapment/
Deposition
Gamma Radiation
Air
* Soil/Sediment
*• Surface Water
Wild Plants
Animals
External Exposure
Inhalation
Incidental Ingestion
Dermal
Inhalation
Ingestion
Dermal
Inhalation
Ingestion
Dermal
Inhalation
Ingestion
External Exposure
Inhalation
Dermal/Direct Contact
Ingestion
Trophic Transfer
Dermal/Direct Contact
Ingestion
Trophic Transfer
Ingestion
Ingestion
Trophic Transfer
Gamma Radiation
Air
Soil/Sediment
Water
Plants/Animals
Notes:
X Indicates the exposure pathway is potentially complete and is evaluated in the risk assessment except as noted.
- Indicates the exposure pathway is not complete or de minimus and is not evaluated in the risk assessment
1The human health risk evaluation does not include ingestion of surface water or groundwater by humans.
2 The human health risk evaluation does not include ingestion, dermal (metals only), and inhalation of wild plants by this receptor.
3 The human health risk evaluation does not include ingestion of home-raised animals (meat, milk, and eggs) and hunted animals (meat only) for this receptor.
4 The ecological risk evaluation does not include evaluation of external exposure to gamma radiation.
5 Potential exposures include inhalation of ambient air and air in burrows. The ecological risk evaluation does not include evaluation of the inhalation pathway.
6 The ecological risk evaluation does not include evaluation of direct contact with or ingestion of surface water.
AUM Abandoned uranium mine
Figure 12. Section 9 Lease Mines Conceptual Site Model Wire Diagram
-------
Proposed Excavation Area
^3 APE Boundary
: 7 J Navajo Nation Boundary
n PLSS Section Boundary
— Road
— Little Colorado River
Drainage
Notes:
APE Area of potential effect
PLSS Public Land Survey System
1 inch = 600 Feet
1:7,200
600 300 0
N
W i-J^-E
S
600
~ Feet
SECTION 9 LEASE MINES
PROPOSED EXCAVATION AREA
Prepared For: U.S. EPA Region 9
5®
Task Order No.:
020
Location:
COCONINO COUNTY, AZ
Prepared By:
It
TETRA TECH
Contract No.:
68HE0923D0002
1 0/1 4/2024
Coordinate System:
NAD 1983 State Plane Arizona East
FIRS 0201 Feet Transverse Mercator
Figure No.:
13
-------
Section 10
Section 09
TENORM-1
TENORM-7
TENORM-6
TENORM-5
TENORM-3
Notes:
Volumes of material in each of the 64 removal areas
were estimated using the following stepwise approach
in order of depth: 1. If there is bedrock evident, stop at
that depth, then; 2. Use available test pit radium-226
results from Appendix E in the RSE Phase III report
(EA 2020) to modify Step 2 depth, then; 3. Use local
estimated depth of TENORM (although some
locations indicate 1 inch estimated depth, the
minimum excavation depth will be set to 6 inches in
practice).
APE Area of potential effect
AUM Abandoned uranium mine
bgs Below ground surface
CY Cubic yard
EA Engineering Analytics, Inc.
ft Foot
PLSS Public Land Survey System
RSE Removal site evaluation
TENORM Technologically enhanced naturally
occurring radioactive material
TENORM-2
TENORM
Area
Section
No.
Estimated
Volume (CY)
TENORM-4
Total Volume (CY) 14,711
Area-Weighted Depth (ft bgs)
H 0.5
¦I 0.6
0.7
H o.g
H 1.0
1.1
1.6
1.8
H 1.9
H 2.8
3.0
¦I 3.1
C1 AUM Boundary
|_j APE Boundary
^3 PLSS Section Boundary
Navajo Nation Boundary
Drainage
¦—¦ Little Colorado River
1 inch = 600 Feet
1:7,200
600 300 0
N
S
600
I Feet
SECTION 9 LEASE MINES
REMOVAL VOLUMES
Prepared For: U.S. EPA Region 9
SEz
Prepared By:
It
TETRA TECH
1999 Harrison Street, Suite 500
Oakland, CA 94612
Task Order No.:
020
Contract No.:
68HE0923D0002
Location:
COCONINO COUNTY, AZ
1 0/1 4/2024
Coordinate System:
NAD 1983 State Plane Arizona East
FIPS 0201 Feet Transverse Mercator
Figure No.:
14
-------
Section 09
Section 10
Candidate Cap 02
AUM 457
Borrow Area 02
AUM 458
Borrow Area 01
Candidate
AUM 459
Haul Road
cm Borrow Area
Q Candidate Cap Area
Proposed Excavation Area
^3 APE Boundary
. J Navajo Nation Boundary
!i—" PLSS Section Boundary
- - Road
Drainage
— Little Colorado River
Notes:
APE Area of potential effect
PLSS Public Land Survey System
1 inch = 600 Feet
1:7,200
N
W E
S
600 300 0 600
~ Feet
SECTION 9 LEASE MINES
ALTERNATIVE 2 - CONSOLIDATE
AND CAP ALL WASTE ONSITE
Prepared For: U.S. EPA Region 9
SEz
Prepared By:
It
TETRA TECH
1999 Harrison Street, Suite 500
Oakland, CA 94612
Task Order No.:
020
Contract No.:
68HE0923D0002
Location:
COCONINO COUNTY, AZ
1 1/6/2024
Coordinate System:
NAD 1983 State Plane Arizona East
FIRS 0201 Feet Transverse Mercator
Figure No.:
15
-------
AUM 457
Candidate Cap
Borrow Area
AUM 458
Section 09
Section 10
AUM 459
Haul Road
l~~l LaydownArea
~ Borrow Area
| Consolidate and Cap
[_] Proposed Western Regional Repository
Proposed Excavation Area
(EjI APE Boundary
rj Navajo Nation Boundary
[~;n PLSS Section Boundary
— - Road
Drainage
— Little Colorado River
Notes:
APE Area of potential effect
AUM Abandoned uranium mine
PLSS Public Land Survey System
1 inch = 600 Feet
1:7,200
N
S
600 300 0 600
~ Feet
SECTION 9 LEASE MINES
ALTERNATIVE 3 - DISPOSAL OF
ALL MINE WASTE AT A WESTERN
AUM REGIONAL REPOSITORY
Prepared For: U.S. EPA Region 9
Pr
spared
It
iy:
TETRA TECH
1999 Harrison Street, Suite 500
Oakland, CA 94612
Task Order No.:
020
Contract No.:
68HE0923D0002
Location:
COCONINO COUNTY, AZ
Date:
1 1/1 1/2024
Coordinate System:
NAD 1983 State Plane Arizona East
FIRS 0201 Feet Transverse Mercator
Figure No.:
16
-------
EJJco
Eureka
NevJ&a
A'a-m Srnrn
fen op ah
/altov
J P*Tfc
Pihruhip
Las Vegas
Henderson
Oyiltti
Energy Solutions
Clive Facility, Inc.
©
e
Total Travel Distance
53 Miles
Salt Lake
City
I . \ *r e
. White City
taenia!
~r«n
Total Travel Distance
JSq--
[ *¦-
M
66 Miles
m
Total Travel Distance
47 Miles
£D
Ely
-rr><
Total Travel Distance
18 Miles
Total Travel Distance
16 Miles
Graid
Jundum
Utah
U tah
ft cli 1-H :1
Total Travel Distance
34 Miles
Total Travel Distance
23 Miles
r.«dst civ
Total Travel Distance
288 Miles
Gl m t.i
Si*i. i^-F^-slari-
hW'l M-i-t
Qbn C
V-h'iImiAH'
San
N a
s=bi
jp
•St George
Page
fliwl
K.-^entn
Farming ton
TubaCity
x*—
Section 9
Lease Mines
Gallup
X Section 9 Lease Mines
© Proposed Disposal Facility
Proposed Haul Road
1 inch = 40 Miles
40
1:2,534,400
20 0
N
W-sS^s-E
S
40
1 Miles
SECTION 9 LEASE MINES
ALTERNATIVE 4 - DISPOSAL OF
ALL MINE WASTE IN OFFSITE
CONSERVATION AND RECOVERY
ACT (RCRA)-LICENSED FACILITY
Prepared For: U.S. EPA Region S
Task Order No.:
020
Location:
COCONINO COUNTY, AZ
Prepared By:
It
TETRA TECH
1999 Harrison Street, Suite 500
Oakland, CA 94612
Contract No.:
68HE0923D0002
1 1/6/2024
Coordinate System:
NAD 1983 State Plane Arizona East
FIRS 0201 Feet Transverse Mercator
Figure No.:
17
-------
I: ¦ -.1 Surficial Restoration
I" ¦ 1 Borrow Area
Q Candidate Cap Area2
~ LaydownArea3
Ig APE Boundary
l5TJ Navajo Nation Boundary
n PLSS Section Boundary
Road
Drainage
— Little Colorado River
Notes:
1The restoration areas will be graded to a natural
contour (shallow removal < 1 foot) or backfilled
(depth > 2 feet) with clean fill; contour graded for
drainage; and revegetated with native seed and
planted shrubs in selected locations.
2Evapotranspiration cap constructed of 36 inches
of clean fill and local gravel as required by final
design. Grading for drainage and top cap layer
may include a soil layer for revegetation and
protective desert gravel surface depending on
location and surrounding conditions.
3Laydown area will be ripped to remove
compaction graded to contour and revegetated.
APE Area of potential effect
PLSS Public Land Survey System
1 inch = 600 Feet
1:7,200
600 300 0
N
S
600
~ Feet
SECTION 9 LEASE MINES
ALTERNATIVE 2
PROPOSED SURFICIAL
RESTORATION ACTIVITIES
Prepared For: U.S. EPA Region 9
5®
Task Order No.:
020
Location:
COCONINO COUNTY, AZ
Prepared By:
It
TETRA TECH
Contract No.:
68HE0923D0002
1 1/4/2024
Coordinate System:
NAD 1983 State Plane Arizona East
FIRS 0201 Feet Transverse Mercator
Figure No.:
18
-------
Surficia! Restoration
CD Borrow Area
Q Cap2
r~T1 LaydownArea3
^3 APE Boundary
l~~l PLSS Section Boundary
Navajo Nation Boundary
Road
Drainage
Little Colorado River
Notes:
1The restoration areas will be graded to a natural
contour (shallow removal < 1 foot) or backfilled
(depth > 2 feet) with clean fill; contour graded for
drainage; and revegetated with native seed and
planted shrubs in selected locations.
2Evapotranspiration cap constructed of 36 inches
of clean fill and local gravel as required by final
design. Grading for drainage and top cap layer
may include a soil layer for revegetation and
protective desert gravel surface depending on
location and surrounding conditions.
3Laydown area will be ripped to remove
compaction graded to contour and revegetated.
APE Area of potential effect
PLSS Public Land Survey System
1 inch = 600 Feet
1:7,200
600 300 0
W
600
1 Feet
SECTION 9 LEASE MINES
ALTERNATIVE 3
PROPOSED SURFICIAL
RESTORATION ACTIVITIES
Prepared For: U.S. EPA Region 9
5®
Task Order No.:
020
Location:
COCONINO COUNTY, AZ
Prepared By:
It
TETRA TECH
Contract No.:
68HE0923D0002
1 1/4/2024
Coordinate System:
NAD 1983 State Plane Arizona East
FIRS 0201 Feet Transverse Mercator
Figure No.:
19
-------
I: ¦ -.1 Surficia! Restoration1
~ Laydown Area2
^3 APE Boundary
Navajo Nation Boundary
PLSS Section Boundary
Road
Drainage
Little Colorado River
Notes:
1The restoration areas will be graded to a natural
contour (shallow removal < 1 foot) or backfilled
(depth > 2 feet) with clean fill; contour graded for
drainage; and revegetated with native seed and
planted shrubs in selected locations.
2Laydown area will be ripped to remove
compaction, graded to contour, and revegetated.
APE Area of potential effect
PLSS Public Land Survey System
1 inch = 600 Feet
1:7,200
600 300 0
N
S
600
~ Feet
SECTION 9 LEASE MINES
ALTERNATIVE 4 -
PROPOSED SURFICIAL
RESTORATION ACTIVITIES
Prepared For: U.S. EPA Region 9
5®
Task Order No.:
020
Location:
COCONINO COUNTY, AZ
Prepared By:
It
TETRA TECH
Contract No.:
68HE0923D0002
1 1/4/2024
Coordinate System:
NAD 1983 State Plane Arizona East
FIRS 0201 Feet Transverse Mercator
Figure No.:
20
-------
TABLES
-------
Table 1. Cameron, Arizona Summary of Climate and Meteorology
Parameter
Value
Annual Low Temperature
u_
o
CO
Annual High Temperature
75 °F
Annual Average Precipitation
5.57 inches
Range of Monthly Average Precipitation
0.08 inch in June
0.83 inch in August
Average Wind Speed in Page, Arizona3
5 miles per hour
Prevailing Wind Direction in Page, Arizona3
West
Annual Average Pan Evaporation in Page, Arizona3
80.57 inches
Notes:
Values are from U.S. Climate Data (2023).
a The closest site with wind speed, wind direction, and pan evaporation data is Page, Arizona (Western
Regional Climate Center 2023a, 2023b, 2023c).
°F Degree Fahrenheit
References:
U.S. Climate Data. 2023. "Climate Cameron - Arizona and Weather Averages Cameron."
https://www.usclimatedata.com/climate/cameron/arizona/united-states/usaz0025.
Western Regional Climate Center. 2023a. "Average Wind Speeds - MPH."
https://wrcc.dri.edu/Climate/comp_table_show.php?stype=wind_speed_avg.
Western Regional Climate Center. 2023b. "Evaporation Stations."
https://wrcc.dri.edu/Climate/comp_table_show.php?stype=pan_evap_avg.
Western Regional Climate Center. 2023c. "Prevailing Wind Direction."
https://wrcc.dri.edu/Climate/comp_table_show.php?stype=wind_dir_avg.
Page 1 of 1
-------
Table 2. Western AUM Region Regional BTVs
Geologic Unit
Radium-226
(pCi/g)
Arsenic
(mg/kg)
Molybdenum
(mg/kg)
Uranium
(mg/kg)
Vanadium
(mg/kg)
Alluvium
3.2
5.9
2.6
3.9
83
Petrified Forest Member
3.9
4.2
1.8
7.7
56
Shinarump Member
1.5
18
0.7
1.5
62
Notes:
The BTV is the UTL95-95 of the Western AUM Region background dataset grouped by geologic unit (Tetra Tech, Inc.
2024). Only BTVs for geologic units present at the Section 9 Lease Mines are shown.
AUM Abandoned uranium mine
BTV Background threshold value
mg/kg Milligram per kilogram
pCi/g Picocurie per gram
UTL95-95 95 percent upper tolerance limit with 95 percent coverage
References:
Tetra Tech, Inc. 2024. "Navajo Abandoned Uranium Mines Regional Background Methodology." Interim Final.
May 13.
Page 1 of 1
-------
Table 3. Background Comparison
COC/COEC
Section 9 Lease Mines
Quaternary Alluvium
(0-6 inch bgs)
Western Regional Background
Quaternary Alluvium
(0-6 inch bgs)
Two-Population Statistical Tests
Final Conclusion
for Background
Screen
Sample Size
Detection
Frequency
(Percent)
Sample Size
Detection
Frequency
(Percent)
Gehan3
Tarone-Ware3
Wilcoxon-Mann-
Whitney15
Quantile0
Detected
Total
Detected
Total
Site >
Background?
Site >
Background?
Site >
Background?
Site > Background?
Site >
Background?
Radium-226
23
23
100%
283
286
99%
Yes
Yes
--
--
Yes
Arsenic
18
23
78%
275
276
100%
Yes
Yes
--
--
Yes
Molybdenum
18
23
78%
103
276
37%
Yes
Yes
--
--
Yes
Selenium
11
23
48%
130
276
47%
Yes
Yes
--
--
Yes
Uranium
12
23
52%
276
276
100%
Yes
Yes
--
--
Yes
Vanadium
22
23
96%
276
276
100%
Yes
Yes
--
--
Yes
COC/COEC
Section 9 Lease Mines
Petrified Forest Member Soil Samples
(0-6 inch bgs)
Western Regional Background
Petrified Forest Member
(0-6 inch bgs)
Two-Population Statistical Tests
Final Conclusion
for Background
Screen
Sample Size
Detection
Frequency
(Percent)
Sample Size
Detection
Frequency
(Percent)
Gehan3
Tarone-Ware3
Wilcoxon-Mann-
Whitney15
Quantile0
Detected
Total
Detected
Total
Site >
Background?
Site >
Background?
Site >
Background?
Site > Background?
Site >
Background?
Radium-226
11
11
100%
105
105
100%
--
--
Yes
Yes
Yes
Arsenic
11
11
100%
105
105
100%
--
--
Yes
Yes
Yes
Molybdenum
11
11
100%
63
105
60%
Yes
Yes
--
--
Yes
Selenium
7
11
64%
65
105
62%
Yes
No
--
--
Yes
Uranium
9
11
82%
105
105
100%
Yes
Yes
--
--
Yes
Vanadium
9
11
82%
105
105
100%
No
No
--
No
No
COC/COEC
Section 9 Lease Mines
Shinarump Member Soil Samples
(0-6 inch bgs)
Western Regional Background
Shinarump Member
(0-6 inch bgs)
Two-Population Statistical Tests
Final Conclusion
for Background
Screen
Sample Size
Detection
Frequency
(Percent)
Sample Size
Detection
Frequency
(Percent)
Gehan3
Tarone-Ware3
Wilcoxon-Mann-
Whitney15
Quantile0
Detected
Total
Detected
Total
Site >
Background?
Site >
Background?
Site >
Background?
Site > Background?
Site >
Background?
Radium-226
28
28
100%
63
63
100%
--
--
Yes
Yes
Yes
Arsenic
26
28
93%
60
63
95%
Yes
Yes
--
--
Yes
Molybdenum
27
28
96%
5
63
8%
Yes
Yes
--
--
Yes
Selenium
12
28
43%
52
63
83%
No
No
--
*
No
Uranium
16
28
57%
63
63
100%
Yes
Yes
--
--
Yes
Vanadium
24
28
86%
63
63
100%
No
No
--
No
No
Notes:
Bold indicates site soil concentrations are greater than background concentrations for the geologic unit.
a Gehan and Tarone-Ware are tests of central tendency and are only used when multiple nondetect results are present in the dataset (USEPA 2022a).
b Wilcoxon-Mann-Whitney is a test of central tendency and can only be used when all data are detected or a single detection limit is identified for the nondetected results.
c Quantile is a test performed to confirm the conclusion that the upper tails of site concentrations are less than those for background. Quantile tests were not performed in cases where the two-population tests for central tendency indicated that the site
concentrations are greater than background. Quantile tests were performed using ProUCL Version 4.1.01 (USEPA 2010).
Page 1 of 2
-------
Table 3. Background Comparison
Notes (Continued):
* Quantile test could not be performed because there are non-detect values in the in the highest quantile.
Not applicable
bgs Below ground surface
COC Contaminant of concern
COEC Contaminant of ecological concern
USEPA U.S. Environmental Protection Agency
References:
U.S. Environmental Protection Agency (USEPA). 2010. "ProUCL Statistical Software for Environmental Applications for Data Sets with and without Nondetect Observation." Version 4.1.01. Prepared by A. Singh and A.K. Singh. EPA/600/R-07/041. May.
USEPA. 2022. "ProUCL Statistical Software for Environmental Applications for Data Sets with and without Nondetect Observations." Version 5.2. June 14.
Page 2 of 2
-------
Table 4. Risk Management Summary
Candidate COC or COEC
Exposure
Unit
Land Use/
Receptor
Soil
Interval
Radium-226
Arsenic
Barium
Chromium
Cobalt
Lead
Manganese
Mercury
Molybdenum
Selenium
Thallium
Uranium
Vanadium
Surface
COC
—
—
—
—
—
—
Trespasser
Subsurface
COC
-
-
-
-
-
-
Site-Wide
Plants,
Invertebrates,
Surface
COEC
Co-
MDC<
Cr(lll)
not a
COPEC
MDC<
MDC<
MDC<
Co-
Co-
Co-
Co-
Co-
Co-
Birds,
Mammals
Loc
PERG
PERG
PERG
PERG
Loc
Loc
Loc
Loc
Loc
Loc
Plants,
Subsurface
COEC
Co-
MDC<
Cr(lll)
not a
COPEC
MDC<
MDC<
Co-
Co-
Co-
Co-
Co-
Mammals
Loc
PERG
PERG
PERG
Loc
Loc
Loc
Loc
Loc
Notes:
Bold indicates an identified final COC or COEC recommended for removal action.
—
Contaminant is not a candidate COC or COEC in the exposure unit and depth interval
<
Less than
Co-Loc
Co-located with radium-226 preliminary removal action extent
COC
Contaminant of concern
COEC
Contaminant of ecological concern
COPEC
Contaminant of potential ecological concern
Cr(lll)
Trivalent chromium
MDC
Maximum detected concentration
PERG
Preliminary ecological removal goal
Page 1 of 1
-------
Table 5. Selected Soil RAG for Each COC and COEC
COC /
COEC
Units
Human
Health
PRG1
NAUM
PERG2
BTV3
Removal
Action
Goal4
Basis for
Removal
Action Goal
Quaternary Alluvium
Surface Soil (0-6 inches bgs) and Subsurface Soil (0-60 inches bgs)
Radium-2265
pCi/g
12
40
3.2
12
Human
Health PRG
Western Regional Background Petrified Forest Member
Surface Soil (0-6 inches bgs) and Subsurface Soil (0-60 inches bgs)
Radium-2265
pCi/g
12
40
3.9
12
Human
Health PRG
Western Regional Background Shinarump
Surface Soil (0-6 inches bgs) and Subsurface Soil (0-60 inches bgs)
Radium-2265
pCi/g
12
40
1.5
12
Human
Health PRG
Notes:
1 The human health PRG is based on a trespasser scenario and calculated using the NAUM Risk Calculator
(USEPA 2024b).
2 Development of PERGs is described in USEPA (2024c).
3 The BTVs for soil are UTL95-95s for the Western Abandoned Uranium Mine Region (Tetra Tech, Inc. 2024).
4 The RAG is the lesser of the human health PRG and NAUM PERG unless either risk-based preliminary
removal goal is less than the BTV. If the BTV is higher than the human health PRG or NAUM PERG, the
RAG is based on the BTV to address material distinguishable from background. The BTV is used to
represent background for delineating contaminated areas.
5 Assumption of secular equilibrium for radium-226 is protective for the calculation of risk-based screening
levels. Adjusted toxicity values are used to incorporate all toxicity for the entire uranium-238 decay chain in
the development of the PRG. Site data for radium-226 are used to evaluate the extent of radionuclides
above RAGs.
bgs Below ground surface
BTV Background threshold value
COC Contaminant of concern
COEC Contaminant of ecological concern
NAUM Navajo abandoned uranium mine
pCi/g Picocurie per gram
PERG Preliminary ecological removal goal
PRG Preliminary removal goal
RAG Removal action goal
UTL95-95 95% upper tolerance limit with 95% coverage
USEPA U.S. Environmental Protection Agency
References:
Tetra Tech, Inc. 2024. "Navajo Abandoned Uranium Mines Regional Background Methodology." Interim Final.
May 13.
U.S. Environmental Protection Agency (USEPA). 2024b. "Navajo Abandoned Uranium Mine Risk Calculator."
Version 1.03. March
USEPA. 2024c. "Navajo Abandoned Uranium Mines Program Preliminary Ecological Removal Goals for Metals and
Radionuclides in Soil for Navajo Abandoned Uranium Mine Sites." Draft. March.
Page 1 of 1
-------
Table 6. General Response Actions, Technologies, and Process Options Screening Summary
General
Response
Actions
Response
Action
Technology
Process Options
Description
Screening Comment
No Action
None
Not applicable
No action
Not applicable
Institutional
Controls
Access
Restrictions
Land Use Controls
Implement administrative
restrictions to control current
and future land use.
Potentially effective in conjunction with other
technologies; reduces opportunities for
community exposure during typical land use
activities. Protective in areas of a site with
mineralized bedrock that cannot be
addressed under CERCLA. Requires
implementing authorities.
Access
Restrictions
Physical Barriers
Install gate at road, signs and
fence around waste piles and
mine shafts, and berms to limit
vehicle access.
Potentially effective in conjunction with other
technologies; limits access to physical
hazards and direct exposure to
radionuclides and radon gas; however,
would require annual inspection and repair
for vandalism.
Engineering
Controls
Surface
Controls
Consolidation,
Grading,
Revegetation, and
Erosion Protection
Combine mine waste in a
smaller common area. Return
waste to mine openings,
benches, and pits.
Grade waste piles to reduce
slopes for managing erosion
and runoff.
Add amendments and seed to
revegetate and establish an
erosion-resistant ground
surface.
Install sedimentation basins,
run-on and runoff controls, and
diversion ditches.
Effective in conjunction with other
technologies; reduces physical hazards
through backfilling of mine openings and
pits; limits exposed waste surface area
through consolidation; limits erosion of soil
and migration to drainages; reduces
stormwater run-on and runoff; effective for
material impinging on drainages; readily
implementable. Does not fully address direct
exposure, leaching, or potential wind
erosion and migration off site.
Soil Binder
Apply a chemical binder to soil
to reduce wind and water
erosion of soil.
Potentially effective in conjunction with other
process options; limits mobility of metals
and radionuclides to downwind receptors;
does not address direct exposure, leaching,
or stormwater erosion; not protective over
long term; readily implementable.
Page 1 of 5
-------
Table 6. General Response Actions, Technologies, and Process Options Screening Summary
General
Response
Actions
Response
Action
Technology
Process Options
Description
Screening Comment
Engineering
Controls
Sorting
Sorting
Soil and waste sorting is a
standard process applied as an
intermediate step between soil
or waste excavation and onsite
or offsite treatment or disposal
methods. The process goal is to
segregate highly contaminated
material from less contaminated
material, allowing for different
treatment or disposal options.
Sorting reduces waste volume requiring
treatment or disposal, increases the volume
of material that can remain on site with
limited or no treatment or containment, and
allows classification of waste to reduce
volume requiring more costly treatment or
disposal options. A cost analysis is
necessary to determine if sorting is
beneficial. Sorting is not retained because it
is not effective when waste is relatively
homogeneous.
Containment
Earthen Cover
(Evapotranspiration)
Apply soil cover over in situ or
consolidated mine waste;
establish vegetation to stabilize
surface; waste materials are
consolidated or left in place.
Reduces gamma and suspected
radon gas exposure.
Limits direct exposure and reduces gamma
irradiation and radon gas flux; surface water
infiltration would be reduced; should be
combined with surface controls;
implementable but would require a
somewhat flat area and regrading. Earthen
covers on moderate to steep slopes are not
successful without benching. Retained for
remote areas where access is limited and
direct exposure and gamma irradiation
reduction through soil shielding is the
primary goal.
Earthen Cover with
Upper HDPE or
Geosynthetic Clay
Liner
Install clay layer, HDPE, or
geosynthetic clay liner within
cover over mine waste to
reduce rainwater infiltration and
radon flux; establish vegetation
to stabilize surface; waste
materials are consolidated or
left in place. Reduces gamma
and radon exposure.
Limits direct exposure and reduces gamma
irradiation; surface water infiltration and
radon flux would be eliminated; should be
combined with surface controls;
implementable but would require a
somewhat flat area and regrading. Earthen
covers on steep slopes are not successful
without benching. Not retained because of
the increased cost and time required for a
negligible increase in effectiveness relative
to an earthen cap.
Page 2 of 5
-------
Table 6. General Response Actions, Technologies, and Process Options Screening Summary
General
Response
Actions
Response
Action
Technology
Process Options
Description
Screening Comment
Engineering
Controls
Offsite Disposal
Class A LLRWor
RCRA C Hazardous
Waste Disposal
Facility
Excavate mine waste, sort,
transport, and dispose of waste
at an offsite Class A LLRW or
RCRA C hazardous waste
disposal facility; leachate
generation characteristics may
require stabilization.
Removes onsite direct exposure and
gamma irradiation by isolating waste at an
offsite LLRW or hazardous waste disposal
facility where waste is covered or
encapsulated; readily implementable.
However, transport, any pretreatment, and
disposal costs may be cost prohibitive
because of the long haul distances required.
Transportation costs should be weighed
against long-term O&M costs associated
with onsite disposal.
Excavation
and Treatment
Physical/
Chemical
Treatment
Milling/
Reprocessing
Excavate mine waste, sort,
transport, and process waste at
an operating mill for economic
recovery of uranium; dispose of
tailings at a mill tailings disposal
facility.
Removes onsite direct exposure and
gamma irradiation by processing waste at
an off-Navajo Nation mill; processed waste
(tailings) is covered or encapsulated in a
disposal cell; readily implementable. Not
retained because a mill in compliance with
the CERCLA Off-Site Rule is not currently
available.
Soil Washing/ Acid
Extraction
Excavate mine waste, sort, and
screen waste to increase
percentage of fines for acid
digestion. Solubilize uranium
and other metals via dissolution
or acid leaching and recover by
precipitation. Dispose of fines,
process solutions, and oversize
of materials.
Treatability testing required. Not retained
because effectiveness is questionable;
increases mobility by partial dissolution of
contaminants; difficulty encountered
because of gravel-to-rock-sized waste rock
and disseminated nature of uranium;
increases toxicity of fines; requires disposal
of treated fines and oversize material; cost
prohibitive.
Page 3 of 5
-------
Table 6. General Response Actions, Technologies, and Process Options Screening Summary
General
Response
Actions
Response
Action
Technology
Process Options
Description
Screening Comment
Excavation
and Treatment
Physical/
Chemical
Treatment
Ablation
Excavate mine waste and
screen to segregate oversized
materials for crushing or
disposal. Mix waste with
makeup water to form a slurry.
Inject opposing slurry streams
to impact one another, causing
collisions between particles
resulting in disassociation of
fine-grained, intergranular, and
mineralized material (uranium
minerals) from coarser-grained
sands. Dewater and reuse bulk
of material on site.
Concentrates disposed of on or
off site.
Treatability testing required; implementable
but full scale not demonstrated for uranium;
effectiveness depends on the form of
mineral deposition (surface or within the
particle), the number of passes through
collision chamber, and feed concentration.
Pilot-scale studies began in summer 2022 to
test the feasibility of the technology for
uranium at three sites on the Navajo Nation.
Ablation technologies have not
demonstrated sufficient throughput to
address a large volume of waste rock. One
of the goals of the pilot studies is to evaluate
scale up designs and economics. If ablation
is determined to be successful and scalable
after the pilot study, a future draft of the
EE/CA may incorporate ablation as an
alternative.
Stabilization/
Solidification
Excavate mine waste and
screen waste to remove
oversized materials. Mix waste
with solidifying agents to
facilitate a physical or chemical
change in leachability and
mobility of contaminants. Cure
material and dispose of on or off
site.
Readily implementable. Not retained
because treatability testing is required;
waste would still require disposal following
stabilization; increases volume; requires a
significant amount of water; cost prohibitive.
Containment is equally effective.
In-Place
Treatment
Physical/
Chemical
Treatment
Stabilization
Stabilize waste constituents
in situ when combined with
injected stabilizing agents.
Not retained because treatability testing is
required; more difficulty encountered
because of gravel-to-rock-sized waste rock;
does not reduce gamma irradiation;
potentially implementable but requires a
large amount of stabilizing agents and
water; cost prohibitive. Containment is
equally effective.
Page 4 of 5
-------
Table 6. General Response Actions, Technologies, and Process Options Screening Summary
General
Response
Actions
Response
Action
Technology
Process Options
Description
Screening Comment
Physical/
Chemical
Treatment
Solidification
Uses solidifying agents in
conjunction with deep soil
mixing techniques to facilitate a
physical or chemical change in
the mobility of contaminants.
Not retained because treatability testing is
required; more difficulty encountered in
gravel-to-rock-sized waste rock; does not
reduce gamma irradiation; potentially
implementable but requires a large amount
of solidifying agents and water; cost
prohibitive. Containment is equally effective.
In-Place
Treatment
Thermal
Treatment
Vitrification
Uses extremely high
temperature to melt and
volatilize all components of the
solid media; the molten material
is cooled and, in the process,
vitrified into a non-leachable
form.
Not retained because extensive treatability
testing is required; difficulties may be
encountered in establishing adequate
containment; does not reduce gamma
irradiation; not implementable because of
the remoteness of the site (no high-voltage
electrical infrastructure); cost prohibitive.
Vegetative
Treatment
Phytoextraction/
Phytostabilization
Uptake of contaminants by plant
roots and accumulation of
contaminants within plant
shoots and leaves.
Immobilization of contaminants
at interfaces of roots and soil by
absorption or adsorption;
precipitation or complexation in
root zone binding to humic
matter in the root zone.
Extensive treatability testing is required for
phytostabilization of radionuclides;
phytoextraction requires harvesting and
disposing of vegetative growth containing
radionuclides and fencing to exclude
livestock and wildlife to prevent vegetative
bioaccumulation. May require irrigation in
arid environments. Long-term
protectiveness has not been demonstrated,
and O&M costs may be prohibitive.
Notes:
Eliminated process options are shaded.
CERCLA Comprehensive Environmental Response, Compensation, and Liability Act
EE/CA Engineering evaluation/cost analysis
HDPE High-density polyethylene
LLRW Low-level radioactive waste
O&M Operation and maintenance
RCRA Resource Conservation and Recovery Act
Page 5 of 5
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Table 7. Applicable or Relevant and Appropriate Requirements and To Be Considered
Requirements for Section 9 Lease Mines
Table 7a, Table 7b, and Table 7c list the federal and State of Arizona chemical-, location-, and
action-specific applicable or relevant and appropriate requirements (ARAR) and to be considered
(TBC) materials, respectively, that have been identified for all the alternative response actions
described in the draft engineering evaluation/cost analysis (EE/CA) for the Section 9 Lease
Mines. The U.S. Environmental Protection Agency (USEPA) did not identify federal
chemical-specific ARARs or TBCs because potential federal chemical-specific ARARs are not
as conservative as the risk-based cleanup standards developed for this action. Chemical-related
requirements tied to an action such as cover design were included in the action-specific table.
USEPA did identify a State of Arizona chemical-specific ARAR, which supports the human
health removal action goal for radium-226. Identification and evaluation of ARARs is an iterative
process that continues throughout the response process. As a better understanding is gained of
site conditions, contaminants, and response alternatives, the lists of ARARs, TBCs, and their
relevance to the removal action may change. ARARs and TBCs are finalized in the action
memorandum for the selected response action.
Cleanup standards were derived through the USEPA risk assessment process, in accordance with
the following USEPA guidance and the State of Arizona potential chemical-specific ARAR:
• Office of Solid Waste and Emergency Response (OSWER) Directive No. 9200.4-18,
"Establishment of Cleanup Levels for CERCLA Sites with Radioactive Contamination"
(August 1997)
• OSWER Directive No. 9200.4-23, "Clarification of the Role of Applicable, or Relevant
and Appropriate Requirements in Establishing Preliminary Remediation Goals under
CERCLA" (August 1997)
• OSWER Directive No. 9200.4-25, "Use of Soil Cleanup Criteria in 40 CFR Part 192 as
Remediation Goals for CERCLA Sites" (February 1998)
• OSWER Directive No. 9200.4-40, "Radiation Risk Assessment at CERCLA Sites: Q&A"
(May 2014)
The EE/CA for which the ARARs tables were prepared does not address groundwater; therefore,
ARARs for groundwater are not included. If any groundwater contamination is found at the
Section 9 Lease Mines, the related ARARs will be addressed at that time.
Page 1 of 8
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Table 7a. Chemical-Specific ARARs
Media
Requirement
Requirement Synopsis
Prerequisites, Status, and Rationale
Soil
STATE OF ARIZONA
Soil Remediation Standards
AAC R18-7-203(A)(3) and R18-7-
206
Under R18-7-203(A), a person subject to
Article 18 shall remediate soil so that any
concentration of contaminants remaining in
soil after remediation is equal to one of the
following: (1) background; (2) pre-determined
remediation standards; or (3) site-specific
remediation standards.
Under R18-7-206, a person may elect to
remediate to a residential or a non-residential
site-specific remediation standard derived
from a site-specific human health risk
assessment. A site-specific remediation
standard may be used if it is based on: (1) a
deterministic methodology; (2) a probabilistic
methodology; or (3) an alternative
methodology commonly accepted in the
scientific community.
Relevant and Appropriate
The State of Arizona soil remediation
standards are applicable to a person legally
required to conduct remediation under
programs administered by the ADEQ. Since
this site is being addressed pursuant to
CERCLA, these requirements are not
applicable.
USEPA has identified a site-specific human
health RAG for radium-226 that is protective
of a recreational visitor, which was
considered the reasonable maximum
exposure scenario for the site. This RAG
was derived using a deterministic
methodology and is commonly accepted in
the scientific community. This complies with
the State of Arizona Soil Remediation
Standards ARARs.
Notes:
AAC Arizona Administrative Code
ADEQ Arizona Department of Environmental Quality
ARAR Applicable or relevant and appropriate requirement
CERCLA Comprehensive Environmental Response, Compensation, and Liability Act
RAG Removal action goal
USEPA U.S. Environmental Protection Agency
Page 2 of 8
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Table 7b. Location-Specific ARARs
Media/Resource
Requirement
Requirement Synopsis
Prerequisites, Status, and Rationale
Cultural Resources
FEDERAL
The Native American Graves
Protection and Repatriation
Act
25 U.S.C. §§ 3002(c) and (d)
43 CFR §§ 10.3(b)-(c) and
10.4(b)-(e)
Protects Native American cultural items
from unpermitted removal and excavation
and requires the protection of such items
in the event of inadvertent discovery.
Excavation or removal of cultural items
must be done under procedures required
by this Act and the Archaeological
Resources Protection Act (§ 3(c)(1)).
Applicable.
This Act is identified as a potential
ARAR because the site is near the
Navajo Nation Reservation.
Substantive requirements are
applicable if cultural items (meaning
human remains and associated or
unassociated funerary objects, sacred
objects, or cultural patrimony) are
inadvertently discovered or are
intentionally excavated or removed
within the area to be disturbed.
If cultural items are discovered, on-
going activity in the area of discovery
must stop, the relevant Indian tribe
official must be notified immediately,
and reasonable effort must be made to
protect such cultural items.
Cultural Resources
FEDERAL
National Historic
Preservation Act
54 U.S.C. §§ 306101(a),
306102, 306107,and 306108
36 CFR §§ 800.3(a) and (c);
800.4(a)-(c); 800.5(a)-(b);
800.6(a)-(b); 800.10(a);
800.13(b)-(d)
Federal agencies are required to consider
the effects of federally funded (in whole or
in part) activity on any historic property,
minimize harm to any National Historic
Landmark, and nominate qualifying historic
property for inclusion on the National
Register of Historic Places. Federal
agencies may be required to identify
historic properties, determine whether the
proposed activity will have an adverse
effect on historic properties, and develop
alternatives or modifications to the
proposed action that could avoid,
minimize, or mitigate adverse effects
through the National Historic Preservation
Act Section 106 process.
Applicable.
Substantive requirements are
applicable if the federally funded
activity could adversely affect historic
property (meaning a prehistoric or
historic district, site, building, structure,
or object) included on, or eligible for
inclusion on, the National Register of
Historic Places.
A cultural resource survey was
completed in 2017. No cultural
resources were identified on the site.
Page 3 of 8
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Table 7b. Location-Specific ARARs
Media/Resource
Requirement
Requirement Synopsis
Prerequisites, Status, and Rationale
Cultural Resources
FEDERAL
Preservation of Historical and
Archaeological Data
54 U.S.C. §§ 312502(a) and
312503
Protects significant scientific, prehistorical,
historical, and archaeological data. When
a federal agency action may cause
irreparable loss or destruction of significant
data, the agency must notify DOI and
either recover, protect, and preserve the
data, or request DOI to do so.
Applicable.
Substantive requirements are
applicable if federal agency action may
cause irreparable loss or destruction to
significant scientific, prehistorical,
historical, or archaeological data.
A cultural resource survey was
completed in 2017. No cultural
resources were identified on the site.
Cultural Resources
FEDERAL
Archaeological Resources
Protection Act of 1979
16 U.S.C. §§ 470cc(a)-(c) and
470ee(a)
43 CFR §§ 7.4(a), 7.5(a), 7.7,
7.8(a), 7.9(c), and 7.35
Prohibits the excavation, removal,
damage, or alteration or defacement of
archaeological resources on public or
Indian lands unless by permit or exception.
Applicable.
Substantive requirements are
applicable if eligible archaeological
resources are located within the area to
be disturbed.
A portion of the removal action will
occur on public land (BLM). A cultural
resource survey was completed in
2017. No cultural resources were
identified on the site.
Biological Resources
FEDERAL
Migratory Bird Treaty Act
16 U.S.C. § 703(a)
50 CFR §§ 10.13 and 21.10
Prohibits the killing, capturing, taking, and
incidental taking of protected migratory
bird species, their parts, nests, and eggs
without DOI's prior approval. The species
of protected migratory birds are listed at 50
CFR § 10.13.
Applicable.
Substantive requirements are
applicable if migratory birds or their
nests are present at or near the site.
Biological Resources
FEDERAL
Bald and Golden Eagle
Protection Act
16 U.S.C. §§ 668(a)
50 CFR §§ 22.10; 22.80(a),
(c)-(f); 22.85(a)-(b) and (d)-(e)
50 CFR § 13.21(b)
Prohibits the unpermitted taking, including
the killing, disturbing, or incidental taking,
of bald and golden eagles, their parts,
nests, and eggs.
Applicable.
Substantive requirements applicable if
bald or golden eagles or their nests are
identified at or near the site.
Page 4 of 8
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Table 7b. Location-Specific ARARs
Media/Resource
Requirement
Requirement Synopsis
Prerequisites, Status, and Rationale
Biological Resources
FEDERAL
Endangered Species Act
16 U.S.C. §§ 1531(c);
1536(a)(2), (c)-(d), (g)-(h), and
(I); 1538(a) and (g); 1539(a)
50 CFR §§ 17.21 (a)-(c);
17.22(b); 17.31(a) and
(c);17.32(b); 17.82; and
17.94(a)
50 CFR §§ 402.09; 402.12
(a)-(b) and (i); 402.14(a);
402.15(a)
Federal agencies must ensure that any
activities funded, carried out, or authorized
by them do not jeopardize the continued
existence of any threatened or
endangered species nor result in the
destruction or alteration of such species'
habitats. The list of endangered and
threatened species can be found at
50 CFR Part 17, Subpart B.
Applicable.
Substantive requirements applicable if
endangered or threatened species are
identified at the site.
A biological survey was completed and
no endangered or threatened species
were identified on the site.
Notes:
§ Section
§§ Sections
ARAR Applicable or relevant and appropriate requirement
BLM Bureau of Land Management
CFR Code of Federal Regulations
DOI U.S. Department of the Interior
TBC To be considered
U.S.C. United States Code
Page 5 of 8
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Table 7c. Action-Specific ARARs
Media
Requirement
Requirement Synopsis
Prerequisites, Status, and Rationale
Air
FEDERAL
Clean Air Act
42U.S.C. §§ 7401, etseq.
40 CFR § 61.92
Emissions of radionuclides (other than
radon) to the ambient air from DOE facilities
shall not exceed those amounts that would
cause any member of the public to receive in
any year an effective dose equivalent of
10 mrem/yr.
Relevant and appropriate.
This standard is applicable to a DOE facility.
The NAUM sites are not DOE facilities;
therefore, this standard is not applicable
However, this standard has been determined
to be relevant and appropriate during
removal action activities because of potential
emissions of radionuclides during excavation
of the waste and movement of the waste.
Air
FEDERAL
Clean Air Act
42U.S.C. §§ 7401, etseq.
40 CFR § 61.222(a)
Radon-222 emissions to the ambient air
from a uranium mill tailings pile that is no
longer operational shall not exceed
20 pCi/m2-sec.
Relevant and appropriate.
These requirements are applicable to
nonoperational uranium mill tailings piles.
The Site's waste to be disposed of is not
uranium mill tailings. These requirements
have been determined to be relevant and
appropriate to the design of the engineered
cover to be constructed in Alternative 2,
which consists of onsite containment of the
contaminated soil and uranium waste rock.
Water
FEDERAL
Clean Water Act
33 U.S.C. § 1342(p)(3)(A)
NPDES- Stormwater Discharges
40 CFR § 450.21
Requires BMPs to abate discharges of
pollutants from stormwater discharges and
erosion and sediment control BMPs. All
treatment and control systems and facilities
will be properly operated and maintained.
Applicable
The construction in Alternatives 2 and 3
would affect more than one acre. Therefore,
stormwater controls are necessary.
Repository
FEDERAL
Uranium Mill Tailings Radiation
Control Act
42 USC §§ 7918 and 2022
40 CFR §§192.02(a) and (d)
Requires design of uranium mill tailings
disposal sites to provide for control of
residual radioactive materials for up to 1,000
years to the extent reasonably achievable
and, in any case, for at least 200 years. The
uranium mill tailings disposal site must also
be designed and stabilized in a manner that
minimizes the need for future maintenance.
Relevant and Appropriate
These standards are applicable to UMTRCA
Title I sites. The Site is not a Title I Site;
therefore, these requirements are not
applicable. These requirements have been
determined to be relevant and appropriate to
the design of the engineered cover to be
constructed under Alternative 2, which
consists of onsite containment of the
contaminated soil and uranium waste rock.
Page 6 of 8
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Table 7c. Action-Specific ARARs
Media
Requirement
Requirement Synopsis
Prerequisites, Status, and Rationale
Repository
FEDERAL
NRC Regulations
Domestic Licensing of Source
Material
10 CFR Part 40, Appendix A.
Criteria 1, 4, 6(1), 6(3), 6(5) and
6(7)
In selecting and designing uranium mill
tailings disposal sites, certain criteria must
be considered, including remoteness,
hydrologic and topographic features,
potential for erosion and vegetation.
Disposal sites must be covered by an
earthen cap, or approved alterative, that
meets certain control requirements, including
limiting the release of radon-222 to the
atmosphere. When the final radon barrier is
placed in phases, verification of the
radon-222 release rate must be completed
for each portion of the final radon barrier as
it is emplaced. Waste or rock with elevated
levels of radium must not be placed near the
surface of disposal sites. Disposal sites must
be closed in a manner that, to the extent
necessary, controls, minimizes, or eliminates
post closure escape of non-radiological
hazardous constituents, leachate,
contaminated rainwater, or waste
decomposition products to the ground or
surface waters or atmosphere.
Relevant and Appropriate
These standards are applicable to applicants
for licenses to possess and use source
material in conjunction with uranium and
thorium milling or byproduct material at sites
formerly associated with such milling. This
Site was not used for milling uranium and
does not contain mill tailings. These
requirements have been determined to be
relevant and appropriate to the design of the
engineered cover to be constructed in
Alternative 2, which consists of onsite
containment for the contaminated soil and
uranium waste rock.
Repository
FEDERAL
NRC Regulations
Protection of the General
Population from Releases of
Radioactivity
10 CFR §61.41
"Concentrations of radioactive material
which may be released to the general
environment in groundwater, surface water,
air, soil, plants, or animals must not result in
an annual dose exceeding an equivalent of
25 millirems to the whole body, 75 millirems
to the thyroid, and 25 millirems to any other
organ of any member of the public.
Reasonable effort should be made to
maintain releases of radioactivity in effluents
to the general environment as low as is
reasonably achievable."
Relevant and Appropriate
This standard is applicable to NRC sites. The
Site is not an NRC site; therefore, this
requirement is not applicable. This standard
was found to be relevant and appropriate to
the design of the engineered cover to be
constructed in Alternative 2 for the onsite
containment of contaminated soil and
uranium waste rock.
Page 7 of 8
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Table 7c. Action-Specific ARARs
Media
Requirement
Requirement Synopsis
Prerequisites, Status, and Rationale
Air
STATE OF ARIZONA
Clean Air Act
Emissions from Existing and
New Nonpoint Sources
Construction of Roadways
AAC R18-2-605(A)
No person shall construct a roadway without
taking reasonable precautions to prevent
excessive amounts of particulate matter from
becoming airborne. Dust and other
particulates shall be kept to a minimum by
employing temporary dust suppressants,
wetting down, detouring, or by other
reasonable means.
Applicable
Haul roads are planned to be constructed for
the onsite repository and for the excavation.
Dust suppression would be used during
construction of the haul roads.
Air
STATE OF ARIZONA
Clean Air Act
Emissions from Existing and
New Nonpoint Sources
Mineral Tailings
AAC R18-2-608
No person shall operate mineral tailings piles
without taking reasonable precautions to
prevent excessive amounts of particulate
matter from becoming airborne. Reasonable
precautions shall mean wetting, chemical
stabilization, revegetation, or other such
measures.
Relevant and appropriate
The Site has no mineral tailings piles.
However, the alternatives include the
excavation and movement of mine waste,
which is similar to mineral tailings piles. Dust
suppression would be used during the
excavation and movement of the mine waste.
Water
STATE OF ARIZONA
State of Arizona 2020
Construction General Permit
The operator shall design, install, and
maintain erosion and sediment control, site
stabilization, pollution prevention, and
controls for allowable non-stormwater
discharges and dewatering activities, and
surface outlets.
TBC
Construction activities in Alternatives 2 and 3
affect more than 1 acre. The substantive
provisions of this permit would be used as
guidance to comply with the Clean Water Act
stormwater control requirements.
Notes:
§
Section
§§
Sections
AAC
Arizona Administrative Code
ARAR
Applicable or relevant and appropriate requirement
BMP
Best management practices
CFR
Code of Federal Regulations
DOE
U.S. Department of Energy
mrem/yr
Millirem per year
NAUM
Navajo abandoned uranium mine
NPDES
National Pollutant Discharge Elimination System
NRC
U.S. Nuclear Regulatory Commission
pCi/m2-sec
Picocurie per square meter per second
TBC
To be considered
UMTRCA
Uranium Mill Tailings Radiation Control Act
U.S.C.
United States Code
Page 8 of 8
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APPENDIX A
SCOPING INVESTIGATION SUMMARY MEMORANDUM
-------
It
TETRA TECH
Technical Memorandum
To:
Estrella Armijo
Cc:
From:
Kato T. Dee, Geologist/Project Manager, Tetra Tech
Date:
June 30, 2024
Subject: Response, Assessment, and Evaluation Services 2 Contract, Task Order 020 - Babbitt
Ranches Field Scoping Summary: February 6-10, 2024
OVERVIEW
The U.S. Environmental Protection Agency (USEPA) tasked Tetra Tech, Inc. to conduct a field
event with repository scoping and disturbance mapping to support the development of the
engineering evaluation/cost analysis (EE/CA) and non-time-critical removal action planning
and oversight.
This technical memorandum summarizes the data gaps field scoping activities completed by
Tetra Tech, Inc. February 6 through 10, 2024, at the mines on Section 9, most of Abandoned
Uranium Mine (AUM) 457, AUM 458, and a small portion of AUM 459. Field scoping activities
followed the approved Section 9 Lease Mines work plan and field sampling plan. The Section 9
Lease Mines site is adjacent to the Navajo Nation on private land owned by Babbitt Ranches,
LLC near Cameron, Coconino County, Arizona.
The objectives of the field event were to map site features, identify locations for potential onsite
waste repositories, confirm removal action areas, and select appropriate removal action
alternatives for the EE/CA. The data collected during this field event were used to prepare the
draft final and final EE/CAs. In addition to disturbance mapping and repository scoping,
additional soil samples were collected to support risk assessment, lateral delineation of
contamination, and secular equilibrium evaluation of the site.
During the field scoping event, an area of Section 9 was evaluated as a potential waste repository
for onsite management EE/CA alternatives. The potential repository location is on a small mesa
in the northwestern corner of Section 9 and is evaluated in the EE/CA.
The following sections provide an overview of field activities along with any available
associated maps or preliminary results.
DISTURBANCE MAPPING
Disturbance mapping was conducted to support identification of disturbed and undisturbed areas
within the Section 9 Lease Mines. The primary purpose of disturbance mapping was to define the
geospatial distribution and lateral extent of mining-related physical disturbances across the
Section 9 investigation area, identified as the area of potential effect (APE) and North APE in
1999 Harrison Street, Suite 500, Oakland, CA 94612
Tel 510.302.6300 Fax 510.433.0830
www.tetratech .com
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past investigations. The areas within the Section 9 Lease Mines boundaries identified in the
removal site evaluation (RSE) (Engineering Analytics, Inc. [EA] 2021) have been investigated
by previous contractors. Therefore, disturbance mapping efforts focused on delineation of
previously identified mine pits and waste piles at AUM 457 and AUM 458, roads, and
exploration areas across the Section 9 Lease Mines. In addition to mapping mining-related
disturbance features across the site, locations with elevated gamma radiation measurements
documented in the RSE report outside of known mining and exploration areas were investigated
to note disturbances, if observed, or identify if elevated gamma radiation measurements were
from naturally occurring radioactive material (NORM).
Field observations documented during disturbance mapping are provided on Figure 1, including
those recorded as point features and mapped as polygon features. All field observations were
collected in an ArcGIS Survey 123 form that allows field staff to enter metadata as lines of
evidence in identifying if the feature is disturbed or undisturbed. For each field observation, field
notes and photographs were also recorded and are available on the USEPA Region 9 AUM
GeoPlatform. The classifications of disturbance types and undisturbed areas based on field
observations are shown on Figure 2. Disturbance mapping results for AUM 457 and AUM 458
are presented on Figure 3 and Figure 4, respectively.
Figure 5 presents the site drainage pathways and hydrology with the field-verified disturbance
map to identify potential waste transport pathways to be used for risk assessment and EE/CA
alternative development.
A photographic log of disturbance mapping observations is provided in Attachment 1. The
EE/CA will include a comprehensive photographic log to highlight more features associated with
the Section 9 Lease Mines.
SURFACE SOIL SAMPLING
Supplemental surface soil sampling was conducted across the Section 9 Lease Mines to further
characterize surface soils and provide a sufficient number of soil samples for completing risk
assessment exposure point concentration calculations, lateral delineation of contamination for the
EE/CA, and secular equilibrium calculations following the Navajo AUM risk assessment
methodology (USEPA 2024). Surface and subsurface soil sampling was previously conducted
during the site inspection (Weston Solutions, Inc. 2014) and RSE (EA 2021). Additional soil
sampling was conducted to meet USEPA requirements for the characterization of AUM sites and
to supplement the risk assessment completed during Phase III of the RSE.
Surface soil samples were collected from 0 to 6 inches below ground surface at 20 locations
across the Section 9 Lease Mines: 10 samples within the mine boundaries of AUM 457 and
AUM 458 and 10 samples in the APE outside the mine boundaries. Sample locations were
judgmentally selected based on the results of the walkover gamma radiation survey completed in
the RSE investigation. The sample locations were accessible, and no sample locations were
relocated by more than 5 feet laterally during sampling except for location APE-SS03, which
was relocated by 50 feet from the original location because of proximity to the road. One sample
location, 458-SS06, was randomly chosen for duplicate soil sampling before starting the
field event.
Page 2 of 4
TETRA TECH
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Soil samples were submitted for analysis of metals and metalloids by USEPA Method 6020;
mercury by USEPA Method 7471B; multiple radionuclides, including radium-226, uranium-238,
thorium-232, polonium-210, and lead-210 by gamma spectroscopy by U.S. Department of
Energy EH-300; and isotopic uranium and isotopic thorium by U.S. Department of Energy
HASL-300. Four samples were randomly selected for measurement of hexavalent chromium by
USEPA Method 7196A.
The laboratory results of the supplemental surface soil sampling are provided in Table 1 and will
be subsequently analyzed while updating the risk assessment and EE/CA. Soil sampling results
are shown for AUM 457, AUM 458, and the APE on Figure 6, Figure 7, and Figure 8,
respectively.
REPOSITORY SCOPING
Repository scoping was conducted to support development of removal action alternatives for the
EE/CA for the Section 9 Lease Mines. Removal action alternatives for AUM sites include onsite
management options, such as consolidating and capping mining waste in an onsite waste
repository.
Potential locations on Section 9 for an onsite waste repository were identified during the field
scoping investigation using the following suitability criteria:
• Size - The size of the site determines the volume of material that can be stored on site.
Generally, increased site size reduces engineering and operations and maintenance
(O&M) costs.
• Access - Distance from established roads and other mine sites in the region directly
impact hauling costs. Sites located centrally within the region or close to major roadways
have reduced construction and O&M costs.
• Topography - Flatter sites reduce engineering costs and O&M. Repository locations on
steeper sites often have stricter design criteria and phasing with less flexibility for
incoming volume fluctuations.
• Distance from drainage pathways - Sites located away from major waterways like the
Little Colorado River (LCR) and major drainage features provide better protection from
erosive conditions, reduce contamination migration, and preserve room for mitigation
controls and sampling downgradient from a repository location.
Several locations in the northwest corner of Section 9 about 1 mile from the LCR (Figure 9)
meet the screening criteria for an onsite repository. Section 9 is accessed off U.S. Highway 89,
and an improved gravel road, Indian Route 6728, provides direct access to potential repository
locations. The terrain is flat with limited upgradient stormwater inflows, and no major drainage
pathways are near the site. Additionally, local borrow sources offer a range of materials for
repository construction, including basalt, sand, gravel, and clay resources. Minor drainage
pathways are adjacent to the primary Section 9 location, but none pass through the site itself.
Page 3 of 4
TETRA TECH
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SUMMARY
The field scoping event at the Section 9 Lease Mines conducted in February 2024 comprised
disturbance mapping, surface soil sampling, and repository scoping activities. Field observations
of disturbance features, such as locations and characteristics of waste rock piles, will be used to
improve delineation of areas of technically enhanced naturally occurring radioactive material
(TENORM) and estimate waste volumes for use in the EE/CA. Results from the surface soil
samples collected during the field scoping are presented here and will be subsequently analyzed
alongside past soil sampling results from the site inspection and RSE to update the risk
assessment and secular equilibrium calculations. Repository scoping was successful, and
multiple locations passed screening criteria for onsite consolidation of waste from AUM 457 and
AUM 458 and for consolidation of waste.
Data collected during the field scoping event at the Section 9 Lease Mines will be incorporated
into the selection of removal action alternatives, update to the risk assessment including secular
equilibrium calculations, determination of the appropriate cleanup level(s) for the contaminant(s)
of concern, and identification of the removal action footprint for the final EE/CA.
REFERENCES
Engineering Analytics, Inc. (EA). 2021. "Removal Site Evaluation Report, Babbitt Ranches,
LLC - Milestone Hawaii Stewardship Project (Section 9 Lease Abandoned Uranium
Mine)." Draft. Comprehensive Environmental Response, Compensation, and Liability
Act Docket No. 2016-13. March 18.
U.S. Environmental Protection Agency (USEPA). 2024. "Navajo Abandoned Uranium Mines
Risk Calculator." Version 1.03. February.
Weston Solutions, Inc. 2014. "Site Inspection Report, Section 9 Lease Abandoned Uranium
Mine, Coconino County, Arizona." U.S. Environmental Protection Agency (USEPA) ID
No. NNN000909110. Prepared for USEPA Region 9. June.
Page 4 of 4
TETRA TECH
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FIGURES
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TRcs
TRcs
Disturbance Features (HSA, DA, and Field Verified)
= Berm
Accumulation/Deposition Area - Surficial
Accumulation/Deposition area - Volumetric
Concrete Pad
Dozer Cut
Drainage Buffer
Drainage (Flows through Site)
Exploratory / Access Road
Little Colorado River Flood Plain
Shallow Mine Waste
I I Waste Pile
Disturbance Types (HSA, DA, and Field Verified)
Exploration
::3 Mining Related
Undisturbed
1__| Proposed Repository Location
_"l Geologic Contact
Drainage
i Res
TRcs
TRcs
TRcs
4 /
TRcs V
kTRcs
~ _ N I
1 ' TRcs 1 «
TRcs
Disturbance Features - Field Observations
Disturbed
Exploration
A Cleared Area
A Dozer Berm
A Drill Trail
O Exploratory Borehole
A Impacted Soil
X Mining Exploration Debris
A Vegetation
Hydrology
4 Drainage - Other
Production Mining
4 Production Mine Debris
Concrete Pad
^ Haul Road
Soil
Undisturbed
^ Inaccessible - Cliff
tt Mass Wasting
^ Mineralized Outcrop
4 Stream
+ Vegetation / Soil / Old-Growth Trees
¦ Bedrock
Notes:
DA
HSA
TRcp
TRcs
Desktop analysis
Historical site evaluation
Chinle Formation Petrified Forest Member
Chinle Formation Shinarump Member
1 inch = 660 Feet
1:7,920
660
330
N
S
660
1 Feet
SECTION 9 LEASE
FIELD VERIFIED DISTURBANCE
MAPPING RESULTS WITH
FIELD OBSERVATIONS
Prepared For: U.S. EPA Region 9
y
Prepared By:
It
TETRA TECH
1999 Harrison Street, Suite 500
Oakland, CA 94612
Task Order No.:
020
Contract No.:
68HE0923D0002
Location:
COCONINO COUNTY, AZ
7/2/2024
Coordinate System:
NAD 1983 State Plane Arizona Central
FIPS 0202 Feet Transverse Mercator
Figure No.:
A-1
-------
•»»
>
s
V ~
Qay
)
\
1
C^V4M \C
) i*i \ \ X( , \ ~
J/N-/AP sJ
i-— n—y ' Z. \T^-\
z''" ~V - > / / ** * Qay s
<^( ,<-< ,'^v '// ;/*
Pj fy j ^—¦ — —'^, y \ Qay I ^Jf \
/ -J > (,'<^'U<^7'''s~tv^ V\ / °a- /
V V C /I I VQay VoTy/ /^""" ..Qay J I C^TRcs L.N \ "* /^\
TRcs y ¦> C \ / J ,3\ Z 1
1 \
I \
\ \
\ Qay V
\ \
Disturbance Features (HSA, DA, and Field Verified)
6 Exploratory Borehole
Berm
Accumulation/Deposition Area - Surficial
Accumulation/Deposition Area - Volumetric
Concrete Pad
Dozer Cut
Drainage Buffer
Drainage (Flows through Site)
Exploratory / Access Road
Little Colorado River Flood Plain
Haul Road
Shallow Mine Waste
I I Waste Pile
Disturbance Types (HSA, DA, and Field Verified)
Exploration
Mining Related
Undisturbed
|__| Proposed Repository Location
Geologic Contact
£ Minearlized Outcrop
Drainage
Notes:
DA
HSA
TRcp
TRcs
Desktop analysis
Historical site evaluation
Chinle Formation Petrified Forest Member
Chinle Formation Shinarump Member
1 inch = 660 Feet
660
1:7,920
330 0
N
660
1 Feet
SECTION 9 LEASE
FIELD VERIFIED DISTURBANCE
MAPPING RESULTS WITHOUT
FIELD OBSERVATIONS
Prepared For: U.S. EPA Region 9
y
Task Order No.:
020
Location:
COCONINO COUNTY, AZ
Prepared By:
It
TETRA TECH
Contract No.:
68HE0923D0002
7/2/2024
Coordinate System:
NAD 1983 State Plane Arizona Central
FIPS 0202 Feet Transverse Mercator
Figure No.:
A-2
-------
Disturbance Features (HSA, DA, and Field Verified)
O Exploratory Borehole
Berm
Accumulation/Deposition Area - Surficial
Accumulation/Deposition Area - Volumetric
Concrete Pad
Dozer Cut
Drainage Buffer
Drainage (Flows through Site)
Exploratory / Access Road
Little Colorado River Flood Plain
Haul Road
Shallow Mine Waste
r?H Waste Pile
Disturbance Types (HSA, DA, and Field Verified)
Exploration
Mining Related
Undisturbed
i~ J1 Geologic Contact
Drainage
Notes:
AUM
DA
HSA
TRcp
TRcs
Abandoned uranium mine
Desktop analysis
Historical site evaluation
Chinle Formation Petrified Forest Member
Chinle Formation Shinarump Member
1 inch = 160 Feet
1:1,920
160
80
N
S
160
1 Feet
SECTION 9 LEASE
FIELD VERIFIED DISTURBANCE
MAPPING RESULTS - AUM 457
Prepared For: U.S. EPA Region 9
y
Task Order No.:
020
Location:
COCONINO COUNTY, AZ
Prepared By:
It
TETRA TECH
1999 Harrison Street, Suite 500
Oakland, CA 94612
Contract No.:
68HE0923D0002
7/2/2024
Coordinate System:
NAD 1983 State Plane Arizona Central
FIPS 0202 Feet Transverse Mercator
Figure No.:
A-3
-------
TRcp
TRcp
TRcs
: /
.Vw| JggpB
~ i>
Disturbance Features (HSA, DA, and Field Verified)
:fS Exploratory Borehole
Berm
Accumulation/Deposition Area - Surficial
Accumulation/Deposition Area - Volumetric
Concrete Pad
Dozer Cut
Drainage Buffer
Drainage (Flows through Site)
Exploratory / Access Road
Little Colorado River Flood Plain
Haul Road
Shallow Mine WSaste
tC >*1 Waste Pile
Disturbance Types (HSA, DA, and Field Verified)
Exploration
Mining Related
Undisturbed
i~Geologic Contact
Drainage
Notes:
AUM
DA
HSA
TRcp
TRcs
Abandoned uranium mine
Desktop analysis
Historical site evaluation
Chinle Formation Petrified Forest Member
Chinle Formation Shinarump Member
1 inch = 160 Feet
1:1,920
160
80
N
S
160
1 Feet
SECTION 9 LEASE
FIELD VERIFIED DISTURBANCE
MAPPING RESULTS - AUM 458
Prepared For: U.S. EPA Region 9
v
Task Order No.:
020
Location:
COCONINO COUNTY, AZ
Prepared By:
It
TETRA TECH
1999 Harrison Street, Suite 500
Oakland, CA 94612
Contract No.:
68HE0923D0002
7/2/2024
Coordinate System:
NAD 1983 State Plane Arizona Central
FIPS 0202 Feet Transverse Mercator
Figure No.:
A-4
-------
Site Drainage Types
Waste Transport
I I Other
Undisturbed
! ~| Watershed Catchment Boundary
Disturbance Features (HSA, DA, and Field Verified)
Berm
Accumulation/Deposition Area - Surficia!
EH2] Accumulation/Deposition Area - Volumetric
Concrete Pad
Dozer Cut
Drainage Buffer
Drainage (Flows through Site)
Exploratory / Access Road
Haul Road
Shallow Mine Waste
FT^I Waste Pile
Drainage
Notes:
DA Desktop analysis
HSA Historical site evaluation
1 inch = 600 Feet
1:7,200
0 300 600
N
1,200
1 Feet
SECTION 9 LEASE
HYDROLOGY
Prepared For: U.S. EPA Region 9
y
Task Order No.:
020
Location:
COCONINO COUNTY, AZ
Prepared By:
It
TETRA TECH
Contract No.:
68HE0923D0002
7/2/2024
Coordinate System:
NAD 1983 State Plane Arizona Central
FIPS 0202 Feet Transverse Mercator
Figure No.:
A-5
-------
TRcs
-» \
V _
SN\
I N
" \
_ J
r
- v
„ ~
Qa
Z' f
S
457-SS01
Analyte
Result
As (mg/kg)
14 4 N 4
Hg (mg/kg)
0.105 1
Mo (mg/kg)
4 61 N
Ra-226 (pCi/g)
18.6
Se (mg/kg)
6.53 N* ,
U (mg/kg)
26.8 N
V (mg/kg)
203
y
I S
\
r
—
v .—
Qay
457-SS02
*
/
Analyte
Result
/
As (mg/kg)
16.1 N
A
\
Hg (mg/kg)
0.229
n
457-SS03
Mo (mg/kg)
59.7 N
/
Analyte
Result
Ra-226 (pCi/g)
66.7
As (mg/kg)
3 97 J
Se (mg/kg)
1.95 N*
Hg (mg/kg)
0.0257
U (mg/kg)
90.4 N
s
Mo (mq/'kq)
13.9 J
V (mg/kg)
187
\
:•!
Ra-226 (pCi/g)
18.9
/
Se (mg/kg)
2J
/
/
/
U (mg/kg)
15.7 J
V N
V (mg/kg)
29.1
\ ~
' TRcp
1
\
r
Qay
Qay
Pi
vT^cP,C\
* \
)
\ (
-•]
I
N--'
¦ — ¦>» >
_/
457-SS04
Analyte
Result
As (mg/kg)
18.5 N
Hg (mg/kg)
0.165
Mo (mg/kg)
214 N
Ra-226 (pCi/g)
160
Se (mg/kg)
1.29 N*
U (mg/kg)
56 N
V (mg/kg)
40.3
\' v/
\ \ vi
VV'i.
Qay
\\
^ \fN
\\ v
i \ y
>/
I 1
i \
\ )
\
V
v
«- ¦> \
: o
Notes:
1 All soil samples collected from 0-6 inches below ground
surface. Duplicate sample results are excluded.
* A quality control analyte recovery is
outside of specified acceptance criteria
Arsenic
Abandoned uranium mine
Desktop analysis
Historical site assessment
Mercury
Estimated concentration
Milligram per kilogram
Molybdenum
The matrix spike sample recovery is not
within specified control limits
Picocurie per gram
Selenium
Chinle Formation Petrified Forest Member
Chinle Formation Shinarump Member
Uranium
Vanadium
• Soil Sample Location1
Disturbance Features (HSA, DA, and Field Verified)
d Exploratory Borehole
Berm
Accumulation/Deposition Area - Surficial
|*.*-V|:;l| Accumulation/Deposition Area - Volumetric
Concrete Pad
Dozer Cut
Exploratory / Access Road
Haul Road
Shallow Mine \Naste
l~. I Waste Pile
AUM Site Boundary
Data Gaps Investigation Area
i,-Geologic Contact
Drainage
1 inch = 800 Feet
1:9,600
N
S
800
400
800
) Feet
SECTION 9 LEASE MINES
DATA GAPS
SOIL SAMPLING RESULTS - AUM-457
Prepared For: U.S. EPA Region 9
J***.
y
Task Order No.:
020
Location:
COVE CHAPTER
NAVAJO NATION
Prepared By:
It
TETRA TECH
1999 Harrison Street, Suite 500
Oakland, CA 94612
Contract No.:
68HE0923D0002
7/2/2024
Coordinate System:
NAD 1983 State Plane Arizona East
FIPS 0201 Feet Transverse Mercator
Figure No.:
A-6
-------
Qay
Qa\
.no
r Y
N/-
y
BfTrra^fc'
TRcp I
<3
458-SS03
Analyte
Result
As (mg/'kg)
30.9 N
Hg (mg/'kg)
0.344
Mo (mg/kg)
78.6 N
Ra-226 (pCi/g)
134
Se (mg/kg)
1.35 N*
U (mg/kg)
126 N
V (mg/kg)
5.22
Qay
_!: I
TRcs
458-SS01
Analyte
Result
As (mg/kg)
22 7 N
Hg (mg/kg)
0.204
Mo (mg/kg)
173 N
Ra-226 (pCi/g)
30.9
Se (mg/kg)
1.47 N*
U (mg/kg)
41.5 N
V (mg/kg)
12.6
( X \
¦ ~ v.l \
458-SS04
Analyte
Result
As (mg/kg)
17.6 N
Hg (mg/kg)
0.156
Mo (mg/kg)
191 N
Ra-226 (pCi/g)
48.3
Se (mg/kq)
1.06 N*
U (mg/kg)
108 N
V (mg/kg)
14.9
V?i
TRcs
Qay
f\-j
Qay
./ -
\
\
\x
wv \u
>S\S^s
1
** ¦>
458-SS02
Analyte
Result
As (mg/kg)
22.4 N
Hg (mg/kg)
0.192
Mo (mg/kg)
141 N
Ra-226 (pCi/g)
37.7
Se (mg/kg)
1 N"
U (mg/kg)
48.3 N
V (mg/kg)
8.45
Qay
I TRcp./^^-' f
\ U
,->J /
l\l\/
¦ w
Qay
Qay
V gay ^
458-SS06
Analyte
Result
As (mg/kg)
21.7 N
Hg (mg/kg)
0.111 J
Mo (mg/kg)
126 N
Ra-226 (pCi/g)
29.3 J
Se (mg/kg)
2 32 J
U (mg/kg)
44 J
V (mg/kg)
14.2
\ >
Qay
') A
' i \
2ay
Qay
Notes:
1 All soil
surface
samples collected from 0-6 inches below ground
Duplicate sample results are excluded.
A quality control analyte recovery is
outside of specified acceptance criteria
Abandoned uranium mine
Arsenic
Desktop analysis
Historical site assessment
Mercury
Estimated concentration
Milligram per kilogram
Molybdenum
The matrix spike sample recovery is not
within specified control limits
Picocurie per gram
Selenium
Chinle Formation Petrified Forest Member
Chinle Formation Shinarump Member
Uranium
Vanadium
• Soil Sample Location1
Disturbance Features (HSA, DA, and Field Verified)
d Exploratory Borehole
Berm
Accumulation/Deposition Area - Surficial
|*.*-V|:;l| Accumulation/Deposition Area - Volumetric
Concrete Pad
Dozer Cut
Exploratory / Access Road
Haul Road
Shallow Mine \Naste
I*. I Waste Pile
AUM Site Boundary
Data Gaps Investigation Area
Drainage
1 inch = 800 Feet
1:9,600
800
400
800
) Feet
SECTION 9 LEASE MINES
DATA GAPS
SOIL SAMPLING RESULTS - AUM 458
Prepared For: U.S. EPA Region 9
Prepared By:
It
TETRA TECH
1999 Harrison Street, Suite 500
Oakland, CA 94612
Task Order No.:
020
Contract No.:
68HE0923D0002
Location:
COVE CHAPTER 7/2/2024
NAVAJO NATION
Coordinate System:
NAD 1983 State Plane Arizona East
FIPS 0201 Feet Transverse Mercator
-------
v (rng/kg)
TRcs
TRcs
v. J
TRcs /
APE-SS03
Analyte
Result
As (mg/kg)
3.55
Hg (mg/kg)
0.0224 U
Mo (mg/kg)
0.133 J
Ra-226 (pCi/g)
2.83
Se (mg/kg)
2.3
U (mg/kg)
3 77
V (mg/kg)
191
APE-SS01
Analyte
Result
As (mg/kg)
4.39
Hg (mg/kg)
0.118
Mo (mg/kg)
12.8
Ra-226 (pCi/g)
10.4
Se (mg/kg)
2.49
U (mg/kg)
18
V (mg/kg)
29.4
/TRcs"^ y /
-¦> Qay
I '/ S I
Qay ^ TRcs
Qay
APE-SS07
Analyte
Result
As (mg/kg)
9.09
Hg (mg/kg)
0.0121 J
Mo (mg/kg)
110
Ra-226 (pCi/g)
15.4
Se (mg/kq)
1.28
U (mg/kg)
18 3 J
V (mg/kg)
5.09 J
X
APE-SS08
Analyte
Result
As (mg/kg)
0.961
Hg (mg/kg)
0.0216 U
Mo (mg/kg)
0.245
Ra-226 (pCi/g)
1.27
Se (mg/kg)
1.49
U (mg/kq)
0.99
V (mg/kg)
12.4
APE-SS05
Analyte
Result
As (mg/kq)
171
Hg (mg/kg)
0.0214 U
Mo (mg/kg)
0.258
Ra-226 (pCi/g)
1.35
Se (mg/kq)
3.15
U (mg/kg)
1.58
V (mg/kg)
12.9
\-y
\ -r
i
/
I
APE-SS02
Analyte
As (mg/kg)
Hg (mg/kg)
Mo (mg/kg)
Ra-226 (pCi/g)
Se (mg/kg)
U (mg/kg)
Result
0.0242 U
Notes:
'All soil
surface.
samples collected from 0-6 Inches below ground
Duplicate sample results are excluded.
*
A quality control analyte recovery is
outside of specified acceptance criteria
APE
Area of potential effect
As
Arsenic
AUM
Abandoned uranium mine
DA
Desktop analysis
HSA
Historical site assessment
Hg
Mercury
J
Estimated concentration
mg/kg
Milligram per kilogram
Mo
Molybdenum
pCi/g
Picocurie per gram
Se
Selenium
TRcp
Chinle Formation Petrified Forest member
TRcs
Chinle Formation Shinarump member
U
Not detected
U
Uranium
V
Vanadium
TRcs
v-yo I \
/ JlTRcP- t 1 TRcp A
I /i^j /vv> - v \
„ ~ —A
<>.K
i Ns
TRcs
K
TRcs
' /"TRCS>
£ ? 1 Q
APE-SS04
Analyte
Result v
As (mq/kq)
1.71
Hg (mg/kg)
0.0236 U
Mo (mg/kg)
1.26
Ra-226 (pCi/g)
2.3
Se (mg/kq)
2.23 i
U (mg/kg)
3.56
V (mg/kg)
32 %
APE-SS06
Analyte
Result
As (mq/kq)
0.749 J
Hg (mg/kg)
0.0116 J
Mo (mg/kg)
0.4
Ra-226 (pCi/g)
1.51
Se (mg/kq)
0.795 J
U (mg/kg)
173
V (mg/kg)
17
APE-SS09
Analyte
Result
As (mg/kg)
4.07
Hg (mg/kg)
0.016 J
Mo (mg/kg)
7.74
Ra-226 (pCi/g)
5.67
Se (mg/kq)
1.06
U (mg/kg)
5.92
V (mg/kg)
11.6
JtlMV i
i:
TRcs
» i
i /
i'',
TRcp
*TRcs "
- -v
APE-SS10
Analyte
Result
As (mg/kg)
1 28
Hg (mg/kg)
0.0224 U
Mo (mg/kg)
0.553
Ra-226 (pCi/g)
141
Se (mg/kg)
1.14
U (mg/kg)
1.23
V (mg/kg)
21
( *
\
I TRcp
/ / "N
• Soil Sample Location
Disturbance Features (HSA, DA, and Field Verified)
C3 Exploratory Borehole
!== Berm
Accumulation/Deposition Area - Surficial
Accumulation/Deposition Area - Volumetric
Concrete Pad
Dozer Cut
Exploratory / Access Road
Haul Road
Shallow Mine Waste
I-. I Waste Pile
^3 AUM Site Boundary
Data Gaps Investigation Area
~Geologic Contact
Drainage
1 inch = 800 Feet
1:9,600
N
S
800
400
800
) Feet
SECTION 9 LEASE MINES
DATA GAPS
SOIL SAMPLING RESULTS - APE
Prepared For: U.S. EPA Region 9
y
Prepared By:
It
TETRA TECH
1999 Harrison Street, Suite 500
Oakland, CA 94612
Task Order No.:
020
Contract No.:
68HE0923D0002
Location:
COVE CHAPTER
NAVAJO NATION
7/2/2024
Coordinate System:
NAD 1983 State Plane Arizona East
FIPS 0201 Feet Transverse Mercator
Figure No.:
A-8
-------
[ Proposed Repository Location
|__| AUM Site Boundary
Data Gaps Investigation Area
Chirtle Formation Ore-Bearing Members
~ Petrified Forest - TRcp
Shinarump - TRcs
Drainage
Note:
AUM
Abandoned uranium mine
1 inch = 600 Feet
1:7,200
600 300 0
N
S
600
~ Feet
SECTION 9 LEASE MINES
PROPOSED REPOSITORY LOCATION
Prepared For: U.S. EPA Region 9
Ts
I
v
Task Order No.:
020
Location:
COVE CHAPTER
NAVAJO NATION
Prepared By:
It
TETRA TECH
Contract No.:
68HE0923D0002
7/2/2024
Coordinate System:
NAD 1983 State Plane Arizona East
FIPS 0201 Feet Transverse Mercator
Figure No.:
A-9
-------
TABLE
-------
Table 1. Section 9 Lease Mines Data Gaps Surface Soil Sampling Results
Sample Number:
457-SS01-01-020624
457-SS02-01-020624
457-SS03-01-020624
457-SS04-01-020624
458-SS01-01-020624
458-SS02-01 -020624
Samplinq Location:
457-SS01
457-SS02
457-SS03
457-SS04
458-SS01
458-SS02
Matrix:
Soil
Soil
Soil
Soil
Soil
Soil
Sample Type:
Field Sample
Field Sample
Field Sample
Field Sample
Field Sample
Field Sample
Sample Depth (inches
0-6
0-6
0-6
0-6
0-6
0-6
Date Sampled:
2/6/2024
2/6/2024
2/6/2024
2/6/2024
2/6/2024
2/6/2024
CAS Number
Analyte
Method
Result Qualifier
Result Qualifier
Result Qualifier
Result Qualifier
Result Qualifier
Result Qualifier
METALS (mq/kq)
7429-90-5
Aluminum
SW6020
6230
4550
6890
3480
4540
3320
7440-36-0
Antimony
SW6020
1.87
U
1.74
U
1.83
U
1.88
U
1.89
U
1.94
U
7440-38-2
Arsenic
SW6020
14.4
N
16.1
N
3.97
J
18.5
N
22.7
N
22.4
N
7440-39-3
Barium
SW6020
151
*
236
*
189
J
327
*
314
*
256
*
7440-41-7
Beryllium
SW6020
0.467
0.667
0.653
0.424
1.16
0.641
7440-42-8
Boron
SW6020
1.79
J
2.17
J
2.95
J
1.75
J
2.76
J
1.68
J
7440-43-9
Cadmium
SW6020
0.148
J
0.748
0.109
J
0.794
0.252
0.2
7440-70-2
Calcium
SW6020
2170
4270
9490
3980
2170
1060
7440-47-3
Chromium
SW6020
5.82
5
5.3
4.9
6.58
6.44
7440-48-4
Cobalt
SW6020
23.7
N
28
N
4.19
J
7.45
N
2.93
N
2.01
N
7440-50-8
Copper
SW6020
7.97
N*
22.7
N*
15.9
J
10.3
N*
9.46
N*
7.35
N*
18540-29-9
Hexavalent Chromium
SW7196A
0.138
0.0997
U
7439-89-6
Iron
SW6020
10500
8360
6160
6180
9170
8120
7439-92-1
Lead
SW6020
9.25
N
16.5
N
9.26
J
74.8
N
17.8
N
12.5
N
7439-93-2
Lithium
SW6020
14
N
5.82
N
7.77
J
3.94
N
3.7
N
2.41
N
7439-95-4
Magnesium
SW6020
899
1130
1490
1520
518
300
7439-96-5
Manganese
SW6020
56.8
*
144
*
308
J
148
*
30.3
*
19.5
*
7439-97-6
Mercury
SW7471B
0.105
0.229
0.0257
0.165
0.204
0.192
7439-98-7
Molybdenum
SW6020
4.61
N
59.7
N
13.9
J
214
N
173
N
141
N
7440-02-0
Nickel
SW6020
6.98
N
15.2
N
4.8
J
6.99
N
3.04
N
1.7
N
7782-49-2
Selenium
SW6020
6.53
N*
1.95
N*
2
J
1.29
N*
1.47
N*
1
N*
7440-22-4
Silver
SW6020
0.468
U
0.0955
J-
0.458
0.2
J-
0.473
U
0.486
U
7440-23-5
Sodium
SW6020
975
N
407
N
555
J
396
N
91.1
N
64.7
N
7440-28-0
Thallium
SW6020
0.347
J
0.791
0.506
2.82
5.21
5.61
7440-29-1
Thorium
SW6020
7.65
6.55
8.15
4.24
7.06
5.81
7440-61-1
Uranium
SW6020
26.8
N
90.4
N
15.7
J
56
N
41.5
N
48.3
N
7440-62-2
Vanadium
SW6020
20.3
18.7
29.1
40.3
12.6
8.45
7440-66-6
Zinc
SW6020
21.4
N
31.9
N
10.9
J
61.9
N
8.39
N
5.19
N
RADIONUCLIDES (pCi/q)
14255-04-0
Lead-210
EH300
13.1
34.2
14
96.1
14.4
19.6
U
13981-52-7
Polonium-210
EH300
81.1
12.6
20.8
J
152
86
39.7
13982-63-3
Radium-226
EH300
18.6
66.7
18.9
160
30.9
37.7
14274-82-9
Thorium-228
HASL300
1.99
1.6
2.12
0.839
1.43
1.38
14269-63-7
Thorium-230a
HASL300
28.8
96.3
28.6
225
26.3
43.8
14269-63-7
Thorium-230g
EH300
18.6
66.7
18.9
160
30.9
37.7
7440-29-1
Thorium-232
HASL300
1.67
1.56
1.84
2.1
1.23
1.48
13968-55-3/13966-29-5
Uranium-233/234
HASL300
22.1
37.5
7.55
23.2
13.2
20.8
13966-29-5
Uranium-234
EH300
18.6
66.7
18.9
160
30.9
37.7
15117-96-1/13982-70-2
Uranium-235/236
HASL300
1.2
1.99
0.433
1.23
0.596
1.56
7440-61-1
Uranium-238a
HASL300
22.4
35.4
8.91
31.6
16.7
23
7440-61-1
Uranium-238g
EH300
15.5
46
8.05
30.5
24.7
29.8
Page 1 of 4
-------
Table 1. Section 9 Lease Mines Data Gaps Surface Soil Sampling Results
Sample Number:
458-SS03-01 -020624
458-SS04-01-020624
458-SS05-01 -020624
458-SS06-01-020624
458-SS06-02-020624
APE-SS01-01-020624
Samplinq Location:
458-SS03
458-SS04
458-SS05
458-SS06
458-SS06
APE-SS01
Matrix:
Soil
Soil
Soil
Soil
Soil
Soil
Sample Type:
Field Sample
Field Sample
Field Sample
Field Sample
Field Duplicate
Field Sample
Sample Depth (inches
0-6
0-6
0-6
0-6
0-6
0-6
Date Sampled:
2/6/2024
2/6/2024
2/6/2024
2/6/2024
2/6/2024
2/6/2024
CAS Number
Analyte
Method
Result Qualifier
Result Qualifier
Result Qualifier
Result Qualifier
Result Qualifier
Result Qualifier
METALS (mq/kq)
7429-90-5
Aluminum
SW6020
1810
3730
6930
4530
4420
10500
7440-36-0
Antimony
SW6020
1.82
U
1.76
U
1.81
U
1.76
U
1.84
U
1.84
U
7440-38-2
Arsenic
SW6020
30.9
N
17.6
N
1.09
N
21.7
N
21.1
4.39
7440-39-3
Barium
SW6020
335
*
234
*
56.9
*
273
J
173
J
142
7440-41-7
Beryllium
SW6020
0.289
0.652
1.68
0.818
0.928
1.57
7440-42-8
Boron
SW6020
0.785
J
1.76
J
3.57
2.38
J
2.66
J
5.77
7440-43-9
Cadmium
SW6020
0.329
0.316
0.0555
J
0.247
0.251
0.244
7440-70-2
Calcium
SW6020
2270
2290
2510
714
586
3680
7440-47-3
Chromium
SW6020
2.11
3.68
4.81
5.93
5.54
7.46
7440-48-4
Cobalt
SW6020
5.1
N
3.18
N
4.41
N
3.8
N
3.37
9.45
7440-50-8
Copper
SW6020
3.76
N*
7.74
N*
9.98
N*
10.2
N*
11
17.8
18540-29-9
Hexavalent Chromium
SW7196A
7439-89-6
Iron
SW6020
3290
5010
1680
7880
7160
13300
7439-92-1
Lead
SW6020
47.6
N
21
N
29.1
N
12.9
N
13.7
12.9
7439-93-2
Lithium
SW6020
2.26
N
3.8
N
15.1
N
3.75
N
3.72
12.6
7439-95-4
Magnesium
SW6020
199
1000
549
346
271
1570
7439-96-5
Manganese
SW6020
19
*
91.2
*
35.9
*
19.7
*
15
68.2
7439-97-6
Mercury
SVW471B
0.344
0.156
0.037
0.111
J
0.167
J
0.118
7439-98-7
Molybdenum
SW6020
78.6
N
191
N
0.228
N
126
N
121
12.8
7440-02-0
Nickel
SW6020
2.34
N
3.44
N
2.78
N
2.88
N
2.78
7.04
7782-49-2
Selenium
SW6020
1.35
N*
1.06
N*
2.16
N*
2.32
J
1.57
J
2.49
7440-22-4
Silver
SW6020
0.455
U
0.208
J-
0.453
U
0.441
U
0.46
U
0.461
U
7440-23-5
Sodium
SW6020
120
N
182
N
48.5
N
75.7
N
63
1910
7440-28-0
Thallium
SW6020
1.17
3.88
0.349
U
2.68
2.65
0.768
7440-29-1
Thorium
SW6020
8.95
7.06
18
7.83
7.34
8.55
7440-61-1
Uranium
SW6020
126
N
108
N
15.9
N
44
J
90.6
J
18
7440-62-2
Vanadium
SW6020
5.22
14.9
12.7
14.2
11.9
29.4
7440-66-6
Zinc
SW6020
7.97
N
9.97
N
11.7
N
9.15
N
8.54
21.5
RADIONUCLIDES (pCi/q)
14255-04-0
Lead-210
EH300
76.4
50
U
29.2
U
20.6
37.1
21.7
13981-52-7
Polonium-210
EH300
21.7
34.8
23.2
5.11
J
21.9
J
5.49
13982-63-3
Radium-226
EH300
134
48.3
12.2
29.3
J
34.5
J
10.4
14274-82-9
Thorium-228
HASL300
1.42
1.28
3.32
1.52
1.08
1.29
14269-63-7
Thorium-230a
HASL300
63.4
66.1
9.22
28.5
J
23.2
J
7.76
14269-63-7
Thorium-230g
EH300
134
48.3
12.2
29.3
34.5
10.4
7440-29-1
Thorium-232
HASL300
1.55
1.66
2.78
1.71
1.41
1.52
13968-55-3/13966-29-5
Uranium-233/234
HASL300
27.6
24
6.42
16.7
14.8
6.52
13966-29-5
Uranium-234
EH300
134
48.3
12.2
29.3
J
34.5
J
10.4
15117-96-1/13982-70-2
Uranium-235/236
HASL300
2.08
1.84
0.568
1.16
1.24
0.296
7440-61-1
Uranium-238a
HASL300
39.8
35.5
6.39
20.9
18.9
7.4
7440-61-1
Uranium-238g
EH300
56.4
27.3
9.36
25.3
17.9
8.75
Page 2 of 4
-------
Table 1. Section 9 Lease Mines Data Gaps Surface Soil Sampling Results
Sample Number:
APE-SS02-01-020624
APE-SS03-01-020624
APE-SS04-01-020624
APE-SS05-01-020624
APE-SS06-01-020624
APE-SS07-01-020624
Samplinq Location:
APE-SS02
APE-SS03
APE-SS04
APE-SS05
APE-SS06
APE-SS07
Matrix:
Soil
Soil
Soil
Soil
Soil
Soil
Sample Type:
Field Sample
Field Sample
Field Sample
Field Sample
Field Sample
Field Sample
Sample Depth (inches
0-6
0-6
0-6
0-6
0-6
0-6
Date Sampled:
2/6/2024
2/6/2024
2/6/2024
2/6/2024
2/6/2024
2/6/2024
CAS Number
Analyte
Method
Result Qualifier
Result Qualifier
Result Qualifier
Result Qualifier
Result Qualifier
Result Qualifier
METALS (mq/kq)
7429-90-5
Aluminum
SW6020
6560
12100
18400
6070
6710
2210
7440-36-0
Antimony
SW6020
1.79
U
1.85
U
2.04
U
2.01
U
1.81
U
1.8
U
7440-38-2
Arsenic
SW6020
1.2
3.55
1.71
1.71
0.749
J
9.09
7440-39-3
Barium
SW6020
424
24.8
347
198
223
52.2
7440-41-7
Beryllium
SW6020
0.571
1.19
1.18
0.538
0.726
0.373
7440-42-8
Boron
SW6020
2.78
J
4.43
6.78
2.51
J
2.32
J
1.04
J
7440-43-9
Cadmium
SW6020
0.0715
J
0.196
U
0.0378
J
0.0241
J
0.122
J
0.125
J
7440-70-2
Calcium
SW6020
12900
3180
10200
4400
5610
1750
7440-47-3
Chromium
SW6020
8.28
5.01
7.78
2.82
5
3.05
J
7440-48-4
Cobalt
SW6020
5.03
4.95
4.72
1.87
3.5
0.641
7440-50-8
Copper
SW6020
9.36
8.2
12.8
6.64
6.99
5.48
18540-29-9
Hexavalent Chromium
SW7196A
0.247
J
7439-89-6
Iron
SW6020
15200
17400
15900
5130
8130
1660
7439-92-1
Lead
SW6020
7.34
6.65
9.86
4.48
5.4
4.03
J
7439-93-2
Lithium
SW6020
5.04
9.24
16.5
4.66
6.97
0.861
J
7439-95-4
Magnesium
SW6020
3960
2550
2750
1180
1970
155
J
7439-96-5
Manganese
SW6020
385
50.1
155
119
110
4.96
7439-97-6
Mercury
SW7471B
0.0242
U
0.0224
U
0.0236
U
0.0214
U
0.0116
J
0.0121
J
7439-98-7
Molybdenum
SW6020
0.413
0.133
J
1.26
0.258
0.4
110
7440-02-0
Nickel
SW6020
12.5
5.26
4.75
2.24
4.57
0.437
7782-49-2
Selenium
SW6020
1.5
2.3
2.23
3.15
0.795
J
1.28
7440-22-4
Silver
SW6020
0.447
U
0.462
U
0.51
U
0.501
U
0.454
U
0.45
U
7440-23-5
Sodium
SW6020
879
5090
6640
328
223
36.6
J
7440-28-0
Thallium
SW6020
0.393
U
0.283
J
0.143
J
0.369
U
0.371
u
0.413
7440-29-1
Thorium
SW6020
6.01
6.26
9.18
7.12
4.93
3.86
7440-61-1
Uranium
SW6020
2.87
3.77
3.56
1.58
1.73
18.3
J
7440-62-2
Vanadium
SW6020
32.9
19.1
32
12.9
17
5.09
J
7440-66-6
Zinc
SW6020
11.4
23
19.9
10.8
9.15
2.69
J
RADIONUCLIDES (pCi/q)
14255-04-0
Lead-210
EH300
13.3
U
2.01
19.9
U
12.9
U
6.28
u
32.7
UJ
13981-52-7
Polonium-210
EH300
1.94
1.18
1.84
1.05
1.45
12.2
13982-63-3
Radium-226
EH300
1.94
2.83
2.3
1.35
1.51
15.4
14274-82-9
Thorium-228
HASL300
1.18
1.08
2.04
0.936
1
0.971
14269-63-7
Thorium-230a
HASL300
2.22
2.03
2.33
1.03
1.28
10.1
14269-63-7
Thorium-230g
EH300
1.94
2.83
2.3
1.35
1.51
15.4
7440-29-1
Thorium-232
HASL300
1.41
1.76
2.53
0.816
1.11
0.666
13968-55-3/13966-29-5
Uranium-233/234
HASL300
1.62
2.43
2.07
0.991
1.31
8.96
13966-29-5
Uranium-234
EH300
1.94
2.83
2.3
1.35
1.51
15.4
15117-96-1/13982-70-2
Uranium-235/236
HASL300
0.292
U
0.462
U
0.308
U
0.42
U
0.224
u
1.14
7440-61-1
Uranium-238a
HASL300
1.32
2.53
2.19
0.749
1.05
11.3
7440-61-1
Uranium-238g
EH300
2.99
U
2.04
4.79
U
3.81
U
2.22
u
9.32
U
Page 3 of 4
-------
Table 1. Section 9 Lease Mines Data Gaps Surface Soil Sampling Results
Sample Number:
APE-SS08-01-020624
APE-SS09-01-020624
APE-SS10-01-020624
Samplinq Location:
APE-SS08
APE-SS09
APE-SS10
Matrix:
Soil
Soil
Soil
Sample Type:
Field Sample
Field Sample
Field Sample
Sample Depth (inches
0-6
0-6
0-6
Date Sampled:
2/6/2024
2/6/2024
2/6/2024
CAS Number
Analyte
Method
Result Qualifier
Result Qualifier
Result Qualifier
METALS (mq/kq)
7429-90-5
Aluminum
SW6020
3650
3670
7620
7440-36-0
Antimony
SW6020
1.89
U
1.81
U
1.73
U
7440-38-2
Arsenic
SW6020
0.961
4.07
1.28
7440-39-3
Barium
SW6020
238
212
273
7440-41-7
Beryllium
SW6020
0.333
0.408
0.468
7440-42-8
Boron
SW6020
1.94
J
2.45
J
5.8
7440-43-9
Cadmium
SW6020
0.186
U
0.187
U
0.172
U
7440-70-2
Calcium
SW6020
4500
4650
14000
7440-47-3
Chromium
SW6020
3.57
3.19
8.51
7440-48-4
Cobalt
SW6020
2.03
5.32
4.98
7440-50-8
Copper
SW6020
4.87
6.15
8.69
18540-29-9
Hexavalent Chromium
SW7196A
0.145
U
7439-89-6
Iron
SW6020
6150
6110
10800
7439-92-1
Lead
SW6020
4.27
6.33
5.29
7439-93-2
Lithium
SW6020
3.2
4.43
5.15
7439-95-4
Magnesium
SW6020
1660
1390
5890
7439-96-5
Manganese
SW6020
176
104
262
7439-97-6
Mercury
SW7471B
0.0216
U
0.016
J
0.0224
U
7439-98-7
Molybdenum
SW6020
0.245
7.74
0.553
7440-02-0
Nickel
SW6020
4.36
3.69
13.2
7782-49-2
Selenium
SW6020
1.49
1.06
1.14
7440-22-4
Silver
SW6020
0.0999
J-
0.453
U
0.433
U
7440-23-5
Sodium
SW6020
302
424
786
7440-28-0
Thallium
SW6020
0.373
U
0.389
0.345
U
7440-29-1
Thorium
SW6020
7.14
4.85
5.01
7440-61-1
Uranium
SW6020
0.99
5.92
1.23
7440-62-2
Vanadium
SW6020
12.4
11.6
21
7440-66-6
Zinc
SW6020
8.46
13.2
16.4
RADIONUCLIDES (pCi/q)
14255-04-0
Lead-210
EH300
5.16
U
22.6
U
1.14
13981-52-7
Polonium-210
EH300
1.38
4.87
1.33
13982-63-3
Radium-226
EH300
1.27
5.67
1.41
14274-82-9
Thorium-228
HASL300
0.823
1.44
1.27
14269-63-7
Thorium-230a
HASL300
1.39
4.22
0.924
14269-63-7
Thorium-230g
EH300
1.27
5.67
1.41
7440-29-1
Thorium-232
HASL300
1.25
0.929
1.29
13968-55-3/13966-29-5
Uranium-233/234
HASL300
0.99
2.8
0.841
13966-29-5
Uranium-234
EH300
1.27
5.67
1.41
15117-96-1/13982-70-2
Uranium-235/236
HASL300
0.381
U
0.372
U
0.162
U
7440-61-1
Uranium-238a
HASL300
1.41
2.93
1.31
7440-61-1
Uranium-238g
EH300
1.75
5.36
U
0.965
Notes:
* A quality control analyte recovery is outside of specified acceptance criteria
bgs Below ground surface pCi/g Picocurie per gram
CAS Chemical Abstracts Service U Not considered detected. The associated number is the reported concentration
J The analyte was detected at the reported concentration; the quantitation is an estimate
J- The analyte was detected at the reported concentration; the quantitation is an estimate and may be biased low
mg/kg Milligram per kilogram
N The matrix spike sample recovery is not within specified control limits
Page 4 of 4
-------
ATTACHMENT 1
DISTURBANCE MAPPING PHOTOGRAPHIC LOG
-------
Attachment 1: Disturbance Mapping Photographic Log
@
The following photographs were taken during the Response, Assessment, and Evaluation
Services 2 Task Order 020 field scoping event at the Section 9 Lease Mines from February 6 to
10, 2024. A more comprehensive photographic log will be developed for the engineering
evaluation/cost analysis. All disturbance mapping observations with photographs and notes are
available on the U.S. Environmental Protection Agency Region 9 Abandoned Uranium Mine
(AUM) GeoPlatform.
Field Observations - Undisturbed Areas
PHOTOGRAPH 1
Date: 02/06/2024
Location:
35.729999;
-111.326361
Feature: Mineralized
outcrop
Description: Outcrop
of mineralized
Shinarump Member
exposed from natural
erosion located next
to Indian Road 6728.
Contract No. 68HE0923D0002, Task Order 020
1-1
-------
Attachment 1: Disturbance Mapping Photographic Log
@
PHOTOGRAPH 2
Date: 02/06/2024
Location:
35.733213;
-111.334057
Feature: Mineralized
outcrop
Description: Lower
Petrified Forest
Member; likely
naturally occurring
radioactive material;
gamma survey for the
removal site
evaluation recorded
40 to 90,000 counts
per minute (cpm)
during mapping.
PHOTOGRAPH 3
Date: 02/07/2024
Location:
35.735000;
111.324383
Feature: Vegetation,
soil, and old-growth
trees; exploratory
dozer cut
Description:
Large exploratory
dozer cut in
exploratory area
south of AUM 457.
Contract No. 68HE0923D0002, Task Order 020
1-2
-------
Attachment 1: Disturbance Mapping Photographic Log
@
PHOTOGRAPH 5
Date: 02/08/2024
Location:
35.736952;
-111.324326
Feature:
Drill trail
Description:
Exploratory drill trail
in exploratory area
south of AUM 457.
PHOTOGRAPH 6
Date: 02/07/2024
Location:
35.737197;
-111.325271
Feature:
Exploratory
borehole
Description:
Exploratory
borehole (wood
plug in forefront) in
exploration area
south of AUM 457.
Contract No. 68HE0923D0002, Task Order 020
1-3
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Attachment 1: Disturbance Mapping Photographic Log
It
Field Observations - Mine-Related Disturbed Areas (Production
Mine Features)
PHOTOGRAPH 7
Date: 02/07/2024
Location:
35.739281;
-111.324434
Feature:
Mine waste pile
Description:
Unreclaimed mine
waste pile at AUM
457 approximately
12 feet high; gamma
readings up to
390,000 cpm.
PHOTOGRAPH 8
Date: 02/06/20124
Location:
35.730493;
-111.331163
Feature:
Mine waste pile
Description:
Waste pile near
western side of Atlas
AUM boundary in
AUM 458; 6 to 10
feet high, flattens out
into slope from dozer
push-off; larger
waste rock present.
Contract No. 68HE0923D0002, Task Order 020
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Attachment 1: Disturbance Mapping Photographic Log
@
PHOTOGRAPH 9
Date: 02/08/2024
Location:
35.739538;
-111.323738
Feature:
Concrete structure
related to mill facility
Description:
Approximately 36-
foot-high structure at
AUM 457, gamma
readings from 90 to
300,000 cpm.
PHOTOGRAPH 10
Date: 02/07/2024
Location:
35.738422;
-111.325347
Feature:
Haul road
Description:
Haul road to AUM
457.
Contract No. 68HE0923D0002, Task Order 020
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Attachment 1: Disturbance Mapping Photographic Log
@
PHOTOGRAPH 11
Date: 02/07/2024
Location:
35.738881;
-111.324294
Feature:
Concrete pad
Description:
Approximately
20-square-foot
concrete pad at AUM
457, gamma readings
up to 70,000 cpm.
Field Observations - Mine-Related Disturbed Areas
(Reclamation Features)
No photographs are available for reclamation features because the site has not undergone any
mine reclamation.
Contract No. 68HE0923D0002, Task Order 020
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Attachment 1: Disturbance Mapping Photographic Log
@
Field Observations - Hydrology in Disturbed Areas
PHOTOGRAPH 12
Date: 02/06/2024
Location:
35.729520;
-111.331035
Feature:
Drainage, waste
transport
Description:
Drainage from AUM
458.
-V- ... y
PHOTOGRAPH 13
Date: 02/06/2024
Location:
35.733745;
111.325043
Feature:
Drainage-Other
Description:
Drainage in
exploration area
south of AUM 457.
Contract No. 68HE0923D0002, Task Order 020
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Attachment 1: Disturbance Mapping Photographic Log
It
PHOTOGRAPH 14
Date: 02/07/2024
Location:
35.740821;
-111.336997
Feature:
Undisturbed drainage
Description: Natural
drainage; no evidence
of mining-related
disturbance.
Contract No. 68HE0923D0002, Task Order 020
1-8
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APPENDIX B
RISK ASSESSMENT
-------
Navajo Abandoned Uranium Mines
Western Abandoned Uranium Mine Region
Coconino County, Arizona
Draft Final
Appendix B
Risk Assessment
Section 9 Lease Mines
Engineering Evaluation/Cost Analysis
Response, Assessment, and Evaluation Services 2
Contract No. 68HE0923D0002
Task Order 020
July 2024
Submitted to
U.S. Environmental Protection Agency
Submitted by
Tetra Tech, Inc.
1999 Harrison Street, Suite 500
Oakland, CA 94612
TETRA TECH
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Appendix B: Section 9 Lease Mines Risk Assessment
TABLE OF CONTENTS
Section Page
ACRONYMS AND ABBREVIATIONS B-iv
1.0 BACKGROUND AND ENVIRONMENTAL SETTING B-1
1.1 MINE HISTORY AND LOCATION B-1
1.2 GEOLOGY, HYDROGEOLOGY, AND HYDROLOGY B-2
1.2.1 Geology B-2
1.2.2 Hydrogeology B-3
1.2.3 Hydrology B-3
1.3 LAND USE B-3
1.4 ECOLOGICAL SETTING B-4
1.4.1 Climate B-4
1.4.2 Vegetation B-5
1.4.3 Wildlife B-5
1.4.4 Special Status Species B-5
2.0 DATA USED IN THE RISK ASSESSMENT B-6
2.1 AVAILABLE DATA B-6
2.2 DATA REDUCTION METHODS B-7
2.3 EXPOSURE UNITS B-7
2.4 EXPOSURE POINT CONCENTRATIONS B-8
2.5 EVALUATION OF SECULAR EQUILIBRIUM B-8
3.0 HUMAN HEALTH RISK ASSESSMENT B-9
3.1 DATA EVALUATION AND IDENTIFICATION OF CONTAMINANTS OF
POTENTIAL CONCERN B-9
3.2 EXPOSURE ASSESSMENT B-9
3.2.1 Conceptual Site Model B-10
3.2.2 Human Health Receptors, Exposure Pathways, and Exposure
Parameters B-10
3.2.3 Exposure Parameters B-ll
3.3 TOXICITY ASSESSMENT B-ll
3.3.1 Carcinogenic Effects B-12
3.3.2 Noncarcinogenic Effects B-12
3.3.3 Sources of Toxicity Values and Other Contaminant-Specific
Parameters B-12
3.4 RISK CHARACTERIZATION B-12
3.4.1 Estimates of Cancer Risk and Noncancer Hazard B-13
3.4.2 Uncertainty Associated with the Human Health Risk Assessment B-14
Contract No. 68HE0923D0002, Task Order 020 B-i
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Appendix B: Section 9 Lease Mines Risk Assessment
4.0 ECOLOGICAL RISK ASSESSMENT B-16
4.1 PROBLEM FORMULATION B-16
4.1.1 Ecological Habitat and Biological Resources B-17
4.1.2 Stressors and Constituents of Interest Selection B-17
4.1.3 Potentially Complete Exposure Pathways B-17
4.1.4 Assessment Endpoints B-18
4.1.5 Measurement Endpoints B-18
4.1.6 Conceptual Site Model B-20
4.2 ANALYSIS OF EXPOSURE AND EFFECTS B-20
4.2.1 Exposure Estimates B-20
4.2.2 Ecological Effects B-20
4.3 RISK CHARACTERIZATION B-21
4.3.1 Screening-Level Ecological Risk Assessment for Contaminants of
Potential Ecological Concern B-21
4.3.2 Screening-Level Ecological Risk Assessment Refinement B-21
4.3.3 Candidate Contaminants of Ecological Concern B-22
4.4 UNCERTAINTY ANALYSIS ASSOCIATED WITH THE ECOLOGICAL
RISK ASSESSMENT B-23
4.4.1 Exposure Estimates B-23
4.4.2 Nondetected Contaminants of Potential Ecological Concern B-24
4.4.3 Combined Exposures Across Media B-24
4.4.4 Risk to Plant and Invertebrate Communities B-25
5.0 RISK ASSESSMENT RESULTS SUMMARY B-26
6.0 REFERENCES B-27
EXHIBITS
Exhibit B-l. Receptor Evaluated B-l 1
Exhibit B-2. Cancer Risks and Noncancer Hazards B-l3
Exhibit B-3. Candidate Contaminants of Concern B-l4
Exhibit B-4. Site-Wide Candidate Contaminants of Ecological Concern B-23
Exhibit B-5. Candidate Contaminants of Concern or Contaminants of Ecological Concern
for Soil B-26
Contract No. 68HE0923D0002, Task Order 020 B-ii
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Appendix B: Section 9 Lease Mines Risk Assessment
FIGURES
Figure B-l. Section 9 Lease Mines Location and Access
Figure B-2. Section 9 Lease Mines Exposure Unit with Risk Assessment Sample Locations
Figure B-3. Section 9 Lease Mines Exposure Unit Sample Locations - Overview
Figure B-4. Section 9 Lease Mines Exposure Unit Sample Locations - AUM 457
Figure B-5. Section 9 Lease Mines Exposure Unit Sample Locations - AUM 458
Figure B-6. Section 9 Lease Mines Conceptual Site Model
TABLES
Table B-l. Soil Results Data Summary and Contaminant of Potential Concern Screening
Table B-2. Exposure Unit Summary of Land Use, Geologic Formation, Type, Area, and
Available Samples
Table B-3. Human Health Exposure Parameters
Table B-4. Exposure Point Concentrations for Human Health Risk Assessment
Table B-5. Human Health Risk and Hazard Calculations
Table B-6. Human Health Risk and Hazard Summary by Exposure Pathway
Table B-7. Human Health Risk and Hazard Summary and Identification of Candidate
Contaminants of Concern
Table B-8. Screening-Level Ecological Risk Assessment Screening for Soil
Table B-9. Exposure Point Concentrations for Ecological Risk Assessment
Table B-10. Comparison of Individual Sample Results to Plant and Invertebrate No Observed
Effect Concentrations
Table B-l 1. Screening-Level Ecological Risk Assessment Refinement for Soil - Birds
Table B-l2. Screening-Level Ecological Risk Assessment Refinement for Soil - Mammals
ATTACHMENTS
Attachment B-l. Data Used in the Risk Assessment
Attachment B-2. Preliminary Determination for Secular Equilibrium at the Section 9 Lease
Mines
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Appendix B: Section 9 Lease Mines Risk Assessment
"It
ACRONYMS AND ABBREVIATION
AUM
ml
Abandoned uranium mine
bgs
BLM
CERCLA
COC
COEC
COI
COPC
COPEC
CSM
Eco-SSL
EE/CA
EPC
ERA
ERICA
ESL
EU
HHRA
HQ
LANL
LCR
Below ground surface
Bureau of Land Management
Comprehensive Environmental Response, Compensation, and Liability Act
Contaminant of concern
Contaminant of ecological concern
Constituent of interest
Contaminant of potential concern
Contaminant of potential ecological concern
Conceptual site model
Ecological soil screening level
Engineering evaluation/cost analysis
Exposure point concentration
Ecological risk assessment
Environmental Risks from Ionising Contaminants: Assessment and
Management
Ecological screening level
Exposure unit
Human health risk assessment
Hazard quotient
Los Alamos National Laboratory
Little Colorado River
N3B
NAUM
NOEC
NORM
ORNL
OSWER
RfC
RfD
RME
RSL
Newport News Nuclear BWXT-Los Alamos, LLC
Navajo abandoned uranium mine
No observed effect concentration
Naturally occurring radioactive material
Oak Ridge National Laboratory
Office of Solid Waste and Emergency Response
Reference concentration
Reference dose
Reasonable maximum exposure
Regional screening level
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Appendix B: Section 9 Lease Mines Risk Assessment
"It
ACRONYMS AND ABBREVIATIONS (CONTINUE
J
SE
Secular equilibrium
SF
Slope factor
SLERA
Screening-level ecological risk assessment
SWCA
SWCA Environmental Consultants
TENORM
Technologically enhanced naturally occurring radioactive material
Tetra Tech
Tetra Tech, Inc.
UCL95
95 percent upper confidence limit
US EPA
U.S. Environmental Protection Agency
Weston
Weston Solutions, Inc.
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Appendix B: Section 9 Lease Mines Risk Assessment
1.0 BACKGROUND AND ENVIRONMENTAL SETTIN
ml
The Section 9 Lease Mines are on private and federal property adjacent to the Navajo Nation and
the investigation and remediation of the site is being addressed under the Navajo Abandoned
Uranium Mines (NAUM) program. The purpose of this NAUM program site-specific risk
assessment is to estimate current and future human health risk under appropriate reasonable
maximum exposure (RME) scenarios and ecological risk focused on the known ecosystems for
the region. The results of the risk assessment are used to assist in removal action decisions at the
Section 9 Lease Mines.
The human health risk assessment (HHRA) identifies candidate human health contaminants of
concern (COC) for each exposure unit (EU) while the ecological risk assessment (ERA)
identifies candidate contaminants of ecological concern (COEC) for the site. The results of the
risk assessment serve as lines of evidence in determining the extent of soil removal necessary at
the Section 9 Lease Mines to meet the removal action goals. See the "Navajo Abandoned
Uranium Mines Risk Assessment Methodology" (U.S. Environmental Protection Agency
[USEPA] 2024c) for additional information for conducting risk assessments at NAUM sites.
The Navajo Nation and surrounding areas contain areas of naturally elevated levels of uranium.
Starting in the 1940s, large amounts of uranium were mined in the southwest United States.
Mining has brought more uranium to the surface of the earth, making exposure to people, plants,
and animals more likely. Uranium is a naturally occurring radioactive material (NORM), and the
effects of mining can lead to technologically enhanced naturally occurring radioactive material
(TENORM).
Examples of TENORM at the Section 9 Lease Mines include waste rock piles, burial cells,
contaminated access roads, areas contaminated by eroding waste and windblown dust, and
adjacent drainages receiving potentially contaminated runoff.
1.1 MINE HISTORY AND LOCATION
The Section 9 Lease Mines include Abandoned Uranium Mines (AUM) 457 and 458 and a small
northern portion of AUM 459 (see Figure B-l). The following subsections describe the site
location, type of mines and operational status, regulatory history, features and landscape,
geology and hydrology, land use and populations, sensitive ecosystems and habitat, and
meteorology and climate. Former open pit mining operation facilities are located on AUMs 457
and 458. Figure 3 of the main engineering evaluation/cost analysis (EE/CA) report provides the
locations of major site features for AUMs 457 and 458, including pit areas, observed
unreclaimed waste piles and mining debris, and remnants of former structures.
The Section 9 Lease Mines site is 10.8 air miles and 14.5 road miles from Cameron, Arizona.
The elevation is 4,206 feet above mean sea level. The Section 9 Lease Mines area is currently
not used by the property owners although evidence of trespassing is apparent at the site.
The site is in the Little Colorado River (LCR) valley in Coconino County, Arizona, on the west
side of the LCR at 35.734 degrees latitude and -111.328 degrees longitude (see Figure B-l). The
Navajo Nation surrounds the site to the north and east. The site is largely on land owned by
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Appendix B: Section 9 Lease Mines Risk Assessment
Babbitt Ranches, LLC and CO Bar, Inc. in Section 9 with a small portion on federal land
managed by the Bureau of Land Management (BLM) in Section 10. Land ownership for the site
and locations of mine boundaries that were established from historical records and observations
are shown on Figure 2 of the main EE/CA report.
AUM 457 is 16.5 acres and contained within Section 9 except for the easternmost boundary on
the banks of the LCR, which is in Section 10 on BLM land. AUM 457 includes a former borrow
pit and pond. Concrete foundations and two 30-foot-tall walls from the Benson Upgrader (the ore
processing plant demolished in 1961) are near the center of the AUM boundary (Weston
Solutions, Inc. [Weston] 2011). The main foundation covers a footprint of approximately 100
feet by 50 feet, and a smaller foundation south of the larger concrete pad measures 20 feet by 20
feet.
AUM 458 is 9.3 acres and contained entirely within Section 9. AUM 458 is 0.25 mile west of the
LCR and includes uranium waste rock, mining debris, and a recessed pit near the center of the
AUM (Weston 2011). A regional drainage, Mays Wash, is east and immediately to the south of
the AUM boundary.
For additional details on the Section 9 Lease Mines mine history and site features, see
Section 2.0 of the main EE/CA report. Appendix A of the EE/CA report contains site images that
show the condition of the site at the time of the site visit in February 2024.
1.2 GEOLOGY, HYDROGEOLOGY, AND HYDROLOGY
The following subsections describe the geology, hydrogeology, and hydrology of the Section 9
Lease Mines. For more information, see Section 2.1.5 of the main EE/CA report.
1.2.1 Geology
The geology of the Cameron area is characterized by layered sedimentary units typical of the
Colorado Plateau. The complex geologic history and long-term stability of the Colorado Plateau
allowed for the mineralization of uranium, and the Cameron area contains abundant uranium ore
deposits that are found primarily in the upper Triassic Chinle Formation. Quaternary-age
materials, comprising sedimentary alluvium, sand, and gravel deposits, overlay the Triassic
Chinle Formation. Fluvial sandstones in the lower part of the Petrified Forest Member of the
Chinle Formation contain most of the uranium deposits around Cameron with a lesser amount
found in the Shinarump Member of the Chinle Formation. The Moenkopi Formation underlies
the Chinle Formation and is exposed in areas near the LCR and other washes where overlying
deposits have been eroded (Chenoweth 1993). Ore bodies occur at the surface to a depth of
130 feet and vary in size from a single mineralized fossil log to hundreds of feet in length
(Chenoweth and Malan 1973). General descriptions of the three relevant geological units are
presented below in descending stratigraphic order (Bollin and Kerr 1958; Dubiel and others
1991):
• Petrified Forest Member of the Chinle Formation (Late Triassic, 237 to 201 million
years ago): Red and brown fluvial sandstones and floodplain mudstone deposits with
volcanic ash and carbonaceous material.
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Appendix B: Section 9 Lease Mines Risk Assessment
• Shinarump Member of the Chinle Formation (Late Triassic, 237 to 201 million
years ago): White to yellow and gray sandstone and conglomerate with minor gray
mudstone. Fluvial channel and valley fill deposits were incised into the underlying
Moenkopi Formation. Sediments were deposited as lenticular beds that contain
carbonaceous material.
• Quaternary Alluvium (Holocene, less than 11,700 years ago): Quaternary-age
materials, comprising sedimentary alluvium, sand, and gravel deposits, overlay the
Triassic Chinle Formation.
A map showing the geologic units for the site and vicinity are presented on Figure 4 of the main
EE/CA report.
1.2.2 Hydrogeology
No wells were identified near the Section 9 Lease Mines that would confirm the occurrence and
depth of groundwater. No known drinking water wells or sources are within 1 mile of the site
(Weston 2012). The Section 9 Lease Mines are located above the Chinle Aquifer.
1.2.3 Hydrology
Most precipitation at the Section 9 Lease Mines occurs from July to October as monsoon
thunderstorms. The annual evaporation rate is nearly five times the precipitation rate;
consequently, most streams in the area are ephemeral or have flowing water only during storms
or rapid snowmelt. The dry conditions and high-intensity rains cause quick saturation of the
surface soils, preventing precipitation from penetrating deeper. As a result, intense rainfall drives
surface flow into canyon washes, generating short-term and fast-moving streams. These streams
produce arroyos that cut through the sedimentary bedrock in the canyons and erode sediments
that are transported downstream to be deposited as alluvium.
Water that discharges from the seeps travels through a fracture flow system, which makes
identifying water flow paths difficult. The concentrations of potential contaminants found in the
water may be attributable to mineralized rock in the mine workings or flow through naturally
occurring mineralized rock. A summary of the occurrence, drainage pattern, and chemical
characteristics of surface water is presented in Appendix J of the "Western Agency Tronox
Mines Removal Site Evaluation Report" (Tetra Tech, Inc. [Tetra Tech] 2019).
1.3 LAND USE
A land easement prohibiting residential use of land owned by Babbitt Ranches, LLC within
Section 9 was established in 2019 (Engineering Analytics, Inc. 2021). Accessing the site is
prohibited for purposes other than for maintenance of the main access road and inspection of the
property. The site is not currently used for livestock, agricultural, or other purposes. No
structures are in use at the site, and no structures will be built on the site in the future.
The people most likely to access the portion of the site within Section 9 are periodic workers,
including employees of Babbitt Ranches, LLC and CO Bar, Inc., and possible trespassers, which
are likely to be recreators camping on BLM land that are trespassing onto deed-restricted
Contract No. 68HE0923D0002, Task Order 020
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Appendix B: Section 9 Lease Mines Risk Assessment
Section 9 property. Recreators on BLM land, as well as BLM staff, can access the portion of the
site on Section 10. No long-term practicable physical barrier solutions limit movement between
Sections 9 and 10; thus, a person legally accessing BLM-managed land on Section 10 may also
likely trespass on Section 9. Thus, a trespasser scenario based on BLM recreator inputs was
selected as the most appropriate RME scenario for the Section 9 Lease Mines.
Activities that occur near or on the site that may expose people to soil contaminants include
camping, gathering firewood, walking, hiking, and using all-terrain vehicles. Persons traversing
the site may be exposed to contaminated dust by inhalation of particulate matter. Whole body
(external) radiation may be experienced by people on or near the site.
1.4 ECOLOGICAL SETTING
The Section 9 Lease Mines are in a remote area with a revegetated, previously disturbed mine
area. Wildlife inhabiting the area may directly ingest radionuclides and chemicals, which may
then be transported to the organs or other sites within the wildlife receptor.
In 2016, the U.S. Fish and Wildlife Service determined that no federally listed or proposed
endangered or threatened species are present at or near the site and that no critical habitats for
such species exist at the site (SWCA Environmental Consultants [SWCA] 2016). The biological
resources survey assessed other special status plant and animal species that were identified by the
State of Arizona and Navajo Nation as potentially relevant to the site and found a low likelihood
of occurrence of these species at the site (SWCA 2016). Sparse vegetation at the site is not ideal
for many ecological receptors; therefore, the potential for occurrence of Navajo endangered
species and State of Arizona species of greatest conservation need is very low at the site.
At the time of the biological survey in 2016, no aquatic vegetation was observed in the dry
channel of the LCR, and no aquatic life was observed in standing pools from recent rain events
in the channel bed. Further, wetland features previously identified by USEPA (Weston 2014)
were not observed and are not present at the site (SWCA 2016).
Tetra Tech recognizes that these findings are outdated, and a new biological assessment will be
conducted at least 2 years before removal activities. However, because the area is largely
unchanged since the 2016 biological assessment, no major changes to this original assessment
are expected.
1.4.1 Climate
The site lies in a semi-arid climate with a high annual net pan evaporation rate of 81 inches per
year with an average annual rainfall of 5.6 inches. The average annual low temperature is 43 °F
with an average annual high temperature of 75 °F. Wind is predominately from the west with an
average wind speed of 5 miles per hour. Extreme heat in the summer (100 °F) and cold in the
winter (-34 °F) can occur. Climate data that occurs within Ecoregion 22p is summarized in the
NAUM risk assessment methodology (USEPA 2024c).
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Appendix B: Section 9 Lease Mines Risk Assessment
**
It
1.4.2 Vegetation
Ecoregion 22 represents a large transitional region between the drier shrublands and wooded
higher-relief tablelands of the Colorado Plateaus (Ecoregion 20) in the north and the lower,
hotter, less vegetated ecoregions to the west and east. Ecoregion 22p is the Little Colorado
Valley/Painted Desert, which is characterized by irregular plains, valleys, and basins with
meandering river floodplain, alluvial terraces, and adjacent mesas, buttes, hills, and badlands.
Streams are mostly ephemeral and intermittent. Higher, forest-covered mountainous ecoregions
border the region on the northeast and south (Ecoregion 23). Common plant species include
mound saltbush (Atriplex obovata), four-wing saltbush {Atriplex canescens), shadscale (Atriplex
confertifolia), alkali sacaton (Sporobolus airoides), galleta grass (Pleuraphis jamesii), gyp
dropseed {Sporobolus nealley!), black grama (Bouteloua eriopoda), Indian ricegrass (Stipa
hymenoides), yucca (Yucca baccata, Yucca glauca), Mormon tea (.Ephedra nevadensis), and
black greasewood (Sarcobatus vermiculatus). On floodplains, vegetation is mostly exotic
tamarisk (Tamarix ramosissima) with some scattered cottonwood (Populusspp.) and willow
(.Salicaceae spp.).
1.4.3 Wildlife
Gunnison prairie dogs (Cynomys gunnisom) are a keystone species in many of the sagebrush
ecosystems, and their burrows provide habitat for other wildlife, including burrowing owls
(.Athene cunicularia), weasels (Mustela spp.), badgers (Taxidea taxus), and a variety of snakes.
1.4.4 Special Status Species
The U.S. Fish and Wildlife Service determined that no federally listed or proposed endangered or
threatened species are present at or near the site and that no critical habitats for such species exist
at the site (SWCA 2016).
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Appendix B: Section 9 Lease Mines Risk Assessment
**
It
2.0 DATA USED IN THE RISK ASSESSMENT
ml
Data compilation and management tasks conducted for the Section 9 Lease Mines risk
assessment included the selection of useable data and evaluation of sample depth intervals and
selection of depth intervals to be evaluated. At this time, gamma data are not considered
definitive data and, therefore, were not used in the risk assessment. However, gamma data were
used to help delineate TENORM boundaries and to establish the footprint for the risk assessment
and will be used for future removal decisions.
The compiled investigation data for the constituents of interest (COI) were reviewed to confirm
that the appropriate data were used in the risk assessment. Essential nutrients such as calcium,
magnesium, potassium, and sodium are not retained as COIs. The data were separated by the
depth intervals to be evaluated prior to calculating the exposure point concentrations (EPC) and
other statistical values. Figure B-2 presents an overview of the locations of the available soil
samples used in the risk assessment for the Section 9 Lease Mines.
2.1 AVAILABLE DATA
Evaluation of potential human and ecological exposure at the Section 9 Lease Mines is limited to
radionuclides and metals in soil. All available data for samples collected within the EU (see
Section 2.3) were used in the risk assessments. Table B-l provides the summary statistics for all
soil sample results available for the risk assessment. Attachment B-1 presents the results of all
soil samples used in the risk assessment.
A data useability assessment was conducted to confirm that the useability of the laboratory data
is consistent with USEPA (1992a) guidance. Data validation of all results used in the risk
assessment was performed per the guidelines for data review (USEPA 2004, 2020). The
following key data validation flags were considered in the data reduction process:
• Estimated values (flagged with "J" qualifiers) should be treated as detected
concentrations.
• Rejected data (flagged with "R" qualifiers) should not be included in the risk assessment
datasets because of deficiencies in meeting quality control criteria. No data in the datasets
were rejected.
• Results with final validation qualifiers containing a "U" or "UJ" are nondetect values
included in the risk assessment datasets. The method reporting limit was used as the
value for nondetect results.
Four samples from the Section 9 Lease Mines were analyzed for hexavalent chromium because
the field sampling plan (Tetra Tech 2024) was prepared prior to completion of the NAUM
risk assessment methodology (USEPA 2024c). At the time of sampling in February 2024,
analysis for hexavalent chromium was being discussed as a potential additional requirement in
the risk assessment methodology, thus the analyses were requested rather than having a
potential data gap.
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Appendix B: Section 9 Lease Mines Risk Assessment
The four hexavalent chromium results were not used in the quantitative risk assessment. Three of
the four samples were nondetect for hexavalent chromium, and one sample (APE-SS07-01-
020624) had a detection (0.247 mg/kg) below the method reporting limit. Review of the
laboratory report for the detected result raised concern that the detected concentration may not be
an actual detection and may instead be caused by spectral interference from other metals present
in the sample, notably molybdenum and vanadium. Evidence of this includes that the matrix
spike sample, which was performed on the sample with the detection, had a result lower than that
of the unspiked sample even though the spike concentration was much higher than the native
concentration and the recovery was still within quality criteria. Despite this, the assumption
made for the risk assessment was that the total chromium results were 100 percent hexavalent
chromium to provide a more protective assessment. Use of total chromium results relies on data
from inductively coupled plasma mass spectroscopy that is commonly used for evaluation of
metals for use in risk assessments.
2.2 DATA REDUCTION METHODS
The metals and radiological data were queried to select the best result for each unique
combination of sample media, location ID, sample date, and sample depth for which duplicate
data exist. These procedures conservatively select one result for original and field duplicate
pairs. For duplicate samples, the maximum detected concentration of the original and field
duplicate result was selected as the result for use in the risk assessment. If both the original and
field duplicate results are nondetect, the result associated with the higher reporting limit was
used.
2.3 EXPOSURE UNITS
An EU is a geographic area with a particular land use within which an exposed receptor (a
person, animal, or plant) may reasonably be assumed to move at random and where contact
across the EU is equally likely over the course of an exposure duration. The Section 9 Lease
Mines EU was developed by identifying areas of contiguous TENORM contamination and
anticipated future land use. Areas of NORM, such as natural mineralized outcrops and
nonimpacted areas in the northeastern portion of the site, although not included in the
TENORM boundary, were also included within the risk assessment boundary because a
receptor would also be exposed to the NORM areas when at the site. The risk assessment
boundary (the entirety of all areas evaluated within the EU) was established via soil sampling
and augmented through examination of gamma survey data. See Section 2.3 of the main
EE/CA report for descriptions of previous investigations and Section 2.4 of the main EE/CA
report for the extent of contamination.
Based on the site evaluation and summarized in Table B-2, the Section 9 Lease Mines are being
evaluated as a single EU for the HHRA and ERA. The existing or anticipated future land use for
an area is key in selecting the potential receptors evaluated in the HHRA conducted for a site.
The RME receptor for the HHRA was selected based on site knowledge. This HHRA only
evaluates the RME receptor at the EU. Figure B-3 through Figure B-5 provide the locations of
samples used in the risk assessment.
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2.4 EXPOSURE POINT CONCENTRATIONS
To determine concentrations in environmental media (for example, surface soil) to which people
and ecological receptors might be exposed, representative statistics are calculated from the
datasets. Soil samples were grouped by sample depth to correspond to the surface and subsurface
soil intervals evaluated in the risk assessment. Surface soil samples are those collected from 0 to
6 inches below ground surface (bgs) while subsurface soil samples are those collected from 0 up
to 72 inches bgs. As described in the NAUM risk assessment methodology (USEPA 2024c),
these soil depths were selected to incorporate more data from the NAUM sites. A depth of
72 inches was selected for potential human health exposures because deeper soil could become
exposed in the future by erosion. In addition, plants in desert settings commonly have roots to
72 inches bgs. Thus, uptake to plants from contamination at depth is a complete exposure
pathway for the ERA. Furthermore, burrowing animals are evaluated in the ERA; 72 inches bgs
is an appropriate exposure depth for evaluating these ecological receptors.
The process provided in Appendix D of the NAUM risk assessment methodology (USEPA
2024c) was used to calculate the EPC for each contaminant of potential concern (COPC). The
approach and calculations for EPCs follow USEPA (1989, 1992b, 2000a, 2002, 2022) guidance.
The 95 percent upper confidence limit (UCL95) of the mean values were calculated for each
COPC using ProUCL 5.2 (USEPA 2022). A minimum of 10 samples and 4 detected results are
required for a given contaminant to calculate the UCL95 that can be used as the EPC. If the
dataset was smaller than 10 samples or the number of detections was less than 4, the maximum
detected concentration should be used as the EPC. In cases where the UCL95 exceeds the
maximum detected concentration, the maximum detected concentration was used as the soil
EPC. If a nonradioactive COPC was not detected in a sample when entering data into ProUCL,
the sample reporting limit was used as the numerical value for that sample for EPC calculations.
2.5 EVALUATION OF SECULAR EQUILIBRIUM
A site-specific secular equilibrium (SE) preliminary determination was conducted on the
Section 9 Lease Mines radiological dataset. A range of equilibrium conditions were observed;
however, the site-wide disequilibrium factor was 0.7 and the overall conclusion is that
uranium-238 is in SE with its decay products. When uranium-238 is in SE, site data for
radium-226 in conjunction with uranium-238 in SE toxicity values can be used to calculate the
risk for the entire uranium-238 decay chain (USEPA 2024c). Attachment B-2 presents a
summary of the SE preliminary determination and calculation of the disequilibrium factor.
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3.0 HUMAN HEALTH RISK ASSESSMENT
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The HHRA evaluates whether site-related contaminants detected in soil pose unacceptable risks
to potential current and future people at a site under conditions at the time of the EE/CA
(unremediated conditions) (USEPA 1989). The HHRA results will serve, along with other
factors (such as the ERA and the three National Oil and Hazardous Substances Pollution
Contingency Plan and EE/CA criteria of feasibility, implementability, and cost), as a basis for
risk management decisions. The HHRA is intended to provide input for risk management
decision-making for a site while maintaining a conservative approach protective of the people at
a site. The methodology for the HHRA is based on the NAUM risk assessment methodology
(USEPA 2024c) with the exception that the screening levels used in the COPC screening.
Default resident screening values from the RSL (USEPA 2024e) were used in the COPC
screening because the site is not located on the Navajo Nation. Table B-l through Table B-7
present data and analysis associated with the HHRA.
3.1 DATA EVALUATION AND IDENTIFICATION OF CONTAMINANTS OF POTENTIAL
CONCERN
There are only samples available between 0 and 60 inches bgs. Samples analyzed by a certified
laboratory were used to screen for COPCs for the HHRA. Samples at the Section 9 Lease Mines
were analyzed for metals and radium-226. The NAUM Risk Calculator (USEPA 2024d) was
used to calculate the COPC screening levels. The maximum detected concentrations of
contaminants were screened using the default resident soil screening levels, based on a target
cancer risk of one in one million (1x10 6) and a noncancer target hazard quotient of 0.1 except
for lead. The lead screening value is based on the regional screening level (RSL) for residential
soil (USEPA 2024e). These conservative screening levels were used to identify and include all
contaminants that could contribute to cumulative risk in the cancer risk calculations, and to
ensure that the contaminants affecting the same target organ are accounted for in the noncancer
hazard calculations. For contaminants with both cancer and noncancer health effects, the lower
of the two screening levels was used for screening.
Any contaminant with a maximum detected concentration exceeding its COPC screening level is
retained as a COPC for the HHRA risk calculations. Table B-l provides the COPC screening for
the available Section 9 Lease Mines soil data. Based on the screening, the following
contaminants were identified as COPCs and are included in the risk estimates in the HHRA:
uranium-238 in SE, aluminum, arsenic, cadmium, chromium, cobalt, iron, manganese, mercury,
molybdenum, thallium, uranium, and vanadium.
3.2 EXPOSURE ASSESSMENT
The exposure assessment is the process of measuring or estimating intensity, frequency, and
duration of human exposure to a contaminant in the environment. The exposure assessment
considers land use assumptions, discusses the mechanisms by which people might contact
COPCs in environmental media, and characterizes exposure factors (for example, time on site).
The intake assumptions are combined with the estimated concentration for each COPC, called
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the EPC, to quantitatively estimate the contaminant exposure for the receptors at the EU. In
accordance with USEPA (1989) guidance, an exposure assessment consists of three steps:
1. Characterization of the exposure setting (physical environment and potential receptors)
2. Identification of exposure pathways (constituent sources, exposure points, and
exposure routes)
3. Quantification of pathway-specific exposures (receptor intake calculations using the
EPC and exposure assumptions)
3.2.1 Conceptual Site Model
The risk assessment conceptual site model (CSM) describes the exposure setting and identifies
potentially complete exposure pathways by which receptors (people, plants, and animals) could
contact site-related contamination. The CSM is used throughout the site investigation and
removal processes to (1) provide a framework for addressing potential risks, (2) evaluate the
need for additional data acquisition activities, and (3) evaluate health risks and the need for
corrective measures. As defined in Volume 1, Part A, of the "Risk Assessment Guidance for
Superfund" (USEPA 1989), the following four elements are necessary to form a complete
exposure pathway:
• A source or release from a source
• A mechanism of release and transport
• A point of contact for potential receptors
• An exposure route
If any one of the four elements are missing, the exposure pathway is incomplete. In general, only
potentially complete exposure pathways are evaluated in the HHRA. The removal actions at
NAUM sites are focused on removing soil as the source of contamination. Removal of
contaminated soil should remove the source of contamination to surface water and groundwater.
There is no current or expected future exposure to groundwater at the site. See Section 1.4 of the
main EE/CA report for further discussion on the sources and extent of contamination. The
site-specific CSM for the Section 9 Lease Mines is presented on Figure B-6.
3.2.2 Human Health Receptors, Exposure Pathways, and Exposure Parameters
The areas of concern for soil contamination at the Section 9 Lease Mines are AUMs 457 and
458, and the northern portion of AUM 459 located on Section 9. AUM 457 includes a former
borrow pit, a pond, concrete foundations, and two 30-foot-tall walls from the ore processing
plant while AUM 458 includes uranium waste rock, mining debris, and a recessed pit near the
center of the AUM (Weston 2011). In addition, waste piles, debris, haul roads, and specific
step-out areas indicated by elevated radium-226 soil sampling results or scan and static survey
results within Section 9 are included in the risk assessment boundary. The drainages adjacent to
and downstream of the mines are also areas of potential contamination.
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Consistent with Comprehensive Environmental Response, Compensation, and Liability Act
(CERCLA) methodology, the risks and hazards related to removal activities at the site are
anticipated to be managed within acceptable levels using engineering controls and personal
protective equipment. Therefore, potential exposures to contaminants by removal action workers
are not evaluated in the risk assessment, but worker protections should be included for removal
actions at the site.
The CSM (Figure B-6) describes the exposure setting and identifies potentially complete
exposure pathways by which people could contact site-related contamination.
Consistent with the NAUM risk assessment methodology (USEPA 2024c), the HHRA only
evaluates the RME individual at the EU. Trespassers are assumed to have greater exposure than
workers who rarely visit the site; therefore, the BLM recreator on Section 10 who trespasses onto
Section 9 was selected as the RME individual for the site. Exhibit B-l presents the RME receptor
selected and a description of the exposure scenario.
Exhibit B-1. Receptor Evaluated
Receptor Name
Receptor Description
Trespasser
A person (adult and child) who is on the site for 2 weeks per year for
26 years to camp and recreate. Includes external exposure to radiation,
incidental ingestion of soil, dermal exposure to soil (metals only), and
inhalation of soil or dust.
The specific exposure inputs for the receptor evaluated in the HHRA are provided in Table B-3.
3.2.3 Exposure Parameters
Exposure inputs for the trespasser receptor are based on a BLM recreator due to the unrestricted
access of BLM property within Section 10 and the lack of a physical barrier that limits
movement between Sections 9 and 10; thus, a person legally accessing BLM-managed land on
Section 10 could trespass onto Section 9. Camping is generally permitted on BLM land for
14 days of every 28 days. For this HHRA, a trespasser was assumed to return to the Section 9
Lease Mines site yearly for 26 years and to be on site for 24 hours a day during a 2-week visit.
3.3 TOXICITY ASSESSMENT
The toxicity assessment describes the relationship between a dose of a contaminant and the
potential likelihood of an adverse health effect. The purpose of the toxicity assessment is to
quantitatively estimate the inherent toxicity of COPCs for use in risk characterization. Potential
effects of contaminants are separated into two categories: cancer and noncancer effects. Some
contaminants can cause cancer while others can cause noncancer health effects such as
neurological problems, kidney disease, and thyroid disease. Some contaminants, such as arsenic,
have both cancer and noncancer health effects. Potential health risks for radionuclide COPCs are
evaluated only for cancer risks while metals COPCs are evaluated for both cancer risks and
noncancer hazards as appropriate.
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3.3.1 Carcinogenic Effects
For carcinogens, such as radionuclides, USEPA assumes that no dose is low enough to not cause
an adverse health effect and that the risk increases as the dose increases.
Potential carcinogenic effects resulting from human exposure to contaminants are estimated
quantitatively using cancer slope factors (SF), which represent the theoretical increased risk
per milligram of constituent intake per kilogram body weight per day (inverse of milligram
per kilogram per day). Oral SFs are toxicity values for evaluating the probability of an
individual developing cancer from oral exposure to contaminant levels over a lifetime. The
oral SF is also used in the dermal exposure pathway with an absorption factor applied for the
nonradioactive contaminants.
The inhalation unit risk factor is defined as the upper-bound excess lifetime cancer risk estimated
to result from continuous exposure to a contaminant at a concentration of 1 microgram per cubic
meter in air. SFs or inhalation unit risk factors are used to estimate a theoretical upper-bound
lifetime probability of an individual developing cancer from exposure to a potential carcinogen.
3.3.2 Noncarcinogenic Effects
Potential noncarcinogenic effects resulting from human exposure to contaminants are generally
estimated quantitatively using chronic reference doses (RfD) and chronic reference
concentrations (RfC). The RfD, expressed in units of daily dose (in milligrams per kilogram per
day), is an estimate of the daily maximum level of exposure to human populations (including
sensitive sub-populations) that is likely to be without an appreciable risk of deleterious effects
(USEPA 1989). The oral RfD is also used in the dermal exposure pathway with an absorption
factor applied. USEPA has derived RfCs for inhalation exposures for some contaminants. An
inhalation RfC is similar to an RfD. If the concentration of a contaminant in air to which a
human is exposed is lower than the RfC, no appreciable risk for noncancer health effects results
from that exposure.
3.3.3 Sources of Toxicity Values and Other Contaminant-Specific Parameters
USEPA (2003) established a hierarchy of human health toxicity values for CERCLA; this
hierarchy should be followed for selecting the toxicity values used in the HHRA. This HHRA
used the toxicity values used in the NAUM Risk Calculator (USEPA 2024d), which are provided
in Table 4 and Table 5 of the NAUM risk assessment methodology (USEPA 2024c) for
radionuclides and metals, respectively.
3.4 RISK CHARACTERIZATION
In general, risk characterization proceeds by combining the results of the exposure and toxicity
assessments. In standard CERCLA HHRAs, exposures are calculated by use of medium-specific
EPCs (Table B-4) and a series of pathway-specific exposure parameters. These exposures are
then multiplied or divided by analyte-specific toxicity factors (for example, SFs, unit risk factors,
RfDs, and RfCs) to generate receptor- and exposure pathway-specific risks and hazards.
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3.4.1 Estimates of Cancer Risk and Noncancer Hazard
Human health exposure factors were calculated for each applicable receptor and COPCs for all
the potentially complete soil-related exposure pathways. For metal COPCs with both
carcinogenic and noncarcinogenic toxicity, intake factors were calculated for both cancer and
noncancer for each relevant exposure pathway. The methods, assumptions, and inputs for the
calculation of the intake factors is provided in the NAUM risk assessment methodology (USEPA
2024c). Table B-5 presents the calculated cumulative cancer risk and noncancer hazard for each
COPC by soil depth interval. That is, the risk was summed for all the exposure pathways relevant
to the receptor.
Table B-6 provides a summary of the cumulative risk by exposure pathway. This HHRA only
evaluates the RME receptor at the single EU, and these results are used for risk management
decisions for the site.
The intake factors used in the HHRA were calculated using the NAUM Risk Calculator (USEPA
2024d). The USEPA's RSL Calculator considers only direct soil exposures (for example, soil
ingestion, dermal contact, and inhalation of fugitive dust). The NAUM Risk Calculator generates
exposure pathway-specific cancer risks and noncancer hazards, as well as external exposure to
radiation and direct exposure to radiation in soil through incidental ingestion and inhalation. The
complete set of equations and inputs for calculating exposure inputs for receptors is provided in
the NAUM risk assessment methodology (USEPA 2024c).
The cumulative cancer risk for the age-adjusted adult and child receptors and noncancer hazards
for the adult and child receptors and soil depth interval are provided in Table B-7 and
summarized in Exhibit B-2.
Exhibit B-2. Cancer Risks and Noncancer Hazards
Exposure Unit
Soil Interval
Cancer
Risk
Adult
Noncancer
Hazard
Child
Noncancer
Hazard
Section 9 Lease Mines -
Trespasser
Surface Soil
8x10"4
0.04
0.5
Subsurface Soil
5x10"4
0.03
0.3
Notes:
Bolded values exceed the target cancer risk or target hazard quotient.
Candidate COCs were identified based on the estimated cancer risk exceeding the target cancer
risk of 1x10 4 or the estimated noncancer hazard exceeding the target hazard quotient of 1 for
the RME receptor at the EU. COPCs with a cancer risk within the USEPA risk range of 1x10 6
to 1x10 4 are italicized on Table B-7. Target organ analyses were not performed for any
scenario-media combination because no instances arose where the target organ hazard index
exceeded 1 and no individual COPC had a hazard exceeding 1. Exhibit B-3 presents the
candidate COCs as identified in Table B-7.
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Exhibit B-3. Candidate Contaminants of Concern
Exposure Unit
Soil Interval
Cancer
Risk
Noncancer
Hazard
Section 9 Lease Mines -
Trespasser
Surface Soil
Uranium-238 in SE
-
Subsurface Soil
Uranium-238 in SE
-
Notes:
Not applicable
SE Secular equilibrium
3.4.2 Uncertainty Associated with the Human Health Risk Assessment
Uncertainties are inherent in the process of quantitative risk assessments based on the use of
environmental sampling results, assumptions regarding exposure, and the quantitative
representation of contaminant toxicity. Analysis of the critical areas of uncertainty in a risk
assessment provides a better understanding of the quantitative results through the identification
of the uncertainties that most significantly affect the results.
USEPA (1989) guidance stresses the importance of providing an in-depth analysis of
uncertainties so that risk managers are better informed when evaluating risk assessment
conclusions. Potentially significant sources of uncertainty for this risk assessment are discussed
in the following subsections. The NAUM risk assessment methodology (USEPA 2024c)
provides general HHRA uncertainty discussions for topics applicable to all NAUM sites.
3.4.2.1 Conceptual Site Model and Reasonable Maximum Exposed Receptor Selection
The most significant site-specific uncertainty associated with the Section 9 Lease Mines HHRA
is the selection of the RME receptor. EUs used in NAUM risk assessments and future removal
actions within the TENORM area are developed by identifying areas of TENORM with the same
expected human health receptors. The RME receptor was selected based on site knowledge. If
the selected receptor is less conservative than the actual future land use (for example, trespasser
is selected, but the actual use is residential), the HHRA would not be protective. Likewise, if the
future land use is less intensive than the receptor selected (for example, residential is selected,
but the actual use is trespasser), the HHRA would be overly protective. This uncertainty is
moderate. The direction of the uncertainty is more likely to be overprotective because of the
conservative selection methodology used to identify the RME receptor for the EU.
3.4.2.2 Sample Design and Exposure Point Concentrations
The sampling collection for the site was not based on a random sampling design. Instead,
sampling was biased toward known areas of contamination based on the results of gamma
surveys. Thus, while some areas do not have the same level of sampling coverage as others,
those areas are not likely to have elevated levels of contamination based on the site survey
techniques employed before collection of discrete samples for laboratory analysis. The
uncertainty associated with the sample collection is moderate, but the samples used in the risk
assessment are likely to overestimate the actual site risk because of the biased nature of the
samples collected at the site.
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Four hexavalent chromium samples were collected from the Section 9 Lease Mines but were not
used in the risk assessment. In lieu of the hexavalent chromium results and to be health
protective, analytical results for total chromium were evaluated in this HHRA assuming the
chromium concentration is in the form of the more toxic hexavalent chromium. Three of the
four hexavalent chromium samples were nondetect, and one hexavalent chromium sample had a
detection (0.25 mg/kg) that would result in an EPC of 0.25 mg/kg, which is less than the EPC
derived using the total chromium results (5.0 mg/kg). Use of the EPC associated with the more
robust total chromium dataset is more conservative than using the EPC for hexavalent chromium
associated with the single detected result.
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4.0 ECOLOGICAL RISK ASSESSMEN
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An ERA is the process for evaluating how likely the environment will be impacted as a result of
exposure to one or more environmental stressors, such as radionuclides or metals. The objective
of the ERA is to evaluate whether ecological receptors may be adversely affected by exposure to
contaminants. The ERA is intended to provide input for risk management decision-making at
each site while maintaining a conservative approach protective of ecological populations and
communities. This ERA follows the guidelines in the NAUM risk assessment methodology
(USEPA 2024c).
As described in USEPA (1993) EE/CA guidance, a risk assessment is used to help justify a
removal action, identify what current or potential exposures should be prevented, and focus on
the specific problem that the removal action is intended to address. NAUM ERAs include a
screening-level ecological risk assessment (SLERA) and SLERA refinement. The SLERA
includes Steps 1 and 2 of USEPA's eight-step ERA process (USEPA 1997) and is intended to
provide a conservative estimate using maximum site concentrations of potential ecological risks
and compensate for uncertainty in a precautionary manner by incorporating conservative
assumptions. The SLERA refinement includes a refinement of Steps 1 and 2 and is intended to
provide additional information for risk managers. Candidate COECs are identified based on the
results of the SLERA refinement for soil. Table B-l, Table B-2, and Table B-8 through
Table B-l2 present data and analysis associated with the ERA.
Consistent with standard risk assessment practice and USEPA (1992a, 1998, 2023) guidance, the
ERA is presented in three major phases:
• Problem formulation
• Analysis of exposure and effects
• Risk characterization
4.1 PROBLEM FORMULATION
The problem formulation phase is a planning and scoping process that establishes the goals,
breadth, and focus of the risk assessment. The product of the problem formation is a CSM that
identifies the environmental values to be protected (assessment endpoints), data needed, and
analyses to be used. The components of the problem formulation include:
• Ecological habitat and biological resources
• Stressors and COI selection
• Potentially complete exposure pathways
• Assessment endpoints
• Measurement endpoints
• Ecological CSM
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The SLERA includes the screening-level problem formulation (Step 1), exposure estimation,
effects evaluation, and screening-level risk calculation (Step 2) of the USEPA risk assessment
process. The maximum detected concentration across the site is used as the EPC in the SLERA,
which is compared with the minimum no observed effect concentration (NOEC) for all
ecological receptors. The product of the SLERA is a list of contaminants of potential ecological
concern (COPEC) in affected media that are recommended for further ecological assessment.
The SLERA refinement provides additional information for risk managers. For plants and
invertebrates, the SLERA refinement includes a point-by-point comparison of individual sample
results to plant and invertebrate NOECs. For free-ranging birds and mammals, the SLERA
refinement uses an estimate of the average concentration as the EPC to represent exposure to
free-ranging birds and mammals and includes a comparison of the EPC with the minimum
NOEC for birds and mammals.
At the conclusion of the SLERA refinement, the candidate COECs are identified. For plants and
invertebrates, analytes with any individual sample results exceeding the plant and invertebrate
NOEC will be identified as candidate COECs, and for birds and mammals, analytes with a
refined hazard quotient (HQ) equal to or greater than 1.0 will be identified as candidate COECs.
These analytes are called candidate COECs (rather than COECs) because the analytes have not
yet undergone a background evaluation, which will be completed in the EE/CA. The background
evaluation should not be performed as part of the risk assessment.
4.1.1 Ecological Habitat and Biological Resources
The ecological habitat and biological resources at the Section 9 Lease Mines are described in
Section 1.4.
4.1.2 Stressors and Constituents of Interest Selection
All detected metals and radionuclides in soil were considered COIs in this ERA. Essential
nutrients that are not priority pollutants, such as calcium, magnesium, potassium, and sodium,
were not retained as COIs. See Section 2.4 of the main EE/CA report for further discussion on
the sources and extent of contamination. Samples collected within soil (0 to 60 inches bgs) at the
site were used in this risk assessment.
4.1.3 Potentially Complete Exposure Pathways
A contaminant must be able to travel from the source to the representative receptor and must be
taken up by the receptor through one or more exposure routes for an exposure pathway to be
considered complete. Potential exposure pathways that may result in receptor contact with
contaminants in the environment include soils, sediment, surface water, groundwater, air, and
food-chain transfer. Soil and sediment are the primary exposure media of concern. Surface water
from seeps and ephemeral streams is also a primary exposure medium of concern for aquatic
invertebrates and a secondary exposure medium of concern for terrestrial receptors; however,
no surface water samples are available for the Section 9 Lease Mines. Potential exposure
pathways are shown in the CSM (Figure B-6). Discussion of the exposure pathways for
ecological receptors is provided in the NAUM risk assessment methodology (USEPA 2024c).
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Soil exposures are evaluated in the ERA for the Section 9 Lease Mines. The removal actions at
NAUM sites are focused on removing soil because the removal of contaminated soil should
remove the source of contamination to surface water and groundwater. Exposure to surface water
or groundwater is assumed to be minimal because the presence of surface water at the Section 9
Lease Mines is intermittent and groundwater is too deep for ecological receptors to access.
4.1.4 Assessment Endpoints
USEPA (1997) defines assessment endpoints as explicit expressions of the actual
environmental values (for example, ecological resources) that are to be protected. Assessment
endpoints are environmental characteristics that, if impaired, would indicate a need for action
by risk managers.
The assessment endpoints identified for evaluation in the ERA were based on the ecological
habitat, stressors and COPECs, and potentially complete exposure pathways identified in
Section 4.1 and depicted on the CSM (Figure B-6). Each assessment endpoint is intended to
protect the local populations of the identified resources. The assessment endpoints used to
evaluate the potential ecological risk to receptors typical of the area at the Section 9 Lease
Mines were:
• Protection of terrestrial plants
• Protection of terrestrial invertebrates
• Protection of herbivorous birds
• Protection of insectivorous birds
• Protection of carnivorous birds
• Protection of herbivorous mammals
• Protection of insectivorous mammals
• Protection of carnivorous mammals
4.1.5 Measurement Endpoints
Measurement endpoints related to the assessment endpoints were identified because assessment
endpoints are usually not amenable to direct measurement. USEPA (1997) defines a
measurement endpoint as a measurable ecological characteristic that is related to the valued
characteristic chosen as the assessment endpoint and is a measure of biological effects (such as
mortality, reproduction, or growth). Measurement endpoints for soil and sediment for both
radionuclides and metals are described below.
For radionuclides in soil, ecological screening levels (ESL) for the NAUM program were
developed by Tetra Tech (Appendix F of the NAUM risk assessment methodology [USEPA
2024c]). An ecological radiation dose assessment was performed for radionuclides in the
uranium-238 decay chain using the dose assessment model Environmental Risks from Ionising
Contaminants: Assessment and Management (ERICA). The ERICA model is scientifically
robust, follows approaches recommended by the International Commission on Radiation
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Protection for radiation protection of the environment, and provides dose assessment for
uranium-238 and all its decay progeny. Using the ERICA Tool (Brown and others 2008; Larsson
2008), ESLs were calculated for the following radionuclides or groups of radionuclides in soil
for terrestrial organisms:
• Uranium-238 in SE (adjusted radium-226) adjusted to account for the entire uranium-238
decay chain
• Radium-226 in SE (adjusted radium-226) adjusted to account for radium-226 and
decay products
• Individual radionuclides uranium-238, uranium-234, and thorium-230
ESLs are based on dose rates where no effects have been observed and, therefore, are NOECs.
For all radionuclides, the limiting ESLs are for lichen-biyophytes and small burrowing animals
at 4 and 6 picocuries per gram, respectively. The ESLs are designed for use for comparison with
radium-226 site concentrations. Use of site data for radium-226 reduces the number of analytical
methods needed to evaluate risks from radionuclides. Furthermore, radium-226 concentrations
can be correlated to gamma survey results, which provides an efficient and reliable way to
evaluate the extent of radiation contamination.
For metals for soil, USEPA (2024d) ecological soil screening levels (Eco-SSL) are used as the
primary source for NOEC levels. Eco-SSLs are available for the protection of terrestrial plants,
invertebrates, birds, and mammals from the three primary feeding groups (herbivores,
insectivores, and carnivores). The Eco-SSLs for soil-dwelling invertebrates and plants are based
on direct contact with soil by plants and soil-dwelling organisms living in impacted soil. The
Eco-SSLs for upper-trophic-level wildlife are based on incidental ingestion of soil and ingestion
of food sources that have bioaccumulated contaminants. The no effect Eco-SSL is based on a
no observed adverse effect level-based toxicity reference value that is protective of wildlife
populations and sensitive individuals because it represents an exposure that is not associated with
an adverse effect. The Eco-SSLs are intended to be conservative screening values that can be
used to eliminate contaminants not associated with unacceptable risks (USEPA 2005).
Where an Eco-SSL is not available for a COPEC and receptor combination (for example, total
mercury, thallium, and uranium), a no observed adverse effect level-based toxicity value from
the Los Alamos National Laboratory (LANL) EcoRisk database (Newport News Nuclear
BWXT-Los Alamos, LLC [N3B] 2022) is selected as the screening level. The LANL EcoRisk
database includes ESLs for plant, invertebrate, avian, and mammalian receptors. Soil
invertebrate and plant screening levels were also taken from the Oak Ridge National Laboratory
(ORNL) (Efroymson, Will, and Suter II 1997; Efroymson, Will, Suter II, and Wooten 1997) if a
screening level was not available as an Eco-SSL or from the LANL EcoRisk database. No
Eco-SSL or LANL values for mammals were available for molybdenum; therefore, screening
values were taken from ORNL's "Preliminary Remediation Goals for Ecological Endpoints"
(Efroymson, Suter II, Sample, and Jones 1997).
The screening levels selected from USEPA Eco-SSLs, LANL ESLs, and ORNL for metals and
developed from ERICA (for radionuclides) for use in the SLERA screening are the lowest
NOECs for all receptor groups (that is, the lowest of the plant, invertebrate, bird [herbivorous,
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insectivorous, and carnivorous], and mammal [herbivorous, insectivorous, and carnivorous]
NOECs) for each COPEC. The screening levels are provided in Table B-8.
4.1.6 Conceptual Site Model
The CSM illustrates exposure pathways to be evaluated in the ERA and provides other key
information such as contaminant sources, release and transport mechanisms, and the relative
importance of exposure pathways to specific receptor groups. The CSM incorporates all
components of the problem formulation as discussed above and illustrated on Figure B-6.
4.2 ANALYSIS OF EXPOSURE AND EFFECTS
In the analysis phase, exposure to stressors (metals and radionuclides) and their relationship to
ecological effects are evaluated. A determination is made of (1) the degree to which ecological
receptors are exposed and (2) whether that level of exposure is likely to cause harmful
ecological effects.
4.2.1 Exposure Estimates
For the SLERA, a single site-wide exposure area that included all data collected within the
Section 9 Lease Mines EU was used for the evaluation of potential risk to ecological receptors.
Exposure estimates for the SLERA for soil are the maximum detected concentrations for COIs in
soil compared to the minimum screening levels for all receptors (plants, invertebrates, birds
[herbivorous, insectivorous, and carnivorous], and mammals [herbivorous, insectivorous, and
carnivorous]). For each detected analyte, the maximum detected concentrations used in the
SLERA for each COPEC are presented in Table B-8 for soil.
Following the comparison of the maximum detection to the NOEC, a SLERA refinement of
exposure was completed by assessing site data within surface and subsurface soils and using the
EPC instead of the maximum detected concentration to evaluate risk to free-ranging receptors
(birds and mammals) for the assessment of wildlife. Surface and subsurface soils include depth
intervals of 0 to 6 inches bgs for surface soil and 0 to 60 inches bgs for subsurface soil (see
Section 2.4). The EPCs used in the SLERA refinement for birds and mammals for each COPEC
are presented in Table B-9. For the SLERA refinement for plants and invertebrates, individual
sample concentrations are used in a point-by-point comparison.
4.2.2 Ecological Effects
Ecological effects of potential concern are those that can impact populations by causing adverse
effects on development, reproduction, and survival (USEPA 1997). Literature-based NOECs as
described in Section 4.1.5 were used in the ERA to characterize potential effects from direct
contact and uptake through the food web to terrestrial ecological receptors, including vegetation,
soil invertebrates, birds, and mammals.
For the SLERA, an HQ was calculated as the ratio of the maximum contaminant concentration to
the screening level (NOEC) by COPEC and receptor. HQs greater than or equal to 1.0 indicate
potential unacceptable risk to plants, invertebrates, birds, and mammals based on a conservative
comparison of the maximum detected concentration to the minimum NOEC-based screening
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level for all receptors. HQs less than 1.0 indicate little to no potential ecological risk for a given
COPEC, and the COPEC is excluded from further consideration (that is, the COPEC was not
evaluated in the SLERA refinement). The SLERA HQ was calculated as follows:
Maximum Detected Concentration
SLERA HQ =
Screening Level (NOEC or ESL)
To better understand potential risk to free-ranging receptors, the site-wide EPC (based on the
lesser of the UCL95 and maximum detected concentration) will be used as a refinement in the
SLERA refinement using NOECs based on birds and mammals. The refined SLERA HQ is
calculated as follows:
EPC
Refined SLERA HQ =
Screening Level (NOEC or ESL)
Because plant and soil invertebrates are not mobile, concentration data from each sample
location should be compared to the plant and invertebrate NOEC-based screening levels in a
separate table.
4.3 RISK CHARACTERIZATION
In the risk characterization phase, potential risk is estimated through integration of exposure and
effects, potential risks are considered in the context of uncertainties associated with the SLERA,
and risk descriptions are provided.
4.3.1 Screening-Level Ecological Risk Assessment for Contaminants of Potential
Ecological Concern
HQs, which represent the ratio of the maximum detected concentration in the environmental
medium to the screening levels, are presented in Table B-8 for soil. Contaminants in soil for
which the HQ was greater than or equal to 1.0 were uranium-238 in SE (adjusted radium-226),
arsenic, barium, cadmium, chromium, cobalt, lead, manganese, mercury, molybdenum, nickel,
selenium, thallium, uranium, vanadium, and zinc.
4.3.2 Screening-Level Ecological Risk Assessment Refinement
The SLERA refinement incorporates components of Step 3 of USEPA's eight-step ERA process
to refine the soil risk estimates from the SLERA (USEPA 2000b, 2001). The SLERA refinement
involves assessing plants and invertebrates on a point-by-point basis and wildlife (birds and
mammals) based on a refined EPC.
4.3.2.1 Plants and Soil Invertebrates
Plants and soil invertebrates are not mobile; therefore, comparison of the EPC to the NOEC (for
metals) or ESL (for radionuclides) may not appropriately assess whether potential unacceptable
risk to plants and invertebrates exists. Therefore, a comparison on a point-by-point basis using
the plant and invertebrate NOECs is required. COPECs are identified as candidate COECs if at
least one sample result exceeds the plant or soil invertebrate NOEC or ESL for surface soil, or
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the plant NOEC or ESL for subsurface soil. Table B-10 presents a comparison of individual
surface soil sample results to NOECs or ESLs for the plant and invertebrate communities, and of
individual subsurface soil sample results to NOECs or ESL for the plant communities
(invertebrates are not exposed to soil at depths greater than 6 inches). For plants and
invertebrates, analytes with any individual sample results exceeding the plant and invertebrate
NOEC or ESL are identified as candidate COECs.
Candidate COECs for plants were uranium-238 in SE, arsenic, barium, chromium, cobalt, lead
(surface soil only), manganese, mercury, molybdenum, selenium, thallium (surface soil only),
uranium, and vanadium (surface soil only). Candidate COECs for invertebrates were uranium-
238 in SE, arsenic, barium, chromium, manganese, mercury, and selenium.
4.3.2.2 Birds and Mammals
For free-ranging wildlife, the EPCs were calculated on a site-wide basis for contaminants with
analyte-specific HQs that are equal to or greater than 1.0 in the SLERA. SLERA refinement risk
estimates were calculated by dividing EPCs by the minimum NOEC or ESL for birds and
mammals for each COPEC in surface soil and by dividing EPCs by the NOEC or ESL for
insectivorous mammals in subsurface soil (birds and non-burrowing mammals are not exposed to
soil at depths greater than 6 inches).
Table B-l 1 and Table B-12 present HQs for birds and mammals, respectively. Candidate COECs
for birds and mammals were identified for analytes with HQs greater than 1.0 based on the
comparison of the EPC (UCL95) to the minimum screening level (minimum NOEC or ESL for
wildlife).
Candidate COECs for birds were uranium-238 in SE, lead, mercury, molybdenum, selenium,
thallium, and vanadium. Candidate COECs for mammals were uranium-238 in SE, barium,
selenium, and thallium.
4.3.3 Candidate Contaminants of Ecological Concern
Candidate COECs were identified based on available laboratory and toxicological data for the
Section 9 Lease Mines. The SLERA results indicate that risk is above a level of concern for the
contaminants listed in Exhibit B-4.
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Appendix B: Section 9 Lease Mines Risk Assessment
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Exhibit B-4. Site-Wide Candidate Contaminants of Ecological Concern
Candidate Contaminant of Ecological Concern
Receptor
Soil
Interval
Uranium-238 in SE
Arsenic
Barium
Chromium
Cobalt
Lead
Manganese
Mercury
Molybdenum
Selenium
Thallium
Uranium
Vanadium
Plants
Surface Soil
X
X
X
X
X
X
X
X
X
X
X
X
X
Subsurface Soil
X
X
X
X
X
-
X
X
X
X
-
X
-
Invertebrates
Surface Soil
X
X
X
X
-
-
X
X
-
X
-
-
-
Birds
Surface Soil
X
X
-
X
X
X
X
-
X
Mammals
Surface Soil
X
-
X
X
X
-
-
Subsurface Soil
X
-
X
X
X
-
-
Notes:
Not a candidate COEC
X Candidate COEC
COEC Contaminant of ecological concern
SE Secular equilibrium
4.4 UNCERTAINTY ANALYSIS ASSOCIATED WITH THE ECOLOGICAL RISK
ASSESSMENT
Uncertainty plays an important role in risk-based decision-making and is, therefore,
incorporated explicitly into the risk characterization process. Identifying known sources of
uncertainty is a critical component of an ERA because conservative default assumptions
incorporated into the ERA protocol are associated with substantial uncertainty. The ERA
process is based on assumptions and extrapolations to evaluate potential risk to ecological
receptors. These assumptions are intentionally conservative and may result in overestimates of
site-specific risk to ensure that no COPECs that pose actual risk are eliminated from the ERA.
The primary components of uncertainties include those associated with site data and exposure,
the development and use of toxicity values, and interpretation of HQs to estimate potential risk to
representative receptors. The NAUM risk assessment methodology (USEPA 2024c) provides
more general ERA uncertainty discussions for topics applicable to all NAUM sites.
4.4.1 Exposure Estimates
Because Tetra Tech evaluated the Section 9 Lease Mines using limited collected data, all
concentrations measured are, therefore, only estimates of concentrations that may occur
throughout the site (with associated error). As with any site investigation, uncertainty will be
associated with the representativeness of the samples both spatially and temporally. Soil samples
were collected during three events:
• Site investigation in 2013
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Appendix B: Section 9 Lease Mines Risk Assessment
• Removal site evaluation in 2018
• Data gaps investigation in 2024
The sampling events were conducted by different entities; therefore, the data collection methods
were likely not consistent. Figure B-3 through Figure B-5 show the sample locations. Spatial
variability is limited because soil samples used in the risk assessment were primarily collected
within the disturbed area of the site. Temporal variability is limited because soil sampling
methods because of the known environmental fate of the COPECs (lack of degradation).
Four hexavalent chromium samples were collected from the Section 9 Lease Mines but were not
used in the risk assessment. In lieu of the hexavalent chromium results and to be health
protective, analytical results for total chromium were evaluated in this ERA assuming the
chromium concentration is in the form of the more toxic hexavalent chromium. Three of the
hexavalent chromium four samples were nondetect, and one hexavalent chromium sample had a
detection (0.25 mg/kg) that would result in an EPC of 0.25 mg/kg, which is less than the EPC
derived using the total chromium results (5.0 mg/kg). Use of the EPC associated with the more
robust total chromium dataset is more conservative than using the EPC for hexavalent chromium
associated with the single detected result, is less than the minimum NOEC (0.34 mg/kg) for all
ecological receptors.
4.4.2 Nondetected Contaminants of Potential Ecological Concern
Little uncertainty is involved with the analytical analysis for soil at the Section 9 Lease Mines
except for antimony. Antimony was not detected in any sample, but some samples have reporting
limits greater than ESLs. This possibility was described in the NAUM risk assessment
methodology (USEPA 2024c) with the lowest no-effect ESL for antimony of 0.27 mg/kg as
compared to the typical method detection limits for metals methods ranging from 0.5 mg/kg to
3 mg/kg. For this site, there were no detections of antimony, but the detection limits in soil
ranged from 33 mg/kg to 1.73 mg/kg. The lowest no-effect level screening value for antimony is
protective of the mammalian ground insectivore and is an order of magnitude lower than the next
lowest Eco-SSL of 4.9 mg/kg protective of mammalian carnivores. The other soil screening
levels include the following: 11 mg/kg protective of plants, 78 mg/kg protective of soil
invertebrates, and 10 mg/kg protective of mammalian herbivores. There is uncertainty associated
with the assessment of antimony and protection of ecological receptors; however, most of the
detection limits are below the screening level protective of mammalian herbivores and plants,
and all the detection limits are below the screening level protective of soil invertebrates. This
analysis identifies the uncertainty that concentrations of antimony could be present at the site
below the detection limits but greater than calculated screening level protective of certain classes
(e.g., ground insectivores) of ecological receptors.
4.4.3 Combined Exposures Across Media
The design of the ecological screening process and use of media-based screening levels assumes
isolation of exposure (for example, risk from exposure to soil is not added to the risk from
exposure to surface water). The risk analysis does not account for exposure to COPECs in
drinking water, but the magnitude of this uncertainty is unknown.
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4.4.4 Risk to Plant and Invertebrate Communities
To address the potential risk to plant and invertebrate communities, concentration data from each
sample are compared to the conservative screening values protective of individual plants and
invertebrates (NOECs and ESLs). Table B-10 presents this analysis so that risk managers can
evaluate the potential risk to these communities by sample location.
Aluminum and iron do not have screening values for either community. The magnitude of the
impacts of aluminum and iron on nonmobile communities is unknown. Six additional COIs at
the Section 9 Lease Mines (cobalt, molybdenum, silver, thallium, uranium, and vanadium) do not
have soil invertebrate screening values. The magnitude of the impacts of these metals on the soil
invertebrate community is unknown.
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Appendix B: Section 9 Lease Mines Risk Assessment
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5.0 RISK ASSESSMENT RESULTS SUMMARY
The HHRA and SLERA results indicate human health and ecological risk exceed the acceptable
risk levels. Candidate COCs were identified based on available laboratory and toxicological data
at the Section 9 Lease Mines, and candidate COECs were identified on a site-wide basis. The
HHRA and ERA results indicate that risk is above a level of concern for the contaminants listed
in Exhibit B-5.
Exhibit B-5. Candidate Contaminants of Concern or Contaminants of Ecological Concern
for Soil
Contaminant
Exposure
Unit
Receptor
Media
Uranium-238 in SE
Arsenic
Barium
Chromium
Cobalt
Lead
Manganese
Mercury
Molybdenum
Selenium
Thallium
Uranium
Vanadium
Site-Wide
Trespasser
Surface and
Subsurface
Soil
X
Site-Wide
Plants
Surface Soil
X
X
X
X
X
X
X
X
X
X
X
X
X
Subsurface
Soil
X
X
X
X
X
--
X
X
X
X
--
X
--
Site-Wide
Invertebrates
Surface Soil
X
X
X
X
"
--
X
X
--
X
Site-Wide
Birds
Surface Soil
X
X
"
X
X
X
X
"
X
Site-Wide
Mammals
Surface and
Subsurface
Soil
X
"
X
X
X
"
"
Notes:
—
Not a candidate COC or COEC. Not recommended for further evaluation in the EE/CA.
X
Candidate COC and/or COEC. Recommended for further evaluation in the EE/CA.
coc
Contaminant of concern
COEC
Contaminant of ecological concern
EE/CA
Engineering evaluation/cost analysis
SE
Secular equilibrium
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6.0 REFERENC
ml
Bollin, E.M., and P.F. Kerr. 1958. "Uranium Mineralization Near Cameron, Arizona." New
Mexico Geological Society, Ninth Field Conference, Proceedings Paper.
Brown, J.E., B. Alfonso, R. Avila, N.A. Beresford, D. Copplestone, G. Prohl, and A. Ulanovsky.
2008. "The ERICA Tool." Journal of Environmental Radioactivity. Volume 99, Issue 9.
Pages 1371 through 1383.
Chenoweth, W.L., and R.C. Malan. 1973. "The Uranium Deposits of Northeastern Arizona."
New Mexico Geological Society 24th Annual Fall Field Conference Guidebook.
Chenoweth, W.L. 1993. "Geology and Production History of the Uranium Ore Deposits in the
Cameron Area, Coconino County, Arizona." Arizona Geological Survey Report 93-B.
Dubiel, R.F., J.T. Parrish, J.M. Parrish, and S.C. Good. 1991. "The Pangean Megamonsoon:
Evidence from the Upper Triassic Chinle Formation, Colorado Plateau." PALAIOS.
Volume 6. Number 4. Pages 347 through 370.
Efroymson, R.A., M.E. Will, and G.W. Suter II. 1997. "Toxicological Benchmarks for
Contaminants of Potential Concern for Effects on Soil and Litter Invertebrates and
Heterotrophic Process." Revised. ES/ER/TM-126/R2. Oak Ridge National Laboratories,
Oak Ridge, TN.
Efroymson, R.A., M.E. Will, G.W. Suter II, and A.C. Wooten. 1997. "Toxicological
Benchmarks for Screening Contaminants of Potential Concern for Effects on Terrestrial
Plants." Revised. ES/ER/TM-85/R3. Oak Ridge National Laboratories, Oak Ridge, TN.
Efroymson, R.A., G.W. Suter II, B.E. Sample, and D.S. Jones. 1997. "Preliminary Remediation
Goals for Ecological Endpoints." ES/ER/TM-162/R2. Oak Ridge National Laboratories,
Oak Ridge, TN.
Engineering Analytics, Inc. 2021. "Removal Site Evaluation Report, Babbitt Ranches, LLC -
Milestone Hawaii Stewardship Project (Section 9 Lease Abandoned Uranium Mine)."
Draft. Comprehensive Environmental Response, Compensation, and Liability Act
(CERCLA) Docket No. 2016-13. March 18.
Larsson, C.M. 2008. "An Overview of the ERICA Integrated Approach to the Assessment and
Management of Environmental Risks from Ionising Contaminants." Journal of
Environmental Radioactivity. Volume 99, Issue 9. Pages 1364 through 1370.
Newport News Nuclear BWXT-Los Alamos, LLC (N3B). 2022. "ECORISK Database."
Release 4.3. 701067. Document EM2020-0575. September.
SWCA Environmental Consultants (SWCA). 2016. "Biological Resources Survey, Babbitt
Ranches Milestone Hawaii Reclamation Project (Section 9 Lease AUM Removal
Action), Coconino County, Arizona." Prepared for Babbitt Ranches, LLC. December.
Contract No. 68HE0923D0002, Task Order 020
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Tetra Tech. 2019. "Western Agency Tronox Mines Removal Site Evaluation Report." Response,
Assessment, and Evaluation Services. Contract No. EP-S9-17-03. Task Order 0001.
October 10.
Tetra Tech. 2024. "Draft Field Sampling Plan Section 9 Lease Mines, Cameron, Arizona
Western Abandoned Uranium Mine Region." Response, Assessment, and Evaluation
Services. Contract No. 68HE0923D0002. Task Order 0020. January.
U.S. Environmental Protection Agency (USEPA). 1989. "Risk Assessment Guidance for
Superfund Volume I - Human Health Evaluation Manual, Part A." Interim Final. Office
of Emergency and Remedial Response. EPA/540/1-89/002. December.
USEPA. 1992a. "Guidance for Data Useability in Risk Assessment (Part A)." Office of
Emergency and Remedial Response. Publication 9285.7-09A. April.
USEPA. 1992b. "Supplemental Guidance to RAGS [Risk Assessment Guidance for Superfund]:
Calculating the Concentration Term." Intermittent Bulletin, Volume 1, No. 1. Publication
9285.7-081.
USEPA. 1993. "Guidance on Conducting Non-Time-Critical Removal Actions under CERCLA."
Office of Solid Waste and Emergency Response (OSWER) 9360.0-32. August.
USEPA. 1997. "ERA Guidance for Superfund: Process for Designing and Conducting ERAs."
Interim Final. EPA/540/R-97/006. June.
USEPA. 1998. "Guidelines for Ecological Assessment." Office of Research and Development.
EPA/630/R-5/002FA. April.
USEPA. 2000a. "Guidance for Data Quality Assessment: Practical Methods for Data Analysis:
USEPA QA/G-9, QA97 Version." USEPA/600/R-96/084. Office of Research and
Development. July.
USEPA. 2000b. "Amended Guidance on Ecological Risk Assessment at Military Bases: Process
Considerations, Timing of Activities, and Inclusion of Stakeholders." Memorandum from
Ted W. Simon, Ph.D., Office of Technical Services. June 23.
USEPA. 2001. "The Role of Screening-Level Risk Assessments and Refining Contaminants of
Concern in Baseline Ecological Risk Assessments." OSWER. EPA 540/F-01/014. June.
USEPA. 2002. "Calculating Exposure Point Concentrations at Hazardous Waste Sites."
OSWER. Directive 9285.6-10. December.
USEPA. 2003. "Human Health Toxicity Values in Superfund Risk Assessments." OSWER
Directive 9285.7-53. December 5.
USEPA. 2004. "Multi-Agency Radiological Laboratory Analytical Protocols Manual." NUREG-
1576/EPA 402-B-04-001A/NTIS PB2004-105421. July.
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USEPA. 2005. "Guidance for Developing Ecological Soil Screening Levels." February.
USEPA. 2020. "National Functional Guidelines for Inorganic Superfund Methods Data Review."
Office of Land and Emergency Management. 9240.0-66/EPA 540-R-20-006. November.
USEPA. 2022. "ProUCL Statistical Software for Environmental Applications for Data Sets with
and without Nondetect Observations." Version 5.2.0. June 14.
USEPA. 2023. "Interim Ecological Soil Screening Level Documents." Accessed July 20.
https://www.epa.gov/chemical-research/interim-ecological-soil-screening-level-
documents.
USEPA. 2024a. "Updated Residential Soil Lead Guidance for CERCLA Sites and RCRA
Corrective Action Facilities." Office of Land and Emergency Management. January 17.
USEPA. 2024b. "Preliminary Remediation Goals for Radionuclides (PRG)." February.
https://epa-prgs.ornl.gov/cgi-bin/radionuclides/rprg_search.
USEPA. 2024c. "Navajo Abandoned Uranium Mine Risk Assessment Methodology." Draft
Final. March.
USEPA. 2024d. "Navajo Abandoned Uranium Mine Risk Calculator." Version 1.03. March.
USEPA. 2024e. "Regional Screening Levels (RSLs)." May 14. https://epa-prgs.ornl.gov/cgi-
bin / chemicals/csl_search.
Weston Solutions, Inc. (Weston). 2011. "Navajo Abandoned Uranium Mine Site Screen Report."
January.
Weston. 2012. "Preliminary Assessment, Section 9 Lease Abandoned Uranium Mine, Coconino
County, Arizona." Report Prepared for USEPA Region 9. November.
Weston. 2014. "Site Inspection Report, Section 9 Lease Abandoned Uranium Mine, Coconino
County, Arizona." Report Prepared for USEPA Region 9. June.
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FIGURES
-------
Farmwrjioi
Section 9 Lease Mines
Cameron
Gray Mountain
~ Populated Place
AUM Site Locations
T-™T1 Section 9 Lease Mine
Other AUM Site
PLSS Section Boundary
Section 9
Navajo Nation AUM Regions
~ Central Region
Eastern Region
North Central Region
Northern Region
Southern Region
Western Region
~ Navajo Nation Boundary
Paved Road
Unpaved Road
Drainage
Notes:
AUM Abandoned uranium mine
PLSS Public Land Survey System
1 inch = 7,400 Feet
1:88,800
7,400 3,700 0
N
7,400
i Feet
SECTION 9 LEASE MINES
LOCATION AND ACCESS
Prepared For: U.S. EPA Region 9
v.
v
Prepared By:
It
TETRA TECH
1999 Harrison Street, Suite 500
Oakland, CA 94612
Task Order No.:
0020
Contract No.:
68HE0923D0002
Location:
COCONINO COUNTY, AZ
6/27/2024
Coordinate System:
NAD 1983 State Plane Arizona Central
FIPS 0202 Feet Transverse Mercator
Figure No.:
B-1
-------
/ V
I ~
w \
7
/¦¦N
I
I TRCP
/ /Is—- /\—" w
- ^ ^ v _ ss~\zr -
^ \V^ / ~ N. Qay^ ^ — -
/--—3
|TRcp
S> !
~> ^ -
, f \
TRcp
\ X iQi V AUM 458
* O
**7TRcp
Soil Sample Location
Risk Assessment Boundary
TENORM Boundary
Section 9 Lease Mines AUM Site
Geologic Contact
PLSS Section Boundary
Babbit Ranches Property Boundary
BLM Land Boundary
Navajo Nation Boundary
Access Road
Drainage
Notes:
AUM
BLM
Qay
TENORM
TRcp
TRcs
Abandoned uranium mine
Bureau of Land Management
Quaternary Alluvium
Technologically enhanced naturally
occurring radioactive material
Chinle Formation Petrified Forest Member
Chinle Formation Shinarump Member
1 inch = 620 Feet
1:7,440
620 310 0
SECTION 9 LEASE MINES
EXPOSURE UNIT WITH
RISK ASSESSMENT SAMPLE LOCATIONS
Prepared For: U.S. EPA Region 9
J***.
Task Order No.:
0020
Location:
COCONINO COUNTY, AZ
Prepared By:
It
TETRA TECH
1999 Harrison Street, Suite 500
Oakland, CA 94612
Contract No.:
68HE0923D0002
6/27/2024
Coordinate System:
NAD 1983 State Plane Arizona Central
FIPS 0202 Feet Transverse Mercator
Figure No.:
B-2
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APE-SS02-01-020624
APE-SS01-01-020624
Drain-TP2-0.5-1.0-120418.
DrairvTP2-1.0-1.5-120418
MRD-TP1-0.5-1.0-120518
MRD-TP1-1.5-2.0-120518
MRD-TP1-2.5-3.0-120518
LCR-TP11-2.0-2.5-120318
APE-SS04-01-020624
LCR-TP12-0-0.5^120318'
LCR-TP12-1.0-1.5-120318
APE-SS05-01-020624
A PE-SS06-01-020624
457-TP14-0-0.5-120318
457-TP15-0-0.5-120618,
457-TP15-0.5-1.0-120618
SS07-01-020624
APE-SS09-01-020624
Drain-TP1(>0-0.5-120318,
Drain-TP16-1.0-1.5-120318
APE-SS08-01-020624
MHR-TP17-0-0.5-120618,
MHR-TP17-2.0-2.5-120618
APE-SS10-01 -020624
MHR-TP22-0-0.5-120518,
MHR-TP22-1.0-1.5-120518
459-TP23-0-0.5-120618,
459-TP23-0.5-1.0-120618,
459-TP23-Z5Vcfl 20618
APE-SS03-01-020624
Soil Sample Locations1
• Sediment Sample (0-6 inches bgs}
Surface Soil Sample (0-6 inches bgs)
A (includes all laboratory samples with
bottom depth < 6 inches)
Subsurface Soil Sample (below 6 inches bgs)
O (includes all laboratory samples with
top depth > 6 inches and < 60 inches)
Risk Assessment Boundary
It 111 Section 9 Lease Mines AUM Site
Site Features
== Berm
Accumulation/Deposition Area - Surficial
Accumulation/Deposition Area - Volumetric
Concrete Pad
rrm Dozer Cut
Haul Road
Shallow Mine Waste
Waste Pile
Access Road
Drainage
Notes:
1 Sample IDs for AUM 457 and AUM 458 are
shown on the following figures.
AUM Abandoned uranium mine
bgs Below ground surface
1 inch = 620 Feet
1:7,440
620 310 0
N
S
620
I Feet
SECTION 9 LEASE MINES
EXPOSURE UNIT
SAMPLE LOCATIONS
OVERVI EW
Prepared For: U.S. EPA Region 9
v
Prepared By:
It
TETRA TECH
1999 Harrison Street, Suite 500
Oakland, CA 94612
Task Order No.:
0020
Contract No.:
68HE0923D0002
Location:
COCONINO COUNTY, AZ
6/27/2024
Coordinate System:
NAD 1983 State Plane Arizona Central
FIPS 0202 Feet Transverse Mercator
Figure No.:
B-3
-------
457-SS02-01 -020624
457-TP4-2.0-2.5-120418,
457-TP4-3.0-3.5-120418
457-TP6-0-0.5-120418,
457-TP6-1.0-1.5-120418
457-SS03-01 -020624
457-SS04-01 -020624
Soil Sample Locations1
• Sediment Sample (0-6 inches bgs)
Surface Soil Sample (0-6 inches bgs)
A (includes all laboratory samples with
bottom depth < 6 inches)
Subsurface Soil Sample (below 6 inches bgs)
O (includes all laboratory samples with
top depth > 6 inches and < 60 inches)
Risk Assessment Boundary
It 111 Section 9 Lease Mines AUM Site
Site Features
== Berm
Concrete Pad
rrrn Dozer Cut
Shallow Mine Waste
Waste Pile
Access Road
Drainage
Notes:
1Sample IDs for outside of the AUM 457
boundary are shown on Figure B-3.
AUM Abandoned uranium mine
bgs Below ground surface
1 inch = 160 Feet
1:1,920
160 80 0
N
S
160
I Feet
SECTION 9 LEASE MINES
EXPOSURE UNIT
SAMPLE LOCATIONS - AUM 457
Prepared For: U.S. EPA Region 9
v.
v
Prepared By:
It
TETRA TECH
1999 Harrison Street, Suite 500
Oakland, CA 94612
Task Order No.:
0020
Contract No.:
68HE0923D0002
Location:
COCONINO COUNTY, AZ
6/27/2024
Coordinate System:
NAD 1983 State Plane Arizona Central
FIPS 0202 Feet Transverse Mercator
Figure No.:
B-4
-------
Soil Sample Locations1
• Sediment Sample (0-6 inches bgs}
Surface Soil Sample (0-6 inches bgs)
A (includes all laboratory samples with
bottom depth < 6 inches)
Subsurface Soil Sample (below 6 inches bgs)
O (includes all laboratory samples with
top depth > 6 inches and < 60 inches)
Risk Assessment Boundary
It 111 Section 9 Lease Mines AUM Site
Site Features
Accumulation/Deposition Area - Surficial
run Dozer Cut
Shallow Mine Waste
Waste Pile
Access Road
Notes:
1Sample IDs for outside of the AUM 458
boundary are shown on Figure B-3.
AUM Abandoned uranium mine
bgs Below ground surface
1 inch = 100 Feet
1:1,200
100 50 0
N
S
100
I Feet
SECTION 9 LEASE MINES
EXPOSURE UNIT
SAMPLE LOCATIONS - AUM 458
Prepared For: U.S. EPA Region 9
y
Task Order No.:
0020
Location:
COCONINO COUNTY, AZ
Prepared By:
It
TETRA TECH
Contract No.:
68HE0923D0002
6/27/2024
Coordinate System:
NAD 1983 State Plane Arizona Central
FIPS 0202 Feet Transverse Mercator
Figure No.:
B-5
-------
APPLICABLE HUMAN EXPOSURE SCENARIOS
ECOLOGICAL EXPOSURE SCENARIOS
PRIMARY SOURCES OF
CONTAMINATION
SOURCE MEDIA
PRIMARY RELEASE
MECHANISMS
SECONDARY SOURCES
OF CONTAMINATION
SECONDARY RELEASE
MECHANISMS
EXPOSURE MEDIA
EXPOSURE
ROUTES
TRESPASSER
EXPOSURE
ROUTES
PLANTS AND BIRDS AND
INVERTEBRATES MAMMALS
Background
Sources
(Natural In Situ
Material)
s
Highwalls
>
v
—/
Waste Rock,
Mining Debris, and
Open Pits at AUMs
457 and 458
Rock and Soil
-+• Radioactive Decay
Radon Gas
Emanation
Gamma Radiation
Ambient Air
Air
Wind Erosion
Erosion via
-> Stormwateror
Snowmelt Runoff
Mass Wasting
Soil
Onsite Drainages —
Surface Water
t
Sediment
~1
Alluvial
Groundwater
Storm water/
Snowmelt Runoff
Gamma Radiation
Air
Soil/Sediment
Water
Plants/Animals
Notes:
X Indicates the exposure pathway is potentially complete and is evaluated in the risk assessment except as noted.
- Indicates the exposure pathway is not complete or de minimis and is not evaluated in the risk assessment.
1 The human health risk evaluation does not include ingestion of surface water or groundwater by humans.
2 The human health risk evaluation does not include ingestion, dermal (metals only), and inhalation of wild plants by this receptor.
3 The human health risk evaluation does not include ingestion of home-raised animals (meat, milk, and eggs) and hunted animals (meat only) for this receptor.
4 The ecological risk evaluation does not include evaluation of external exposure to gamma radiation.
5 Potential exposures include inhalation of ambient air and air in burrows. The ecological risk evaluation does not include evaluation of the inhalation pathway.
6 The ecological risk evaluation does not include evaluation of direct contact with or ingestion of surface water.
AUM Abandoned uranium mine
Leaching/
Dissolution
Entrapment/
Deposition
Plant Uptake/
Uptake through
Food Chain
Soil/Sediment
*1 Surface Water
Wild Plants
Animals
External Exposure
Inhalation
Incidental Ingestion
Dermal
Inhalation
Ingestion
Dermal
Inhalation
Ingestion
Dermal
Inhalation
Ingestion
External Exposure
Inhalation
Dermal/Direct Contact
Ingestion
Trophic Transfer
Dermal/Direct Contact
Ingestion
Trophic Transfer
Ingestion
Ingestion
Trophic Transfer
Figure B-6. Section 9 Lease Mines Conceptual Site Model
-------
TABLES
-------
Table B-1. Soil Results Data Summary and Contaminant of Potential Concern Screening
Minimum
Maximum
Location of
Maximum Detected
Concentration13
Depth of
COPC
Screening
Level0
Include
Constituent of
Interest3
Detection
Frequency13
Units
Detected
Concentration
(qualifier)13
Detected
Concentration
(qualifier)13
Maximum
Concentration
(inches bgs)b
Constituent
as a
COPC?d
Radionuclides
Uranium-238 in SEe
110 / 110
pCi/g
0.977
945
457-SS-7A
0-6
0.012
Yes
Metals
Aluminum
63 / 63
mg/kg
1,100 D
18,400
APE-SS04-01-020624
0-6
7,670
Yes
Antimony
0 / 63
mg/kg
-
—
—
—
3.1
No
Arsenic
96/110
mg/kg
0.749 J
230 D
457-SS-7A
0-6
0.68
Yes
Barium
63 / 63
mg/kg
24.8
1,100 D
457-SS-7A
0-6
1,500
No
Beryllium
21 / 35
mg/kg
0.289
1.68
458-SS05-01-020624
0-6
15
No
Cadmium
18 / 56
mg/kg
0.0241 J
1 JD
457-SS-7A
0-6
0.71
Yes
Chromium
42 / 63
mg/kg
2.11
8.51
APE-SS10-01 -020624
0-6
1.32
Yes
Cobalt
41 / 63
mg/kg
0.641
47 JD
459-SS-2C
12-18
2.3
Yes
Copper
49 / 63
mg/kg
3.76 N*
37 D
457-SS-7A
0-6
313
No
Iron
63 / 63
mg/kg
1,660
97,000 D
458-SS-6A
0-6
5,480
Yes
Lead
63 / 63
mg/kg
4 JD
150 D
457-SS-7A
0-6
200
No
Manganese
61 / 63
mg/kg
4.96
540 D
DRN-SD-4
0-6
179
Yes
Mercury
84 / 110
mg/kg
0.0012 J
8.7
457-SS-8A
0-6
2.4
Yes
Molybdenum
97 / 110
mg/kg
0.133 J
2,000 D
457-SS-7A
0-6
39
Yes
Nickel
59 / 63
mg/kg
0.437
17 JD
DRN-SD-1
0-6
137
No
Selenium
45 / 110
mg/kg
0.056 J
37 JD
458-SS-6A
0-6
39
No
Silver
4 / 63
mg/kg
0.0955 J-
0.208 J-
458-SS04-01-020624
0-6
39
No
Thallium
16 / 63
mg/kg
0.143 J
26 JD
457-SS-7A
0-6
0.078
Yes
Uranium
69 / 110
mg/kg
0.99
970 D
457-SS-7A
0-6
1.6
Yes
Vanadium
97 / 110
mg/kg
3.6
390 D
457-SS-7A
0-6
39
Yes
Zinc
33 / 63
mg/kg
2.69 J
66 JD
457-SS-7A
0-6
2,350
No
Notes:
a Bolded contaminants are selected as human health COPCs because the maximum detected concentration exceeds the COPC screening level.
b Includes all soil samples, including duplicate samples, with analytical results from the Section 9 Lease Mines collected during the site evaluation (Weston 2014),
removal site evaluation (EA 2021), and 2024 data gaps investigation sampling (Tetra Tech 2024).
c The COPC screening levels were calculated using the NAUM Risk Calculator (USEPA 2024d) and exposure assumptions for a default resident based on a
target hazard quotient of 0.1 and a target cancer risk of one in one million (1E-06), except for lead. The lead screening value is based on the USEPA Regional
Screening Level (RSL) for lead (USEPA 2024e).
d A contaminant is included as a COPC for the human health risk assessment if the maximum detected concentration exceeds the COPC screening level.
e When uranium-238 is in SE, site data for radium-226 in conjunction with uranium-238 in SE toxicity values can be used to calculate the risk for the entire
uranium-238 decay chain.
Page 1 of 2
-------
Table B-1. Soil Results Data Summary and Contaminant of Potential Concern Screening
Notes (continued):
bgs
Below ground surface
COPC
Contaminant of potential concern
D
Dilution
EA
Engineering Analytics, Inc.
J
Estimated concentration
J-
Estimated concentration, biased low
mg/kg
Milligram per kilogram
N*
Matrix spike sample recovery is not within specified control limits
NAUM
Navajo abandoned uranium mine
pCi/g
Picocurie per gram
SE
Secular equilibrium
Tetra T ech
Tetra Tech, Inc.
USEPA
U.S. Environmental Protection Agency
Weston
Weston Solutions, Inc.
References:
Engineering Analytics, Inc. (EA). 2021. "Removal Site Evaluation Report, Babbitt Ranches, LLC - Milestone Hawaii Stewardship Project (Section 9 Lease
Abandoned Uranium Mine)." Draft. Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Docket No. 2016-13. March 18.
Tetra Tech, Inc. (Tetra Tech). 2024. "Section 9 Lease Mines Data Gap Investigation Report." Response, Assessment, and Evaluation Services 2. Contract No.
68HE0923D0002. May.
U.S. Environmental Protection Agency (USEPA). 2024c. "Navajo Abandoned Uranium Mines Risk Assessment Methodology." Draft Final. March.
USEPA. 2024e. "Regional Screening Levels (RSLs)." May 14. https://epa-prgs.ornl.gov/cgi-bin/chemicals/csl_search.
Weston Solutions, Inc. (Weston). 2014. "Site Inspection Report, Section 9 Lease Abandoned Uranium Mine, Coconino County, Arizona." Report Prepared for
U.S. Environmental Protection Agency Region 9. June.
Page 2 of 2
-------
Table B-2. Exposure Unit Summary of Land Use, Geologic Formation, Type, Area, and Available Samples
Exposure
Unit
Land Use/
Receptor
Geologic
Formation
Type
Area
(acre)
Number of Surface Soil
(or Sediment) Samples
(0-6 inches bgs)a
Number of Subsurface Soil Samples
(0-60 inches bgs)a
Section 9
Lease Mines
Trespasser and
Ecological
Receptors
Qay
TRcp
TRcs
TENORM
406
72 - Radiological
72 - Arsenic, Mercury, Molybdenum,
Selenium, Uranium, Vanadium
53 - Aluminum, Antimony, Barium,
Chromium, Cobalt, Copper, Iron, Lead,
Manganese, Nickel, Silver, Thallium, Zinc
48 - Cadmium
32 - Beryllium
110 - Radiological
110 - Arsenic, Mercury, Molybdenum,
Selenium, Uranium, Vanadium
63 - Aluminum, Antimony, Barium,
Chromium, Cobalt, Copper, Iron, Lead,
Manganese, Nickel, Silver, Thallium, Zinc
56 - Cadmium
35 - Beryllium
Notes:
a Includes all soil samples, including duplicate samples, with analytical results from the Section 9 Lease Mines collected during the site evaluation (Weston 2014), removal site
evaluation (EA 2021), and 2024 data gaps investigation (Tetra Tech 2024).
bgs Below ground surface
EA Engineering Analytics, Inc.
Qay Quaternary Alluvium
TENORM Technologically enhanced naturally occurring radioactive material
Tetra Tech Tetra Tech, I nc.
TRcp Petrified Forest Member of the Chinle Formation
TRcs Shinarump Member of the Chinle Formation
Weston Weston Solutions, Inc.
References:
Engineering Analytics, Inc. (EA). 2021. "Removal Site Evaluation Report, Babbitt Ranches, LLC - Milestone Hawaii Stewardship Project (Section 9 Lease
Abandoned Uranium Mine)." Draft. Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Docket No. 2016-13. March 18.
Tetra Tech, Inc. (Tetra Tech). 2024. "Section 9 Lease Mines Data Gap Investigation Report." Response, Assessment, and Evaluation Services 2. Contract No.
68HE0923D0002. May.
Weston Solutions, Inc. (Weston). 2014. "Site Inspection Report, Section 9 Lease Abandoned Uranium Mine, Coconino County, Arizona." Report Prepared for U.S. Environmental
Protection Agency Region 9. June.
Page 1 of 1
-------
Table B-3. Human Health Exposure Parameters
Input Parameter
Symbol
Units
Receptor
Trespassera
Common Parameters
Exposure Duration - Adult
ED
years
24
Exposure Duration - Child
EDc
years
2
Exposure Duration - Lifetime Total
EDa
years
26
Exposure Time - Lifetime Total
t
years
26
Averaging Time - Cancer
ATc
days
25,550
Averaging Time - Noncancer - Adult
ATnc
days
8,760
Averaging Time - Noncancer - Child
ATnc
days
730
Exposure Frequency - Adult
EFa
days/year
14
Exposure Frequency - Child
EFc
days/year
14
Body Weight - Adult
BWa
kg
80
Body Weight - Child
BWc
kg
15
Conversion Factor 1
CF1
g/mg
1/1,000
Conversion Factor 2
CF2
kg/mg
1/1,000,000
Conversion Factor 3
CF3
day/hours
1/24
Conversion Factor 4
CF4
g/kg
1,000
Conversion Factor 5
CF5
year/days
1/365
Conversion Factor 6
CF6
kg/g
1/1,000
Conversion Factor 7
CF7
pCi/Bq
27.027
Decay Constant
A
1/year
Radionuclide-specific from the PRG
Calculator (USEPA 2024b)
Soi
Ingestion Parameters
Onsite Soil Ingestion Rate - Adult
IRSa
mg/day
100
Onsite Soil Ingestion Rate - Child
IRSc
mg/day
200
Dust Inhalation Parameters
Inhalation Rate when Exposed - Adult
IRAres-a
m3/day
25
Inhalation Rate when Exposed - Child
IRAres-c
m3/day
10
Exposure Time - Adult
ETa
hours/day
24
Exposure Time - Child
ETc
hours/day
24
City/Climatic Zone
-
-
Cameron, AZ (Climatic Zone 3)
Mean Annual Wind Speed
Um
m/s
5.0
Areal extent of site surface soil
As
acres
406
Fraction of Vegetative Cover
V
-
0.1
Particulate Emission Factor
PEF
m3/kg
1.36E+08
Radiation External Exposure Parameters
Gamma Shielding Factor - Outdoor
GSF0
-
1
Exposure Time on Site Outdoors - Adult
ETa.0
hours/day
24
Exposure Time on Site Outdoors - Child
ETC_0
hours/day
24
Metals Dermal Exposure Parameters
Surface Area - Adult
SAa
cm2/day
6,032
Surface Area - Child
SAc
cm2/day
2,373
Adherence Factor - Adult
AFa
mg/cm2
0.12
Adherence Factor - Child
AFc
mg/cm2
0.2
Page 1 of 2
-------
Table B-3. Human Health Exposure Parameters
Notes:
a Potential trespassers at Section 9 Lease Mines are assumed to have the same exposure assumptions as a BLM
recreator due to the open access of BLM property within Section 10 and the lack of a physical barrier that limits
movement between Sections 9 and 10. A person legally accessing BLM-managed land on Section 10 could
trespass on Section 9.
References:
U.S. Environmental Protection Agency (USEPA). 2024b. "Preliminary Remediation Goals for Radionuclides (PRG)."
February, https://epa-prgs.ornl.gov/cgi-bin/radionuclides/rprg_search.
AZ
BLM
cm2/day
g/kg
g/mg
kg
kg/g
kg/mg
m/s
m3/day
m3/kg
mg/cm2
mg/day
pCi/Bq
PRG
USEPA
Not applicable
Arizona
Bureau of Land Management
Square centimeter per day
Gram per kilogram
Gram per milligram
Kilogram
Kilogram per gram
Kilogram per milligram
Meter per second
Cubic meter per day
Cubic meter per kilogram
Milligram per square centimeter
Milligram per day
Picocurie per becquerel
Preliminary remediation goal
U.S. Environmental Protection Agency
Page 2 of 2
-------
Table B-4. Exposure Point Concentrations for Human Health Risk Assessment
Section 9 Lease Mines
COPCa
Units
Detection
Frequency
Number of
High
Nondetect
Results'3
Maximum
Concentration
(qualifier)
Location of Maximum
Concentration
Arithmetic
Meanc
UCL95 /
Distribution1
Exposure Point
Concentration
Value0
Statistic0
Methodf
Surface Soil (0-6 inches bgs)
Radium-226
pCi/g
62 / 62
0
945
457-SS-7A
58.77
96.8
LN
97
UCL95
(14)
Aluminum
mg/kg
46 / 46
0
18,400
APE-SS04-01-020624
4,526
5,319
LN
5,320
UCL95
(14)
Arsenic
mg/kg
55 / 62
0
230 D
457-SS-7A
20.16
29.07
LN
29
UCL95
(15)
Cadmium
mg/kg
17 / 42
0
1 JD
457-SS-7A
0.228
0.309
G
0.31
UCL95
(5)
Chromium
mg/kg
34 / 45
2
8.51
APE-SS10-01 -020624
4.526
5.009
N
5.00
UCL95
(2)
Cobalt
mg/kg
34 / 45
2
28
457-SS02-01-020624
8.349
10.47
G
10
UCL95
(5)
Iron
mg/kg
46 / 46
0
97,000 D
458-SS-6A
11,555
15,254
NP
15,300
UCL95
(14)
Manganese
mg/kg
45 / 46
0
540 D
DRN-SD-4
145.1
182.2
G
182
UCL95
(5)
Mercury
mg/kg
47 / 62
0
8.7
457-SS-8A
0.251
0.531
LN
0.53
UCL95
(15)
Molybdenum
mg/kg
56 / 62
0
2,000 D
457-SS-7A
142.6
241.7
G
242
UCL95
(7)
Thallium
mg/kg
15 / 45
2
26 JD
457-SS-7A
1.872
3.104
LN
3.1
UCL95
(13)
Uranium
mg/kg
37 / 62
0
970 D
457-SS-7A
38.54
69.05
LN
69
UCL95
(15)
Vanadium
mg/kg
55 / 62
0
390 D
457-SS-7A
29.07
41.89
NP
42
UCL95
(15)
Page 1 of 3
-------
Table B-4. Exposure Point Concentrations for Human Health Risk Assessment
Section 9 Lease Mines
COPCa
Units
Detection
Frequency
Number of
High
Nondetect
Results'3
Maximum
Concentration
(qualifier)
Location of Maximum
Concentration
Arithmetic
Meanc
UCL95 /
Distribution1
Exposure Point
Concentration
Value0
Statistic0
Methodf
Subsurface Soil (0-60 inches bgs)
Radium-226
pCi/g
100 / 100
0
945
457-SS-7A
42.40
65.41
NP
65
UCL95
(14)
Aluminum
mg/kg
56 / 56
0
18,400
APE-SS04-01-020624
4,145
4,823
LN
4,820
UCL95
(14)
Arsenic
mg/kg
88 / 100
0
230 D
457-SS-7A
15.67
21.18
NP
21
UCL95
(15)
Cadmium
mg/kg
17 / 56
0
1.00 JD
457-SS-7A
0.224
0.293
G
0.29
UCL95
(7)
Chromium
mg/kg
37 / 55
2
8.51
APE-SS10-01-020624
4.243
4.681
N
4.70
UCL95
(3)
Cobalt
mg/kg
38 / 56
2
47 JD
459-SS-2C
8.925
11.18
G
11
UCL95
(7)
Iron
mg/kg
56 / 56
0
97,000 D
458-SS-6A
11034
13,985
NP
14,000
UCL95
(14)
Manganese
mg/kg
55 / 56
0
540 D
DRN-SD-4
138
167.7
G
168
UCL95
(7)
Mercury
mg/kg
76 / 100
0
8.7
457-SS-8A
0.179
0.36
LN
0.36
UCL95
(15)
Molybdenum
mg/kg
89 / 100
0
2,000 D
457-SS-7A
105.80
167.9
G
168
UCL95
(7)
Thallium
mg/kg
15 / 55
2
26 JD
457-SS-7A
1.772
2.838
LN
2.8
UCL95
(13)
Uranium
mg/kg
65 / 100
0
970 D
457-SS-7A
31.15
50.28
NP
50
UCL95
(15)
Vanadium
mg/kg
88 / 100
0
390 D
457-SS-7A
25.75
33.44
NP
33
UCL95
(15)
Page 2 of 3
-------
Table B-4. Exposure Point Concentrations for Human Health Risk Assessment
Notes:
a EPCs calculated if "Yes" for "Include Constituent as a COPC?" on Table B-1.
b Number of nondetect results that exceeded the maximum detected concentration. These results were not included in the statistical calculations.
c The arithmetic mean for datasets with nondetected results is calculated using the KM method.
d Following USEPA (2002, 2022b) guidance, this value may be estimated by a 95, 97.5, or 99 percent UCL depending on the sample size, skewness, and degree of
6eTi§§r@tii0sing the Shapiro-Wilk W or Lilliefors test for normal and lognormal distributions and the Anderson-Darling and Kolmogorov-Smirnov tests for gamma
distributions. A 5 percent level of significance was used in all tests. Distribution tests were conducted only for samples with at least four detected results.
f The EPC is the lesser of the UCL95 (or UCL99) and the maximum detected concentration. The maximum detected concentration is the default when there are fewer
than 10 samples or fewer than 4 detected results. See Appendix D of the "Navajo Abandoned Uranium Mines Risk Assessment Methodology" report (USEPA 2024c).
9 The statistical methods for selectin 9 ^e exposure point concentration are as follows (not all are used):
95% KM BCA UCL
95% Percentile Bootstrap UCL
95% KM Percentile Bootstrap UCL
99% Bootstrap-t UCL
99% KM Percentile Bootstrap UCL
(1)
Maximum detected concentration
(7)
95% Gamma Approximate KM-UCL
(13)
(2)
95% Student's t UCL
(8)
95% H-UCL
(14)
(3)
95% KM (t) UCL
(9)
95% H-UCL (KM log)
(15)
(4)
95% Adjusted Gamma UCL
(10)
95% Bootstrap-t UCL
(16)
(5)
95% Gamma Adjusted KM-UCL
(11)
95% KM Bootstrap-t UCL
(17)
(6)
95% Approximate Gamma UCL
(12)
95% BCA UCL
BCA
Bias-corrected accelerated bootstrap method
LN
Lognormal distribution
bgs
Below ground surface
mg/kg
Milligram per kilogram
COPC
Contaminant of potential concern
N
Normal distribution
D
Dilution
NP
Nonparametric distribution
EPC
Exposure point concentration
pCi/g
Picocurie per gram
G
Gamma distribution
UCL
Upper confidence limit
H-UCL
UCL based upon Land's H-statistic
UCL95
95 percent upper confidence limit
J
Estimated concentration
UCL99
99 percent upper confidence limit
KM
Kaplan-Meier
USEPA
U.S. Environmental Protection Agency
References:
U.S. Environmental Protection Agency (USEPA). 2002. "Calculating Exposure Point Concentrations at Hazardous Waste Sites." Office of Solid Waste and Emergency
Response. Directive 9285.6-10. December.
USEPA. 2022b. "ProUCL Statistical Software for Environmental Applications for Data Sets with and without Nondetect Observations." Version 5.2.0. June 14.
USEPA. 2024c. "Navajo Abandoned Uranium Mines Risk Assessment Methodology." Draft Final. March.
Page 3 of 3
-------
Table B-5. Human Health Risk and Hazard Calculations
Section 9 Lease Mines - Trespasser
COPCa
EPCb
Units
Cancer
lntakec
Units
Slope
Factor/
Unit Riskd
Units
Cancer
Risk6
Adult
Noncancer
Intake
Units
RfD /
RfCd
Units
Noncancer
Hazardf
Child
Noncancer
lntakec
Units
RfD /
RfCd
Units
Noncancer
Hazardf
Adult
Child
Exposure Medium: Surface Soil (0-6 inches bgs
Exposure Route: Incidental Soil Ingestion
Uranium-238 in SE
9.7E+01
pCi/g
3.8E+03
pCi/g
6.2E-09
Risk/pCi/g
2.4E-05
—
—
—
—
—
—
—
—
—
—
Radionuclide Cancer Total
2E-05
Radionuclide Noncancer Total
—
Radionuclide Noncancer Total
—
Aluminum
5.3E+03
mg/kg
—
—
—
—
—
2.5E-04
mg/kg-day
1.0E+00
mg/kg-day
0.00025
2.7E-03
mg/kg-day
1.0E+00
mg/kg-day
0.0027
Arsenic
2.9E+01
mg/kg
7.5E-07
mg/kg-day
1.5E+00
(mg/kg-day)"1
1.1E-06
8.4E-07
mg/kg-day
3.0E-04
mg/kg-day
0.0028
8.9E-06
mg/kg-day
3.0E-04
mg/kg-day
0.030
Cadmium
3.1E-01
mg/kg
—
—
—
—
—
1.5E-08
mg/kg-day
1.0E-04
mg/kg-day
0.00015
1.6E-07
mg/kg-day
1.0E-04
mg/kg-day
0.0016
Chromium
5.0E+00
mg/kg
3.7E-07
mg/kg-day
5.0E-01
(mg/kg-day)"1
1.9E-07
2.4E-07
mg/kg-day
3.0E-03
mg/kg-day
0.000080
2.6E-06
mg/kg-day
3.0E-03
mg/kg-day
0.00085
Cobalt
1.0E+01
mg/kg
—
—
—
—
—
4.8E-07
mg/kg-day
3.0E-04
mg/kg-day
0.0016
5.1E-06
mg/kg-day
3.0E-04
mg/kg-day
0.017
Iron
1.5E+04
mg/kg
—
—
—
—
—
7.3E-04
mg/kg-day
7.0E-01
mg/kg-day
0.0010
7.8E-03
mg/kg-day
7.0E-01
mg/kg-day
0.011
Manganese
1.8E+02
mg/kg
—
—
—
—
—
8.7E-06
mg/kg-day
2.4E-02
mg/kg-day
0.00036
9.3E-05
mg/kg-day
2.4E-02
mg/kg-day
0.0039
Mercury
5.3E-01
mg/kg
—
—
—
—
—
2.5E-08
mg/kg-day
3.0E-04
mg/kg-day
0.000085
2.7E-07
mg/kg-day
3.0E-04
mg/kg-day
0.00090
Molybdenum
2.4E+02
mg/kg
—
—
—
—
—
1.2E-05
mg/kg-day
5.0E-03
mg/kg-day
0.0023
1.2E-04
mg/kg-day
5.0E-03
mg/kg-day
0.025
Thallium
3.1E+00
mg/kg
—
—
—
—
—
1.5E-07
mg/kg-day
1.0E-05
mg/kg-day
0.015
1.6E-06
mg/kg-day
1.0E-05
mg/kg-day
0.16
Uranium
6.9E+01
mg/kg
—
—
—
—
—
3.3E-06
mg/kg-day
2.0E-04
mg/kg-day
0.017
3.5E-05
mg/kg-day
2.0E-04
mg/kg-day
0.18
Vanadium
4.2E+01
mg/kg
—
—
—
—
—
2.0E-06
mg/kg-day
5.0E-03
mg/kg-day
0.00040
2.1E-05
mg/kg-day
5.0E-03
mg/kg-day
0.0043
Metals Cancer Total
1E-06
Metals Noncancer Total
0.04
Metals Noncancer Total
0.4
Exposure Route Cancer Total
2E-05
Exposure Route Noncancer Total
0.04
Exposure Route Noncancer Total
0.4
Exposure Medium: Surface Soil (0-6 inches bgs)
Exposure Route: External Ex
posure
Uranium-238 in SE
9.7E+01
pCi/g
8.7E+01
pCi/g
8.5E-06
risk/year
pCi/g
7.4E-04
--
--
--
--
--
--
--
--
--
--
Radionuclide Cancer Total
7E-04
Radionuclide Noncancer Total
—
Radionuclide Noncancer Total
—
Exposure Route Cancer Total
7E-04
Exposure Route Noncancer Total
—
Exposure Route Noncancer Total
—
Exposure Route: Dermal Exposure
Aluminum
5.3E+03
mg/kg
—
—
—
—
—
—
—
1.0E+00
mg/kg-day
—
—
—
1.0E+00
mg/kg-day
—
Arsenic
2.9E+01
mg/kg
9.0E-08
mg/kg-day
1.5E+00
(mg/kg-day)"1
1.4E-07
1.8E-07
mg/kg-day
3.0E-04
mg/kg-day
0.00059
1.1E-06
mg/kg-day
3.0E-04
mg/kg-day
0.0035
Cadmium
3.1E-01
mg/kg
—
—
—
—
—
2.5E-09
mg/kg-day
1.0E-04
mg/kg-day
0.000025
1.5E-08
mg/kg-day
1.0E-04
mg/kg-day
0.00015
Chromium
5.0E+00
mg/kg
—
—
5.0E-01
(mg/kg-day)"1
—
—
—
3.0E-03
mg/kg-day
—
—
—
3.0E-03
mg/kg-day
—
Cobalt
1.0E+01
mg/kg
—
—
—
—
—
—
—
3.0E-04
mg/kg-day
—
—
—
3.0E-04
mg/kg-day
—
Iron
1.5E+04
mg/kg
—
—
—
—
—
—
—
7.0E-01
mg/kg-day
—
—
—
7.0E-01
mg/kg-day
—
Manganese
1.8E+02
mg/kg
—
—
—
—
—
—
—
2.4E-02
mg/kg-day
—
—
—
2.4E-02
mg/kg-day
—
Mercury
5.3E-01
mg/kg
—
—
—
—
—
—
—
3.0E-04
mg/kg-day
—
—
—
3.0E-04
mg/kg-day
—
Molybdenum
2.4E+02
mg/kg
—
—
—
—
—
—
—
5.0E-03
mg/kg-day
—
—
—
5.0E-03
mg/kg-day
—
Thallium
3.1E+00
mg/kg
—
—
—
—
—
—
—
1.0E-05
mg/kg-day
—
—
—
1.0E-05
mg/kg-day
—
Uranium
6.9E+01
mg/kg
—
—
—
—
—
—
—
2.0E-04
mg/kg-day
—
—
—
2.0E-04
mg/kg-day
—
Vanadium
4.2E+01
mg/kg
—
—
—
—
—
—
—
5.0E-03
mg/kg-day
—
—
—
5.0E-03
mg/kg-day
—
Metals Cancer Total
1E-07
Metals Noncancer Total
0.0006
Metals Noncancer Total
0.004
Exposure Route Cancer Total
1E-07
Exposure Route Noncancer Total
0.0006
Exposure Route Noncancer Total
0.004
Page 1 of 4
-------
Table B-5. Human Health Risk and Hazard Calculations
Section 9 Lease Mines - Trespasser
COPCa
EPCb
Units
Cancer
lntakec
Units
Slope
Factor/
Unit Riskd
Units
Cancer
Risk6
Adult
Noncancer
Intake
Units
RfD /
RfCd
Units
Noncancer
Hazardf
Child
Noncancer
lntakec
Units
RfD /
RfCd
Units
Noncancer
Hazardf
Adult
Child
Exposure Medium: Surface Soil (0-6 inches bgs
Exposure Route: Inhalation of Particulates
Uranium-238 in SE
9.7E+01
pCi/g
3.8E+01
pCi
1.5E-07
Risk/pCi
5.5E-06
—
—
—
—
—
—
—
—
—
—
Radionuclide Cancer Total
5E-06
Radionuclide Noncancer Total
—
Radionuclide Noncancer Total
—
Aluminum
5.3E+03
mg/kg
—
—
—
—
—
1.5E-06
mg/m3
5.0E-03
mg/m3
0.00030
1.5E-06
mg/m3
5.0E-03
mg/m3
0.00030
Arsenic
2.9E+01
mg/kg
3.0E-06
ug/rn3
4.3E-03
(ug/m3)"1
1.3E-08
8.2E-09
mg/m3
1.5E-05
mg/m3
0.00055
8.2E-09
mg/m3
1.5E-05
mg/m3
0.00055
Cadmium
3.1E-01
mg/kg
3.2E-08
ug/m3
1.8E-03
(ug/m3y1
5.8E-11
8.8E-11
mg/m3
1.0E-05
mg/m3
0.0000088
8.8E-11
mg/m3
1.0E-05
mg/m3
0.0000088
Chromium
5.0E+00
mg/kg
1.1E-06
ug/m3
8.4E-02
(ug/m3y1
9.0E-08
1.4E-09
mg/m3
1.0E-04
mg/m3
0.000014
1.4E-09
mg/m3
1.0E-04
mg/m3
0.000014
Cobalt
1.0E+01
mg/kg
1.0E-06
ug/m3
9.0E-03
(ug/m3)"1
9.4E-09
2.8E-09
mg/m3
6.0E-06
mg/m3
0.00047
2.8E-09
mg/m3
6.0E-06
mg/m3
0.00047
Iron
1.5E+04
mg/kg
—
—
—
—
—
—
—
—
—
—
—
—
—
—
Manganese
1.8E+02
mg/kg
—
—
—
—
—
5.1E-08
mg/m3
5.0E-05
mg/m3
0.0010
5.1E-08
mg/m3
5.0E-05
mg/m3
0.0010
Mercury
5.3E-01
mg/kg
—
—
—
—
—
1.5E-10
mg/m3
3.0E-04
mg/m3
0.00000050
1.5E-10
mg/m3
3.0E-04
mg/m3
0.00000050
Molybdenum
2.4E+02
mg/kg
—
—
—
—
—
6.8E-08
mg/m3
2.0E-03
mg/m3
0.000034
6.8E-08
mg/m3
2.0E-03
mg/m3
0.000034
Thallium
3.1E+00
mg/kg
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
Uranium
6.9E+01
mg/kg
—
—
—
—
—
1.9E-08
mg/m3
4.0E-05
mg/m3
0.00049
1.9E-08
mg/m3
4.0E-05
mg/m3
0.00049
Vanadium
4.2E+01
mg/kg
—
—
—
—
—
1.2E-08
mg/m3
1.0E-04
mg/m3
0.00012
1.2E-08
mg/m3
1.0E-04
mg/m3
0.00012
Metals Cancer Total
1E-07
Metals Noncancer Total
0.003
Metals Noncancer Total
0.003
Exposure Route Cancer Total
6E-06
Exposure Route Noncancer Total
0.003
Exposure Route Noncancer Total
0.003
Surface Soil (0-6 inches bgs) Receptor Cancer Risk Total
8E-04
Receptor/Media Noncancer Hazard Total
0.04
Receptor/Media Noncancer Hazard Total
0.4
Page 2 of 4
-------
Table B-5. Human Health Risk and Hazard Calculations
Section 9 Lease Mines - Trespasser
COPCa
EPCb
Units
Cancer
lntakec
Units
Slope
Factor/
Unit Riskd
Units
Cancer
Risk6
Adult
Noncancer
Intake
Units
RfD /
RfCd
Units
Noncancer
Hazardf
Child
Noncancer
lntakec
Units
RfD /
RfCd
Units
Noncancer
Hazardf
Adult
Child
Exposure Medium: Subsurface Soil (0-60 inches bgs)
Exposure Route: Incidental Soil Ingestion
Uranium-238 in SE
6.5E+01
pCi/g
2.6E+03
pCi/g
6.2E-09
Risk/pCi/g
1.6E-05
—
—
—
—
—
—
—
—
—
—
Radionuclide Cancer Total
2E-05
Radionuclide Noncancer Total
—
Radionuclide Noncancer Total
—
Aluminum
4.8E+03
mg/kg
—
—
—
—
—
2.3E-04
mg/kg-day
1.0E+00
mg/kg-day
0.00023
2.5E-03
mg/kg-day
1.0E+00
mg/kg-day
0.0025
Arsenic
2.1E+01
mg/kg
5.4E-07
mg/kg-day
1.5E+00
(mg/kg-day)"1
8.1E-07
6.1E-07
mg/kg-day
3.0E-04
mg/kg-day
0.0020
6.4E-06
mg/kg-day
3.0E-04
mg/kg-day
0.021
Cadmium
2.9E-01
mg/kg
—
—
—
—
—
1.4E-08
mg/kg-day
1.0E-04
mg/kg-day
0.00014
1.5E-07
mg/kg-day
1.0E-04
mg/kg-day
0.0015
Chromium
4.7E+00
mg/kg
3.5E-07
mg/kg-day
5.0E-01
(mg/kg-day)"1
1.7E-07
2.3E-07
mg/kg-day
3.0E-03
mg/kg-day
0.000075
2.4E-06
mg/kg-day
3.0E-03
mg/kg-day
0.00080
Cobalt
1.1E+01
mg/kg
—
—
—
—
—
5.3E-07
mg/kg-day
3.0E-04
mg/kg-day
0.0018
5.6E-06
mg/kg-day
3.0E-04
mg/kg-day
0.019
Iron
1.4E+04
mg/kg
—
—
—
—
—
6.7E-04
mg/kg-day
7.0E-01
mg/kg-day
0.00096
7.2E-03
mg/kg-day
7.0E-01
mg/kg-day
0.010
Manganese
1.7E+02
mg/kg
—
—
—
—
—
8.0E-06
mg/kg-day
2.4E-02
mg/kg-day
0.00034
8.6E-05
mg/kg-day
2.4E-02
mg/kg-day
0.0036
Mercury
3.6E-01
mg/kg
—
—
—
—
—
1.7E-08
mg/kg-day
3.0E-04
mg/kg-day
0.000058
1.8E-07
mg/kg-day
3.0E-04
mg/kg-day
0.00061
Molybdenum
1.7E+02
mg/kg
—
—
—
—
—
8.1E-06
mg/kg-day
5.0E-03
mg/kg-day
0.0016
8.6E-05
mg/kg-day
5.0E-03
mg/kg-day
0.017
Thallium
2.8E+00
mg/kg
—
—
—
—
—
1.3E-07
mg/kg-day
1.0E-05
mg/kg-day
0.013
1.4E-06
mg/kg-day
1.0E-05
mg/kg-day
0.14
Uranium
5.0E+01
mg/kg
—
—
—
—
—
2.4E-06
mg/kg-day
2.0E-04
mg/kg-day
0.012
2.6E-05
mg/kg-day
2.0E-04
mg/kg-day
0.13
Vanadium
3.3E+01
mg/kg
—
—
—
—
—
1.6E-06
mg/kg-day
5.0E-03
mg/kg-day
0.00032
1.7E-05
mg/kg-day
5.0E-03
mg/kg-day
0.0034
Metals Cancer Total
1E-06
Metals Noncancer Total
0.03
Metals Noncancer Total
0.4
Exposure Route Cancer Total
2E-05
Exposure Route Noncancer Total
0.03
Exposure Route Noncancer Total
0.4
Exposure Medium: Subsurface Soil (0-60 inches bgs)
Exposure Route: External Ex
posure
Uranium-238 in SE
6.5E+01
pCi/g
5.8E+01
pCi/g
8.5E-06
risk/year
pCi/g
5.0E-04
--
--
--
--
--
--
--
--
--
--
Radionuclide Cancer Total
5E-04
Radionuclide Noncancer Total
—
Radionuclide Noncancer Total
—
Exposure Route Cancer Total
5E-04
Exposure Route Noncancer Total
—
Exposure Route Noncancer Total
—
Exposure Route: Dermal Exposure
Aluminum
4.8E+03
mg/kg
—
—
—
—
—
—
—
1.0E+00
mg/kg-day
—
—
—
1.0E+00
mg/kg-day
—
Arsenic
2.1E+01
mg/kg
6.5E-08
mg/kg-day
1.5E+00
(mg/kg-day)"1
9.8E-08
1.3E-07
mg/kg-day
3.0E-04
mg/kg-day
0.00043
7.6E-07
mg/kg-day
3.0E-04
mg/kg-day
0.0025
Cadmium
2.9E-01
mg/kg
—
—
—
—
—
2.4E-09
mg/kg-day
1.0E-04
mg/kg-day
0.000024
1.4E-08
mg/kg-day
1.0E-04
mg/kg-day
0.00014
Chromium
4.7E+00
mg/kg
—
—
5.0E-01
(mg/kg-day)"1
—
—
—
3.0E-03
mg/kg-day
—
—
—
3.0E-03
mg/kg-day
—
Cobalt
1.1E+01
mg/kg
—
—
—
—
—
—
—
3.0E-04
mg/kg-day
—
—
—
3.0E-04
mg/kg-day
—
Iron
1.4E+04
mg/kg
—
—
—
—
—
—
—
7.0E-01
mg/kg-day
—
—
—
7.0E-01
mg/kg-day
—
Manganese
1.7E+02
mg/kg
—
—
—
—
—
—
—
2.4E-02
mg/kg-day
—
—
—
2.4E-02
mg/kg-day
—
Mercury
3.6E-01
mg/kg
—
—
—
—
—
—
—
3.0E-04
mg/kg-day
—
—
—
3.0E-04
mg/kg-day
—
Molybdenum
1.7E+02
mg/kg
—
—
—
—
—
—
—
5.0E-03
mg/kg-day
—
—
—
5.0E-03
mg/kg-day
—
Thallium
2.8E+00
mg/kg
—
—
—
—
—
—
—
1.0E-05
mg/kg-day
—
—
—
1.0E-05
mg/kg-day
—
Uranium
5.0E+01
mg/kg
—
—
—
—
—
—
—
2.0E-04
mg/kg-day
—
—
—
2.0E-04
mg/kg-day
—
Vanadium
3.3E+01
mg/kg
—
—
—
—
—
—
—
5.0E-03
mg/kg-day
—
—
—
5.0E-03
mg/kg-day
—
Metals Cancer Total
1E-07
Metals Noncancer Total
0.0004
Metals Noncancer Total
0.003
Exposure Route Cancer Total
1E-07
Exposure Route Noncancer Total
0.0004
Exposure Route Noncancer Total
0.003
Page 3 of 4
-------
Table B-5. Human Health Risk and Hazard Calculations
Section 9 Lease Mines - Trespasser
COPCa
EPCb
Units
Cancer
lntakec
Units
Slope
Factor/
Unit Riskd
Units
Cancer
Risk6
Adult
Noncancer
lntakec
Units
RfD /
RfCd
Units
Noncancer
Hazardf
Child
Noncancer
lntakec
Units
RfD /
RfCd
Units
Noncancer
Hazardf
Adult
Child
Exposure Medium: Subsurface Soil (0-60 inches bgs)
Exposure Route: Inhalation of Particulates
Uranium-238 in SE
6.5E+01
pCi/g
2.5E+01
pCi
1.5E-07
Risk/pCi
3.7E-06
—
—
—
—
—
—
—
—
—
—
Radionuclide Cancer Total
4E-06
Radionuclide Noncancer Total
—
Radionuclide Noncancer Total
—
Aluminum
4.8E+03
mg/kg
—
—
—
—
—
1.4E-06
mg/m3
5.0E-03
mg/m3
0.00027
1.4E-06
mg/m3
5.0E-03
mg/m3
0.00027
Arsenic
2.1E+01
mg/kg
2.2E-06
ug/rn3
4.3E-03
(ug/m3)"1
9.5E-09
5.9E-09
mg/m3
1.5E-05
mg/m3
0.00040
5.9E-09
mg/m3
1.5E-05
mg/m3
0.00040
Cadmium
2.9E-01
mg/kg
3.0E-08
ug/m3
1.8E-03
(ug/m3y1
5.5E-11
8.2E-11
mg/m3
1.0E-05
mg/m3
0.0000082
8.2E-11
mg/m3
1.0E-05
mg/m3
0.0000082
Chromium
4.7E+00
mg/kg
9.5E-07
ug/m3
8.4E-02
(ug/m3y1
8.0E-08
1.3E-09
mg/m3
1.0E-04
mg/m3
0.000013
1.3E-09
mg/m3
1.0E-04
mg/m3
0.000013
Cobalt
1.1E+01
mg/kg
1.2E-06
ug/m3
9.0E-03
(ug/m3)"1
1.0E-08
3.1E-09
mg/m3
6.0E-06
mg/m3
0.00052
3.1E-09
mg/m3
6.0E-06
mg/m3
0.00052
Iron
1.4E+04
mg/kg
—
—
—
—
—
—
—
—
—
—
—
—
—
—
Manganese
1.7E+02
mg/kg
—
—
—
—
—
4.7E-08
mg/m3
5.0E-05
mg/m3
0.00095
4.7E-08
mg/m3
5.0E-05
mg/m3
0.00095
Mercury
3.6E-01
mg/kg
—
—
—
—
—
1.0E-10
mg/m3
3.0E-04
mg/m3
0.00000034
1.0E-10
mg/m3
3.0E-04
mg/m3
0.00000034
Molybdenum
1.7E+02
mg/kg
—
—
—
—
—
4.7E-08
mg/m3
2.0E-03
mg/m3
0.000024
4.7E-08
mg/m3
2.0E-03
mg/m3
0.000024
Thallium
2.8E+00
mg/kg
—
—
—
—
—
—
—
—
—
—
—
—
—
—
—
Uranium
5.0E+01
mg/kg
—
—
—
—
—
1.4E-08
mg/m3
4.0E-05
mg/m3
0.00035
1.4E-08
mg/m3
4.0E-05
mg/m3
0.00035
Vanadium
3.3E+01
mg/kg
—
—
—
—
—
9.3E-09
mg/m3
1.0E-04
mg/m3
0.000093
9.3E-09
mg/m3
1.0E-04
mg/m3
0.000093
Metals Cancer Total
1E-07
Metals Noncancer Total
0.003
Metals Noncancer Total
0.003
Exposure Route Cancer Total
4E-06
Exposure Route Noncancer Total
0.003
Exposure Route Noncancer Total
0.003
Subsurface Soil (0-60 inches bgs) Receptor Cancer Risk Total
5E-04
Receptor/Media Noncancer Hazard Total
0.04
Receptor/Media Noncancer Hazard Total
0.4
Notes:
a COPCs are the constituents of interest with a maximum detected concentration exceeding the COPC screening level (see Table B-1).
b EPCs are provided on Table B-4.
c The intakes are the EPC multiplied by the exposure parameters and any applicable contaminant-specific inputs (see Table B-3 for exposure inputs, Table 4 of the NAUM risk assessment methodology [USEPA 2024c] for contaminant-specific inputs).
d The toxicity values are provided in Table 4 of the NAUM risk assessment methodology (USEPA 2024c).
e The cancer risk for each contaminant for each exposure pathway is calculated by multiplying the cancer intake value with the toxicity value as follows:
For contaminant i : Risk, = Cancer Intake, x Toxicity Factor,
f The noncancer hazard for each contaminant for each exposure pathway is calculated by dividing the noncancer intake value by the toxicity value as follows:
For contaminant i : Hazard, = Noncancer Intake, / Toxicity Factor,
-
Not applicable
NAUM
Navajo abandoned uranium mine
Mg/m3
Microgram per cubic meter
pCi
Picocurie
bgs
Below ground surface
pCi/g
Picocurie per gram
COPC
Contaminant of potential concern
RfC
Reference concentration
EPC
Exposure point concentration
RfD
Reference dose
mg/kg
Milligram per kilogram
SE
Secular equilibrium
mg/kg-day
Milligram per kilogram per day
USEPA
U.S. Environmental Protection Agency
mg/m3
Milligram per cubic meter
Reference:
U.S. Environmental Protection Agency (USEPA). 2024c. "Navajo Abandoned Uranium Mines Risk Assessment Methodology." Draft Final. March.
Page 4 of 4
-------
Table B-6. Human Health Risk and Hazard Summary by Exposure Pathway
Section 9 Lease Mines - Trespasser
COPC
EPC
Units
Incidental Soil Ingestion
External Exposure /
Dermal Contact
Inhalation of Particulates
Total Risk or Hazard
Cancer
Risk
Adult
Hazard
Child
Hazard
Cancer
Risk
Adult
Hazard
Child
Hazard
Cancer
Risk
Adult
Hazard
Child
Hazard
Cancer
Risk
Adult
Hazard
Child
Hazard
Surface Soil (0-6 inches bgs)
Uranium-238 in
SE
9.7E+01
pCi/g
2.4E-05
-
-
7.4E-04
-
-
5.5E-06
-
-
8.0E-04
-
-
Aluminum
5.3E+03
mg/kg
-
0.00025
0.0027
-
-
-
-
0.00030
0.00030
-
0.00060
0.0030
Arsenic
2.9E+01
mg/kg
1.1E-06
0.0028
0.030
1.4E-07
0.00059
0.0035
1.3E-08
0.00055
0.00055
1.0E-06
0.0040
0.030
Cadmium
3.1E-01
mg/kg
-
0.00015
0.0016
-
0.000025
0.00015
5.8E-11
0.0000088
0.0000088
6.0E-11
0.00020
0.0020
Chromium
5.0E+00
mg/kg
1.9E-07
0.000080
0.00085
-
—
—
9.0E-08
0.000014
0.000014
3.0E-07
0.000090
0.00090
Cobalt
1.0E+01
mg/kg
-
0.0016
0.017
-
-
-
9.4E-09
0.00047
0.00047
9.0E-09
0.0020
0.020
Iron
1.5E+04
mg/kg
-
0.0010
0.011
—
-
-
-
—
-
—
0.0010
0.010
Manganese
1.8E+02
mg/kg
-
0.00036
0.0039
-
-
-
-
0.0010
0.0010
-
0.0010
0.0050
Mercury
5.3E-01
mg/kg
—
0.000085
0.00090
—
-
—
-
0.00000050
0.00000050
—
0.000090
0.00090
Molybdenum
2.4E+02
mg/kg
-
0.0023
0.025
-
-
-
-
0.000034
0.000034
-
0.0020
0.0200
Thallium
3.1E+00
mg/kg
—
0.015
0.16
—
-
-
—
-
-
—
0.010
0.20
Uranium
6.9E+01
mg/kg
-
0.017
0.18
-
-
-
-
0.00049
0.00049
-
0.020
0.20
Vanadium
4.2E+01
mg/kg
-
0.00040
0.0043
-
—
—
-
0.00012
0.00012
—
0.00050
0.0040
Exposure Pathway
Risk/Hazard Total
2E-05
0.04
0.4
7E-04
0.0006
0.004
6E-06
0.003
0.003
8E-04
0.04
0.4
Page 1 of 2
-------
Table B-6. Human Health Risk and Hazard Summary by Exposure Pathway
Section 9 Lease Mines - Trespasser
COPC
EPC
Units
Incidental Soil Ingestion
External Exposure /
Dermal Contact
Inhalation of Particulates
Total Risk or Hazard
Cancer
Risk
Adult
Hazard
Child
Hazard
Cancer
Risk
Adult
Hazard
Child
Hazard
Cancer
Risk
Adult
Hazard
Child
Hazard
Cancer
Risk
Adult
Hazard
Child
Hazard
Subsurface Soil (0-60 inches bgs)
Uranium-238 in
SE
6.5E+01
pCi/g
1.6E-05
-
-
5.0E-04
-
-
3.7E-06
-
-
5.0E-04
-
-
Aluminum
4.8E+03
mg/kg
-
0.00023
0.0025
-
-
-
-
0.00027
0.00027
-
0.00050
0.0030
Arsenic
2.1E+01
mg/kg
8.1E-07
0.0020
0.021
9.8E-08
0.00043
0.0025
9.5E-09
0.00040
0.00040
9.0E-07
0.0030
0.020
Cadmium
2.9E-01
mg/kg
-
0.00014
0.0015
-
0.000024
0.00014
5.5E-11
0.0000082
0.0000082
5.0E-11
0.00020
0.0020
Chromium
4.7E+00
mg/kg
1.7E-07
0.000075
0.00080
-
—
—
8.0E-08
0.000013
0.000013
3.0E-07
0.000090
0.00080
Cobalt
1.1E+01
mg/kg
-
0.0018
0.019
-
-
-
1.0E-08
0.00052
0.00052
1.0E-08
0.0020
0.020
Iron
1.4E+04
mg/kg
—
0.00096
0.010
—
-
-
-
—
-
—
0.0010
0.010
Manganese
1.7E+02
mg/kg
-
0.00034
0.0036
-
-
-
-
0.00095
0.00095
-
0.0010
0.0050
Mercury
3.6E-01
mg/kg
—
0.000058
0.00061
-
—
—
-
0.00000034
0.00000034
—
0.000060
0.00060
Molybdenum
1.7E+02
mg/kg
-
0.0016
0.017
-
-
-
-
0.000024
0.000024
-
0.0020
0.0200
Thallium
2.8E+00
mg/kg
—
0.013
0.14
—
-
-
—
-
—
-
0.010
0.10
Uranium
5.0E+01
mg/kg
-
0.012
0.13
-
-
-
-
0.00035
0.00035
-
0.010
0.10
Vanadium
3.3E+01
mg/kg
-
0.00032
0.0034
-
—
—
-
0.000093
0.000093
—
0.00040
0.0030
Exposure Pathway
Risk/Hazard Total
2E-05
0.03
0.4
5E-04
0.0004
0.003
4E-06
0.003
0.003
5E-04
0.04
0.4
Notes:
Results are from Table B-5.
-
Not applicable
bgs
Below ground surface
COPC
Contaminant of potential concern
EPC
Exposure point concentration
mg/kg
Milligram per kilogram
pCi/g
Picocurie per gram
SE
Secular equilibrium
Page 2 of 2
-------
Table B-7. Human Health Risk and Hazard Summary and Identification of Candidate
Contaminants of Concern
Section 9 Lease Mines - Trespasser
COPCa
Units
Exposure Point
Concentration
Cancer
Riskbcd
Noncancer Hazardbd 8
Adult
Child
Surface Soil
0-6 inches bgs)
Radionuclidesf
Uranium-238 in SE
pCi/g
9.7E+01
8.0E-04
--
--
Radionuclide Total
8E-04
--
--
Metals h
Aluminum
mg/kg
5.3E+03
-
0.00060
0.0030
Arsenic
mg/kg
2.9E+01
2.0E-06
0.0040
0.030
Cadmium
mg/kg
3.1E-01
6.0E-11
0.00020
0.0020
Chromium
mg/kg
5.0E+00
3.0E-07
0.000090
0.00090
Cobalt
mg/kg
1.0E+01
9.0E-09
0.0020
0.020
Iron
mg/kg
1.5E+04
--
0.0010
0.010
Manganese
mg/kg
1.8E+02
--
0.0010
0.0050
Mercury
mg/kg
5.3E-01
--
0.0001
0.00090
Molybdenum
mg/kg
2.4E+02
--
0.0020
0.0200
Thallium
mg/kg
3.1E+00
--
0.010
0.20
Uranium
mg/kg
6.9E+01
--
0.020
0.20
Vanadium
mg/kg
4.2E+01
--
0.00050
0.0040
Metal Total
2E-06
0.04
0.5
Cumulative Risk/Hazard Total
8E-04
0.04
0.5
Subsurface Soil (0-60 inches bgs)
Radionuclides1
Uranium-238 in SE
pCi/g
6.5E+01
5.0E-04
--
--
Radionuclide Total
5E-04
--
--
Metals'1
Aluminum
mg/kg
4.8E+03
--
0.00050
0.0030
Arsenic
mg/kg
2.1E+01
1.0E-06
0.0030
0.020
Cadmium
mg/kg
2.9E-01
5.0E-11
0.00020
0.0020
Chromium
mg/kg
4.7E+00
2.0E-07
0.000090
0.00080
Cobalt
mg/kg
1.1E+01
1.0E-08
0.0020
0.020
Iron
mg/kg
1.4E+04
--
0.0010
0.010
Manganese
mg/kg
1.7E+02
--
0.0010
0.0050
Mercury
mg/kg
3.6E-01
--
0.000060
0.00060
Molybdenum
mg/kg
1.7E+02
--
0.0020
0.020
Thallium
mg/kg
2.8E+00
--
0.010
0.10
Uranium
mg/kg
5.0E+01
--
0.010
0.10
Vanadium
mg/kg
3.3E+01
--
0.00040
0.0030
Metal Total
1E-06
0.03
0.3
Cumulative Risk/Hazard Total
5E-04
0.03
0.3
Page 1 of 2
-------
Table B-7. Human Health Risk and Hazard Summary and Identification of Candidate
Contaminants of Concern
Notes:
a Bolded COPCs are selected as candidate COCs because cancer risk is greater than one in ten thousand (1E-04)
or noncancer hazard is greater than 1. Italicized COPCs are contaminants within the USEPA's cancer risk range
(cancer risk greater than 1 in 1 million [1E-06] and less than or equal to 1 E-04).
b Bolded values are values greater than the target cancer risk of one in ten thousand (1 E-04) or noncancer target
hazard of 1. Italicized values are within the USEPA's acceptable cancer risk range (cancer risk greater than
1E-06 and less than or equal to 1E-04). Total risks and total hazards are reported to one significant digit; thus, values
are commonly rounded. In practice, values can be slightly higher than the stated cutoff but still be considered equal to
the cutoff because of rounding.
c Cancer risks are provided on Table B-5.
d The methodology for calculating the risks and hazards and the inputs for cancer and noncancer equations are
provided in the "Navajo Abandoned Uranium Mines Risk Assessment Methodology" report (USEPA 2024c).
e Noncancer hazards are presented on Table B-5.
f For radionuclides, uranium-238 is assumed to be in SE with its decay chain; that is, all decay chain
nuclides are present in equal activity concentrations. In this case, the risk from radium-226 and its decay products
(that is, radium-226 in SE) will account for most of the risk from the uranium-238 decay chain.
h Chromium is evaluated using the assumption that it is 100 percent hexavalent chromium (USEPA 2024c).
-
Not applicable
bgs
Below ground surface
COC
Contaminant of concern
COPC
Contaminant of potential concern
mg/kg
Milligram per kilogram
pCi/g
Picocurie per gram
SE
Secular equilibrium
USEPA
U.S. Environmental Protection Agency
Reference:
U.S. Environmental Protection Agency (USEPA). 2024c. "Navajo Abandoned Uranium Mines Risk Assessment
Methodology." Draft Final. March.
Page 2 of 2
-------
Table B-8. Screening-Level Ecological Risk Assessment Screening for Soil
Constituent of Interest3
Detection
Frequency13
Maximum
Detected
Concentration
(qualifier)13
Plant
NOEC
Soil
Invertebrates
NOEC
Avian
Herbivore
NOEC
Avian
Ground
Insectivore
NOEC
Avian
Carnivore
NOEC
Mammalian
Herbivore
NOEC
Mammalian
Ground
Insectivore
NOEC
Mammalian
Carnivore
NOEC
Minimum
NOEC
HQ based on
Minimum
NOECc
Include
Contaminant as
COPEC in SLERA
Refinement?01
Radionuclides (pCi/q)e
Uranium-238 in SE
(Adjusted Radium-226)
110 / 110
945
4.0
230
15
15
15
6.0
6.0
6.0
4.0
240
Yes
Metals (mq/kqf9
Aluminum
63 / 63
18,400
NSL
NSL
NSL
NSL
NSL
NSL
NSL
NSL
NSL
NSL
No
Antimony
0 / 63
--
11
78
NSL
NSL
NSL
10
0.27
4.9
0.27
—
No (Not Detected)
Arsenic
96 / 110
230 D
18
6J3
67
43
1,100
170
46
170
6.8
34
Yes
Barium
63 / 63
1,100 D
110
330
720
820
7.500
3,200
200
9,100
110
10
Yes
Beryllium
21 / 35
1.68
2j5
40
NSL
NSL
NSL
21
34
90
2.5
0.67
No
Cadmium
18 / 56
1.0 JD
32
140
28
0.77
630
73
0.36
84
0.36
2.8
Yes
Chromium11
42 / 63
8.51
0.35
0.34
78
26
780
380
34
180
0.34
25
Yes
Cobalt
41 / 63
47 JD
13
NSL
270
120
1,300
2,100
230
470
13
3.6
Yes
Copper
49 / 63
37 D
70
80
76
80
1,600
1,100
49
560
49
0.76
No
Iron
63 / 63
97,000 D
NSL
NSL
NSL
NSL
NSL
NSL
NSL
NSL
NSL
NSL
No
Lead
63 / 63
150 D
120
1,700
46
11
510
1,200
56
460
11
14
Yes
Manganese
61 / 63
540 D
220
450
4,300
4,300
650,000
5,300
4,000
6,200
220
2.5
Yes
Mercury
84 / 110
8.7
0.3
0.05
0.067
0.013
0.058
23
1.7
76
0.013
670
Yes
Molybdenum''j
97 / 110
2,000 D
2
NSL
18
15
90
635
4.8
64
2
1,000
Yes
Nickel
59 / 63
17 JD
38
280
210
20
2,800
340
10
130
10
1.7
Yes
Selenium
45 / 110
37 JD
0.52
4.1
2.2
1.2
83
2.7
0.63
2.8
0.52
71
Yes
Silver
4 / 63
0.208 J-
560
NSL
69
4.2
930
1,500
14
990
4.2
0.050
No
Thallium
16 / 63
26 JD
0.050
NSL
6.9
4.5
48
1.2
0.42
5.0
0.050
520
Yes
Uranium
69 / 110
970 D
25
NSL
1.500
1.100
14.000
1.000
480
4.800
25
39
Yes
Vanadium
97 / 110
390 D
60
NSL
13
7.8
140
1,300
280
580
7.8
50
Yes
Zinc
33 / 63
66 JD
160
120
950
46
30,000
6,800
79
10,000
46
1.4
Yes
Notes:
Grey highlighted cells indicate the maximum concentration exceeds the NOEC for the receptor group.
a Bolded contaminants are selected as COPECs for the SLERA refinement because the HQ is greater than or equal to 1.0.
b Includes soil samples collected site-wide from all depths. Includes all duplicate soil samples. See Table B-1 for the summary statistics for each contaminant.
c HQ is calculated by dividing the maximum concentration by the minimum NOEC. Bolded HQ values indicate HQs greater than 1.0.
d A contaminant is included as a COPEC for the SLERA refinement if the calculated HQ is greater than 1.0.
e Radionuclide ESLs are based on dose assessments using the ERICA Tool (Brown and others 2008) for terrestrial animals and plants (see Appendix F of the "Navajo Abandoned Uranium Mines Risk Assessment Methodology" Report [USEPA 2024c]).
ESLs for uranium-238 in SE are based on individual radium-226 ESLs that are adjusted to include doses from all progeny of uranium-238 in SE. Site data for radium-226 are used to evaluate uranium-238 in SE.
f NOECs for metals are based on the Eco-SSL (USEPA 2023a) unless underlined, bolded, or italicized.
g Underlined values are based on LANL no effect level ESLs (N3B 2022) for contaminants for which Eco-SSLs are not available.
h Chromium is evaluated using the assumption that it is 100 percent hexavalent chromium (USEPA 2024b). LANL chromium screening values are based on Cr(VI) (hexavalent chromium) for plants and invertebrates (N3B 2022)
and Cr(lll) (trivalent chromium) for birds and mammals (USEPA 2023). Eco-SSLs for hexavalent chromium are not available for birds, and the hexavalent chromium Eco-SSLs for mammals are higher than the trivalent chromium
values (USEPA 2023).
' Bold value for molybdenum is based on Oak Ridge National Laboratory no effect level for plants for which neither an Eco-SSL nor LANL ESL is available (Efroymson, Will, Suter II, and Wooten 1997).
j Italicized values for molybdenum are based on the Oak Ridge National Laboratory preliminary remediation goals for ecological receptors (Efroymson, Suter II, Sample, and Jones 1997) for mammals for which Eco-SSLs and LANL NOECs
are not available.
Page 1 of 2
-------
Table B-8. Screening-Level Ecological Risk Assessment Screening for Soil
Notes (Continued):
ESL
HQ
J
J-
SLERA
COPEC
D
NSL
pCi/g
SE
USEPA
Eco-SSL
ERICA
LANL
mg/kg
N3B
NOEC
Not applicable
Contaminant of potential ecological concern
Dilution
Ecological soil screening level
Environmental Risk from Ionising Contaminants: Assessment and Management
Ecological screening level
Hazard quotient
Estimated concentration
Estimated concentration, biased low
Los Alamos National Laboratory
Milligram per kilogram
Newport News Nuclear BWXT-Los Alamos, LLC
No observed effect concentration
No screening level
Picocurie per gram
Secular equilibrium
Screening-level ecological risk assessment
U.S. Environmental Protection Agency
References:
Brown, J.E., B. Alfonso, R. Avila, N.A. Beresford, D. Copplestone, G. Prohl, and A. Ulanovsky. 2008. "The ERICA Tool." Journal of Environmental Radioactivity. Volume 99, Issue 9. Pages 1371 through 1383.
Efroymson, R.A., M.E. Will, and G.W. Suter II. 1997. "Toxicological Benchmarks for Contaminants of Potential Concern for Effects on Soil and Litter Invertebrates and Heterotrophic Process."
ES/ER/TM-126/R2. Oak Ridge National Laboratories, Oak Ridge, TN.
Efroymson, R.A., M.E. Will, G.W. Suter II, and A.C. Wooten. 1997. "Toxicological Benchmarks for Screening Contaminants of Potential Concern for Effects on Terrestrial Plants."
ES/ER/TM-85/R3. Oak Ridge National Laboratories, Oak Ridge, TN.
Newport News Nuclear BWXT-Los Alamos, LLC (N3B). 2022. "ECORISK Database." Release 4.3. 701067. Document EM2020-0575. September.
U.S. Environmental Protection Agency (USEPA). 2023. "Interim Ecological Soil Screening Level Documents." Accessed July 20. https://www.epa.gov/chemical-research/interim-ecological-soil-screening-level-documents.
USEPA. 2024c. "Navajo Abandoned Uranium Mines Risk Assessment Methodology." Draft Final. March.
Page 2 of 2
-------
Table B-9. Exposure Point Concentrations for Ecological Risk Assessment
Site-Wide
Contaminant
Units
Detection
Frequency
Number of
High
Nondetect
Results3
Maximum
Concentration
(qualifier)
Location of
Maximum
Concentration
Arithmetic
Meanb
UCL95 /
Distribution
Exposure Point
Concentration
Valued
Statisticd
Method6
Surface Soil (0-6 inches bgs)
Radium-226
pCi/g
62 / 62
0
945
457-SS-7A
58.77
96.77
LN
97
UCL95
(14)
Arsenic
mg/kg
55 / 62
0
230 D
457-SS-7A
20.16
29.07
LN
29
UCL95
(15)
Barium
mg/kg
46 / 46
0
1,100 D
457-SS-7A
269.10
316.50
G
317
UCL95
(4)
Cadmium
mg/kg
17 / 42
0
1 JD
457-SS-7A
0.23
0.31
G
0.31
UCL95
(5)
Chromium
mg/kg
34 / 45
2
8.51
APE-SS10-01-020624
4.53
5.01
N
5.0
UCL95
(2)
Cobalt
mg/kg
34 / 45
2
28
457-SS02-01-020624
8.35
10.47
G
10
UCL95
(5)
Lead
mg/kg
46 / 46
0
150 D
457-SS-7A
24.86
32.44
LN
32
UCL95
(14)
Manganese
mg/kg
45 / 46
0
540 D
DRN-SD-4
145.10
182.20
G
182
UCL95
(5)
Mercury
mg/kg
47 / 62
0
8.7
457-SS-8A
0.25
0.53
LN
0.53
UCL95
(15)
Molybdenum
mg/kg
56 / 62
0
2,000 D
457-SS-7A
142.60
241.70
G
242
UCL95
(7)
Nickel
mg/kg
44 / 46
0
17 JD
DRN-SD-1
6.46
7.63
G
7.6
UCL95
(5)
Selenium
mg/kg
30 / 62
0
37 JD
458-SS-6A
1.67
2.84
LN
2.8
UCL95
(15)
Thallium
mg/kg
15 / 45
2
26 JD
457-SS-7A
1.87
3.10
LN
3.1
UCL95
(13)
Uranium
mg/kg
37 / 62
0
970 D
457-SS-7A
38.54
69.05
LN
69
UCL95
(15)
Vanadium
mg/kg
55 / 62
0
390 D
457-SS-7A
29.07
41.89
NP
42
UCL95
(15)
Zinc
mg/kg
29 / 45
2
66 JD
457-SS-7A
18.10
22.73
G
23
UCL95
(5)
Page 1 of 3
-------
Table B-9. Exposure Point Concentrations for Ecological Risk Assessment
Site-Wide
Contaminant
Units
Detection
Frequency
Number of
High
Nondetect
Results3
Maximum
Concentration
(qualifier)
Location of
Maximum
Concentration
Arithmetic
Meanb
UCL95 /
Distribution
Exposure Point
Concentration
Valued
Statisticd
Method6
Subsurface Soil (0-60 inches bgs)
Radium-226
pCi/g
100 / 100
0
945
457-SS-7A
42.40
65.41
NP
65
UCL95
(14)
Arsenic
mg/kg
88 / 100
0
230 D
457-SS-7A
15.67
21.18
NP
21
UCL95
(15)
Barium
mg/kg
56 / 56
0
1,100 D
457-SS-7A
261.20
298.10
G
298
UCL95
(6)
Cadmium
mg/kg
17 / 56
0
1 JD
457-SS-7A
0.22
0.29
G
0.29
UCL95
(7)
Chromium
mg/kg
37 / 55
2
8.51
APE-SS10-01-020624
4.24
4.68
N
4.7
UCL95
(3)
Cobalt
mg/kg
38 / 56
2
47 JD
459-SS-2C
8.93
11.18
G
11
UCL95
(7)
Lead
mg/kg
56 / 56
0
150 D
457-SS-7A
21.97
28.23
NP
28
UCL95
(14)
Manganese
mg/kg
55 / 56
0
540 D
DRN-SD-4
137.90
167.70
G
168
UCL95
(7)
Mercury
mg/kg
76 / 100
0
8.7
457-SS-8A
0.18
0.36
LN
0.36
UCL95
(15)
Molybdenum
mg/kg
89 / 100
0
2,000 D
457-SS-7A
105.80
167.90
G
168
UCL95
(7)
Nickel
mg/kg
53 / 56
0
17 JD
DRN-SD-1
6.22
7.19
G
7.2
UCL95
(7)
Selenium
mg/kg
43 / 100
0
37 JD
458-SS-6A
1.05
1.74
LN
1.7
UCL95
(15)
Thallium
mg/kg
15 / 55
2
26 JD
457-SS-7A
1.77
2.84
LN
2.8
UCL95
(13)
Uranium
mg/kg
65 / 100
0
970 D
457-SS-7A
31.15
50.28
NP
50
UCL95
(15)
Vanadium
mg/kg
88 / 100
0
390 D
457-SS-7A
25.75
33.44
NP
33
UCL95
(15)
Zinc
mg/kg
29 / 55
2
66 JD
457-SS-7A
16.64
20.33
G
20
UCL95
(7)
Notes:
a Number of nondetect results that exceeded the maximum detected concentration. These results were not included in the statistical calculations.
b The arithmetic mean for datasets with nondetected results is calculated using the Kaplan-Meier method.
c Tested using the Shapiro-Wilk Wor Lilliefors test for normal and lognormal distributions and the Anderson-Darling and Kolmogorov-Smirnov tests for gamma
distributions. A 5 percent level of significance was used in all tests. Distribution tests were conducted only for samples with at least four detected results.
Distributions not confirmed as N, LN, or G were treated as NP in all statistical calculations.
d The EPC is the lesser of the UCL95 (or UCL99) and the maximum detected concentration. The maximum detected concentration is the default when there are
fewer than 10 samples or fewer than four detected results. See Appendix D of the "Navajo Abandoned Uranium Mines Risk Assessment Methodology" report
(USEPA 2024c).
Page 2 of 3
-------
Table B-9. Exposure Point Concentrations for Ecological Risk Assessment
Notes (Continued):
e The statistical methods for selecting the exposure point concentration are as follows (not all are used):
(1)
Maximum detected concentration
(7)
95%
Gamma Approximate KM-UCL
(13)
95% KM BCA UCL
(2)
95% Student's t UCL
(8)
95%
H-UCL
(14)
95% Percentile Bootstrap UCL
(3)
95% KM (t) UCL
(9)
95%
H-UCL (KM log)
(15)
95% KM Percentile Bootstrap UCL
(4)
95% Adjusted Gamma UCL
(10)
95%
Bootstrap-t UCL
(16)
99% Bootstrap-t UCL
(5)
95% Gamma Adjusted KM-UCL
(11)
95%
KM Bootstrap-t UCL
(17)
99% KM Percentile Bootstrap UCL
(6)
95% Approximate Gamma UCL
(12)
95%
BCA UCL
BCA Bias-corrected accelerated bootstrap method
bgs Below ground surface
D Dilution
EPC Exposure point concentration
G Gamma distribution
H-UCL UCL based upon Land's H-statistic
J Estimated concentration
KM Kaplan-Meier
LN Lognormal distribution
mg/kg Milligram per kilogram
N Normal distribution
NP Nonparametric distribution
pCi/g Picocurie per gram
UCL Upper confidence limit
UCL95 95 percent upper confidence limit
UCL99 99 percent upper confidence limit
USEPA U.S. Environmental Protection Agency
Reference:
U.S. Environmental Protection Agency (USEPA). 2024c. "Navajo Abandoned Uranium Mines Risk Assessment Methodology." Draft Final. March.
Page 3 of 3
-------
Table B-10. Comparison of Individual Sample Results to Plant and Invertebrate No Observed Effect Concentrations
Sample Identification
Sample
Bottom
Depth
(inches
bgs)d
COPEC:3
Uranium-238
in SE
(Adjusted
Radium-226)b
Antimony
Arsenic
Barium
Cadmium
Chromium0
Cobalt
Lead
Manganese
Mercury
Molybdenum
Nickel
Selenium
Thallium
Uranium
Vanadium
Zinc
Plant NOEC:d
4.0
11
18
110
32
0.35
13
120
220
0.3
2
38
0.52
0.050
25
60
160
Soil Invertebrate
NOEC:d
230
78
6.8
330
140
0.34
NSL
1,700
450
0.05
NSL
280
4.1
NSL
NSL
NSL
120
Units:
pCi/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
mg/kg
mg/kg
mg/kg
Surface Soil (0-6 inches bgs)e
457-SS01-01-020624
6
18.6
1.87 U
14.4
151
0.148
5.82
23.7
9.25
56.8
0.105
4.61
6.98
6.53
0.347
26.8
20.3
21.4
457-SS02-01-020624
6
66.7
1.74 U
16.1
236
0.748
5
28
16.5
144
0.229
59.7
15.2
1.95
0.791
90.4
18.7
31.9
457-SS03-01-020624
6
18.9
1.83 U
3.97
189
0.109
5.3
4.19
9.26
308
0.0257
13.9
4.8
2
0.506
15.7
29.1
10.9
457-SS04-01-020624
6
160
1.88 U
18.5
327
0.794
4.9
7.45
74.8
148
0.165
214
6.99
1.29
2.82
56
40.3
61.9
457-SS-10A
6
2.87
6.5 U
3.2 U
320
1 U
3.8
9.5 U
18
250
0.028
10 U
6.6
2.9 U
15 U
98 U
35
28
457-SS-11A
6
411
6 U
72
510
0.94 U
7.1
10
66
180
0.88
910
9.1
2.7 U
14 U
430 U
70
55
457-SS-12A
6
3.19
6.2 U
3 U
310
0.96 U
4.6
9 U
18
240
0.032
9.6 U
6.9
2.8 U
15 U
110 U
34
30
457-SS-1A
6
156
6.4 U
83
310
1 U
3.1 U
13
40
15
0.31
420
8
2.9 U
15 U
390 U
13 U
20
457-SS-2A
6
30.1
5.8 U
7.3
280
0.9 U
2.8
8.7
10
280
0.024
61
6
2.6 U
14 U
120 U
24
18 U
457-SS-3A
6
57.1
6.1 U
37
260
0.95 U
3
8.9 U
32
190
0.1
180
6.3
2.7 U
14 U
130 U
32
25
457-SS-4A
6
3.32
6.4 U
3.2 U
300
1 U
4.5
9.4 U
44
250
0.016
10 U
6.6
2.9 U
15 U
120 U
37
31
457-SS-5A
6
8.37
6.4 U
3.1 U
250
0.99 U
4.1
11
12
170
0.021
9.9 U
5.6
2.9 U
15 U
130 U
35
20 U
457-SS-6A
6
382
5.8 U
54
390
0.91 U
3.5
9.4
52
180
0.8
650
7.7
2.6 U
14 U
350 U
57
58
457-SS-7A
6
945
6.4 U
230
1100
1
8
23
150
110
1.3
2000
11
3.4
26
970
390
66
457-SS-8A
6
747
6.1 U
98
590
0.95 U
7.1
15
77
170
8.7
960
9.7
2.7 U
14 U
470 U
210
46
457-SS-9A
6
27.2
6.3 U
19
340
0.98 U
3 U
9.2 U
26
230
0.037
140
5.5
2.8 U
15 U
110 U
26
19 U
457-TP14-0-0.5-120318
6
2.94
-
-
-
-
-
-
-
-
0.00006 U
0.58
-
0.32
-
-
4
-
457-TP14-0-0.5-120318 DUP
6
-
-
0.97
-
-
-
-
-
-
-
-
-
-
-
1.4
-
-
457-TP15-0-0.5-120618
6
8.2
-
9.9
-
-
-
-
-
-
0.02
30
-
0.054 U
-
6.7
15
-
457-TP3-0-0.5-120418
6
-
-
-
-
-
-
-
-
-
-
35
-
0.092
-
-
27
-
457-TP3-0-0.5-120418 DUP
6
12.5
-
17
-
-
-
-
-
-
0.018
-
-
-
-
19
-
-
457-TP5-0-0.5-120418
6
3.00
-
2.6
-
-
-
-
-
-
0.000064 U
3.6
-
0.055 U
-
4.5
39
-
457-TP6-0-0.5-120418
6
1.76
-
2
-
-
-
-
-
-
0.000058 U
3
-
0.26
-
2.7
27
-
458-SS01-01-020624
6
30.9
1.89 U
22.7
314
0.252
6.58
2.93
17.8
30.3
0.204
173
3.04
1.47
5.21
41.5
12.6
8.39
458-SS02-01-020624
6
37.7
1.94 U
22.4
256
0.2
6.44
2.01
12.5
19.5
0.192
141
1.7
1
5.61
48.3
8.45
5.19
458-SS03-01-020624
6
134
1.82 U
30.9
335
0.329
2.11
5.1
47.6
19
0.344
78.6
2.34
1.35
1.17
126
5.22
7.97
458-SS04-01-020624
6
48.3
1.76 U
17.6
234
0.316
3.68
3.18
21
91.2
0.156
191
3.44
1.06
3.88
108
14.9
9.97
458-SS05-01-020624
6
12.2
1.81 U
1.09
56.9
0.0555
4.81
4.41
29.1
35.9
0.037
0.228
2.78
2.16
0.349 U
15.9
12.7
11.7
458-SS06-01-020624
6
—
—
21.7
273
-
5.93
3.8
—
19.7
—
126
2.88
2.32
2.68
—
14.2
9.15
458-SS06-02-020624
6
34.50
1.84 U
—
—
0.251
—
—
13.7
—
0.167
—
—
—
—
90.6
—
—
458-SS-1A
6
51.80
6.4 U
31
390
1 U
3.4
17
16
81
0.093
180
3.8
2.9 U
15 U
55 U
15
20 U
458-SS-2A
6
9.84
6.5 U
3.2 U
160
1 U
3.1 U
13
13
110
0.015
18
5.1
2.9 U
15 U
53 U
14
20 U
458-SS-3A
6
39.10
6.3 U
31
200
0.98 U
3 U
9.2 U
18
29
0.36
440
2.2
2.8 U
15 U
150 U
12
19 U
458-SS-4A
6
11.10
8.3 U
12
500
1.3 U
4 U
12
17
32
0.028
48
4.9
3.7 U
20 U
88 U
16 U
26 U
458-SS-5A
6
28.70
6.6 U
7.9
67
1 U
3.1 U
9.6 U
9.1
24
0.043
130
10
3 U
15 U
170 U
13 U
20 U
458-SS-6A
6
83.50
33 U
160
99
5.1 U
16 U
48 U
110
7.9 U
0.33
840
12 U
37
78 U
370 U
65 U
100 U
458-SS-7A
6
93.40
33 U
140
70
5.6 U
17 U
52 U
68
8.6 U
0.35
490
13 U
35
84 U
290 U
70 U
110 U
458-SS-8A
6
16.70
6.3 U
9.4
150
0.98 U
3 U
9.9
13
39
0.086
87
3.2
2.8 U
15 U
52 U
12
19 U
458-TP19-0-0.5-120518
6
73.90
—
30
—
-
—
—
—
—
0.21
350
—
0.53
—
110
17
—
458-TP20-0.5-1.0-120518
6
24.10
—
30
—
-
—
—
—
—
0.16
160
—
0.21
—
44
8.1
—
458-TP20-0-0.5-120518
6
6.18
-
18
-
-
-
-
-
-
0.1
22
-
0.14
-
12
17
-
458-TP21 -0-0.5-120518
6
6.88
-
8.5
-
-
-
-
-
-
0.04
14
-
0.049 U
-
9.3
12
-
459-SS-2A
6
9.23
5.7 U
9.7
260
0.88 U
2.7 U
8.3 U
4.7
78
0.022
46
3.8
2.6 U
13 U
46 U
11 U
18 U
459-TP23-0-0.5-120618
6
15.9
-
-
-
-
-
-
-
-
0.019
52
-
-
-
-
6.7
-
Page 1 of 4
-------
Table B-10. Comparison of Individual Sample Results to Plant and Invertebrate No Observed Effect Concentrations
Sample Identification
Sample
Bottom
Depth
(inches
bgs)d
COPEC:3
Uranium-238
in SE
(Adjusted
Radium-226)b
Antimony
Arsenic
Barium
Cadmium
Chromium0
Cobalt
Lead
Manganese
Mercury
Molybdenum
Nickel
Selenium
Thallium
Uranium
Vanadium
Zinc
Plant NOEC:d
4.0
11
18
110
32
0.35
13
120
220
0.3
2
38
0.52
0.050
25
60
160
Soil Invertebrate
NOEC:d
230
78
6.8
330
140
0.34
NSL
1,700
450
0.05
NSL
280
4.1
NSL
NSL
NSL
120
Units:
pCi/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
mg/kg
mg/kg
mg/kg
459-TP23-0-0.5-120618 DUP
6
-
-
7.4
-
-
-
-
-
-
-
-
-
0.053 U
-
9.7
-
-
APE-SS01 -01-020624
6
10.4
1.84 U
4.39
142
0.244
7.46
9.45
12.9
68.2
0.118
12.8
7.04
2.49
0.768
18
29.4
21.5
APE-SS02-01 -020624
6
1.94
1.79 U
1.2
424
0.0715
8.28
5.03
7.34
385
0.0242 U
0.413
12.5
1.5
0.393 U
2.87
32.9
11.4
APE-SS03-01-020624
6
2.83
1.85 U
3.55
24.8
0.196 U
5.01
4.95
6.65
50.1
0.0224 U
0.133
5.26
2.3
0.283
3.77
19.1
23
APE-SS04-01-020624
6
2.3
2.04 U
1.71
347
0.0378
7.78
4.72
9.86
155
0.0236 U
1.26
4.75
2.23
0.143
3.56
32
19.9
APE-SS05-01-020624
6
1.35
2.01 U
1.71
198
0.0241
2.82
1.87
4.48
119
0.0214 U
0.258
2.24
3.15
0.369 U
1.58
12.9
10.8
APE-SS06-01-020624
6
1.51
1.81 U
0.749
223
0.122
5
3.5
5.4
110
0.0116
0.4
4.57
0.795
0.371 U
1.73
17
9.15
APE-SS07-01-020624
6
15.4
1.8 U
9.09
52.2
0.125
3.05
0.641
4.03
4.96
0.0121
110
0.437
1.28
0.413
18.3
5.09
2.69
APE-SS08-01-020624
6
1.27
1.89 U
0.961
238
0.186 U
3.57
2.03
4.27
176
0.0216 U
0.245
4.36
1.49
0.373 U
0.99
12.4
8.46
APE-SS09-01-020624
6
5.67
1.81 U
4.07
212
0.187 U
3.19
5.32
6.33
104
0.016
7.74
3.69
1.06
0.389
5.92
11.6
13.2
APE-SS10-01-020624
6
1.41
1.73 U
1.28
273
0.172 U
8.51
4.98
5.29
262
0.0224 U
0.553
13.2
1.14
0.345 U
1.23
21
16.4
Drain-TP16-0-0.5-120318
6
1.23
-
1.7
-
-
-
-
-
-
0.000058 U
0.27
-
0.051 U
-
1.3
24
-
Drain-TP7-0-0.5-120418
6
5.71
-
2.7
-
-
-
-
-
-
0.000062 U
18
-
0.12
-
6
19
-
Drain-TP8-0-0.5-120418
6
37.5
-
6.3
-
-
-
-
-
-
0.019
37
-
0.32
-
14
25
-
DRN-SD-1
6
1.3
6.5 U
3.2 U
180
1 U
6.4
14
6.2
270
0.011 U
10 U
17
2.9 U
15 U
110 U
26
20 U
DRN-SD-2
6
0.977
6.3 U
3.1 U
210
0.99 U
4.9
10
5.8
260
0.011 U
9.9 U
14
2.9 U
15 U
72 U
24
20 U
DRN-SD-4 (DUP)
6
3.74
6.4 U
3.2 U
180
1 U
5.3
9.4 U
5.9
540
0.011 U
10 U
14
2.9 U
15 U
86 U
24
20 U
LCR-TP12-0-0.5-120318
6
1.48
-
2.4
-
-
-
-
-
-
0.000071 U
0.71
-
0.06 U
-
1.8
25
-
MHR-TP17-0-0.5-120618
6
8.7
-
8.2
-
-
-
-
-
-
0.0027
27
-
0.054 U
-
11
20
-
MHR-TP22-0-0.5-120518
6
2.69
-
2.1
-
-
-
-
-
-
0.065
0.2
-
0.054 U
-
2.7
13
-
RIV-SD-2
6
21.2
-
11
360
-
-
-
12
-
-
34
-
-
-
-
26
-
RIV-SD-6
6
-
6.7 U
-
-
1 U
3.2 U
9.8 U
-
370
0.29
-
3.2
3 U
16 U
180 U
-
21 U
S9L-SS-1A
6
13
6.1 U
13
75
0.96 U
2.9 U
9 U
38
25
0.2
160
2.2 U
2.8 U
14 U
150 U
12 U
19 U
S9L-SS-2A
6
65.2
6.4 U
-
-
0.99 U
-
20
-
-
0.073
-
-
2.9 U
15 U
170 U
-
20 U
S9L-SS-4A
6
-
-
15
330
-
4.7
-
34
170
-
32
9.5
-
-
-
25
-
WET-SD-3
6
64.4
7.5 U
29
130
1.2 U
4.7
25
26
130
0.039
220
9.8
3.4 U
18 U
180 U
15 U
32
WET-SD-4
6
7.29
8.4 U
15
320
1.3 U
4 U
12 U
22
360
0.031
37
7.4
3.8 U
20 U
160 U
25
30
Frequency of Plant NOEC Exceedance:
46/65
0/49
19/65
42/49
0/49
36/49
8/49
1/49
13/49
9/65
46/65
0/49
24/65
15/49
11/65
3/65
0/49
Frequency of Soil Invertebrate NOEC Exceedance:
4/65
0/49
38/65
11/49
0/49
36/49
NA
0/49
1/49
27/65
NA
0/49
3/65
NA
NA
NA
0/49
Frequency of Plant and Soil Invertebrate Exceedance:
4/65
0/49
19/65
11/49
0/49
36/49
8/49
0/49
1/49
9/65
46/65
0/49
3/65
15/49
11/65
3/65
0/49
Analyte Identified as Surface Soil Candidate COEC? f
Yes (P/l)
No
Yes (P/l)
Yes (P/l)
No
Yes (P/l)
Yes(P)
Yes (P)
Yes (P/l)
Yes (P/l)
Yes(P)
No
Yes (P/l)
Yes (P)
Yes(P)
Yes(P)
No
Page 2 of 4
-------
Table B-10. Comparison of Individual Sample Results to Plant and Invertebrate No Observed Effect Concentrations
Sample Identification
Sample
Bottom
Depth
(inches
bgs)d
COPEC:3
Uranium-238
in SE
(Adjusted
Radium-226)b
Antimony
Arsenic
Barium
Cadmium
Chromium0
Cobalt
Lead
Manganese
Mercury
Molybdenum
Nickel
Selenium
Thallium
Uranium
Vanadium
Zinc
Plant NOEC:d
4.0
11
18
110
32
0.35
13
120
220
0.3
2
38
0.52
0.050
25
60
160
Soil Invertebrate
NOEC:d
230
78
6.8
330
140
0.34
NSL
1,700
450
0.05
NSL
280
4.1
NSL
NSL
NSL
120
Units:
pCi/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
mg/kg
mg/kg
mg/kg
Subsurface Soil (6-60 inches bgs)e
457-SS-2B
12
3.06
5.8 U
2.9 U
290
0.9 U
2.8 U
8.5 U
7.7
110
0.012
9 U
2.3
2.6 U
14 U
110 U
20
18 U
457-SS-4B
12
1.93
6.1 U
3 U
360
0.95 U
5
8.9 U
7.5
190
0.012
9.5 U
9.3
2.8 U
14 U
100 U
28
19 U
457-TP15-0.5-1.0-120618
12
7.54
-
6.6
-
-
-
-
-
-
0.026
6.7
-
0.055 U
-
5.7
9.2
-
457-TP5-0.5-1.0-120418
12
1.93
-
2.4
-
-
-
-
-
-
0.000064 U
1.4
-
0.18
-
2
39
-
458-SS-2B
12
6.01
6.5 U
3.2 U
170
1 U
3.1 U
13
6.9
100
0.011 U
10 U
5.4
2.9 U
15 U
53 U
13
20 U
458-SS-4B
12
18.7
5.8 U
12
160
0.9 U
2.8 U
18
13
38
0.074
87
4.3
2.6 U
14 U
120 U
11 U
18 U
458-TP18-0.5-1.0-120518
12
14
-
19
-
-
-
-
-
-
0.071
72
-
0.74
-
15
12
-
458-TP19-0.5-1.0-120518
12
126
-
55
-
-
-
-
-
-
0.54
820
-
0.46
-
140
13
-
458-TP21-0.5-1.0-120518
12
5.64
-
23
-
-
-
-
-
-
0.074
23
-
0.3
-
8.3
19
-
459-SS-2B
12
10.1
6.8 U
7.3
260
-
3.3 U
10 U
5.6
77
0.029
32
3.9
3.1 U
16 U
56 U
13 U
21 U
459-TP23-0.5-1.0-120618
12
19.7
-
8.2
-
-
-
-
-
-
0.032
55
-
0.17
-
15
9.8
-
Drain-TP2-0.5-1.0-120418
12
2.82
-
3.7
-
-
-
-
-
-
0.0065
3.5
-
0.051 U
-
3.4
41
-
Drain-TP8-0.5-1.0-120418
12
31.3
-
12
-
-
-
-
-
-
0.028
53
-
0.23
-
21
23
-
MRD-TP1-0.5-1.0-120518
12
31.6
-
1.3
-
-
-
-
-
-
0.081
8
-
0.054 U
-
45
16
-
457-SS-2C
18
2.47
6.6 U
3.2 U
250
1 u
3.1 U
9.6 U
7.5
110
0.012
10 U
2.3 U
3 U
15 U
140 U
21
20 U
457-SS-4C
18
1.07
6.7 U
3.3 U
230
1 u
5.9
9.7 U
6.3
250
0.011 U
10 U
11
3 U
16 U
120 U
30
21 U
457-TP6-1.0-1.5-120418
18
1.61
-
1.8
-
-
-
-
-
-
0.000061 U
0.71
-
0.048 U
-
1.6
32
-
458-SS-2C
18
22.8
6.7 U
4.5
180
1 u
3.2 U
9.8 U
12
78
0.081
69
3.7
3 U
16 U
55 U
13 U
21 U
458-SS-4C
18
21.5
6.3 U
42
230
0.99 U
3.1
12
14
20
0.14
110
4.4
2.9 U
15 U
190 U
12 U
20 U
458-TP20-1.0-1.5-120518
18
19.8
-
39
-
-
-
-
-
-
0.26
130
-
0.7
-
42
7.9
-
459-SS-2C
18
9.76
7.7 U
8
120
-
3.7 U
47
6
72
0.033
36
5.4
3.5 U
18 U
64 U
15 U
24 U
Drain-TP16-1.0-1.5-120318
18
1.2
-
2
-
-
-
-
-
-
0.000062 U
0.2
-
0.052 U
-
1.3
29
-
Drain-TP2-1.0-1.5-120418
18
2.69
-
3.4
-
-
-
-
-
-
0.0012
2.1
-
0.058 U
-
3.9
42
-
Drain-TP7-1.0-1.5-120418
18
1.69
-
1.7
-
-
-
-
-
-
0.000058 U
7.9
-
0.15
-
3.6
17
-
LCR-TP12-1.0-1.5-120318
18
1.86
-
2.6
-
-
-
-
-
-
0.0089
0.71
-
0.056 U
-
2
26
-
MHR-TP22-1.0-1.5-120518
18
4.14
-
2.4
-
-
-
-
-
-
0.082
0.37
-
0.17
-
3.9
8.4
-
MRD-TP1-1.5-2.0-120518
24
71.8
-
1.7
-
-
-
-
-
-
0.33
0.84
-
0.35
-
180
21
-
457-TP4-2.0-2.5-120418
30
5.92
-
2.4
-
-
-
-
-
-
0.0095
4.3
-
0.053 U
-
5.6
29
-
458-TP18-2.0-2.5-120518
30
4.08
-
5.3
-
-
-
-
-
-
0.017
12
-
0.052 U
-
6.8
13
-
LCR-TP11-2.0-2.5-120318
30
1.81
-
2.4
-
-
-
-
-
-
0.0099
0.77
-
0.061 U
-
1.5
23
-
LCR-TP9-2.0-2.5-120318
30
58.2
-
10
-
-
-
-
-
-
0.17
78
-
0.047 U
-
28
16
-
MHR-TP17-2.0-2.5-120618
30
1.64
-
2
-
-
-
-
-
-
0.000062 U
13
-
0.047 U
-
3.9
21
-
459-TP23-2.5-3.0-120618
36
10.1
-
8.3
-
-
-
-
-
-
0.02
28
-
0.056
-
8.9
13
-
Drain-TP8-2.5-3.0-120418
36
1.76
-
2.2
-
-
-
-
-
-
0.000059 U
6.5
-
0.057
-
2.8
21
-
MRD-TP1-2.5-3.0-120518
36
3.94
-
0.92
-
-
-
-
-
-
0.002
1.5
-
0.052 U
-
21
49
-
457-TP4-3.0-3.5-120418
42
2.46
-
2
-
-
-
-
-
-
0.00006 U
2.8
-
0.054 U
-
3.4
22
-
LCR-TP9-3.0-3.5-120318
42
55.7
-
7.9
-
-
-
-
-
-
0.16
34
-
0.074
-
37
21
-
LCR-TP9-4.5-5.0-120318
60
7.37
-
3.6
-
-
-
-
-
-
0.028
18
-
0.063 U
-
16
22
-
Frequency of Plant NOEC Exceedance:
22/38
0/10
5/38
10/10
0/8
3/10
2/10
0/10
1/10
2/38
25/38
0/10
2/38
0/10
6/38
0/38
0/10
Analyte Identified as Subsurface Soil Candidate COEC? f
Yes (P)
No
Yes (P)
Yes(P)
No
Yes (P)
Yes(P)
No
Yes (P)
Yes(P)
Yes(P)
No
Yes (P)
No
Yes (P)
No
No
Page 3 of 4
-------
Table B-10. Comparison of Individual Sample Results to Plant and Invertebrate No Observed Effect Concentrations
Notes:
Exceeds the plant NOEC
Exceeds soil invertebrate NOEC
Exceeds both soil invertebrate and plant NOECs
a A constituent is included as a COPEC if the calculated SLERA HQ is greater than or equal to 1.0 (see Table B-8).
b The NOECs for uranium-238 in SE are based on individual radium-226 ESLs that are adjusted to include doses from all progeny of uranium-238 in SE. Site data for radium-226 are used to evaluate uranium-238 in SE.
c Chromium is evaluated using the assumption that it is 100 percent hexavalent chromium (USEPA 2024c). LANL chromium screening values are based on Cr(VI) (hexavalent chromium) for plants and invertebrates (Newport News Nuclear BWXT-Los Alamos, LLC. 2022).
d Screening levels for plants and invertebrates are NOECs (see Table B-8).
6 Plants are exposed to surface and subsurface soil from 0 to 72 inches bgs; however, the deepest samples collected at hte site are 60 inches bgs. Soil invertebrates are exposed to surface soil (0 to 6 inches bgs) only; subsurface soil samples results are not compared to soil invertebrates NOECs.
f COPECs are identified as candidate COECs if at least one sample result exceeds the plant or soil invertebrate NOEC for surface soil or the plant NOEC for subsurface soil. "P" refers to plant and "I" refers to invertebrate.
bgs
COEC
COPEC
ESL
HQ
LANL
mg/kg
NOEC
NSL
pCi/g
Ra-226
SE
SLERA
U
USEPA
Not analyzed
Below ground surface
Contaminant of ecological concern
Contaminant of potential ecological concern
Ecological screening level
Hazard quotient
Los Alamos National Laboratory
Milligram per kilogram
No observed effect concentration
No screening level
Picocurie per gram
Radium-226
Secular equilibrium
Screening-level ecological risk assessment
Not detected
U.S. Environmental Protection Agency
References:
Newport News Nuclear BWXT-Los Alamos, LLC. 2022. "ECORISK Database." Release 4.3. 701067. Document EM2020-0575. September.
U.S. Environmental Protection Agency (USEPA). 2024c. "Navajo Abandoned Uranium Mines Risk Assessment Methodology." Draft Final. March.
Page 4 of 4
-------
Table B-11. Screening-Level Ecological Risk Assessment Refinement for Soil - Birds
Site-Wide
COPEC3
EPCb
Avian
Herbivore
NOECc
Avian
Ground
Insectivore
NOECc
Avian
Carnivore
NOECc
Minimum
Avian NOEC
Refined HQ
based on
Minimum Avian
NOECd
Include
Contaminant as
Candidate COEC
for Birds?6
Surface Soil (0-6 inches bgs)
Radionuclides (pCi/gf
Uranium-238 in SE
(Adjusted Radium-226)
97
15
15
15
15
6.5
Yes
Metals (mg/kg)
Arsenic
29
67
43
1,100
43
0.67
No
Barium
317
720
820
7,500
720
0.44
No
Cadmium
0.31
28
0.77
630
0.77
0.40
No
Chromium9
5.0
78
26
780
26
0.19
No
Cobalt
10
270
120
1,300
120
0.083
No
Lead
32
11
510
1,200
11
2.9
Yes
Manganese
182
4,300
650,000
5,300
4,300
0.042
No
Mercury
0.53
0.013
0.058
23.000
0.013
41
Yes
Molybdenum
242
15
90
NSL
15
16
Yes
Nickel
7.6
20
2,800
340
20
0.38
No
Selenium
2.8
1.2
83.0
3
1.2
2.3
Yes
Thallium
3.1
4.5
48
1.2
1.2
2.6
Yes
Uranium
69
1,100
14,000
1,000
1,000
0.069
No
Vanadium
42
7.8
140
1,300
7.8
5.4
Yes
Zinc
23
46
30,000
6,800
46
0.50
No
Notes:
Grey highlighted cells indicate the EPC exceeds the NOEC for the receptor group.
a Bolded COPECs have a HQ greater than 1.0.
b EPCs are provided in Table B-9.
cSee Table B-8 for sources of NOECs.
d HQ is calculated by dividing the EPC by the minimum NOEC. Bolded HQ values indicate HQs greater than or equal to 1.0.
e A contaminant is identified as a candidate COEC if the HQ (HQ based on minimum NOEC) is greater than or equal to 1.0.
f ESLs for uranium-238 in SE are based on individual radium-226 ESLs that are adjusted to include doses from all progeny of uranium-238 in SE. Site data for
radium-226 are used to evaluate uranium-238 in SE.
Page 1 of 2
-------
Table B-11. Screening-Level Ecological Risk Assessment Refinement for Soil - Birds
Notes (Continued):
g Chromium is evaluated using the assumption that it is 100 percent hexavalent chromium (USEPA 2024c). Eco-SSLs for hexavalent chromium are not available for
birds; therefore, Cr(lll) (trivalent chromium) Eco-SSLs were used (USEPA 2023).
bgs
Below ground surface
COEC
Contaminant of ecological concern
COPEC
Contaminant of potential ecological concern
Eco-SSL
Ecological soil screening level
EPC
Exposure point concentration
ESL
Ecological screening level
HQ
Hazard quotient
mg/kg
Milligram per kilogram
NOEC
No observed effect concentration
NSL
No screening level
pCi/g
Picocurie per gram
SE
Secular equilibrium
USEPA
U.S. Environmental Protection Agency
References:
U.S. Environmental Protection Agency (USEPA). 2023. "Interim Ecological Soil Screening Level Documents." Accessed July 20.
https://vwwv.epa.gov/chemical-research/interim-ecological-soil-screening-level-documents.
USEPA. 2024c. "Navajo Abandoned Uranium Mines Risk Assessment Methodology." Draft Final. March.
Page 2 of 2
-------
Table B-12. Screening-Level Ecological Risk Assessment Refinement for Soil - Mammals
Site-Wide
Mammalian
Mammalian
Ground
Insectivore
NOEC°
Mammalian
Minimum
NOEC
Refined HQ
based on
Include
Contaminant as
COPEC3
EPCb
Herbivore
NOECc
Carnivore
NOEC°
Minimum
Mammalian
Candidate
COEC for
NOECd
Mammals?8
Surface Soil (0-6 inches bgs)
Radionuclides (pCi/qf
Uranium-238 in SE
(Adjusted Radium-226)
97
6.0
6.0
6.0
6.0
16
Yes
Metals (mg/kg)
Arsenic
29
170
46
170
46
0.63
No
Barium
317
3,200
200
9,100
200
1.6
Yes
Cadmium
0.31
73
0.36
84
0.36
0.86
No
Chromium9
5.0
380
34
180
34
0.15
No
Cobalt
10
2,100
230
470
230
0.043
No
Lead
32
1,200
56
460
56
0.57
No
Manganese
182
5,300
4,000
6,200
4,000
0.046
No
Mercury
0.53
23
1.7
76
1.7
0.31
No
Molybdenum
242
NSL
NSL
NSL
NSL
—
--
Nickel
7.6
340
10
130
10
0.76
No
Selenium
2.8
2.7
0.63
2.8
0.63
4.4
Yes
Thallium
3.1
1.2
0.42
5.0
0.42
7.4
Yes
Uranium
69
1,000
480
4,800
480
0.14
No
Vanadium
42
1,300
280
580
280
0.15
No
Zinc
23
6,800
79
10,000
79
0.29
No
Page 1 of 3
-------
Table B-12. Screening-Level Ecological Risk Assessment Refinement for Soil - Mammals
Site-Wide
Mammalian
Mammalian
Ground
Insectivore
NOEC0
Mammalian
Minimum
NOEC
Refined HQ
based on
Include
Contaminant as
COPEC3
EPCb
Herbivore
NOECc
Carnivore
NOEC0
Minimum
Mammalian
Candidate
COEC for
NOECd
Mammals?8
Subsurface Soil (0-60 inches bgs)
Radionuclides (pCi/qf
Uranium-238 in SE
(Adjusted Radium-226)
65
6.0
6.0
6.0
6.0
11
Yes
Metals (mg/kg)
Arsenic
21
170
46
170
46
0.46
No
Barium
298
3,200
200
9,100
200
1.5
Yes
Cadmium
0.29
73
0.36
84
0.36
0.81
No
Chromium9
4.7
380
34
180
34
0.14
No
Cobalt
11
2,100
230
470
230
0.048
No
Lead
28
1,200
56
460
56
0.50
No
Manganese
168
5,300
4,000
6,200
4,000
0.042
No
Mercury
0.36
23
1.7
76
2
0.21
No
Molybdenum
168
NSL
NSL
NSL
NSL
--
--
Nickel
7.2
340
10
130
10
0.72
No
Selenium
1.7
2.7
0.63
2.8
0.63
2.7
Yes
Thallium
2.8
1.2
0.42
5.0
0.42
6.7
Yes
Uranium
50
1,000
480
4,800
480
0.10
No
Vanadium
33
1,300
280
580
280
0.12
No
Zinc
20
6,800
79
10,000
79
0.25
No
Notes:
Grey highlighted cells indicate the EPC exceeds the NOEC for the receptor group.
a Bolded COPECs have a HQ greater than 1.0.
b EPCs are provided in Table B-9.
cSee Table B-8 for sources of NOECs.
d HQ is calculated by dividing the EPC by the minimum NOEC. Bolded HQ values indicate HQs equal to or greater than 1.0.
e A contaminant is identified as a candidate COEC if the HQ (HQ based on minimum NOEC) is equal to or greater than 1.0.
Page 2 of 3
-------
Table B-12. Screening-Level Ecological Risk Assessment Refinement for Soil - Mammals
Notes (Continued):
f ESLs for uranium-238 in SE are based on individual radium-226 ESLs that are adjusted to include doses from all progeny of uranium-238 in SE. Site data for
radium-226 are used to evaluate uranium-238 in SE.
g Chromium is evaluated using the assumption that it is 100 percent hexavalent chromium (USEPA 2024c). No speciated chromium data are available.
Cr(III) (trivalent chromium) Eco-SSLs were used for mammals because the hexavalent chromium Eco-SSLs for mammals are higher than the trivalent
chromium values (USEPA 2023).
-
Not applicable
bgs
Below ground surface
COEC
Contaminant of ecological concern
COPEC
Contaminant of potential ecological concern
Eco-SSL
Ecological soil screening level
EPC
Exposure point concentration
ESL
Ecological screening level
HQ
Hazard quotient
mg/kg
Milligram per kilogram
NOEC
No observed effect concentration
pCi/g
Picocurie per gram
SE
Secular equlibrium
USEPA
U.S. Environmental Protection Agency
References:
U.S. Environmental Protection Agency (USEPA). 2023. "Interim Ecological Soil Screening Level Documents." Accessed July 20.
https://vwwv.epa.gov/chemical-research/interim-ecological-soil-screening-level-documents.
USEPA. 2024c. "Navajo Abandoned Uranium Mines Risk Assessment Methodology." Draft Final. March.
Page 3 of 3
-------
ATTACHMENT B-l
DATA USED IN THE RISK ASSESSMENT
-------
Attachment B-1. Data Used in the Risk Assessment
Sample ID
Sample
Date
Geologic
Unit
Latitude
Longitude
Sample
Top Depth
(inches bgs)
Sample
Bottom Depth
(inches bgs)
Analytical
Method
Analyte
Units
Result and
Qualifier
Reporting
Limit
457-SS01-01-020624
2/6/2024
Qay
35.74115498
-111.3249375
0
6
SW6020B
Aluminum
mg/kg
6,230
8790
457-SS01-01-020624
2/6/2024
Qay
35.74115498
-111.3249375
0
6
SW6010D
Antimony
mg/kg
1.87
U
1870
457-SS01-01-020624
2/6/2024
Qay
35.74115498
-111.3249375
0
6
SW6020B
Arsenic
mg/kg
14.4
N
879
457-SS01-01-020624
2/6/2024
Qay
35.74115498
-111.3249375
0
6
SW6020B
Barium
mg/kg
151
*
703
457-SS01-01-020624
2/6/2024
Qay
35.74115498
-111.3249375
0
6
SW6020B
Beryllium
mg/kg
0.467
87.9
457-SS01-01-020624
2/6/2024
Qay
35.74115498
-111.3249375
0
6
SW6020B
Cadmium
mg/kg
0.148
J
176
457-SS01-01-020624
2/6/2024
Qay
35.74115498
-111.3249375
0
6
SW6020B
Chromium
mg/kg
5.82
528
457-SS01-01-020624
2/6/2024
Qay
35.74115498
-111.3249375
0
6
SW6020B
Cobalt
mg/kg
23.7
N
176
457-SS01-01-020624
2/6/2024
Qay
35.74115498
-111.3249375
0
6
SW6020B
Copper
mg/kg
7.97
N*
352
457-SS01-01-020624
2/6/2024
Qay
35.74115498
-111.3249375
0
6
SW6020B
Iron
mg/kg
10,500
176000
457-SS01-01-020624
2/6/2024
Qay
35.74115498
-111.3249375
0
6
SW6020B
Lead
mg/kg
9.25
N
352
457-SS01-01-020624
2/6/2024
Qay
35.74115498
-111.3249375
0
6
SW6020B
Manganese
mg/kg
56.8
*
879
457-SS01-01-020624
2/6/2024
Qay
35.74115498
-111.3249375
0
6
SW7471 B
Mercury
mg/kg
0.105
21.7
457-SS01-01-020624
2/6/2024
Qay
35.74115498
-111.3249375
0
6
SW6020B
Molybdenum
mg/kg
4.61
N
176
457-SS01-01-020624
2/6/2024
Qay
35.74115498
-111.3249375
0
6
SW6020B
Nickel
mg/kg
6.98
N
352
457-SS01-01-020624
2/6/2024
Qay
35.74115498
-111.3249375
0
6
EH 300
Radium-226
pCi/g
18.6
0.227
457-SS01-01-020624
2/6/2024
Qay
35.74115498
-111.3249375
0
6
SW6020B
Selenium
mg/kg
6.53
N*
879
457-SS01-01-020624
2/6/2024
Qay
35.74115498
-111.3249375
0
6
SW6010D
Silver
mg/kg
0.468
U
468
457-SS01-01-020624
2/6/2024
Qay
35.74115498
-111.3249375
0
6
SW6020B
Thallium
mg/kg
0.347
J
352
457-SS01-01-020624
2/6/2024
Qay
35.74115498
-111.3249375
0
6
SW6020B
Uranium
mg/kg
26.8
N
35.2
457-SS01-01-020624
2/6/2024
Qay
35.74115498
-111.3249375
0
6
SW6020B
Vanadium
mg/kg
20.3
3520
457-SS01-01-020624
2/6/2024
Qay
35.74115498
-111.3249375
0
6
SW6020B
Zinc
mg/kg
21.4
N
3520
457-SS02-01-020624
2/6/2024
Qay
35.74096079
-111.324933
0
6
SW6020B
Aluminum
mg/kg
4,550
10000
457-SS02-01-020624
2/6/2024
Qay
35.74096079
-111.324933
0
6
SW6010D
Antimony
mg/kg
1.74
U
1740
457-SS02-01-020624
2/6/2024
Qay
35.74096079
-111.324933
0
6
SW6020B
Arsenic
mg/kg
16.1
N
1000
457-SS02-01-020624
2/6/2024
Qay
35.74096079
-111.324933
0
6
SW6020B
Barium
mg/kg
236
*
8030
457-SS02-01-020624
2/6/2024
Qay
35.74096079
-111.324933
0
6
SW6020B
Beryllium
mg/kg
0.667
100
457-SS02-01-020624
2/6/2024
Qay
35.74096079
-111.324933
0
6
SW6020B
Cadmium
mg/kg
0.748
201
457-SS02-01-020624
2/6/2024
Qay
35.74096079
-111.324933
0
6
SW6020B
Chromium
mg/kg
5
602
457-SS02-01-020624
2/6/2024
Qay
35.74096079
-111.324933
0
6
SW6020B
Cobalt
mg/kg
28
N
201
457-SS02-01-020624
2/6/2024
Qay
35.74096079
-111.324933
0
6
SW6020B
Copper
mg/kg
22.7
N*
401
457-SS02-01-020624
2/6/2024
Qay
35.74096079
-111.324933
0
6
SW6020B
Iron
mg/kg
8,360
20100
457-SS02-01-020624
2/6/2024
Qay
35.74096079
-111.324933
0
6
SW6020B
Lead
mg/kg
16.5
N
401
457-SS02-01-020624
2/6/2024
Qay
35.74096079
-111.324933
0
6
SW6020B
Manganese
mg/kg
144
*
1000
457-SS02-01-020624
2/6/2024
Qay
35.74096079
-111.324933
0
6
SW7471 B
Mercury
mg/kg
0.229
22.9
457-SS02-01-020624
2/6/2024
Qay
35.74096079
-111.324933
0
6
SW6020B
Molybdenum
mg/kg
59.7
N
201
457-SS02-01-020624
2/6/2024
Qay
35.74096079
-111.324933
0
6
SW6020B
Nickel
mg/kg
15.2
N
401
457-SS02-01-020624
2/6/2024
Qay
35.74096079
-111.324933
0
6
EH 300
Radium-226
pCi/g
66.7
0.372
457-SS02-01-020624
2/6/2024
Qay
35.74096079
-111.324933
0
6
SW6020B
Selenium
mg/kg
1.95
N*
1000
457-SS02-01-020624
2/6/2024
Qay
35.74096079
-111.324933
0
6
SW6010D
Silver
mg/kg
0.0955
J-
436
457-SS02-01-020624
2/6/2024
Qay
35.74096079
-111.324933
0
6
SW6020B
Thallium
mg/kg
0.791
401
457-SS02-01-020624
2/6/2024
Qay
35.74096079
-111.324933
0
6
SW6020B
Uranium
mg/kg
90.4
N
40.1
457-SS02-01-020624
2/6/2024
Qay
35.74096079
-111.324933
0
6
SW6020B
Vanadium
mg/kg
18.7
4010
457-SS02-01-020624
2/6/2024
Qay
35.74096079
-111.324933
0
6
SW6020B
Zinc
mg/kg
31.9
N
4010
457-SS03-01-020624
2/6/2024
Qay
35.74001051
-111.325111
0
6
SW6020B
Aluminum
mg/kg
6,890
10000
457-SS03-01-020624
2/6/2024
Qay
35.74001051
-111.325111
0
6
SW6010D
Antimony
mg/kg
1.83
U
1830
457-SS03-01-020624
2/6/2024
Qay
35.74001051
-111.325111
0
6
SW6020B
Arsenic
mg/kg
3.97
J
1000
457-SS03-01-020624
2/6/2024
Qay
35.74001051
-111.325111
0
6
SW6020B
Barium
mg/kg
189
J
803
457-SS03-01-020624
2/6/2024
Qay
35.74001051
-111.325111
0
6
SW6020B
Beryllium
mg/kg
0.653
100
457-SS03-01-020624
2/6/2024
Qay
35.74001051
-111.325111
0
6
SW6020B
Cadmium
mg/kg
0.109
J
201
457-SS03-01-020624
2/6/2024
Qay
35.74001051
-111.325111
0
6
SW6020B
Chromium
mg/kg
5.3
602
457-SS03-01-020624
2/6/2024
Qay
35.74001051
-111.325111
0
6
SW6020B
Cobalt
mg/kg
4.19
J
201
457-SS03-01-020624
2/6/2024
Qay
35.74001051
-111.325111
0
6
SW6020B
Copper
mg/kg
15.9
J
401
457-SS03-01-020624
2/6/2024
Qay
35.74001051
-111.325111
0
6
SW7196A
xavalent Chromi
mg/kg
0.138
U
0.345
457-SS03-01-020624
2/6/2024
Qay
35.74001051
-111.325111
0
6
SW6020B
Iron
mg/kg
6,160
20100
457-SS03-01-020624
2/6/2024
Qay
35.74001051
-111.325111
0
6
SW6020B
Lead
mg/kg
9.26
J
401
457-SS03-01-020624
2/6/2024
Qay
35.74001051
-111.325111
0
6
SW6020B
Manganese
mg/kg
308
J
10000
457-SS03-01-020624
2/6/2024
Qay
35.74001051
-111.325111
0
6
SW7471B
Mercury
mg/kg
0.0257
23.1
457-SS03-01-020624
2/6/2024
Qay
35.74001051
-111.325111
0
6
SW6020B
Molybdenum
mg/kg
13.9
J
201
457-SS03-01-020624
2/6/2024
Qay
35.74001051
-111.325111
0
6
SW6020B
Nickel
mg/kg
4.8
J
401
457-SS03-01-020624
2/6/2024
Qay
35.74001051
-111.325111
0
6
EH 300
Radium-226
pCi/g
18.9
0.217
457-SS03-01-020624
2/6/2024
Qay
35.74001051
-111.325111
0
6
SW6020B
Selenium
mg/kg
2
J
1000
457-SS03-01-020624
2/6/2024
Qay
35.74001051
-111.325111
0
6
SW6010D
Silver
mg/kg
0.458
U
458
457-SS03-01-020624
2/6/2024
Qay
35.74001051
-111.325111
0
6
SW6020B
Thallium
mg/kg
0.506
401
457-SS03-01-020624
2/6/2024
Qay
35.74001051
-111.325111
0
6
SW6020B
Uranium
mg/kg
15.7
J
40.1
457-SS03-01-020624
2/6/2024
Qay
35.74001051
-111.325111
0
6
SW6020B
Vanadium
mg/kg
29.1
4010
457-SS03-01-020624
2/6/2024
Qay
35.74001051
-111.325111
0
6
SW6020B
Zinc
mg/kg
10.9
J
4010
457-SS04-01-020624
2/6/2024
Qay
35.73921099
-111.3245257
0
6
SW6020B
Aluminum
mg/kg
3,480
8860
457-SS04-01-020624
2/6/2024
Qay
35.73921099
-111.3245257
0
6
SW6010D
Antimony
mg/kg
1.88
U
1880
457-SS04-01-020624
2/6/2024
Qay
35.73921099
-111.3245257
0
6
SW6020B
Arsenic
mg/kg
18.5
N
886
457-SS04-01-020624
2/6/2024
Qay
35.73921099
-111.3245257
0
6
SW6020B
Barium
mg/kg
327
*
7090
457-SS04-01-020624
2/6/2024
Qay
35.73921099
-111.3245257
0
6
SW6020B
Beryllium
mg/kg
0.424
88.6
457-SS04-01-020624
2/6/2024
Qay
35.73921099
-111.3245257
0
6
SW6020B
Cadmium
mg/kg
0.794
177
457-SS04-01-020624
2/6/2024
Qay
35.73921099
-111.3245257
0
6
SW6020B
Chromium
mg/kg
4.9
531
457-SS04-01-020624
2/6/2024
Qay
35.73921099
-111.3245257
0
6
SW6020B
Cobalt
mg/kg
7.45
N
177
457-SS04-01-020624
2/6/2024
Qay
35.73921099
-111.3245257
0
6
SW6020B
Copper
mg/kg
10.3
N*
354
457-SS04-01-020624
2/6/2024
Qay
35.73921099
-111.3245257
0
6
SW7196A
xavalent Chromi
mg/kg
0.0997
U
0.249
457-SS04-01-020624
2/6/2024
Qay
35.73921099
-111.3245257
0
6
SW6020B
Iron
mg/kg
6,180
17700
457-SS04-01-020624
2/6/2024
Qay
35.73921099
-111.3245257
0
6
SW6020B
Lead
mg/kg
74.8
N
354
457-SS04-01-020624
2/6/2024
Qay
35.73921099
-111.3245257
0
6
SW6020B
Manganese
mg/kg
148
*
886
457-SS04-01-020624
2/6/2024
Qay
35.73921099
-111.3245257
0
6
SW7471B
Mercury
mg/kg
0.165
24.1
457-SS04-01-020624
2/6/2024
Qay
35.73921099
-111.3245257
0
6
SW6020B
Molybdenum
mg/kg
214
N
1770
457-SS04-01-020624
2/6/2024
Qay
35.73921099
-111.3245257
0
6
SW6020B
Nickel
mg/kg
6.99
N
354
457-SS04-01-020624
2/6/2024
Qay
35.73921099
-111.3245257
0
6
EH 300
Radium-226
pCi/g
160
0.502
457-SS04-01-020624
2/6/2024
Qay
35.73921099
-111.3245257
0
6
SW6020B
Selenium
mg/kg
1.29
N*
886
457-SS04-01-020624
2/6/2024
Qay
35.73921099
-111.3245257
0
6
SW6010D
Silver
mg/kg
0.2
J-
469
457-SS04-01-020624
2/6/2024
Qay
35.73921099
-111.3245257
0
6
SW6020B
Thallium
mg/kg
2.82
354
457-SS04-01-020624
2/6/2024
Qay
35.73921099
-111.3245257
0
6
SW6020B
Uranium
mg/kg
56
N
35.4
Page 1 of 20
-------
Attachment B-1. Data Used in the Risk Assessment
Sample ID
Sample
Date
Geologic
Unit
Latitude
Longitude
Sample
Top Depth
(inches bgs)
Sample
Bottom Depth
(inches bgs)
Analytical
Method
Analyte
Units
Result and
Qualifier
Reporting
Limit
457-SS04-01-020624
2/6/2024
Qay
35.73921099
-111.3245257
0
6
SW6020B
Vanadium
mg/kg
40.3
3540
457-SS04-01-020624
2/6/2024
Qay
35.73921099
-111.3245257
0
6
SW6020B
Zinc
mg/kg
61.9
N
3540
457-SS-10A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
6010C DOD
Aluminum
mg/kg
3,400
D
NR
457-SS-10A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
6010C DOD
Antimony
mg/kg
6.5
U
NR
457-SS-10A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
6010C DOD
Arsenic
mg/kg
3.2
U
NR
457-SS-10A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
6010C DOD
Barium
mg/kg
320
D
NR
457-SS-10A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
6010C DOD
Beryllium
mg/kg
1.7
U
NR
457-SS-10A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
6010C DOD
Cadmium
mg/kg
1
U
NR
457-SS-10A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601OC DOD
Chromium
mg/kg
3.8
JD
NR
457-SS-10A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601OC DOD
Cobalt
mg/kg
9.5
U
NR
457-SS-10A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Copper
mg/kg
8.6
JD
NR
457-SS-10A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Iron
mg/kg
15,000
D
NR
457-SS-10A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Lead
mg/kg
18
D
NR
457-SS-10A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Manganese
mg/kg
250
D
NR
457-SS-10A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Mercury
mg/kg
0.028
J
NR
457-SS-10A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Molybdenum
mg/kg
10
U
NR
457-SS-10A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Nickel
mg/kg
6.6
JD
NR
457-SS-10A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
GA-01 -R
Radium-226
pCi/g
2.87
NR
457-SS-10A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Selenium
mg/kg
2.9
U
NR
457-SS-10A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Silver
mg/kg
2.4
U
NR
457-SS-10A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Thallium
mg/kg
15
U
NR
457-SS-10A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Uranium
mg/kg
98
U
NR
457-SS-10A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Vanadium
mg/kg
35
JD
NR
457-SS-10A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Zinc
mg/kg
28
JD
NR
457-SS-11A
8/6/2013
Qay
35.73950347
-111.3240351
0
6
601 OC DOD
Aluminum
mg/kg
3,300
D
NR
457-SS-11A
8/6/2013
Qay
35.73950347
-111.3240351
0
6
601 OC DOD
Antimony
mg/kg
6
U
NR
457-SS-11A
8/6/2013
Qay
35.73950347
-111.3240351
0
6
601 OC DOD
Arsenic
mg/kg
72
D
NR
457-SS-11A
8/6/2013
Qay
35.73950347
-111.3240351
0
6
601 OC DOD
Barium
mg/kg
510
D
NR
457-SS-11A
8/6/2013
Qay
35.73950347
-111.3240351
0
6
601 OC DOD
Beryllium
mg/kg
1.6
U
NR
457-SS-11A
8/6/2013
Qay
35.73950347
-111.3240351
0
6
601 OC DOD
Cadmium
mg/kg
0.94
U
NR
457-SS-11A
8/6/2013
Qay
35.73950347
-111.3240351
0
6
601 OC DOD
Chromium
mg/kg
7.1
JD
NR
457-SS-11A
8/6/2013
Qay
35.73950347
-111.3240351
0
6
601 OC DOD
Cobalt
mg/kg
10
JD
NR
457-SS-11A
8/6/2013
Qay
35.73950347
-111.3240351
0
6
601 OC DOD
Copper
mg/kg
20
JD
NR
457-SS-11A
8/6/2013
Qay
35.73950347
-111.3240351
0
6
601 OC DOD
Iron
mg/kg
15,000
D
NR
457-SS-11A
8/6/2013
Qay
35.73950347
-111.3240351
0
6
601 OC DOD
Lead
mg/kg
66
D
NR
457-SS-11A
8/6/2013
Qay
35.73950347
-111.3240351
0
6
601 OC DOD
Manganese
mg/kg
180
D
NR
457-SS-11A
8/6/2013
Qay
35.73950347
-111.3240351
0
6
601 OC DOD
Mercury
mg/kg
0.88
NR
457-SS-11A
8/6/2013
Qay
35.73950347
-111.3240351
0
6
601 OC DOD
Molybdenum
mg/kg
910
D
NR
457-SS-11A
8/6/2013
Qay
35.73950347
-111.3240351
0
6
601 OC DOD
Nickel
mg/kg
9.1
JD
NR
457-SS-11A
8/6/2013
Qay
35.73950347
-111.3240351
0
6
GA-01 -R
Radium-226
pCi/g
411
NR
457-SS-11A
8/6/2013
Qay
35.73950347
-111.3240351
0
6
601 OC DOD
Selenium
mg/kg
2.7
U
NR
457-SS-11A
8/6/2013
Qay
35.73950347
-111.3240351
0
6
601 OC DOD
Silver
mg/kg
2.2
U
NR
457-SS-11A
8/6/2013
Qay
35.73950347
-111.3240351
0
6
601 OC DOD
Thallium
mg/kg
14
U
NR
457-SS-11A
8/6/2013
Qay
35.73950347
-111.3240351
0
6
601 OC DOD
Uranium
mg/kg
430
U
NR
457-SS-11A
8/6/2013
Qay
35.73950347
-111.3240351
0
6
601 OC DOD
Vanadium
mg/kg
70
D
NR
457-SS-11A
8/6/2013
Qay
35.73950347
-111.3240351
0
6
601 OC DOD
Zinc
mg/kg
55
JD
NR
457-SS-12A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Aluminum
mg/kg
3,900
D
NR
457-SS-12A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Antimony
mg/kg
6.2
U
NR
457-SS-12A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Arsenic
mg/kg
3
U
NR
457-SS-12A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Barium
mg/kg
310
D
NR
457-SS-12A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Beryllium
mg/kg
1.6
U
NR
457-SS-12A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Cadmium
mg/kg
0.96
U
NR
457-SS-12A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Chromium
mg/kg
4.6
JD
NR
457-SS-12A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Cobalt
mg/kg
9
U
NR
457-SS-12A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Copper
mg/kg
9
JD
NR
457-SS-12A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Iron
mg/kg
15,000
D
NR
457-SS-12A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Lead
mg/kg
18
D
NR
457-SS-12A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Manganese
mg/kg
240
D
NR
457-SS-12A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Mercury
mg/kg
0.032
J
NR
457-SS-12A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Molybdenum
mg/kg
9.6
U
NR
457-SS-12A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Nickel
mg/kg
6.9
JD
NR
457-SS-12A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
GA-01 -R
Radium-226
pCi/g
3.19
NR
457-SS-12A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Selenium
mg/kg
2.8
U
NR
457-SS-12A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Silver
mg/kg
2.2
U
NR
457-SS-12A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Thallium
mg/kg
15
U
NR
457-SS-12A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Uranium
mg/kg
110
U
NR
457-SS-12A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Vanadium
mg/kg
34
JD
NR
457-SS-12A
8/6/2013
Qay
35.73895147
-111.3242831
0
6
601 OC DOD
Zinc
mg/kg
30
JD
NR
457-SS-1A
8/6/2013
Qay
35.74135147
-111.3253241
0
6
601 OC DOD
Aluminum
mg/kg
1,400
D
NR
457-SS-1A
8/6/2013
Qay
35.74135147
-111.3253241
0
6
601 OC DOD
Antimony
mg/kg
6.4
U
NR
457-SS-1A
8/6/2013
Qay
35.74135147
-111.3253241
0
6
601 OC DOD
Arsenic
mg/kg
83
D
NR
457-SS-1A
8/6/2013
Qay
35.74135147
-111.3253241
0
6
601 OC DOD
Barium
mg/kg
310
D
NR
457-SS-1A
8/6/2013
Qay
35.74135147
-111.3253241
0
6
601 OC DOD
Beryllium
mg/kg
1.7
U
NR
457-SS-1A
8/6/2013
Qay
35.74135147
-111.3253241
0
6
601 OC DOD
Cadmium
mg/kg
1
U
NR
457-SS-1A
8/6/2013
Qay
35.74135147
-111.3253241
0
6
601 OC DOD
Chromium
mg/kg
3.1
U
NR
457-SS-1A
8/6/2013
Qay
35.74135147
-111.3253241
0
6
601 OC DOD
Cobalt
mg/kg
13
JD
NR
457-SS-1A
8/6/2013
Qay
35.74135147
-111.3253241
0
6
601 OC DOD
Copper
mg/kg
27
D
NR
457-SS-1A
8/6/2013
Qay
35.74135147
-111.3253241
0
6
601 OC DOD
Iron
mg/kg
7,200
D
NR
457-SS-1A
8/6/2013
Qay
35.74135147
-111.3253241
0
6
601 OC DOD
Lead
mg/kg
40
D
NR
457-SS-1A
8/6/2013
Qay
35.74135147
-111.3253241
0
6
601 OC DOD
Manganese
mg/kg
15
D
NR
457-SS-1A
8/6/2013
Qay
35.74135147
-111.3253241
0
6
601 OC DOD
Mercury
mg/kg
0.31
NR
457-SS-1A
8/6/2013
Qay
35.74135147
-111.3253241
0
6
601 OC DOD
Molybdenum
mg/kg
420
D
NR
457-SS-1A
8/6/2013
Qay
35.74135147
-111.3253241
0
6
601 OC DOD
Nickel
mg/kg
8
JD
NR
457-SS-1A
8/6/2013
Qay
35.74135147
-111.3253241
0
6
GA-01 -R
Radium-226
pCi/g
156
NR
457-SS-1A
8/6/2013
Qay
35.74135147
-111.3253241
0
6
601 OC DOD
Selenium
mg/kg
2.9
U
NR
457-SS-1A
8/6/2013
Qay
35.74135147
-111.3253241
0
6
601 OC DOD
Silver
mg/kg
2.3
U
NR
457-SS-1A
8/6/2013
Qay
35.74135147
-111.3253241
0
6
601 OC DOD
Thallium
mg/kg
15
U
NR
457-SS-1A
8/6/2013
Qay
35.74135147
-111.3253241
0
6
601 OC DOD
Uranium
mg/kg
390
U
NR
Page 2 of 20
-------
Attachment B-1. Data Used in the Risk Assessment
Sample ID
Sample
Date
Geologic
Unit
Latitude
Longitude
Sample
Top Depth
(inches bgs)
Sample
Bottom Depth
(inches bgs)
Analytical
Method
Analyte
Units
Result and
Qualifier
Reporting
Limit
457-SS-1A
8/6/2013
Qay
35.74135147
-
11.3253241
0
6
6010C DOD
Vanadium
mg/kg
13
U
NR
457-SS-1A
8/6/2013
Qay
35.74135147
-
11.3253241
0
6
6010C DOD
Zinc
mg/kg
20
JD
NR
457-SS-2A
8/6/2013
Qay
35.73975247
-
11.3229631
0
6
6010C DOD
Aluminum
mg/kg
3,600
D
NR
457-SS-2A
8/6/2013
Qay
35.73975247
-
11.3229631
0
6
6010C DOD
Antimony
mg/kg
5.8
U
NR
457-SS-2A
8/6/2013
Qay
35.73975247
-
11.3229631
0
6
6010C DOD
Arsenic
mg/kg
7.3
JD
NR
457-SS-2A
8/6/2013
Qay
35.73975247
-
11.3229631
0
6
6010C DOD
Barium
mg/kg
280
D
NR
457-SS-2A
8/6/2013
Qay
35.73975247
-
11.3229631
0
6
601OC DOD
Beryllium
mg/kg
1.5
U
NR
457-SS-2A
8/6/2013
Qay
35.73975247
-
11.3229631
0
6
601OC DOD
Cadmium
mg/kg
0.9
U
NR
457-SS-2A
8/6/2013
Qay
35.73975247
-
11.3229631
0
6
601 OC DOD
Chromium
mg/kg
2.8
JD
NR
457-SS-2A
8/6/2013
Qay
35.73975247
-
11.3229631
0
6
601 OC DOD
Cobalt
mg/kg
8.7
JD
NR
457-SS-2A
8/6/2013
Qay
35.73975247
-
11.3229631
0
6
601 OC DOD
Copper
mg/kg
8.6
JD
NR
457-SS-2A
8/6/2013
Qay
35.73975247
-
11.3229631
0
6
601 OC DOD
Iron
mg/kg
10,000
D
NR
457-SS-2A
8/6/2013
Qay
35.73975247
-
11.3229631
0
6
601 OC DOD
Lead
mg/kg
10
D
NR
457-SS-2A
8/6/2013
Qay
35.73975247
-
11.3229631
0
6
601 OC DOD
Manganese
mg/kg
280
D
NR
457-SS-2A
8/6/2013
Qay
35.73975247
-
11.3229631
0
6
601 OC DOD
Mercury
mg/kg
0.024
J
NR
457-SS-2A
8/6/2013
Qay
35.73975247
-
11.3229631
0
6
601 OC DOD
Molybdenum
mg/kg
61
D
NR
457-SS-2A
8/6/2013
Qay
35.73975247
-
11.3229631
0
6
601 OC DOD
Nickel
mg/kg
6
JD
NR
457-SS-2A
8/6/2013
Qay
35.73975247
-
11.3229631
0
6
GA-01 -R
Radium-226
pCi/g
30.1
NR
457-SS-2A
8/6/2013
Qay
35.73975247
-
11.3229631
0
6
601 OC DOD
Selenium
mg/kg
2.6
U
NR
457-SS-2A
8/6/2013
Qay
35.73975247
-
11.3229631
0
6
601 OC DOD
Silver
mg/kg
2.1
U
NR
457-SS-2A
8/6/2013
Qay
35.73975247
-
11.3229631
0
6
601 OC DOD
Thallium
mg/kg
14
U
NR
457-SS-2A
8/6/2013
Qay
35.73975247
-
11.3229631
0
6
601 OC DOD
Uranium
mg/kg
120
U
NR
457-SS-2A
8/6/2013
Qay
35.73975247
-
11.3229631
0
6
601 OC DOD
Vanadium
mg/kg
24
JD
NR
457-SS-2A
8/6/2013
Qay
35.73975247
-
11.3229631
0
6
601 OC DOD
Zinc
mg/kg
18
U
NR
457-SS-2B
8/6/2013
Qay
35.73975247
-
11.3229631
6
12
601 OC DOD
Aluminum
mg/kg
3,300
D
NR
457-SS-2B
8/6/2013
Qay
35.73975247
-
11.3229631
6
12
601 OC DOD
Antimony
mg/kg
5.8
U
NR
457-SS-2B
8/6/2013
Qay
35.73975247
-
11.3229631
6
12
601 OC DOD
Arsenic
mg/kg
2.9
U
NR
457-SS-2B
8/6/2013
Qay
35.73975247
-
11.3229631
6
12
601 OC DOD
Barium
mg/kg
290
D
NR
457-SS-2B
8/6/2013
Qay
35.73975247
-
11.3229631
6
12
601 OC DOD
Beryllium
mg/kg
1.5
U
NR
457-SS-2B
8/6/2013
Qay
35.73975247
-
11.3229631
6
12
601 OC DOD
Cadmium
mg/kg
0.9
U
NR
457-SS-2B
8/6/2013
Qay
35.73975247
-
11.3229631
6
12
601 OC DOD
Chromium
mg/kg
2.8
U
NR
457-SS-2B
8/6/2013
Qay
35.73975247
-
11.3229631
6
12
601 OC DOD
Cobalt
mg/kg
8.5
U
NR
457-SS-2B
8/6/2013
Qay
35.73975247
-
11.3229631
6
12
601 OC DOD
Copper
mg/kg
6.9
JD
NR
457-SS-2B
8/6/2013
Qay
35.73975247
-
11.3229631
6
12
601 OC DOD
Iron
mg/kg
11,000
D
NR
457-SS-2B
8/6/2013
Qay
35.73975247
-
11.3229631
6
12
601 OC DOD
Lead
mg/kg
7.7
JD
NR
457-SS-2B
8/6/2013
Qay
35.73975247
-
11.3229631
6
12
601 OC DOD
Manganese
mg/kg
110
D
NR
457-SS-2B
8/6/2013
Qay
35.73975247
-
11.3229631
6
12
601 OC DOD
Mercury
mg/kg
0.012
J
NR
457-SS-2B
8/6/2013
Qay
35.73975247
-
11.3229631
6
12
601 OC DOD
Molybdenum
mg/kg
9
U
NR
457-SS-2B
8/6/2013
Qay
35.73975247
-
11.3229631
6
12
601 OC DOD
Nickel
mg/kg
2.3
JD
NR
457-SS-2B
8/6/2013
Qay
35.73975247
-
11.3229631
6
12
GA-01 -R
Radium-226
pCi/g
3.06
NR
457-SS-2B
8/6/2013
Qay
35.73975247
-
11.3229631
6
12
601 OC DOD
Selenium
mg/kg
2.6
U
NR
457-SS-2B
8/6/2013
Qay
35.73975247
-
11.3229631
6
12
601 OC DOD
Silver
mg/kg
2.1
U
NR
457-SS-2B
8/6/2013
Qay
35.73975247
-
11.3229631
6
12
601 OC DOD
Thallium
mg/kg
14
U
NR
457-SS-2B
8/6/2013
Qay
35.73975247
-
11.3229631
6
12
601 OC DOD
Uranium
mg/kg
110
U
NR
457-SS-2B
8/6/2013
Qay
35.73975247
-
11.3229631
6
12
601 OC DOD
Vanadium
mg/kg
20
JD
NR
457-SS-2B
8/6/2013
Qay
35.73975247
-
11.3229631
6
12
601 OC DOD
Zinc
mg/kg
18
U
NR
457-SS-2C
8/6/2013
Qay
35.73975247
-
11.3229631
12
18
601 OC DOD
Aluminum
mg/kg
3,000
D
NR
457-SS-2C
8/6/2013
Qay
35.73975247
-
11.3229631
12
18
601 OC DOD
Antimony
mg/kg
6.6
U
NR
457-SS-2C
8/6/2013
Qay
35.73975247
-
11.3229631
12
18
601 OC DOD
Arsenic
mg/kg
3.2
U
NR
457-SS-2C
8/6/2013
Qay
35.73975247
-
11.3229631
12
18
601 OC DOD
Barium
mg/kg
250
D
NR
457-SS-2C
8/6/2013
Qay
35.73975247
-
11.3229631
12
18
601 OC DOD
Beryllium
mg/kg
1.7
U
NR
457-SS-2C
8/6/2013
Qay
35.73975247
-
11.3229631
12
18
601 OC DOD
Cadmium
mg/kg
1
U
NR
457-SS-2C
8/6/2013
Qay
35.73975247
-
11.3229631
12
18
601 OC DOD
Chromium
mg/kg
3.1
U
NR
457-SS-2C
8/6/2013
Qay
35.73975247
-
11.3229631
12
18
601 OC DOD
Cobalt
mg/kg
9.6
U
NR
457-SS-2C
8/6/2013
Qay
35.73975247
-
11.3229631
12
18
601 OC DOD
Copper
mg/kg
7.4
U
NR
457-SS-2C
8/6/2013
Qay
35.73975247
-
11.3229631
12
18
601 OC DOD
Iron
mg/kg
10,000
D
NR
457-SS-2C
8/6/2013
Qay
35.73975247
-
11.3229631
12
18
601 OC DOD
Lead
mg/kg
7.5
JD
NR
457-SS-2C
8/6/2013
Qay
35.73975247
-
11.3229631
12
18
601 OC DOD
Manganese
mg/kg
110
D
NR
457-SS-2C
8/6/2013
Qay
35.73975247
-
11.3229631
12
18
601 OC DOD
Mercury
mg/kg
0.012
J
NR
457-SS-2C
8/6/2013
Qay
35.73975247
-
11.3229631
12
18
601 OC DOD
Molybdenum
mg/kg
10
U
NR
457-SS-2C
8/6/2013
Qay
35.73975247
-
11.3229631
12
18
601 OC DOD
Nickel
mg/kg
2.3
U
NR
457-SS-2C
8/6/2013
Qay
35.73975247
-
11.3229631
12
18
GA-01 -R
Radium-226
pCi/g
2.47
NR
457-SS-2C
8/6/2013
Qay
35.73975247
-
11.3229631
12
18
601 OC DOD
Selenium
mg/kg
3
U
NR
457-SS-2C
8/6/2013
Qay
35.73975247
-
11.3229631
12
18
601 OC DOD
Silver
mg/kg
2.4
U
NR
457-SS-2C
8/6/2013
Qay
35.73975247
-
11.3229631
12
18
601 OC DOD
Thallium
mg/kg
15
U
NR
457-SS-2C
8/6/2013
Qay
35.73975247
-
11.3229631
12
18
601 OC DOD
Uranium
mg/kg
140
U
NR
457-SS-2C
8/6/2013
Qay
35.73975247
-
11.3229631
12
18
601 OC DOD
Vanadium
mg/kg
21
JD
NR
457-SS-2C
8/6/2013
Qay
35.73975247
-
11.3229631
12
18
601 OC DOD
Zinc
mg/kg
20
U
NR
457-SS-3A
8/6/2013
Qay
35.73950747
-
11.3245071
0
6
601 OC DOD
Aluminum
mg/kg
2,200
D
NR
457-SS-3A
8/6/2013
Qay
35.73950747
-
11.3245071
0
6
601 OC DOD
Antimony
mg/kg
6.1
U
NR
457-SS-3A
8/6/2013
Qay
35.73950747
-
11.3245071
0
6
601 OC DOD
Arsenic
mg/kg
37
D
NR
457-SS-3A
8/6/2013
Qay
35.73950747
-
11.3245071
0
6
601 OC DOD
Barium
mg/kg
260
D
NR
457-SS-3A
8/6/2013
Qay
35.73950747
-
11.3245071
0
6
601 OC DOD
Beryllium
mg/kg
1.6
U
NR
457-SS-3A
8/6/2013
Qay
35.73950747
-
11.3245071
0
6
601 OC DOD
Cadmium
mg/kg
0.95
U
NR
457-SS-3A
8/6/2013
Qay
35.73950747
-
11.3245071
0
6
601 OC DOD
Chromium
mg/kg
3
JD
NR
457-SS-3A
8/6/2013
Qay
35.73950747
-
11.3245071
0
6
601 OC DOD
Cobalt
mg/kg
8.9
U
NR
457-SS-3A
8/6/2013
Qay
35.73950747
-
11.3245071
0
6
601 OC DOD
Copper
mg/kg
15
JD
NR
457-SS-3A
8/6/2013
Qay
35.73950747
-
11.3245071
0
6
601 OC DOD
Iron
mg/kg
14,000
D
NR
457-SS-3A
8/6/2013
Qay
35.73950747
-
11.3245071
0
6
601 OC DOD
Lead
mg/kg
32
D
NR
457-SS-3A
8/6/2013
Qay
35.73950747
-
11.3245071
0
6
601 OC DOD
Manganese
mg/kg
190
D
NR
457-SS-3A
8/6/2013
Qay
35.73950747
-
11.3245071
0
6
601 OC DOD
Mercury
mg/kg
0.1
NR
457-SS-3A
8/6/2013
Qay
35.73950747
-
11.3245071
0
6
601 OC DOD
Molybdenum
mg/kg
180
D
NR
457-SS-3A
8/6/2013
Qay
35.73950747
-
11.3245071
0
6
601 OC DOD
Nickel
mg/kg
6.3
JD
NR
457-SS-3A
8/6/2013
Qay
35.73950747
-
11.3245071
0
6
GA-01-R
Radium-226
pCi/g
57.1
NR
457-SS-3A
8/6/2013
Qay
35.73950747
-
11.3245071
0
6
601 OC DOD
Selenium
mg/kg
2.7
U
NR
457-SS-3A
8/6/2013
Qay
35.73950747
-
11.3245071
0
6
601 OC DOD
Silver
mg/kg
2.2
U
NR
457-SS-3A
8/6/2013
Qay
35.73950747
-
11.3245071
0
6
601 OC DOD
Thallium
mg/kg
14
U
NR
457-SS-3A
8/6/2013
Qay
35.73950747
-
11.3245071
0
6
601 OC DOD
Uranium
mg/kg
130
U
NR
Page 3 of 20
-------
Attachment B-1. Data Used in the Risk Assessment
Sample ID
Sample
Date
Geologic
Unit
Latitude
Longitude
Sample
Top Depth
(inches bgs)
Sample
Bottom Depth
(inches bgs)
Analytical
Method
Analyte
Units
Result and
Qualifier
Reporting
Limit
457-SS-3A
8/6/2013
Qay
35.73950747
-111.3245071
0
6
6010C DOD
Vanadium
mg/kg
32
JD
NR
457-SS-3A
8/6/2013
Qay
35.73950747
-111.3245071
0
6
6010C DOD
Zinc
mg/kg
25
JD
NR
457-SS-4A
8/6/2013
TRcs
35.73896947
-111.3234651
0
6
6010C DOD
Aluminum
mg/kg
3,000
D
NR
457-SS-4A
8/6/2013
TRcs
35.73896947
-111.3234651
0
6
6010C DOD
Antimony
mg/kg
6.4
U
NR
457-SS-4A
8/6/2013
TRcs
35.73896947
-111.3234651
0
6
6010C DOD
Arsenic
mg/kg
3.2
U
NR
457-SS-4A
8/6/2013
TRcs
35.73896947
-111.3234651
0
6
6010C DOD
Barium
mg/kg
300
D
NR
457-SS-4A
8/6/2013
TRcs
35.73896947
-111.3234651
0
6
6010C DOD
Beryllium
mg/kg
1.7
U
NR
457-SS-4A
8/6/2013
TRcs
35.73896947
-111.3234651
0
6
6010C DOD
Cadmium
mg/kg
1
U
NR
457-SS-4A
8/6/2013
TRcs
35.73896947
-111.3234651
0
6
6010C DOD
Chromium
mg/kg
4.5
JD
NR
457-SS-4A
8/6/2013
TRcs
35.73896947
-111.3234651
0
6
6010C DOD
Cobalt
mg/kg
9.4
U
NR
457-SS-4A
8/6/2013
TRcs
35.73896947
-111.3234651
0
6
6010C DOD
Copper
mg/kg
7.3
U
NR
457-SS-4A
8/6/2013
TRcs
35.73896947
-111.3234651
0
6
6010C DOD
Iron
mg/kg
16,000
D
NR
457-SS-4A
8/6/2013
TRcs
35.73896947
-111.3234651
0
6
6010C DOD
Lead
mg/kg
44
D
NR
457-SS-4A
8/6/2013
TRcs
35.73896947
-111.3234651
0
6
601OC DOD
Manganese
mg/kg
250
D
NR
457-SS-4A
8/6/2013
TRcs
35.73896947
-111.3234651
0
6
601OC DOD
Mercury
mg/kg
0.016
J
NR
457-SS-4A
8/6/2013
TRcs
35.73896947
-111.3234651
0
6
601 OC DOD
Molybdenum
mg/kg
10
U
NR
457-SS-4A
8/6/2013
TRcs
35.73896947
-111.3234651
0
6
601 OC DOD
Nickel
mg/kg
6.6
JD
NR
457-SS-4A
8/6/2013
TRcs
35.73896947
-111.3234651
0
6
GA-01 -R
Radium-226
pCi/g
3.32
NR
457-SS-4A
8/6/2013
TRcs
35.73896947
-111.3234651
0
6
601 OC DOD
Selenium
mg/kg
2.9
U
NR
457-SS-4A
8/6/2013
TRcs
35.73896947
-111.3234651
0
6
601 OC DOD
Silver
mg/kg
2.3
U
NR
457-SS-4A
8/6/2013
TRcs
35.73896947
-111.3234651
0
6
601 OC DOD
Thallium
mg/kg
15
U
NR
457-SS-4A
8/6/2013
TRcs
35.73896947
-111.3234651
0
6
601 OC DOD
Uranium
mg/kg
120
U
NR
457-SS-4A
8/6/2013
TRcs
35.73896947
-111.3234651
0
6
601 OC DOD
Vanadium
mg/kg
37
JD
NR
457-SS-4A
8/6/2013
TRcs
35.73896947
-111.3234651
0
6
601 OC DOD
Zinc
mg/kg
31
JD
NR
457-SS-4B
8/6/2013
TRcs
35.73896947
-111.3234651
6
12
601 OC DOD
Aluminum
mg/kg
3,000
D
NR
457-SS-4B
8/6/2013
TRcs
35.73896947
-111.3234651
6
12
601 OC DOD
Antimony
mg/kg
6.1
U
NR
457-SS-4B
8/6/2013
TRcs
35.73896947
-111.3234651
6
12
601 OC DOD
Arsenic
mg/kg
3
U
NR
457-SS-4B
8/6/2013
TRcs
35.73896947
-111.3234651
6
12
601 OC DOD
Barium
mg/kg
360
D
NR
457-SS-4B
8/6/2013
TRcs
35.73896947
-111.3234651
6
12
601 OC DOD
Beryllium
mg/kg
1.6
U
NR
457-SS-4B
8/6/2013
TRcs
35.73896947
-111.3234651
6
12
601 OC DOD
Cadmium
mg/kg
0.95
U
NR
457-SS-4B
8/6/2013
TRcs
35.73896947
-111.3234651
6
12
601 OC DOD
Chromium
mg/kg
5
JD
NR
457-SS-4B
8/6/2013
TRcs
35.73896947
-111.3234651
6
12
601 OC DOD
Cobalt
mg/kg
8.9
U
NR
457-SS-4B
8/6/2013
TRcs
35.73896947
-111.3234651
6
12
601 OC DOD
Copper
mg/kg
7.5
JD
NR
457-SS-4B
8/6/2013
TRcs
35.73896947
-111.3234651
6
12
601 OC DOD
Iron
mg/kg
13,000
D
NR
457-SS-4B
8/6/2013
TRcs
35.73896947
-111.3234651
6
12
601 OC DOD
Lead
mg/kg
7.5
JD
NR
457-SS-4B
8/6/2013
TRcs
35.73896947
-111.3234651
6
12
601 OC DOD
Manganese
mg/kg
190
D
NR
457-SS-4B
8/6/2013
TRcs
35.73896947
-111.3234651
6
12
601 OC DOD
Mercury
mg/kg
0.012
J
NR
457-SS-4B
8/6/2013
TRcs
35.73896947
-111.3234651
6
12
601 OC DOD
Molybdenum
mg/kg
9.5
U
NR
457-SS-4B
8/6/2013
TRcs
35.73896947
-111.3234651
6
12
601 OC DOD
Nickel
mg/kg
9.3
JD
NR
457-SS-4B
8/6/2013
TRcs
35.73896947
-111.3234651
6
12
GA-01-R
Radium-226
pCi/g
1.93
NR
457-SS-4B
8/6/2013
TRcs
35.73896947
-111.3234651
6
12
601 OC DOD
Selenium
mg/kg
2.8
U
NR
457-SS-4B
8/6/2013
TRcs
35.73896947
-111.3234651
6
12
601 OC DOD
Silver
mg/kg
2.2
U
NR
457-SS-4B
8/6/2013
TRcs
35.73896947
-111.3234651
6
12
601 OC DOD
Thallium
mg/kg
14
U
NR
457-SS-4B
8/6/2013
TRcs
35.73896947
-111.3234651
6
12
601 OC DOD
Uranium
mg/kg
100
U
NR
457-SS-4B
8/6/2013
TRcs
35.73896947
-111.3234651
6
12
601 OC DOD
Vanadium
mg/kg
28
JD
NR
457-SS-4B
8/6/2013
TRcs
35.73896947
-111.3234651
6
12
601 OC DOD
Zinc
mg/kg
19
U
NR
457-SS-4C
8/6/2013
TRcs
35.73896947
-111.3234651
12
18
601 OC DOD
Aluminum
mg/kg
3,800
D
NR
457-SS-4C
8/6/2013
TRcs
35.73896947
-111.3234651
12
18
601 OC DOD
Antimony
mg/kg
6.7
U
NR
457-SS-4C
8/6/2013
TRcs
35.73896947
-111.3234651
12
18
601 OC DOD
Arsenic
mg/kg
3.3
U
NR
457-SS-4C
8/6/2013
TRcs
35.73896947
-111.3234651
12
18
601 OC DOD
Barium
mg/kg
230
D
NR
457-SS-4C
8/6/2013
TRcs
35.73896947
-111.3234651
12
18
601 OC DOD
Beryllium
mg/kg
1.8
U
NR
457-SS-4C
8/6/2013
TRcs
35.73896947
-111.3234651
12
18
601 OC DOD
Cadmium
mg/kg
1
U
NR
457-SS-4C
8/6/2013
TRcs
35.73896947
-111.3234651
12
18
601 OC DOD
Chromium
mg/kg
5.9
JD
NR
457-SS-4C
8/6/2013
TRcs
35.73896947
-111.3234651
12
18
601 OC DOD
Cobalt
mg/kg
9.7
U
NR
457-SS-4C
8/6/2013
TRcs
35.73896947
-111.3234651
12
18
601 OC DOD
Copper
mg/kg
8.7
JD
NR
457-SS-4C
8/6/2013
TRcs
35.73896947
-111.3234651
12
18
601 OC DOD
Iron
mg/kg
15,000
D
NR
457-SS-4C
8/6/2013
TRcs
35.73896947
-111.3234651
12
18
601 OC DOD
Lead
mg/kg
6.3
JD
NR
457-SS-4C
8/6/2013
TRcs
35.73896947
-111.3234651
12
18
601 OC DOD
Manganese
mg/kg
250
D
NR
457-SS-4C
8/6/2013
TRcs
35.73896947
-111.3234651
12
18
601 OC DOD
Mercury
mg/kg
0.011
U
NR
457-SS-4C
8/6/2013
TRcs
35.73896947
-111.3234651
12
18
601 OC DOD
Molybdenum
mg/kg
10
U
NR
457-SS-4C
8/6/2013
TRcs
35.73896947
-111.3234651
12
18
601 OC DOD
Nickel
mg/kg
11
JD
NR
457-SS-4C
8/6/2013
TRcs
35.73896947
-111.3234651
12
18
GA-01 -R
Radium-226
pCi/g
1.07
NR
457-SS-4C
8/6/2013
TRcs
35.73896947
-111.3234651
12
18
601 OC DOD
Selenium
mg/kg
3
U
NR
457-SS-4C
8/6/2013
TRcs
35.73896947
-111.3234651
12
18
601 OC DOD
Silver
mg/kg
2.4
U
NR
457-SS-4C
8/6/2013
TRcs
35.73896947
-111.3234651
12
18
601 OC DOD
Thallium
mg/kg
16
U
NR
457-SS-4C
8/6/2013
TRcs
35.73896947
-111.3234651
12
18
601 OC DOD
Uranium
mg/kg
120
U
NR
457-SS-4C
8/6/2013
TRcs
35.73896947
-111.3234651
12
18
601 OC DOD
Vanadium
mg/kg
30
JD
NR
457-SS-4C
8/6/2013
TRcs
35.73896947
-111.3234651
12
18
601 OC DOD
Zinc
mg/kg
21
U
NR
457-SS-5A
8/6/2013
Qay
35.74002547
-111.3236841
0
6
601 OC DOD
Aluminum
mg/kg
3,200
D
NR
457-SS-5A
8/6/2013
Qay
35.74002547
-111.3236841
0
6
601 OC DOD
Antimony
mg/kg
6.4
U
NR
457-SS-5A
8/6/2013
Qay
35.74002547
-111.3236841
0
6
601 OC DOD
Arsenic
mg/kg
3.1
U
NR
457-SS-5A
8/6/2013
Qay
35.74002547
-111.3236841
0
6
601 OC DOD
Barium
mg/kg
250
D
NR
457-SS-5A
8/6/2013
Qay
35.74002547
-111.3236841
0
6
601 OC DOD
Beryllium
mg/kg
1.7
U
NR
457-SS-5A
8/6/2013
Qay
35.74002547
-111.3236841
0
6
601 OC DOD
Cadmium
mg/kg
0.99
U
NR
457-SS-5A
8/6/2013
Qay
35.74002547
-111.3236841
0
6
601 OC DOD
Chromium
mg/kg
4.1
JD
NR
457-SS-5A
8/6/2013
Qay
35.74002547
-111.3236841
0
6
601 OC DOD
Cobalt
mg/kg
11
JD
NR
457-SS-5A
8/6/2013
Qay
35.74002547
-111.3236841
0
6
601 OC DOD
Copper
mg/kg
8.6
JD
NR
457-SS-5A
8/6/2013
Qay
35.74002547
-111.3236841
0
6
601 OC DOD
Iron
mg/kg
15,000
D
NR
457-SS-5A
8/6/2013
Qay
35.74002547
-111.3236841
0
6
601 OC DOD
Lead
mg/kg
12
D
NR
457-SS-5A
8/6/2013
Qay
35.74002547
-111.3236841
0
6
601 OC DOD
Manganese
mg/kg
170
D
NR
457-SS-5A
8/6/2013
Qay
35.74002547
-111.3236841
0
6
601 OC DOD
Mercury
mg/kg
0.021
J
NR
457-SS-5A
8/6/2013
Qay
35.74002547
-111.3236841
0
6
601 OC DOD
Molybdenum
mg/kg
9.9
U
NR
457-SS-5A
8/6/2013
Qay
35.74002547
-111.3236841
0
6
601 OC DOD
Nickel
mg/kg
5.6
JD
NR
457-SS-5A
8/6/2013
Qay
35.74002547
-111.3236841
0
6
GA-01 -R
Radium-226
pCi/g
8.37
NR
457-SS-5A
8/6/2013
Qay
35.74002547
-111.3236841
0
6
601 OC DOD
Selenium
mg/kg
2.9
U
NR
457-SS-5A
8/6/2013
Qay
35.74002547
-111.3236841
0
6
601 OC DOD
Silver
mg/kg
2.3
U
NR
457-SS-5A
8/6/2013
Qay
35.74002547
-111.3236841
0
6
601 OC DOD
Thallium
mg/kg
15
U
NR
457-SS-5A
8/6/2013
Qay
35.74002547
-111.3236841
0
6
601 OC DOD
Uranium
mg/kg
130
U
NR
Page 4 of 20
-------
Attachment B-1. Data Used in the Risk Assessment
Sample ID
Sample
Date
Geologic
Unit
Latitude
Longitude
Sample
Top Depth
(inches bgs)
Sample
Bottom Depth
(inches bgs)
Analytical
Method
Analyte
Units
Result and
Qualifier
Reporting
Limit
457-SS-5A
8/6/2013
Qay
35.74002547
-
11.3236841
0
6
6010C DOD
Vanadium
mg/kg
35
JD
NR
457-SS-5A
8/6/2013
Qay
35.74002547
-
11.3236841
0
6
6010C DOD
Zinc
mg/kg
20
U
NR
457-SS-6A
8/6/2013
Qay
35.73950347
-
11.3240351
0
6
6010C DOD
Aluminum
mg/kg
3,000
D
NR
457-SS-6A
8/6/2013
Qay
35.73950347
-
11.3240351
0
6
6010C DOD
Antimony
mg/kg
5.8
U
NR
457-SS-6A
8/6/2013
Qay
35.73950347
-
11.3240351
0
6
6010C DOD
Arsenic
mg/kg
54
D
NR
457-SS-6A
8/6/2013
Qay
35.73950347
-
11.3240351
0
6
6010C DOD
Barium
mg/kg
390
D
NR
457-SS-6A
8/6/2013
Qay
35.73950347
-
11.3240351
0
6
6010C DOD
Beryllium
mg/kg
1.5
U
NR
457-SS-6A
8/6/2013
Qay
35.73950347
-
11.3240351
0
6
6010C DOD
Cadmium
mg/kg
0.91
U
NR
457-SS-6A
8/6/2013
Qay
35.73950347
-
11.3240351
0
6
601OC DOD
Chromium
mg/kg
3.5
JD
NR
457-SS-6A
8/6/2013
Qay
35.73950347
-
11.3240351
0
6
601OC DOD
Cobalt
mg/kg
9.4
JD
NR
457-SS-6A
8/6/2013
Qay
35.73950347
-
11.3240351
0
6
601 OC DOD
Copper
mg/kg
16
JD
NR
457-SS-6A
8/6/2013
Qay
35.73950347
-
11.3240351
0
6
601 OC DOD
Iron
mg/kg
13,000
D
NR
457-SS-6A
8/6/2013
Qay
35.73950347
-
11.3240351
0
6
601 OC DOD
Lead
mg/kg
52
D
NR
457-SS-6A
8/6/2013
Qay
35.73950347
-
11.3240351
0
6
601 OC DOD
Manganese
mg/kg
180
D
NR
457-SS-6A
8/6/2013
Qay
35.73950347
-
11.3240351
0
6
601 OC DOD
Mercury
mg/kg
0.8
NR
457-SS-6A
8/6/2013
Qay
35.73950347
-
11.3240351
0
6
601 OC DOD
Molybdenum
mg/kg
650
D
NR
457-SS-6A
8/6/2013
Qay
35.73950347
-
11.3240351
0
6
601 OC DOD
Nickel
mg/kg
7.7
JD
NR
457-SS-6A
8/6/2013
Qay
35.73950347
-
11.3240351
0
6
GA-01 -R
Radium-226
pCi/g
382
NR
457-SS-6A
8/6/2013
Qay
35.73950347
-
11.3240351
0
6
601 OC DOD
Selenium
mg/kg
2.6
U
NR
457-SS-6A
8/6/2013
Qay
35.73950347
-
11.3240351
0
6
601 OC DOD
Silver
mg/kg
2.1
U
NR
457-SS-6A
8/6/2013
Qay
35.73950347
-
11.3240351
0
6
601 OC DOD
Thallium
mg/kg
14
U
NR
457-SS-6A
8/6/2013
Qay
35.73950347
-
11.3240351
0
6
601 OC DOD
Uranium
mg/kg
350
U
NR
457-SS-6A
8/6/2013
Qay
35.73950347
-
11.3240351
0
6
601 OC DOD
Vanadium
mg/kg
57
D
NR
457-SS-6A
8/6/2013
Qay
35.73950347
-
11.3240351
0
6
601 OC DOD
Zinc
mg/kg
58
JD
NR
457-SS-7A
8/6/2013
Qay
35.73981447
-
11.3238291
0
6
601 OC DOD
Aluminum
mg/kg
5,900
D
NR
457-SS-7A
8/6/2013
Qay
35.73981447
-
11.3238291
0
6
601 OC DOD
Antimony
mg/kg
6.4
U
NR
457-SS-7A
8/6/2013
Qay
35.73981447
-
11.3238291
0
6
601 OC DOD
Arsenic
mg/kg
230
D
NR
457-SS-7A
8/6/2013
Qay
35.73981447
-
11.3238291
0
6
601 OC DOD
Barium
mg/kg
1,100
D
NR
457-SS-7A
8/6/2013
Qay
35.73981447
-
11.3238291
0
6
601 OC DOD
Beryllium
mg/kg
1.7
U
NR
457-SS-7A
8/6/2013
Qay
35.73981447
-
11.3238291
0
6
601 OC DOD
Cadmium
mg/kg
1
JD
NR
457-SS-7A
8/6/2013
Qay
35.73981447
-
11.3238291
0
6
601 OC DOD
Chromium
mg/kg
8
JD
NR
457-SS-7A
8/6/2013
Qay
35.73981447
-
11.3238291
0
6
601 OC DOD
Cobalt
mg/kg
23
JD
NR
457-SS-7A
8/6/2013
Qay
35.73981447
-
11.3238291
0
6
601 OC DOD
Copper
mg/kg
37
D
NR
457-SS-7A
8/6/2013
Qay
35.73981447
-
11.3238291
0
6
601 OC DOD
Iron
mg/kg
18,000
D
NR
457-SS-7A
8/6/2013
Qay
35.73981447
-
11.3238291
0
6
601 OC DOD
Lead
mg/kg
150
D
NR
457-SS-7A
8/6/2013
Qay
35.73981447
-
11.3238291
0
6
601 OC DOD
Manganese
mg/kg
110
D
NR
457-SS-7A
8/6/2013
Qay
35.73981447
-
11.3238291
0
6
601 OC DOD
Mercury
mg/kg
1.3
NR
457-SS-7A
8/6/2013
Qay
35.73981447
-
11.3238291
0
6
601 OC DOD
Molybdenum
mg/kg
2,000
D
NR
457-SS-7A
8/6/2013
Qay
35.73981447
-
11.3238291
0
6
601 OC DOD
Nickel
mg/kg
11
JD
NR
457-SS-7A
8/6/2013
Qay
35.73981447
-
11.3238291
0
6
GA-01 -R
Radium-226
pCi/g
945
NR
457-SS-7A
8/6/2013
Qay
35.73981447
-
11.3238291
0
6
601 OC DOD
Selenium
mg/kg
3.4
JD
NR
457-SS-7A
8/6/2013
Qay
35.73981447
-
11.3238291
0
6
601 OC DOD
Silver
mg/kg
2.3
U
NR
457-SS-7A
8/6/2013
Qay
35.73981447
-
11.3238291
0
6
601 OC DOD
Thallium
mg/kg
26
JD
NR
457-SS-7A
8/6/2013
Qay
35.73981447
-
11.3238291
0
6
601 OC DOD
Uranium
mg/kg
970
D
NR
457-SS-7A
8/6/2013
Qay
35.73981447
-
11.3238291
0
6
601 OC DOD
Vanadium
mg/kg
390
D
NR
457-SS-7A
8/6/2013
Qay
35.73981447
-
11.3238291
0
6
601 OC DOD
Zinc
mg/kg
66
JD
NR
457-SS-8A
8/6/2013
Qay
35.73962753
-
11.3237631
0
6
601 OC DOD
Aluminum
mg/kg
6,600
D
NR
457-SS-8A
8/6/2013
Qay
35.73962753
-
11.3237631
0
6
601 OC DOD
Antimony
mg/kg
6.1
U
NR
457-SS-8A
8/6/2013
Qay
35.73962753
-
11.3237631
0
6
601 OC DOD
Arsenic
mg/kg
98
D
NR
457-SS-8A
8/6/2013
Qay
35.73962753
-
11.3237631
0
6
601 OC DOD
Barium
mg/kg
590
D
NR
457-SS-8A
8/6/2013
Qay
35.73962753
-
11.3237631
0
6
601 OC DOD
Beryllium
mg/kg
1.6
U
NR
457-SS-8A
8/6/2013
Qay
35.73962753
-
11.3237631
0
6
601 OC DOD
Cadmium
mg/kg
0.95
U
NR
457-SS-8A
8/6/2013
Qay
35.73962753
-
11.3237631
0
6
601 OC DOD
Chromium
mg/kg
7.1
JD
NR
457-SS-8A
8/6/2013
Qay
35.73962753
-
11.3237631
0
6
601 OC DOD
Cobalt
mg/kg
15
JD
NR
457-SS-8A
8/6/2013
Qay
35.73962753
-
11.3237631
0
6
601 OC DOD
Copper
mg/kg
21
JD
NR
457-SS-8A
8/6/2013
Qay
35.73962753
-
11.3237631
0
6
601 OC DOD
Iron
mg/kg
15,000
D
NR
457-SS-8A
8/6/2013
Qay
35.73962753
-
11.3237631
0
6
601 OC DOD
Lead
mg/kg
77
D
NR
457-SS-8A
8/6/2013
Qay
35.73962753
-
11.3237631
0
6
601 OC DOD
Manganese
mg/kg
170
D
NR
457-SS-8A
8/6/2013
Qay
35.73962753
-
11.3237631
0
6
601 OC DOD
Mercury
mg/kg
8.7
NR
457-SS-8A
8/6/2013
Qay
35.73962753
-
11.3237631
0
6
601 OC DOD
Molybdenum
mg/kg
960
D
NR
457-SS-8A
8/6/2013
Qay
35.73962753
-
11.3237631
0
6
601 OC DOD
Nickel
mg/kg
9.7
JD
NR
457-SS-8A
8/6/2013
Qay
35.73962753
-
11.3237631
0
6
GA-01-R
Radium-226
pCi/g
747
NR
457-SS-8A
8/6/2013
Qay
35.73962753
-
11.3237631
0
6
601 OC DOD
Selenium
mg/kg
2.7
U
NR
457-SS-8A
8/6/2013
Qay
35.73962753
-
11.3237631
0
6
601 OC DOD
Silver
mg/kg
2.2
U
NR
457-SS-8A
8/6/2013
Qay
35.73962753
-
11.3237631
0
6
601 OC DOD
Thallium
mg/kg
14
U
NR
457-SS-8A
8/6/2013
Qay
35.73962753
-
11.3237631
0
6
601 OC DOD
Uranium
mg/kg
470
U
NR
457-SS-8A
8/6/2013
Qay
35.73962753
-
11.3237631
0
6
601 OC DOD
Vanadium
mg/kg
210
D
NR
457-SS-8A
8/6/2013
Qay
35.73962753
-
11.3237631
0
6
601 OC DOD
Zinc
mg/kg
46
JD
NR
457-SS-9A
8/6/2013
TRcs
35.73946947
-
11.3231171
0
6
601 OC DOD
Aluminum
mg/kg
2,400
D
NR
457-SS-9A
8/6/2013
TRcs
35.73946947
-
11.3231171
0
6
601 OC DOD
Antimony
mg/kg
6.3
U
NR
457-SS-9A
8/6/2013
TRcs
35.73946947
-
11.3231171
0
6
601 OC DOD
Arsenic
mg/kg
19
D
NR
457-SS-9A
8/6/2013
TRcs
35.73946947
-
11.3231171
0
6
601 OC DOD
Barium
mg/kg
340
D
NR
457-SS-9A
8/6/2013
TRcs
35.73946947
-
11.3231171
0
6
601 OC DOD
Beryllium
mg/kg
1.7
U
NR
457-SS-9A
8/6/2013
TRcs
35.73946947
-
11.3231171
0
6
601 OC DOD
Cadmium
mg/kg
0.98
U
NR
457-SS-9A
8/6/2013
TRcs
35.73946947
-
11.3231171
0
6
601 OC DOD
Chromium
mg/kg
3
U
NR
457-SS-9A
8/6/2013
TRcs
35.73946947
-
11.3231171
0
6
601 OC DOD
Cobalt
mg/kg
9.2
U
NR
457-SS-9A
8/6/2013
TRcs
35.73946947
-
11.3231171
0
6
601 OC DOD
Copper
mg/kg
7.1
JD
NR
457-SS-9A
8/6/2013
TRcs
35.73946947
-
11.3231171
0
6
601 OC DOD
Iron
mg/kg
12,000
D
NR
457-SS-9A
8/6/2013
TRcs
35.73946947
-
11.3231171
0
6
601 OC DOD
Lead
mg/kg
26
D
NR
457-SS-9A
8/6/2013
TRcs
35.73946947
-
11.3231171
0
6
601 OC DOD
Manganese
mg/kg
230
D
NR
457-SS-9A
8/6/2013
TRcs
35.73946947
-
11.3231171
0
6
601 OC DOD
Mercury
mg/kg
0.037
NR
457-SS-9A
8/6/2013
TRcs
35.73946947
-
11.3231171
0
6
601 OC DOD
Molybdenum
mg/kg
140
D
NR
457-SS-9A
8/6/2013
TRcs
35.73946947
-
11.3231171
0
6
601 OC DOD
Nickel
mg/kg
5.5
JD
NR
457-SS-9A
8/6/2013
TRcs
35.73946947
-
11.3231171
0
6
GA-01 -R
Radium-226
pCi/g
27.2
NR
457-SS-9A
8/6/2013
TRcs
35.73946947
-
11.3231171
0
6
601 OC DOD
Selenium
mg/kg
2.8
U
NR
457-SS-9A
8/6/2013
TRcs
35.73946947
-
11.3231171
0
6
601 OC DOD
Silver
mg/kg
2.3
U
NR
457-SS-9A
8/6/2013
TRcs
35.73946947
-
11.3231171
0
6
601 OC DOD
Thallium
mg/kg
15
U
NR
457-SS-9A
8/6/2013
TRcs
35.73946947
-
11.3231171
0
6
601 OC DOD
Uranium
mg/kg
110
U
NR
Page 5 of 20
-------
Attachment B-1. Data Used in the Risk Assessment
Sample ID
Sample
Date
Geologic
Unit
Latitude
Longitude
Sample
Top Depth
(inches bgs)
Sample
Bottom Depth
(inches bgs)
Analytical
Method
Analyte
Units
Result and
Qualifier
Reporting
Limit
457-SS-9A
8/6/2013
TRcs
35.73946947
-
11.3231171
0
6
6010C DOD
Vanadium
mg/kg
26
JD
NR
457-SS-9A
8/6/2013
TRcs
35.73946947
-
11.3231171
0
6
6010C DOD
Zinc
mg/kg
19
U
NR
457-TP14-0-0.5-120318
12/3/2018
TRcp
35.73529905
-
11.3253575
0
6
SW6020
Arsenic
mg/kg
0.94
NR
457-TP14-0-0.5-120318
12/3/2018
TRcp
35.73529905
-
11.3253575
0
6
SW7471
Mercury
mg/kg
0.00006
U
NR
457-TP14-0-0.5-120318
12/3/2018
TRcp
35.73529905
-
11.3253575
0
6
SW6010
Molybdenum
mg/kg
0.58
J
NR
457-TP14-0-0.5-120318
12/3/2018
TRcp
35.73529905
-
11.3253575
0
6
713R14
Radium-226
pCi/g
2.94
M3
NR
457-TP14-0-0.5-120318
12/3/2018
TRcp
35.73529905
-
11.3253575
0
6
SW6010
Selenium
mg/kg
0.32
J
NR
457-TP14-0-0.5-120318
12/3/2018
TRcp
35.73529905
-
11.3253575
0
6
SW6020
Uranium
mg/kg
1.4
NR
457-TP14-0-0.5-120318
12/3/2018
TRcp
35.73529905
-
11.3253575
0
6
SW6010
Vanadium
mg/kg
4
NR
457-TP14-0-0.5-120318 DUP
12/3/2018
TRcp
35.73529905
-
11.3253575
0
6
SW6020
Arsenic
mg/kg
0.97
NR
457-TP14-0-0.5-120318 DUP
12/3/2018
TRcp
35.73529905
-
11.3253575
0
6
SW7471
Mercury
mg/kg
5.7E-05
U
NR
457-TP14-0-0.5-120318 DUP
12/3/2018
TRcp
35.73529905
-
11.3253575
0
6
SW6010
Molybdenum
mg/kg
0.55
J
NR
457-TP14-0-0.5-120318 DUP
12/3/2018
TRcp
35.73529905
-
11.3253575
0
6
713R14
Radium-226
pCi/g
2.93
M3
NR
457-TP14-0-0.5-120318 DUP
12/3/2018
TRcp
35.73529905
-
11.3253575
0
6
SW6010
Selenium
mg/kg
0.051
U
NR
457-TP14-0-0.5-120318 DUP
12/3/2018
TRcp
35.73529905
-
11.3253575
0
6
SW6020
Uranium
mg/kg
1.4
NR
457-TP14-0-0.5-120318 DUP
12/3/2018
TRcp
35.73529905
-
11.3253575
0
6
SW6010
Vanadium
mg/kg
3.6
NR
457-TP15-0.5-1.0-120618
12/6/2018
TRcs
35.73255134
-
11.3258167
6
12
SW6020
Arsenic
mg/kg
6.6
NR
457-TP15-0.5-1.0-120618
12/6/2018
TRcs
35.73255134
-
11.3258167
6
12
SW7471
Mercury
mg/kg
0.026
J
NR
457-TP15-0.5-1.0-120618
12/6/2018
TRcs
35.73255134
-
11.3258167
6
12
SW6010
Molybdenum
mg/kg
6.7
NR
457-TP15-0.5-1.0-120618
12/6/2018
TRcs
35.73255134
-
11.3258167
6
12
713R14
Radium-226
pCi/g
7.54
M3
NR
457-TP15-0.5-1.0-120618
12/6/2018
TRcs
35.73255134
-
11.3258167
6
12
SW6010
Selenium
mg/kg
0.055
U
NR
457-TP15-0.5-1.0-120618
12/6/2018
TRcs
35.73255134
-
11.3258167
6
12
SW6020
Uranium
mg/kg
5.7
NR
457-TP15-0.5-1.0-120618
12/6/2018
TRcs
35.73255134
-
11.3258167
6
12
SW6010
Vanadium
mg/kg
9.2
NR
457-TP15-0-0.5-120618
12/6/2018
TRcs
35.73255134
-
11.3258167
0
6
SW6020
Arsenic
mg/kg
9.9
NR
457-TP15-0-0.5-120618
12/6/2018
TRcs
35.73255134
-
11.3258167
0
6
SW7471
Mercury
mg/kg
0.02
J
NR
457-TP15-0-0.5-120618
12/6/2018
TRcs
35.73255134
-
11.3258167
0
6
SW6010
Molybdenum
mg/kg
30
NR
457-TP15-0-0.5-120618
12/6/2018
TRcs
35.73255134
-
11.3258167
0
6
713R14
Radium-226
pCi/g
8.2
M3
NR
457-TP15-0-0.5-120618
12/6/2018
TRcs
35.73255134
-
11.3258167
0
6
SW6010
Selenium
mg/kg
0.054
U
NR
457-TP15-0-0.5-120618
12/6/2018
TRcs
35.73255134
-
11.3258167
0
6
SW6020
Uranium
mg/kg
6.7
NR
457-TP15-0-0.5-120618
12/6/2018
TRcs
35.73255134
-
11.3258167
0
6
SW6010
Vanadium
mg/kg
15
NR
457-TP3-0-0.5-120418
12/4/2018
Qay
35.7409476
-
11.3247049
0
6
SW6020
Arsenic
mg/kg
14
NR
457-TP3-0-0.5-120418
12/4/2018
Qay
35.7409476
-
11.3247049
0
6
SW7471
Mercury
mg/kg
0.015
J
NR
457-TP3-0-0.5-120418
12/4/2018
Qay
35.7409476
-
11.3247049
0
6
SW6010
Molybdenum
mg/kg
35
NR
457-TP3-0-0.5-120418
12/4/2018
Qay
35.7409476
-
11.3247049
0
6
713R14
Radium-226
pCi/g
12.1
M3
NR
457-TP3-0-0.5-120418
12/4/2018
Qay
35.7409476
-
11.3247049
0
6
SW6010
Selenium
mg/kg
0.092
J
NR
457-TP3-0-0.5-120418
12/4/2018
Qay
35.7409476
-
11.3247049
0
6
SW6020
Uranium
mg/kg
8
NR
457-TP3-0-0.5-120418
12/4/2018
Qay
35.7409476
-
11.3247049
0
6
SW6010
Vanadium
mg/kg
27
NR
457-TP3-0-0.5-120418 DUP
12/4/2018
Qay
35.7409476
-
11.3247049
0
6
SW6020
Arsenic
mg/kg
17
NR
457-TP3-0-0.5-120418 DUP
12/4/2018
Qay
35.7409476
-
11.3247049
0
6
SW7471
Mercury
mg/kg
0.018
J
NR
457-TP3-0-0.5-120418 DUP
12/4/2018
Qay
35.7409476
-
11.3247049
0
6
SW6010
Molybdenum
mg/kg
25
NR
457-TP3-0-0.5-120418 DUP
12/4/2018
Qay
35.7409476
-
11.3247049
0
6
713R14
Radium-226
pCi/g
12.5
M3
NR
457-TP3-0-0.5-120418 DUP
12/4/2018
Qay
35.7409476
-
11.3247049
0
6
SW6010
Selenium
mg/kg
0.054
U
NR
457-TP3-0-0.5-120418 DUP
12/4/2018
Qay
35.7409476
-
11.3247049
0
6
SW6020
Uranium
mg/kg
19
NR
457-TP3-0-0.5-120418 DUP
12/4/2018
Qay
35.7409476
-
11.3247049
0
6
SW6010
Vanadium
mg/kg
24
NR
457-TP4-2.0-2.5-120418
12/4/2018
Qay
35.74010083
-
11.3234451
24
30
SW6020
Arsenic
mg/kg
2.4
NR
457-TP4-2.0-2.5-120418
12/4/2018
Qay
35.74010083
-
11.3234451
24
30
SW7471
Mercury
mg/kg
0.0095
J
NR
457-TP4-2.0-2.5-120418
12/4/2018
Qay
35.74010083
-
11.3234451
24
30
SW6010
Molybdenum
mg/kg
4.3
NR
457-TP4-2.0-2.5-120418
12/4/2018
Qay
35.74010083
-
11.3234451
24
30
713R14
Radium-226
pCi/g
5.92
M3
NR
457-TP4-2.0-2.5-120418
12/4/2018
Qay
35.74010083
-
11.3234451
24
30
SW6010
Selenium
mg/kg
0.053
U
NR
457-TP4-2.0-2.5-120418
12/4/2018
Qay
35.74010083
-
11.3234451
24
30
SW6020
Uranium
mg/kg
5.6
NR
457-TP4-2.0-2.5-120418
12/4/2018
Qay
35.74010083
-
11.3234451
24
30
SW6010
Vanadium
mg/kg
29
NR
457-TP4-3.0-3.5-120418
12/4/2018
Qay
35.74010083
-
11.3234451
36
42
SW6020
Arsenic
mg/kg
2
NR
457-TP4-3.0-3.5-120418
12/4/2018
Qay
35.74010083
-
11.3234451
36
42
SW7471
Mercury
mg/kg
0.00006
U
NR
457-TP4-3.0-3.5-120418
12/4/2018
Qay
35.74010083
-
11.3234451
36
42
SW6010
Molybdenum
mg/kg
2.8
NR
457-TP4-3.0-3.5-120418
12/4/2018
Qay
35.74010083
-
11.3234451
36
42
713R14
Radium-226
pCi/g
2.46
M3
NR
457-TP4-3.0-3.5-120418
12/4/2018
Qay
35.74010083
-
11.3234451
36
42
SW6010
Selenium
mg/kg
0.054
U
NR
457-TP4-3.0-3.5-120418
12/4/2018
Qay
35.74010083
-
11.3234451
36
42
SW6020
Uranium
mg/kg
3.4
NR
457-TP4-3.0-3.5-120418
12/4/2018
Qay
35.74010083
-
11.3234451
36
42
SW6010
Vanadium
mg/kg
22
NR
457-TP5-0.5-1.0-120418
12/4/2018
TRcp
35.73956684
-
11.3249528
6
12
SW6020
Arsenic
mg/kg
2.4
NR
457-TP5-0.5-1.0-120418
12/4/2018
TRcp
35.73956684
-
11.3249528
6
12
SW7471
Mercury
mg/kg
6.4E-05
U
NR
457-TP5-0.5-1.0-120418
12/4/2018
TRcp
35.73956684
-
11.3249528
6
12
SW6010
Molybdenum
mg/kg
1.4
NR
457-TP5-0.5-1.0-120418
12/4/2018
TRcp
35.73956684
-
11.3249528
6
12
713R14
Radium-226
pCi/g
1.93
M3
NR
457-TP5-0.5-1.0-120418
12/4/2018
TRcp
35.73956684
-
11.3249528
6
12
SW6010
Selenium
mg/kg
0.18
J
NR
457-TP5-0.5-1.0-120418
12/4/2018
TRcp
35.73956684
-
11.3249528
6
12
SW6020
Uranium
mg/kg
2
NR
457-TP5-0.5-1.0-120418
12/4/2018
TRcp
35.73956684
-
11.3249528
6
12
SW6010
Vanadium
mg/kg
39
NR
457-TP5-0-0.5-120418
12/4/2018
TRcp
35.73956684
-
11.3249528
0
6
SW6020
Arsenic
mg/kg
2.6
NR
457-TP5-0-0.5-120418
12/4/2018
TRcp
35.73956684
-
11.3249528
0
6
SW7471
Mercury
mg/kg
6.4E-05
U
NR
457-TP5-0-0.5-120418
12/4/2018
TRcp
35.73956684
-
11.3249528
0
6
SW6010
Molybdenum
mg/kg
3.6
NR
457-TP5-0-0.5-120418
12/4/2018
TRcp
35.73956684
-
11.3249528
0
6
713R14
Radium-226
pCi/g
3
M3
NR
457-TP5-0-0.5-120418
12/4/2018
TRcp
35.73956684
-
11.3249528
0
6
SW6010
Selenium
mg/kg
0.055
U
NR
457-TP5-0-0.5-120418
12/4/2018
TRcp
35.73956684
-
11.3249528
0
6
SW6020
Uranium
mg/kg
4.5
NR
457-TP5-0-0.5-120418
12/4/2018
TRcp
35.73956684
-
11.3249528
0
6
SW6010
Vanadium
mg/kg
39
NR
457-TP6-0-0.5-120418
12/4/2018
Qay
35.73988842
-
11.3231471
0
6
SW6020
Arsenic
mg/kg
2
NR
457-TP6-0-0.5-120418
12/4/2018
Qay
35.73988842
-
11.3231471
0
6
SW7471
Mercury
mg/kg
5.8E-05
U
NR
457-TP6-0-0.5-120418
12/4/2018
Qay
35.73988842
-
11.3231471
0
6
SW6010
Molybdenum
mg/kg
3
NR
457-TP6-0-0.5-120418
12/4/2018
Qay
35.73988842
-
11.3231471
0
6
713R14
Radium-226
pCi/g
1.76
M3
NR
457-TP6-0-0.5-120418
12/4/2018
Qay
35.73988842
-
11.3231471
0
6
SW6010
Selenium
mg/kg
0.26
J
NR
457-TP6-0-0.5-120418
12/4/2018
Qay
35.73988842
-
11.3231471
0
6
SW6020
Uranium
mg/kg
2.7
NR
457-TP6-0-0.5-120418
12/4/2018
Qay
35.73988842
-
11.3231471
0
6
SW6010
Vanadium
mg/kg
27
NR
457-TP6-1.0-1.5-120418
12/4/2018
Qay
35.73988842
-
11.3231471
12
18
SW6020
Arsenic
mg/kg
1.8
NR
457-TP6-1.0-1.5-120418
12/4/2018
Qay
35.73988842
-
11.3231471
12
18
SW7471
Mercury
mg/kg
6.1E-05
U
NR
457-TP6-1.0-1.5-120418
12/4/2018
Qay
35.73988842
-
11.3231471
12
18
SW6010
Molybdenum
mg/kg
0.71
J
NR
457-TP6-1.0-1.5-120418
12/4/2018
Qay
35.73988842
-
11.3231471
12
18
713R14
Radium-226
pCi/g
1.61
M3
NR
457-TP6-1.0-1.5-120418
12/4/2018
Qay
35.73988842
-
11.3231471
12
18
SW6010
Selenium
mg/kg
0.048
U
NR
457-TP6-1.0-1.5-120418
12/4/2018
Qay
35.73988842
-
11.3231471
12
18
SW6020
Uranium
mg/kg
1.6
NR
457-TP6-1.0-1.5-120418
12/4/2018
Qay
35.73988842
-
11.3231471
12
18
SW6010
Vanadium
mg/kg
32
NR
458-SS01-01-020624
2/6/2024
TRcs
35.73049648
-
11.3311852
0
6
SW6020B
Aluminum
mg/kg
4,540
9240
458-SS01-01-020624
2/6/2024
TRcs
35.73049648
-
11.3311852
0
6
SW6010D
Antimony
mg/kg
1.89
U
1890
Page 6 of 20
-------
Attachment B-1. Data Used in the Risk Assessment
Sample ID
Sample
Date
Geologic
Unit
Latitude
Longitude
Sample
Top Depth
(inches bgs)
Sample
Bottom Depth
(inches bgs)
Analytical
Method
Analyte
Units
Result and
Qualifier
Reporting
Limit
458-SS01 -01 -020624
2/6/2024
TRcs
35.73049648
-111.3311852
0
6
SW6020B
Arsenic
mg/kg
22.7
N
924
458-SS01 -01 -020624
2/6/2024
TRcs
35.73049648
-111.3311852
0
6
SW6020B
Barium
mg/kg
314
*
7390
458-SS01-01-020624
2/6/2024
TRcs
35.73049648
-111.3311852
0
6
SW6020B
Beryllium
mg/kg
1.16
92.4
458-SS01-01-020624
2/6/2024
TRcs
35.73049648
-111.3311852
0
6
SW6020B
Cadmium
mg/kg
0.252
185
458-SS01 -01 -020624
2/6/2024
TRcs
35.73049648
-111.3311852
0
6
SW6020B
Chromium
mg/kg
6.58
555
458-SS01-01-020624
2/6/2024
TRcs
35.73049648
-111.3311852
0
6
SW6020B
Cobalt
mg/kg
2.93
N
185
458-SS01-01-020624
2/6/2024
TRcs
35.73049648
-111.3311852
0
6
SW6020B
Copper
mg/kg
9.46
N*
370
458-SS01 -01 -020624
2/6/2024
TRcs
35.73049648
-111.3311852
0
6
SW6020B
Iron
mg/kg
9,170
18500
458-SS01-01-020624
2/6/2024
TRcs
35.73049648
-111.3311852
0
6
SW6020B
Lead
mg/kg
17.8
N
370
458-SS01-01-020624
2/6/2024
TRcs
35.73049648
-111.3311852
0
6
SW6020B
Manganese
mg/kg
30.3
*
924
458-SS01-01-020624
2/6/2024
TRcs
35.73049648
-111.3311852
0
6
SW7471B
Mercury
mg/kg
0.204
21.2
458-SS01-01-020624
2/6/2024
TRcs
35.73049648
-111.3311852
0
6
SW6020B
Molybdenum
mg/kg
173
N
185
458-SS01-01-020624
2/6/2024
TRcs
35.73049648
-111.3311852
0
6
SW6020B
Nickel
mg/kg
3.04
N
370
458-SS01-01-020624
2/6/2024
TRcs
35.73049648
-111.3311852
0
6
EH300
Radium-226
pCi/g
30.9
0.292
458-SS01-01-020624
2/6/2024
TRcs
35.73049648
-111.3311852
0
6
SW6020B
Selenium
mg/kg
1.47
N*
924
458-SS01-01-020624
2/6/2024
TRcs
35.73049648
-111.3311852
0
6
SW6010D
Silver
mg/kg
0.473
U
473
458-SS01-01-020624
2/6/2024
TRcs
35.73049648
-111.3311852
0
6
SW6020B
Thallium
mg/kg
5.21
370
458-SS01-01-020624
2/6/2024
TRcs
35.73049648
-111.3311852
0
6
SW6020B
Uranium
mg/kg
41.5
N
37
458-SS01-01-020624
2/6/2024
TRcs
35.73049648
-111.3311852
0
6
SW6020B
Vanadium
mg/kg
12.6
3700
458-SS01-01-020624
2/6/2024
TRcs
35.73049648
-111.3311852
0
6
SW6020B
Zinc
mg/kg
8.39
N
3700
458-SS02-01-020624
2/6/2024
TRcs
35.7302868
-111.3300088
0
6
SW6020B
Aluminum
mg/kg
3,320
9400
458-SS02-01-020624
2/6/2024
TRcs
35.7302868
-111.3300088
0
6
SW6010D
Antimony
mg/kg
1.94
U
1940
458-SS02-01-020624
2/6/2024
TRcs
35.7302868
-111.3300088
0
6
SW6020B
Arsenic
mg/kg
22.4
N
940
458-SS02-01-020624
2/6/2024
TRcs
35.7302868
-111.3300088
0
6
SW6020B
Barium
mg/kg
256
*
7520
458-SS02-01-020624
2/6/2024
TRcs
35.7302868
-111.3300088
0
6
SW6020B
Beryllium
mg/kg
0.641
94
458-SS02-01-020624
2/6/2024
TRcs
35.7302868
-111.3300088
0
6
SW6020B
Cadmium
mg/kg
0.2
188
458-SS02-01-020624
2/6/2024
TRcs
35.7302868
-111.3300088
0
6
SW6020B
Chromium
mg/kg
6.44
564
458-SS02-01-020624
2/6/2024
TRcs
35.7302868
-111.3300088
0
6
SW6020B
Cobalt
mg/kg
2.01
N
188
458-SS02-01-020624
2/6/2024
TRcs
35.7302868
-111.3300088
0
6
SW6020B
Copper
mg/kg
7.35
N*
376
458-SS02-01-020624
2/6/2024
TRcs
35.7302868
-111.3300088
0
6
SW6020B
Iron
mg/kg
8,120
18800
458-SS02-01-020624
2/6/2024
TRcs
35.7302868
-111.3300088
0
6
SW6020B
Lead
mg/kg
12.5
N
376
458-SS02-01-020624
2/6/2024
TRcs
35.7302868
-111.3300088
0
6
SW6020B
Manganese
mg/kg
19.5
*
940
458-SS02-01-020624
2/6/2024
TRcs
35.7302868
-111.3300088
0
6
SW7471B
Mercury
mg/kg
0.192
21
458-SS02-01-020624
2/6/2024
TRcs
35.7302868
-111.3300088
0
6
SW6020B
Molybdenum
mg/kg
141
N
188
458-SS02-01-020624
2/6/2024
TRcs
35.7302868
-111.3300088
0
6
SW6020B
Nickel
mg/kg
1.7
N
376
458-SS02-01-020624
2/6/2024
TRcs
35.7302868
-111.3300088
0
6
EH300
Radium-226
pCi/g
37.7
0.312
458-SS02-01-020624
2/6/2024
TRcs
35.7302868
-111.3300088
0
6
SW6020B
Selenium
mg/kg
1
N*
940
458-SS02-01-020624
2/6/2024
TRcs
35.7302868
-111.3300088
0
6
SW6010D
Silver
mg/kg
0.486
U
486
458-SS02-01-020624
2/6/2024
TRcs
35.7302868
-111.3300088
0
6
SW6020B
Thallium
mg/kg
5.61
376
458-SS02-01-020624
2/6/2024
TRcs
35.7302868
-111.3300088
0
6
SW6020B
Uranium
mg/kg
48.3
N
37.6
458-SS02-01-020624
2/6/2024
TRcs
35.7302868
-111.3300088
0
6
SW6020B
Vanadium
mg/kg
8.45
3760
458-SS02-01-020624
2/6/2024
TRcs
35.7302868
-111.3300088
0
6
SW6020B
Zinc
mg/kg
5.19
N
3760
458-SS03-01-020624
2/6/2024
TRcp
35.73063509
-111.3303975
0
6
SW6020B
Aluminum
mg/kg
1,810
9020
458-SS03-01-020624
2/6/2024
TRcp
35.73063509
-111.3303975
0
6
SW6010D
Antimony
mg/kg
1.82
U
1820
458-SS03-01-020624
2/6/2024
TRcp
35.73063509
-111.3303975
0
6
SW6020B
Arsenic
mg/kg
30.9
N
902
458-SS03-01-020624
2/6/2024
TRcp
35.73063509
-111.3303975
0
6
SW6020B
Barium
mg/kg
335
*
7220
458-SS03-01-020624
2/6/2024
TRcp
35.73063509
-111.3303975
0
6
SW6020B
Beryllium
mg/kg
0.289
90.2
458-SS03-01-020624
2/6/2024
TRcp
35.73063509
-111.3303975
0
6
SW6020B
Cadmium
mg/kg
0.329
180
458-SS03-01-020624
2/6/2024
TRcp
35.73063509
-111.3303975
0
6
SW6020B
Chromium
mg/kg
2.11
541
458-SS03-01-020624
2/6/2024
TRcp
35.73063509
-111.3303975
0
6
SW6020B
Cobalt
mg/kg
5.1
N
180
458-SS03-01-020624
2/6/2024
TRcp
35.73063509
-111.3303975
0
6
SW6020B
Copper
mg/kg
3.76
N*
361
458-SS03-01-020624
2/6/2024
TRcp
35.73063509
-111.3303975
0
6
SW6020B
Iron
mg/kg
3,290
18000
458-SS03-01-020624
2/6/2024
TRcp
35.73063509
-111.3303975
0
6
SW6020B
Lead
mg/kg
47.6
N
361
458-SS03-01-020624
2/6/2024
TRcp
35.73063509
-111.3303975
0
6
SW6020B
Manganese
mg/kg
19
*
902
458-SS03-01-020624
2/6/2024
TRcp
35.73063509
-111.3303975
0
6
SW7471B
Mercury
mg/kg
0.344
22.6
458-SS03-01-020624
2/6/2024
TRcp
35.73063509
-111.3303975
0
6
SW6020B
Molybdenum
mg/kg
78.6
N
180
458-SS03-01-020624
2/6/2024
TRcp
35.73063509
-111.3303975
0
6
SW6020B
Nickel
mg/kg
2.34
N
361
458-SS03-01-020624
2/6/2024
TRcp
35.73063509
-111.3303975
0
6
EH300
Radium-226
pCi/g
134
0.543
458-SS03-01-020624
2/6/2024
TRcp
35.73063509
-111.3303975
0
6
SW6020B
Selenium
mg/kg
1.35
N*
902
458-SS03-01-020624
2/6/2024
TRcp
35.73063509
-111.3303975
0
6
SW6010D
Silver
mg/kg
0.455
U
455
458-SS03-01-020624
2/6/2024
TRcp
35.73063509
-111.3303975
0
6
SW6020B
Thallium
mg/kg
1.17
361
458-SS03-01-020624
2/6/2024
TRcp
35.73063509
-111.3303975
0
6
SW6020B
Uranium
mg/kg
126
N
36.1
458-SS03-01-020624
2/6/2024
TRcp
35.73063509
-111.3303975
0
6
SW6020B
Vanadium
mg/kg
5.22
3610
458-SS03-01-020624
2/6/2024
TRcp
35.73063509
-111.3303975
0
6
SW6020B
Zinc
mg/kg
7.97
N
3610
458-SS04-01-020624
2/6/2024
TRcs
35.73040801
-111.3308695
0
6
SW6020B
Aluminum
mg/kg
3,730
9870
458-SS04-01-020624
2/6/2024
TRcs
35.73040801
-111.3308695
0
6
SW6010D
Antimony
mg/kg
1.76
U
1760
458-SS04-01-020624
2/6/2024
TRcs
35.73040801
-111.3308695
0
6
SW6020B
Arsenic
mg/kg
17.6
N
987
458-SS04-01-020624
2/6/2024
TRcs
35.73040801
-111.3308695
0
6
SW6020B
Barium
mg/kg
234
*
7900
458-SS04-01-020624
2/6/2024
TRcs
35.73040801
-111.3308695
0
6
SW6020B
Beryllium
mg/kg
0.652
98.7
458-SS04-01-020624
2/6/2024
TRcs
35.73040801
-111.3308695
0
6
SW6020B
Cadmium
mg/kg
0.316
197
458-SS04-01-020624
2/6/2024
TRcs
35.73040801
-111.3308695
0
6
SW6020B
Chromium
mg/kg
3.68
592
458-SS04-01-020624
2/6/2024
TRcs
35.73040801
-111.3308695
0
6
SW6020B
Cobalt
mg/kg
3.18
N
197
458-SS04-01-020624
2/6/2024
TRcs
35.73040801
-111.3308695
0
6
SW6020B
Copper
mg/kg
7.74
N*
395
458-SS04-01-020624
2/6/2024
TRcs
35.73040801
-111.3308695
0
6
SW6020B
Iron
mg/kg
5,010
19700
458-SS04-01 -020624
2/6/2024
TRcs
35.73040801
-111.3308695
0
6
SW6020B
Lead
mg/kg
21
N
395
458-SS04-01-020624
2/6/2024
TRcs
35.73040801
-111.3308695
0
6
SW6020B
Manganese
mg/kg
91.2
*
987
458-SS04-01 -020624
2/6/2024
TRcs
35.73040801
-111.3308695
0
6
SW7471B
Mercury
mg/kg
0.156
22.9
458-SS04-01-020624
2/6/2024
TRcs
35.73040801
-111.3308695
0
6
SW6020B
Molybdenum
mg/kg
191
N
1970
458-SS04-01-020624
2/6/2024
TRcs
35.73040801
-111.3308695
0
6
SW6020B
Nickel
mg/kg
3.44
N
395
458-SS04-01-020624
2/6/2024
TRcs
35.73040801
-111.3308695
0
6
EH300
Radium-226
pCi/g
48.3
0.375
458-SS04-01-020624
2/6/2024
TRcs
35.73040801
-111.3308695
0
6
SW6020B
Selenium
mg/kg
1.06
N*
987
458-SS04-01-020624
2/6/2024
TRcs
35.73040801
-111.3308695
0
6
SW6010D
Silver
mg/kg
0.208
J-
439
458-SS04-01-020624
2/6/2024
TRcs
35.73040801
-111.3308695
0
6
SW6020B
Thallium
mg/kg
3.88
395
458-SS04-01-020624
2/6/2024
TRcs
35.73040801
-111.3308695
0
6
SW6020B
Uranium
mg/kg
108
N
39.5
458-SS04-01-020624
2/6/2024
TRcs
35.73040801
-111.3308695
0
6
SW6020B
Vanadium
mg/kg
14.9
3950
458-SS04-01 -020624
2/6/2024
TRcs
35.73040801
-111.3308695
0
6
SW6020B
Zinc
mg/kg
9.97
N
3950
458-SS05-01-020624
2/6/2024
TRcp
35.72990332
-111.3307021
0
6
SW6020B
Aluminum
mg/kg
6,930
8730
458-SS05-01-020624
2/6/2024
TRcp
35.72990332
-111.3307021
0
6
SW6010D
Antimony
mg/kg
1.81
U
1810
Page 7 of 20
-------
Attachment B-1. Data Used in the Risk Assessment
Sample ID
Sample
Date
Geologic
Unit
Latitude
Longitude
Sample
Top Depth
(inches bgs)
Sample
Bottom Depth
(inches bgs)
Analytical
Method
Analyte
Units
Result and
Qualifier
Reporting
Limit
458-SS05-01 -020624
2/6/2024
TRcp
35.72990332
-
11.3307021
0
6
SW6020B
Arsenic
mg/kg
1.09
N
873
458-SS05-01 -020624
2/6/2024
TRcp
35.72990332
-
11.3307021
0
6
SW6020B
Barium
mg/kg
56.9
*
698
458-SS05-01-020624
2/6/2024
TRcp
35.72990332
-
11.3307021
0
6
SW6020B
Beryllium
mg/kg
1.68
87.3
458-SS05-01-020624
2/6/2024
TRcp
35.72990332
-
11.3307021
0
6
SW6020B
Cadmium
mg/kg
0.0555
J
175
458-SS05-01 -020624
2/6/2024
TRcp
35.72990332
-
11.3307021
0
6
SW6020B
Chromium
mg/kg
4.81
524
458-SS05-01-020624
2/6/2024
TRcp
35.72990332
-
11.3307021
0
6
SW6020B
Cobalt
mg/kg
4.41
N
175
458-SS05-01-020624
2/6/2024
TRcp
35.72990332
-
11.3307021
0
6
SW6020B
Copper
mg/kg
9.98
N*
349
458-SS05-01 -020624
2/6/2024
TRcp
35.72990332
-
11.3307021
0
6
SW6020B
Iron
mg/kg
1,680
17500
458-SS05-01-020624
2/6/2024
TRcp
35.72990332
-
11.3307021
0
6
SW6020B
Lead
mg/kg
29.1
N
349
458-SS05-01-020624
2/6/2024
TRcp
35.72990332
-
11.3307021
0
6
SW6020B
Manganese
mg/kg
35.9
*
873
458-SS05-01-020624
2/6/2024
TRcp
35.72990332
-
11.3307021
0
6
SW7471B
Mercury
mg/kg
0.037
23.1
458-SS05-01-020624
2/6/2024
TRcp
35.72990332
-
11.3307021
0
6
SW6020B
Molybdenum
mg/kg
0.228
N
175
458-SS05-01-020624
2/6/2024
TRcp
35.72990332
-
11.3307021
0
6
SW6020B
Nickel
mg/kg
2.78
N
349
458-SS05-01-020624
2/6/2024
TRcp
35.72990332
-
11.3307021
0
6
EH300
Radium-226
pCi/g
12.2
0.264
458-SS05-01-020624
2/6/2024
TRcp
35.72990332
-
11.3307021
0
6
SW6020B
Selenium
mg/kg
2.16
N*
873
458-SS05-01-020624
2/6/2024
TRcp
35.72990332
-
11.3307021
0
6
SW6010D
Silver
mg/kg
0.453
U
453
458-SS05-01-020624
2/6/2024
TRcp
35.72990332
-
11.3307021
0
6
SW6020B
Thallium
mg/kg
0.349
U
349
458-SS05-01-020624
2/6/2024
TRcp
35.72990332
-
11.3307021
0
6
SW6020B
Uranium
mg/kg
15.9
N
34.9
458-SS05-01-020624
2/6/2024
TRcp
35.72990332
-
11.3307021
0
6
SW6020B
Vanadium
mg/kg
12.7
3490
458-SS05-01-020624
2/6/2024
TRcp
35.72990332
-
11.3307021
0
6
SW6020B
Zinc
mg/kg
11.7
N
3490
458-SS06-01-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Aluminum
mg/kg
4,530
9250
458-SS06-01-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6010D
Antimony
mg/kg
1.76
U
1760
458-SS06-01-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Arsenic
mg/kg
21.7
N
925
458-SS06-01-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Barium
mg/kg
273
J
7400
458-SS06-01-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Beryllium
mg/kg
0.818
92.5
458-SS06-01-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Cadmium
mg/kg
0.247
185
458-SS06-01-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Chromium
mg/kg
5.93
555
458-SS06-01-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Cobalt
mg/kg
3.8
N
185
458-SS06-01-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Copper
mg/kg
10.2
N*
370
458-SS06-01-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Iron
mg/kg
7,880
18500
458-SS06-01-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Lead
mg/kg
12.9
N
370
458-SS06-01-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Manganese
mg/kg
19.7
*
925
458-SS06-01-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW7471B
Mercury
mg/kg
0.111
J
23.8
458-SS06-01-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Molybdenum
mg/kg
126
N
185
458-SS06-01-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Nickel
mg/kg
2.88
N
370
458-SS06-01-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
EH 300
Radium-226
pCi/g
29.3
J
0.304
458-SS06-01-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Selenium
mg/kg
2.32
J
925
458-SS06-01-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6010D
Silver
mg/kg
0.441
U
441
458-SS06-01-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Thallium
mg/kg
2.68
370
458-SS06-01-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Uranium
mg/kg
44
J
37
458-SS06-01-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Vanadium
mg/kg
14.2
3700
458-SS06-01-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Zinc
mg/kg
9.15
N
3700
458-S S06-02-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Aluminum
mg/kg
4,420
9970
458-S S06-02-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6010D
Antimony
mg/kg
1.84
U
1840
458-S S06-02-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Arsenic
mg/kg
21.1
997
458-S S06-02-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Barium
mg/kg
173
J
797
458-S S06-02-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Beryllium
mg/kg
0.928
99.7
458-S S06-02-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Cadmium
mg/kg
0.251
199
458-S S06-02-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Chromium
mg/kg
5.54
598
458-S S06-02-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Cobalt
mg/kg
3.37
199
458-S S06-02-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Copper
mg/kg
11
399
458-S S06-02-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Iron
mg/kg
7,160
19900
458-S S06-02-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Lead
mg/kg
13.7
399
458-S S06-02-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Manganese
mg/kg
15
997
458-S S06-02-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW7471 B
Mercury
mg/kg
0.167
J
22.2
458-S S06-02-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Molybdenum
mg/kg
121
199
458-S S06-02-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Nickel
mg/kg
2.78
399
458-S S06-02-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
EH 300
Radium-226
pCi/g
34.5
J
0.387
458-S S06-02-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Selenium
mg/kg
1.57
J
997
458-S S06-02-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6010D
Silver
mg/kg
0.46
U
460
458-S S06-02-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Thallium
mg/kg
2.65
399
458-S S06-02-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Uranium
mg/kg
90.6
J
39.9
458-S S06-02-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Vanadium
mg/kg
11.9
3990
458-S S06-02-020624
2/6/2024
TRcp
35.73003514
-
11.3300376
0
6
SW6020B
Zinc
mg/kg
8.54
3990
458-SS-1A
8/7/2013
TRcs
35.73080647
-
11.3308141
0
6
6010C DOD
Aluminum
mg/kg
2,200
D
NR
458-SS-1A
8/7/2013
TRcs
35.73080647
-
11.3308141
0
6
6010C DOD
Antimony
mg/kg
6.4
U
NR
458-SS-1A
8/7/2013
TRcs
35.73080647
-
11.3308141
0
6
6010C DOD
Arsenic
mg/kg
31
D
NR
458-SS-1A
8/7/2013
TRcs
35.73080647
-
11.3308141
0
6
601OC DOD
Barium
mg/kg
390
D
NR
458-SS-1A
8/7/2013
TRcs
35.73080647
-
11.3308141
0
6
601OC DOD
Beryllium
mg/kg
1.7
U
NR
458-SS-1A
8/7/2013
TRcs
35.73080647
-
11.3308141
0
6
601 OC DOD
Cadmium
mg/kg
1
U
NR
458-SS-1A
8/7/2013
TRcs
35.73080647
-
11.3308141
0
6
601 OC DOD
Chromium
mg/kg
3.4
JD
NR
458-SS-1A
8/7/2013
TRcs
35.73080647
-
11.3308141
0
6
601 OC DOD
Cobalt
mg/kg
17
JD
NR
458-SS-1A
8/7/2013
TRcs
35.73080647
-
11.3308141
0
6
601 OC DOD
Copper
mg/kg
8.6
JD
NR
458-SS-1A
8/7/2013
TRcs
35.73080647
-
11.3308141
0
6
601 OC DOD
Iron
mg/kg
11,000
D
NR
458-SS-1A
8/7/2013
TRcs
35.73080647
-
11.3308141
0
6
601 OC DOD
Lead
mg/kg
16
D
NR
458-SS-1A
8/7/2013
TRcs
35.73080647
-
11.3308141
0
6
601 OC DOD
Manganese
mg/kg
81
D
NR
458-SS-1A
8/7/2013
TRcs
35.73080647
-
11.3308141
0
6
601 OC DOD
Mercury
mg/kg
0.093
NR
458-SS-1A
8/7/2013
TRcs
35.73080647
-
11.3308141
0
6
601 OC DOD
Molybdenum
mg/kg
180
D
NR
458-SS-1A
8/7/2013
TRcs
35.73080647
-
11.3308141
0
6
601 OC DOD
Nickel
mg/kg
3.8
JD
NR
458-SS-1A
8/7/2013
TRcs
35.73080647
-
11.3308141
0
6
GA-01-R
Radium-226
pCi/g
51.8
NR
458-SS-1A
8/7/2013
TRcs
35.73080647
-
11.3308141
0
6
601 OC DOD
Selenium
mg/kg
2.9
U
NR
458-SS-1A
8/7/2013
TRcs
35.73080647
-
11.3308141
0
6
601 OC DOD
Silver
mg/kg
2.3
U
NR
458-SS-1A
8/7/2013
TRcs
35.73080647
-
11.3308141
0
6
601 OC DOD
Thallium
mg/kg
15
U
NR
458-SS-1A
8/7/2013
TRcs
35.73080647
-
11.3308141
0
6
601 OC DOD
Uranium
mg/kg
55
U
NR
458-SS-1A
8/7/2013
TRcs
35.73080647
-
11.3308141
0
6
601 OC DOD
Vanadium
mg/kg
15
JD
NR
458-SS-1A
8/7/2013
TRcs
35.73080647
-
11.3308141
0
6
601 OC DOD
Zinc
mg/kg
20
U
NR
458-S S-2A
8/7/2013
TRcs
35.73108047
-
11.3300391
0
6
601 OC DOD
Aluminum
mg/kg
2,100
D
NR
458-S S-2A
8/7/2013
TRcs
35.73108047
-
11.3300391
0
6
601 OC DOD
Antimony
mg/kg
6.5
U
NR
Page 8 of 20
-------
Attachment B-1. Data Used in the Risk Assessment
Sample ID
Sample
Date
Geologic
Unit
Latitude
Longitude
Sample
Top Depth
(inches bgs)
Sample
Bottom Depth
(inches bgs)
Analytical
Method
Analyte
Units
Result and
Qualifier
Reporting
Limit
458-SS-2A
8/7/2013
TRcs
35.73108047
-
11.3300391
0
6
6010C DOD
Arsenic
mg/kg
3.2
U
NR
458-SS-2A
8/7/2013
TRcs
35.73108047
-
11.3300391
0
6
6010C DOD
Barium
mg/kg
160
D
NR
458-SS-2A
8/7/2013
TRcs
35.73108047
-
11.3300391
0
6
6010C DOD
Beryllium
mg/kg
1.7
U
NR
458-SS-2A
8/7/2013
TRcs
35.73108047
-
11.3300391
0
6
6010C DOD
Cadmium
mg/kg
1
U
NR
458-SS-2A
8/7/2013
TRcs
35.73108047
-
11.3300391
0
6
6010C DOD
Chromium
mg/kg
3.1
U
NR
458-SS-2A
8/7/2013
TRcs
35.73108047
-
11.3300391
0
6
6010C DOD
Cobalt
mg/kg
13
JD
NR
458-SS-2A
8/7/2013
TRcs
35.73108047
-
11.3300391
0
6
6010C DOD
Copper
mg/kg
7.4
U
NR
458-SS-2A
8/7/2013
TRcs
35.73108047
-
11.3300391
0
6
6010C DOD
Iron
mg/kg
6,700
D
NR
458-SS-2A
8/7/2013
TRcs
35.73108047
-
11.3300391
0
6
6010C DOD
Lead
mg/kg
13
D
NR
458-SS-2A
8/7/2013
TRcs
35.73108047
-
11.3300391
0
6
6010C DOD
Manganese
mg/kg
110
D
NR
458-SS-2A
8/7/2013
TRcs
35.73108047
-
11.3300391
0
6
6010C DOD
Mercury
mg/kg
0.015
J
NR
458-SS-2A
8/7/2013
TRcs
35.73108047
-
11.3300391
0
6
6010C DOD
Molybdenum
mg/kg
18
JD
NR
458-SS-2A
8/7/2013
TRcs
35.73108047
-
11.3300391
0
6
6010C DOD
Nickel
mg/kg
5.1
JD
NR
458-SS-2A
8/7/2013
TRcs
35.73108047
-
11.3300391
0
6
GA-01-R
Radium-226
pCi/g
9.84
NR
458-SS-2A
8/7/2013
TRcs
35.73108047
-
11.3300391
0
6
6010C DOD
Selenium
mg/kg
2.9
U
NR
458-SS-2A
8/7/2013
TRcs
35.73108047
-
11.3300391
0
6
6010C DOD
Silver
mg/kg
2.4
U
NR
458-SS-2A
8/7/2013
TRcs
35.73108047
-
11.3300391
0
6
6010C DOD
Thallium
mg/kg
15
U
NR
458-SS-2A
8/7/2013
TRcs
35.73108047
-
11.3300391
0
6
6010C DOD
Uranium
mg/kg
53
U
NR
458-SS-2A
8/7/2013
TRcs
35.73108047
-
11.3300391
0
6
601OC DOD
Vanadium
mg/kg
14
JD
NR
458-SS-2A
8/7/2013
TRcs
35.73108047
-
11.3300391
0
6
601OC DOD
Zinc
mg/kg
20
U
NR
458-SS-2B
8/7/2013
TRcs
35.73108047
-
11.3300391
6
12
601 OC DOD
Aluminum
mg/kg
2,100
D
NR
458-SS-2B
8/7/2013
TRcs
35.73108047
-
11.3300391
6
12
601 OC DOD
Antimony
mg/kg
6.5
U
NR
458-SS-2B
8/7/2013
TRcs
35.73108047
-
11.3300391
6
12
601 OC DOD
Arsenic
mg/kg
3.2
U
NR
458-SS-2B
8/7/2013
TRcs
35.73108047
-
11.3300391
6
12
601 OC DOD
Barium
mg/kg
170
D
NR
458-SS-2B
8/7/2013
TRcs
35.73108047
-
11.3300391
6
12
601 OC DOD
Beryllium
mg/kg
1.7
U
NR
458-SS-2B
8/7/2013
TRcs
35.73108047
-
11.3300391
6
12
601 OC DOD
Cadmium
mg/kg
1
U
NR
458-SS-2B
8/7/2013
TRcs
35.73108047
-
11.3300391
6
12
601 OC DOD
Chromium
mg/kg
3.1
U
NR
458-SS-2B
8/7/2013
TRcs
35.73108047
-
11.3300391
6
12
601 OC DOD
Cobalt
mg/kg
13
JD
NR
458-SS-2B
8/7/2013
TRcs
35.73108047
-
11.3300391
6
12
601 OC DOD
Copper
mg/kg
7.4
U
NR
458-SS-2B
8/7/2013
TRcs
35.73108047
-
11.3300391
6
12
601 OC DOD
Iron
mg/kg
6,900
D
NR
458-SS-2B
8/7/2013
TRcs
35.73108047
-
11.3300391
6
12
601 OC DOD
Lead
mg/kg
6.9
JD
NR
458-SS-2B
8/7/2013
TRcs
35.73108047
-
11.3300391
6
12
601 OC DOD
Manganese
mg/kg
100
D
NR
458-SS-2B
8/7/2013
TRcs
35.73108047
-
11.3300391
6
12
601 OC DOD
Mercury
mg/kg
0.011
U
NR
458-SS-2B
8/7/2013
TRcs
35.73108047
-
11.3300391
6
12
601 OC DOD
Molybdenum
mg/kg
10
U
NR
458-SS-2B
8/7/2013
TRcs
35.73108047
-
11.3300391
6
12
601 OC DOD
Nickel
mg/kg
5.4
JD
NR
458-SS-2B
8/7/2013
TRcs
35.73108047
-
11.3300391
6
12
GA-01-R
Radium-226
pCi/g
6.01
NR
458-SS-2B
8/7/2013
TRcs
35.73108047
-
11.3300391
6
12
601 OC DOD
Selenium
mg/kg
2.9
U
NR
458-SS-2B
8/7/2013
TRcs
35.73108047
-
11.3300391
6
12
601 OC DOD
Silver
mg/kg
2.4
U
NR
458-SS-2B
8/7/2013
TRcs
35.73108047
-
11.3300391
6
12
601 OC DOD
Thallium
mg/kg
15
U
NR
458-SS-2B
8/7/2013
TRcs
35.73108047
-
11.3300391
6
12
601 OC DOD
Uranium
mg/kg
53
U
NR
458-SS-2B
8/7/2013
TRcs
35.73108047
-
11.3300391
6
12
601 OC DOD
Vanadium
mg/kg
13
JD
NR
458-SS-2B
8/7/2013
TRcs
35.73108047
-
11.3300391
6
12
601 OC DOD
Zinc
mg/kg
20
U
NR
458-SS-2C
8/7/2013
TRcs
35.73108047
-
11.3300391
12
18
601 OC DOD
Aluminum
mg/kg
1,600
D
NR
458-SS-2C
8/7/2013
TRcs
35.73108047
-
11.3300391
12
18
601 OC DOD
Antimony
mg/kg
6.7
U
NR
458-SS-2C
8/7/2013
TRcs
35.73108047
-
11.3300391
12
18
601 OC DOD
Arsenic
mg/kg
4.5
JD
NR
458-SS-2C
8/7/2013
TRcs
35.73108047
-
11.3300391
12
18
601 OC DOD
Barium
mg/kg
180
D
NR
458-SS-2C
8/7/2013
TRcs
35.73108047
-
11.3300391
12
18
601 OC DOD
Beryllium
mg/kg
1.8
U
NR
458-SS-2C
8/7/2013
TRcs
35.73108047
-
11.3300391
12
18
601 OC DOD
Cadmium
mg/kg
1
U
NR
458-SS-2C
8/7/2013
TRcs
35.73108047
-
11.3300391
12
18
601 OC DOD
Chromium
mg/kg
3.2
U
NR
458-SS-2C
8/7/2013
TRcs
35.73108047
-
11.3300391
12
18
601 OC DOD
Cobalt
mg/kg
9.8
U
NR
458-SS-2C
8/7/2013
TRcs
35.73108047
-
11.3300391
12
18
601 OC DOD
Copper
mg/kg
7.6
U
NR
458-SS-2C
8/7/2013
TRcs
35.73108047
-
11.3300391
12
18
601 OC DOD
Iron
mg/kg
5,300
D
NR
458-SS-2C
8/7/2013
TRcs
35.73108047
-
11.3300391
12
18
601 OC DOD
Lead
mg/kg
12
D
NR
458-SS-2C
8/7/2013
TRcs
35.73108047
-
11.3300391
12
18
601 OC DOD
Manganese
mg/kg
78
D
NR
458-SS-2C
8/7/2013
TRcs
35.73108047
-
11.3300391
12
18
601 OC DOD
Mercury
mg/kg
0.081
NR
458-SS-2C
8/7/2013
TRcs
35.73108047
-
11.3300391
12
18
601 OC DOD
Molybdenum
mg/kg
69
D
NR
458-SS-2C
8/7/2013
TRcs
35.73108047
-
11.3300391
12
18
601 OC DOD
Nickel
mg/kg
3.7
JD
NR
458-SS-2C
8/7/2013
TRcs
35.73108047
-
11.3300391
12
18
GA-01 -R
Radium-226
pCi/g
22.8
NR
458-SS-2C
8/7/2013
TRcs
35.73108047
-
11.3300391
12
18
601 OC DOD
Selenium
mg/kg
3
U
NR
458-SS-2C
8/7/2013
TRcs
35.73108047
-
11.3300391
12
18
601 OC DOD
Silver
mg/kg
2.4
U
NR
458-SS-2C
8/7/2013
TRcs
35.73108047
-
11.3300391
12
18
601 OC DOD
Thallium
mg/kg
16
U
NR
458-SS-2C
8/7/2013
TRcs
35.73108047
-
11.3300391
12
18
601 OC DOD
Uranium
mg/kg
55
U
NR
458-SS-2C
8/7/2013
TRcs
35.73108047
-
11.3300391
12
18
601 OC DOD
Vanadium
mg/kg
13
U
NR
458-SS-2C
8/7/2013
TRcs
35.73108047
-
11.3300391
12
18
601 OC DOD
Zinc
mg/kg
21
U
NR
458-SS-3A
8/7/2013
TRcs
35.73057947
-
11.3298161
0
6
601 OC DOD
Aluminum
mg/kg
1,700
JD
NR
458-SS-3A
8/7/2013
TRcs
35.73057947
-
11.3298161
0
6
601 OC DOD
Antimony
mg/kg
6.3
UJ
NR
458-SS-3A
8/7/2013
TRcs
35.73057947
-
11.3298161
0
6
601 OC DOD
Arsenic
mg/kg
31
D
NR
458-SS-3A
8/7/2013
TRcs
35.73057947
-
11.3298161
0
6
601 OC DOD
Barium
mg/kg
200
JD
NR
458-SS-3A
8/7/2013
TRcs
35.73057947
-
11.3298161
0
6
601 OC DOD
Beryllium
mg/kg
1.7
U
NR
458-SS-3A
8/7/2013
TRcs
35.73057947
-
11.3298161
0
6
601 OC DOD
Cadmium
mg/kg
0.98
U
NR
458-SS-3A
8/7/2013
TRcs
35.73057947
-
11.3298161
0
6
601 OC DOD
Chromium
mg/kg
3
U
NR
458-SS-3A
8/7/2013
TRcs
35.73057947
-
11.3298161
0
6
601 OC DOD
Cobalt
mg/kg
9.2
U
NR
458-SS-3A
8/7/2013
TRcs
35.73057947
-
11.3298161
0
6
601 OC DOD
Copper
mg/kg
15
JD
NR
458-SS-3A
8/7/2013
TRcs
35.73057947
-
11.3298161
0
6
601 OC DOD
Iron
mg/kg
8,300
JD
NR
458-SS-3A
8/7/2013
TRcs
35.73057947
-
11.3298161
0
6
601 OC DOD
Lead
mg/kg
18
D
NR
458-SS-3A
8/7/2013
TRcs
35.73057947
-
11.3298161
0
6
601 OC DOD
Manganese
mg/kg
29
D
NR
458-SS-3A
8/7/2013
TRcs
35.73057947
-
11.3298161
0
6
601 OC DOD
Mercury
mg/kg
0.36
J
NR
458-SS-3A
8/7/2013
TRcs
35.73057947
-
11.3298161
0
6
601 OC DOD
Molybdenum
mg/kg
440
JD
NR
458-SS-3A
8/7/2013
TRcs
35.73057947
-
11.3298161
0
6
601 OC DOD
Nickel
mg/kg
2.2
JD
NR
458-SS-3A
8/7/2013
TRcs
35.73057947
-
11.3298161
0
6
GA-01 -R
Radium-226
pCi/g
39.1
NR
458-SS-3A
8/7/2013
TRcs
35.73057947
-
11.3298161
0
6
601 OC DOD
Selenium
mg/kg
2.8
U
NR
458-SS-3A
8/7/2013
TRcs
35.73057947
-
11.3298161
0
6
601 OC DOD
Silver
mg/kg
2.3
UJ
NR
458-SS-3A
8/7/2013
TRcs
35.73057947
-
11.3298161
0
6
601 OC DOD
Thallium
mg/kg
15
UJ
NR
458-SS-3A
8/7/2013
TRcs
35.73057947
-
11.3298161
0
6
601 OC DOD
Uranium
mg/kg
150
U
NR
458-SS-3A
8/7/2013
TRcs
35.73057947
-
11.3298161
0
6
601 OC DOD
Vanadium
mg/kg
12
JD
NR
458-SS-3A
8/7/2013
TRcs
35.73057947
-
11.3298161
0
6
601 OC DOD
Zinc
mg/kg
19
U
NR
458-SS-4A
8/7/2013
TRcs
35.73016647
-
11.3303641
0
6
601 OC DOD
Aluminum
mg/kg
2,800
D
NR
458-SS-4A
8/7/2013
TRcs
35.73016647
-
11.3303641
0
6
601 OC DOD
Antimony
mg/kg
8.3
U
NR
Page 9 of 20
-------
Attachment B-1. Data Used in the Risk Assessment
Sample ID
Sample
Date
Geologic
Unit
Latitude
Longitude
Sample
Top Depth
(inches bgs)
Sample
Bottom Depth
(inches bgs)
Analytical
Method
Analyte
Units
Result and
Qualifier
Reporting
Limit
458-SS-4A
8/7/2013
TRcs
35.73016647
-111.3303641
0
6
6010C DOD
Arsenic
mg/kg
12
JD
NR
458-SS-4A
8/7/2013
TRcs
35.73016647
-111.3303641
0
6
6010C DOD
Barium
mg/kg
500
D
NR
458-SS-4A
8/7/2013
TRcs
35.73016647
-111.3303641
0
6
6010C DOD
Beryllium
mg/kg
2.2
U
NR
458-SS-4A
8/7/2013
TRcs
35.73016647
-111.3303641
0
6
6010C DOD
Cadmium
mg/kg
1.3
U
NR
458-SS-4A
8/7/2013
TRcs
35.73016647
-111.3303641
0
6
6010C DOD
Chromium
mg/kg
4
U
NR
458-SS-4A
8/7/2013
TRcs
35.73016647
-111.3303641
0
6
6010C DOD
Cobalt
mg/kg
12
JD
NR
458-SS-4A
8/7/2013
TRcs
35.73016647
-111.3303641
0
6
6010C DOD
Copper
mg/kg
9.4
U
NR
458-SS-4A
8/7/2013
TRcs
35.73016647
-111.3303641
0
6
6010C DOD
Iron
mg/kg
6,300
D
NR
458-SS-4A
8/7/2013
TRcs
35.73016647
-111.3303641
0
6
6010C DOD
Lead
mg/kg
17
D
NR
458-SS-4A
8/7/2013
TRcs
35.73016647
-111.3303641
0
6
6010C DOD
Manganese
mg/kg
32
D
NR
458-SS-4A
8/7/2013
TRcs
35.73016647
-111.3303641
0
6
6010C DOD
Mercury
mg/kg
0.028
J
NR
458-SS-4A
8/7/2013
TRcs
35.73016647
-111.3303641
0
6
6010C DOD
Molybdenum
mg/kg
48
JD
NR
458-SS-4A
8/7/2013
TRcs
35.73016647
-111.3303641
0
6
6010C DOD
Nickel
mg/kg
4.9
JD
NR
458-SS-4A
8/7/2013
TRcs
35.73016647
-111.3303641
0
6
GA-01-R
Radium-226
pCi/g
11.1
NR
458-SS-4A
8/7/2013
TRcs
35.73016647
-111.3303641
0
6
6010C DOD
Selenium
mg/kg
3.7
U
NR
458-SS-4A
8/7/2013
TRcs
35.73016647
-111.3303641
0
6
6010C DOD
Silver
mg/kg
3
U
NR
458-SS-4A
8/7/2013
TRcs
35.73016647
-111.3303641
0
6
6010C DOD
Thallium
mg/kg
20
U
NR
458-SS-4A
8/7/2013
TRcs
35.73016647
-111.3303641
0
6
601OC DOD
Uranium
mg/kg
88
U
NR
458-SS-4A
8/7/2013
TRcs
35.73016647
-111.3303641
0
6
601OC DOD
Vanadium
mg/kg
16
U
NR
458-SS-4A
8/7/2013
TRcs
35.73016647
-111.3303641
0
6
601 OC DOD
Zinc
mg/kg
26
U
NR
458-SS-4B
8/7/2013
TRcs
35.73016647
-111.3303641
6
12
601 OC DOD
Aluminum
mg/kg
2,100
D
NR
458-SS-4B
8/7/2013
TRcs
35.73016647
-111.3303641
6
12
601 OC DOD
Antimony
mg/kg
5.8
U
NR
458-SS-4B
8/7/2013
TRcs
35.73016647
-111.3303641
6
12
601 OC DOD
Arsenic
mg/kg
12
D
NR
458-SS-4B
8/7/2013
TRcs
35.73016647
-111.3303641
6
12
601 OC DOD
Barium
mg/kg
160
D
NR
458-SS-4B
8/7/2013
TRcs
35.73016647
-111.3303641
6
12
601 OC DOD
Beryllium
mg/kg
1.5
U
NR
458-SS-4B
8/7/2013
TRcs
35.73016647
-111.3303641
6
12
601 OC DOD
Cadmium
mg/kg
0.9
U
NR
458-SS-4B
8/7/2013
TRcs
35.73016647
-111.3303641
6
12
601 OC DOD
Chromium
mg/kg
2.8
U
NR
458-SS-4B
8/7/2013
TRcs
35.73016647
-111.3303641
6
12
601 OC DOD
Cobalt
mg/kg
18
JD
NR
458-SS-4B
8/7/2013
TRcs
35.73016647
-111.3303641
6
12
601 OC DOD
Copper
mg/kg
7.2
JD
NR
458-SS-4B
8/7/2013
TRcs
35.73016647
-111.3303641
6
12
601 OC DOD
Iron
mg/kg
6,700
D
NR
458-SS-4B
8/7/2013
TRcs
35.73016647
-111.3303641
6
12
601 OC DOD
Lead
mg/kg
13
D
NR
458-SS-4B
8/7/2013
TRcs
35.73016647
-111.3303641
6
12
601 OC DOD
Manganese
mg/kg
38
D
NR
458-SS-4B
8/7/2013
TRcs
35.73016647
-111.3303641
6
12
601 OC DOD
Mercury
mg/kg
0.074
NR
458-SS-4B
8/7/2013
TRcs
35.73016647
-111.3303641
6
12
601 OC DOD
Molybdenum
mg/kg
87
D
NR
458-SS-4B
8/7/2013
TRcs
35.73016647
-111.3303641
6
12
601 OC DOD
Nickel
mg/kg
4.3
JD
NR
458-SS-4B
8/7/2013
TRcs
35.73016647
-111.3303641
6
12
GA-01-R
Radium-226
pCi/g
18.7
NR
458-SS-4B
8/7/2013
TRcs
35.73016647
-111.3303641
6
12
601 OC DOD
Selenium
mg/kg
2.6
U
NR
458-SS-4B
8/7/2013
TRcs
35.73016647
-111.3303641
6
12
601 OC DOD
Silver
mg/kg
2.1
U
NR
458-SS-4B
8/7/2013
TRcs
35.73016647
-111.3303641
6
12
601 OC DOD
Thallium
mg/kg
14
U
NR
458-SS-4B
8/7/2013
TRcs
35.73016647
-111.3303641
6
12
601 OC DOD
Uranium
mg/kg
120
U
NR
458-SS-4B
8/7/2013
TRcs
35.73016647
-111.3303641
6
12
601 OC DOD
Vanadium
mg/kg
11
U
NR
458-SS-4B
8/7/2013
TRcs
35.73016647
-111.3303641
6
12
601 OC DOD
Zinc
mg/kg
18
U
NR
458-SS-4C
8/7/2013
TRcs
35.73016647
-111.3303641
12
18
601 OC DOD
Aluminum
mg/kg
2,300
D
NR
458-SS-4C
8/7/2013
TRcs
35.73016647
-111.3303641
12
18
601 OC DOD
Antimony
mg/kg
6.3
U
NR
458-SS-4C
8/7/2013
TRcs
35.73016647
-111.3303641
12
18
601 OC DOD
Arsenic
mg/kg
42
D
NR
458-SS-4C
8/7/2013
TRcs
35.73016647
-111.3303641
12
18
601 OC DOD
Barium
mg/kg
230
D
NR
458-SS-4C
8/7/2013
TRcs
35.73016647
-111.3303641
12
18
601 OC DOD
Beryllium
mg/kg
1.7
U
NR
458-SS-4C
8/7/2013
TRcs
35.73016647
-111.3303641
12
18
601 OC DOD
Cadmium
mg/kg
0.99
U
NR
458-SS-4C
8/7/2013
TRcs
35.73016647
-111.3303641
12
18
601 OC DOD
Chromium
mg/kg
3.1
JD
NR
458-SS-4C
8/7/2013
TRcs
35.73016647
-111.3303641
12
18
601 OC DOD
Cobalt
mg/kg
12
JD
NR
458-SS-4C
8/7/2013
TRcs
35.73016647
-111.3303641
12
18
601 OC DOD
Copper
mg/kg
8
JD
NR
458-SS-4C
8/7/2013
TRcs
35.73016647
-111.3303641
12
18
601 OC DOD
Iron
mg/kg
9,600
D
NR
458-SS-4C
8/7/2013
TRcs
35.73016647
-111.3303641
12
18
601 OC DOD
Lead
mg/kg
14
D
NR
458-SS-4C
8/7/2013
TRcs
35.73016647
-111.3303641
12
18
601 OC DOD
Manganese
mg/kg
20
D
NR
458-SS-4C
8/7/2013
TRcs
35.73016647
-111.3303641
12
18
601 OC DOD
Mercury
mg/kg
0.14
NR
458-SS-4C
8/7/2013
TRcs
35.73016647
-111.3303641
12
18
601 OC DOD
Molybdenum
mg/kg
110
D
NR
458-SS-4C
8/7/2013
TRcs
35.73016647
-111.3303641
12
18
601 OC DOD
Nickel
mg/kg
4.4
JD
NR
458-SS-4C
8/7/2013
TRcs
35.73016647
-111.3303641
12
18
GA-01 -R
Radium-226
pCi/g
21.5
NR
458-SS-4C
8/7/2013
TRcs
35.73016647
-111.3303641
12
18
601 OC DOD
Selenium
mg/kg
2.9
U
NR
458-SS-4C
8/7/2013
TRcs
35.73016647
-111.3303641
12
18
601 OC DOD
Silver
mg/kg
2.3
U
NR
458-SS-4C
8/7/2013
TRcs
35.73016647
-111.3303641
12
18
601 OC DOD
Thallium
mg/kg
15
U
NR
458-SS-4C
8/7/2013
TRcs
35.73016647
-111.3303641
12
18
601 OC DOD
Uranium
mg/kg
190
U
NR
458-SS-4C
8/7/2013
TRcs
35.73016647
-111.3303641
12
18
601 OC DOD
Vanadium
mg/kg
12
U
NR
458-SS-4C
8/7/2013
TRcs
35.73016647
-111.3303641
12
18
601 OC DOD
Zinc
mg/kg
20
U
NR
458-SS-5A
8/7/2013
TRcs
35.73054647
-111.3305961
0
6
601 OC DOD
Aluminum
mg/kg
2,300
D
NR
458-SS-5A
8/7/2013
TRcs
35.73054647
-111.3305961
0
6
601 OC DOD
Antimony
mg/kg
6.6
U
NR
458-SS-5A
8/7/2013
TRcs
35.73054647
-111.3305961
0
6
601 OC DOD
Arsenic
mg/kg
7.9
JD
NR
458-SS-5A
8/7/2013
TRcs
35.73054647
-111.3305961
0
6
601 OC DOD
Barium
mg/kg
67
D
NR
458-SS-5A
8/7/2013
TRcs
35.73054647
-111.3305961
0
6
601 OC DOD
Beryllium
mg/kg
1.7
U
NR
458-SS-5A
8/7/2013
TRcs
35.73054647
-111.3305961
0
6
601 OC DOD
Cadmium
mg/kg
1
U
NR
458-SS-5A
8/7/2013
TRcs
35.73054647
-111.3305961
0
6
601 OC DOD
Chromium
mg/kg
3.1
U
NR
458-SS-5A
8/7/2013
TRcs
35.73054647
-111.3305961
0
6
601 OC DOD
Cobalt
mg/kg
9.6
U
NR
458-SS-5A
8/7/2013
TRcs
35.73054647
-111.3305961
0
6
601 OC DOD
Copper
mg/kg
21
JD
NR
458-SS-5A
8/7/2013
TRcs
35.73054647
-111.3305961
0
6
601 OC DOD
Iron
mg/kg
4,600
D
NR
458-SS-5A
8/7/2013
TRcs
35.73054647
-111.3305961
0
6
601 OC DOD
Lead
mg/kg
9.1
JD
NR
458-SS-5A
8/7/2013
TRcs
35.73054647
-111.3305961
0
6
601 OC DOD
Manganese
mg/kg
24
D
NR
458-SS-5A
8/7/2013
TRcs
35.73054647
-111.3305961
0
6
601 OC DOD
Mercury
mg/kg
0.043
NR
458-SS-5A
8/7/2013
TRcs
35.73054647
-111.3305961
0
6
601 OC DOD
Molybdenum
mg/kg
130
D
NR
458-SS-5A
8/7/2013
TRcs
35.73054647
-111.3305961
0
6
601 OC DOD
Nickel
mg/kg
10
JD
NR
458-SS-5A
8/7/2013
TRcs
35.73054647
-111.3305961
0
6
GA-01 -R
Radium-226
pCi/g
28.7
NR
458-SS-5A
8/7/2013
TRcs
35.73054647
-111.3305961
0
6
601 OC DOD
Selenium
mg/kg
3
U
NR
458-SS-5A
8/7/2013
TRcs
35.73054647
-111.3305961
0
6
601 OC DOD
Silver
mg/kg
2.4
U
NR
458-SS-5A
8/7/2013
TRcs
35.73054647
-111.3305961
0
6
601 OC DOD
Thallium
mg/kg
15
U
NR
458-SS-5A
8/7/2013
TRcs
35.73054647
-111.3305961
0
6
601 OC DOD
Uranium
mg/kg
170
U
NR
458-SS-5A
8/7/2013
TRcs
35.73054647
-111.3305961
0
6
601 OC DOD
Vanadium
mg/kg
13
U
NR
458-SS-5A
8/7/2013
TRcs
35.73054647
-111.3305961
0
6
601 OC DOD
Zinc
mg/kg
20
U
NR
458-SS-6A
8/7/2013
TRcp
35.72974047
-111.3308571
0
6
601 OC DOD
Aluminum
mg/kg
2,300
D
NR
458-SS-6A
8/7/2013
TRcp
35.72974047
-111.3308571
0
6
601 OC DOD
Antimony
mg/kg
33
U
NR
Page 10 of 20
-------
20518
20518
20518
20518
20518
20518
20518
20518
20518
20518
20518
20518
20518
20518
20518
20518
20518
20518
20518
20518
20518
Attachment B-1. Data Used in the Risk Assessment
Sample
Date
Geologic
Unit
Latitude
Longitude
Sample
Top Depth
(inches bgs)
Sample
Bottom Depth
(inches bgs)
Analytical
Method
Analyte
8/7/2013
TRcp
35.72974047
11.3308571
0
6010C DOD
Arsenic
8/7/2013
TRcp
35.72974047
11.3308571
0
6010C DOD
Barium
8/7/2013
TRcp
35.72974047
11.3308571
6010C DOD
Beryllium
8/7/2013
TRcp
35.72974047
11.3308571
6010C DOD
Cadmium
8/7/2013
TRcp
35.72974047
11.3308571
6010C DOD
Chromium
8/7/2013
TRcp
35.72974047
11.3308571
6010C DOD
Cobalt
8/7/2013
TRcp
35.72974047
11.3308571
6010C DOD
Copper
8/7/2013
TRcp
35.72974047
11.3308571
6010C DOD
Iron
8/7/2013
TRcp
35.72974047
11.3308571
601OC DOD
Lead
8/7/2013
TRcp
35.72974047
11.3308571
601 OC DOD
Manganese
8/7/2013
TRcp
35.72974047
11.3308571
601 OC DOD
Mercury
8/7/2013
TRcp
35.72974047
11.3308571
601 OC DOD
Molybdenum
8/7/2013
TRcp
35.72974047
11.3308571
601 OC DOD
Nickel
8/7/2013
TRcp
35.72974047
11.3308571
GA-01-R
Radium-226
8/7/2013
TRcp
35.72974047
11.3308571
601 OC DOD
Selenium
8/7/2013
TRcp
35.72974047
11.3308571
601 OC DOD
Silver
8/7/2013
TRcp
35.72974047
11.3308571
601 OC DOD
Thallium
8/7/2013
TRcp
35.72974047
11.3308571
601 OC DOD
Uranium
8/7/2013
TRcp
35.72974047
11.3308571
601 OC DOD
Vanadium
8/7/2013
TRcp
35.72974047
11.3308571
601 OC DOD
Zinc
8/7/2013
TRcp
35.72974047
11.3308571
601 OC DOD
Aluminum
8/7/2013
TRcp
35.72974047
11.3308571
601 OC DOD
Antimony
8/7/2013
TRcp
35.72974047
11.3308571
601 OC DOD
Arsenic
8/7/2013
TRcp
35.72974047
11.3308571
601 OC DOD
Barium
8/7/2013
TRcp
35.72974047
11.3308571
601 OC DOD
Beryllium
8/7/2013
TRcp
35.72974047
11.3308571
601 OC DOD
Cadmium
8/7/2013
TRcp
35.72974047
11.3308571
601 OC DOD
Chromium
8/7/2013
TRcp
35.72974047
11.3308571
601 OC DOD
Cobalt
8/7/2013
TRcp
35.72974047
11.3308571
601 OC DOD
Copper
8/7/2013
TRcp
35.72974047
11.3308571
601 OC DOD
Iron
8/7/2013
TRcp
35.72974047
11.3308571
601 OC DOD
Lead
8/7/2013
TRcp
35.72974047
11.3308571
601 OC DOD
Manganese
8/7/2013
TRcp
35.72974047
11.3308571
601 OC DOD
Mercury
8/7/2013
TRcp
35.72974047
11.3308571
601 OC DOD
Molybdenum
8/7/2013
TRcp
35.72974047
11.3308571
601 OC DOD
Nickel
8/7/2013
TRcp
35.72974047
11.3308571
GA-01 -R
Radium-226
8/7/2013
TRcp
35.72974047
11.3308571
601 OC DOD
Selenium
8/7/2013
TRcp
35.72974047
11.3308571
601 OC DOD
Silver
8/7/2013
TRcp
35.72974047
11.3308571
601 OC DOD
Thallium
8/7/2013
TRcp
35.72974047
11.3308571
601 OC DOD
Uranium
8/7/2013
TRcp
35.72974047
11.3308571
601 OC DOD
Vanadium
8/7/2013
TRcp
35.72974047
11.3308571
601 OC DOD
Zinc
8/7/2013
TRcs
35.72986747
11.3299731
601 OC DOD
Aluminum
8/7/2013
TRcs
35.72986747
11.3299731
601 OC DOD
Antimony
8/7/2013
TRcs
35.72986747
11.3299731
601 OC DOD
Arsenic
8/7/2013
TRcs
35.72986747
11.3299731
601 OC DOD
Barium
8/7/2013
TRcs
35.72986747
11.3299731
601 OC DOD
Beryllium
8/7/2013
TRcs
35.72986747
11.3299731
601 OC DOD
Cadmium
8/7/2013
TRcs
35.72986747
11.3299731
601 OC DOD
Chromium
8/7/2013
TRcs
35.72986747
11.3299731
601 OC DOD
Cobalt
8/7/2013
TRcs
35.72986747
11.3299731
601 OC DOD
Copper
8/7/2013
TRcs
35.72986747
11.3299731
601 OC DOD
Iron
8/7/2013
TRcs
35.72986747
11.3299731
601 OC DOD
Lead
8/7/2013
TRcs
35.72986747
11.3299731
601 OC DOD
Manganese
8/7/2013
TRcs
35.72986747
11.3299731
601 OC DOD
Mercury
8/7/2013
TRcs
35.72986747
11.3299731
601 OC DOD
Molybdenum
8/7/2013
TRcs
35.72986747
11.3299731
601 OC DOD
Nickel
8/7/2013
TRcs
35.72986747
11.3299731
GA-01 -R
Radium-226
8/7/2013
TRcs
35.72986747
11.3299731
601 OC DOD
Selenium
8/7/2013
TRcs
35.72986747
11.3299731
601 OC DOD
Silver
8/7/2013
TRcs
35.72986747
11.3299731
601 OC DOD
Thallium
8/7/2013
TRcs
35.72986747
11.3299731
601 OC DOD
Uranium
8/7/2013
TRcs
35.72986747
11.3299731
601 OC DOD
Vanadium
8/7/2013
TRcs
35.72986747
11.3299731
601 OC DOD
Zinc
12/5/2018
TRcs
35.73055255
11.3308955
12
SW6020
Arsenic
12/5/2018
TRcs
35.73055255
11.3308955
12
SW7471
Mercury
12/5/2018
TRcs
35.73055255
11.3308955
12
SW6010
Molybdenum
12/5/2018
TRcs
35.73055255
11.3308955
12
713R14
Radium-226
12/5/2018
TRcs
35.73055255
11.3308955
12
SW6010
Selenium
12/5/2018
TRcs
35.73055255
11.3308955
12
SW6020
Uranium
12/5/2018
TRcs
35.73055255
11.3308955
12
SW6010
Vanadium
12/5/2018
TRcs
35.73055255
11.3308955
24
30
SW6020
Arsenic
12/5/2018
TRcs
35.73055255
11.3308955
24
30
SW7471
Mercury
12/5/2018
TRcs
35.73055255
11.3308955
24
30
SW6010
Molybdenum
12/5/2018
TRcs
35.73055255
11.3308955
24
30
713R14
Radium-226
12/5/2018
TRcs
35.73055255
11.3308955
24
30
SW6010
Selenium
12/5/2018
TRcs
35.73055255
11.3308955
24
30
SW6020
Uranium
12/5/2018
TRcs
35.73055255
11.3308955
24
30
SW6010
Vanadium
12/5/2018
TRcs
35.73022964
11.3304343
12
SW6020
Arsenic
12/5/2018
TRcs
35.73022964
11.3304343
12
SW7471
Mercury
12/5/2018
TRcs
35.73022964
11.3304343
12
SW6010
Molybdenum
12/5/2018
TRcs
35.73022964
11.3304343
12
713R14
Radium-226
12/5/2018
TRcs
35.73022964
11.3304343
12
SW6010
Selenium
12/5/2018
TRcs
35.73022964
11.3304343
12
SW6020
Uranium
12/5/2018
TRcs
35.73022964
11.3304343
12
SW6010
Vanadium
12/5/2018
TRcs
35.73022964
11.3304343
SW6020
Arsenic
12/5/2018
TRcs
35.73022964
11.3304343
SW7471
Mercury
12/5/2018
TRcs
35.73022964
11.3304343
SW6010
Molybdenum
Page 11 of 20
-------
! ID
20518
20518
20518
20518
i-120518
i-120518
i-120518
i-120518
i-120518
i-120518
i-120518
20518
20518
20518
20518
20518
20518
20518
i-120518
i-120518
i-120518
i-120518
i-120518
i-120518
i-120518
i-120518
i-120518
i-120518
i-120518
i-120518
i-120518
i-120518
20518
20518
20518
20518
20518
20518
20518
Attachment B-1. Data Used in the Risk Assessment
Sample
Date
Geologic
Unit
Latitude
Longitude
Sample
Top Depth
(inches bgs)
Sample
Bottom Depth
(inches bgs)
Analytical
Method
Analyte
12/5/2018
TRcs
35.73022964
11.3304343
0
713R14
Radium-226
12/5/2018
TRcs
35.73022964
11.3304343
0
SW6010
Selenium
12/5/2018
TRcs
35.73022964
11.3304343
SW6020
Uranium
12/5/2018
TRcs
35.73022964
11.3304343
SW6010
Vanadium
12/5/2018
TRcs
35.73049751
11.3297397
SW6020
Arsenic
12/5/2018
TRcs
35.73049751
11.3297397
SW7471
Mercury
12/5/2018
TRcs
35.73049751
11.3297397
SW6010
Molybdenum
12/5/2018
TRcs
35.73049751
11.3297397
713R14
Radium-226
12/5/2018
TRcs
35.73049751
11.3297397
SW6010
Selenium
12/5/2018
TRcs
35.73049751
11.3297397
SW6020
Uranium
12/5/2018
TRcs
35.73049751
11.3297397
SW6010
Vanadium
12/5/2018
TRcs
35.73049751
11.3297397
SW6020
Arsenic
12/5/2018
TRcs
35.73049751
11.3297397
SW7471
Mercury
12/5/2018
TRcs
35.73049751
11.3297397
SW6010
Molybdenum
12/5/2018
TRcs
35.73049751
11.3297397
713R14
Radium-226
12/5/2018
TRcs
35.73049751
11.3297397
SW6010
Selenium
12/5/2018
TRcs
35.73049751
11.3297397
SW6020
Uranium
12/5/2018
TRcs
35.73049751
11.3297397
SW6010
Vanadium
12/5/2018
TRcs
35.73049751
11.3297397
12
18
SW6020
Arsenic
12/5/2018
TRcs
35.73049751
11.3297397
12
18
SW7471
Mercury
12/5/2018
TRcs
35.73049751
11.3297397
12
18
SW6010
Molybdenum
12/5/2018
TRcs
35.73049751
11.3297397
12
18
713R14
Radium-226
12/5/2018
TRcs
35.73049751
11.3297397
12
18
SW6010
Selenium
12/5/2018
TRcs
35.73049751
11.3297397
12
18
SW6020
Uranium
12/5/2018
TRcs
35.73049751
11.3297397
12
18
SW6010
Vanadium
12/5/2018
TRcp
35.7298768
11.3300571
12
SW6020
Arsenic
12/5/2018
TRcp
35.7298768
11.3300571
12
SW7471
Mercury
12/5/2018
TRcp
35.7298768
11.3300571
12
SW6010
Molybdenum
12/5/2018
TRcp
35.7298768
11.3300571
12
713R14
Radium-226
12/5/2018
TRcp
35.7298768
11.3300571
12
SW6010
Selenium
12/5/2018
TRcp
35.7298768
11.3300571
12
SW6020
Uranium
12/5/2018
TRcp
35.7298768
11.3300571
12
SW6010
Vanadium
12/5/2018
TRcp
35.7298768
11.3300571
SW6020
Arsenic
12/5/2018
TRcp
35.7298768
11.3300571
SW7471
Mercury
12/5/2018
TRcp
35.7298768
11.3300571
SW6010
Molybdenum
12/5/2018
TRcp
35.7298768
11.3300571
713R14
Radium-226
12/5/2018
TRcp
35.7298768
11.3300571
SW6010
Selenium
12/5/2018
TRcp
35.7298768
11.3300571
SW6020
Uranium
12/5/2018
TRcp
35.7298768
11.3300571
SW6010
Vanadium
8/7/2013
TRcs
35.72816647
11.3263311
6010C DOD
Aluminum
8/7/2013
TRcs
35.72816647
11.3263311
6010C DOD
Antimony
8/7/2013
TRcs
35.72816647
11.3263311
6010C DOD
Arsenic
8/7/2013
TRcs
35.72816647
11.3263311
6010C DOD
Barium
8/7/2013
TRcs
35.72816647
11.3263311
6010C DOD
Beryllium
8/7/2013
TRcs
35.72816647
11.3263311
6010C DOD
Cadmium
8/7/2013
TRcs
35.72816647
11.3263311
6010C DOD
Chromium
8/7/2013
TRcs
35.72816647
11.3263311
6010C DOD
Cobalt
8/7/2013
TRcs
35.72816647
11.3263311
6010C DOD
Copper
8/7/2013
TRcs
35.72816647
11.3263311
6010C DOD
Iron
8/7/2013
TRcs
35.72816647
11.3263311
6010C DOD
Lead
8/7/2013
TRcs
35.72816647
11.3263311
6010C DOD
Manganese
8/7/2013
TRcs
35.72816647
11.3263311
6010C DOD
Mercury
8/7/2013
TRcs
35.72816647
11.3263311
6010C DOD
Molybdenum
8/7/2013
TRcs
35.72816647
11.3263311
6010C DOD
Nickel
8/7/2013
TRcs
35.72816647
11.3263311
GA-01-R
Radium-226
8/7/2013
TRcs
35.72816647
11.3263311
6010C DOD
Selenium
8/7/2013
TRcs
35.72816647
11.3263311
6010C DOD
Silver
8/7/2013
TRcs
35.72816647
11.3263311
6010C DOD
Thallium
8/7/2013
TRcs
35.72816647
11.3263311
6010C DOD
Uranium
8/7/2013
TRcs
35.72816647
11.3263311
6010C DOD
Vanadium
8/7/2013
TRcs
35.72816647
11.3263311
6010C DOD
Zinc
8/7/2013
TRcs
35.72816647
11.3263311
12
6010C DOD
Aluminum
8/7/2013
TRcs
35.72816647
11.3263311
12
6010C DOD
Antimony
8/7/2013
TRcs
35.72816647
11.3263311
12
601OC DOD
Arsenic
8/7/2013
TRcs
35.72816647
11.3263311
12
601 OC DOD
Barium
8/7/2013
TRcs
35.72816647
11.3263311
12
601 OC DOD
Beryllium
8/7/2013
TRcs
35.72816647
11.3263311
12
601 OC DOD
Cadmium
8/7/2013
TRcs
35.72816647
11.3263311
12
601 OC DOD
Chromium
8/7/2013
TRcs
35.72816647
11.3263311
12
601 OC DOD
Cobalt
8/7/2013
TRcs
35.72816647
11.3263311
12
601 OC DOD
Copper
8/7/2013
TRcs
35.72816647
11.3263311
12
601 OC DOD
Iron
8/7/2013
TRcs
35.72816647
11.3263311
12
601 OC DOD
Lead
8/7/2013
TRcs
35.72816647
11.3263311
12
601 OC DOD
Manganese
8/7/2013
TRcs
35.72816647
11.3263311
12
601 OC DOD
Mercury
8/7/2013
TRcs
35.72816647
11.3263311
12
601 OC DOD
Molybdenum
8/7/2013
TRcs
35.72816647
11.3263311
12
601 OC DOD
Nickel
8/7/2013
TRcs
35.72816647
11.3263311
12
GA-01-R
Radium-226
8/7/2013
TRcs
35.72816647
11.3263311
12
601 OC DOD
Selenium
8/7/2013
TRcs
35.72816647
11.3263311
12
601 OC DOD
Silver
8/7/2013
TRcs
35.72816647
11.3263311
12
601 OC DOD
Thallium
8/7/2013
TRcs
35.72816647
11.3263311
12
601 OC DOD
Uranium
8/7/2013
TRcs
35.72816647
11.3263311
12
601 OC DOD
Vanadium
8/7/2013
TRcs
35.72816647
11.3263311
12
601 OC DOD
Zinc
8/7/2013
TRcs
35.72816647
11.3263311
12
18
601 OC DOD
Aluminum
8/7/2013
TRcs
35.72816647
11.3263311
12
18
601 OC DOD
Antimony
8/7/2013
TRcs
35.72816647
11.3263311
12
18
601 OC DOD
Arsenic
8/7/2013
TRcs
35.72816647
11.3263311
12
18
601 OC DOD
Barium
8/7/2013
TRcs
35.72816647
11.3263311
12
18
601 OC DOD
Beryllium
Page 12 of 20
-------
Attachment B-1. Data Used in the Risk Assessment
Sample ID
Sample
Date
Geologic
Unit
Latitude
Longitude
Sample
Top Depth
(inches bgs)
Sample
Bottom Depth
(inches bgs)
Analytical
Method
Analyte
Units
Result and
Qualifier
Reporting
Limit
459-SS-2C
8/7/2013
TRcs
35.72816647
-111.3263311
12
18
6010C DOD
Cadmium
mg/kg
1.2
U
NR
459-SS-2C
8/7/2013
TRcs
35.72816647
-111.3263311
12
18
6010C DOD
Chromium
mg/kg
3.7
U
NR
459-SS-2C
8/7/2013
TRcs
35.72816647
-111.3263311
12
18
6010C DOD
Cobalt
mg/kg
47
JD
NR
459-SS-2C
8/7/2013
TRcs
35.72816647
-111.3263311
12
18
6010C DOD
Copper
mg/kg
8.7
U
NR
459-SS-2C
8/7/2013
TRcs
35.72816647
-111.3263311
12
18
6010C DOD
Iron
mg/kg
4,700
D
NR
459-SS-2C
8/7/2013
TRcs
35.72816647
-111.3263311
12
18
6010C DOD
Lead
mg/kg
6
JD
NR
459-SS-2C
8/7/2013
TRcs
35.72816647
-111.3263311
12
18
6010C DOD
Manganese
mg/kg
72
D
NR
459-SS-2C
8/7/2013
TRcs
35.72816647
-111.3263311
12
18
6010C DOD
Mercury
mg/kg
0.033
J
NR
459-SS-2C
8/7/2013
TRcs
35.72816647
-111.3263311
12
18
6010C DOD
Molybdenum
mg/kg
36
JD
NR
459-SS-2C
8/7/2013
TRcs
35.72816647
-111.3263311
12
18
6010C DOD
Nickel
mg/kg
5.4
JD
NR
459-SS-2C
8/7/2013
TRcs
35.72816647
-111.3263311
12
18
GA-01-R
Radium-226
pCi/g
9.76
NR
459-SS-2C
8/7/2013
TRcs
35.72816647
-111.3263311
12
18
601OC DOD
Selenium
mg/kg
3.5
U
NR
459-SS-2C
8/7/2013
TRcs
35.72816647
-111.3263311
12
18
601OC DOD
Silver
mg/kg
2.8
U
NR
459-SS-2C
8/7/2013
TRcs
35.72816647
-111.3263311
12
18
601 OC DOD
Thallium
mg/kg
18
U
NR
459-SS-2C
8/7/2013
TRcs
35.72816647
-111.3263311
12
18
601 OC DOD
Uranium
mg/kg
64
U
NR
459-SS-2C
8/7/2013
TRcs
35.72816647
-111.3263311
12
18
601 OC DOD
Vanadium
mg/kg
15
U
NR
459-SS-2C
8/7/2013
TRcs
35.72816647
-111.3263311
12
18
601 OC DOD
Zinc
mg/kg
24
U
NR
459-TP23-0.5-1.0-120618
12/6/2018
TRcs
35.72805225
-111.326359
6
12
SW6020
Arsenic
mg/kg
8.2
NR
459-TP23-0.5-1.0-120618
12/6/2018
TRcs
35.72805225
-111.326359
6
12
SW7471
Mercury
mg/kg
0.032
NR
459-TP23-0.5-1.0-120618
12/6/2018
TRcs
35.72805225
-111.326359
6
12
SW6010
Molybdenum
mg/kg
55
NR
459-TP23-0.5-1.0-120618
12/6/2018
TRcs
35.72805225
-111.326359
6
12
713R14
Radium-226
pCi/g
19.7
M3,G
NR
459-TP23-0.5-1.0-120618
12/6/2018
TRcs
35.72805225
-111.326359
6
12
SW6010
Selenium
mg/kg
0.17
J
NR
459-TP23-0.5-1.0-120618
12/6/2018
TRcs
35.72805225
-111.326359
6
12
SW6020
Uranium
mg/kg
15
NR
459-TP23-0.5-1.0-120618
12/6/2018
TRcs
35.72805225
-111.326359
6
12
SW6010
Vanadium
mg/kg
9.8
NR
459-TP23-0-0.5-120618
12/6/2018
TRcs
35.72805225
-111.326359
0
6
SW6020
Arsenic
mg/kg
7.1
NR
459-TP23-0-0.5-120618
12/6/2018
TRcs
35.72805225
-111.326359
0
6
SW7471
Mercury
mg/kg
0.019
J
NR
459-TP23-0-0.5-120618
12/6/2018
TRcs
35.72805225
-111.326359
0
6
SW6010
Molybdenum
mg/kg
52
NR
459-TP23-0-0.5-120618
12/6/2018
TRcs
35.72805225
-111.326359
0
6
713R14
Radium-226
pCi/g
15.9
M3
NR
459-TP23-0-0.5-120618
12/6/2018
TRcs
35.72805225
-111.326359
0
6
SW6010
Selenium
mg/kg
0.047
U
NR
459-TP23-0-0.5-120618
12/6/2018
TRcs
35.72805225
-111.326359
0
6
SW6020
Uranium
mg/kg
8.3
NR
459-TP23-0-0.5-120618
12/6/2018
TRcs
35.72805225
-111.326359
0
6
SW6010
Vanadium
mg/kg
6.7
NR
459-TP23-0-0.5-120618 DUP
12/6/2018
TRcs
35.72805225
-111.326359
0
6
SW6020
Arsenic
mg/kg
7.4
NR
459-TP23-0-0.5-120618 DUP
12/6/2018
TRcs
35.72805225
-111.326359
0
6
SW7471
Mercury
mg/kg
0.0069
J
NR
459-TP23-0-0.5-120618 DUP
12/6/2018
TRcs
35.72805225
-111.326359
0
6
SW6010
Molybdenum
mg/kg
38
NR
459-TP23-0-0.5-120618 DUP
12/6/2018
TRcs
35.72805225
-111.326359
0
6
713R14
Radium-226
pCi/g
14
M3
NR
459-TP23-0-0.5-120618 DUP
12/6/2018
TRcs
35.72805225
-111.326359
0
6
SW6010
Selenium
mg/kg
0.053
U
NR
459-TP23-0-0.5-120618 DUP
12/6/2018
TRcs
35.72805225
-111.326359
0
6
SW6020
Uranium
mg/kg
9.7
NR
459-TP23-0-0.5-120618 DUP
12/6/2018
TRcs
35.72805225
-111.326359
0
6
SW6010
Vanadium
mg/kg
5.5
NR
459-TP23-2.5-3.0-120618
12/6/2018
TRcs
35.72805225
-111.326359
30
36
SW6020
Arsenic
mg/kg
8.3
NR
459-TP23-2.5-3.0-120618
12/6/2018
TRcs
35.72805225
-111.326359
30
36
SW7471
Mercury
mg/kg
0.02
J
NR
459-TP23-2.5-3.0-120618
12/6/2018
TRcs
35.72805225
-111.326359
30
36
SW6010
Molybdenum
mg/kg
28
NR
459-TP23-2.5-3.0-120618
12/6/2018
TRcs
35.72805225
-111.326359
30
36
713R14
Radium-226
pCi/g
10.1
M3,G
NR
459-TP23-2.5-3.0-120618
12/6/2018
TRcs
35.72805225
-111.326359
30
36
SW6010
Selenium
mg/kg
0.056
J
NR
459-TP23-2.5-3.0-120618
12/6/2018
TRcs
35.72805225
-111.326359
30
36
SW6020
Uranium
mg/kg
8.9
NR
459-TP23-2.5-3.0-120618
12/6/2018
TRcs
35.72805225
-111.326359
30
36
SW6010
Vanadium
mg/kg
13
NR
APE-SS01-01-020624
2/6/2024
Qay
35.74127889
-111.3309996
0
6
SW6020B
Aluminum
mg/kg
10,500
97700
APE-SS01-01-020624
2/6/2024
Qay
35.74127889
-111.3309996
0
6
SW6010D
Antimony
mg/kg
1.84
U
1840
APE-SS01-01-020624
2/6/2024
Qay
35.74127889
-111.3309996
0
6
SW6020B
Arsenic
mg/kg
4.39
977
APE-SS01-01-020624
2/6/2024
Qay
35.74127889
-111.3309996
0
6
SW6020B
Barium
mg/kg
142
782
APE-SS01-01-020624
2/6/2024
Qay
35.74127889
-111.3309996
0
6
SW6020B
Beryllium
mg/kg
1.57
97.7
APE-SS01-01-020624
2/6/2024
Qay
35.74127889
-111.3309996
0
6
SW6020B
Cadmium
mg/kg
0.244
195
APE-SS01-01-020624
2/6/2024
Qay
35.74127889
-111.3309996
0
6
SW6020B
Chromium
mg/kg
7.46
586
APE-SS01-01-020624
2/6/2024
Qay
35.74127889
-111.3309996
0
6
SW6020B
Cobalt
mg/kg
9.45
195
APE-SS01-01-020624
2/6/2024
Qay
35.74127889
-111.3309996
0
6
SW6020B
Copper
mg/kg
17.8
391
APE-SS01-01-020624
2/6/2024
Qay
35.74127889
-111.3309996
0
6
SW6020B
Iron
mg/kg
13,300
195000
APE-SS01-01-020624
2/6/2024
Qay
35.74127889
-111.3309996
0
6
SW6020B
Lead
mg/kg
12.9
391
APE-SS01-01-020624
2/6/2024
Qay
35.74127889
-111.3309996
0
6
SW6020B
Manganese
mg/kg
68.2
977
APE-SS01-01-020624
2/6/2024
Qay
35.74127889
-111.3309996
0
6
SW7471 B
Mercury
mg/kg
0.118
23.7
APE-SS01-01-020624
2/6/2024
Qay
35.74127889
-111.3309996
0
6
SW6020B
Molybdenum
mg/kg
12.8
195
APE-SS01-01-020624
2/6/2024
Qay
35.74127889
-111.3309996
0
6
SW6020B
Nickel
mg/kg
7.04
391
APE-SS01-01-020624
2/6/2024
Qay
35.74127889
-111.3309996
0
6
EH300
Radium-226
pCi/g
10.4
0.253
APE-SS01-01-020624
2/6/2024
Qay
35.74127889
-111.3309996
0
6
SW6020B
Selenium
mg/kg
2.49
977
APE-SS01-01-020624
2/6/2024
Qay
35.74127889
-111.3309996
0
6
SW6010D
Silver
mg/kg
0.461
U
461
APE-SS01-01-020624
2/6/2024
Qay
35.74127889
-111.3309996
0
6
SW6020B
Thallium
mg/kg
0.768
391
APE-SS01-01-020624
2/6/2024
Qay
35.74127889
-111.3309996
0
6
SW6020B
Uranium
mg/kg
18
39.1
APE-SS01-01-020624
2/6/2024
Qay
35.74127889
-111.3309996
0
6
SW6020B
Vanadium
mg/kg
29.4
3910
APE-SS01-01-020624
2/6/2024
Qay
35.74127889
-111.3309996
0
6
SW6020B
Zinc
mg/kg
21.5
3910
APE-SS02-01-020624
2/6/2024
TRcp
35.74136614
-111.3270867
0
6
SW6020B
Aluminum
mg/kg
6,560
9810
APE-SS02-01-020624
2/6/2024
TRcp
35.74136614
-111.3270867
0
6
SW6010D
Antimony
mg/kg
1.79
U
1790
APE-SS02-01-020624
2/6/2024
TRcp
35.74136614
-111.3270867
0
6
SW6020B
Arsenic
mg/kg
1.2
981
APE-SS02-01-020624
2/6/2024
TRcp
35.74136614
-111.3270867
0
6
SW6020B
Barium
mg/kg
424
7850
APE-SS02-01-020624
2/6/2024
TRcp
35.74136614
-111.3270867
0
6
SW6020B
Beryllium
mg/kg
0.571
98.1
APE-SS02-01-020624
2/6/2024
TRcp
35.74136614
-111.3270867
0
6
SW6020B
Cadmium
mg/kg
0.0715
J
196
APE-SS02-01-020624
2/6/2024
TRcp
35.74136614
-111.3270867
0
6
SW6020B
Chromium
mg/kg
8.28
589
APE-SS02-01-020624
2/6/2024
TRcp
35.74136614
-111.3270867
0
6
SW6020B
Cobalt
mg/kg
5.03
196
APE-SS02-01-020624
2/6/2024
TRcp
35.74136614
-111.3270867
0
6
SW6020B
Copper
mg/kg
9.36
393
APE-SS02-01-020624
2/6/2024
TRcp
35.74136614
-111.3270867
0
6
SW6020B
Iron
mg/kg
15,200
196000
APE-SS02-01-020624
2/6/2024
TRcp
35.74136614
-111.3270867
0
6
SW6020B
Lead
mg/kg
7.34
393
APE-SS02-01-020624
2/6/2024
TRcp
35.74136614
-111.3270867
0
6
SW6020B
Manganese
mg/kg
385
9810
APE-SS02-01-020624
2/6/2024
TRcp
35.74136614
-111.3270867
0
6
SW7471 B
Mercury
mg/kg
0.0242
U
24.2
APE-SS02-01-020624
2/6/2024
TRcp
35.74136614
-111.3270867
0
6
SW6020B
Molybdenum
mg/kg
0.413
196
APE-SS02-01-020624
2/6/2024
TRcp
35.74136614
-111.3270867
0
6
SW6020B
Nickel
mg/kg
12.5
393
APE-SS02-01-020624
2/6/2024
TRcp
35.74136614
-111.3270867
0
6
EH300
Radium-226
pCi/g
1.94
0.118
APE-SS02-01-020624
2/6/2024
TRcp
35.74136614
-111.3270867
0
6
SW6020B
Selenium
mg/kg
1.5
981
APE-SS02-01-020624
2/6/2024
TRcp
35.74136614
-111.3270867
0
6
SW6010D
Silver
mg/kg
0.447
U
447
APE-SS02-01-020624
2/6/2024
TRcp
35.74136614
-111.3270867
0
6
SW6020B
Thallium
mg/kg
0.393
U
393
APE-SS02-01-020624
2/6/2024
TRcp
35.74136614
-111.3270867
0
6
SW6020B
Uranium
mg/kg
2.87
39.3
APE-SS02-01-020624
2/6/2024
TRcp
35.74136614
-111.3270867
0
6
SW6020B
Vanadium
mg/kg
32.9
3930
Page 13 of 20
-------
Attachment B-1. Data Used in the Risk Assessment
Sample ID
Sample
Date
Geologic
Unit
Latitude
Longitude
Sample
Top Depth
(inches bgs)
Sample
Bottom Depth
(inches bgs)
Analytical
Method
Analyte
Units
Result and
Qualifier
Reporting
Limit
APE-SS02-01-020624
2/6/2024
TRcp
35.74136614
-111.3270867
0
6
SW6020B
Zinc
mg/kg
11.4
3930
APE-SS03-01-020624
2/6/2024
TRcp
35.73871225
-111.3362055
0
6
SW6020B
Aluminum
mg/kg
12,100
98000
APE-SS03-01-020624
2/6/2024
TRcp
35.73871225
-111.3362055
0
6
SW6010D
Antimony
mg/kg
1.85
U
1850
APE-SS03-01-020624
2/6/2024
TRcp
35.73871225
-111.3362055
0
6
SW6020B
Arsenic
mg/kg
3.55
980
APE-SS03-01-020624
2/6/2024
TRcp
35.73871225
-111.3362055
0
6
SW6020B
Barium
mg/kg
24.8
784
APE-SS03-01-020624
2/6/2024
TRcp
35.73871225
-111.3362055
0
6
SW6020B
Beryllium
mg/kg
1.19
98
APE-SS03-01-020624
2/6/2024
TRcp
35.73871225
-111.3362055
0
6
SW6020B
Cadmium
mg/kg
0.196
U
196
APE-SS03-01-020624
2/6/2024
TRcp
35.73871225
-111.3362055
0
6
SW6020B
Chromium
mg/kg
5.01
588
APE-SS03-01-020624
2/6/2024
TRcp
35.73871225
-111.3362055
0
6
SW6020B
Cobalt
mg/kg
4.95
196
APE-SS03-01-020624
2/6/2024
TRcp
35.73871225
-111.3362055
0
6
SW6020B
Copper
mg/kg
8.2
392
APE-SS03-01-020624
2/6/2024
TRcp
35.73871225
-111.3362055
0
6
SW6020B
Iron
mg/kg
17,400
196000
APE-SS03-01-020624
2/6/2024
TRcp
35.73871225
-111.3362055
0
6
SW6020B
Lead
mg/kg
6.65
392
APE-SS03-01-020624
2/6/2024
TRcp
35.73871225
-111.3362055
0
6
SW6020B
Manganese
mg/kg
50.1
980
APE-SS03-01-020624
2/6/2024
TRcp
35.73871225
-111.3362055
0
6
SW7471B
Mercury
mg/kg
0.0224
U
22.4
APE-SS03-01-020624
2/6/2024
TRcp
35.73871225
-111.3362055
0
6
SW6020B
Molybdenum
mg/kg
0.133
J
196
APE-SS03-01-020624
2/6/2024
TRcp
35.73871225
-111.3362055
0
6
SW6020B
Nickel
mg/kg
5.26
392
APE-SS03-01-020624
2/6/2024
TRcp
35.73871225
-111.3362055
0
6
EH300
Radium-226
pCi/g
2.83
0.162
APE-SS03-01-020624
2/6/2024
TRcp
35.73871225
-111.3362055
0
6
SW6020B
Selenium
mg/kg
2.3
980
APE-SS03-01-020624
2/6/2024
TRcp
35.73871225
-111.3362055
0
6
SW6010D
Silver
mg/kg
0.462
U
462
APE-SS03-01-020624
2/6/2024
TRcp
35.73871225
-111.3362055
0
6
SW6020B
Thallium
mg/kg
0.283
J
392
APE-SS03-01-020624
2/6/2024
TRcp
35.73871225
-111.3362055
0
6
SW6020B
Uranium
mg/kg
3.77
39.2
APE-SS03-01-020624
2/6/2024
TRcp
35.73871225
-111.3362055
0
6
SW6020B
Vanadium
mg/kg
19.1
3920
APE-SS03-01-020624
2/6/2024
TRcp
35.73871225
-111.3362055
0
6
SW6020B
Zinc
mg/kg
23
3920
APE-SS04-01-020624
2/6/2024
Qay
35.73902991
-111.3262952
0
6
SW6020B
Aluminum
mg/kg
18,400
92700
APE-SS04-01-020624
2/6/2024
Qay
35.73902991
-111.3262952
0
6
SW6010D
Antimony
mg/kg
2.04
U
2040
APE-SS04-01-020624
2/6/2024
Qay
35.73902991
-111.3262952
0
6
SW6020B
Arsenic
mg/kg
1.71
927
APE-SS04-01-020624
2/6/2024
Qay
35.73902991
-111.3262952
0
6
SW6020B
Barium
mg/kg
347
7410
APE-SS04-01-020624
2/6/2024
Qay
35.73902991
-111.3262952
0
6
SW6020B
Beryllium
mg/kg
1.18
92.7
APE-SS04-01-020624
2/6/2024
Qay
35.73902991
-111.3262952
0
6
SW6020B
Cadmium
mg/kg
0.0378
J
185
APE-SS04-01-020624
2/6/2024
Qay
35.73902991
-111.3262952
0
6
SW6020B
Chromium
mg/kg
7.78
556
APE-SS04-01-020624
2/6/2024
Qay
35.73902991
-111.3262952
0
6
SW6020B
Cobalt
mg/kg
4.72
185
APE-SS04-01-020624
2/6/2024
Qay
35.73902991
-111.3262952
0
6
SW6020B
Copper
mg/kg
12.8
371
APE-SS04-01-020624
2/6/2024
Qay
35.73902991
-111.3262952
0
6
SW6020B
Iron
mg/kg
15,900
185000
APE-SS04-01-020624
2/6/2024
Qay
35.73902991
-111.3262952
0
6
SW6020B
Lead
mg/kg
9.86
371
APE-SS04-01-020624
2/6/2024
Qay
35.73902991
-111.3262952
0
6
SW6020B
Manganese
mg/kg
155
927
APE-SS04-01-020624
2/6/2024
Qay
35.73902991
-111.3262952
0
6
SW7471B
Mercury
mg/kg
0.0236
U
23.6
APE-SS04-01-020624
2/6/2024
Qay
35.73902991
-111.3262952
0
6
SW6020B
Molybdenum
mg/kg
1.26
185
APE-SS04-01-020624
2/6/2024
Qay
35.73902991
-111.3262952
0
6
SW6020B
Nickel
mg/kg
4.75
371
APE-SS04-01-020624
2/6/2024
Qay
35.73902991
-111.3262952
0
6
EH 300
Radium-226
pCi/g
2.3
0.198
APE-SS04-01-020624
2/6/2024
Qay
35.73902991
-111.3262952
0
6
SW6020B
Selenium
mg/kg
2.23
927
APE-SS04-01-020624
2/6/2024
Qay
35.73902991
-111.3262952
0
6
SW6010D
Silver
mg/kg
0.51
U
510
APE-SS04-01-020624
2/6/2024
Qay
35.73902991
-111.3262952
0
6
SW6020B
Thallium
mg/kg
0.143
J
371
APE-SS04-01-020624
2/6/2024
Qay
35.73902991
-111.3262952
0
6
SW6020B
Uranium
mg/kg
3.56
37.1
APE-SS04-01-020624
2/6/2024
Qay
35.73902991
-111.3262952
0
6
SW6020B
Vanadium
mg/kg
32
3710
APE-SS04-01-020624
2/6/2024
Qay
35.73902991
-111.3262952
0
6
SW6020B
Zinc
mg/kg
19.9
3710
APE-SS05-01-020624
2/6/2024
TRcs
35.73613483
-111.3298466
0
6
SW6020B
Aluminum
mg/kg
6,070
9210
APE-SS05-01-020624
2/6/2024
TRcs
35.73613483
-111.3298466
0
6
SW6010D
Antimony
mg/kg
2.01
U
2010
APE-SS05-01-020624
2/6/2024
TRcs
35.73613483
-111.3298466
0
6
SW6020B
Arsenic
mg/kg
1.71
921
APE-SS05-01-020624
2/6/2024
TRcs
35.73613483
-111.3298466
0
6
SW6020B
Barium
mg/kg
198
7370
APE-SS05-01-020624
2/6/2024
TRcs
35.73613483
-111.3298466
0
6
SW6020B
Beryllium
mg/kg
0.538
92.1
APE-SS05-01-020624
2/6/2024
TRcs
35.73613483
-111.3298466
0
6
SW6020B
Cadmium
mg/kg
0.0241
J
184
APE-SS05-01-020624
2/6/2024
TRcs
35.73613483
-111.3298466
0
6
SW6020B
Chromium
mg/kg
2.82
553
APE-SS05-01-020624
2/6/2024
TRcs
35.73613483
-111.3298466
0
6
SW6020B
Cobalt
mg/kg
1.87
184
APE-SS05-01-020624
2/6/2024
TRcs
35.73613483
-111.3298466
0
6
SW6020B
Copper
mg/kg
6.64
369
APE-SS05-01-020624
2/6/2024
TRcs
35.73613483
-111.3298466
0
6
SW6020B
Iron
mg/kg
5,130
18400
APE-SS05-01-020624
2/6/2024
TRcs
35.73613483
-111.3298466
0
6
SW6020B
Lead
mg/kg
4.48
369
APE-SS05-01-020624
2/6/2024
TRcs
35.73613483
-111.3298466
0
6
SW6020B
Manganese
mg/kg
119
921
APE-SS05-01-020624
2/6/2024
TRcs
35.73613483
-111.3298466
0
6
SW7471 B
Mercury
mg/kg
0.0214
U
21.4
APE-SS05-01-020624
2/6/2024
TRcs
35.73613483
-111.3298466
0
6
SW6020B
Molybdenum
mg/kg
0.258
184
APE-SS05-01-020624
2/6/2024
TRcs
35.73613483
-111.3298466
0
6
SW6020B
Nickel
mg/kg
2.24
369
APE-SS05-01-020624
2/6/2024
TRcs
35.73613483
-111.3298466
0
6
EH300
Radium-226
pCi/g
1.35
0.176
APE-SS05-01-020624
2/6/2024
TRcs
35.73613483
-111.3298466
0
6
SW6020B
Selenium
mg/kg
3.15
921
APE-SS05-01-020624
2/6/2024
TRcs
35.73613483
-111.3298466
0
6
SW6010D
Silver
mg/kg
0.501
U
501
APE-SS05-01-020624
2/6/2024
TRcs
35.73613483
-111.3298466
0
6
SW6020B
Thallium
mg/kg
0.369
U
369
APE-SS05-01-020624
2/6/2024
TRcs
35.73613483
-111.3298466
0
6
SW6020B
Uranium
mg/kg
1.58
36.9
APE-SS05-01-020624
2/6/2024
TRcs
35.73613483
-111.3298466
0
6
SW6020B
Vanadium
mg/kg
12.9
3690
APE-SS05-01-020624
2/6/2024
TRcs
35.73613483
-111.3298466
0
6
SW6020B
Zinc
mg/kg
10.8
3690
APE-SS06-01-020624
2/6/2024
Qay
35.73580051
-111.324986
0
6
SW6020B
Aluminum
mg/kg
6,710
9280
APE-SS06-01-020624
2/6/2024
Qay
35.73580051
-111.324986
0
6
SW6010D
Antimony
mg/kg
1.81
U
1810
APE-SS06-01-020624
2/6/2024
Qay
35.73580051
-111.324986
0
6
SW6020B
Arsenic
mg/kg
0.749
J
928
APE-SS06-01-020624
2/6/2024
Qay
35.73580051
-111.324986
0
6
SW6020B
Barium
mg/kg
223
7430
APE-SS06-01-020624
2/6/2024
Qay
35.73580051
-111.324986
0
6
SW6020B
Beryllium
mg/kg
0.726
92.8
APE-SS06-01-020624
2/6/2024
Qay
35.73580051
-111.324986
0
6
SW6020B
Cadmium
mg/kg
0.122
J
186
APE-SS06-01-020624
2/6/2024
Qay
35.73580051
-111.324986
0
6
SW6020B
Chromium
mg/kg
5
557
APE-SS06-01-020624
2/6/2024
Qay
35.73580051
-111.324986
0
6
SW6020B
Cobalt
mg/kg
3.5
186
APE-SS06-01-020624
2/6/2024
Qay
35.73580051
-111.324986
0
6
SW6020B
Copper
mg/kg
6.99
371
APE-SS06-01-020624
2/6/2024
Qay
35.73580051
-111.324986
0
6
SW6020B
Iron
mg/kg
8,130
18600
APE-SS06-01-020624
2/6/2024
Qay
35.73580051
-111.324986
0
6
SW6020B
Lead
mg/kg
5.4
371
APE-SS06-01-020624
2/6/2024
Qay
35.73580051
-111.324986
0
6
SW6020B
Manganese
mg/kg
110
928
APE-SS06-01-020624
2/6/2024
Qay
35.73580051
-111.324986
0
6
SW7471B
Mercury
mg/kg
0.0116
J
22.1
APE-SS06-01-020624
2/6/2024
Qay
35.73580051
-111.324986
0
6
SW6020B
Molybdenum
mg/kg
0.4
186
APE-SS06-01-020624
2/6/2024
Qay
35.73580051
-111.324986
0
6
SW6020B
Nickel
mg/kg
4.57
371
APE-SS06-01-020624
2/6/2024
Qay
35.73580051
-111.324986
0
6
EH 300
Radium-226
pCi/g
1.51
0.144
APE-SS06-01-020624
2/6/2024
Qay
35.73580051
-111.324986
0
6
SW6020B
Selenium
mg/kg
0.795
J
928
APE-SS06-01-020624
2/6/2024
Qay
35.73580051
-111.324986
0
6
SW601OD
Silver
mg/kg
0.454
U
454
APE-SS06-01-020624
2/6/2024
Qay
35.73580051
-111.324986
0
6
SW6020B
Thallium
mg/kg
0.371
U
371
APE-SS06-01-020624
2/6/2024
Qay
35.73580051
-111.324986
0
6
SW6020B
Uranium
mg/kg
1.73
37.1
APE-SS06-01-020624
2/6/2024
Qay
35.73580051
-111.324986
0
6
SW6020B
Vanadium
mg/kg
17
3710
Page 14 of 20
-------
Attachment B-1. Data Used in the Risk Assessment
Sample ID
Sample
Date
Geologic
Unit
Latitude
Longitude
Sample
Top Depth
(inches bgs)
Sample
Bottom Depth
(inches bgs)
Analytical
Method
Analyte
Units
Result and
Qualifier
Reporting
Limit
APE-SS06-01-020624
2/6/2024
Qay
35.73580051
-111.324986
0
6
SW6020B
Zinc
mg/kg
9.15
3710
APE-SS07-01-020624
2/6/2024
TRcs
35.73422809
-111.3323634
0
6
SW6020B
Aluminum
mg/kg
2,210
9210
APE-SS07-01-020624
2/6/2024
TRcs
35.73422809
-111.3323634
0
6
SW6010D
Antimony
mg/kg
1.8
U
1800
APE-SS07-01-020624
2/6/2024
TRcs
35.73422809
-111.3323634
0
6
SW6020B
Arsenic
mg/kg
9.09
921
APE-SS07-01-020624
2/6/2024
TRcs
35.73422809
-111.3323634
0
6
SW6020B
Barium
mg/kg
52.2
737
APE-SS07-01-020624
2/6/2024
TRcs
35.73422809
-111.3323634
0
6
SW6020B
Beryllium
mg/kg
0.373
92.1
APE-SS07-01-020624
2/6/2024
TRcs
35.73422809
-111.3323634
0
6
SW6020B
Cadmium
mg/kg
0.125
J
184
APE-SS07-01-020624
2/6/2024
TRcs
35.73422809
-111.3323634
0
6
SW6020B
Chromium
mg/kg
3.05
J
553
APE-SS07-01-020624
2/6/2024
TRcs
35.73422809
-111.3323634
0
6
SW6020B
Cobalt
mg/kg
0.641
184
APE-SS07-01-020624
2/6/2024
TRcs
35.73422809
-111.3323634
0
6
SW6020B
Copper
mg/kg
5.48
368
APE-SS07-01-020624
2/6/2024
TRcs
35.73422809
-111.3323634
0
6
SW7196A
xavalent Chromi
mg/kg
0.247
J
0.318
APE-SS07-01-020624
2/6/2024
TRcs
35.73422809
-111.3323634
0
6
SW6020B
Iron
mg/kg
1,660
18400
APE-SS07-01-020624
2/6/2024
TRcs
35.73422809
-111.3323634
0
6
SW6020B
Lead
mg/kg
4.03
J
368
APE-SS07-01-020624
2/6/2024
TRcs
35.73422809
-111.3323634
0
6
SW6020B
Manganese
mg/kg
4.96
921
APE-SS07-01-020624
2/6/2024
TRcs
35.73422809
-111.3323634
0
6
SW7471B
Mercury
mg/kg
0.0121
J
23.3
APE-SS07-01-020624
2/6/2024
TRcs
35.73422809
-111.3323634
0
6
SW6020B
Molybdenum
mg/kg
110
184
APE-SS07-01-020624
2/6/2024
TRcs
35.73422809
-111.3323634
0
6
SW6020B
Nickel
mg/kg
0.437
368
APE-SS07-01-020624
2/6/2024
TRcs
35.73422809
-111.3323634
0
6
EH300
Radium-226
pCi/g
15.4
0.314
APE-SS07-01-020624
2/6/2024
TRcs
35.73422809
-111.3323634
0
6
SW6020B
Selenium
mg/kg
1.28
921
APE-SS07-01-020624
2/6/2024
TRcs
35.73422809
-111.3323634
0
6
SW6010D
Silver
mg/kg
0.45
U
450
APE-SS07-01-020624
2/6/2024
TRcs
35.73422809
-111.3323634
0
6
SW6020B
Thallium
mg/kg
0.413
368
APE-SS07-01-020624
2/6/2024
TRcs
35.73422809
-111.3323634
0
6
SW6020B
Uranium
mg/kg
18.3
J
36.8
APE-SS07-01-020624
2/6/2024
TRcs
35.73422809
-111.3323634
0
6
SW6020B
Vanadium
mg/kg
5.09
J
3680
APE-SS07-01-020624
2/6/2024
TRcs
35.73422809
-111.3323634
0
6
SW6020B
Zinc
mg/kg
2.69
J
3680
APE-SS08-01-020624
2/6/2024
TRcs
35.73262085
-111.3290006
0
6
SW6020B
Aluminum
mg/kg
3,650
9310
APE-SS08-01-020624
2/6/2024
TRcs
35.73262085
-111.3290006
0
6
SW6010D
Antimony
mg/kg
1.89
U
1890
APE-SS08-01-020624
2/6/2024
TRcs
35.73262085
-111.3290006
0
6
SW6020B
Arsenic
mg/kg
0.961
931
APE-SS08-01-020624
2/6/2024
TRcs
35.73262085
-111.3290006
0
6
SW6020B
Barium
mg/kg
238
7450
APE-SS08-01-020624
2/6/2024
TRcs
35.73262085
-111.3290006
0
6
SW6020B
Beryllium
mg/kg
0.333
93.1
APE-SS08-01-020624
2/6/2024
TRcs
35.73262085
-111.3290006
0
6
SW6020B
Cadmium
mg/kg
0.186
U
186
APE-SS08-01-020624
2/6/2024
TRcs
35.73262085
-111.3290006
0
6
SW6020B
Chromium
mg/kg
3.57
559
APE-SS08-01-020624
2/6/2024
TRcs
35.73262085
-111.3290006
0
6
SW6020B
Cobalt
mg/kg
2.03
186
APE-SS08-01-020624
2/6/2024
TRcs
35.73262085
-111.3290006
0
6
SW6020B
Copper
mg/kg
4.87
373
APE-SS08-01-020624
2/6/2024
TRcs
35.73262085
-111.3290006
0
6
SW6020B
Iron
mg/kg
6,150
18600
APE-SS08-01-020624
2/6/2024
TRcs
35.73262085
-111.3290006
0
6
SW6020B
Lead
mg/kg
4.27
373
APE-SS08-01-020624
2/6/2024
TRcs
35.73262085
-111.3290006
0
6
SW6020B
Manganese
mg/kg
176
931
APE-SS08-01-020624
2/6/2024
TRcs
35.73262085
-111.3290006
0
6
SW7471B
Mercury
mg/kg
0.0216
U
21.6
APE-SS08-01-020624
2/6/2024
TRcs
35.73262085
-111.3290006
0
6
SW6020B
Molybdenum
mg/kg
0.245
186
APE-SS08-01-020624
2/6/2024
TRcs
35.73262085
-111.3290006
0
6
SW6020B
Nickel
mg/kg
4.36
373
APE-SS08-01-020624
2/6/2024
TRcs
35.73262085
-111.3290006
0
6
EH300
Radium-226
pCi/g
1.27
0.119
APE-SS08-01-020624
2/6/2024
TRcs
35.73262085
-111.3290006
0
6
SW6020B
Selenium
mg/kg
1.49
931
APE-SS08-01-020624
2/6/2024
TRcs
35.73262085
-111.3290006
0
6
SW6010D
Silver
mg/kg
0.0999
J-
473
APE-SS08-01-020624
2/6/2024
TRcs
35.73262085
-111.3290006
0
6
SW6020B
Thallium
mg/kg
0.373
U
373
APE-SS08-01-020624
2/6/2024
TRcs
35.73262085
-111.3290006
0
6
SW6020B
Uranium
mg/kg
0.99
37.3
APE-SS08-01-020624
2/6/2024
TRcs
35.73262085
-111.3290006
0
6
SW6020B
Vanadium
mg/kg
12.4
3730
APE-SS08-01-020624
2/6/2024
TRcs
35.73262085
-111.3290006
0
6
SW6020B
Zinc
mg/kg
8.46
3730
APE-SS09-01-020624
2/6/2024
TRcs
35.73250079
-111.3257922
0
6
SW6020B
Aluminum
mg/kg
3,670
9350
APE-SS09-01-020624
2/6/2024
TRcs
35.73250079
-111.3257922
0
6
SW6010D
Antimony
mg/kg
1.81
U
1810
APE-SS09-01-020624
2/6/2024
TRcs
35.73250079
-111.3257922
0
6
SW6020B
Arsenic
mg/kg
4.07
935
APE-SS09-01-020624
2/6/2024
TRcs
35.73250079
-111.3257922
0
6
SW6020B
Barium
mg/kg
212
7480
APE-SS09-01-020624
2/6/2024
TRcs
35.73250079
-111.3257922
0
6
SW6020B
Beryllium
mg/kg
0.408
93.5
APE-SS09-01-020624
2/6/2024
TRcs
35.73250079
-111.3257922
0
6
SW6020B
Cadmium
mg/kg
0.187
U
187
APE-SS09-01-020624
2/6/2024
TRcs
35.73250079
-111.3257922
0
6
SW6020B
Chromium
mg/kg
3.19
561
APE-SS09-01-020624
2/6/2024
TRcs
35.73250079
-111.3257922
0
6
SW6020B
Cobalt
mg/kg
5.32
187
APE-SS09-01-020624
2/6/2024
TRcs
35.73250079
-111.3257922
0
6
SW6020B
Copper
mg/kg
6.15
374
APE-SS09-01-020624
2/6/2024
TRcs
35.73250079
-111.3257922
0
6
SW6020B
Iron
mg/kg
6,110
18700
APE-SS09-01-020624
2/6/2024
TRcs
35.73250079
-111.3257922
0
6
SW6020B
Lead
mg/kg
6.33
374
APE-SS09-01-020624
2/6/2024
TRcs
35.73250079
-111.3257922
0
6
SW6020B
Manganese
mg/kg
104
935
APE-SS09-01-020624
2/6/2024
TRcs
35.73250079
-111.3257922
0
6
SW7471B
Mercury
mg/kg
0.016
J
21.2
APE-SS09-01-020624
2/6/2024
TRcs
35.73250079
-111.3257922
0
6
SW6020B
Molybdenum
mg/kg
7.74
187
APE-SS09-01-020624
2/6/2024
TRcs
35.73250079
-111.3257922
0
6
SW6020B
Nickel
mg/kg
3.69
374
APE-SS09-01-020624
2/6/2024
TRcs
35.73250079
-111.3257922
0
6
EH300
Radium-226
pCi/g
5.67
0.164
APE-SS09-01-020624
2/6/2024
TRcs
35.73250079
-111.3257922
0
6
SW6020B
Selenium
mg/kg
1.06
935
APE-SS09-01-020624
2/6/2024
TRcs
35.73250079
-111.3257922
0
6
SW6010D
Silver
mg/kg
0.453
U
453
APE-SS09-01-020624
2/6/2024
TRcs
35.73250079
-111.3257922
0
6
SW6020B
Thallium
mg/kg
0.389
374
APE-SS09-01-020624
2/6/2024
TRcs
35.73250079
-111.3257922
0
6
SW6020B
Uranium
mg/kg
5.92
37.4
APE-SS09-01-020624
2/6/2024
TRcs
35.73250079
-111.3257922
0
6
SW6020B
Vanadium
mg/kg
11.6
3740
APE-SS09-01-020624
2/6/2024
TRcs
35.73250079
-111.3257922
0
6
SW6020B
Zinc
mg/kg
13.2
3740
APE-SS10-01-020624
2/6/2024
Qay
35.72981921
-111.32459
0
6
SW6020B
Aluminum
mg/kg
7,620
8620
APE-SS10-01-020624
2/6/2024
Qay
35.72981921
-111.32459
0
6
SW6010D
Antimony
mg/kg
1.73
U
1730
APE-SS10-01-020624
2/6/2024
Qay
35.72981921
-111.32459
0
6
SW6020B
Arsenic
mg/kg
1.28
862
APE-SS10-01-020624
2/6/2024
Qay
35.72981921
-111.32459
0
6
SW6020B
Barium
mg/kg
273
6900
APE-SS10-01-020624
2/6/2024
Qay
35.72981921
-111.32459
0
6
SW6020B
Beryllium
mg/kg
0.468
86.2
APE-SS10-01-020624
2/6/2024
Qay
35.72981921
-111.32459
0
6
SW6020B
Cadmium
mg/kg
0.172
U
172
APE-SS10-01-020624
2/6/2024
Qay
35.72981921
-111.32459
0
6
SW6020B
Chromium
mg/kg
8.51
517
APE-SS10-01-020624
2/6/2024
Qay
35.72981921
-111.32459
0
6
SW6020B
Cobalt
mg/kg
4.98
172
APE-SS10-01-020624
2/6/2024
Qay
35.72981921
-111.32459
0
6
SW6020B
Copper
mg/kg
8.69
345
APE-SS10-01-020624
2/6/2024
Qay
35.72981921
-111.32459
0
6
SW7196A
xavalent Chromi
mg/kg
0.145
U
0.361
APE-SS10-01-020624
2/6/2024
Qay
35.72981921
-111.32459
0
6
SW6020B
Iron
mg/kg
10,800
172000
APE-SS10-01-020624
2/6/2024
Qay
35.72981921
-111.32459
0
6
SW6020B
Lead
mg/kg
5.29
345
APE-SS10-01-020624
2/6/2024
Qay
35.72981921
-111.32459
0
6
SW6020B
Manganese
mg/kg
262
8620
APE-SS10-01-020624
2/6/2024
Qay
35.72981921
-111.32459
0
6
SW7471B
Mercury
mg/kg
0.0224
U
22.4
APE-SS10-01-020624
2/6/2024
Qay
35.72981921
-111.32459
0
6
SW6020B
Molybdenum
mg/kg
0.553
172
APE-SS10-01-020624
2/6/2024
Qay
35.72981921
-111.32459
0
6
SW6020B
Nickel
mg/kg
13.2
345
APE-SS10-01-020624
2/6/2024
Qay
35.72981921
-111.32459
0
6
EH 300
Radium-226
pCi/g
1.41
0.111
APE-SS10-01-020624
2/6/2024
Qay
35.72981921
-111.32459
0
6
SW6020B
Selenium
mg/kg
1.14
862
APE-SS10-01-020624
2/6/2024
Qay
35.72981921
-111.32459
0
6
SW6010D
Silver
mg/kg
0.433
U
433
APE-SS10-01-020624
2/6/2024
Qay
35.72981921
-111.32459
0
6
SW6020B
Thallium
mg/kg
0.345
U
345
Page 15 of 20
-------
Attachment B-1. Data Used in the Risk Assessment
Sample ID
Sample
Date
Geologic
Unit
Latitude
Longitude
Sample
Top Depth
(inches bgs)
Sample
Bottom Depth
(inches bgs)
Analytical
Method
Analyte
Units
Result and
Qualifier
Reporting
Limit
APE-SS10-01-020624
2/6/2024
Qay
35.72981921
-111.32459
0
6
SW6020B
Uranium
mg/kg
1.23
34.5
APE-SS10-01-020624
2/6/2024
Qay
35.72981921
-111.32459
0
6
SW6020B
Vanadium
mg/kg
21
3450
APE-SS10-01-020624
2/6/2024
Qay
35.72981921
-111.32459
0
6
SW6020B
Zinc
mg/kg
16.4
3450
Drain-TP16-0-0.5-120318
12/3/2018
Qay
35.73125649
-111.3266748
0
6
SW6020
Arsenic
mg/kg
1.7
NR
Drain-TP16-0-0.5-120318
12/3/2018
Qay
35.73125649
-111.3266748
0
6
SW7471
Mercury
mg/kg
5.8E-05 U
NR
Drain-TP16-0-0.5-120318
12/3/2018
Qay
35.73125649
-111.3266748
0
6
SW6010
Molybdenum
mg/kg
0.27 J
NR
Drain-TP16-0-0.5-120318
12/3/2018
Qay
35.73125649
-111.3266748
0
6
713R14
Radium-226
pCi/g
1.23 M3
NR
Drain-TP16-0-0.5-120318
12/3/2018
Qay
35.73125649
-111.3266748
0
6
SW6010
Selenium
mg/kg
0.051 U
NR
Drain-TP16-0-0.5-120318
12/3/2018
Qay
35.73125649
-111.3266748
0
6
SW6020
Uranium
mg/kg
1.3
NR
Drain-TP16-0-0.5-120318
12/3/2018
Qay
35.73125649
-111.3266748
0
6
SW6010
Vanadium
mg/kg
24
NR
Drain-TP16-1.0-1.5-120318
12/3/2018
Qay
35.73125649
-111.3266748
12
18
SW6020
Arsenic
mg/kg
2
NR
Drain-TP16-1.0-1.5-120318
12/3/2018
Qay
35.73125649
-111.3266748
12
18
SW7471
Mercury
mg/kg
6.2E-05 U
NR
Drain-TP16-1.0-1.5-120318
12/3/2018
Qay
35.73125649
-111.3266748
12
18
SW6010
Molybdenum
mg/kg
0.2 J
NR
Drain-TP16-1.0-1.5-120318
12/3/2018
Qay
35.73125649
-111.3266748
12
18
713R14
Radium-226
pCi/g
1.2 M3,G
NR
Drain-TP16-1.0-1.5-120318
12/3/2018
Qay
35.73125649
-111.3266748
12
18
SW6010
Selenium
mg/kg
0.052 U
NR
Drain-TP16-1.0-1.5-120318
12/3/2018
Qay
35.73125649
-111.3266748
12
18
SW6020
Uranium
mg/kg
1.3
NR
Drain-TP16-1.0-1.5-120318
12/3/2018
Qay
35.73125649
-111.3266748
12
18
SW6010
Vanadium
mg/kg
29
NR
Drain-TP2-0.5-1.0-120418
12/4/2018
Qay
35.74170359
-111.3242333
6
12
SW6020
Arsenic
mg/kg
3.7
NR
Drain-TP2-0.5-1.0-120418
12/4/2018
Qay
35.74170359
-111.3242333
6
12
SW7471
Mercury
mg/kg
0.0065 J
NR
Drain-TP2-0.5-1.0-120418
12/4/2018
Qay
35.74170359
-111.3242333
6
12
SW6010
Molybdenum
mg/kg
3.5
NR
Drain-TP2-0.5-1.0-120418
12/4/2018
Qay
35.74170359
-111.3242333
6
12
713R14
Radium-226
pCi/g
2.82 M3,G
NR
Drain-TP2-0.5-1.0-120418
12/4/2018
Qay
35.74170359
-111.3242333
6
12
SW6010
Selenium
mg/kg
0.051 U
NR
Drain-TP2-0.5-1.0-120418
12/4/2018
Qay
35.74170359
-111.3242333
6
12
SW6020
Uranium
mg/kg
3.4
NR
Drain-TP2-0.5-1.0-120418
12/4/2018
Qay
35.74170359
-111.3242333
6
12
SW6010
Vanadium
mg/kg
41
NR
Drain-TP2-1.0-1.5-120418
12/4/2018
Qay
35.74170359
-111.3242333
12
18
SW6020
Arsenic
mg/kg
3.4
NR
Drain-TP2-1.0-1.5-120418
12/4/2018
Qay
35.74170359
-111.3242333
12
18
SW7471
Mercury
mg/kg
0.0012 J
NR
Drain-TP2-1.0-1.5-120418
12/4/2018
Qay
35.74170359
-111.3242333
12
18
SW6010
Molybdenum
mg/kg
2.1
NR
Drain-TP2-1.0-1.5-120418
12/4/2018
Qay
35.74170359
-111.3242333
12
18
713R14
Radium-226
pCi/g
2.69 M3,G
NR
Drain-TP2-1.0-1.5-120418
12/4/2018
Qay
35.74170359
-111.3242333
12
18
SW6010
Selenium
mg/kg
0.058 U
NR
Drain-TP2-1.0-1.5-120418
12/4/2018
Qay
35.74170359
-111.3242333
12
18
SW6020
Uranium
mg/kg
3.9
NR
Drain-TP2-1.0-1.5-120418
12/4/2018
Qay
35.74170359
-111.3242333
12
18
SW6010
Vanadium
mg/kg
42
NR
Drain-TP7-0-0.5-120418
12/4/2018
TRcs
35.73951855
-111.3235367
0
6
SW6020
Arsenic
mg/kg
2.7
NR
Drain-TP7-0-0.5-120418
12/4/2018
TRcs
35.73951855
-111.3235367
0
6
SW7471
Mercury
mg/kg
6.2E-05 U
NR
Drain-TP7-0-0.5-120418
12/4/2018
TRcs
35.73951855
-111.3235367
0
6
SW6010
Molybdenum
mg/kg
18
NR
Drain-TP7-0-0.5-120418
12/4/2018
TRcs
35.73951855
-111.3235367
0
6
713R14
Radium-226
pCi/g
5.71 M3
NR
Drain-TP7-0-0.5-120418
12/4/2018
TRcs
35.73951855
-111.3235367
0
6
SW6010
Selenium
mg/kg
0.12 J
NR
Drain-TP7-0-0.5-120418
12/4/2018
TRcs
35.73951855
-111.3235367
0
6
SW6020
Uranium
mg/kg
6
NR
Drain-TP7-0-0.5-120418
12/4/2018
TRcs
35.73951855
-111.3235367
0
6
SW6010
Vanadium
mg/kg
19
NR
Drain-TP7-1.0-1.5-120418
12/4/2018
TRcs
35.73951855
-111.3235367
12
18
SW6020
Arsenic
mg/kg
1.7
NR
Drain-TP7-1.0-1.5-120418
12/4/2018
TRcs
35.73951855
-111.3235367
12
18
SW7471
Mercury
mg/kg
5.8E-05 U
NR
Drain-TP7-1.0-1.5-120418
12/4/2018
TRcs
35.73951855
-111.3235367
12
18
SW6010
Molybdenum
mg/kg
7.9
NR
Drain-TP7-1.0-1.5-120418
12/4/2018
TRcs
35.73951855
-111.3235367
12
18
713R14
Radium-226
pCi/g
1.69 M3
NR
Drain-TP7-1.0-1.5-120418
12/4/2018
TRcs
35.73951855
-111.3235367
12
18
SW6010
Selenium
mg/kg
0.15 J
NR
Drain-TP7-1.0-1.5-120418
12/4/2018
TRcs
35.73951855
-111.3235367
12
18
SW6020
Uranium
mg/kg
3.6
NR
Drain-TP7-1.0-1.5-120418
12/4/2018
TRcs
35.73951855
-111.3235367
12
18
SW6010
Vanadium
mg/kg
17
NR
Drain-TP8-0.5-1.0-120418
12/4/2018
TRcs
35.7394395
-111.3233345
6
12
SW6020
Arsenic
mg/kg
12
NR
Drain-TP8-0.5-1.0-120418
12/4/2018
TRcs
35.7394395
-111.3233345
6
12
SW7471
Mercury
mg/kg
0.028 J
NR
Drain-TP8-0.5-1.0-120418
12/4/2018
TRcs
35.7394395
-111.3233345
6
12
SW6010
Molybdenum
mg/kg
53
NR
Drain-TP8-0.5-1.0-120418
12/4/2018
TRcs
35.7394395
-111.3233345
6
12
713R14
Radium-226
pCi/g
31.3 M3
NR
Drain-TP8-0.5-1.0-120418
12/4/2018
TRcs
35.7394395
-111.3233345
6
12
SW6010
Selenium
mg/kg
0.23 J
NR
Drain-TP8-0.5-1.0-120418
12/4/2018
TRcs
35.7394395
-111.3233345
6
12
SW6020
Uranium
mg/kg
21
NR
Drain-TP8-0.5-1.0-120418
12/4/2018
TRcs
35.7394395
-111.3233345
6
12
SW6010
Vanadium
mg/kg
23
NR
Drain-TP8-0-0.5-120418
12/4/2018
TRcs
35.7394395
-111.3233345
0
6
SW6020
Arsenic
mg/kg
6.3
NR
Drain-TP8-0-0.5-120418
12/4/2018
TRcs
35.7394395
-111.3233345
0
6
SW7471
Mercury
mg/kg
0.019 J
NR
Drain-TP8-0-0.5-120418
12/4/2018
TRcs
35.7394395
-111.3233345
0
6
SW6010
Molybdenum
mg/kg
37
NR
Drain-TP8-0-0.5-120418
12/4/2018
TRcs
35.7394395
-111.3233345
0
6
713R14
Radium-226
pCi/g
37.5 M3
NR
Drain-TP8-0-0.5-120418
12/4/2018
TRcs
35.7394395
-111.3233345
0
6
SW6010
Selenium
mg/kg
0.32 J
NR
Drain-TP8-0-0.5-120418
12/4/2018
TRcs
35.7394395
-111.3233345
0
6
SW6020
Uranium
mg/kg
14
NR
Drain-TP8-0-0.5-120418
12/4/2018
TRcs
35.7394395
-111.3233345
0
6
SW6010
Vanadium
mg/kg
25
NR
Drain-TP8-2.5-3.0-120418
12/4/2018
TRcs
35.7394395
-111.3233345
30
36
SW6020
Arsenic
mg/kg
2.2
NR
Drain-TP8-2.5-3.0-120418
12/4/2018
TRcs
35.7394395
-111.3233345
30
36
SW7471
Mercury
mg/kg
5.9E-05 U
NR
Drain-TP8-2.5-3.0-120418
12/4/2018
TRcs
35.7394395
-111.3233345
30
36
SW6010
Molybdenum
mg/kg
6.5
NR
Drain-TP8-2.5-3.0-120418
12/4/2018
TRcs
35.7394395
-111.3233345
30
36
713R14
Radium-226
pCi/g
1.76 M3
NR
Drain-TP8-2.5-3.0-120418
12/4/2018
TRcs
35.7394395
-111.3233345
30
36
SW6010
Selenium
mg/kg
0.057 J
NR
Drain-TP8-2.5-3.0-120418
12/4/2018
TRcs
35.7394395
-111.3233345
30
36
SW6020
Uranium
mg/kg
2.8
NR
Drain-TP8-2.5-3.0-120418
12/4/2018
TRcs
35.7394395
-111.3233345
30
36
SW6010
Vanadium
mg/kg
21
NR
DRN-SD-1
8/8/2013
Qay
35.72931547
-111.3265101
0
6
6010C DOD
Aluminum
mg/kg
4,500 D
NR
DRN-SD-1
8/8/2013
Qay
35.72931547
-111.3265101
0
6
6010C DOD
Antimony
mg/kg
6.5 U
NR
DRN-SD-1
8/8/2013
Qay
35.72931547
-111.3265101
0
6
6010C DOD
Arsenic
mg/kg
3.2 U
NR
DRN-SD-1
8/8/2013
Qay
35.72931547
-111.3265101
0
6
6010C DOD
Barium
mg/kg
180 D
NR
DRN-SD-1
8/8/2013
Qay
35.72931547
-111.3265101
0
6
6010C DOD
Beryllium
mg/kg
1.7 U
NR
DRN-SD-1
8/8/2013
Qay
35.72931547
-111.3265101
0
6
6010C DOD
Cadmium
mg/kg
1 U
NR
DRN-SD-1
8/8/2013
Qay
35.72931547
-111.3265101
0
6
6010C DOD
Chromium
mg/kg
6.4 JD
NR
DRN-SD-1
8/8/2013
Qay
35.72931547
-111.3265101
0
6
6010C DOD
Cobalt
mg/kg
14 JD
NR
DRN-SD-1
8/8/2013
Qay
35.72931547
-111.3265101
0
6
6010C DOD
Copper
mg/kg
9.4 JD
NR
DRN-SD-1
8/8/2013
Qay
35.72931547
-111.3265101
0
6
601OC DOD
Iron
mg/kg
13,000 D
NR
DRN-SD-1
8/8/2013
Qay
35.72931547
-111.3265101
0
6
601OC DOD
Lead
mg/kg
6.2 JD
NR
DRN-SD-1
8/8/2013
Qay
35.72931547
-111.3265101
0
6
601 OC DOD
Manganese
mg/kg
270 D
NR
DRN-SD-1
8/8/2013
Qay
35.72931547
-111.3265101
0
6
601 OC DOD
Mercury
mg/kg
0.011 U
NR
DRN-SD-1
8/8/2013
Qay
35.72931547
-111.3265101
0
6
601 OC DOD
Molybdenum
mg/kg
10 U
NR
DRN-SD-1
8/8/2013
Qay
35.72931547
-111.3265101
0
6
601 OC DOD
Nickel
mg/kg
17 JD
NR
DRN-SD-1
8/8/2013
Qay
35.72931547
-111.3265101
0
6
GA-01 -R
Radium-226
pCi/g
1.3
NR
DRN-SD-1
8/8/2013
Qay
35.72931547
-111.3265101
0
6
601 OC DOD
Selenium
mg/kg
2.9 U
NR
DRN-SD-1
8/8/2013
Qay
35.72931547
-111.3265101
0
6
601 OC DOD
Silver
mg/kg
2.4 U
NR
DRN-SD-1
8/8/2013
Qay
35.72931547
-111.3265101
0
6
601 OC DOD
Thallium
mg/kg
15 U
NR
DRN-SD-1
8/8/2013
Qay
35.72931547
-111.3265101
0
6
601 OC DOD
Uranium
mg/kg
110 U
NR
DRN-SD-1
8/8/2013
Qay
35.72931547
-111.3265101
0
6
601 OC DOD
Vanadium
mg/kg
26 JD
NR
DRN-SD-1
8/8/2013
Qay
35.72931547
-111.3265101
0
6
601 OC DOD
Zinc
mg/kg
20 U
NR
Page 16 of 20
-------
Attachment B-1. Data Used in the Risk Assessment
Sample ID
Sample
Date
Geologic
Unit
Latitude
Longitude
Sample
Top Depth
(inches bgs)
Sample
Bottom Depth
(inches bgs)
Analytical
Method
Analyte
Units
Result and
Qualifier
Reporting
Limit
DRN-SD-2
8/8/2013
Qay
35.73094747
-111.3273461
0
6
6010C DOD
Aluminum
mg/kg
4,200 D
NR
DRN-SD-2
8/8/2013
Qay
35.73094747
-111.3273461
0
6
6010C DOD
Antimony
mg/kg
6.3 U
NR
DRN-SD-2
8/8/2013
Qay
35.73094747
-111.3273461
0
6
6010C DOD
Arsenic
mg/kg
3.1 U
NR
DRN-SD-2
8/8/2013
Qay
35.73094747
-111.3273461
0
6
6010C DOD
Barium
mg/kg
210 D
NR
DRN-SD-2
8/8/2013
Qay
35.73094747
-111.3273461
0
6
6010C DOD
Beryllium
mg/kg
1.7 U
NR
DRN-SD-2
8/8/2013
Qay
35.73094747
-111.3273461
0
6
6010C DOD
Cadmium
mg/kg
0.99 U
NR
DRN-SD-2
8/8/2013
Qay
35.73094747
-111.3273461
0
6
6010C DOD
Chromium
mg/kg
4.9 JD
NR
DRN-SD-2
8/8/2013
Qay
35.73094747
-111.3273461
0
6
6010C DOD
Cobalt
mg/kg
10 JD
NR
DRN-SD-2
8/8/2013
Qay
35.73094747
-111.3273461
0
6
601OC DOD
Copper
mg/kg
9.2 JD
NR
DRN-SD-2
8/8/2013
Qay
35.73094747
-111.3273461
0
6
601OC DOD
Iron
mg/kg
12,000 D
NR
DRN-SD-2
8/8/2013
Qay
35.73094747
-111.3273461
0
6
601 OC DOD
Lead
mg/kg
5.8 JD
NR
DRN-SD-2
8/8/2013
Qay
35.73094747
-111.3273461
0
6
601 OC DOD
Manganese
mg/kg
260 D
NR
DRN-SD-2
8/8/2013
Qay
35.73094747
-111.3273461
0
6
601 OC DOD
Mercury
mg/kg
0.011 U
NR
DRN-SD-2
8/8/2013
Qay
35.73094747
-111.3273461
0
6
601 OC DOD
Molybdenum
mg/kg
9.9 U
NR
DRN-SD-2
8/8/2013
Qay
35.73094747
-111.3273461
0
6
601 OC DOD
Nickel
mg/kg
14 JD
NR
DRN-SD-2
8/8/2013
Qay
35.73094747
-111.3273461
0
6
GA-01 -R
Radium-226
pCi/g
0.977
NR
DRN-SD-2
8/8/2013
Qay
35.73094747
-111.3273461
0
6
601 OC DOD
Selenium
mg/kg
2.9 U
NR
DRN-SD-2
8/8/2013
Qay
35.73094747
-111.3273461
0
6
601 OC DOD
Silver
mg/kg
2.3 U
NR
DRN-SD-2
8/8/2013
Qay
35.73094747
-111.3273461
0
6
601 OC DOD
Thallium
mg/kg
15 U
NR
DRN-SD-2
8/8/2013
Qay
35.73094747
-111.3273461
0
6
601 OC DOD
Uranium
mg/kg
72 U
NR
DRN-SD-2
8/8/2013
Qay
35.73094747
-111.3273461
0
6
601 OC DOD
Vanadium
mg/kg
24 JD
NR
DRN-SD-2
8/8/2013
Qay
35.73094747
-111.3273461
0
6
601 OC DOD
Zinc
mg/kg
20 U
NR
DRN-SD-3
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Aluminum
mg/kg
3,000 D
NR
DRN-SD-3
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Antimony
mg/kg
6 U
NR
DRN-SD-3
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Arsenic
mg/kg
3 U
NR
DRN-SD-3
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Barium
mg/kg
100 D
NR
DRN-SD-3
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Beryllium
mg/kg
1.6 U
NR
DRN-SD-3
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Cadmium
mg/kg
0.94 U
NR
DRN-SD-3
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Chromium
mg/kg
4.7 JD
NR
DRN-SD-3
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Cobalt
mg/kg
8.8 U
NR
DRN-SD-3
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Copper
mg/kg
7.9 JD
NR
DRN-SD-3
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Iron
mg/kg
10,000 D
NR
DRN-SD-3
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Lead
mg/kg
4 JD
NR
DRN-SD-3
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Manganese
mg/kg
360 D
NR
DRN-SD-3
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Mercury
mg/kg
0.011 U
NR
DRN-SD-3
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Molybdenum
mg/kg
9.4 U
NR
DRN-SD-3
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Nickel
mg/kg
13 JD
NR
DRN-SD-3
8/8/2013
Qay
35.73128747
-111.3262291
0
6
GA-01 -R
Radium-226
pCi/g
1.37
NR
DRN-SD-3
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Selenium
mg/kg
2.7 U
NR
DRN-SD-3
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Silver
mg/kg
2.2 U
NR
DRN-SD-3
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Thallium
mg/kg
14 U
NR
DRN-SD-3
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Uranium
mg/kg
52 U
NR
DRN-SD-3
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Vanadium
mg/kg
22 JD
NR
DRN-SD-3
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Zinc
mg/kg
19 U
NR
DRN-SD-4
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Aluminum
mg/kg
3,300 D
NR
DRN-SD-4
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Antimony
mg/kg
6.4 U
NR
DRN-SD-4
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Arsenic
mg/kg
3.2 U
NR
DRN-SD-4
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Barium
mg/kg
180 D
NR
DRN-SD-4
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Beryllium
mg/kg
1.7 U
NR
DRN-SD-4
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Cadmium
mg/kg
1 U
NR
DRN-SD-4
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Chromium
mg/kg
5.3 JD
NR
DRN-SD-4
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Cobalt
mg/kg
9.4 U
NR
DRN-SD-4
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Copper
mg/kg
7.9 JD
NR
DRN-SD-4
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Iron
mg/kg
11,000 D
NR
DRN-SD-4
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Lead
mg/kg
5.9 JD
NR
DRN-SD-4
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Manganese
mg/kg
540 D
NR
DRN-SD-4
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Mercury
mg/kg
0.011 U
NR
DRN-SD-4
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Molybdenum
mg/kg
10 U
NR
DRN-SD-4
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Nickel
mg/kg
14 JD
NR
DRN-SD-4
8/8/2013
Qay
35.73128747
-111.3262291
0
6
GA-01 -R
Radium-226
pCi/g
3.74
NR
DRN-SD-4
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Selenium
mg/kg
2.9 U
NR
DRN-SD-4
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Silver
mg/kg
2.3 U
NR
DRN-SD-4
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Thallium
mg/kg
15 U
NR
DRN-SD-4
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Uranium
mg/kg
86 U
NR
DRN-SD-4
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Vanadium
mg/kg
24 JD
NR
DRN-SD-4
8/8/2013
Qay
35.73128747
-111.3262291
0
6
601 OC DOD
Zinc
mg/kg
20 U
NR
LCR-TP11-2.0-2.5-120318
12/3/2018
TRcs
35.73897172
-111.3227054
24
30
SW6020
Arsenic
mg/kg
2.4
NR
LCR-TP11-2.0-2.5-120318
12/3/2018
TRcs
35.73897172
-111.3227054
24
30
SW7471
Mercury
mg/kg
0.0099 J
NR
LCR-TP11-2.0-2.5-120318
12/3/2018
TRcs
35.73897172
-111.3227054
24
30
SW6010
Molybdenum
mg/kg
0.77 J
NR
LCR-TP11-2.0-2.5-120318
12/3/2018
TRcs
35.73897172
-111.3227054
24
30
713R14
Radium-226
pCi/g
1.81 M3,G
NR
LCR-TP11-2.0-2.5-120318
12/3/2018
TRcs
35.73897172
-111.3227054
24
30
SW6010
Selenium
mg/kg
0.061 U
NR
LCR-TP11-2.0-2.5-120318
12/3/2018
TRcs
35.73897172
-111.3227054
24
30
SW6020
Uranium
mg/kg
1.5
NR
LCR-TP11-2.0-2.5-120318
12/3/2018
TRcs
35.73897172
-111.3227054
24
30
SW6010
Vanadium
mg/kg
23
NR
LCR-TP12-0-0.5-120318
12/3/2018
TRcs
35.73867986
-111.3226603
0
6
SW6020
Arsenic
mg/kg
2.4
NR
LCR-TP12-0-0.5-120318
12/3/2018
TRcs
35.73867986
-111.3226603
0
6
SW7471
Mercury
mg/kg
7.1E-05 U
NR
LCR-TP12-0-0.5-120318
12/3/2018
TRcs
35.73867986
-111.3226603
0
6
SW6010
Molybdenum
mg/kg
0.71 J
NR
LCR-TP12-0-0.5-120318
12/3/2018
TRcs
35.73867986
-111.3226603
0
6
713R14
Radium-226
pCi/g
1.48 M3,G
NR
LCR-TP12-0-0.5-120318
12/3/2018
TRcs
35.73867986
-111.3226603
0
6
SW6010
Selenium
mg/kg
0.06 U
NR
LCR-TP12-0-0.5-120318
12/3/2018
TRcs
35.73867986
-111.3226603
0
6
SW6020
Uranium
mg/kg
1.8
NR
LCR-TP12-0-0.5-120318
12/3/2018
TRcs
35.73867986
-111.3226603
0
6
SW6010
Vanadium
mg/kg
25
NR
LCR-TP12-1.0-1.5-120318
12/3/2018
TRcs
35.73867986
-111.3226603
12
18
SW6020
Arsenic
mg/kg
2.6
NR
LCR-TP12-1.0-1.5-120318
12/3/2018
TRcs
35.73867986
-111.3226603
12
18
SW7471
Mercury
mg/kg
0.0089 J
NR
LCR-TP12-1.0-1.5-120318
12/3/2018
TRcs
35.73867986
-111.3226603
12
18
SW6010
Molybdenum
mg/kg
0.71 J
NR
LCR-TP12-1.0-1.5-120318
12/3/2018
TRcs
35.73867986
-111.3226603
12
18
713R14
Radium-226
pCi/g
1.86 M3,G
NR
LCR-TP12-1.0-1.5-120318
12/3/2018
TRcs
35.73867986
-111.3226603
12
18
SW6010
Selenium
mg/kg
0.056 U
NR
LCR-TP12-1.0-1.5-120318
12/3/2018
TRcs
35.73867986
-111.3226603
12
18
SW6020
Uranium
mg/kg
2
NR
LCR-TP12-1.0-1.5-120318
12/3/2018
TRcs
35.73867986
-111.3226603
12
18
SW6010
Vanadium
mg/kg
26
NR
LCR-TP9-2.0-2.5-120318
12/3/2018
TRcs
35.73935962
-111.3228092
24
30
SW6020
Arsenic
mg/kg
10
NR
Page 17 of 20
-------
Attachment B-1. Data Used in the Risk Assessment
Sample ID
Sample
Date
Geologic
Unit
Latitude
Longitude
Sample
Top Depth
(inches bgs)
Sample
Bottom Depth
(inches bgs)
Analytical
Method
Analyte
Units
Result and
Qualifier
Reporting
Limit
LCR-TP9-2.0-2.5-120318
12/3/2018
TRcs
35.73935962
-111.3228092
24
30
SW7471
Mercury
mg/kg
0.17
NR
LCR-TP9-2.0-2.5-120318
12/3/2018
TRcs
35.73935962
-111.3228092
24
30
SW6010
Molybdenum
mg/kg
78
NR
LCR-TP9-2.0-2.5-120318
12/3/2018
TRcs
35.73935962
-111.3228092
24
30
713R14
Radium-226
pCi/g
58.2
M3
NR
LCR-TP9-2.0-2.5-120318
12/3/2018
TRcs
35.73935962
-111.3228092
24
30
SW6010
Selenium
mg/kg
0.047
U
NR
LCR-TP9-2.0-2.5-120318
12/3/2018
TRcs
35.73935962
-111.3228092
24
30
SW6020
Uranium
mg/kg
28
NR
LCR-TP9-2.0-2.5-120318
12/3/2018
TRcs
35.73935962
-111.3228092
24
30
SW6010
Vanadium
mg/kg
16
NR
LCR-TP9-3.0-3.5-120318
12/3/2018
TRcs
35.73935962
-111.3228092
36
42
SW6020
Arsenic
mg/kg
7.9
NR
LCR-TP9-3.0-3.5-120318
12/3/2018
TRcs
35.73935962
-111.3228092
36
42
SW7471
Mercury
mg/kg
0.16
NR
LCR-TP9-3.0-3.5-120318
12/3/2018
TRcs
35.73935962
-111.3228092
36
42
SW6010
Molybdenum
mg/kg
34
NR
LCR-TP9-3.0-3.5-120318
12/3/2018
TRcs
35.73935962
-111.3228092
36
42
713R14
Radium-226
pCi/g
55.7
M3
NR
LCR-TP9-3.0-3.5-120318
12/3/2018
TRcs
35.73935962
-111.3228092
36
42
SW6010
Selenium
mg/kg
0.074
J
NR
LCR-TP9-3.0-3.5-120318
12/3/2018
TRcs
35.73935962
-111.3228092
36
42
SW6020
Uranium
mg/kg
37
NR
LCR-TP9-3.0-3.5-120318
12/3/2018
TRcs
35.73935962
-111.3228092
36
42
SW6010
Vanadium
mg/kg
21
NR
LCR-TP9-4.5-5.0-120318
12/3/2018
TRcs
35.73935962
-111.3228092
54
60
SW6020
Arsenic
mg/kg
3.6
NR
LCR-TP9-4.5-5.0-120318
12/3/2018
TRcs
35.73935962
-111.3228092
54
60
SW7471
Mercury
mg/kg
0.028
J
NR
LCR-TP9-4.5-5.0-120318
12/3/2018
TRcs
35.73935962
-111.3228092
54
60
SW6010
Molybdenum
mg/kg
18
NR
LCR-TP9-4.5-5.0-120318
12/3/2018
TRcs
35.73935962
-111.3228092
54
60
713R14
Radium-226
pCi/g
7.37
M3,G
NR
LCR-TP9-4.5-5.0-120318
12/3/2018
TRcs
35.73935962
-111.3228092
54
60
SW6010
Selenium
mg/kg
0.063
U
NR
LCR-TP9-4.5-5.0-120318
12/3/2018
TRcs
35.73935962
-111.3228092
54
60
SW6020
Uranium
mg/kg
16
NR
LCR-TP9-4.5-5.0-120318
12/3/2018
TRcs
35.73935962
-111.3228092
54
60
SW6010
Vanadium
mg/kg
22
NR
MHR-TP17-0-0.5-120618
12/6/2018
TRcs
35.73049136
-111.3259239
0
6
SW6020
Arsenic
mg/kg
8.2
NR
MH R-TP17-0-0.5-120618
12/6/2018
TRcs
35.73049136
-111.3259239
0
6
SW7471
Mercury
mg/kg
0.0027
J
NR
MHR-TP17-0-0.5-120618
12/6/2018
TRcs
35.73049136
-111.3259239
0
6
SW6010
Molybdenum
mg/kg
27
NR
MH R-TP17-0-0.5-120618
12/6/2018
TRcs
35.73049136
-111.3259239
0
6
713R14
Radium-226
pCi/g
8.7
M3
NR
MHR-TP17-0-0.5-120618
12/6/2018
TRcs
35.73049136
-111.3259239
0
6
SW6010
Selenium
mg/kg
0.054
U
NR
MHR-TP17-0-0.5-120618
12/6/2018
TRcs
35.73049136
-111.3259239
0
6
SW6020
Uranium
mg/kg
11
NR
MHR-TP17-0-0.5-120618
12/6/2018
TRcs
35.73049136
-111.3259239
0
6
SW6010
Vanadium
mg/kg
20
NR
MH R-TP17-2.0-2.5-120618
12/6/2018
TRcs
35.73049136
-111.3259239
24
30
SW6020
Arsenic
mg/kg
2
NR
MH R-TP17-2.0-2.5-120618
12/6/2018
TRcs
35.73049136
-111.3259239
24
30
SW7471
Mercury
mg/kg
6.2E-05
U
NR
MH R-TP17-2.0-2.5-120618
12/6/2018
TRcs
35.73049136
-111.3259239
24
30
SW6010
Molybdenum
mg/kg
13
NR
MH R-TP17-2.0-2.5-120618
12/6/2018
TRcs
35.73049136
-111.3259239
24
30
713R14
Radium-226
pCi/g
1.64
M3
NR
MH R-TP17-2.0-2.5-120618
12/6/2018
TRcs
35.73049136
-111.3259239
24
30
SW6010
Selenium
mg/kg
0.047
U
NR
MH R-TP17-2.0-2.5-120618
12/6/2018
TRcs
35.73049136
-111.3259239
24
30
SW6020
Uranium
mg/kg
3.9
NR
MH R-TP17-2.0-2.5-120618
12/6/2018
TRcs
35.73049136
-111.3259239
24
30
SW6010
Vanadium
mg/kg
21
NR
MH R-TP22-0-0.5-120518
12/5/2018
TRcp
35.72912061
-111.3315926
0
6
SW6020
Arsenic
mg/kg
2.1
NR
MH R-TP22-0-0.5-120518
12/5/2018
TRcp
35.72912061
-111.3315926
0
6
SW7471
Mercury
mg/kg
0.065
NR
MH R-TP22-0-0.5-120518
12/5/2018
TRcp
35.72912061
-111.3315926
0
6
SW6010
Molybdenum
mg/kg
0.2
J
NR
MH R-TP22-0-0.5-120518
12/5/2018
TRcp
35.72912061
-111.3315926
0
6
713R14
Radium-226
pCi/g
2.69
M3
NR
MH R-TP22-0-0.5-120518
12/5/2018
TRcp
35.72912061
-111.3315926
0
6
SW6010
Selenium
mg/kg
0.054
U
NR
MH R-TP22-0-0.5-120518
12/5/2018
TRcp
35.72912061
-111.3315926
0
6
SW6020
Uranium
mg/kg
2.7
NR
MH R-TP22-0-0.5-120518
12/5/2018
TRcp
35.72912061
-111.3315926
0
6
SW6010
Vanadium
mg/kg
13
NR
MHR-TP22-1.0-1.5-120518
12/5/2018
TRcp
35.72912061
-111.3315926
12
18
SW6020
Arsenic
mg/kg
2.4
NR
MHR-TP22-1.0-1.5-120518
12/5/2018
TRcp
35.72912061
-111.3315926
12
18
SW7471
Mercury
mg/kg
0.082
NR
MHR-TP22-1.0-1.5-120518
12/5/2018
TRcp
35.72912061
-111.3315926
12
18
SW6010
Molybdenum
mg/kg
0.37
J
NR
MHR-TP22-1.0-1.5-120518
12/5/2018
TRcp
35.72912061
-111.3315926
12
18
713R14
Radium-226
pCi/g
4.14
M3
NR
MHR-TP22-1.0-1.5-120518
12/5/2018
TRcp
35.72912061
-111.3315926
12
18
SW6010
Selenium
mg/kg
0.17
J
NR
MHR-TP22-1.0-1.5-120518
12/5/2018
TRcp
35.72912061
-111.3315926
12
18
SW6020
Uranium
mg/kg
3.9
NR
MHR-TP22-1.0-1.5-120518
12/5/2018
TRcp
35.72912061
-111.3315926
12
18
SW6010
Vanadium
mg/kg
8.4
NR
MRD-TP1-0.5-1.0-120518
12/5/2018
Qay
35.74119642
-111.3312742
6
12
SW6020
Arsenic
mg/kg
1.3
NR
MRD-TP1-0.5-1.0-120518
12/5/2018
Qay
35.74119642
-111.3312742
6
12
SW7471
Mercury
mg/kg
0.081
NR
MRD-TP1-0.5-1.0-120518
12/5/2018
Qay
35.74119642
-111.3312742
6
12
SW6010
Molybdenum
mg/kg
8
NR
MRD-TP1-0.5-1.0-120518
12/5/2018
Qay
35.74119642
-111.3312742
6
12
713R14
Radium-226
pCi/g
31.6
M3
NR
MRD-TP1-0.5-1.0-120518
12/5/2018
Qay
35.74119642
-111.3312742
6
12
SW6010
Selenium
mg/kg
0.054
U
NR
MRD-TP1-0.5-1.0-120518
12/5/2018
Qay
35.74119642
-111.3312742
6
12
SW6020
Uranium
mg/kg
45
NR
MRD-TP1-0.5-1.0-120518
12/5/2018
Qay
35.74119642
-111.3312742
6
12
SW6010
Vanadium
mg/kg
16
NR
MRD-TP1-1.5-2.0-120518
12/5/2018
Qay
35.74119642
-111.3312742
18
24
SW6020
Arsenic
mg/kg
1.7
NR
MRD-TP1-1.5-2.0-120518
12/5/2018
Qay
35.74119642
-111.3312742
18
24
SW7471
Mercury
mg/kg
0.33
NR
MRD-TP1-1.5-2.0-120518
12/5/2018
Qay
35.74119642
-111.3312742
18
24
SW6010
Molybdenum
mg/kg
0.84
J
NR
MRD-TP1-1.5-2.0-120518
12/5/2018
Qay
35.74119642
-111.3312742
18
24
713R14
Radium-226
pCi/g
71.8
M3
NR
MRD-TP1-1.5-2.0-120518
12/5/2018
Qay
35.74119642
-111.3312742
18
24
SW6010
Selenium
mg/kg
0.35
J
NR
MRD-TP1-1.5-2.0-120518
12/5/2018
Qay
35.74119642
-111.3312742
18
24
SW6020
Uranium
mg/kg
180
NR
MRD-TP1-1.5-2.0-120518
12/5/2018
Qay
35.74119642
-111.3312742
18
24
SW6010
Vanadium
mg/kg
21
NR
MRD-TP1-2.5-3.0-120518
12/5/2018
Qay
35.74119642
-111.3312742
30
36
SW6020
Arsenic
mg/kg
0.92
NR
MRD-TP1-2.5-3.0-120518
12/5/2018
Qay
35.74119642
-111.3312742
30
36
SW7471
Mercury
mg/kg
0.002
J
NR
MRD-TP1-2.5-3.0-120518
12/5/2018
Qay
35.74119642
-111.3312742
30
36
SW6010
Molybdenum
mg/kg
1.5
NR
MRD-TP1-2.5-3.0-120518
12/5/2018
Qay
35.74119642
-111.3312742
30
36
713R14
Radium-226
pCi/g
3.94
M3
NR
MRD-TP1-2.5-3.0-120518
12/5/2018
Qay
35.74119642
-111.3312742
30
36
SW6010
Selenium
mg/kg
0.052
U
NR
MRD-TP1-2.5-3.0-120518
12/5/2018
Qay
35.74119642
-111.3312742
30
36
SW6020
Uranium
mg/kg
21
NR
MRD-TP1-2.5-3.0-120518
12/5/2018
Qay
35.74119642
-111.3312742
30
36
SW6010
Vanadium
mg/kg
49
NR
RIV-SD-2
8/8/2013
Qay
35.73954747
-111.3224681
0
6
6010C DOD
Aluminum
mg/kg
2,000
D
NR
RIV-SD-2
8/8/2013
Qay
35.73954747
-111.3224681
0
6
6010C DOD
Antimony
mg/kg
6.2
U
NR
RIV-SD-2
8/8/2013
Qay
35.73954747
-111.3224681
0
6
6010C DOD
Arsenic
mg/kg
11
D
NR
RIV-SD-2
8/8/2013
Qay
35.73954747
-111.3224681
0
6
6010C DOD
Barium
mg/kg
360
D
NR
RIV-SD-2
8/8/2013
Qay
35.73954747
-111.3224681
0
6
6010C DOD
Beryllium
mg/kg
1.6
U
NR
RIV-SD-2
8/8/2013
Qay
35.73954747
-111.3224681
0
6
6010C DOD
Cadmium
mg/kg
0.96
U
NR
RIV-SD-2
8/8/2013
Qay
35.73954747
-111.3224681
0
6
6010C DOD
Chromium
mg/kg
3
U
NR
RIV-SD-2
8/8/2013
Qay
35.73954747
-111.3224681
0
6
6010C DOD
Cobalt
mg/kg
9
U
NR
RIV-SD-2
8/8/2013
Qay
35.73954747
-111.3224681
0
6
6010C DOD
Copper
mg/kg
7
U
NR
RIV-SD-2
8/8/2013
Qay
35.73954747
-111.3224681
0
6
6010C DOD
Iron
mg/kg
10,000
D
NR
RIV-SD-2
8/8/2013
Qay
35.73954747
-111.3224681
0
6
601OC DOD
Lead
mg/kg
12
D
NR
RIV-SD-2
8/8/2013
Qay
35.73954747
-111.3224681
0
6
601OC DOD
Manganese
mg/kg
250
D
NR
RIV-SD-2
8/8/2013
Qay
35.73954747
-111.3224681
0
6
601 OC DOD
Mercury
mg/kg
0.25
NR
RIV-SD-2
8/8/2013
Qay
35.73954747
-111.3224681
0
6
601 OC DOD
Molybdenum
mg/kg
34
JD
NR
RIV-SD-2
8/8/2013
Qay
35.73954747
-111.3224681
0
6
601 OC DOD
Nickel
mg/kg
2.7
JD
NR
RIV-SD-2
8/8/2013
Qay
35.73954747
-111.3224681
0
6
GA-01-R
Radium-226
pCi/g
21.2
NR
RIV-SD-2
8/8/2013
Qay
35.73954747
-111.3224681
0
6
601 OC DOD
Selenium
mg/kg
2.8
U
NR
RIV-SD-2
8/8/2013
Qay
35.73954747
-111.3224681
0
6
601 OC DOD
Silver
mg/kg
2.3
U
NR
RIV-SD-2
8/8/2013
Qay
35.73954747
-111.3224681
0
6
601 OC DOD
Thallium
mg/kg
15
U
NR
Page 18 of 20
-------
Attachment B-1. Data Used in the Risk Assessment
Sample ID
Sample
Date
Geologic
Unit
Latitude
Longitude
Sample
Top Depth
(inches bgs)
Sample
Bottom Depth
(inches bgs)
Analytical
Method
Analyte
Units
Result and
Qualifier
Reporting
Limit
RIV-SD-2
8/8/2013
Qay
35.73954747
-
11.3224681
0
6
6010C DOD
Uranium
mg/kg
160
U
NR
RIV-SD-2
8/8/2013
Qay
35.73954747
-
11.3224681
0
6
6010C DOD
Vanadium
mg/kg
26
JD
NR
RIV-SD-2
8/8/2013
Qay
35.73954747
-
11.3224681
0
6
6010C DOD
Zinc
mg/kg
19
U
NR
RIV-SD-6
8/8/2013
Qay
35.73954747
-
11.3224681
0
6
6010C DOD
Aluminum
mg/kg
2,300
D
NR
RIV-SD-6
8/8/2013
Qay
35.73954747
-
11.3224681
0
6
6010C DOD
Antimony
mg/kg
6.7
U
NR
RIV-SD-6
8/8/2013
Qay
35.73954747
-
11.3224681
0
6
6010C DOD
Arsenic
mg/kg
7.6
JD
NR
RIV-SD-6
8/8/2013
Qay
35.73954747
-
11.3224681
0
6
6010C DOD
Barium
mg/kg
210
D
NR
RIV-SD-6
8/8/2013
Qay
35.73954747
-
11.3224681
0
6
6010C DOD
Beryllium
mg/kg
1.8
U
NR
RIV-SD-6
8/8/2013
Qay
35.73954747
-
11.3224681
0
6
6010C DOD
Cadmium
mg/kg
1
U
NR
RIV-SD-6
8/8/2013
Qay
35.73954747
-
11.3224681
0
6
6010C DOD
Chromium
mg/kg
3.2
U
NR
RIV-SD-6
8/8/2013
Qay
35.73954747
-
11.3224681
0
6
601OC DOD
Cobalt
mg/kg
9.8
U
NR
RIV-SD-6
8/8/2013
Qay
35.73954747
-
11.3224681
0
6
601OC DOD
Copper
mg/kg
7.6
U
NR
RIV-SD-6
8/8/2013
Qay
35.73954747
-
11.3224681
0
6
601 OC DOD
Iron
mg/kg
11,000
D
NR
RIV-SD-6
8/8/2013
Qay
35.73954747
-
11.3224681
0
6
601 OC DOD
Lead
mg/kg
10
D
NR
RIV-SD-6
8/8/2013
Qay
35.73954747
-
11.3224681
0
6
601 OC DOD
Manganese
mg/kg
370
D
NR
RIV-SD-6
8/8/2013
Qay
35.73954747
-
11.3224681
0
6
601 OC DOD
Mercury
mg/kg
0.29
NR
RIV-SD-6
8/8/2013
Qay
35.73954747
-
11.3224681
0
6
601 OC DOD
Molybdenum
mg/kg
21
JD
NR
RIV-SD-6
8/8/2013
Qay
35.73954747
-
11.3224681
0
6
601 OC DOD
Nickel
mg/kg
3.2
JD
NR
RIV-SD-6
8/8/2013
Qay
35.73954747
-
11.3224681
0
6
GA-01-R
Radium-226
pCi/g
18.1
NR
RIV-SD-6
8/8/2013
Qay
35.73954747
-
11.3224681
0
6
601 OC DOD
Selenium
mg/kg
3
U
NR
RIV-SD-6
8/8/2013
Qay
35.73954747
-
11.3224681
0
6
601 OC DOD
Silver
mg/kg
2.4
U
NR
RIV-SD-6
8/8/2013
Qay
35.73954747
-
11.3224681
0
6
601 OC DOD
Thallium
mg/kg
16
U
NR
RIV-SD-6
8/8/2013
Qay
35.73954747
-
11.3224681
0
6
601 OC DOD
Uranium
mg/kg
180
U
NR
RIV-SD-6
8/8/2013
Qay
35.73954747
-
11.3224681
0
6
601 OC DOD
Vanadium
mg/kg
26
JD
NR
RIV-SD-6
8/8/2013
Qay
35.73954747
-
11.3224681
0
6
601 OC DOD
Zinc
mg/kg
21
U
NR
S9L-SS-1A
8/6/2013
TRcp
35.73785247
-
11.3252901
0
6
601 OC DOD
Aluminum
mg/kg
3,000
D
NR
S9L-SS-1A
8/6/2013
TRcp
35.73785247
-
11.3252901
0
6
601 OC DOD
Antimony
mg/kg
6.1
U
NR
S9L-SS-1A
8/6/2013
TRcp
35.73785247
-
11.3252901
0
6
601 OC DOD
Arsenic
mg/kg
13
D
NR
S9L-SS-1A
8/6/2013
TRcp
35.73785247
-
11.3252901
0
6
601 OC DOD
Barium
mg/kg
75
D
NR
S9L-SS-1A
8/6/2013
TRcp
35.73785247
-
11.3252901
0
6
601 OC DOD
Beryllium
mg/kg
1.6
U
NR
S9L-SS-1A
8/6/2013
TRcp
35.73785247
-
11.3252901
0
6
601 OC DOD
Cadmium
mg/kg
0.96
U
NR
S9L-SS-1A
8/6/2013
TRcp
35.73785247
-
11.3252901
0
6
601 OC DOD
Chromium
mg/kg
2.9
U
NR
S9L-SS-1A
8/6/2013
TRcp
35.73785247
-
11.3252901
0
6
601 OC DOD
Cobalt
mg/kg
9
U
NR
S9L-SS-1A
8/6/2013
TRcp
35.73785247
-
11.3252901
0
6
601 OC DOD
Copper
mg/kg
21
JD
NR
S9L-SS-1A
8/6/2013
TRcp
35.73785247
-
11.3252901
0
6
601 OC DOD
Iron
mg/kg
4,700
D
NR
S9L-SS-1A
8/6/2013
TRcp
35.73785247
-
11.3252901
0
6
601 OC DOD
Lead
mg/kg
38
D
NR
S9L-SS-1A
8/6/2013
TRcp
35.73785247
-
11.3252901
0
6
601 OC DOD
Manganese
mg/kg
25
D
NR
S9L-SS-1A
8/6/2013
TRcp
35.73785247
-
11.3252901
0
6
601 OC DOD
Mercury
mg/kg
0.2
NR
S9L-SS-1A
8/6/2013
TRcp
35.73785247
-
11.3252901
0
6
601 OC DOD
Molybdenum
mg/kg
160
D
NR
S9L-SS-1A
8/6/2013
TRcp
35.73785247
-
11.3252901
0
6
601 OC DOD
Nickel
mg/kg
2.2
U
NR
S9L-SS-1A
8/6/2013
TRcp
35.73785247
-
11.3252901
0
6
GA-01 -R
Radium-226
pCi/g
13
NR
S9L-SS-1A
8/6/2013
TRcp
35.73785247
-
11.3252901
0
6
601 OC DOD
Selenium
mg/kg
2.8
U
NR
S9L-SS-1A
8/6/2013
TRcp
35.73785247
-
11.3252901
0
6
601 OC DOD
Silver
mg/kg
2.2
U
NR
S9L-SS-1A
8/6/2013
TRcp
35.73785247
-
11.3252901
0
6
601 OC DOD
Thallium
mg/kg
14
U
NR
S9L-SS-1A
8/6/2013
TRcp
35.73785247
-
11.3252901
0
6
601 OC DOD
Uranium
mg/kg
150
U
NR
S9L-SS-1A
8/6/2013
TRcp
35.73785247
-
11.3252901
0
6
601 OC DOD
Vanadium
mg/kg
12
U
NR
S9L-SS-1A
8/6/2013
TRcp
35.73785247
-
11.3252901
0
6
601 OC DOD
Zinc
mg/kg
19
U
NR
S9L-SS-2A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Aluminum
mg/kg
2,900
D
NR
S9L-SS-2A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Antimony
mg/kg
6.4
U
NR
S9L-SS-2A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Arsenic
mg/kg
11
D
NR
S9L-SS-2A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Barium
mg/kg
260
D
NR
S9L-SS-2A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Beryllium
mg/kg
1.7
U
NR
S9L-SS-2A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Cadmium
mg/kg
0.99
U
NR
S9L-SS-2A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Chromium
mg/kg
3.4
JD
NR
S9L-SS-2A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Cobalt
mg/kg
20
JD
NR
S9L-SS-2A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Copper
mg/kg
10
JD
NR
S9L-SS-2A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Iron
mg/kg
11,000
D
NR
S9L-SS-2A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Lead
mg/kg
29
D
NR
S9L-SS-2A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Manganese
mg/kg
160
D
NR
S9L-SS-2A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Mercury
mg/kg
0.073
NR
S9L-SS-2A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Molybdenum
mg/kg
31
JD
NR
S9L-SS-2A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Nickel
mg/kg
8.3
JD
NR
S9L-SS-2A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
GA-01 -R
Radium-226
pCi/g
65.2
NR
S9L-SS-2A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Selenium
mg/kg
2.9
U
NR
S9L-SS-2A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Silver
mg/kg
2.3
U
NR
S9L-SS-2A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Thallium
mg/kg
15
U
NR
S9L-SS-2A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Uranium
mg/kg
170
U
NR
S9L-SS-2A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Vanadium
mg/kg
25
JD
NR
S9L-SS-2A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Zinc
mg/kg
20
U
NR
S9L-SS-4A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Aluminum
mg/kg
3,200
D
NR
S9L-SS-4A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Antimony
mg/kg
5.5
U
NR
S9L-SS-4A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Arsenic
mg/kg
15
D
NR
S9L-SS-4A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Barium
mg/kg
330
D
NR
S9L-SS-4A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Beryllium
mg/kg
1.5
U
NR
S9L-SS-4A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Cadmium
mg/kg
0.86
U
NR
S9L-SS-4A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Chromium
mg/kg
4.7
JD
NR
S9L-SS-4A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Cobalt
mg/kg
16
JD
NR
S9L-SS-4A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Copper
mg/kg
12
JD
NR
S9L-SS-4A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Iron
mg/kg
12,000
D
NR
S9L-SS-4A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Lead
mg/kg
34
D
NR
S9L-SS-4A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Manganese
mg/kg
170
D
NR
S9L-SS-4A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Mercury
mg/kg
0.056
NR
S9L-SS-4A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Molybdenum
mg/kg
32
JD
NR
S9L-SS-4A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Nickel
mg/kg
9.5
JD
NR
S9L-SS-4A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
GA-01 -R
Radium-226
pCi/g
57.3
NR
S9L-SS-4A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Selenium
mg/kg
2.5
U
NR
S9L-SS-4A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Silver
mg/kg
2
U
NR
S9L-SS-4A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
601 OC DOD
Thallium
mg/kg
13
U
NR
Page 19 of 20
-------
Attachment B-1. Data Used in the Risk Assessment
Sample ID
Sample
Date
Geologic
Unit
Latitude
Longitude
Sample
Top Depth
(inches bgs)
Sample
Bottom Depth
(inches bgs)
Analytical
Method
Analyte
Units
Result and
Qualifier
Reporting
Limit
S9L-SS-4A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
6010C DOD
Uranium
mg/kg
140
U
NR
S9L-SS-4A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
6010C DOD
Vanadium
mg/kg
25
JD
NR
S9L-SS-4A
8/7/2013
TRcs
35.73061747
-
11.3261391
0
6
6010C DOD
Zinc
mg/kg
18
JD
NR
WET-SD-3
8/7/2013
TRcs
35.73033157
-
11.3306429
0
6
6010C DOD
Aluminum
mg/kg
3,600
D
NR
WET-SD-3
8/7/2013
TRcs
35.73033157
-
11.3306429
0
6
6010C DOD
Antimony
mg/kg
7.5
U
NR
WET-SD-3
8/7/2013
TRcs
35.73033157
-
11.3306429
0
6
6010C DOD
Arsenic
mg/kg
29
D
NR
WET-SD-3
8/7/2013
TRcs
35.73033157
-
11.3306429
0
6
6010C DOD
Barium
mg/kg
130
D
NR
WET-SD-3
8/7/2013
TRcs
35.73033157
-
11.3306429
0
6
6010C DOD
Beryllium
mg/kg
2
U
NR
WET-SD-3
8/7/2013
TRcs
35.73033157
-
11.3306429
0
6
6010C DOD
Cadmium
mg/kg
1.2
U
NR
WET-SD-3
8/7/2013
TRcs
35.73033157
-
11.3306429
0
6
6010C DOD
Chromium
mg/kg
4.7
JD
NR
WET-SD-3
8/7/2013
TRcs
35.73033157
-
11.3306429
0
6
6010C DOD
Cobalt
mg/kg
25
JD
NR
WET-SD-3
8/7/2013
TRcs
35.73033157
-
11.3306429
0
6
6010C DOD
Copper
mg/kg
17
JD
NR
WET-SD-3
8/7/2013
TRcs
35.73033157
-
11.3306429
0
6
6010C DOD
Iron
mg/kg
7,600
D
NR
WET-SD-3
8/7/2013
TRcs
35.73033157
-
11.3306429
0
6
6010C DOD
Lead
mg/kg
26
D
NR
WET-SD-3
8/7/2013
TRcs
35.73033157
-
11.3306429
0
6
6010C DOD
Manganese
mg/kg
130
D
NR
WET-SD-3
8/7/2013
TRcs
35.73033157
-
11.3306429
0
6
601OC DOD
Mercury
mg/kg
0.039
NR
WET-SD-3
8/7/2013
TRcs
35.73033157
-
11.3306429
0
6
601OC DOD
Molybdenum
mg/kg
220
D
NR
WET-SD-3
8/7/2013
TRcs
35.73033157
-
11.3306429
0
6
601 OC DOD
Nickel
mg/kg
9.8
JD
NR
WET-SD-3
8/7/2013
TRcs
35.73033157
-
11.3306429
0
6
GA-01 -R
Radium-226
pCi/g
64.4
NR
WET-SD-3
8/7/2013
TRcs
35.73033157
-
11.3306429
0
6
601 OC DOD
Selenium
mg/kg
3.4
U
NR
WET-SD-3
8/7/2013
TRcs
35.73033157
-
11.3306429
0
6
601 OC DOD
Silver
mg/kg
2.8
U
NR
WET-SD-3
8/7/2013
TRcs
35.73033157
-
11.3306429
0
6
601 OC DOD
Thallium
mg/kg
18
U
NR
WET-SD-3
8/7/2013
TRcs
35.73033157
-
11.3306429
0
6
601 OC DOD
Uranium
mg/kg
180
U
NR
WET-SD-3
8/7/2013
TRcs
35.73033157
-
11.3306429
0
6
601 OC DOD
Vanadium
mg/kg
15
U
NR
WET-SD-3
8/7/2013
TRcs
35.73033157
-
11.3306429
0
6
601 OC DOD
Zinc
mg/kg
32
JD
NR
WET-SD-4
8/8/2013
TRcs
35.73927696
-
11.3227143
0
6
601 OC DOD
Aluminum
mg/kg
8,800
D
NR
WET-SD-4
8/8/2013
TRcs
35.73927696
-
11.3227143
0
6
601 OC DOD
Antimony
mg/kg
8.4
U
NR
WET-SD-4
8/8/2013
TRcs
35.73927696
-
11.3227143
0
6
601 OC DOD
Arsenic
mg/kg
15
D
NR
WET-SD-4
8/8/2013
TRcs
35.73927696
-
11.3227143
0
6
601 OC DOD
Barium
mg/kg
320
D
NR
WET-SD-4
8/8/2013
TRcs
35.73927696
-
11.3227143
0
6
601 OC DOD
Beryllium
mg/kg
2.2
U
NR
WET-SD-4
8/8/2013
TRcs
35.73927696
-
11.3227143
0
6
601 OC DOD
Cadmium
mg/kg
1.3
U
NR
WET-SD-4
8/8/2013
TRcs
35.73927696
-
11.3227143
0
6
601 OC DOD
Chromium
mg/kg
4
U
NR
WET-SD-4
8/8/2013
TRcs
35.73927696
-
11.3227143
0
6
601 OC DOD
Cobalt
mg/kg
12
U
NR
WET-SD-4
8/8/2013
TRcs
35.73927696
-
11.3227143
0
6
601 OC DOD
Copper
mg/kg
10
JD
NR
WET-SD-4
8/8/2013
TRcs
35.73927696
-
11.3227143
0
6
601 OC DOD
Iron
mg/kg
13,000
D
NR
WET-SD-4
8/8/2013
TRcs
35.73927696
-
11.3227143
0
6
601 OC DOD
Lead
mg/kg
22
D
NR
WET-SD-4
8/8/2013
TRcs
35.73927696
-
11.3227143
0
6
601 OC DOD
Manganese
mg/kg
360
D
NR
WET-SD-4
8/8/2013
TRcs
35.73927696
-
11.3227143
0
6
601 OC DOD
Mercury
mg/kg
0.031
J
NR
WET-SD-4
8/8/2013
TRcs
35.73927696
-
11.3227143
0
6
601 OC DOD
Molybdenum
mg/kg
37
JD
NR
WET-SD-4
8/8/2013
TRcs
35.73927696
-
11.3227143
0
6
601 OC DOD
Nickel
mg/kg
7.4
JD
NR
WET-SD-4
8/8/2013
TRcs
35.73927696
-
11.3227143
0
6
GA-01 -R
Radium-226
pCi/g
7.29
NR
WET-SD-4
8/8/2013
TRcs
35.73927696
-
11.3227143
0
6
601 OC DOD
Selenium
mg/kg
3.8
U
NR
WET-SD-4
8/8/2013
TRcs
35.73927696
-
11.3227143
0
6
601 OC DOD
Silver
mg/kg
3.1
U
NR
WET-SD-4
8/8/2013
TRcs
35.73927696
-
11.3227143
0
6
601 OC DOD
Thallium
mg/kg
20
U
NR
WET-SD-4
8/8/2013
TRcs
35.73927696
-
11.3227143
0
6
601 OC DOD
Uranium
mg/kg
160
U
NR
WET-SD-4
8/8/2013
TRcs
35.73927696
-
11.3227143
0
6
601 OC DOD
Vanadium
mg/kg
25
JD
NR
WET-SD-4
8/8/2013
TRcs
35.73927696
-
11.3227143
0
6
601 OC DOD
Zinc
mg/kg
30
JD
NR
Notes:
*
Duplicate analysis not within control limits
bgs
Below ground surface
D
Reported value is from a dilution
DOD
U.S. Department of Defense
G
Gamma spectroscopy
J
Estimated concentration
J-
Estimated concentration, biased low
JD
Estimated concentration based on dilution
M3
The requested minimum detected concentration was not met, but the reported activity is greater than the reported minimum detected concentration
mg/kg
Milligram per kilogram
N
Matrix spike sample recovery is not within specified control limits
NR
Not reported
pCi/g
Picocurie per gram
Qay
Quaternary alluvium
TRcp
Petrified Forest Member of the Chinle formaation
TRcs
Shinarump Member of the Chinle Formation
U
Not detected
UJ
Not detected, reporting limit is estimated
Page 20 of 20
-------
ATTACHMENT B~2
PRELIMINARY DETERMINATION OF SECULAR EQUILIBRIUM AT
THE SECTION 9 LEASE MINES
-------
Attachment B-2: Preliminary Determination for Secular Equilibrium at the Section 9 Lease Mines
1.0 PURPOSE AND PROCEDURE FOR SECULAR EQUILIBRIUM ANALYSIS
The assumption of uranium-238 (U-238) in secular equilibrium (SE) for most abandoned
uranium mines (AUM) where neither waste rock nor ore was processed is likely appropriate and
protective (Galloway and others 2020). However, verification of this SE assumption should be
verified using site data following the Navajo abandoned uranium mine risk assessment
methodology (USEPA 2024). A preliminary determination of whether a site is in SE be
conducted by comparing the paired concentrations of U-238 and radium-226 (Ra-226) at a site.
If the site is in secular equilibrium, the paired concentrations will have concentration ratios of 1.
However, the ratios of the soil concentrations will vary from 1; thus, an upper-bound threshold
value for mean of the ratios of paired concentrations of 1.4 was determined to be sufficiently
protective for risk assessment (Tetra Tech, Inc. 2024) because there is a potential for the risk to
be underestimated is less than 5 percent. If the site-specific disequilibrium factor (DF),
calculated as the average of the ratios of paired U-238 and Ra-226 concentrations within the site,
is less than or equal to 1.4, the site can be considered in SE for the purposes of the risk
assessment. This attachment to the risk assessment summarizes the preliminary determination for
SE in soils sampled at the Section 9 Lease Mines.
2.0 DESCRIPTION OF SITE AND SOIL SAMPLING
m|
This evaluation includes all samples in the risk assessment dataset with both Ra-226 and U-238
results. The sample results used are provided in Table B2-1. For each sample, soil concentrations
of U-238 and Ra-226 were measured using alpha and gamma spectroscopy, respectively. The
reporting limit was used as the value for nondetected results of U-238. Soil samples were
collected from AUM 457, AUM 458, a small portion of AUM 459 within Section 9, and several
other technologically enhanced naturally occurring radioactive material (TENORM) locations
such as drainages, roads, and disturbed sites (see Figure B-5 of Appendix B of the Section 9
Lease Mines engineering evaluation and cost analysis). These TENORM sites include waste rock
piles, burial cells, contaminated access roads, areas contaminated by eroding waste and
windblown dust, and adjacent drainages receiving potentially contaminated runoff. These AUMs
are geographically distinct; however, based on the site evaluation, the Section 9 Lease Mines are
being evaluated as a single exposure unit for the human health risk assessment and ecological
risk assessment.
3.0 STATISTICAL ANALYSIS FOR SECULAR EQUILIBRIU
The ratio of U-238/Ra-226 (that is, a DF) is used as a metric for testing the SE assumption. A
site in SE has an average DF is 1. Summary statistics of the DFs were calculated, and the mean
DF was compared to the upper-bound screening value of 1.4. Quality assurance was also
performed to confirm that enough samples were taken to support a statistically robust
conclusion. Table B2-2 provides the summary statistics. Figure B2-1 presents a box and
whisker plot of the ratios.
Contract No. 68HE0923D0002, Task Order 020
B2-1
-------
Tt
Attachment B-2: Preliminary Determination for Secular Equilibrium at the Section 9 Lease Mines
The following conclusions were reached:
A range of equilibrium conditions were observed; however, the average site DF was 0.7,
below the upper-bound screening level.
The total number of samples taken (n=61) was sufficient for concluding that the DF
estimation is statistically defensible.
The site is in SE among U-238 and its decay products is protective for the risk
assessment.
4.0 REFERENC
Galloway, L.D., M.B. Bellamy, F.G. Dolislager, H.J. Ringer, E.A. Asano, D.J. Stewart, K.A.
Noto, and others. 2020. "Bateman Equation Adaptation for Solving and Integrating Peak
Activity into EPA ELCR and Dose Models." Prepared by Oak Ridge National
Laboratory. Managed by UT-Batelle, LLC for the U.S. Department of Energy. Contract
DE-AC05-00OR22725. ORNL/TM-2020/1780. October.
Tetra Tech, Inc. 2024. "Assessment of Secular Equilibrium for the Uranium-238 Decay Chain in
Soil Standard Operating Procedure." April.
U.S. Environmental Protection Agency (USEPA). 2024. "Navajo Abandoned Uranium Mine
Risk Assessment Methodology." Draft Final. March.
Contract No. 68HE0923D0002, Task Order 020
B2-2
-------
FIGURE
-------
2
o
1.8
1.6
o
1.4
1.2
1
0.8
0.6
X
0.4
0.2
0
Note: The middle line in the box represents the median; the "X" is the mean, the lower and upper bounds of the blue box represent the 1 st and 3rd quartiles; the
whisker indicates the upper and lower ratios within 1.5 times the interquartile range; and the outliers (single data points) are ratios exceeding 1.5 times the
interquartile range beyond the 1st and 3rd quartiles.
Figure B2-1. Box and Whisker Plot of the Ratio of the Uranium-238 to Radium-226 Soil Concentrations
-------
TABLES
-------
Table B2-1. Preliminary Determination of Secular Equilibrium for the Section 9 Lease
Mines and Calculation of Site Disequilibrium Factor
Sample ID
Bottom
Depth
(inches
bgs)
Location
Zone
Ra-226
(pCi/g)
Ra-226
Qualifier
U-238
(pCi/g)
U-238
Qualifier
U-238/
Ra-226
(DF)
457-SS01-01-020624
6
Waste Pile
18.6
22.4
1.2
457-SS02-01-020624
6
Waste Pile
66.7
35.4
0.53
457-SS03-01-020624
6
PMD
18.9
8.91
0.47
457-SS04-01-020624
6
Waste Pile
160
31.6
0.2
457-SS-1A
6
PMD
156
76.1
0.49
457-SS-10A
6
PMD
2.87
3.07
1.1
457-SS-12A
6
PMD
3.19
2.04
U
0.64
457-SS-11A
6
PMD
411
164
0.4
457-SS-6A
6
PMD
382
167
0.44
457-SS-2A
6
PMD
30.1
7.53
0.25
457-SS-2B
12
PMD
3.06
4.45
1.5
457-SS-2C
18
PMD
2.47
4.67
1.9
457-SS-3A
6
PMD
57.1
21.9
0.38
457-SS-4A
6
PMD
3.32
2.47
0.74
457-SS-4B
12
PMD
1.93
1.06
U
0.55
457-SS-4C
18
PMD
1.07
1.43
u
1.3
457-SS-5A
6
PMD
8.37
5.47
0.7
457-SS-7A
6
PMD
945
328
0.35
457-SS-8A
6
PMD
747
266
0.4
457-SS-9A
6
PMD
27.2
8.16
0.3
458-SS-1A
6
PMD
51.8
18.7
0.4
458-SS-2A
6
PMD
9.84
8.36
0.8
458-SS-2B
12
PMD
6.01
4.38
0.7
458-SS-2C
18
PMD
22.8
11.3
0.5
458-SS-3A
6
PMD
39.1
34.4
0.9
458-SS-4A
6
PMD
11.1
7.04
0.6
458-SS-4B
12
PMD
18.7
11.1
0.6
458-SS-4C
18
PMD
21.5
16.6
0.8
458-SS-5A
6
PMD
28.7
16.2
0.6
458-SS-6A
6
PMD
83.5
72.9
0.9
458-SS-7A
6
PMD
93.4
76.3
0.8
458-SS-8A
6
PMD
16.7
7.73
0.5
458-SS01-01-020624
6
PMD
30.9
16.7
0.5
458-SS02-01-020624
6
PMD
37.7
23
0.6
458-SS03-01-020624
6
Waste Pile
134
39.8
0.3
458-SS04-01-020624
6
Waste Pile
48.3
35.5
0.7
Page 1 of 2
-------
Table B2-1. Preliminary Determination of Secular Equilibrium for the Section 9 Lease
Mines and Calculation of Site Disequilibrium Factor (Continued)
Sample ID
Bottom
Depth
(inches
bgs)
Location
Zone
Ra-226
(pCi/g)
Ra-226
Qualifier
U-238
(pCi/g)
U-238
Qualifier
U-238/
Ra-226
(DF)
458-SS05-01-020624
6
PMD
12.2
6.39
0.5
458-SS06-01-020624
6
Waste Pile
34.5
J
20.9
0.6
459-SS-2A
6
PMD
9.23
4.36
0.5
459-SS-2B
12
PMD
10.1
5.8
0.6
459-SS-2C
18
PMD
9.76
6.57
0.7
APE-SS01-01-020624
6
PMD
10.4
7.4
0.7
APE-SS02-01 -020624
6
General
1.94
1.32
0.7
APE-SS03-01 -020624
6
Road
2.83
2.53
0.9
APE-SS04-01 -020624
6
Road
2.3
2.19
1.0
APE-SS05-01-020624
6
General
1.35
0.749
0.6
APE-SS06-01-020624
6
PMD
1.51
1.05
0.7
APE-SS07-01-020624
6
PMD
15.4
11.3
0.7
APE-SS08-01-020624
6
Drainage
1.27
1.41
1.1
APE-SS09-01-020624
6
PMD
5.67
2.93
0.5
APE-SS10-01 -020624
6
Drainage
1.41
1.31
0.9
DRN-SD-1
6
Drainage
1.3
0.618
U
0.5
DRN-SD-2
6
Drainage
0.977
0.552
U
0.6
DRN-SD-3
6
Drainage
1.37
0.967
u
0.7
DRN-SD-4
6
Drainage
3.74
1.04
u
0.3
RIV-SD-2
6
General
21.2
8.16
0.4
S9L-SS-1A
6
General
13
15
1.2
S9L-SS-2A
6
General
65.2
13.3
0.2
S9L-SS-4A
6
General
57.3
15
0.3
WET-SD-3
6
General
64.4
62.8
1.0
WET-SD-4
6
General
7.29
0.758
u
0.1
Notes:
The evaluation includes all samples in the risk assessment dataset with both Ra-226 and U-238 results available.
The reporting limit was used as the value for nondetected results of U-238.
bgs
Below ground surface
DF
Disequilibrium factor
J
Estimated value
pCi/g
Picocurie per gram
PMD
Potential mining disturbance
Ra-226
Radium-226
U
Not detected
U-238
Uranium-238
Page 2 of 2
-------
Table B2-2. Summary Statistics of the U-238/Ra-226 Ratio and
Results of the Quality Assurance Test
Statistic
Ratio U-238/Ra-226 Soil Concentrations (DF)
Mean of the Ratio
0.7
Standard Deviation
0.3
Number of Samples1
61
Quality Assurance Test for Adequate Number of Samples
Width of Grey Region (A)
o
II
p
1
Standard Deviation of Data (a)
0.3
Relative Shift
0.4/0.3 = 1.33
Number of Samples Required in Exposure Unit for
Relative Shift of 1.33 and pa and pp =0.05
21
Notes:
1 The evaluation includes all samples in the risk assessment dataset with both Ra-226 and U-238 results
available. The reporting limit was used as the value for nondetected results of U-238.
DF Disequilibrium factor
pa Probability of a Type 1 error (incorrect rejection of the null hypothesis)
pp Probability of a Type 2 error (incorrect acceptance of the null hypothesis)
Ra-226 Radium-226
U-238 Uranium-238
Page 1 of 1
-------
APPENDIX C
CONTAMINANT DISTRIBUTION
-------
Estimated Radium-226 (pCi/g)1
Notes:
1The estimated radium-226 interpolated surface was
generated using gamma survey data from Section 9 Lease
Mines.
2BTV is based on the 95 percent upper tolerance limit with
95 percent coverage of the background dataset.
3Results for soil samples are presented using the same
color scheme as the interpolated results.
4The site-wide exposure unit is the same for the trespasser
and ecological receptors.
<2.0
40
> PERG
AUM
bgs
HH
pCi/g
PRG
PERG
Qay
RAG
TENORM
TRcp
TRcs
Abandoned uranium mine
Below ground surface
Human health
Picocurie per gram
Preliminary removal goal
Preliminary ecological removal goal
Quaternary alluvium
Removal action goal
Technologically enhanced naturally
occurring radioactive material
Chinle Formation Petrified Forest member
Chinle Formation Shinarump member
Soil Sample Locations1
SJ Surface Soil (0-3 and 0-6 inches bgs)
TENORM Boundary
^3 Exposure Unit Boundary
Site Features
Accumulation / Deposition Area
(Surficial / Volumetric)
i' I Waste Pile (Surficial / Volumetric)
~Geologic Contact
Access Road
Drainage
1 inch = 620 Feet
1:7,440
620 310 0
N
W-sS^s-E
S
620
I Feet
SECTION 9 LEASE
RADIUM-226 SAMPLE RESULTS
AND ESTIMATED RADIUM-226
CONCENTRATIONS WITHIN
THE TENORM BOUNDARY
Prepared For: U.S. EPA Region 9
'\Mi
Task Order No.:
0020
Location:
COCONINO COUNTY. AZ
Prepared By:
It
TETRA TECH
1999 Harrison Street, Suite 500
Oakland, CA 94612
Contract No.:
68HE0923D0002
6/21/2024
Coordinate System:
NAD 1983 State Plane Arizona Central
FIPS 0202 Feet Transverse Mercator
Figure No.:
C-1
-------
N
/
Qay f "
s.
J
IM -
/
V
f
¦>
I
I
/
/
TRcp^ ^
' \
s
/ / / ¦ /
Js a. /| TRcs 1 ft'
TRcs ¦*~«TRcs ;
j i'"-'\ -i
I t i i tiJ
N rN
H N
\ ErS/^N
Qay
Arsenic Surface Soil Concentration (mg/kg)
©
©
<5.0
5.0-5.9
5.9-18
18-68
> 68
< TRcp BTV1
TRcp BTV - Qay BTV
Qay BTV - TRcs BTV
TRcs BTV - PERG
> PERG
CS Laboratory or Instrumental Nondetect Result
Radium-226 Removal Action Extent
£™TENORM Boundary
|_| Exposure Unit Boundary2
Site Features
Accumulation / Deposition Area
(Surficial / Volumetric)
I I Waste Pile (Surficial / Volumetric)
Geologic Contact
Access Road
Drainage
Notes:
1BTV is based on the 95 percent upper tolerance limit
with 95 percent coverage of the background dataset.
2The site-wide exposure unit is the same for the
trespasser and ecological receptors.
AUM Abandoned uranium mine
BTV Background threshold value
mg/kg Milligram per kilogram
PERG Preliminary ecological removal goal
Qay Quaternary alluvium
TENORM Technologically enhanced naturally
occurring radioactive material
TRcp Chinle Formation Petrified Forest member
TRcs Chinle Formation Shinarump member
1 inch = 620 Feet
1:7,440
620 310 0
N
W-sS^s-E
S
620
I Feet
SECTION 9 LEASE
ARSENIC SURFACE SOIL RESULTS
WITHIN THE TENORM BOUNDARY
Prepared For: U.S. EPA Region 9
'\Mi
Task Order No.:
0020
Location:
COCONINO COUNTY. AZ
Prepared By:
It
TETRA TECH
1999 Harrison Street, Suite 500
Oakland, CA 94612
Contract No.:
68HE0923D0002
6/1 9/2024
Coordinate System:
NAD 1983 State Plane Arizona Central
FIPS 0202 Feet Transverse Mercator
Figure No.:
C-3
-------
N
/
Qay f "
s.
J
/
V
f
I
I
y < T »f f
TRcs ¦*~«TRcs ;
1 Qay y >
I ? > / i £ Ssti
N rN
H N
\ ErS/^N
Qay
Mercury Surface Soil Concentration (mg/kg)1
@ s 0.5 (PERG)
O >0.5 (PERG)
0 Laboratory or Instrumental Nondetect Result
Radium-226 Removal Action Extent
™TENORM Boundary
[ 11 Exposure Unit Boundary2
Site Features
Accumulation / Deposition Area
(Surficial / Volumetric)
[ ] Waste Pile (Surficial / Volumetric)
i-_"l Geologic Contact
Access Road
Drainage
Notes:
1The Western AUM Region background dataset does
not include mercury data.
2The site-wide exposure unit is the same for the
trespasser and ecological receptors.
AUM
mg/kg
PERG
Qay
TENORM
TRcp
TRcs
Abandoned uranium mine
Milligram per kilogram
Preliminary ecological removal goal
Quaternary alluvium
Technologically enhanced naturally
occurring radioactive material
Chinle Formation Petrified Forest member
Chinle Formation Shinarump member
1 inch = 620 Feet
1:7,440
620 310 0
N
W-sS^s-E
S
620
I Feet
SECTION 9 LEASE
MERCURY SURFACE SOIL RESULTS
WITHIN THE TENORM BOUNDARY
Prepared For: U.S. EPA Region 9
'\Mi
Task Order No.:
0020
Location:
COCONINO COUNTY. AZ
Prepared By:
It
TETRA TECH
1999 Harrison Street, Suite 500
Oakland, CA 94612
Contract No.:
68HE0923D0002
6/21/2024
Coordinate System:
NAD 1983 State Plane Arizona Central
FIPS 0202 Feet Transverse Mercator
Figure No.:
C-3
-------
N
/
Qay f "
s.
J
i i £ Ea
N rN
S\ X
s
Qay
Molybdenum Surface Soil Concentration (mg/kg)
©
<0.7
< TRcs BTV1
©
00
ci
TRcs BTV-TRcp BTV
©
CD
c\i
CO
TRcp BTV - Qay BTV
©
2.6 - 430
Qay BTV - PERG
o
>430
> PERG
CS Laboratory or Instrumental Nondetect Result
Radium-226 Removal Action Extent
£™^ TENORM Boundary
|_| Exposure Unit Boundary2
Site Features
Accumulation / Deposition Area
(Surficial / Volumetric)
I I Waste Pile (Surficial / Volumetric)
~ Geologic Contact
Access Road
Drainage
Notes:
1BTV is based on the 95 percent upper tolerance limit
with 95 percent coverage of the background dataset.
2The site-wide exposure unit is the same for the
trespasser and ecological receptors.
AUM Abandoned uranium mine
BTV Background threshold value
mg/kg Milligram per kilogram
PERG Preliminary ecological removal goal
Qay Quaternary alluvium
TENORM Technologically enhanced naturally
occurring radioactive material
TRcp Chinle Formation Petrified Forest member
TRcs Chinle Formation Shinarump member
1 inch = 620 Feet
1:7,440
620 310 0
N
W-sS^s-E
S
620
I Feet
SECTION 9 LEASE
MOLYBDENUM SURFACE SOIL RESULTS
WITHIN THE TENORM BOUNDARY
Prepared For: U.S. EPA Region 9
'\Mi
Task Order No.:
0020
Location:
COCONINO COUNTY. AZ
Prepared By:
It
TETRA TECH
1999 Harrison Street, Suite 500
Oakland, CA 94612
Contract No.:
68HE0923D0002
6/21/2024
Coordinate System:
NAD 1983 State Plane Arizona Central
FIPS 0202 Feet Transverse Mercator
Figure No.:
C-4
-------
N
/
Qay f "
s.
J
j IO /V
/
V
f
_L_
I
I
Is' / _*ri TRcs 1 !
TRcs ¦*~«TRcs ;
j im\ -i
I a I I
.
N rN
S\ X
s
Qay
Selenium Surface Soil Concentration (mg/kg)
©
©
<2.0
2.0-3.4
3.4-3.5
3.5-7.0
> 7.0
< TRcp BTV1
TRcp BTV - PERG
PERG-TRcs BTV
TRcs BTV - Qay BTV
> Qay BTV
©
rj
Laboratory or Instrumental Nondetect Result
Radium-226 Removal Action Extent
TENORM Boundary
|_| Exposure Unit Boundary2
Site Features
Accumulation / Deposition Area
(Surficial / Volumetric)
I I Waste Pile (Surficial / Volumetric)
i~ Geologic Contact
Access Road
Drainage
Notes:
1BTV is based on the 95 percent upper tolerance limit
with 95 percent coverage of the background dataset.
2The site-wide exposure unit is the same for the
trespasser and ecological receptors.
AUM Abandoned uranium mine
BTV Background threshold value
mg/kg Milligram per kilogram
PERG Preliminary ecological removal goal
Qay Quaternary alluvium
TENORM Technologically enhanced naturally
occurring radioactive material
TRcp Chinle Formation Petrified Forest member
TRcs Chinle Formation Shinarump member
1 inch = 620 Feet
1:7,440
620 310 0
N
S
620
I Feet
SECTION 9 LEASE
SELENIUM SURFACE SOIL RESULTS
WITHIN THE TENORM BOUNDARY
Prepared For: U.S. EPA Region 9
'\Mi
Task Order No.:
0020
Location:
COCONINO COUNTY. AZ
Prepared By:
It
TETRA TECH
1999 Harrison Street, Suite 500
Oakland, CA 94612
Contract No.:
68HE0923D0002
6/21/2024
Coordinate System:
NAD 1983 State Plane Arizona Central
FIPS 0202 Feet Transverse Mercator
Figure No.:
C-5
-------
N
/
Qay f "
s.
J
A- s
I TRcP \ ^ - - -V
I *
— x _ J /> ';
V1 ' / / ?S /,~i' • *
\\ jA / J(TRcs I //day ^ ^7
V -> TRcs *~*««TRcs - LJJ_ 8 t g_
x r^.
s\
S r
AUM
Abandoned uranium mine
mg/kg
Milligram per kilogram
ay
PERG
Preliminary ecological removal goal
\
Qay
Quaternary alluvium
TENORM
Technologically enhanced naturally
occurring radioactive material
TRcp
Chinle Formation Petrified Forest member
TRcs
Chinle Formation Shinarump member
Qay
Thallium Surface Soil Concentration (mg/kg)1
# s 0.5 (PERG)
O >0.5 (PERG)
0 Laboratory or Instrumental Nondetect Result
Radium-226 Removal Action Extent
™TENORM Boundary
ll' 11 Exposure Unit Boundary2
Site Features
Accumulation / Deposition Area
(Surficial / Volumetric)
[ 1 Waste Pile (Surficial / Volumetric)
i-_"l Geologic Contact
Access Road
Drainage
Notes:
1The Western AUM Region background dataset does
not include thallium data.
2The site-wide exposure unit is the same for the
trespasser and ecological receptors.
1 inch = 620 Feet
1:7,440
620 310 0
N
W-sS^s-E
S
620
I Feet
SECTION 9 LEASE
THALLIUM SURFACE SOIL RESULTS
WITHIN THE TENORM BOUNDARY
Prepared For: U.S. EPA Region 9
'\Mi
Task Order No.:
0020
Location:
COCONINO COUNTY. AZ
Prepared By:
It
TETRA TECH
1999 Harrison Street, Suite 500
Oakland, CA 94612
Contract No.:
68HE0923D0002
6/21/2024
Coordinate System:
NAD 1983 State Plane Arizona Central
FIPS 0202 Feet Transverse Mercator
Figure No.:
C-6
-------
N
/
Qay f "
s.
J
•' V
S\ . v
— s~~\ \\( \
" —' v _ v—or-
.^--\\^x /y^oayj
^/T°"" )y -O
«"* TRcs ¦*~«TRcs ;
11 cm. - &
I a I 11 I
N rN
S\ X
s
Qay
Uranium Surface Soil Concentration (rng/kg)
©
<1.6
< TRcs BTV1
©
1.6-3.9
TRcs BTV - Qay BTV
•
CO
CO
^4
Qay BTV - TRcp BTV
G
7.7 - 250
TRcp BTV - PERG
O
> 250
> PERG
0
Laboratory or Instrumental Nondetect Result
Radium-226 Removal Action Extent
£™^ TENORM Boundary
|_| Exposure Unit Boundary2
Site Features
Accumulation / Deposition Area
(Surficial / Volumetric)
I I Waste Pile (Surficial / Volumetric)
i~ Geologic Contact
Access Road
Drainage
Notes:
1BTV is based on the 95 percent upper tolerance limit
with 95 percent coverage of the background dataset.
2The site-wide exposure unit is the same for the
trespasser and ecological receptors.
AUM
BTV
mg/kg
PERG
Qay
TENORM
TRcp
TRcs
Abandoned uranium mine
Background threshold value
Milligram per kilogram
Preliminary ecological removal goal
Quaternary alluvium
Technologically enhanced naturally
occurring radioactive material
Chinle Formation Petrified Forest member
Chinle Formation Shinarump member
1 inch = 620 Feet
1:7,440
620 310 0
N
W-sS^s-E
S
620
I Feet
SECTION 9 LEASE
URANIUM SURFACE SOIL RESULTS
WITHIN THE TENORM BOUNDARY
Prepared For: U.S. EPA Region 9
'\Mi
Task Order No.:
0020
Location:
COCONINO COUNTY. AZ
Prepared By:
It
TETRA TECH
1999 Harrison Street, Suite 500
Oakland, CA 94612
Contract No.:
68HE0923D0002
6/21/2024
Coordinate System:
NAD 1983 State Plane Arizona Central
FIPS 0202 Feet Transverse Mercator
Figure No.:
C-7
-------
N
/
Qay f "
s.
J
IM -
/
V
f
¦>
I
I
IS < +f i\ TRcs 1 ' ' '
TRcs ¦*~«TRcs ;
1 Qay y >
i l l L
.
N rN
S\ X
s
Qay
Vanadium Surface Soil Concentration (rng/kg)
©
©
<56
56-62
62-80
80-83
> 83
< TRcp BTV1
TRcp BTV-TRcs BTV
TRcs BTV - PERG
PERG - Qay BTV
> Qay BTV
©
rj
Laboratory or Instrumental Nondetect Result
Radium-226 Removal Action Extent
TENORM Boundary
|_| Exposure Unit Boundary2
Site Features
Accumulation / Deposition Area
(Surficial / Volumetric)
I I Waste Pile (Surficial / Volumetric)
i~ Geologic Contact
Access Road
Drainage
Notes:
1BTV is based on the 95 percent upper tolerance limit
with 95 percent coverage of the background dataset.
2The site-wide exposure unit is the same for the
trespasser and ecological receptors.
AUM Abandoned uranium mine
BTV Background threshold value
mg/kg Milligram per kilogram
PERG Preliminary ecological removal goal
Qay Quaternary alluvium
TENORM Technologically enhanced naturally
occurring radioactive material
TRcp Chinle Formation Petrified Forest member
TRcs Chinle Formation Shinarump member
1 inch = 620 Feet
1:7,440
620 310 0
N
S
620
I Feet
SECTION 9 LEASE
VANADIUM SURFACE SOIL RESULTS
WITHIN THE TENORM BOUNDARY
Prepared For: U.S. EPA Region 9
'\Mi
Task Order No.:
0020
Location:
COCONINO COUNTY. AZ
Prepared By:
It
TETRA TECH
1999 Harrison Street, Suite 500
Oakland, CA 94612
Contract No.:
68HE0923D0002
6/21/2024
Coordinate System:
NAD 1983 State Plane Arizona Central
FIPS 0202 Feet Transverse Mercator
Figure No.:
C-8
-------
APPENDIX D
COST ANALYSIS
-------
Table D-1. Section 9 Lease Mines, Comparison of Costs for Each Alternative
Alternative
Capital Cost
Inspection and
Maintenance Costs
(NPV of 10 Years)1
Cap O&M Cost
(NPV of 30 Years)
Net Present Value
(3.5%)
Section 9 Lease Mines
Alternative 2
$ 3,451,000
$ 78,000
$ 95,000
$ 3,624,000
Alternative 3
$ 3,821,000
$ 102,000
$ 95,000
$ 4,018,000
Alternative 4
$ 12,676,000
$ 78,000
$
$ 12,754,000
Note:
1 Excludes cap maintenance
Not applicable
NPV Net present value
O&M Operation and maintenance
Page 1 of 1
-------
Table D-2. Section 9 Lease Mines, Cost Rollup for Alternative 2
Cost Component
Section 9 Lease Mines Totals
Excavated Surface Area (SF)
283,449
Excavated Volume (LCY)
14,784
Capital Costs
Access Road Construction
$
74,495
Waste Excavation and Hauling
$
257,619
Site and Road Restoration
$
314,516
Onsite Consolidation and Cap
$
1,466,272
Construction
Subtotal Construction
$
2,112,903
Non-Construction
$
1,337,739
Total Capital Costs
$
3,450,642
NPV Costs (3.5% discount rate)1
Capital Costs
$
3,450,642
10-Year Site Inspection
$
28,107
10-Year Maintenance
$
49,657
30-Year Onsite Cap
$
95,080
Total NPV Costs
$
3,623,486
Notes:
LCY
NPV
O&M
SF
Present worth analysis produces a single figure
representing the amount of money that, if
invested in the base year and disbursed as
needed, would be sufficient to cover all costs
associated with the alternative. For projects that
will last less than 1 year (generally, projects that
do not require O&M), the present worth is simply
the one time cost of performing the action.
Loose cubic yard
Net present value
Operation and maintenance
Square foot
Page 1 of 1
-------
Table D-3. Section 9 Lease Mines, Cost Rollup for Alternative 3
Cost Component
Section 9 Lease Mines Totals
Excavated Surface Area (SF)
283,449
Excavated Volume (LCY)
14,784
Capital Costs
Access Road Construction
$
108,881
Waste Excavation and Hauling
$
346,551
Site and Road Restoration
$
415,282
Onsite Consolidation and Cap
$
1,466,272
Construction
Subtotal Construction
$
2,336,986
Non-Construction
$
1,484,432
Total Capital Costs
$
3,821,418
NPV Costs (3.5% discount rate)1
Capital Costs
$
3,821,418
10-Year Site Inspection
$
36,540
10-Year Maintenance
$
64,973
30-Year Onsite Cap
$
95,080
Total NPV Costs
$
4,018,010
Notes:
LCY
NPV
O&M
SF
Present worth analysis produces a single figure
representing the amount of money that, if
invested in the base year and disbursed as
needed, would be sufficient to cover all costs
associated with the alternative. For projects that
will last less than 1 year (generally, projects that
do not require O&M), the present worth is simply
the one time cost of performing the action.
Loose cubic yard
Net present value
Operation and maintenance
Square foot
Page 1 of 1
-------
Table D-4. Section 9 Lease Mines, Cost Rollup for Alternative 4
Cost Component
Section 9 Lease Mines Totals
Excavated Surface Area (SF)
283,449
Excavated Volume (CY)
14,784
Capital Costs
Access Road Construction
$
74,495
Waste Excavation and Loading
$
1,049,405
Site and Road Restoration
$
248,897
Waste Hauling to LLRW Facility
$
2,974,929
Disposal at LLRW Facility
$
6,431,040
Subtotal Construction
$
10,778,766
Non-Construction
$
1,897,620
Total Capital Costs
$
12,676,386
NPV Costs (3.5% discount rate)1
Capital Costs
$
12,676,386
10-Year Site Inspection
$
28,107
10-Year Maintenance
$
49,657
Total NPV Costs
$
12,754,150
Notes:
Present worth analysis produces a single
figure representing the amount of money that,
if invested in the base year and disbursed as
needed, would be sufficient to cover all costs
associated with the alternative. For projects
that will last less than 1 year (generally,
projects that do not require O&M), the present
worth is simply the one time cost of
performing the action.
LCY Loose cubic yard
LLRW Low-level radioactive waste
NPV Net present value
O&M Operation and maintenance
SF Square foot
Page 1 of 1
-------
Table D-5. Section 9 Lease Mines, Cost Estimate Scenario Assumptions for Alternative 2,
Multiple Locations Consolidate and Cap on Site
Technology
Assumptions
Cost Effects
Excavation
Methods
Waste removed will be removed with a
large excavator unless specified.
Excavators can operate on steeper terrain than
bulldozers and are better at moving waste uphill.
Bulldozers cost less to operate. Spider excavators or
other specialized equipment are more expensive.
Any disturbed surface will be restored
using grading and erosion controls.
Quantities of erosion control materials and grading
may be lower than estimated.
All waste specified in the risk
assessment will be excavated.
Volumes of excavated waste may be lower than
estimated.
The site is accessible to haul trucks
and trucks can be easily loaded.
Accessing difficult-to-reach mines increases costs.
O&M inspection of the mine site will be
completed for 10 years.
More O&M inspections increase costs.
Soil and
Waste Sorting
Waste will be sorted based on grain
size; rock greater than 3 inches will be
segregated.
N/A
Waste will be processed through the
screening plant using an excavator.
N/A
Consolidation
and Cap
Waste will consolidated nearby on-site
and capped at consolidation area.
Greater distance to consolidate waste increases costs.
Waste will be consolidated into two
areas: a 3.5-acre and a 2.5-acre
areas, both of which will be graded.
Consolidation into a larger area decreases the cost for
relocating the waste; however, it increases cost for
cover soil.
Waste will be consolidated from
multiple locations.
Consolidating waste from multiple locations increases
costs.
A bulldozer will be used to excavate
borrow soil.
Use of an excavator may increase costs.
Multiple cells will be required to be
opened and closed.
Multiple mobilizations to open/close cells increases
costs.
ET cap will be 3 feet of soil with a
biobarrier and capillary break, but no
liner.
Adding biobarrier, capillary break, or liner increases
costs.
No bottom liner or leachate collection
system will be installed.
Adding bottom liner or leachate collection system
increases costs
Bulldozer will be used to move borrow
soil to form cap.
Use of an excavator may increase costs.
O&M inspection of the cap will be
conducted for 30 years.
More O&M inspections will increase costs.
Water
Water will be hauled in from Cameron,
Arizona.
Drilling a water well would incur additional capital
costs, but lower operating costs.
Notes:
ET Evapotranspiration
N/A Not applicable - inherent assumption
O&M Operation and maintenance
Page 1 of 1
-------
Table D-6. Section 9 Lease Mines, Crew Time Productivity Calculations for Alternative 2,
Multiple Locations Consolidate and Cap on Site
Step
Section 9 Lease Mines Haul / Access Road Installation
1
Action
Qty
Unit
Production/Day
Days
Section 9 Lease Mines Access Road Building
9,445
LCY
3,089
3.1
Control Days
3
Step
Section 9 Lease Mines Excavation and Hauling
2
Action
Qty
Unit
Production/Day
Days
Waste Removal AUM 458 (AUM 459 portion 807
LCY) - Standard Excavator or Dozer / Loader
1,580
LCY
3,027
0.9
Waste Removal placed at AUM 457 - Standard
Excavator or Dozer / Loader
16,900
LCY
3,027
6.2
18,480
LCY
Control Days
7
Step
Section 9 Lease Mines Site Reclamation
3
Action
Qty
Unit
Production/Day
Days
Dozer Contour Grading
37,462
SY
4,000
9.4
Soil Backfill
18,480
LCY
3,027
7.2
Water Bars
1,275
CY
536
2.4
Rock-Lined Ditch (6 Feet by 3 Feet)
671
CY
1,099
0.6
Rock Berm (4 Feet by 3 Feet)
549
CY
1,099
0.5
Rock Fields and Rock Cover (1 Foot High)
319
CY
1,099
0.3
Control Days
19
TOTAL PROJECT DAYS
28
Slowest Rate Project Days
15
Notes:
AC Acre
AUM Abandoned uranium mine
CY Cubic yard
LCY Loose cubic yard
QTY Quantity
SY Square yard
Page 1 of 1
-------
Table D-7. Section 9 Lease Mines, Cost Estimate Details for Alternative 2,
Multiple Locations Consolidate and Cap on Site
Engineering Design
Crew
Unit
Amount
Price
Cost
Project Manager
N/A
Hour
200
$ 187.45
$ 37,490
Project Engineer
N/A
Hour
800
$ 144.74
$ 115,793
Design Engineer
N/A
Hour
400
$ 187.45
$ 74,980
CAD/GIS Operator
N/A
Hour
200
$ 121.01
$ 24,203
Admin
N/A
Hour
80
$ 79.49
$ 6,359
Reproduction
N/A
LS
3
$ 593.20
$ 1,780
$ 260,605
Planning Documents
Crew
Unit
Amount
Price
Cost
Project Manager
N/A
Hour
100
$ 187.45
$ 18,745
Project Engineer
N/A
Hour
400
$ 144.74
$ 57,896
CAD/GIS Operator
N/A
Hour
100
$ 121.01
$ 12,101
Admin
N/A
Hour
40
$ 79.49
$ 3,180
Reproduction
N/A
LS
3
$ 593.20
$ 1,780
$ 93,702
Resource Surveys
Crew
Unit
Amount
Price
Cost
Cultural Resources Mitigation
N/A
Each
0
$ 44,366.94
$
Biological Resources Mitigation
N/A
Each
1
$ 88,733.88
$ 88,734
Geotechnical Testing and Report
N/A
Each
1
$ 88,733.88
$ 88,734
Pre-Project Aerial LiDAR Survey
N/A
Each
0
$ 35,592.00
$
Post-Project Aerial LiDAR Survey
N/A
Each
1
$ 133,100.82
$ 133,101
$ 310,569
Confirmation Sampling
Crew
Unit
Amount
Price
Cost
Developing Sampling and Analysis Plan
Project Geologist
N/A
Hour
180
$ 187.45
$ 33,741
Project Manager
N/A
Hour
90
$ 131.69
$ 11,852
CAD/GIS Operator
N/A
Hour
90
$ 144.74
$ 13,027
Project Chemist
N/A
Hour
180
$ 131.69
$ 23,704
Health and Safety Manager
N/A
Hour
90
$ 179.15
$ 16,123
Admin
N/A
Hour
36
$ 79.49
$ 2,862
Reproduction
N/A
LS
3
$ 296.60
$ 890
Sampling - Gamma Only
Sampling Team - Staff Geologist
N/A
Hour
40
$ 91.35
$ 3,690
Sampling Team - Staff Engineer
N/A
Hour
40
$ 96.10
$ 3,881
Travel
N/A
Day
8
$ 201.69
$ 1,670
Per Diem (96/55)
N/A
Day
8
$ 179.15
$ 1,483
Miscellaneous Field Supplies and Expenses
N/A
LS
1
$ 22,680.38
$ 22,680
Lab Analysis
N/A
LS
0
$ 7,307.23
$
XRF Surveying
Sampling Team - Staff Geologist
N/A
Hour
0
$ 91.35
$
Sampling Team - Staff Engineer
N/A
Hour
0
$ 96.10
$
Travel
N/A
Day
0
$ 201.69
$
Per Diem (96/55)
N/A
Day
0
$ 179.15
$
Miscellaneous Field Supplies and Expenses
N/A
LS
0
$ 22,680.38
$
Lab Analysis
N/A
LS
0
$ 7,307.23
$
Frisking Equipment
N/A
Month
0
$ 170.84
$
$ 135,603
Page 1 of 5
-------
Table D-7. Section 9 Lease Mines, Cost Estimate Details for Alternative 2,
Multiple Locations Consolidate and Cap on Site
Reporting
Crew
Unit
Amount
Price
Cost
Project Geologist
N/A
Hour
158
$ 124.57
$ 19,682
Project Manager
N/A
Hour
79
$ 207.62
$ 16,402
Project Engineer
N/A
Hour
237
$ 144.74
$ 34,304
Chemist
N/A
Hour
79
$ 131.69
$ 10,404
CAD/GIS Operator
N/A
Hour
79
$ 121.01
$ 9,560
Admin
N/A
Hour
32
$ 79.49
$ 2,504
Reproduction
N/A
LS
3
$ 593.20
$ 1,780
$ 94,635
Mobilization/Demobilization
Crew
Unit
Amount
Price
Cost
Crew Mileage
N/A
Mile
1,568
$ 0.67
$ 1,051
Per Diem
N/A
Day
15
$ 182.00
$ 2,730
Labor
N/A
Day
15
$ 355.92
$ 5,339
Standard Equipment Mileage
N/A
Mile
1,568
$ 0.67
$ 1,051
Standard Equipment Rental
N/A
Day
2
$ 20,948.76
$ 41,898
$ 52,067
Haul Road Building
Crew
Daily
Unit#
Days
Cost
Excavator 3.5 CY ~ 80K-100K lb.
B12D
$ 4,346.97
1
3
$ 13,292
Dozer D6
B10M
$ 3,478.17
1
3
$ 10,636
Grader 30,000 lb.
B11L
$ 2,863.38
1
3
$ 8,756
Water Truck
B45
$ 1,054.71
4
3
$ 12,900
Brush Chipper
B7
$ 3,119.05
1
3
$ 9,537
Loader 5cy+
B10U
$ 2,411.88
1
3
$ 7,375
Off Road Haul Truck (17 CY)
B34F
$ 1,962.09
2
3
$ 11,999
Total
$ 74,495
Excavation & Hauling
Crew
Daily
Unit#
Days
Cost
Loader 5CY+
B10U
$ 2,411.88
2
6
$ 24,826
Off Road Haul Truck (17 CY)
B34A
$ 1,962.09
6
6
$ 60,588
Grader 30,000 lb.
B11L
$ 2,863.38
2
6
$ 29,473
Water Truck
B45
$ 1,054.71
4
6
$ 21,712
Dozer D6
B10M
$ 3,478.17
2
6
$ 35,801
Excavator 3.5 CY ~ 80K-100K lb.
B12D
$ 4,346.97
2
6
$ 44,744
Total
$ 217,144
Onsite Restoration
Crew
Daily
Unit#
Days
Cost
Off Road Haul Truck (17 CY)
B34F
$ 1,962.09
4
6
$ 47,921
Loader 5CY+
B10U
$ 2,411.88
2
6
$ 29,453
Grader 30,000 lb.
B11L
$ 2,863.38
1
2
$ 6,810
Excavator 3.5 CY ~ 80K-100K lb.
B12D
$ 4,346.97
2
6
$ 53,084
Dozer D6
B10M
$ 3,478.17
2
12
$ 81,694
Water Truck
B45
$ 1,054.71
4
12
$ 49,545
Rip Rap Class II 18"-24"
NA
$ 53.37
862.0
1
$ 46,009
Total
$ 314,516
Page 2 of 5
-------
Table D-7. Section 9 Lease Mines, Cost Estimate Details for Alternative 2,
Multiple Locations Consolidate and Cap on Site
Construction Contractor Site Overhead
Crew
Unit
Amount
Price
Cost
Project Manager (10% of time)
N/A
Hour
15
$
207.62
$
3,170
Site Superintendent
N/A
Hour
153
$
226.60
$
34,601
H&S Officer
N/A
Hour
153
$
100.84
$
15,398
QA/QC Officer
N/A
Hour
153
$
100.84
$
15,398
Field Clerk
N/A
Hour
153
$
22.54
$
3,442
Fuel for Site Vehicles
N/A
Month
4
$
581.34
$
2,515
Port-o-let Rental (4)
N/A
Month
3
$
246.77
$
754
Job Trailers (1)
N/A
Month
1
$
319.14
$
244
Storage Boxes (1)
N/A
Month
1
$
112.11
$
86
Field Office Lights/HVAC (1)
N/A
Month
1
$
212.37
$
162
Generator (1)
N/A
Month
2
$
2,847.36
$
4,348
Fuel for Generator
N/A
Gallons
458
$
4.75
$
2,174
Telephone/internet (1)
N/A
Month
1
$
455.58
$
348
Field Office Equipment
N/A
Month
1
$
272.87
$
208
Field Office Supplies
N/A
Month
1
$
113.89
$
87
Trash (1 dumpster)
N/A
Month
1
$
1,079.62
$
824
Clin 1034 High Volume Air Sampling (4)
N/A
Month
3
$
454.39
$
1,388
Clin 1025 Ludlum 2121 and 43-10-1
N/A
Month
1
$
326.26
$
249
Air Monitoring Lab Confirmation Sampling (5
samples per day)
N/A
Day
61
$
711.84
$
43,478
Clin 1036 Personal Air Monitor
N/A
Month
8
$
242.03
$
2,003
Clin 1038 Personal Dust Monitor
N/A
Month
8
$
1,844.85
$
15,272
Clin 1068 Personal Dosimeter Badge
N/A
Month
8
$
70.00
$
579
Truck Scales
N/A
Month
1
$
355.92
$
272
$
147,000
Third-Party Oversight
Crew
Unit
Amount
Price
Cost
Travel and Lodging (1 person)
N/A
Day
15
$
179.15
$
2,735
Labor
N/A
Hour
153
$
94.91
$
14,493
Car Rental (1 car)
N/A
Month
1
$
474.56
$
362
Car Fuel
N/A
Month
1
$
901.66
$
688
$
18,279
Level of Accuracy (20%)
Crew
Unit
Amount
Price
Cost
20% of Construction Cost
N/A
N/A
N/A
N/A
$
129,326
GRAND
TOTAL
$
1,984,370
Page 3 of 5
-------
Table D-7. Section 9 Lease Mines, Cost Estimate Details for Alternative 2,
Multiple Locations Consolidate and Cap on Site
Onsite O&M Costs
Crew
Unit
Amount
Price
Cost
Annual Inspection (1 person crew, 1 day, 10
hrs/day)
N/A
Hour
10
$ 100.84
$ 1,008
Inspection Crew Travel and Lodging
N/A
LS
1
$ 791.31
$ 791
Preperation of Semi-annual Reports
(Professional Engineer)
N/A
Hour
8
$ 142.37
$ 1,139
Inspection Event Cost
$ 2,939
Inspection Contingency (15%)
$ 171
Total Inspection Event Cost
$ 3,110
Maintenance Crew Travel and Lodging
N/A
LS
1
$ 2,434.49
$ 2,434
Mobilization and Demobilization of Dozer,
and 17 CY Articulated Dump Truck
N/A
LS
1
$ 20,654.80
$ 20,655
Dozer Rental and Labor
B81
Day
3
$ 3,478.52
$ 10,436
Articulated Dump Truck (17 CY) Rental and
Labor
B34F
Day
3
$ 1,962.09
$ 5,886
Riprap Class II
N/A
CY
64
$ 53.39
$ 3,409
Construction Overhead
N/A
LS
1
$ 18,090.70
$ 18,091
O&M Annual Cost
$ 60,911
O&M Contingency (15%)
$ 9,137
Total O&M Annual Cost
$ 70,047
Contractor Site Overhead O&M
Crew
Unit
Amount
Price
Cost
Site Superintendent
N/A
Hour
30
$ 226.60
$ 6,798.07
H&S Officer
N/A
Hour
30
$ 100.84
$ 3,025.32
Fuel for Site Vehicles
N/A
Month
0.5
$ 6,976.03
$ 3,139.21
Port-o-let Rental (1)
N/A
Month
0.2
$ 246.77
$ 37.02
Generator (1)
N/A
Month
0.15
$ 2,847.36
$ 427.10
Fuel for Generator
N/A
Gallons
90
$ 4.75
$ 427.10
Telephone/internet (1)
N/A
Month
0.15
$ 455.58
$ 68.34
Trash (1 dumpster)
N/A
Month
0.15
$ 1,079.62
$ 161.94
Clin 1034 High Volume Air Sampling (3)
N/A
Month
0.5
$ 454.39
$ 204.48
Clin 1025 Ludlum 2121 and 43-10-1
N/A
Month
0.15
$ 326.26
$ 48.94
Air Monitoring Lab Confirmation Sampling (3
samples per day)
N/A
Day
3
$ 711.84
$ 2,135.52
Clin 1036 Personal Air Monitor
N/A
Month
0.8
$ 242.03
$ 181.52
Clin 1038 Personal Dust Monitor
N/A
Month
0.8
$ 1,844.85
$ 1,383.64
Clin 1068 Personal Dosimeter Badge
N/A
Month
0.8
$ 70.00
$ 52.50
$ 18,090.70
Page 4 of 5
-------
Table D-7. Section 9 Lease Mines, Cost Estimate Details for Alternative 2,
Multiple Locations Consolidate and Cap on Site
Notes:
"
Inch
CAD
Computer-aided design
CY
Cubic yard
GIS
Geographic information system
H&S
Health and safety
HP
Horsepower
hr
Hour
HVAC
Heating, ventilation, and air conditioning
K
Thousand
lb.
Pound
LF
Linear foot
LiDAR
Light detection and ranging
LS
Lump sum
N/A
Not applicable
O&M
Operation and maintenance
QA/QC
Quality assurance/quality control
SY
Square yard
XRF
X-ray fluorescence
Page 5 of 5
-------
Table D-8. Section 9 Lease Mines, Cost Estimate Summary for Alternative 2,
Multiple Locations Consolidate and Cap on Site
Haul Road Building
Unit Cost
Excavator 3.5 cy ~ 80K-100K lb.
$ 13,292
Dozer D6
$ 10,636
Grader 30,000 lb.
$ 8,756
Water Truck
$ 12,900
Off Road Haul Truck
$ 11,999
Loader 5cy+
$ 7,375
Brush Chipper
$ 9,537
Subtotals Step 1
$ 74,495
Excavation and Hauling
Unit Cost
Loader 5cy+
$ 29,453
Off Road Haul Truck (17 CY)
$ 71,881
Grader 30,000 lb.
$ 34,967
Water Truck
$ 25,760
Dozer D6
$ 42,474
Excavator 3.5 cy ~ 80K-100K lb.
$ 53,084
Subtotals Step 2
$ 257,619
Onsite Restoration
Unit Cost
Off Road Haul Truck (17 CY)
$ 47,921
Loader 5cy+
$ 29,453
Grader 30,000 lb.
$ 6,810
Excavator 3.5 cy ~ 80K-100K lb.
$ 53,084
Dozer D6
$ 81,694
Water Truck
$ 49,545
Rip Rap Class II 18"-24"
$ 46,009
Subtotals Step 3
$ 314,516
Subtotal Construction
$ 646,631
Other Costs
Unit Cost
Non-Construction Costs
Engineering Design
$ 260,605
Planning Documents
$ 93,702
Resource Surveys
$ 310,569
Confirmation Sampling
$ 135,603
Reporting
$ 94,635
Contractor Site Overhead and Miscellaneous Costs
$ 147,000
Mobilization / Demobilization
$ 52,067
Travel+ Lodging (Construction Workers)
$ 95,954
Level of Accuracy (20%)
$ 129,326
Third-Party Oversight
$ 18,279
Subtotals Step 6
$ 1,337,739
Total Site Capital Costs
$ 1,984,370
Inspections and Maintenance Event Costs
Unit Cost
Annual Inspection (1 person crew, 1 day, 10 hrs/day)
$ 1,008
Inspection Crew Travel and Lodging
$ 791
Preperation of Report (Professional Engineer)
$ 1,139
Subtotal Inspection Costs
$ 2,939
Inspection Contingencies (15%)
$ 441
Total Yearly Inspection Costs
$ 3,380
Page 1 of 2
-------
Table D-8. Section 9 Lease Mines, Cost Estimate Summary for Alternative 2,
Multiple Locations Consolidate and Cap on Site
Present Value of Inspection Costs Based on 10-Year Life at 3.50% (PV
Factor = 8.317)
$ 28,107
Maintenance Crew Travel and Lodging
$ 2,434
Mobilization and Demobilization of Dozer, Loader, and 17 CY Articulated Dump
Truck
$ 20,655
Dozer Rental and Labor
$ 10,436
Articulated Dump Truck (17 CY) Rental and Labor
$ 5,886
Riprap Class II
$ 3,409
Construction Overhead
$ 18,091
Subtotal Maintenance Costs
$ 60,911
Maintenance Contingencies (15%)
$ 9,137
Total Maintenance Costs
$ 70,047
Maintenance Cost (Year 10)
Present Value of Maintenance Costs Based on 10-Year Life at 3.50% (PV
Factor = 0.7089)
$ 49,657
AUM 458 ET Cap
AUM 458 Cap Construction Cost
$ 599,949
AUM 458 Cap Total O&M Costs (30 Years)
$ 47,419
AUM 458 ET Cap Cost per CY (Construction, 10-Year Operations, and 30-
Year O&M Cost)
$ 512
AUM 458 ET Cap Total Cost
$ 647,369
AUM 457 ET Cap
AUM 457 Cap Construction Cost
$ 866,322
AUM 457 Cap Total O&M Costs (30 Years)
$ 47,661
AUM 457 ET Cap Cost per CY (Construction, 10-Year Operations, and 30-
Year O&M Cost)
$ 68
AUM 457 ET Cap Total Cost
$ 913,983
Grand Total Capital Costs
$ 3,450,642
Total Inspection and Maintenance Cost
$ 77,764
Total Cap O&M Cost (30 Years)
$ 95,080
Total Costs
$ 3,623,486
Notes:
"
Inch
AC
Acre
AUM
Abandoned uranium mine
CY
Cubic yard
ET
Evapotranspiration
HP
Horsepower
hr
Hour
K
Thousand
lb.
Pound
O&M
Operation and maintenance
PV
Present value
Page 2 of 2
-------
Table D-9. Section 9 Lease Mines, AUM 458 Cap Cost Details for Alternative 2, Multiple Locations Consolidate and Cap on Site
Site Measurements
QTY
Unit
QTY
Unit
Repository Area
2.46
AC
107,326
SF
Repository Topsoil 3"
994
CY
Borrow Topsoil 3" (1.5 AC)
605
CY
Clean Fill Volume (Volume From Estimate
calculator)
11,927
CY
Waste Volume
2,271
CY
Laydown Area (google earth)
1.6
AC
69,696
SF
Laydown topsoil 3"
645
CY
Engineering Design
Equipment List
Crew
Unit
Amount
Price
Cost
Project Manager
Hour
33
$
187.45
$
6,188
Project Engineer
Hour
131.8
$
144.74
$
19,078
Design Engineer
Hour
65.9
$
187.45
$
12,354
CAD/GIS Operator
Hour
33.0
$
121.01
$
3,995
Admin
Hour
13
$
79.49
$
1,048
Reproduction
LS
3
$
593.20
$
1,513
$
44,175
Site Prep
Equipment List
Crew
Daily
Unit
Days
Cost
Storm Drain Channel Excavation (includes
laydown +25%)
Excavator 3.5 CY = 300
CY/hr.
B-12D
$4,347.92
1
1.1
$
4,806
Riprap Class II 18"-24"
$ 61.69
461
$
28,431
Storm Drain Channel Armoring (Riprap) (includes
laydown and Pond +25%)
Excavator 3.5 CY = 300
CY/hr.
B-12D
$4,347.92
1
0.2
$
933
Loader 5.5 CY
B-10U
$2,411.88
1
0.2
$
517
$
29,881
Storm Drain Pond Excavation (includes laydown
+25%)
Excavator 3.5 CY = 300
CY/hr.
B-12D
$4,347.92
1
1.8
$
7,861
$
42,548
Page 1 of 4
-------
Table D-9. Section 9 Lease Mines, AUM 458 Cap Cost Details for Alternative 2, Multiple Locations Consolidate and Cap on Site
Excavation
Equipment List
Crew
Daily
Unit
Days
Cost
Excavator 3.5 CY = 300
CY/hr.
B-12D
$4,347.92
1
5.7
$
24,889
Repository and Soil Borrow Excavation and
Stockpiling
Off-Road Haul Truck 22
CY
B34F
$ 1,962.09
2
5.7
$
22,463
Dozer 300 HP
B-10M
$3,478.17
1
5.7
$
19,910
Water Truck
B-59
$ 1,334.69
1
5.7
$
7,640
$
74,903
Loader 5.5 CY
B-10U
$2,411.88
1
5.7
$
13,806
Borrow Material Screening
Screen Plant
$ 5,605.74
1
5.7
$
32,089
Water Truck
B-59
$ 1,334.69
1
5.7
$
7,640
$
53,536
$
128,438
Operation
Equipment List
Crew
Daily
Unit
Days
Cost
Loader 5. 5 CY
B-10U
$2,411.88
1
1.7
$
4,156
Screen Plant
$5,605.74
1
1.7
$
9,660
Waste Screening
Off-Road Haul Truck
B34F
$ 1,962.09
1
1.7
$
3,381
Dozer 300 HP
B-10M
$3,478.17
1
1.7
$
5,994
Water Truck
B-59
$ 1,334.69
1
1.7
$
2,300
$
25,492
Waste Grading of Each Lift + Waste Compaction
30,000 lb. Grader
B-32A
$4,574.76
1
1.7
$
7,884
of Each Lift
Water Truck
B-59
$ 1,334.69
1
1.7
$
2,300
$
10,184
$
35,676
Closure
Equipment List
Crew
Daily
Unit
Days
Cost
Waste Final Grading
30,000 lb. Grader
B-11L
$2,863.38
1
0.7
$
1,999
Water Truck
B-59
$ 1,334.69
1
0.7
$
932
$
2,931
Loader 5.5 CY
B-10U
$2,411.88
1
4.8
$
11,643
Off-Road Haul Truck
B34F
$ 1,962.09
1
4.8
$
9,472
Cap Cover Installation
Dozer 300 HP
B-10M
$3,478.17
1
4.8
$
16,791
30,000 lb. Grader
B-11L
$2,863.38
1
4.8
$
13,823
Water Truck
B-59
$ 1,334.69
1
4.8
$
6,443
$
58,172
$
61,102
Page 2 of 4
-------
Table D-9. Section 9 Lease Mines, AUM 458 Cap Cost Details for Alternative 2, Multiple Locations Consolidate and Cap on Site
Reclamation
Equipment List
Crew
Unit
Amount
Price
Cost
Hay Bales/Wattles and Silt Fence
LF
635
$ 10.14
$ 6,441
Fertilizer, Seed, and Mulch
SY
3,442
$ 4.77
$ 16,417
$ 22,859
Other Line Items
Equipment List
Crew
Unit
Amount
Price
Cost
Fence
LF
1,322
$ 7.15
$ 9,456
Survey
AC
2.1
$ 4,063.42
$ 8,510
$ 17,966
Subtotal Construction Costs
$ 308,588
Contractor Site Overhead
$ 104,299
Travel + Lodging:
$ 49,076
Mobilization / Demobilization:
$ 73,661
Level of Accuracy (20%)
$ 61,718
Total Construction Cost:
$ 599,949
30-Year Maintenance Costs Every 10 Years
Operation
Equipment List
Crew
Unit
Unit Cost
Amount
Cost
Site Inspections
N/A
EA
$ 1,483.00
1
$ 1,483
Annual Maintenance Travel and Lodging
N/A
LS
$ 595.57
1
$ 596
Mobilization / Demobilization
N/A
LS
$ 7,531.74
1
$ 7,532
Construction Overhead
N/A
LS
$ 5,350.72
1
$ 5,351
Standard Excavator Rental and Labor
Excavator 3.5 CY = 300
CY/hr.
B-12D
Day
$ 4,346.97
1
$ 4,347
Articulated Dump Truck Rental and Labor
Off-Road Haul Truck
B-34F
Day
$ 1,962.31
1
$ 1,962
Range Fencing Repair
N/A
LF
$ 7.15
156
$ 1,112
Riprap Material and Hauling
N/A
CY
$ 65.25
54
$ 3,538
Subtotal Maintenance Event Costs
$ 25,921
Maintenance Contingencies
15%
$ 3,888
Total Maintenance Event Cost
$ 29,809
Page 3 of 4
-------
Table D-9. Section 9 Lease Mines, AUM 458 Cap Cost Details for Alternative 2, Multiple Locations Consolidate and Cap on Site
30-Year Maintenance Costs (Years 1-10)
Present Value of Maintenance Costs Based on 10-
Year Life at 3.50%
PV Factor = 0.7089
$ 21,131
30-Year Maintenance Costs (Years 11-20)
Present Value of Maintenance Costs Based on 20-
Year Life at 3.50%
PV Factor = 0.5026
$ 14,982
30-Year Maintenance Costs (Years 21-30)
Present Value of Maintenance Costs Based on 30-
Year Life at 3.50%
PV Factor = 0.3563
$ 10,621
Total Maintenance Cost
$ 46,734
Total Present Worth
$ 647,369
Cost Per CY:
$ 512
Notes:
1
Foot
"
Inch
AC
Acre
AUM
Abandoned uranium mine
CAD
Computer-aided design
CY
Cubic yard
EQ
Equipment
GIS
Geographic information system
hr
Hour
lb.
Pound
LF
Linear foot
LS
Lump sum
N/A
Not applicable
O&M
Operation and maintenance
PV
Present value
SY
Square yard
Page 4 of 4
-------
Table D-10. Section 9 Lease Mines, AUM 457 Cost Details for Alternative 2, Multiple Locations Consolidate and Cap on Site
Site Measurements
QTY
Unit
QTY
Unit
Repository Area
2.54
AC
110,731
SF
Repository Topsoil 3"
1,025
CY
Borrow Topsoil 3" (1.5 AC)
605
CY
Clean Fill Volume (Volume From Estimate
calculator)
12,312
CY
Waste Volume
15,089
CY
Laydown Area (google earth)
1.3
AC
54,886
SF
Laydown topsoil 3"
508
CY
Engineering Design
Equipment List
Crew
Unit
Amount
Price
Cost
Project Manager
Hour
33
$
187.45
$
6,188
Project Engineer
Hour
131.8
$
144.74
$
19,078
Design Engineer
Hour
65.9
$
187.45
$
12,354
CAD/GIS Operator
Hour
33.0
$
121.01
$
3,995
Admin
Hour
13
$
79.49
$
1,048
Reproduction
LS
3
$
593.20
$
1,513
$
$
44,175
Site Prep
Equipment List
Crew
Daily
Unit
Days
Cost
Storm Drain Channel Excavation (includes laydown
+25%)
Excavator 3.5 CY = 300
CY/hr.
B-12D
$4,347.92
1
1.11
$
4,806
Riprap Class II 18"-24"
$ 61.69
464
$
28,651
Storm Drain Channel Armoring (Riprap) (includes
laydown and Pond +25%)
Excavator 3.5 CY = 300
CY/hr.
B-12D
$4,347.92
1
0.22
$
962
Loader 5.5 CY
B-10U
$2,411.88
1
0.22
$
534
$
30,147
Storm Drain Pond Excavation (includes laydown
+25%)
Excavator 3.5 CY = 300
CY/hr.
B-12D
$4,347.92
1
1.81
$
7,861
$
43,175
Page 1 of 4
-------
Table D-10. Section 9 Lease Mines, AUM 457 Cost Details for Alternative 2, Multiple Locations Consolidate and Cap on Site
Excavation
Equipment List
Crew
Daily
Unit
Days
Cost
Excavator 3.5 CY = 300
CY/hr.
B-12D
$4,347.92
1
5.82
$
25,318
Repository and Soil Borrow Excavation and
Stockpiling
Off-Road Haul Truck 22
CY
B34F
$ 1,962.09
2
5.82
$
22,850
Dozer 300 HP
B-10M
$3,478.17
1
5.82
$
20,253
Water Truck
B-59
$ 1,334.69
1
5.82
$
7,772
$
76,193
Loader 5.5 CY
B-10U
$2,411.88
1
5.82
$
14,044
Borrow Material Screening
Screen Plant
$ 5,605.74
1
5.82
$
32,642
Water Truck
B-59
$ 1,334.69
1
5.82
$
7,772
$
54,458
$
130,651
Operation
Equipment List
Crew
Daily
Unit
Days
Cost
Loader 5.5 CY
B-10U
$2,411.88
1
11.5
$
27,620
Screen Plant
$ 5,605.74
1
11.5
$
64,194
Waste Screening
Off-Road Haul Truck
B34F
$ 1,962.09
1
11.5
$
22,469
Dozer 300 HP
B-10M
$3,478.17
1
11.5
$
39,830
Water Truck
B-59
$ 1,334.69
1
11.5
$
15,284
$
169,398
Waste Grading of Each Lift + Waste Compaction
30,000 lb. Grader
B-32A
$4,574.76
1
11.5
$
52,388
of Each Lift
Water Truck
B-59
$ 1,334.69
1
11.5
$
15,284
$
67,672
$
201,509
Closure
Equipment List
Crew
Daily
Unit
Days
Cost
Waste Final Grading
30,000 lb. Grader
B-11L
$2,863.38
1
0.7
$
2,062
Water Truck
B-59
$ 1,334.69
1
0.7
$
961
$
3,024
Loader 5.5 CY
B-10U
$2,411.88
1
5.0
$
12,020
Off-Road Haul Truck
B34F
$ 1,962.09
1
5.0
$
9,778
Cap Cover Installation
Dozer 300 HP
B-10M
$3,478.17
1
5.0
$
17,334
30,000 lb. Grader
B-11L
$2,863.38
1
5.0
$
14,270
Water Truck
B-59
$ 1,334.69
1
5.0
$
6,652
$
60,053
$
53,615
Page 2 of 4
-------
Table D-10. Section 9 Lease Mines, AUM 457 Cost Details for Alternative 2, Multiple Locations Consolidate and Cap on Site
Reclamation
Equipment List
Crew
Unit
Amount
Price
Cost
Hay Bales/Wattles and Silt Fence
LF
655
$ 10.14
$ 6,646
Fertilizer, Seed, and Mulch
SY
3,551
$ 4.77
$ 16,938
$ 23,584
Other Line Items
Equipment List
Crew
Unit
Amount
Price
Cost
Fence
LF
1,900
$ 7.15
$ 13,591
Survey
AC
2
$ 4,063.42
$ 8,780
$ 22,371
Subtotal Construction Costs
$ 519,567
Contractor Site Overhead
$ 106,265
Travel + Lodging:
$ 54,125
Mobilization / Demobilization:
$ 73,661
Level of Accuracy (20%)
$ 103,913
Total Construction Cost:
$ 866,322
30-Year Annual PRSC Costs (Years 1-10)
Operation
Equipment List
Crew
Unit
Unit Cost
Amount
Cost
Site Inspections
N/A
EA
$ 1,483.00
1
$ 1,483
Annual Maintenance Travel and Lodging
N/A
LS
$ 595.57
1
$ 596
Mobilization / Demobilization
N/A
LS
$ 7,531.74
1
$ 7,532
Construction Overhead
N/A
LS
$ 5,350.72
1
$ 5,351
Standard Excavator Rental and Labor
Excavator 3.5 CY = 300
CY/hr.
B-12D
Day
$ 4,346.97
1
$ 4,347
Articulated Dump Truck Rental and Labor
Off-Road Haul Truck
B-34F
Day
$ 1,962.31
1
$ 1,962
Range Fencing Repair
N/A
LF
$ 7.15
224
$ 1,599
Rip-Rap Material and Hauling
N/A
CY
$ 65.25
55
$ 3,565
Subtotal Maintenance Costs
$ 26,434
Maintenance Contingencies
15%
$ 3,965
Total Maintenance Event Cost
$ 30,400
Page 3 of 4
-------
Table D-10. Section 9 Lease Mines, AUM 457 Cost Details for Alternative 2, Multiple Locations Consolidate and Cap on Site
30-Year Maintenance Costs (Years 1-10)
Present Value of Maintenance Costs Based on 10-
Year Life at 3.50%
PV Factor = 0.7089
$ 21,550
30-Year Maintenance Costs (Years 11-20)
Present Value of Maintenance Costs Based on 20-
Year Life at 3.50%
PV Factor = 0.5026
$ 15,279
30-Year Maintenance Costs (Years 21-30)
Present Value of Maintenance Costs Based on 30-
Year Life at 3.50%
PV Factor = 0.3563
$ 10,831
Total Maintenance Cost
$ 47,661
Total Present Worth
$ 913,983
Cost Per CY:
00
<0
Notes:
Foot
Inch
AUM
Abandoned uranium mine
AC
Acre
CAD
Computer-aided design
CY
Cubic yard
EQ
Equipment
GIS
Geographic information system
hr
Hour
lb.
Pound
LF
Linear foot
LS
Lump sum
N/A
Not applicable
O&M
Operation and maintenance
PV
Present value
SY
Square yard
Page 4 of 4
-------
Table D-11. Section 9 Lease Mines, Cost Estimate Scenario Assumptions for Alternative 3,
Single Location Consolidate and Cap on Site
Technology
Assumptions
Cost Effects
Waste removed by a large excavator
unless specified.
Excavators can operate on steeper terrain than
bulldozers and are better at moving waste uphill.
Bulldozers cost less to operate. Spider excavators or
other specialized equipment are more expensive.
Excavation
Methods
Any disturbed surface restored using
grading and erosion controls.
Quantities of erosion control materials and grading
may be lower than estimated.
All waste specified in the risk
assessment will be excavated.
Volumes of excavated waste may be lower than
estimated.
The site is accessible to haul trucks
and trucks will be easily loaded.
Accessing difficult-to-reach mines increases costs.
O&M inspection of the mine site will be
completed for 10 years.
More O&M inspections will increase costs.
Soil and
Waste Sorting
Waste will be sorted based on grain
size; rock greater than 3 inches will be
segregated.
N/A
Waste will be processed through the
screening plant using an excavator.
N/A
Waste will be consolidated nearby on-
site and capped at consolidation area.
Greater distance to consolidate increases costs.
Waste will be consolidated into a 1.2-
acre area and graded.
Consolidation into a larger area decreases the cost for
relocating the waste; however, it increases cost for
cover soil.
Waste will be consolidated from
multiple locations.
Consolidating waste from multiple locations increases
costs.
A bulldozer will be used to excavate
borrow soil.
Use of an excavator may increase costs.
Consolidation
and Cap
Multiple cells will be required to be
opened and closed.
Multiple mobilizations to open/close cells increases
costs.
ET cap will be 3 feet of soil with a
biobarrier and capillary break, but no
liner.
Adding biobarrier, capillary break, or liner will increase
costs
No bottom liner or leachate collection
system will be installed.
Adding bottom liner or leachate collection system
increases costs.
Bulldozer will be used to move borrow
soil to form cap.
Use of an excavator may increase costs
O&M inspection of the cap will be
conducted for 30 years.
More O&M inspections increases costs.
Water
Water will be hauled in from Cameron,
Arizona.
Drilling a water well would incur additional capital
costs, but lower operating costs.
Notes:
ET
N/A
O&M
Evapotranspiration
Not applicable - inherent assumption
Operation and maintenance
Page 1 of 1
-------
Table D-12. Section 9 Lease Mines, Crew Time Productivity Calculations for Alternative 3,
Single Location Consolidate and Cap on Site
Step
Section 9 Lease Mines Haul / Access Road Installation
1
Action
Qty
Unit
Production/Day
Days
Section 9 Lease Mines Access Road Building
11,499
LCY
2,573
4.5
Control Days
4
Step
Section 9 Lease Mines Excavation and Hauling
2
Action
Qty
Unit
Production/Day
Days
Waste Removal AUM 458 (AUM 459 portion 807
LCY) - Standard Excavator or Dozer / Loader
1,580
LCY
2,250
0.7
Waste Removal placed at AUM 457 - Standard
Excavator or Dozer / Loader
16,900
LCY
2,250
7.5
18,480
LCY
Control Days
8
Step
Section 9 Lease Mines Site Reclamation
3
Action
Qty
Unit
Production/Day
Days
Dozer Contour Grading
52,901
SY
4,000
13.2
Soil Backfill
18,480
LCY
3,027
8.2
Water Bars
1,552
CY
536
2.9
Rock-Lined Ditch (6 Feet by 3 Feet)
771
CY
1,099
0.7
Rock Berm (4 Feet by 3 Feet)
616
CY
1,099
0.6
Rock Fields and Rock Cover (1 Foot High)
356
CY
1,099
0.3
Control Days
26
TOTAL PROJECT DAYS
39
Slowest Rate Project Days
21
Notes:
AC Acre
AUM Abandoned uranium mine
CY Cubic yard
LCY Loose cubic yard
QTY Quantity
SY Square yard
Page 1 of 1
-------
Table D-13. Section 9 Lease Mines, Cost Estimate Details for Alternative 3,
Single Location Consolidate and Cap on Site
Engineering Design
Crew
Unit
Amount
Price
Cost
Project Manager
N/A
Hour
200
$ 187.45
$ 37,490
Project Engineer
N/A
Hour
800
$ 144.74
$ 115,793
Design Engineer
N/A
Hour
400
$ 187.45
$ 74,980
CAD/GIS Operator
N/A
Hour
200
$ 121.01
$ 24,203
Admin
N/A
Hour
80
$ 79.49
$ 6,359
Reproduction
N/A
LS
3
$ 593.20
$ 1,780
$ 260,605
Planning Documents
Crew
Unit
Amount
Price
Cost
Project Manager
N/A
Hour
100
$ 187.45
$ 18,745
Project Engineer
N/A
Hour
400
$ 144.74
$ 57,896
CAD/GIS Operator
N/A
Hour
100
$ 121.01
$ 12,101
Admin
N/A
Hour
40
$ 79.49
$ 3,180
Reproduction
N/A
LS
3
$ 593.20
$ 1,780
$ 93,702
Resource Surveys
Crew
Unit
Amount
Price
Cost
Cultural Resources Mitigation
N/A
Each
0
$ 44,366.94
$
Biological Resources Mitigation
N/A
Each
1
$ 88,733.88
$ 88,734
Geotechnical Testing and Report
N/A
Each
1
$ 88,733.88
$ 88,734
Pre-Project Aerial LiDAR Survey
N/A
Each
0
$ 35,592.00
$
Post-Project Aerial LiDAR Survey
N/A
Each
1
$ 133,100.82
$ 133,101
$ 310,569
Confirmation Sampling
Crew
Unit
Amount
Price
Cost
Developing Sampling and Analysis Plan
Project Geologist
N/A
Hour
180
$ 187.45
$ 33,741
Project Manager
N/A
Hour
90
$ 131.69
$ 11,852
CAD/GIS Operator
N/A
Hour
90
$ 144.74
$ 13,027
Project Chemist
N/A
Hour
180
$ 131.69
$ 23,704
Health and Safety Manager
N/A
Hour
90
$ 179.15
$ 16,123
Admin
N/A
Hour
36
$ 79.49
$ 2,862
Reproduction
N/A
LS
3
$ 296.60
$ 890
Sampling
Sampling Team - Staff Geologist
N/A
Hour
40
$ 91.35
$ 3,690
Sampling Team - Staff Engineer
N/A
Hour
40
$ 96.10
$ 3,881
Travel
N/A
Day
8
$ 201.69
$ 1,670
Per Diem (96/55)
N/A
Day
8
$ 179.15
$ 1,483
Miscellaneous Field Supplies and Expenses
N/A
LS
1
$ 22,680.38
$ 22,680
Lab Analysis
N/A
LS
0
$ 7,307.23
$
XRF Surveying
Sampling Team - Staff Geologist
N/A
Hour
0
$ 91.35
$
Sampling Team - Staff Engineer
N/A
Hour
0
$ 96.10
$
Travel
N/A
Day
0
$ 201.69
$
Per Diem (96/55)
N/A
Day
0
$ 179.15
$
Miscellaneous Field Supplies and Expenses
N/A
LS
0
$ 22,680.38
$
Lab Analysis
N/A
LS
0
$ 7,307.23
$
Frisking Equipment
N/A
Month
0
$ 170.84
$
$ 135,603
Page 1 of 5
-------
Table D-13. Section 9 Lease Mines, Cost Estimate Details for Alternative 3,
Single Location Consolidate and Cap on Site
Reporting
Crew
Unit
Amount
Price
Cost
Project Geologist
N/A
Hour
158
$ 124.57
$ 19,682
Project Manager
N/A
Hour
79
$ 207.62
$ 16,402
Project Engineer
N/A
Hour
237
$ 144.74
$ 34,304
Chemist
N/A
Hour
79
$ 131.69
$ 10,404
CAD/GIS Operator
N/A
Hour
79
$ 121.01
$ 9,560
Admin
N/A
Hour
32
$ 79.49
$ 2,504
Reproduction
N/A
LS
3
$ 593.20
$ 1,780
$ 94,635
Mobilization/Demobilization
Crew
Unit
Amount
Price
Cost
Crew Mileage
N/A
Mile
1,568
$ 0.67
$ 1,051
Per Diem
N/A
Day
15
$ 182.00
$ 2,730
Labor
N/A
Day
15
$ 355.92
$ 5,339
Standard Equipment Mileage
N/A
Mile
1,568
$ 0.67
$ 1,051
Standard Equipment Rental
N/A
Day
2
$ 24,853.61
$ 49,707
$ 59,877
Haul Road Building
Crew
Daily
Unit#
Days
Cost
Excavator 3.5 CY ~ 80K-100K lb.
B12D
$ 4,346.97
1
4
$ 19,427
Dozer D6
B10M
$ 3,478.17
1
4
$ 15,545
Grader 30,000 lb.
B11L
$ 2,863.38
1
4
$ 12,797
Water Truck
B45
$ 1,054.71
4
4
$ 18,855
Brush Chipper
B7
$ 3,119.05
1
4
$ 13,940
Loader 5cy+
B10U
$ 2,411.88
1
4
$ 10,779
Off Road Haul Truck (17 CY)
B34F
$ 1,962.09
2
4
$ 17,538
Total
$ 108,881
Excavation & Hauling
Crew
Daily
Unit#
Days
Cost
Loader 5CY+
B10U
$ 2,411.88
2
8
$ 39,621
Off Road Haul Truck (17 CY)
B34A
$ 1,962.09
6
8
$ 96,695
Grader 30,000 lb.
B11L
$ 2,863.38
2
8
$ 47,037
Water Truck
B45
$ 1,054.71
4
8
$ 34,652
Dozer D6
B10M
$ 3,478.17
2
8
$ 57,137
Excavator 3.5 CY ~ 80K-100K lb.
B12D
$ 4,346.97
2
8
$ 71,409
Total
$ 346,551
Onsite Restoration
Crew
Daily
Unit#
Days
Cost
Off Road Haul Truck (17 CY)
B34F
$ 1,962.09
4
8
$ 64,464
Loader 5CY+
B10U
$ 2,411.88
2
8
$ 39,621
Grader 30,000 lb.
B11L
$ 2,863.38
1
3
$ 8,291
Excavator 3.5 CY ~ 80K-100K lb.
B12D
$ 4,346.97
2
8
$ 71,409
Dozer D6
B10M
$ 3,478.17
2
16
$ 112,141
Water Truck
B45
$ 1,054.71
4
16
$ 68,011
Rip Rap Class II 18"-24"
NA
$ 53.37
862.0
1
$ 51,346
Total
$ 415,282
Page 2 of 5
-------
Table D-13. Section 9 Lease Mines, Cost Estimate Details for Alternative 3,
Single Location Consolidate and Cap on Site
Construction Contractor Site Overhead
Crew
Unit
Amount
Price
Cost
Project Manager (10% of time)
N/A
Hour
21
$ 207.62
$ 4,339
Site Superintendent
N/A
Hour
209
$ 226.60
$ 47,352
H&S Officer
N/A
Hour
209
$ 100.84
$ 21,073
QA/QC Officer
N/A
Hour
209
$ 100.84
$ 21,073
Field Clerk
N/A
Hour
209
$ 22.54
$ 4,710
Fuel for Site Vehicles
N/A
Month
6
$ 581.34
$ 3,442
Port-o-let Rental (4)
N/A
Month
4
$ 246.77
$ 1,031
Job Trailers (1)
N/A
Month
1
$ 319.14
$ 333
Storage Boxes (1)
N/A
Month
1
$ 112.11
$ 117
Field Office Lights/HVAC (1)
N/A
Month
1
$ 212.37
$ 222
Generator (1)
N/A
Month
2
$ 2,847.36
$ 5,950
Fuel for Generator
N/A
Gallons
627
$ 4.75
$ 2,975
Telephone/internet (1)
N/A
Month
1
$ 455.58
$ 476
Field Office Equipment
N/A
Month
1
$ 272.87
$ 285
Field Office Supplies
N/A
Month
1
$ 113.89
$ 119
Trash (1 dumpster)
N/A
Month
1
$ 1,079.62
$ 1,128
Clin 1034 High Volume Air Sampling (4)
N/A
Month
4
$ 454.39
$ 1,899
Clin 1025 Ludlum 2121 and 43-10-1
N/A
Month
1
$ 326.26
CO
Air Monitoring Lab Confirmation Sampling (5
samples per day)
N/A
Day
81
$ 711.84
$ 57,458
Clin 1036 Personal Air Monitor
N/A
Month
11
$ 242.03
$ 2,668
Clin 1038 Personal Dust Monitor
N/A
Month
11
$ 1,844.85
$ 20,335
Clin 1068 Personal Dosimeter Badge
N/A
Month
11
$ 70.00
$ 772
Truck Scales
N/A
Month
1
$ 355.92
$ 372
$ 198,470
Third-Party Oversight
Crew
Unit
Amount
Price
Cost
Travel and Lodging (1 person)
N/A
Day
21
$ 179.15
$ 3,744
Labor
N/A
Hour
209
$ 94.91
$ 19,833
Car Rental (1 car)
N/A
Month
1
$ 474.56
$ 496
Car Fuel
N/A
Month
1
$ 901.66
$ 942
$ 25,015
Level of Accuracy (20%)
Crew
Unit
Amount
Price
Cost
20% of Construction Cost
N/A
N/A
N/A
N/A
$ 174,143
GRAND
TOTAL
$ 2,355,146
Page 3 of 5
-------
Table D-13. Section 9 Lease Mines, Cost Estimate Details for Alternative 3,
Single Location Consolidate and Cap on Site
Onsite O&M Costs
Crew
Unit
Amount
Price
Cost
Annual Inspection (1 person crew, 1 day, 10
hrs/day)
N/A
Hour
10
$ 110.50
$ 1,105
Inspection Crew Travel and Lodging
N/A
LS
1
$ 867.08
$ 867
Preperation of Semi-annual Reports
(Professional Engineer)
N/A
Hour
8
$ 156.00
$ 1,248
Inspection Event Cost
$ 3,220
Inspection Contingency (15%)
$ 483
Total Inspection Event Cost
$ 3,703
Maintenance Crew Travel and Lodging
N/A
LS
1
$ 2,667.60
$ 2,668
Mobilization and Demobilization of Dozer,
and 17 CY Articulated Dump Truck
N/A
LS
1
$ 19,425.28
$ 19,425
Dozer Rental and Labor
B81
Day
3
$ 3,811.60
$ 11,435
Articulated Dump Truck (17 CY) Rental and
Labor
B34F
Day
3
$ 2,149.97
$ 6,450
Riprap Class II
N/A
CY
93
$ 45.00
$ 4,169
Construction Overhead
N/A
LS
1
$ 19,822.92
$ 19,823
O&M Annual Cost
$ 63,969
O&M Contingency (15%)
$ 9,595
Total O&M Annual Cost
$ 73,565
Contractor Site Overhead O&M
Crew
Unit
Amount
Price
Cost
Site Superintendent
N/A
Hour
39
$ 191.00
$ 7,449.00
H&S Officer
N/A
Hour
39
$ 85.00
$ 3,315.00
Fuel for Site Vehicles
N/A
Month
0.6
$ 5,880.00
$ 3,439.80
Port-o-let Rental (1)
N/A
Month
0.2
$ 208.00
$ 40.56
Generator (1)
N/A
Month
0.20
$ 2,400.00
$ 468.00
Fuel for Generator
N/A
Gallons
117
$ 4.00
$ 468.00
Telephone/internet (1)
N/A
Month
0.20
$ 384.00
$ 74.88
Trash (1 dumpster)
N/A
Month
0.20
$ 910.00
$ 177.45
Clin 1034 High Volume Air Sampling (3)
N/A
Month
0.6
$ 383.00
$ 224.06
Clin 1025 Ludlum 2121 and 43-10-1
N/A
Month
0.20
$ 275.00
$ 53.63
Air Monitoring Lab Confirmation Sampling (3
samples per day)
N/A
Day
4
$ 600.00
$ 2,340.00
Clin 1036 Personal Air Monitor
N/A
Month
1.0
$ 204.00
$ 198.90
Clin 1038 Personal Dust Monitor
N/A
Month
1.0
$ 1,555.00
$ 1,516.13
Clin 1068 Personal Dosimeter Badge
N/A
Month
1.0
$ 59.00
$ 57.53
$ 19,822.92
Page 4 of 5
-------
Table D-13. Section 9 Lease Mines, Cost Estimate Details for Alternative 3,
Single Location Consolidate and Cap on Site
Notes:
"
Inch
CAD
Computer-aided design
CY
Cubic yard
GIS
Geographic information system
H&S
Health and safety
HP
Horsepower
hr
Hour
HVAC
Heating, ventilation, and air conditioning
K
Thousand
lb.
Pound
LF
Linear foot
LiDAR
Light detection and ranging
LS
Lump sum
N/A
Not applicable
O&M
Operation and maintenance
QA/QC
Quality assurance/quality control
SY
Square yard
XRF
X-ray fluorescence
Page 5 of 5
-------
Table D-14. Section 9 Lease Mines, Cost Estimate Summary for Alternative 3,
Single Location Consolidate and Cap on Site
Haul Road Building
Unit Cost
Excavator 3.5 cy ~ 80K-100K lb.
$ 19,427
Dozer D6
$ 15,545
Grader 30,000 lb.
$ 12,797
Water Truck
$ 18,855
Off Road Haul Truck
$ 17,538
Loader 5cy+
$ 10,779
Brush Chipper
$ 13,940
Subtotals Step 1
$ 108,881
Excavation and Hauling
Unit Cost
Loader 5cy+
$ 39,621
Off Road Haul Truck (17 CY)
$ 96,695
Grader 30,000 lb.
$ 47,037
Water Truck
$ 34,652
Dozer D6
$ 57,137
Excavator 3.5 cy ~ 80K-100K lb.
$ 71,409
Subtotals Step 2
$ 346,551
Onsite Restoration
Unit Cost
Off Road Haul Truck (17 CY)
$ 64,464
Loader 5cy+
$ 39,621
Grader 30,000 lb.
$ 8,291
Excavator 3.5 cy ~ 80K-100K lb.
$ 71,409
Dozer D6
$ 112,141
Water Truck
$ 68,011
Rip Rap Class II 18"-24"
$ 51,346
Subtotals Step 3
$ 415,282
Subtotal Construction
$ 870,714
Other Costs
Unit Cost
Non-Construction Costs
Engineering Design
$ 260,605
Planning Documents
$ 93,702
Resource Surveys
$ 310,569
Confirmation Sampling
$ 135,603
Reporting
$ 94,635
Contractor Site Overhead and Miscellaneous Costs
$ 198,470
Mobilization / Demobilization
$ 59,877
Travel+ Lodging (Construction Workers)
$ 131,814
Level of Accuracy (20%)
$ 174,143
Third-Party Oversight
$ 25,015
Subtotals Step 6
$ 1,484,432
Total Site Capital Costs
$ 2,355,146
Inspections and Maintenance Event Costs
Unit Cost
Annual Inspection (1 person crew, 1 day, 10 hrs/day)
$ 1,311
Inspection Crew Travel and Lodging
$ 1,029
Preperation of Report (Professional Engineer)
$ 1,481
Subtotal Inspection Costs
$ 3,820
Inspection Contingencies (15%)
$ 573
Total Yearly Inspection Costs
$ 4,393
Page 1 of 2
-------
Table D-14. Section 9 Lease Mines, Cost Estimate Summary for Alternative 3,
Single Location Consolidate and Cap on Site
Present Value of Inspection Costs Based on 10-Year Life at 3.50% (PV
Factor = 8.317)
$ 36,540
Maintenance Crew Travel and Lodging
$ 3,165
Mobilization and Demobilization of Dozer, Loader, and 17 CY Articulated Dump
Truck
$ 26,851
Dozer Rental and Labor
$ 13,566
Articulated Dump Truck (17 CY) Rental and Labor
$ 7,652
Riprap Class II
$ 4,946
Construction Overhead
$ 23,518
Subtotal Maintenance Costs
$ 79,698
Maintenance Contingencies (15%)
$ 11,955
Total Maintenance Costs
$ 91,653
Maintenance Cost (Year 10)
Present Value of Maintenance Costs Based on 10-Year Life at 3.50% (PV
Factor = 0.7089)
$ 64,973
AUM 458 ET Cap
AUM 458 Cap Construction Cost
$ 705,827
AUM 458 Cap Total O&M Costs (30 Years)
$ 47,419
AUM 458 ET Cap Cost per CY (Construction, 10-Year Operations, and 30-
Year O&M Cost)
$ 596
AUM 458 ET Cap Total Cost
$ 753,246
AUM 457 ET Cap
AUM 457 Cap Construction Cost
$ 1,019,208
AUM 457 Cap Total O&M Costs (30 Years)
$ 47,661
AUM 457 ET Cap Cost per CY (Construction, 10-Year Operations, and 30-
Year O&M Cost)
$ 79
AUM 457 ET Cap Total Cost
$ 1,066,869
Grand Total Capital Costs
$ 4,080,181
Total Inspection and Maintenance Cost
$ 101,512
Total Cap O&M Cost (30 Years)
$ 95,080
Total Costs
$ 4,276,773
Notes:
"
Inch
AC
Acre
AUM
Abandoned uranium mine
CY
Cubic yard
ET
Evapotranspiration
HP
Horsepower
hr
Hour
K
Thousand
lb.
Pound
O&M
Operation and maintenance
PV
Present value
Page 2 of 2
-------
Table D-15. Section 9 Lease Mines, AUM 458 Cap Cost Details for Alternative 3, Single Location Consolidate and Cap on Site
Site Measurements
QTY
Unit
QTY
Unit
Repository Area
2.46
AC
107,326
SF
Repository Topsoil 3"
994
CY
Borrow Topsoil 3" (1.5 AC)
605
CY
Clean Fill Volume (Volume From Estimate
calculator)
11,927
CY
Waste Volume
2,271
CY
Laydown Area (google earth)
1.6
AC
69,696
SF
Laydown topsoil 3"
645
CY
Engineering Design
Equipment List
Crew
Unit
Amount
Price
Cost
Project Manager
Hour
33
$
187.45
$
6,188
Project Engineer
Hour
131.8
$
144.74
$
19,078
Design Engineer
Hour
65.9
$
187.45
$
12,354
CAD/GIS Operator
Hour
33.0
$
121.01
$
3,995
Admin
Hour
13
$
79.49
$
1,048
Reproduction
LS
3
$
593.20
$
1,513
$
44,175
Site Prep
Equipment List
Crew
Daily
Unit
Days
Cost
Storm Drain Channel Excavation (includes
laydown +25%)
Excavator 3.5 CY = 300
CY/hr.
B-12D
$4,347.92
1
1.1
$
4,806
Riprap Class II 18"-24"
$ 61.69
461
$
28,431
Storm Drain Channel Armoring (Riprap) (includes
laydown and Pond +25%)
Excavator 3.5 CY = 300
CY/hr.
B-12D
$4,347.92
1
0.2
$
933
Loader 5.5 CY
B-10U
$2,411.88
1
0.2
$
517
$
29,881
Storm Drain Pond Excavation (includes laydown
+25%)
Excavator 3.5 CY = 300
CY/hr.
B-12D
$4,347.92
1
1.8
$
7,861
$
42,548
Page 1 of 4
-------
Table D-15. Section 9 Lease Mines, AUM 458 Cap Cost Details for Alternative 3, Single Location Consolidate and Cap on Site
Excavation
Equipment List
Crew
Daily
Unit
Days
Cost
Excavator 3.5 CY = 300
CY/hr.
B-12D
$4,347.92
1
5.7
$
24,889
Repository and Soil Borrow Excavation and
Stockpiling
Off-Road Haul Truck 22
CY
B34F
$ 1,962.09
2
5.7
$
22,463
Dozer 300 HP
B-10M
$3,478.17
1
5.7
$
19,910
Water Truck
B-59
$ 1,334.69
1
5.7
$
7,640
$
74,903
Loader 5.5 CY
B-10U
$2,411.88
1
5.7
$
13,806
Borrow Material Screening
Screen Plant
$ 5,605.74
1
5.7
$
32,089
Water Truck
B-59
$ 1,334.69
1
5.7
$
7,640
$
53,536
$
128,438
Operation
Equipment List
Crew
Daily
Unit
Days
Cost
Loader 5. 5 CY
B-10U
$2,411.88
1
1.7
$
4,156
Screen Plant
$5,605.74
1
1.7
$
9,660
Waste Screening
Off-Road Haul Truck
B34F
$ 1,962.09
1
1.7
$
3,381
Dozer 300 HP
B-10M
$3,478.17
1
1.7
$
5,994
Water Truck
B-59
$ 1,334.69
1
1.7
$
2,300
$
25,492
Waste Grading of Each Lift + Waste Compaction
30,000 lb. Grader
B-32A
$4,574.76
1
1.7
$
7,884
of Each Lift
Water Truck
B-59
$ 1,334.69
1
1.7
$
2,300
$
10,184
$
35,676
Closure
Equipment List
Crew
Daily
Unit
Days
Cost
Waste Final Grading
30,000 lb. Grader
B-11L
$2,863.38
1
0.7
$
1,999
Water Truck
B-59
$ 1,334.69
1
0.7
$
932
$
2,931
Loader 5.5 CY
B-10U
$2,411.88
1
4.8
$
11,643
Off-Road Haul Truck
B34F
$ 1,962.09
1
4.8
$
9,472
Cap Cover Installation
Dozer 300 HP
B-10M
$3,478.17
1
4.8
$
16,791
30,000 lb. Grader
B-11L
$2,863.38
1
4.8
$
13,823
Water Truck
B-59
$ 1,334.69
1
4.8
$
6,443
$
58,172
$
61,102
Page 2 of 4
-------
Table D-15. Section 9 Lease Mines, AUM 458 Cap Cost Details for Alternative 3, Single Location Consolidate and Cap on Site
Reclamation
Equipment List
Crew
Unit
Amount
Price
Cost
Hay Bales/Wattles and Silt Fence
LF
635
$ 10.14
$ 6,441
Fertilizer, Seed, and Mulch
SY
3,442
$ 4.77
$ 16,417
$ 22,859
Other Line Items
Equipment List
Crew
Unit
Amount
Price
Cost
Fence
LF
1,322
$ 7.15
$ 9,456
Survey
AC
2.1
$ 4,063.42
$ 8,510
$ 17,966
Subtotal Construction Costs
$ 308,588
Contractor Site Overhead
$ 104,299
Travel + Lodging:
$ 49,076
Mobilization / Demobilization:
$ 73,661
Level of Accuracy (20%)
$ 61,718
Total Construction Cost:
$ 599,949
30-Year Maintenance Costs Every 10 Years
Operation
Equipment List
Crew
Unit
Unit Cost
Amount
Cost
Site Inspections
N/A
EA
$ 1,483.00
1
$ 1,483
Annual Maintenance Travel and Lodging
N/A
LS
$ 595.57
1
$ 596
Mobilization / Demobilization
N/A
LS
$ 7,531.74
1
$ 7,532
Construction Overhead
N/A
LS
$ 5,350.72
1
$ 5,351
Standard Excavator Rental and Labor
Excavator 3.5 CY = 300
CY/hr.
B-12D
Day
$ 4,346.97
1
$ 4,347
Articulated Dump Truck Rental and Labor
Off-Road Haul Truck
B-34F
Day
$ 1,962.31
1
$ 1,962
Range Fencing Repair
N/A
LF
$ 7.15
156
$ 1,112
Riprap Material and Hauling
N/A
CY
$ 65.25
54
$ 3,538
Subtotal Maintenance Event Costs
$ 25,921
Maintenance Contingencies
15%
$ 3,888
Total Maintenance Event Cost
$ 29,809
Page 3 of 4
-------
Table D-15. Section 9 Lease Mines, AUM 458 Cap Cost Details for Alternative 3, Single Location Consolidate and Cap on Site
30-Year Maintenance Costs (Years 1-10)
Present Value of Maintenance Costs Based on 10-
Year Life at 3.50%
PV Factor = 0.7089
$ 21,131
30-Year Maintenance Costs (Years 11-20)
Present Value of Maintenance Costs Based on 20-
Year Life at 3.50%
PV Factor = 0.5026
$ 14,982
30-Year Maintenance Costs (Years 21-30)
Present Value of Maintenance Costs Based on 30-
Year Life at 3.50%
PV Factor = 0.3563
$ 10,621
Total Maintenance Cost
$ 46,734
Total Present Worth
$ 647,369
Cost Per CY:
$ 512
Notes:
1
Foot
"
Inch
AC
Acre
AUM
Abandoned uranium mine
CAD
Computer-aided design
CY
Cubic yard
EQ
Equipment
GIS
Geographic information system
hr
Hour
lb.
Pound
LF
Linear foot
LS
Lump sum
N/A
Not applicable
O&M
Operation and maintenance
PV
Present value
SY
Square yard
Page 4 of 4
-------
Table D-16. Section 9 Lease Mines, AUM 457 Cost Details for Alternative 3, Single Location Consolidate and Cap on Site
Site Measurements
QTY
Unit
QTY
Unit
Repository Area
2.54
AC
110,731
SF
Repository Topsoil 3"
1,025
CY
Borrow Topsoil 3" (1.5 AC)
605
CY
Clean Fill Volume (Volume From Estimate
calculator)
12,312
CY
Waste Volume
15,089
CY
Laydown Area (google earth)
1.3
AC
54,886
SF
Laydown topsoil 3"
508
CY
Engineering Design
Equipment List
Crew
Unit
Amount
Price
Cost
Project Manager
Hour
33
$
187.45
$
6,188
Project Engineer
Hour
131.8
$
144.74
$
19,078
Design Engineer
Hour
65.9
$
187.45
$
12,354
CAD/GIS Operator
Hour
33.0
$
121.01
$
3,995
Admin
Hour
13
$
79.49
$
1,048
Reproduction
LS
3
$
593.20
$
1,513
$
$
44,175
Site Prep
Equipment List
Crew
Daily
Unit
Days
Cost
Storm Drain Channel Excavation (includes laydown
+25%)
Excavator 3.5 CY = 300
CY/hr.
B-12D
$4,347.92
1
1.11
$
4,806
Riprap Class II 18"-24"
$ 61.69
464
$
28,651
Storm Drain Channel Armoring (Riprap) (includes
laydown and Pond +25%)
Excavator 3.5 CY = 300
CY/hr.
B-12D
$4,347.92
1
0.22
$
962
Loader 5.5 CY
B-10U
$2,411.88
1
0.22
$
534
$
30,147
Storm Drain Pond Excavation (includes laydown
+25%)
Excavator 3.5 CY = 300
CY/hr.
B-12D
$4,347.92
1
1.81
$
7,861
$
43,175
Page 1 of 4
-------
Table D-16. Section 9 Lease Mines, AUM 457 Cost Details for Alternative 3, Single Location Consolidate and Cap on Site
Excavation
Equipment List
Crew
Daily
Unit
Days
Cost
Excavator 3.5 CY = 300
CY/hr.
B-12D
$4,347.92
1
5.82
$
25,318
Repository and Soil Borrow Excavation and
Stockpiling
Off-Road Haul Truck 22
CY
B34F
$ 1,962.09
2
5.82
$
22,850
Dozer 300 HP
B-10M
$3,478.17
1
5.82
$
20,253
Water Truck
B-59
$ 1,334.69
1
5.82
$
7,772
$
76,193
Loader 5.5 CY
B-10U
$2,411.88
1
5.82
$
14,044
Borrow Material Screening
Screen Plant
$ 5,605.74
1
5.82
$
32,642
Water Truck
B-59
$ 1,334.69
1
5.82
$
7,772
$
54,458
$
130,651
Operation
Equipment List
Crew
Daily
Unit
Days
Cost
Loader 5.5 CY
B-10U
$2,411.88
1
11.5
$
27,620
Screen Plant
$ 5,605.74
1
11.5
$
64,194
Waste Screening
Off-Road Haul Truck
B34F
$ 1,962.09
1
11.5
$
22,469
Dozer 300 HP
B-10M
$3,478.17
1
11.5
$
39,830
Water Truck
B-59
$ 1,334.69
1
11.5
$
15,284
$
169,398
Waste Grading of Each Lift + Waste Compaction
30,000 lb. Grader
B-32A
$4,574.76
1
11.5
$
52,388
of Each Lift
Water Truck
B-59
$ 1,334.69
1
11.5
$
15,284
$
67,672
$
201,509
Closure
Equipment List
Crew
Daily
Unit
Days
Cost
Waste Final Grading
30,000 lb. Grader
B-11L
$2,863.38
1
0.7
$
2,062
Water Truck
B-59
$ 1,334.69
1
0.7
$
961
$
3,024
Loader 5.5 CY
B-10U
$2,411.88
1
5.0
$
12,020
Off-Road Haul Truck
B34F
$ 1,962.09
1
5.0
$
9,778
Cap Cover Installation
Dozer 300 HP
B-10M
$3,478.17
1
5.0
$
17,334
30,000 lb. Grader
B-11L
$2,863.38
1
5.0
$
14,270
Water Truck
B-59
$ 1,334.69
1
5.0
$
6,652
$
60,053
$
53,615
Page 2 of 4
-------
Table D-16. Section 9 Lease Mines, AUM 457 Cost Details for Alternative 3, Single Location Consolidate and Cap on Site
Reclamation
Equipment List
Crew
Unit
Amount
Price
Cost
Hay Bales/Wattles and Silt Fence
LF
655
$ 10.14
$ 6,646
Fertilizer, Seed, and Mulch
SY
3,551
$ 4.77
$ 16,938
$ 23,584
Other Line Items
Equipment List
Crew
Unit
Amount
Price
Cost
Fence
LF
1,900
$ 7.15
$ 13,591
Survey
AC
2
$ 4,063.42
$ 8,780
$ 22,371
Subtotal Construction Costs
$ 519,567
Contractor Site Overhead
$ 106,265
Travel + Lodging:
$ 54,125
Mobilization / Demobilization:
$ 73,661
Level of Accuracy (20%)
$ 103,913
Total Construction Cost:
$ 866,322
30-Year Annual PRSC Costs (Years 1-10)
Operation
Equipment List
Crew
Unit
Unit Cost
Amount
Cost
Site Inspections
N/A
EA
$ 1,483.00
1
$ 1,483
Annual Maintenance Travel and Lodging
N/A
LS
$ 595.57
1
$ 596
Mobilization / Demobilization
N/A
LS
$ 7,531.74
1
$ 7,532
Construction Overhead
N/A
LS
$ 5,350.72
1
$ 5,351
Standard Excavator Rental and Labor
Excavator 3.5 CY = 300
CY/hr.
B-12D
Day
$ 4,346.97
1
$ 4,347
Articulated Dump Truck Rental and Labor
Off-Road Haul Truck
B-34F
Day
$ 1,962.31
1
$ 1,962
Range Fencing Repair
N/A
LF
$ 7.15
224
$ 1,599
Rip-Rap Material and Hauling
N/A
CY
$ 65.25
55
$ 3,565
Subtotal Maintenance Costs
$ 26,434
Maintenance Contingencies
15%
$ 3,965
Total Maintenance Event Cost
$ 30,400
Page 3 of 4
-------
Table D-16. Section 9 Lease Mines, AUM 457 Cost Details for Alternative 3, Single Location Consolidate and Cap on Site
30-Year Maintenance Costs (Years 1-10)
Present Value of Maintenance Costs Based on 10-
Year Life at 3.50%
PV Factor = 0.7089
$ 21,550
30-Year Maintenance Costs (Years 11-20)
Present Value of Maintenance Costs Based on 20-
Year Life at 3.50%
PV Factor = 0.5026
$ 15,279
30-Year Maintenance Costs (Years 21-30)
Present Value of Maintenance Costs Based on 30-
Year Life at 3.50%
PV Factor = 0.3563
$ 10,831
Total Maintenance Cost
$ 47,661
Total Present Worth
$ 913,983
Cost Per CY:
00
<0
Notes:
Foot
Inch
AUM
Abandoned uranium mine
AC
Acre
CAD
Computer-aided design
CY
Cubic yard
EQ
Equipment
GIS
Geographic information system
hr
Hour
lb.
Pound
LF
Linear foot
LS
Lump sum
N/A
Not applicable
O&M
Operation and maintenance
PV
Present value
SY
Square yard
Page 4 of 4
-------
Table D-17. Section 9 Lease Mines, Cost Estimate Scenario Assumptions for Alternative 4,
Disposal in Offsite RCRA-Licensed Facility
Technology
Assumptions
Cost Effects
Excavation
Methods
Waste will be removed with a large
excavator unless specified.
Excavators can operate on steeper terrain than
bulldozers and are better at moving waste uphill.
Bulldozers cost less to operate. Spider excavators or
other specialized equipment are more expensive.
Any disturbed surface will be restored
using grading and erosion controls.
Quantities of erosion control materials and grading
may be lower than estimated.
All waste specified in the risk
assessment will be excavated
Volumes of excavated waste may be lower than
estimated.
The site is accessible to haul trucks
and trucks can be easily loaded.
Accessing difficult-to-reach mines increases costs.
The waste excavation area will require
cover soil or amendment
If cover soil or amendments are required, costs will
increase.
O&M inspection of the mine site will be
completed for 10 years.
More O&M inspections increases costs.
Hazardous
Waste Landfill
or Licensed
Low-Level
Radioactive
Waste Facility
Waste will go to Deer Trail, Colorado
(690 miles); Andrews, Texas (730
miles); Grand View, Idaho (800 miles);
orClive, Utah (515 miles).
Waste will go to the closest facility that is accepting
waste: Clive, Utah.
Waste will be transported 565 miles in
highway-legal trucks from the site to
the disposal facility in Clive, Utah.
Greater distance to repository increases costs.
Waste weighs 1.5 tons per cubic yard.
Higher density waste increases costs.
Tipping fee at Deer Trail, Colorado
($435/CY); could not acquire tipping
fee from Clive, Utah.
Higher tipping fee increases costs; current tipping fees
are from previous cost estimate.
Assumes up to 20 trucks every 3 days
are available
Realistic quantity of trucks may be less. Fewer trucks
reduces production time and requires more time on the
site, increasing costs.
Notes:
CY Cubic yard
O&M Operation and maintenance
RCRA Resource Conservation and Recovery Act
Page 1 of 1
-------
Table D-18. Section 9 Lease Mines, Crew Time Productivity Calculations for Alternative 4,
Disposal in Offsite RCRA-Licensed Facility
Step
Section 9 Lease Mines Haul / Access Road Installation
1
Action
Qty
Unit
Production/Day
Days
Section 9 Lease Mines Access Road Building
9,445
LCY
3,089
3.1
Control Days
3
Step
Section 9 Lease Mines Excavation and Hauling
2
Action
Qty
Unit
Production Rate
Days
Waste Removal, Areas 1-12 (AUM 459 portion 807
LCY) - Standard Excavator or Dozer / Loader
1,580
LCY
1,513
1.0
Waste Removal, Areas 13-29 - Standard
Excavator or Dozer / Loader
16,900
LCY
1,513
11.2
18,480
LCY
Control Days
12
Step
Section 9 Lease Mines Site Reclamation
3
Action
Qty
Unit
Production/Day
Days
Dozer Contour Grading
37,462
SY
4,000
9.4
Soil Backfill
18,480
LCY
1,513
12.2
Water Bars
1,275
CY
536
2.4
Rock-Lined Ditch (6 Feet by 3 Feet)
671
CY
1,099
0.6
Rock Berm (4 Feet by 3 Feet)
549
CY
1,099
0.5
Rock Fields and Rock Cover (1 Foot High)
319
CY
1,099
0.3
Control Days
25
TOTAL PROJECT DAYS
41
Slowest Rate Project Days
27
Step
Haul from Section 9 Lease Mines to Low-Level Radioactive Waste Facility
4
Action
Qty
Unit
Production/Day
Days
Available Number of Trucks:
20
Number of Trips per day per truck (515 miles
round trip, 43 MPH, 8 hour work day):
0.33
Trips
Total CY Hauled per day (16.7 CY Trucks)
110
CY
Number of Days to Haul Waste
18,480
CY
110
168
Control Days
168
Notes:
AC Acre
AUM Abandoned uranium mine
CY Cubic yard
LCY Loose cubic yard
QTY Quantity
RCRA Resource Conservation and Recovery Act
SY Square yard
Page 1 of 1
-------
Table D-19. Section 9 Lease Mines, Cost Estimate Details for Alternative 4,
Disposal in Offsite RCRA-Licensed Facility
Engineering Design
Crew
Unit
Amount
Price
Cost
Project Manager
N/A
Hour
200
$ 187.45
$ 37,490
Project Engineer
N/A
Hour
800
$ 144.74
$ 115,793
Design Engineer
N/A
Hour
400
$ 187.45
$ 74,980
CAD/GIS Operator
N/A
Hour
200
$ 121.01
$ 24,203
Admin
N/A
Hour
80
$ 79.49
$ 6,359
Reproduction
N/A
LS
3
$ 593.20
$ 1,780
$ 260,605
Planning Documents
Crew
Unit
Amount
Price
Cost
Project Manager
N/A
Hour
100
$ 187.45
$ 18,745
Project Engineer
N/A
Hour
400
$ 144.74
$ 57,896
CAD/GIS Operator
N/A
Hour
100
$ 121.01
$ 12,101
Admin
N/A
Hour
40
$ 79.49
$ 3,180
Reproduction
N/A
LS
3
$ 593.20
$ 1,780
$ 93,702
Resource Surveys
Crew
Unit
Amount
Price
Cost
Cultural Resources Mitigation
N/A
Each
0
$ 44,366.94
$
Biological Resources Mitigation
N/A
Each
1
$ 88,733.88
$ 88,734
Geotechnical Testing and Report
N/A
Each
1
$ 88,733.88
$ 88,734
Pre-Project Aerial LiDAR Survey
N/A
Each
0
$ 35,592.00
$
Post-Project Aerial LiDAR Survey
N/A
Each
1
$ 133,100.82
$ 133,101
$ 310,569
Confirmation Sampling
Crew
Unit
Amount
Price
Cost
Developing Sampling and Analysis Plan
Project Geologist
N/A
Hour
180
$ 187.45
$ 33,741
Project Manager
N/A
Hour
90
$ 131.69
$ 11,852
CAD/GIS Operator
N/A
Hour
90
$ 144.74
$ 13,027
Project Chemist
N/A
Hour
180
$ 131.69
$ 23,704
Health and Safety Manager
N/A
Hour
90
$ 179.15
$ 16,123
Admin
N/A
Hour
36
$ 79.49
$ 2,862
Reproduction
N/A
LS
3
$ 296.60
$ 890
Sampling
Sampling Team - Staff Geologist
N/A
Hour
40
$ 91.35
$ 3,690
Sampling Team - Staff Engineer
N/A
Hour
40
$ 96.10
$ 3,881
Travel
N/A
Day
8
$ 201.69
$ 1,670
Per Diem (96/55)
N/A
Day
8
$ 179.15
$ 1,483
Miscellaneous Field Supplies and Expenses
N/A
LS
1
$ 22,680.38
$ 22,680
Lab Analysis
N/A
LS
0
$ 7,307.23
$
XRF Surveying
Sampling Team - Staff Geologist
N/A
Hour
0
$ 91.35
$
Sampling Team - Staff Engineer
N/A
Hour
0
$ 96.10
$
Travel
N/A
Day
0
$ 201.69
$
Per Diem (96/55)
N/A
Day
0
$ 179.15
$
Miscellaneous Field Supplies and Expenses
N/A
LS
0
$ 22,680.38
$
Lab Analysis
N/A
LS
0
$ 7,307.23
$
Frisking Equipment
N/A
Month
0
$ 170.84
$
$ 135,603
Page 1 of 5
-------
Table D-19. Section 9 Lease Mines, Cost Estimate Details for Alternative 4,
Disposal in Offsite RCRA-Licensed Facility
Reporting
Crew
Unit
Amount
Price
Cost
Project Geologist
N/A
Hour
158
$ 124.57
$ 19,682
Project Manager
N/A
Hour
79
$ 207.62
$ 16,402
Project Engineer
N/A
Hour
237
$ 144.74
$ 34,304
Chemist
N/A
Hour
79
$ 131.69
$ 10,404
CAD/GIS Operator
N/A
Hour
79
$ 121.01
$ 9,560
Admin
N/A
Hour
32
$ 79.49
$ 2,504
Reproduction
N/A
LS
3
$ 593.20
$ 1,780
$ 94,635
Mobilization/Demobilization
Crew
Unit
Amount
Price
Cost
Crew Mileage
N/A
Mile
1,568
$ 0.67
$ 1,051
Per Diem
N/A
Day
15
$ 182.00
$ 2,730
Labor
N/A
Day
15
$ 355.92
$ 5,339
Standard Equipment Mileage
N/A
Mile
1,568
$ 0.67
$ 1,051
Standard Equipment Rental
N/A
Day
2
$ 20,948.76
$ 41,898
$ 52,067
Haul Road Building
Crew
Daily
Unit#
Days
Cost
Excavator 3.5 CY ~ 80K-100K lb.
B12D
$ 4,346.97
1
3
$ 13,292
Dozer D6
B10M
$ 3,478.17
1
3
$ 10,636
Grader 30,000 lb.
B11L
$ 2,863.38
1
3
$ 8,756
Water Truck
B45
$ 1,054.71
4
3
$ 12,900
Brush Chipper
B7
$ 3,119.05
1
3
$ 9,537
Loader 5cy+
B10U
$ 2,411.88
1
3
$ 7,375
Off Road Haul Truck (17 CY)
B34F
$ 1,962.09
2
3
$ 11,999
Total
$ 74,495
Excavation & Loading
Crew
Daily
Unit#
Days
Cost
Loader 5CY+
B10U
$ 2,411.88
1
12
$ 29,453
Off Road Haul Truck (16.7 CY)
B34A
$ 1,962.09
1
12
$ 23,960
Grader 30,000 lb.
B11L
$ 2,863.38
1
12
$ 34,967
Water Truck
B45
$ 1,054.71
2
90
$ 189,717
Dozer D6
B10M
$ 3,478.17
1
12
$ 42,474
Excavator 3.5 CY ~ 80K-100K lb.
B12D
$ 4,346.97
1
168
$ 728,833
Total
$ 1,049,405
Site Reclamation
Crew
Daily
Unit#
Days
Cost
Off Road Haul Truck (17 CY)
B34F
$ 1,962.09
2
12
$ 47,921
Loader 5CY+
B10U
$ 2,411.88
1
12
$ 29,453
Grader 30,000 lb.
B11L
$ 2,863.38
1
2
$ 6,810
Excavator 3.5 CY ~ 80K-100K lb.
B12D
$ 4,346.97
1
12
$ 53,084
Dozer D6
B10M
$ 3,478.17
1
12
$ 40,847
Water Truck
B45
$ 1,054.71
2
12
$ 24,773
Rip Rap Class II 18"-24"
NA
$ 53.37
862
1
$ 46,009
Total
$ 248,897
Page 2 of 5
-------
Table D-19. Section 9 Lease Mines, Cost Estimate Details for Alternative 4,
Disposal in Offsite RCRA-Licensed Facility
Construction Contractor Site Overhead
Crew
Unit
Amount
Price
Cost
Project Manager (10% of time)
N/A
Hour
27
$
207.62
$
5,706
Site Superintendent
N/A
Hour
275
$
226.60
$
62,273
H&S Officer
N/A
Hour
275
$
100.84
$
27,713
QA/QC Officer
N/A
Hour
275
$
100.84
$
27,713
Field Clerk
N/A
Hour
275
$
22.54
$
6,195
Fuel for Site Vehicles
N/A
Month
8
$
581.34
$
4,526
Port-o-let Rental (4)
N/A
Month
5
$
246.77
$
1,356
Job Trailers (1)
N/A
Month
1
$
319.14
$
439
Storage Boxes (1)
N/A
Month
1
$
112.11
$
154
Field Office Lights/HVAC (1)
N/A
Month
1
$
212.37
$
292
Generator (1)
N/A
Month
3
$
2,847.36
$
7,825
Fuel for Generator
N/A
Gallons
824
$
4.75
$
3,912
Telephone/internet (1)
N/A
Month
1
$
455.58
$
626
Field Office Equipment
N/A
Month
1
$
272.87
$
375
Field Office Supplies
N/A
Month
1
$
113.89
$
156
Trash (1 dumpster)
N/A
Month
1
$
1,079.62
$
1,483
Clin 1034 High Volume Air Sampling (4)
N/A
Month
5
$
454.39
$
2,497
Clin 1025 Ludlum 2121 and 43-10-1
N/A
Month
1
$
326.26
$
448
Air Monitoring Lab Confirmation Sampling (5
samples per day)
N/A
Day
86
$
711.84
$
61,208
Clin 1036 Personal Air Monitor
N/A
Month
12
$
242.03
$
2,905
Clin 1038 Personal Dust Monitor
N/A
Month
12
$
1,844.85
$
22,142
Clin 1068 Personal Dosimeter Badge
N/A
Month
12
$
70.00
$
840
Truck Scales
N/A
Month
1
$
355.92
$
489
$
241,275
Third-Party Oversight
Crew
Unit
Amount
Price
Cost
Travel and Lodging (1 person)
N/A
Day
27
$
179.15
$
4,923
Labor
N/A
Hour
275
$
94.91
$
26,083
Car Rental (1 car)
N/A
Month
1
$
474.56
$
652
Car Fuel
N/A
Month
1
$
901.66
$
1,239
$
32,897
Level of Accuracy (20%)
Crew
Unit
Amount
Price
Cost
20% of Construction Cost
N/A
N/A
N/A
N/A
$
274,559
GRAND
TOTAL
$
3,270,418
Page 3 of 5
-------
Table D-19. Section 9 Lease Mines, Cost Estimate Details for Alternative 4,
Disposal in Offsite RCRA-Licensed Facility
Onsite O&M Costs
Crew
Unit
Amount
Price
Cost
Annual Inspection (1 person crew, 1 day, 10
hrs/day)
N/A
Hour
10
$ 100.84
$ 1,008
Inspection Crew Travel and Lodging
N/A
LS
1
$ 791.31
$ 791
Preperation of Semi-annual Reports
(Professional Engineer)
N/A
Hour
8
$ 142.37
$ 1,139
Inspection Event Cost
$ 2,939
Inspection Contingency (15%)
$ 171
Total Inspection Event Cost
$ 3,110
Maintenance Crew Travel and Lodging
N/A
LS
1
$ 2,434.49
$ 2,434
Mobilization and Demobilization of Dozer,
and 17 CY Articulated Dump Truck
N/A
LS
1
$ 20,654.80
$ 20,655
Dozer Rental and Labor
B81
Day
3
$ 3,478.52
$ 10,436
Articulated Dump Truck (17 CY) Rental and
Labor
B34F
Day
3
$ 1,962.09
$ 5,886
Riprap Class II
N/A
CY
64
$ 53.39
$ 3,409
Construction Overhead
N/A
LS
1
$ 18,090.70
$ 18,091
O&M Annual Cost
$ 60,911
O&M Contingency (15%)
$ 9,137
Total O&M Annual Cost
$ 70,047
Contractor Site Overhead O&M
Crew
Unit
Amount
Price
Cost
Site Superintendent
N/A
Hour
30
$ 226.60
$ 6,798.07
H&S Officer
N/A
Hour
30
$ 100.84
$ 3,025.32
Fuel for Site Vehicles
N/A
Month
0.5
$ 6,976.03
$ 3,139.21
Port-o-let Rental (1)
N/A
Month
0.2
$ 246.77
$ 37.02
Generator (1)
N/A
Month
0.15
$ 2,847.36
$ 427.10
Fuel for Generator
N/A
Gallons
90
$ 4.75
$ 427.10
Telephone/internet (1)
N/A
Month
0.15
$ 455.58
$ 68.34
Trash (1 dumpster)
N/A
Month
0.15
$ 1,079.62
$ 161.94
Clin 1034 High Volume Air Sampling (3)
N/A
Month
0.5
$ 454.39
$ 204.48
Clin 1025 Ludlum 2121 and 43-10-1
N/A
Month
0.15
$ 326.26
$ 48.94
Air Monitoring Lab Confirmation Sampling
(3 samples per day)
N/A
Day
3
$ 711.84
$ 2,135.52
Clin 1036 Personal Air Monitor
N/A
Month
0.8
$ 242.03
$ 181.52
Clin 1038 Personal Dust Monitor
N/A
Month
0.8
$ 1,844.85
$ 1,383.64
Clin 1068 Personal Dosimeter Badge
N/A
Month
0.8
$ 70.00
$ 52.50
$ 18,090.70
Page 4 of 5
-------
Table D-19. Section 9 Lease Mines, Cost Estimate Details for Alternative 4,
Disposal in Offsite RCRA-Licensed Facility
Notes:
"
Inch
CAD
Computer-aided design
CY
Cubic yard
GIS
Geographic information system
H&S
Health and safety
HP
Horsepower
hr
Hour
HVAC
Heating, ventilation, and air conditioning
K
Thousand
lb.
Pound
LF
Linear foot
LiDAR
Light detection and ranging
LS
Lump sum
N/A
Not applicable
O&M
Operation and maintenance
QA/QC
Quality assurance/quality control
RCRA
Resource Conservation and Recovery Act
SY
Square yard
XRF
X-ray fluorescence
Page 5 of 5
-------
Table D-20. Section 9 Lease Mines, Cost Estimate Summary for Alternative 4,
Disposal in Offsite RCRA-Licensed Facility
Haul Road Building
Unit Cost
Excavator 3.5 CY ~ 80K-100K lb.
$ 13,292
Dozer D6
$ 10,636
Grader 30,000 lb.
$ 8,756
Water Truck
$ 12,900
Off Road Haul Truck
$ 11,999
Loader 5 CY+
$ 7,375
Brush Chipper
$ 9,537
Subtotals Step 1
$ 74,495
Excavation and Loading
Unit Cost
Loader 5 CY+
$ 29,453
Off-Road Haul Truck (17 CY)
$ 23,960
Grader 30,000 lb.
$ 34,967
Water Truck
$ 189,717
Dozer D6
$ 42,474
Excavator 3.5 CY ~ 80K-100K lb.
$ 728,833
Subtotals Step 2
$ 1,049,405
Onsite Restoration
Unit Cost
Off-Road Haul Truck (17 CY)
$ 47,921
Loader 5 CY+
$ 29,453
Grader 30,000 lb.
$ 6,810
Excavator 3.5 CY ~ 80K-100K lb.
$ 53,084
Dozer D6
$ 40,847
Water Truck
$ 24,773
Riprap Class II 18"-24"
$ 46,009
Subtotals Step 3
$ 248,897
Subtotal Construction
$ 1,372,797
Other Costs
Unit Cost
Non-Construction Costs
Engineering Design
$ 260,605
Planning Documents
$ 93,702
Resource Surveys
$ 310,569
Confirmation Sampling
$ 135,603
Reporting
$ 94,635
Contractor Site Overhead
$ 241,275
Mobilization / Demobilization
$ 52,067
Travel+ Lodging (Construction Workers)
$ 401,708
Level of Accuracy (20%)
$ 274,559
Third-Party Oversight
$ 32,897
Subtotals Step 6
$ 1,897,620
Total Site Capital Costs
$ 3,270,418
Inspections and Maintenance Event Costs
Unit Cost
Annual Inspection (1 person crew, 1 day, 10 hrs/day)
$ 1,008
Inspection Crew Travel and Lodging
$ 791
Preperation of Report (Professional Engineer)
$ 1,139
Subtotal O&M Costs
$ 2,939
Contingencies (15%)
$ 441
Total Inspection Event Cost
$ 3,380
Page 1 of 2
-------
Table D-20. Section 9 Lease Mines, Cost Estimate Summary for Alternative 4,
Disposal in Offsite RCRA-Licensed Facility
Present Value of Inspection Costs Based on 10-Year Life at 3.50% (PV
Factor = 8.317)
$
28,107
Maintenance Crew Travel and Lodging
$
2,434
Mobilization and Demobilization of Dozer and 17 CY Articulated Dump Truck
$
20,655
Dozer Rental and Labor
$
10,436
Articulated Dump Truck (17 CY) Rental and Labor
$
5,886
Riprap Class II
$
3,409
Construction Overhead
$
18,091
Subtotal Maintenance Event Costs
$
60,911
Maintenance Contingencies (15%)
$
9,137
Total Maintenance Event Costs
$
70,047
Maintenance Cost (Year 10)
Present Value of Maintenance Costs Based on 10-Year Life at 3.50% (PV
Factor = 0.7089)
$
49,657
Waste Hauling Cost
Waste Hauling Cost per CY
$
201
Waste Total Hauling Cost
$
2,974,929
Low-Level Radioactive Waste Disposal Cost
Low-Level Radioactive Waste Cost per CY
$
435
Low-Level Radioactive Waste Disposal Cost
$
6,431,040
Grand Total Capital Costs
$
12,676,386
Total Onsite Inspection and Maintenance Cost
$
77,764
Total Costs
$
12,754,150
Notes:
Inch
AC
Acre
CY
Cubic yard
ET
HP
hr
Evapotranspiration
Horsepower
Hour
K
Thousand
lb.
Pound
O&M
Operation and maintenance
PV
Present value
RCRA
Resource Conservation and
Recovery Act
Page 2 of 2
-------
APPENDIX E
POST-REMOVAL VISUALIZATION
-------
Site Features
= Berm
Surface Water Drainage Pathway
~ Concrete Pad
Dozer Cut
1Sl3 Pit Area Identified in RSE
Shallow Mine Waste
F. • 1 Waste Pile
f~ 1 Area of Potential Effect
AUM Boundary
— Road
Little Colorado River
Notes:
AUM
RSE
Abandoned uranium mine
Removal site evaluation
1 inch = 200 Feet
1:2,400
200 100 0
w
200
I Feet
SECTION 9 LEASE MINES PROPOSED
POST-SURF!CIAL RESTORATION ACTIVITIES:
AUM 457, ALTERNATIVE 2
(MULTIPLE LOCATION CONSOLIDATE AND CAP)
Prepared For: U.S. EPA Region 9
Task Order No.:
020
Location:
COALMINE CANYON CHAPTER
NAVAJO NATION
Prepared By:
It
TETRA TECH
Contract No.:
68HE0923D0002
7/1 6/2024
Coordinate System:
NAD 1983 State Plane Arizona East
FIRS 0201 Feet Transverse Mercator
Figure No.:
E-1
-------
Post-Restoration
Site Features
= Berrn
Surface Water Drainage Pathway
~ Concrete Pad
Dozer Cut
Bn Pit Area Identified in RSE
Shallow Mine Waste
Waste Pile
Area of Potential Effect
AUM Boundary
Road
Little Colorado River
Notes:
AUM
RSE
Abandoned uranium mine
Removal site evaluation
1 inch = 200 Feet
1:2,400
200 100 0
w
200
I Feet
SECTION 9 LEASE MINES PROPOSED
POST-SURFICIAL RESTORATION ACTIVITIES:
AUM 457, ALTERNATIVE 3
(SINGLE LOCATION CONSOLIDATE AND CAP)
AND ALTERNATIVE 4 (OFFSITE DISPOSAL)
Prepared For: U.S. EPA Region 9
Prepared By:
It
TETRA TECH
1999 Harrison Street, Suite 500
Oakland, CA 94612
Task Order No.:
020
Contract No.:
68HE0923D0002
Location:
COALMINE CANYON CHAPTER
NAVAJO NATION
7/1 6/2024
Coordinate System:
NAD 1983 State Plane Arizona East
FIRS 0201 Feet Transverse Mercator
Figure No.:
E-2
-------
Prepared By:
SECTION 9 LEASE MINES PROPOSED
POST-SURF!CIAL RESTORATION ACTIVITIES:
AUM 458, ALTERNATIVE 2
(MULTIPLE LOCATION CONSOLIDATE AND CAP)
Task Order No.:
Contract No.:
68HE0923D0002
Location:
COALMINE CANYON CHAPTER
NAVAJO NATION
7/2/2024
Coordinate System:
NAD 1983 State Plane Arizona Central
FIRS 0202 Feet Transverse Mercator
Figure No.:
E-3
1 inch = 120 Feet
~ Feet
Site Features
Surface Water Drainage Pathway
Dozer cuts
lOl Pit Area Identified in RSE
Shallow Mine Waste
I? 'v-J Waste Pile
I I Area of Potential Effect
l~~l AUM Site Boundary
— Road
Mays Wash
Notes:
AUM Abandoned uranium mine
RSE Removal site evaluation
Prepared For: U.S. EPA Region 9
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Site Features
Surface Water Drainage Pathway
Dozer cuts
RTJ Pit Area Identified in RSE
Shallow Mine Waste
I? 'v j Waste Pile
I I Area of Potential Effect
l~~l AUM Site Boundary
— Road
Mays Wash
Notes:
AUM
RSE
Abandoned uranium mine
Removal site evaluation
1 inch = 120 Feet
1:1,440
120 60 0
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S
120
~ Feet
SECTION 9 LEASE MINES PROPOSED
POST-SURFICIAL RESTORATION ACTIVITIES:
AUM 458, ALTERNATIVE 3
(SINGLE LOCATION CONSOLIDATE AND CAP)
AND ALTERNATIVE 4 (OFFSITE DISPOSAL)
Prepared For: U.S. EPA Region 9
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Task Order No.:
^ :
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020
Location:
COALMINE CANYON CHAPTER
NAVAJO NATION
Prepared By:
TETRA TECH
Contract No.:
68HE0923D0002
7/2/2024
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t2?
Coordinate System:
NAD 1983 State Plane Arizona Central
FIRS 0202 Feet Transverse Mercator
Figure No.:
E-4
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