Quivira Mines

Coyote Canyon, Pinedale, and Standing Rock
Chapters, Navajo Nation, New Mexico

Final

Engineering Evaluation/Cost Analysis

March 2024

It

TETRA TECH


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Quivira Mines

Coyote Canyon, Pinedale, and Standing Rock
Chapters, Navajo Nation, New Mexico

Final

Engineering Evaluation/Cost Analysis

Response, Assessment, and Evaluation Services 2
Contract No. 68HE0923D0002
Task Order 001

March 2024

Submitted to
U.S. Environmental Protection Agency

Submitted by
Tetra Tech, Inc.
1999 Harrison Street, Suite 500
Oakland, CA 94612

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TETRA TECH


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Engineering Evaluation/Cost Analysis, Quivira Mines	__

TABLE OF CONTENTS

Section	Page

ACRONYMS AM) ABBREVIATIONS	vi

1.0 EXECUTIVE SUMMARY	1

1.1	PURPOSE OF THE ENGINEERING EVALUATION/COST
ALTERNATIVES ANALYSIS	1

1.2	SITE CHARACTERIZATION	 1

1.3	REMOVAL ACTION OBJECTIVES	3

1.4	IDENTIFICATION OF REMOVAL ACTION ALTERNATIVES	3

1.5	COMPARATIVE ANALYSIS OF REMOVAL ACTION ALTERNATIVES	4

2.0 SITE CHARACTERIZATION	6

2.1	SITE DESCRIPTION AND BACKGROUND	6

2.1.1	Site Location	6

2.1.2	Type of Mine and Operational Status	7

2.1.3	Regulatory Hi story	13

2.1.4	Site Features and Landscape	14

2.1.5	Geology, Hydrogeology, and Hydrology	15

2.1.6	Land Use and Populations	17

2.1.7	Sensitive Ecosystems	18

2.1.8	Meteorology and Climate	20

2.2	PREVIOUS RECLAMATION AND REMOVAL ACTIONS	21

2.3	PREVIOUS SITE INVESTIGATIONS	22

2.4	SOURCE, NATURE, AND EXTENT OF CONTAMINATION	23

2.4.1	Background Threshold Values	23

2.4.2	Source and Nature of Contamination	25

2.4.3	Extent of Contamination	27

2.5	RISK ASSESSMENT	32

2.5.1	Purpose	32

2.5.2	Exposure Units	32

2.5.3	Human Health Risk Assessment	33

2.5.4	Ecological Risk Assessment	36

2.5.5	Risk Assessment Results Summary	37

2.6	RISK MANAGEMENT ANALYSIS	38

2.6.1	Comparison of Site Concentrations of Candidate Contaminants of
Concern and Contaminants of Ecological Concern to Background
Concentrations	40

2.6.2	Consideration of Natural Forms of Chromium	42

2.6.3	Preliminary Removal Goals for Human Health and Ecological Health	43

2.6.4	Co-Location Assessment	44

2.6.5	Refinement of the Ecological Risk Assessment Candidate Contaminants

of Ecological Concern	46

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2.6.6 Risk Management Summary and Conclusions	49

2.7 REMOVAL ACTION EXTENT	50

2.7.1	Numerical Removal Action Goals	50

2.7.2	Other Removal Action Extent Considerations	51

3.0 IDENTIFICATION OF REMOVAL ACTION OBJECTIVES	53

3.1	REMOVAL ACTION OBJECTIVES	53

3.2	STATUTORY LIMITS ON REMOVAL ACTIONS	53

3.3	REMOVAL SCOPE	54

3.4	REMOVAL SCHEDULE	54

4.0 IDENTIFICATION AND ANALYSIS OF REMOVAL ACTION ALTERNATIVES ...55

4.1	DEVELOPMENT AND SCREENING OF ALTERNATIVES	55

4.1.1	Summary of Technology Identification and Screening	55

4.1.2	Summary of Alternative Development	61

4.1.3	Applicable or Relevant and Appropriate Requirements	64

4.2	DESCRIPTION 01 ALTERNATIVES	66

4.2.1	Common Elements	66

4.2.2	Description of Removal Action Alternatives	73

4.3	DETAILED ANALYSIS OF ALTERNATIVES	77

4.3.1	Effectiveness Criterion	78

4.3.2	Implementability Criterion	79

4.3.3	Cost Criterion	79

4.3.4	Cost Estimating Process	79

4.3.5	Alternative 1: No Action	80

4.3.6	Alternative 2: Consolidate and Cap All Waste On Site	82

4.3.7	Alternative 3: Dispose of All Mine Waste Off Site at Red Rocks
Disposal Facility	86

4.3.8	Alternative 4: Dispose of All Mine Waste Off Site at a Resource
Conservation and Recovery Act C or Low-Level Radioactive Waste
Facility	91

5.0 COMPARATIVE ANALYSIS OF ALTERNATIVES	97

5.1	COMPARATIVE ANALYSIS APPROACH	97

5.2	SUMMARY OF COMPARATIVE ANALYSIS	97

5.2.1	Effectiveness	97

5.2.2	Implementability	102

5.2.3	Projected Costs	105

6.0 RECOMMENDED ALTERNATIVE	107

7.0 REFERENCES	109

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EXHIBITS

Exhibit 1. Summary of Alternative Ratings	4

Exhibit 2. Chapter Populations in 2019	18

Exhibit 3. Precipitation Frequency Estimates	21

Exhibit 4. Background Threshold Values	25

Exhibit 5. Quivira Mines Receptors	34

Exhibit 6. Cancer Risks and Noncancer Hazards	1

Exhibit 7. Candidate COCs Identified Based on Cancer Risks and Noncancer Hazards	1

Exhibit 8. Site-Wide Candidate COECs	37

Exhibit 9. Candidate COCs and Candidate COECs Recommended for Further Evaluation	37

Exhibit 10. Background Comparison Results Summary	41

Exhibit 11. Human Health Preliminary Removal Goals and NAUM Preliminary Ecological

Removal Goals for Candidate COC and COECs in Soil Above Background	44

Exhibit 12. Radium-226 Removal Action Goal Development	45

Exhibit 13. Comparison of Site-Wide EPCs to NAUM PERGs for Soil	48

Exhibit 14. COCs Recommended for Removal Action	49

Exhibit 15. Selected RAG for Each COC	51

Exhibit 16. Alternative 2 Cost Breakdown	86

Exhibit 17. Red Rocks Transportation and Tipping Costs	87

Exhibit 18. Alternative 3 Cost Breakdown	91

Exhibit 19. Disposal Facility Transportation and Tipping Costs	92

Exhibit 20. Alternative 4 Cost Breakdown	96

Exhibit 21. Comparative Rating of Alternatives	97

Exhibit 22. Potential Community and Worker Impacts	99

Exhibit 23. Environmental Impacts of Alternatives	100

Exhibit 24. Construction Completion Time for Alternatives	101

Exhibit 25. Alternative Costs and Ratings	105

PHOTOS

Photo 1. CR-1 Waste Rock Pile (Looking West)	9

Photo 2. CR-1 Headframe and Industrial Buildings (Looking North)	10

Photo 3. CR-1 Settling Ponds (Looking Northeast)	10

Photo 4. CR-1 Settling Ponds (Looking Southeast)	11

Photo 5. CR-1E Settling Pond	11

Photo 6. CR-1E Headframe and Industrial Buildings (Looking Northeast)	12

Photo 7. Proto Ore Stockpile at the Kerr-McGee Pond Area (Looking East)	12

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FIGURES

Figure 1. Quivira Mines Location

Figure 2. Quivira CR-1 Mine Site Features

Figure 3. Quivira CR-1E Mine Site Features

Figure 4. Kerr-McGee Ponds Site Features

Figure 5. Local Geology and Background Study Areas

Figure 6. Local Soils and Background Study Areas

Figure 7. Conceptual Drawing of Historic Releases and Water Flow

Figure 8. Land Use Designations

Figure 9. Monthly Average Temperature, Precipitation, and Evaporation
Figure 10. Gallup, New Mexico Wind Rose Diagram
Figure 11. Prior Removal Action Locations
Figure 12. Quivira Mines Transport Model
Figure 13. Quivira Mines Conceptual Site Model Wire Diagram
Figure 14. 2022 CR-1 Transect Gamma Scan Measurements
Figure 15. 2022 CR-1E Transect Gamma Scan Measurements
Figure 16. 2022 Kerr-McGee Ponds Transect Gamma Scan Measurements
Figure 17. CR-1 Correlated and Laboratory Ra-226 Results in Surface Soils
Figure 18. CR-1E Correlated and Laboratory Ra-226 Results in Surface Soils
Figure 19. Kerr-McGee Ponds Correlated and Laboratory Ra-226 Results in Surface Soils
Figure 20. CR-1 Distribution of Ra-226 in Surface and Subsurface Soils
Figure 21. CR-1 Waste Pile Vertical Extent of Ra-226 at Depths Greater Than 6 Feet Below
Grade

Figure 22. CR-1E Distribution of Ra-226 in Surface and Subsurface Soils
Figure 23. CR-1E Vertical Extent of Ra-226 at Depths Greater Than 6 Feet Below Grade
Figure 24. Kerr-McGee Ponds Distribution of Ra-226 above 2.0 pCi/g in Surface and Subsurface
Soils

Figure 25. Kerr-McGee Ponds Distribution of Ra-226 above 5.4 pCi/g in Surface and Subsurface
Soils

Figure 26. Kerr-McGee Ponds Vertical Extent of Ra-226 at Depths Greater Than 6 Feet
Figure 27. Graphic Depiction of Navajo Residential Exposure Pathways including the Dine
Lifeways

Figure 28. CR-1 Surface and Subsurface Removal Action Extent
Figure 29. CR-1E Surface and Subsurface Removal Action Extent
Figure 30. Kerr-McGee Ponds Surface and Subsurface Removal Action Extent
Figure 31. Proposed Laydown Area, Access Roads, and Exclusion Areas
Figure 32. Alternative 2 Waste Excavation, Transfer, and Onsite Consolidation
Figure 33. Alternative 2 Waste Capping and Site Restoration
Figure 34. Alternative 2 Typical Waste Consolidation Area Features
Figure 35. Alternatives 3 and 4 Waste Excavation and Offsite Disposal
Figure 36. Alternatives 3 and 4 Site Restoration

Figure 37. Alternative 3 Haul Routes from Quivira Mines to Red Rocks Disposal Facility
Figure 38. Alternative 3 Offsite Disposal at Proposed Red Rocks Disposal Facility
Figure 39. Alternative 4 Haul Route from Quivira Mines to Deer Trail, Colorado, Disposal
Facility

Figure 40. Alternative 4 Haul Route from Quivira Mines to Andrews, Texas, Disposal Facility

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TABLES

Table 1. Mine Features and Dimensions for Quivira Mines

Table 2. Comparison of Quivira Mines Surface Soil with Bartlett Barren Member of Crevasse

Canyon Formation (BSA-2) Background Surface Soil
Table 3. Risk Management Summary

Table 4. Quivira Mines Selection of Soil Removal Action Goal for Each COC and COEC
Table 5. General Response Actions, Technologies, and Process Options
Table 6. Applicable or Relevant and Appropriate Requirements and to Be Considered
Requirements for Quivira Mines

APPENDICES

Appendix A. Quivira Mines Site Images

Appendix B. Contaminant Distribution

Appendix C. Risk Assessment

Appendix D. Environmental Metrics Analysis

Appendix E. Cost Analysis

Appendix F. Post-Removal Visualizations

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Engineering Evaluation/Cost Analysis, Quivira Mines

ACRONYMS AND ABBREVIATION

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Section

Degree Fahrenheit

ARAR
AUM

Applicable or relevant and appropriate requirement
Abandoned uranium mine

bgs
BIA
BSA
BTV

Below ground surface
Bureau of Indian Affairs
Background study area
Background threshold value

CERCLA	Comprehensive Environmental Response, Compensation, and Liability Act

CFR	Code of Federal Regulations

CChe	Carbon dioxide equivalent

COC	Contaminant of concern

COEC	Contaminant of ecological concern

COPC	Contaminant of potential concern

COPEC	Contaminant of potential ecological concern

CR-1	Quivira Church Rock No. 1 Mine

CR-1E	Quivira Church Rock No. 1 East Mine

CR-2	Quivira Church Rock No. 2 Mine

CRA	Conestoga Rovers and Associates Ltd.

CSM	Conceptual site model

EE/CA	Engineering evaluation/cost analysis

EPC	Exposure point concentration

ERA	Ecological risk assessment

ERRG	Engineering/Remediation Resources Group, Inc.

ESA	Endangered Species Act

ET	Evapotranspiration

EU	Exposure unit

FOD	Frequency of detection

g/cm3	Gram per cubic centimeter

gpm	Gallon per minute

HDPE	High-density polyethylene

HELP	Hydrologic Evaluation of Landfill Performance

HHRA	Human health risk assessment

HI	Hazard index

HQ	Hazard quotient

IC	Institutional control

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ACRONYMS AND ABBREVIATIONS (CONTINUE

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Kerr-McGee	Kerr-McGee Corporation

LLRW	Low-level radioactive waste

MWH

Montgomery Watson Harza

NAMLRD

Navajo Nation Abandoned Mine Lands Reclamation Department

NAUM

Navajo abandoned uranium mine

NCP

National Oil and Hazardous Substances Pollution Contingency Plan

NECR

Northeast Church Rock

NESL

Navajo Endangered Species List

NNDFW

Navajo Nation Department of Fish and Wildlife

NNDWR

Navajo Nation Department of Water Resources

NNEPA

Navajo Nation Environmental Protection Agency

NNMD

Navajo Nation Minerals Department

NORM

Naturally occurring radioactive material

NRC

U.S. Nuclear Regulatory Commission

NTUA

Navajo Tribal Utility Authority

OSHA

Occupational Safety and Health Administration

OSWER

Office of Solid Waste and Emergency Response

pCi/g

Picocurie per gram

PERG

Preliminary ecological removal goal

PRG

Preliminary removal goal

psf

Pound per square foot

Quivira Mines

Quivira Mines Site

Ra-226

Radium-226

RAG

Removal action goal

RAO

Removal action objective

RBSL

Risk-based screening level

RCRA

Resource Conservation and Recovery Act

RME

Reasonable maximum exposure

RSE

Removal site evaluation

SE

Secular equilibrium

SENES

SENES Consultants Limited

SLERA

Screening-level ecological risk assessment

SPLP

Synthetic precipitation leaching procedure

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ACRONYMS AND ABBREVIATIONS (CONTINUE

I

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TBC
TCLP
TCRA
TENORM
Tetra Tech

To be considered

Toxicity characteristic leaching procedure
Time-critical removal action

Technologically enhanced naturally occurring radioactive material
Tetra Tech, Inc.

U-234	Uranium-23 4

U-238	Uranium-23 8

UNC	United Nuclear Corporation

US ACE	U.S. Army Corps of Engineers

USEPA	U.S. Environmental Protection Agency

UTL95-95	95 percent upper tolerance limit with 95 percent coverage

WCS	Waste Control Specialists

Weston	Weston Solutions, Inc.

WRS	Wilcoxon rank sum

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1.0 EXECUTIVE SUMMAR

L

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The U.S. Environmental Protection Agency (USEPA) prepared this engineering evaluation/cost
analysis (EE/CA) report regarding the Quivira Mines Site (Quivira Mines) near Gallup, New
Mexico, in the Navajo Nation.

1.1 PURPOSE OF THE ENGINEERING EVALUATION/COST ALTERNATIVES ANALYSIS

The purpose of this EE/CA is to evaluate cleanup alternatives to address human and ecological
health risks at the Quivira Mines. These cleanup alternatives are developed and evaluated in the
context of the Navajo Nation Fundamental Laws and in accordance with the Comprehensive
Environmental Response, Compensation, and Liability Act (CERCLA). In this report, the
Quivira Mines comprises the Quivira Church Rock No. 1 Mine (CR-1), Quivira Church Rock
No. 1 East Mine (CR-1E), and Kerr-McGee Corporation (Kerr-McGee) Ponds (Figure 1).

1.2 SITE CHARACTERIZATION

CR-1 and CR-1E were leased for underground mining operations between approximately 1972
and 1986. A third leased location, the Quivira Church Rock No. 2 Mine (CR-2), is about 3 miles
northwest of CR-1, but CR-2 was never developed and an investigation found no evidence of
environmental impacts from mining at this location (Weston Solutions, Inc. [Weston] 2015). A
fourth leased location, the Kerr-McGee Ponds, received sediment from settling ponds at CR-1
and CR-1E, where the sediment was dewatered; proto ore was also stored in a stockpile at this
location. CR-1 and CR-1E are on Navajo Nation lands, and the Kerr-McGee Ponds are on
private lands. The Quivira Mines are approximately 20 miles northeast of Gallup, New Mexico
(Figure 1). Access to the area is via New Mexico State Road 566. The Coyote Canyon, Standing
Rock, and Pinedale Chapters of the Navajo Nation intersect nearby. Active mining included
sinking shafts and excavating underground workings at CR-1 and CR-1E and extracting ore from
1,500 to 1,850 feet below ground surface (bgs). CR-1 and CR-1E were reclaimed in 1985 to
1986 by backfilling 14-foot and 12 foot diameter shafts with proto ore and sealing with a steel
and concrete plug, backfilling vent holes with waste rock and sealing with a steel and concrete
plug, removing mine equipment and buildings, removing sediment from the settling ponds, and
grading and covering the waste piles with 6 to 12 inches of material (Quivira Mining Company
1987). The Kerr-McGee Ponds were reclaimed in 1980 to 1982 by removing the pond berms and
former proto ore stockpile (Weston 2019a).

Except for remnants of former mine operations and reclamation, the Quivira Mines are currently
undeveloped although livestock grazing occasionally occurs where perimeter fencing is
compromised. Land use on the Navajo Nation is mainly low-density, single-family residential
and open grazing with some gathering of traditional plants and herbs. Several residences are
within 700 feet of CR-1 and 800 feet of CR-1E. Other land use activities on the Navajo Nation
may include hiking, wood gathering, and hunting. Land use at the Kerr-McGee Ponds is
industrial and open space and is limited by private ownership by the United Nuclear Corporation
(UNC). Continuation of current land uses is expected for the foreseeable future. Nearby
residents, UNC outdoor workers, and open space users could be exposed to contaminants at the
Quivira Mines via incidental ingestion of soil, external radiation from contaminants, and

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inhalation of dust. Residents could also be exposed to contaminants through livestock or wildlife
meat and plant consumption. The likely future land uses at the Quivira Mines are:

•	Kee'da'whii teeh (full-time Navajo resident) - Areas are easy to access and relatively
flat except where waste rock piles are present.

•	Kqq ei doo nahaazah dah (difficult access open space user) - Areas are difficult to
get to because the land is steep. This land use also includes arroyos that are difficult to
get to because of challenging features such as steep sidewalls.

•	UNC Outdoor Worker (non-Navajo lands) - Privately-owned areas with former
mine-related operations.

The nature and extent of contamination at the Quivira Mines were assessed with various
technologies during the removal site evaluation (RSE) completed in September 2011 (SENES
2011). An assessment of the Kerr-McGee Ponds was conducted in 2017 (Weston 2019a). Data
gap investigations were conducted in 2015 and 2022 (Tetra Tech 2023b). Most of the waste at
the site is from excavated waste rock and occurs as reclaimed waste piles and settling and
dewatering pond areas. Areas with contamination outside the waste rock piles and ponds are
from mining-related activities.

As part of this EE/CA, risk assessments at the site were conducted to evaluate the potential risk
posed to human and ecological health by mine-related contamination. The results of the human
health risk assessment (HHRA) and ecological risk assessment (ERA) are used to help in
removal action decisions at the Quivira Mines through the EE/CA process. The purpose of the
risk assessment is to evaluate current and future human health risk under reasonable maximum
exposure (RME) scenarios and ecological risk based on the known ecosystems for the region.
The results of the HHRA and ERA indicate that risks are present at the Quivira Mines for
human and ecological receptors. At the site, radium-226 (Ra-226) and uranium are the
human health risk contaminants of concern (COC); and Ra-226, uranium-234 (U-234), and
uranium-238 (U-238) are contaminants of ecological concern (COEC). A removal action is
recommended for contamination associated with COCs and COECs at the Quivira Mines.

Human health and ecological removal action goals (RAG) were derived for COCs and COECs.
The RAG is the lesser of the human health preliminary remediation goal (PRG) or preliminary
ecological removal goal (PERG). When one or both PRGs or PERGs are less than the
background threshold value (BTV), the BTV becomes the RAG. For purposes of the final
EE/CA, the BTV is used to represent background for delineating contaminated areas.

Multiple lines of evidence were used to develop the removal action extent at the Quivira Mines,
including the extent of Ra-226 in surface soil and sediment, extent of contamination of other
COCs and COECs not co-located with Ra-226, surface and subsurface waste areas, transport
pathways, potential disturbed mineralized areas, potential accessibility considerations, and risk
management considerations. The removal action extent covers an estimated 63 acres at the
Quivira Mines. An estimated 1,005,500 bank cubic yards of mine waste and contaminated
soil will be addressed by removal action.

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1.3	REMOVAL ACTION OBJECTIVES

The removal action objectives (RAO) of this soil removal action are to:

•	Prevent exposure to soil with contaminants from mining activities that would pose an
unacceptable risk to human health with the reasonably anticipated future land use and
traditional Navajo lifeways

•	Prevent exposure to soil with contaminants from mining activities that would pose an
unacceptable risk to plants, animals, and other ecological receptors

•	Prevent offsite migration of contaminants from mining activities that would pose an
unacceptable risk to human or ecologic health by soil, surface water, groundwater, or air

Options to be analyzed include response actions that would allow for unrestricted residential and
Dine Lifeways use, as well as response actions that would include land use restrictions limiting
residential use and grazing on portions of the site on the Navajo Nation. Options to be analyzed
on UNC property include response actions that would allow for unrestricted use by outdoor
workers. The intent of the response action is to address the surface and subsurface contaminated
soils and waste rock at the Quivira Mines. These RAOs have been developed to be considerate of
Dine Lifeways.

1.4	IDENTIFICATION OF REMOVAL ACTION ALTERNATIVES

The following removal action alternatives were considered as part of this EE/CA. Each
alternative was evaluated against the criteria of effectiveness, implementability, and cost.

•	Alternative l:No Action (this must always be evaluated to provide a baseline for
comparison) - 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 On Site - Addresses RAOs by
excavating waste rock piles, residual waste rock, and contaminated soils; hauling the
waste to a common onsite location; consolidating the waste in a repository; and capping
the repository. An evapotranspiration (ET) cap would be used that is protective and
would limit contaminant migration. The repository would be inspected and maintained
in perpetuity. Land use restrictions would exist on the repository.

•	Alternative 3: Dispose of All Mine Waste Off Site at Red Rocks Disposal Facility -

Address RAOs by excavating waste rock piles, residual waste rock, and contaminated
soils and hauling the waste to and disposing of the waste off site at the Red Rocks
disposal facility near Thoreau, New Mexico. Off-Navajo Nation disposal is protective
and would not require long-term onsite maintenance or land use restrictions.

•	Alternative 4: Dispose of All Mine Waste Off Site at a Resource Conservation and
Recovery Act (RCRA) C or Low-Level Radioactive Waste (LLRW) Facility -

Addresses RAOs by excavating waste rock piles, residual waste rock, and contaminated
soils and hauling and disposing of the waste at an offsite RCRA C and State of Colorado

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radiological licensed facility, such as the Clean Harbors Deer Trail facility in Deer Trail,
Colorado, or an LLRW facility licensed by the U.S. Nuclear Regulatory Commission
(NRC), such as the Waste Control Specialists (WCS) in Andrews, Texas. Off-Navajo
Nation disposal is protective and would not require long-term onsite maintenance or land
use restrictions.

For the applicable removal action alternatives, plant life that matches the natural landscape will
be planted on restored excavation areas and covers. All temporary roads built for construction
will also be removed, and the site will be restored. The consolidation and capping of waste will
address geomorphic recontouring and revegetation of land to match the natural landscape. For
Alternative 3, an evaluation of rail and truck haul routes is provided in Section 4.1.2 and in Tetra
Tech (2024).

1.5 COMPARATIVE 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. Exhibit 1 presents an overview of
the comparative analysis results.

Exhibit 1. Summary of Alternative Ratings

Alternative

Attainment
of Threshold
Criteria3

Effectiveness

Implementability

Cost Rating
(Million)b

1

No Action

Fail

Short-Term: Average
Long-Term: Very Poor

Tech: Very Good
Admin: Very Good

Very Good
($0)

2

Consolidate and Cap
All Waste On Site

Pass

Short-Term: Average
Long-Term: Good

Tech: Good
Admin: Good

Good
($61.6)

3

Dispose of All Mine
Waste Off Site at
Red Rocks Disposal
Facility

Pass

Short-Term: Average
Long-Term: Very Good

Tech: Very Good
Admin: Average

Poor
($182.5)

4

Dispose of All Mine
Waste Off Site at a
RCRA C or LLRW
Facility

Pass

Short-Term: Very Poor
Long-Term: Very Good

Tech: Very Good
Admin: Good

Very Poor
($563)

Notes:

a	Threshold criteria are (a) overall protection and (b) compliance with applicable or relevant and appropriate

requirements.
b	Estimated costs are net present value.

Admin Administrative feasibility
LLRW Low-level radioactive waste
RCRA Resource Conservation and Recovery Act
Tech Technical feasibility

The recommended alternative for the Quivira Mines is Alternative 3 (dispose of all mine waste
off site at Red Rocks disposal facility). While the alternative is twice the price of Alternative 2
(consolidate and cap at the Quivira Mines), it removes the waste from the Red Water Pond Road
and Pipeline Canyon Road communities and consolidates the waste at a dedicated facility
capable of long-term management of the waste.

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Though USEPA has identified a recommended alternative, USEPA will solicit input from
Navajo Nation officials, regulators, chapter representatives, other stakeholders, and the
community on the final EE/CA and recommended alternative during a public comment period.
USEPA and the Navajo Nation Environmental Protection Agency (NNEPA) will hold a public
meeting during the comment period to listen to input.

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2.0 SITE CHARACTERIZATIO

J

This section presents the site description and background; previous reclamation and removal
actions; previous site investigations; source, nature, and extent of contamination; and risk
assessment of the Quivira Mines.

2.1 SITE DESCRIPTION AND BACKGROUND

The Quivira Mines comprises the CR-1 mine, the CR-1E mine, and the Kerr-McGee Ponds. CR-
1 and CR-1E contain waste rock piles, pond areas, and mining debris while the Kerr-McGee
Ponds does not contain any mining residuals at the surface. CR-2, located about 3 miles
northwest of CR-1, was never developed and does not require cleanup.

The following subsections describe the site location, type of mines and operational status,
regulatory history, site features and landscape, geology and hydrology, land use and populations,
sensitive ecosystems, and meteorology and climate. Appendix A contains site images that show
the current condition of the Quivira Mines.

2.1.1 Site Location

The Quivira Mines is within the Eastern Abandoned Uranium Mine (AUM) Region of the
Navajo Nation approximately 20 miles northeast of Gallup, New Mexico (Figure 1). The site is
located within the Red Water Pond Road and Pipeline Canyon Road communities in the Coyote
Canyon and Standing Rock Chapters of the Navajo Nation. The Church Rock Chapter is also
located to the southwest of CR-1. Sections of land owned by Bureau of Land Management are
located west of CR-1 within the Church Rock Chapter and south of CR-1 near the UNC Mill
Facility. The UNC Mill Facility is on private property within the Pinedale Chapter (Figure 1).
The site is accessed via State Road 566.

According to the "Red Water Pond Road and Pipeline Canyon Road Residents' Resolution"
(Red Water Pond Road and Pipeline Canyon Residents 2006), more than 50 Navajo families live
in the Red Water Pond Road area of the Coyote Canyon Chapter and the Pipeline Canyon Road
area of the Standing Rock Chapter. Nearest residences are approximately 700 feet south of CR-1,
800 feet northeast of CR-1E, and 3,000 feet northwest of the Kerr-McGee Ponds. No public or
commercial buildings are within 0.5 mile of the Quivira Mines. Current surrounding land use
includes residential and agricultural grazing (for livestock such as sheep, cattle, and horses).
Navajo families may collect piny on nuts, herbs, and plants from the surrounding area for food,
medicinal, and ceremonial purposes.

The geographic coordinates at the center of CR-1 are 35.665448° north latitude and 108.500970°
west. CR-1 is located along Red Water Pond Road north of State Road 566 (Figure 2). The mine
surface disturbance encompasses about 42 acres with 147 acres of underground workings
extending toward CR-1E (Weston 2010).

The geographic coordinates at the center of CR-1E are 35.66597° north latitude, and
108.489614° west longitude (Figure 3). CR-1E is located east of and along Indian Route 7049

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(Pipeline Canyon Road) approximately 0.5 mile east of CR-1. The mine surface disturbance
encompasses about 10.5 acres with 97 acres of underground workings extending toward CR-1.

In early 2017, USEPA became aware that Kerr-McGee had operated sediment drying ponds and
a proto ore storage area on UNC land previously leased from the State of New Mexico. This
area, referred to as the Kerr-McGee Ponds, is approximately 2,000 feet south of CR-1E with
geographic coordinates of 35.658767° north latitude, and 108.491410° west longitude (Figure 4).
In addition, an office building and training facility had been located nearby to the south.
Preliminary assessment work during summer 2017 indicated the presence of elevated gamma
activity in surface soils at the Kerr-McGee Ponds (Weston 2019a).

Two additional sites are located near the Quivira Mines and are being addressed under separate
actions by UNC (Figure 1):

•	Northeast Church Rock (NECR) Mine approximately 0.5 mile southwest of CR-1

•	UNC Mill Facility approximately 1 mile south of CR-1

USEPA also assessed five vent holes (VH-1 through VH-5) associated with the Quivira Mines
(Weston 2016, 2019b) (Figure 1):

•	VH-1 is located approximately 0.5 mile west-southwest of CR-1 with geographic
coordinates of 35.662375° north latitude and 108.513108° west longitude for the center
of the vent hole. A single-family residence is located approximately 620 feet northeast of
the VH-1 vent hole.

•	VH-2 is located approximately 5,000 feet west-southwest of CR-1 with geographic
coordinates of 35.661423° north latitude and 108.520014° west longitude. A
single-family residence is located approximately 750 feet from the VH-2 vent hole.

•	VH-3 is located approximately 3,500 feet east of CR-1E with geographic coordinates of
35.664606° north latitude and 108.477477° west longitude. VH-3 is within an 8-acre,
fenced-in area 0.35 mile west of an active sheep farm and residence comprising

two houses and several smaller structures. Additionally, a residence is located 0.25 mile
north of the VH3 fenced-in area.

•	VH-4 is located approximately 1,500 feet east of CR-1 on a topographic ridge with
geographic coordinates of 35.66559° north latitude and 108.4948° west longitude. The
nearest residence is approximately 2,300 feet northeast of VH-4.

•	VH-5 is located approximately 2,000 feet east of CR-1E with geographic coordinates of
35.6651° north latitude and 108.4822° west longitude. VH-5 is 0.3 mile west of the
nearest residence.

2.1.2 Type of Mine and Operational Status

The surface estate of the Quivira Mines is owned by the United States in trust for the Navajo
Nation and is part of the Navajo Nation Reservation (SENES Consultants Limited [SENES]
2010). An estimated 5,760 acres of land was leased for mining from the Bureau of Indian

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Affairs (BIA) as owner of the mineral estate under the Navajo Tribal Uranium Leases 14-0-
0603-9987 (CR-1) and 14-20-0603-9988 (CR-1E). Kerr-McGee conducted exploration of the
CR-1 and CR-1E leases in the late 1960s (SENES 2010). Kerr-McGee and then its subsidiary,
Kerr-McGee Nuclear, which later changed its name to the Quivira Mining Corporation, began
development of the mines in 1974 and produced ore from 1974 until 1986 at CR-1 and from
1976 until 1985 at CR-1E. Kerr-McGee also operated sediment dewatering ponds and a proto ore
storage area on land leased from the State of New Mexico approximately 2,000 feet south of
CR-1E. The Quivira Mining Corporation surrendered the leased properties in February 1987,
and the company was sold to the predecessor company of Rio Algom Mining LLC in 1988
(SENES 2011).

The Quivira Mines were large underground uranium mines in the Westwater Canyon Member of
the Morrison Formation 1,500 to 1,850 feet below ground. The CR-1 shaft was 14 feet in
diameter and 1,850 deep while the CR-1E shaft was 12 feet in diameter and 1,650 feet deep. The
mines were wet and required ongoing dewatering during operations. Water pumped from the
mine working was discharged to settling ponds before discharge to Unnamed Arroyo #2 and the
Pipeline Canyon Arroyo. The CR-1 underground workings covered 147 acres while the CR-1E
underground workings covered 97 acres (Weston 2010). The mines were ventilated via five
ventholes at the surface. Uranium ore was hoisted 1,850 and 1,650 feet to the ground surface at
CR-1 and CR-1E via shafts, respectively.

Atomic Energy Commission records indicate production of 3,139,784 pounds of uranium from
ore mined at CR-1 and 1,447,463 pounds of uranium from ore mined at CR-1E (Weston 2010).
Ore contained on average 0.266 percent (2,660 milligrams per kilogram) uranium. An estimated
1.3 million tons of ore from CR-1 and CR-1E was shipped to and processed at the Quivira
Mining Corporation's Ambrosia Lake Mill, approximately 50 miles to the east and north of
Grants, New Mexico.

Aboveground operations at CR-1 covered 42 acres and included a former industrial area, a waste
rock area, and a former pond area (Figure 2). CR-1 is dominated by a single large waste rock pile
with a 30- to 50-foot elevation difference between the top and toe of the slope (Photo 1). A
number of surface structures existed during the operating years, including a shaft collar and head
frame (Photo 2), ventilation raises, and ore stockpile area; office, hoist house, maintenance
shops, and warehousing complex; mobile equipment repair shop; fuel and oil storage facilities;
main electrical transformer and switch gear; explosive storage area; and internal roads and water
drainage to divert water from the waste areas and rock storage areas (SENES 2010). The former
pond area contained seven ponds (Photo 3 and Photo 4).

Aboveground operations at CR-1E covered 10.5 acres and included a waste rock area, a former
pond area (Photo 5), and former industrial areas (Figure 3). Two small soil-covered waste rock
stockpiles, with a 7- to 10-foot elevation difference between the top and toe of the slope, are
located in the north-central portion of CR-1E. A number of surface structures existed during the
operating years, including a shaft collar and head frame (Photo 6), ventilation raises, hoist house
and maintenance shops, and fuel and oil storage facilities (SENES 2010).

Following cessation of operations at CR-1 and CR-1E in 1985 or 1986, the shafts were backfilled
with proto ore and sealed with a steel and concrete plug, vent holes were backfilled with waste

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rock and sealed with a steel and concrete plug, sediment ponds were scraped and filled, and
wastes were consolidated at one location at each lease area. The wastes (mainly waste rock and
low-grade ore with less than 0.10 percent uranium) were capped with 6 to 12 inches of fill
material. Erosion and a general lack of maintenance have degraded the CR-1 cap. At CR-1, the
wastes are in stockpiles as high as 50 feet above the original grade with steep slopes along the
margins. Estimated volume of the CR-1 waste pile, industrial area, and former sedi ment ponds
is 929,200 bank cubic yards. Wastes at CR-1E are below the surrounding land grade (rather
than in an above grade pile), and erosion is not significant. Estimated volume of waste at
CR-1E including the waste rock, former pond, and industrial and step-out areas is 49,300 bank
cubic yards.

The Kerr-McGee Ponds covered an area of 9 acres and included four sediment dewatering ponds
and a proto ore storage area (Photo 7) on UNC land previously leased from the State of New
Mexico (Figure 4). Pond sediment and proto ore were received from CR-1 and CR-1E. The
various work areas were reportedly closed and the proto ore and pond berms removed during
reclamation and place at CR-1, when the State of New Mexico transferred the land at the mill to
UNC. Preliminary assessment work during summer 2017 indicated the presence of elevated
gamma activity in surface soils (Weston 2019a). Approximately 27,000 bank cubic yards of
contaminated soil remains at the Kerr-McGee Ponds area.

Photo 1. CR-1 Waste Rock Pile (Looking West)

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Photo 2. CR-1 Headframe and Industrial Buildings (Looking North)

Photo 3. CR-1 Settling Ponds (Looking Northeast)

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Photo 4. CR-1 Settling Ponds (Looking Southeast)

Photo 5. CR-1E Settling Pond

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Photo 6. CR-1E Headframe and Industrial Buildings (Looking Northeast)

Photo 7. Proto Ore Stockpile at the Kerr-McGee Pond Area (Looking East)

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The five vent holes (VH-1 through VH-5) associated with the Quivira Mines have elevated
gamma activity in surface soils and elevated concentrations of Ra-226 in surface and shallow
subsurface soil (Weston 2016). In 2015 and 2016, USEPA assessed the vent holes and found that
all five vent holes had elevated gamma activity in surface soils and detections of Ra-226 in
surface and shallow subsurface soil above the site-specific 2-picocuries-per-gram (pCi/g) action
level for Ra-226. Based on the relatively uniform grain size, color, volume, and distribution,
most vent hole wastes are likely drilling muds that were used to lubricate the drill string during
vent hole installation operations.

In summer and fall 2017, USEPA conducted removal operations at five vent holes (Weston
2019b). Approximately 10,300 bank cubic yards of soil was excavated from the areas
surrounding the vent holes and placed on top of the CR-1 waste rock pile. Residual contaminants
remain immediately adjacent to the concrete vent shaft caps. Because of the interception of
bedrock, not all contaminated material with Ra-226 concentrations above the action level was
excavated from VH-2, VH-3, and VH-5.

2.1.3 Regulatory History

The Quivira Mines were operated by Kerr-McGee and then its subsidiary, Kerr-McGee Nuclear,
which later changed its name to the Quivira Mining Corporation. Kerr-McGee began
development of the Quivira Mines in 1974 and performed mining operations from approximately
1976 to 1985. Rio Algom Mining LLC purchased the mine lease in 1988. The Quivira Mine
Corporation merged with Rio Algom Mining LLC in October 2001. Rio Algom Mining LLC is
now an indirect subsidiary of the mining conglomerate BHP Billiton.

This Quivira Mines removal action is being completed under CERCLA and the National Oil and
Hazardous Substances Pollution Contingency Plan (NCP). In November 2014, the U.S. District
Court for the Southern District of New York approved a settlement agreement to resolve
fraudulent conveyance claims against Kerr-McGee and related subsidiaries of Anadarko
Petroleum Corporation {In re Tronox Inc., No. 09-10156 (Bankruptcy, Southern District of New
York, Nov. 23, 2010)). Included in the Tronox settlement were $90 million in funds for the
assessment and remediation of the Quivira Mines.

Multiple investigations of the Quivira Mines completed from 2008 through 2022 are summarized
in Section 2.3. Reclamation activities at the Quivira Mines were completed between 1980 to
1986; and multiple removal actions were completed between 2010 and 2017 and are summarized
in Section 2.2.

The nearby NECR Mine operated at approximately the same time as the Quivira Mines, and its
ore was processed at the nearby UNC Mill Facility. USEPA Region 9 signed an action
memorandum (USEPA 2011) selecting placement and capping of the approximately 1 million
bank cubic yards of waste at the UNC Mill Facility.

The nearby UNC Mill Facility is a closed uranium mill with tailings ponds formerly operated
by and currently owned by UNC, a subsidiary of the General Electric Company. The UNC
Mill Facility is a National Priorities List or Superfund site, EPA ID #NMD030443303, with

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two operable units—Ground Water Operable Unit 1 and Surface Soil Operable Unit 2
(USEPA 2015).

2.1.4 Site Features and Landscape

All mine workings at the Quivira Mines were established underground, and no mineralized rock
is present at the surface. All mine features are aboveground and include shafts, adits, waste piles,
mine debris, industrial areas, proto ore stockpile areas, access roads, and former ponds (Figure 2
through Figure 4). Reclamation of the shafts, adits, industrial areas, waste rock piles, and settling
ponds occurred in 1986 and 1987 as specified in the abandonment and reclamation plan
submitted by the Quivira Mining Company (1987).

CR-1 is located along Red Water Pond Road on the north side of an unnamed arroyo at the base
of a mesa. CR-1 was reclaimed following the closeout of operations in 1986, and the mine lease
area includes a former industrial area, waste rock area, former settling pond area, and reclaimed
14-foot-diameter shaft and adit (Figure 2). The former industrial area at CR-1 is defined as the
area where industrial buildings and ancillary structures were formerly located. During operating
years, surface structures included a shaft collar and head frame, ventilation raises, and ore
stockpile area; an office building, a hoist house, maintenance shops, and a warehousing complex;
mobile equipment repair shop; fuel and oil storage facilities; main electrical transformer and
switch gear; explosive storage area; and internal roads and drainage channels to divert water
from the waste and rock storage areas. The buildings were razed at the closeout of operations in
1986, and the area has been graded (SENES 2010). A waste rock pile is located on the western
and southern portion of CR-1 adjacent to Unnamed Arroyo #2 to the south and Red Water Pond
Road on the west (Figure 2). The waste rock pile has a 30- to 45-foot face, which is mostly
sloped 3H: IV. Most waste rock material within the stockpile is a fine to medium sand with little
to no coarse sand or gravel.

CR-1E is located on a terrace immediately northwest of Pipeline Canyon Road and Pipeline
Canyon Arroyo adjacent to a mesa. CR-1E includes a former industrial area, a waste rock pile
area, two adits, a 12-foot-diameter shaft, a former settling pond area, and surrounding areas with
contaminated soil (Figure 3). The former industrial area at CR-1E is defined as the area where
industrial buildings and ancillary structures were formerly located. The former structures at
CR-1E were similar to those at CR-1 but smaller in scale. The buildings were razed at the
closeout of operations, and most of the area appears to have been covered with soil and rock
(SENES 2010). Two small soil-covered waste rock stockpiles slightly above grade in height are
in the north-central portion of the lease area. Most of the waste rock material within the stockpile
is a fine to medium sand with little to no coarse sand or gravel. The small former pond area has
been defined according to depictions on historical aerial photographs of a settling pond
constructed for and used in mining operations.

The Kerr-McGee Ponds are within a flat fenced area on an alluvial terrace in Pipeline Canyon
0.5 mile south of CR-1E and southeast of Pipeline Canyon Road and Pipeline Canyon Arroyo
(Figure 4). This area contains former ponds used to dewater pond sediment from former mining
operations at CR-1 and CR-1E. The former Quivira Mines uranium mining operations used
three, and later four, overflow ponds at the Kerr-McGee Ponds. Dried sediment was then stored
in a proto ore stockpile immediately east of the dewatering ponds.

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2.1.5 Geology, Hydrogeology, and Hydrology

The following subsections describe the geology, hydrogeology, and hydrology of the
Quivira Mines.

2.1.5.1 Geology

Surface geology (Figure 5) differs in each area of the Quivira Mines:

•	CR-1 surface geology consists of the Dalton and Bartlett Barren Members of the
Crevasse Canyon Formation on the northern hillslopes and Quaternary alluvium on the
southern slopes.

•	CR-1E surface geology consists of the Dalton Sandstone Member of the Crevasse
Canyon Formation on the northern hillslopes and the Mulatto Tongue of Mancos Shale
and Quaternary alluvium on the mine terrace.

•	The Kerr-McGee Ponds is on fluvially deposited Quaternary alluvium that overlies the
Mulatto Tongue of Mancos Shale, which is expressed on south-adjacent hillslopes.

No mineralization occurs in the surface geologies; however, areas of elevated activity are present
north of CR-1. Soil types throughout the Quivira Mines are shown on Figure 6.

CR-1 and CR-1E lie in the Church Rock Mining District of the Grants Uranium Belt within the
San Juan Geologic Basin. The primary ore-bearing unit in the Grants Uranium Belt and Church
Rock Mining District is the Morrison Formation (Brister and Hoffman 2002). Three members of
the Morrison Formation are listed below in stratigraphic order (oldest to youngest):

•	Recapture Member consists of grayish-red siltstone and claystone.

•	Westwater Canyon Member consists principally of medium- to coarse-grained arkosic
sandstones interbedded with mudstone units of variable thicknesses.

•	Brushy Basin Member consists of mudstone formed from volcanic ash falls.

At CR-1 and CR-1E, the uranium ore was mined primarily from the Westwater Canyon Member
approximately 1,800 feet below grade. Uranium mineralization within the Westwater Canyon
Member occurs as both tabular and roll-type deposits.

After deposition of the Morrison Formation during the late Jurassic period, no sediments were
preserved in the San Juan Basin until the late Cretaceous period, including the Dakota Sandstone,
Mancos Shale, and Gallup Sandstone. The Mancos Shale is a regional groundwater-confining
unit. The Gallup Formation occurs as the Lower Gallup Sandstone and the Upper Gallup
Sandstone and contains the first (uppermost) local bedrock groundwater. The Upper Cretaceous
Crevasse Canyon Formation is within the Mesa Verde Group and overlies and interfingers with
the Gallup Sandstone. The Upper Cretaceous Crevasse Canyon Formation (including Dalton
Sandstone and Bartlett Barren Members) comprises silty shale, laminated siltstone, sandstone
with a clay matrix, coal, shaly siltstone, and silty sandstone. All geologic units below the Quivira
Mines dip to the northeast. Alluvium overlies the sedimentary bedrock. A stratigraphic profile of
these units is shown on Figure 7.

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2.1.5.2	Hydrogeology

The main water-bearing strata below the Quivira Mines, from shallowest to deepest, are the
alluvial deposits, Upper Gallup Sandstone, Lower Gallup Sandstone, Dakota Sandstone, and
Westwater Canyon Member (Figure 7). Because of the northeast dip of the rock units, each of
these strata outcrops along the Pipeline Canyon Arroyo to the far southwest of the area. Aquifer
recharge occurs along the arroyos primarily as rainfall infiltrates the shallow subsurface into the
alluvial groundwater that moves southwesterly, following the same slope as the ground surface
contours. Alluvial groundwater is transmitted to the underlying water-bearing strata at contacts
between the strata and alluvium. Groundwater in the water-bearing strata generally flows
northeast, following the regional dip of the bedrock strata. With the cessation of mining and deep
aquifer dewatering, the local arroyos are no longer a major recharge source to the aquifers. A
potentiometric surface map of the Upper Gallup Sandstone in the area shows a northeast flow
direction following the regional dip (USEPA 2010a).

The main uranium-bearing rock unit (Morrison Formation) includes the water-bearing Westwater
Canyon Member. Depth to groundwater in the Westwater Canyon Member is 1,500 to 1,850 feet
bgs. No shaft construction records are available pertaining to the Quivira Mines other than shaft
diameters and total depths; however, such records are available regarding the nearby NECR
Mine. According to the drilling log for one nearby NECR Mine shaft constructed in 1968 and
1969, the first encounter with groundwater occurred at approximately 400 feet bgs in the lower
portion of the Upper Gallup Sandstone (Montgomery Watson Harza [MWH] 2003). Inflow of
water from this formation amounted to 30 to 50 gallons per minute (gpm). The mine shaft
drilling logs indicate no encounter with groundwater again until the Dakota Sandstone at the base
of the Mancos Shale. Groundwater inflows from the Dakota Sandstone were 800 gpm, and
inflows from the Westwater Canyon Member were 1,500 to 2,000 gpm (MWH 2003). The
Westwater Canyon Member was dewatered during mining operations, but water levels have been
recovering since the cessation of mining. A regional cone of depression from mine dewatering
will likely result in multiple decades of groundwater recovery. The local communities rely on
municipal water provided by the Navajo Tribal Utility Authority (NTUA) with only limited local
groundwater use for livestock watering.

2.1.5.3	Hydrology

Most precipitation at the Quivira 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. The alluvium in the canyons and on valley floors
consists of fine-grained sand with interbedded silty clay layers. The alluvium directly overlies
sedimentary bedrock and aids in the transfer of surface water through the shallow groundwater
zone in the alluvium to the deeper sedimentary bedrock aquifers (Figure 7).

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A series of arroyos exist throughout the Quivira Mines and surrounding area. CR-1 is physically
separated from the NECR Mine and the residences on Red Water Pond Road to the south by
Unnamed Arroyo #2 that runs along the southern boundary of CR-1 (Figure 2). Unnamed
Arroyo #2 drains approximately 4,700 acres upstream of the confluence with Pipeline Canyon
Arroyo. The width of Unnamed Arroyo #2 typically ranges from 15 to 35 feet with sidewalls
10 to 15 feet high. Abutting the southern side of CR-1, the arroyo drains from west to east and
flattens out to a floodplain near its junction with the Pipeline Canyon Arroyo, south of CR-1.

The Pipeline Canyon Arroyo is immediately southeast of CR-1E (Figure 3) and drains
approximately 6,700 acres upstream of the confluence with Unnamed Arroyo #2. The width of
the Pipeline Canyon Arroyo typically ranges from 15 to 25 feet with sidewalls 10 to 25 feet high.
This arroyo drains from northeast to southwest and flattens out to a floodplain near its junction
with Unnamed Arroyo #2, south of CR-1. A small tributary arroyo also drains an area north of
the Kerr-McGee Ponds.

A large quantity of mine water (2,500 to 5,000 gpm) was extracted from the Westwater Canyon
Member to allow access to ore during mining operations at the NECR Mine and Quivira Mines
and to process ore at the UNC Mill Facility (Engineering/Remediation Resources Group, Inc.
[ERRG] 2011). An estimated 93 billion gallons of water was pumped from the mine workings
and for process water during mine and milling operations (ERRG 2011). Extracted groundwater
was discharged via a series of ponds to surface water in Unnamed Arroyo #2 and the Pipeline
Canyon Arroyo. Similar dewatering activities at the NECR Mine contributed a large flow to
Unnamed Arroyo #2 during mining operations. The surface water, in turn, recharged the
groundwater in alluvium and the Upper and Lower Gallup Formations along the Pipeline Canyon
Arroyo near the UNC Mill Facility to the southwest of the Quivira Mines.

2.1.6 Land Use and Populations

More than 50 Navajo families live in the Red Water Pond Road area of the Coyote Canyon
Chapter and the Pipeline Canyon Road area of the Standing Rock Chapter (Red Water Pond
Road Community Association and Southwest Research and Information Center 2012). Figure 8
shows approximate locations of the Red Water Pond Road community area and the Pipeline
Canyon Road community area. The nearest residences are approximately 700 feet south of CR-1
and 800 feet north of CR-1E. No public or commercial buildings are within 0.5 mile of the
Quivira Mines.

The nearest urban populations are concentrated in Gallup and Church Rock. Gallup is
approximately 20 miles from the Quivira Mines and had an estimated population of 21,899 in
2020 (U.S. Census Bureau 2021). Church Rock is approximately 12 miles from the Quivira
Mines and had an estimated population of 1,100 in 2019 (U.S. Census Bureau 2019). Exhibit 2
shows the Navajo population and the non-Navajo population for Coyote Canyon, Pinedale, and
Standing Rock chapters and other nearby chapters as determined by the 2019 U.S. census
(Navajo Nation Division of Community Development 2019).

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Exhibit 2. Chapter Populations in 2019

Chapter

Navajo Population

Non-Navajo Population

Total

Church Rock

2,596

87

2,683

Coyote Canyon

726

43

769

Pinedale

1,217

14

1,231

Standing Rock

522

1

523

Note:

Chapter populations are from the 2019 U.S. census (Navajo Nation 2019).

The Quivira Mines is a former industrial site that is currently used by wildlife and livestock
where perimeter fencing is compromised. Current surrounding land uses include agricultural
grazing (for livestock such as sheep, cattle, and horses), residential, and industrial (UNC
property). Navajo families may collect piny on nuts, herbs, and plants from the surrounding area
for food, medicinal, and ceremonial purposes (USEPA 2009a). The following potential future
land uses were identified at the Quivira Mines (Figure 8); these land uses are further described in
Section 2.5.3 by pairing users of the land, otherwise known as receptors, with land areas
as follows:

•	Kee'da'whii teeh (full-time Navajo resident) - Areas that are easily accessible and
relatively flat.

•	Kqq ei doo nahaazah dah (difficult access open space user) - Areas that are difficult to
access because of deeply incised arroyos.

•	UNC outdoor worker - Areas of the former Kerr-McGee Ponds and arroyos on
privately-owned land with industrial land use.

Additionally, a water line easement runs through the CR-1 pond area and crosses Unnamed
Arroyo #2. The water line is scheduled to be rerouted. Marathon Petroleum has a 35-foot-wide
easement for petroleum pipelines located along the southeast margin of CR-1E and adjacent to
the Pipeline Canyon Road. The pipeline easement cannot be disturbed during removal activities
without detailed consultation with Marathon Petroleum and other utilities using the easement.

2.1.7 Sensitive Ecosystems

SENES (2011) completed a vegetation survey in 2011 as part of the RSE report for the Quivira
Mines. The survey identified good plant diversity with a mixture of native shrubs, grasses, and
forbs although cover values varied based on grazing pressure. Tetra Tech (2022a, 2023a)
performed rare plant surveys in 2022 and 2023 to assess the potential for investigation activities
to affect Endangered Species Act (ESA)-listed species, critical habitats, and Navajo Nation
Department of Fish and Wildlife (NNDFW)-listed sensitive species.

The habitat in the Quivira Mines area consists of upland communities of intermountain basins
semi-desert grassland, intermountain basins greasewood flat, intermountain basins semi-desert
shrub steppe, and Colorado Plateau pinyon-juniper woodlands and is bordered by Colorado
plateau mixed bedrock canyon and tableland. The 2022 field survey identified the dominant
species throughout the project footprint as sagebrush (Artemisia tridentata ssp. tridentata),

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globemallow (Sphaeralcea ambigua), rabbitbrush (Ericameria nauseosa), filaree storksbill
(Erodium cicutarium), cheatgrass (Bromus tectorum), Indian ricegrass (Achnatherum
hymenoides), needle and thread grass (Hesperostipa comata), greasewood (Sarcobatus
vermiculatus), two-needle pinyon (Pinus edulis), and Utah juniper (,Juniperus osteosperma). No
plant species of management interest or rare plant species were observed during the 2022 survey.

Dominant plant species identified during the 2023 field survey included all plant species
identified during the 2022 field surveys, as well as Palmer's penstemon (Penstemon pal men),
Douglas' milk-vetch (,Astragalus douglassii), yellow sweet clover (Melilotus officinalis), desert
prince's plume (Stanleyapinnata), ground plum {Astragalus crassicarpus), fragrant evening
primrose (iOenothera cespitosa), spiny star (Escobaria vivipara), whole leaf paintbrush
{Castilleja Integra), and hoary tansy aster (Dieteria canescens). Other plants species observed to
a lesser extent included Gambel oak (Quercus gambelii), Russian olive (Elaeagnus angustifolia),
alfalfa (Medicago saliva), Stansbury's cliffrose (Purshia stansburyana), alder leaf mountain
mahogany (Cercocarpus montanus), rose heath (Chaetopappa ericoides), woolly locoweed
(Astragalus mollisssimus), fineleaf woolly-white (Hymenopappus filifolius), and toad flax
penstemon (Penstemon linarioides). Significant habitat for Naturita milk-vetch (Astragalus
naturitensis) was found within the action area during the 2023 survey; Naturita milk-vetch is a
Navajo Endangered Species List (NESL) sensitive species. Follow-up surveys are proposed in
2024 before construction activities to refine exclusion zones and mitigation measures.

Tetra Tech (2022a) performed a nesting bird survey in 2022 for the Quivira Mines area to assess
the potential for investigation and construction activities to affect ESA-listed species, critical
habitats, migratory birds protected by the Migratory Bird Treaty Act, and NNDFW-listed
sensitive species. All suitable nesting areas were surveyed during the field survey, and no active
raptor species nests were identified. However, one common raven (Corvus corax) nest was
located between CR-1 and CR-1E. Avian and wildlife species observed at the Quivira Mines
were the common raven, house finch (Haemorphous mexicanus), rock wren (,Salpinctes
obsoletus), Gunnison prairie dog (Cynomys gunnisoni), western fence lizard {Sceloporus
occidentalis), and bullsnake (Pituophis catenifer sayi).

Tetra Tech (2023a) performed another nesting bird survey in 2023 for the Quivira Mines and
Kerr-McGee Ponds. Burrowing owls (Athene cunicularia) and a great horned owl (Bubo
virginianus) nest were identified within the survey area. All suitable nesting areas were
surveyed, and no other nests or sensitive habitats were documented for sensitive species
potentially affected by construction activities. Other avian and wildlife species observed included
all species identified in 2022, as well as a red-tailed hawk (Buteo jamaicensis). Follow-up
surveys for burrowing owls are proposed in 2024 before construction activities to refine
exclusion zones and mitigation measures.

A biological assessment was conducted for the Quivira Mines that reviewed the most recent
species lists for the area provided by the U.S. Fish and Wildlife Service and NNDFW (Tetra
Tech 2022b). All potential species in the area that are federally threatened, endangered,
candidates for listing, or are included on NESL were evaluated for potential to occur at the site.
The biological assessment concluded that no federally listed species have the potential to occur
in the Quivira Mines area and that no critical habitats for any ESA-listed species are within the
area. The biological assessment concluded that investigation and construction activities will

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have no effect on the ESA-listed Mexican spotted owl (Slrix occidentalis liicida), southwestern
willow flycatcher (Empidonax traillii extimus), yellow-billed cuckoo (Coccyzus americanus ssp.
occidentalis), Zuni bluehead sucker (Catostomus discobolus yarrowi), Colorado pikeminnow
(Ptychocheilus lucius), razorback sucker (Xyrauchen texanus), or Zuni fleabane (Erigeron
rhizomatus) and will have no effect on these species' designated critical habitats. A separate
assessment may be required for construction activities that will occur over a longer time frame
during any removal action.

The biological assessment identified three NESL species with the potential to occur in the
Quivira Mines area: golden eagle (Aquila chrysaetos), mountain plover (iCharadrius montanus),
and Naturita milk-vetch; however, these species do not require an effects determination (Tetra
Tech 2022b). The biological assessment identified conservation measures for NESL species to
protect the continued existence of the above-listed species in the Quivira Mines area during the
proposed action.

2.1.8 Meteorology and Climate

Climate at the Quivira Mines is semiarid with a high annual net pan evaporation rate of 54 inches
per year, far exceeding the annual precipitation of 11.08 inches. Daily temperature and
precipitation data from Western Regional Climate Center Station 293422 in Gallup, New
Mexico, (about 20 miles southwest of the Quivira Mines) was examined for years 1976 to 2016
(Western Regional Climate Center 2018). Data from 2016 to the present from this station and
other stations near the Quivira Mines were not available. The station data indicate the following
weather trends:

•	Annual average maximum temperature is 66.0 degrees Fahrenheit (°F), and annual
average minimum temperature is 31.6 °F.

•	Average maximum monthly temperatures peak in July at 87.7 °F, and average minimum
monthly temperatures are lowest in December at 13.4 °F.

•	Average annual precipitation is 11.08 inches.

•	The most precipitation typically occurs in July and August, averaging 1.72 and
1.92 inches, respectively.

•	The least amount of precipitation typically occurs in June, averaging 0.42 inch.

•	The area receives approximately 30.6 inches of snow from October to May, primarily
from November through April.

Figure 9 shows the City of Gallup monthly average temperature, precipitation, pan evaporation,
and snowfall. Wind typically originates from the southwest (Figure 10).

Exhibit 3 provides precipitation frequency estimates over several average recurrence intervals for
the City of Gallup from the National Oceanic and Atmospheric Administration (2006). For
example, a 10-minute storm in this area that deposits 0.994 inch of rain is likely to occur once
every 100 years. These estimates provide a better description of precipitation event intensities
and how durations could affect the Quivira Mines and associated arroyos.

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Exhibit 3. Precipitation Frequency Estimates

Duration

Average Recurrence Interval

1 Year

5 Years

100 Years

1,000 Years

5 Minutes

0.195

0.338

0.654

0.955

10 Minutes

0.296

0.515

0.994

1.45

30 Minutes

0.494

0.859

1.66

2.43

2 Hours

0.725

1.23

2.44

3.66

Note:

Precipitation frequency estimates in inches based on frequency analysis of partial duration series. Estimates have an
upper bound confidence interval at 90 percent. Estimates are from the National Oceanic and Atmospheric
Administration (2006).

2.2 PREVIOUS RECLAMATION AND REMOVAL ACTIONS

Previous mine reclamation and removal activities at the Quivira Mines are summarized
chronologically below and shown on Figure 11 while reclaimed features are detailed in Table 1:

•	1980 to 1982: Reclamation of the former Kerr-McGee Ponds on UNC property included
removal of the pond berms and former proto ore stockpile and grading to match the
surrounding land (Weston 2019a). The reclaimed material was placed in Pond 1 at CR-1.
The estimated remaining volume of contaminated soils at the Kerr-McGee Ponds is
34,000 bank cubic yards.

•	1985 or 1986: Reclamation of CR-1 and CR-1E included specified removals of mine
dewatering pumps; mine equipment including hoists, compressors, headframes, and
generators; buildings; and foundations. The sediment ponds were scraped and filled, and
wastes were consolidated at one location at each mine. The wastes (mainly waste rock
and low-grade ore with less than 0.10 percent uranium) were capped with 6 to 12 inches
of fill material. Estimated volume of the CR-1 waste pile and former sediment ponds is
929,200 bank cubic yards. Wastes at CR-1E are in a low waste pile blended into the
surrounding topography (rather than in an above-grade pile), and erosion is not
significant. Estimated volume of waste at CR-1E including the waste rock, former pond,
and industrial and step-out areas is 49,300 bank cubic yards. No record of execution of
this work is available from the mine owners, but current visual conditions indicate that
this work was completed as specified in the reclamation work plan (Quivira Mining
Company 1987).

•	2010: Time-critical removal action (TCRA) to repair fences, grade and seed the western
slopes of the CR-1 waste pile, install sediment control structures to CR-1, and repair mine
access roads and the Red Water Pond Road (USEPA 2010c). USEPA repaired the bridge
near the CR-1 waste pile.

•	2010: TCRA removal of approximately 110,000 bank cubic yards of soil from Step-Out
Area #1 associated with the NECR Mine (Figure 11). Excavated soil was placed in a soil
consolidation area within the NECR Mine (MWH 2010).

•	2012: TCRA to excavate 17,374 bank cubic yards of contaminated soil, place excavated
materials onto the waste rock stockpile at CR-1, reconstruct the road and shoulder area

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between State Road 566 and Unnamed Arroyo #2, and revegetate disturbed areas)
(Conestoga Rovers and Associates Ltd. [CRA] and SENES 2013).

•	2012: TCRA removal of approximately 32,000 bank cubic yards of impacted soils from
the East Drainage Area associated with the NECR Mine (Figure 11). Excavated soil was
placed in a soil consolidation area within the NECR Mine (MWH 2013).

•	2017: Vent shaft removal activities at five ventilation shafts included excavating a
combined estimated 10,293 bank cubic yards of impacted soil from VH-1, VH-2, VH-3,
VH-4, VH-5, and bridge abutments. All excavated material was consolidated into the
CR-1 waste pile. Residual contaminants remain immediately adjacent to the concrete vent
shaft caps to avoid disturbance of the closures. Any remaining residual waste at these
locations is 3 to 10 feet bgs and was capped with a minimum of 3 feet of clean fill
material (Weston 2019b).

•	2023 and 2024: Erosion control efforts to limit further offsite migration of waste and
improve nearby erosion and sedimentation conditions.

2.3 PREVIOUS SITE INVESTIGATIONS

The nature and extent of the contamination at CR-1, CR-1E, and the Kerr-McGee Ponds were
delineated via gamma scans and soil sampling and analysis. Based on results of the scans and
sample analysis, most of the waste is within the fenced areas at CR-1, CR-1E, and the
Kerr-McGee Ponds.

Previous environmental investigations for the Quivira Mines include:

•	Initial gamma screening investigations in 2008 and 2009 to conduct a surface screen for
gamma radiation at CR-1, CR-1E, arroyos up and downstream of the site, Red Water
Pond Road, and the cornfield of a local resident (Weston 2010).

•	RSE field investigations in 2010 and 2011 including collection and analysis of surface
and subsurface soil and static and scan gamma surveys at CR-1, CR-1E, Unnamed
Arroyo #2, the Pipeline Canyon Arroyo, Red Water Pond Road, and Pipeline Canyon
Road (SENES 2011).

•	Supplemental soil sampling and static and scan surveys in 2011 by USEPA at two former
cornfields, a former irrigation storage pond that stored water pumped from the mine,

and portions of Unnamed Arroyo #2 upstream from CR-1 (Ecology and Environment,
Inc. 2012).

•	Vent hole assessment work between 2011 and 2017 to assess the gamma activity
in the surface soil of the five vent holes associated with the Quivira Mines (Weston
2016, 2019b).

•	Data gap collection of additional soil borings in 2015 to better delineate the lateral and
vertical extents of contamination associated with CR-1 and CR-1E (data collected by
Weston and not published). The data were used, together with data collected previously
by SENES (2011), to estimate the total volume of waste rock at the two mines in this
EE/CA.

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•	A Kerr-McGee Ponds assessment in 2017 including collection and analysis of surface
and subsurface soil samples (Weston 2019a).

•	Data gap investigation in summer 2022 including identification and sampling of three
background study areas (BSA) for different geologies at the site, refining the lateral and
vertical extent of contamination at the site, construction of wells in alluvium at CR-1,
geotechnical test pits in waste piles and borrow soil, installation of soil moisture probes,
and installation of a weather station (Tetra Tech 2023b).

Because of the significant depth to groundwater, arid climate, and interbedded, confining
geology in the region, rainfall and surface water infiltration do not directly impact confined
groundwater in the Westwater Canyon Member. Moreover, no drinking water wells are currently
completed in the Westwater Canyon Member near the Quivira Mines. Groundwater impacts to
shallow groundwater from the adjacent NECR Mine and UNC Mill Facility were evaluated by
USEPA in 2023 (USEPA 2023). No direct pathway is available from the surface waste rock at
the Quivira Mines to the Westwater Canyon Member. Potential impact of the Quivira Mines on
shallow alluvium groundwater was evaluated during a 2022 data gaps investigation. Two wells
were installed in alluvium and screened at the alluvium-bedrock interface at CR-1. An
insufficient volume of water was present in the wells to sample. Water in the wells has been
checked each quarter, but no water has been present. Therefore, the scope of this EE/CA focuses
only on the nature and extent of contamination at the site in surface and near-surface soil.

2.4 SOURCE, NATURE, AND EXTENT OF CONTAMINATION

The source, nature, and extent of waste materials at the Quivira Mines were characterized during
the RSE investigation and follow-on investigations. The following subsections present the
calculation of BTVs, results of the investigations, sources and nature of contamination, and
extent of contamination.

2.4.1 Background Threshold Values

CR-1 is within 1 mile of the NECR Mine and was initially thought to be in the same geological
setting. Thus, background levels developed for the NECR Mine (MWH 2006) were originally
also applied to the Quivira Mines. However, after analysis, the data did not appear to fit the
varied Quivira Mines site geologies. Therefore, background studies were conducted at the
Quivira Mines in summer 2022 (Tetra Tech 2023b).

BSAs were sampled in three different geologies: Quaternary alluvium, Mulatto Tongue of
Manco Shale, and Bartlett Barren Member of the Crevasse Canyon Formation (Figure 5). The
Dalton Sandstone Member is a vertical cliff forming unit at the site and was not sampled because
it has limited exposure. BSAs were selected to be up- or cross-wind to releases at the Quivira
and NECR Mines and the UNC Mill Facility. Exposed geologic units at each lease area are
described below.

•	CR-1 Exposed Units. The Bartlett Barren Member is located at CR-1 upslope of the
CR-1 waste pile and lower pond area. A cliff forming unit, the Dalton Sandstone
Member, is located between the Bartlett Barren Member and Mulatto Tongue of Mancos
Shale at CR-1. The Mulatto Tongue of the Mancos Shale is present at the base of the cliff

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at CR-1. Similar to the area south of the Kerr-McGee Ponds, a unit of the Mulatto
Tongue of the Mancos Shale may also be present locally above the Dalton Sandstone
Member as evidenced by gamma activity in bedrock above. Quaternary alluvium is
present at the toe of the CR-1 waste pile and lower pond area drainage and is derived
from upslope geologic units.

•	CR-1E Exposed Units. A cliff forming unit, the Dalton Sandstone Member, is located
upslope of CR-1E. The Mulatto Tongue of the Mancos Shale underlies most of CR-1E.
Quaternary alluvium is present at and downslope of CR-1E and is derived from
upslope geologic units. The Quaternary alluvium overlies the Mulatto Tongue of the
Mancos Shale bedrock locally.

•	Kerr-McGee Ponds Exposed Units. The Mulatto Tongue of the Mancos Shale is
present on the hillslopes surrounding the Kerr-McGee Ponds area. A cliff-forming unit,
the Dalton Sandstone Member, is located between units of the Mulatto Tongue of the
Mancos Shale. Quaternary alluvium is present at the Kerr-McGee Ponds area and is
derived from upslope geologic units.

BTVs for each BSA were calculated (Exhibit 4) based on the 95 percent upper tolerance limit
with 95 percent coverage (UTL95-95) (Tetra Tech 2023b). The limit represents a 95 percent
probability (or confidence) that 95 percent of samples from background are below that value.

To identify the appropriate BTV for each lease area, the range of Ra-226 and metals
concentrations in non-mining impacted alluvium at and around each lease area were compared
to BTVs from each BSA. Ra-226 is discussed below as it is the primary risk driver at AUM
lease areas.

•	The BTV for Ra-226 in Quaternary alluvium (BSA-1), derived from the Bartlett Barren
Member, Gibson Coal Member, and Point Lookout Member, is lower than the 1.5 to

2 pCi/g range of Ra-226 concentrations in non-mining impacted alluvium at and around
CR-1, CR-1E, and the Kerr-McGee Ponds. This suggests that concentrations of Ra-226 in
alluvium are influenced by upslope parent material such as the Mulatto Tongue of the
Mancos Shale (BSA-5) at CR-1E and the Kerr-McGee Ponds and the Bartlett Barren
Member (BSA-2) and Mulatto Tongue of the Mancos Shale (BSA-5) upslope of CR-1.

•	The BTV for Ra-226 in alluvium derived from the Mulatto Tongue of the Mancos Shale
(BSA-5), is about 2 pCi/g higher than Ra-226 concentrations in non-mining impacted
alluvium at and around CR-1, CR-1E, and the Kerr-McGee Ponds. This suggests that
concentrations of Ra-226 in alluvium are not influenced by upslope parent material
such as the Mulatto Tongue of the Mancos Shale (BSA-5) at CR-1E and the
Kerr-McGee Ponds.

•	The BTV for Ra-226 in alluvium derived for the Bartlett Barren Member (BSA-2) was
compared to the non-mining impacted alluvium at and around CR-1, CR-1E, and the
Kerr-McGee Ponds and found to be within the 1.5 to 2 pCi/g range of observed values.
Therefore, UTL95-95 values for the Bartlett Barren Member (BSA-2) were used to
identify BTVs, COCs, and COECs at the Quivira Mines.

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Exhibit 4. Background Threshold Values

Analyte 1

Quaternary Alluvium
(BSA-1)

Bartlett Barren Member
of the Crevasse Canyon
Formation
(BSA-2)

Mulatto Tongue of
Mancos Shale
(BSA-5)

ProLICL

UTL95-95

from
ProLICL

ProLICL

UTL95-95

from
ProLICL

ProLICL

UTL95-95

from
ProLICL



Distribution

Distribution

Distribution

Aluminum

Nonparametric

4,800

Normal

6,004

Normal

6,731

Antimony

Normal

0.202

Normal

0.291

Normal

0.121

Arsenic

Normal

6.556

Nonparametric

8.9

Normal

6.476

Barium

Normal

88.5

Normal

110.9

Normal

170.8

Beryllium

Normal

0.55

Gamma

1.036

Normal

0.559

Cadmium

Normal

0.2

Nonparametric

0.42

Normal

0.11

Chromium

Nonparametric

4.8

Normal

6.263

Normal

7.704

Cobalt

Nonparametric

8.1

Normal

8.602

Normal

5.028

Copper

Normal

11.54

Nonparametric

27

Gamma

10.37

Iron

Nonparametric

12,000

Normal

19,094

Normal

15,805

Lead

Nonparametric

14

Normal

17.09

Nonparametric

11

Manganese

Nonparametric

240

Normal

360.5

Normal

287.4

Molybdenum

Nonparametric

0.43

Normal

0.406

Normal

0.471

Nickel

Nonparametric

11

Normal

10.11

Normal

9.492

Selenium

Normal

1.22

Nonparametric

2.5

Normal

1.475

Silver

Normal

0.06

Nonparametric

0.2

Gamma

0.122

Thallium

Nonparametric

0.5

Nonparametric

0.41

Lognormal

0.28

Uranium

Gamma

0.991

Nonparametric

2.4

Normal

0.907

Vanadium

Nonparametric

11

Normal

17.93

Normal

15.64

Zinc

Nonparametric

110

Nonparametric

100

Normal

42.75

Radium-226

Normal

1.321

Normal

1.954

Normal

3.975

Gamma
Radiation

Nonparametric

12,600

Nonparametric

13,700

Nonparametric

13,100

Notes:

1	Units for metals are milligram per kilogram; units for Radium-226 are picocurie per gram; and units for

gamma are counts per minute.

BSA	Background study area

UTL95-95 95 percent upper tolerance limit with 95 percent coverage
2.4.2 Source and Nature of Contamination

The main source of contamination at the Quivira Mines is waste rock1 derived from the
uranium-bearing Westwater Canyon Member from an estimate depth of 1,800 feet below grade
that was brought to the surface at CR-1 and CR-1E along with uranium ore. Dewatering of the
Westwater Canyon Member was required to conduct mining. Mine water was brought to the

1 Waste rock or overburden consists of rock and target minerals in concentrations too low for economic recovery. It
is removed from the earth along with the ore. Waste rock includes granular, broken rock that ranges from fine sand
to large boulders, depending on the nature of the formation and mining methods employed.

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surface and discharged to settling ponds at CR-1 and CR-1E. Fines settled in the ponds and were
periodically removed for uranium recovery. Settled solids from these ponds along with drilling
fluids were dewatered at the Kerr-McGee Ponds, and proto ore encountered during drilling, as
well as dewatered solids, were also stockpiled for uranium recovery.

The areas of concern at the Quivira Mines for soil contamination are CR-1, CR-1E, and the
Kerr-McGee Ponds, as well as step-out areas around CR-1 and CR-1E indicated by elevated
Ra-226 soil sampling results and scan and static gamma survey results. Potential impacts to
adjacent arroyos are also of concern.

Figure 12 presents the transport pathways at the Quivira Mines and a typical cross-section
through the CR-1 waste pile. The primary contaminant transport pathways are slope failure and
erosion of waste or contaminated soil by surface water, deposition in adjacent arroyos, and
subsequent erosion and redeposition in the arroyos during storm events. Wind erosion of waste
may also move contamination from the surface of the mine waste to adjacent areas; however, the
waste rock piles at CR-1 and CR-1E were covered with soil during reclamation. Therefore, most
wind deposition would have occurred during mining operations. Fluvial and aeolian waste
deposits may be remobilized and transported off site. Radon gas emanation and the leaching and
dissolution of metals and radionuclides from waste rock piles may also occur. The conceptual
site model (CSM) wire diagram presented on Figure 13 shows the sources of contamination,
release mechanisms, and exposure media, as well as potential human health and ecological
receptors and exposure pathways (discussed in Section 2.5).

2.4.2.1 Waste Characteristics

The RSE included collection of two composite samples of waste rock from CR-1 for analysis for
metals leachability via both the toxicity characteristic leaching procedure (TCLP) and the
synthetic precipitation leaching procedure (SPLP). The RSE also included analyses of a
composite sample of waste rock from CR-1E for metals leachability via both TCLP and SPLP.
All TCLP results were below detection limits and below regulatory criteria, indicating that the
waste does not exhibit a RCRA toxicity characteristic for hazardous waste if sent for disposal off
site (SENES 2011). Reporting limits for SPLP data were above USEPA and Navajo surface
water quality criteria and inconclusive.

A 2022 data gap investigation included collection of seven composite samples of waste rock for
evaluation of leachability using TCLP and SPLP methodologies for metals and radionuclides
(Tetra Tech 2023b). All TCLP results were below regulatory criteria, indicating that the waste
does not exhibit a RCRA toxicity characteristic for hazardous waste if sent for disposal off site.
SPLP metals and radionuclide results were compared to USEPA and Navajo surface water
quality criteria. Ra-226, aluminum, barium, lead, selenium, and uranium in leachate from waste
exceeded surface water quality criteria, indicating that leachate generated could impact surface
water quality at the Quivira Mines. Groundwater is not present in waste rock or alluvium at CR-1
or CR-1E but is present at depth below the Kerr-McGee Ponds. A monitoring well network is
present originating at the UNC Mill Facility tailings ponds and extending beyond the
Kerr-McGee Ponds to track contaminant migration in the Upper Gallup Sandstone.

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2A.2.2 Geotechnical Characteristics

Geotechnical borings were advanced and test pits were excavated during summer 2022 at CR-1,
CR-1E, the Kerr-McGee Ponds, and potential soil borrow areas. Geotechnical samples were
analyzed for dry and wet bulk density, porosity, constant and falling head conductivity, particle
size distribution, Atterberg limits, standard Proctor compaction, direct shear, and swell or
collapse. The borrow soil samples were also analyzed for agronomic viability. The purpose of
the geotechnical testing was to understand the physical characteristics of the waste and borrow
soil to support radon and hydraulic modeling, suitability of the borrow soil for use as cover
material, waste and borrow soil compaction requirements, plasticity of the waste and borrow soil,
and loading limits before failure.

The mine waste has bulk densities ranging from 1.88 to 1.99 grams per cubic centimeter (g/cm3)
and porosities ranging from 31.4 to 37.5 percent. Saturated hydraulic conductivities ranged from
1.1 x 10"4 to 8 x 10"6, which are indicative of fine sand to loams. Particle size distributions ranged
from silty sands to a sandy lean clay. Clay slickens were observed in the CR-1 waste rock pile.
Atterberg testing identified a liquid limit of 33, plastic limit of 16, and plasticity index of 17 for
the sandy lean clay sample. Proctor compaction testing identified optimum moisture contents
ranging from 11.4 to 15.8 percent with maximum dry bulk densities of 1.74 to 1.91 g/cm3.

Direct shear friction angles ranged from 30 degrees (243 pounds per square foot [psf] cohesion)
to 35 degrees (114 psf cohesion) under loads ranging from 200 to 6,000 psf. In general, the mine
waste is silty and clay sands and exhibits a moderate amount of cohesiveness. Swelling or
collapse is not a concern.

The borrow material has bulk densities ranging from 1.83 to 1.94 g/cm3 and porosities ranging
from 34.4 to 39.6 percent. Saturated hydraulic conductivities ranged from 1 x 10"4 to 7.2 x 10"6,
which are indicative of fine sand to loams. Particle size distributions ranged from silty sands to a
sandy lean clay. Atterberg testing identified a liquid limit of 33, plastic limit of 18, and plasticity
index of 15 for the sandy lean clay sample. Proctor compaction testing identified optimum
moisture contents ranging from 13.4 to 16.6 percent with maximum dry bulk densities of 1.68 to
1.83 g/cm3. Direct shear friction angles ranged from 30 degrees (95 psf cohesion) to 41 degrees
(36 psf cohesion) under loads ranging from 200 to 4,000 psf. In general, the borrow soil is silty
sands and exhibits a low amount of cohesiveness. Swelling or collapse is not a concern.

2.4.3 Extent of Contamination

Data characterizing the extent of contamination collected through the measurement of
radioactivity through gamma scan surveys and total and leachable metals and radionuclides
concentrations during the RSE investigation (SENES 2011) and 2022 data gap investigation
(Tetra Tech 2023b) are used to identify contamination migration pathways and support the risk
assessment and removal decisions. The following subsections describe the results of the RSE
investigation (SENES 2011), Kerr-McGee Ponds removal assessment (Weston 2019a), and 2022
data gap investigation (Tetra Tech 2023b).

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2.4.3.1	Technologically Enhanced Naturally Occurring Radioactive Material and
Naturally Occurring Radioactive Material

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 Quivira Mines include waste rock piles, waste in former settling and
dewatering ponds, contaminated former industrial areas, contaminated onsite access roads, and
areas contaminated by eroding waste.

Areas undisturbed by mining activity are considered NORM and may include upslope land;
bedrock outcrops outside the area of mining activity; alluvium derived from bedrock outcrops
outside the area of mining activity; and inclusions of bedrock outcrops within an area at CR-1
and CR-1E otherwise disturbed by mining activity. At the Quivira Mines, bedrock outcrops
along the cliff bands at CR-1 and CR-1E and upslope of the Kerr-McGee Ponds undisturbed by
mining are considered NORM. Even though the outcrops are not mineralized, they do exhibit
elevated gamma levels and may contribute to elevated Ra-226 and metals concentrations
downslope of these outcrops. In addition, five of the nine former ponds (Ponds 4, 5, 6a, 6b, and
6c) in the lower pond area at CR-1 were reclaimed in 1985 and 1986, which involved excavation
of pond sediments and backfilling with clean borrow material. The source of the borrow material
was not documented but is thought to be the stockpiled material on the northernmost portion of
the CR-1 upslope of the ponds. The borrow material should be considered NORM and does not
require further action. Further, the backfilled borrow material concentrations of radionuclides
and metals are similar to BTVs at BSA-2 (Bartlett Barren Member), which has been identified as
the background for the Quivira Mines.

Figure 14 through Figure 16 present the elevated gamma radiation measurements for the
Quivira Mines. The extent of TENORM at the Quivira Mines as evidenced by observations of
mine waste, mining activity, elevated gamma radiation measurements, and extent of Ra-226 in
soils is shown on Figure 17 through Figure 19. No outcrops of mineralized rock were observed
within the TENORM boundaries; however, outcrops of NORM are present within and upslope of
CR-1 and CR-1E. Contamination from the UNC Mill Facility is present to the south of the
Kerr-McGee Ponds (Figure 16).

2.4.3.2	Gamma Radiation in Surface and Subsurface Soils

Results of gamma surveys at CR-1, CR-1E, and the Kerr-McGee Ponds, as well as in the
Pipeline Canyon Arroyo and Unnamed Arroyo #2, are shown on Figure 14 through Figure 16.
The figures show the extent of elevated gamma radiation at CR-1 and CR-1E, which includes the
waste rock pile, ponds, and industrial areas, and at the Kerr-McGee Ponds, which includes the
former dewatering ponds, proto ore stockpile, and lay down yard. The central area of CR-1,
shown in black Crosshatch, was previously surveyed using static gamma counts rather than a
gamma walkover survey and shows lower gamma activity because of a reclamation cover. An
additional gamma walkover survey across the remainder of CR-1 was conducted in 2022 and
identified erosional migration downslope of the waste pile. Elevated gamma radiation upslope of
the CR-1 waste pile and industrial area is related to NORM outcrops rather than windblown
contamination. Gamma radiation at CR-1E correlates with known waste piles and the industrial
area. Limited impacts were identified in the CR-1 and CR-1E adjacent arroyos, which is

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expected given the high energy environment during monsoon rains. Gamma radiation at the
Kerr-McGee Ponds was correlated with the former dewatering ponds, former proto ore stockpile,
and laydown area; however, elevated gamma radiation was also identified upslope to the east,
downgradient to the west (as expected), and to the far south. The elevated gamma upslope
followed a dirt road to the west, but no evidence of mining activity was present. The elevated
gamma to the far south is associated with another site on UNC lands.

2.4.3.3 Metals and Radionuclides in Surface and Subsurface Soils

Limited metals sampling was conducted in subsurface soils at CR-1 and CR-1E in 2011. A more
robust metals evaluation was conducted at the Kerr-McGee Ponds in 2017. In 2022, additional
metals data were collected from surface and subsurface borings at all three lease areas.

Modeled Ra-226 data were plotted to assess if the data correlated with areas of NORM and
TENORM at each lease area to verify that only TENORM would be cleaned up. During this
evaluation, the Quaternary alluvium BSA selected to establish BTVs based on local geology
were lower than areas not impacted by mining at CR-1, CR-1E, and the Kerr-McGee Ponds,
resulting in overestimation of areas requiring cleanup. Ra-226 concentrations in these
unimpacted areas appear to be the result of eroded material from a combination of upslope parent
geologies. Therefore, several model runs were evaluated for CR-1, CR-1E, and the Kerr-McGee
Ponds using the Bartlett Barren Member BSA to better match the local geology, TENORM
extent, and observed Ra-226 concentrations in areas not impacted by mining. Use of the Bartlett
Barren Member BTV of 2 pCi/g was assessed to be the best fit for site conditions. Individual
gamma survey data points converted to estimated Ra-226 were interpolated within the areas
where gamma data are available to create a continuous surface of estimated Ra-226
concentrations at the site (Appendix B, Figure B-l).

Ra-226 surface and subsurface soil concentrations were compared to a cleanup goal of 2 pCi/g
for the portion of the Quivira Mines on Navajo lands and 5.4 pCi/g (PRG) for the portion of the
Kerr-McGee Ponds on UNC property. Figure 17, Figure 18, and Figure 19 show the model
results for Ra-226 at CR-1, CR-1E, and the Kerr-McGee Ponds, respectively. An area of elevated
Ra-226 concentrations south of the site is associated with contaminant migration from another
UNC site to the south and will be addressed separately by UNC. Correlated Ra-226 results are
shown on the left panel of each figure, and the best fit comparison between model results above
2 pCi/g or 5.4 pCi/g at Kerr-McGee Ponds and measured Ra-226 data are shown on the right
panel. Correlated Ra-226 results were in agreement with the gamma radiation results described
in Section 2.4.3.2.

CR-1 Results. The lateral extent and vertical extent of measured Ra-226 contamination at CR-1
and the adjacent arroyo are shown on Figure 20 and Figure 21, respectively. Measured surface
results are in good agreement with gamma-correlated Ra-226 results. Ra-226 was observed in
migrating mine waste along the toe of the CR-1 waste pile slopes. As expected with a
reclamation cover, Ra-226 in subsurface samples in the CR-1 waste pile are elevated.
Contamination extended to the bottom of the waste (up to 59 feet below grade) and did not
appear to have migrated vertically into underlying native soil. Elevated Ra-226 was also
observed in unreclaimed Ponds 1, la, 2, and 3, extending up to 19 feet below grade. Elevated
Ra-226 was also observed at 6 to 7 feet below grade, which is greater than the reclaimed depths

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at Ponds 5, 6b, and 6c. The mean Ra-226 concentration at CR-1 was 14.6 pCi/g in surface soils
and 12.6 pCi/g in subsurface soils (0 to 72 inches bgs). The maximum Ra-226 concentration was
468 pCi/g in subsurface soils. The distribution of Ra-226 at CR-1 is shown in Appendix B,

Figure B-l. The distribution of candidate metals of concern at CR-1 (arsenic, barium, chromium,
selenium, uranium, and vanadium) with sufficient data available for plotting are shown in
Appendix B, Figure B-2 through Figure B-7. The presence of metals of concern correlated with
the location of mine waste.

CR-1E Results. The lateral extent and vertical extent of measured Ra-226 contamination at
CR-1E and the adjacent arroyo are shown on Figure 22 and Figure 23, respectively. Measured
surface results are in good agreement with gamma-correlated Ra-226 results. Ra-226 was
observed in migrating mine waste around the perimeter of the CR-1E waste piles and on the
ramp road onto the mine near the pond. As expected with a reclamation cover, Ra-226 in
subsurface samples in the CR-1E waste piles are elevated. Contamination extended to the bottom
of the waste (up to 16 feet below grade) and did not appear to have migrated vertically into
underlying native soil. Elevated Ra-226 was also observed up to 5 feet below grade in the
northern industrial area and 12 feet below grade in the pond. The mean Ra-226 concentration at
CR-1E was 6 pCi/g in surface soils and 30.9 pCi/g in subsurface soils (0 to 72 inches bgs). The
maximum Ra-226 concentration was 429 pCi/g in subsurface soils. The distribution of Ra-226 at
CR-1E is shown in Appendix B, Figure B-l. The distribution of candidate metals of concern at
CR-1E (arsenic, barium, chromium, selenium, uranium, and vanadium) with sufficient data
available for plotting are shown in Appendix B, Figure B-2 through Figure B-7. The presence of
metals of concern correlated with the location of mine waste.

Kerr-McGee Ponds Results. The lateral extent and vertical extent of measured Ra-226
contamination at the Kerr-McGee Ponds on Navajo Nation and UNC property are shown on
Figure 24 and Figure 25, respectively. The vertical extent of Ra-226 at the Kerr-McGee Ponds is
shown on Figure 26. Measured surface results are in good agreement with gamma-correlated
Ra-226 results. Contamination extends to a depth of 2 feet on the Navajo Nation side of the fence
line. The mean Ra-226 concentration on Navajo Nation land north of the Kerr-McGee Ponds was
5.3 pCi/g in surface soils and 4.3 pCi/g in subsurface soils (0 to 72 inches bgs). The maximum
Ra-226 concentration was 9.3 pCi/g in subsurface soils. Contamination generally did not extend
below a depth of 1 foot on UNC property except where dewatering ponds were located where
contamination extended up to 6 feet below grade. The mean Ra-226 concentration on UNC
property at the Kerr-McGee Ponds was 9.5 pCi/g in surface soils and 8.2 pCi/g in subsurface
soils (0 to 72 inches bgs). The maximum Ra-226 concentration was 143 pCi/g in subsurface
soils. Ra-226 was observed migrating to the west. Elevated Ra-226 to the far south is associated
with another UNC site. Elevated Ra-226 to the east and upgradient of the area is likely
associated with the migration of NORM from surrounding hillslopes; however, two small soil
piles had elevated Ra-226. The distribution of Ra-226 at Kerr-McGee Ponds is shown in
Appendix B, Figure B-l. The distribution of candidate metals of concern at the Kerr-McGee
Ponds (arsenic, barium, chromium, selenium, uranium, and vanadium) with sufficient data
available for plotting are shown in Appendix B, Figure B-2 through Figure B-7. The presence of
metals of concern generally correlated with the location of mine waste.

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2.4.3.4 Mine Water

Historically, groundwater was pumped out of the Westwater Canyon Member during mining
activities at the NECR Mine and Quivira Mines and discharged to the Unnamed Arroyo adjacent
to the mines. Mine water from the Unnamed Arroyo discharged to the Pipeline Canyon Arroyo.
Two alluvium monitoring wells were constructed to bedrock below the CR-1 waste rock pile and
the CR-1 lower pond area. No wells were installed at CR-1E because of the shallow depth to
bedrock. Insufficient groundwater to collect samples has been observed at the two CR-1
alluvium wells.

However, previous groundwater investigations have occurred in alluvium which follows the
erosional surface of the Upper Gallup Sandstone down valley to the south and then west and
two aquifers which dip to the northeast beneath the NECR Mine and UNC Mill Facility (USEPA
2023). The UNC Mill Facility used conventional acid leach and solvent extraction methods to
extract uranium. The acid-waste tailings mixture was pumped to tailings disposal ponds located
adjacent to the Pipeline Canyon Arroyo.

During operations at the Quivira Mines, NECR Mine, and UNC Mill Facility, the following
releases introduced dissolved uranium, Ra-226, gross alpha, and other contaminants into area
groundwater (USEPA 2023):

•	Mine water discharges to the Unnamed Arroyo from groundwater extracted from the
Westwater Canyon Member during mining activities at the NECR Mine and Quivira
Mines. Mine water in the arroyo infiltrated into the underlying alluvium and, eventually,
into the Upper Gallup Sandstone, which either created a new source of groundwater or
mixed with existing groundwater.

•	Acidic wastewater seepage from UNC Mill Facility tailings disposal ponds into the
underlying alluvium and Upper Gallup Sandstone formations beneath the UNC Mill
Facility and Pipeline Canyon Arroyo.

•	A 1979 UNC Mill Facility tailings dam breach release to the lower Pipeline Canyon area
at the UNC Mill Facility and further downstream into the Puerco River.

Based on these historical releases and the hydrogeology of the area, three water-bearing zones
were identified as possibly impacted: alluvium, the Upper Gallup Sandstone aquifer, and the
Westwater Canyon aquifer (USEPA 2023). The alluvium along the Unnamed Arroyo and further
north along Pipeline Canyon are no longer water bearing and have drained to the south and west
down valley. The alluvium is wetted and geochemistry impacted along Pipeline Canyon Arroyo
near the UNC Mill Facility. The geochemistry of the Upper Gallup Sandstone aquifer is
impacted by UNC mill tailings pond releases and a Ra-226 plume is oriented to the northeast
beneath Pipeline Canyon. These three water-bearing zones are extensively monitored by UNC.
The geochemistry of the Westwater Canyon Aquifer was modified by dewatering, oxygen
introduction, and rewatering after cessation of mining in both mines.

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2.5 RISK ASSESSMENT

Appendix C presents the complete risk assessment. The risk assessment uses laboratory sampling
data from the Quivira 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. Appendix C,

Table C-l, provides a summary of the sample results available for the Quivira Mines, and
Appendix C, Attachment C-l, provides the full dataset used in the risk assessment. Appendix C,
Figure C-2, presents the locations of the soil samples used in the risk assessment. The following
subsections present the purpose of the risk assessment, describe the exposure units (EU), 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 RME scenarios and ecological risk focused on the known ecosystems for the region.
This risk assessment was performed using procedures in USEPA (2001) guidance on risk
assessment and focuses on the completed exposure pathways, primary risk drivers, and source
material as indicated in the "Guidance on Conducting Non-Time-Critical Removal Actions under
CERCLA" (USEPA 1993). The results of the risk assessment are used to assist in removal action
decisions for a site. The HHRA identifies the risk posed to human health by contaminants at the
site and human health candidate COCs at each EU. The ERA identifies the risks posed to
ecological receptors by contaminants at the site and candidate COECs at each EU. The
methodology for the HHRA and ERA is presented in detail in the Navajo Abandoned Uranium
Mines (NAUM) program risk assessment methodology (USEPA 2024a).

2.5.2	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 reside or move at random and where
contact across the EU is equally likely over the course of an exposure duration. The Quivira
Mines EUs were developed by identifying areas of contiguous TENORM contamination and
anticipated future land use. The risk assessment boundary (the entirety of all areas evaluated
within EUs) was established via soil sampling and augmented through examination of gamma
survey data. Areas of NORM, such as natural mineralized outcrops and nonimpacted areas in the
northwestern portion of the site, although not included in the TENORM boundary, were also
included within the risk assessment boundary and as part of the EU because a receptor would
also be exposed to the NORM area when at the site. Appendix C, Table C-2 and Figure C-3
through Figure C-9, present the EUs identified at the site and provide the area and samples
available for each EU; land uses are described in Section 2.1.6. Based on the site evaluation, the
following six EUs were identified at the Quivira Mines. The ERA is conducted on a site-wide
basis; all HHRA EUs were combined to create the site-wide EU.

• CR-1 - The former CR-1 mine is 53 acres and on the Navajo Nation. Several residences
are nearby with the nearest residence approximately 700 feet from the former mine.
Therefore, the Kee'da'whii teeh (full-time Navajo resident) was selected as the RME
receptor for the CR-1 EU.

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•	CR-1E - The former CR-1E mine is 14 acres and on the Navajo Nation. Several
residences are nearby with the nearest residence approximately 800 feet from the former
mine . Therefore, the Kee'da'whii teeh (full-time Navajo resident) was selected as the
RME receptor for the CR-1E EU.

•	Kerr-McGee Ponds on the Navajo Nation - A 2-acre portion of the former
Kerr-McGee Ponds is on the Navajo Nation. Several residences are nearby with the
nearest residence approximately 3,000 feet from the Kerr-McGee Ponds. Therefore, the
Kee'da'whii teeh (full-time Navajo resident) was selected as the RME receptor for the
Kerr-McGee Ponds on the Navajo Nation EU.

•	Kerr-McGee Ponds on UNC Property - A 19-acre portion of the former Kerr-McGee
Ponds is on privately-owned land and fenced property. Therefore, the UNC outdoor
worker was selected as the RME receptor for the Kerr-McGee Ponds on UNC
Property EU.

•	Arroyos on the Navajo Nation - A 16-acre portion of the impacted arroyos is on the
Navajo Nation. The impacted arroyos are deep with steep sides and, thus, difficult

to access. Therefore, the Kqq ei doo nahaazah dah (difficult access open space user) was
selected as the RME receptor for the Arroyos on the Navajo Nation EU.

•	Arroyos on UNC Property - A 3-acre portion of the impacted arroyos is on
privately-owned land and fenced property. Therefore, the UNC outdoor worker was
selected as the RME receptor for the Arroyos on UNC Property EU.

•	Site-Wide - A 137-acre area encompasses all the human health exposures units for
evaluation of the ecological receptors at the Quivira Mines.

2.5.3 Human Health Risk Assessment

This subsection describes the key elements of the HHRA methodology. An HHRA is the process
for evaluating how people are impacted as a result of 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, breathing contaminated dust, touching
contaminated materials, or radiation emanating from soil). This risk assessment uses
Navajo-specific exposure scenarios, as explained below, to determine how a person can be
exposed to contamination at AUMs on the Navajo Nation. For areas on UNC property, a
site-specific outdoor worker was used in the risk assessment. This HHRA focuses on soil
contamination only. The HHRA does not include ingestion of surface water or groundwater by
people or animals. Safe drinking water is supplied to residents in the Quivira Mines area.

Wells used for livestock have been tested and are upgradient of the known groundwater
contamination in the area. The arroyos are mostly dry, and the ponds are dry since mine
operations have stopped.

The HHRA evaluates whether site-related contaminants of potential concern (COPC) 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, 1993). The HHRA includes the
following components: data evaluation and selection of COPCs, exposure assessment, toxicity
assessment, and risk characterization.

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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 1x10 6
cancer risk and a hazard index of 0.1 for a Navajo resident. Appendix C, Table C-l, provides the
COPC screening. Based on the screening, the following contaminants were identified as COPCs
and are included in the risk estimates in the HHRA: Ra-226 in secular equilibrium, aluminum,
arsenic, barium, cadmium, cobalt, copper, iron, manganese, molybdenum, selenium, thallium,
uranium, and vanadium.

The exposure assessment is the process of measuring or estimating intensity, frequency, and
duration of human exposure to a contaminant in the environment. The CSM describes the
exposure setting and identifies potentially complete exposure pathways by which receptors
(both people and ecological) could contact site-related contaminants. The CSM is provided on
Figure 13.

Exhibit 5 presents a brief description of each receptor along with the associated geographic
distribution. The specific exposure pathways and inputs for these receptors evaluated in the
HHRA are provided in Appendix C, Table C-3. Figure 27 presents a graphic depiction of Navajo
residential exposure pathways, including the Dine Lifeways.

Exhibit 5. Quivira Mines Receptors

Exposure Units

Receptor Name

Receptor Description

CR-1, CR-1 E, and
Kerr-McGee
Ponds on the
Navajo Nation

Kee'da'whff teeh
(Full-Time Navajo
Resident)

Members of the Navajo Nation that live full time at a site.
Includes external exposure to radiation, incidental ingestion
of soil, dermal exposure to soil (metals only), inhalation of soil
(or dust), ingestion of homegrown produce and gathered wild
plants, and consumption of animal products from raised
animals (meat, milk, and eggs) and hunted animals (meat),
as well as plant exposures (ingestion, dermal, and inhalation)
from Dine Lifeways practices including medicinal and
ceremonial exposures.

Arroyos on the
Navajo Nation

Kqq ei doo

nahaazah dah
(Difficult Access
Open Space
User)

A member of the Navajo Nation that enters the arroyo 1 hour
per day for 30 days a year to collect plants, herd animals, or
hunt. Includes external exposure to radiation, incidental
ingestion of soil, dermal exposure to soil (metals only),
inhalation of soil (or dust), ingestion of homegrown produce
and gathered wild plants, and consumption of animal
products from raised animals (meat and milk) and hunted
animals (meat), as well as plant exposures (ingestion,
dermal, and inhalation) from Dine Lifeways practices
including medicinal and ceremonial exposures

Kerr-McGee
Ponds and
Arroyos on UNC
Property

UNC Outdoor
Worker

A worker that is assumed present on site 8 hours per day,
2 days per week, 50 weeks per year. Exposure pathways
evaluated include external exposure to radiation, incidental
ingestion of soil, dermal exposure to soil (metals only), and
inhalation of soil (or dust).

Notes:

CR-1	Quivira Church Rock No. 1 Mine

CR-1E	Quivira Church Rock No. 1 East Mine

Kerr-McGee	Kerr-McGee Corporation

UNC	United Nuclear Corporation

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The toxicity assessment identifies the toxicity parameters needed for the risk assessment. The
toxicity values used in the streamlined HHRA are all standard values provided by USEPA. Risk
characterization proceeds by combining the results of the exposure and toxicity assessments. For
the NAUM program HHRAs, the risk characterization process described in Appendix C was
used.

The intake factors for all exposure pathways used in the HHRA were calculated using the
NAUM Risk Calculator (USEPA 2024b). The cumulative cancer risk for the age-adjusted adult
and child and noncancer hazard for the child receptor (or adult receptor in the case of the outdoor
worker) for each EU and soil interval are provided in Appendix C, Table C-7, and summarized in
Exhibit 6.

Exhibit 6. Cancer Risks and Noncancer Hazards

Exposure Unit

Soil Interval

Cancer Risk

Adult
Noncancer
Hazard

Child
Noncancer
Hazard

CR-1

Surface Soil

1x102

8

10

Subsurface Soil

3x102

8

10

CR-1 E

Surface Soil

2x10 2

8

10

Subsurface Soil

8x10 2

10

20

Kerr-McGee Ponds on the
Navajo Nation

Surface Soil

2x10 2

9

10

Subsurface Soil

2x10 2

9

10

Kerr-McGee Ponds on
UNC Property

Surface Soil

2x10 4

0.05

-

Subsurface Soil

2x10 4

0.08

-

Arroyos on the Navajo Nation

Surface Soil

6x10 4

5

0.5

Subsurface Soil

6x10 4

8

0.7

Arroyos on UNC Property

Surface Soil

2x10"5

0.03

-

Subsurface Soil

2x10"5

0.03

-

Notes:

Bolded values exceed the target cancer risk or target hazard quotient.

Not applicable
CR-1	Quivira Church Rock No. 1 Mine

CR-1E	Quivira Church Rock No. 1 East Mine

Kerr-McGee Kerr-McGee Corporation
UNC	United Nuclear Corporation

Candidate COCs are identified based on the cancer risk exceeding the target cancer risk of 1x10 4
or a noncancer hazard of 1 for the RME receptor at the EU. Exhibit 7 presents the candidate
COCs for each EU and soil interval as identified in Appendix C, Table C-7.

Exhibit 7. Candidate COCs Identified Based on Cancer Risks and Noncancer Hazards

Exposure Unit

Soil Interval

Cancer Risk

Noncancer Hazard

CR-1

Surface and Surface

Radium-226 in SE
Arsenic
Chromium1

Cobalt
Iron
Manganese
Thallium
Uranium

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Exhibit 7. Candidate COCs Identified Based on Cancer Risks and Noncancer Hazards

(Continued)

Exposure Unit

Soil Interval

Cancer Risk

Noncancer Hazard

CR-1 E

Surface and Surface

Radium-226 in SE
Arsenic
Chromium1

Arsenic
Cobalt
Iron
Manganese
Thallium
Uranium

Kerr-McGee Ponds on the
Navajo Nation

Surface and Surface

Radium-226 in SE
Arsenic
Chromium1

Cobalt
Iron
Manganese
Thallium
Uranium

Kerr-McGee Ponds on UNC
Property

Surface and Surface

Radium-226 in SE

-

Arroyos on the Navajo Nation

Surface and Surface

Radium-226 in SE
Arsenic

Manganese

Arroyos on UNC Property

Surface and Surface

-

-

Notes:

1	No speciation data are available for chromium; therefore, chromium is assumed to be 100 percent

hexavalent chromium.

No COC identified based on a cancer target risk of 1 x104 or noncancer target hazard of 1.
COC	Contaminant of concern

CR-1	Quivira Church Rock No. 1 Mine

CR-1E	Quivira Church Rock No. 1 East Mine

Kerr-McGee Kerr-McGee Corporation
SE	Secular equilibrium

UNC	United Nuclear Corporation

2.5.4 Ecological Risk Assessment

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 lease area while maintaining a conservative approach protective of ecological populations
and communities. This ERA follows the guidelines in the NAUM risk assessment methodology
(USEPA 2024a).

As described in USEPA (1993a) 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 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.

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The ERA evaluated the Quivira Mines as a single site-wide EU. The SLERA COPECs for soil at
the Quivira Mines are presented in Appendix C, Table C-8. Contaminants in soil for which the
hazard quotient was greater than or equal to 1.0 were U-238, U-234, Ra-226, arsenic, barium,
chromium, lead, manganese, nickel, selenium, thallium, uranium, vanadium, and zinc.

Candidate COECs and the calculated hazard quotient risk estimates are listed in Appendix C,
Table C-10 for plants and invertebrates, Table C-l 1 for birds, and Table C-12 for mammals. The
site-wide candidate COECs are summarized in Exhibit 8.

Exhibit 8. Site-Wide Candidate COECs





Candidate Contaminant of Ecological Concern

Receptor

Soil
Interval

Uranium-238

Uranium-234

Radium-226 in SE

Arsenic

Barium

Chromium

Lead

Manganese

Selenium

Thallium

Uranium

Vanadium

Zinc

Plants

Surface Soil

--

--

X

--

X

X

X

X

X

X

X

--

--

Subsurface Soil

X

X

X

--

X

X

--

X

X

X

X

--

--

Invertebrates

Surface Soil

--

--

"

X

X

X

--

--

X









Birds

Surface Soil













X

--

X

"

"

X

X

Mammals

Surface Soil

















X









Subsurface Soil

--

--

X











X









Notes:

Not a candidate COEC

X	Candidate COEC

SE	Secular equilibrium

2.5.5 Risk Assessment Results Summary

Candidate COCs and COECs were identified based on available laboratory data. The HHRA and
ERA results indicate that risk is above a level of concern for the contaminants listed in Exhibit 9.

Exhibit 9. Candidate COCs and Candidate COECs Recommended for Further Evaluation

Exposure
Unit

Media

Candidate COC or COEC

Uranium-238

Uranium-234

Radium-226 in SE

Arsenic

Barium

Chromium1

Cobalt

Iron

Lead

Manganese

Selenium

Thallium

Uranium

Vanadium

Zinc



Surface/































CR-1

Subsurface

—

—

X

X

—

X

X

X

—

X

—

X

X

—

—



Soil































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Engineering Evaluation/Cost Analysis, Quivira Mines

It

l.,U.4..L	u	

Exhibit 9. Candidate COCs and Candidate COECs Recommended for Further Evaluation

(Continued)





Candidate COC or COEC

Exposure
Unit

Media

Uranium-238

Uranium-234

Radium-226 in SE

Arsenic

Barium

Chromium1

Cobalt

Iron

Lead

Manganese

Selenium

Thallium

Uranium

Vanadium

Zinc

CR-1E

Surface/
Subsurface
Soil

--

--

X

X

--

X

X

X

--

X

--

X

X

--

--

Kerr-McGee
Ponds on the
Navajo Nation

Surface/
Subsurface
Soil

--

--

X

X

--

X

X

X

--

X

--

X

X

--

--

Kerr-McGee
Ponds on
UNC Property

Surface/
Subsurface
Soil

--

--

X

























Arroyos on
the Navajo
Nation

Surface/
Subsurface
Soil

--

--

X

X











X











Arroyos on
UNC Property

Surface/
Subsurface
Soil































Site-Wide

Surface Soil

--

--

X

X

X

X

"

"

X

X

X

X

X

X

X

(Ecological
Risk)

Subsurface
Soil

X2

X2

X

"

X

X







X

X

X

X

--

--

Notes:

X

COC

COEC

CR-1

CR-1E

EE/CA

Kerr-McGee

SE

UNC

No speciation data are available for chromium; therefore, chromium is assumed to be 100 percent
hexavalent chromium.

Uranium-234 and uranium-238 concentrations exceed the ecological no observed effect concentration

for plants in a single subsurface sample (location KMP-SB28 from 60 to 66 inches below ground

surface) in Kerr-McGee Ponds on UNC Property. This area is considered a hot spot and any

recommendations for uranium-234 and uranium-238 apply only to the hot spot.

Not a candidate COC or COEC. Not recommended for further evaluation in this EE/CA.

Candidate COC and/or COEC. Recommended for further evaluation in this EE/CA.

Contaminant of concern

Contaminant of ecological concern

Quivira Church Rock No. 1 Mine

Quivira Church Rock No. 1 East Mine

Engineering evaluation/cost analysis

Kerr-McGee Corporation

Secular equilibrium

United Nuclear Corporation

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. By understanding the potential adverse effects posed by candidate COCs and

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COECs and the removal actions themselves, risk managers can balance the costs and benefits of
the available removal alternatives. Understanding the uncertainties associated with risk
assessment is critical to evaluating the overall protection of any remedy (USEPA 1997a).

U-238 and its decay products is the primary COC at the Quivira Mines. U-238, U-234, Th-230,
and Ra-226 in secular equilibrium were evaluated in the risk assessment to include toxicity from
all radionuclides in the U-238 decay chain. For risk management, site data for Ra-226 were used
to represent the soil concentration of U-238; however, the human health PRGs for the Navajo
resident and the UNC outdoor worker 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 Quivira Mines identified numerous candidate COCs and COECs.
Radiological contamination is the predominant risk driver at the Quivira Mines; thus, the extent
of Ra-226 above the selected RAG will primarily be used to establish the extent of the removal
action. No candidate COCs were identified in the Arroyos on UNC Property EU; therefore, this
EU is not discussed further in the risk management section. In addition to Ra-226, candidate
COCs at the site are arsenic, chromium, cobalt, iron, manganese, thallium, and uranium, and
candidate COECs are arsenic, barium, chromium, lead, manganese, selenium, thallium, uranium,
vanadium, and zinc. U-234 and U-238 are also candidate COECs at a single location
(KMP-SB28) in subsurface soil at the Kerr-McGee Ponds on UNC Property EU.

The NAUM risk management process involves assessment of various lines of evidence for
candidate COCs and COECs. Lines of evidence considered in the risk management process
include:

•	Refinement of candidate COCs and COECs:

o Comparison of site concentrations to background concentrations (Table 2). Candidate
COCs and COECs below background are removed from further analysis.

o Consideration of natural forms of chromium

o Assessment of co-location via a comparison of the metals distribution to the Ra-226
preliminary removal action extent. Metal COCs and COECs with concentrations
above human health PRGs and 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:

o Potential impacts of site risks for candidate COECs based on a comparison of site
concentrations to NAUM PERGs (USEPA 2024c)

o Analysis of contaminant distribution

o Assessment of other uncertainties

Refinement of the exposures, inputs, and uncertainties for candidate COCs is not warranted
because the HHRA was developed using Navajo-specific exposure scenarios and a site-specific

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scenario for private property. 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 discusses the natural forms of
chromium, Section 2.6.3 presents and describes the human health PRGs and NAUM PERGs,
Section 2.6.4 presents the co-location analysis, Section 2.6.5 presents the refinement of candidate
COECs, and Section 2.6.6 presents a summary of risk management conclusions and decisions.

Table 3 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 COC
or COEC that is not considered for removal action.

2.6.1 Comparison of Site Concentrations of Candidate Contaminants of Concern and
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 Quivira Mines, the background comparison
used the Bartlett Barren Member of the Crevasse Canyon Formation (BSA-2) 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
(2002a, 2010, 2022) statistical guidance for evaluating background concentrations of chemicals
in soil. The background comparison results are presented in Table 2 for each human health and
ecological risk EU.

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 2022).

If the first-tier tests indicated that the site concentrations are greater than background
concentrations, no further testing was conducted. If the first-tier tests indicated that the site
concentrations are 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, 2002c, 2010). Two-sided statistical tests are used in all
cases and employ 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.

The Quantile test (Johnson, Verrill, and Moore II 1987; USEPA 1994, 2000b, 2002b, 2010) was
conducted for all metals where the Gehan, Tarone-Ware, and Wilcoxon-Mann-Whitney tests did

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not reject the null hypothesis (that is, when the median site and background concentrations were
concluded not to be 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, 2002c, 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 10 presents the background comparison results for the Quivira Mines EUs. In addition to
Ra-226, uranium was found at concentrations greater than background in all human health EUs
where the analyte was identified as a candidate COC, except for the Arroyos on the Navajo
Nation EU, and is recommended for further evaluation in the EE/CA at those EUs. In addition to
Ra-226, arsenic, barium, chromium, selenium, uranium, and vanadium were found at
concentrations greater than background in the ecological site-wide EU, and are recommended for
further evaluation in the EE/CA.

Exhibit 10. Background Comparison Results Summary

Exposure Unit

Candidate COC or COEC Background Comparison Result

Uranium-238

Uranium-234

Radium-226 in SE

Arsenic

Barium

Chromium

Cobalt

Iron

Lead

Manganese

Selenium

Thallium

Uranium

Vanadium

Zinc

CR-1

--

--

>BG

BG

~

~

CR-1E

--

--

>BG

BG

BG

~

~

Kerr-McGee Ponds
on the Navajo Nation

--

--

>BG

BG

BG

--

--

Kerr-McGee Ponds
on UNC Property

--

--

>BG

























Arroyos on the Navajo
Nation

--

--

BG

>BG

>BG

>BG

>BG

>BG

--

--

BG

BG

>BG


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Engineering Evaluation/Cost Analysis, Quivira Mines

Exhibit 10. Background Comparison Results Summary (Continued)

Notes (Continued):

Not a candidate COC or COEC for exposure unit/receptor combination. Background comparison was
not conducted for this analyte and exposure unit.

BG	Site concentrations are greater than background concentrations. Candidate COC or COEC is

recommended for further evaluation in the EE/CA.

COC	Contaminant of concern

COEC Contaminant of ecological concern
CR-1	Quivira Church Rock No. 1 Mine

CR-1E Quivira Church Rock No. 1 East Mine
EE/CA Engineering evaluation/cost analysis
Kerr-McGee Kerr-McGee Corporation
SE	Secular equilibrium

UNC	United Nuclear Corporation

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 (CrIII) is the most common oxidation state
and an essential dietary element that aids normal glucose, protein, and fat metabolisms (Agency
for Toxic Substances and Disease Registry 2012). Hexavalent chromium (CrVI) is the most toxic
chromium ion and is a known human carcinogen.

Hexavalent chromium is almost exclusively produced from industrial processes and only
expected from natural sources atNAUM sites at much lower concentrations. 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. Hexavalent chromium is a known human carcinogen
when inhaled and has been shown to cause tumors in mice and rats when ingested in drinking
water, but little evidence indicates that ingesting trivalent chromium, a dietary supplement, poses
any toxic or carcinogenic risk to humans (USEPA 1998b).

In rare instances in nature, hexavalent chromium may form minerals with uranium; however,
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; that is, the sites do not contain ultramafic rock and serpentine soils, which are the
most likely natural source of hexavalent chromium. Furthermore, weather conditions of 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 in soil is typically found in
higher pH (more basic), in aerobic conditions, in low amounts of organic matter, and with
manganese and iron oxides. Trivalent chromium is cationic and adsorbs onto clay particles,
organic matter, metal oxyhydroxides, and other negatively charged particles in contrast to
hexavalent chromium, which does not interact significantly with clay or organic matter. Finally,

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desert sandy-loam soils typically contain low amounts of organic matter. Soils from Quivira
Mines have measured pH between 7.8 and 8.5.

The lines of evidence presented above suggest that chromium at the Quivira Mines is likely
present in 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 chromium is 24 milligrams per kilogram, which is below both
the COPC screening level for trivalent chromium in the HHRA (79 mg/kg) and the lowest
trivalent chromium NOEC in the ERA (34 mg/kg) (based on the mammalian 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 Quivira Mines.

2.6.3 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 level 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).

Exhibit 11 presents the human health PRGs and NAUM PERGs for soil for candidate COCs and
COCs greater than background.

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Exhibit 11. Human Health Preliminary Removal Goals and NAUM Preliminary Ecological
Removal Goals for Candidate COC and COECs in Soil Above Background

Candidate
COC/COEC

Unit

Human Health PRG
Navajo Resident1

Human Health PRG
UNC Outdoor Worker1

NAUM PERG2

Uranium-23434

pCi/g

--

--

430

Uranium-23834

pCi/g

--

--

480

Radium-2265

pCi/g

0.050

5.4

40

Arsenic

mg/kg

--

--

68

Barium

mg/kg

--

--

1,400

Chromium

mg/kg

--

--

250

Selenium

mg/kg

--

--

3.4

Uranium

mg/kg

3.2

--

250

Vanadium

mg/kg

--

--

80

Notes:

1

COC

COEC

Kerr-McGee

mg/kg

NAUM

pCi/g

PERG

PRG

SE

UNC

USEPA

Human health PRGs are from the NAUM Risk Calculator (USEPA 2024b). PRGs for carcinogenic
contaminants are based on a target cancer risk of 1x10 4, and PRGs for noncarcinogenic contaminants
are based on a target noncancer hazard quotient of 1.0.

NAUM PERGs are based on the most sensitive ecological receptor (USEPA 2024c). The NAUM PERG
is applicable site-wide except for uranium-234 and uranium-238 (see note 4).

The NAUM PERG is the minimum PERG for the individual radionuclide.

Uranium-234 and uranium-238 concentrations exceed the ecological no observed effect concentration

for plants in a single subsurface sample (location KMP-SB28 from 60 to 66 inches below ground

surface) in the Kerr-McGee Ponds on UNC Property exposure unit. This area is considered a hot spot,

and any recommendations for uranium-234 and uranium-238 apply only to the hot spot.

Site data for radium-226 are used to evaluate the extent of radionuclides above human health PRGs

and NAUM PERGs. The human health PRG for radium-226 is the PRG for uranium-238 in SE. The

radium-226 NAUM PERG is the minimum PERG for uranium-238 in SE for all feeding guilds (USEPA

2024c) and is based on the individual radium-226 PERG adjusted to include doses from all progeny of

uranium-238 in SE as described in Appendix F of USEPA (2024a).

Not a candidate COC

Contaminant of concern

Contaminant of ecological concern

Kerr-McGee Corporation

Milligram per kilogram

Navajo abandoned uranium mine

Picocurie per gram

Preliminary ecological removal goal

Preliminary removal goal

Secular equilibrium

United Nuclear Corporation

U.S. Environmental Protection Agency

2.6.4 Co-Location Assessment

The Ra-226 removal action extent encompasses a large portion of the TENORM area at the
Quivira Mines (Appendix B, Figure B-l). The source of the contamination is from historical
uranium mining activities, and the mining waste. 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 metals candidate COCs and COECs exceeding
background concentrations are co-located with Ra-226 via a comparison of the metals
distribution to the Ra-226 preliminary removal action extent.

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2.6.4.1 Development ofRadium-226 Removal Action Extent

The Ra-226 RAG for all EUs is the lesser of the human health PRG and the NAUM PERG
unless either of the preliminary goals is less than the BTV. On the Navajo Nation, the RAG is
based on the BTV because the human health PRGs for all receptors are lower than each of the
geology-specific BTVs. On UNC property, the RAG is based on the human health PRG for the
UNC outdoor worker. No cleanup is recommended in the site-wide EU to address risk to
ecological receptors per the evaluation presented in Section 2.6.5.1. The Ra-226 EPC in the site-
wide EU is 5.9 pCi/g, which does not exceed the NAUM PERG of 40 pCi/g; therefore, Ra-226 is
not a COEC. Exhibit 12 presents the comparison of the human health PRGs, NAUM PERGs, and
geology-specific BTVs for Ra-226 that were considered to establish the RAG.

Exhibit 12. Radium-226 Removal Action Goal Development

Exposure Unit

HH PRG1

NAUM
PERG2

BTV3

Radium-226
RAG

Basis
for RAG

Navajo
Resident

DAOS

UNC
Outdoor
Worker

CR-1

0.050

--

--

40

2.0

2.0

BTV

CR-1E

0.050

--

--

40

2.0

2.0

BTV

Kerr-McGee Ponds
on the Navajo Nation

0.050

--

--

40

2.0

2.0

BTV

Kerr-McGee Ponds
on UNC Property

--

--

5.4

40

2.0

5.4

HH PRG

Arroyos on the
Navajo Nation

--

0.33

--

40

2.0

2.0

BTV

Notes:

Units are in picocuries per gram.

1	HH PRGs are the PRGs for uranium-238 in SE from the NAUM Risk Calculator (USEPA 2024b) and are
based on a target cancer risk of 1x10 4. Site data for radium-226 are used to evaluate the extent of
radionuclides above PRGs.

2	The NAUM PERG is applicable site-wide. The NAUM PERG presented is the minimum PERG for
uranium-238 in SE for all feeding guilds (USEPA 2024c). The NAUM PERG for uranium-238 in SE is
based on the individual radium-226 NAUM PERG that is adjusted to include doses from all progeny of
uranium-238 in SE as described in Appendix F of USEPA (2024a). Site data for radium-226 are used to
evaluate the extent of radionuclides above the NAUM PERG.

3	The BTV is the UTL95-95 for nonduplicate analytical data. If outliers are removed, the BTV is the
UTL95-95 for the dataset with extreme outliers removed (Tetra Tech, Inc. 2023a).

Not applicable
BTV	Background threshold value

CR-1	Quivira Church Rock No. 1 Mine

CR-1E Quivira Church Rock No. 1 East Mine
DAOS Difficult access open space
HH	Human health

Kerr-McGee Kerr-McGee Corporation
NAUM Navajo abandoned uranium mine
PERG Preliminary ecological removal goal
PRG	Preliminary removal goal

RAG	Removal action goal

SE	Secular equilibrium

UNC	United Nuclear Corporation

USEPA U.S. Environmental Protection Agency
UTL95-95 95 percent upper tolerance limit with 95 percent coverage

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The estimated Ra-226 interpolated surface was generated using gamma survey data from the
Quivira Mines as discussed in Section 2.4.3.3. Gamma survey results were converted from
counts per minute to estimated Ra-226 concentrations in pCi/g. For each EU, 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.

2.6.4.2 Assessment of Metals Co-Location with the Radium-226 Preliminary Removal
Action Extent

The distribution of candidate metal COCs and COECs was compared with the Ra-226
preliminary removal action extent to identify whether concentrations of candidate COCs and
COECs at concentrations above background are co-located with the Ra-226 preliminary removal
action extent. Appendix B, Figure B-2 through Figure B-7, presents the soil sample results for
each candidate metal COC and COEC above background overlain with the Ra-226 preliminary
removal action extent with results screened against relevant BTVs, human health PRGs, and
NAUM PERGs. For candidate COCs and COECs for which RAGs are developed in
Section 2.7.1, the results are also screened against the RAG.

At the Quivira Mines, the extent of barium, chromium, and vanadium (Appendix B, Figure B-3,
Figure B-4, and Figure B-7) above the NAUM PERG and BTVs is entirely co-located within the
preliminary Ra-226 removal action extent or the waste rock stockpile that is planned for
removal. Further assessment of the extent of barium, chromium, and vanadium will not result
in a change in the removal action extent and, therefore, barium, chromium, and vanadium will
not be considered for further evaluation and are not identified as COECs recommended for
removal action.

2.6.5 Refinement of the Ecological Risk Assessment Candidate Contaminants of
Ecological Concern

Per USEPA (1999), ecological risk management decisions should be based on sound science and
clear rationale. As described in USEPA (1999) guidance, establishing preliminary removal goals
for ecological receptors is difficult because of the following:

•	Lack of broadly applicable and quantifiable toxicological data

•	Number and variety of species potentially present at an EU

•	Differences in susceptibility of different species at different life stages to COECs

•	Recuperative potential of different species following exposure

•	Variation in environmental bioavailability of the candidate COECs

The selected remedies should be protective of ecological receptors in both the short and long
term. Because ecological receptors at an EU are within a larger ecosystem, remedies selected for
protection of these receptors should also assume protection of the ecosystem components upon
which they depend or support. Removal actions should not be designed to protect organisms on
an individual basis but, instead, should be designed to protect local populations and communities

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of biota. Evaluation of these factors was incorporated in the EE/CA in the evaluation of the
effectiveness of the removal action alternatives in Section 4.3.

Risk managers should consider the following principles when making ecological
management decisions.

•	The potential impact of site risks. When evaluating ecological risks and the
potential for response alternatives to achieve acceptable levels of protection, managers
should consider the following:

o Magnitude or degree of the predicted responses of receptors to the range of
COEC levels

o Severity of the impact (for example, how many species will be affected)
o Areal extent and duration over which effects may occur
o Potential for recovery of the affected receptors

•	Actions that will reduce ecological risks to levels that will result in the recovery
and maintenance of healthy local populations and communities of biota. Managers
should consider the actions that will result in an ability for the site to sustain an
ecological structure and function of the local populations, communities, and habitats.
The benefit of risk reduction should be weighed against the ecological cost of habitat
destruction. Excavation destroys plant cover and removes valuable topsoil, which leads to
the degradation of biologically rich areas (Whicker and others 2004). This consideration
is particularly important in vegetated areas because those areas may be used by
ecological receptors and revegetation may be difficult to establish and slow to mature
once established.

•	Input from the public and stakeholders. Through the EE/CA Superfund public
comment process and NNEPA review, managers should consider the input or issues
voiced from stakeholders, such as community groups, on any perceived negative short- or
long-term impact of the removal action.

To support managers in understanding the site risks and to provide managers with a balanced
recommendation so that the ecological structure and function can recover and be sustainable for
the long-term risk, risk management should include:

•	Development of NAUM PERGs using average exposure assumptions instead of
conversative assumptions and comparison with representative site concentrations (for
example, UCL95)

•	Evaluation of analytical data uncertainties, such as frequency of detection (FOD)

•	Inclusion of other lines of evidence, including bioavailability, area use factors, and
seasonality of exposures (Appendix C contains more information on these uncertainties)

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2.6.5.1 Comparison of Metals Site Concentrations with Preliminary Ecological
Removal Goals for Candidate Contaminants of Ecological Concern

To refine site risks associated with metal candidate COECs for soil above background that are
not entirely co-located within the Ra-226 preliminary removal action extent (arsenic, selenium,
and uranium), estimates of the site-wide EPC (using UCL95 concentrations) at the Quivira
Mines were compared with NAUM PERGs. Exhibit 13 presents the results of the comparison of
the site-wide EPCs to the NAUM PERGs.

As shown in Exhibit 13, the site-wide EPCs for U-234, U-238, Ra-226, arsenic, selenium, and
uranium are less than the NAUM PERGs; therefore, these candidate COECS are not
recommended for removal action.

Exhibit 13. Comparison of Site-Wide EPCs to NAUM PERGs for Soil

Candidate
COEC

Unit

Site-Wide EPC1 -
Surface Soil

Site-Wide EPC1 -
Subsurface Soil

NAUM PERG2

Candidate COEC
EPC > PERG

Uranium-234

pCi/g

--

12

430

No

Uranium-238

pCi/g

--

12

480

No

Radium-226

pCi/g

5.9

16

40

No

Arsenic

mg/kg

5.7

--

68

No

Selenium

mg/kg

3.0

3.1

3.4

No

Uranium

mg/kg

6.2

16

250

No

Notes:

1	EPC as indicated in Appendix C, Table C-9.

2	NAUM PERGs are based on the most sensitive ecological receptor
Not a candidate COEC for the depth interval

COEC	Contaminant of ecological concern

EPC	Exposure point concentration

mg/kg	Milligram per kilogram

NAUM	Navajo abandoned uranium mine

pCi/g	Picocurie per gram

PERG	Preliminary ecological removal goal

2.6.5.2 Assessment of Contaminant Distribution

An analyte could be identified as a candidate COC or COEC and be only detected infrequently in
an EU (for example, less than 5 percent with at least 20 samples). Because of low FOD, the
exposure and resulting risk could be unreasonably elevated and overly conservative. COCs and
COECs should not be removed simply based on the FOD of less than 5 percent, but each case
should be reviewed for analytical certainty and if low FOD potentially indicates a unique hot
spot for risk management consideration. At the Quivira Mines, FOD is greater than 5 percent for
all candidate COCs and COECs.

Risk managers should also consider the assessment of nonmobile ecological receptors (for
example, plant and soil invertebrate communities). Plants and soil invertebrates represent the
basis of the ecological food chain and site concentrations were evaluated in the ERA against the
NOEC or ESL on a point-by-point basis (see Appendix C, Table C-10). Although the use of
literature-based soil toxicity values protective of soil invertebrates and plants is conservative,

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risk managers should compare the areas under consideration for removal action with those
locations that have concentrations that exceed a risk-based soil concentration. Appendix B
presents the distribution of all candidate COECs within the TENORM boundary compared to the
NAUM PERGs and geology-specific BTVs. At the Quivira Mines, candidate COECs greater
than background concentrations based on exceedance of a plant or invertebrate NOEC are
U-238, U-234, Ra-226, barium, chromium, selenium, and uranium.

2.6.6 Risk Management Summary and Conclusions

Based on the HHRA and ERA for the Quivira Mines, candidate COCs for soil are Ra-226,
arsenic, chromium, cobalt, iron, manganese, thallium, and uranium, and candidate COECs for
soil are U-234, U-238, Ra-226, arsenic, barium, chromium, lead, manganese, selenium, thallium,
uranium, vanadium, and zinc. Following the lines of evidence considered in the risk management
analysis in the prior subsections, removal action is recommended as follows:

•	To address excess human health risk from Ra-226 contamination at the CR-1, CR-1E,
Kerr-McGee Ponds on UNC Property, and Arroyos on the Navajo Nation EUs, removal
of Ra-226 above the applicable RAG for each human health EU is recommended.

•	To address excess human health risk at the CR-1, CR-1E, and Kerr-McGee Ponds on the
Navajo Nation EUs from uranium, removal of uranium above the applicable RAG for
each human health EU is recommended.

The conclusions for candidate COCs are based on the results of the risk assessment, background
comparison, and co-location analysis. Conclusions for candidate COECs also include
consideration of the results of a comparison of the site-wide EPCs with the NAUM PERGs, and
are supported by the assessment of uncertainties that are likely to overestimate risk estimates in
the ERA. Exhibit 14 provides the COCs recommended for removal at each human health EU.
No COECs were identified at the site-wide EU, and no removal action is recommended to
address ecological risk at the Quivira Mines. Table 3 presents the results of the risk management
analysis and identifies the final COCs recommended for removal action, as well as the rationale
for refinement of each candidate COC or COEC, which are not considered for removal action.

Exhibit 14. COCs Recommended for Removal Action

Exposure Unit

Receptor

Surface Soil
COCs

Subsurface Soil
COCs

CR-1

Kee'da'whn teeh
(Navajo Resident)

Radium-226
Uranium

Radium-226
Uranium

CR-1E

Kee'da'whn teeh
(Navajo Resident)

Radium-226
Uranium

Radium-226
Uranium

Kerr-McGee Ponds
on the Navajo Nation

Kee'da'whn teeh
(Navajo Resident)

Radium-226
Uranium

Radium-226
Uranium

Kerr-McGee Ponds
on UNC Property

UNC Outdoor Worker

Radium-226

Radium-226

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Exhibit 14. COCs Recommended for Removal Action (Continued)

Exposure Unit

Receptor

Surface Soil
COCs

Subsurface Soil
COCs

Arroyos on the Navajo Nation

Kqq ei doo nahaazah dah
(Difficult Access Open
Space User)

--

--

Arroyos on UNC Property

Kee'da'whn teeh
(UNC Outdoor Worker)

--

--

Site-Wide

Plants, Invertebrates,
Birds, Mammals

--

--

Notes:

No COCs or COECs were identified
COC	Contaminant of concern

COEC Contaminant of ecological concern
CR-1	Quivira Church Rock No. 1 Mine

CR-1E Quivira Church Rock No. 1 East Mine
Kerr-McGee Kerr-McGee Corporation
UNC	United Nuclear Corporation

2.7 REMOVAL ACTION EXTENT

Multiple lines of evidence were used to develop the removal action extent at the Quivira Mines,
including the extent of Ra-226 in surface soil, extent of contamination of other COCs and
COECs outside the Ra-226 extent, risk management considerations, surface and subsurface
waste areas, transport pathways, and disturbed mineralized areas.

2.7.1 Numerical Removal Action Goals

Following the risk management assessment, removal action is recommended for soil for Ra-226
and uranium at the Quivira Mines and for uranium-238 and uranium-234 in the hot spot in the
Kerr-McGee Ponds on UNC Property EU. RAGs were derived for each applicable receptor, EU,
and COC or COEC recommended for removal action. COCs and COECs were identified based
on available laboratory data, comparison to background levels, and other lines of evidence as
summarized in Section 2.6.4.

Table 4 presents the comparison of inputs used to develop the final RAGs for each COC in soil.
No COECs were identified at the site-wide EU, and no removal action is recommended to
address ecological risk at the Quivira Mines. The final RAG is the lesser of the human health
PRG and the NAUM PERG, when applicable, unless either the PRG or PERG is less than the
BTV. If the BTV is greater than the human health PRG or NAUM PERG, the final RAG is to
address material that is distinguishable from background. For purposes of this EE/CA, the BTV
calculated for the Bartlett Barren Member of the Crevasse Canyon Formation (BSA-2) is used to
represent background for delineating contaminated areas. However, the BTVs may not be
representative of the blending of geologic materials from upslope areas and additional lines of
evidence may be considered to identify the cleanup extent. Exhibit 15 provides the selected
numerical RAG for each COC recommended for removal at each EU.

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Exhibit 15. Selected RAG for Each COC

COC

Unit

Exposure Unit

RAG

RAG Basis

Radium-226

pCi/g

CR-1, CR-1E, and Kerr-McGee Ponds
on the Navajo Nation

2.0

BTV1

Kerr-McGee Ponds on UNC Property

5.4

HH PRG
UNC Outdoor Worker

Uranium

mg/kg

CR-1, CR-1E, and Kerr-McGee Ponds
on the Navajo Nation

3.2

HH PRG
Navajo Resident

Notes:

No COECs were identified.

The BTV is used to represent background for delineating contaminated areas.

BTV	Background threshold value

COC	Contaminant of concern

COEC	Contaminant of ecological concern

CR-1	Quivira Church Rock No. 1 Mine

CR-1E	Quivira Church Rock No. 1 East Mine

HH	Human health

Kerr-McGee Kerr-McGee Corporation

mg/kg	Milligram per kilogram

pCi/g	Picocurie per gram

RAG	Removal action goal

PRG	Preliminary removal goal

UNC	United Nuclear Corporation

2.7.2 Other Removal Action Extent Considerations

The preliminary removal action extent was modified based on the evaluation of additional lines
of evidence as follows:

•	Surface and subsurface waste areas: Waste rock piles and unreclaimed ponds were
included in the removal action area. Reclaimed ponds and those backfilled portions of
reclaimed ponds no longer containing TENORM were excluded.

•	Transport pathways: No additional mine features and areas (such as waste rock
piles and ponds) with potential for future transport of waste material downgradient
were identified.

•	Disturbed mineralized areas: No mineralized areas are located at the surface at the
Quivira Mines. All mining was conducted at depth. However, an upslope area at CR-1,
above the cliff band bounding the north side of the mine, was excluded because the area
contains only NORM bedrock outcrops of the Bartlett Barren Member and potentially
Mulatto Tongue of the Mancos Shale that are slightly higher than the Ra-226 RAG.

No mine waste was observed in this upslope area or in the swales draining the area.

•	Accessibility and risk management considerations: No inaccessible areas are present
at the Quivira Mines. However, the arroyos adjacent to the mines are deeply incised and
difficult to access. Ra-226 was identified above the RAG in the Unnamed and Pipeline
Canyon Arroyos adjacent to CR-1 and CR-1E; however, EPCs for the two arroyos were
below the RAG. Arroyo soils data collected in 2010-2011 do not reflect more recent
conditions from soil mobility during monsoon events. Recent gamma scanning did not

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identify correlated Ra-226 values above the RAG. Therefore, no actionable risk was
identified in the two arroyos.

Figure 28, Figure 29, and Figure 30 present the proposed removal action extent at CR-1, CR-1E,
and the Kerr-McGee Ponds, respectively. The total calculated surface area is 62.9 acres, and the
total estimated volume is 1,005,500 bank cubic yards within the proposed removal action area.
The removal action extent by component is as follows:

•	CR-1 Waste Pile, Industrial Area, Lower Ponds, and Step-Out Areas: 38.8 acres;
estimated 929,200 bank cubic yards

•	CR-1E Waste Pile, Pond, Industrial Areas, and Step-Out Areas: 11.5 acres; estimated
49,300 bank cubic yards

•	Kerr-McGee Ponds Areas: 12.7 acres; estimated 27,000 bank cubic yards

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3.0 IDENTIFICATION OF REMOVAL ACTION OBJECTIVES

J

This section presents the 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. Taking current and
potential future land use and Navajo cultural considerations into account, the RAOs are to:

•	Prevent exposure to soil with contaminants from mining activities that would pose an
unacceptable risk to human health with the reasonably anticipated future land use and
traditional Navajo lifeways

•	Prevent exposure to soil with contaminants from mining activities that would pose an
unacceptable risk to plants, animals, and other ecological receptors

•	Prevent offsite migration of contaminants from mining activities that would pose an
unacceptable risk to human or ecologic health by soil, surface water, groundwater, or air

The reasonably anticipated reuse is generally residential although areas with steep terrain,
difficult access, or other similar use constraints are identified in the risk assessment and
addressed with reduced exposure parameters. These types of land use include seasonal sheep
camps, difficult access open space, easy access open space, and drainages and ravines. Other
land uses on the Navajo Nation also include livestock grazing, gardening, and wood and plant
gathering. The anticipated reuse is industrial for outdoor workers for the Kerr-McGee Ponds on
privately-owned UNC land.

The COCs, COECs, and numeric RAGs are listed in Section 2.7.

USEPA identified general response actions, screened potential technologies, and developed
alternatives in Section 4.1 that will satisfy the RAOs listed above. Section 4.2 describes the
retained removal action alternatives for the Quivira Mines, and Section 4.3 presents a detailed
analysis of the removal action alternatives with respect to NCP effectiveness, implementability,
and cost criteria. Section 5.0 presents a comparative analysis of the removal action alternatives.

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 because 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 all solid media contamination at the Quivira
Mines under the assumption that this will be the final action regarding solid media at the site.
The removal action will also protect against potential future impacts on groundwater and surface
water. Post-removal action site controls will be included under an alternative that does not
specify complete removal of contaminants to an offsite location.

3.4	REMOVAL SCHEDULE

NCP requires a minimum public comment period of 30 days following release of the proposed
final EE/CA by USEPA. USEPA and NNEPA will work together to respond to comments
received during the public comment period and publish an action memorandum following the
response to comments. USEPA will provide public notification of the removal action schedule
upon issuance of the action memorandum.

During implementation of the selected removal action alternative(s), 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
4 and 18 years, depending on alternative selected. Annual post-removal site controls (termed
maintenance within this EE/CA for brevity) include annual inspections and maintenance of
graded and revegetated site surfaces will be necessary at restored areas for at least the first
30 years after restoration because of the long time frame required to reestablish native
vegetation. Annual inspections and maintenance of a repository cap, if selected, will occur as
specified in a site-specific, long-term surveillance plan (prepared in accordance with 10 Code of
Federal Regulations [CFR] § 40.28) with inspection frequencies adjusted based on cover or cap
stability and inspection findings. A 100-year maintenance period is used for onsite capping
alternative cost estimating and comparison purposes.

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> — 	 I

This section identifies and analyzes the removal action alternatives for the Quivira Mines.

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 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 the applicable or relevant and
appropriate requirements (ARAR).

4.1.1 Summary of Technology Identification and Screening

The removal action alternative development process involves identifying general response
actions, technology types, and process options that may satisfy RAOs. Table 5 presents the
general response actions that were considered for the AUMs and includes 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 (protection and compliance with ARARs) or substantive
implementability criteria (technical, administrative, availability, and local acceptance), which are
detailed 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 is protective.

Institutional Controls. ICs include the implementation of access restrictions to control current
and future land use, including traditional Dine Lifeways. ICs would not reduce waste migration
from the site but could be used to protect human health by administratively restricting access to
affected areas. In addition, these restrictions may be used in conjunction with other technologies
to protect an implemented action. While the ICs are not effective as stand-alone remedies, they
are retained as components of alternatives that include capping waste on Navajo lands.

Potentially applicable ICs consist of land use and access restrictions that are described below.

•	Chapter land use plans - Land use plans are used on Navajo lands similar to zoning on
private lands to control current and future land uses.

•	Deed restrictions - Deed restrictions do not exist on Navajo lands.

•	Navajo Land Department homesite lease approvals - Building a home on Navajo
lands requires a homesite lease from the Navajo Land Department. The Navajo Land

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Department may restrict homesite leases on or near areas with hazardous conditions from
mining activities.

•	Environmental control easements - Environmental control easements are intended for
use at sites that contain or may contain hazardous wastes or substances that may threaten
public health, safety, or welfare or the environment if certain land uses are permitted or if
certain activities are performed on these sites. Environmental control easements are
primarily used to address residual contamination.

Engineering Controls. Engineering controls are used primarily to reduce exposure to
contaminants. These goals are accomplished 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; onsite containment and
consolidation; backfilling of cuts, benches, and pits; and backfilling of underground voids.

•	Surface controls - Surface control measures are used primarily to reduce contaminant
transport, direct exposure, and the 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 measures are retained at
the Quivira Mines for use in conjunction with other technologies.

•	Physical barriers - Physical barriers may include portal closure or site access controls
such as fencing and signage. Physical constraints of the location of AUM waste at many
of the sites may be restrictive to traditional heavy earthwork equipment because of steep
grades and limited working area. These process options are usually integrated with other
technologies to various degrees based on site characteristics and are not effective as a
stand-alone technology. Portal closures will be retained for infilled adits at the Quivira
Mines. The vertical shafts were closed during reclamation but will be closed again if
disturbed during remedy implementation.

•	Sorting - Soil and waste sorting is a standard process applied as an intermediate step
between soil or waste excavation and onsite or off-Navajo Nation 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 the 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 the volume requiring more costly treatment or disposal
options. A full-scale study is planned as part of a TCRA at the Cove Chapter. The goal of
the study is to segregate material at or below cleanup goals from waste requiring offsite
disposal. Sorting is retained and may be considered in conjunction with onsite
consolidation and containment at the Quivira Mines to remove higher concentration
waste for offsite disposal.

•	Onsite consolidation and containment - Mine waste can be consolidated and capped to
prevent exposure. Waste from all areas of the site is gathered together, or consolidated,
and then capped. Typically, the cap is an ET cap designed to minimize water infiltration
and leaching of contaminants, control erosion, control radon emissions, and limit
exposure to contaminants. The containment may be directly on site; or waste from

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multiple mines can be consolidated and capped at one mine site as a combined action
under CERCLA § 104(d)(4). Combined actions are considered "on site" and, thus, retain
the CERCLA permit exemption for onsite actions. Consolidation and containment is
retained at the Quivira Mines.

•	Backfilling of cuts, benches, and pits - Backfilling of aboveground mine workings with
mine waste occurs when mine waste is excavated and consolidated in cuts, benches, and
pits in isolated areas. The mine waste can be either treated to stabilize or solidify as
needed. Placement of mine waste would need to consider surrounding slope steepness
and minimize slope with engineered rock walls to reduce potential for slope failure.
Placing a soil cover over the waste (containment) would be required to reduce erosion
and promote vegetative growth. These mine features do not exist at the Quivira Mines;
therefore, backfilling is not retained.

•	Backfilling of underground voids - Backfilling of underground mine workings with
mine waste occurs when mine waste is pushed or pumped down vertical mine workings
(shafts, stopes, and vents) or injection wells, or transported or pumped into and placed
within horizontal workings (adits, drifts, and stopes) and underground vertical workings
(shafts, chutes, raises, winzes, and declines). Mine waste can be placed dry or wet,
depending on access to and whether the mine workings are flooded. Dry placement
requires reopening and rehabilitating adits and shafts for entry and providing a means for
material movement (conveyor). Dry placement at the Quivira Mines is not retained given
that the mine workings are 1,500 to 1,800 feet below grade and wet.

Wet placement requires creating a slurry that can flow or be pumped into the
underground mine workings. Approximately 4,000 gallons of water per cubic yard of
waste is typically required to create a 5 percent solids slurry. Forming a paste mixture
with less water (about 670 gallons of water per cubic yard of waste) is possible, but
directional placement would be required. Locating mine voids and drilling of multiple
large diameter boreholes would also be required to inject slurry. Once injected, the slurry
could partially separate back into solid and water, and this contaminated water could
migrate to surface water or groundwater. Cement or another solidifying agent could be
added to the slurry to reduce separation but would increase the volume of imported
materials and decrease the amount of waste that could be disposed of in the workings.
Wet placement is retained at the Quivira Mines; however, the mine shafts are already
backfilled, requiring drilling of multiple deep injection wells to reach flooded workings.

Disposal. Mine waste can be excavated and disposed of on or off site as a potential remedy.
Onsite disposal may be applicable at mines where waste is consolidated or for locations where a
separate onsite repository would be constructed. Offsite disposal may be applicable if the
disposal site is accessible to a large volume of truck traffic and the waste can be hauled to an on-
or off-Navajo Nation regional repository or a RCRA C or LLRW facility licensed to receive
radiological waste. Pretreatment of waste using solidification or stabilization to address potential
leachability may be considered where repository design does not address the potential for
leachate generation. On- or offsite disposal and on- or off-Navajo Nation disposal are retained
for the Quivira Mines.

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Treatment. CERCLA and NCP express a preference for the treatment of waste that significantly
and permanently reduces the volume, toxicity, or mobility of contaminants in selecting remedial
actions, where such treatment is practicable. CERCLA § 121(b), 40 CFR § 300.430(a)(l)(iii),
and USEPA (1991a) guidance on principal threat and low-level threat waste describe how to
identify wastes that may be appropriate for treatment. Principal threat wastes are those source
materials considered to be highly toxic or highly 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 has fully considered whether the site contained any principal threat waste, whether that
waste could safely be contained using engineering controls, and whether any treatment options
may be practicable for the waste at the site. As a result of its investigation and analysis, USEPA
concluded that, while individual samples at the site contained higher levels of contaminants that
might be considered principal threat waste, the waste at the site is extremely variable and
heterogeneous and USEPA found no distinct areas of waste rock that were clearly
distinguishable as meeting the definitions of principal threat waste in USEPA (1991a) guidance.
However, to be consistent with USEPA's preference for treatment, USEPA did fully evaluate a
complete range of treatment options. A summary of the treatment evaluation is discussed below.

Ex Situ Treatment. Excavation and treatment involve the removal of waste from a source area
and subsequent treatment using processes that chemically, physically, or thermally reduce
contaminant toxicity, mobility, or volume. Treatment processes have the primary objective of
either (1) concentrating chemicals for additional treatment, disposal, or recovery of valuable
constituents or (2) reducing the mobility of the chemicals. A short screening summary of
different ex situ treatment classes is described below.

• Physical and chemical treatments - Physical treatment processes use physical

separation and the 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. The net result of chemical treatment processes is
a reduction of toxicity and mobility of contaminants in the solid media. Different types of
physical and chemical treatments screened include soil washing, acid extraction, ablation,
milling, solidification, and stabilization.

o Soil washing is a treatment process that involves washing the contaminated waste
(with water) in a heap, vat, or agitated vessel to dissolve water-soluble contaminants.
The most common forms of uranium oxides attached to sand particles in waste rock at
the site have low solubility in water, rendering soil washing ineffective for removal to
below cleanup goals. Dewatered precipitates and sludge must be disposed of at a mill
or RCRA C or LLRW facility licensed to receive radiological waste because of the
concentrating of radionuclides. Because of the low concentrations of uranium in the
waste rock, varying solubilities at different pH ranges for radionuclides and metals,
and limited demonstrated application for AUM wastes, soil washing likely would not
meet cleanup goals and was not retained.

o Acid extraction is similar to soil washing except an acidic solution instead of water
is applied to the waste rock or other contaminated media in a heap, vat, or agitated

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vessel. Acid extraction would dissolve a portion of the mineralized uranium attached
to the sand particles; however, some percentage could remain bound in the sand
particles. Dissolved contaminants are subsequently precipitated for additional
treatment and disposal. Based on the uranium mineralization in the waste rock and
varying solubilities of radionuclides and metals at different pH ranges, acid extraction
likely would not decrease concentrations of all contaminants below cleanup goals and
was not retained.

o Ablation can be applied to sandstone-hosted uranium mineralization where the
uranium minerals form a crust on the sand grains. The ablation process mixes water
and waste rock into a slurry and impacts opposing slurry streams, causing collisions
between the sandstone particles and fragments and removing the uranium minerals
coating the sand grains. Uranium mass then shifts from coarse-grain to fine-grain
fraction, resulting in a much smaller volume of waste requiring disposal. Pilot-scale
studies at three sites on the Navajo Nation, including the Quivira Mines, has shown
that up to 95 percent removal of uranium mass from the coarse sand fraction can be
achieved, that the treated materials are not RCRA hazardous, and do not generate
leachable metals or radionuclides above EPA and Navajo Nation water quality
standards. Concentrates are disposed of off site at a RCRA C or LLRW facility
licensed to receive radiological waste. However, ablation has not been able to achieve
low cleanup goals for unrestricted use, such as those established for the Quivira
Mines and Section 32 and 33 Mines. Instead, ablation can be used to reduce uranium
mass for waste consolidated on site and to reduce migration potential. Ablation was
not retained as a standalone or pretreatment treatment technology because it would
increase costs without significantly reducing risk.

o Milling is an offsite commercial process that removes uranium by a combination of
several methods, including pulverization and acid extraction. Concentrations of
uranium in the waste rock at the site are low, so any processing would, therefore,
yield only a minimal amount of uranium. Additionally, milling does not remove
Ra-226 and the resulting mill waste is neither less toxic nor less mobile than the
source material. Thus, milling was not retained for treatment of uranium mine waste.
Milling may be considered as a pretreatment step for recovering uranium before
disposal in a tailings disposal facility; however, an operational mill that is in
compliance with the CERCLA Off-Site Rule is not located within the region and
milling alone as a pretreatment step was also not retained.

o Solidification and stabilization are processes that either physically encapsulates or
chemically alters mine waste to reduce contaminant leachability, mobility, or toxicity.
Neither process addresses radiation concerns. Solidification involves mixing waste
with a binder material such as cement, fly ash, clay, or geopolymers. Stabilization
involves mixing waste with a neutralizing material such as lime/fly ash and
pozzolan/cement. The binder or neutralizing material would have to be hauled to the
site, and a batch plant would need to be set up to mix the material with waste. The
mixing process requires a large quantity of water for binding to occur; therefore, a
water source must be developed or water must be imported from off site. Once the
material is solidified or stabilized, it may be placed into a repository or in
aboveground mine workings as stackable blocks or gravel admixture; however, the

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volume of waste requiring disposal greatly increases because of the addition of
binding and neutralizing agents. Furthermore, unless placed in a disposal cell or
repository, the solidified or stabilized material may break apart when exposed to
freeze-thaw and precipitation, potentially increasing leachability. On- or offsite
disposal options are protective and use fewer resources. As a result, solidification and
stabilization were not retained.

•	Thermal treatment - Thermal treatment technologies apply very high levels of heat to
the excavated soil in a reactor to volatilize and oxidize contaminants and render them
amenable to additional processing. Thermal treatment is typically used for organic
contaminants and is not effective on radionuclides and metals in soils.

In Situ Treatment. In situ treatment involves treating the contaminated medium where it is
currently located. In situ technologies reduce the mobility and toxicity 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. A short screening
summary of different in situ treatment classes is described below.

•	Physical and chemical treatments - Potentially applicable in situ physical and chemical
treatment technologies include soil stabilization and solidification. In situ stabilization
and solidification are similar to conventional ex situ stabilization in that a solidifying
agent (or combination of agents) induces a chemical or physical change in the mobility or
toxicity of the contaminants. The in situ process uses deep-mixing techniques to allow
maximum contact of the solidifying agents with the contaminated medium. The
technologies were not retained because the waste pile depth and the hillslope orientation
of the waste pile would make the in situ approach problematic. In addition, exposure to
external irradiation by treated materials would remain unless covered with a calculated
depth of soil.

•	Thermal treatment - In situ vitrification is a process used to melt contaminated
solid media in situ to immobilize radionuclides and metals into a glass-like, inert,
non-leachable solid matrix. Vitrification requires significant energy to generate sufficient
current to force the solid medium to act as a continuous electrical conductor. In situ
vitrification has been demonstrated only at the pilot scale, and treatment costs are
extremely high compared with other treatment technologies. The technology does not
address exposure from external irradiation from treated materials and is not considered a
feasible option because the infrastructure necessary to deliver high-voltage electricity to a
site is unavailable and portable generators cannot provide sufficient voltage, which makes
the startup and treatment cost prohibitive. Therefore, in situ vitrification was not retained.

•	Vegetative treatment - Vegetation treatment (also known as phytoremediation) is an
innovative process that uses plants to remove, transfer, stabilize, or destroy contaminants
in soil or sediment. Phytoremediation methods applicable to AUM waste are limited to
phytoextraction and phytostabilization. Much of the contamination at the site is located in
30- to 60-foot-deep piles, and not all of the waste would be easily accessible by plant
roots. Moreover, because radionuclides and metals cannot be biodegraded, plants used in
phytoremediation must be harvested and sent for disposal as a radioactive waste and
prevention of human or animal consumption of the plants would be necessary. Because of

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the depth of waste, limited depth of root penetration, and harvested material handling
requirements, phytoremediation was not retained.

If the treatments discussed above or any other treatment methods are shown to be effective and
practicable before selection of a remedy, 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 protective, effective, and implementable for the Quivira Mines.
ICs, surface controls, and access controls are feasible but not as stand-alone 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 for the Quivira Mines:

•	Excavation, Onsite Ablation, Onsite Capping of Treated Material, and Offsite
Disposal of Concentrates. Ablation may not be able to attain background levels for all
waste, therefore, this potential future disposal alternative would utilize ablation as
pretreatment step to reduce Ra-226 and uranium concentrations posing a risk to people
and ecological receptors and volume before treated material is consolidated and covered
onsite. The pretreatment step offers more contaminant removal than simple onsite
consolidation and capping as contaminant mass remaining on site is reduced by up to

95 percent. Ablation pretreatment could be retained after additional scalability testing and
where a viable offsite disposal alternative at a similar cost is not available and the
community would like contaminant mass and volume reduction before onsite
consolidation and capping.

•	Excavation and Disposal at Uranium Mill Tailings Radiation Control Act Sites.

Several Uranium Mill Tailings Radiation Control Act sites, including the UNC Mill
Facility, assessed for disposal of the Quivira Mines waste were considered infeasible
because those sites were closed, had insufficient capacity to receive the waste, or had
groundwater contamination issues that could prohibit disposal under the CERCLA
Off-Site Rule.

•	Excavation and Disposal at Unlicensed Disposal Facilities. Use of two currently
unlicensed locations for new disposal facilities at abandoned coal mines near Grants and
Fort Wingate was considered infeasible because of limitations under 10 United States
Code 2692. Factors included the long time required to license new disposal facilities,
whether the coal mines could meet licensing requirements, and contamination issues at
both sites that could prohibit disposal under the CERCLA Off-Site Rule.

•	Excavation and Disposal at 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

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infeasible at this time because of potential contamination issues that would 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
obtained from USEPA.

•	Excavation and Disposal at the UNC Mill Facility Tailings Area. The UNC Mill
Facility tailings area was selected as the preferred alternative for disposal of
contaminated soil from the NECR Mine. However, disposal of waste from the site at the
UNC Mill Facility tailings area is considered administratively infeasible for the
following reasons:

o The property owner (UNC) is unwilling to accept the waste at this time.

o The process to design placement of the NECR Mine waste at the UNC Mill Facility
tailings area was completed in 2018 (MWH 2018). The design indicates little
likelihood that extra capacity to accept waste from the Quivira Mines would exist
after the NECR Mine removal action. Moreover, evaluating the required changes to
the remedial design would delay the remedial process for the NECR Mine.

o The UNC Mill Facility tailings area is under an NRC license that must be amended
by NRC before placement of any waste. NRC estimates that it will make a decision
on the license amendment request in 2022. Adding waste from the site to that license
termination process would result in further delays.

o The U.S. Department of Energy Legacy Management Program assumes land

ownership and long-term maintenance responsibility for mill sites after termination of
NRC licenses. Adding waste from the site to the design would necessitate
additional delays.

o Both USEPA and the community are committed to implementing both the Quivira
Mines and NECR Mine actions within the smallest possible time frame to minimize
impacts on the community. However, transport and placement of waste from both the
NECR Mine and the Quivira Mines to the UNC Mill Facility tailings area
concurrently would increase potential for construction and transportation bottlenecks
and delays.

Excavation and disposal at the UNC Mill Facility tailings area was eliminated as an
option from this EE/CA because too many legal, administrative, and implementation
hurdles would have to be addressed that would likely add years to both the Quivira Mines
and NECR Mine removal actions.

•	Use of Both Upper and Lower Synthetic Liners for Repositories. Onsite disposal was
evaluated as a removal alternative. Each onsite disposal alternative involves two cover
options: (1) using a store-and-release (also known as ET) cover, and (2) using an upper
synthetic liner with a store-and-release cover. Use of both an upper and lower liner has
been screened out as an option because this would add significant additional cost
without adding additional protection. AHydrologic Evaluation of Landfill Performance
(HELP) model was used to evaluate the difference in percolation through 3- and 4-feet
deep ET cap systems. The models showed annual percolation through the cover at
amounts less than the accuracy of the model (0.002453 inch for the ET cap of 3 feet and

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0.001598 inch for the ET cap of 4 feet). Because precipitation measurement inputs into
the model are only accurate to 0.1 or 0.01 inch, the modeled percolation value is zero.
This modeling indicates that no liners are necessary to prevent infiltration into the wastes
with an ET cap ranging from 3 to 4 feet in depth.

•	Evaluation of Rail Transport of Waste to Disposal Facilities. Two off-Navajo Nation
disposal facilities are set up to receive railcars containing waste rock: a RCRA C landfill
in Deer Trail, Colorado, and a LLRW facility in Andrews, Texas. Rail transport was
evaluated considering three options: (1) extending a rail line from Gallup to the Old
Church Rock Mine about 5 miles from the Quivira Mines, (2) trucking waste 30 miles to
an existing rail spur near High Country Transportation, and (3) trucking waste 14 miles to
a new loading facility along the main rail lines on the Interstate 40 corridor. Because of
costs to purchase land along a right-of-way, costs to construct bridges across arroyos,
long permitting lead times, and a cost of construction of $3 to $4 million per mile, the
option to extend a rail line to the Quivira Mines was assessed to not be viable. Trucking
mileage to an existing rail spur near High Country Transportation is approximately the
same mileage as to the Red Rocks disposal facility, passing through Gallup twice, and
scheduling of loaded and return railcars would require scheduling and holds from the
railroad. Consequently, the option was assessed to not be viable for transport to the

Red Rocks disposal facility. Construction of a loading facility adjacent to the main rail
lines on the Interstate 40 corridor was initially deemed not viable because the BNSF
Railway representatives informed USEPA that no loading facilities could be placed along
the main transit lines in that area. Further, even if allowed, property would have to be
purchased or leased, the loading facility would need to be designed and constructed, and
a spur off the main transit lines would need to be reviewed, approved, and constructed
(Tetra Tech 2024).

USEPA also visited potential rail spur and loading/unloading sites in the Gallup area
(14 miles) and in the Thoreau area (48 miles) from the Quivira Mines and determined
that transloading facilities would need to be constructed and operated to receive the waste
from trucks and transfer into railcars and would create another area requiring cleanup at
the end of the project. USEPA determined that trucking the waste through the
communities would be no different than hauling waste to the Red Rocks disposal facility.
Waste transfer and scheduling would also add additional years to cleanup of the Quivira
Mines. Therefore, USEPA determined that rail transport would have limited benefit to the
local community and was assessed to not be viable (Tetra Tech 2024).

•	Evaluation of Truck Transport of Waste to Disposal Facilities. Two main haul routes
were considered for trucking waste from the Quivira Mines to the Red Rocks disposal
facility: (1) south on State Highway 566 to Interstate 40, exiting Interstate 40 at Thoreau,
and then north on State Highway 371 to the facility; and (2) south on State Highway 566
to Pinedale Road/State Highway 11-49 and then south on State Highway 371 to the
facility. These routes are the most direct or safest routes and were both assessed as viable.
Option 1 using the Interstate 40 corridor is the recommended route because of road safety
and capacity, less additive traffic impact from other mines on the Option 2 route, and
fewer communities impacted (Tetra Tech 2024). Exiting Interstate 40 at Thoreau
provides an overpass to the high-traffic railroad lines that parallel Interstate 40. At-grade
crossing of these main rail transit lines with thousands of haul trucks, as envisioned by

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screened-out options, is a risk to the truck drivers, trains on the main transit lines, and
nearby communities (Tetra Tech 2024).

Retained Removal Action Alternatives. 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 - No new treatment, containment, or response action would
occur at the site. Maintenance of the existing soil cover and site controls would continue.
The No Action alternative has been included as a requirement of NCP and to provide a
basis for comparison of the remaining alternatives. Exposure to COCs by human and
ecological receptors would not be reduced.

•	Alternative 2: Consolidate and Cap All Waste On Site - All waste rock and
contaminated soils from the Quivira Mines with concentrations above the action levels
would be consolidated and capped on site. A store-and-release cover (ET cap) will be
used. The cover would be designed to meet performance criteria to achieve specified
radon flux attenuation goals.

•	Alternative 3: Dispose of All Mine Waste Off Site at Red Rocks Disposal Facility -

Waste rock and contaminated soils with concentrations above the action levels would be
excavated and disposed of at a State of New Mexico permitted offsite disposal facility
located adjacent to but managed separately from the Red Rocks Municipal landfill near
Thoreau, New Mexico. Waste would be transported south on State Highway 566 to
Interstate 40, exiting Interstate 40 at Thoreau, and north on State Highway 371 to the Red
Rocks disposal facility.

•	Alternative 4: Dispose of All Mine Waste Off Site at a RCRA C or LLRW Facility -

Waste rock and contaminated soils with concentrations above the action levels would be
excavated and disposed of at a RCRA C and State of Colorado radiological licensed
facility, such as the Clean Harbors RCRA C facility in Deer Trail, Colorado, or an
NRC licensed LLRW facility, such as the WCS facility in Andrews, Texas. Waste
would be transported south on State Highway 566 to Interstate 40, east to Interstate 25,
north on Interstate 25, northeast on State Highway 24, and north on State Highway 71 to
Deer Trail.

Retained removal action alternatives listed above are fully described in Section 4.2.2 and are
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 Quivira Mines was comprehensive, and
no ARARs were rejected based on the exigencies of the situation. The Quivira Mines is located
on Navajo Nation and UNC lands. Pursuant to NCP at 40 CFR § 300.5, the term "state" includes
American Indian tribes. Therefore, for the purposes of evaluating potential ARARs, Navajo
requirements will be treated the same as state requirements. The identification of ARARs is an

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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 other "To Be Considered" (TBC) criteria
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. The onsite actions
evaluated in this EE/CA will occur on Navajo Nation and UNC lands. Navajo Nation statutory
and regulatory requirements were evaluated as potential ARARs for Navajo Nation lands
(USEPA 1991b). State of New Mexico has regulatory jurisdiction on UNC lands but not on
Navajo Nation lands. Compliance with ARARs requires compliance only with the substantive
requirements contained within the statute or regulation and, pursuant to CERCLA § 121(e)(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 State of New Mexico ARARs and Navajo Nation ARARs. For a State of
New Mexico or Navajo Nation requirement to be identified as a potential ARAR, the
requirement must be more stringent than the corresponding 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.

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•	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.

•	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 this response action are presented and analyzed in Table 6 by ARAR
category and address requirements specific to the alternatives for the Quivira Mines.

4.2 DESCRIPTION OF ALTERNATIVES

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 through 4 are provided in the following subsections.

4.2.1.1 Common Elements for Construction and Restoration

Common removal action elements at the Quivira Mines for construction and restoration for
Alternatives 2 through 4 are described below.

Site Preparation. A laydown area would be established after biological and cultural resource
clearances near the Quivira Mines (Figure 31). Laydown areas 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 Quivira Mines. Construction
of a new construction supply well near the onsite repository would be needed to provide water
for the project. Utility water could be obtained approximately 20 miles from the City of Gallup
depending on existing infrastructure and the volume of water available. Well depths would likely
range from 500 to 700 feet for the Upper Gallup aquifer and 850 to 1,000 feet for the Lower
Gallup aquifer if Gallup water is not available. Generators for site power would be used to run
the well pump. Therefore, power for the project would be provided by diesel generators for the
temporary work site (laydown) and well site location (if constructed). The diesel generators
would require bulk fuel storage at the laydown area, as well as daily storage on the project site. A
secondary containment area would be constructed around generators, storage tanks, and fueling
area. The generators would provide power for various types of construction equipment, lighting
systems, and pumps. A water storage tank for the water trucks would also be required. If a well
is constructed, it could be left after completion of the removal action for use by the Navajo
community for irrigation or livestock.

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Cultural and Biological Exclusion and Timing. Cultural resource surveys were conducted in
2010 for CR-1 and CR-1E (SENES 2011) and in 2022 for the preliminary removal action area by
Dinetahdoo Cultural Resources Management. The results of these surveys would be reviewed
and used where possible for planning and removal design. Additional surveys would be
performed after design by a Navajo Nation-approved archeologist, and compliance requirements
for cultural resources would be specified by USEPA with concurrence by the Navajo Nation
Heritage and Historic Preservation Department. For the purposes of this EE/CA and consistent
with other CERCLA actions taken in this area, cultural resources can assume to be avoided or
protected during site work activities and that no special status plant or animal species would be
identified that would limit site work activities.

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. NNDFW and previous
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 need to be surveyed before earthmoving activities. If any natural resources are found, then
ARARs would be identified.

The removal actions would involve construction of access and haul roads and a laydown area.
Therefore, additional field surveys and reports of both natural and cultural resources in the
proposed work areas would be required in consultation with the Navajo Nation. The surveys
must conclude that 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. During the response and restoration activities, site access would be restricted by the
existing fence and temporary fencing that would be constructed where the existing fence may
need to be removed to perform work. Security would be maintained during all non-working
hours while site work is occurring. The site foreperson and the health and safety officer would be
responsible for personnel while they are on the site. To restrict access, the site would remain
completely fenced throughout the duration of construction activities. Temporary fencing would
be used whenever the perimeter fence must be removed for construction access. Alternate
entrances that may be required for portions of the work would be secured when not in use. If
work is occurring at CR-1, CR-1E, and the Kerr-McGee Ponds simultaneously, security would
be provided at all lease areas. USEPA and its authorized representatives, including its
contractors, and representatives of NNEPA 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.

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The alternatives being considered require an extensive amount of soil and water hauling over
several years. An access road would be constructed from Pipeline Canyon Road to the east side
of CR-1 to minimize disturbance of nearby residence along Red Water Pond Road (Figure 31).
CR-1E access to the Kerr-McGee Ponds would use existing access roads and Pipeline Canyon
Road. Existing access roads and Pipeline Canyon Road are graded dirt roads and would not
support 22-cubic-yard (33-ton) off-road articulated haul truck or 16.5-cubic-yard (25-ton)
on-highway haul truck and construction equipment movement. Existing access roads and
Pipeline Canyon Road would require widening and surfacing with gravel or pavement to reduce
dust generation, including water conveyances along and passing under the roads for year-round
operations. During transport on site (between CR-1, CR-1E, and the Kerr-McGee Ponds) and
off site (State Road 566), traffic controls would be necessary. A traffic control plan would be
developed and followed throughout operations. Even with precautions, nearby paved roads
would require maintenance to protect the roadway and road users. To maintain road load limits,
scales would be used to weigh the trucks that navigate Navajo Nation roadways. Observing road
and bridge 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 Red Water Pond
Road and Pipeline Canyon Road as needed.

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 and within the community. Air monitoring stations would be positioned and
operated to monitor dust and airborne contaminant concentrations during grubbing, excavating,
stockpiling, loading of bulk carriers, managing the stockpile, and restoring the site. Air
monitoring results and dust suppression measures would be used to document that offsite
migration of contaminants at unacceptable activity concentrations does not occur, maintain
compliant air quality conditions and a safe working environment, and protect the health of
nearby residents, workers, the general public, and the environment. Frequent water spraying
would be used during soil moving activities at all work zones and for dust suppression. Water
would be sourced from an offsite source or a permanent well installed near CR-1.

Dust Control. Off-road haul routes and site excavation and restoration areas would be wetted so
that dust generation is minimized. Frequent water spraying would be used during soil moving
activities for dust suppression. Further, rock fields and grating would be used to reduce 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 or pumped from a new construction well as
described earlier. Alternate methods of dust control, such as chemical polymers, gravel cover,
recycle 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 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 drainage patterns to the extent possible.
Activities at the Quivira Mines must be evaluated for potential impacts on federally listed species
and critical habitat and for certification to meet the substantive requirements of the National

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Pollutant Discharge Elimination System Multi-Sector General Permit. Once the site has been
stabilized, monitoring of construction stormwater runoff would cease and post-removal action
site controls would be initiated. The cost estimates include provisions for ongoing cover
maintenance and erosion control and fence inspection and repair.

Excavation Approach. Waste rock piles and contaminated soils containing metals and
radionuclides above RAGs are the removal areas of concern (Figure 28 through Figure 30). The
estimated 1,005,500 bank cubic yards of waste is easily accessible. Waste excavation methods
considered for the Quivira Mines include standard- to large-size excavators and loaders. Waste
rock piles would be removed to native soil interface after which excavation would proceed in
lifts using field screening techniques such as gamma scanning and X-ray fluorescence
measurements until RAGs are attained. In some areas, excavation may extend to bedrock, at
which point excavation would stop. Confirmation sampling and final status survey sampling
would be conducted to verify attainment of RAGs and RAOs. Waste rock and contaminated soils
would be temporarily stockpiled for load out. Borrow material would first be obtained from on
site; additional imported borrow material may be needed.

Waste Handling and Transfer. For cost estimating purposes, 22-cubic-yard (33-ton) articulated
haul trucks were assumed for onsite transport and 16.5-cubic-yard (25-ton) on-highway haul
trucks were assumed for offsite transport. Waste would be transferred on site using existing and
temporary access roads and Pipeline Canyon Road (Figure 31). Waste transferred off site would
use Pipeline Canyon Road to State Road 566 to avoid the Red Water Pond Road residential
community. No transfer station would be required because the site can be accessed with multiple
types of trucks. Dry brushing of all truck beds and wheels would occur before each truck leaves
the site. During muddy conditions, scraping and spraying of truck tires will also be conducted.
Traffic control planning and implementation would be required for Pipeline Canyon Road and at
the entrance to State Road 566.

Site Restoration Activities. USEPA has developed a matrix to identify the different features and
areas of the Quivira Mines requiring restoration and the typical restoration approaches for each
feature and area. Site restoration approaches for each mine feature and area are described below:

•	Waste excavation areas - Excavated areas would be backfilled and compacted with soil
from a local borrow area, contour graded to match adjacent topography, covered with an
erosion control blanket, and seeded using local grasses and forbs. Upslope soil and rock
berms and drainage ditch system would be used to divert run-on around the restored and
disturbed areas.

•	Mine portals - The shafts and adits at CR-1 and CR-1E (Figure 2 and Figure 3) were
closed during reclamation; however, the top of the two adits at CR-1E are currently
uncovered. Further, waste excavation activities may disturb these mine portals.

Therefore, the mine portal locations would be evaluated during the removal action to
verify the integrity of the closure and corrective actions would be taken to repair or
augment existing portal closures.

•	Access roads - Access roads needed for CR-1E and the Kerr-McGee Ponds already
exist; however, a new temporary access road would be constructed from Pipeline Canyon
Road to CR-1 (Figure 31). Improvements would be made to the existing access roads and

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Pipeline Canyon Road to allow construction traffic. After successful restoration of the
disturbed areas of the site, the temporary access roads would be obliterated. Overbank
materials would be moved back onto the road surface. The road pathways would be
contour graded to match surrounding grade and seeded using local grasses and forbs.
Water control bars 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.

•	Fencing - Domestic livestock would not be allowed to enter the site until it is fully
restored. Temporary 4-strand barbed wire fencing would be erected around the restored
area (site and borrow area) to protect revegetation efforts from grazing over a period of
up to 30 years. Once vegetation is restored and the site has stabilized, perimeter fencing
at the Quivira Mines may be removed except where a repository is present. Repository
perimeter fencing and signage would remain indefinitely. Restoration activities may take
30 years or more before adequate vegetation is in place and final stabilization is achieved.

•	Livestock controls - In addition to fencing, berms or barricades would be constructed on
temporary access roads and benches to reduce ease of access for livestock over the short
term and allow for successful revegetation.

4.2.1.2 Common Elements for Maintenance

Common removal action elements at the Quivira Mines for maintenance for Alternatives 2
through 4 are described below.

This cost assumes maintenance of the ET cap would be required in perpetuity, but for cost
estimating purposes was assumed to include cap inspections, erosion repairs, and revegetation
for 30 years and cap inspections for up to 100 years. USEPA would be responsible for the
long-term maintenance of the repository. Restoration maintenance at the Quivira Mines would
consist of 10 years of erosion repairs and inspections and 30 years of vegetation surveys and
maintenance of revegetation efforts.

Maintenance after Site Restoration. Maintenance at the Quivira Mines would consist of
10 years of erosion repairs with inspections, vegetation surveys, and maintenance of revegetation
efforts extending up to 30 years for restored areas of the site, including excavation areas,
removed roads, and borrow areas. For cost estimating purposes, maintenance would include:

•	Inspection and vegetation survey in late spring (up to 30 years)

•	Vegetation maintenance, including reseedings and removing weeds (first 10 years and as
needed up to 30 years)

•	Erosion control inspection and maintenance survey after the monsoon season (first
10 years)

•	Maintenance of the access road until vegetation and restored areas have stabilized (first
10 years)

•	Repairs to erosional features and water control berms (first 10 years)

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On-Navajo Repository Closure and Long-Term Maintenance. Activities common to
Alternative 2 include:

•	Final grading, surface erosion controls, and revegetation of the onsite repository cap
would be designed to limit the visual impact by mimicking local terrain and using local
soils and vegetation (Appendix F).

•	Erosion controls on the cap may include biodegradable matting and wattles and use
berms and ditches to direct run-on water around the repository.

•	Temporary range fencing would be installed around restored areas during the
revegetation period to stop livestock from disturbing the soil cover and
revegetation efforts.

•	Permanent fencing and signage would be installed and maintained around the repository
to control or restrict grazing and access since overgrazing, livestock foot traffic, or
vehicle traffic could damage the cap. A gate would be installed to provide access for
periodic rotational grazing on the cap.

Land use controls would be required for waste placed in a repository to protect the response
action. The form of the land use controls would likely be a land withdrawal or an environmental
covenant, such as an easement to restrict future residential use or activities that would disturb
the cap.

Annual inspection and maintenance of the repository covers would be conducted as specified in a
long-term surveillance plan (10 CFR § 40.28) with inspection frequencies adjusted based on the
cover stability and inspection findings. The annual inspection would consist of checking for
erosion and animal burrows and verifying the integrity of erosion controls. Maintenance would
consist of filling burrows, filling and grading eroded surfaces, clearing accumulated erosion
materials, replanting vegetation, and repairing access roads. Maintenance costs were developed
based on a 100-year duration for the earthen covers placed on top of radiological waste contained
within an onsite repository. For cost estimating purposes, maintenance would include:

•	Inspection and vegetation survey in late spring (up to 30 years)

•	Vegetation maintenance, including reseedings and removing weeds (first 10 years and as
needed up to 30 years)

•	Erosion control inspection and maintenance survey after the monsoon season (up to
100 years)

•	Repairs to erosional features and water control berms (first 10 years and as needed up to
30 years)

The repository would be maintained in perpetuity. Additional maintenance costs beyond 100
years assumed for cost estimating purposes will depend on inspection results and updates to the
long-term surveillance plan.

CERCLA Off-Site Rule. Alternatives that involve transportation off site for disposal or
consolidation into a regional repository would require compliance with the CERCLA Off-Site
Rule. In general, the CERCLA Off-Site Rule requires that facilities that accept contaminated or

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hazardous wastes from a CERCLA site must follow all applicable regulations and laws (that is,
they must be approved to take those wastes and be in compliance with the applicable federal,
state, and local requirements to do so). The licensed disposal facilities considered for any
alternatives involving offsite consolidation into a repository would be required to have existing
approval under the CERCLA Off-Site Rule.

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 through 4,
unavoidable impacts are expected and include:

•	Existing vegetation at the Quivira Mines is limited to scrub and grasses with a few small
trees. Geomorphic design of the onsite repository may require removal of juniper trees
northeast of the site. Disturbed areas would be reclaimed after construction, but
reestablishing the existing vegetation will take time.

•	Local populations using Pipeline Canyon Road and State Road 566 will be
inconvenienced by heavy equipment activity during the February to November
construction period and by increased truck traffic on Pipeline Canyon Road, State
Road 566, and all other access roads near the site and offsite disposal facility. Generation
of dust on access roads would be minimized through spraying with water during
construction and hauling activities or using chemical polymers, gravel cover, recycle
asphalt, or paving of access and haul roads. Noise would be limited to normal work hours
to avoid disturbing local residents.

•	Disruption of sensitive species and habitat during construction activities is not anticipated
at the Quivira Mines based on previous biological surveys. If sensitive species are
subsequently identified during a biological survey before the removal action, the timing
and location of construction activities would be adjusted to limit disturbance and
biological monitoring would be conducted during construction activities.

•	Cultural resources were not identified at the Quivira Mines during previous actions.
However, cultural resources were identified west of CR-1 and east of the Kerr-McGee
Ponds. A cultural resource specialist would be consulted during the removal design to
avoid sensitive areas during proposed construction activities. Cultural resource monitors
would be on site during construction activities to oversee that resources are not disturbed
and identify any resources uncovered during excavation activities.

•	Increased risk of traffic accidents and fatalities and greenhouse gas emissions is
anticipated because of the trucking of fill, cover material, and waste. As the haul distance
increases, the potential risks also increase. Water would be required for dust control
during excavation, waste compaction, and restoration, and on roads during waste hauling.
Water use, trucking mileage, greenhouse gas emissions, and traffic accident and fatalities
are discussed for each alternative in Section 4.3.

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4.2.2 Description of Removal Action Alternatives

The following subsections present descriptions of the five removal action alternatives identified
in Section 4.1.2. All haul roads, laydown areas, water sources, and truck and access roads needed
for the removal actions are shown on Figure 31.

4.2.2.1	Alternative 1: No Action

Under Alternative 1, radionuclide and metal COCs and COECs in the waste piles and
surrounding soils would not be addressed. No land use controls, signage, range fencing, or
barriers would be used to limit access at the site. Existing perimeter site fencing would remain.
No removal or site stabilization activities would occur.

4.2.2.2	Alternative 2: Consolidate and Cap All Waste On Site

Alternative 2 includes consolidation and capping waste on site in a repository. Geomorphic
design would be used to enhance the aesthetics of the repository and improve erosion control.
The design approach would be to blend the repository into adjacent hillslopes to mimic
topography and bedrock outcrops and to plant native vegetation compatible with repository cap
and adjacent landscape. An example of a geomorphic design concept for CR-1 is shown in
Appendix F.

Under Alternative 2, the RAOs would be accomplished through excavation, hauling, and
consolidation of an estimated 1,005,500 bank cubic yards or 1,256,875 loose cubic yards of
waste from the Quivira Mines in an onsite repository at or near CR-1 (including a canyon
repository); containment of waste in the onsite repository; and implementation and maintenance
of site restoration measures and land use and access controls to protect the repository and site
restoration process. For cost estimating purposes a 3 mile radius was assumed around CR-1 for
the furthest potential repository location. Site excavation and restoration elements common to all
action alternatives are described in Section 4.2.1.1.

Containment in an onsite repository would involve the construction of an engineered cap over
the consolidated mine waste. Based on HELP modeling, an ET cap of 36 inches of a soil and
gravel admixture is assumed to prevent infiltration of precipitation and snowmelt, control radon
gas flux, and reduce gamma activity to background. For cost estimating purposes a 48-inch
cap is assumed, which is what was the ET cap design that will be used at NECR to cap the
tailings. The ET cap can be designed to be stable on slopes between 5:1 and 3:1 and allow for
slow dispersion of radon gas. Natural, local vegetation would be established on the ET cap. The
ET cap would allow for grazing but would not be suitable as a location for irrigated agriculture
or building development.

Waste would be placed and consolidated in such a manner as to mimic surrounding topography
and benched to create sandstone-faced terraces to blend into the landscape. Every effort would
be made to place waste within draws and box canyons areas and minimize the use of a
monolithic stockpile that is currently present at the site. Nearby sources of soil for cap
construction are available along Pipeline Canyon and include the fluvial deposits in the drainage

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and above the earthen dam northeast of CR-1E. Investigations of these borrow sources
performed in 2022 indicated that the soils are suitable material for an ET cap.

Waste from CR-1, CR-1E, and the Kerr-McGee Ponds would be hauled and consolidated at an
onsite repository. Work sequencing assumes that all waste will be placed and compacted in the
repository before capping begins. Excavation areas for Alternative 2 are shown on Figure 32, and
capping and restoration areas are shown on Figure 33. Typical waste consolidation area features
are shown on Figure 34. The onsite repository construction and maintenance costs are based on
the volume of waste contributed to the repository from CR-1, CR-1E, and the Kerr-McGee
Ponds. The overall estimated duration of the project is 4 years.

Site restoration activities include backfilling and grading of waste excavation areas, erosion
controls, and revegetation. Permanent fencing and signage would be installed and maintained
around the repository to prevent damage to the cap. A gate will be installed to provide access for
periodic rotational grazing on the cap. Site restoration activities common to all action alternatives
are described in Section 4.2.1.1. Post-removal visualizations of the restored Quivira Mines are
included in Appendix F.

Removal Action Components

Additional information regarding individual components is provided in Section 4.2.1.1.
Components of the removal action include:

•	Excavation of all waste from CR-1, CR-1E, and the Kerr-McGee Ponds

•	Excavation and stockpiling of borrow soil for repository cover and site restoration

•	Consolidation of excavated waste from all lease areas in an onsite repository within
3 miles of CR-1

•	Construction of an engineered cover over consolidated waste at the onsite repository

•	Construction and maintenance of permanent fencing and signage around the onsite
repository and installation of a gate to provide access for periodic rotational grazing on
the cap

•	Backfilling and restoration at CR-1, CR-1E, the Kerr-McGee Ponds, and the borrow
areas with short-term erosion and stormwater controls, grading, and revegetation

•	Construction of temporary fencing and signage around the onsite repository and around
excavated areas at CR-1E, the Kerr-McGee Ponds, and the borrow areas

•	Long-term cover maintenance at the onsite repository as described in Section 4.2.1.2

•	Maintenance of site restoration areas as described in Section 4.2.1.2

4.2.2.3 Alternative 3: Dispose of All Mine Waste Off Site at Red Rocks Disposal Facility

Alternative 3 is the disposal of waste off site at the Red Rocks disposal facility in McKinley
County, New Mexico. Under Alternative 3, the RAOs would be accomplished through
excavation, transport, and off-Navajo Nation disposal of mine waste and contaminated soil. The
site would be reclaimed through implementation of site restoration measures followed by

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maintenance of restored features and use of access controls to protect the site restoration process.
Site excavation and restoration elements common to all action alternatives are described in
Section 4.2.1.1.

An estimated 1,005,500 bank cubic yards or 1,256,875 loose cubic yards of waste from the
Quivira Mines would be hauled 44 miles off the Navajo Nation and disposed of at a specially
designed and managed disposal area at the Red Rocks disposal facility adjacent to the existing
landfill. This area would be created at the facility to manage only this type of waste. The waste
would not be mixed with municipal waste at the neighboring landfill. The facility would have
separate equipment and a separate workforce, and workers would be specially trained to
transport and manage the waste. Waste would be transported on the recommended haul route:
south on State Highway 566 to Interstate 40, exiting Interstate 40 at Thoreau, and north on State
Highway 371 to the Red Rocks disposal facility. Further discussion of the evaluation of haul
routes is provided in Section 4.1.2 and Tetra Tech (2024). The hauling of waste would comply
with applicable Navajo and state permitting requirements for the transport of radioactive
materials. No TCLP metals results exceeded the toxicity characteristic levels; therefore, the
waste piles at the Quivira Mines do not exhibit RCRA hazardous waste characteristics.
No pretreatment of the waste is expected to be required before disposal.

The waste also falls under the Bevill Amendment exemption and would not be regulated as a
RCRA waste in this scenario. In general, the CERCLA Off-Site Rule requires that facilities that
accept 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 be in compliance
with the applicable federal, state, and local requirements to do so). The waste disposal facility
would be located on the same property, but separate from the Red Rocks Landfill and operated
under State of New Mexico Groundwater Discharge and Mining permits.

Site restoration activities include backfilling and grading of waste excavation areas, erosion
controls, and revegetation. Site restoration activities common to all action alternatives are
described in Section 4.2.1.1. The Red Rocks disposal facility is 44 miles from the site. A
Stennett analysis was prepared by the U.S. Army Corps of Engineers (USACE) to evaluate the
safety for site workers at the proposed Red Rocks disposal facility during waste tipping,
consolidation, and capping. The Stennett analysis indicated that facility workers would be safe
under the exposure scenario used to develop the analysis. Considerations of the analysis included
the characteristics of the waste including contaminant concentrations, as well as construction
equipment, methods, and durations of worker exposure (USACE 2022).

Figure 35 and Figure 36 show the proposed waste excavation and site restoration areas for
Alternative 3 at the Quivira Mines. For Alternative 3, waste would be transported to and
disposed of at the Red Rocks disposal facility in McKinley County, New Mexico. The
recommended 44-mile haul route to the Red Rocks disposal facility is depicted on Figure 37. The
proposed disposal cell at the Red Rocks disposal facility is shown on Figure 38. The overall
estimated duration of the project is 4.5 years.

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Removal Action Components

Additional information regarding individual components is provided in Section 4.2.1.1.
Components of the removal action include:

•	Excavation of waste from CR-1, CR-1E, and the Kerr-McGee Ponds

•	Excavation and stockpiling of borrow soil for site restoration

•	Hauling and offsite disposal of excavated contaminated soils at the Red Rocks
disposal facility

•	Backfilling and site restoration at CR-1, CR-1E, the Kerr-McGee Ponds, and the borrow
areas with short-term erosion and stormwater controls, grading, and revegetation

•	Construction of temporary fencing and signage around excavated and borrow areas

•	Maintenance of site restoration areas as described in Section 4.2.1.2

4.2.2 A Alternative 4: Dispose of All Mine Waste OffSite at a Resource Conservation
and Recovery Act C or Low-Level Radioactive Waste Facility

Alternative 4 requires the disposal of waste off site at a RCRA C and State of Colorado
radiological licensed facility, such as the Clean Harbors facility in Deer Trail, Colorado, or an
NRC licensed LLRW facility, such as the WCS in Andrews, Texas, depending on waste
concentration and acceptance limits. Under Alternative 4, the RAOs would be accomplished
through excavation, transport, and off-Navajo Nation disposal of mine waste and contaminated
soil. The site would be reclaimed through implementation of site restoration measures followed
by maintenance of restored features and use of access controls to protect the site restoration
process. Site excavation and restoration elements common to all action alternatives are described
in Section 4.2.1.1.

An estimated 1,005,500 bank cubic yards or 1,256,875 loose cubic yards of waste from the
Quivira Mines would be hauled 625 miles off the Navajo Nation and disposed of at the Clean
Harbors facility in Colorado or 501 miles to the WCS facility in Texas. Waste would be
transported on the recommended haul route: south on State Highway 566 to Interstate 40, east to
Interstate 25, north on Interstate 25, northeast on State Highway 24, and north on State
Highway 71 to Deer Trail, Colorado. Further discussion of the evaluation of haul routes is
provided in Section 4.1.2 and Tetra Tech (2024).

The hauling of waste would comply with applicable Navajo and state permitting requirements
for the transport of radioactive materials. Site restoration activities include backfilling and
grading of waste excavation areas, erosion controls, and revegetation. Site restoration activities
common to all action alternatives are described in Section 4.2.1.1.

The Clean Harbors facility, permitted to receive RCRA Class C hazardous waste and licensed by
the State of Colorado to receive radioactive material, and the WCS facility, licensed by NRC to
receive LLRW, are both in compliance with the CERCLA Off-Site Rule. In general, the
CERCLA Off-Site Rule requires that facilities that accept contaminated or hazardous wastes
from a CERCLA site must follow all applicable regulations and laws (that is, they must be

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approved to take those wastes and be in compliance with the applicable federal, state, and local
requirements to do so). The licensed disposal facilities considered for any alternatives involving
offsite disposal would be required to have existing approval under the CERCLA Off-Site Rule.

Disposal at a permitted or licensed facility is a standard disposal method that involves transport
to and disposal at the applicable waste disposal facility. Permitted or licensed 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. No TCLP metals results exceeded the toxicity characteristic levels; therefore,
the waste piles at the Quivira Mines do not exhibit RCRA hazardous waste characteristics. No
pretreatment of the waste is expected to be required before disposal.

Figure 35 and Figure 36 show the proposed waste excavation and site restoration areas for
Alternative 4 at the Quivira Mines. For Alternative 4, the waste would be transported to and
disposed of at the Clean Harbors RCRA C facility in Deer Trail, Colorado, or the WCS facility
licensed by NRC to receive LLRW in Andrews, Texas. The recommended haul routes to the
Deer Trail, Colorado, and Andrew, Texas, disposal facilities are depicted on Figure 39 and
Figure 40, respectively. The shipment of waste by rail was determined not to be a viable option
(see Section 4.1.2 and Tetra Tech [2024]). The overall estimated duration of the project is 17 to
18 years.

Removal Action Components

Additional information regarding individual components is provided in Section 4.2.1.1.
Components of the removal action include:

•	Excavation of waste from CR-1, CR-1E, and the Kerr-McGee Ponds

•	Excavation and stockpiling of borrow soil for site restoration

•	Hauling and offsite disposal of excavated contaminated soils at the Clean Harbors or
WCS facility

•	Backfilling and site restoration at CR-1, CR-1E, the Kerr-McGee Ponds, and the borrow
areas with short-term erosion and stormwater controls, grading, and revegetation

•	Construction of temporary fencing and signage around excavated and borrow areas

•	Maintenance of site restoration areas as described in Section 4.2.1.2

4.3 DETAILED ANALYSIS OF ALTERNATIVES

As required by NCP and described in USEPA (1993) guidance, retained removal action
alternatives are evaluated individually against the following three broad criteria: effectiveness,
implementability, and cost.

In addition, based on USEPA (2016) guidance, five key elements in greener cleanup activities
should be considered throughout the remedy selection process:

•	Minimize total energy use and maximize renewable energy use

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•	Minimize air pollutants and carbon dioxide equivalent (CChe) 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

For the purposes of alternative evaluation in this EE/CA, these five elements were considered but
a quantitative analysis will not completed until a preferred remedy is selected. NCP evaluation
criteria are described below.

4.3.1 Effectiveness Criterion

This criterion evaluates the threshold criteria of protection and compliance with ARARs, along
with short- and long-term effectiveness and permanence, and reduction in toxicity, mobility, and
volume of waste.

•	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 land use controls. Based on effectiveness and ARAR compliance,
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 condition and from
construction work, fuel consumption, greenhouse gas emissions, water use, waste and
materials management, ecosystem protection, and traffic accident and fatality risk during
implementation, and also takes into account the time necessary to complete the action.

•	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 to manage the risk posed by wastes remaining at the site.

•	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.

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4.3.2	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.

•	Availability of Required Services and Materials - This criterion evaluates whether
staff, equipment services, disposal locations are available in the necessary time frames for
construction and maintenance activities. This criterion was combined with technical
feasibility for this EE/CA.

•	Administrative Feasibility - This criterion considers regulatory approval and
scheduling constraints.

•	Tribal, Supporting Agency, and Community Acceptance - These criteria are
initially addressed in this final EE/CA after input from Navajo Nation and supporting
agencies. Additional input will be received during the public comment period on the final
EE/CA and addressed in the responsiveness summary of the action memorandum.

4.3.3	Cost Criterion

The types of costs assessed include the following:

•	Capital costs, including both direct and indirect costs

•	Annual maintenance costs

•	Net present value 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 2023 dollars).

4.3.4	Cost Estimating Process

Cost estimates were prepared in accordance with USEPA (2000) guidelines using engineer's
estimates, unit costs (cubic yard, linear feet, and square foot quantities) from RSMeans 2023 cost
estimating software (Gordian 2023), and vendor quotes. Gallup, New Mexico, was used as the
reference city in the RSMeans software to ensure unit costs for labor, equipment, and supplies
where applicable to work in the region. Unit costs were validated and adjusted where necessary
by verifying that the crew size, equipment, and time allotted for an activity (production rate)
were applicable to earthwork at a large mining construction site in the region.

In accordance with USEPA (1993, 2000) guidance, the engineering costs are estimates that are
expected to be within plus 50 to minus 30 percent of the actual project cost (based on year 2023
dollars). Only the rolled up construction and capital costs, maintenance costs for site restoration,
long-term maintenance costs for repositories, and net present values are presented for each
alternative. Cost details and assumptions are presented in Appendix E.

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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, Navajo Nation tax for on-Navajo Nation activities, 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.

The needs for maintenance costs were identified, including the need for site restoration for a
period of 10 years to address any erosion and 30 years to conduct vegetation surveys and address
any revegetation efforts, and including the need for cap and cover inspection and maintenance
for a period of 30 years and inspection from 31 to 100 years for onsite consolidation and
capping. Project duration (30 years versus 100 years) varies depending on the alternative being
evaluated and is addressed in the cost discussion for each alternative. Any onsite repository
will be maintained in perpetuity. Additional maintenance costs beyond 100 years assumed for
cost estimating purposes, will depend on inspection results and updates to the long-term
surveillance plan.

Common capital and maintenance costs for each removal action alternative include access road
construction, access road reclamation, site restoration, and annual maintenance of site restoration
efforts over 30 years. Annual inspection and maintenance of the repository cap (erosion repairs
and vegetation replanting) would be intensive for the first 30 years because of erosion and
revegetation efforts but would decrease after vegetation is established and consist of inspection
only for years 31 to 100. Maintenance of site restoration and cap restoration efforts is addressed
in Section 4.2.1.2 in more detail. The net present value of each removal action alternative
provides the basis for the cost comparison. The net present value 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 7 percent discount rate as specified in USEPA (1993) guidance.

4.3.5 Alternative 1: No Action

This subsection provides the detailed analysis of the No Action alternative organized by NCP
evaluation criteria. The No Action alternative is included as a baseline for evaluating the effects
of no action and comparing no action to the other alternatives.

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4.3.5.1	Effectiveness

Overall Protection of Public Health and the Environment - The No Action alternative is
not protective and 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 the
No Action alternative.

Compliance with ARARs - Under this alternative, there are no ARARs 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 - 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 activities would
occur, no additional energy use, greenhouse gas emissions, 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. While the
health risks would not be addressed, there is little exposure under current use conditions, so
short-term exposure risk is low.

Long-Term Effectiveness and Permanence - The No Action alternative does not offer any
long-term effectiveness and permanence in reducing potential risks to human and ecological
receptors. No controls or long-term measures would be implemented to control COCs or COECs
at the site other than routine maintenance consisting of erosion and stormwater control,
vegetation maintenance, and site cover and existing fencing repair.

This alternative would not provide control through treatment of soils with concentrations of
Ra-226 above the action level or reduce volume or mobility of contaminants. The resultant risks
associated with the No Action alternative would be similar to those that existed at the time of the
RSE field investigations with no increased protection of human health and the environment.

This alternative would not alter the potential exposure to or transport of contaminated soils from
the Quivira Mines. Surface water discharge from the site to both Unnamed Arroyo #2 and the
Pipeline Canyon Arroyo would have continued potential to transport contaminated soils to the
downstream watershed. Nearby residents would continue to be potentially exposed to wind- and
water-borne contaminants. Domestic livestock and their owners and caretakers would potentially
be exposed to surface soil contamination through direct contact and dust inhalation.

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.

4.3.5.2	Implementability

Technical Feasibility and Availability of Services and Materials - Alternative 1 is readily
implementable because no construction is involved. This alternative would not impact the ability

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to conduct removal or remedial actions in the future. No services or materials would be needed
to implement Alternative 1.

Administrative Feasibility - Alternative 1 is administratively feasible as taking no action
is feasible.

4.3.5.3 Costs

No removal action costs would be incurred for Alternative 1 as it involves no removal activities
and no legal or administrative activities.

4.3.6 Alternative 2: Consolidate and Cap All Waste On Site

Alternative 2 assumes that contaminated soils with concentrations above the action levels
would be excavated, hauled up to 3 miles, and consolidated in an onsite repository at or near
CR-1, including a canyon repository. An estimated 57,140 truckloads of waste (90 truckloads per
day) would be transported to the onsite repository using on-highway haul trucks holding 22 cubic
yards (33 tons) of waste.

4.3.6.1 Effectiveness

Overall Protection of Public Health and the Environment - Alternative 2 is protective of
human health and the environment as the contaminated soils exceeding the action level at CR-1,
CR-1E, and the Kerr-McGee Ponds would be consolidated and covered at an onsite repository.
The capped area would be covered with a soil ET cap. The engineered cap is a physical barrier
that offers protection from water infiltration and percolation into the contaminated soils, protects
groundwater resources, and provides adequate shielding from ionizing radiation to protect human
health and the environment. The cover would prevent direct contact between the wastes and the
public or the environment. Proper construction and design of the cover includes the
establishment of vegetation, which reduces erosion. Proper stormwater controls and maintenance
of the cover would prevent release of the contaminated soils back into the environment. A
100-year maintenance period is used for onsite capping alternative cost estimating and
comparison purposes. Additional maintenance costs beyond 100 years will depend on inspection
results and updates to the long-term surveillance plan.

Compliance with ARARs - Alternative 2 would meet federal, state, and Navajo Nation ARARs
for the Quivira Mines. Common ARARs for Alternative 2 are found in Table 6.

Short-Term Effectiveness - The primary considerations for short-term effectiveness are
protection of the community, workers, and environment during and shortly after implementation.
Alternative 2 involves excavating, loading haul trucks, and hauling waste between CR-1, CR-1E,
the Kerr-McGee Ponds, and an onsite repository; consolidation and capping of waste; importing
backfill soil; and restoring the lease areas.

• Protection of the Community during Removal Action - Under Alternative 2, a
preselected USEPA contractor would perform the removal action. Most construction
work will be at CR-1, CR-1E, and the Kerr-McGee Ponds and at the selected repository
location. Impacts to the community are expected to be limited because waste would

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remain local, limiting hauling through the community. Construction will create noise and
some dust. Dust control measures, such as water spraying, would be used during
excavation, repository construction, waste compaction, and capping of the waste.
However, some dust generation is unavoidable. Air monitors would be placed around the
construction zone at the site and repositories to measure potential risks to the community.
Trucks hauling equipment and supplies would also add noise. However, the trucks would
be routed east of the Quivira Mines to Pipeline Canyon Road and then onto temporary
access road to CR-1 to the east of the residences on Red Water Pond Road.

This alternative disturbs a large amount of waste because of excavation and
consolidation, requires hauling a portion of soils on roads shared by nearby communities,
and has up to a 4-year duration. Haul trucks hauling the waste between lease areas would
be covered if they pass through the community. Truck traffic would be coordinated under
a transportation plan for routes, times of operation, and onsite traffic rules. Attempts
would be made to minimize trucking across Navajo Nation roadways. Emergency spill
containment and cleanup contingencies would be included in the transportation plan to
address material spills. Alternative 2 is estimated to require 691,290 miles of hauling
over 4 years, which would result in a 22.4 percent increase in (or 0.23 additional) traffic
accidents and 1.04 percent increase in (or 0.01 additional) traffic fatalities (Appendix D,
Table D-2).

• Protection of Workers - All removal actions would be performed by a

USEPA-contracted construction company prequalified to remediate uranium mine waste.
Onsite workers would require standard 40-hour Occupational Safety and Health
Administration (OSHA) hazardous materials training and radiation awareness training
and would be adequately protected by using appropriate personal protective equipment
and following safe work practices and standards. Radiation exposure monitoring would
be required. Short-term impacts to air quality in the surrounding environment may occur
during excavation and loading of waste for offsite transport. Dust suppression and
monitoring would be required to reduce worker exposure to or inhalation of radionuclides
in particulates. Decontamination of workers and equipment would be required before
exiting the site.

Under Alternative 2, heavy equipment would be used to clear and grub, excavate,
transfer, load, and transport waste to the onsite repository; consolidate waste and
construction a cap on the onsite repository; and reclaim the site by grading the footprints
of the removal areas, applying growth media, and applying native seed and soil
amendments for local vegetation establishment. Potential exposure and protection
procedures for workers engaged in these activities would be addressed in a site safety and
health plan. During excavation and material handling activities, measures would be taken
to reduce fugitive dust emissions and associated impacts to workers. Water would be
imported for dust control, and workers in the controlled area would use appropriate safety
equipment and implement safety practices such as air monitoring. Work areas would be
secured (for example, marked or fenced) for access by authorized personnel only.

Short-term risks of physical injury would exist for site workers during construction,
primarily related to operating equipment during access road construction, waste
excavation, site restoration, and repository construction. All workers would be required to
wear personal dosimeters to ensure that exposure does not exceed OSHA limits.

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•	Environmental Impacts - Even with control measures, short-term environmental
impacts could occur from excavation and placement of waste in an onsite repository.
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. Other environmental impacts include fuel burning and releasing of emissions
that would lead to climate impacts. The threat to the environment is low because the
waste rock hauling would be a short distance and consolidation and capping would occur
within 4 years in comparison to hauling off site over a 4.5- to 18-year time frame
(Alternatives 3 and 4). 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 exposure to uranium and radionuclides would be minimal.

•	Environmental Metrics Analysis - A qualitative evaluation of all environmental metrics
was conducted. The results are presented in Appendix D, Table D-l. Alternative 2 has an
overall moderate greenness score of 28 out of 48 (where a higher number is good). Fuel
consumption and greenhouse gas emissions were also quantitatively evaluated for
Alternative 2, where onsite hauling, material import, and water import is estimated to
consume 120,290 gallons of fuel and generate 1,200 metric tons of greenhouse gas
(CChe) emissions over 697,680 miles travelled (Appendix D, Table D-2).

•	Time Until Removal Action Objectives Are Achieved - The time period to implement
Alternative 2 is estimated to be 4 years following 1-2 years of design, bidding, planning,
and permitting. Construction may be extended depending on schedule-limiting factors
such as monsoon rains and snowfall.

Long-Term Effectiveness and Permanence - Alternative 2 is effective over the long term. The
cover for Alternative 2 would be an engineered ET cap. Landfills and mines in the southwestern
U.S. are routinely closed on site with ET caps and a maintenance plan. The Navajo Nation
Abandoned Mine Lands Reclamation Department (NAMLRD) has a demonstration repository in
the Tse Tah area, and Tetra Tech (2021) has prepared a white paper that provides additional
support for the use of ET caps. Cover maintenance is a well-established practice. Since
contaminated soils would remain on the site, potential exposure reductions to those accessing the
site would be dependent on the maintenance of the cover. Drainage features and stormwater
controls would be included in the design so that surface water would be diverted from the capped
areas and aid in prolonging the integrity of the cover. Alternative 2 is expected to effectively
mitigate the long-term effects on potential human and ecological receptors for as long as the
cover and permanent fencing and signage are maintained. A gate would be installed to provide
access for periodic rotational grazing on the cap. An engineered ET cap would meet the RAOs
and ARARs and be protective of human health and the environment for at least 200 years.

Reduction of Toxicity, Mobility, or Volume through Treatment- Alternative 2 employs
no treatment, so no reductions in toxicity, mobility, or volume through active treatment
would occur.

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4.3.6.2	Implementability

Technical Feasibility and Availability of Services and Materials- Alternative 2 would use
conventional techniques, materials, and labor for the excavation and associated activities.
The Quivira Mines are readily accessible. Excavation would be scheduled and performed to
maximize direct loading and promote worker and public safety. Engineering controls for
fugitive dust and site monitoring would be used to minimize exposure of sensitive receptors
to radioisotopes.

Alternative 2 consists mainly of simple earthwork and material hauling and repository cap
construction. Construction and environmental monitoring equipment and services are all readily
available. Labor would be available both on the Navajo Nation and in the regional market.

Access to approximately 24 million gallons of water for dust suppression, waste compaction, and
cover and backfill compaction is necessary, which would be obtained through construction of an
onsite water well or trucked in from the Gallup municipal supply. Sources of borrow material are
enough to meet the needs for fill, topsoil, and gravel for capping options under all potential cap
designs and for restoration after excavation. Some specialized labor for adit and shaft closure
after excavation may be required depending on if these features are discovered during
construction and their condition.

Alternative 2 would be completed as a single phase, and no future removal actions are
anticipated. Maintenance of the repository cap would be required for up to a 100-year period and
reevaluated thereafter. The expertise and equipment needed for long-term monitoring and
maintenance of the repository cap, erosional features and controls, and revegetation are
available. Run-on water control berms and drainage ditches at the repository would be repaired
as necessary. Permanent range fencing and warning signs around the repository would also be
checked and repaired or replaced as necessary.

Administrative Feasibility - Alternative 2 is administratively implementable and would require
coordination between USEPA, NNEPA, UNC, NAMLRD, the Navajo Nation Department of
Water Resources (NNDWR), the Navajo Nation Minerals Department (NNMD), and the
Coyote Canyon, Pinedale, and Standing Rock Chapters to address federal and Navajo ARARs.
The contaminated soils would be transported within CR-1 for consolidation and from the
Kerr-McGee Ponds and CR-1E to CR-1. Construction of an engineered cover at an onsite
repository would not require permitting because of the Bevill Amendment exemption and the
contaminated soils are considered LLRW and not RCRA hazardous waste. In addition, permits
are not required for onsite CERCLA actions. Onsite CERCLA actions must comply with the
substantive requirements of any Navajo local permit but not with the administrative
requirements. Community and stakeholder engagement may be significant because the waste
would remain on the Navajo Nation. Negotiations with the Navajo Nation or other landowners
with potential offsite soil borrow sources would need to be conducted and agreements crafted.

4.3.6.3	Costs

The total cost is estimated to be $61.6 million or $62 per bank cubic yard for Alternative 2
(Appendix E, Table E-l through Table E-2). This cost assumes that maintenance of the ET cap
would be required in perpetuity but, for cost estimating purposes, was assumed to include cap

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inspections, erosion repairs, and revegetation for 30 years and cap inspections for up to
100 years. USEPA would be responsible for the long-term maintenance of the repository.
Restoration maintenance at the Quivira Mines would consist of 10 years of erosion repairs and
inspections and up to 30 years of vegetation surveys and maintenance of revegetation efforts. A
breakdown of the major cost categories associated with implementing Alternative 2 is presented
in Exhibit 16.

Exhibit 16. Alternative 2 Cost Breakdown

Cost Component

Alternative 2

Estimated Excavated Surface Area (Acres)

62.9

Estimated Excavated Volume (Bank Cubic Yards)

1,005,500

Estimated Excavated Volume (Loose Cubic Yards)

1,256,875

Direct Capital Costs

Field Overhead and Oversight

$6,608,000

General Site Work

$156,000

Earthwork

$19,326,000

Transportation and Consolidation

$19,756,000

Subtotal Direct Capital Costs

$45,847,000

Indirect Capital Costs

$6,274,000

Subtotal Capital Costs

$52,121,000

Capital Cost Contingency (15%)

$7,758,150

Total Capital Costs

$59,879,000

Maintenance Costs

Present Worth of 10, 30, and 100 Years of Maintenance (Depending on
Activity) at a Discount Rate of 7%

$1,377,000

Contingency Allowance (25%)

$344,300

Total Present Worth Maintenance Cost

$1,721,000

Total Cost

$61,600,000

4.3.7 Alternative 3: Dispose of All Mine Waste Off Site at Red Rocks Disposal Facility

Alternative 3 assumes that contaminated soils with concentrations above the action levels would
be excavated and transported 44 miles to the Red Rocks state-permitted disposal facility in
McKinley County, New Mexico. The 44-mile recommended haul route for the waste is assumed
to be Pipeline Canyon Road to Highway 566 to Interstate 40 and then Interstate 40 from
Church Rock to Thoreau and the facility (Figure 37). An estimated 76,180 truckloads of waste
(96 truckloads per day) would be transported to the Red Rocks disposal facility using
on-highway haul trucks holding 16.5 cubic yards (25 tons) of waste. Waste would be transported
on the recommended haul route: south on State Highway 566 to Interstate 40, exiting
Interstate 40 at Thoreau, and north on State Highway 371 to the Red Rocks disposal facility.
Further discussion of the evaluation of haul routes is provided in Section 4.1.2 and Tetra Tech
(2024). Exhibit 17 presents the processing and transportation costs for the Red Rocks disposal
facility. The facility is currently a RCRA D landfill and is not licensed to accept uranium mine
waste. However, the facility has additional adjacent land where a State of New Mexico permit
for a new facility that can accept uranium mine waste for permanent disposal is planned. The

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State of New Mexico is not opposed to the facility development and has provided guidance on
how such a facility would be permitted. US ACE (2022) evaluated the operations of the facility in
a Stennett analysis and determined that, under the operating conditions assumed, the facility
would be safe for workers.

Exhibit 17. Red Rocks Transportation and Tipping Costs

Receiving Facility

Processing and Transportation Costs

Red Rocks Disposal Facility

$95.40 per loose cubic yard*

Note:

*	Exact costs have not been obtained for the Red Rocks disposal facility yet. This placeholder cost is for the

Red Rocks disposal facility and will be updated with information from the facility when available.

4.3.7.1 Effectiveness

Overall Protection of Public Health and the Environment - Alternative 3 would protect
human health and the environment as the contaminated soils exceeding the action level at the
Quivira Mines would be excavated for offsite transportation and disposal at the Red Rocks
disposal facility, a permitted facility designed to manage radioactive waste. This alternative
would significantly minimize potential long-term exposure to contaminated soils from the
Quivira Mines. Potential short-term exposures during excavation, transport, and at the final
disposal site would be managed through engineering controls.

From a contaminant exposure perspective, Alternative 3 is protective of human health and the
environment. However, highway fatality calculations indicate shipping soils to the Red Rocks
disposal facility for disposal would result in an increase of a highway traffic accidents. This is
discussed further in the evaluation of short-term effectiveness.

Compliance with ARARs - Alternative 3 would meet federal, state, and Navajo Nation ARARs
for the Quivira Mines. Common ARARs across Alternatives 2 through 4 are found in Table 6.

Short-Term Effectiveness - Under Alternative 3 all waste would be excavated, loaded into haul
trucks, transported, and disposed of off site at the Red Rocks disposal facility. The short-term
impacts to the community, workers, and environment under Alternative 3 are as described below.

• Protection of the Community during Removal Action - Under this alternative, a
preselected USEPA contractor would perform the removal action. Most construction
work will be at CR-1, CR-1E, and the Kerr-McGee Ponds. Impacts to the community
would include noise and some dust. Dust control measures, such as water spraying,
would be used during waste excavation and loading for offsite transport. However, some
dust generation is unavoidable. Air monitors would be placed around the construction
zone to measure potential risks to the community. Trucks hauling equipment and supplies
would also add noise. Traffic will be routed around the communities to the maximum
extent possible but construction traffic will mix with community traffic on Pipeline
Canyon Road, State Road 566,1-40, and through Thoreau to the facility. However, the
trucks would be routed east of the Quivira Mines to Pipeline Canyon Road and then onto
the State Road 566 to avoid the residences on Red Water Pond Road. This alternative

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also leaves the waste in place for the 3 to 5 years of state permitting, design, and
facility construction.

This alternative excavates all of the waste, requires hauling all of the waste through
communities and on highways, and has the second longest overall duration (4.5 years).
Bulk carriers hauling the containerized wastes off site would be covered, secured, and
weighed to document compliance with total and axle load limits. Truck traffic would be
coordinated under a transportation plan for routes, times of operation, and onsite traffic
rules. Emergency spill containment and cleanup contingencies would also be included in
the transportation plan. Alternative 3 is estimated to require 7.1 million miles of hauling
over approximately 4.5 years (depending on fleet size), resulting in a 229 percent
increase in (or 2.3 additional) traffic accidents and an 10.7 percent increase in (or
0.11 additional) traffic fatalities (Appendix D, Table D-2).

•	Protection of Workers during Removal Action - All removal actions would be
performed by an EPA-contracted construction company pre-qualified to remediate
uranium mine waste. Onsite workers would require standard 40-hour OSHA hazardous
materials training and radiation awareness training and would be adequately protected by
using appropriate personal protective equipment and following safe work practices and
standards. Radiation exposure monitoring would be required. Short-term impacts to air
quality in the surrounding environment may occur during excavation and loading of
waste for offsite transport. Dust suppression and monitoring would be required to ensure
that workers are not exposed to or inhale radionuclides in particulates. Decontamination
of workers and equipment would be required before exiting the site.

Under Alternative 3, heavy equipment would be used to clear and grub, excavate,
transfer, load, and transport waste to a facility, as well as reclaim the site by grading the
footprints of the removal areas, applying growth media, and applying native seed and soil
amendments for local vegetation establishment. Potential exposure and protection
procedures for workers engaged in these activities would be addressed in a site safety and
health plan. During excavation and material handling activities, measures would be taken
to reduce fugitive dust emissions and associated impacts to workers. Water would be
imported for dust control, and workers in the controlled area would use appropriate safety
equipment and implement safety practices such as air monitoring. Work areas would be
secured (for example, marked or fenced) to ensure access by authorized personnel only.

Short-term risks of physical injury would exist for site workers during construction,
primarily related to operating equipment during access road construction, waste
excavation, site restoration, and repository construction. All workers would be required to
wear personal dosimeters to ensure that exposure does not exceed OSHA limits.

•	Environmental Impacts - Even with control measures, short-term environmental
impacts could occur from excavation, hauling, and placement of waste in an offsite
repository. These environmental impacts may include residual track-in and track-out
effects of soil and mud, noise, disturbed vegetation, and dust generation. Other
environmental impacts include additional fuel burning and releasing of emissions that
would lead to increased climate impacts. However, the threat to the environment is
moderate because the waste rock could be hauled off site over a 5-year time frame in
comparison to a 17- to 18-year time frame for Alternative 4. In addition, revegetation

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would expedite the return of native flora once cleanup actions are complete. However,
revegetation may not occur immediately. The short-term threat posed by exposure to
uranium and radionuclides would be minimal.

•	Environmental Metrics Analysis - A qualitative evaluation of all environmental metrics
was conducted. The results are presented in Appendix D, Table D-l. Alternative 3 has an
overall moderate greenness score of 21 out of 48 (where a higher number is good). Fuel
consumption and greenhouse gas emissions were also quantitatively evaluated for
Alternative 3, where offsite hauling, fill material import, and water import is estimated to
consume 1,226,462 gallons of fuel and generate 12,600 metric tons of greenhouse gas
(CChe) emissions over 7.1 million miles travelled (Appendix D, Table D-2).

•	Time until Removal Action Objectives Are Achieved - Excavation, hauling
off-Navajo Nation, and disposal of waste at the Red Rocks disposal facility would meet
preliminary RAOs in the short term. The construction time required to achieve RAOs
for Alternative 3 would be approximately 4.5 years. Construction may be extended
depending on schedule-limiting factors such as truck availability, monsoon rains,

and snowfall.

Long-Term Effectiveness and Permanence - Since all contaminated soils would be excavated
and removed from the site, potential exposure reductions to receptors accessing the site would
be permanent. Long-term maintenance is low under this alternative because it focuses on
native vegetation re-establishment only and does not require repository maintenance.

Alternative 3 is expected to effectively mitigate the long-term effects on potential onsite
human and ecological receptors.

Reduction of Toxicity, Mobility, or Volume through Treatment - Alternative 3 employs
no treatment, so no reductions in toxicity, mobility, or volume through active treatment
would occur.

Managing waste at landfills reduces the overall mobility of bulk waste but does not treat the
waste. Alternative 3 does not reduce contaminant toxicity, mobility, or volume through
treatment. Under Alternative 3, waste would be disposed of at the Red Rocks disposal facility
near Gallup, New Mexico, which is or would be permitted for uranium mine waste disposal.

4.3.7.2 Implemen tability

Technical Feasibility and Availability of Services and Materials - Alternative 3 is technically
feasible and would use conventional techniques, materials, and labor for the excavation and
associated activities. The Quivira Mines is readily accessible. Excavation would be scheduled
and performed to maximize direct loading and ensure worker and public safety. Engineering
controls for fugitive dust and site monitoring would be used to control potential exposures to
sensitive receptors. Profiling and manifesting of the material would be done in coordination with
the transporters and the offsite disposal facility. Some specialized labor for adit and shaft closure
after excavation may be required depending on if these features are discovered during
construction and what their condition is.

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Alternative 3 consists mainly of simple earthwork and material hauling. Construction and
environmental monitoring equipment and services are all readily available. Labor would be
available both on the Navajo Nation and in the regional market. Access to approximately
27 million gallons of water for dust suppression and compaction of backfill is necessary, which
would be obtained through construction of an onsite water well or trucked in from the Gallup
municipal supply. Sources of borrow material near the site are adequate to meet the needs for fill
and topsoil for restoration after excavation.

Alternative 3 would be completed as a single phase, and no future removal actions are
anticipated. Maintenance of site restoration erosional controls and revegetation efforts would
be required. Run-on water control berms, drainage ditches, and sediment detention basins
would be repaired, as necessary. Temporary range fencing would also be checked and repaired,
as necessary.

The Red Rocks disposal facility does not currently have an operating permit. Because all waste
would be disposed of off site, reliance on the ability to obtain an operating permit and future
disposal capacity of the Red Rocks disposal facility brings some uncertainty to the availability of
services at the time of the removal action. However, the State has indicated how the facility
could be permitted and estimates a time frame for permitting of 1 to 2 years. However, an overall
3- to 5-year time frame is estimated for permitting and facility design.

Administrative Feasibility - Alternative 3 is administratively implementable and would require
coordination between USEPA, NNEPA, UNC, NAMLRD, NNDWR, NNMD, and the Coyote
Canyon, Pinedale, and Standing Rock Chapters to address federal and Navajo ARARs, but
federal permits for onsite actions under CERCLA are not required. This alternative would also
require the Red Rocks disposal facility to successfully obtain a groundwater discharge permit
from the State of New Mexico and develop the transportation, operation, and closure plans.
Finally, negotiations with the Navajo Nation or other landowners with potential offsite soil
borrow sources would need to be conducted and agreements crafted.

Alternative 3 is administratively feasible. It would require State of New Mexico to issue a
groundwater discharge permit to facilitate uranium mine waste disposal at the facility. The
permitting options were identified by the State, and they estimated the permit process, which
includes a public comment period, would take 1 to 2 years. However, an overall 3- to 5-year time
frame is estimated for permitting and facility design.

4.3.7.3 Costs

The total cost for Alternative 3 is estimated to be $182.5 million or $182 per bank cubic yard
(Appendix E, Table E-3 and Table E-4). This cost assumes the Red Rocks disposal facility
would be responsible for the long-term maintenance of the wastes it receives. Restoration
maintenance at the Quivira Mines would consist of 10 years of erosion repairs and inspections
and 30 years of vegetation surveys and maintenance of revegetation efforts. A breakdown of the
major cost categories associated with implementing Alternative 3 for the Quivira Mines is
presented in Exhibit 18.

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Exhibit 18. Alternative 3 Cost Breakdown

Cost Component

Alternative 3

Estimated Excavated Surface Area (Acres)

62.9

Estimated Excavated Volume (Bank Cubic Yards)

1,005,500

Estimated Excavated Volume (Loose Cubic Yards)

1,256,875

Direct Capital Costs

Field Overhead and Oversight

$7,552,000

General Site Work

$156,000

Earthwork

$14,626,000

Transportation and Disposal

$126,180,000

Subtotal Direct Capital Costs

$148,515,000

Indirect Capital Costs

$8,965,000

Subtotal Capital Costs

$157,480,000

Capital Cost Contingency (15%)

$23,622,000

Total Capital Costs

$181,102,000

Maintenance Costs

Present Worth of 10 and 30 Years of Maintenance (Depending on
Activity) at a Discount Rate of 7%

$1,148,000

Contingency Allowance (25%)

$287,000

Total Present Worth Maintenance Cost

$1,435,000

Total Cost

$182,537,000

4.3.8 Alternative 4: Dispose of All Mine Waste Off Site at a Resource Conservation
and Recovery Act C or Low-Level Radioactive Waste Facility

Alternative 4 assumes that contaminated soils with concentrations above the action levels would
be excavated and disposed of at a RCRA C and State of Colorado radiological licensed facility,
such as the Clean Harbors facility in Deer Trail, Colorado, or an NRC-licensed LLRW facility,
such as the WCS in Andrews, Texas. Disposal at the WCS LLRW facility in Andrews, Texas,
may be considered where Ra-226 concentration in waste or contaminated soil exceeds 222 pCi/g,
or the annual acceptance limit at the Clean Harbors facility is reached. An estimated
76,180 truckloads of waste (25 truckloads per day) would be transported to the Clean Harbors or
WCS facilities using on-highway haul trucks holding 16.5 cubic yards (25 tons) of waste. Waste
would be transported on the recommended haul route: south on State Highway 566 to
Interstate 40, east to Interstate 25, north on Interstate 25, northeast on State Highway 24, and
north on State Highway 71 to Deer Trail. Further discussion of the evaluation of haul routes is
provided in Section 4.1.2 and Tetra Tech (2024).

Exhibit 19 presents the processing and transportation costs for the Clean Harbors and WCS
facilities. The Deer Trail facility currently has the appropriate permitting, licensing, bonding, and
CERCLA Off-Site Rule approvals. For the purposes of the detailed and comparative analysis of
this alternative, all mine waste will be disposed of at the Deer Trail facility because of lower
transportation and tipping costs. A change to the disposal facility, such as the WCS facility in
Andrews, Texas, could be selected in the action memorandum, if necessary, to address volume

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and concentration limits at the Deer Trail facility. The 625-mile recommended haul route for the
waste to the Deer Trail facility is assumed to be Pipeline Canyon Road to Highway 566 to
Interstate 40 to Interstate 25 to Highway 24 to Highway 71 and the Deer Trail facility
(Figure 39) while the recommended 501-mile haul route to the WCS facility is assumed to be
Pipeline Canyon Road to Highway 566 to Interstate 40 to Highway 285 to Highway 62 to
Highway 176 and the WCS facility (Figure 40).

Exhibit 19. Disposal Facility Transportation and Tipping Costs

Receiving Facility

Transportation and Tipping Costs

Clean Harbors RCRA C Deer Trail facility

$285 per loose cubic yard

Waste Control Specialist LLRW facility

$375 per loose cubic yard

Notes:

LLRW Low-level radioactive waste

RCRA Resource Conservation and Recovery Act

4.3.8.1 Effectiveness

Overall Protection of Public Health and the Environment - Alternative 4 would protect
human health and the environment as the contaminated soils exceeding the action level at the
Quivira Mines would be excavated and removed for offsite transportation and disposal at a
permitted and licensed facility designed to manage radioactive waste. This alternative would
significantly minimize potential long-term exposure to contaminated soils from the Quivira
Mines. Potential short-term exposures during excavation, transport, and disposal would be
managed through engineering controls.

From a contaminant exposure perspective, Alternative 4 is protective of human health and the
environment. However, highway fatality calculations indicate shipping soils to Deer Trail for
disposal would result in a large increase in highway traffic accidents and fatalities. This is
discussed further in the evaluation of short-term effectiveness.

Compliance with ARARs - Alternative 4 would meet federal, state, and Navajo Nation ARARs
for the Quivira Mines. Common ARARs across Alternatives 2 through 4 are found in Table 6.

Short-Term Effectiveness - Under Alternative 4 all waste would be excavated, loaded into haul
trucks, transported, and disposed of off site. The short-term impacts to the community, workers,
and environment under Alternative 4 are as described below.

• Protection of the Community during Removal Action - Under this alternative, a
preselected USEPA contractor would perform the removal action. Most construction
work will be at CR-1, CR-1E, and the Kerr-McGee Ponds. Impacts to the community
would include noise and some dust. This is expected to be more disturbance than either
Alternative 2 or 3 because of the significantly longer duration (17 to 18 years) of this
action. Dust control measures, such as water spraying, would be used during waste
excavation and loading for offsite transport. However, some dust generation is
unavoidable. Air monitors would be placed around the construction zone to measure
potential risks to the community. Trucks hauling equipment and supplies would also add
noise. Traffic will be routed around the communities to the maximum extent possible but

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for 17 to 18 years construction traffic will mix with community traffic on Pipeline
Canyon Road, State Road 566, and the interstate highways taken to the facility. However,
the trucks would be routed east of the Quivira Mines to Pipeline Canyon Road and then
onto the State Road 566 to avoid the residences on Red Water Pond Road.

This alternative excavates all of the waste, requires hauling all of the waste through
communities and on highways, and has the longest overall duration because of the
hauling distance. Bulk carriers hauling the containerized wastes off site would be
covered, secured, and weighed to document compliance with total and axle load limits.
Truck traffic would be coordinated under a transportation plan for routes, times of
operation, and onsite traffic rules. Emergency spill containment and cleanup
contingencies would also be included in the transportation plan. Alternative 4 is
estimated to require 97 million miles of hauling over 17 to 18 years (depending on fleet
size), resulting in a 3,120 percent increase in (or 31.2 additional) traffic accidents and a
146 percent increase in (or 1.46 additional) traffic fatalities (Appendix D, Table D-2).

•	Protection of Workers during Removal Action - All removal actions would be
performed by an EPA-contracted construction company pre-qualified to remediate
LLRW. Onsite workers would require standard 40-hour OSHA hazardous materials
training and radiation awareness training and would be adequately protected by using
appropriate personal protective equipment and following safe work practices and
standards. Radiation exposure monitoring would be required. Short-term impacts to air
quality in the surrounding environment may occur during excavation and loading of
waste for offsite transport. Dust suppression and monitoring would be required to ensure
that workers are not exposed to or inhale radionuclides in particulates. Decontamination
of workers and equipment would be required before exiting the site.

Under Alternative 4, heavy equipment would be used to clear and grub, excavate,
transfer, load, and transport waste to a facility, as well as reclaim the site by grading the
footprints of the removal areas, applying growth media, and applying native seed and soil
amendments for local vegetation establishment. Potential exposure and protection
procedures for workers engaged in these activities would be addressed in a site safety and
health plan. During excavation and material handling activities, measures would be taken
to reduce fugitive dust emissions and associated impacts to workers. Water would be
imported for dust control, and workers in the controlled area would use appropriate safety
equipment and implement safety practices such as air monitoring. Work areas would be
secured (for example, marked or fenced) to ensure access by authorized personnel only.

Short-term risks of physical injury would exist for site workers during construction,
primarily related to operating equipment during access road construction, waste
excavation, site restoration, and repository construction. All workers would be required to
wear personal dosimeters to ensure that exposure does not exceed OSHA limits.

•	Environmental Impacts - Even with control measures, short-term environmental
impacts could occur from excavation, hauling, and placement of waste in an offsite
repository. These environmental impacts may include residual track-in and track-out
effects of soil and mud, noise, disturbed vegetation, and dust generation. Other
environmental impacts include a very high rate of fuel burning and releasing of emissions
from long distance hauling that would lead to very large climate impacts. The threat to

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the environment is very high because the waste rock would take 4 times as long to haul
off site to Deer Trail, Colorado (17 to 18 years) than it would take to haul to Red Rocks
disposal facility (4.5 years) under Alternative 3. 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 exposure to uranium and
radionuclides would be minimal.

•	Environmental Metrics Analysis - A qualitative evaluation of all environmental metrics
was conducted. The results are presented in Appendix D, Table D-l. Alternative 4 has an
overall low greenness score of 11 out of 48 (where a higher number is good). Fuel
consumption and greenhouse gas emissions were also quantitatively evaluated for
Alternative 4, where offsite hauling and material import is estimated to consume

16.7 million gallons of fuel and generate 172,100 metric tons of greenhouse gas (CChe)
emissions over 97 million miles travelled (Appendix D, Table D-2).

•	Time until Removal Action Objectives Are Achieved - Excavation, hauling
off-Navajo Nation, and disposal of waste at the Deer Trail disposal facility would meet
preliminary RAOs in the short term. The construction time required to achieve RAOs for
Alternative 4 would be approximately 17 to 18 years based on the 625-mile distance to
the disposal facility, the 3-day turnaround time between the site and the disposal facility,
and likely limited availability of trucks for transportation. If additional haul trucks can be
dedicated to the project (more than 25 trucks a day), then the project duration can be
decreased up to the maximum number of trucks that can be loaded per day. Construction
may be extended depending on schedule-limiting factors such as truck availability,
monsoon rains, and snowfall.

Long-Term Effectiveness and Permanence -Since all contaminated soils would be excavated
and removed from the site, potential exposure reductions to receptors accessing the site would
be permanent. Long-term maintenance is low under this alternative because it focuses on
native vegetation re-establishment only and does not require repository maintenance.

Alternative 4 is expected to effectively mitigate the long-term effects on potential onsite
human and ecological receptors.

Reduction of Toxicity, Mobility, or Volume through Treatment - Alternative 4 employs
no treatment, so no reductions in toxicity, mobility, or volume through active treatment
would occur.

Managing waste at landfills reduces the overall mobility of bulk waste but does not treat the
waste. Alternative 4 does not reduce contaminant toxicity, mobility, or volume through
treatment. Under Alternative 4, waste would be disposed of at RCRA C facility in Deer Trail,
Colorado, which is licensed to accept uranium mine waste.

4.3.8.2 Implementability

Technical Feasibility and Availability of Services and Materials - Alternative 4 is technically
feasible because it would use conventional techniques, materials, and labor for the excavation
and associated activities. The Quivira Mines is readily accessible. Excavation would be
scheduled and performed to maximize direct loading and ensure worker and public safety.

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Engineering controls for fugitive dust and site monitoring would be used to control potential
exposures to sensitive receptors. Profiling and manifesting of the material would be done in
coordination with the transporters and the offsite landfill. Some specialized labor for adit and
shaft closure after excavation may be required depending on if these features are discovered
during construction and what their condition is.

Alternative 4 consists mainly of simple earthwork and material hauling. Construction and
environmental monitoring equipment and services are all readily available. Labor would be
available both on the Navajo Nation and in the regional market. Access to approximately
99 million gallons of water for dust suppression and backfill compaction is necessary, which
would be obtained through construction of an onsite water well or trucked in from the Gallup
municipal water supply. Sources of borrow material near the site are adequate to meet the needs
for fill and topsoil for restoration after excavation.

Alternative 4 would be completed as a single phase, and no future removal actions are
anticipated. Maintenance of site restoration erosional controls and revegetation efforts would
be required. Run-on water control berms, drainage ditches, and sediment detention basins
would be repaired, as necessary. Temporary range fencing would also be checked and repaired,
as necessary.

The disposal of waste at the Deer Trail hazardous waste landfill has a haul distance of 625 miles,
resulting in a 3-day turnaround time for haul trucks and construction over a 17- to 18-year
period, at least 4 times as long as Alternative 3. The Deer Trail facility is currently in compliance
with their operating permits and with the CERCLA Off-Site Rule. Because all waste would be
disposed of off site, reliance on the disposal capacity of the Deer Trail facility brings uncertainty
to the availability of services at the time of and throughout the 17- to 18-year duration of the
removal action. A change to the disposal facility could be selected in the action memorandum
if necessary.

Administrative Feasibility - Alternative 4 is administratively implementable and would require
coordination between USEPA, NNEPA, UNC, NAMLRD, NNDWR, NNMD, and the Coyote
Canyon, Pinedale, and Standing Rock Chapters to address federal and Navajo ARARs, but
federal permits for onsite actions under CERCLA are not required. Finally, negotiations with the
Navajo Nation or other landowners with potential offsite soil borrow sources would need to be
conducted and agreements crafted.

Alternative 4 is administratively feasible since shipping of waste (ore for reprocessing) is fairly
common and would only require scheduling and obtaining the necessary permits. All
contaminated soil is anticipated to be accepted by licensed facilities. Offsite disposal of
materials from a CERCLA site must comply with the CERCLA Off-Site Rule. The facility
identified to dispose of the waste has approval under the Off-Site Rule and would need to
maintain such approval.

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4.3.8.3 Costs

The total cost for Alternative 4 is estimated to be $563 million or $560 per bank cubic yard
(Appendix E, Table E-5 and Table E-6). This cost assumes the Clean Harbors RCRA C Deer
Trail facility would be responsible for the long-term maintenance of the wastes it receives.
Restoration maintenance at the Quivira Mines would consist of 10 years of erosion repairs and
inspections and 30 years of vegetation surveys and maintenance of revegetation efforts. A
breakdown of the major cost categories associated with implementing Alternative 4 is presented
in Exhibit 20.

Exhibit 20. Alternative 4 Cost Breakdown

Cost Component

Alternative 4

Estimated Excavated Surface Area (Acres)

62.9

Estimated Excavated Volume (Bank Cubic Yards)

1,005,500

Estimated Excavated Volume (Loose Cubic Yards)

1,256,875

Direct Capital Costs

Field Overhead and Oversight

$22,320,000

General Site Work

$156,000

Earthwork

$24,137,000

Transportation and Disposal

$382,304,300

Subtotal Direct Capital Costs

$428,917,000

Indirect Capital Costs

$59,389,000

Subtotal Capital Costs

$488,306,000

Capital Cost Contingency (15%)

$73,245,900

Total Capital Costs

$561,552,000

Maintenance Costs

Present Worth of 10 and 30 Years of Maintenance (Depending on
Activity) at a Discount Rate of 7%

$1,148,000

Contingency Allowance (25%)

$287,000

Total Present Worth Maintenance Cost

$1,435,000

Total Cost

$562,987,000

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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 the evaluation of the relative effectiveness,
implementability, and cost between alternatives. The comparative analysis ranks the three
criteria for each alternative qualitatively as very poor, poor, average, good, or very good.

5.1 COMPARATIVE ANALYSIS APPROACH

The final step of this EE/CA is to conduct a comparative analysis of the removal action
alternatives. This analysis evaluates 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 COMPARATIVE ANALYSIS

All alternatives except for Alternative 1 meet the threshold criterion of being protective of
public health and the environment. Exhibit 21 presents a comparative rating of alternatives.

Exhibit 21. Comparative Rating of Alternatives

Alternative

Attainment of
Threshold
Criteria3

Effectiveness

Implementability

Cost Rating
(Million)b

1

No Action

Fail

Short-Term: Average
Long-Term: Very Poor

Tech: Very Good
Admin: Very Good

Very Good
($0)

2

Consolidate and
Cap All Waste On
Site

Pass

Short-Term: Average
Long-Term: Good

Tech: Good
Admin: Good

Good
($61.6)

3

Dispose of All
Mine Waste Off
Site at Red Rocks
Disposal Facility

Pass

Short-Term: Average
Long-Term: Very Good

Tech: Very Good
Admin: Average

Poor
($182.5)

4

Dispose of All
Mine Waste Off
Site at a RCRA C
or LLRW Facility

Pass

Short-Term: Very Poor
Long-Term: Very Good

Tech: Very Good
Admin: Good

Very Poor
($563)

Notes:

a	Threshold criteria are (a) overall protection and (b) compliance with applicable or relevant and appropriate

requirements.

b	Estimated costs are net present value.

Admin	Administrative feasibility

LLRW	Low-level radioactive waste

RCRA	Resource Conservation and Recovery Act

Tech	Technical feasibility

5.2.1 Effectiveness

Effectiveness comprises two threshold criteria (protection and compliance with ARARs) and
includes short- and long-term effectiveness and permanence of the remedy.

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5.2.1.1	Protection of Human Health and the Environment

All alternatives except for 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 federal and Navajo ARARs
identified in Table 6.

5.2.1.3	Short-Term Effectiveness (during Removal Action)

Short-term effectiveness comprises four criteria: protection of the community and workers
during the removal action, environmental impacts, and time to meet RAOs. Overall short-term
effectiveness is rated Average for Alternative 1, Average for Alternative 2, Average for
Alternative 3, and Very Poor for Alternative 4.

Protection of the Community during Removal Action

The Alternative 2 haul route between lease areas is away from the community, would be in use
over a shorter duration (4 years), and is rated Good. Water would be used for dust suppression
on roads and speed would be limited to reduce dust generation and to minimize potential for
accidents. This alternative creates the least traffic and dust impacts to the community as truck
traffic would only be increased on the Pipeline Canyon Road to transport waste and construction
materials for onsite repository construction. No excavated waste would be hauled through the
community on Red Water Pond Road or on State Road 566. Lower haul miles through the
community would also result in fewer traffic accidents.

The Alternatives 3 and 4 haul routes from the lease areas are via temporary access roads to
Pipeline Canyon Road and then via State Road 566 towards Gallup, would be in use over
moderate (4.5 years) to very long (17 to 18 years) durations, would have the highest impact on
traffic, truck and dust emissions, and would have the moderate to very high likelihood of on-
highway traffic accidents and fatalities. Further discussion of the evaluation of haul routes is
provided in Section 4.1.2 and Tetra Tech (2024). Water would be used for dust suppression on
roads, loads would be covered, and speed would be limited to reduce dust generation and to
minimize potential for accidents. Therefore, Alternatives 3 and 4 are rated Average and
Very Poor because of the respective moderate to very long project durations and moderate to
very long round-trip distances to the disposal facilities. Extended project durations increase the
amount of water required for dust suppression. In addition, Alternative 3 leaves the waste in
place for 3 to 5 years before the Red Rocks disposal facility is permitted, designed, and
constructed, so the potential for exposure to mine waste exists for that duration. Because of the
very long time frame to move the waste, Alternative 4 would leave the waste in place onsite for a
longer time frame than Alternatives 2 and 3.

Estimated accidents and fatalities resulting from on- and offsite trucking of waste, import of
fill, and import of water are presented in Exhibit 22. Onsite disposal is safest from a traffic
perspective, followed by Alternative 3, and then Alternative 4. Alternative 4 has a very high
probability of a traffic fatality.

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Alternative 1 is rated Very Good as no removal activities would be conducted to impact
the community.

Exhibit 22. Potential Community and Worker Impacts

Removal
Alternatives

Water Import
(million
gallon)

Truckloads
and Miles
Traveled3

Project
Duration

Accident Risk

Fatality Risk

Alternative 1:
No Action

0

0

0

0

0

Alternative 2:
Consolidate and Cap
All Waste On Site

23.7

85,423
(0.69 million)

4 years

Low
(22.4% or
0.23 accident)

Low
(1.1% or
« 1 fatality)

Alternative 3:

Disposal of All Mine
Waste Off Site at Red
Rocks Disposal
Facility

26.7

101,182
(7.1 million)

4.5 years

Moderate
(229% or 2.3
accidents)

Low
(10.7% or
« 1 fatality)

Alternative 4:
Disposal of All Mine
Waste Off Site at a
RCRA C or LLRW
Facility

98.8

119,206
(97 million)

17 to 18
years

Very High
(3,120% or
31.2 accidents)

Very High
(146% or
1.5 fatalities

Notes:

a	Truckloads and mileage includes mine waste, backfill, and water truckloads.

LLRW Low-level radioactive waste

RCRA Resource Conservation and Recovery Act

Protection of Workers during Removal Action

Worker protection primarily involves radiation exposure, dust inhalation hazards, physical
injury, and traffic accidents. The contractors that will perform the actions are pre-qualified by
EPA to perform work with low-level radioactive wastes at CERCLA sites, so they are expected
to have the training and experience to mitigate risks associated with the action. All action
alternatives 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 a repository, which
introduces an additional level of threat to workers because of additional handling activities and
duration of exposure during consolidation and capping. A Stennett analysis has been completed
for Alternative 3, which shows that the operation of the disposal facility is safe for facility
workers under the parameters of the analysis (USACE 2022). However, the risk associated with
repository construction are greatly exceeded by risk associated with hauling waste off site.

The rate of traffic accidents and fatalities is proportional to the amount of hauling for that
alternative. For the action alternatives, the total haul distance on all roadways for Alternative 2 is
3 miles (maximum distance from CR-1), Alternative 3 is 44 miles (disposal at the Red Rocks
disposal facility), and Alternative 4 is 625 miles (disposal at the Clean Harbors Deer Trail
facility). Traffic risks associated with each alternative are addressed above in Exhibit 22.

Even though Alternative 2 poses an additional hazard associated with additional handling and
exposure to waste during consolidation and capping, the long-haul distances for off-Navajo

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Nation disposal pose the greatest accident threat to truck drivers. Therefore, Alternative 3 was
rated Average because of a medium haul distance of 44 miles, and Alternative 4 was rated
Very Poor because of a long-haul distance of 625 miles. Alternative 2 is rated Good based on
the small footprints and short haul distances. Alternative 1 is rated Very Good as no removal
activities would be conducted to impact workers.

Environmental Impacts

All of the action alternatives will involve excavation of waste and substantial site disturbance.
Shorter construction durations under Alternative 2 minimize the potential for construction-
related environmental impacts to occur in the during road construction, waste excavation, and
site restoration that would require mitigation, and shorter haul distances minimize impacts that
would occur both between the lease areas and on public roads. These impacts may include
residual track-in and track-out effects of soil and mud, noise, nuisance, soil spills during waste
hauling, sedimentation of local drainages, and harmful emissions. Alternative 3 would cause
additional impacts because of the longer 4.5-year project duration while Alternative 4 impacts
would require 17 to 18 years to complete. These additional impacts are primarily related to
hauling distances and duration.

Water pumping or import would also have an impact, depending on source, import distance, and
volume required for dust control and waste compaction. The nearest potential water source is
approximately 20 miles away in Gallup, and the sustainable productivity of a new construction
well is unknown. Onsite consolidation and capping under Alternative 2 would use less water
than offsite hauling because of the shorter project duration (4 years) compared to 4.5-year and
17- to 18-year project durations for Alternatives 3 and 4. Finally, onsite consolidation and
capping would result in less noise and activity disturbance of sensitive biological species because
of the overall shorter project duration.

Environmental Metrics Analysis

A qualitative evaluation of environmental metrics for each action alternative was conducted for
the EE/CA. The metrics do not include post-removal site maintenance activities. The results are
presented in Appendix D, Table D-l. Exhibit 23 presents the environmental impacts of the
alternatives, including water use, greenhouse gas metrics, and a qualitative greenness score for
each alternative.

Exhibit 23. Environmental Impacts of Alternatives

Removal
Alternatives

Water
Import
(million
gallon)

Estimated
Diesel Use
(gallon)

All Truckloads
and Miles
Traveled3

Greenhouse
Gas Emissions
(metric ton CCtee)

Greenness
Scoreb

Alternative 1:

Low

Low

Low

Low

Very Good

No Action

(0)

(0)

(0)

(0)

(48/48)

Alternative 2:





Low
85,423
(0.69 million)





Consolidate and

Moderate

Low

Low

Good

Cap All Waste On
Site

(23.7)

(0.12 million)

(1,200)

(28/48)

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Exhibit 23. Environmental Impacts of Alternatives (Continued)

Removal
Alternatives

Water
Import
(million
gallon)

Estimated
Diesel Use
(gallon)

All Truckloads
and Miles
Traveled3

Greenhouse
Gas Emissions
(metric ton CCtee)

Greenness
Scoreb

Alternative 3:
Disposal of All
Mine Waste Off
Site at Red Rocks
Disposal Facility

Moderate
(26.7)

Moderate
(1.22 million)

Moderate
101,182
(7.1 million)

Moderate
(12,500)

Average
(21/48)

Alternative 4:
Disposal of All
Mine Waste Off
Site at a RCRA C
or LLRW Facility

Very High
(98.8)

Very High
(16.6 million)

Very High
119,206
(97 million)

Very High
(170,900)

Very Poor
(11/48)

Notes:

a	Truckloads and mileage includes mine waste, backfill, and water truckloads.

b	The higher the greenness score, the less impact on the environment. See Appendix D, Table D-1.

CChe Carbon dioxide equivalent

LLRW Low-level radioactive waste

RCRA Resource Conservation and Recovery Act

Alternative 2 is rated Good because of the least amount of water used for compaction and dust
control, least amount of species disturbance because of the shortest project durations, shorter
haul distances that require less energy, and smaller greenhouse gas footprint than offsite hauling
under Alternatives 3 and 4. However, Alternative 2 could limit future land uses because of the
need to protect repository caps. Alternatives 3 and 4 are rated Average and Very Poor because
of the increased water use for dust control and species disturbance over moderate to very long
project durations and moderate and to very large energy requirements and greenhouse gases
produced by the truckloads of waste hauled off site to local and regional disposal facilities and
water imported for dust control. Alternative 1 is rated Very Good as no action would occur.

Time until Removal Action Objectives Are Achieved

A summary of the construction completion time for each alternative is presented in Exhibit 24.
All action alternatives (aside from Alternative 1: No Action) could be completed between 4 and
18 years. Alternatives 2 and 3 are similar, but Alternative 4 time to completion is very long and
is limited by the number of trucks and a 3-day turnaround time for the haul trucks.

Exhibit 24. Construction Completion Time for Alternatives

Alternative

Construction Completion Time

Alternative 1: No Action

0 year

Alternative 2: Consolidate and Cap All Waste On Site

4 years

Alternative 3: Disposal of All Mine Waste OffSite at
Red Rocks Disposal Facility

4.5 years

Alternative 4: Disposal of All Mine Waste OffSite at a
RCRA C or LLRW Facility

17 to 18 years

Notes:

LLRW Low-level radioactive waste	RCRA Resource Conservation and Recovery Act

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5.2.1.4 Long-Term Effectiveness and Permanence (after Removal Action)

For all action alternatives, waste removal or containment from source areas would reduce the
magnitude of residual risk to background levels for radionuclides. Noncancer hazards would be
removed, and the risk to ecological receptors would be reduced to levels below known effects
concentrations and background levels. None of the alternatives reduce the toxicity, mobility, or
volume through treatment.

Alternatives 3 and 4 are rated Very Good as sources of risk at the site would be removed and
waste disposed of off the Navajo Nation. The cap and liner at the disposal facilities would
eliminate exposure pathways. Alternatives 3 and 4 would also allow for unrestricted future use of
the entire site. Removing waste from the Navajo Nation eliminates the long-term surveillance
requirements associated with a repository under Alternative 2. The receiving facilities would be
responsible for the long-term maintenance of the waste under Alternatives 3 and 4.

Alternative 2 would consolidate all waste in a repository. Permanence of risk reduction would
rely on the repository design standards (at least 200 years) to minimize long-term maintenance,
but long-term surveillance of the repository by USEPA would still be required. Alternative 2 is
rated Good. Although the onsite repositories are expected to be protective in both the short and
long term, the ET cap will require long-term maintenance and monitoring. Replacement of
repository components would not be required because their lifespan is indefinite, especially
under a monitoring and maintenance regime.

Alternative 1 is rated Very Poor because no removal action would be performed. Human health
risk may be partially reduced through increased awareness of risks, but no reduction in risk to the
ecosystem would occur. Uncontrolled and untreated waste would remain and continue to be
accessible by humans and animals and subject to potential migration to uncontaminated or less
contaminated areas.

5.2.2 Implementability

Implementability comprises two criteria: (1) technical feasibility and availability of services and
materials, and (2) administrative feasibility.

5.2.2.1 Technical Feasibility and Availability of Services and Materials

Action alternatives consist mainly of simple earthwork and material hauling. The alternatives are
technically feasible with labor available through the local and regional market and equipment
and materials located 1.5 to 2 hours away.

The action alternatives would be completed as a single phase, and no future remedial actions are
anticipated. Short-term monitoring of site restoration features will occur under all action
alternatives while long-term monitoring and maintenance, particularly inspection and repair of
erosional features and controls and revegetation, would be required for Alternative 2 onsite
repository. Experienced contractors, construction equipment, and materials are available within
the region.

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Engineering Evaluation/Cost Analysis, Quivira Mines

Among the action alternatives, Alternatives 3 and 4 are the most technically feasible to
implement as all waste is removed from the Quivira Mines to offsite disposal facilities. Design
methods, construction practices, and engineering requirements are well documented and
understood. However, the reliance on the disposal capacity of contracted services brings
uncertainty to the availability of off-Navajo Nation disposal capacity. Therefore, Alternatives 3
and 4 are rated Very Good.

Alternative 2 is technically feasible as waste is consolidated in an onsite repository. Design
methods, construction practices, and engineering requirements are well documented and
understood. Because all waste under Alternative 2 would be disposed of on site, no reliance on
the treatment, storage, or disposal capacity of contracted services would be required. Therefore,
Alternative 2 is rated Good.

Alternative 1 is rated Very Good as it is readily implementable and no construction is involved.
Alternative 1 would not impact the ability to conduct removal or remedial actions in the future.
No services or materials would be needed because no removal action would be performed.

5.2.2.2	Administrative Feasibility

Administratively, Alternative 3 is rated Average because it will require a groundwater discharge
permit from the State of New Mexico, which is supportive of the Red Rocks disposal facility.
Alternative 4 is rated Good as it requires the least amount of design, permitting, and approvals
from and coordination with USEPA, NNEPA, UNC, NAMLRD, NNDWR, NNMD, and the
Coyote Canyon, Pinedale, and Standing Rock Chapters as no onsite repository would be
involved. Post-remedy inspections, reviews, and land use controls would be limited in
comparison to onsite repository construction. However, limitations and delays on waste
acceptance at off-Navajo Nation facilities are possible because of the volume of waste or
disposal facility permit limitations.

Alternative 2 is rated Good as less design, permitting, approvals, and coordination with
USEPA, NNEPA, UNC, NAMLRD, NNDWR, NNMD, and the Coyote Canyon, Pinedale, and
Standing Rock Chapters is required for an onsite repository in comparison to Alternative 3 with
an offsite repository.

Alternative 1 is rated Very Good as taking no action is feasible.

5.2.2.3	Tribal, Supporting Agency, and Community Acceptance

USEPA and NNEPA believe that Alternative 3 (dispose of all mine waste off site at the Red
Rocks disposal facility) has the highest likelihood of acceptance by the Navajo Nation, State of
New Mexico, and Red Water Pond and Pipeline Canyon communities. Community acceptance
may be reduced by a 3- to 5-year delay for permitting, design, and facility construction and a
4.5-year waste hauling period with increased community disruption, noise, and haul truck traffic
volume on local highways.

USEPA and NNEPA believe that Alternative 2 (consolidate and cap all waste on site) may not
receive acceptance from the Navajo Nation and the local communities because it does not require
removal of all wastes from the communities. Alternative 2 is more easily implementable (1 to

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2 years of design and 4 years of construction) and will have significantly lower community
disruption, noise, and truck traffic impacts because of limited hauling of waste through the
community than Alternative 3.

USEPA and NNEPA believe that Alternative 4 (dispose of all mine waste off site at a RCRA C
or LLRW facility) might be acceptable to the Navajo Nation and the community because all
waste would be removed from the community; however, the longer construction period will
cause 17 to 18 years of community disruption, noise, and haul truck traffic because of the large
volume of waste, 3-day turnaround time, and long roundtrip distance (up to 625 miles) to the
RCRA C or LLRW disposal facility. Navajo Nation, State of New Mexico, and community
acceptance will be further addressed through the public comment process.

Alternatives 2 and 3 would provide potential job opportunities during construction and
short-term monitoring and maintenance. Alternative 2 would provide additional opportunities
during the required long-term inspection and maintenance of the ET cap. Alternatives 3 and 4
would provide additional job opportunities for truck drivers hauling waste to the offsite disposal
facilities. No long-term maintenance would occur under Alternatives 3 and 4.

Community input received during informal community meetings and workshops have identified
concerns related to moving radioactive materials through the community, traffic, and safety of
leaving the waste on site or placing the waste in the Red Rocks disposal facility. The following
potential mitigations could address community concerns:

•	Dust will be controlled using water during loading and on haul roads. Air monitoring will
evaluate dust leaving the site to identify changes required, including applying more water
or stopping work on a windy day.

•	Before leaving the site, each truck will be inspected to ensure loads are covered, loose
material has been cleaned and removed to avoid tracking material off site and scanned for
radioactivity to safely pass through communities.

•	Strict limits will be set for truck load volume and weight leaving the site to reduce
damage to road surfaces.

•	Protection will be achieved through a combination of time and distance. For example,
the exposure from a truck passing by on a road or highway is lower as exposure time
decreases with the truck's speed. Distance also minimizes exposure, where low levels
of gamma activity from waste rock decrease rapidly when measuring from even several
feet away.

•	A traffic control plan will be prepared to control haul routes, haul times, and days and to
identify and avoid locations of schools or other sensitive populations.

•	An accident contingency plan will be prepared to plan for responding to a haul truck
accident. Typically, an accidental spill of waste rock presents a smaller danger compared
to an accident involving gasoline, propane, or other chemical. A waste rock spill can be
quickly contained and cleaned up with a front end loader and a gamma detector.

•	Waste material will be transferred from trucks only at a controlled area at the Red Rocks
disposal facility designed for material handling and with dust control and spill response

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materials. Waste rock will not be mixed with other municipal waste. Dust will be
controlled using water. Air monitoring will evaluate dust leaving the site to identify any
changes required, including applying more water or stopping work on a windy day.

• Long-term risk to the community around the Red Rocks disposal facility is low because
the disposal cell is isolated from the community, waste rock will be covered daily during
operation, will be closed with an engineered cap, and monitoring wells in shallow
groundwater will detect any potential releases.

This EE/CA will be available to the public for a 30-day public comment period to give
community members an opportunity to review and comment on the documents, especially the
recommended alternative proposed in the EE/CA. During the public comment period, a public
meeting will be held to present information contained in the EE/CA and to solicit questions and
comments from the community. USEPA will coordinate scheduling and provide formal
announcement of the public comment period and meeting. This process offers the community
and other stakeholders the opportunity to provide input and comment for the USEPA to take into
consideration when making decisions about the site cleanup.

5.2.3 Projected Costs

A summary of the cost for each alternative is presented in Exhibit 25. Alternative costs are
presented as a rating (comparing each alternative to the others) and as the total estimated cost
based on 2023 price evaluations for each alternative.

Exhibit 25. Alternative Costs and Ratings

Alternative

Capital
Cost

Orisite Maintenance
Present Value 7%
Discount Rate

Total Present
Value Cost

Cost Rating

Alternative 1:
No Action

$0

$0

$0

Very Good

Alternative 2: Consolidate
and Cap All Waste On
Site

$59.9
million

$1,7million
(100 years)

$61.6 million

Good

Alternative 3:

Disposal of All Mine
Waste Off Site at Red
Rocks Disposal Facility

$181.1
million

$1.4 million
(30 years)

$182.5 million

Average

Alternative 4:

Disposal of All Mine
Waste Off Site at a RCRA
C or LLRW Facility

$561.6
million

$1.4 million
(30 years)

$563 million

Very Poor

Notes:

Higher cost alternatives rate lower in cost ratings, which is consistent with the rating scheme where low equals less
desirable.

LLRW Low-level radioactive waste

RCRA Resource Conservation and Recovery Act

Present values, including maintenance costs, for each action alternative using a baseline 30-year
project duration for site restoration maintenance and 100-year cap maintenance under CERCLA

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Engineering Evaluation/Cost Analysis, Quivira Mines

for onsite consolidation and capping (Alternative 2) at a 7 percent discount rate specified in
USEPA (1993) guidance are summarized in Exhibit 25.

Alternative 1 is the least expensive because no construction and maintenance costs are incurred
and is rated Very Good. Alternative 2 ($61.6 million) is rated Good and is $121 million less
than Alternative 3. Alternative 3 is rated Average and Alternative 4 is rated Very Poor because
their respective costs are 3 to 9.1 times higher than Alternative 2, and Alternative 4 costs are
3.1 times more than Alternative 3.

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Engineering Evaluation/Cost Analysis, Quivira Mines

6.0 RECOMMENDED ALTERNATIV

J

As required by NCP and described in USEPA (1993) guidance, alternatives were evaluated
individually against the following three broad criteria: effectiveness, implementability, and cost
(see Section 4.3). Section 5.0 includes a comparative analysis evaluating the strengths and
weaknesses of each alternative relative to the other alternatives with respect to the three criteria
and in achieving RAOs.

USEPA's recommended alternative for the Quivira Mines is Alternative 3 (dispose of all
mine wastes at Red Rocks disposal facility). The primary elements of the recommended
alternative are:

•	Excavation of an estimated 1,005,500 bank cubic yards or 1,256,875 loose cubic yards of
waste from the Quivira Mines to the cleanup goals identified in Exhibit 15.

•	Completion of permitting, design, and construction of the Red Rocks disposal facility,
which is expected to take 3 to 5 years.

•	Transportation of an estimated 1,256,875 loose cubic yards of waste from the Quivira
Mines in covered trucks over the 44-mile recommended haul route to the Red Rocks
disposal facility over 4.5 years for disposal in a separate facility and disposal cell from
the municipal landfill.

•	The recommended truck haul route is south on State Highway 566 to Interstate 40,
exiting Interstate 40 at Thoreau, and north on State Highway 371 to the Red Rocks
disposal facility. Section 4.1.2 and Tetra Tech (2024) provides an evaluation of rail and
truck haul routes.

•	Site restoration at CR-1, CR-1E, and the Kerr-McGee Ponds by regrading, implementing
erosion and stormwater controls, backfilling, amending, and revegetating the areas.

•	Preparation of a short-term monitoring and maintenance plan after the remedy is
identified in the action memorandum.

•	Short-term monitoring and maintenance of the site restoration areas for 30 years.

•	Long-term monitoring and maintenance of the Red Rocks disposal facility, which would
be the responsibility of the Northwest New Mexico Regional Solid Waste Authority
supported by financial assurance bonding.

The largest capital costs for Alternative 3 are excavation, transportation, and disposal of the mine
wastes at the Red Rocks disposal facility. A Stennett analysis showed this alternative to be safe
for disposal facility workers receiving waste under the parameters of the analysis (USACE
2022). RAOs and cleanup levels for surface soil, air, and radiation would be achieved at the
completion of the remedy construction. A 10- to-3 0-year period of recovery will be needed to
achieve site vegetative restoration, depending on precipitation patterns.

The cost estimate for Alternative 3 is included in Exhibit 18 and Appendix E. The total cost for
Alternative 3 is estimated to be $182.5 million, which is 3 times higher than Alternative 2
(consolidate and cap all waste on site) and 3.1 times less than Alternative 4 (dispose of all mine
waste at a RCRA C or LLRW facility).

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Engineering Evaluation/Cost Analysis, Quivira Mines

All action alternatives are protective. Alternatives 3 and 4 remove waste from the Red Water
Pond and Pipeline Canyon communities while the capped waste remains in the community in
Alternative 2. Alternative 3 transports the waste 44 miles for disposal compared to 625 miles in
Alternative 4. The shorter distance would produce significantly lower diesel exhaust emissions
from long-haul transportation and also significantly reduce community disruption from noise and
potential traffic accidents and fatalities.

USEPA and NNEPA expect that Alternative 3 will be more acceptable to the Navajo Nation and
the local communities than Alternatives 1 and 2 because all waste would be removed from the
site, resulting in unrestricted land use once vegetation is reestablished. All alternatives would
provide job opportunities to the community during construction, waste hauling and short-term
maintenance while Alternatives 2 and 3 would provide long-term inspection and maintenance
job opportunities at on- and off-site repositories. Training programs would be used to develop
job skills to allow the local community to participate in both short- and long-term construction
and maintenance opportunities.

Next Steps

Though USEPA has identified a recommended alternative, USEPA will solicit input from
Navajo Nation officials, regulators, chapter representatives, other stakeholders, and community
on this final EE/CA and recommended alternative during a public comment period. USEPA
and NNEPA will hold a public meeting during the comment period to listen to input. USEPA
will select a final removal action alternative after reviewing and considering all information
submitted during the public comment period. Comments received at the public meeting and the
final removal action alternative will be documented in an action memorandum. USEPA may
modify the recommended alternative or select another alternative presented in this EE/CA
based on new information or public comments. Therefore, interested parties are encouraged to
review and comment on all of the removal action alternatives presented in this EE/CA.

USEPA will carefully consider Navajo Nation Fundamental Law and Dine Lifeways in its
restoration approach.

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Engineering Evaluation/Cost Analysis, Quivira Mines

7.0 REFERENC

J

Brister, B.S., and G.K. Hoffman. 2002. "Fundamental Geology of San Juan Basin Energy
Resources." In New Mexico's Energy, Present and Future: Policy, Production,
Economics, and the Environment. Pages 21 through 25. New Mexico Bureau of Geology
and Mineral Resources. Socorro, New Mexico.

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.

Conestoga Rovers and Associates Ltd. (CRA) and SENES Consultants Limited (SENES). 2013.
"Red Water Pond Road Removal Action, Church Rock Site, McKinley County, NM."
February.

Ecology and Environment, Inc. 2012. "Quivira Mine Screening-Level Investigation Report."

Engineering/Remediation Resources Group, Inc. (ERRG). 2011. "Regional Groundwater
Assessment of Impacts from Historic Releases of the NECR Mine and UNC Mill
Facilities Navajo Nation." September.

Gordian. 2023. "RSMeans Data." Version 2023.

Harper, Barbara L. 2007. "Traditional Tribal Subsistence Exposure Scenario and Risk

Assessment Guidance Manual." Oregon State University Department of Public Health
and Confederated Tribes of the Umatilla Indian Reservation. United State Environmental
Protection Agency Grant Number EPA-STAR-J1-R831046. August.

Meteoblue. 2020. "Simulated Historical Climate and Weather Data for Gallup: Wind Rose."
Accessed April 24.

https://www.meteoblue.com/en/weather/historyclimate/climatemodelled/gallup_united-
states-of-america_5468773.

Montgomery Watson Harza (MWH). 2003. "Northeast Church Rock Mine Site Assessment."
July.

MWH. 2006. "Technical Memorandum: Results of Background and Radium-226 Correlation
Sampling, Northeast Church Rock Mine Site, United Nuclear Corporation." October.

MWH. 2010. "Northeast Church Rock Mine Interim Removal Action Completion Report."

June 29.

MWH. 2013. "Northeast Church Rock Mine Eastern Drainage Removal Action Completion
Report." March 13.

MWH. 2018. "Northeast Church Rock 95% Design Report, United Nuclear Corporation." July.

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Engineering Evaluation/Cost Analysis, Quivira Mines

Navajo Nation Division of Community Development. 2019. "Navajo Population (5-Year
Estimate) by Chapter." https://navajoprofile.wind.enavajo.org.

National Oceanic and Atmospheric Administration. 2006. "Atlas 14 Point Precipitation

Frequency Estimates: NM." National Weather Service, Hydrometeorological Design
Studies Center, U.S. Department of Commerce. July 15.
https://hdsc.nws. noaa.gov/hdsc/pfds/pfds_map_cont.html?bkmrk=nm.

Quivira Mining Company. 1987. "Abandonment and Reclamation Plan, Church Rock I, IE, and
II Mines, Navajo Nation Lease 14-20-20603-9988. Church Rock, New Mexico. January.

Red Water Pond Road Community Association and Southwest Research and Information Center.
2012. "History through Pictures Past and Present of the Red House People." Revised
September.

Red Water Pond Road and Pipeline Canyon Residents. 2006. "Red Water Pond Road and
Pipeline Canyon Residents' Resolution." August 15.

SENES Consultants Limited (SENES). 2010. "Removal Evaluation Work Plan, Church Rock
Sites 1 and IE, Phase II." Redlined Version. December.

SENES. 2011. "Interim Removal Action, Final Removal Site Evaluation (RSE) Report for

Northeast Church Rock - Quivira Site Evaluation for Church Rock (CR-1) and (CR-1E)
Mine Sites." September.

Tetra Tech, Inc. (Tetra Tech). 2021. "Application of Evapotranspiration Cover in the
Southwest." February.

Tetra Tech. 2022a. "Technical Memorandum, Biological Survey Report, Quivira Mines and

Kerr-McGee Ponds, Eastern Abandoned Uranium Mine Region." Prepared for the Navajo
Nation Department of Fish and Game. June 3.

Tetra Tech. 2022b. "Quivira Mines and Kerr-McGee Ponds Biological Assessment." Response,
Assessment, and Evaluation Services. Contract No. EP-S9-17-03.

Tetra Tech. 2023a. "Preconstruction Biological Survey Report, Eastern Abandoned Uranium
Mine Region, Quivira Mines." Prepared for the Navajo Nation Department of Fish and
Game. July 31.

Tetra Tech. 2023b. "Quivira Mines Data Gaps Investigation Transmittal Memorandum."

Response, Assessment, and Evaluation Services. Contract No. EP-S9-17-03. September.

Tetra Tech. 2023c. "Navajo Abandoned Uranium Mines Program, Navajo Abandoned Uranium
Mine Site, Ecological Removal Goal Development for Metals in Soil." Draft. December.

Tetra Tech. 2024. "Quivira Mines Waste Rail and Truck Haul Route Evaluation." February 12.

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Engineering Evaluation/Cost Analysis, Quivira Mines

U.S. Army Corps of Engineers (USACE). 2022. "Technical Memorandum; Disposal of Uranium
Mine Spoils Stennett Evaluation." Draft. December.

U.S. Census Bureau. 2019. "Church Rock, New Mexico, Population Estimate." Accessed
March 16. http://factfinder.census.gov/faces/nav/jsf/pages/community_facts.xhtml.

U.S. Census Bureau. 2021. "Gallup, New Mexico, Population Estimate." Accessed
September 30.

http://factf1nder.census.g0v/faces/tableservices/j sf/pages/productview.xhtml?src=CF.

U.S. Environmental Protection Agency (USEPA). 1989. "Risk Assessment Guidance for

Superfund (RAGS). Volume I, Human Health Evaluation Manual (Part A)." Interim
Final. EPA/540/1-89/002. Office of Emergency and Remedial Response. December.
https://www.epa.gov/sites/production/files/2015-09/documents/rags_a.pdf.

USEPA. 1991a. "A Guide to Principal Threat and Low Level Threat Wastes." Office of Solid
Waste and Emergency Response (OSWER). 9380.3-06FS. November.

USEPA. 1991b. "Superfund Removal Procedures, Guidance on the Consideration of ARARs
During Removal Actions." OSWER. 9360.3-02, August.

USEPA. 1993. "Conducting Non-Time Critical Removal Actions Under CERCLA." OSWER.
EPA540-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." Environmental Response Team. EPA-
540-R-97-006. OSWER. Directive No. 9285.7-25. June.

USEPA. 1999. "Ecological Risk Assessment and Risk Management Principles for Superfund
Sites." OSWER Directive 9285.7-28P.

USEPA. 2000. "A Guide to Developing and Documenting Cost Estimates during the Feasibility
Study." OSWER. 9355.0-75, July.

USEPA. 2001. "Risk Assessment Guidance for Superfund: Volume I Human Health Evaluation
Manual (Part D, Standardized Planning, Reporting, and Review of Superfund Risk
Assessments)." Publication 9285.7-47. December.

USEPA. 2002a. "Supplemental Guidance for Developing Soil Screening Levels for Superfund
Sites" OSWER. 9355.4-24. December.

http://www.epa.gov/superfund/health/conmedia/soil/index.htm.

USEPA. 2002b. "Calculating Exposure Point Concentrations at Hazardous Waste Sites."
OSWER. 9285.6-10. Office of Emergency and Remedial Response. December.

USEPA. 2010a. E-mail Regarding Faxes Containing Historic Church Rock Maps. From Cynthia
Wetmore, USEPA. To Robin L. Mock, ERRG. January.

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USEPA. 2010b. "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. 2010c. "Action Memorandum for Interim Actions pertaining to Red Water Pond Road,
Site Stabilization and Characterization, Northeast Church Rock Quivira Mine Site."
August 24.

USEPA. 2011. "Action Memorandum: Request for a Non-Time-Critical Removal Action at the
Northeast Church Rock Mine Site, McKinley County, New Mexico, Pinedale Chapter of
the Navajo Nation." September 29.

USEPA. 2015. "United Nuclear Corporation (McKinley County) New Mexico. Site Status
Summary." February 11.

USEPA. 2016. "Memorandum: Consideration of Greener Cleanup Activities in the Superfund
Cleanup Process." August 2.

USEPA. 2022. "ProUCL Technical Guide: Statistical Software for Environmental Applications
for Data Sets with and without Nondetect Observations." Version 5.2.0. June 14.

USEPA. 2023. "Impact of Mine Water Discharge in the Upper Gallup, Zone 3". December.

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 Site."
Draft. March.

Western Regional Climate Center. 2018. "Gallup Municipal Airport, New Mexico (293422)."
July 22.

Weston Solutions, Inc. (Weston). 2010. "Expanded Site Screening, North East Church Rock -
Quivira Mines, Navajo Nation, New Mexico." April.

Weston. 2015. "Removal Assessment Report for Quivira Mine Church Rock No. 2 Mine Site,
Navajo Nation, McKinley County, New Mexico." Draft. September.

Weston. 2016. "Removal Assessment Report for Quivira Mine Site Features Including Quivira
Vent Holes 1 through 4, Navajo Nation, McKinley County, New Mexico." October 24.

Weston. 2019a. "Quivira Tronox Mine Former Dewatering Ponds Removal Assessment Report,
Navajo Nation, New Mexico." March.

Weston. 2019b. "Quivira Tronox Mine Removal Action Report for Quivira Vent Holes 1
through 5, Navajo Nation, McKinley County, New Mexico." March.

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Westwater Resources. 2018. "Technical Report on the Ambrosia Lake Uranium Project,
McKinley County, New Mexico, USA." March 30.

Whicker, F.W., T.G. Hinton, M. M. MacDonell, J.E. Pinder III, and L.J. Habegger. 2004.

"Avoiding Destructive Remediation at DOE Sites." Science. Volume 303. Pages 1,615
through 1,616.

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FIGURES


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CF 1	Quivira Tronox Church Rock

CR-1E	Quivira Tronox Church Rock No. 1 East Mine Site

CR-2	Quivira Tronox Church Rock No. 2 Mine Site

Kerr-McGee	Kerr-McGee Corporation

Drainage	Bureau of Land Management Property

- Road	~ Navajo Nation Boundary

Former Vent Hole Closed by Removal Action	Navajo Nation Chapter Boundary
Kerr-McGee Ponds Investigation Boundary Navajo Nation Regions

Northeast Church Rock Mine Area	Central Region

Church Rock Mine Lease Area	Eastern Region

I	1100-Foot Step-Out Boundary	North Central Re9'on

I	1 Kerr-McGee Ponds Fenceline	Northern Re9ion

United Nuclear Corporation Site Area	Southern Region

(Private Property)	Western Re9ion

N

Feet

0

2,000

4,000

Prepared for: U.S. EPA Region 9

Prepared By:

TETRA TECH

QUIVIRA MINES LOCATION

Task Order No.:

0001

Location:

QUIVIRA MINES

-

	

Contract No.:
68HE0923D0002

Date:

3/6/2024

Figure No

1


-------
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—
-------
I I CR-1E Lease Boundary
LT3 CR-1E 100-Foot Step-Out Boundary
L7Jj CR-1E Former Buildings
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I I Former Industrial Area

	Pipeline Canyon Road

	 Pipeline Canyon Arroyo

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Mine Site

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QUIVIRA CR-1E MINE
SITE FEATURES

Prepared For: U.S. EPA Region 9

m

Prepared By:

TETRATECH

Task Order No.:

000 1

Contract No.:

68HE0923D0002

QUIVIRA MINES

3/6/2024

Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:


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United Nuclear
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I I Kerr-McGee Ponds Fenceline

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Navajo Nation Chapter Boundary

Note:

Kerr-McGee Kerr-McGee Corporation

Prepared for: U.S. EPA Region 9

Prepared By:

TETRA TECH

WVf'fc

KERR-MCGEE PONDS SITE FEATURES

Task Order No.:

0001

Location:

QUIVIRA MINES

Contract No.:
68HE0923D0002

Date:

3/6/2024


-------
COYOTE CANYON CHAPTER

PINEDALE CHAPTER

err-McG
Ponds

Notes:

CR-1

CR-1E

Kerr-McGee

Quivira Tronox Church Rock No. 1 Mine Site
Quivira Tronox Church Rock No. 1 East Mine Site
Kerr-McGee Corporation

I I Background Study Area

I I Lease Boundary

Kerr-McGee Ponds
L II Investigation Boundary

Kerr-McGee Ponds Fenceline

Navajo Nation Chapter Boundary

Geology

Quaternary Alluvium, Valley Fill Member,
Undifferentiated (Qa)

Crevasse Canyon Formation,

Bartlett Barren Member (Kcb)

Crevasse Canyon Formation,

Dalton Sandstone Member (Kcda)

Crevasse Canyon Formation,

Dilco Coal Member (Kcdi)

Crevasse Canyon Formation,

Gibson Coal Member (Keg)

Crevasse Canyon Formation,

Mulatto Tongue of Mancos
Shale Member (Kcda)

Crevasse Canyon Formation,

Point Lookout Member (Kpl)

—~ Erosion from Upslope to Dovvnslope Areas

N

S

1 inch = 1,000 feet
1:12,000

1,000

500

1,000
I Feet

LOCAL GEOLOGY AND
BACKGROUND STUDY AREAS

Prepared For: U.S. EPA Region 9

{&)
% M*#

Prepared By:

TETRATECH

Task Order No.:

000 1

Contract No.:

68HE0923D0002

QUIVIRA MINES

3/6/2024

Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:


-------


V

COYOTE CANYON CHAPTER



CR-1E

Soil Type

Uranium mined lands
Toldohn-Vessilla-Rock outcrop complex
Parkelei-Fraguni complex
Parkelei family-Evpark complex
Parkelei family-Fraguni complex
Sparank-San Mateo-Zia complex
Doakum fine sandy loam
Vessilla-Rock outcrop complex
Rock outcrop-Eagleye-Atchee complex
Evpark-Arabrab complex
Parkelei-Evpark fine sandy loam
Mentmore loam
Buckle fine sandy loam

State Highway 566

W''f 'wBST



• { . /

mmSt

BSA-05

STANDING ROCK CHAPTER

PINEDALE CHAPTER

Kerr-McGee
Ponds

Notes:

CR-1	Quivira Tronox Church Rock No. 1 Mine Site

CR-1E	Quivira Tronox Church Rock No. 1 East Mine Site

Kerr-McGee	Kerr-McGee Corporation

EH Background Study Area Former Kerr-McGee Pond
— Road li i Kerr-McGee Ponds Lease Boundary

Arroyos Former Stockpile Area /\
II 1 Quivira Lease Boundary Kerr-McGee Ponds Fenceline

t;l 100-Foot Step-Out Boundary Navajo Nation Chapter Boundary N

0 1,000 2,000

Prepared for: U.S. EPA Region 9

$ O ii

LOCAL SOILS AND BACKGROUND STUDY AREAS

Prepared By:

Task Order No.:

0001

Contract No.:
68HE0923D0002

Figure No:

6

Location:

QUIVIRA MINES

Date:

09/10/2020


-------
HISTORIC
TAILINGS DISPOSAL CELLS

DISCHARGE FROM
MINE DEWATERING "

Quivira CR-1 Mine
Waste Rock Pile

SEEPAGE FROM MINE
WATER DISCHARGE INTO
ALLUVIUM FROM
PIPE LINE ARROYO

NOT TO SCALE

NW

Source:

Westwater Resources, 2018. "Technical Report on the Ambrosia Lake
Uranium Project, McKinley County, New Mexico, USA." March 30.

WASTE ROCK/ PLACED
BACK IN MINE

sw

Notes:

CR-1 Church Rock Mine No.1
NECR Northeast Church Rock
UNC United Nuclear Corporation

Legend

Mine

—	Tributary Alignment

-	- Ephemeral Stream

Geologic Contact
Water Flow Direction

Historic Release



Prepared By:

"T^J TETRATECH

CONCEPTUAL DRAWING OF HISTORIC
RELEASES AND WATER FLOW

Task Order No.:

TO 0001

NAVAJO NATION

Contract No.:

68HE0923D0002

2/21/24


-------
Legend

Homesites	United Nuclear Corporation
	Road Boundary (Private Property)

Navajo Nation Chapter Boundary	I	> Community Area

I Mine Boundary
I I Kerr-McGee Pond Fenceline
Kerr-McGee Ponds
Investigation Boundary
Northeast Church Rock
Mine Boundary

Land Use

Navajo Residential
Navajo Difficult Access Open Space
Bureau of Land Management Property United Nuclear Corporation Outdoor Worker
Existing Water Pipeline Easement
Proposed Water Pipeline Easement
Communication Line	i Feet

Natural Gas Line	0	1,100	2,200

Petroleum Line

Prepared for: U.S. EPA Region 9

Prepared By:

TETRA TECH

LAND USE DESIGNATIONS

Task Order No.:

0001

Location:

QUIVIRA MINES

Contract No.:
68HE0923D0002

Date:

3/4/2024

Figure No

8


-------
Gallup Municipal Airport Monthly Climate Summary
Period of Record 01/08/1973 to 06/10/2016

EO !n.|	Areragc Sr»a«v Death {In.) ¦ Are-rage Pan E^aaof a ton {in.)

Data taken from hCtpi://wrcc.dri.edu/cgi-hiiVcliMAIN.pl7nm3425

¦Areragc Mat TcmpcralLire (F|

-Averse Mm. Tmparaftn (F)

Unofficial values based on averages/sums of smoothed daily data. Information is computed
from available daily data during the 1973-2016 period. Smoothing, missing data, and
observation-time changes may cause these 1973-2016 values to differ from official National
Climatic Data Center (NCDC) values. This table is presented for use at locations that don't
have official NCDC data. No adjustments were made for missing data or time of observation.

Pan Evaporation data is from Western Regional Climate Center: Comparative Table (dri.edu)
- Gallup Ranger Station

Data taken from https://wrcc.dri.edu/cgi-bin/cliMAIN.pl7nm3425 and
https://wrcc.dri. edu/Climate/comp_table_show.php?stype=pan_evap_avg

Prepared for: U.S. EPA Region 9

(i O |\

MONTHLY AVERAGE
TEMPERATURE, PRECIPITATION,
AND EVAPOTRANSPIRATION

Prepared By:

H TETRATECH

Task Order No.:

T00001

Contract No.:

68HE0923D0002

Figure No.:

9

Location:

QUIVIRA MINES

Date:

02/21/24

Date Saved: 1/19/2023


-------
N

NNW

NNE

750

NW

NE

WNW

W

WSW

SW

ENE

\

ESE

SE

ssw

SSE

0

>17

>0
>24

>3
>31

>7

>38 mph

>12

rnph Miles per hour

SOURCE: REPRODUCED FROM

METEOBLUE CLIMATE DIAGRAMS

(https://vww.meteoblue.com/en/weather/

historyclimate/climatemodelled/

gal lu p_u n ited-states-of-

america_5468773)

Prepared for: U.S. EPA Region 9

Prepared By:

TETRATECH

1999 Harrison Street, Suite 500

Oakland, CA94612

GALLUP, NEW MEXICO
WIND ROSE DIAGRAM

Task Order No.:

TO 0001

Quivira Mines

Contract No.:

68HE0923D0002

2/21/24

Figure No.:

10


-------
Pipeline Canyon Road
Community/Area

J quivira i	

i MINE^M*	*1 #

CR-1E

QUIVIRA • / /J
J VENT HOLE 4	QUIVIRA

VENT HOLE 5

Red Water Pond Road Community Area

QUIVIRA
^ENTiHOLTe 3

:^K|

Eastern Drainage*!

QUIVIRA;:,- ^

t quivir^i^HB :^veni«e-1

Coyote Canyon Chapter vent hole 2

Step-Out

[Removal

Area #1

Standing Rock Chapter

Pinedaie Chapter

Kerr-McGee

NORTHEAST
CHURCH ROCK

mm

Ponds

MINE

UNITED NUCLEAR
CORPORATION MILL
(PRIVATE PROPERTY)

Notes:

CR-1
CR-1E
CR-2

Kerr-McGee

Quivira Tronox Church Rock No. 1 Mine Site
Quivira Tronox Church Rock No, 1 East Mine Site
Quivira Tronox Church Rock No. 2 Mine Site
Kerr-McGee Corporation

Quivira Mine Lease Boundary

Northeast Church Rock Mine Boundary

United Nuclear Corporation Site
Area (Private Property)

Red Water Pond Road Removal Area

Quivira Vent Hole Removal Area

ll III Kerr-McGee Ponds Fenceline

Kerr-McGee Ponds
Investigation Boundary

Northeast Church Rock Removal Area

[__J Community Area

	Access Route

rs?i Waste from Removal Actions

Navajo Nation Chapter Boundary

Bureau of Land Management Property

N

W E

1 inch = 1,500 feet

1:18,000

o

1,500 750	0	1,500

~ Feet

PRIOR REMOVAL ACTION LOCATIONS

Prepared For: U.S. EPA Region 9





Prepared By:

TETRATECH

Task Order No.:

000 1

Contract No.:

68HE0923D0002

Location:

QUIVIRA MINES

3/4/2024

Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:

11


-------
1,000'

1,250'

1,500'

1,750'

1" = 200 feet

TRANSPORT PATHWAY MODEL

2,000'

2,250'

2,500'

Prepared for: U.S. EPA Region 9

/^t%.

feszzf

QUIVIRA MINES
TRANSPORT MODEL

Prepared By:

-ft tetratech

Task Order No.:

TO 0001

Contract No.:

68HE0923D002

Figure No.:

12

Location:

Quivira Mines

Date:

02/21/24


-------
APPLICABLE HUMAN EXPOSURE SCENARIOS	ECOLOGICAL EXPOSURE SCENARIOS

United Nuclear

PRIMARY SOURCES OF PRIMARY RELEASE SECONDARY SOURCES SECONDARY RELEASE EXPOSURE Kee'da'whu teeh Kqq ei doo nahaazah dah Corporation	EXPOSURE Plants and Birds and

CONTAMINATION SOURCE MEDIA MECHANISMS OF CONTAMINATION MECHANISMS EXPOSURE MEDIA ROUTES (Full-Time Navajo Resident) (Difficult Access Open Space) Outdoor Worker	ROUTES Invertebrates Mammals

Background
Sources
(Natural In Situ
Material)

Waste Rock Piles

Former Detention
and Dewatering
Ponds, Former
Industrial Areas,
and Roads

Underground
Mine Workings

Exposed Ore, Rock,
Soil

Surface Mine
Waste

Subsurface Mine
Waste
(if brought to
surface)

Radioactive Decay

Radon Gas
Emanation

Wind Erosion

Erosion via
Storm or
Snowmelt Runoff

Mass Wasting

Gamma Radiation

Ambient Air

Soil

Storm water/
Snowmelt Runoff

Leaching/
Dissolution

Surface Water

t

Sediment

Entrainment/
Deposition

Alluvial
Groundwater

Subsurface
Ore Body

Leaching/
Dissolution

Mine Workings,

Porous or
Fracture Flow

Groundwater

Wells, Seeps, and
Springs (Formation
Groundwater)

Plant Uptake/
Uptake through
Food Chain

Gamma Radiation
Air

Soil/Sediment
Water

Plants/Animals

Air

Soil/Sediment

Surface Water

Groundwater

Cultivated Plants

Wild Plants

Animals

External Exposure

Inhalation

Incidental Ingestion
Dermal
Inhalation

Ingestion
Dermal
Inhalation

Ingestion
Dermal
Inhalation

Ingestion

Ingestion
Dermal
Inhalation

Ingestion

External Exposure

Inhalation

Dermal/Direct Contact
Ingestion
Trophic Transfer

Dermal/Direct Contact
Ingestion
Trophic Transfer

Ingestion

Ingestion
Trophic Transfer

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

1	The human health risk evaluation does not include inhalation of radon by humans or animals. Because radon is a gas and readily disperses in outdoor air, the risk in outdoor is considered to be minimal. Radon in indoor air is a potential risk for future residential receptors; however, radon
exposure is building specific and the buildings are not currently present and, thus, cannot be evaluated. Furthermore, because radon is a known risk in the area, any future buildings would likely be constructed to mitigate this known risk.

2	The human health risk evaluation does not include ingestion of surface water or groundwater by humans or animals. Safe drinking water is supplied to residents in the Quivira Tronox Mines area. Wells used for livestock have been tested and are upgradient of the known groundwater contamination in the area.
The arroyos are mostly dry, and the ponds are dry since mine operations have stopped. If surface or groundwater use patterns change in the future, the risk from use should be evaluated.

3	The human health risk evaluation includes ingestion of select cultivated plants (crops) by this receptor. Scenario inputs were provided by the Navajo Nation Environmental Protection Agency (NNEPA) (2021).

4	The human health risk evaluation includes ingestion, dermal (metals only), and inhalation of select wild herbs and medicinal plants by this receptor. Scenario inputs were provided by NNEPA (2021).

5	The human health risk evaluation includes ingestion of home-raised animals (meat, milk, and eggs) and hunted animals (meat only) for this receptor. Scenario inputs were provided by NNEPA (2021).

6	The ecological risk evaluation includes evaluation of external radiation based on exposure to gamma-emitting radionuclides from contaminated soil and evaluation of internal radiation through plant uptake, incidental soil ingestion, and food web uptake (Los Alamos National Laboratory 2015).

7	Potential exposures include inhalation of ambient air and air in burrows and underground mines. The ecological risk evaluation does not include evaluation of the inhalation pathway.

8	The ecological risk evaluation does not include evaluation of direct contact with or ingestion of surface water.

References:

Navajo Nation Environmental Protection Agency (NNEPA). 2021. "Navajo Tribe Provisional Reasonable Maximum Exposures RME for the Navajo Risk Assessments." Draft. September 15.

Los Alamos National Laboratory. 2015. "Screening-Level Ecological Risk Assessment Methods." Revision 4. EP2015-0174. October 29.

Figure 13. Quivira Mines Conceptual Site Model Wire Diagram


-------


Mine Lease Boundary

Area predominately covered by
static gamma measurements

Gamma Rate (cpm)

< 13,700	< BTV

13,700 - 27,400	1 x BTV - 2 x BTV

27,400-41,100	2 x BTV - 3 x BTV

41,100-54,800	3 x BTV - 4 x BTV

54,800 - 68,500	4 x BTV - 5 x BTV
> 68,500 > 5 x BTV

Notes:

BTV	Background threshold value

cpm	Counts per minute

CR-1	Quivira Tronox Church Rock No. 1 Mine Site

1 inch = 300 feet

1:3,600

N

S

250 125 0	250

i Feet

2022 CR-1 TRANSECT
GAMMA SCAN MEASUREMENTS

Prepared For: U.S. EPA Region 9

(&)

Prepared By:

TETRA TECH

It

Task Order No.:

Contract No



000 1

68HE0923D0002

Location:

QUIVIRA MINES

Date:

3/4/2024

Coordinate System:



Figure No.:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

14


-------

-------
rag	* y*

'if v •

^	¦	Fa

Kerr-McGee Ponds
Investigation Boundary

|__| UNC Mill Site Boundary

~ Contamination Associated with a
UNC Site Further to the Southeast

Gamma Rate (cpm)

•	< 13,700	< BTV

13,700 - 27,400	1 x BTV - 2 x BTV

27,400-41,100	2 x BTV - 3 x BTV

•	41,100-54,800	3 x BTV - 4 x BTV

•	54,800 - 68,500	4 x BTV - 5 x BTV

> 68,500

> 5 x BTV

Navajo Nation
UnftecF Nii



Pi '

¦ %. „&• i

,"V

- -



w

j*!C'

tl

M	•

Notes:

BTV	Background threshold value

cpm	Counts per minute

Kerr-McGee	Kerr-McGee Corporation

UNC	United Nuclear Corporation

1 inch = 300 feet

1:3,600

200 100 0

2022 KERR-MCGEE PONDS
TRANSECT GAMMA
SCAN MEASUREMENTS

Prepared For: U.S. EPA Region 9





(A?

Prepared By:

TETRATECH

Task Order No.:

000 1

QUIVIRA MINES

Contract No.:

68HE0923D0002

3/4/2024

I Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:

16


-------
Prepared By:

TETRATECH

Mine Lease Boundary

Interpolated Ra-226 Greater than 2 pCi/g

Data Excluded from Ra-226 Interpolation
as Known Contaminated Area Previously
Addressed by Static Gamma Survey

L J TENORM Boundary

V/\ Reclaimed Ponds Backfilled with NORM

Interpolated Ra-226 (pCi/g)

~ <2.0	£BTV

20-40 1 x BIV - 2 xBTV
4 0 _ 6.0 2 x BTV " 3 x BTV

6.0 - 8.0 3 x BTV " 4 x BTV

8.0-10 4 x BTV - 5 x BTV
>10	> 5 x BTV

Surface Soil Samples - Ra-226

O Below RAG of 2 pCi/g
O Above RAG of 2 pCi/g

Notes:

BTV	Background threshold value

CR-1	Quivira Tronox Church Rock No. 1 Mine Site

NORM	Naturally occuring radioactive material

pCi/g	Picocurie per gram

RAG	Removal action goal

Ra-226	Radium-226

TENORM Technologically enhanced naturally occurring
radioactive material

1 inch = 700 feet

1:8,400

~ Feet

CR-1 CORRELATED AND
LABORATORY RA-226
RESULTS IN SURFACE SOILS

Prepared For: U.S. EPA Region 9

Task Order No.:

000 1

Contract No.:

68HE0923D0002

QUIVIRA MINES

3/4/2024

Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:


-------
>v;.

. »t«L 1 Vw*»>

1

tiZE '. » .**t ;^^• ¦•vi.'* #¦" "	~ w.^

• *~



%. if w- • - ' % 'ml	•*^r 1 J±-

h	* V*;

-^w "+•*+ r

«¦&

W

¦*rW,



•* •¦? ••sr?

/¦ *

\

\v>

V. X

9- \ t; »-. •• - «¦

¦jr?-3?-

' j3'

~ IflfV-* ;: •

fF»> TVfl %,_
*

?¦
*

;? v* »

1 JwB

|__J Mine Lease Boundary

Interpolated Ra-226 Greater than 2 pCi/g
I j TENORM Boundary
Interpolated Ra-226 (pCi/g)

1 1 < 2.0	s BTV

2.0 - 4.0 1 x BTV " 2 x BTV
~ 4.0 - 6.0 2 x BTV - 3 x BTV
6.0-8.0 3 x BTV - 4 x BTV
8.0-10 4 x BTV - 5 x BTV
>10	>5 xBTV

Surface Soil Samples - Ra-226
O Below RAG of 2 pCi/g
O Above RAG of 2 pCi/g

Notes:



BTV

Background threshold value

CR-1E

Quivira Tronox Church Rock No. 1 East



Mine Site

pCi/g

Picocurie per gram

RAG

Removal action goal

Ra-226

Radium-226

TENORM

Technologically enhanced naturally



occurring radioactive material

1 inch = 300 feet

1:3,600

300	150	0

W

N

-fE

300
~ Feet

CR-1E CORRELATED AND

LABORATORY RA-226
RESULTS IN SURFACE SOILS

Prepared For: U.S. EPA Region 9

i^t)

PfiCtf*-'"'

Prepared By:

TETRATECH

Task Order No.:

000 1

QUIVIRA MINES

Contract No.:

68HE0923D0002

3/6/2024

Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:

18


-------
Navajo Nation

Navajo Nation

United Nuclear
^Corporation

United Nuclear
Corporation

Prepared By:

TETRATECH

Background threshold value
Kerr-McGee Corporation
Picocurie per gram
Removal action goal
Radium-226
Navajo Nation

Technologically enhanced naturally
occurring radioactive material
United Nuclear Corporation

-

Notes:

BTV

Kerr-McGee

pCi/g

RAG

Ra-226

NN

TENORM

UNC



Kerr-McGee Ponds
Investigation Boundary

Kerr-McGee Ponds Fenceline

UNC Site Boundary

~ Contamination Associated with a
UNC Site Further to the Southeast

Interpolated Ra-226 Greater than 2 pCi/g

Interpolated Ra-226 Greater than 5.4 pCi/g, which
is Based on a UNC Worker Exposure Scenario

I j TENORM Boundary

Interpolated Ra-226 (pCi/g)

I | < 2.0	- BTV

~	2.0 - 4.0	1 x BTV - 1 x BTV

~	4.0 - 6.0	1 x BTV - 2 x BTV
6.0-8,0 2 x BTV - 4 x BTV
8.0-10 4 x BTV - 5 x BTV
>10 > 5 x BTV

Surface Soil Samples - Ra-226
Below NN RAG of 2.0 pCi/g
or UNC RAG of 5.4 pCi/g

Above NN RAG of 2.0 pCi/g
or UNC RAG of 5.4 pCi/g

1 inch = 500 feet

1:6,000

KERR-MCGEE PONDS
CORRELATED AND
LABORATORY RA-226
RESULTS IN SURFACE SOILS

Prepared For: U.S. EPA Region 9

.-ttDSr*.

\sh}

r

QUIVIRA MINES

3/4/2024

Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:

Task Order No.:

000 1

Contract No.:

68HE0923D0002


-------
Prepared By:

TETRATECH

I I Mine Lease Boundary
L3*J TENORM Boundary
Surface Soil Samples1 - Ra-226
O Below RAG of 2 pCi/g
O CR-1 Sample Above RAG of 2 pCi/g
O Arroyo Sample Above RAG of 2 pCi/g
Subsurface Soil Samples2 - Ra-226
_ Below RAG of 2 pCi/g
Q CR-1 Sample Above RAG of 2 pCi/g
Arroyo Sample Above RAG of 2 pCi/g

Note:

"Surface soil samples are 0 to 6 inches below grade.
2Subsurface soil samples are 6 to 72 inches below
grade.

CR-1 Quivira Tronox Church Rock No. 1

Mine Site
pCi/g Picocurie per gram
RAG	Removal action goal

Ra-226 Radium-226
TENORM Technologically enhanced naturally
occurring radioactive material

1 inch = 400 feet

1:4,800

~ Feet

CR-1 DISTRIBUTION
OF RA-226 IN SURFACE
AND SUBSURFACE SOILS

Prepared For: U.S. EPA Region 9

l#7l

Task Order No.:

000 1

Contract No.:

68HE0923D0002

QUIVIRA MINES

3/4/2024

Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:


-------
6-7.5 ft



1.16

7.5-9 ft



0.86

9-10.5 ft



1.24

10.5-12 ft



1.23

10.5-12 ft



1.01.

12-13.5 ft



y?

9-10.5 ft



1.12

13.5-15 ft



1.35

19.5-21 ft



1.08

30-31.5 ft



1.01

40-41.5 ft



1.08

45-46.5 ft



1.06

6-7.5 ft



11.6

7.5-9 ft



1.6

7.5-9 ft



1.31

9-10.5 ft



1.54

10.5-12 ft



1.29

12-13.5 ft



0.96

i3.5-15 ft



1.44

15-16.5 ft



1.44

15-16.5 ft



1.36

16.5-18 ft



1.87

18-19.5 ft



1.52

r — ^

_ 	 36-37.5 fl

"t ~*33S9T.9ft

/

/ t

S J
/



6-7.5 ft



1.19

7.5-9 ft



1.52

9-10.5 ft



1.06

10.5-12 ft



1.54

12-13.5 ft



1.17

13.5-15 ft



1.45

15-16.5 ft



1.47

15-16.5 ft



1.4

16.5-18 ft



1.45

16.5-18 ft



1.46

18-19.5 ft



1.5

19.5-21 ft



1.23

21-22.5 ft



1.5

22.5-24 ft



1.45

5-6.5 ft



95 -

10-11.5 ft



7.6

15-16.5 ft



26.5

20-21.5 ft



3.46

25-26.5 ft



3.56

2&£6.5ft



2.71

^ 30-31?&t



5.06

35-36.5 ft



1.63

5-6.5 ft



41.9

/ —



5-6.5 ft



42.9 -







10-10.75 ft



31.2







15-16.5 ft



67







15-16.5 ft



59.1

5-6.5 ft



43.6

20-21.5 ft



50.9

10-11.5 ft



56.9

25-26.5 ft



51.6

15-16.5 ft



70.9

30-31.5 ft



5.15

15-16.5 ft



70.9

30-31.5 ft



4.97

20-21.5 ft



56.1

35-36.5 ft



4.83

25-26.5 ft



53.3

40-41.5 ft



4.89

30-31.5 ft



77

45.5-46.5 ft



18.8

35-36.5 ft



71.3

50-51.5 ft



5.69

35-36.5 ft



73.5







40-41.5 ft



59.2







45-46.5 ft



69.3







45-46.5 ft



79.2







50-51.5 ft



43.3







55-56.5 ft



11.8







57.5-59 ft



2.96

""e-fSTt

—

68.9

6-7.5 ft





7.5-9 ft



328

9-10.5 ft



472

10.5-12 ft



10.9

12-13.5 ft



3.51

12-13.5 ft



3.09







6-7.5 ft



1.51







		7.5-9 ft



1.2







9-10.5 ft



1.06







9-10.5 ft



1.09







10.5-12 ft



1.26

6-7.5 ft



3.67

10.5-12 ft



0.97

- 7.5-9 ft



1.34

12-13.5 ft



1.11

9-10.5 ft



1.48

13.5-15 ft



1.76

10.5-12 ft



1.58

15-16.5 ft



1.47

12-13.5 ft



1.44

15-16.5 ft



1.18

13.5-15 ft



1.39

16.5-18 ft



1.56

15-16.5 ft



1.37

18-19.5 ft



1.35

15-16.5 ft



1.24

19.5-21 ft



1.58

16.5-18 ft



1.66

21-22.5 ft



1.35

18-19.5 ft



1.54

22.5-24 ft



1.44







24-25.5 ft



1.19

^ 6-7.5 ft



1.29

6-7.5 ft



1.52

7.5-9 ft



2.81

9-10.5 ft



0.95

9-10.5 ft



0.94

10.5-12 ft



1.6

12-13.5 ft



1.74

13.5-15 ft



1.42

15-16.5 ft



1.5

16.5-18 ft



1.54

18-19.5 ft



1.34

^3^5 ft
7.5-feit
9-10.51
9-10.5 ft|
10.5-12 ft
10.5-12 ft
13.5-15 ft
15-16.5 ft
16.5-18 ft
18-19.5 ft







6-7.5 ft









7.5-9 ft









— 9-10.5 ft









10.5-12 ft









12-13.5 ft



	6-7.5 ft



1.1

13.5-15 ft

—

6-7.5 ft



1.3

13.5-15 ft

—

7.5-9 ft



1.11

15-16.5 ft

—

9-10.5 ft



1.76

15-16.5 ft



10.5-12 ft



1.6

16.5-18 ft

—

12-13.5 ft



1.19

18-19.5 ft

—

13.5-15 ft



1.31



—

15-16.5 ft



1.33





16.5-18 ft



1.65





18-19.5 ft



1.22





Notes:



CR-1

Quivira Tronox Church Rock No. 1



Mine Site

ft

Foot

pCi/g

Picocurie per gram

Ra-226

Radium-226

TENORM

Technologically enhanced naturally



occurring radioactive material

© Soil Sample Location
I I 100-Foot Step-Out Boundary
I I Mine Lease Boundary
LTj TENORM Boundary
Borehole Legend

Depth
Range

Lab

Result

(pCi/g)

Color

Illustrative Data Ranges
Ra-226

(pCi/g)

Above 100

50 to 100
20 to 50
10 to 20
2 to 10

Description

Above 50x Removal Action
Goal

Up to 50x Removal Action
Goal

Up to 25x Removal Action
Goal

Up to 10x Removal Action
Goal

Up to 5x Removal Action
Goal

1:3,000

250	125

Below 2 Below Removal Action Goal
N

S

1 inch - 250 feet

250
I Feet

CR-1 WASTE PILE
VERTICAL EXTENT
OF RA-226 AT DEPTHS
GREATER THAN 6 FEET
BELOW GRADE

Prepared For: U.S. EPA Region 9

{&)

Prepared By:

TETRATECH

Task Order No.:

000 1

Location:

QUIVIRA MINES

Contract No.:

68HE0923D0002

3/4/2024

Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:

21


-------


I I Mine Lease Boundary
U"j TENORM Boundary
Surface Soil Samples1 - Ra-226
O Below RAG of 2 pCi/g
O CR-1E Sample Above RAG of 2 pCi/g
O Arroyo Sample Above RAG of 2 pCi/g
Subsurface Soil Samples2 - Ra-226
_ Below RAG of 2 pCi/g
Q CR-1 E Sample Above RAG of 2 pCi/g
Arroyo Sample Above RAG of 2 pCi/g

Note:

1Surface soil samples are 0 to 6 inches below grade.
2Subsurface soil samples are 6 to 72 inches below
grade.

CR-1E Quivira Tronox Church Rock No. 1 East

Mine Site
pCi/g Picocurie per gram
RAG	Removal action goal

Ra-226 Radium-226
TENORM Technologically enhanced naturally
occurring radioactive material

1 inch = 250 feet
1:3,000

250	125	0

N

W E
S

250
! Feet

CR-1 E DISTRIBUTION OF

RA-226 IN SURFACE
AND SUBSURFACE SOILS

Prepared For: U.S. EPA Region 9

0§z)

%

Prepared By:

TETRATECH

Task Order No.:

000 1

Contract No.:

68HE0923D0002

QUIVIRA MINES

3/4/2024

Coordinate System:

Figure No.:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

22


-------
I





V /

Notes:

CR-1E Quivira Tronox Church Rock No. 1 East

Mine Site
ft	Foot

pCi/g Picocurie per gram
Ra-226 Radium-226

TENORM Technologically enhanced naturally
occurring radioactive material

© Soil Sample Location
i i 100-Foot Step-Out Boundary
[ ] Mine Lease Boundary
L J TENORM Boundary
Borehole Legend

Depth
Range

Lab

Result

(pCi/g)

Color

Illustrative Data Ranges
Ra-226
(pCi/g)

Above 50x Removal Action

Description

Above 100

50 to 100

20 to 50

10 to 20

2 to 10

Goal

Up to 50x Removal Action
Goal

Up to 25x Removal Action
Goal

Up to 10x Removal Action
Goal

Up to 5x Removal Action
Goal

1:1,800

150	75

Below 2 Below Removal Action Goal
N

S

1 inch - 150 feet

150
I Feet

CR-1E VERTICAL EXTENT
OF RA-226 AT DEPTHS
GREATER THAN 6 FEET
BELOW GRADE

Prepared For: U.S. EPA Region 9

{&)

Prepared By:

TETRATECH

Task Order No.:

000 1

Location:

QUIVIRA MINES

Contract No.:

68HE0923D0002

3/4/2024

Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:

23


-------
NAVAJO

NAT

ON

UN

NUGL EAR

»s

GORPORAT

(5" La

>y /'

/' /

//7 /	"

/

// - /

//

-



|7« *

.

X

\\

\ \



/

.

*

U



*



JM" .2,

~

*



/«



Kerr-McGee Ponds
Investigation Boundary

I I Kerr-McGee Ponds Fenceline

United Nuclear Corporation Site Boundary

LJ*j TENORM Boundary

Surface Soil Samples1 - Ra-226

O Below RAG of 2 pCi/g

Kerr-McGee Ponds Sample on Navajo
® Nation Above RAG of 2 pCi/g

O Arroyo Sample Above RAG of 2 pCi/g
Subsurface Soil Samples2 - Ra-226

l~l Below RAG of 2 pCi/g

Kerr-McGee Ponds Sample on Navajo
Nation Above RAG of 2 pCi/g

Arroyo Sample Above RAG of 2 pCi/g

1 inch = 300 feet

1:3,600

300	150	0

KERR-MCGEE PONDS
DISTRIBUTION OF RA-226
ABOVE 2 PCI/G IN SURFACE
AND SUBSURFACE SOILS

Prepared For: U.S. EPA Region 9

Note:



1Surface soil samples are 0 to 6 inches below grade.

2Subsurface soil samples are 6 to 72 inches below

grade.



Kerr-McGee

Kerr-McGee Corporation

pCi/g

Picocurie per gram

RAG

Removal action goal

Ra-226

Radium-226

TENORM

Technologically enhanced naturally



occurring radioactive material

Prepared By:

Task Order No.:

QUIVIRA MINES

iSz)

% -Kit**

TETRATECH

Contract No.:

68HE0923D0002
3/4/2024

Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:


-------
Prepared By:

TETRATECH

KERR-MCGEE PONDS
DISTRIBUTION OF RA-226
ABOVE 5,4 PCI/G IN
SURFACE AND SUBSURFACE SOILS

Prepared For: U.S. EPA Region 9

Q8z>

Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:

Task Order No.:

Contract No.:

68HE0923D0002

1 inch = 220 feet

1:2,640

220	110	0

Location:

QUIVIRA MINES

Date:

3/4/2024

Kerr-McGee Ponds
Investigation Boundary

I I Kerr-McGee Ponds Fenceline

LTj TENORM Boundary

Surface Soil Samples1 - Ra-226

O Below RAG of 5.4 pCi/g

O Above RAG of 5.4 pCi/g

Subsurface Soil Samples2 - Ra-226

Below RAG of 5.4 pCi/g

Above RAG of 5.4 pCi/g

Note:

'Surface soil samples are 0 to 6 inches below grade.
2Subsurface soil samples are 6 to 72 inches below
grade.

Kerr-McGee Kerr-McGee Corporation
pCi/g	Picocurie per gram

RAG	Removal action goal

Ra-226	Radium-226

TENORM Technologically enhanced naturally
occurring radioactive material


-------
9.5-10 ft 0.
19.5-20 ft ^rf.95





U&13TT 1.3

9.5-10 ft 0.74
.5-15 ft 1.38

6.5-7 ft 0.91
9.5-10 ft 0.7

-KM P-SB43

KMP-SB45

KMP-SB44

^ >—14.5-15 ft 1.33

?r	

KMP-SB46

.5-8 ft 0.93
ft 1.3

Color

Illustrative Data Ranges - Navajo Nation
Ra-226

(pCi/g)	Description

Above 50x Removal Action
Above 100 „ .!

Goal

50 to 100

20 to 50

10 to 20

2 to 10

Up to 50x Removal Action
Goal

Up to 25x Removal Action
Goal

Up to 10x Removal Action
Goal

Up to 5x Removal Action
Goal

Below 2 Below Removal Action Goal

Navajo Nation

United Nuclear
Corporation Site

Illustrative Data Ranges - UNC Property

Color

Ra-226
{pCi/g)

Above 200

100 to 200

40 to 100

20 to 40

5.4 to 20

Below 5.4

Description

Above 37x Outdoor Worker
Screening Level

Up to 37x Outdoor Worker
Screening Level

Up to 18.5x Outdoor Worker
Screening Level

Up to 7.4x Outdoor Worker
Screening Level

Up to 3.7x Outdoor Worker
Screening Level

Below Outdoor Worker
Screening Level

© Soil Sample Location
UNC Mill Boundary
II I Kerr-McGee Ponds Investigation Boundary
I I Kerr-McGee Pond Fenceline
j_""j TENORM Boundary

Borehole Legend

Depth
Range

Lab

Result

(pCi/g)

Notes:

1Removai Action Goal of 2.0 pCi/g is based on the
background threshold value for Ra-226. The background
threshold value is based on the 95 percent upper tolerance
limit with 95 percent coverage of the background dataset.
ft	Foot

Kerr-McGee Kerr-McGee Corporation

pCi/g	Picocurie per gram

Ra-226 Radium-226

TENORM Technologically enhanced naturally

occurring radioactive material
UNC	United Nuclear Corporation

1 inch - 150 feet
1:1,800

150	75	0

N

S

150
I Feet

KERR-MCGEE PONDS
VERTICAL EXTENT OF

RA-226 AT DEPTHS
GREATER THAN 6 FEET
BELOW GRADE

Prepared For: U.S. EPA Region 9

% M*#

Prepared By:

TETRATECH

Task Order No.:

000 1

Location:

QUIVIRA MINES

Contract No.:

68HE0923D0002

3/6/2024

Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:

26


-------
AIR AND OUST
INHALATION

Pfffp!

w

PROCESSING

DIRECT SOIL
EXPOSURE

GARDEN PRODUCE

M H II
nil mm

mi ifii imti

GROUNDWATER

AQUATIC

FOODS

SURFACE
WATER USE

SEDIMENT
EXPOSURE

GATHERED
FOODS

Notes:

Some exposure pathways depicted above are not included in the exposure assessment. See the conceptual site model wire
diagrams (Figure 13) for a description of the included pathways.

Adapted from Harper and others (2007).

Prepared for: U.S. EPA Region 9

Prepared By:

TETRATECH

"It

GRAPHIC DEPICTION OF NAVAJO RESIDENTIAL EXPOSURE
PATHWAYS INCLUDING THE DINE LIFEWAYS

Task Order No.:

TO 0001

Location:

NAVAJO NATION

Contract No.:
68HE0923D0002

Date:

2/21/24

Figure No:

27


-------
Pond

Pond 1

Pond 4

Pond 1a

Pond 3

Notes:

"Waste pile removal depth was variable but
generally extends to bedrock. A separate cut and fill
analysis is being conducted in CAD 3D to assess
waste pile volume.

2Removal extent is based on correlated and laboratory
Ra-226 and uranium data exceeding removal action goals.
CR-1 Quivira Tronox Church Rock No. 1 Mine Site
ft	Foot

Ra-226 Radium-226
TENORM Technologically enhanced naturally
occurring radioactive material

Pond

I I Mine Lease Boundary

L3*J TENORM Boundary

I I Waste Pile Removal Action Extent1

I 0 Former Pond

Removal Action Extent Depth (ft)2

I I 1

pr	^

L\«r .			

Pond 6a	^

m-kk-

r	;lk»3

1 inch = 200 feet
1:2,400

200	100	C

CR-1 SURFACE AND SUBSURFACE
REMOVAL ACTION EXTENT

Prepared For: U.S. EPA Region 9

(&)

Prepared By:

TETRATECH

Task Order No.:

QUIVIRA MINES

Contract No.:

68HE0923D0002

3/4/2024

Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:


-------
Prepared By:

TETRATECH

CR-1E SURFACE AND SUBSURFACE
REMOVAL ACTION EXTENT

Prepared For: U.S. EPA Region 9

($Sz>

Task Order No.:

0001

Contract No.:

68HE0923D0002

QUIVIRA MINES

3/4/2024

Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:

I I Mine Lease Boundary
L~j TENORM Boundary
I I Waste Pile Removal Action Extent1
Removal Action Extent Depth (ft)2

I I 1
m 1-5

2.5
~ 5

Notes:

1Waste pile removal depth is variable but
generally extends to bedrock. A separate cut and fill
analysis is being conducted in CAD 3D to assess
waste pile volume,

2Removal extent is based on correlated and
laboratory Ra-226 and uranium data exceeding
removal action goals.

CR-1E Quivira Tronox Church Rock No. 1 East

Mine Site
ft	Foot

Ra-226 Radium-226
TENORM Technologically enhanced naturally
occurring radioactive material

1 inch = 140 feet	N

w

1:1,680

s

140	70	0	140

~i Feet


-------
United Nuclealr*
Corporation Site



4 ^"Spsjpi

>

fcr]^w	*

s

>

1¥/ ill ^ "iJ.-*;

^$SK

/

/

* e *'-'

,j i i ,.'!"

dBP1.

ul

Kerr-McGee Ponds
Investigation Boundary

Kerr-McGee Ponds Fenceline

UNC Site Boundary

Contamination Associated with a
UNC Site Further to the Southeast

| | TENORM Boundary

Navajo Nation Removal Action Extent Depth (ft)12

~ 2

Navajo Nation I UNC Removal Action Extent Depth (ft)1

1 inch = 140 feet

1:1,680

140	70

KERR-MCGEE PONDS
SURFACE AND SUBSURFACE
REMOVAL ACTION EXTENT

Notes:

'Removal extent is based on correlated and
laboratory Ra-226 and uranium data exceeding
RAGs on Navajo Nation and Ra-226, U-234,
and U-238 on UNC Property.

2Removal action extent is based off the Ra-226
RAG of 2.0 pCi/g.

3Removal action extent is based off the Ra-226
RAG of 5.4 pCi/g.
ft	Foot

Kerr-McGee Kerr-McGee Corporation
pCi/g	Picocurie per gram

Removal action goal
Radium-226

Technologically enhanced naturally
occurring radioactive material
Uranium-234
Uranium-238

United Nuclear Corporation
~

Prepared For: U.S. EPA Region 9

Prepared By:

Task Order No.:

TETRATECH

Contract No.:

68HE0923D0002

RAG
Ra-226
TENORM

U-234
U-238
UNC

QUIVIRA MINES

3/4/2024

Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:


-------
STANDING ROCK CHAPTER

Kerr-McGee Ponds

United Nuclear Corporation
(Private Property)^H

	

I

• "r '	*"V

. * '¦ \ *r\.

*?*»¦.£ "iw.

~ *#** * '

Ufmspm: • Bfe.

:¦ - :^vNv, • • • '	¦ ir-

— 	1

ss

Mr*

• « *• / , "/•' * »'*	* V£\* S* * VV *»	" 7	.%	* * -A £ * s '

;	¦¦¦¦¦ . 	

S««»t-h<,m»d	I a,„.hom,d I

Hk'vat?*

ca.

s>f

¦/J'' ii^L

>r*

¦y

COYOTE CANYON CHAPTER
PINEDALE CHAPTER

	

Ow

-—

2

# Biologia! Observation

Proposed Access Road

	 Existing Road

I I Mine Lease Boundary

United Nuclear Corporation Site
Boundary (Private Property)

Northeast Church Rock Mine Boundary

Navajo Nation Chapter Boundary

Proposed Soii Borrow Area

Proposed Laydown Area

I I Kerr-McGee Ponds Fenceiine

Kerr-McGee Ponds
Investigation Boundary

Proposed CR-1 and CR-1E
Removal Action Extent

Kerr-McGee Ponds Proposed
Removal Action Extent

I 111 Biological Exclusion Zone - 660 feet

¦ m. Sensitive habitat with strong potential
kis-a for Naturita milk-vetch to occur

b&^l Habitation Area Exclusion Area

Cultural Exclusion Area

Cultural Resource Field Cleared Areas

1 inch = 800 feet
1:9,600

3	400	800

PROPOSED LAYDOWN AREA,
ACCESS ROADS,
AND EXCLUSION AREAS

Prepared For: U.S. EPA Region 9

Prepared By:

TETRA TECH

*<* pm0^

Task Order No.:

Contract No.:

68HE0923D0002

Notes:

CR-1	Quivira Tronox Church Rock No. 1 Mine Site

CR-1E	Quivira Tronox Church Rock No. 1 East Mine Site
Kerr-McGee Kerr-McGee Corporation

"-***¦	" ¦ I	I--.

Location:

QUIVIRA MINES

Coordinate System:

NAD 1983 State Plane New Mexico
West FIPS 3003 Feet Tansverse

3/4/2024

Figure No.:

31


-------
taw	- Mu - >

Canyon Respository

7'.'

STANDING ROCK CHAPTER

PINEDALE CHAPTER

Kerr-McGee Ponds

Prepared By:

TETRATECH

1999 Harrison Street, Suite 500
Oakland, CA94612

[ I Mine Lease Boundary

United Nuclear Corporation Site
Boundary (Private Property)

Navajo Nation Chapter Boundary

Kerr-McGee Ponds Fenceline

Proposed Laydown Area

Kerr-McGee Ponds
Investigation Boundary

Potential Soil Borrow Area to Be Used
for Waste Cap and Site Restoration

Proposed Access Road

	 Existing Road

Removal Action Extent

Proposed On-site Consolidation Area1

Notes:

'Only one on-site consolidation area will be used.
CR-1	Quivira Tronox Church Rock No. 1

Mine Site

CR-1E Quivira Tronox Church Rock No. 1

East Mine Site
Kerr-McGee Kerr-McGee Corporation

1 inch = 500 feet

1:6,000

500	250	0	500

~i Feet

ALTERNATIVE 2

WASTE EXCAVATION, TRANSFER,
AND ONSITE CONSOLIDATION

Prepared For: U.S. EPA Region 9

(A)

Task Order No.:

000 1

Contract No.:

68HE0923D0002

Location:

QUIVIRA MINES

3/6/2024

Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:


-------


CR/IE

Canyon
Respository,

COYOTE CANYON CHAPTER

STANDING ROCKxCHAPTER

PINEDALE CHAPTER

	

Notes:

1Only one onsite consolidation area will be used.

CR-1	Quivira Tronox Church Rock No. 1 Mine Site

CR-1E Quivira Tronox Church Rock No. 1 East Mine Site
Kerr-McGee Kerr-McGee Corporation

Drainage

Remove Access Road and Restore Surface

— - Existing Road

Permanent Fencing with Gate to Allow
x ~~ Rotational Grazing

X — Temporary Fencing

Kerr-McGee Ponds
Investigation Boundary

I I Kerr-McGee Ponds Fenceline

|__| Mine Lease Boundary

United Nuclear Corporation Site
Boundary (Private Property)

Navajo Nation Chapter Boundary

If I Arroyo

~ Restore Borrow Areas
Restore Laydown Area
Potential Onsite Repository1
Site Restoration Area

1 inch = 700 feet

N

1:8,400	f

s

700	350	0	700

~ Feet

ALTERNATIVE 2

WASTE CAPPING AND
SITE RESTORATION

Prepared For: U.S. EPA Region 9

Q\

Prepared By:

TETRATECH

Task Order No.:

000 1

Contract No.:

68HE0923D0002

Location:

QUIVIRA MINES

3/1 4/2024

Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:

33


-------
m •

f- - > z -

^'3tf9$T&-ij '"T V^-t "5T5^i

- ^ ~, -. ^ 3? " ¦ S^^V4 -

	_^x._.

" ^
' / K.. ¦

EVAPOTRANSPIRATION CAP
GRADED TO CAPTURE AND
INFILTRATE PRECIPITATION



r^m^

wm

-¦?*.¦* ¦ v<*..

sH

Ml

• • v -	,..'

SsiS^I -	•	' 'i... *'

'- l ' K~iuSr

te - ... > - v	¦¦ • I

•* • - . •	• . I ¦ %.

SSSIPI-'- ':¦-¦¦ •	Il31

.-¦'. ¦ 'U-	'"-. 1 ¦»* « • *•. JBwMflrag

>¦'. V •' K ' ;

Prepared for: U.S. EPA Region £

LEGEND

EVAPOTRANSPIRATION CAP AND CONTOURS
RUNOFF FLOW PATH
DRAINAGE CONTROL DITCHES

o

SEz

Prepared by:

TETRATECH

*> *
y

- ¦ '	' 4S -

" - '

1 ^

ALTERNATIVE 2
TYPICAL WASTE CONSOLIDATION AREA FEATURES

Task Order No.:

TO 0001

QUIVIRA MINES

Contract No

68HE0923D0002

02/21/24

Figure No.:

34


-------
r-^—:¦——

3Jk	L-nJI



¦ - vs

1856

\\

\ cy

\5

a>

v..a

^ a!*-' -J' 'M

¦ «V. ¦ •,"*% f -£ , . *T »_• ; ."*»'¦ -

r ?/. W&&M

COYOTE CANYON CHAPTER /

ufi " *

¦t



.« ^

':.- "T »

	



*>

/<"

^	\ •X\?vk/ >L^vN

W/
-------
Remove Access Road and Restore Surface

	 Existing Road

X — Temporary Fencing

[ | Mine Lease Boundary

Kerr-McGee Ponds
Investigation Boundary

I I Kerr-McGee Ponds Fenceline

United Nuclear Corporation Site Boundary

Navajo Nation Chapter Boundary

[ | Arroyo

Restore Borrow Area

Restore Laydown Area

Site Restoration Area

Notes:

CR-1	Quivira Tronox Church Rock No. 1

Mine Site

CR-1E Quivira Tronox Church Rock No. 1

East Mine Site
Kerr-McGee Kerr-McGee Corporation

1 inch = 700 feet
1:8,400

700	350	0

N

W E

S

700
~ Feet

ALTERNATIVES 3 AND 4
SITE RESTORATION

Prepared For: U.S. EPA Region 9

•>

($)
m nut**

Prepared By:

TETRATECH

1999 Harrison Street, Suite 500
Oakland, CA94612

Task Order No.:

000 1

Location:

QUIVIRA MINES

Contract No.:

68HE0923D0002

3/4/2024

Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:

36


-------
Crownpoint

North Route via HWY N11-49

Proposed Haul Route to
Red Rocks Disposal Facility
Paved: 34.6 miles - from CR-1
34 miles - from CR-1E
Unpaved: 2.7 miles - from CR-1
3.5 miles - from CR-1E

Pinedale

Mariano Lake

rChurch Rock
ftjujrch Rock

Rehoboth

lyanbito

Thoreau

Coordinate System: NAD 1983 StatePlane New Mexico West FIPS 3003 FeetTransverse Mercator

Prepared By:

TETRATECH

Task Order No.: 0001

Contract No.:

68HE0923D0002

Location:

MCKINLEY COUNTY, NEW MEXICO

Date:

3/4/2024

Figure No.:

37

Haul Route Type	A CR-1 arid CR-1 E

Paved	£ Kerr-McGee Porids

—* Unpaved	q QjSp0sal Facility

— Recommended Route a	..

Chapter House

Prepared for: U.S. EPA Region 9

ALTERNATIVE 3 HAUL ROUTES FROM QUIVIRA MINES
TO RED ROCK DISPOSAL FACILITY

Notes:

CR-1	Quivira Tronox Church Rock No. 1 Mine Si^=

CR-1 E	Quivira Tronox Church Rock No. 1 East Mine Site

HWY	Highway
Kerr-McGee Kerr-McGee Corporation

4

"* Miles

Fort Wingate

Recommended South Route via

I-40 Proposed Haul Route to Red
Rocks Disposal Facility
Paved: 40.7 miles - from CR-1

40.2 miles - from CR-1 E
Unpaved: 2.7 miles - from CR-1
3.5 miles - from CR-1E

Disposal

Facility

Smith Lake
... ~

Smith Lake

Red Rock


-------
Coordinate System: NAD 1983 StatePlane New Mexico West FIPS 3003 FeetTransverse Mercator

	 —______

CR-1 —v y— CR-1E	Crcwnpoint M

CR-1	Quivira Tronox Church Rock No. 1 Mine Site

CR-1E	Quivira Tronox Church Rock No. 1 East Mine Site

Kerr-MCGee • Keir-MCGee corpftfatiorT 	¦	—-

|__| Office
i i Scale House

Proposed Red Rocks Mine
Waste Disposal Area

Existing Red Rocks Landfill
I	' Facility

Facility Boundary
~ CR-1 and CR-1 E
A Kerr-McGee Ponds
O Red Rocks Disposal Facility

Haul Route Type

	 Paved

Recommended Route
Existing Haul Road
New Haul Road

Prepared for: U.S. EPA Region 9

y,,B

w

Prepared By:

^ TETRATECH

ALTERNATIVE 3 OFFSITE DISPOSAL AT
PROPOSED RED ROCKS FACILITY

Task Order No.:

0001

Location:

MCKINLEY COUNTY, NEW MEXICO

Contract No.:

68HG0923D0002

3/4/2024

Figure No.:

38


-------
Coordinate System: NAD 1983 StatePlane New Mexico West FIPS 3003 FeetTransverse Mercator

Boulder

ettver

Deer Tra Landf

and
iction

Quivira Mines to 1-40
Proposed Haul Route to
Interstate 40

Paved: 8.4 miles - from CR-1 and CR-1E
Unpaved: 3.5 miles - from CR-1
3.7 miles - from CR-1 E

ueblo

Farmingtcn

Church Rock to Deer Trail, CO
Proposed Haul Route to
Deer Trail Disposal Facility
Paved: 613 miles

Inset Extent

Santa Fe

Amarillo



buquerque

Miles

Haul Route Type A CR-1 arid CR-1 E

Paved A Kerr-McGee Ponds
—Unpaved ® Landfi|]
Recommended Route

Prepared for: U.S. EPA Region 9

ALTERNATIVE 4 HAUL ROUTE FROM QUIVIRA MINES TO
DEER TRAIL, COLORADO, DISPOSAL FACILITY

Prepared By:

-|^ TETRATECH

Task Order No.: 0001

Contract No.:

68IIE0923D0002

Figure No.:

39

Location:

MCKINLEY COUNTY, NEW MEXICO

Date:

3/4/2024


-------
Coordinate System: NAD 1983 StatePlane New Mexico West FIPS 3003 FeetTransverse Mercator

fjep}	Farmington

Church Rock to Andrews, TX

Proposed Haul Route to
V\foste Control Specialists LLC
Paved: 489 miles

Prepared By:

Task Order No.: 0001

Contract No.:

68HE0923D0002

Location:

MCKINLEY COUNTY, NEW MEXICO

Date:

3/4/2024

Figure No.:

40

Haul Route Type

	 Paved

	 Unpaved

• Preferred Route

A CR-1 arid CR-1E
A Kerr-McGee Porids
© Landfill

Prepared for: U.S. EPA Region 9

HAUL ROUTE FROM QUIVIRA MINES TO WASTE CONTROL
SPECIALISTS, ANDREWS, TEXAS, DISPOSAL FACILITY

Waste Control
Specialists

LuUlioeK

Midland

jy

Odessa

Quivira Mines to I-40

Proposed Haul Route to
Interstate 40

8.4 miles - from CR-1 and CR-1 E
Unpaved: 3.5 miles - from CR-1
3.7 miles - from CR-1 E

Tucson


-------
TABLES


-------
Table 1. Mine Features and Dimensions for Quivira Mines

Feature

Reclamation
Status

Reclamation Description

Dimensions

Quivira Church Rock No. 1 Mine (CR-1)

Shaft

Reclaimed

Sediments and waste rock were placed in shaft, grizzlies were
placed over all openings, and the shaft was capped with a 4-foot

concrete cap.

14 feet in diameter

Adit

Reclaimed

Infilled with rock and closed.

Undocumented

Waste Rock and
Former Ponds 1 to 3

Reclaimed

Sediments were excavated and placed in shaft.

15.4 acres

Former Industrial Area North

Reclaimed

Mine equipment and buildings were removed and foundations

destroyed.

4.7 acres

Former Industrial Area
Central

Reclaimed

Mine equipment and buildings were removed and foundations

destroyed.

1.5 acres

Former Industrial Area East

Reclaimed

Mine equipment and buildings were removed and foundations

destroyed.

0.7 acre

Former Ponds 4 and 5

Reclaimed

Sediments were excavated and placed in shaft.

3.6 acres

Former Pond 6

Reclaimed

Sediments were excavated and placed in shaft.

2.6 acres

Step-Out Areas

Unreclaimed

No reclamation completed.

8.5 acres

RWPR Waste

Reclaimed

Excavated and consolidated on CR-1 with soil cover.

1.2 acres
17,374 cubic yards

Vent Flole / Bridge Abutment
Waste

Reclaimed

Excavated and consolidated on CR-1 with soil cover.

4.7 acres
10,293 cubic yards

Page 1 of 2


-------
Table 1. Mine Features and Dimensions for Quivira Mines

Feature

Reclamation
Status

Reclamation Description

Dimensions

Quivira Church Rock No. 1 East Mine (CR-1E)

Shaft

Reclaimed

Sediments and waste rock were placed in shaft, grizzlies were
placed over all openings, and the shaft was capped with a 4-foot

concrete cap.

12 feet in diameter

Adit 1

Reclaimed

Infilled with rock; partially open.

Undocumented

Adit 2

Reclaimed

Infilled with rock; partially open.

Undocumented

Waste Rock and
Former Pond

Reclaimed

Waste rock consolidated into two piles. Pond sediment was
excavated and placed in shaft.

5 acres

Former Industrial Area North

Reclaimed

Mine equipment and buildings were removed and foundations

destroyed.

1.8 acres

Former Industrial Area South

Reclaimed

Mine equipment and buildings were removed and foundations

destroyed.

0.3 acre

Step-Out Areas

Unreclaimed

No reclamation completed.

2.9 acres

Kerr-McGee Corporation Ponds

Former Ponds

Reclaimed

Unlined pond berms were knocked down.

0.47 acre

Former Stockpile Area

Reclaimed

Proto-ore stockpile was removed.

1.1 acres
31,060 cubic yards

Equipment Storage Area

Reclaimed

Equipment was removed.

3.73 acres

Note:

RWPR Red Water Pond Road

Page 2 of 2


-------
Table 2. Comparison of Quivira Surface Soil with Bartlett Barren Member of Crevasse Canyon Formation (BSA-2) Background Surface Soil

coc

Church Rock No. 1
Mine Soil
(0-6 inch bgs)

BSA-2 Soil
(0-6 inch bgs)

Two-Population Statistical Tests

Final
Conclusion
for

Background
Screen

Sample Size

Detection
Frequency
(Percent)

Sample Size

Detection
Frequency
(Percent)

Gehana

Ta rone-
Ware3

Wilcoxon-

Mann-
Whitneyb

Quantile0

Detected

Total

Detected

Total

Site >
Background?

Site >
Background?

Site >
Background?

Site >
Background?

Site >
Background?

Radium-226

150

150

100%

36

36

100%

-

-

Yes

-

Yes

Arsenic

30

30

100%

36

36

100%

-

-

No

No

No

Chromium

30

30

100%

36

36

100%

-

-

No

No

No

Manganese

30

30

100%

36

36

100%

-

-

No

No

No

Thallium

30

30

100%

36

36

100%

-

-

No

No

No

Uranium

86

86

100%

36

36

100%

—

—

Yes

—

Yes

COC

Church Rock No. 1 East
Mine Soil
(0-6 inch bgs)

BSA-2 Soil
(0-6 inch bgs)

Two-Population Statistical Tests

Final
Conclusion
for

Background
Screen

Sample Size

Detection
Frequency
(Percent)

Sample Size

Detection
Frequency
(Percent)

Gehana

Ta rone-
Ware3

Wilcoxon-

Mann-
Whitnevb

Quantilec

Detected

Total

Detected

Total

Site >
Background?

Site >
Background?

Site >
Background?

Site >
Background?

Site >
Background?

Radium-226

67

67

100%

36

36

100%

—

—

Yes

—

Yes

Arsenic

15

15

100%

36

36

100%

—

—

No

No

No

Chromium

15

15

100%

36

36

100%

—

—

Yes

—

Yes

Manganese

15

15

100%

36

36

100%

—

—

No

No

No

Thallium

15

15

100%

36

36

100%

—

—

No

No

No

Uranium

15

15

100%

36

36

100%

-

-

Yes

-

Yes

Page 1 of 3


-------
Table 2. Comparison of Quivira Surface Soil with Bartlett Barren Member of Crevasse Canyon Formation (BSA-2) Background Surface Soil

coc

Kerr-McGee Ponds on the
Navajo Nation Soil
(0-6 inch bgs)

BSA-2 Soil
(0-6 inch bgs)

Two-Population Statistical Tests

Final
Conclusion
for

Background
Screen

Sample Size

Detection
Frequency
(Percent)

Sample Size

Detection
Frequency
(Percent)

Gehana

Ta rone-
Ware3

Wilcoxon-

Mann-
Whitnevb

Quantilec

Detected

Total

Detected

Total

Site >
Background?

Site >
Background?

Site >
Background?

Site >
Background?

Site >
Background?

Radium-226

5

5

100%

36

36

100%

-

-

Yes

-

Yes

Arsenic

5

5

100%

36

36

100%

-

-

No

No

No

Chromium

5

5

100%

36

36

100%

—

—

Yes

—

Yes

Manganese

3

3

100%

36

36

100%

-

-

No

No

No

Thallium

3

3

100%

36

36

100%

-

-

No

No

No

Uranium

5

5

100%

36

36

100%

-

-

Yes

-

Yes

COC

Kerr-McGee Ponds on
UNC Property Soil
(0-6 inch bgs)

BSA-2 Soil
(0-6 inch bgs)

Two-Population Statistical Tests

Final
Conclusion
for

Background
Screen

Sample Size

Detection
Frequency
(Percent)

Sample Size

Detection
Frequency
(Percent)

Gehana

Ta rone-
Ware3

Wilcoxon-

Mann-
Whitnevb

Quantile0

Detected

Total

Detected

Total

Site >
Background?

Site >
Background?

Site >
Background?

Site >
Background?

Site >
Background?

Radium-226

54

54

100%

36

36

100%

-

-

Yes

-

Yes

COC

Arroyos on the
Navajo Nation Soil
(0-6 inch bgs)

BSA-2 Soil
(0-6 inch bgs)

Two-Population Statistical Tests

Final
Conclusion
for

Background
Screen

Sample Size

Detection
Frequency
(Percent)

Sample Size

Detection
Frequency
(Percent)

Gehana

Ta rone-
Ware3

Wilcoxon-

Mann-
Whitnevb

Quantile0

Detected

Total

Detected

Total

Site >
Background?

Site >
Background?

Site >
Background?

Site >
Background?

Site >
Background?

Radium-226

90

90

100%

36

36

100%

—

—

No

No

No

Arsenic

3

3

100%

36

36

100%

—

—

No

No

No

Manganese

1

1

100%

36

36

100%

-

-

-

-

No

Page 2 of 3


-------
Table 2. Comparison of Quivira Surface Soil with Bartlett Barren Member of Crevasse Canyon Formation (BSA-2) Background Surface Soil

COEC

Site-Wide Soil
(0-6 inch bgs)

BSA-2 Soil
(0-6 inch bgs)

Two-Population Statistical Tests

Final
Conclusion
for

Background
Screen

Sample Size

Detection
Frequency
(Percent)

Sample Size

Detection
Frequency
(Percent)

Gehan"

Tarone-
Ware3

Wilcoxon-

Mann-
Whitnevb

Quantile0

Detected

Total

Detected

Total

Site >
Background?

Site >
Background?

Site >
Background?

Site >
Background?

Site >
Background?

Uranium-238

10

10

100%

5

36

14%

Yes

Yes

—

—

Yes

Uranium-234

10

10

100%

3

3

100%

—

—

No

Yes

Yes

Radium-226

379

379

100%

36

36

100%

—

—

Yes

—

Yes

Arsenic

108

108

100%

36

36

100%

—

—

Yes

—

Yes

Barium

108

108

100%

36

36

100%

—

—

Yes

—

Yes

Chromium

108

108

100%

36

36

100%

—

—

Yes

—

Yes

Lead

108

108

100%

36

36

100%

—

—

No

No

No

Manganese

85

85

100%

36

36

100%

—

—

No

No

No

Selenium

118

118

100%

36

36

100%

—

—

Yes

—

Yes

Thallium

84

85

99%

36

36

100%

No

No

—

No

No

Uranium

164

164

100%

36

36

100%

—

—

Yes

—

Yes

Vanadium

108

108

100%

36

36

100%

—

—

Yes

—

Yes

Zinc

85

85

100%

36

36

100%

-

-

No

No

No

Notes:

Bold indicates site soil concentrations are greater than background concentrations.

a	Gehan and Tarone-Ware are tests of central tendency and only used when multiple nondetect results are present in the dataset (USEPA 2022).

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 2010b).

Not applicable
bgs	Below ground surface

BSA	Background study area

COC	Contaminant of concern

COEC	Contaminant of ecological concern

Kerr-McGee	Kerr-McGee Corporation

UNC	United Nuclear Corporation

USEPA	U.S. Environmental Protection Agency

References:

U.S. Environmental Protection Agency (USEPA). 2010b. "ProUCL Statistical Software for Environmental Applications for Data Sets with and without Nondetect Observation."
U^^0^d2^.^"Vro[?6&rfec^nic'aPi§SKie:n^tal:istiMr'§oftware^oPln"wonmenl^Applications for Data Sets with and without Nondetect Observations." Version 5.2.0. June 14.

Page 3 of 3


-------
Table 3. Risk Management Summary

Exposure
Unit

Land Use/
Receptor

Soil
Interval

Candidate COC or COEC

Uranium-
238

Uranium-
234

Radium-226
inSE

Arsenic

Barium

Chromium

Cobalt

Iron

Lead

Manganese

Selenium

Thallium

Uranium

Vanadium

Zinc

CR-1

Kee'da'whn teeh
(Full-time Navajo
Resident)

Surface

--

--

COC

< BG

--

< BG

< BG

< BG

--

< BG

--

< BG

COC

--

~

Subsurface

--

--

COC

< BG

--

< BG

< BG

< BG

~

< BG

~

< BG

COC

~

~

CR-1E

Kee'da'whn teeh
(Full-time Navajo
Resident)

Surface

--

--

COC

< BG

--

Cr(lll) not a
COPC

< BG

< BG

~

< BG

~

< BG

COC

--

--

Subsurface

--

--

COC

< BG

--

Cr(lll) not a
COPC

< BG

< BG

~

< BG

--

< BG

COC

~

~

Kerr-McGee
Ponds on the
Navajo Nation

Kee'da'whn teeh
(Full-time Navajo
Resident)

Surface

--

--

COC

< BG

--

Cr(lll) not a
COPC

< BG

< BG

--

< BG

~

< BG

COC

~

~

Subsurface

--

--

COC

< BG

--

Cr(lll) not a
COPC

< BG

< BG

~

< BG

~

< BG

COC

~

~

Kerr-McGee
Ponds on
UNC Property

UNC Outdoor
Worker

Surface

--

--

COC

--

--

--

--

--

~

--

~

--

--

~

~

Subsurface

--

--

COC

--

--

--

--

--

~

--

~

--

--

--

--

Arroyos on the
Navajo Nation

Kqq ei doo
nahaazah dah
(Difficult Access
Open Space User)

Surface

--

--

< BG

< BG

--

--

--

--

~

< BG

--

--

--

~

~

Subsurface

--

--

< BG

< BG

--

~

--

--

--

< BG

~

--

~

~

~

Arroyos on
UNC Property

UNC Outdoor
Worker

Surface

--

--

--

--

--

~

--

~

~

--

~

--

~

~

~

Subsurface

--

--

--

--

--

~

~

~

~

--

~

~

--

~

~

Site-Wide

Plants,

Invertebrates,
Birds, Mammals

Surface

--

--

EPC <
PERG

EPC <
PERG

Co-Loc

Cr(lll) not a
COPEC

~

~

< BG

< BG

EPC <
PERG

< BG

EPC <
PERG

Co-Loc

< BG

Subsurface

EPC <
PERG

EPC <
PERG

EPC <
PERG

--

Co-Loc

Cr(lll) not a
COPEC

~

~

--

< BG

EPC <
PERG

< BG

EPC <
PERG

--

--

Notes:

Bold indicates an identified final COC recommended for removal action; no COECs were recommended for removal.

Contaminant is not a candidate COC or COEC in the exposure unit and depth interval.
BG	Background	Cr(lll)

COC	Contaminant of concern	EPC

COEC	Contaminant of ecological concern	Kerr-McGee

Co-Loc	Co-located with radium-226 preliminary removal action extent	PERG

COPC	Contaminant of potential concern	PRG

COPEC	Contaminant of potential ecological concern	SE

CR-1	Quivira Church Rock No. 1 Mine	UNC

CR-1E	Quivira Church Rock No. 1 East Mine

Trivalent chromium
Exposure point concentration
Kerr-McGee Corporation
Preliminary ecological removal goal
Preliminary removal goal
Secular equilibrium
United Nuclear Corporation

Page 1 of 1


-------
Table 4. Quivira Mines Selection of Soil Removal Action Goal for Each COC and COEC

COCI
COEC

Units

Human
Health
PRG1

NAUM
PERG2

BTV

RAG

Basis for
RAG

Quivira Church Rock No. 1 Mine - Kee'da'whii teeh (Full-Time Navajo Resident)

Surface Soil (0-6 inches bgs) and Subsurface Soil (0-72 inches bgs)

Radium-226

pCi/g

0.050

2.0

2.0

BTV

Uranium

mg/kg

3.2

2.4

3.2

HH PRG

Quivira Church Rock No. 1 East Mine - Kee'da'whii teeh (Full-Time Navajo Resident)

Surface Soil (0-6 inches bgs) and Subsurface Soil (0-72 inches bgs)

Radium-226

pCi/g

0.050

2.0

2.0

BTV

Uranium

mg/kg

3.2

2.4

3.2

HH PRG

Kerr-McGee Ponds on the Navajo Nation - Kee'da'whii teeh (Full-Time Navajo Resident)

Surface Soil (0-6 inches bgs) and Subsurface Soil (0-72 inches bgs)

Radium-226

pCi/g

0.050

2.0

2.0

BTV

Kerr-McGee Ponds on United Nuclear Corporation Property - UNC Outdoor Worker

Surface Soil (0-6 inches bgs)

Radium-226

pCi/g

5.4

2.0

5.4

HH PRG

Subsurface Soil (6-72 inches bgs)

Radium-226

pCi/g

5.4

2.0

5.4

HH PRG

Arroyos on the Navajo Nation - Kpp ei doo nahaazah dah (Difficult Access Open Space User)

Surface Soil (0-6 inches bgs) and Subsurface Soil (0-72 inches bgs)

No COCs or COECs Identified

Arroyos on United Nuclear Corporation Property - UNC Outdoor Worker

Surface Soil (0-6 inches bgs) and Subsurface Soil (0-36 inches bgs)

No COCs or COECs Identified

Notes:

1	The human health PRG is based on the RME receptor assumed at each EU and calculated using the NAUM Risk
Calculator (USEPA 2024b).

2	No COECs were identified; no removal action is recommended to address ecological risk.

3	The BTVs for soil are UTL95-95s from the Bartlett Barren Member (Tetra Tech, Inc. 2023b).

4	The RAG is the lesser of the human health PRG and NAUM PERG, when applicable, unless either is less than the BTV.

If the BTV is greater than the human health PRG or NAUM PERG, the final RAG is to address material that is distinguishable
from background.

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.

-

Not a COEC

pCi/g

Picocurie per gram

bgs

Below ground surface

PERG

Preliminary ecological removal goal

BTV

Background threshold value

PRG

Preliminary removal goal

COC

Contaminant of concern

RAG

Removal action goal

COEC

Contaminant of ecological concern

RME

Reasonable maximum exposure

EU

Exposure unit

UNC

United Nuclear Corporation

HH

Human health

UTL95-95

95% upper tolerance limit with

mg/kg

Milligram per kilogram



95% coverage

NAUM

Navajo abandoned uranium mine

USEPA

U.S. Environmental Protection Agency

Page 1 of 2


-------
Table 4. Quivira Mines Selection of Soil Removal Action Goal for Each COC and COEC

References:

Tetra Tech, Inc. 2023b. "Quivira Mines Data Gaps Investigation Transmittal Memorandum." Response, Assessment, and

Evaluation Services. Contract No. EP-S9-17-03. September.

U.S. Environmental Protection Agency (USEPA). 2024b. "Navajo Abandoned Uranium Mine Risk Calculator." Version 1.03.
March.

Page 2 of 2


-------
Table 5. General Response Actions, Technologies, and Process Options

General
Response
Actions

Response Action
Technology

Process Options

No Action

None

Not Applicable



Land Use Controls

Chapter Land Use Plans

Institutional

Homesite Lease Approval

Controls

Access Restrictions

Deed Restrictions



Environmental Control Easements



Physical Barriers

Fencing/Barrier



Surface Controls

Consolidation, Grading, Revegetation,
and Erosion Protection





Soil Binder



Segregation

Soil Sorting



Backfilling of Mine

Backfilling of Cuts, Benches, and Pits

Engineering
Controls

Workings

Backfilling of Underground Voids



Earthen Cover



Containment

Earthen Cover with Upper HDPE or
Geosynthetic Clay Liner



Regional Disposal

On-Navajo Nation Regional Repository



Off-Navajo Nation Regional Repository



Off-Navajo Nation
Disposal

Non-RCRA, Class A LLRW, or RCRA C Hazardous
Waste Disposal Facility with State License to Receive
Radioactive Material





Soil Washing





Acid Extraction

Excavation and
Treatment

Physical/Chemical

Ablation

Treatment

Milling/Reprocessing



Solidification





Stabilization



Thermal Treatment

Vitrification



Physical/Chemical

Solidification

In-Place

Treatment

Stabilization

T reatment

Thermal Treatment

Vitrification



Vegetative Treatment

Phytoextraction/Phytostabilization

Notes:

HDPE	High-density polyethylene

LLRW	Low-level radioactive waste

RCRA	Resource Conservation and Recovery Act

Page 1 of 1


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Table 6. Applicable or Relevant and Appropriate Requirements and To Be Considered

Requirements for Quivira Mines

Table 6a and Table 6b list the federal and Navajo Nation location- and action-specific applicable
or relevant and appropriate requirements (ARAR) and "To Be Considered" (TBC) requirements,
respectively, that have been identified for all the alternative response actions described in the
engineering evaluation/cost analysis (EE/CA) for the Quivira Tronox Mine Site (Quivira Mines).
The U.S. Environmental Protection Agency (USEPA) did not identify chemical-specific ARARs
or TBCs because potential federal, State of New Mexico, and Navajo Nation chemical-specific
ARARs were not as conservative as the risk-based cleanup standards developed for this action.
Chemical-related requirements tied to an action such as cap design were included in the action-
specific table (Table 6b). Identification and evaluation of ARARs is an iterative process that
continues throughout the response process. As site conditions, contaminants, and response
alternatives at the Quivira Mines are better understood, the ARARs and 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.

•	"Clarification of the Role of Applicable, or Relevant and Appropriate Requirements in
Establishing Preliminary Remediation Goals under CERCLA" (USEPA 1997a)

•	"Establishment of Cleanup Levels for CERCLA [Comprehensive Environmental
Response, Compensation, and Liability Act] Sites with Radioactive Contamination"
(USEPA 1997b)

•	"Use of Soil Cleanup Criteria in 40 CFR Part 192 as Remediation Goals for CERCLA
Sites" (USEPA 1998)

•	"Radiation Risk Assessment at CERCLA Sites: Q&A" (USEPA 2014)

The following Navajo Nation laws, regulations, and guidance are not considered ARARs or
TBCs for the response actions anticipated by this EE/CA; however, they are listed here because
situations may arise during implementation of the alternatives discussed in the EE/CA or during
future actions at the Quivira Mines where these requirements may be applicable.

•	Navajo Nation CERCLA. 4 Navajo Nation Code (N.N.C.) Sections (§§) 2101-2805 - The
Navajo Nation CERCLA requirements must be complied with during implementation of
the response action if petroleum contamination is discovered at the Quivira Mines
because Navajo Nation CERCLA Section (§) 2104.Q includes petroleum in the definition
of hazardous substance. Based on site investigations thus far, petroleum contamination is
not anticipated.

•	Navajo Nation Underground and Aboveground Storage Tank Act of 2012 (NNSTA).
4 N.N.C. §§ 1501-1577 - If any permanent storage tanks are found at a site, including
both underground and aboveground storage tanks and tanks holding not only petroleum
but any hazardous substances, NNSTA § 1542(C) (1) requires removal of the tanks. (The

Page 1 of 13


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Table 6. Applicable or Relevant and Appropriate Requirements and To Be Considered

Requirements for Quivira Mines

guidance for temporary/mobile storage tanks brought on site is included in Table 6b as a
TBC because that situation is anticipated to arise.)

•	Navajo Nation Business Opportunity Act. 5 N.N.C. §§ 201-214. and the Navajo
Preference in Employment Act. 15 N.N.C. §§ 601-619 - While these are not
environmental regulations and, therefore, are not ARARs, these regulations give
preference to Navajo Nation businesses and individuals when hiring employees and
contractors to perform the response actions anticipated by this EE/CA.

•	Navajo Nation Dine Radioactive Materials Transportation Act (RMTA). 18 N.N.C.

§§ 1304-1307 - RMTA is not applicable to onsite activities; however, its requirements
may be applicable to transportation on public roads on the Navajo Nation between sites
that are subject to a combined action pursuant to CERCLA § 104(d)(4), as well as for
shipment of radioactive materials through the Navajo Nation generally. RMTA § 1307
includes specific requirements that are not found in federal law, including advance notice
of the transportation of radioactive and related substances, equipment, vehicles, persons,
and materials over and across the Navajo Nation, as well as license fees, bonding
requirements, route restrictions, and curfews.

The EE/CAs for which the ARARs tables below were prepared do not address groundwater and,

therefore, ARARs for groundwater are not included. If any groundwater contamination is found

at the Quivira Mines, the related ARARs will be addressed at that time.

References:

U.S. Environmental Protection Agency (USEPA). 1997a. "Clarification of the Role of

Applicable, or Relevant and Appropriate Requirements in Establishing Preliminary
Remediation Goals under CERCLA." Office of Solid Waste and Emergency Response
(OSWER) Directive No. 9200.4-23. August.

USEPA. 1997b. "Establishment of Cleanup Levels for CERCLA Sites with Radioactive
Contamination." OSWER Directive No. 9200.4-18. August.

USEPA. 1998. "Use of Soil Cleanup Criteria in 40 CFR Part 192 as Remediation Goals for
CERCLA Sites." OSWER Directive No. 9200.4-25. February.

USEPA. 2014. "Radiation Risk Assessment at CERCLA Sites: Q&A." OSWER Directive
No. 9200.4-40. May.

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Table 6a. Location-Specific ARARs and TBC Information

Media

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 (Section 3 (c)(1)).

Applicable

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
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 or objects and minimize harm to any National
Historic Landmark. Federal agencies may be required to
identify historic properties or objects, determine whether
proposed activity will have an adverse effect on historic
properties or objects, and develop alternatives or
modifications to the proposed action that could avoid,
minimize, or mitigate adverse effects through the National
Historic Preservation Act's Section 106 process.

Applicable

Substantive requirements are
applicable if a 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.

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 DO I and either recover, protect, and
preserve the data itself or request DOI to do so.

Applicable

Substantive requirements are
applicable if a federal agency action
may cause irreparable loss or
destruction to significant scientific,
prehistorical, historical, or
archaeological data.

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Table 6a. Location-Specific ARARs and TBC Information

Media

Requirement

Requirement Synopsis

Prerequisites, Status, and
Rationale

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 within the area to be
disturbed.

Cultural
Resources

FEDERAL

American Indian
Religious Freedom Act

42 U.S.C. § 1996

Policy of the United States to protect access to and the use
of religious, ceremonial, and burial sites and sacred objects
by Native American groups.

TBC

Policy should be followed if Native
American sacred sites are identified
within the area to be disturbed.

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. Protected migratory birds
species 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 are
applicable if bald or golden eagles or
their nests are identified at or near the
site.

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Table 6a. Location-Specific ARARs and TBC Information

Media

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 or result in the destruction or alteration of such
species' habitats. Endangered and threatened species are
listed at 50 CFR Part 17, Subpart B.

Applicable

Substantive requirements are
applicable if endangered or
threatened species are identified at
the site.

Cultural
Resources

NAVAJO NATION

Navajo Nation Cultural
Resources Protection Act

11 N.N.C. §§ 1003(S);
1021; and 1031

Prohibits alteration, damage, excavation, defacement,
destruction, or removal of cultural properties.

Applicable

Substantive requirements are
applicable to activities at the AUM
sites where cultural resources may be
encountered.

Cultural

NAVAJO NATION

Navajo Nation Policy for
the Disposition of
Cultural Resources
Collections

Sections 2 and 6.1

(These sections would
trigger other provisions in
the policy)

Establishes procedures and guidelines to be followed for
excavation (as a last resort) and disposition of cultural
resources recovered on the Navajo Nation, including the
handling of inadvertent discovery.

TBC

TBC for activities on AUM sites where
cultural resources may be
encountered.

Resources





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Table 6a. Location-Specific ARARs and TBC Information

Media

Requirement

Requirement Synopsis

Prerequisites, Status, and
Rationale

Cultural
Resources

NAVAJO NATION

Navajo Nation Guidelines
for the Treatment of
Discovery Situations

Establish procedures and guidelines to be followed in any
situation involving the discovery of cultural or historic
property, including historical and prehistoric archaeological
sites and traditional cultural properties and human remains
whether or not previously identified.

TBC

NNFIFIPD performs these functions
pursuant to a contract with BIA under
which NNFIFIPD serves as the BIA's
agent.

Cultural
Resources

NAVAJO NATION

Navajo Nation Policy for
the Protection of
Jishchaa: Gravesites,
Human Remains, and
Funerary Items

Establishes principles for locating and handling of gravesites,
human remains, and associated artifacts and soil in the area
to be disturbed by AUM removal activities. See in particular
Section IV (Traditional Concerns), which contains
requirements if the AUM activity comes into contact with
gravesites, human remains, or funerary items. It imposes
specific requirements for how to navigate around, prepare
for, and respond to burial grounds and uncovered remains.
See also Section V (Encountering Gravesites, Human
Remains, and Funerary Items), which specifies the
procedures when an inadvertent discovery is made. Sections
VI and VII contain additional requirements in that event.

TBC

Biological
Resources

NAVAJO NATION

Navajo Nation
Endangered Species Act

17 N.N.C. §§ 500-508

Navajo Nation
Endangered Species List

- Resource Committee
Resolution RCAU-103-05

NNESA § 507 makes it unlawful for any person to "take,
possess, transport, export, process, sell or offer for sale or
ship any species or subspecies of wildlife" listed as
endangered or threatened on federal or Navajo Nation lists,
which also protect those species' critical habitat. NNESA §§
500-504 and 506-508 also protect, to various extents, game
fish, game birds, songbirds, game animals, fur-bearing
animals (all defined under § 500), and hawks, vultures, and
owls from being taken.

The Navajo Nation Endangered Species List includes
species that are not on the federal list. It also provides
broader criteria for when species would be listed based on
their prospects of survival or recruitment within the Navajo
Nation (see categories "G2" and "G3"). Category G4 provides
a means for the Navajo Nation Department of Fish and
Wildlife to include additional species (or exclude species),
making it possible for the list to change during the course of
work.

Applicable

Substantive requirements applicable
if protected species or habitat are
identified within the area to be
disturbed on AUM sites.

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Table 6a. Location-Specific ARARs and TBC Information

Notes:

§	Section

§§	Sections

ARAR	Applicable or relevant and appropriate requirement

AUM	Abandoned uranium mine

BIA	Bureau of Indian Affairs

CFR	Code of Federal Regulations

DOI	U.S. Department of the Interior

N. N. C.	Navajo Nation Code

NNESA	Navajo Nation Endangered Species Act

NNHHPD	Navajo Nation Heritage and Historic Preservation Department

TBC	To be considered

U.S.C.	United States Code

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Table 6b. Action-Specific ARARs and TBC Information

Media

Requirement

Requirement Synopsis

Prerequisites, Status, and
Rationale

Air

FEDERAL

Clean Air Act

42 U.S.C. §§ 7401, ef seq.

40 CFR § 61.92

Emissions of radionuclides 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 millirems per year.

Relevant and Appropriate

This standard is applicable to a DOE
facility. The site is not a DOE facility;
therefore, this standard is not applicable.
Flowever, 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

42 U.S.C. §§ 7401, ef seq.

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 picocuries per square meter per second.

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, including erosion and sediment
control BMPs. All treatment and control systems and
facilities will be properly operated and maintained.

Applicable

If there are discharges to WOTUS.

Relevant and Appropriate

If there are discharges to Navajo Nation
surface waters (as defined in Table 206.1
of Navajo Nation Surface Water Quality
Standards 2015).

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Table 6b. Action-Specific ARARs and TBC Information

Media

Requirement

Requirement Synopsis

Prerequisites, Status, and
Rationale

Water

FEDERAL

Clean Water Act

33 U.S.C. § 1342(p)

NPDES 2022 Construction
General Permit for
Stormwater Discharges
from Construction
Activities

Part 2. Technology-Based
Effluent Limitations.
Section 2.2. Erosion and
Sediment Control
Requirements,

Subsection 2.2.1.

Requires implementation of erosion and sediment
controls to minimize the discharge of pollutants in
stormwater from construction activities. Natural buffers or
equivalent erosion and sediment controls must be
provided and maintained for discharges to receiving
waters within 50 feet of the site's earth disturbances.
For any discharges to receiving waters within 50 feet of
the site's earth disturbances, one of the following
alternatives must be complied with:

i.	Provide and maintain a 50-foot undisturbed natural
buffer

ii.	Provide and maintain an undisturbed natural buffer that
is less than 50 feet and is supplemented by erosion and
sediment controls that achieve, in combination, the
sediment load reduction equivalent to a 50-foot
undisturbed natural buffer

iii.	If infeasible to provide and maintain an undisturbed
natural buffer of any size, implement erosion and
sediment controls to achieve the sediment load reduction
equivalent to a 50-foot undisturbed natural buffer.

Applicable

For operators of construction activities if
weather events necessitating stormwater
runoff controls occur during onsite
excavation, waste consolidation, and
repository construction.

Water

FEDERAL

Clean Water Act

33 U.S.C. § 1344

CWA § 404(b) Guidelines
40 CFR §§ 230.10;
230.61, and 230.71-76

Prohibits the unpermitted discharge of dredge or fill
material into WOTUS other than incidental fallback.
Should dredge and fill material be discharged to a
WOTUS, the chemical, biological, and physical impacts
to the WOTUS must be tested and evaluated. Any
adverse effects shall be minimized by treating the
material before discharge, limiting the mobility of the
discharge materials and avoiding or limiting impacts to
WOTUS that serve as wildlife habitat, recreational space,
or other use by humans.

Applicable

If there are discharges to WOTUS.

Relevant and Appropriate

If there are discharges to Navajo Nation
surface waters (as defined in NNCWA
§ 1302(43) and listed in Table 206.1 of
Navajo Nation Surface Water Quality
Standards 2015).

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Table 6b. Action-Specific ARARs and TBC Information

Media

Requirement

Requirement Synopsis

Prerequisites, Status, and
Rationale

Water

FEDERAL
Clean Water Act
33 U.S.C. § 1344
CWA § 404

Nationwide Permit 38 -
Clean Up of Hazardous
and Toxic Waste

Onsite CERCLA actions conducted by a federal agency
that involve the discharge of dredged or fill material into
WOTUS must comply with the substantive requirements
of the Nationwide Permit 38 general conditions, as
appropriate, and any regional or case-specific conditions
recommended by the U.S. Army Corps of Engineers
district engineer after consultation.

Applicable

If there are discharges to WOTUS.

Relevant and Appropriate

If there are discharges to Navajo Nation
surface waters (as defined in NNCWA
§ 1302(43) and listed in Table 206.1 of
Navajo Nation Surface Water Quality
Standards 2015).

Repository

FEDERAL

Uranium Mill Tailings
Radiation Control Act

42 U.S.C. §§ 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.

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Table 6b. Action-Specific ARARs and TBC Information

Media

Requirement

Requirement Synopsis

Prerequisites, Status, and
Rationale

Repository

FEDERAL

Uranium Mill Tailings
Radiation Control Act

42 U.S.C. §§ 7918 and
2022

10 CFR Part 40,

Appendix A. Criterions 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
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 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 that 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, which consists of onsite
containment of contaminated soil and
uranium waste rock.

All

NEW MEXICO
NMAC§ 20.3.13.1317

Requires the protection of the general population from the
release of radioactivity.

Relevant and Appropriate

This regulation is the same as 40 CFR
§ 192. This requirement is not applicable
to the site but is relevant and appropriate.

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Table 6b. Action-Specific ARARs and TBC Information

Media

Requirement

Requirement Synopsis

Prerequisites, Status, and
Rationale

All

NEW MEXICO
NMAC § 20.3.4

Establishes standards for protection against radiation.

Relevant and Appropriate

This regulation is the same as 10 CFR
§ 20. This requirement is not applicable to
the site but is relevant and appropriate.

Soil

NEW MEXICO

NMAC §§ 19.10.5.507 and
19.10.5.508

Establishes performance and reclamation standards and
requirements for noncoal mining operations.

Relevant and Appropriate

This regulation provides revegetation
requirements for existing noncoal mining
operations, as well as other reclamation
requirements.

Soil and
Water

NEW MEXICO

New Mexico Soil and
Water Conservation
District Act

New Mexico Statutes
Annotated 73-20-25

Establishes state authority to control and prevent soil
erosion, prevent floodwater and sediment damage to soil,
and conserve natural resources.

TBC

This regulation will be a TBC to the extent
that it does not conflict with CERCLA, the
National Contingency Plan, 40 CFR Part
300, or other federal requirements.

Soil

NEW MEXICO

Joint Guidance for the
Cleanup and
Reclamation of Existing
Uranium Mining
Operations in New
Mexico (March 2016)

This guidance is used to assist mine site responsible
parties in addressing soil radiation at existing uranium
mines as part of reclamation activities.

TBC

This guidance will be a TBC to the extent
that it does not conflict with CERCLA, the
National Contingency Plan, 40 CFR Part
300, or other federal requirements.

Soil

NEW MEXICO

Guidance for Soil
Suitability, Revegetation
and Self-Sustaining
Ecosystem (1996)

Used to implement and evaluate vegetation success and
soil cover material properties and reclamation.

TBC

This guidance will be a TBC for restoration
of excavated or covered waste.

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Table 6b. Action-Specific ARARs and TBC Information

Media

Requirement

Requirement Synopsis

Prerequisites, Status, and
Rationale

All

NAVAJO NATION

Navajo Nation
Fundamental Law 1
N.N.C. §§ 201-206

Navajo Nation Guidance
on the Uniform Application
of Fundamental Law to
AUM Cleanup Activities
(2022)

The Navajo people have an obligation under the Navajo
Nation Fundamental Law to listen to elders and medicine
people and respect, preserve, and protect Mother Earth
as stewards and guardians for the benefit of future
generations.

The 2020 guidance explains the principles of the Navajo
Nation Fundamental Law and how the principles would
be applied at the various stages of AUM cleanup.

TBC

Navajo Nation Fundamental Law and the
2022 guidance will be TBCs to the extent
that they do not conflict with CERCLA, the
National Contingency Plan, 40 CFR Part
300, or other federal requirements.

Soil and
Water

NAVAJO NATION

Navajo Nation
Underground and
Aboveground Storage
Tank Act of 2012 -
4 N.N.C. §§ 1501-1577, as
amended

NNEPA Storage Tank
Program Guidance No. 3
(ASTs at Construction
Sites) - Section III
(Operating Guidelines)

Regulates storage of petroleum and other regulated
substances in underground tanks and ASTs. This
guidance clarifies that the NNSTA applies to ASTs that
are temporarily placed at construction sites within the
Navajo Nation. It requires such ASTs to file tank
information forms with NNEPA, locate the tank within a
secondary containment area, secure the tank to prevent
movement on the containment surface or mount it on
metal skids (not on an elevated stilt rack), and contact
the Navajo Nation Storage Tank Program for an
inspection of the AST to check for evidence of soil
contamination both before the first deposit of a regulated
substance and when the AST is removed from the site.

TBC

Guidance should be followed for AUM
response activities requiring ASTs to be
brought to sites (for example, for fuel
needed for equipment and vehicles).

Notes:

§	Section

§§	Sections

ARAR	Applicable or relevant and appropriate requirement

AST	Aboveground storage tank

AUM	Abandoned uranium mine

BMP	Best management practice

CERCLA	Comprehensive Environmental Response, Compensation, and

Liability Act

CFR	Code of Federal Regulations

CWA	Clean Water Act

DOE	U.S. Department of Energy

NMAC	New Mexico Administrative Code

N. N. C.	Navajo Nation Code

NNCWA	Navajo Nation Clean Water Act

NNEPA	Navajo Nation Environmental Protection Agency

NNSTA	Navajo Nation Underground and Aboveground Storage Tank Act

NPDES	National Pollutant Discharge Elimination System

NRC	U.S. Nuclear Regulatory Commission

TBC	To be considered

UMTRCA	Uranium Mill Tailings Radiation Control Act

U.S.C.	United States Code

WOTUS	Waters of the U.S.

Page 13 of 13


-------
APPENDIX A

QUIVIRA MINES SITE IMAGES


-------
"It

Appendix A: Quivira Mines Site images		

Location:

CR-1, facing
south.

Description:

Red Water Pond
Road Bridge at
Unnamed
Arroyo,

Photograph 2
Date: 5/16/22

Location:

CR-1, facing
north.

Description:

View of CR-1
main gate at
Red Water Pond
Road.

The following photos were taken during visits to the Quivira Church Rock 1 Mine (CR-1),
Church Rock 1 East Mine (CR 110, and Kerr-McGee Corporation (Kerr-McGee) Ponds in
January 2020 and April, May, and June 2022.

Photograph 1

Date: 5/16/22

Contract No. 68HE0923D0G02, Task Order 001

A-l


-------
"It

Appendix A: Quivira Mines Site images		

Photograph 3
Date: 4/12/22

Location:

CR-1 at Red
Water Pond
Road, facing
northwest.

Description:

Culvert draining
CR-1 access
road.

Photograph 4
Date: 4/12/22

• rffri:	i- -

Location:

CR-1, facing
south.

Description:

Overview of the
main waste rock
pile, Red Water
Pond Road,
Unnamed
Arroyo, and
access to site.

Contract No. 68HE0923D0G02, Task Order 001

A-2


-------
Appendix A: Quivira Mines Site Images	l__.

Photograph 5
Date: 4/12/22

Location:

CR-1, facing
southeast.

Description:

Overview of the
top of the main
waste rock pile
and smaller
waste pile from
the time-critical
removal action
area.

Photograph 6
Date: 4/12/22

Location:

CR-1, facing
east.

Description:

Overview of the
top of the main
waste rock pile
and industrial

area.

Contract No. 68HE0923D0G02, Task Order 001

A-3


-------
"It

Appendix A: Quivira Mines Site images		



03$. -r. :.rT ',-r '

jyS^ps^^f *

Photograph 7
Date: 4/12/22

Location:

CR-1, facing
east.

Description:

Close-up view
of the industrial
area behind the
waste pile.

Photograph 8
Date: 1/24/20

Location:

CR-1, facing
southwest.

Description:

View of the top
of the waste pile
and adjacent
community.

Contract No. 68HE0923D0G02, Task Order 001

A-4


-------
Appendix A: Quivira Mines Site images

It

Photograph 9
Date: 1/24/20

Location:

CR 1, facing
east.

Description:

View across the
top of the waste
pile with the
lower ponds
area at upper
right.

Photograph 10
Date: 1/24/20

Location:

CR 1, facing
north.

Description:

View of the top
of the waste pile
with the
industrial area
beyond.

Contract No. 68HE0923D0G02, Task Order 001

A-5


-------
"It

Appendix A: Quivira Mines Site images		

Photograph 12
Date: 4/12/22

Location:

CR-1, facing
west.

Description:

Toe of the south
side of CR 1
waste rock pile.

Photograph 11

Date: 4/12/22

Location:

CR-1, facing
east.

Description:

Toe of the south
side of CR-l
waste rock pile.

Contract No. 68HE0923D0G02, Task Order 001

A-6


-------
"It

Appendix A: Quivira Mines Site images		

Photograph 13
Date: 1/24/20

Location:

CR-1, facing
northeast.

Description:

Rills and
erosion on the
main waste pile.

Photograph 14

Date: 5/09/22

Location:

CR-1, facing
east.

Description:

Ponds access
road filled with
vegetation.

Contract No. 68HE0923D0G02, Task Order 001

A-7


-------
"It

Appendix A: Quivira Mines Site images		

Photograph 15
Date: 6/01/22

Location:

CR 1. facing
east.

Description:

Ponds access
road after being
cleared and
graded.

Photograph 16
Date: 5/10/22

Location:

CR-1, facing
east.

Description:

Overlooking the
upper ponds
area.

East Elevation

0 270°W (T) • 35.666289, -108.500278 +5 m A 2139 m

099°E(T)*35.666241,-108.500406±5m A 2119m

Win

Contract No. 68HE0923D0G02, Task Order 001

A-8


-------
"It

Appendix A: Quivira Mines Site images		



E



si:



S



H

60

1 • 1 • 1

90

120

i • i

ISO

. 1 . 1 .

its

, J . | . | ,

210

, | . | .

±J

0136'SE(T)» 35.666286, -108.499795 ±3 m a 2113 m

Photograph 17
Date: 5/9/22

Location:

CR 1. facing
southeast.

Description:

Overlooking the
upper ponds
area.

Photograph 18
Date: 5/09/22

Location:

CR 1. facing
south.

Description:

Overlooking the
lower ponds
area.

Contract No. 68HE0923D0G02, Task Order 001

A-9


-------
Appendix A: Quivira Mines Site images

It

Photograph 19
Date: 5/09/22

W

270

NW

NE

Location:

CR-1, facing
north.

Description:

Overview of the
lower ponds
area with an
outcrop and
waste pile in the
upper left.



:V*v;

l * t-s a &&&%





-i'

9l3v£*

p9



Photograph 20
Date: 1/24/20

Location:

CR-1, facing
west.

Description:

Facing the main
waste pile from
the ponds area.

0 355'N (T)« 35.663857, -108.499577 +3 m i 2109 m

Contract No. 68HE0923D0G02, Task Order 001

A-10


-------
Appendix A: Quivira Mines Site images

It

Z'-'T "
mf-^7W?f r*:

t£9H|

Photograph 21
Date: 1/24/20

Location:

CR-1 lower
pond area,
facing west.

Description:

Overview of the
lower pond area
and proximity
of residences.

Photograph 22
Date: 1/24/20

Location:

CR-1 Unnamed
Arroyo adjacent
to lower pond
area, facing
northwest.

Description:

Overview of the
waste pile in
background,
pond area in
middle, and
arroyo in
foreground.

Contract No. 68HE0923D0G02, Task Order 001

A-ll


-------
"It

Appendix A: Quivira Mines Site images		

Photograph 23
Date: 1/24/20

Location:

CR-1 lower
pond area,
facing north.

Description:

Erosion and
runoff from the
lower pond area.

O 60"NE (T) » 35.662264, -108.50222 +14 m A. 2081 m

mm

Photograph 24
Date: 4/13/22

Location:

Unnamed
Arroyo adjacent
to CR-1 lower
pond area,
facing east.

Description:

Erosion and
runoff from the
lower pond area
entering the
arroyo.

Contract No. 68HE0923D0G02, Task Order 001

A-12


-------
"It

Appendix A: Quivira Mines Site images		

Photograph 25
Date: 4/13/22

Location:

CR-1 northeast
of the waste pile
and pond area,
facing
southwest.

Description:

Gap in the site
fence. Note the
juniper trees
growing in the
undisturbed area
of the site.

Photograph 26
Date: 1/24/20

Location:

CR-1E, facing
west.

Description:

Western end of
CR-1E along
the utility
pipeline
alignment.

Contract No. 68HE0923D0G02, Task Order 001

A-13


-------
Appendix A: Quivira Mines Site images

It

Photograph 27
Date: 1/24/20

Location:

CR-1E, facing
south.

Description:

Western end of
CR-1E looking
across the road
toward the
Pipeline Canyon
Arroyo.

Photograph 28
Date: 1/24/20

Location:

CR-1E, facing
east.

Description:

Eastern end of
CR-lEthe site.

Contract No. 68HE0923D0G02, Task Order 001

A-14


-------
"It

Appendix A: Quivira Mines Site images		

Photograph 29
Date: 1/24/20

Location:

CR-1E, facing
southeast.

Description:

View from the
northern edge of
site near the adit
with waste rock
to middle left.

Photograph 30

Date: 1/24/20

Location:

CR-1E, facing
northeast.

Description:

Overview of
eastern end of
CR-1E site.

Contract No. 68HE0923D0G02, Task Order 001	A-15


-------
"It

Appendix A: Quivira Mines Site images		

Photograph 31
Date: 4/12/22

Location:

Pipeline Canyon
Arroyo adjacent
to CR- IE.

Description:

Pipe from CR-
1E discharging
to arroyo.

Heavy erosion
is visible below
the culvert
leading into the
arroyo.

Photograph 32

Date: 4/12/22

Location:

Pipeline Canyon
Arroyo, facing
east.

Description:

Debris inside of
the arroyo
adjacent to CR-
1E,

Contract No. 68HE0923D0G02, Task Order 001

A-16


-------
"It

Appendix A: Quivira Mines Site images		

Photograph 33
Date: 4/12/22

Location:

CR-1E Pipeline
Canyon Arroyo,
facing
southeast.

Description:

The arroyo
adjacent to CR-
1E.

Photograph 34
Date: 4/12/22

Location:

Kerr-McGee
Ponds, facing
northeast.

Description:

Properly
boundary and
access road
along the
northern edge of
Kerr-McGee
Ponds area.

0 54'NE(T)t 35.659663,-108.491071 +13 m a 2126 m

Contract No. 68HE0923D0G02, Task Order 001

A-17


-------
Appendix A: Quivira Mines Site images

It

Photograph 35
Date: 4/11/22

Location:

Kerr-McGee
Ponds, facing
southeast.

Description:

Cattle on Kerr-
McGee Ponds
area.

Photograph 36
Date: 7/18/17

Location:

Kerr-McGee
Ponds, facing
down.

Description:

Location of
surface sample
KMP-23. Note
the typical brush
cover of the site.

Contract No. 68HE0923D0G02, Task Order 001

A-18


-------
"It

Appendix A: Quivira Mines Site images		

Photograph 37
Date: 7/18/17

Location:

Kerr-McGee
Ponds, facing
south.

Description:

Location of a
subsurface
sample. Note the
heavy brush
cover in this
area of the site.

Photograph 38
Date: 7/18/17

Location:

Arroyo
upstream of
Kerr-McGee
Ponds, facing
northeast.

Description:

Collecting
surface soil
sample KMP-12
in unnamed
arroyo north of
the United
Nuclear
Corporation
property line.

Contract No. 68HE0923D0G02, Task Order 001

A-19


-------
"It

Appendix A: Quivira Mines Site images		

Photograph 39
Date: 7/18/17

Location:

Arroyo
upstream of
Kerr-McGee
Ponds, facing
southwest.

Description:

Collecting
sample KMP-11
in unnamed
arroyo north of
the United
Nuclear
Corporation
property line.

Contract No. 68HE0923D0G02, Task Order 001

A-20


-------
APPENDIX B

CONTAMINANT DISTRIBUTION


-------


, / '¦-



~ V\

SN

-

Notes:

1The estimated radium-226 interpolated surface was generated
using gamma survey data from Quivira Mines. Gamma survey
results were converted from counts per minute to estimated
radium-226 concentrations ira^pCi/g using a linear site-specific
gamma-radium model (Model #2).

2BTV is based on the 95 percent upper tolerance limit with 95
percent coverage of the background dataset. The BTV is the RAG
for a I exposure units on the Navajo Nation.

3Results for soil samples are presented using the same color
scheme as the interpolated results.

Abbreviations:

BTV

CR-1

CR-1E

HH

KMP

NN

pCi/g

PERG

PRG

RAG

TENORM
UNC

Background threshold value
Quivira Tronox Church Rock No. 1
Mine Site

Quivira Tronox Church Rock No. 1
East Mine Site
Human health
Kerr-McGee Pond
Navajo Nation
Picocurie per gram
Preliminary ecological removal goal
Preliminary removal goal
Removal action goal
Technologica ly enhanced natura ly
occuring radioactive material
United nuclear corporation

ESTIMATED RADIUM-226 AND RADIUM-226
RESULTS WITHIN THE
TENORM BOUNDARY

Prepared For: U.S. EPA Region 9

Prepared By:

TETRATECH

Estimated Radium-226 (pCi/g)1

~ s 0.050	s HH PRG (Resident)

1 inch = 600 feet

1:7,200

600 300	0

Task Order No.:

Contract No.:

68HE0923D0002

QUIVIRA MINES

3/4/2024

Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:

Arroyo on
' theNN

f I 0.050 -2.0
| I 2.0-5.4
I I 5.4-40

I | >40

Soil Sample Locations3

~ Surface Soil (0-6 inches bgs)
j TENORM
Radium-226 Removal Action Extent
KXXl Removal Action Extent
Exposure Units
{ 1 CR-1
5 ICR-1E
1 1 KMP on the NN
8 I KMP on the UNC
J ] Arroyo on the NN
I ] Arroyo on the UNC

Site-wide (Ecological Risk)

HH PRG (Resident) -
RAG (BTV)2

RAG (BTV) - RAG (HH
PRG UNC Worker)

RAG (HH PRG UNC
Worker) - PERG

> PERG


-------
Site Features
~ Waste Rock Area

Former Stockpile Area

Abbreviations:



BTV

Background threshold value

CR-1

Quivira Tronox Church Rock No. 1



Mine Site

CR-1E

Quivira Tronox Church Rock No. 1



East Mine Site

COC

Contaminant of Concern

DAOS

Difficult access open space

HH

Human health

KMP

Kerr-McGee Pond

mg/kg

Mi ligram per kilogram

NN

Navajo Nation

PERG

Preliminary ecological removal goal

PRG

Preliminary removal goal

TENORM

Technologica ly enhanced natura ly



occuring radioactive material

UNC

United nuclear corporation

Notes:

1The arsenic interpolated surface was generated using surface soil
sample results from Quivira Mine in nonlinear areas with sufficient
data available for interpolation.

2BTV is based on the 95 percent upper tolerance limit with 95
percent coverage of the background dataset.

3Arsenic was not identified as a candidate COC for the UNC
Worker exposure scenario. Arsenic site concentrations exceed
background concentrations site-wide, but are less than background
in all HH ELJs, and was not identified as a COC. PRGs are
provided for context because arsenic was identified as a candidate
COC on UNC Property.

"Results for soil samples are presented using the same color
scheme as the interpolated results.

KMP on
e'UNCJ

Arroyo on
the UNC

Interpolated Arsenic (mg/kg)1

HH PRG (Resident)2

I I £ 2.5
I I 2.5-7.5
I I 7.5-8.9
I I 8.9-68
UD 68-750 PERG-HH PRG (UNC Worker)3

HH PRG (Resident) -
HH PRG (DAOS)

HH PRG (DAOS) - BTV2
BTV-PERG

Soil Sample Locations4
~ Surface Soil (0-6 inches bgs)

Radium-226 Removal Action Extent
|>5<5l Removal Action Extent
L" jTENORM
Exposure Units
~ CR-1
II ICR-1E
i \ KMP on the NN
[ 1 KMP on the UNC
II I Arroyo on the NN
|__| Arroyo on the UNC

Site-wide (Ecological Risk)

1 inch = 600 feet
1:7,200

600	300	0

N

W-^|"--E

S

600

I Feet

ARSENIC RESULTS

WITHIN THE
TENORM BOUNDARY

Prepared For: U.S. EPA Region 9



Prepared By:

TETRATECH

Task Order No.:

0001

QUIVIRA MINES

Contract No.:

68H E092 3 D0002

3/6/2024

Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:

B-2


-------
Abbreviations:



BTV

Background threshold value

CR-1

Quivira Tronox Church Rock No. 1



Mine Site

CR-1E

Quivira Tronox Church Rock No. 1



East Mine Site

DAOS

Difficult access open space

HH

Human health

KMP

Kerr-McGee Pond

mg/kg

Milligram per kilogram

NN

Navajo Nation

PERG

Preliminary ecological removal goal

TENORM

Technologically enhanced naturally



occuring radioactive material

UNC

United nuclear corporation

Notes:

^The barium interpolated surface was generated using surface soil
sample results from Quivira Mine in non-linear areas with su ficient
data available for interpolation.

ZBTV 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.

Interpolated Barium (mg/kg)1
I I < 111

I I 111 - 1,400

I I 1,400 -2,800

< BTV
BTV-PERG
PERG - 2 x PERG
>2x PERG

I I >2,800
Soil Sample Locations3

~ Surface Soil (0-6 inches bgs)

[v.V:::--l Radium-226 Removal Action Extent
Removal Action Extent

(_ J TENORM
Exposure Units

I	1 CR-1
n CR-1E

I	I	I KMP on the NN

I	Ti KMP on the UNC

II	I Arroyo on the NN

Arroyo on the UNC
Site-wide (Ecological Risk)

1 inch = 600 feet
1:7,200

600	300	0

BARIUM RESULTS
WITHIN THE
TENORM BOUNDARY

Prepared For: U.S. EPA Region 9

Prepared By:

TETRATECH

Task Order No.:

Contract No.:

68H E 09 2 3 D0002

QUIVIRA MINES

3/6/2024

Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:

Site Features

Waste Rock Area
Former Stockpile Area


-------
Site Features
~ Waste Rock Area

Former Stockpile Area

Abbreviations:



BTV

Background threshold value

CR-1

Quivira Tronox Church Rock No. 1



Mine Site

CR-1E

Quivira Tronox Church Rock No. 1



East Mine Site

DAOS

Di ficult access open space

HH

Human health

KMP

Kerr-McGee Pond

mg/kg

Mi ligram per kilogram

NN

Navajo Nation

PERG

Preliminary ecological removal goal

TENORM

Technologica ly enhanced natura ly



occuring radioactive material

UNC

United nuclear corporation

KMP oml
iheUNC:



Notes

1The chromium interpolated surface was generated using surface
soil sample results from Quivira Mine in non-linear areas with
sufficient data available for interpolation.

2BTV is based on the 95 percent upper tolerance limit with 95
percent coverage of the background dataset.

'Results for soil samples are presented using the same color
scheme as the interpolated results.

Arroyo on
the UNC

ft



Interpolated Chromium (mg/kg)1
I I <6.3

I i 6.3-250

~ 250 - 500

I I >500

< BTV
BTV-PERG
PERG - 2 x PERG
>2x PERG

Soil Sample Locations3
~ Surface Soil (0-6 inches bgs)

Radium-226 Removal Action Extent
Removal Action Extent

L i tenorm

Exposure Units
8 I CR-1

II	I CR-1E

III	1 KMP on the NN

i I KMP on the UNC

1	| Arroyo on the NN

I I Arroyo on the UNC

Site-wide (Ecological Risk)

1 inch = 600 feet
1:7,200

600	300	0

N

W E

S

600

I Feet

CHROMIUM RESULTS

WITHIN THE
TENORM BOUNDARY

Prepared For: U.S. EPA Region 9

(

Prepared By:

TETRATECH

Task Order No.:

0001

QUIVIRA MINES

Contract No.:

68H E092 3 D0002

3/6/2024

Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:

B-4


-------
Notes:

1The selenium interpolated surface was generated using surface
soil sample results from Quivira Mine in non-linear areas with
sufficient data available for interpolation.

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.

Abbreviations:

BTV

CR-1

CR-1E

DAOS

HH

KMP

mg/kg

NN

PERG
TENORM

UNC

Background threshold value
Quivira Tronox Church Rock No. 1
Mine Site

Quivira Tronox Church Rock No. 1
East Mine Site
Di ficult access open space
Human health
Kerr-McGee Pond
Mi ligram per kilogram
Navajo Nation
Preliminary ecological removal goal
Technologica ly enhanced natura ly
occuring radioactive material
United nuclear corporation

*	1

"It

SELENIUM RESULTS
WITHIN THE

TENORM BOUNDARY

Task Order No.:

Contract No.:

68H E 09 2 3 D0002

QUIVIRA MINES

3/6/2024

Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:

Interpolated Selenium (mg/kg)1
~~ s 2.5	< BTV2

m 2.5-3.4	BTV-PERG

~ 3.4-6.8	PERG - 2 x PERG

I I >6.8	> 2 x PERG

Soil Sample Locations3

~ Surface Soil (0-6 inches bgs)

Ivi'.v-i-l Radium-226 Removal Action Extent
Removal Action Extent

L | TENORM
Exposure Units
I I CR-1
5 I CR-1E

I	I KMP on the NN

j I KMP on the UNC

II	1 Arroyo on the NN

[f ] Arroyo on the UNC

Site-wide (Ecological Risk)

1 inch = 600 feet	*

W^>-- E

1:7,200	I

s

600	300	0	600

~i Feet

Prepared For: U.S. EPA Region 9

Site Features
~ Waste Rock Area

Former Stockpile Area

TETRATECH



Prepared By:


-------
Notes:

'The uranium interpolated surface was generated using surface
soil sample results from Quivira Mine in non-linear areas with
sufficient data available for interpolation,

2BTV is based on the 95 percent upper tolerance limit with 95
percent coverage of the background dataset. The RAG applies to
exposure units on the Navajo Nation only. Uranium was not
identified as a COC in exposure units on UNC property.

3Results for soil samples are presented using the same color
scheme as the interpolated results.

Abbreviations:

BTV

CR-1

CR-1E

COC

HH

KMP

mg/kg

NN

PERG
RAG

TENORM
UNC

Background threshold value
Quivira Tronox Church Rock No. 1
Mine Site

Quivira Tronox Church Rock No. 1

East Mine Site

Contaminant of concern

Human health

Kerr-McGee Pond

Mi ligram per kilogram

Navajo Nation

Preliminary ecological removal goal
Removal action goal
Technologica ly enhanced natura ly
occuring radioactive material
United nuclear corporation

Prepared For: U.S. EPA Region 9

Prepared By:

TETRATECH

*

it

URANIUM RESULTS
WITHIN THE

TENORM BOUNDARY

Task Order No.:

Contract No.:

68H E 09 2 3 D0002

QUIVIRA MINES

3/6/2024

Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:

Interpolated Uranium (mg/kg)1

~	<2.4	^BTV2

I I 2.4 - 3.2 BTV - RAG (HH PRG Resident)2
I I 3.2 - 250 RAG (HH PRG Resident) - PERG

~	>250	> PERG
Soil Sample Locations3

O Surface Soil (0-6 inches bgs)
I>Radium-226 Removal Action Extent
Removal Action Extent

(_ j TENORM
Exposure Units
I I CR-1
I I CR-1E
8 I KMP on the NN
I I KMP on the UNC
Arroyo on the NN
(__J Arroyo on the UNC

Site-wide (Ecological Risk)

1 inch = 600 feet	*

W^>-- E

1:7,200	J

s

600	300	0	600

~i Feet

Arroyo on
the NN


-------
Abbreviations:



BTV

Background threshold value

CR-1

Quivira Tronox Church Rock No. 1



Mine Site

CR-1E

Quivira Tronox Church Rock No. 1



East Mine Site

DAOS

Difficult access open space

HH

Human health

KMP

Kerr-McGee Pond

mg/kg

Milligram per kilogram

NN

Navajo Nation

PERG

Preliminary ecological removal goal

TENORM

Technologically enhanced naturally



occuring radioactive material

UNC

United nuclear corporation

Notes:

1The vanadium interpolated surface was generated using surface
soil sample results from Quivira Mine in nonlinear areas with
su ficient data available for interpolation.

2BTV is based on the 95 percent upper tolerance limit with 95
percent coverage of the background dataset.

"Results for soil samples are presented using the same color
scheme as the interpolated results.

Prepared By:

TETRATECH

Task Order No.:

Contract No.:

68H E 09 2 3 D0002

QUIVIRA MINES

3/6/2024

Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:

Estimated Vanadium (mg/kg)1

<18	< BTV2

I I 18-80	BTV-PERG

80- 160	PERG - 2 x PERG

~ >160	> 2 x PERG

Soil Sample Locations4
~ Surface Soil (0-6 inches bgs)

Radium-226 Removal Action Extent
Removal Action Extent

I TENORM
Exposure Units
I I CR-1
I I CR-1E
I I KMP on the NN
I I KMP on the UNC
I I Arroyo on the NN
Lj Arroyo on the UNC

Site-wide (Ecological Risk)

1 inch = 600 feet	*

W^>-- E

1:7,200	I

s

600	300	0	600

~i Feet

VANADIUM RESULTS

WITHIN THE
TENORM BOUNDARY

Prepared For: U.S. EPA Region 9

Arroyo on
' theNN

Site Features
~ Waste Rock Area

Former Stockpile Area


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APPENDIX C
RISK ASSESSMENT


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Quivira Mines
Coyote Canyon, Pinedale, and Standing Rock
Chapters, Navajo Nation, New Mexico

Final
Appendix C
Risk Assessment

Response, Assessment, and Evaluation Services 2
Contract No. 68HE0923D0002
Task Order 001

March 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 C: Quivira Mines Risk Assessment

TABLE OF CONTENTS

Section	Page

ACRONYMS AND ABBREVIATIONS	C-iv

1.0 BACKGROUND AND ENVIRONMENTAL SETTING	C-1

1.1	MINE HISTORY AND LOCATION	C-1

1.2	GEOLOGY, HYDROGEOLOGY, AND HYDROLOGY	C-2

1.2.1	Geology	C-2

1.2.2	Hydrogeology	C-3

1.2.3	Hydrology	C-3

1.3	LAND USE	C-4

1.4	ECOLOGICAL SETTING	C-4

1.4.1	Climate	C-5

1.4.2	Vegetation	C-5

1.4.3	Wildlife	C-6

1.4.4	Special Status Species	C-6

2.0 DATA USED IN THE RISK ASSESSMENT	C-7

2.1	AVAILABLE DATA	C-7

2.2	DATA REDUCTION METHODS	C-8

2.3	EXPOSURE UNITS	C-8

2.4	EXPOSURE POINT CONCENTRATIONS	C-9

2.5	EVALUATION OF SECULAR EQUILIBRIUM	C-10

3.0 HUMAN HEALTH RISK ASSESSMENT	C-l 1

3.1	DATA EVALUATION AND IDENTIFICATION OF CONTAMINANTS

OF POTENTIAL CONCERN	C-l 1

3.2	EXPOSURE ASSESSMENT	C-l 1

3.2.1	Conceptual Site Model	C-l2

3.2.2	Human Health Receptors, Exposure Pathways, and Exposure
Parameters	C-l 2

3.2.3	Exposure Parameters	C-15

3.3	TOXICITY ASSESSMENT	C-15

3.3.1	Carcinogenic Effects	C-15

3.3.2	Noncarcinogenic Effects	C-l6

3.3.3	Sources of Toxicity Values and Other Contaminant-Specific
Parameters	C-l 6

3.4	RISK CHARACTERIZATION	C-16

3.4.1	Estimates of Cancer Risk and Noncancer Hazard	C-16

3.4.2	Uncertainty Associated with the Human Health Risk Assessment	C-19

4.0 ECOLOGICAL RISK ASSESSMENT	C-22

4.1 PROBLEM FORMULATION	C-22

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4.1.1	Ecological Habitat and Biological Resources	C-23

4.1.2	Stressors and Contaminants of Potential Ecological Concern

Selection	C-23

4.1.3	Potentially Complete Exposure Pathways	C-23

4.1.4	Assessment Endpoints	C-24

4.1.5	Measurement Endpoints	C-24

4.1.6	Conceptual Site Model	C-26

4.2	ANALYSIS OF EXPOSURE AND EFFECTS	C-26

4.2.1	Exposure Estimates	C-26

4.2.2	Ecological Effects	C-26

4.3	RISK CHARACTERIZATION	C-27

4.3.1	Screening-Level Ecological Risk Assessment for Contaminants of
Potential Ecological Concern	C-27

4.3.2	Screening-Level Ecological Risk Assessment Refinement	C-27

4.3.3	Candidate Contaminants of Ecological Concern	C-28

4.4	UNCERTAINTY ASSOCIATED WITH THE ECOLOGICAL RISK
ASSESSMENT	C-29

4.4.1	Exposure Estimates	C-29

4.4.2	Nondetected Contaminants of Potential Ecological Concern	C-31

4.4.3	Combined Exposures Across Media and Exposure Units	C-31

4.4.4	Risk to Plant and Invertebrate Communities	C-31

5.0 RISK ASSESSMENT RESULTS SUMMARY	C-32

6.0 REFERENCES	C-34

EXHIBITS

Exhibit C-l. Receptors Evaluated at Each Exposure Unit	C-13

Exhibit C-2. Cancer Risks and Noncancer Hazards	C-l7

Exhibit C-3. Candidate COCs Identified Based on Cancer Risks and Noncancer Hazards	C-18

Exhibit C-4. Site-Wide Candidate COECs	C-29

Exhibit C-5. Candidate Contaminants of Concern or Contaminants of Ecological Concern

for Soil	C-33

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Appendix C: Quivira Mines Risk Assessment

FIGURES

Figure C-l. Mine Location

Figure C-2. Exposure Units and Sample Locations

Figure C-3. Quivira Church Rock No. 1 Mine Exposure Unit with Sample Locations - West Side
Figure C-4. Quivira Church Rock No. 1 Mine Exposure Unit with Sample Locations - East Side
Figure C-5. Quivira Church Rock No. 1 East Mine Exposure Unit with Sample Locations
Figure C-6. Kerr-McGee Ponds on the Navajo Nation Exposure Unit with Sample Locations
Figure C-7. Kerr-McGee Ponds on United Nuclear Corporation Property Exposure Unit with
Sample Locations

Figure C-8. Arroyos on the Navajo Nation Exposure Unit with Sample Locations
Figure C-9. Arroyos on United Nuclear Corporation Property Exposure Unit with Sample
Locations

Figure C-10. Quivira Mines Risk Assessment Conceptual Site Model

TABLES

Table C-l. Soil Results Data Summary and Contaminant of Potential Concern Screening
Table C-2. Exposure Unit Summary of Land Use, Geologic Formation, Type, Area, and

Available Samples
Table C-3. Human Health Exposure Parameters

Table C-4. Exposure Point Concentrations for Human Health Risk Assessment
Table C-5.1. Human Health Risk and Hazard Calculations - Quivira Church Rock Mine No. 1
Table C-5.2. Human Health Risk and Hazard Calculations - Quivira Church Rock Mine No. 1
East

Table C-5.3. Human Health Risk and Hazard Calculations - Kerr-McGee Ponds on the Navajo
Nation

Table C-5.4. Human Health Risk and Hazard Calculations - Kerr-McGee Ponds on United

Nuclear Corporation Property
Table C-5.5. Human Health Risk and Hazard Calculations - Arroyos on the Navajo Nation
Table C-5.6. Human Health Risk and Hazard Calculations - Arroyos on United Nuclear

Corporation Property
Table C-6. Human Health Risk and Hazard Summary by Exposure Pathway
Table C-7. Human Health Risk and Hazard Summary and Identification of Candidate

Contaminants of Concern
Table C-8. Ecological Risk Assessment Screening for Soil
Table C-9. Exposure Point Concentrations for Ecological Risk Assessment
Table C-10. Comparison of Individual Sample Results to Plant and Invertebrate NOECs
Table C-l 1. Screening-Level Ecological Risk Assessment Refinement for Soil - Birds
Table C-l2. Screening-Level Ecological Risk Assessment Refinement for Soil - Mammals

ATTACHMENTS

Attachment C-l. Data Used in the Risk Assessment

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		 **

It

ACRONYMS AND ABBREVIATION

J

°F

Degree Fahrenheit

bgs

Below ground surface

CERCLA

COC

COEC

COPC

COPEC

CR-1

CR-1E

CSM

Comprehensive Environmental Response, Compensation, and Liability Act

Contaminant of concern

Contaminant of ecological concern

Contaminant of potential concern

Contaminant of potential ecological concern

Quivira Church Rock Mine No. 1

Quivira Church Rock Mine No. 1 East

Conceptual site model

Eco-SSL	Ecological soil screening level

EE/CA	Engineering evaluation/cost analysis

EPC	Exposure point concentration

ERA	Ecological risk assessment

ERICA	Environmental Risks from Ionizing Contaminants: Assessment and

Management

ESA	Endangered Species Act

ESL	Ecological screening level

EU	Exposure unit

HHRA	Human health risk assessment

HI	Hazard index

HQ	Hazard quotient

IUR	Inhalation unit risk

Kerr-McGee	Kerr-McGee Corporation

LANL	Los Alamos National Laboratory

LOEC	Lowest observed effect concentration

mg/kg-day	Milligram per kilogram per day

N3B	Newport News Nuclear BWXT-Los Alamos, LLC

NAUM	Navajo abandoned uranium mine

NESL	Navajo Endangered Species List

NNEPA	Navajo Nation Environmental Protection Agency

NNDFW	Navajo Nation Department of Fish and Wildlife

NOEC	No observed effect concentration

NORM	Naturally occurring radioactive material

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It

ACRONYMS AND ABBREVIATIONS (CONTINUE

I

J

ODL

ORNL

OSWER

Other Dine Lifeways

Oak Ridge National Laboratory

Office of Solid Waste and Emergency Response

Quivira Mines Quivira Mines Site

RfC	Reference concentration

RfD	Reference dose

RME	Reasonable maximum exposure

RSL	Regional screening level

SE	Secular equilibrium

SF	Slope factor

SLERA	Screening-level ecological risk assessment

TENORM	Technologically enhanced naturally occurring radioactive material

Tetra Tech	Tetra Tech, Inc.

TCR	Target cancer risk

U3O8	Triuranium octoxide

UCL95	95 percent upper confidence limit

UNC	United Nuclear Corporation

USEPA	U.S. Environmental Protection Agency

Weston	Weston Solutions, Inc.

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1.0 BACKGROUND AND ENVIRONMENTAL SETTIN

J

The purpose of the 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 Quivira Mines Site (Quivira Mines). This Navajo abandoned uranium
mine (NAUM) risk assessment was performed using "Guidance on Conducting Non-Time-
Critical Removal Actions under Comprehensive Environmental Response, Compensation, and
Liability Act (CERCLA)" (U.S. Environmental Protection Agency [USEPA] 1993) and, thus,
does not include or require all elements of a baseline risk assessment (USEPA 1993, 2001). The
human health risk assessment (HHRA) identifies human health contaminants of concern (COC)
recommended for removal in each exposure unit (EU) while the ecological risk assessment
(ERA) identifies contaminants of ecological concern (COEC) recommended for removal in each
EU. The results of the risk assessment are used to determine removal action goals and serve as
lines of evidence in determining the extent of soil removal necessary at the Quivira Mines to
meet the removal action goals. See the NAUM risk assessment methodology (USEPA 2024b)
report for additional information for conducting standardized risk assessments at NAUM sites.

The Navajo Nation contains areas of naturally high levels of uranium. Starting in the 1940s,
large amounts of uranium were mined on the Navajo Nation. Mining has brought more uranium
to the surface of the earth, making exposure to people 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 Quivira Mines include waste rock piles, waste in former settling
and dewatering ponds, contaminated former industrial areas, contaminated onsite access roads,
areas contaminated by eroding waste and windblown dust, and adjacent arroyos receiving
contaminated runoff.

1.1 MINE HISTORY AND LOCATION

The Quivira Mines are located on the Navajo Nation approximately 20 miles northeast of Gallup,
New Mexico (Figure C-l). The Quivira Mines include two former mine leases: Quivira Church
Rock Mine No. 1 (CR-1) and Quivira Church Rock Mine No. 1 East (CR-1E), both in Coyote
Canyon and Standing Rock Chapters of the Navajo Nation. The two former mines are about
0.5 mile apart from each other, with CR-1 located along Red Water Pond Road north of New
Mexico State Road 566 and CR-1E located east of and along Indian Route 7049 (Pipeline
Canyon Road) (see Figure 1 of the main engineering evaluation/cost analysis [EE/CA] report).

Aboveground operations encompass 42 acres at CR-1 and 10.5 acres at CR-1E, each including a
former industrial area, waste rock area, and former pond area (see Figure 2 and Figure 3 of the
main EE/CA report).

Atomic Energy Commission records indicate that during operation between 1974 and 1986, an
estimated 1.3 million tons of ore from CR-1 and CR-1E was shipped to and processed at the
Quivira Mining Corporation's Ambrosia Lake Mill, approximately 50 miles to the east and north
of Grants, New Mexico. A total of 3,139,784 pounds of uranium (triuranium octoxide [U3O8])

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were produced from CR-1 and 1,447,463 pounds of U3O8 were produced from CR-1E (Weston
Solutions, Inc. [Weston] 2010).

The Quivira Mines were very large underground uranium mines located approximately 1,500 to
1,800 feet below ground surface (bgs). The mines were wet and required ongoing dewatering
during operations. Water pumped from the mine workings was discharged to settling ponds that
emptied to Unnamed Arroyo #2 and Pipeline Canyon Arroyo (Figure C-l).

The Kerr-McGee Corporation (Kerr-McGee) Ponds covers an area of approximately 9 acres and
includes four sediment dewatering ponds and a proto ore storage area on United Nuclear
Corporation (UNC) land previously leased from the State of New Mexico (see Figure 4 of the
main EE/CA report). The former Kerr-McGee Ponds are approximately 2,000 feet south of
CR-1E within the Pinedale Chapter of the Navajo Nation. Pond sediment and proto ore was
received from CR-1 and CR-1E mines. The various work areas were reportedly closed when the
State of New Mexico transferred the land at the mill to UNC.

See Section 2.1 of the main EE/CA report for additional information on the history and location
of the Quivira Mines.

1.2 GEOLOGY, HYDROGEOLOGY, AND HYDROLOGY

The following subsections describe the geology, hydrogeology, and hydrology of the Quivira
Mines. For more information, see Section 2.1.5 of the main EE/CA report.

1.2.1 Geology

The Quivira Mines lie within the Colorado Plateau physiographic province at the juncture of the
San Juan Basin, Zuni Uplift, and Defiance Uplift. Underlying the Quivira Mines is the Crevasse
Canyon Formation that consists of unsaturated mudstones, sandstone, and coal beds. Beneath the
Crevasse Canyon Formation are the Gallup and Mancos Shale Formations. The Mancos Shale,
with a thickness of 500 to 800 feet, acts largely as an aquitard. Beneath the Mancos Shale
Formation are the Dakota and Morrison Formations. The primary uranium ore body is found in
the Westwater Canyon Sandstone Member of the Morrison Formation.

Surface geology (see Figure 5 of the main EE/CA report) differs in each area of the
Quivira Mines:

•	CR-1 surface geology consists of the Dalton and Bartlett Barren Members of the
Crevasse Canyon Formation and the Mulatto Tongue of Mancos Shale on the northern
slopes and Quaternary alluvium on the southern slopes.

•	CR-1E surface geology consists of the Dalton Member of the Crevasse Canyon
Formation on the northern hillslopes and the Mulatto Tongue of Mancos Shale and
Quaternary alluvium on the site terrace.

•	The former Kerr-McGee Ponds is on fluvially deposited Quaternary alluvium
that overlies the Mulatto Tongue of Mancos Shale, which is expressed on
south-adjacent hillslopes.

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It

No mineralization occurs in the surface geologies; however, areas of elevated activity are present
north of CR-1. Soil types throughout the Quivira Mines are shown on Figure 6 of the main
EE/CA report. Additional information on site geology is provided in Section 2.1.5.1 of the main
EE/CA report.

The waste rock material within the stockpiles at CR-1 and CR-1E is a fine-grained material.
In general, the soil stratigraphy at the base of both the Unnamed Arroyo #2 and the Pipeline
Arroyo is consistent with the fine- to medium-grained soils encountered at the lease areas of
CR-1 and CR-1E.

1.2.2	Hydrogeology

The main uranium-bearing rock unit (Morrison Formation) includes the water-bearing Westwater
Canyon Member. Based on data provided by UNC for the Northeast Church Rock Mine, the
depth to groundwater in the Westwater Canyon Sandstone Member is 1,500 to 1,800 feet
(Weston 2010).

Rainfall and surface water infiltration do not directly impact groundwater in the Westwater
Canyon Member as a result of a combination of arid climate, depth to groundwater, and the
number and thickness of intervening confining layers. In addition, no drinking water wells are
completed in the Westwater Canyon Member near the Quivira Mines. Therefore, groundwater is
not considered in the risk assessment. If any work is considered necessary to address
groundwater in the future, that work will be part of a separate action. The scope of this EE/CA is
to present alternatives for surface and near-surface soil remedies only. Additional information on
site hydrogeology is provided in Section 2.1.5.2 of the main EE/CA report.

1.2.3	Hydrology

Most precipitation at the Quivira 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.

A series of arroyos exist throughout the Quivira Mines and surrounding areas. Unnamed Arroyo
#2 runs along the southern boundary of CR-1 while the Pipeline Canyon Arroyo is immediately
southeast of CR-1E (Figure C-l). The width of Unnamed Arroyo #2 typically ranges from 15 to
35 feet with sidewalls 10 to 15 feet high. The width of the Pipeline Canyon Arroyo typically
ranges from 15 to 25 feet with sidewalls 10 to 25 feet high. Additional information on site
hydrogeology is provided in Section 2.1.5.3 of the main EE/CA report.

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1.3	LAND USE

The Quivira Mines are in a sparsely vegetated area of shrubs, grasses, and forbs mixed with
pinyon-juniper forests. In some places, the underbrush is predominately sagebrush (Artemisia
tridentata ssp. Tridentata), while in others, heavily grazed areas of bare ground are prevalent.
More than 50 Navajo families live in the Red Water Pond Road area of the Coyote Canyon
Chapter and the Pipeline Canyon Road area of the Standing Rock Chapter (Red Water Pond
Road Community Association and Southwest Research and Information Center 2012). Figure 8
of the main EE/CA report shows the approximate locations of the Red Water Pond Road and
Pipeline Canyon Road community areas. The nearest residences are approximately 700 feet
south of CR-1 and 800 feet north of CR-1E. No public or commercial buildings are within
0.5 mile of the Quivira Mines.

Current surrounding land use includes agricultural grazing (for livestock such as sheep, cattle,
and horses). Navajo families may collect pinyon nuts, herbs, and plants from the surrounding
area for food, medicinal, and ceremonial purposes.

The Quivira Mines, as well as the former Kerr-McGee Ponds and arroyos on the Navajo Nation,
are currently undeveloped. Activities that occur near or on the site that may expose people to soil
contaminants include walking or hiking, livestock grazing, and foraging for plants or herbs.
Future development may also expose residents to impacted soil. Radionuclides and other
chemicals in the soil may be absorbed by plants and consumed by livestock, wildlife, and people.
Persons traversing the site may be exposed to contaminated dust by inhalation of particulate
matter. Whole body (external) radiation may be experienced by nearby people on or near the
Quivira Mines. The portion of the former Kerr-McGee Ponds on UNC property has a few
buildings and trailers within the property boundary.

While the Quivira Mines site is fenced and the current use of the immediately surrounding areas
is open space, a residential land use scenario was developed to incorporate an unrestricted tribal
use scenario that may include future residential and cultural and ceremonial uses of the resources
at the Quivira Mines. This receptor is appropriate because the nearby land use is residential and
no land use restrictions are in place to prevent the site from being used for future residential use.

1.4	ECOLOGICAL SETTING

The Quivira Mines are in a remote area with a revegetated, previously disturbed mine area
potentially providing habitat for ecological receptors. Wildlife inhabiting the Quivira Mines may
directly ingest radionuclides and chemicals, which may then be transported to the organs or other
sites within the wildlife receptor.

The Quivira Mines are primarily within an Area 3 wildlife sensitive area as identified by the
Navajo Nation Department of Fish and Wildlife (NNDFW). Area 3 wildlife sensitive areas
are classified as a less sensitive area containing a low and fragmented concentration of
endangered and rare plant, animal, and game species on the Navajo Nation (NNDFW 2022).
Therefore, development can proceed as recommended by NNDFW with few exceptions. A
small portion of the Quivira Mines on the northwest side is within an Area 1 wildlife sensitive
area. Area 1 wildlife sensitive areas are classified as highly sensitive areas containing the best

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habitat and highest concentrations of endangered and rare plant, animal, and game species on the
Navajo Nation. NNDFW recommends no development in Area 1 wildlife sensitive areas with
few exceptions.

Tetra Tech, Inc. (Tetra Tech) (2022a) conducted a biological assessment for the Quivira Mines
area that included a desktop survey of habitats to assess the impacts that investigative and future
removal activities may have on affected Endangered Species Act (ESA)-listed species, critical
habitats, migratory birds protected by the Migratory Bird Treaty Act, and NNDFW-listed
sensitive species that may occur within 0.5 mile of the site. Plants were also included in the
desktop survey.

Tetra Tech (2022b) also conducted a field survey at the Quivira Mines area before investigation
activities in May 2022 and observed no rare plant species, plant species of management interest,
or federally listed or sensitive species.

1.4.1	Climate

The Navajo Nation lies in a semi-arid climate with a high annual net pan evaporation rate of
54 inches per year. The nearby city of Gallup receives an average annual rainfall of 11 inches.
Wind for 11 months of the year typically originates from the southwest, and in the month of
August, originates predominantly from the south. The winter average temperature is 29 degrees
Fahrenheit (°F) with an average temperature in summer of 68 °F. Extreme heat in the summer
(100 °F) and cold in the winter (-34 °F) can occur. Additional information on site climate is
provided in Section 2.1.8 of the main EE/CA report.

1.4.2	Vegetation

A vegetation survey was completed in 2011 as part of the removal site evaluation report for the
Quivira Mines area (SENES Consultants Limited 2011). The survey identified good plant
diversity with a mixture of native shrubs, grasses, and forbs although cover values varied based
on grazing pressure. Tetra Tech (2022b) performed a rare plant survey in 2022 to assess the
potential for investigation activities to affect ESA-listed species, critical habitats, and NNDFW-
listed sensitive species.

The habitat in the Quivira Mines area consists of upland communities of intermountain basins
semi-desert grassland, intermountain basins greasewood flat, and intermountain basins
semi-desert shrub steppe bordered by Colorado Plateau pinyon-juniper woodlands. The field
survey identified the dominant species throughout the project footprint as sagebrush,
globemallow (Sphaeralcea ambigua), rabbitbrush (Ericameria nauseosa), filaree storksbill
(Erodium cicutarium), cheatgrass (Bromus tectorum), Indian ricegrass (Achnatherum
hymenoides), needle and thread grass (Hesperostipa comata), greasewood (Sarcobatus
vermiculatus), two-needle piny on (Pinus edulis), and Utah juniper (Juniperus osteosperma).
No plant species of management interest or rare plant species were observed during the surveys.

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1.4.3	Wildlife

Tetra Tech (2022b) performed a nesting bird survey in 2022 for the Quivira Mines area to assess
the potential for investigation activities to affect ESA-listed species, critical habitats, migratory
birds protected by the Migratory Bird Treaty Act, and NNDFW-listed sensitive species. All
suitable nesting areas were surveyed during the field survey, and no active raptor species nests
were identified. However, one common raven (Corvus corax) nest was located between CR-1
and CR-1E. Avian and wildlife species observed at the Quivira Mines were the common raven,
house finch (Haemorphous mexicanus), rock wren (Salpinctes obsoletus), Gunnison prairie dog
(Cynomysgunnisoni), western fence lizard (Sceloporus occidentalis), and bullsnake (Pituophis
catenifer sayl).

1.4.4	Special Status Species

Tetra Tech (2022a) conducted a biological assessment for the Quivira Mines that reviewed the
most recent species lists for the area provided by the U.S. Fish and Wildlife Service and
NNDFW. All potential species in the area that are federally threatened, endangered, candidates
for listing, or included on the Navajo Endangered Species List (NESL) were evaluated for
potential to occur at the site. The biological assessment concluded that no federally listed species
have the potential to occur in the Quivira Mines area and that no critical habitats for any
ESA-listed species are within the area. The biological assessment concluded that the current
proposed action for the Quivira Mines, which includes surface and subsurface soil sampling,
trenching, detention basin cleanout, and well construction, will have no effect on the Mexican
spotted owl (Strix occidentalis lucida), southwestern willow flycatcher (Empidonax traillii
extimus), yellow-billed cuckoo (Coccyzus americanus ssp. Occidentalis), Zuni bluehead sucker
(Catostomus discobolusyarrowl), or Zuni fleabane (Erigeron rhizomatus), and have no effect on
these species' designated critical habitats. A separate assessment may be required for
construction activities that will occur over a longer time frame during any removal action.

The Tetra Tech (2022a) biological assessment identified three NESL species with the potential to
occur in the Quivira Mines area: golden eagle (Aquila chrysaetos), mountain plover (Charadrius
montanus), and Naturita milk-vetch (Astragalus naturitensis)', however, these species do not
require an effects determination. The biological assessment identified conservation measures for
NESL species to protect the continued existence of the above-listed species in the Quivira Mines
area during the proposed removal action.

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2.0 DATA USED IN THE RISK ASSESSMENT

J

Data compilation and management tasks conducted for the Quivira Mines risk assessment
included the selection of useable data, 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 delineate
TENORM boundaries and to establish the footprint for risk assessment and will be used for
future removal decisions.

The compiled investigation data for the constituents of interest (COI) were reviewed to ensure
that the appropriate data were used for the evaluation of each EU. Essential nutrients such as
calcium, magnesium, potassium, and sodium are not retained as COIs. Separation of data into the
depth intervals to be evaluated, and calculation of the exposure point concentration (EPC) and
other statistical values.

Figure C-2 provides an overview of the locations of the available soil samples used in the risk
assessment for the Quivira Mines.

2.1 AVAILABLE DATA

Evaluation of potential human and ecological exposures at the Quivira Mines is limited to
radionuclides and metals in soil. Soil samples were collected from 0 up to 72 inches bgs.

Table C-l provides the summary of all available sample results for the Quivira Mines risk
assessment. Table C-2 provides the summary of soil samples available for each Quivira Mines
EU. No speciation data are available for chromium; therefore, chromium is assumed to be
100 percent hexavalent chromium. Attachment C-l presents the complete dataset for all
available soil samples used in the Quivira Mines risk assessment.

A data useability assessment is conducted to confirm that the useability of the laboratory data is
consistent with USEPA guidance (1992b). Data validation of all results used in the risk
assessment should be performed per the guidelines for data review (USEPA 2004, 2020). Data
validation reports should be reviewed, and the following key data validation flags should be
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.

•	Results with final validation qualifiers containing a "U" or "UJ" are nondetect values
included as part of the risk assessment datasets. The method reporting limit should be
used as the value for nondetect results.

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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 result are nondetect, the result associated with the lower reporting limit was used.
The complete dataset used in the risk assessment is provided in Attachment C-1.

2.3	EXPOSURE UNITS

An EU is an 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 Quivira Mines EUs were developed by identifying areas of contiguous TENORM
contamination and anticipated 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. See Section 2.0 of the main
EE/CA report for descriptions of the previous investigations and extent of contamination at
the Quivira Mines.

Based on the site evaluation and summarized in Table C-2, the following EUs were identified at
the Quivira Mines. The ecological risk assessment evaluation is conducted on a site-wide basis.

•	CR-1 - The former CR-1 mine is located on the Navajo Nation and is 53 acres. Several
residences are located nearby with the nearest residence approximately 700 feet from the
former mine. Therefore, the Kee'da'whii teeh (full-time Navajo resident) was selected as
the RME receptor for the CR-1 EU.

•	CR-1E - The former CR-1E mine is located on the Navajo Nation and is 14 acres.
Several residences are located nearby with the nearest residence approximately 800 feet
from the former mine. Therefore, the Kee'da'whii teeh (full-time Navajo resident) was
selected as the RME receptor for the CR-1E EU.

•	Former Kerr-McGee Ponds on the Navajo Nation - A 2-acre portion of the former
Kerr-McGee Ponds is located on the Navajo Nation. Several residences are located
nearby with the nearest residence approximately 3,000 feet from the Kerr-McGee Ponds.
Therefore, the Kee'da'whii teeh (full-time Navajo resident) was selected as the RME
receptor for the CR-1E EU.

•	Former Kerr-McGee Ponds on UNC Property - A 19-acre portion of the former
Kerr-McGee Ponds is on privately-owned land and fenced property. Therefore, the
UNC outdoor worker was selected as the RME receptor for the Kerr-McGee Ponds on
UNC property.

•	Arroyos on the Navajo Nation - A 16-acre portion of the impacted arroyos is on the
Navajo Nation. The impacted arroyos are deep with steep sides and, thus, difficult

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to access. Therefore, the Kqq ei doo nahaazah dah (difficult access open space) was
selected as the RME receptor for the affected arroyos on the Navajo Nation.

•	Arroyos on UNC Property - A 3-acre portion of the impacted arroyos is on
privately-owned land and fenced property. Therefore, the UNC outdoor worker was
selected as the RME receptor for the affected arroyos on UNC property.

•	Site-Wide - A 137-acre area that encompasses all the human health EUs for evaluation
of the ecological receptors at the Quivira Mines.

The existing or anticipated future land use for an area is key in determining the potential
receptors evaluated in the HHRA conducted for a site. Local chapters determine how areas
within their jurisdiction can and cannot be used.

This HHRA only evaluates the RME receptors at an EU. For the EUs on the Navajo Nation,
except for the arroyos, the Navajo-specific receptor of Kee'da'whii teeh (full-time Navajo
resident) was identified as the RME receptor. The arroyos are deep with very steep sides and
difficult to access; thus, for the arroyos on the Navajo Nation, the Navajo-specific receptor of
Kqq ei doo nahaazah dah (difficult access open space) was identified as the RME receptor. For
the EUs on UNC property, the site-specific UNC outdoor worker was identified as the RME
receptor. Figure C-3 through Figure C-9 provide the locations of samples used in the risk
assessment for each EU.

2.4 EXPOSURE POINT CONCENTRATIONS

To calculate concentrations in environmental media (for example, surface soil) to which people
and ecological receptors might be exposed, representative statistics are calculated from the
datasets for each EU. The available soil data for the site were divided by the EUs identified in
Section 2.3 Soil samples are further divided 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 bgs while subsurface soil samples are those collected from 0 up to
72 inches bgs. As described in the NAUM risk assessment methodology (USEPA 2024b), these
soil depths were selected to incorporate the use of more of the available 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 both the HHRA and ERA. Furthermore, burrowing animals are evaluated
in the ERA; 72 inches bgs is an appropriate exposure depth for evaluating these ecological
receptors, which may be hunted by members of the Navajo Nation.

The process provided in Appendix D of the NAUM risk assessment methodology (USEPA
2024b) report was used to calculate the EPC for each COPC. The approach and calculations for
EPCs follow USEPA (1989, 1992c, 2000a, 2002, 2015) guidance. The 95 percent upper
confidence limit (UCL95) of the mean values were calculated for each COPC using ProUCL 5.2
(USEPA 2022b). 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

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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) evaluation was conducted on the Quivira Mines dataset.
A range of equilibrium conditions were observed; however, the overall conclusion is that
uranium-238 is not in SE with thorium-230 or radium-226. Thus, uranium-238, uranium-234,
and thorium-230 will be included in the risk calculations along with radium-226 in SE. The
assumption that radium-226 in SE is health protective (USEPA 2024b).

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3.0 HUMAN HEALTH RISK ASSESSMENT

J

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 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. The methodology for the HHRA is based on the
NAUM risk assessment methodology (USEPA 2024b). Table C-l through Table C-7 present
data and analysis associated with the HHRA.

3.1 DATA EVALUATION AND IDENTIFICATION OF CONTAMINANTS OF
POTENTIAL CONCERN

All samples collected between 0 and 72 inches below ground surface (bgs) and analyzed by a
certified laboratory were used to screen for contaminants of potential concern (COPC) for the
HHRA. Samples at the Quivira Mines were analyzed for metals and radionuclides. The
maximum detected concentrations of contaminants were screened using the Kee'da'whii teeh
(full-time Navajo resident) soil screening levels using a target cancer risk (TCR) of 1 in 1 million
(1x10 6) and a noncancer target hazard quotient of 0.1 provided in the NAUM risk assessment
methodology (USEPA 2024b) report. These conservative screening levels were used to ensure
contaminants that could substantially contribute to cumulative cancer risk are retained in the risk
calculations and 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 C-l provides the COPC screening for
the available Quivira Mines data. Based on the screening, the following contaminants were
identified as COPCs and are included in the risk estimates in the HHRA: uranium-238,
uranium-234, thorium-230, radium-226, aluminum, arsenic, barium, cadmium, cobalt, copper,
iron, manganese, molybdenum, selenium, 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 at each
EU, called the EPC (see Section 2.4), to quantitatively estimate the contaminant exposure for the
receptors at a given EU. The EPCs used in the HHRA, grouped by EU and soil depth interval,
are presented in Table C-4. In accordance with USEPA (1989) guidance, an exposure assessment
consists of three steps:

1. Characterization of the exposure setting (physical environment and potential receptors)

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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 CSM describes the exposure setting and identifies potentially complete
exposure pathways by which receptors (people, plants, and animals) could come in contact with
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. For the HHRA, exposure to surface water or groundwater is
considered to be minimal as water is supplied on the Navajo Nation. At the Quivira Mines,
the presence of surface water is ephemeral. Thus, water exposure is not evaluated in the
Quivira Mines risk assessment; data collection was focused on the characterization of soil and
sediment only.

Soil and sediment data from 0 up to 72 inches bgs were used to evaluate potential risks to people.
Drainages at the site are dry for most of the year, and, therefore, sediment results were evaluated
as soil. See Section 2.4 of the main EE/CA report for further discussion on the sources and extent
of contamination. The site-specific CSM for the Quivira Mines is presented on Figure C-10.

3.2.2	Human Health Receptors, Exposure Pathways, and Exposure Parameters

The areas of concern for soil contamination at the Quivira Mines include the CR-1 and CR-1E
lease areas and specific step-out areas indicated by elevated radium-226 soil sampling results or
scan and static survey results. The arroyos adjacent to the mines, and former pond areas
downstream of the mines and arroyos, were also identified as areas of potential contamination

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because of dewatering activities during mine operations. The following receptors were assumed
to present in the areas of potential contamination:

•	Kee'da'whii teeh (full-time Navajo resident) at the mines and the portion of the former
Kerr-McGee Ponds on the Navajo Nation that are easy to access and relatively flat except
where waste rock piles are present

•	Kqq ei doo nahaazah dah (difficult access open space) for the arroyos on the Navajo
Nation impacted by the mines (these areas include arroyos that are difficult to get to
because of challenging features such as steep sidewalls)

•	UNC outdoor worker for the portions of the former Kerr-McGee Ponds and arroyos on
private property

Consistent with Superfund 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 abandoned uranium mine
workers will not be evaluated in the risk assessment, but worker protections should be included
for removal actions at the site.

The CSM (Figure C-10) describes the exposure setting and identifies potentially complete
exposure pathways by which people could come contact site-related contamination.

Consistent with the NAUM risk assessment methodology (USEPA 2024b), the HHRA only
evaluates the RME individual at an EU. Exhibit C-l presents the RME receptor selected at each
EU and a description of the exposure scenario.

Exhibit C-1. Receptors Evaluated at Each Exposure Unit

Exposure Unit

Receptor Name

Receptor Description

CR-1, CR-1E,
and the portion
of Kerr-McGee
Ponds on the
Navajo Nation

Kee'da'whff teeh
(Full-Time Navajo
Resident)

Members of the Navajo Nation (adult and child) that live full
time at a site. Includes external exposure to radiation,
incidental ingestion of soil, dermal exposure to soil (metals
only), inhalation of soil (or dust), ingestion of homegrown
produce and gathered wild plants, and consumption of animal
products from raised animals (meat, milk, and eggs) and
hunted animals (meat), as well as plant exposures (ingestion,
dermal, and inhalation) from Dine lifeways practices including
medicinal and ceremonial exposures.

Arroyos on the
Navajo Nation

Kqq eidoo

nahaazah dah
(Difficult Access
Open Space)

A member of the Navajo Nation (adult and child) that enters
the arroyo 1 hour per day for 30 days a year to collect plants,
herd animals, or hunt. Includes external exposure to radiation,
incidental ingestion of soil, dermal exposure to soil (metals
only), inhalation of soil (or dust), ingestion of homegrown
produce and gathered wild plants, and consumption of animal
products from raised animals (meat and milk) and hunted
animals (meat), as well as plant exposures (ingestion, dermal,
and inhalation) from Dine lifeways practices including
medicinal and ceremonial exposures.

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Exhibit C-1. Receptors Evaluated at Each Exposure Unit (Continued)

Exposure Unit

Receptor Name

Receptor Description

Kerr-McGee
Ponds and
Arroyos on UNC
Property

UNC Outdoor
Worker

An adult worker that is assumed to be present on site for
8 hours per day, 2 days per week for 50 weeks per year.
Exposure pathways evaluated include external exposure to
radiation, incidental ingestion of soil, dermal exposure to soil
(metals only), and inhalation of soil (or dust).

Notes:

CR-1	Quivira Church Rock Mine No. 1

CR-1E	Quivira Church Rock Mine No. 1 East

Kerr-McGee Kerr-McGee Corporation
UNC	United Nuclear Corporation

The following list provides the RME scenarios evaluated at the Quivira Mines and the potentially
complete human exposure pathways. The specific exposure inputs for these receptors evaluated
in the HHRA are provided in Table C-3.

•	Kee'da'whu teeh (Full-Time Navajo Resident - Adult and Child):

o Potential exposure to gamma radiation via external exposure

o Potential exposure to site-related contaminants in soil through incidental ingestion,
dermal contact, and inhalation

o Potential exposure to site-related contaminants in homegrown produce through
ingestion

o Potential exposure to site-related contaminants in gathered plants via ingestion or
inhalation or both and potential exposure to metals on gathered plants via dermal
contact (the plant exposure pathway includes use of plants for medicinal and
ceremonial purposes)

o Potential exposure to site-related contaminants in animal products (raised and hunted)
via ingestion

•	Kqq ei doo nahaazah dah (Difficult Access Open Space - Adult and Child):

o Potential exposure to gamma radiation via external exposure

o Potential exposure to site-related contaminants in soil through incidental ingestion,
dermal contact, and inhalation

o Potential exposure to site-related contaminants in gathered plants via ingestion or
inhalation or both and potential exposure to metals present in gathered plants via
dermal contact (the plant exposure pathway includes use of plants for medicinal and
ceremonial purposes)

o Potential exposure to site-related contaminants in animal products (raised and hunted)
via ingestion

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• UNC Outdoor Worker (Adult):

o Potential exposure to gamma radiation via external exposure

o Potential exposure to site-related contaminants in soil through incidental ingestion,
dermal contact, and inhalation

3.2.3 Exposure Parameters

Exposure inputs for the Navajo receptors are the Navajo Nation Environmental Protection
Agency (NNEPA) inputs for the receptors evaluated at the NAUM sites. The Navajo receptor
exposure parameters are provided in Table C-3. The rationale for the exposure inputs provided
by NNEPA are included as Attachment 1 of the NAUM risk assessment methodology (USEPA
2024b) report. Appendix B of the NAUM risk assessment methodology report provides
discussion of the non-standard exposure pathways evaluated in the Navajo-specific exposure
scenarios, including selection of input parameters for plant and animal consumption pathways.

The UNC outdoor worker scenario was developed with USEPA Region 9 for application to EUs
on properties owned by UNC. The input parameters for the UNC outdoor worker are provided in
Table C-3.

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 risk and
noncancer hazards as appropriate. No speciation data are available for chromium; therefore,
chromium is assumed to be 100 percent hexavalent chromium.

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, which is presented as [mg/kg-day]4). 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.

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The inhalation unit risk (IUR) factor is defined as the upper-bound excess lifetime cancer risk
estimated to result from continuous exposure to a chemical at a concentration of 1 microgram per
cubic meter in air. SFs or IUR factors are used to estimate a theoretical upper-bound lifetime
probability of an individual developing cancer as a result of 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 Superfund; 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 2024c), which are provided
in Table 4 and Table 5 of the NAUM risk assessment methodology (USEPA 2024b) for
radionuclides and metals, respectively. This HHRA used the toxicity values used in the NAUM
Risk Calculator (USEPA 2024c) and provided in Table 4 and Table 5 of the NAUM risk
assessment methodology (USEPA 2024b) report 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 Superfund HHRAs, exposures are calculated by use of medium-specific
EPCs and a series of pathway-specific exposure parameters. These exposures are then multiplied
or divided by analyte-specific toxicity values (for example, SFs, unit risk factors, RfDs, and
RfCs) to generate receptor- and exposure pathway-specific risks and hazards.

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 for each Navajo-specific scenario is provided in the NAUM risk
assessment methodology (USEPA 2024b) report. Table C-5.1 through Table C-5.6 present the
calculated cumulative cancer risk and noncancer hazard for each COPC for each EU by soil
depth interval. That is, the risk is summed for all the exposure pathways relevant to each
receptor.

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Table C-6 provides a summary of the cumulative risk by exposure pathway for each EU. This
HHRA only evaluates the RME receptor at an EU and these results are used for risk management
decisions for the site; however, cumulative site-wide cancer risks and noncancer hazards for a
receptor who is exposed to multiple Quivira Mines EUs is calculated and presented in the
uncertainty section (Section 3.4.2).

The intake factors used in the HHRA were calculated using the NAUM Risk Calculator (USEPA
2024c). 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, including animal product and
produce consumption pathways, and exposure pathways specific to the Navajo, 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 Navajo receptors is provided in the NAUM risk assessment methodology (USEPA
2024b) report.

The cumulative cancer risk for the age-adjusted adult and child receptors and noncancer hazards
for the adult and child receptors for each EU and soil depth interval are provided in Table C-7
and summarized in Exhibit C-2.

Exhibit C-2. Cancer Risks and Noncancer Hazards

Exposure Unit

Soil Interval

Cancer Risk

Adult
Noncancer
Hazard

Child
Noncancer
Hazard

CR-1

Surface Soil

1x102

8

10

Subsurface Soil

3x102

8

10

CR-1 E

Surface Soil

2x10 2

8

10

Subsurface Soil

8x10 2

10

20

Kerr-McGee Ponds on the
Navajo Nation

Surface Soil

2x10 2

9

10

Subsurface Soil

2x10 2

9

10

Kerr-McGee Ponds on UNC
Property

Surface Soil

2x10 4

0.05

—

Subsurface Soil

2x10 4

0.08

—

Arroyos on the Navajo Nation

Surface Soil

6x10 4

5

0.5

Subsurface Soil

6x10 4

8

0.7

Arroyos on UNC Property

Surface Soil

2x10"5

0.03

—

Subsurface Soil

2x10"5

0.03

-

Notes:

Bolded values exceed the target cancer risk (1x104) or target hazard quotient (1).

Not applicable
CR-1	Quivira Church Rock Mine No. 1

CR-1E	Quivira Church Rock Mine No. 1 East

Kerr-McGee Kerr-McGee Corporation
UNC	United Nuclear Corporation

Candidate COCs are identified based on the cancer risk exceeding the TCR of 1x10 4 or a
noncancer hazard of 1 for the RME receptor at the EU. COPCs with a cancer risk within the
USEPA risk range of greater than 1x10 6 to 1x10 4 are indicated on Table C-7. Target organ
analyses were not performed for any scenario-media combination because no instances arose

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where the target organ hazard index exceeded 1 and no individual COPC had a hazard
exceeding 1. Exhibit C-3 presents the candidate COCs for each EU as identified in Table C-7.

Exhibit C-3. Candidate COCs Identified Based on Cancer Risks and Noncancer Hazards

Exposure Unit

Soil Interval

Cancer Risk

Noncancer Hazard

CR-1

Surface Soil

Radium-226 in SE
Arsenic
Chromium1

Cobalt
Iron
Manganese
Thallium
Uranium

Subsurface Soil

Radium-226 in SE
Arsenic
Chromium1

Cobalt
Iron
Manganese
Thallium
Uranium

CR-1 E

Surface Soil

Radium-226 in SE
Arsenic
Chromium1

Arsenic
Cobalt
Iron
Manganese
Thallium
Uranium

Subsurface Soil

Radium-226 in SE
Arsenic
Chromium1

Arsenic
Cobalt
Iron
Manganese
Thallium
Uranium

Kerr-McGee Ponds on the
Navajo Nation

Surface Soil

Radium-226 in SE
Arsenic
Chromium1

Cobalt
Iron
Manganese
Thallium
Uranium

Subsurface Soil

Radium-226 in SE
Arsenic
Chromium1

Cobalt
Iron
Manganese
Thallium
Uranium

Kerr-McGee Ponds on UNC
Property

Surface Soil

Radium-226 in SE

—

Subsurface Soil

Radium-226 in SE

--

Arroyos on the Navajo Nation

Surface Soil

Radium-226 in SE
Arsenic

Manganese

Subsurface Soil

Radium-226 in SE
Arsenic

Manganese

Arroyos on UNC Property

Surface Soil

—

—

Subsurface Soil

-

-

Notes:

1	No speciation data are available for chromium; therefore, chromium is assumed to be 100 percent

hexavalent chromium.

No contaminants of concern for the exposure unit based on human health risk assessment results.
CR-1	Quivira Church Rock Mine No. 1

CR-1E	Quivira Church Rock Mine No. 1 East

Kerr-McGee Kerr-McGee Corporation
SE	Secular equilibrium

UNC	United Nuclear Corporation

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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 2024b)
provides more general HHRA uncertainty discussions for topics applicable to all NAUM sites.

3.4.2.1	Uncertainty in the Conceptual Site Model

The CSM for the Quivira Mines incorporates several assumptions regarding the completeness
and reasonableness of the exposure scenarios presumed at the site. The primary assumptions
seem evidently valid. Examples include:

•	Potential future use of areas for Kee'da'whii teeh (full-time Navajo resident) within
CR-1, CR-1E, the former Kerr-McGee Ponds, and the arroyos on the Navajo Nation —
Many examples of nearby full-time residences on the Navajo Nation are available.

•	Potential future use of UNC areas — These areas will remain as industrial use with a
site-specific onsite worker receptor.

•	The NAUM Risk Calculator used to calculate the risk-based screening levels incorporates
numerous Navajo-specific exposure pathways. Therefore, any potential to underestimate
total exposure by a Kee'da'whii teeh (full-time Navajo resident) receptor is expected to
be small to moderate.

•	Risk-based screening levels for the site-specific UNC outdoor worker were calculated
using standard exposure parameters with a reduced number of days on site per year

(2 days per week for 50 weeks per year for a total of 100 days per year on site). The total
exposure by an onsite worker is expected to be overestimated by this evaluation as any
UNC outdoor worker would be dividing time spent at the multiple UNC sites in the area
and limited maintenance is necessary at the former Kerr-McGee Ponds and portion of the
arroyos on UNC property.

3.4.2.2	Uncertainty in 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 and X-ray fluorescence samples. Thus, while some areas do not have the same level of
sampling coverage as others, those areas are not likely to have high 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

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in the risk assessment are likely to overestimate the actual site risk because of the biased nature
of the samples collected at the site.

Risks and hazards were calculated using maximum detected concentrations as EPCs for
contaminants with fewer than 10 results for the two arroyo EUs. Use of maximum detected
concentrations as EPCs likely overestimated risks.

3.4.2.3	Uncertainty in Reasonable Maximum Exposure Receptor Selection and
Exposure Parameters

The most significant site-specific uncertainty associated with the HHRA is the selection of the
RME receptor for each EU. EUs used in the 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 for each EU was selected based on the
criteria provided in the NAUM risk assessment methodology (USEPA 2024b) report and site
knowledge. If the receptor selected is less conservative than the actual future land use, 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 easy access open space), the
HHRA would be overly protective. This uncertainty is moderate, and the direction of the
uncertainty is more likely to be overprotective because of the conservative selection
methodology used to identify the RME receptor for each area.

3.4.2.4	Uncertainty in Use ofHexavalent Chromium Toxicity for Chromium

Hexavalent chromium is not expected to be present in large concentrations at former uranium
mining sites because site operations did not concentrate or use hexavalent chromium. The
assumption of 100 percent hexavalent chromium overestimates the cancer risk from samples
analyzed for total chromium by an unknown amount.

3.4.2.5	Site- Wide Risk Estimates

This HHRA only evaluates the RME receptor at an EU, and the results of the HHRA are used in
making risk management decisions for the site. A potential site uncertainty is that a single
receptor may visit multiple areas at a site and, thus, be exposed to more than one EU.

Kee'da'whii teeh (full-time Navajo resident) was evaluated at three areas; therefore, the risk and
hazards from these areas cannot appropriately be added together as that would assume the
receptor lives on all three sites simultaneously.

However, a resident living at CR-1 may go into the adjacent arroyo (difficult access open space)
to gather plants or hunt. Because of the overlap in the exposure assumptions for plant and animal
ingestion and Other Dine Lifeways (ODL) pathways between the Navajo-specific receptors,
adding the calculated exposures from the receptors at each EU is not possible without counting
the plant, animal, and ODL exposures multiple times. Potential additive scenarios were identified
as follows:

• CR-1 full-time Navajo resident and difficult access open space user of arroyos on the
Navajo Nation

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•	CR-1E full-time Navajo resident and difficult access open space user of arroyos on the
Navajo Nation

•	Former Kerr-McGee Ponds full-time Navajo resident and difficult access open space user
of arroyos on the Navajo Nation

•	UNC outdoor worker on former Kerr-McGee Ponds and arroyos on UNC property

To calculate the cumulative risk and hazard that account for possible exposures to different EUs
without double counting the plant, animal, and ODL exposures pathways, a time-weighted
average approach was applied to the combined EUs. However, the actual time a receptor spends
in any area is unknown and introduces a potentially large amount of uncertainty. The following
bullets discuss the potential additive scenarios identified:

•	CR-1 full-time Navajo resident and difficult access open space user of arroyos on the
Navajo Nation — The total time on site for this potential scenario would be 99.6 percent
of time spent at CR-1 and 0.4 percent of time in the arroyo. Thus, combining these
scenarios results in a cancer risk and noncancer hazard essentially equal to the full-time
Navajo resident living at CR-1. The cancer risk for surface soil would be 1x10 2, and the
estimated risk for subsurface soil would be 3x10 2. The noncancer hazard would be 10 for
a child and 8 for an adult for both surface and subsurface soil intervals.

•	CR-1E full-time Navajo resident and difficult access open space user of arroyos on the
Navajo Nation — The total time on site for this potential scenario would be 99.6 percent
of time spent at CR-1E and 0.4 percent of time in the arroyo. Thus, combining these
scenarios results in a cancer risk and noncancer hazard essentially equal to the full-time
Navajo resident living at CR-1E. The cancer risk for surface soil would be 2x10 2, and the
estimated risk for subsurface soil would be 8x10 2. The noncancer hazard would be 10 for
a child and 8 for an adult for surface soil and 20 for a child and 10 for an adult for
subsurface soil.

•	Former Kerr-McGee Ponds full-time Navajo resident and difficult access open space user
of arroyos on the Navajo Nation — The total time on site for this potential scenario
would be 99.6 percent of time spent at the former Kerr-McGee Ponds on the Navajo
Nation and 0.4 percent of time in the arroyo. Thus, combining these scenarios results in a
cancer risk and noncancer hazard essentially equal to the full-time Navajo resident living
at the former Kerr-McGee Ponds. The cancer risk is estimated to be 2x10 2 for both
surface and subsurface soil intervals. The noncancer hazard is 10 for a child and 9 for an
adult for both surface and subsurface soil intervals.

•	UNC outdoor worker on former Kerr-McGee Ponds and arroyos on UNC property —
These scenarios do not have overlapping exposures and so the cancer risk and noncancer
hazards can be added from these two areas for an individual worker receptor who is
exposed to both areas. The total risk from both areas is 3x10 4 for surface soil and 2x10 4
for subsurface soil. The total noncancer hazard would be 0.07 for both surface and
subsurface soil intervals.

The actual exposure to any EU at the Quivira Mines is likely overestimated by the scenarios used
to evaluate the EUs. Combining the exposures likely compounds the uncertainty and still
overestimates the exposure and resulting risk and hazard at the site.

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4.0 ECOLOGICAL RISK ASSESSMEN

J

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 chemicals. The
objective of the ERA is to evaluate whether ecological receptors may be adversely affected by
exposure to site-related 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 2024b).

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 C-2 and Table C-8 through Table C-12 present
data and analysis associated with the ERA.

Consistent with standard risk assessment practice and USEPA (1992b, 1998, 2022a) 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 Quivira Mines are described in Section 1.4.
The Quivira Mines are primarily within an Area 3 wildlife sensitive area.

4.1.2	Stressors and Contaminants of Potential Ecological Concern Selection

All detected inorganic chemicals and radionuclides in soil were considered COIs in this SLERA.
Essential nutrients that are not priority pollutants, such as calcium, magnesium, potassium, and
sodium, were not retained as COIs. No speciation data are available for chromium; therefore,
chromium is assumed to be 100 percent hexavalent chromium. 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 72 inches bgs) were used in the risk assessment as described in
Section 2.1.

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. Complete exposure pathways present the greatest potential risk of adverse
effects for receptors of concern at a site. 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 at this site. Potential exposure pathways are diagrammed in the CSM (Figure C-10).

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Discussion of the exposure pathways for ecological receptors at NAUM sites is provided in the
NAUM risk assessment methodology (USEPA 2024b).

Soil exposures are evaluated in the SLERA for the Quivira Mines. The removal actions at the
Quivira Mines are focused on removing waste and soil as the removal of both 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 Quivira
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 4.1.3 and depicted on the CSM (Figure C-10). 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 Quivira 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 (see Appendix F of the NAUM risk assessment methodology [USEPA
2024b] report). An ecological radiation dose assessment was performed for radionuclides in the
uranium-238 decay chain using the dose assessment model Environmental Risks from Ionizing

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Contaminants: Assessment and Management (ERICA). The ERICA model is scientifically
robust, follows approaches recommended by the International Commission on Radiation
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 (2023a) 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 a USEPA 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).

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The screening levels selected from USEPA Eco-SSLs (USEPA 2023a), LANL ESLs (N3B
2022), and ORNL (Efroymson, Will, and Suter II 1997; Efroymson, Will, Suter II, and Wooten
1997) 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, insectivorous, and carnivorous], and mammal [herbivorous, insectivorous, and
carnivorous] NOECs) for each COPEC. The screening levels are provided in Table C-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 C-10.

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
Quivira Mines EUs were 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 C-8.

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
UCL95 (for analytes where sufficient data were available) instead of the maximum 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
72 inches bgs for subsurface soil (see Section 2.1). The EPCs used in the SLERA refinement for
birds and mammals for each COPEC were calculated per the procedure in Section 2.4 and are
presented in Table C-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 effects
concentrations (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.

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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
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 soil to the screening
levels, are presented in Table C-8. Contaminants for which the HQ was greater than or equal to
1.0 were uranium-238, uranium-234, radium-226, arsenic, barium, chromium, lead, manganese,
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.

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4.3.2.1	Plants and Soil Invertebrates

Plants and soil invertebrates are not mobile; therefore, comparison of the UCL95 to the NOEC
or ESL 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 the plant
NOEC or ESL for subsurface soil. Table C-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 bgs). 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 (subsurface only), uranium-234 (subsurface
only), radium-226 in SE, arsenic (surface only), barium, chromium, lead (surface only),
manganese, selenium, thallium, and uranium. Candidate COECs for invertebrates were arsenic,
barium, chromium, and selenium.

4.3.2.2	Birds and Mammals

For free-ranging wildlife, the EPCs are 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 are 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
mammals in subsurface soil (birds and non-burrowing mammals are not exposed to soil at depths
greater than 6 inches bgs).

Table C-l 1 and Table C-12 present HQs for birds and mammals, respectively. Candidate
COECs for birds and mammals are 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 lead, selenium, vanadium, and zinc. Candidate COECs for
mammals were radium-226 in SE (subsurface soil only) and selenium.

4.3.3 Candidate Contaminants of Ecological Concern

Candidate COECs were identified based on available laboratory and toxicological data for the
Quivira Mines. The SLERA results indicate that risk is above a level of concern for the
contaminants listed in Exhibit C-4.

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Exhibit C-4. Site-Wide Candidate COECs





Candidate COEC









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soils at the Quivira Mines was assumed to represent the entire site to ensure protectiveness.
However, this method creates bias in the data toward the more disturbed or affected
environments at the site and is likely to overestimate COPEC exposure concentrations.

Similarly, in the SLERA refinement, an EPC for each COPEC for surface and subsurface soils
was used to estimate exposures and ensure protectiveness. The use of the UCL95 concentration
may under- or overestimate COPEC concentrations used to characterize conditions throughout
the site, depending on their actual site-wide distribution. In addition, portions of the site are bare
ground and do not provide habitat or foraging area for some ecological receptors. Bare ground
areas are included in the evaluation; however, the nature of the bare ground areas (toxicity, lack
of soil, etc.) is unknown.

Site-specific bulk chemistry concentrations were compared with toxicity benchmarks values such
as USEPA Eco-SSLs and LANL ESLs as an indicator of the potential for adverse effects. Bulk
chemistry results for onsite samples likely overestimate the bioavailable fraction of each COPEC
as the results do not consider whether the contaminant is bound to soil particles or other
compounds that could prevent uptake by plants and invertebrates, or absorption upon direct
contact or ingestion by higher trophic-level receptors.

The ERA assumes that all receptors live and forage solely at the site; however, this assumption is
not necessarily true for the avian and larger mammalian receptors, which can forage over larger
areas and are not likely to be consistently exposed to COPECs in soil at the estimated site
concentrations. Mobile ecological receptors could be exposed to areas beyond the site boundary
depending on the foraging and home range of the particular species. The use of media-based
screening levels does not account for the size of the site or the foraging area. Nonmobile
receptors, such as the plant and soil invertebrate communities, are assessed by sample, and small
ranging receptors, such as small mammals, would likely remain within the site boundaries if
sufficient food and shelter were available. However, free-ranging wildlife, such as raptors, large
herbivores, and top-level predators, would travel beyond the site boundary. Furthermore, use of a
site can vary seasonally. Therefore, the actual amount of soil or prey ingested from the site
would likely be less than the values used in the risk calculations, resulting in an overestimate of
risk. The impact of this uncertainty is species dependent but likely small given that those
receptors that would travel beyond the site boundary have large home ranges.

As with any site investigation, uncertainty will be associated with the representativeness of the
samples both spatially and temporally. Soil samples were collected from over a period of
12 years by multiple contractors, and sampling methods and analytical methods may not have
been consistent. Figure C-3 through Figure C-9 show the sample locations for each EU. Spatial
variability is limited because soil samples used in the risk assessment were all collected within
the disturbed area of the mines and the Kerr-McGee Ponds. Temporal variability is limited
because soil sampling methods were consistent among sampling events and because of the
known environmental fate of the COPECs (lack of degradation).

Contract No. 68HE0923D0002, Task Order 001

C-30


-------
Appendix C: Quivira Mines Risk Assessment

4.4.2	Nondetected Contaminants of Potential Ecological Concern

Little uncertainty is involved with the analytical analysis for soil at the Quivira Mines as all
COPECs were detected in soil above their respective detection limits in at least some samples.

4.4.3	Combined Exposures Across Media and Exposure Units

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). Because surface water is present irregularly in the arroyos, an aquatic
community would unlikely become established; however, birds, mammals, and reptiles could
ingest the water when it is available. The risk analysis does not account for exposure to COPECs
in drinking water, but the magnitude of this uncertainty is unknown.

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. Table C-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 COPECs
at the Quivira 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.

Contract No. 68HE0923D0002, Task Order 001

C-31


-------
Appendix C: Quivira Mines Risk Assessment

5.0 RISK ASSESSMENT RESULTS SUMMAR

J

The HHRA and SLERA results indicate human health and ecological risk exceed the acceptable
risk levels. Candidate COCs and COECs were identified based on available laboratory and
toxicological data at the CR-1, CR-1E, Kerr-McGee Ponds on the Navajo Nation, Kerr-McGee
Ponds on UNC property, and arroyos on the Navajo Nation EUs. No candidate COCs or COECs
were identified for the arroyos on UNC property EU. The HHRA and ERA results indicate that
risk is above a level of concern for the contaminants listed in Exhibit C-5.

Contract No. 68HE0923D0002, Task Order 001

C-32


-------
Appendix C: Quivira Mines Risk Assessment

"It

Exhibit C-5. Candidate Contaminants of Concern or Contaminants of Ecological Concern for Soil





Candidate COC or COEC

Exposure Unit

Soil Interval

CO
CM
¦

E

3

'E

TO
D

00
PO
CM
¦

E

3

'E

<0

L.

Z)

Radium-226 in SE

Arsenic

Barium

Chromium2

Cobalt

Iron

Lead

Manganese

Selenium

Thallium

Uranium

Vanadium

Zinc

CR-1

Surface and
Subsurface Soils

-

-

X

X

-

X

X

X

-

X

-

X

X

-

-

CR-1 E

Surface and
Subsurface Soils

-

-

X

X

-

X

X

X

-

X

-

X

X

-

-

Kerr-McGee Ponds
on the Navajo Nation

Surface and
Subsurface Soils

-

-

X

X

-

X

X

X

-

X

-

X

X

-

-

Kerr-McGee Ponds
on UNC Property

Surface and
Subsurface Soils

-

-

X

-

-

-

-

-

-

-

-

-

-

-

-

Arroyos on the
Navajo Nation

Surface and
Subsurface Soils

-

-

X

X

-

-

-

-

-

X

-

-

-

-

-

Arroyos on UNC
Property

Surface and
Subsurface Soils

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

Site-Wide

Surface Soil

-

-

X

X

X

X

-

-

X

X

X

X

X

X

X

(Ecological)

Subsurface Soil

X

X

X

-

X

X

-

-

-

X

X

X

X

-

-

Notes:

X

COC

COEC

CR-1

CR-1E

EE/CA

Uranium-234 and uranium-238 concentrations exceed the ecological no observed effects concentration for plants in a single subsurface sample
(location KMP-SB28 from 60 to 66 inches below ground surface) in the Kerr-McGee Ponds on UNC Property EU. This area is considered a hot
spot, and any recommendations for uranium-234 and uranium-238 apply only to this hot spot.

No speciation data are available for chromium; therefore, chromium is assumed to be 100 percent hexavalent chromium.

Not a candidate COC or COEC. Not recommended for further evaluation in the EE/CA.

Candidate COC and/or COEC. Recommended for further evaluation in the EE/CA.

Contaminant of concern
Contaminant of ecological concern
Quivira Church Rock Mine No. 1
Quivira Church Rock Mine No. 1 East
Engineering evaluation/cost analysis

EPC	Exposure point concentration

Kerr-McGee	Kerr-McGee Corporation

mg/kg	Milligram per kilogram

SE	Secular equilibrium

UNC	United Nuclear Corporation

Contract No. 68HE0923D0002, Task Order 001

C-33


-------
Appendix C: Quivira Mines Risk Assessment

6.0 REFERENC

J

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.

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.

Los Alamos National Laboratory. 2015. "Screening-Level Ecological Risk Assessment
Methods." Revision 4. EP2015-0174. October 29.

Navajo Nation Department of Fish and Wildlife (NNDFW). 2022. "Biological Resource Land-
Use Clearance Policies and Procedures." https://nndfw.org/zones/rcp.html.

Navajo Nation Environmental Protection Agency. 2021. "Navajo Tribe Provisional Reasonable
Maximum Exposures for the Navajo Risk Assessments." Draft. September 15.

Newport News Nuclear BWXT-Los Alamos, LLC (N3B). 2022. "ECORISK Database."

Release 4.3. 701067. Document EM2020-0575. Los Alamos National Laboratory.
September.

Red Water Pond Road Community Association and Southwest Research and Information Center.
2012. "History through Pictures Past and Present of the Red House People." Revised
September.

SENES Consultants Limited. 2011. "Interim Removal Action, Final Removal Site Evaluation
Report for Northeast Church Rock - Quivira Site Evaluation for Church Rock (CR-1)
and (CR-1E) Mine Sites." September.

Tetra Tech, Inc. (Tetra Tech). 2022a. "Quivira Mines and Kerr-McGee Ponds Biological

Assessment." Response, Assessment, and Evaluation Services. Contract No. EP-S9-17-
03.

Tetra Tech. 2022b. "Technical Memorandum, Biological Survey Report, Quivira Mines and

Kerr-McGee Ponds, Eastern Abandoned Uranium Mine Region." Prepared for the Navajo
Nation Department of Fish and Game. June 3.

Contract No. 68HE0923D0002, Task Order 001

C-34


-------
Appendix C: Quivira Mines Risk Assessment

It

Tetra Tech. 2023. "Quivira Mines Data Gaps Investigation Transmittal Memorandum."

Response, Assessment, and Evaluation Services. Contract No. EP-S9-17-03. September.

U.S. Environmental Protection Agency (USEPA). 1989. "Risk Assessment Guidance for

Superfund Volume I - Human Health Evaluation Manual, Part A." EPA/540/1-89/002.

USEPA. 1992a. "Framework for Ecological Risk Assessment. Risk Assessment Forum."
EPA/630/R- 92/001. February.

USEPA. 1992b. "Guidance for Data Useability in Risk Assessment (Part A)." Office of Solid
Waste and Emergency Response (OSWER). Publication 9285.7-09A. April.

USEPA. 1992c. "Supplemental Guidance to [Risk Assessment Guidance for Superfund] RAGS:
Calculating the Concentration Term." Intermittent Bulletin, Volume 1, No. 1. Publication
9285.7-081. May.

USEPA. 1993. "Guidance on Conducting Non-Time-Critical Removal Actions Under
CERCLA." 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.

USEPA. 2005. "Guidance for Developing Ecological Soil Screening Levels." February.

Contract No. 68HE0923D0002, Task Order 001

C-35


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Appendix C: Quivira Mines Risk Assessment

It

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. 2022a. "EPA EcoBox (A Toolbox for Ecological Risk Assessors)." Accessed May.
https://www.epa.gov/ecobox.

USEPA. 2022b. "ProUCL Version 5.2.0 Statistical Software for Environmental Applications for
Data Sets with and without Nondetect Observations." June 14.

USEPA. 2023a. "Interim Ecological Soil Screening Level Documents." Accessed July 20.
https://www.epa.gov/chemical-research/interim-ecological-soil-screening-level-
documents.

USEPA. 2023b. "Preliminary Remediation Goals for Radionuclides (PRG)." September.
https://epa-prgs.ornl.gov/cgi-bin/radionuclides/rprg_search.

USEPA. 2023c. "Regional Screening Levels (RSLs)." November, https://epa-prgs.ornl.gov/cgi-
bin / chemicals/csl_search.

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. "Navajo Abandoned Uranium Mine Risk Assessment Methodology." Draft
Final. March.

USEPA. 2024c. "Navajo Abandoned Uranium Mine Risk Calculator." Version 1.03. March.

Weston Solution, Inc. (Weston). 2010. "Expanded Site Screening, North East Church Rock -
Quivira Mines, Navajo Nation, New Mexico." April.

Contract No. 68HE0923D0002, Task Order 001

C-36


-------
FIGURES


-------
.6

BBIHI

¦#

• a®

« ¦

QU V RATRONOX M NES

Farmington

Quivira
Tronox
Mines

FJagsti ft

Red Water Pond Road

Qu v ra Vent

H° 0 2

STANDING ROCK CHAPTER

KerrMcGee PINEDALE CHAPTER

Ponds Area

Defiance

CHURCH ROCK

chapter*

UN TED NUCLEAR
CORPORAT ON PROPERTY

Gallup

COYOTE CANYON CHAPTER

Notes:





CR-1

Quivira Tronox Church Rock No.

1 Mine Site

CR-1E

Quivira Tronox Church Rock No.

1 East Mine Site

Kerr-McGee

Kerr-McGee Corporation



Legend

Drainage
	Road

Navajo Nation Chapter Boundary

Navajo Nation Regions

Former Vent Hole Closed by Removal Action	Central Region

Kerr-McGee Ponds Investigation Boundary	Eastern Region

Quivira Tronox Mine Lease Area	North Central Region

f II 100-Foot Step-Out Boundary	Northern Region

United Nuclear Corporation Property	Southern Region

I i Navajo Nation Boundary	Western Region

Prepared for: U.S. EPA Region 9

Prepared By:

i Feet

2,000

4,000

TETRATECH

MINE LOCATION

Task Order No.:

0001

Location:

QUIVIRA TRONOX MINES

Window Rock

Detail Area

Contract No.:
68HE0923D0002

Date:

3/8/2024

Figure No

C-1


-------
^ wdroM. *;•¦	^

_fV* |n r*? \	*_ •' X



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J*££

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Rock No. 1 Mine Site (CR-1)

	

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- >*^ R •; v

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a





hln

Surface Soil Sample (0-6 inches bgs)
~ (includes all lab samples with
bottom depth < 6 inches bgs)

Subsurface Soil Sample (below 6 inches bgs)
~ (includes all lab samples with bottom
depth > 6 inches and < 72 inches bgs)

Exposure Units1,2

Church Rock Mine No. 1
Church Rock Mine No. 1 East

Kerr-McGee Ponds on the
Navajo Nation

Kerr-McGee Ponds on United
Nuclear Corporation Property

Arroyos on Navajo Nation

Arroyos on United Nuclear
Corporation Property

Site-Wide (for Ecological Risk)

1 inch - 600 feet
1:7,200

600	300	0

EXPOSURE UNITS AND
SAMPLE LOCATIONS

ED

Prepared For: U.S. EPA Region 9

41

^ MKf-

1/

* i»k'	-^K

,w

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Kerr-McGee Ponds Area

¦ Prepared By:

TETRATECH

Wxjm



Twf;



Task Order No.:

000 1

Arroyos on United Nuclear
Corporation Property

United Nuclear Corporation Outdoor
Worker

Site-Wide

Ecological Receptors

	

( 1

IT.

		rzl

Notes:

'Exposure unit boundaries are based on TENORM
determination for each area.

2Ecological risk is evaluated on a site-wide basis,
bgs	Below ground surface

Kerr-McGee Kerr-McGee Corporation

Location:

QUIVIRA TRONOX MINES

Contract No.:

68HE0923D0002

3/8/2024

Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:

C-2


-------
Soil Sample Locations

Surface Soil Sample (0-6 inches bgs)
A (includes all lab samples with
bottom depth < 6 inches bgs)

_ Subsurface Soil Sample (below 6 inches bgs)
|_| (includes all lab samples with bottom
depth > 6 inches and < 72 inches bgs)

I I Mine Lease Boundary

Kerr-McGee Ponds
Investigation Boundary

I I Kerr-McGee Ponds Fenceline

Exposure Units

Church Rock Mine No. 1
Arroyos on Navajo Nation
Site-Wide (for Ecological Risk)

1 inch = 150 feet
1:1,800

150	75	0

N

S

150
I Feet

QUIVIRA CHURCH ROCK NO. 1
MINE EXPOSURE UNIT WITH
SAMPLE LOCATIONS - WEST SIDE

Prepared For: U.S. EPA Region 9

(0/

*>4	

Prepared By:

Notes:

Church Rock Mine No. 1 was evaluated in the risk
assessment as a single exposure unit. Two figures
of the sample locations were necessary to provide
legible sample identification labels,
bgs	Below ground surface

CR-1	Quivira Church Rock No. 1 Mine

CR-1E	Quivira Church Rock No. 1 East

Mine

EU	Exposure unit

Kerr-McGee Kerr-McGee Corporation

TETRATECH

Task Order No.:

000 1

QUIVIRA MINES

Contract No.:

68HE0923D0002

3/8/2024

Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:

C-3


-------
Soil Sample Locations

Surface Soil Sample (0-6 inches bgs)
A (includes all lab samples with
bottom depth < 6 inches bgs)

_ Subsurface Soil Sample (below 6 inches bgs)
|_| (includes all lab samples with bottom
depth > 6 inches and < 72 inches bgs)

I I Mine Lease Boundary

Kerr-McGee Ponds
Investigation Boundary

I I Kerr-McGee Ponds Fenceline

Exposure Units

Church Rock Mine No. 1

Arroyos on Navajo Nation

Site-Wide (for Ecological Risk)

1 inch = 180 feet
1:2,160

180	90	0

N

W E

S

180
I Feet

QUIVIRA CHURCH ROCK NO. 1
MINE EXPOSURE UNIT WITH
SAMPLE LOCATIONS - EAST SIDE

Prepared For: U.S. EPA Region 9



Prepared By:

Notes:

Church Rock Mine No. 1 was evaluated in the risk
assessment as a single exposure unit. Two figures
of the sample locations were necessary to provide
legible sample identification labels,
bgs	Below ground surface

CR-1	Quivira Church Rock No. 1 Mine

CR-1E Quivira Church Rock No. 1 East
Mine

EU	Exposure unit

Kerr-McGee Kerr-McGee Corporation

TETRATECH

Task Order No.:

000 1

QUIVIRA MINES

Contract No.:

68HE0923D0002

3/8/2024

Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:

C-4


-------
Soil Sample Locations

A

Surface Soil Sample (0-6 inches bgs)
(includes all lab samples with
bottom depth < 6 inches bgs)

_ Subsurface Soil Sample (below 6 inches bgs)
|_| (includes all lab samples with bottom
depth > 6 inches and < 72 inches bgs)

I I Mine Lease Boundary

Kerr-McGee Ponds
Investigation Boundary

I I Kerr-McGee Ponds Fenceline

Exposure Units

Church Rock Mine No. 1 East

Arroyos on Navajo Nation

Site-Wide (for Ecological Risk)

Notes:
bgs
CR-1
CR-1E

EU

Below ground surface
Quivira Church Rock No. 1 Mine
Quivira Church Rock No. 1 East
Mine

Exposure unit

Kerr-McGee Kerr-McGee Corporation

1 inch = 200 feet
1:2,400

200	100	0

N

W E

S

200
I Feet

QUIVIRA CHURCH
ROCK NO. 1 EAST MINE
EXPOSURE UNIT
WITH SAMPLE LOCATIONS

Prepared For: U.S. EPA Region 9

% .R^

Prepared By:

TETRATECH

Task Order No.:

000 1

QUIVIRA MINES

Contract No.:

68HE0923D0002

3/8/2024

Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:

C-5


-------
Kerr-McGee Roi

NAVAJO

UNITED NL
CORPORATI

Note:

bgs	Below ground surface

CR-1	Quivira Troriox Church Rock No. 1

Mine Site

CR-1E Quivira Tronox Church Rock No. 1

East Mine Site
EU	Exposure Unit

Kerr-McGee Kerr-McGee Corporation

Soil Sample Locations

Surface Soil Sample (0-6 inches bgs)
A (includes all lab samples with
bottom depth < 6 inches bgs)

_ Subsurface Soil Sample (below 6 inches bgs)
|_| (includes all lab samples with bottom
depth > 6 inches and < 72 inches bgs)

Mine Lease Boundary

Kerr-McGee Ponds
Investigation Boundary

I I Kerr-McGee Ponds Fenceline

United Nuclear Corporation Site Boundary

Exposure Units

Kerr-McGee Ponds on the
Navajo Nation

Kerr-McGee Ponds on United
Nuclear Corporation Property

Arroyos on Navajo Nation

Arroyos on United Nuclear
Corporation Property

Site-Wide (for Ecological Risk)

1 inch = 150 feet
1:1,800

150	75	0

N

W E

S

150
Feet

KERR-MCGEE PONDS ON THE
NAVAJO NATION EXPOSURE
UNIT WITH SAMPLE LOCATIONS

Prepared For: U.S. EPA Region 9

Prepared By:

TETRA TECH

It

Task Order No.:

000 1

QUIVIRA MINES

Contract No.:

68HE0923D0002

3/8/2024

Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:

C-6


-------
Kerr-McGee Ponds

N A VA J O^NATIO N

UNITED. NUG1!E'A'R1
GO PRORATION SHE

Location:

EU

Kerr-McGee

Soil Sample Locations

Surface Soil Sample (0-6 inches bgs)
A (includes all lab samples with
bottom depth < 6 inches bgs)

_ Subsurface Soil Sample (below 6 inches bgs)
|_| (includes all lab samples with bottom
depth > 6 inches and < 72 inches bgs)

I I Mine Lease Boundary

Kerr-McGee Ponds
Investigation Boundary

I I Kerr-McGee Ponds Fenceline

United Nuclear Corporation Site Boundary

Exposure Units

Kerr-McGee Ponds on the
Navajo Nation

Kerr-McGee Ponds on United
Nuclear Corporation Property

Arroyos on Navajo Nation

Arroyos on United Nuclear
Corporation Property

EU - Site-Wide (for Ecological Risk)

1 inch = 200 feet
1:2,400

200	100	0

KERR-MCGEE PONDS ON UNITED
NUCLEAR CORPORATION PROPERTY
EXPOSURE UNIT
WITH SAMPLE LOCATIONS

Prepared For: U.S. EPA Region 9



| Prepared By:

TETRATECH

I Task Order No.:

Below ground surface

Quivira Tronox Church Rock No. 1

Mine Site

Quivira Tronox Church Rock No. 1
East Mine Site
Exposure unit
Kerr-McGee Corporation

QUIVIRA MINES

Contract No.:

68HE0923D0002

3/8/2024

I Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:


-------
CRUA-001

CRUA-005

CRUA-006

CRUA-004

CRUA-010

CRUA-002

CRUA-003

CRUA-012

CRUA-008

CRUA-020

CRUA-014

CRUA-009 RWPR-029

CRUA-017

CRUA-

CRUA-025

CRUA-016

CRUA-018

CRUA-029

CRUA-028

CRUA-030

CRUA-032

CRUA-031

Unnamed Arroyo #2

CRUA-033

SSVAJO naIMn

lUNHiEDlNUCliEAR
E0RHQRAT1ON SITE



CRUA-007

CRUA-019

'^=CRUA-021

CRUA-022

'/ 4

L * i ras-

£



Land Use

Difficult Access Open Space
Navajo Resident

United Nuclear Corporation Worker

mSSSM

1,000 2,000 Feet

Kerr-McGee Ponds



7 JA-028



¦MK

",sCRUA-034l

Hk > * «

CRUA-035
CRUA-036

CRPA-U1

CRPA-014

CRPA-f 10

Rj pefne^Ca riyon Arroyo

CRPA-007

CRPA-006

Location:



CRPA-012
CRPA-011

CRPA-006

CRPA-009

..

CRPA-013

Soil Sample Locations

Surface Soil Sample (0-6 inches bgs)
A (includes all lab samples with
bottom depth < 6 inches bgs)

Subsurface Soil Sample (below 6 inches bgs)
I | (includes all lab samples with bottom
depth > 6 inches and < 72 inches bgs)

[__J Mine Lease Boundary

Kerr-McGee Ponds
Investigation Boundary

I I Kerr-McGee Ponds Fenceline

United Nuclear Corporation Site Boundary

Exposure Units

Church Rock Mine No. 1

Church Rock Mine No. 1 East

Kerr-McGee Ponds on the
Navajo Nation

Kerr-McGee Ponds on United
Nuclear Corporation Property

Arroyos on Navajo Nation

Arroyos on United Nuclear
Corporation Property

Site-Wide (for Ecological Risk)

1 inch = 600 feet

1:7,200

600	300	0

CRPA-004
CRPA-005

KMA-SS02

ARROYOS ON THE NAVAJO
NATION EXPOSURE UNIT
WITH SAMPLE LOCATIONS

Prepared For: U.S. EPA Region 9

\mi

%	

Prepared By:

TETRATECH

I Task Order No.:

Note:





bgs

Below ground surface



CR-1

Quivira Tronox Church Rock No.

1



Mine Site



CR-1E

Quivira Tronox Church Rock No.

1



East Mine Site



EU

Exposure unit



QUIVIRA MINES

Contract No.:

68HE0923D0002

3/8/2024

Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Kerr-McGee Kerr-McGee Corporation

Figure No.:


-------
¦united nuclear

CORPORATION SITE

CRUA-038

CRUA-039

CRPA-001

CRUA-037

CRPA-002

CRPA-003

Location:

S

Detail Area

1,000 2,000 Feet

Kerr-McGee Ponds



• mp	Jd!	 _ii

irV- . "-.v'

INi^

nKB»* Ji Wgy# (J

• ^»vv	'

PH — i.* :>• V : ,*fV< :v'A 1 • -

jftUnnamed'Arroyo #2|

-- V$'J

• *

Af'v

iVM IpV<& 'r £ LV®k'*

Irf¦ '• Xv,

If *rt5 • ' *	*

idfc	mv-;

V 'jJL u -»	w' «. . t„



[F^p'eljne CanyonTArroyo]

KMA-SS01

Soil Sample Locations

Surface Soil Sample (0-6 inches bgs)
A (includes all lab samples with
bottom depth < 6 inches bgs)

_ Subsurface Soil Sample (below 6 inches bgs)
|_| (includes all lab samples with bottom
depth > 6 inches and < 72 inches bgs)

Kerr-McGee Ponds
Investigation Boundary

I I Kerr-McGee Ponds Fenceline

United Nuclear Corporation Site Boundary

Exposure Units

Kerr-McGee Ponds on the
Navajo Nation

Kerr-McGee Ponds on United
Nuclear Corporation Property

Arroyos on Navajo Nation

Arroyos on United Nuclear
Corporation Property

Site-Wide (for Ecological Risk)

1 inch = 200 feet
1:2,400

200	100	0

ARROYOS ON UNITED NUCLEAR
CORPORATION PROPERTY

EXPOSURE UNIT
WITH SAMPLE LOCATIONS

Prepared For: U.S. EPA Region 9

C<- il .

siv • i

:>• p :i

.. ' '*
\ *

$ Q \

\WJ

%	

I n Prepared By:

TETRATECH

Task Order No.:

Note:

bgs

CR-1

CR-1E

Contract No.:

68HE0923D0002

• w- f J9

_JL	- - • /•••

Below ground surface
Quivira Tronox Church Rock No. 1 |
Mine Site

Quivira Tronox Church Rock No. 1
East Mine Site	M

Exposure unit

QUIVIRA MINES

3/8/2024

EU

Kerr-McGee Kerr-McGee Corporation

Coordinate System:

NAD 1983 State Plane New Mexico West
FIPS 3003 Feet Transverse Mercator

Figure No.:

	

	


-------
APPLICABLE HUMAN EXPOSURE SCENARIOS	ECOLOGICAL EXPOSURE SCENARIOS

United Nuclear

PRIMARY SOURCES OF PRIMARY RELEASE SECONDARY SOURCES SECONDARY RELEASE EXPOSURE Kee'da'whn teeh Kqq ei doo nahaazah dah Corporation	EXPOSURE Plants and Birds and

CONTAMINATION SOURCE MEDIA MECHANISMS OF CONTAMINATION MECHANISMS EXPOSURE MEDIA ROUTES (Full-Time Navajo Resident) (Difficult Access Open Space) Outdoor Worker	ROUTES Invertebrates Mammals

Background
Sources
(Natural In Situ
Material)

Waste Rock Piles

Former Detention
and Dewatering
Ponds, Former
Industrial Areas,
and Roads

Underground
Mine Workings

Exposed Ore, Rock,
Soil

r



\



Surface Mine





Waste



L



J

Subsurface Mine
Waste
(if brought to
surface)

Radioactive Decay

Radon Gas
Emanation

Wind Erosion

Erosion via
Storm or
Snowmelt Runoff

Mass Wasting

Ambient Air

Soil

Surface Water

i

Sediment

~~J—

Alluvial
Groundwater

Subsurface



	Leaching/

Ore Body

Dissolution

I I

. Mine Workings,
Porous or
Fracture Flow

Groundwater

Stormwater/
Snowmelt Runoff

Leaching/
Dissolution

Entrainment/
Deposition

Wells, Seeps, and
Springs
(Formation
Groundwater)

Plant Uptake/
Uptake through
Food Chain

Gamma Radiation
Air

Soil/Sediment
Water

Plants/Animals

Gamma Radiation

Air

Soil/Sediment

Surface Water

Groundwater

Cultivated Plants

Wild Plants

Animals

External Exposure

Inhalation

Incidental Ingestion
Dermal
Inhalation

Ingestion
Dermal
Inhalation

Ingestion
Dermal
Inhalation

Ingestion

Ingestion
Dermal
Inhalation

Ingestion

External Exposure

Inhalation

Dermal/Direct Contact
Ingestion
Trophic Transfer

Dermal/Direct Contact
Ingestion
Trophic Transfer

Ingestion

Ingestion
Trophic Transfer

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 inhalation of radon by humans or animals. Because radon is a gas and readily disperses in outdoor air, the risk in outdoor is minimal. Radon in indoor air is a potential risk for future residential receptors; however, radon
exposure is building-specific and the buildings are not currently present and, thus, cannot be evaluated. Furthermore, because radon is a known risk in the area, any future buildings would likely be constructed to mitigate this known risk.

2	The human health risk evaluation does not include ingestion of surface water or groundwater by humans or animals. Safe drinking water is supplied to residents in the Quivira Tronox Mines area. Wells used for livestock have been tested and are upgradient of the known groundwater contamination in the area.
The arroyos are mostly dry, and the ponds are dry since mine operations have stopped. If surface or groundwater use patterns change in the future, the risk from use should be evaluated.

3	The human health risk evaluation includes ingestion of select cultivated plants (crops) by this receptor. Scenario inputs were provided by the Navajo Nation Environmental Protection Agency (NNEPA) (2021).

4	The human health risk evaluation includes ingestion, dermal (metals only), and inhalation of select wild herbs and medicinal plants by this receptor. Scenario inputs were provided by NNEPA (2021).

5	The human health risk evaluation includes ingestion of home-raised animals (meat, milk, and eggs) and hunted animals (meat only) for this receptor. Scenario inputs were provided by NNEPA (2021).

6	The ecological risk evaluation includes evaluation of external radiation based on exposure to gamma-emitting radionuclides from contaminated soil and evaluation of internal radiation through plant uptake, incidental soil ingestion, and food web uptake (Los Alamos National Laboratory [LANL] 2015).

7	Potential exposures include inhalation of ambient air and air in burrows and underground mines. The ecological risk evaluation does not include evaluation of the inhalation pathway.

8	The ecological risk evaluation does not include evaluation of direct contact with or ingestion of surface water.

References:

Los Alamos National Laboratory (LANL). 2015. "Screening-Level Ecological Risk Assessment Methods." Revision 4. EP2015-0174. October 29.

Navajo Nation Environmental Protection Agency (NNEPA). 2021. "Navajo Tribe Provisional Reasonable Maximum Exposures RME for the Navajo Risk Assessments." Draft. September 15.

Figure C-10. Quivira Mines Risk Assessment Conceptual Site Model


-------
TABLES


-------
Table C-1. Soil Results Data Summary and Contaminant of Potential Concern Screening

Constituent of
Interest3

Detection
Frequency13

Units

Minimum
Detected
Concentration
(qualifier)b

Maximum
Detected
Concentration
(qualifier)b

Location of
Maximum
Concentration13

Depth of
Maximum
Concentration
(inches bgs)b

COPC
Screening
Level0

Include
Constituent
as a
COPC?d

Radionuclides 8

Uranium-238

41 / 160

pCi/g

0.7

52.1

KMP-SB28-0042-0048-01

42-48

0.032

Yes

Uranium-234

24 / 24

pCi/g

0.7

49.4

KMP-SB28-0060-0066-02

60-66

0.028

Yes

Thorium-230

41 / 41

pCi/g

0.76

92 M3

CELI-502 SS3 3-4.5

36-54

0.13

Yes

Radium-226

797 / 797

pCi/g

0.41 LT,G

468 M3,G

C1LP-401 SS4 4.5-6

54-72

0.00053

Yes

Metals

Aluminum

126 / 126

mg/kg

1,400

9,600

KMP-SB24-0048-0054-01

48-54

1,710

Yes

Antimony

125 / 126

mg/kg

0.038 J

0.26

KMP-SS75-0000-0003-02

0-3

0.45

No

Arsenic

175 / 175

mg/kg

2

11

KMP-12-00

0-2

0.025

Yes

Barium

169 / 169

mg/kg

20

420

CR1E-SS15-0000-0003-01

0-3

197

Yes

Beryllium

126 / 126

mg/kg

0.2

1.0

CR1E-SS12-0000-0003-01

0-3

3.5

No

Cadmium

154 / 169

mg/kg

0.043 J

0.25

CR1-SS21-0000-0003-01

0-3

0.052

Yes

Chromium

169 / 169

mg/kg

2.3

24 J

KMP-SS75-0000-0003-02

0-3

0.027

Yes

Cobalt

126 / 126

mg/kg

2.5

10

CR1E-SS12-0000-0003-01

0-3

0.30

Yes

Copper

126 / 126

mg/kg

3.2

21

CR1-SS21-0000-0003-01

0-3

8.0

Yes

Iron

126 / 126

mg/kg

5,000

23,000

CR1E-SS10-0000-0003-01

0-3

865

Yes

Lead

169 / 169

mg/kg

4.8

130 J

KMP-SS75-0000-0003-02

0-3

200

No

Manganese

126 / 126

mg/kg

89

400

KMA-SS02-0012-0018-01

12-18

4.5

Yes

Molybdenum

165 / 175

mg/kg

0.15 J

1.8

CELI-502 SS9

36-54

1.5

Yes

Nickel

126 / 126

mg/kg

2.7

20

CR1E-SS07-0000-0003-01

0-3

28

No

Selenium

170 / 175

mg/kg

0.47 J

37

KMP-16-18

18-24

1.8

Yes

Silver

29 / 169

mg/kg

0.057 J

0.19

KMP-22-18

18-24

2.3

No

Thallium

126 / 126

mg/kg

0.048

0.22

CR1E-SS12-0000-0003-01

0-3

0.0098

Yes

Uranium

226 / 226

mg/kg

0.37

210

CELI-502 SS3 3-4.5

36-54

0.32

Yes

Vanadium

175 / 175

mg/kg

5.4

58

KMP-16-18

18-24

8.2

Yes

Zinc

126 / 126

mg/kg

18

95

KMP-SS75-0000-0003-01

0-3

174

No

Notes:

a Bolded constituents are selected as human health COPCs because based on the maximum detected concentration, the cancer risk is greater than one in one

million (1E-06) or noncancer hazard quotient is greater than 0.1.
b Includes soil and sediment samples collected from all depths from within the risk assessment boundary at all exposure units.

c The COPC screening levels are calculated using the NAUM Risk Calculator (USEPA 2024c) for the Kee'da'whn teeh (full-time Navajo resident) using a target risk of

1E-06 and target hazard quotient of 0.1 except for lead. The lead screening value is based on the recommended RSL for residential soil (USEPA 2024a).
d A constituent 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 not in SE, site data for uranium-238, uranium-234, and thorium-230 in conjunction with radium-226 in SE toxicity values can be used to calculate the
risk for the entire U-238 decay chain.

Page 1 of 2


-------
Table C-1. Soil Results Data Summary and Contaminant of Potential Concern Screening

Notes (Continued):

f In the absence of speciated chromium data, chromium is evaluated using the assumption that it is 100 percent hexavalent chromium (USEPA 2024b).
No speciated chromium data are available.

bgs

Below ground surface

COPC

Contaminant of potential concern

G

Sample density differs by more than 15 percent of the LCS density

J

Estimated concentration

LCS

Laboratory control sample

LT

Less than

M3

The requested MDC was not met, but the reported activity is greater than the reported MDC

MDC

Minimum detectable concentration

mg/kg

Milligram per kilogram

NAUM

Navajo abandoned uranium mine

pCi/g

Picocurie per gram

RSL

Regional screening level

USEPA

U.S. Environmental Protection Agency

References:



U.S. Environmental Protection Agency (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. "Navajo Abandoned Uranium Mines Risk Assessment Methodology." Draft Final. March.

USEPA. 2024c. "Navajo Abandoned Uranium Mine Risk Calculator." Version 1.03. March.

Page 2 of 2


-------
Table C-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)3

Number of Subsurface Soil
Samples
(0-72 inches bgs)3

Quivira Tronox Church
Rock Mine
No. 1

Kee'da'whn teeh
(Full-Time Navajo
Resident)

Kcb
Kcda
Alluvium

Waste Piles
TENORM

53.3

Radium-226: 142
Uranium-238, Uranium-234, and
Thorium-230: 3
Uranium: 82
Metals: 30

Radium-226: 302
Uranium-238, Uranium-234, and
Thorium-230: 3
Uranium: 82
Arsenic, Molybdenum, Selenium,
Vanadium: 32
All Other Metals: 30

Quivira Tronox Church
Rock Mine
No. 1 East

Kee'da'whn teeh
(Full-Time Navajo
Resident)

Kcc
Kmm
Alluvium

Waste Piles
TENORM

13.9

Radium-226: 65
Uranium-238, Uranium-234, and
Thorium-230: 2
Metals: 15

Radium-226: 123
Uranium-238, Uranium-234, and

Thorium-230: 2
Arsenic, Molybdenum, Selenium,
Uranium, Vanadium: 19
All Other Metals: 15

Kerr-McGee Ponds on
the Navajo Nation

Kee'da'whn teeh
(Full-Time Navajo
Resident)

Kmm
Alluvium

TENORM

2.23

Radium-226: 5
Uranium-238, Uranium-234, and
Thorium-230: 1
Arsenic, Barium, Cadmium,
Chromium, Lead, Molybdenum,
Selenium, Silver, Uranium,
Vanadium: 5
All Other Metals: 3

Radium-226: 7
Uranium-238, Uranium-234,

Thorium-230: 1
Arsenic, Barium, Cadmium,
Chromium, Lead, Molybdenum,
Selenium, Silver, Uranium,
Vanadium: 7
All Other Metals: 5

Kerr-McGee Ponds on

United Nuclear
Corporation Property

United Nuclear
Corporation Outdoor
Worker

Kmm
Alluvium

TENORM

19.2

Radium-226: 54
Uranium-238, Uranium-234, and
Thorium-230: 4
Arsenic, Barium, Cadmium,
Chromium, Lead, Molybdenum,
Selenium, Silver, Uranium,
Vanadium: 54
All Other Metals: 35

Radium-226: 96
Uranium-238, Uranium-234 and
Thorium-230: 8
Arsenic, Barium, Cadmium,
Chromium, Lead, Molybdenum,
Selenium, Silver, Uranium,
Vanadium: 96
All Other Metals: 61

Arroyos on the Navajo
Nation

Kqq ei doo nahaazah
dah (Difficult Access
Open Space)

Alluvium

TENORM

16.1

Radium-226: 94
Uranium: 7
Arsenic, Barium, Cadmium,
Chromium, Lead, Molybdenum,
Selenium, Silver, Vanadium: 3
All Other Metals: 1

Radium-226: 135
Uranium: 9
Arsenic, Barium, Cadmium,
Chromium, Lead, Molybdenum,
Selenium, Silver, Vanadium: 4
All Other Metals: 2

Page 1 of 2


-------
Table C-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)3

Number of Subsurface Soil
Samples
(0-72 inches bgs)3

Arroyos on United
Nuclear Corporation
Property

United Nuclear
Corporation Outdoor
Worker

Alluvium

TENORM

3.25

Radium-226: 13
Metals: 1

Radium-226: 20
Metals: 2

Ecological Risk Assessment

Site-Wide

Ecological Receptors

Kcb
Kcc
Kcda
Kmm
Alluvium

Entire Site

137

Radium-226: 375
Uranium-238, Uranium-234, and
Thorium-230: 10
Uranium: 164
Arsenic, Barium, Cadmium,
Chromium, Lead, Molybdenum,
Selenium, Silver, Vanadium: 108
All Other Metals: 85

Radium-226: 683
Uranium-238, Uranium-234, and
Thorium-230: 14
Uranium: 213
Arsenic, Molybdenum, Selenium,
Vanadium: 160
Barium, Cadmium, Chromium,
Lead, Silver: 154
All Other Metals: 115

Notes:

a The total number of samples per area used in the risk assessment.

bgs	Below ground surface

Kcb	Bartlett Barren Member

Kcc	Crevasse Canyon Formation

Kcda	Dalton Sandstone Member

Kerr-McGee	Kerr-McGee Corporation

Kmm	Mulatto Tongue of Mancos Shale

TENORM	Technologically enhanced naturally occurring radioactive material

Page 2 of 2


-------
Table C-3. Human Health Exposure Parameters

Input Parameter

Symbol

Units

Receptor

Kee'da'whii teeh
(Full-time Navajo
Resident)3

Kqq ei doo
nahaazah dah
(Difficult Access
Open Space)3

UNC Outdoor
Workerb

Common Parameters

Exposure Duration - Adult

ED

years

69

69

25

Exposure Duration - Child

EDc

years

6

6

—

Exposure Duration - Lifetime Total

EDa

years

75

75

25

Exposure Time - Lifetime Total

t

years

75

75

25

Averaging Time - Cancer

ATc

days

27,375

27,375

25,550

Averaging Time - Noncancer - Adult

ATnc

days

25,185

25,185

9,125

Averaging Time - Noncancer - Child

ATnc

days

2,190

2,190

—

Exposure Frequency - Adult

EFa

days/year

350

30

100

Exposure Frequency - Child

EFc

days/year

350

30

—

Consumption Exposure Frequency for Animal and
Plant Products - Adult

CEFa

days/year

350

30

0

Consumption Exposure Frequency for Animal and
Plant Products - Child

CEFc

days/year

350

30

-

Body Weight - Adult

BWa

kg

80

80

80

Body Weight - Child

BWc

kg

15

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

fl/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

27.03

Decay Constant

A

1/year

Radionuclide-specific

Soil Ingestion Parameters

Onsite Soil Ingestion Rate - Adult

IRSa

mg/day

360

15

100

Onsite Soil Ingestion Rate - Child

IRSc

mg/day

400

17

-

Page 1 of 6


-------
Table C-3. Human Health Exposure Parameters

Input Parameter

Symbol

Units

Receptor

Kee'da'whii teeh
(Full-time Navajo
Resident)3

Kqq ei doo
nahaazah dah
(Difficult Access
Open Space)3

UNC Outdoor
Workerb

Dust Inhalation Parameters

Inhalation Rate when Exposed - Adult

IRAres-a

m3/day

25

25

20

Inhalation Rate when Exposed - Child

IRAres-c

m3/day

10

10

-

Exposure Time - Adult

ETa

hours/day

22

1

8

Exposure Time - Child

ETc

hours/day

22

1

—

City/Climatic Zone

—

—

Albuquerque, New Mexico

Mean Annual Wind Speed

Um

m/s

4.02

Areal extent of site surface soil contamination

As

acres

0.5

Fraction of Vegetative Cover

V

—

0.5

Particulate Emission Factor

PEF

m3/kg

6.61 E+09

Radiation External Exposure Parameters

Gamma Shielding Factor - Outdoor

GSF0

-

1

1

1

Gamma Shielding Factor - Indoor

GSFj

0.7

-

-

Exposure Time on Site Outdoors - Adult

ETa.0

hours/day

12

1

8

Exposure Time on Site Indoors - Adult

ETaH

10

1

0

Exposure Time on Site Outdoors - Child

ETC.0

hours/day

12

1

-

Exposure Time on Site Indoors - Child

o

1—
LU

10

1

-

Metals Dermal Exposure Parameters

Surface Area - Adult

SAa

cm2/day

6,032

6,032

6,032

Surface Area - Child

SAc

cm2/day

2,373

2,373

-

Adherence Factor - Adult

AFa

mg/cm2

0.07

0.07

0.07

Adherence Factor - Child

AFc

mg/cm2

0.2

0.2

-

Plant Consumption Parameters

Total Plant Ingestion Rate - Adult

IRa

g/day

834

834

—

Total Plant Ingestion Rate - Child

IRc

g/day

417

417

—

Produce
Contaminated
Fraction

Annual Average

CFproduce

—

0.55

—

—

Fall

—

—

0.75

—

—

Winter

—

—

0.5

—

—

Spring

—

—

0.3

—

—

Summer

—

—

0.65

—

—

Herbs/medicinal

CFmedicinal

-

100%

8.3%

-

Page 2 of 6


-------
Table C-3. Human Health Exposure Parameters









Receptor

Input Parameter

Symbol

Units

Kee'da'whii teeh
(Full-time Navajo
Resident)3

Kqq ei doo
nahaazah dah
(Difficult Access
Open Space)3

UNC Outdoor
Workerb

Plant Consumption Parameters (continued)



Corn - White



—

10%

—

—



Corn - Blue



—

10%

—

—



Corn - Yellow



—

5%

—

—



Corn - Red Speckled



—

3%

—

—



Corn - Sweet Corn



—

2%

—

—



Squash - Pumpkin



—

2%

—

—



Squash - Other Squash



—

8%

—

—



Melons - Watermelon



—

5%

—

—



Melons - Cantaloupe



—

5%

—

—



Tree Fruit - Apples



—

5%

—

—

Diet Fraction

Tree Fruit - Apricots

DF

—

5%

—

—



Tree Fruit - Peaches



—

5%

—

—



Other Vegetables - Beans



—

10%

—

—



Other Vegetables - Brussels
Sprouts



-

2%

-

-



Other Vegetables - Cucumbers



—

2%

—

—



Other Vegetables - Tomatoes



—

2%

—

—



Other Vegetables - Chili



—

5%

—

—



Other Vegetables - Onions



—

2%

—

—



Other Vegetables - Potatoes



—

2%

—

—



Herbs and Medicinal



—

10%

10%

—

Plant-Soil Transfer Factor

Bvwet

pCi/g-fresh plant
per pCi/g-dry soil

Plant-specific based on plant typec

-

Mass-Loading Factor

MLF

g-dry soil per
q-fresh plant

Plant-specific based on plant typec

-

Page 3 of 6


-------
Table C-3. Human Health Exposure Parameters









Receptor

Input Parameter

Symbol

Units

Kee'da'whii teeh
(Full-time Navajo
Resident)3

Kqq ei doo
nahaazah dah
(Difficult Access
Open Space)3

UNC Outdoor
Workerb

Animal Consumption Parameters

Total Animal Ingestion Rate - Adult

IRa

g/day

983

983

—

Total Animal Ingestion Rate - Child

IRc

g/day

491.5

491.5

—



Chicken

CF

—

5%

5%

—



Chicken Eggs

CF

—

75%

75%

—



Beef

CF

—

25%

25%

—



Milk - Cow

CF

—

1%

1%

—



Pig

CF

—

5%

5%

—



Goat

CF

—

100%

100%

—



Milk - Goat

CF

—

100%

100%

—

Contaminated
Fraction

Sheep

CF

—

90%

90%

—

Milk - Sheep

CF

—

90%

90%

—

Horse

CF

—

100%

100%

—



Domesticated Turkey

CF

—

5%

5%

—



Wild Turkey

CF

—

2%

2%

—



Deer

CF

—

2%

2%

—



Elk

CF

—

2%

2%

—



Rabbit

CF

—

100%

100%

—



Prairie Dog

CF

—

100%

100%

—



Badger

CF

—

100%

100%

—



Chicken

DF

—

20%

20%

—



Chicken Eggs

DF

—

7%

7%

—



Beef

DF

—

25%

25%

—



Milk - Cow

DF

—

6%

6%

—



Pig

DF

—

7%

7%

—



Goat

DF

—

5%

5%

—



Milk - Goat

DF

—

1%

1%

—



Sheep

DF

—

20%

20%

—

Diet Fraction

Milk - Sheep

DF

—

0%

0%

—



Horse

DF

—

1%

1%

—



Domesticated Turkey

DF

—

0.3%

0.3%

—



Wild Turkey

DF

—

0.2%

0.2%

—



Deer

DF

—

3%

3%

—



Elk

DF

—

3%

3%

—



Rabbit

DF

—

1%

1%

—



Prairie Dog

DF

—

1%

1%

—



Badger

DF

-

1%

1%

—

Page 4 of 6


-------
Table C-3. Human Health Exposure Parameters

Input Parameter

Symbol

Units

Receptor

Kee'da'whii teeh
(Full-time Navajo
Resident)3

Kqq ei doo
nahaazah dah
(Difficult Access
Open Space)3

UNC Outdoor
Workerb

Animal Consumption Parameters

continued)

Mass-Loading Factor for Pasture

MLFpasture

g-dry soil per
a-drv plant

0.25

-

Density of Milk

pm

kg/L

1.03

-

Soil Intake Rate

Qs

kg/day

Animal-specificd

-

Fodder Intake Rate

Qp

kg/day

Animal-specificd

-

Bioaccumulation Factor for Metals

Ba

day/kg

Animal-specificd

-

Other Dine Lifeways 8

Age-Adjusted
Ingestion Rate
of Medicinal
Plants

Navajo Tea

IFadj

g/day

1.0

1.0

—

Sumac (Skunkbush and Other)

IFadj

g/day

6.4

6.4

—

Soaptree Yucca

IFadj

g/day

6.4

6.4

—

Sagebrush

IFadj

g/day

12.9

12.9

—

Corn Pollen and Other Corn

IFadj

g/day

19.3

19.3

—

Other Plant Types

IFadj

g/day

6.4

6.4

—

Adult Dermal
Rate of
Medicinal Plants

Navajo Tea

DCRa

g/day

2.1

2.1

—

Sumac (Skunkbush and Other)

DCRa

g/day

38.6

38.6

—

Soaptree Yucca

DCRa

g/day

38.6

38.6

—

Sagebrush

DCRa

g/day

12.9

12.9

—

Corn Pollen and Other Corn

DCRa

g/day

38.6

38.6

—

Other Plant Types

DCRa

g/day

6.4

6.4

—

Mass of Plant
Available for
Inhalation

Sagebrush

IMa

g/day

25.7

25.7

—

Corn Pollen and Other Corn

IMa

g/day

12.9

12.9

—

Other Plant Types

IMa

g/day

6.4

6.4

—

Inhalation
Fraction

Sagebrush

IF

—

10%

10%

—

Corn Pollen and Other Corn

IF

—

10%

10%

—

Other Plant Types

IF

-

10%

10%

-

Page 5 of 6


-------
Table C-3. Human Health Exposure Parameters

Notes:

a Exposure inputs for the Navajo receptors provided by NNEPA (2021).

b Default values for the UNC outdoor worker receptor are from the PRG Calculator (USEPA 2023b) and RSL Calculator (USEPA 2023c) except for days per week

^l^l^nl^eaficll^pGts^reyrom^ppln'Six feaof&e^avajo^ln8oned Uranium Mines Risk Assessment Methodology" (USEPA 2024b).
d Animal-specific inputs are from Appendix B of the "Navajo Abandoned Uranium Mines Risk Assessment Methodology" (USEPA 2024b).
e Input parameters for Other Dine Lifeways were only provided for adult receptors (NNEPA 2021).

-

Not applicable

m/s

Meter per second

cm2/day

Square centimeter per day

m3/day

Cubic meter per day

day/kg

Day per kilogram

m3/kg

Cubic meter per kilogram

g

Gram

mg/cm2

Milligram per square centimeter

g/day

Gram per day

mg/day

Milligram per day

g/kg

Gram per kilogram

NNEPA

Navajo Nation Environmental Protection Agency

g/mg

Gram per milligram

pCi/Bq

Picocurie per becquerel

kg

Kilogram

pCi/g

Picocurie per gram

kg/day

Kilogram per day

PRG

Preliminary remediation goal

kg/g

Kilogram per gram

RSL

Regional screening level

kg/L

Kilogram per liter

UNC

United Nuclear Corporation

kg/mg

Kilogram per milligram

USEPA

U.S. Environmental Protection Agency

References:







Navajo Nation Environmental Protection Agency (NNEPA). 2021. "Navajo Tribe Provisional Reasonable Maximum Exposures for the Navajo Risk Assessments."

yr§ft.^9^t5f¥fflM)'t^l5Protection Agency (USEPA). 2023b. "Preliminary Remediation Goals for Radionuclides (PRG)." September.

https://epa-prgs.ornl.gov/cgi-bin/radionuclides/rprg_search.

USEPA. 2023c. "Regional Screening Levels (RSLs)." November, https://epa-prgs.ornl.gov/cgi-bin/chemicals/csl_search.

USEPA. 2024b. "Navajo Abandoned Uranium Mines Risk Assessment Methodology." Draft Final. March.

Page 6 of 6


-------
Table C-4. Exposure Point Concentrations for Human Health Risk Assessment

Church Rock Mine No. 1

COPCa

Units

Detection
Frequency

Number of

High
Nondetect
Results'3

Maximum
Concentration
(qualifier)

Location of Maximum
Concentration

Arithmetic
Mean0

UCL95 /
Distribution1

Exposure Point Concentration

Value6

Statistic®

Methodf

Surface Soil (0-6 inches bgs)

Uranium-238

pCi/g

3 / 3

-

1.12

CR1-SS16-0000-0003-01

0.987

-

-

1.1

Maximum

(1)

Uranium-234

pCi/g

3 / 3

-

1.21

CR1-SS16-0000-0003-01

0.977

-

-

1.2

Maximum

(1)

Thorium-230

pCi/g

3 / 3

-

1.71

CR1-SS15-0000-0003-01

1.343

-

-

1.7

Maximum

(1)

Radium-226

pCi/g

150 / 150

-

48.5 M3

RWPR-SS-002 (1.5-2)

5.464

6.68

NP

6.7

UCL95

(14)

Aluminum

mg/kg

30 / 30

-

7,000

CR1-SS21-0000-0003-01

4,267

4,633

N

4,600

UCL95

(2)

Arsenic

mg/kg

30 / 30

-

6.1

CR1-SS25-0000-0003-01,
CR1-SS26-0000-0003-01

4.613

4.904

N

4.9

UCL95

(2)

Barium

mg/kg

30 / 30

-

330

CR1-SS24-0000-0003-01

92.13

110.5

NP

110

UCL95

(14)

Cadmium

mg/kg

29 / 30

0

0.25

CR1-SS21-0000-0003-01

0.129

0.144

N

0.14

UCL95

(3)

Chromium

mg/kg

30 / 30

-

13

CR1-SS32-0000-0003-01

5.257

5.98

LN

6.0

UCL95

(14)

Cobalt

mg/kg

30 / 30

-

8.3

CR1-SS21-0000-0003-01

5.63

6.066

N

6.1

UCL95

(2)

Copper

mg/kg

30 / 30

-

21

CR1-SS21-0000-0003-01

10.46

11.85

N

12

UCL95

(2)

Iron

mg/kg

30 / 30

-

13,000

CR1-SS09-0000-0003-01,
CR1-SS21-0000-0003-01,
CR1-SS26-0000-0003-01

10,163

10726

N

11,000

UCL95

(2)

Manganese

mg/kg

30 / 30

-

200

CR1-SS24-0000-0003-01,
CR1-SS25-0000-0003-01

151.6

160.4

N

160

UCL95

(2)

Molybdenum

mg/kg

30 / 30

-

1 J

CR1-SS26-0000-0003-01

0.288

0.321

N

0.32

UCL95

(2)

Selenium

mg/kg

30 / 30

-

14

CR1-SS28-0000-0003-01

2

3.38

NP

3.4

UCL95

(14)

Thallium

mg/kg

30 / 30

-

0.21

CR1-SS21-0000-0003-01

0.125

0.137

N

0.14

UCL95

(2)

Uranium

mg/kg

86 / 86

-

61

RWPR-SS-002 (1.5-2)

5.504

7.315

LN

7.3

UCL95

(14)

Vanadium

mg/kg

30 / 30

-

20

CR1-SS26-0000-0003-01,
CR1-SS28-0000-0003-01

13.34

14.33

N

14

UCL95

(2)

Page 1 of 13


-------
Table C-4. Exposure Point Concentrations for Human Health Risk Assessment

Church Rock Mine No. 1

COPCa

Units

Detection
Frequency

Number of

High
Nondetect
Results'3

Maximum
Concentration
(qualifier)

Location of Maximum
Concentration

Arithmetic
Mean0

UCL95 /
Distribution1

Exposure Point Concentration

Value6

Statistic®

Methodf

Subsurface Soil (0-72 inches bgs)

Uranium-238

pCi/g

3 / 3

-

1.12

CR1-SS16-0000-0003-01

0.987

-

-

1.1

Maximum

(1)

Uranium-234

pCi/g

3 / 3

-

1.21

CR1-SS16-0000-0003-01

0.977

-

-

1.2

Maximum

(1)

Thorium-230

pCi/g

3 / 3

-

1.71

CR1-SS15-0000-0003-01

1.343

-

-

1.7

Maximum

(1)

Radium-226

pCi/g

302 / 302

-

468 M3,G

C1LP-401 SS4 4.5-6

13.000

17.15

NP

17

UCL95

(14)

Aluminum

mg/kg

30 / 30

-

7,000

CR1-SS21-0000-0003-01

4,267

4,633

N

4,600

UCL95

(2)

Arsenic

mg/kg

32 / 32

-

6.1

CR1-SS25-0000-0003-01,
CR1-SS26-0000-0003-01

4.544

4.827

N

4.8

UCL95

(2)

Barium

mg/kg

30 / 30

-

330

CR1-SS24-0000-0003-01

92.13

110.5

NP

110

UCL95

(14)

Cadmium

mg/kg

29 / 30

0

0.25

CR1-SS21-0000-0003-01

0.129

0.144

N

0.14

UCL95

(3)

Chromium

mg/kg

30 / 30

-

13

CR1-SS32-0000-0003-01

5.257

5.98

LN

6.0

UCL95

(14)

Cobalt

mg/kg

30 / 30

-

8.3

CR1-SS21-0000-0003-01

5.63

6.066

N

6.1

UCL95

(2)

Copper

mg/kg

30 / 30

-

21

CR1-SS21-0000-0003-01

10.46

11.85

N

12

UCL95

(2)

Iron

mg/kg

30 / 30

-

13,000

CR1-SS09-0000-0003-01,
CR1-SS21-0000-0003-01,
CR1-SS26-0000-0003-01

10,163

10726

N

11,000

UCL95

(2)

Manganese

mg/kg

30 / 30

-

200

CR1-SS24-0000-0003-01,
CR1-SS25-0000-0003-01

151.6

160.4

N

160

UCL95

(2)

Molybdenum

mg/kg

30 / 32

2

1 J

CR1-SS26-0000-0003-01

0

0

N

0.32

UCL95

(3)

Selenium

mg/kg

30 / 32

0

14

CR1-SS28-0000-0003-01

2

3.138

NP

3.1

UCL95

(15)

Thallium

mg/kg

30 / 30

-

0.21

CR1-SS21-0000-0003-01

0.125

0.137

N

0.14

UCL95

(2)

Uranium

mg/kg

82 / 82

-

61

RWPR-SS-002 (1.5-2)

5.504

7.315

LN

7.3

UCL95

(14)

Vanadium

mg/kg

32 / 32

-

20

CR1-SS26-0000-0003-01,
CR1-SS28-0000-0003-01

13.15

14.1

N

14

UCL95

(2)

Page 2 of 13


-------
Table C-4. Exposure Point Concentrations for Human Health Risk Assessment

Church Rock Mine No. 1 East

COPCa

Units

Detection
Frequency

Number of

High
Nondetect
Results'3

Maximum
Concentration
(qualifier)

Location of Maximum
Concentration

Arithmetic
Mean0

UCL95 /
Distribution1

Exposure Point Concentration

Value6

Statistic®

Methodf

Surface Soil (0-6 inches bgs)

Uranium-238

pCi/g

2 / 2

-

1.27

CR1E-SS07-0000-0003-01

1.115

-

-

1.3

Maximum

(1)

Uranium-234

pCi/g

2 / 2

-

1.35

CR1E-SS07-0000-0003-01

1.195

-

-

1.4

Maximum

(1)

Thorium-230

pCi/g

2 / 2

-

3.57

CR1E-SS07-0000-0003-01

2.365

-

-

3.6

Maximum

(1)

Radium-226

pCi/g

65 / 65

-

86.3 M3,G

CESS-041 (2-6)

6.156

9.31

NP

9.3

UCL95

(14)

Aluminum

mg/kg

14 / 14

-

8,400

CR1E-SS10-0000-0003-01

5,621

6,257

NP

6,300

UCL95

(14)

Arsenic

mg/kg

14 / 14

-

10

CR1E-SS10-0000-0003-01

5.714

6.616

N

6.6

UCL95

(2)

Barium

mg/kg

14 / 14

-

420

CR1E-SS15-0000-0003-01

116.4

161.9

LN

160

UCL95

(14)

Cadmium

mg/kg

14 / 14

-

0.23

CR1E-SS12-0000-0003-01

0.106

0.13

N

0.13

UCL95

(2)

Chromium

mg/kg

14 / 14

-

22

CR1E-SS07-0000-0003-01

8.0

10.1

N

10

UCL95

(2)

Cobalt

mg/kg

14 / 14

-

10

CR1E-SS12-0000-0003-01

6.071

6.927

N

6.9

UCL95

(2)

Copper

mg/kg

14 / 14

-

19

CR1E-SS12-0000-0003-01

10.91

12.73

N

13

UCL95

(2)

Iron

mg/kg

14 / 14

-

23,000

CR1E-SS10-0000-0003-01

13,907

15786

NP

16,000

UCL95

(14)

Manganese

mg/kg

14 / 14

-

290

CR1E-SS12-0000-0003-01

181.4

202.1

NP

200

UCL95

(14)

Molybdenum

mg/kg

14 / 14

-

0.40

CR1E-SS12-0000-0003-01,
CR1E-SS15-0000-0003-01

0.27

0.308

N

0.31

UCL95

(2)

Selenium

mg/kg

14 / 14

-

5

CR1E-SS14-0000-0003-01

2

2.957

G

3.0

UCL95

(4)

Thallium

mg/kg

14 / 14

-

0.22

CR1E-SS12-0000-0003-01

0.137

0.156

N

0.16

UCL95

(2)

Uranium

mg/kg

14 / 14

-

6.3

CR1E-SS17-0000-0003-01

2.727

3.58

N

3.6

UCL95

(2)

Vanadium

mg/kg

14 / 14

-

23

CR1E-SS12-0000-0003-01

14.86

16.35

N

16

UCL95

(2)

Page 3 of 13


-------
Table C-4. Exposure Point Concentrations for Human Health Risk Assessment

Church Rock Mine No. 1 East

COPCa

Units

Detection
Frequency

Number of

High
Nondetect
Results'3

Maximum
Concentration
(qualifier)

Location of Maximum
Concentration

Arithmetic
Mean0

UCL95 /
Distribution1

Exposure Point Concentration

Value6

Statistic®

Methodf

Subsurface Soil (0-72 inches bgs)

Uranium-238

pCi/g

2 / 2

-

1.27

CR1E-SS07-0000-0003-01

1.115

-

-

1.3

Maximum

(1)

Uranium-234

pCi/g

2 / 2

-

1.35

CR1E-SS07-0000-0003-01

1.195

-

-

1.4

Maximum

(1)

Thorium-230

pCi/g

2 / 2

-

3.57

CR1E-SS07-0000-0003-01

2.365

-

-

3.6

Maximum

(1)

Radium-226

pCi/g

121 / 121

-

429 M3

CELA-039 (27-33)

31.370

43.02

NP

43.0

UCL99

(14)

Aluminum

mg/kg

14 / 14

-

8,400

CR1E-SS10-0000-0003-01

5,621

6,257

NP

6,300

UCL95

(14)

Arsenic

mg/kg

18 / 18

-

10

CR1E-SS10-0000-0003-01

5.456

6.292

N

6.3

UCL95

(2)

Barium

mg/kg

14 / 14

-

420

CR1E-SS15-0000-0003-01

116.4

161.9

LN

160

UCL95

(14)

Cadmium

mg/kg

14 / 14

-

0.23

CR1E-SS12-0000-0003-01

0.106

0.13

N

0.13

UCL95

(2)

Chromium

mg/kg

14 / 14

-

22

CR1E-SS07-0000-0003-01

8.0

10.1

N

10.00

UCL95

(2)

Cobalt

mg/kg

14 / 14

-

10

CR1E-SS12-0000-0003-01

6.071

6.927

N

6.9

UCL95

(2)

Copper

mg/kg

14 / 14

-

19

CR1E-SS12-0000-0003-01

10.91

12.73

N

13

UCL95

(2)

Iron

mg/kg

14 / 14

-

23,000

CR1E-SS10-0000-0003-01

13,907

15786

NP

16,000

UCL95

(14)

Manganese

mg/kg

14 / 14

-

290

CR1E-SS12-0000-0003-01

181.4

202.1

NP

200

UCL95

(14)

Molybdenum

mg/kg

15 / 18

0

1.8

CR1E-SS12-0000-0003-01,
CR1E-SS15-0000-0003-01

0.355

0.513

N

0.51

UCL95

(15)

Selenium

mg/kg

15 / 18

0

23

CR1E-SS14-0000-0003-01

3

5.399

G

5.4

UCL95

(15)

Thallium

mg/kg

14 / 14

-

0.22

CR1E-SS12-0000-0003-01

0.137

0.156

N

0.16

UCL95

(2)

Uranium

mg/kg

16 / 16

-

210

CELI-502 SS3 3-4.5

20.07

41.94

N

42

UCL95

(14)

Vanadium

mg/kg

18 / 18

-

28

CELI-502 SS9

15.89

17.74

N

18

UCL95

(2)

Page 4 of 13


-------
Table C-4. Exposure Point Concentrations for Human Health Risk Assessment

Kerr-McGee Ponds on the Navajo Nation

COPCa

Units

Detection
Frequency

Number of

High
Nondetect
Results'3

Maximum
Concentration
(qualifier)

Location of Maximum
Concentration

Arithmetic
Meanc

UCL95 /
Distribution1

Exposure Point Concentration

Value6

Statistic®

Methodf

Surface Soil (0-6 inches bgs)

Uranium-238

pCi/g

1 / 1

-

1.13

KM P-SS74-0000-0003-01

-

-

-

1.1

Maximum

(1)

Uranium-234

pCi/g

1 / 1

-

0.97

KM P-SS74-0000-0003-01

-

-

-

1.0

Maximum

(1)

Thorium-230

pCi/g

1 / 1

-

2.04

KMP-SS74-0000-0003-01

-

-

-

2.0

Maximum

(1)

Radium-226

pCi/g

5 / 5

-

9.3 J

KM P-SB44-0000-0006-01

5.292

-

-

9.3

Maximum

(1)

Aluminum

mg/kg

3 / 3

-

6,900

KM P-SS49-0000-0003-02

6,333

-

-

6,900

Maximum

(1)

Arsenic

mg/kg

5 / 5

-

5.9

KM P-SS49-0000-0003-02

5.46

-

-

5.9

Maximum

(1)

Barium

mg/kg

5 / 5

-

82

KM P-SB44-0000-0006-01

71.4

-

-

82

Maximum

(1)

Cadmium

mg/kg

5 / 5

-

0.16 J

KMP-SB44-0000-0006-01

0.11

-

-

0.16

Maximum

(1)

Chromium

mg/kg

5 / 5

-

8.2

KMP-14D-00

7.22

-

-

8.2

Maximum

(1)

Cobalt

mg/kg

3 / 3

-

5.2

KMP-SS49-0000-0003-02

4.8

-

-

5.2

Maximum

(1)

Copper

mg/kg

3 / 3

-

11

KMP-SB44-0000-0006-01

9.233

-

-

11

Maximum

(1)

Iron

mg/kg

3 / 3

-

15,000

KM P-SS49-0000-0003-02

13,667

-

-

15,000

Maximum

(1)

Manganese

mg/kg

3 / 3

-

230

KM P-SB44-0000-0006-01

213.3

-

-

230

Maximum

(1)

Molybdenum

mg/kg

5 / 5

-

1 J

KMP-14-00

0.436

-

-

0.55

Maximum

(1)

Selenium

mg/kg

5 / 5

-

2.9

KMP-14D-00

2.080

-

-

2.9

Maximum

(1)

Thallium

mg/kg

3 / 3

-

0.15

KMP-SB44-0000-0006-01,
KM P-SS49-0000-0003-02

0.14

-

-

0.15

Maximum

(1)

Uranium

mg/kg

5 / 5

-

6.2

KM P-SB44-0000-0006-01

2.142

-

-

6.2

Maximum

(1)

Vanadium

mg/kg

5 / 5

-

17

KMP-14-00

15

-

-

17

Maximum

(1)

Page 5 of 13


-------
Table C-4. Exposure Point Concentrations for Human Health Risk Assessment

Kerr-McGee Ponds on the Navajo Nation

COPCa

Units

Detection
Frequency

Number of

High
Nondetect
Results'3

Maximum
Concentration
(qualifier)

Location of Maximum
Concentration

Arithmetic
Meanc

UCL95 /
Distribution1

Exposure Point Concentration

Value6

Statistic®

Methodf

Subsurface Soil (0-66 inches bgs)

Uranium-238

pCi/g

1 / 1

-

1.13

KM P-SS74-0000-0003-01

-

-

-

1.1

Maximum

(1)

Uranium-234

pCi/g

1 / 1

-

0.97

KM P-SS74-0000-0003-01

-

-

-

1.0

Maximum

(1)

Thorium-230

pCi/g

1 / 1

-

2.04

KMP-SS74-0000-0003-01

-

-

-

2.0

Maximum

(1)

Radium-226

pCi/g

7 / 7

-

9.3 J

KM P-SB44-0000-0006-01

4.293

-

-

9.3

Maximum

(1)

Aluminum

mg/kg

5 / 5

-

6,900

KM P-SS49-0000-0003-02

6,500

-

-

6,900

Maximum

(1)

Arsenic

mg/kg

7 / 7

-

5.9

KM P-SS49-0000-0003-02

5.557

-

-

5.9

Maximum

(1)

Barium

mg/kg

7 / 7

-

82

KM P-SB44-0000-0006-01

69.57

-

-

82

Maximum

(1)

Cadmium

mg/kg

7 / 7

-

0.16 J

KM P-SB44-0000-0006-01

0.0974

-

-

0.16

Maximum

(1)

Chromium

mg/kg

7 / 7

-

8.2

KMP-14D-00

7.214

-

-

8.2

Maximum

(1)

Cobalt

mg/kg

5 / 5

-

5.2

KM P-SS49-0000-0003-02

4.92

-

-

5.2

Maximum

(1)

Copper

mg/kg

5 / 5

-

11

KM P-SB44-0000-0006-01

8.96

-

-

11

Maximum

(1)

Iron

mg/kg

5 / 5

-

15,000

KM P-SS49-0000-0003-02

14,000

-

-

15,000

Maximum

(1)

Manganese

mg/kg

5 / 5

-

230

KM P-SB44-0000-0006-01

214

-

-

230

Maximum

(1)

Molybdenum

mg/kg

7 / 7

-

1 J

KMP-14-00

0.416

-

-

0.55

Maximum

(1)

Selenium

mg/kg

7 / 7

-

2.9

KMP-14D-00

1.843

-

-

2.9

Maximum

(1)

Thallium

mg/kg

5 / 5

-

0.15

KMP-SB44-0000-0006-01,
KM P-SS49-0000-0003-02

0.14

-

-

0.15

Maximum

(1)

Uranium

mg/kg

7 / 7

-

6.2

KM P-SB44-0000-0006-01

2.164

-

-

6.2

Maximum

(1)

Vanadium

mg/kg

7 / 7

-

17

KMP-14-00

14.71

-

-

17

Maximum

(1)

Page 6 of 13


-------
Table C-4. Exposure Point Concentrations for Human Health Risk Assessment

Kerr-McGee Ponds on United Nuclear Corporation Property

COPCa

Units

Detection
Frequency

Number of

High
Nondetect
Results'3

Maximum
Concentration
(qualifier)

Location of Maximum
Concentration

Arithmetic
Mean0

UCL95 /
Distribution1

Exposure Point Concentration

Value6

Statistic®

Methodf

Surface Soil (0-6 inches bgs)

Uranium-238

pCi/g

4 / 4

-

2.43

KM P-SS66-0000-0003-01

1.63

-

-

2.4

Maximum

(1)

Uranium-234

pCi/g

4 / 4

-

2.43

KM P-SS50-0000-0003-01

1.68

-

-

2.4

Maximum

(1)

Thorium-230

pCi/g

4 / 4

-

3.41

KMP-SS50-0000-0003-01

2.17

-

-

3.4

Maximum

(1)

Radium-226

pCi/g

54 / 54

-

68.1 M3

KMP-SS75-0000-0003-01

9.51

12.66

LN

13

UCL95

(14)

Aluminum

mg/kg

35 / 35

-

8,300

KMP-SS55-0000-0003-01

6,309

6,553

N

6,600

UCL95

(2)

Arsenic

mg/kg

54 / 54

-

9.2

KMP-07-00

5.731

5.965

N

6.0

UCL95

(2)

Barium

mg/kg

54 / 54

-

170

KMP-SS75-0000-0003-01,
KM P-SS77-0000-0003-01

76.13

82.85

NP

83

UCL95

(14)

Cadmium

mg/kg

51 / 54

0

0.19 J

KMP-SS77-0000-0003-01

0.0995

0.107

N

0.11

UCL95

(3)

Chromium

mg/kg

54 / 54

-

24 J

KM P-SS75-0000-0003-02

7.944

8.546

NP

8.5

UCL95

(14)

Cobalt

mg/kg

35 / 35

-

6.7

KMP-SS55-0000-0003-01

4.966

5.151

N

5.2

UCL95

(2)

Copper

mg/kg

35 / 35

-

18

KM P-SS75-0000-0003-02

9.657

10.52

G

11

UCL95

(4)

Iron

mg/kg

35 / 35

-

19,000

KMP-SS55-0000-0003-01

14609

15207

N

15,000

UCL95

(2)

Manganese

mg/kg

35 / 35

-

310

KMP-SS77-0000-0003-01

210

218

N

220

UCL95

(2)

Molybdenum

mg/kg

50 / 54

0

2

KM P-SS75-0000-0003-02

1

1

N

0.57

UCL95

(3)

Selenium

mg/kg

54 / 54

-

21

KMP-17-00

3

3.963

NP

4.0

UCL95

(14)

Thallium

mg/kg

35 / 35

-

0.18

KMP-SS55-0000-0003-01,
KM P-SS76-0000-0003-01

0.13

0.136

N

0.14

UCL95

(2)

Uranium

mg/kg

54 / 54

-

40

KMP-17-00

5.963

7.684

LN

7.7

UCL95

(14)

Vanadium

mg/kg

54 / 54

-

41

KMP-17-00

17.63

19.04

NP

19

UCL95

(14)

Page 7 of 13


-------
Table C-4. Exposure Point Concentrations for Human Health Risk Assessment

Kerr-McGee Ponds on United Nuclear Corporation Property

COPCa

Units

Detection
Frequency

Number of

High
Nondetect
Results'3

Maximum
Concentration
(qualifier)

Location of Maximum
Concentration

Arithmetic
Meanc

UCL95 /
Distribution1

Exposure Point Concentration

Value6

Statistic®

Methodf

Subsurface Soil (0-72 inches bgs)

Uranium-238

pCi/g

00
00

-

51.5

KMP-SB28-0060-0066-01

7.684

-

-

52

Maximum

(1)

Uranium-234

pCi/g

8 / 8

-

49.4

KMP-SB28-0060-0066-01

7.436

-

-

49

Maximum

(1)

Thorium-230

pCi/g

8 / 8

-

3.41

KMP-SS50-0000-0003-01

1.638

-

-

3.4

Maximum

(1)

Radium-226

pCi/g

96 / 96

-

143.1

KMP-16-18

8.237

11.51

NP

12

UCL95

(14)

Aluminum

mg/kg

61 / 61

-

9,600

KM P-SB24-0048-0054-01

6,413

6,629

N

6,600

UCL95

(2)

Arsenic

mg/kg

96 / 96

-

9.2

KMP-07-00

5.61

5.78

NP

5.8

UCL95

(14)

Barium

mg/kg

96 / 96

-

190

KMP-16-18

70.03

75.33

NP

75

UCL95

(14)

Cadmium

mg/kg

83 / 96

0

0.19 J

KMP-SS77-0000-0003-01

0.0877

0.093

G

0.093

UCL95

(7)

Chromium

mg/kg

96 / 96

-

24 J

KM P-SS75-0000-0003-02

7.685

8.059

NP

8.1

UCL95

(14)

Cobalt

mg/kg

61 / 61

-

7.9

KM P-SB24-0048-0054-01

5.048

5.207

NP

5.2

UCL95

(14)

Copper

mg/kg

61 / 61

-

18

KM P-SS75-0000-0003-02

9.22

9.78

LN

9.8

UCL95

(14)

Iron

mg/kg

61 / 61

-

22,000

KM P-SB24-0048-0054-01

14,480

14952

N

15,000

UCL95

(2)

Manganese

mg/kg

61 / 61

-

310

KMP-SS77-0000-0003-01

212.1

219.2

NP

220

UCL95

(14)

Molybdenum

mg/kg

91 / 96

0

2

KMP-SB28-0036-0042-01

1

1

LN

0.63

UCL95

(15)

Selenium

mg/kg

96 / 96

-

37

KMP-16-18

3

3.746

NP

3.7

UCL95

(14)

Thallium

mg/kg

61 / 61

-

0.21

KMP-SB24-0048-0054-01

0.133

0.138

NP

0.14

UCL95

(14)

Uranium

mg/kg

96 / 96

-

190

KM P-SB28-0042-0048-01

18.58

24.85

NP

25

UCL95

(14)

Vanadium

mg/kg

96 / 96

-

58

KMP-16-18

16.91

18.04

NP

18

UCL95

(14)

Page 8 of 13


-------
Table C-4. Exposure Point Concentrations for Human Health Risk Assessment

Arroyos on the Navajo Nation

COPCa

Units

Detection
Frequency

Number of

High
Nondetect
Results'3

Maximum
Concentration
(qualifier)

Location of Maximum
Concentration

Arithmetic
Mean0

UCL95 /
Distribution1

Exposure Point Concentration

Value6

Statistic®

Methodf

Surface Soil (0-6 inches bgs)

Uranium-238

pCi/g

0 / 0

-

-

-

-

..

-

-

-

Uranium-234

pCi/g

0 / 0

-

-

-

-

-

-

-

-

Thorium-230

pCi/g

0 / 0

-

-

-

-

..

-

-

-

Radium-226

pCi/g

94 / 94

-

3.05

CRUA-020.2 (2-6)

1.254

1.326 N

1.3

UCL95

(2)

Aluminum

mg/kg

1 / 1

-

4,700

KMA-SS02-0000-0003-01

-

..

4,700

Maximum

(1)

Arsenic

mg/kg

3 / 3

-

11

KMP-12-00

7.667

-

11

Maximum

(1)

Barium

mg/kg

3 / 3

-

74

KMP-11-00

64

..

74

Maximum

(1)

Cadmium

mg/kg

3 / 3

-

0.064 J

KMP-12-00

0.0545

..

0.064

Maximum

(1)

Chromium

mg/kg

3 / 3

-

6.7

KMP-12-00

5.767

..

6.7

Maximum

(1)

Cobalt

mg/kg

1 / 1

-

4.0

KMA-SS02-0000-0003-01

-

-

4.0

Maximum

(1)

Copper

mg/kg

1 / 1

-

5.1

KMA-SS02-0000-0003-01

-

..

5.1

Maximum

(1)

Iron

mg/kg

1 / 1

-

12,000

KMA-SS02-0000-0003-01

-

-

12,000

Maximum

(1)

Manganese

mg/kg

1 / 1

-

200

KMA-SS02-0000-0003-01

-

..

200

Maximum

(1)

Molybdenum

mg/kg

3 / 3

-

0.81 J

KMP-12-00

0.557

-

0.81

Maximum

(1)

Selenium

mg/kg

3 / 3

-

1.5

KMP-12-00

1.2

..

1.5

Maximum

(1)

Thallium

mg/kg

1 / 1

-

0.092

KMA-SS02-0000-0003-01

-

..

0.092

Maximum

(1)

Uranium

mg/kg

7 / 7

-

2.9

RWPR-SS-029 (0-6)

1.186

..

2.9

Maximum

(1)

Vanadium

mg/kg

3 / 3

-

25

KMP-12-00

17.67

-

25

Maximum

(1)

Page 9 of 13


-------
Table C-4. Exposure Point Concentrations for Human Health Risk Assessment

Arroyos on the Navajo Nation

COPCa

Units

Detection
Frequency

Number of

High
Nondetect
Results'3

Maximum
Concentration
(qualifier)

Location of Maximum
Concentration

Arithmetic
Mean0

UCL95 /
Distribution1

Exposure Point Concentration

Value6

Statistic®

Methodf

Subsurface Soil (0-36 inches bgs)

Uranium-238

pCi/g

0 / 0

-

-

-

-

..

-

-

-

Uranium-234

pCi/g

0 / 0

-

-

-

-

-

-

-

-

Thorium-230

pCi/g

0 / 0

-

-

-

-

..

-

-

-

Radium-226

pCi/g

135 / 135

-

3.28

CRUA-020.3 (30-36)

1.414

1.492 G

1.5

UCL95

(6)

Aluminum

mg/kg

2 / 2

-

4,700

KMA-SS02-0000-0003-01

4450

..

4,700

Maximum

(1)

Arsenic

mg/kg

4 / 4

-

11

KMP-12-00

7.15

-

11

Maximum

(1)

Barium

mg/kg

4 / 4

-

75

KMA-SS02-0012-0018-01

66.75

..

75

Maximum

(1)

Cadmium

mg/kg

4 / 4

-

0.073 J

KMA-SS02-0012-0018-01

0.0613

..

0.073

Maximum

(1)

Chromium

mg/kg

4 / 4

-

6.7

KMP-12-00

5.45

..

6.7

Maximum

(1)

Cobalt

mg/kg

2 / 2

-

4.5

KMA-SS02-0012-0018-01

4.25

-

4.5

Maximum

(1)

Copper

mg/kg

2 / 2

-

5.1

KMA-SS02-0000-0003-01

5.1

..

5.1

Maximum

(1)

Iron

mg/kg

2 / 2

-

15,000

KM A-SS02-0012-0018-01

13,500

-

15,000

Maximum

(1)

Manganese

mg/kg

2 / 2

-

400

KM A-SS02-0012-0018-01

300

..

400

Maximum

(1)

Molybdenum

mg/kg

4 / 4

-

0.81 J

KMP-12-00

0.53

-

0.81

Maximum

(1)

Selenium

mg/kg

4 / 4

-

1.5

KMP-12-00

1.125

..

1.5

Maximum

(1)

Thallium

mg/kg

2 / 2

-

0.092

KMA-SS02-0000-0003-01

0.087

-

0.092

Maximum

(1)

Uranium

mg/kg

9 / 9

-

2.9

RWPR-SS-029 (0-6)

1.262

..

2.9

Maximum

(1)

Vanadium

mg/kg

4 / 4

-

25

KMP-12-00

16.5

-

25

Maximum

(1)

Page 10 of 13


-------
Table C-4. Exposure Point Concentrations for Human Health Risk Assessment

Arroyos on United Nuclear Corporation Property

COPCa

Units

Detection
Frequency

Number of

High
Nondetect
Results'3

Maximum
Concentration
(qualifier)

Location of Maximum
Concentration

Arithmetic
Meanc

UCL95 /
Distribution1

Exposure Point Concentration

Value6

Statistic®

Methodf

Surface Soil (0-6 inches bgs)

Uranium-238

pCi/g

0 / 0

-

-

-

-

..

-

-

-

Uranium-234

pCi/g

0 / 0

-

-

-

-

-

-

-

-

Thorium-230

pCi/g

0 / 0

-

-

-

-

..

-

-

-

Radium-226

pCi/g

13 / 13

-

1.55 G

CRPA-003.2 (2-6)

0.94

1.075 N

1.1

UCL95

(2)

Aluminum

mg/kg

1 / 1

-

4,400

KM A-SS01-0000-0003-01

-

..

4,400

Maximum

(1)

Arsenic

mg/kg

1 / 1

-

4.6

KM A-SS01-0000-0003-01

-

-

4.6

Maximum

(1)

Barium

mg/kg

1 / 1

-

48

KM A-SS01-0000-0003-01

-

..

48

Maximum

(1)

Cadmium

mg/kg

1 / 1

-

0.054 J

KMA-SS01-0000-0003-01

-

..

0.054

Maximum

(1)

Chromium

mg/kg

1 / 1

-

5

KM A-SS01-0000-0003-01

-

..

5.0

Maximum

(1)

Cobalt

mg/kg

1 / 1

-

4.4

KMA-SS01-0000-0003-01

-

-

4.4

Maximum

(1)

Copper

mg/kg

1 / 1

-

4.7

KM A-SS01-0000-0003-01

-

..

4.7

Maximum

(1)

Iron

mg/kg

1 / 1

-

13,000

KM A-SS01-0000-0003-01

-

-

13,000

Maximum

(1)

Manganese

mg/kg

1 / 1

-

240

KM A-SS01-0000-0003-01

-

..

240

Maximum

(1)

Molybdenum

mg/kg

1 / 1

-

0.28

KM A-SS01-0000-0003-01

-

-

0.28

Maximum

(1)

Selenium

mg/kg

11 / 11

-

1.55

KMA-SS01-0000-0003-01

0.942

1.102 N

1.1

UCL95

(2)

Thallium

mg/kg

0 / 1

0

0.057 U

KMA-SS01-0000-0003-01

-

..

0.057

Maximum-ND

-

Uranium

mg/kg

1 / 1

-

0.091

KM A-SS01-0000-0003-01

-

..

0.09

Maximum

(1)

Vanadium

mg/kg

1 / 1

-

0.53

KM A-SS01-0000-0003-01

-

-

0.53

Maximum

(1)

Page 11 of 13


-------
Table C-4. Exposure Point Concentrations for Human Health Risk Assessment

Arroyos on United Nuclear Corporation Property

COPCa

Units

Detection
Frequency

Number of

High
Nondetect
Results'3

Maximum
Concentration
(qualifier)

Location of Maximum
Concentration

Arithmetic
Mean0

UCL95 /
Distribution1

Exposure Point Concentration

Value6

Statistic®

Methodf

Subsurface Soil (0-36 inches bgs)

Uranium-238

pCi/g

0 / 0

-

-

-

-

..

-

-

-

Uranium-234

pCi/g

0 / 0

-

-

-

-

..

-

-

-

Thorium-230

pCi/g

0 / 0

-

-

-

-

..

-

-

-

Radium-226

pCi/g

20 / 20

-

1.83 G

CRUA-037.3 (30-36)

0.976

1.101 N

1.1

UCL95

(2)

Aluminum

mg/kg

2 / 2

-

4,700

KM A-SS01-0012-0018-01

4,550

..

4,700

Maximum

(1)

Arsenic

mg/kg

2 / 2

-

4.8

KM A-SS01-0012-0018-01

4.7

..

5

Maximum

(1)

Barium

mg/kg

2 / 2

-

62

KM A-SS01-0012-0018-01

55

..

62

Maximum

(1)

Cadmium

mg/kg

2 / 2

-

0.055 J

KM A-SS01-0012-0018-01

0.0545

..

0.055

Maximum

(1)

Chromium

mg/kg

2 / 2

-

5

KM A-SS01-0012-0018-01

4.95

..

5.0

Maximum

(1)

Cobalt

mg/kg

2 / 2

-

4.4

KMA-SS01-0000-0003-01

4.15

-

4.4

Maximum

(1)

Copper

mg/kg

2 / 2

-

5.4

KM A-SS01-0012-0018-01

5.05

..

5.4

Maximum

(1)

Iron

mg/kg

2 / 2

-

15,000

KM A-SS01-0012-0018-01

14,000

-

15,000

Maximum

(1)

Manganese

mg/kg

2 / 2

-

280

KM A-SS01-0012-0018-01

260

..

280

Maximum

(1)

Molybdenum

mg/kg

2 / 2

-

0.28

KMA-SS01-0000-0003-01,
KM A-SS01-0012-0018-01

0.28

-

0.28

Maximum

(1)

Selenium

mg/kg

18 / 18

-

1.83

KMA-SS01-0000-0003-01

0.981

1.12 N

1.1

UCL95

(2)

Thallium

mg/kg

0 / 2

0

0.059 U

KMA-SS01-0000-0003-01

-

..

0.059

Maximum-ND

-

Uranium

mg/kg

2 / 2

-

0.091

KM A-SS01-0012-0018-01

0.0885

..

0.09

Maximum

(1)

Vanadium

mg/kg

2 / 2

-

0.62

KM A-SS01-0012-0018-01

0.575

-

1

Maximum

(1)

Notes:

a EPCs calculated if "Yes" for "Include Constituent as a COPC?" on Table C-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 Tested using 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.
Distributions not confirmed as N, LN, or G were treated as NP in all statistical calculations.

8 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 USEPA (2024b).

Page 12 of 13


-------
Table C-4. Exposure Point Concentrations for Human Health Risk Assessment

Notes (continued):

f 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)

(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%

BCAUCL



95% KM BCAUCL

95% Percentile Bootstrap UCL

95% KM Percentile Bootstrap UCL

99% Bootstrap-t UCL

99% KM Percentile Bootstrap UCL

Not applicable

BCA	Bias-corrected accelerated bootstrap method

bgs	Below ground surface

COPC	Contaminant of potential concern

EPC	Exposure point concentration

G (data qualifier) Sample density differs by more than 15% of the LCS density.

G (distribution)	Gamma distribution

H-UCL	UCL based upon Land's H-statistic

J	Estimated concentration

Kerr-McGee	Kerr-McGee Corporation

KM	Kaplan-Meier

LN	Lognormal distribution

M3	The requested MDC was not met, but the reported activity is greater than the reported MDC

mg/kg	Milligram per kilogram

N	Normal distribution

ND	Nondetect

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). 2024b. "Navajo Abandoned Uranium Mines Risk Assessment Methodology." Draft Final. March.

Page 13 of 13


-------
Table C-5.1. Human Health Risk and Hazard Calculations - Quivira Church Rock Mine No. 1

Church Rock Mine No. 1 - Kee'da'whii teeh (Full-Time Resident)

COPCa

EPCb

Units

Cancer
Intake0

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake0

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Child
Noncancer
Intake0

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Child

Exposure Medium: Surface Soil (0-6 inches bgs



Exposure Route: Incidental Soil Ingestion

Uranium-238

1.1

pCi/g

1.0E+04

pCi/g

1.3E-10

risk/pCi/g

1.4E-06

—

—

—

—

—

—

—

—

—

—

Uranium-234

1.2

pCi/g

1.1E+04

pCi/g

1.5E-10

risk/pCi/g

1.7E-06

—

—

—

—

—

—

—

—

—

—

Thorium-230

1.7

pCi/g

1.6E+04

pCi/g

1.7E-10

risk/pCi/g

2.7E-06

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

6.7

pCi/g

6.4E+04

pCi/g

5.7E-09

risk/pCi/g

3.6E-04

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

4E-04

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

4,600

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.0E-02

mg/kg-day

1.0E+00

mg/kg-day

0.020

1.2E-01

mg/kg-day

1.0E+00

mg/kg-day

0.12

Arsenic

4.9

mg/kg

1.8E-05

mg/kg-day

1.5E+00

(mg/kg-day)"1

2.6E-05

1.3E-05

mg/kg-day

3.0E-04

mg/kg-day

0.042

7.4E-05

mg/kg-day

3.0E-04

mg/kg-day

0.25

Barium

110

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.7E-04

mg/kg-day

2.0E-01

mg/kg-day

0.0024

2.9E-03

mg/kg-day

2.0E-01

mg/kg-day

0.014

Cadmium

0.14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.0E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0060

3.6E-06

mg/kg-day

1.0E-04

mg/kg-day

0.036

Chromium

6.0

mg/kg

9.62E-05

mg/kg-day

5.0E-01

(mg/kg-day)"1

4.8E-05

2.6E-05

mg/kg-day

3.0E-03

mg/kg-day

0.0086

1.6E-04

mg/kg-day

3.0E-03

mg/kg-day

0.052

Cobalt

6.1

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.6E-05

mg/kg-day

3.0E-04

mg/kg-day

0.087

1.6E-04

mg/kg-day

3.0E-04

mg/kg-day

0.53

Copper

12

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.2E-05

mg/kg-day

4.0E-02

mg/kg-day

0.0013

3.1E-04

mg/kg-day

4.0E-02

mg/kg-day

0.0078

Iron

11,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.7E-02

mg/kg-day

7.0E-01

mg/kg-day

0.068

2.9E-01

mg/kg-day

7.0E-01

mg/kg-day

0.41

Manganese

160

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.9E-04

mg/kg-day

2.4E-02

mg/kg-day

0.029

4.2E-03

mg/kg-day

2.4E-02

mg/kg-day

0.17

Molybdenum

0.32

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.4E-06

mg/kg-day

5.0E-03

mg/kg-day

0.00028

8.3E-06

mg/kg-day

5.0E-03

mg/kg-day

0.0017

Selenium

3.4

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.5E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0029

8.8E-05

mg/kg-day

5.0E-03

mg/kg-day

0.018

Thallium

0.14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.0E-07

mg/kg-day

1.0E-05

mg/kg-day

0.060

3.6E-06

mg/kg-day

1.0E-05

mg/kg-day

0.36

Uranium

7.3

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.1E-05

mg/kg-day

2.0E-04

mg/kg-day

0.16

1.9E-04

mg/kg-day

2.0E-04

mg/kg-day

0.95

Vanadium

14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.0E-05

mg/kg-day

5.0E-03

mg/kg-day

0.012

3.6E-04

mg/kg-day

5.0E-03

mg/kg-day

0.073

Metals Cancer Total

7E-05

Metals Noncancer Total

0.5

Metals Noncancer Total

3

Exposure Route Cancer Total

4E-04

Exposure Route Noncancer Total

0.5

Exposure Route Noncancer Total

3

Page 1 of 11


-------
Table C-5.1. Human Health Risk and Hazard Calculations - Quivira Church Rock Mine No. 1

Church Rock Mine No. 1 - Kee'da'whii teeh (Full-Time Resident)

COPCa

EPCb

Units

Cancer
Intake0

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake0

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Child
Noncancer
Intake0

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Child

Exposure Medium: Surface Soil (0-6 inches bgs



Exposure Route: External Ex

posure

Uranium-238

1.1

pCi/g

5.6E+01

pCi/g

1.2E-10

risk/year pCi/g

7.0E-09

—

—

—

—

—

—

—

—

—

—

Uranium-234

1.2

pCi/g

6.1E+01

pCi/g

2.5E-10

risk/year pCi/g

1.5E-08

—

—

—

—

—

—

—

—

—

—

Thorium-230

1.7

pCi/g

8.7E+01

pCi/g

8.5E-10

risk/year pCi/g

7.3E-08

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

6.7

pCi/g

3.4E+02

pCi/g

8.4E-06

risk/year pCi/g

2.9E-03

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

3E-03

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Exposure Route Cancer Total

3E-03

Exposure Route Noncancer Total

—

Exposure Route Noncancer Total

—

Exposure Route: Dermal Exposure

Aluminum

4,600

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

Arsenic

4.9

mg/kg

1.0E-06

mg/kg-day

1.5E+00

(mg/kg-day)"1

1.5E-06

7.4E-07

mg/kg-day

3.0E-04

mg/kg-day

0.0025

4.5E-06

mg/kg-day

3.0E-04

mg/kg-day

0.015

Barium

110

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

Cadmium

0.14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.8E-08

mg/kg-day

1.0E-04

mg/kg-day

0.00028

1.7E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0017

Chromium

6.0

mg/kg

—

mg/kg-day

5.0E-01

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

Cobalt

6.1

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

Copper

12

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

Iron

11,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

Manganese

160

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

Molybdenum

0.32

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Selenium

3.4

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Thallium

0.14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

Uranium

7.3

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

Vanadium

14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Metals Cancer Total

2E-06

Metals Noncancer Total

0.003

Metals Noncancer Total

0.02

Exposure Route Cancer Total

2E-06

Exposure Route Noncancer Total

0.003

Exposure Route Noncancer Total

0.02

Page 2 of 11


-------
Table C-5.1. Human Health Risk and Hazard Calculations - Quivira Church Rock Mine No. 1

Church Rock Mine No. 1 - Kee'da'whii teeh (Full-Time Resident)

COPCa

EPCb

Units

Cancer
Intake0

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake0

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Child
Noncancer
Intake0

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Child

Exposure Medium: Surface Soil (0-6 inches bgs



Exposure Route: Inhalation of Particulates

Uranium-238

1.1

pCi/g

9.6E-02

pCi

2.4E-08

risk/pCi

2.3E-09

—

—

—

—

—

—

—

—

—

—

Uranium-234

1.2

pCi/g

1.0E-01

pCi

2.8E-08

risk/pCi

2.9E-09

—

—

—

—

—

—

—

—

—

—

Thorium-230

1.7

pCi/g

1.5E-01

pCi

3.4E-08

risk/pCi

5.0E-09

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

6.7

pCi/g

5.8E-01

pCi

5.9E-08

risk/pCi

3.5E-08

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

4E-08

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

4,600

mg/kg

—

ug/m3

—

(ug/m3y1

—

6.0E-07

mg/m3

5.0E-03

mg/m3

0.00012

6.0E-07

mg/m3

5.0E-03

mg/m3

0.00012

Arsenic

4.9

mg/kg

6.4E-07

ug/m3

4.3E-03

(ug/m3y1

2.7E-09

6.4E-10

mg/m3

1.5E-05

mg/m3

0.000042

6.4E-10

mg/m3

1.5E-05

mg/m3

0.000042

Barium

110

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.4E-08

mg/m3

5.0E-04

mg/m3

0.000029

1.4E-08

mg/m3

5.0E-04

mg/m3

0.000029

Cadmium

0.14

mg/kg

1.8E-08

ug/m3

1.8E-03

(ug/m3)"1

3.3E-11

1.8E-11

mg/m3

1.0E-05

mg/m3

0.0000018

1.8E-11

mg/m3

1.0E-05

mg/m3

0.0000018

Chromium

6.0

mg/kg

1.3E-06

ug/m3

8.4E-02

(ug/m3)"1

1.1E-07

7.8E-10

mg/m3

1.0E-04

mg/m3

0.0000078

7.8E-10

mg/m3

1.0E-04

mg/m3

0.0000078

Cobalt

6.1

mg/kg

7.9E-07

ug/m3

9.0E-03

(ug/m3)"1

7.1E-09

7.9E-10

mg/m3

6.0E-06

mg/m3

0.00013

7.9E-10

mg/m3

6.0E-06

mg/m3

0.00013

Copper

12

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

—

mg/m3

—

mg/m3

—

Iron

11,000

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

—

mg/m3

—

mg/m3

—

Manganese

160

mg/kg

—

ug/m3

—

(ug/m3)"1

—

2.1E-08

mg/m3

5.0E-05

mg/m3

0.00042

2.1E-08

mg/m3

5.0E-05

mg/m3

0.00042

Molybdenum

0.32

mg/kg

—

ug/m3

—

(ug/m3)"1

—

4.2E-11

mg/m3

2.0E-03

mg/m3

0.000000021

4.2E-11

mg/m3

2.0E-03

mg/m3

0.000000021

Selenium

3.4

mg/kg

—

ug/m3

—

(ug/m3)"1

—

4.4E-10

mg/m3

2.0E-02

mg/m3

0.000000022

4.4E-10

mg/m3

2.0E-02

mg/m3

0.000000022

Thallium

0.14

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

—

mg/m3

—

mg/m3

—

Uranium

7.3

mg/kg

—

ug/m3

—

(ug/m3)"1

—

9.5E-10

mg/m3

4.0E-05

mg/m3

0.000024

9.5E-10

mg/m3

4.0E-05

mg/m3

0.000024

Vanadium

14

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.8E-09

mg/m3

1.0E-04

mg/m3

0.000018

1.8E-09

mg/m3

1.0E-04

mg/m3

0.000018

Metals Cancer Total

1E-07

Metals Noncancer Total

0.0008

Metals Noncancer Total

0.0008

Exposure Route Cancer Total

2E-07

Exposure Route Noncancer Total

0.0008

Exposure Route Noncancer Total

0.0008

Exposure Medium: Surface Soil (0-6 inches bgs)

Exposure Route: Plant Consumption

Uranium-238

1.1

pCi/g

7.8E+04

pCi/g

8.7E-11

risk/pCi/g

6.8E-06

—

—

—

—

—

—

—

—

—

—

Uranium-234

1.2

pCi/g

8.5E+04

pCi/g

9.6E-11

risk/pCi/g

8.1E-06

—

—

—

—

—

—

—

—

—

—

Thorium-230

1.7

pCi/g

3.1E+04

pCi/g

1.2E-10

risk/pCi/g

3.6E-06

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

6.7

pCi/g

7.4E+05

pCi/g

3.7E-09

risk/pCi/g

2.7E-03

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

3E-03

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

4,600

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.5E-02

mg/kg-day

1.0E+00

mg/kg-day

0.055

1.4E-01

mg/kg-day

1.0E+00

mg/kg-day

0.14

Arsenic

4.9

mg/kg

6.9E-05

mg/kg-day

1.5E+00

(mg/kg-day)"1

1.0E-04

6.4E-05

mg/kg-day

3.0E-04

mg/kg-day

0.21

1.7E-04

mg/kg-day

3.0E-04

mg/kg-day

0.56

Barium

110

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.5E-03

mg/kg-day

2.0E-01

mg/kg-day

0.013

6.7E-03

mg/kg-day

2.0E-01

mg/kg-day

0.034

Cadmium

0.14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

8.3E-06

mg/kg-day

1.0E-04

mg/kg-day

0.083

2.2E-05

mg/kg-day

1.0E-04

mg/kg-day

0.22

Chromium

6.0

mg/kg

1.68E-04

mg/kg-day

5.0E-01

(mg/kg-day)"1

8.4E-05

7.2E-05

mg/kg-day

3.0E-03

mg/kg-day

0.024

1.9E-04

mg/kg-day

3.0E-03

mg/kg-day

0.064

Cobalt

6.1

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.1E-04

mg/kg-day

3.0E-04

mg/kg-day

0.37

2.9E-04

mg/kg-day

3.0E-04

mg/kg-day

0.98

Copper

12

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.0E-03

mg/kg-day

4.0E-02

mg/kg-day

0.051

5.4E-03

mg/kg-day

4.0E-02

mg/kg-day

0.14

Iron

11,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

--

1.3E-01

mg/kg-day

7.0E-01

mg/kg-day

0.19

3.4E-01

mg/kg-day

7.0E-01

mg/kg-day

0.49

Manganese

160

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.8E-02

mg/kg-day

2.4E-02

mg/kg-day

0.73

4.6E-02

mg/kg-day

2.4E-02

mg/kg-day

1.9

Molybdenum

0.32

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.5E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0070

9.3E-05

mg/kg-day

5.0E-03

mg/kg-day

0.019

Selenium

3.4

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.1E-05

mg/kg-day

5.0E-03

mg/kg-day

0.012

1.6E-04

mg/kg-day

5.0E-03

mg/kg-day

0.033

Thallium

0.14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.4E-06

mg/kg-day

1.0E-05

mg/kg-day

0.14

3.9E-06

mg/kg-day

1.0E-05

mg/kg-day

0.39

Uranium

7.3

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

9.5E-05

mg/kg-day

2.0E-04

mg/kg-day

0.47

2.6E-04

mg/kg-day

2.0E-04

mg/kg-day

1.3

Vanadium

14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.7E-04

mg/kg-day

5.0E-03

mg/kg-day

0.034

4.6E-04

mg/kg-day

5.0E-03

mg/kg-day

0.092

Metals Cancer Total

2E-04

Metals Noncancer Total

2

Metals Noncancer Total

6

Exposure Route Cancer Total

3E-03

Exposure Route Noncancer Total

2

Exposure Route Noncancer Total

6

Page 3 of 11


-------
Table C-5.1. Human Health Risk and Hazard Calculations - Quivira Church Rock Mine No. 1

Church Rock Mine No. 1 - Kee'da'whii teeh (Full-Time Resident)

COPCa

EPCb

Units

Cancer
Intake0

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake0

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Child
Noncancer
Intake0

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Child

Exposure Medium: Surface Soil (0-6 inches bgs



Exposure Route: Animal Consumption

Uranium-238

1.1

pCi/g

8.9E+04

pCi/g

8.7E-11

risk/pCi/g

7.7E-06

—

—

—

—

—

—

—

—

—

—

Uranium-234

1.2

pCi/g

9.7E+04

pCi/g

9.6E-11

risk/pCi/g

9.3E-06

—

—

—

—

—

—

—

—

—

—

Thorium-230

1.7

pCi/g

6.6E+01

pCi/g

1.2E-10

risk/pCi/g

7.9E-09

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

6.7

pCi/g

1.4E+06

pCi/g

3.7E-09

risk/pCi/g

5.2E-03

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

5E-03

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

4,600

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.2E-03

mg/kg-day

1.0E+00

mg/kg-day

0.0032

8.7E-03

mg/kg-day

1.0E+00

mg/kg-day

0.0087

Arsenic

4.9

mg/kg

5.4E-06

mg/kg-day

1.5E+00

(mg/kg-day)"1

8.1E-06

4.8E-06

mg/kg-day

3.0E-04

mg/kg-day

0.016

1.3E-05

mg/kg-day

3.0E-04

mg/kg-day

0.042

Barium

110

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.4E-05

mg/kg-day

2.0E-01

mg/kg-day

0.000072

3.9E-05

mg/kg-day

2.0E-01

mg/kg-day

0.00019

Cadmium

0.14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.2E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0032

8.4E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0084

Chromium

6.0

mg/kg

3.68E-05

mg/kg-day

5.0E-01

(mg/kg-day)"1

1.8E-05

1.6E-05

mg/kg-day

3.0E-03

mg/kg-day

0.0053

4.2E-05

mg/kg-day

3.0E-03

mg/kg-day

0.014

Cobalt

6.1

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.9E-05

mg/kg-day

3.0E-04

mg/kg-day

0.20

1.6E-04

mg/kg-day

3.0E-04

mg/kg-day

0.53

Copper

12

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.1E-04

mg/kg-day

4.0E-02

mg/kg-day

0.0027

2.9E-04

mg/kg-day

4.0E-02

mg/kg-day

0.0072

Iron

11,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.0E-01

mg/kg-day

7.0E-01

mg/kg-day

0.14

2.6E-01

mg/kg-day

7.0E-01

mg/kg-day

0.38

Manganese

160

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.3E-05

mg/kg-day

2.4E-02

mg/kg-day

0.0022

1.4E-04

mg/kg-day

2.4E-02

mg/kg-day

0.0059

Molybdenum

0.32

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.4E-06

mg/kg-day

5.0E-03

mg/kg-day

0.00029

3.8E-06

mg/kg-day

5.0E-03

mg/kg-day

0.00077

Selenium

3.4

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.6E-04

mg/kg-day

5.0E-03

mg/kg-day

0.052

7.1E-04

mg/kg-day

5.0E-03

mg/kg-day

0.14

Thallium

0.14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.5E-06

mg/kg-day

1.0E-05

mg/kg-day

0.25

6.9E-06

mg/kg-day

1.0E-05

mg/kg-day

0.69

Uranium

7.3

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.0E-06

mg/kg-day

2.0E-04

mg/kg-day

0.0051

2.8E-06

mg/kg-day

2.0E-04

mg/kg-day

0.014

Vanadium

14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.5E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0031

4.2E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0084

Metals Cancer Total

3E-05

Metals Noncancer Total

0.7

Metals Noncancer Total

2

Exposure Route Cancer Total

5E-03

Exposure Route Noncancer Total

0.7

Exposure Route Noncancer Total

2

Exposure Medium: Surface Soil (0-6 inches bgs)

Exposure Route: Other Dine Lifeways Plant Ingestion

Uranium-238

1.1

pCi/g

3.6E+04

pCi/g

8.7E-11

risk/pCi/g

3.1E-06

—

—

—

—

—

—

—

—

—

—

Uranium-234

1.2

pCi/g

4.0E+04

pCi/g

9.6E-11

risk/pCi/g

3.8E-06

—

—

—

—

—

—

—

—

—

—

Thorium-230

1.7

pCi/g

1.7E+04

pCi/g

1.2E-10

risk/pCi/g

2.0E-06

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

6.7

pCi/g

4.0E+05

pCi/g

3.7E-09

risk/pCi/g

1.5E-03

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

1E-03

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

4,600

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.3E-02

mg/kg-day

1.0E+00

mg/kg-day

0.033

—

mg/kg-day

1.0E+00

mg/kg-day

—

Arsenic

4.9

mg/kg

3.5E-05

mg/kg-day

1.5E+00

(mg/kg-day)"1

5.2E-05

3.8E-05

mg/kg-day

3.0E-04

mg/kg-day

0.13

—

mg/kg-day

3.0E-04

mg/kg-day

—

Barium

110

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.7E-03

mg/kg-day

2.0E-01

mg/kg-day

0.0083

—

mg/kg-day

2.0E-01

mg/kg-day

—

Cadmium

0.14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.6E-06

mg/kg-day

1.0E-04

mg/kg-day

0.056

—

mg/kg-day

1.0E-04

mg/kg-day

—

Chromium

6.0

mg/kg

5.2E-05

mg/kg-day

5.0E-01

(mg/kg-day)"1

2.6E-05

4.4E-05

mg/kg-day

3.0E-03

mg/kg-day

0.015

—

mg/kg-day

3.0E-03

mg/kg-day

—

Cobalt

6.1

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.7E-05

mg/kg-day

3.0E-04

mg/kg-day

0.22

—

mg/kg-day

3.0E-04

mg/kg-day

—

Copper

12

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.3E-03

mg/kg-day

4.0E-02

mg/kg-day

0.033

—

mg/kg-day

4.0E-02

mg/kg-day

—

Iron

11,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

--

7.8E-02

mg/kg-day

7.0E-01

mg/kg-day

0.11

—

mg/kg-day

7.0E-01

mg/kg-day

—

Manganese

160

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.2E-02

mg/kg-day

2.4E-02

mg/kg-day

0.49

—

mg/kg-day

2.4E-02

mg/kg-day

—

Molybdenum

0.32

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.3E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0047

—

mg/kg-day

5.0E-03

mg/kg-day

—

Selenium

3.4

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.7E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0075

—

mg/kg-day

5.0E-03

mg/kg-day

—

Thallium

0.14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

8.8E-07

mg/kg-day

1.0E-05

mg/kg-day

0.088

—

mg/kg-day

1.0E-05

mg/kg-day

—

Uranium

7.3

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.1E-05

mg/kg-day

2.0E-04

mg/kg-day

0.30

—

mg/kg-day

2.0E-04

mg/kg-day

—

Vanadium

14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.1E-04

mg/kg-day

5.0E-03

mg/kg-day

0.021

—

mg/kg-day

5.0E-03

mg/kg-day

—

Metals Cancer Total

8E-05

Metals Noncancer Total

2

Metals Noncancer Total

—

Exposure Route Cancer Total

2E-03

Exposure Route Noncancer Total

2

Exposure Route Noncancer Total

-

Page 4 of 11


-------
Table C-5.1. Human Health Risk and Hazard Calculations - Quivira Church Rock Mine No. 1

Church Rock Mine No. 1 - Kee'da'whii teeh (Full-Time Resident)

COPCa

EPCb

Units

Cancer
Intake0

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake0

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Child
Noncancer
Intake0

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Child

Exposure Medium: Surface Soil (0-6 inches bgs



Exposure Route: Other Dine Lifeways Plant Dermal

Aluminum

4,600

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

Arsenic

4.9

mg/kg

2.9E-06

mg/kg-day

1.5E+00

(mg/kg-day)"1

4.4E-06

3.2E-06

mg/kg-day

3.0E-04

mg/kg-day

0.011

—

mg/kg-day

3.0E-04

mg/kg-day

—

Barium

110

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

Cadmium

0.14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.2E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0062

—

mg/kg-day

1.0E-04

mg/kg-day

—

Chromium

6.0

mg/kg

—

mg/kg-day

5.0E-01

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

Cobalt

6.1

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

Copper

12

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

Iron

11,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

Manganese

160

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

Molybdenum

0.32

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Selenium

3.4

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Thallium

0.14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

Uranium

7.3

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

Vanadium

14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Metals Cancer Total

4E-06

Metals Noncancer Total

0.02

Metals Noncancer Total

—

Exposure Route Cancer Total

4E-06

Exposure Route Noncancer Total

0.02

Exposure Route Noncancer Total

—

Exposure Medium: Surface Soil (0-6 inches bgs)

Exposure Route: Other Dine Lifeways Plant Inhalation

Uranium-238

1.1

pCi/g

2.5E+02

pCi

2.4E-08

risk/pCi

6.0E-06

—

—

—

—

—

—

—

—

—

—

Uranium-234

1.2

pCi/g

2.8E+02

pCi

2.8E-08

risk/pCi

7.7E-06

—

—

—

—

—

—

—

—

—

—

Thorium-230

1.7

pCi/g

7.7E+01

pCi

3.4E-08

risk/pCi

2.6E-06

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

6.7

pCi/g

4.2E+03

pCi

5.9E-08

risk/pCi

2.5E-04

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

3E-04

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

4,600

mg/kg

—

ug/m3

—

(ug/m3)"1

—

3.3E-04

mg/m3

5.0E-03

mg/m3

0.066

—

mg/m3

5.0E-03

mg/m3

—

Arsenic

4.9

mg/kg

3.5E-04

ug/m3

4.3E-03

(ug/m3)"1

1.5E-06

3.9E-07

mg/m3

1.5E-05

mg/m3

0.026

—

mg/m3

1.5E-05

mg/m3

—

Barium

110

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.7E-05

mg/m3

5.0E-04

mg/m3

0.033

—

mg/m3

5.0E-04

mg/m3

—

Cadmium

0.14

mg/kg

5.2E-05

ug/m3

1.8E-03

(ug/m3)"1

9.3E-08

5.6E-08

mg/m3

1.0E-05

mg/m3

0.0056

—

mg/m3

1.0E-05

mg/m3

—

Chromium

6.0

mg/kg

5.3E-04

ug/m3

8.4E-02

(ug/m3)"1

4.5E-05

8.9E-08

mg/m3

1.0E-04

mg/m3

0.00089

—

mg/m3

1.0E-04

mg/m3

—

Cobalt

6.1

mg/kg

6.7E-04

ug/m3

9.0E-03

(ug/m3)"1

6.0E-06

7.3E-07

mg/m3

6.0E-06

mg/m3

0.12

—

mg/m3

6.0E-06

mg/m3

—

Copper

12

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

—

mg/m3

—

mg/m3

—

Iron

11,000

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

—

mg/m3

—

mg/m3

—

Manganese

160

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.2E-04

mg/m3

5.0E-05

mg/m3

2.3

—

mg/m3

5.0E-05

mg/m3

—

Molybdenum

0.32

mg/kg

—

ug/m3

—

(ug/m3)"1

—

2.3E-07

mg/m3

2.0E-03

mg/m3

0.00012

—

mg/m3

2.0E-03

mg/m3

—

Selenium

3.4

mg/kg

—

ug/m3

—

(ug/m3)"1

—

3.7E-07

mg/m3

2.0E-02

mg/m3

0.000019

—

mg/m3

2.0E-02

mg/m3

—

Thallium

0.14

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

—

mg/m3

—

mg/m3

—

Uranium

7.3

mg/kg

—

ug/m3

—

(ug/m3)"1

—

6.2E-07

mg/m3

4.0E-05

mg/m3

0.016

—

mg/m3

4.0E-05

mg/m3

—

Vanadium

14

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.1E-06

mg/m3

1.0E-04

mg/m3

0.011

—

mg/m3

1.0E-04

mg/m3

—

Metals Cancer Total

5E-05

Metals Noncancer Total

3

Metals Noncancer Total

—

Exposure Route Cancer Total

3E-04

Exposure Route Noncancer Total

3

Exposure Route Noncancer Total

—

Surface Soil (0-6 inches bgs) Receptor Cancer Risk Total

1E-02

Receptor/Media Noncancer Hazard Total

8

Receptor/Media Noncancer Hazard Total

10

Page 5 of 11


-------
Table C-5.1. Human Health Risk and Hazard Calculations - Quivira Church Rock Mine No. 1

Church Rock Mine No. 1 - Kee'da'whii teeh (Full-Time Resident)

COPCa

EPCb

Units

Cancer
Intake0

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake0

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Child
Noncancer
Intake0

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Child

Exposure Medium: Subsurface Soil (0-72 inches bgs)

Exposure Route: Incidental Soil Ingestion

Uranium-238

1.1

pCi/g

1.0E+04

pCi/g

1.3E-10

risk/pCi/g

1.4E-06

—

—

—

—

—

—

—

—

—

—

Uranium-234

1.2

pCi/g

1.1E+04

pCi/g

1.5E-10

risk/pCi/g

1.7E-06

—

—

—

—

—

—

—

—

—

—

Thorium-230

1.7

pCi/g

1.6E+04

pCi/g

1.7E-10

risk/pCi/g

2.7E-06

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

17

pCi/g

1.6E+05

pCi/g

5.7E-09

risk/pCi/g

9.2E-04

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

9E-04

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

4,600

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.0E-02

mg/kg-day

1.0E+00

mg/kg-day

0.020

1.2E-01

mg/kg-day

1.0E+00

mg/kg-day

0.12

Arsenic

4.8

mg/kg

1.7E-05

mg/kg-day

1.5E+00

(mg/kg-day)"1

2.6E-05

1.2E-05

mg/kg-day

3.0E-04

mg/kg-day

0.042

7.2E-05

mg/kg-day

3.0E-04

mg/kg-day

0.24

Barium

110

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.7E-04

mg/kg-day

2.0E-01

mg/kg-day

0.0024

2.9E-03

mg/kg-day

2.0E-01

mg/kg-day

0.014

Cadmium

0.14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.0E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0060

3.6E-06

mg/kg-day

1.0E-04

mg/kg-day

0.036

Chromium

6.00

mg/kg

9.62E-05

mg/kg-day

5.0E-01

(mg/kg-day)"1

4.8E-05

2.6E-05

mg/kg-day

3.0E-03

mg/kg-day

0.0086

1.6E-04

mg/kg-day

3.0E-03

mg/kg-day

0.052

Cobalt

6.1

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.6E-05

mg/kg-day

3.0E-04

mg/kg-day

0.087

1.6E-04

mg/kg-day

3.0E-04

mg/kg-day

0.53

Copper

12

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.2E-05

mg/kg-day

4.0E-02

mg/kg-day

0.0013

3.1E-04

mg/kg-day

4.0E-02

mg/kg-day

0.0078

Iron

11,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.7E-02

mg/kg-day

7.0E-01

mg/kg-day

0.068

2.9E-01

mg/kg-day

7.0E-01

mg/kg-day

0.41

Manganese

160

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.9E-04

mg/kg-day

2.4E-02

mg/kg-day

0.029

4.2E-03

mg/kg-day

2.4E-02

mg/kg-day

0.17

Molybdenum

0.32

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.4E-06

mg/kg-day

5.0E-03

mg/kg-day

0.00028

8.3E-06

mg/kg-day

5.0E-03

mg/kg-day

0.0017

Selenium

3.1

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.3E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0027

8.1E-05

mg/kg-day

5.0E-03

mg/kg-day

0.016

Thallium

0.14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.0E-07

mg/kg-day

1.0E-05

mg/kg-day

0.060

3.6E-06

mg/kg-day

1.0E-05

mg/kg-day

0.36

Uranium

7.3

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.1E-05

mg/kg-day

2.0E-04

mg/kg-day

0.16

1.9E-04

mg/kg-day

2.0E-04

mg/kg-day

0.95

Vanadium

14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.0E-05

mg/kg-day

5.0E-03

mg/kg-day

0.012

3.6E-04

mg/kg-day

5.0E-03

mg/kg-day

0.073

Metals Cancer Total

7E-05

Metals Noncancer Total

0.5

Metals Noncancer Total

3

Exposure Route Cancer Total

1E-03

Exposure Route Noncancer Total

0.5

Exposure Route Noncancer Total

3

Page 6 of 11


-------
Table C-5.1. Human Health Risk and Hazard Calculations - Quivira Church Rock Mine No. 1

Church Rock Mine No. 1 - Kee'da'whii teeh (Full-Time Resident)

COPCa

EPCb

Units

Cancer
Intake0

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake0

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Child
Noncancer
Intake0

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Child

Exposure Medium: Subsurface Soil (0-72 inches bgs)

Exposure Route: External Ex

posure

Uranium-238

1.1

pCi/g

5.6E+01

pCi/g

1.2E-10

risk/year pCi/g

7.0E-09

—

—

—

—

—

—

—

—

—

—

Uranium-234

1.2

pCi/g

6.1E+01

pCi/g

2.5E-10

risk/year pCi/g

1.5E-08

—

—

—

—

—

—

—

—

—

—

Thorium-230

1.7

pCi/g

8.7E+01

pCi/g

8.5E-10

risk/year pCi/g

7.3E-08

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

17

pCi/g

8.7E+02

pCi/g

8.4E-06

risk/year pCi/g

7.3E-03

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

7E-03

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Exposure Route Cancer Total

7E-03

Exposure Route Noncancer Total

—

Exposure Route Noncancer Total

—

Exposure Route: Dermal Exposure

Aluminum

4,600

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

Arsenic

4.8

mg/kg

1.0E-06

mg/kg-day

1.5E+00

(mg/kg-day)"1

1.5E-06

7.2E-07

mg/kg-day

3.0E-04

mg/kg-day

0.0024

4.4E-06

mg/kg-day

3.0E-04

mg/kg-day

0.015

Barium

110

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

Cadmium

0.14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.8E-08

mg/kg-day

1.0E-04

mg/kg-day

0.00028

1.7E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0017

Chromium

6.0

mg/kg

—

mg/kg-day

5.0E-01

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

Cobalt

6.1

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

Copper

12

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

Iron

11,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

Manganese

160

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

Molybdenum

0.32

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Selenium

3.1

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Thallium

0.14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

Uranium

7.3

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

Vanadium

14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Metals Cancer Total

2E-06

Metals Noncancer Total

0.003

Metals Noncancer Total

0.02

Exposure Route Cancer Total

2E-06

Exposure Route Noncancer Total

0.003

Exposure Route Noncancer Total

0.02

Page 7 of 11


-------
Table C-5.1. Human Health Risk and Hazard Calculations - Quivira Church Rock Mine No. 1

Church Rock Mine No. 1 - Kee'da'whii teeh (Full-Time Resident)

COPCa

EPCb

Units

Cancer
Intake0

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake0

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Child
Noncancer
Intake0

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Child

Exposure Medium: Subsurface Soil (0-72 inches bgs)

Exposure Route: Inhalation of Particulates

Uranium-238

1.1

pCi/g

9.6E-02

pCi

2.4E-08

risk/pCi

2.3E-09

—

—

—

—

—

—

—

—

—

—

Uranium-234

1.2

pCi/g

1.0E-01

pCi

2.8E-08

risk/pCi

2.9E-09

—

—

—

—

—

—

—

—

—

—

Thorium-230

1.7

pCi/g

1.5E-01

pCi

3.4E-08

risk/pCi

5.0E-09

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

17

pCi/g

1.5E+00

pCi

5.9E-08

risk/pCi

8.8E-08

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

1E-07

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

4,600

mg/kg

—

ug/m3

—

(ug/m3y1

—

6.0E-07

mg/m3

5.0E-03

mg/m3

0.00012

6.0E-07

mg/m3

5.0E-03

mg/m3

0.00012

Arsenic

4.8

mg/kg

6.2E-07

ug/m3

4.3E-03

(ug/m3y1

2.7E-09

6.2E-10

mg/m3

1.5E-05

mg/m3

0.000042

6.2E-10

mg/m3

1.5E-05

mg/m3

0.000042

Barium

110

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.4E-08

mg/m3

5.0E-04

mg/m3

0.00003

1.4E-08

mg/m3

5.0E-04

mg/m3

0.00003

Cadmium

0.14

mg/kg

1.8E-08

ug/m3

1.8E-03

(ug/m3)"1

3.3E-11

1.8E-11

mg/m3

1.0E-05

mg/m3

0.0000018

1.8E-11

mg/m3

1.0E-05

mg/m3

0.0000018

Chromium

6.0

mg/kg

1.3E-06

ug/m3

8.4E-02

(ug/m3)"1

1.1E-07

7.8E-10

mg/m3

1.0E-04

mg/m3

0.0000078

7.8E-10

mg/m3

1.0E-04

mg/m3

0.0000078

Cobalt

6.1

mg/kg

7.9E-07

ug/m3

9.0E-03

(ug/m3)"1

7.1E-09

7.9E-10

mg/m3

6.0E-06

mg/m3

0.00013

7.9E-10

mg/m3

6.0E-06

mg/m3

0.00013

Copper

12

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

—

mg/m3

—

mg/m3

—

Iron

11,000

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

—

mg/m3

—

mg/m3

—

Manganese

160

mg/kg

—

ug/m3

—

(ug/m3)"1

—

2.1E-08

mg/m3

5.0E-05

mg/m3

0.00042

2.1E-08

mg/m3

5.0E-05

mg/m3

0.00042

Molybdenum

0.32

mg/kg

—

ug/m3

—

(ug/m3)"1

—

4.2E-11

mg/m3

2.0E-03

mg/m3

0.000000021

4.2E-11

mg/m3

2.0E-03

mg/m3

0.000000021

Selenium

3.1

mg/kg

—

ug/m3

—

(ug/m3)"1

—

4.0E-10

mg/m3

2.0E-02

mg/m3

0.000000020

4.0E-10

mg/m3

2.0E-02

mg/m3

0.000000020

Thallium

0.14

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

—

mg/m3

—

mg/m3

—

Uranium

7.3

mg/kg

—

ug/m3

—

(ug/m3)"1

—

9.5E-10

mg/m3

4.0E-05

mg/m3

0.000024

9.5E-10

mg/m3

4.0E-05

mg/m3

0.000024

Vanadium

14

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.8E-09

mg/m3

1.0E-04

mg/m3

0.000018

1.8E-09

mg/m3

1.0E-04

mg/m3

0.000018

Metals Cancer Total

1E-07

Metals Noncancer Total

0.0008

Metals Noncancer Total

0.001

Exposure Route Cancer Total

2E-07

Exposure Route Noncancer Total

0.0008

Exposure Route Noncancer Total

0.001

Exposure Medium: Subsurface Soil (0-72 inches bgs)

Exposure Route: Plant Consumption

Uranium-238

1.1

pCi/g

7.8E+04

pCi/g

8.7E-11

risk/pCi/g

6.8E-06

—

—

—

—

—

—

—

—

—

—

Uranium-234

1.2

pCi/g

8.5E+04

pCi/g

9.6E-11

risk/pCi/g

8.1E-06

—

—

—

—

—

—

—

—

—

—

Thorium-230

1.7

pCi/g

3.1E+04

pCi/g

1.2E-10

risk/pCi/g

3.6E-06

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

17

pCi/g

1.9E+06

pCi/g

3.7E-09

risk/pCi/g

6.9E-03

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

7E-03

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

4,600

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.5E-02

mg/kg-day

1.0E+00

mg/kg-day

0.055

1.4E-01

mg/kg-day

1.0E+00

mg/kg-day

0.14

Arsenic

4.8

mg/kg

6.7E-05

mg/kg-day

1.5E+00

(mg/kg-day)"1

1.0E-04

6.2E-05

mg/kg-day

3.0E-04

mg/kg-day

0.21

1.6E-04

mg/kg-day

3.0E-04

mg/kg-day

0.54

Barium

110

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.5E-03

mg/kg-day

2.0E-01

mg/kg-day

0.013

6.7E-03

mg/kg-day

2.0E-01

mg/kg-day

0.034

Cadmium

0.14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

8.3E-06

mg/kg-day

1.0E-04

mg/kg-day

0.083

2.2E-05

mg/kg-day

1.0E-04

mg/kg-day

0.22

Cobalt

6.1

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.1E-04

mg/kg-day

3.0E-04

mg/kg-day

0.37

2.9E-04

mg/kg-day

3.0E-04

mg/kg-day

0.98

Chromium

6.0

mg/kg

1.7E-04

mg/kg-day

5.0E-01

(mg/kg-day)"1

8.4E-05

7.2E-05

mg/kg-day

3.0E-03

mg/kg-day

0.024

1.9E-04

mg/kg-day

3.0E-03

mg/kg-day

0.064

Copper

12

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.0E-03

mg/kg-day

4.0E-02

mg/kg-day

0.051

5.4E-03

mg/kg-day

4.0E-02

mg/kg-day

0.14

Iron

11,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

--

1.3E-01

mg/kg-day

7.0E-01

mg/kg-day

0.19

3.4E-01

mg/kg-day

7.0E-01

mg/kg-day

0.49

Manganese

160

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.8E-02

mg/kg-day

2.4E-02

mg/kg-day

0.73

4.6E-02

mg/kg-day

2.4E-02

mg/kg-day

1.9

Molybdenum

0.32

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.5E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0070

9.3E-05

mg/kg-day

5.0E-03

mg/kg-day

0.019

Selenium

3.1

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.6E-05

mg/kg-day

5.0E-03

mg/kg-day

0.011

1.5E-04

mg/kg-day

5.0E-03

mg/kg-day

0.030

Thallium

0.14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.4E-06

mg/kg-day

1.0E-05

mg/kg-day

0.14

3.9E-06

mg/kg-day

1.0E-05

mg/kg-day

0.39

Uranium

7.3

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

9.5E-05

mg/kg-day

2.0E-04

mg/kg-day

0.47

2.6E-04

mg/kg-day

2.0E-04

mg/kg-day

1.3

Vanadium

14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.7E-04

mg/kg-day

5.0E-03

mg/kg-day

0.034

4.6E-04

mg/kg-day

5.0E-03

mg/kg-day

0.092

Metals Cancer Total

2E-04

Metals Noncancer Total

2

Metals Noncancer Total

6

Exposure Route Cancer Total

7E-03

Exposure Route Noncancer Total

2

Exposure Route Noncancer Total

6

Page 8 of 11


-------
Table C-5.1. Human Health Risk and Hazard Calculations - Quivira Church Rock Mine No. 1

Church Rock Mine No. 1 - Kee'da'whii teeh (Full-Time Resident)

COPCa

EPCb

Units

Cancer
Intake0

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake0

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Child
Noncancer
Intake0

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Child

Exposure Medium: Subsurface Soil (0-72 inches bgs)

Exposure Route: Animal Consumption

Uranium-238

1.1

pCi/g

8.9E+04

pCi/g

8.7E-11

risk/pCi/g

7.7E-06

—

—

—

—

—

—

—

—

—

—

Uranium-234

1.2

pCi/g

9.7E+04

pCi/g

9.6E-11

risk/pCi/g

9.3E-06

—

—

—

—

—

—

—

—

—

—

Thorium-230

1.7

pCi/g

6.6E+01

pCi/g

1.2E-10

risk/pCi/g

7.9E-09

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

17

pCi/g

3.6E+06

pCi/g

3.7E-09

risk/pCi/g

1.3E-02

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

1E-02

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

4,600

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.2E-03

mg/kg-day

1.0E+00

mg/kg-day

0.0032

8.7E-03

mg/kg-day

1.0E+00

mg/kg-day

0.0087

Arsenic

4.8

mg/kg

5.3E-06

mg/kg-day

1.5E+00

(mg/kg-day)"1

7.9E-06

4.7E-06

mg/kg-day

3.0E-04

mg/kg-day

0.016

1.2E-05

mg/kg-day

3.0E-04

mg/kg-day

0.042

Barium

110

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.4E-05

mg/kg-day

2.0E-01

mg/kg-day

0.000072

3.9E-05

mg/kg-day

2.0E-01

mg/kg-day

0.00019

Cadmium

0.14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.2E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0032

8.4E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0084

Chromium

6.0

mg/kg

3.7E-05

mg/kg-day

5.0E-01

(mg/kg-day)"1

1.8E-05

1.6E-05

mg/kg-day

3.0E-03

mg/kg-day

0.0053

4.2E-05

mg/kg-day

3.0E-03

mg/kg-day

0.0141

Cobalt

6.1

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.9E-05

mg/kg-day

3.0E-04

mg/kg-day

0.20

1.6E-04

mg/kg-day

3.0E-04

mg/kg-day

0.53

Copper

12

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.1E-04

mg/kg-day

4.0E-02

mg/kg-day

0.0027

2.9E-04

mg/kg-day

4.0E-02

mg/kg-day

0.0072

Iron

11,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.0E-01

mg/kg-day

7.0E-01

mg/kg-day

0.14

2.6E-01

mg/kg-day

7.0E-01

mg/kg-day

0.38

Manganese

160

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.3E-05

mg/kg-day

2.4E-02

mg/kg-day

0.0022

1.4E-04

mg/kg-day

2.4E-02

mg/kg-day

0.0059

Molybdenum

0.32

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.4E-06

mg/kg-day

5.0E-03

mg/kg-day

0.00029

3.8E-06

mg/kg-day

5.0E-03

mg/kg-day

0.00077

Selenium

3.1

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.4E-04

mg/kg-day

5.0E-03

mg/kg-day

0.048

6.5E-04

mg/kg-day

5.0E-03

mg/kg-day

0.13

Thallium

0.14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.5E-06

mg/kg-day

1.0E-05

mg/kg-day

0.25

6.9E-06

mg/kg-day

1.0E-05

mg/kg-day

0.69

Uranium

7.3

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.0E-06

mg/kg-day

2.0E-04

mg/kg-day

0.0051

2.8E-06

mg/kg-day

2.0E-04

mg/kg-day

0.014

Vanadium

14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.5E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0031

4.2E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0084

Metals Cancer Total

3E-05

Metals Noncancer Total

0.7

Metals Noncancer Total

2

Exposure Route Cancer Total

1E-02

Exposure Route Noncancer Total

0.7

Exposure Route Noncancer Total

2

Exposure Medium: Subsurface Soil (0-72 inches bgs)

Exposure Route: Other Dine Lifeways Plant Ingestion

Uranium-238

1.1

pCi/g

3.6E+04

pCi/g

8.7E-11

risk/pCi/g

3.1E-06

—

—

—

—

—

—

—

—

—

—

Uranium-234

1.2

pCi/g

4.0E+04

pCi/g

9.6E-11

risk/pCi/g

3.8E-06

—

—

—

—

—

—

—

—

—

—

Thorium-230

1.7

pCi/g

1.7E+04

pCi/g

1.2E-10

risk/pCi/g

2.0E-06

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

17

pCi/g

1.0E+06

pCi/g

3.7E-09

risk/pCi/g

3.8E-03

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

4E-03

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

4,600

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.3E-02

mg/kg-day

1.0E+00

mg/kg-day

0.033

—

mg/kg-day

1.0E+00

mg/kg-day

—

Arsenic

4.8

mg/kg

3.4E-05

mg/kg-day

1.5E+00

(mg/kg-day)"1

5.1E-05

3.7E-05

mg/kg-day

3.0E-04

mg/kg-day

0.12

—

mg/kg-day

3.0E-04

mg/kg-day

—

Barium

110

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.7E-03

mg/kg-day

2.0E-01

mg/kg-day

0.0083

—

mg/kg-day

2.0E-01

mg/kg-day

—

Cadmium

0.14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.6E-06

mg/kg-day

1.0E-04

mg/kg-day

0.056

—

mg/kg-day

1.0E-04

mg/kg-day

—

Chromium

6.0

mg/kg

5.2E-05

mg/kg-day

5.0E-01

(mg/kg-day)"1

2.6E-05

4.4E-05

mg/kg-day

3.0E-03

mg/kg-day

0.015

—

mg/kg-day

3.0E-03

mg/kg-day

—

Cobalt

6.1

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.7E-05

mg/kg-day

3.0E-04

mg/kg-day

0.22

—

mg/kg-day

3.0E-04

mg/kg-day

—

Copper

12

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.3E-03

mg/kg-day

4.0E-02

mg/kg-day

0.033

—

mg/kg-day

4.0E-02

mg/kg-day

—

Iron

11,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

--

7.8E-02

mg/kg-day

7.0E-01

mg/kg-day

0.11

—

mg/kg-day

7.0E-01

mg/kg-day

—

Manganese

160

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.2E-02

mg/kg-day

2.4E-02

mg/kg-day

0.49

—

mg/kg-day

2.4E-02

mg/kg-day

—

Molybdenum

0.32

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.3E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0047

—

mg/kg-day

5.0E-03

mg/kg-day

—

Selenium

3.1

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.4E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0068

—

mg/kg-day

5.0E-03

mg/kg-day

—

Thallium

0.14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

8.8E-07

mg/kg-day

1.0E-05

mg/kg-day

0.088

—

mg/kg-day

1.0E-05

mg/kg-day

—

Uranium

7.3

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.1E-05

mg/kg-day

2.0E-04

mg/kg-day

0.30

—

mg/kg-day

2.0E-04

mg/kg-day

—

Vanadium

14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.1E-04

mg/kg-day

5.0E-03

mg/kg-day

0.021

—

mg/kg-day

5.0E-03

mg/kg-day

—

Metals Cancer Total

8E-05

Metals Noncancer Total

2

Metals Noncancer Total

—

Exposure Route Cancer Total

4E-03

Exposure Route Noncancer Total

2

Exposure Route Noncancer Total

-

Page 9 of 11


-------
Table C-5.1. Human Health Risk and Hazard Calculations - Quivira Church Rock Mine No. 1

Church Rock Mine No. 1 - Kee'da'whii teeh (Full-Time Resident)

COPCa

EPCb

Units

Cancer
Intake0

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake0

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Child
Noncancer
Intake0

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Child

Exposure Medium: Subsurface Soil (0-72 inches bgs)

Exposure Route: Other Dine Lifeways Plant Dermal

Aluminum

4,600

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

Arsenic

4.8

mg/kg

2.9E-06

mg/kg-day

1.5E+00

(mg/kg-day)"1

4.3E-06

3.1E-06

mg/kg-day

3.0E-04

mg/kg-day

0.010

—

mg/kg-day

3.0E-04

mg/kg-day

—

Barium

110

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

Cadmium

0.14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.2E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0062

—

mg/kg-day

1.0E-04

mg/kg-day

—

Chromium

6.0

mg/kg

—

mg/kg-day

5.0E-01

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

Cobalt

6.1

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

Copper

12

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

Iron

11,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

Manganese

160

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

Molybdenum

0.32

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Selenium

3.1

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Thallium

0.14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

Uranium

7.3

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

Vanadium

14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Metals Cancer Total

4E-06

Metals Noncancer Total

0.02

Metals Noncancer Total

—

Exposure Route Cancer Total

4E-06

Exposure Route Noncancer Total

0.02

Exposure Route Noncancer Total

—

Exposure Medium: Subsurface Soil (0-72 inches bgs)

Exposure Route: Other Dine Lifeways Plant Inhalation

Uranium-238

1.1

pCi/g

2.5E+02

pCi

2.4E-08

risk/pCi

6.0E-06

—

—

—

—

—

—

—

—

—

—

Uranium-234

1.2

pCi/g

2.8E+02

pCi

2.8E-08

risk/pCi

7.7E-06

—

—

—

—

—

—

—

—

—

—

Thorium-230

1.7

pCi/g

7.7E+01

pCi

3.4E-08

risk/pCi

2.6E-06

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

17

pCi/g

1.1E+04

pCi

5.9E-08

risk/pCi

6.3E-04

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

7E-04

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

4,600

mg/kg

—

ug/m3

—

(ug/m3)"1

—

3.3E-04

mg/m3

5.0E-03

mg/m3

0.066

—

mg/m3

5.0E-03

mg/m3

—

Arsenic

4.8

mg/kg

3.5E-04

ug/m3

4.3E-03

(ug/m3)"1

1.5E-06

3.8E-07

mg/m3

1.5E-05

mg/m3

0.025

—

mg/m3

1.5E-05

mg/m3

—

Barium

110

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.7E-05

mg/m3

5.0E-04

mg/m3

0.033

—

mg/m3

5.0E-04

mg/m3

—

Cadmium

0.14

mg/kg

5.2E-05

ug/m3

1.8E-03

(ug/m3)"1

9.3E-08

5.6E-08

mg/m3

1.0E-05

mg/m3

0.0056

—

mg/m3

1.0E-05

mg/m3

—

Chromium

6.0

mg/kg

5.3E-04

ug/m3

8.4E-02

(ug/m3)"1

4.5E-05

8.9E-08

mg/m3

1.0E-04

mg/m3

0.00089

—

mg/m3

1.0E-04

mg/m3

—

Cobalt

6.1

mg/kg

6.7E-04

ug/m3

9.0E-03

(ug/m3)"1

6.0E-06

7.3E-07

mg/m3

6.0E-06

mg/m3

0.12

—

mg/m3

6.0E-06

mg/m3

—

Copper

12

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

—

mg/m3

—

mg/m3

—

Iron

11,000

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

—

mg/m3

—

mg/m3

—

Manganese

160

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.2E-04

mg/m3

5.0E-05

mg/m3

2.3

—

mg/m3

5.0E-05

mg/m3

—

Molybdenum

0.32

mg/kg

—

ug/m3

—

(ug/m3)"1

—

2.3E-07

mg/m3

2.0E-03

mg/m3

0.00012

—

mg/m3

2.0E-03

mg/m3

—

Selenium

3.1

mg/kg

—

ug/m3

—

(ug/m3)"1

—

3.4E-07

mg/m3

2.0E-02

mg/m3

0.000017

—

mg/m3

2.0E-02

mg/m3

—

Thallium

0.14

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

—

mg/m3

—

mg/m3

—

Uranium

7.3

mg/kg

—

ug/m3

—

(ug/m3)"1

—

6.2E-07

mg/m3

4.0E-05

mg/m3

0.016

—

mg/m3

4.0E-05

mg/m3

—

Vanadium

14

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.1E-06

mg/m3

1.0E-04

mg/m3

0.011

—

mg/m3

1.0E-04

mg/m3

—

Metals Cancer Total

5E-05

Metals Noncancer Total

o

O

Metals Noncancer Total

—

Exposure Route Cancer Total

7E-04

Exposure Route Noncancer Total

3

Exposure Route Noncancer Total

—

Subsurface Soil (0-72 inches bgs) Receptor Cancer Risk Total

3E-02

Receptor/Media Noncancer Hazard Total

8

Receptor/Media Noncancer Hazard Total

10

Page 10 of 11


-------
Table C-5.1. Human Health Risk and Hazard Calculations - Quivira Church Rock Mine No. 1

Notes:

a COPCs are the constituents of interest with a maximum detected concentration exceeding the COPC screening level (see Table C-1).
b EPCs are provided on Table C-4.

c The intakes are the EPC multiplied by the exposure parameters and any applicable contaminant-specific inputs (see Table C-3 for exposure inputs, Table 4 of the NAUM risk assessment methodology [USEPA 2024b] report for contaminant-specific inputs,

and Appendix B of the NAUM risk assessment methodology [USEPA 2024b] report for equations).
d The toxicity values are provided in Table 4 of the NAUM risk assessment methodology (USEPA 2024b).

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

|jg/m3

Microgram per cubic meter

bgs

Below ground surface

COPC

Contaminant of potential concern

EPC

Exposure point concentration

mg/kg

Milligram per kilogram

mg/kg-day

Milligram per kilogram per day

mg/m3

Milligram per cubic meter

NAUM

Navajo abandoned uranium mine

pCi

Picocurie

pCi/g

Picocurie per gram

RfC

Reference concentration

RfD

Reference dose

SE

Secular equilibrium

USEPA

U.S. Environmental Protection Agency

Reference:

U.S. Environmental Protection Agency (USEPA). 2024b. "Navajo Abandoned Uranium Mines Risk Assessment Methodology." Draft Final. March.

Page 11 of 11


-------
Table C-5.2. Human Health Risk and Hazard Calculations - Quivira Church Rock Mine No. 1 East

Church Rock Mine No. 1 East - Kee'da'whii teeh (Full-Time Resident)

COPCa

EPCb

Units

Cancer
lntakec

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake3

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

1.3

pCi/g

1.2E+04

pCi/g

1.3E-10

risk/pCi/g

1.7E-06

—

—

—

—

—

—

—

—

—

—

Uranium-234

1.4

pCi/g

1.3E+04

pCi/g

1.5E-10

risk/pCi/g

2.0E-06

—

—

—

—

—

—

—

—

—

—

Thorium-230

3.6

pCi/g

3.4E+04

pCi/g

1.7E-10

risk/pCi/g

5.7E-06

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

9.3

pCi/g

8.8E+04

pCi/g

5.7E-09

risk/pCi/g

5.0E-04

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

5E-04

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

6,300

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.7E-02

mg/kg-day

1.0E+00

mg/kg-day

0.027

1.6E-01

mg/kg-day

1.0E+00

mg/kg-day

0.16

Arsenic

6.6

mg/kg

2.4E-05

mg/kg-day

1.5E+00

(mg/kg-day)"1

3.6E-05

1.7E-05

mg/kg-day

3.0E-04

mg/kg-day

0.057

9.9E-05

mg/kg-day

3.0E-04

mg/kg-day

0.33

Barium

160

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.9E-04

mg/kg-day

2.0E-01

mg/kg-day

0.0034

4.2E-03

mg/kg-day

2.0E-01

mg/kg-day

0.021

Cadmium

0.13

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.6E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0056

3.4E-06

mg/kg-day

1.0E-04

mg/kg-day

0.034

Chromium

10

mg/kg

1.60E-04

mg/kg-day

5.0E-01

(mg/kg-day)"1

8.0E-05

4.3E-05

mg/kg-day

3.0E-03

mg/kg-day

0.014

2.6E-04

mg/kg-day

3.0E-03

mg/kg-day

0.087

Cobalt

6.9

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.0E-05

mg/kg-day

3.0E-04

mg/kg-day

0.099

1.8E-04

mg/kg-day

3.0E-04

mg/kg-day

0.60

Copper

13

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.6E-05

mg/kg-day

4.0E-02

mg/kg-day

0.0014

3.4E-04

mg/kg-day

4.0E-02

mg/kg-day

0.0085

Iron

16,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.9E-02

mg/kg-day

7.0E-01

mg/kg-day

0.098

4.2E-01

mg/kg-day

7.0E-01

mg/kg-day

0.59

Manganese

200

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

8.6E-04

mg/kg-day

2.4E-02

mg/kg-day

0.036

5.2E-03

mg/kg-day

2.4E-02

mg/kg-day

0.22

Molybdenum

0.31

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.3E-06

mg/kg-day

5.0E-03

mg/kg-day

0.00027

8.1E-06

mg/kg-day

5.0E-03

mg/kg-day

0.0016

Selenium

3.0

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.3E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0026

7.8E-05

mg/kg-day

5.0E-03

mg/kg-day

0.016

Thallium

0.16

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.9E-07

mg/kg-day

1.0E-05

mg/kg-day

0.069

4.2E-06

mg/kg-day

1.0E-05

mg/kg-day

0.42

Uranium

3.6

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.5E-05

mg/kg-day

2.0E-04

mg/kg-day

0.08

9.4E-05

mg/kg-day

2.0E-04

mg/kg-day

0.47

Vanadium

16

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.9E-05

mg/kg-day

5.0E-03

mg/kg-day

0.014

4.2E-04

mg/kg-day

5.0E-03

mg/kg-day

0.083

Metals Cancer Total

1E-04

Metals Noncancer Total

0.5

Metals Noncancer Total

3

Exposure Route Cancer Total

6E-04

Exposure Route Noncancer Total

0.5

Exposure Route Noncancer Total

3

Page 1 of 11


-------
Table C-5.2. Human Health Risk and Hazard Calculations - Quivira Church Rock Mine No. 1 East

Church Rock Mine No. 1 East - Kee'da'whii teeh (Full-Time Resident)

COPCa

EPCb

Units

Cancer
lntakec

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake3

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: External Exposure

Uranium-238

1.3

pCi/g

6.6E+01

pCi/g

1.2E-10

risk/year pCi/g

8.2E-09

—

—

—

—

—

—

—

—

—

—

Uranium-234

1.4

pCi/g

7.1E+01

pCi/g

2.5E-10

risk/year pCi/g

1.8E-08

—

—

—

—

—

—

—

—

—

—

Thorium-230

3.6

pCi/g

1.8E+02

pCi/g

8.5E-10

risk/year pCi/g

1.6E-07

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

9.3

pCi/g

4.7E+02

pCi/g

8.4E-06

risk/year pCi/g

4.0E-03

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

4E-03

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Exposure Route Cancer Total

4E-03

Exposure Route Noncancer Total

—

Exposure Route Noncancer Total

—

Exposure Route: Dermal Exposure

Aluminum

6,300

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

Arsenic

6.6

mg/kg

1.4E-06

mg/kg-day

1.5E+00

(mg/kg-day)"1

2.1E-06

9.9E-07

mg/kg-day

3.0E-04

mg/kg-day

0.0033

6.0E-06

mg/kg-day

3.0E-04

mg/kg-day

0.020

Barium

160

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

Cadmium

0.13

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.6E-08

mg/kg-day

1.0E-04

mg/kg-day

0.00026

1.6E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0016

Chromium

10

mg/kg

—

mg/kg-day

5.0E-01

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

Cobalt

6.9

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

Copper

13

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

Iron

16,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

Manganese

200

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

Molybdenum

0.31

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Selenium

3.0

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Thallium

0.16

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

Uranium

3.6

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

Vanadium

16

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Metals Cancer Total

2E-06

Metals Noncancer Total

0.004

Metals Noncancer Total

0.02

Exposure Route Cancer Total

2E-06

Exposure Route Noncancer Total

0.004

Exposure Route Noncancer Total

0.02

Page 2 of 11


-------
Table C-5.2. Human Health Risk and Hazard Calculations - Quivira Church Rock Mine No. 1 East

Church Rock Mine No. 1 East - Kee'da'whii teeh (Full-Time Resident)

COPCa

EPCb

Units

Cancer
lntakec

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake3

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

1.3

pCi/g

1.1E-01

pCi

2.4E-08

risk/pCi

2.7E-09

—

—

—

—

—

—

—

—

—

—

Uranium-234

1.4

pCi/g

1.2E-01

pCi

2.8E-08

risk/pCi

3.4E-09

—

—

—

—

—

—

—

—

—

—

Thorium-230

3.6

pCi/g

3.1E-01

pCi

3.4E-08

risk/pCi

1.1E-08

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

9.3

pCi/g

8.1E-01

pCi

5.9E-08

risk/pCi

4.8E-08

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

6E-08

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

6,300

mg/kg

—

ug/m3

—

(ug/m3y1

—

8.2E-07

mg/m3

5.0E-03

mg/m3

0.00016

8.2E-07

mg/m3

5.0E-03

mg/m3

0.00016

Arsenic

6.6

mg/kg

8.6E-07

ug/m3

4.3E-03

(ug/m3y1

3.7E-09

8.6E-10

mg/m3

1.5E-05

mg/m3

0.000057

8.6E-10

mg/m3

1.5E-05

mg/m3

0.000057

Barium

160

mg/kg

—

ug/m3

—

(ug/m3)"1

—

2.1E-08

mg/m3

5.0E-04

mg/m3

0.000042

2.1E-08

mg/m3

5.0E-04

mg/m3

0.000042

Cadmium

0.13

mg/kg

1.7E-08

ug/m3

1.8E-03

(ug/m3)"1

3.0E-11

1.7E-11

mg/m3

1.0E-05

mg/m3

0.0000017

1.7E-11

mg/m3

1.0E-05

mg/m3

0.0000017

Chromium

10

mg/kg

2.1E-06

ug/m3

8.4E-02

(ug/m3)"1

1.8E-07

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

6.9

mg/kg

9.0E-07

ug/m3

9.0E-03

(ug/m3)"1

8.1E-09

9.0E-10

mg/m3

6.0E-06

mg/m3

0.00015

9.0E-10

mg/m3

6.0E-06

mg/m3

0.00015

Copper

13

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

—

mg/m3

—

mg/m3

—

Iron

16,000

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

-

mg/m3

—

mg/m3

—

Manganese

200

mg/kg

—

ug/m3

—

(ug/m3)"1

—

2.6E-08

mg/m3

5.0E-05

mg/m3

0.00052

2.6E-08

mg/m3

5.0E-05

mg/m3

0.00052

Molybdenum

0.31

mg/kg

—

ug/m3

—

(ug/m3)"1

—

4.0E-11

mg/m3

2.0E-03

mg/m3

0.000000020

4.0E-11

mg/m3

2.0E-03

mg/m3

0.000000020

Selenium

3.0

mg/kg

—

ug/m3

—

(ug/m3)"1

—

3.9E-10

mg/m3

2.0E-02

mg/m3

0.000000020

3.9E-10

mg/m3

2.0E-02

mg/m3

0.000000020

Thallium

0.16

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

-

mg/m3

—

mg/m3

—

Uranium

3.6

mg/kg

—

ug/m3

—

(ug/m3)"1

—

4.7E-10

mg/m3

4.0E-05

mg/m3

0.000012

4.7E-10

mg/m3

4.0E-05

mg/m3

0.000012

Vanadium

16

mg/kg

—

ug/m3

—

(ug/m3)"1

—

2.1E-09

mg/m3

1.0E-04

mg/m3

0.000021

2.1E-09

mg/m3

1.0E-04

mg/m3

0.000021

Metals Cancer Total

2E-07

Metals Noncancer Total

0.001

Metals Noncancer Total

0.001

Exposure Route Cancer Total

3E-07

Exposure Route Noncancer Total

0.001

Exposure Route Noncancer Total

0.001

Exposure Medium: Surface Soil (0-6 inches bgs)

Exposure Route: Plant Consumption

Uranium-238

1.3

pCi/g

9.2E+04

pCi/g

8.7E-11

risk/pCi/g

8.0E-06

—

—

—

—

—

—

—

—

—

—

Uranium-234

1.4

pCi/g

9.9E+04

pCi/g

9.6E-11

risk/pCi/g

9.5E-06

—

—

—

—

—

—

—

—

—

—

Thorium-230

3.6

pCi/g

6.5E+04

pCi/g

1.2E-10

risk/pCi/g

7.7E-06

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

9.3

pCi/g

1.0E+06

pCi/g

3.7E-09

risk/pCi/g

3.8E-03

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

4E-03

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

6,300

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

7.6E-02

mg/kg-day

1.0E+00

mg/kg-day

0.076

2.0E-01

mg/kg-day

1.0E+00

mg/kg-day

0.20

Arsenic

6.6

mg/kg

9.2E-05

mg/kg-day

1.5E+00

(mg/kg-day)"1

1.4E-04

8.6E-05

mg/kg-day

3.0E-04

mg/kg-day

0.29

2.2E-04

mg/kg-day

3.0E-04

mg/kg-day

0.75

Barium

160

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.7E-03

mg/kg-day

2.0E-01

mg/kg-day

0.018

9.8E-03

mg/kg-day

2.0E-01

mg/kg-day

0.049

Cadmium

0.13

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

7.7E-06

mg/kg-day

1.0E-04

mg/kg-day

0.077

2.1E-05

mg/kg-day

1.0E-04

mg/kg-day

0.21

Cobalt

6.9

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.2E-04

mg/kg-day

3.0E-04

mg/kg-day

0.41

3.3E-04

mg/kg-day

3.0E-04

mg/kg-day

1.1

Chromium

10

mg/kg

2.80E-04

mg/kg-day

5.0E-01

(mg/kg-day)"1

1.4E-04

1.2E-04

mg/kg-day

3.0E-03

mg/kg-day

0.040

3.2E-04

mg/kg-day

3.0E-03

mg/kg-day

0.11

Copper

13

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.2E-03

mg/kg-day

4.0E-02

mg/kg-day

0.055

5.9E-03

mg/kg-day

4.0E-02

mg/kg-day

0.15

Iron

16,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

--

1.9E-01

mg/kg-day

7.0E-01

mg/kg-day

0.27

5.0E-01

mg/kg-day

7.0E-01

mg/kg-day

0.71

Manganese

200

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.2E-02

mg/kg-day

2.4E-02

mg/kg-day

0.92

5.8E-02

mg/kg-day

2.4E-02

mg/kg-day

2.4

Molybdenum

0.31

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.4E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0068

9.0E-05

mg/kg-day

5.0E-03

mg/kg-day

0.018

Selenium

3.0

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.4E-05

mg/kg-day

5.0E-03

mg/kg-day

0.011

1.4E-04

mg/kg-day

5.0E-03

mg/kg-day

0.029

Thallium

0.16

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.6E-06

mg/kg-day

1.0E-05

mg/kg-day

0.16

4.5E-06

mg/kg-day

1.0E-05

mg/kg-day

0.45

Uranium

3.6

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.7E-05

mg/kg-day

2.0E-04

mg/kg-day

0.23

1.3E-04

mg/kg-day

2.0E-04

mg/kg-day

0.6

Vanadium

16

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.9E-04

mg/kg-day

5.0E-03

mg/kg-day

0.038

5.3E-04

mg/kg-day

5.0E-03

mg/kg-day

0.106

Metals Cancer Total

3E-04

Metals Noncancer Total

3

Metals Noncancer Total

7

Exposure Route Cancer Total

4E-03

Exposure Route Noncancer Total

3

Exposure Route Noncancer Total

7

Page 3 of 11


-------
Table C-5.2. Human Health Risk and Hazard Calculations - Quivira Church Rock Mine No. 1 East

Church Rock Mine No. 1 East - Kee'da'whii teeh (Full-Time Resident)

COPCa

EPCb

Units

Cancer
lntakec

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake3

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: Animal Consumption

Uranium-238

1.3

pCi/g

1.1E+05

pCi/g

8.7E-11

risk/pCi/g

9.1E-06

—

—

—

—

—

—

—

—

—

—

Uranium-234

1.4

pCi/g

1.1E+05

pCi/g

9.6E-11

risk/pCi/g

1.1E-05

—

—

—

—

—

—

—

—

—

—

Thorium-230

3.6

pCi/g

1.4E+02

pCi/g

1.2E-10

risk/pCi/g

1.7E-08

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

9.3

pCi/g

2.0E+06

pCi/g

3.7E-09

risk/pCi/g

7.2E-03

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

7E-03

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

6,300

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.4E-03

mg/kg-day

1.0E+00

mg/kg-day

0.0044

1.2E-02

mg/kg-day

1.0E+00

mg/kg-day

0.012

Arsenic

6.6

mg/kg

7.3E-06

mg/kg-day

1.5E+00

(mg/kg-day)"1

1.1E-05

6.5E-06

mg/kg-day

3.0E-04

mg/kg-day

0.022

1.7E-05

mg/kg-day

3.0E-04

mg/kg-day

0.057

Barium

160

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.1E-05

mg/kg-day

2.0E-01

mg/kg-day

0.000104

5.6E-05

mg/kg-day

2.0E-01

mg/kg-day

0.00028

Cadmium

0.13

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.0E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0030

7.8E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0078

Cobalt

6.9

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.6E-05

mg/kg-day

3.0E-04

mg/kg-day

0.22

1.8E-04

mg/kg-day

3.0E-04

mg/kg-day

0.60

Chromium

10

mg/kg

6.14E-05

mg/kg-day

5.0E-01

(mg/kg-day)"1

3.1E-05

2.6E-05

mg/kg-day

3.0E-03

mg/kg-day

0.0088

7.0E-05

mg/kg-day

3.0E-03

mg/kg-day

0.023

Copper

13

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.2E-04

mg/kg-day

4.0E-02

mg/kg-day

0.0029

3.1E-04

mg/kg-day

4.0E-02

mg/kg-day

0.0078

Iron

16,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.5E-01

mg/kg-day

7.0E-01

mg/kg-day

0.21

3.8E-01

mg/kg-day

7.0E-01

mg/kg-day

0.55

Manganese

200

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.6E-05

mg/kg-day

2.4E-02

mg/kg-day

0.0028

1.8E-04

mg/kg-day

2.4E-02

mg/kg-day

0.0074

Molybdenum

0.31

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.4E-06

mg/kg-day

5.0E-03

mg/kg-day

0.00028

3.7E-06

mg/kg-day

5.0E-03

mg/kg-day

0.00074

Selenium

3.0

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.3E-04

mg/kg-day

5.0E-03

mg/kg-day

0.046

6.3E-04

mg/kg-day

5.0E-03

mg/kg-day

0.13

Thallium

0.16

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.9E-06

mg/kg-day

1.0E-05

mg/kg-day

0.29

7.8E-06

mg/kg-day

1.0E-05

mg/kg-day

0.78

Uranium

3.6

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.0E-07

mg/kg-day

2.0E-04

mg/kg-day

0.0025

1.4E-06

mg/kg-day

2.0E-04

mg/kg-day

0.0068

Vanadium

16

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.8E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0035

4.8E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0096

Metals Cancer Total

4E-05

Metals Noncancer Total

0.8

Metals Noncancer Total

2

Exposure Route Cancer Total

7E-03

Exposure Route Noncancer Total

0.8

Exposure Route Noncancer Total

2

Exposure Medium: Surface Soil (0-6 inches bgs)

Exposure Route: Other Dine Lifeways Plant Ingestion

Uranium-238

1.3

pCi/g

4.3E+04

pCi/g

8.7E-11

risk/pCi/g

3.7E-06

—

—

—

—

—

—

—

—

—

—

Uranium-234

1.4

pCi/g

4.6E+04

pCi/g

9.6E-11

risk/pCi/g

4.4E-06

—

—

—

—

—

—

—

—

—

—

Thorium-230

3.6

pCi/g

3.5E+04

pCi/g

1.2E-10

risk/pCi/g

4.2E-06

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

9.3

pCi/g

5.6E+05

pCi/g

3.7E-09

risk/pCi/g

2.1E-03

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

2E-03

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

6,300

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.5E-02

mg/kg-day

1.0E+00

mg/kg-day

0.045

—

mg/kg-day

1.0E+00

mg/kg-day

—

Arsenic

6.6

mg/kg

4.7E-05

mg/kg-day

1.5E+00

(mg/kg-day)"1

7.0E-05

5.1E-05

mg/kg-day

3.0E-04

mg/kg-day

0.17

—

mg/kg-day

3.0E-04

mg/kg-day

—

Barium

160

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.4E-03

mg/kg-day

2.0E-01

mg/kg-day

0.0120

—

mg/kg-day

2.0E-01

mg/kg-day

—

Cadmium

0.13

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.2E-06

mg/kg-day

1.0E-04

mg/kg-day

0.052

—

mg/kg-day

1.0E-04

mg/kg-day

—

Cobalt

6.9

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

7.6E-05

mg/kg-day

3.0E-04

mg/kg-day

0.25

—

mg/kg-day

3.0E-04

mg/kg-day

—

Chromium

10

mg/kg

8.7E-05

mg/kg-day

5.0E-01

(mg/kg-day)"1

4.4E-05

7.3E-05

mg/kg-day

3.0E-03

mg/kg-day

0.024

—

mg/kg-day

3.0E-03

mg/kg-day

—

Copper

13

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.4E-03

mg/kg-day

4.0E-02

mg/kg-day

0.036

—

mg/kg-day

4.0E-02

mg/kg-day

—

Iron

16,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

--

1.1E-01

mg/kg-day

7.0E-01

mg/kg-day

0.16

—

mg/kg-day

7.0E-01

mg/kg-day

—

Manganese

200

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.5E-02

mg/kg-day

2.4E-02

mg/kg-day

0.61

—

mg/kg-day

2.4E-02

mg/kg-day

—

Molybdenum

0.31

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.3E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0045

—

mg/kg-day

5.0E-03

mg/kg-day

—

Selenium

3.0

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.3E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0066

—

mg/kg-day

5.0E-03

mg/kg-day

—

Thallium

0.16

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.0E-06

mg/kg-day

1.0E-05

mg/kg-day

0.101

—

mg/kg-day

1.0E-05

mg/kg-day

—

Uranium

3.6

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.0E-05

mg/kg-day

2.0E-04

mg/kg-day

0.15

—

mg/kg-day

2.0E-04

mg/kg-day

—

Vanadium

16

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.2E-04

mg/kg-day

5.0E-03

mg/kg-day

0.024

—

mg/kg-day

5.0E-03

mg/kg-day

—

Metals Cancer Total

1E-04

Metals Noncancer Total

2

Metals Noncancer Total

—

Exposure Route Cancer Total

2E-03

Exposure Route Noncancer Total

2

Exposure Route Noncancer Total

-

Page 4 of 11


-------
Table C-5.2. Human Health Risk and Hazard Calculations - Quivira Church Rock Mine No. 1 East

Church Rock Mine No. 1 East - Kee'da'whii teeh (Full-Time Resident)

COPCa

EPCb

Units

Cancer
lntakec

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake3

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: Other Dine Lifeways Plant Dermal

Aluminum

6,300

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

Arsenic

6.6

mg/kg

4.0E-06

mg/kg-day

1.5E+00

(mg/kg-day)"1

5.9E-06

4.3E-06

mg/kg-day

3.0E-04

mg/kg-day

0.014

—

mg/kg-day

3.0E-04

mg/kg-day

—

Barium

160

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

Cadmium

0.13

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.7E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0057

—

mg/kg-day

1.0E-04

mg/kg-day

—

Cobalt

6.9

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

Chromium

10

mg/kg

—

mg/kg-day

5.0E-01

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

Copper

13

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

Iron

16,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

Manganese

200

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

Molybdenum

0.31

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Selenium

3.0

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Thallium

0.16

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

Uranium

3.6

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

Vanadium

16

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Metals Cancer Total

6E-06

Metals Noncancer Total

0.02

Metals Noncancer Total

—

Exposure Route Cancer Total

6E-06

Exposure Route Noncancer Total

0.02

Exposure Route Noncancer Total

—

Exposure Medium: Surface Soil (0-6 inches bgs)

Exposure Route: Other Dine Lifeways Plant Inhalation

Uranium-238

1.3

pCi/g

3.0E+02

pCi

2.4E-08

risk/pCi

7.1E-06

—

—

—

—

—

—

—

—

—

—

Uranium-234

1.4

pCi/g

3.2E+02

pCi

2.8E-08

risk/pCi

9.0E-06

—

—

—

—

—

—

—

—

—

—

Thorium-230

3.6

pCi/g

1.6E+02

pCi

3.4E-08

risk/pCi

5.5E-06

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

9.3

pCi/g

5.9E+03

pCi

5.9E-08

risk/pCi

3.5E-04

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

4E-04

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

6,300

mg/kg

—

ug/m3

—

(ug/m3)"1

—

4.5E-04

mg/m3

5.0E-03

mg/m3

0.091

—

mg/m3

5.0E-03

mg/m3

—

Arsenic

6.6

mg/kg

4.8E-04

ug/m3

4.3E-03

(ug/m3)"1

2.0E-06

5.2E-07

mg/m3

1.5E-05

mg/m3

0.035

—

mg/m3

1.5E-05

mg/m3

—

Barium

160

mg/kg

—

ug/m3

—

(ug/m3)"1

—

2.4E-05

mg/m3

5.0E-04

mg/m3

0.048

—

mg/m3

5.0E-04

mg/m3

—

Cadmium

0.13

mg/kg

4.8E-05

ug/m3

1.8E-03

(ug/m3)"1

8.7E-08

5.2E-08

mg/m3

1.0E-05

mg/m3

0.0052

—

mg/m3

1.0E-05

mg/m3

—

Chromium

10

mg/kg

8.9E-04

ug/m3

8.4E-02

(ug/m3)"1

7.5E-05

7.5E-07

mg/m3

1.0E-04

mg/m3

0.0075

—

mg/m3

1.0E-04

mg/m3

—

Cobalt

6.9

mg/kg

7.6E-04

ug/m3

9.0E-03

(ug/m3)"1

6.8E-06

8.3E-07

mg/m3

6.0E-06

mg/m3

0.14

—

mg/m3

6.0E-06

mg/m3

—

Copper

13

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

—

mg/m3

—

mg/m3

—

Iron

16,000

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

-

mg/m3

—

mg/m3

—

Manganese

200

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.5E-04

mg/m3

5.0E-05

mg/m3

2.9

—

mg/m3

5.0E-05

mg/m3

—

Molybdenum

0.31

mg/kg

—

ug/m3

—

(ug/m3)"1

—

2.3E-07

mg/m3

2.0E-03

mg/m3

0.00011

—

mg/m3

2.0E-03

mg/m3

—

Selenium

3.0

mg/kg

—

ug/m3

—

(ug/m3)"1

—

3.3E-07

mg/m3

2.0E-02

mg/m3

0.000017

—

mg/m3

2.0E-02

mg/m3

—

Thallium

0.16

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

-

mg/m3

—

mg/m3

—

Uranium

3.6

mg/kg

—

ug/m3

—

(ug/m3)"1

—

3.1E-07

mg/m3

4.0E-05

mg/m3

0.008

—

mg/m3

4.0E-05

mg/m3

—

Vanadium

16

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.2E-06

mg/m3

1.0E-04

mg/m3

0.012

—

mg/m3

1.0E-04

mg/m3

—

Metals Cancer Total

8E-05

Metals Noncancer Total

3

Metals Noncancer Total

—

Exposure Route Cancer Total

4E-04

Exposure Route Noncancer Total

3

Exposure Route Noncancer Total

—

Surface Soil (0-6 inches bgs) Receptor Cancer Risk Total

2E-02

Receptor/Media Noncancer Hazard Total

9

Receptor/Media Noncancer Hazard Total

10

Page 5 of 11


-------
Table C-5.2. Human Health Risk and Hazard Calculations - Quivira Church Rock Mine No. 1 East

Church Rock Mine No. 1 East - Kee'da'whii teeh (Full-Time Resident)

COPCa

EPCb

Units

Cancer
lntakec

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake3

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Child
Noncancer
lntakec

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Child

Exposure Medium: Subsurface Soil

0-72 inches bgs)

Exposure Route: Incidental Soil Ingestion

Uranium-238

1.3

pCi/g

1.2E+04

pCi/g

1.3E-10

risk/pCi/g

1.7E-06

—

—

—

—

—

—

—

—

—

—

Uranium-234

1.4

pCi/g

1.3E+04

pCi/g

1.5E-10

risk/pCi/g

2.0E-06

—

—

—

—

—

—

—

—

—

—

Thorium-230

3.6

pCi/g

3.4E+04

pCi/g

1.7E-10

risk/pCi/g

5.7E-06

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

43

pCi/g

4.1E+05

pCi/g

5.7E-09

risk/pCi/g

2.3E-03

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

2E-03

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

6,300

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.7E-02

mg/kg-day

1.0E+00

mg/kg-day

0.027

1.6E-01

mg/kg-day

1.0E+00

mg/kg-day

0.16

Arsenic

6.3

mg/kg

2.3E-05

mg/kg-day

1.5E+00

(mg/kg-day)"1

3.4E-05

1.6E-05

mg/kg-day

3.0E-04

mg/kg-day

0.055

9.5E-05

mg/kg-day

3.0E-04

mg/kg-day

0.32

Barium

160

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.9E-04

mg/kg-day

2.0E-01

mg/kg-day

0.0034

4.2E-03

mg/kg-day

2.0E-01

mg/kg-day

0.021

Cadmium

0.13

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.6E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0056

3.4E-06

mg/kg-day

1.0E-04

mg/kg-day

0.034

Chromium

10

mg/kg

1.60E-04

mg/kg-day

5.0E-01

(mg/kg-day)"1

8.0E-05

4.3E-05

mg/kg-day

3.0E-03

mg/kg-day

0.014

2.6E-04

mg/kg-day

3.0E-03

mg/kg-day

0.087

Cobalt

6.9

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.0E-05

mg/kg-day

3.0E-04

mg/kg-day

0.099

1.8E-04

mg/kg-day

3.0E-04

mg/kg-day

0.60

Copper

13

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.6E-05

mg/kg-day

4.0E-02

mg/kg-day

0.0014

3.4E-04

mg/kg-day

4.0E-02

mg/kg-day

0.0085

Iron

16,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.9E-02

mg/kg-day

7.0E-01

mg/kg-day

0.098

4.2E-01

mg/kg-day

7.0E-01

mg/kg-day

0.59

Manganese

200

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

8.6E-04

mg/kg-day

2.4E-02

mg/kg-day

0.036

5.2E-03

mg/kg-day

2.4E-02

mg/kg-day

0.22

Molybdenum

0.51

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.2E-06

mg/kg-day

5.0E-03

mg/kg-day

0.00044

1.3E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0027

Selenium

5.4

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.3E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0046

1.4E-04

mg/kg-day

5.0E-03

mg/kg-day

0.028

Thallium

0.16

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.9E-07

mg/kg-day

1.0E-05

mg/kg-day

0.069

4.2E-06

mg/kg-day

1.0E-05

mg/kg-day

0.42

Uranium

42

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.8E-04

mg/kg-day

2.0E-04

mg/kg-day

0.90

1.1E-03

mg/kg-day

2.0E-04

mg/kg-day

5.5

Vanadium

18

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

7.7E-05

mg/kg-day

5.0E-03

mg/kg-day

0.015

4.7E-04

mg/kg-day

5.0E-03

mg/kg-day

0.094

Metals Cancer Total

1E-04

Metals Noncancer Total

1.3

Metals Noncancer Total

8

Exposure Route Cancer Total

2E-03

Exposure Route Noncancer Total

1.3

Exposure Route Noncancer Total

8

Page 6 of 11


-------
Table C-5.2. Human Health Risk and Hazard Calculations - Quivira Church Rock Mine No. 1 East

Church Rock Mine No. 1 East - Kee'da'whii teeh (Full-Time Resident)

COPCa

EPCb

Units

Cancer
lntakec

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake3

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Child
Noncancer
lntakec

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Child

Exposure Medium: Subsurface Soil

0-72 inches bgs)

Exposure Route: External Exposure

Uranium-238

1.3

pCi/g

6.6E+01

pCi/g

1.2E-10

risk/year pCi/g

8.2E-09

—

—

—

—

—

—

—

—

—

—

Uranium-234

1.4

pCi/g

7.1E+01

pCi/g

2.5E-10

risk/year pCi/g

1.8E-08

—

—

—

—

—

—

—

—

—

—

Thorium-230

3.6

pCi/g

1.8E+02

pCi/g

8.5E-10

risk/year pCi/g

1.6E-07

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

43

pCi/g

2.2E+03

pCi/g

8.4E-06

risk/year pCi/g

1.8E-02

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

2E-02

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Exposure Route Cancer Total

2E-02

Exposure Route Noncancer Total

—

Exposure Route Noncancer Total

—

Exposure Route: Dermal Exposure

Aluminum

6,300

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

Arsenic

6.3

mg/kg

1.3E-06

mg/kg-day

1.5E+00

(mg/kg-day)"1

2.0E-06

9.5E-07

mg/kg-day

3.0E-04

mg/kg-day

0.0032

5.7E-06

mg/kg-day

3.0E-04

mg/kg-day

0.019

Barium

160

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

Cadmium

0.13

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.6E-08

mg/kg-day

1.0E-04

mg/kg-day

0.00026

1.6E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0016

Chromium

10

mg/kg

—

mg/kg-day

5.0E-01

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

Cobalt

6.9

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

Copper

13

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

Iron

16,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

Manganese

200

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

Molybdenum

0.51

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Selenium

5.4

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Thallium

0.16

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

Uranium

42

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

Vanadium

18

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Metals Cancer Total

2E-06

Metals Noncancer Total

0.003

Metals Noncancer Total

0.02

Exposure Route Cancer Total

2E-06

Exposure Route Noncancer Total

0.003

Exposure Route Noncancer Total

0.02

Page 7 of 11


-------
Table C-5.2. Human Health Risk and Hazard Calculations - Quivira Church Rock Mine No. 1 East

Church Rock Mine No. 1 East - Kee'da'whii teeh (Full-Time Resident)

COPCa

EPCb

Units

Cancer
lntakec

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake3

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Child
Noncancer
lntakec

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Child

Exposure Medium: Subsurface Soil

0-72 inches bgs)

Exposure Route: Inhalation of Particulates

Uranium-238

1.3

pCi/g

1.1E-01

pCi

2.4E-08

risk/pCi

2.7E-09

—

—

—

—

—

—

—

—

—

—

Uranium-234

1.4

pCi/g

1.2E-01

pCi

2.8E-08

risk/pCi

3.4E-09

—

—

—

—

—

—

—

—

—

—

Thorium-230

3.6

pCi/g

3.1E-01

pCi

3.4E-08

risk/pCi

1.1E-08

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

43

pCi/g

3.7E+00

pCi

5.9E-08

risk/pCi

2.2E-07

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

2E-07

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

6,300

mg/kg

—

ug/m3

—

(ug/m3y1

—

8.2E-07

mg/m3

5.0E-03

mg/m3

0.00016

8.2E-07

mg/m3

5.0E-03

mg/m3

0.00016

Arsenic

6.3

mg/kg

8.2E-07

ug/m3

4.3E-03

(ug/m3y1

3.5E-09

8.2E-10

mg/m3

1.5E-05

mg/m3

0.000055

8.2E-10

mg/m3

1.5E-05

mg/m3

0.000055

Barium

160

mg/kg

—

ug/m3

—

(ug/m3)"1

—

2.1E-08

mg/m3

5.0E-04

mg/m3

0.00004

2.1E-08

mg/m3

5.0E-04

mg/m3

0.000042

Cadmium

0.13

mg/kg

1.7E-08

ug/m3

1.8E-03

(ug/m3)"1

3.0E-11

1.7E-11

mg/m3

1.0E-05

mg/m3

0.0000017

1.7E-11

mg/m3

1.0E-05

mg/m3

0.0000017

Chromium

10

mg/kg

2.1E-06

ug/m3

8.4E-02

(ug/m3)"1

1.8E-07

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

6.9

mg/kg

9.0E-07

ug/m3

9.0E-03

(ug/m3)"1

8.1E-09

9.0E-10

mg/m3

6.0E-06

mg/m3

0.00015

9.0E-10

mg/m3

6.0E-06

mg/m3

0.00015

Copper

13

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

—

mg/m3

—

mg/m3

—

Iron

16,000

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

-

mg/m3

—

mg/m3

—

Manganese

200

mg/kg

—

ug/m3

—

(ug/m3)"1

—

2.6E-08

mg/m3

5.0E-05

mg/m3

0.00052

2.6E-08

mg/m3

5.0E-05

mg/m3

0.00052

Molybdenum

0.51

mg/kg

—

ug/m3

—

(ug/m3)"1

—

6.6E-11

mg/m3

2.0E-03

mg/m3

0.000000033

6.6E-11

mg/m3

2.0E-03

mg/m3

0.000000033

Selenium

5.4

mg/kg

—

ug/m3

—

(ug/m3)"1

—

7.0E-10

mg/m3

2.0E-02

mg/m3

0.000000035

7.0E-10

mg/m3

2.0E-02

mg/m3

0.000000035

Thallium

0.16

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

-

mg/m3

—

mg/m3

—

Uranium

42

mg/kg

—

ug/m3

—

(ug/m3)"1

—

5.5E-09

mg/m3

4.0E-05

mg/m3

0.000137

5.5E-09

mg/m3

4.0E-05

mg/m3

0.00014

Vanadium

18

mg/kg

—

ug/m3

—

(ug/m3)"1

—

2.3E-09

mg/m3

1.0E-04

mg/m3

0.000023

2.3E-09

mg/m3

1.0E-04

mg/m3

0.000023

Metals Cancer Total

2E-07

Metals Noncancer Total

0.0011

Metals Noncancer Total

0.001

Exposure Route Cancer Total

4E-07

Exposure Route Noncancer Total

0.0011

Exposure Route Noncancer Total

0.001

Exposure Medium: Subsurface Soil (0-72 inches bgs)

Exposure Route: Plant Consumption

Uranium-238

1.3

pCi/g

9.2E+04

pCi/g

8.7E-11

risk/pCi/g

8.0E-06

—

—

—

—

—

—

—

—

—

—

Uranium-234

1.4

pCi/g

9.9E+04

pCi/g

9.6E-11

risk/pCi/g

9.5E-06

—

—

—

—

—

—

—

—

—

—

Thorium-230

3.6

pCi/g

6.5E+04

pCi/g

1.2E-10

risk/pCi/g

7.7E-06

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

43

pCi/g

4.7E+06

pCi/g

3.7E-09

risk/pCi/g

1.7E-02

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

2E-02

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

6,300

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

7.6E-02

mg/kg-day

1.0E+00

mg/kg-day

0.076

2.0E-01

mg/kg-day

1.0E+00

mg/kg-day

0.20

Arsenic

6.3

mg/kg

8.8E-05

mg/kg-day

1.5E+00

(mg/kg-day)"1

1.3E-04

8.2E-05

mg/kg-day

3.0E-04

mg/kg-day

0.27

2.1E-04

mg/kg-day

3.0E-04

mg/kg-day

0.71

Barium

160

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.7E-03

mg/kg-day

2.0E-01

mg/kg-day

0.018

9.8E-03

mg/kg-day

2.0E-01

mg/kg-day

0.049

Cadmium

0.13

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

7.7E-06

mg/kg-day

1.0E-04

mg/kg-day

0.077

2.1E-05

mg/kg-day

1.0E-04

mg/kg-day

0.21

Chromium

10

mg/kg

2.8E-04

mg/kg-day

5.0E-01

(mg/kg-day)"1

1.4E-04

1.2E-04

mg/kg-day

3.0E-03

mg/kg-day

0.040

3.2E-04

mg/kg-day

3.0E-03

mg/kg-day

0.11

Cobalt

6.9

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.2E-04

mg/kg-day

3.0E-04

mg/kg-day

0.41

3.3E-04

mg/kg-day

3.0E-04

mg/kg-day

1.1

Copper

13

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.2E-03

mg/kg-day

4.0E-02

mg/kg-day

0.055

5.9E-03

mg/kg-day

4.0E-02

mg/kg-day

0.15

Iron

16,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

--

1.9E-01

mg/kg-day

7.0E-01

mg/kg-day

0.27

5.0E-01

mg/kg-day

7.0E-01

mg/kg-day

0.71

Manganese

200

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.2E-02

mg/kg-day

2.4E-02

mg/kg-day

0.92

5.8E-02

mg/kg-day

2.4E-02

mg/kg-day

2.4

Molybdenum

0.51

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.6E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0112

1.5E-04

mg/kg-day

5.0E-03

mg/kg-day

0.030

Selenium

5.4

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

9.7E-05

mg/kg-day

5.0E-03

mg/kg-day

0.019

2.6E-04

mg/kg-day

5.0E-03

mg/kg-day

0.052

Thallium

0.16

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.6E-06

mg/kg-day

1.0E-05

mg/kg-day

0.16

4.5E-06

mg/kg-day

1.0E-05

mg/kg-day

0.45

Uranium

42

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.5E-04

mg/kg-day

2.0E-04

mg/kg-day

2.73

1.5E-03

mg/kg-day

2.0E-04

mg/kg-day

7.6

Vanadium

18

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.2E-04

mg/kg-day

5.0E-03

mg/kg-day

0.043

5.9E-04

mg/kg-day

5.0E-03

mg/kg-day

0.12

Metals Cancer Total

3E-04

Metals Noncancer Total

5

Metals Noncancer Total

14

Exposure Route Cancer Total

2E-02

Exposure Route Noncancer Total

5

Exposure Route Noncancer Total

14

Page 8 of 11


-------
Table C-5.2. Human Health Risk and Hazard Calculations - Quivira Church Rock Mine No. 1 East

Church Rock Mine No. 1 East - Kee'da'whii teeh (Full-Time Resident)

COPCa

EPCb

Units

Cancer
lntakec

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake3

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Child
Noncancer
lntakec

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Child

Exposure Medium: Subsurface Soil

0-72 inches bgs)

Exposure Route: Animal Consumption

Uranium-238

1.3

pCi/g

1.1E+05

pCi/g

8.7E-11

risk/pCi/g

9.1E-06

—

—

—

—

—

—

—

—

—

—

Uranium-234

1.4

pCi/g

1.1E+05

pCi/g

9.6E-11

risk/pCi/g

1.1E-05

—

—

—

—

—

—

—

—

—

—

Thorium-230

3.6

pCi/g

1.4E+02

pCi/g

1.2E-10

risk/pCi/g

1.7E-08

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

43

pCi/g

9.0E+06

pCi/g

3.7E-09

risk/pCi/g

3.3E-02

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

3E-02

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

6,300

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.4E-03

mg/kg-day

1.0E+00

mg/kg-day

0.0044

1.2E-02

mg/kg-day

1.0E+00

mg/kg-day

0.012

Arsenic

6.3

mg/kg

6.9E-06

mg/kg-day

1.5E+00

(mg/kg-day)"1

1.0E-05

6.2E-06

mg/kg-day

3.0E-04

mg/kg-day

0.021

1.6E-05

mg/kg-day

3.0E-04

mg/kg-day

0.055

Barium

160

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.1E-05

mg/kg-day

2.0E-01

mg/kg-day

0.00010

5.6E-05

mg/kg-day

2.0E-01

mg/kg-day

0.00028

Cadmium

0.13

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.0E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0030

7.8E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0078

Chromium

10

mg/kg

6.1E-05

mg/kg-day

5.0E-01

(mg/kg-day)"1

3.1E-05

2.6E-05

mg/kg-day

3.0E-03

mg/kg-day

0.0088

7.0E-05

mg/kg-day

3.0E-03

mg/kg-day

0.023

Cobalt

6.9

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.6E-05

mg/kg-day

3.0E-04

mg/kg-day

0.22

1.8E-04

mg/kg-day

3.0E-04

mg/kg-day

0.60

Copper

13

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.2E-04

mg/kg-day

4.0E-02

mg/kg-day

0.0029

3.1E-04

mg/kg-day

4.0E-02

mg/kg-day

0.0078

Iron

16,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.5E-01

mg/kg-day

7.0E-01

mg/kg-day

0.21

3.8E-01

mg/kg-day

7.0E-01

mg/kg-day

0.55

Manganese

200

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.6E-05

mg/kg-day

2.4E-02

mg/kg-day

0.0028

1.8E-04

mg/kg-day

2.4E-02

mg/kg-day

0.0074

Molybdenum

0.51

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.3E-06

mg/kg-day

5.0E-03

mg/kg-day

0.00046

6.1E-06

mg/kg-day

5.0E-03

mg/kg-day

0.0012

Selenium

5.4

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.2E-04

mg/kg-day

5.0E-03

mg/kg-day

0.083

1.1E-03

mg/kg-day

5.0E-03

mg/kg-day

0.23

Thallium

0.16

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.9E-06

mg/kg-day

1.0E-05

mg/kg-day

0.29

7.8E-06

mg/kg-day

1.0E-05

mg/kg-day

0.78

Uranium

42

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.9E-06

mg/kg-day

2.0E-04

mg/kg-day

0.0294

1.6E-05

mg/kg-day

2.0E-04

mg/kg-day

0.080

Vanadium

18

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.0E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0040

5.4E-05

mg/kg-day

5.0E-03

mg/kg-day

0.011

Metals Cancer Total

4E-05

Metals Noncancer Total

0.9

Metals Noncancer Total

2

Exposure Route Cancer Total

3E-02

Exposure Route Noncancer Total

0.9

Exposure Route Noncancer Total

2

Exposure Medium: Subsurface Soil (0-72 inches bgs)

Exposure Route: Other Dine Lifeways Plant Ingestion

Uranium-238

1.3

pCi/g

4.3E+04

pCi/g

8.7E-11

risk/pCi/g

3.7E-06

—

—

—

—

—

—

—

—

—

—

Uranium-234

1.4

pCi/g

4.6E+04

pCi/g

9.6E-11

risk/pCi/g

4.4E-06

—

—

—

—

—

—

—

—

—

—

Thorium-230

3.6

pCi/g

3.5E+04

pCi/g

1.2E-10

risk/pCi/g

4.2E-06

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

43

pCi/g

2.6E+06

pCi/g

3.7E-09

risk/pCi/g

9.5E-03

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

1E-02

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

6,300

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.5E-02

mg/kg-day

1.0E+00

mg/kg-day

0.045

—

mg/kg-day

1.0E+00

mg/kg-day

—

Arsenic

6.3

mg/kg

4.5E-05

mg/kg-day

1.5E+00

(mg/kg-day)"1

6.7E-05

4.9E-05

mg/kg-day

3.0E-04

mg/kg-day

0.16

—

mg/kg-day

3.0E-04

mg/kg-day

—

Barium

160

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.4E-03

mg/kg-day

2.0E-01

mg/kg-day

0.0120

—

mg/kg-day

2.0E-01

mg/kg-day

—

Cadmium

0.13

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.2E-06

mg/kg-day

1.0E-04

mg/kg-day

0.052

—

mg/kg-day

1.0E-04

mg/kg-day

—

Chromium

10

mg/kg

8.7E-05

mg/kg-day

5.0E-01

(mg/kg-day)"1

4.4E-05

7.3E-05

mg/kg-day

3.0E-03

mg/kg-day

0.024

—

mg/kg-day

3.0E-03

mg/kg-day

—

Cobalt

6.9

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

7.6E-05

mg/kg-day

3.0E-04

mg/kg-day

0.25

—

mg/kg-day

3.0E-04

mg/kg-day

—

Copper

13

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.4E-03

mg/kg-day

4.0E-02

mg/kg-day

0.036

—

mg/kg-day

4.0E-02

mg/kg-day

—

Iron

16,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

--

1.1E-01

mg/kg-day

7.0E-01

mg/kg-day

0.16

—

mg/kg-day

7.0E-01

mg/kg-day

—

Manganese

200

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.5E-02

mg/kg-day

2.4E-02

mg/kg-day

0.61

—

mg/kg-day

2.4E-02

mg/kg-day

—

Molybdenum

0.51

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.7E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0074

—

mg/kg-day

5.0E-03

mg/kg-day

—

Selenium

5.4

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.9E-05

mg/kg-day

5.0E-03

mg/kg-day

0.012

—

mg/kg-day

5.0E-03

mg/kg-day

—

Thallium

0.16

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.0E-06

mg/kg-day

1.0E-05

mg/kg-day

0.10

—

mg/kg-day

1.0E-05

mg/kg-day

—

Uranium

42

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.5E-04

mg/kg-day

2.0E-04

mg/kg-day

1.7

—

mg/kg-day

2.0E-04

mg/kg-day

—

Vanadium

18

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.4E-04

mg/kg-day

5.0E-03

mg/kg-day

0.027

—

mg/kg-day

5.0E-03

mg/kg-day

—

Metals Cancer Total

1E-04

Metals Noncancer Total

3

Metals Noncancer Total

—

Exposure Route Cancer Total

1E-02

Exposure Route Noncancer Total

3

Exposure Route Noncancer Total

-

Page 9 of 11


-------
Table C-5.2. Human Health Risk and Hazard Calculations - Quivira Church Rock Mine No. 1 East

Church Rock Mine No. 1 East - Kee'da'whii teeh (Full-Time Resident)

COPCa

EPCb

Units

Cancer
lntakec

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake3

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Child
Noncancer
lntakec

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Child

Exposure Medium: Subsurface Soil

0-72 inches bgs)

Exposure Route: Other Dine Lifeways Plant Dermal

Aluminum

6,300

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

Arsenic

6.3

mg/kg

3.8E-06

mg/kg-day

1.5E+00

(mg/kg-day)"1

5.7E-06

4.1E-06

mg/kg-day

3.0E-04

mg/kg-day

0.014

—

mg/kg-day

3.0E-04

mg/kg-day

—

Barium

160

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

Cadmium

0.13

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.7E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0057

—

mg/kg-day

1.0E-04

mg/kg-day

—

Chromium

10

mg/kg

—

mg/kg-day

5.0E-01

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

Cobalt

6.9

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

Copper

13

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

Iron

16,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

Manganese

200

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

Molybdenum

0.51

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Selenium

5.4

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Thallium

0.16

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

Uranium

42

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

Vanadium

18

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Metals Cancer Total

6E-06

Metals Noncancer Total

0.02

Metals Noncancer Total

—

Exposure Route Cancer Total

6E-06

Exposure Route Noncancer Total

0.02

Exposure Route Noncancer Total

—

Exposure Medium: Subsurface Soil (0-72 inches bgs)

Exposure Route: Other Dine Lifeways Plant Inhalation

Uranium-238

1.3

pCi/g

3.0E+02

pCi

2.4E-08

risk/pCi

7.1E-06

—

—

—

—

—

—

—

—

—

—

Uranium-234

1.4

pCi/g

3.2E+02

pCi

2.8E-08

risk/pCi

9.0E-06

—

—

—

—

—

—

—

—

—

—

Thorium-230

3.6

pCi/g

1.6E+02

pCi

3.4E-08

risk/pCi

5.5E-06

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

43

pCi/g

2.7E+04

pCi

5.9E-08

risk/pCi

1.6E-03

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

2E-03

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

6,300

mg/kg

—

ug/m3

—

(ug/m3)"1

—

4.5E-04

mg/m3

5.0E-03

mg/m3

0.091

—

mg/m3

5.0E-03

mg/m3

—

Arsenic

6.3

mg/kg

4.5E-04

ug/m3

4.3E-03

(ug/m3)"1

2.0E-06

5.0E-07

mg/m3

1.5E-05

mg/m3

0.033

—

mg/m3

1.5E-05

mg/m3

—

Barium

160

mg/kg

—

ug/m3

—

(ug/m3)"1

—

2.4E-05

mg/m3

5.0E-04

mg/m3

0.048

—

mg/m3

5.0E-04

mg/m3

—

Cadmium

0.13

mg/kg

4.8E-05

ug/m3

1.8E-03

(ug/m3)"1

8.7E-08

5.2E-08

mg/m3

1.0E-05

mg/m3

0.0052

—

mg/m3

1.0E-05

mg/m3

—

Chromium

10

mg/kg

8.9E-04

ug/m3

8.4E-02

(ug/m3)"1

7.5E-05

7.5E-07

mg/m3

1.0E-04

mg/m3

0.0075

—

mg/m3

1.0E-04

mg/m3

—

Cobalt

6.9

mg/kg

7.6E-04

ug/m3

9.0E-03

(ug/m3)"1

6.8E-06

8.3E-07

mg/m3

6.0E-06

mg/m3

0.14

—

mg/m3

6.0E-06

mg/m3

—

Copper

13

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

—

mg/m3

—

mg/m3

—

Iron

16,000

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

-

mg/m3

—

mg/m3

—

Manganese

200

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.5E-04

mg/m3

5.0E-05

mg/m3

2.9

—

mg/m3

5.0E-05

mg/m3

—

Molybdenum

0.51

mg/kg

—

ug/m3

—

(ug/m3)"1

—

3.7E-07

mg/m3

2.0E-03

mg/m3

0.00019

—

mg/m3

2.0E-03

mg/m3

—

Selenium

5.4

mg/kg

—

ug/m3

—

(ug/m3)"1

—

5.9E-07

mg/m3

2.0E-02

mg/m3

0.000030

—

mg/m3

2.0E-02

mg/m3

—

Thallium

0.16

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

-

mg/m3

—

mg/m3

—

Uranium

42

mg/kg

—

ug/m3

—

(ug/m3)"1

—

3.6E-06

mg/m3

4.0E-05

mg/m3

0.089

—

mg/m3

4.0E-05

mg/m3

—

Vanadium

18

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.4E-06

mg/m3

1.0E-04

mg/m3

0.014

—

mg/m3

1.0E-04

mg/m3

—

Metals Cancer Total

8E-05

Metals Noncancer Total

o

O

Metals Noncancer Total

—

Exposure Route Cancer Total

2E-03

Exposure Route Noncancer Total

3

Exposure Route Noncancer Total

—

Subsurface Soil (0-72 inches bgs) Receptor Cancer Risk Total

8E-02

Receptor/Media Noncancer Hazard Total

10

Receptor/Media Noncancer Hazard Total

20

Page 10 of 11


-------
Table C-5.2. Human Health Risk and Hazard Calculations - Quivira Church Rock Mine No. 1 East

Notes:

a COPCs are the constituents of interest with a maximum detected concentration exceeding the COPC screening level (see Table C-1).
b EPCs are provided on Table C-4.

c The intakes are the EPC multiplied by the exposure parameters and any applicable contaminant-specific inputs (see Table C-3 for exposure inputs, Table 4 of the NAUM risk assessment methodology [USEPA 2024b] report for contaminant-specific inputs,

and Appendix B of the NAUM risk assessment methodology [USEPA 2024b] report for equations).
d The toxicity values are provided in Table 4 of the NAUM risk assessment methodology (USEPA 2024b).

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,

COPC

EPC

mg/kg

|jg/m3
bgs

mg/kg-day
mg/m3

Not applicable
Microgram per cubic meter
Below ground surface
Contaminant of potential concern
Exposure point concentration
Milligram per kilogram
Milligram per kilogram per day
Milligram per cubic meter

pCi

pCi/g

RfC

RfD

SE

NAUM

USEPA

Navajo abandoned uranium mine
Picocurie

Picocurie per gram
Reference concentration
Reference dose
Secular equilibrium

U.S. Environmental Protection Agency

Reference:

U.S. Environmental Protection Agency (USEPA). 2024b. "Navajo Abandoned Uranium Mines Risk Assessment Methodology." Draft Final. March.

Page 11 of 11


-------
Table C-5.3. Human Health Risk and Hazard Calculations - Kerr-McGee Ponds on the Navajo Nation

Kerr-McGee Ponds on the Navajo Nation - Kee'da'whii teeh (Full-Time Resident)

COPCa

EPCb

Units

Cancer
lntakec

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk8

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

1.1

pCi/g

1.0E+04

pCi/g

1.3E-10

risk/pCi/g

1.4E-06

—

—

—

—

—

—

—

—

—

—

Uranium-234

0.97

pCi/g

9.2E+03

pCi/g

1.5E-10

risk/pCi/g

1.4E-06

—

—

—

—

—

—

—

—

—

—

Thorium-230

2.0

pCi/g

1.9E+04

pCi/g

1.7E-10

risk/pCi/g

3.2E-06

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

9.3

pCi/g

8.8E+04

pCi/g

5.7E-09

risk/pCi/g

5.0E-04

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

5E-04

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

6,900

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.0E-02

mg/kg-day

1.0E+00

mg/kg-day

0.030

1.8E-01

mg/kg-day

1.0E+00

mg/kg-day

0.18

Arsenic

5.9

mg/kg

2.1E-05

mg/kg-day

1.5E+00

(mg/kg-day)"1

3.2E-05

1.5E-05

mg/kg-day

3.0E-04

mg/kg-day

0.051

8.9E-05

mg/kg-day

3.0E-04

mg/kg-day

0.30

Barium

82

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.5E-04

mg/kg-day

2.0E-01

mg/kg-day

0.0018

2.1E-03

mg/kg-day

2.0E-01

mg/kg-day

0.011

Cadmium

0.16

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.9E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0069

4.2E-06

mg/kg-day

1.0E-04

mg/kg-day

0.042

Chromium

8.2

mg/kg

1.31E-04

mg/kg-day

5.0E-01

(mg/kg-day)"1

6.6E-05

3.5E-05

mg/kg-day

3.0E-03

mg/kg-day

0.012

2.1E-04

mg/kg-day

3.0E-03

mg/kg-day

0.071

Cobalt

5.2

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.2E-05

mg/kg-day

3.0E-04

mg/kg-day

0.075

1.4E-04

mg/kg-day

3.0E-04

mg/kg-day

0.45

Copper

11

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.7E-05

mg/kg-day

4.0E-02

mg/kg-day

0.0012

2.9E-04

mg/kg-day

4.0E-02

mg/kg-day

0.0072

Iron

15,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.5E-02

mg/kg-day

7.0E-01

mg/kg-day

0.092

3.9E-01

mg/kg-day

7.0E-01

mg/kg-day

0.56

Manganese

230

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

9.9E-04

mg/kg-day

2.4E-02

mg/kg-day

0.041

6.0E-03

mg/kg-day

2.4E-02

mg/kg-day

0.25

Molybdenum

0.6

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.4E-06

mg/kg-day

5.0E-03

mg/kg-day

0.00047

1.4E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0029

Selenium

2.9

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.2E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0025

7.5E-05

mg/kg-day

5.0E-03

mg/kg-day

0.015

Thallium

0.15

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.5E-07

mg/kg-day

1.0E-05

mg/kg-day

0.065

3.9E-06

mg/kg-day

1.0E-05

mg/kg-day

0.39

Uranium

6.2

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.7E-05

mg/kg-day

2.0E-04

mg/kg-day

0.13

1.6E-04

mg/kg-day

2.0E-04

mg/kg-day

0.81

Vanadium

17

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

7.3E-05

mg/kg-day

5.0E-03

mg/kg-day

0.015

4.4E-04

mg/kg-day

5.0E-03

mg/kg-day

0.088

Metals Cancer Total

1E-04

Metals Noncancer Total

0.5

Metals Noncancer Total

3

Exposure Route Cancer Total

6E-04

Exposure Route Noncancer Total

0.5

Exposure Route Noncancer Total

3

Page 1 of 11


-------
Table C-5.3. Human Health Risk and Hazard Calculations - Kerr-McGee Ponds on the Navajo Nation

Kerr-McGee Ponds on the Navajo Nation - Kee'da'whii teeh (Full-Time Resident)

COPCa

EPCb

Units

Cancer
lntakec

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk8

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: External Exposure

Uranium-238

1.1

pCi/g

5.6E+01

pCi/g

1.2E-10

risk/year pCi/g

7.0E-09

—

—

—

—

—

—

—

—

—

—

Uranium-234

0.97

pCi/g

4.9E+01

pCi/g

2.5E-10

risk/year pCi/g

1.3E-08

—

—

—

—

—

—

—

—

—

—

Thorium-230

2.0

pCi/g

1.0E+02

pCi/g

8.5E-10

risk/year pCi/g

8.6E-08

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

9.3

pCi/g

4.7E+02

pCi/g

8.4E-06

risk/year pCi/g

4.0E-03

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

4E-03

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Exposure Route Cancer Total

4E-03

Exposure Route Noncancer Total

—

Exposure Route Noncancer Total

—

Exposure Route: Dermal Exposure

Aluminum

6,900

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

Arsenic

5.9

mg/kg

1.2E-06

mg/kg-day

1.5E+00

(mg/kg-day)"1

1.9E-06

8.9E-07

mg/kg-day

3.0E-04

mg/kg-day

0.0030

5.4E-06

mg/kg-day

3.0E-04

mg/kg-day

0.018

Barium

82

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

Cadmium

0.16

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.2E-08

mg/kg-day

1.0E-04

mg/kg-day

0.00032

1.9E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0019

Chromium

8.2

mg/kg

—

mg/kg-day

5.0E-01

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

Cobalt

5.2

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

Copper

11

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

Iron

15,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

Manganese

230

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

Molybdenum

0.6

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Selenium

2.9

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Thallium

0.15

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

Uranium

6.2

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

Vanadium

17

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Metals Cancer Total

2E-06

Metals Noncancer Total

0.003

Metals Noncancer Total

0.02

Exposure Route Cancer Total

2E-06

Exposure Route Noncancer Total

0.003

Exposure Route Noncancer Total

0.02

Page 2 of 11


-------
Table C-5.3. Human Health Risk and Hazard Calculations - Kerr-McGee Ponds on the Navajo Nation

Kerr-McGee Ponds on the Navajo Nation - Kee'da'whii teeh (Full-Time Resident)

COPCa

EPCb

Units

Cancer
lntakec

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk8

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

1.1

pCi/g

9.6E-02

pCi

2.4E-08

risk/pCi

2.3E-09

—

—

—

—

—

—

—

—

—

—

Uranium-234

0.97

pCi/g

8.4E-02

pCi

2.8E-08

risk/pCi

2.3E-09

—

—

—

—

—

—

—

—

—

—

Thorium-230

2.0

pCi/g

1.7E-01

pCi

3.4E-08

risk/pCi

5.9E-09

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

9.3

pCi/g

8.1E-01

pCi

5.9E-08

risk/pCi

4.8E-08

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

6E-08

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

6,900

mg/kg

—

ug/m3

—

(ug/m3y1

—

9.0E-07

mg/m3

5.0E-03

mg/m3

0.00018

9.0E-07

mg/m3

5.0E-03

mg/m3

0.00018

Arsenic

5.9

mg/kg

7.7E-07

ug/m3

4.3E-03

(ug/m3y1

3.3E-09

7.7E-10

mg/m3

1.5E-05

mg/m3

0.000051

7.7E-10

mg/m3

1.5E-05

mg/m3

0.000051

Barium

82

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.1E-08

mg/m3

5.0E-04

mg/m3

0.000021

1.1E-08

mg/m3

5.0E-04

mg/m3

0.000021

Cadmium

0.16

mg/kg

2.1E-08

ug/m3

1.8E-03

(ug/m3)"1

3.7E-11

2.1E-11

mg/m3

1.0E-05

mg/m3

0.0000021

2.1E-11

mg/m3

1.0E-05

mg/m3

0.0000021

Chromium

8.2

mg/kg

1.8E-06

ug/m3

8.4E-02

(ug/m3)"1

1.5E-07

1.1E-09

mg/m3

1.0E-04

mg/m3

0.000011

1.1E-09

mg/m3

1.0E-04

mg/m3

0.000011

Cobalt

5.2

mg/kg

6.8E-07

ug/m3

9.0E-03

(ug/m3)"1

6.1E-09

6.8E-10

mg/m3

6.0E-06

mg/m3

0.00011

6.8E-10

mg/m3

6.0E-06

mg/m3

0.00011

Copper

11

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

—

mg/m3

—

mg/m3

—

Iron

15,000

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

-

mg/m3

—

mg/m3

—

Manganese

230

mg/kg

—

ug/m3

—

(ug/m3)"1

—

3.0E-08

mg/m3

5.0E-05

mg/m3

0.00060

3.0E-08

mg/m3

5.0E-05

mg/m3

0.00060

Molybdenum

0.6

mg/kg

—

ug/m3

—

(ug/m3)"1

—

7.2E-11

mg/m3

2.0E-03

mg/m3

0.000000036

7.2E-11

mg/m3

2.0E-03

mg/m3

0.000000036

Selenium

2.9

mg/kg

—

ug/m3

—

(ug/m3)"1

—

3.8E-10

mg/m3

2.0E-02

mg/m3

0.000000019

3.8E-10

mg/m3

2.0E-02

mg/m3

0.000000019

Thallium

0.15

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

-

mg/m3

—

mg/m3

—

Uranium

6.2

mg/kg

—

ug/m3

—

(ug/m3)"1

—

8.1E-10

mg/m3

4.0E-05

mg/m3

0.000020

8.1E-10

mg/m3

4.0E-05

mg/m3

0.000020

Vanadium

17

mg/kg

—

ug/m3

—

(ug/m3)"1

—

2.2E-09

mg/m3

1.0E-04

mg/m3

0.000022

2.2E-09

mg/m3

1.0E-04

mg/m3

0.000022

Metals Cancer Total

2E-07

Metals Noncancer Total

0.0010

Metals Noncancer Total

0.0010

Exposure Route Cancer Total

2E-07

Exposure Route Noncancer Total

0.0010

Exposure Route Noncancer Total

0.0010

Exposure Medium: Surface Soil (0-6 inches bgs)

Exposure Route: Plant Consumption

Uranium-238

1.1

pCi/g

7.8E+04

pCi/g

8.7E-11

risk/pCi/g

6.8E-06

—

—

—

—

—

—

—

—

—

—

Uranium-234

0.97

pCi/g

6.9E+04

pCi/g

9.6E-11

risk/pCi/g

6.6E-06

—

—

—

—

—

—

—

—

—

—

Thorium-230

2.0

pCi/g

3.6E+04

pCi/g

1.2E-10

risk/pCi/g

4.3E-06

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

9.3

pCi/g

1.0E+06

pCi/g

3.7E-09

risk/pCi/g

3.8E-03

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

4E-03

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

6,900

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

8.3E-02

mg/kg-day

1.0E+00

mg/kg-day

0.083

2.1E-01

mg/kg-day

1.0E+00

mg/kg-day

0.21

Arsenic

5.9

mg/kg

8.3E-05

mg/kg-day

1.5E+00

(mg/kg-day)"1

1.2E-04

7.7E-05

mg/kg-day

3.0E-04

mg/kg-day

0.26

2.0E-04

mg/kg-day

3.0E-04

mg/kg-day

0.67

Barium

82

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.9E-03

mg/kg-day

2.0E-01

mg/kg-day

0.009

5.0E-03

mg/kg-day

2.0E-01

mg/kg-day

0.025

Cadmium

0.16

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

9.4E-06

mg/kg-day

1.0E-04

mg/kg-day

0.094

2.6E-05

mg/kg-day

1.0E-04

mg/kg-day

0.26

Chromium

8.2

mg/kg

2.29E-04

mg/kg-day

5.0E-01

(mg/kg-day)"1

1.1E-04

9.9E-05

mg/kg-day

3.0E-03

mg/kg-day

0.033

2.6E-04

mg/kg-day

3.0E-03

mg/kg-day

0.088

Cobalt

5.2

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

9.4E-05

mg/kg-day

3.0E-04

mg/kg-day

0.31

2.5E-04

mg/kg-day

3.0E-04

mg/kg-day

0.83

Copper

11

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.9E-03

mg/kg-day

4.0E-02

mg/kg-day

0.047

5.0E-03

mg/kg-day

4.0E-02

mg/kg-day

0.12

Iron

15,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

--

1.8E-01

mg/kg-day

7.0E-01

mg/kg-day

0.26

4.7E-01

mg/kg-day

7.0E-01

mg/kg-day

0.66

Manganese

230

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.5E-02

mg/kg-day

2.4E-02

mg/kg-day

1.1

6.7E-02

mg/kg-day

2.4E-02

mg/kg-day

2.8

Molybdenum

0.6

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.1E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0121

1.6E-04

mg/kg-day

5.0E-03

mg/kg-day

0.032

Selenium

2.9

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.2E-05

mg/kg-day

5.0E-03

mg/kg-day

0.010

1.4E-04

mg/kg-day

5.0E-03

mg/kg-day

0.028

Thallium

0.15

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.5E-06

mg/kg-day

1.0E-05

mg/kg-day

0.15

4.2E-06

mg/kg-day

1.0E-05

mg/kg-day

0.42

Uranium

6.2

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

8.1E-05

mg/kg-day

2.0E-04

mg/kg-day

0.40

2.2E-04

mg/kg-day

2.0E-04

mg/kg-day

1.1

Vanadium

17

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.0E-04

mg/kg-day

5.0E-03

mg/kg-day

0.041

5.6E-04

mg/kg-day

5.0E-03

mg/kg-day

0.112

Metals Cancer Total

2E-04

Metals Noncancer Total

3

Metals Noncancer Total

7

Exposure Route Cancer Total

4E-03

Exposure Route Noncancer Total

3

Exposure Route Noncancer Total

7

Page 3 of 11


-------
Table C-5.3. Human Health Risk and Hazard Calculations - Kerr-McGee Ponds on the Navajo Nation

Kerr-McGee Ponds on the Navajo Nation - Kee'da'whii teeh (Full-Time Resident)

COPCa

EPCb

Units

Cancer
lntakec

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk8

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: Animal Consumption

Uranium-238

1.1

pCi/g

8.9E+04

pCi/g

8.7E-11

risk/pCi/g

7.7E-06

—

—

—

—

—

—

—

—

—

—

Uranium-234

0.97

pCi/g

7.9E+04

pCi/g

9.6E-11

risk/pCi/g

7.5E-06

—

—

—

—

—

—

—

—

—

—

Thorium-230

2.0

pCi/g

7.8E+01

pCi/g

1.2E-10

risk/pCi/g

9.3E-09

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

9.3

pCi/g

2.0E+06

pCi/g

3.7E-09

risk/pCi/g

7.2E-03

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

7E-03

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

6,900

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.8E-03

mg/kg-day

1.0E+00

mg/kg-day

0.0048

1.3E-02

mg/kg-day

1.0E+00

mg/kg-day

0.0131

Arsenic

5.9

mg/kg

6.5E-06

mg/kg-day

1.5E+00

(mg/kg-day)"1

9.7E-06

5.8E-06

mg/kg-day

3.0E-04

mg/kg-day

0.019

1.5E-05

mg/kg-day

3.0E-04

mg/kg-day

0.051

Barium

82

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.1E-05

mg/kg-day

2.0E-01

mg/kg-day

0.000053

2.9E-05

mg/kg-day

2.0E-01

mg/kg-day

0.00014

Cadmium

0.16

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.7E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0037

9.6E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0096

Chromium

8.2

mg/kg

5.03E-05

mg/kg-day

5.0E-01

(mg/kg-day)"1

2.5E-05

2.2E-05

mg/kg-day

3.0E-03

mg/kg-day

0.0072

5.8E-05

mg/kg-day

3.0E-03

mg/kg-day

0.019

Cobalt

5.2

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.0E-05

mg/kg-day

3.0E-04

mg/kg-day

0.17

1.4E-04

mg/kg-day

3.0E-04

mg/kg-day

0.45

Copper

11

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

9.9E-05

mg/kg-day

4.0E-02

mg/kg-day

0.0025

2.6E-04

mg/kg-day

4.0E-02

mg/kg-day

0.0066

Iron

15,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.4E-01

mg/kg-day

7.0E-01

mg/kg-day

0.20

3.6E-01

mg/kg-day

7.0E-01

mg/kg-day

0.51

Manganese

230

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

7.6E-05

mg/kg-day

2.4E-02

mg/kg-day

0.0032

2.0E-04

mg/kg-day

2.4E-02

mg/kg-day

0.0085

Molybdenum

0.6

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.5E-06

mg/kg-day

5.0E-03

mg/kg-day

0.00050

6.6E-06

mg/kg-day

5.0E-03

mg/kg-day

0.0013

Selenium

2.9

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.2E-04

mg/kg-day

5.0E-03

mg/kg-day

0.045

6.1E-04

mg/kg-day

5.0E-03

mg/kg-day

0.12

Thallium

0.15

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.7E-06

mg/kg-day

1.0E-05

mg/kg-day

0.27

7.4E-06

mg/kg-day

1.0E-05

mg/kg-day

0.74

Uranium

6.2

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

8.7E-07

mg/kg-day

2.0E-04

mg/kg-day

0.0043

2.4E-06

mg/kg-day

2.0E-04

mg/kg-day

0.012

Vanadium

17

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.9E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0037

5.1E-05

mg/kg-day

5.0E-03

mg/kg-day

0.010

Metals Cancer Total

3E-05

Metals Noncancer Total

0.7

Metals Noncancer Total

2

Exposure Route Cancer Total

7E-03

Exposure Route Noncancer Total

0.7

Exposure Route Noncancer Total

2

Exposure Medium: Surface Soil (0-6 inches bgs)

Exposure Route: Other Dine Lifeways Plant Ingestion

Uranium-238

1.1

pCi/g

3.6E+04

pCi/g

8.7E-11

risk/pCi/g

3.1E-06

—

—

—

—

—

—

—

—

—

—

Uranium-234

0.97

pCi/g

3.2E+04

pCi/g

9.6E-11

risk/pCi/g

3.1E-06

—

—

—

—

—

—

—

—

—

—

Thorium-230

2.0

pCi/g

2.0E+04

pCi/g

1.2E-10

risk/pCi/g

2.3E-06

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

9.3

pCi/g

5.6E+05

pCi/g

3.7E-09

risk/pCi/g

2.1E-03

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

2E-03

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

6,900

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.9E-02

mg/kg-day

1.0E+00

mg/kg-day

0.049

—

mg/kg-day

1.0E+00

mg/kg-day

—

Arsenic

5.9

mg/kg

4.2E-05

mg/kg-day

1.5E+00

(mg/kg-day)"1

6.3E-05

4.5E-05

mg/kg-day

3.0E-04

mg/kg-day

0.15

—

mg/kg-day

3.0E-04

mg/kg-day

—

Barium

82

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.2E-03

mg/kg-day

2.0E-01

mg/kg-day

0.0062

—

mg/kg-day

2.0E-01

mg/kg-day

—

Cadmium

0.16

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.4E-06

mg/kg-day

1.0E-04

mg/kg-day

0.064

—

mg/kg-day

1.0E-04

mg/kg-day

—

Chromium

8.2

mg/kg

7.2E-05

mg/kg-day

5.0E-01

(mg/kg-day)"1

3.6E-05

6.0E-05

mg/kg-day

3.0E-03

mg/kg-day

0.020

—

mg/kg-day

3.0E-03

mg/kg-day

—

Cobalt

5.2

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.7E-05

mg/kg-day

3.0E-04

mg/kg-day

0.19

—

mg/kg-day

3.0E-04

mg/kg-day

—

Copper

11

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.2E-03

mg/kg-day

4.0E-02

mg/kg-day

0.030

—

mg/kg-day

4.0E-02

mg/kg-day

—

Iron

15,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

--

1.1E-01

mg/kg-day

7.0E-01

mg/kg-day

0.15

—

mg/kg-day

7.0E-01

mg/kg-day

—

Manganese

230

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.7E-02

mg/kg-day

2.4E-02

mg/kg-day

0.70

—

mg/kg-day

2.4E-02

mg/kg-day

—

Molybdenum

0.6

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.0E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0080

—

mg/kg-day

5.0E-03

mg/kg-day

—

Selenium

2.9

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.2E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0064

—

mg/kg-day

5.0E-03

mg/kg-day

—

Thallium

0.15

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

9.5E-07

mg/kg-day

1.0E-05

mg/kg-day

0.095

—

mg/kg-day

1.0E-05

mg/kg-day

—

Uranium

6.2

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.1E-05

mg/kg-day

2.0E-04

mg/kg-day

0.26

—

mg/kg-day

2.0E-04

mg/kg-day

—

Vanadium

17

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.3E-04

mg/kg-day

5.0E-03

mg/kg-day

0.026

—

mg/kg-day

5.0E-03

mg/kg-day

—

Metals Cancer Total

1E-04

Metals Noncancer Total

2

Metals Noncancer Total

—

Exposure Route Cancer Total

2E-03

Exposure Route Noncancer Total

2

Exposure Route Noncancer Total

-

Page 4 of 11


-------
Table C-5.3. Human Health Risk and Hazard Calculations - Kerr-McGee Ponds on the Navajo Nation

Kerr-McGee Ponds on the Navajo Nation - Kee'da'whii teeh (Full-Time Resident)

COPCa

EPCb

Units

Cancer
lntakec

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk8

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: Other Dine Lifeways Plant Dermal

Aluminum

6,900

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

Arsenic

5.9

mg/kg

3.5E-06

mg/kg-day

1.5E+00

(mg/kg-day)"1

5.3E-06

3.8E-06

mg/kg-day

3.0E-04

mg/kg-day

0.013

—

mg/kg-day

3.0E-04

mg/kg-day

—

Barium

82

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

Cadmium

0.16

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

7.0E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0070

—

mg/kg-day

1.0E-04

mg/kg-day

—

Chromium

8.2

mg/kg

—

mg/kg-day

5.0E-01

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

Cobalt

5.2

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

Copper

11

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

Iron

15,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

Manganese

230

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

Molybdenum

0.6

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Selenium

2.9

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Thallium

0.15

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

Uranium

6.2

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

Vanadium

17

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Metals Cancer Total

5E-06

Metals Noncancer Total

0.02

Metals Noncancer Total

—

Exposure Route Cancer Total

5E-06

Exposure Route Noncancer Total

0.02

Exposure Route Noncancer Total

—

Exposure Medium: Surface Soil (0-6 inches bgs)

Exposure Route: Other Dine Lifeways Plant Inhalation

Uranium-238

1.1

pCi/g

2.5E+02

pCi

2.4E-08

risk/pCi

6.0E-06

—

—

—

—

—

—

—

—

—

—

Uranium-234

0.97

pCi/g

2.2E+02

pCi

2.8E-08

risk/pCi

6.2E-06

—

—

—

—

—

—

—

—

—

—

Thorium-230

2.0

pCi/g

9.0E+01

pCi

3.4E-08

risk/pCi

3.1E-06

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

9.3

pCi/g

5.9E+03

pCi

5.9E-08

risk/pCi

3.5E-04

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

4E-04

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

6,900

mg/kg

—

ug/m3

—

(ug/m3)"1

—

5.0E-04

mg/m3

5.0E-03

mg/m3

0.099

—

mg/m3

5.0E-03

mg/m3

—

Arsenic

5.9

mg/kg

4.2E-04

ug/m3

4.3E-03

(ug/m3)"1

1.8E-06

4.7E-07

mg/m3

1.5E-05

mg/m3

0.031

—

mg/m3

1.5E-05

mg/m3

—

Barium

82

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.2E-05

mg/m3

5.0E-04

mg/m3

0.025

—

mg/m3

5.0E-04

mg/m3

—

Cadmium

0.16

mg/kg

5.9E-05

ug/m3

1.8E-03

(ug/m3)"1

1.1E-07

6.4E-08

mg/m3

1.0E-05

mg/m3

0.0064

—

mg/m3

1.0E-05

mg/m3

—

Chromium

8.2

mg/kg

7.3E-04

ug/m3

8.4E-02

(ug/m3)"1

6.1E-05

6.1E-07

mg/m3

1.0E-04

mg/m3

0.0061

—

mg/m3

1.0E-04

mg/m3

—

Cobalt

5.2

mg/kg

5.7E-04

ug/m3

9.0E-03

(ug/m3)"1

5.1E-06

6.2E-07

mg/m3

6.0E-06

mg/m3

0.10

—

mg/m3

6.0E-06

mg/m3

—

Copper

11

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

—

mg/m3

—

mg/m3

—

Iron

15,000

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

-

mg/m3

—

mg/m3

—

Manganese

230

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.7E-04

mg/m3

5.0E-05

mg/m3

3.4

—

mg/m3

5.0E-05

mg/m3

—

Molybdenum

0.6

mg/kg

—

ug/m3

—

(ug/m3)"1

—

4.0E-07

mg/m3

2.0E-03

mg/m3

0.00020

—

mg/m3

2.0E-03

mg/m3

—

Selenium

2.9

mg/kg

—

ug/m3

—

(ug/m3)"1

—

3.2E-07

mg/m3

2.0E-02

mg/m3

0.000016

—

mg/m3

2.0E-02

mg/m3

—

Thallium

0.15

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

-

mg/m3

—

mg/m3

—

Uranium

6.2

mg/kg

—

ug/m3

—

(ug/m3)"1

—

5.3E-07

mg/m3

4.0E-05

mg/m3

0.013

—

mg/m3

4.0E-05

mg/m3

—

Vanadium

17

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.3E-06

mg/m3

1.0E-04

mg/m3

0.013

—

mg/m3

1.0E-04

mg/m3

—

Metals Cancer Total

7E-05

Metals Noncancer Total

4

Metals Noncancer Total

—

Exposure Route Cancer Total

4E-04

Exposure Route Noncancer Total

4

Exposure Route Noncancer Total

—

Surface Soil (0-6 inches bgs) Receptor Cancer Risk Total

2E-02

Receptor/Media Noncancer Hazard Total

9

Receptor/Media Noncancer Hazard Total

10

Page 5 of 11


-------
Table C-5.3. Human Health Risk and Hazard Calculations - Kerr-McGee Ponds on the Navajo Nation

Kerr-McGee Ponds on the Navajo Nation - Kee'da'whii teeh (Full-Time Resident)

COPCa

EPCb

Units

Cancer
lntakec

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk8

Adult
Noncancer
Intake

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Child
Noncancer
lntakec

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Child

Exposure Medium: Subsurface Soil

0-72 inches bgs)

Exposure Route: Incidental Soil Ingestion

Uranium-238

1.1

pCi/g

1.0E+04

pCi/g

1.3E-10

risk/pCi/g

1.4E-06

—

—

—

—

—

—

—

—

—

—

Uranium-234

0.97

pCi/g

9.2E+03

pCi/g

1.5E-10

risk/pCi/g

1.4E-06

—

—

—

—

—

—

—

—

—

—

Thorium-230

2.0

pCi/g

1.9E+04

pCi/g

1.7E-10

risk/pCi/g

3.2E-06

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

9.3

pCi/g

8.8E+04

pCi/g

5.7E-09

risk/pCi/g

5.0E-04

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

5E-04

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

6,900

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.0E-02

mg/kg-day

1.0E+00

mg/kg-day

0.030

1.8E-01

mg/kg-day

1.0E+00

mg/kg-day

0.18

Arsenic

5.9

mg/kg

2.1E-05

mg/kg-day

1.5E+00

(mg/kg-day)"1

3.2E-05

1.5E-05

mg/kg-day

3.0E-04

mg/kg-day

0.051

8.9E-05

mg/kg-day

3.0E-04

mg/kg-day

0.30

Barium

82

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.5E-04

mg/kg-day

2.0E-01

mg/kg-day

0.0018

2.1E-03

mg/kg-day

2.0E-01

mg/kg-day

0.011

Cadmium

0.16

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.9E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0069

4.2E-06

mg/kg-day

1.0E-04

mg/kg-day

0.042

Chromium

8.2

mg/kg

1.31E-04

mg/kg-day

5.0E-01

(mg/kg-day)"1

6.6E-05

3.5E-05

mg/kg-day

3.0E-03

mg/kg-day

0.012

2.1E-04

mg/kg-day

3.0E-03

mg/kg-day

0.071

Cobalt

5.2

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.2E-05

mg/kg-day

3.0E-04

mg/kg-day

0.075

1.4E-04

mg/kg-day

3.0E-04

mg/kg-day

0.45

Copper

11

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.7E-05

mg/kg-day

4.0E-02

mg/kg-day

0.0012

2.9E-04

mg/kg-day

4.0E-02

mg/kg-day

0.0072

Iron

15,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.5E-02

mg/kg-day

7.0E-01

mg/kg-day

0.092

3.9E-01

mg/kg-day

7.0E-01

mg/kg-day

0.56

Manganese

230

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

9.9E-04

mg/kg-day

2.4E-02

mg/kg-day

0.041

6.0E-03

mg/kg-day

2.4E-02

mg/kg-day

0.25

Molybdenum

0.6

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.4E-06

mg/kg-day

5.0E-03

mg/kg-day

0.00047

1.4E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0029

Selenium

2.9

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.2E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0025

7.5E-05

mg/kg-day

5.0E-03

mg/kg-day

0.015

Thallium

0.15

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.5E-07

mg/kg-day

1.0E-05

mg/kg-day

0.065

3.9E-06

mg/kg-day

1.0E-05

mg/kg-day

0.39

Uranium

6.2

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.7E-05

mg/kg-day

2.0E-04

mg/kg-day

0.13

1.6E-04

mg/kg-day

2.0E-04

mg/kg-day

0.81

Vanadium

17

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

7.3E-05

mg/kg-day

5.0E-03

mg/kg-day

0.015

4.4E-04

mg/kg-day

5.0E-03

mg/kg-day

0.088

Metals Cancer Total

1E-04

Metals Noncancer Total

0.5

Metals Noncancer Total

3

Exposure Route Cancer Total

6E-04

Exposure Route Noncancer Total

0.5

Exposure Route Noncancer Total

3

Page 6 of 11


-------
Table C-5.3. Human Health Risk and Hazard Calculations - Kerr-McGee Ponds on the Navajo Nation

Kerr-McGee Ponds on the Navajo Nation - Kee'da'whii teeh (Full-Time Resident)

COPCa

EPCb

Units

Cancer
lntakec

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk8

Adult
Noncancer
Intake

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Child
Noncancer
lntakec

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Child

Exposure Medium: Subsurface Soil

0-72 inches bgs)

Exposure Route: External Exposure

Uranium-238

1.1

pCi/g

5.6E+01

pCi/g

1.2E-10

risk/year pCi/g

7.0E-09

—

—

—

—

—

—

—

—

—

—

Uranium-234

0.97

pCi/g

4.9E+01

pCi/g

2.5E-10

risk/year pCi/g

1.3E-08

—

—

—

—

—

—

—

—

—

—

Thorium-230

2.0

pCi/g

1.0E+02

pCi/g

8.5E-10

risk/year pCi/g

8.6E-08

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

9.3

pCi/g

4.7E+02

pCi/g

8.4E-06

risk/year pCi/g

4.0E-03

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

4E-03

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Exposure Route Cancer Total

4E-03

Exposure Route Noncancer Total

—

Exposure Route Noncancer Total

—

Exposure Route: Dermal Exposure

Aluminum

6,900

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

Arsenic

5.9

mg/kg

1.2E-06

mg/kg-day

1.5E+00

(mg/kg-day)"1

1.9E-06

8.9E-07

mg/kg-day

3.0E-04

mg/kg-day

0.0030

5.4E-06

mg/kg-day

3.0E-04

mg/kg-day

0.018

Barium

82

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

Cadmium

0.16

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.2E-08

mg/kg-day

1.0E-04

mg/kg-day

0.00032

1.9E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0019

Chromium

8.2

mg/kg

—

mg/kg-day

5.0E-01

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

Cobalt

5.2

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

Copper

11

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

Iron

15,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

Manganese

230

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

Molybdenum

0.6

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Selenium

2.9

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Thallium

0.15

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

Uranium

6.2

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

Vanadium

17

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Metals Cancer Total

2E-06

Metals Noncancer Total

0.003

Metals Noncancer Total

0.02

Exposure Route Cancer Total

2E-06

Exposure Route Noncancer Total

0.003

Exposure Route Noncancer Total

0.02

Page 7 of 11


-------
Table C-5.3. Human Health Risk and Hazard Calculations - Kerr-McGee Ponds on the Navajo Nation

Kerr-McGee Ponds on the Navajo Nation - Kee'da'whii teeh (Full-Time Resident)

COPCa

EPCb

Units

Cancer
lntakec

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk8

Adult
Noncancer
Intake

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Child
Noncancer
lntakec

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Child

Exposure Medium: Subsurface Soil

0-72 inches bgs)

Exposure Route: Inhalation of Particulates

Uranium-238

1.1

pCi/g

9.6E-02

pCi

2.4E-08

risk/pCi

2.3E-09

—

—

—

—

—

—

—

—

—

—

Uranium-234

0.97

pCi/g

8.4E-02

pCi

2.8E-08

risk/pCi

2.3E-09

—

—

—

—

—

—

—

—

—

—

Thorium-230

2.0

pCi/g

1.7E-01

pCi

3.4E-08

risk/pCi

5.9E-09

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

9.3

pCi/g

8.1E-01

pCi

5.9E-08

risk/pCi

4.8E-08

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

6E-08

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

6,900

mg/kg

—

ug/m3

—

(ug/m3y1

—

9.0E-07

mg/m3

5.0E-03

mg/m3

0.00018

9.0E-07

mg/m3

5.0E-03

mg/m3

0.00018

Arsenic

5.9

mg/kg

7.7E-07

ug/m3

4.3E-03

(ug/m3y1

3.3E-09

7.7E-10

mg/m3

1.5E-05

mg/m3

0.000051

7.7E-10

mg/m3

1.5E-05

mg/m3

0.000051

Barium

82

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.1E-08

mg/m3

5.0E-04

mg/m3

0.000021

1.1E-08

mg/m3

5.0E-04

mg/m3

0.000021

Cadmium

0.16

mg/kg

2.1E-08

ug/m3

1.8E-03

(ug/m3)"1

3.7E-11

2.1E-11

mg/m3

1.0E-05

mg/m3

0.0000021

2.1E-11

mg/m3

1.0E-05

mg/m3

0.0000021

Chromium

8.2

mg/kg

1.8E-06

ug/m3

8.4E-02

(ug/m3)"1

1.5E-07

1.1E-09

mg/m3

1.0E-04

mg/m3

0.0000107

1.1E-09

mg/m3

1.0E-04

mg/m3

0.0000107

Cobalt

5.2

mg/kg

6.8E-07

ug/m3

9.0E-03

(ug/m3)"1

6.1E-09

6.8E-10

mg/m3

6.0E-06

mg/m3

0.00011

6.8E-10

mg/m3

6.0E-06

mg/m3

0.00011

Copper

11

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

—

mg/m3

—

mg/m3

—

Iron

15,000

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

-

mg/m3

—

mg/m3

—

Manganese

230

mg/kg

—

ug/m3

—

(ug/m3)"1

—

3.0E-08

mg/m3

5.0E-05

mg/m3

0.00060

3.0E-08

mg/m3

5.0E-05

mg/m3

0.00060

Molybdenum

0.6

mg/kg

—

ug/m3

—

(ug/m3)"1

—

7.2E-11

mg/m3

2.0E-03

mg/m3

0.000000036

7.2E-11

mg/m3

2.0E-03

mg/m3

0.000000036

Selenium

2.9

mg/kg

—

ug/m3

—

(ug/m3)"1

—

3.8E-10

mg/m3

2.0E-02

mg/m3

0.000000019

3.8E-10

mg/m3

2.0E-02

mg/m3

0.000000019

Thallium

0.15

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

-

mg/m3

—

mg/m3

—

Uranium

6.2

mg/kg

—

ug/m3

—

(ug/m3)"1

—

8.1E-10

mg/m3

4.0E-05

mg/m3

0.000020

8.1E-10

mg/m3

4.0E-05

mg/m3

0.000020

Vanadium

17

mg/kg

—

ug/m3

—

(ug/m3)"1

—

2.2E-09

mg/m3

1.0E-04

mg/m3

0.000022

2.2E-09

mg/m3

1.0E-04

mg/m3

0.000022

Metals Cancer Total

2E-07

Metals Noncancer Total

0.001

Metals Noncancer Total

0.001

Exposure Route Cancer Total

2E-07

Exposure Route Noncancer Total

0.001

Exposure Route Noncancer Total

0.001

Exposure Medium: Subsurface Soil (0-72 inches bgs)

Exposure Route: Plant Consumption

Uranium-238

1.1

pCi/g

7.8E+04

pCi/g

8.7E-11

risk/pCi/g

6.8E-06

—

—

—

—

—

—

—

—

—

—

Uranium-234

0.97

pCi/g

6.9E+04

pCi/g

9.6E-11

risk/pCi/g

6.6E-06

—

—

—

—

—

—

—

—

—

—

Thorium-230

2.0

pCi/g

3.6E+04

pCi/g

1.2E-10

risk/pCi/g

4.3E-06

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

9.3

pCi/g

1.0E+06

pCi/g

3.7E-09

risk/pCi/g

3.8E-03

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

4E-03

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

6,900

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

8.3E-02

mg/kg-day

1.0E+00

mg/kg-day

0.083

2.1E-01

mg/kg-day

1.0E+00

mg/kg-day

0.21

Arsenic

5.9

mg/kg

8.3E-05

mg/kg-day

1.5E+00

(mg/kg-day)"1

1.2E-04

7.7E-05

mg/kg-day

3.0E-04

mg/kg-day

0.26

2.0E-04

mg/kg-day

3.0E-04

mg/kg-day

0.67

Barium

82

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.9E-03

mg/kg-day

2.0E-01

mg/kg-day

0.009

5.0E-03

mg/kg-day

2.0E-01

mg/kg-day

0.025

Cadmium

0.16

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

9.4E-06

mg/kg-day

1.0E-04

mg/kg-day

0.094

2.6E-05

mg/kg-day

1.0E-04

mg/kg-day

0.26

Chromium

8.2

mg/kg

2.3E-04

mg/kg-day

5.0E-01

(mg/kg-day)"1

1.1E-04

9.9E-05

mg/kg-day

3.0E-03

mg/kg-day

0.033

2.6E-04

mg/kg-day

3.0E-03

mg/kg-day

0.088

Cobalt

5.2

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

9.4E-05

mg/kg-day

3.0E-04

mg/kg-day

0.31

2.5E-04

mg/kg-day

3.0E-04

mg/kg-day

0.83

Copper

11

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.9E-03

mg/kg-day

4.0E-02

mg/kg-day

0.047

5.0E-03

mg/kg-day

4.0E-02

mg/kg-day

0.12

Iron

15,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

--

1.8E-01

mg/kg-day

7.0E-01

mg/kg-day

0.26

4.7E-01

mg/kg-day

7.0E-01

mg/kg-day

0.66

Manganese

230

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.5E-02

mg/kg-day

2.4E-02

mg/kg-day

1.1

6.7E-02

mg/kg-day

2.4E-02

mg/kg-day

2.8

Molybdenum

0.6

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.1E-05

mg/kg-day

5.0E-03

mg/kg-day

0.012

1.6E-04

mg/kg-day

5.0E-03

mg/kg-day

0.032

Selenium

2.9

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.2E-05

mg/kg-day

5.0E-03

mg/kg-day

0.010

1.4E-04

mg/kg-day

5.0E-03

mg/kg-day

0.028

Thallium

0.15

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.5E-06

mg/kg-day

1.0E-05

mg/kg-day

0.15

4.2E-06

mg/kg-day

1.0E-05

mg/kg-day

0.42

Uranium

6.2

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

8.1E-05

mg/kg-day

2.0E-04

mg/kg-day

0.40

2.2E-04

mg/kg-day

2.0E-04

mg/kg-day

1.1

Vanadium

17

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.0E-04

mg/kg-day

5.0E-03

mg/kg-day

0.041

5.6E-04

mg/kg-day

5.0E-03

mg/kg-day

0.11

Metals Cancer Total

2E-04

Metals Noncancer Total

3

Metals Noncancer Total

7

Exposure Route Cancer Total

4E-03

Exposure Route Noncancer Total

3

Exposure Route Noncancer Total

7

Page 8 of 11


-------
Table C-5.3. Human Health Risk and Hazard Calculations - Kerr-McGee Ponds on the Navajo Nation

Kerr-McGee Ponds on the Navajo Nation - Kee'da'whii teeh (Full-Time Resident)

COPCa

EPCb

Units

Cancer
lntakec

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk8

Adult
Noncancer
Intake

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Child
Noncancer
lntakec

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Child

Exposure Medium: Subsurface Soil

0-72 inches bgs)

Exposure Route: Animal Consumption

Uranium-238

1.1

pCi/g

8.9E+04

pCi/g

8.7E-11

risk/pCi/g

7.7E-06

—

—

—

—

—

—

—

—

—

—

Uranium-234

0.97

pCi/g

7.9E+04

pCi/g

9.6E-11

risk/pCi/g

7.5E-06

—

—

—

—

—

—

—

—

—

—

Thorium-230

2.0

pCi/g

7.8E+01

pCi/g

1.2E-10

risk/pCi/g

9.3E-09

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

9.3

pCi/g

2.0E+06

pCi/g

3.7E-09

risk/pCi/g

7.2E-03

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

7E-03

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

6,900

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.8E-03

mg/kg-day

1.0E+00

mg/kg-day

0.0048

1.3E-02

mg/kg-day

1.0E+00

mg/kg-day

0.013

Arsenic

5.9

mg/kg

6.5E-06

mg/kg-day

1.5E+00

(mg/kg-day)"1

9.7E-06

5.8E-06

mg/kg-day

3.0E-04

mg/kg-day

0.019

1.5E-05

mg/kg-day

3.0E-04

mg/kg-day

0.051

Barium

82

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.1E-05

mg/kg-day

2.0E-01

mg/kg-day

0.000053

2.9E-05

mg/kg-day

2.0E-01

mg/kg-day

0.00014

Cadmium

0.16

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.7E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0037

9.6E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0096

Chromium

8.2

mg/kg

5.0E-05

mg/kg-day

5.0E-01

(mg/kg-day)"1

2.5E-05

2.2E-05

mg/kg-day

3.0E-03

mg/kg-day

0.0072

5.8E-05

mg/kg-day

3.0E-03

mg/kg-day

0.019

Cobalt

5.2

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.0E-05

mg/kg-day

3.0E-04

mg/kg-day

0.17

1.4E-04

mg/kg-day

3.0E-04

mg/kg-day

0.45

Copper

11

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

9.9E-05

mg/kg-day

4.0E-02

mg/kg-day

0.0025

2.6E-04

mg/kg-day

4.0E-02

mg/kg-day

0.0066

Iron

15,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.4E-01

mg/kg-day

7.0E-01

mg/kg-day

0.20

3.6E-01

mg/kg-day

7.0E-01

mg/kg-day

0.51

Manganese

230

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

7.6E-05

mg/kg-day

2.4E-02

mg/kg-day

0.0032

2.0E-04

mg/kg-day

2.4E-02

mg/kg-day

0.0085

Molybdenum

0.6

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.5E-06

mg/kg-day

5.0E-03

mg/kg-day

0.00050

6.6E-06

mg/kg-day

5.0E-03

mg/kg-day

0.0013

Selenium

2.9

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.2E-04

mg/kg-day

5.0E-03

mg/kg-day

0.045

6.1E-04

mg/kg-day

5.0E-03

mg/kg-day

0.12

Thallium

0.15

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.7E-06

mg/kg-day

1.0E-05

mg/kg-day

0.27

7.4E-06

mg/kg-day

1.0E-05

mg/kg-day

0.74

Uranium

6.2

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

8.7E-07

mg/kg-day

2.0E-04

mg/kg-day

0.0043

2.4E-06

mg/kg-day

2.0E-04

mg/kg-day

0.012

Vanadium

17

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.9E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0037

5.1E-05

mg/kg-day

5.0E-03

mg/kg-day

0.010

Metals Cancer Total

3E-05

Metals Noncancer Total

0.7

Metals Noncancer Total

2

Exposure Route Cancer Total

7E-03

Exposure Route Noncancer Total

0.7

Exposure Route Noncancer Total

2

Exposure Medium: Subsurface Soil (0-72 inches bgs)

Exposure Route: Other Dine Lifeways Plant Ingestion

Uranium-238

1.1

pCi/g

3.6E+04

pCi/g

8.7E-11

risk/pCi/g

3.1E-06

—

—

—

—

—

—

—

—

—

—

Uranium-234

0.97

pCi/g

3.2E+04

pCi/g

9.6E-11

risk/pCi/g

3.1E-06

—

—

—

—

—

—

—

—

—

—

Thorium-230

2.0

pCi/g

2.0E+04

pCi/g

1.2E-10

risk/pCi/g

2.3E-06

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

9.3

pCi/g

5.6E+05

pCi/g

3.7E-09

risk/pCi/g

2.1E-03

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

2E-03

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

6,900

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.9E-02

mg/kg-day

1.0E+00

mg/kg-day

0.049

—

mg/kg-day

1.0E+00

mg/kg-day

—

Arsenic

5.9

mg/kg

4.2E-05

mg/kg-day

1.5E+00

(mg/kg-day)"1

6.3E-05

4.5E-05

mg/kg-day

3.0E-04

mg/kg-day

0.15

—

mg/kg-day

3.0E-04

mg/kg-day

—

Barium

82

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.2E-03

mg/kg-day

2.0E-01

mg/kg-day

0.0062

—

mg/kg-day

2.0E-01

mg/kg-day

—

Cadmium

0.16

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.4E-06

mg/kg-day

1.0E-04

mg/kg-day

0.064

—

mg/kg-day

1.0E-04

mg/kg-day

—

Chromium

8.2

mg/kg

7.2E-05

mg/kg-day

5.0E-01

(mg/kg-day)"1

3.6E-05

6.0E-05

mg/kg-day

3.0E-03

mg/kg-day

0.020

—

mg/kg-day

3.0E-03

mg/kg-day

—

Cobalt

5.2

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.7E-05

mg/kg-day

3.0E-04

mg/kg-day

0.19

—

mg/kg-day

3.0E-04

mg/kg-day

—

Copper

11

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.2E-03

mg/kg-day

4.0E-02

mg/kg-day

0.030

—

mg/kg-day

4.0E-02

mg/kg-day

—

Iron

15,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

--

1.1E-01

mg/kg-day

7.0E-01

mg/kg-day

0.15

—

mg/kg-day

7.0E-01

mg/kg-day

—

Manganese

230

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.7E-02

mg/kg-day

2.4E-02

mg/kg-day

0.70

—

mg/kg-day

2.4E-02

mg/kg-day

—

Molybdenum

0.6

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.0E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0080

—

mg/kg-day

5.0E-03

mg/kg-day

—

Selenium

2.9

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.2E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0064

—

mg/kg-day

5.0E-03

mg/kg-day

—

Thallium

0.15

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

9.5E-07

mg/kg-day

1.0E-05

mg/kg-day

0.095

—

mg/kg-day

1.0E-05

mg/kg-day

—

Uranium

6.2

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.1E-05

mg/kg-day

2.0E-04

mg/kg-day

0.26

—

mg/kg-day

2.0E-04

mg/kg-day

—

Vanadium

17

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.3E-04

mg/kg-day

5.0E-03

mg/kg-day

0.026

—

mg/kg-day

5.0E-03

mg/kg-day

—

Metals Cancer Total

1E-04

Metals Noncancer Total

2

Metals Noncancer Total

—

Exposure Route Cancer Total

2E-03

Exposure Route Noncancer Total

2

Exposure Route Noncancer Total

-

Page 9 of 11


-------
Table C-5.3. Human Health Risk and Hazard Calculations - Kerr-McGee Ponds on the Navajo Nation

Kerr-McGee Ponds on the Navajo Nation - Kee'da'whii teeh (Full-Time Resident)

COPCa

EPCb

Units

Cancer
lntakec

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk8

Adult
Noncancer
Intake

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Child
Noncancer
lntakec

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Child

Exposure Medium: Subsurface Soil

0-72 inches bgs)

Exposure Route: Other Dine Lifeways Plant Dermal

Aluminum

6,900

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

Arsenic

5.9

mg/kg

3.5E-06

mg/kg-day

1.5E+00

(mg/kg-day)"1

5.3E-06

3.8E-06

mg/kg-day

3.0E-04

mg/kg-day

0.013

—

mg/kg-day

3.0E-04

mg/kg-day

—

Barium

82

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

Cadmium

0.16

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

7.0E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0070

—

mg/kg-day

1.0E-04

mg/kg-day

—

Chromium

8.2

mg/kg

—

mg/kg-day

5.0E-01

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

Cobalt

5.2

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

Copper

11

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

Iron

15,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

Manganese

230

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

Molybdenum

0.6

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Selenium

2.9

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Thallium

0.15

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

Uranium

6.2

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

Vanadium

17

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Metals Cancer Total

5E-06

Metals Noncancer Total

0.02

Metals Noncancer Total

—

Exposure Route Cancer Total

5E-06

Exposure Route Noncancer Total

0.02

Exposure Route Noncancer Total

—

Exposure Medium: Subsurface Soil (0-72 inches bgs)

Exposure Route: Other Dine Lifeways Plant Inhalation

Uranium-238

1.1

pCi/g

2.5E+02

pCi

2.4E-08

risk/pCi

6.0E-06

—

—

—

—

—

—

—

—

—

—

Uranium-234

0.97

pCi/g

2.2E+02

pCi

2.8E-08

risk/pCi

6.2E-06

—

—

—

—

—

—

—

—

—

—

Thorium-230

2.0

pCi/g

9.0E+01

pCi

3.4E-08

risk/pCi

3.1E-06

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

9.3

pCi/g

5.9E+03

pCi

5.9E-08

risk/pCi

3.5E-04

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

4E-04

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

6,900

mg/kg

—

ug/m3

—

(ug/m3)"1

—

5.0E-04

mg/m3

5.0E-03

mg/m3

0.099

—

mg/m3

5.0E-03

mg/m3

—

Arsenic

5.9

mg/kg

4.2E-04

ug/m3

4.3E-03

(ug/m3)"1

1.8E-06

4.7E-07

mg/m3

1.5E-05

mg/m3

0.031

—

mg/m3

1.5E-05

mg/m3

—

Barium

82

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.2E-05

mg/m3

5.0E-04

mg/m3

0.025

—

mg/m3

5.0E-04

mg/m3

—

Cadmium

0.16

mg/kg

5.9E-05

ug/m3

1.8E-03

(ug/m3)"1

1.1E-07

6.4E-08

mg/m3

1.0E-05

mg/m3

0.0064

—

mg/m3

1.0E-05

mg/m3

—

Chromium

8.2

mg/kg

7.3E-04

ug/m3

8.4E-02

(ug/m3)"1

6.1E-05

6.1E-07

mg/m3

1.0E-04

mg/m3

0.0061

—

mg/m3

1.0E-04

mg/m3

—

Cobalt

5.2

mg/kg

5.7E-04

ug/m3

9.0E-03

(ug/m3)"1

5.1E-06

6.2E-07

mg/m3

6.0E-06

mg/m3

0.10

—

mg/m3

6.0E-06

mg/m3

—

Copper

11

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

—

mg/m3

—

mg/m3

—

Iron

15,000

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

-

mg/m3

—

mg/m3

—

Manganese

230

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.7E-04

mg/m3

5.0E-05

mg/m3

3.4

—

mg/m3

5.0E-05

mg/m3

—

Molybdenum

0.6

mg/kg

—

ug/m3

—

(ug/m3)"1

—

4.0E-07

mg/m3

2.0E-03

mg/m3

0.00020

—

mg/m3

2.0E-03

mg/m3

—

Selenium

2.9

mg/kg

—

ug/m3

—

(ug/m3)"1

—

3.2E-07

mg/m3

2.0E-02

mg/m3

0.000016

—

mg/m3

2.0E-02

mg/m3

—

Thallium

0.15

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

-

mg/m3

—

mg/m3

—

Uranium

6.2

mg/kg

—

ug/m3

—

(ug/m3)"1

—

5.3E-07

mg/m3

4.0E-05

mg/m3

0.013

—

mg/m3

4.0E-05

mg/m3

—

Vanadium

17

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.3E-06

mg/m3

1.0E-04

mg/m3

0.013

—

mg/m3

1.0E-04

mg/m3

—

Metals Cancer Total

7E-05

Metals Noncancer Total

4

Metals Noncancer Total

—

Exposure Route Cancer Total

4E-04

Exposure Route Noncancer Total

4

Exposure Route Noncancer Total

—

Subsurface Soil (0-72 inches bgs) Receptor Cancer Risk Total

2E-02

Receptor/Media Noncancer Hazard Total

9

Receptor/Media Noncancer Hazard Total

10

Page 10 of 11


-------
Table C-5.3. Human Health Risk and Hazard Calculations - Kerr-McGee Ponds on the Navajo Nation

Notes:

a COPCs are the constituents of interest with a maximum detected concentration exceeding the COPC screening level (see Table C-1).
b EPCs are provided on Table C-4.

c The intakes are the EPC multiplied by the exposure parameters and any applicable contaminant-specific inputs (see Table C-3 for exposure inputs, Table 4 of the NAUM risk assessment methodology [USEPA 2024b] report for contaminant-specific inputs,

and Appendix B of the NAUM risk assessment methodology [USEPA 2024b] report for equations).
d The toxicity values are provided in Table 4 of the NAUM risk assessment methodology (USEPA 2024b).

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,

|jg/m3
bgs
COPC
EPC

Kerr-McGee

mg/kg

mg/kg-day

Not applicable
Microgram per cubic meter
Below ground surface
Contaminant of potential concern
Exposure point concentration
Kerr-McGee Corporation
Milligram per kilogram
Milligram per kilogram per day

mg/m3
NAUM

Milligram per cubic meter
Navajo abandoned uranium mine
Picocurie

Picocurie per gram
Reference concentration
Reference dose
Secular equilibrium

U.S. Environmental Protection Agency

pCi

pCi/g

RfC

RfD

SE

USEPA

Reference:

U.S. Environmental Protection Agency (USEPA). 2024b. "Navajo Abandoned Uranium Mines Risk Assessment Methodology." Draft Final. March.

Page 11 of 11


-------
Table C-5.4. Human Health Risk and Hazard Calculations - Kerr-McGee Ponds on United Nuclear Corporation Property

Kerr-McGee Ponds on United Nuclear Corporation Property - UNC Outdoor Worker

COPCa

EPCb

Units

Cancer Intake0

Units

Slope Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Exposure Medium: Surface Soil (0-6 inches bgs)

Exposure Route: Incidental Soil In

gestion

Uranium-238

2.4

pCi/g

6.0E+02

pCi/g

1.3E-10

risk/pCi/g

8.0E-08

—

—

—

—

—

Uranium-234

2.4

pCi/g

6.0E+02

pCi/g

1.5E-10

risk/pCi/g

8.9E-08

—

—

—

—

—

Thorium-230

3.4

pCi/g

8.5E+02

pCi/g

1.7E-10

risk/pCi/g

1.4E-07

—

—

—

—

—

Radium-226 in SE

13

pCi/g

3.3E+03

pCi/g

5.7E-09

risk/pCi/g

1.8E-05

—

—

—

—

—

Radionuclide Cancer Total

2E-05

Radionuclide Noncancer Total

—

Aluminum

6,600

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.3E-03

mg/kg-day

1.0E+00

mg/kg-day

0.0023

Arsenic

6.0

mg/kg

4.4E-07

mg/kg-day

1.5E+00

(mg/kg-day)"1

6.6E-07

1.2E-06

mg/kg-day

3.0E-04

mg/kg-day

0.0041

Barium

83

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.8E-05

mg/kg-day

2.0E-01

mg/kg-day

0.00014

Cadmium

0.11

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.8E-08

mg/kg-day

1.0E-04

mg/kg-day

0.00038

Chromium

8.5

mg/kg

—

mg/kg-day

5.0E-01

(mg/kg-day)"1

—

2.9E-05

mg/kg-day

3.0E-03

mg/kg-day

0.0097

Cobalt

5.2

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.8E-06

mg/kg-day

3.0E-04

mg/kg-day

0.0059

Copper

11

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.8E-06

mg/kg-day

4.0E-02

mg/kg-day

0.000094

Iron

15,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.1E-03

mg/kg-day

7.0E-01

mg/kg-day

0.0073

Manganese

220

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

7.5E-05

mg/kg-day

2.4E-02

mg/kg-day

0.0031

Molybdenum

0.57

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.0E-07

mg/kg-day

5.0E-03

mg/kg-day

0.000039

Selenium

4.0

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.4E-06

mg/kg-day

5.0E-03

mg/kg-day

0.00027

Thallium

0.14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.8E-08

mg/kg-day

1.0E-05

mg/kg-day

0.0048

Uranium

7.7

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.6E-06

mg/kg-day

2.0E-04

mg/kg-day

0.013

Vanadium

19

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.5E-06

mg/kg-day

5.0E-03

mg/kg-day

0.0013

Metals Cancer Total

7E-07

Metals Noncancer Total

0.05

Exposure Route Cancer Total

2E-05

Exposure Route Noncancer Total

0.05

Page 1 of 6


-------
Table C-5.4. Human Health Risk and Hazard Calculations - Kerr-McGee Ponds on United Nuclear Corporation Property

Kerr-McGee Ponds on United Nuclear Corporation Property - UNC Outdoor Worker

COPCa

EPCb

Units

Cancer Intake0

Units

Slope Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Exposure Medium: Surface Soil (0-6 inches bgs)

Exposure Route: External Exposure

Uranium-238

2.4

pCi/g

4.9E+00

pCi/g

1.2E-10

risk/year pCi/g

6.1E-10

—

—

—

—

—

Uranium-234

2.4

pCi/g

4.9E+00

pCi/g

2.5E-10

risk/year pCi/g

1.2E-09

—

—

—

—

—

Thorium-230

3.4

pCi/g

7.0E+00

pCi/g

8.5E-10

risk/year pCi/g

5.9E-09

—

—

—

—

—

Radium-226 in SE

13

pCi/g

2.7E+01

pCi/g

8.4E-06

risk/year pCi/g

2.2E-04

—

—

—

—

—

Radionuclide Cancer Total

2E-04

Radionuclide Noncancer Total

—

Exposure Route Cancer Total

2E-04

Exposure Route Noncancer Total

—

Exposure Route: Dermal Exposure

Aluminum

6,600

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

Arsenic

6.0

mg/kg

9.3E-08

mg/kg-day

1.5E+00

(mg/kg-day)"1

1.4E-07

2.6E-07

mg/kg-day

3.0E-04

mg/kg-day

0.00087

Barium

83

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

Cadmium

0.11

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.4E-09

mg/kg-day

1.0E-04

mg/kg-day

0.000064

Chromium

8.5

mg/kg

—

mg/kg-day

5.0E-01

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

Cobalt

5.2

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

Copper

11

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

Iron

15,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

Manganese

220

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

Molybdenum

0.57

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Selenium

4.0

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Thallium

0.14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

Uranium

7.7

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

Vanadium

19

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Metals Cancer Total

1E-07

Metals Noncancer Total

0.0009

Exposure Route Cancer Total

1E-07

Exposure Route Noncancer Total

0.0009

Page 2 of 6


-------
Table C-5.4. Human Health Risk and Hazard Calculations - Kerr-McGee Ponds on United Nuclear Corporation Property

Kerr-McGee Ponds on United Nuclear Corporation Property - UNC Outdoor Worker

COPCa

EPCb

Units

Cancer Intake0

Units

Slope Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Exposure Medium: Surface Soil (0-6 inches bgs)

Exposure Route: Inhalation of Particulates

Uranium-238

2.4

pCi/g

6.1E-03

pCi

2.4E-08

risk/pCi

1.4E-10

—

—

—

—

—

Uranium-234

2.4

pCi/g

6.1E-03

pCi

2.8E-08

risk/pCi

1.7E-10

—

—

—

—

—

Thorium-230

3.4

pCi/g

8.6E-03

pCi

3.4E-08

risk/pCi

2.9E-10

—

—

—

—

—

Radium-226 in SE

13

pCi/g

3.3E-02

pCi

5.9E-08

risk/pCi

1.9E-09

—

—

—

—

—

Radionuclide Cancer Total

3E-09

Radionuclide Noncancer Total

—

Aluminum

6,600

mg/kg

—

ug/m3

—

(ug/m3y1

—

9.1E-08

mg/m3

5.0E-03

mg/m3

0.000018

Arsenic

6.0

mg/kg

3.0E-08

ug/m3

4.3E-03

(ug/m3y1

1.3E-10

8.3E-11

mg/m3

1.5E-05

mg/m3

0.0000055

Barium

83

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.1E-09

mg/m3

5.0E-04

mg/m3

0.0000023

Cadmium

0.11

mg/kg

5.4E-10

ug/m3

1.8E-03

(ug/m3)"1

9.8E-13

1.5E-12

mg/m3

1.0E-05

mg/m3

0.00000015

Chromium

8.5

mg/kg

4.5E-09

ug/m3

8.4E-02

(ug/m3)"1

3.8E-10

2.0E-09

mg/m3

1.0E-04

mg/m3

0.000020

Cobalt

5.2

mg/kg

2.6E-08

ug/m3

9.0E-03

(ug/m3)"1

2.3E-10

7.2E-11

mg/m3

6.0E-06

mg/m3

0.000012

Copper

11

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

Iron

15,000

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

Manganese

220

mg/kg

—

ug/m3

—

(ug/m3)"1

—

3.0E-09

mg/m3

5.0E-05

mg/m3

0.000061

Molybdenum

0.57

mg/kg

—

ug/m3

—

(ug/m3)"1

—

7.9E-12

mg/m3

2.0E-03

mg/m3

0.0000000039

Selenium

4.0

mg/kg

—

ug/m3

—

(ug/m3)"1

—

5.5E-11

mg/m3

2.0E-02

mg/m3

0.0000000028

Thallium

0.14

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

Uranium

7.7

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.1E-10

mg/m3

4.0E-05

mg/m3

0.0000027

Vanadium

19

mg/kg

—

ug/m3

—

(ug/m3)"1

—

2.6E-10

mg/m3

1.0E-04

mg/m3

0.0000026

Metals Cancer Total

7E-10

Metals Noncancer Total

0.0001

Exposure Route Cancer Total

3E-09

Exposure Route Noncancer Total

0.0001

Surface Soil (0-6 inches bgs) Receptor Cancer Risk Total

2E-04

Receptor/Media Noncancer Hazard Total

0.05

Page 3 of 6


-------
Table C-5.4. Human Health Risk and Hazard Calculations - Kerr-McGee Ponds on United Nuclear Corporation Property

Kerr-McGee Ponds on United Nuclear Corporation Property - UNC Outdoor Worker

COPCa

EPCb

Units

Cancer Intake0

Units

Slope Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Exposure Medium: Subsurface Soil (0-72 inches bgs)

Exposure Route: Incidental Soil In

gestion

Uranium-238

52

pCi/g

1.3E+04

pCi/g

1.3E-10

risk/pCi/g

1.7E-06

—

—

—

—

—

Uranium-234

49

pCi/g

1.2E+04

pCi/g

1.5E-10

risk/pCi/g

1.8E-06

—

—

—

—

—

Thorium-230

3.4

pCi/g

8.5E+02

pCi/g

1.7E-10

risk/pCi/g

1.4E-07

—

—

—

—

—

Radium-226 in SE

12

pCi/g

3.0E+03

pCi/g

5.7E-09

risk/pCi/g

1.7E-05

—

—

—

—

—

Radionuclide Cancer Total

2E-05

Radionuclide Noncancer Total

—

Aluminum

6,600

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.3E-03

mg/kg-day

1.0E+00

mg/kg-day

0.0023

Arsenic

5.8

mg/kg

4.3E-07

mg/kg-day

1.5E+00

(mg/kg-day)"1

6.4E-07

1.2E-06

mg/kg-day

3.0E-04

mg/kg-day

0.0040

Barium

75

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.6E-05

mg/kg-day

2.0E-01

mg/kg-day

0.00013

Cadmium

0.093

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.2E-08

mg/kg-day

1.0E-04

mg/kg-day

0.00032

Chromium

8.1

mg/kg

—

mg/kg-day

5.0E-01

(mg/kg-day)"1

—

2.8E-05

mg/kg-day

3.0E-03

mg/kg-day

0.0092

Cobalt

5.2

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.8E-06

mg/kg-day

3.0E-04

mg/kg-day

0.0059

Copper

10

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.4E-06

mg/kg-day

4.0E-02

mg/kg-day

0.000084

Iron

15,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.1E-03

mg/kg-day

7.0E-01

mg/kg-day

0.0073

Manganese

220

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

7.5E-05

mg/kg-day

2.4E-02

mg/kg-day

0.0031

Molybdenum

0.63

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.2E-07

mg/kg-day

5.0E-03

mg/kg-day

0.000043

Selenium

3.7

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.3E-06

mg/kg-day

5.0E-03

mg/kg-day

0.00025

Thallium

0.14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.8E-08

mg/kg-day

1.0E-05

mg/kg-day

0.0048

Uranium

25

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

8.6E-06

mg/kg-day

2.0E-04

mg/kg-day

0.0428

Vanadium

18

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.2E-06

mg/kg-day

5.0E-03

mg/kg-day

0.0012

Metals Cancer Total

6E-07

Metals Noncancer Total

0.08

Exposure Route Cancer Total

2E-05

Exposure Route Noncancer Total

0.08

Page 4 of 6


-------
Table C-5.4. Human Health Risk and Hazard Calculations - Kerr-McGee Ponds on United Nuclear Corporation Property

Kerr-McGee Ponds on United Nuclear Corporation Property - UNC Outdoor Worker

COPCa

EPCb

Units

Cancer Intake0

Units

Slope Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Exposure Medium: Subsurface Soil (0-72 inches bgs)

Exposure Route: External Exposure

Uranium-238

52

pCi/g

1.1E+02

pCi/g

1.2E-10

risk/year pCi/g

1.3E-08

—

—

—

—

—

Uranium-234

49

pCi/g

1.0E+02

pCi/g

2.5E-10

risk/year pCi/g

2.5E-08

—

—

—

—

—

Thorium-230

3.4

pCi/g

7.0E+00

pCi/g

8.5E-10

risk/year pCi/g

5.9E-09

—

—

—

—

—

Radium-226 in SE

12

pCi/g

2.5E+01

pCi/g

8.4E-06

risk/year pCi/g

2.1E-04

—

—

—

—

—

Radionuclide Cancer Total

2E-04

Radionuclide Noncancer Total

—

Exposure Route Cancer Total

2E-04

Exposure Route Noncancer Total

—

Exposure Route: Dermal Exposure

Aluminum

6,600

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

Arsenic

5.8

mg/kg

9.0E-08

mg/kg-day

1.5E+00

(mg/kg-day)"1

1.3E-07

2.5E-07

mg/kg-day

3.0E-04

mg/kg-day

0.00084

Barium

75

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

Cadmium

0.093

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.4E-09

mg/kg-day

1.0E-04

mg/kg-day

0.000054

Chromium

8.1

mg/kg

—

mg/kg-day

5.0E-01

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

Cobalt

5.2

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

Copper

10

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

Iron

15,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

Manganese

220

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

Molybdenum

0.63

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Selenium

3.7

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Thallium

0.14

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

Uranium

25

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

Vanadium

18

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Metals Cancer Total

1E-07

Metals Noncancer Total

0.0009

Exposure Route Cancer Total

1E-07

Exposure Route Noncancer Total

0.0009

Page 5 of 6


-------
Table C-5.4. Human Health Risk and Hazard Calculations - Kerr-McGee Ponds on United Nuclear Corporation Property

Kerr-McGee Ponds on United Nuclear Corporation Property - UNC Outdoor Worker

COPCa

EPCb

Units

Cancer Intake0

Units

Slope Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
lntakec

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Exposure Medium: Subsurface Soil (0-72 inches bgs)

Exposure Route: Inhalation of Particulates

Uranium-238

52

pCi/g

1.3E-01

pCi

2.4E-08

risk/pCi

3.1E-09

—

—

—

—

—

Uranium-234

49

pCi/g

1.2E-01

pCi

2.8E-08

risk/pCi

3.4E-09

—

—

—

—

—

Thorium-230

3.4

pCi/g

8.6E-03

pCi

3.4E-08

risk/pCi

2.9E-10

—

—

—

—

—

Radium-226 in SE

12

pCi/g

3.0E-02

pCi

5.9E-08

risk/pCi

1.8E-09

—

—

—

—

—

Radionuclide Cancer Total

9E-09

Radionuclide Noncancer Total

—

Aluminum

6,600

mg/kg

—

ug/m3

—

(ug/m3y1

—

9.1E-08

mg/m3

5.0E-03

mg/m3

0.000018

Arsenic

5.8

mg/kg

2.9E-08

ug/m3

4.3E-03

(ug/m3y1

1.2E-10

8.0E-11

mg/m3

1.5E-05

mg/m3

0.0000053

Barium

75

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.0E-09

mg/m3

5.0E-04

mg/m3

0.0000021

Cadmium

0.093

mg/kg

4.6E-10

ug/m3

1.8E-03

(ug/m3)"1

8.3E-13

1.3E-12

mg/m3

1.0E-05

mg/m3

0.00000013

Chromium

8.1

mg/kg

4.3E-09

ug/m3

8.4E-02

(ug/m3)"1

3.6E-10

1.9E-09

mg/m3

1.0E-04

mg/m3

0.000019

Cobalt

5.2

mg/kg

2.6E-08

ug/m3

9.0E-03

(ug/m3)"1

2.3E-10

7.2E-11

mg/m3

6.0E-06

mg/m3

0.000012

Copper

10

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

Iron

15,000

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

Manganese

220

mg/kg

—

ug/m3

—

(ug/m3)"1

—

3.0E-09

mg/m3

5.0E-05

mg/m3

0.000061

Molybdenum

0.63

mg/kg

—

ug/m3

—

(ug/m3)"1

—

8.7E-12

mg/m3

2.0E-03

mg/m3

0.0000000044

Selenium

3.7

mg/kg

—

ug/m3

—

(ug/m3)"1

—

5.1E-11

mg/m3

2.0E-02

mg/m3

0.0000000026

Thallium

0.14

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

Uranium

25

mg/kg

—

ug/m3

—

(ug/m3)"1

—

3.5E-10

mg/m3

4.0E-05

mg/m3

0.0000086

Vanadium

18

mg/kg

—

ug/m3

—

(ug/m3)"1

—

2.5E-10

mg/m3

1.0E-04

mg/m3

0.0000025

Metals Cancer Total

7E-10

Metals Noncancer Total

0.0001

Exposure Route Cancer Total

9E-09

Exposure Route Noncancer Total

0.0001

Subsurface Soil (0-72 inches bgs) Receptor Cancer Risk Total

2E-04

Receptor/Media Noncancer Hazard Total

0.08

Notes:

a COPCs are the constituents of interest with a maximum detected concentration exceeding the COPC screening level (see Table C-1).
b EPCs are provided on Table C-4.

c The intakes are the EPC multiplied by the exposure parameters and any applicable contaminant-specific inputs (see Table C-3 for exposure inputs, Table 4 of the NAUM risk assessment methodology [USEPA 2024b] report for contaminant-specific inputs,

and Appendix B of the NAUM risk assessment methodology [USEPA 2024b] report for equations).
d The toxicity values are provided in Table 4 of the NAUM risk assessment methodology (USEPA 2024b).

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 equilbrium

mg/kg-day

Milligram per kilogram per day

UNC

United Nuclear Corporation

mg/m3

Milligram per cubic meter

USEPA

U.S. Environmental Protection Agency

Reference:

U.S. Environmental Protection Agency (USEPA). 2024b. "Navajo Abandoned Uranium Mines Risk Assessment Methodology." Draft Final. March.

Page 6 of 6


-------
Table C-5.5. Human Health Risk and Hazard Calculations - Arroyos on the Navajo Nation

Arroyos on the Navajo Nation - Kpp ei doo nahaazah dah (Difficult Access Open Space)

COPCa

EPCb

Units

Cancer
lntakec

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake0

Units

RfD/
RfCd

Units

Noncancer
Hazardf

Child
Noncancer
Intake0

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Child

Exposure Medium: Surface Soil (0-6 inches bgs



Exposure Route: Incidental Soil Ingestion

Uranium-238

—

pCi/g

—

pCi/g

1.3E-10

risk/pCi/g

—

—

—

—

—

—

—

—

—

—

—

Uranium-234

—

pCi/g

—

pCi/g

1.5E-10

risk/pCi/g

—

—

—

—

—

—

—

—

—

—

—

Thorium-230

—

pCi/g

—

pCi/g

1.7E-10

risk/pCi/g

—

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

1.3

pCi/g

4.4E+01

pCi/g

5.7E-09

risk/pCi/g

2.5E-07

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

3E-07

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

4,700

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

7.1E-05

mg/kg-day

1.0E+00

mg/kg-day

0.000071

4.4E-04

mg/kg-day

1.0E+00

mg/kg-day

0.00044

Arsenic

11

mg/kg

1.4E-07

mg/kg-day

1.5E+00

(mg/kg-day)"1

2.1E-07

1.0E-07

mg/kg-day

3.0E-04

mg/kg-day

0.00034

6.2E-07

mg/kg-day

3.0E-04

mg/kg-day

0.0021

Barium

74

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.1E-06

mg/kg-day

2.0E-01

mg/kg-day

0.0000056

6.9E-06

mg/kg-day

2.0E-01

mg/kg-day

0.000034

Cadmium

0.064

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

9.6E-10

mg/kg-day

1.0E-04

mg/kg-day

0.000010

6.0E-09

mg/kg-day

1.0E-04

mg/kg-day

0.000060

Chromium

6.7

mg/kg

3.9E-07

mg/kg-day

5.0E-01

(mg/kg-day)"1

1.9E-07

1.0E-07

mg/kg-day

3.0E-03

mg/kg-day

0.000034

6.2E-07

mg/kg-day

3.0E-03

mg/kg-day

0.00021

Cobalt

4.0

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.0E-08

mg/kg-day

3.0E-04

mg/kg-day

0.00020

3.7E-07

mg/kg-day

3.0E-04

mg/kg-day

0.0012

Copper

5.1

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

7.7E-08

mg/kg-day

4.0E-02

mg/kg-day

0.0000019

4.7E-07

mg/kg-day

4.0E-02

mg/kg-day

0.000012

Iron

12,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.8E-04

mg/kg-day

7.0E-01

mg/kg-day

0.00026

1.1E-03

mg/kg-day

7.0E-01

mg/kg-day

0.0016

Manganese

200

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.0E-06

mg/kg-day

2.4E-02

mg/kg-day

0.00013

1.9E-05

mg/kg-day

2.4E-02

mg/kg-day

0.00078

Molybdenum

0.81

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.2E-08

mg/kg-day

5.0E-03

mg/kg-day

0.0000024

7.5E-08

mg/kg-day

5.0E-03

mg/kg-day

0.000015

Selenium

1.5

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.3E-08

mg/kg-day

5.0E-03

mg/kg-day

0.0000045

1.4E-07

mg/kg-day

5.0E-03

mg/kg-day

0.000028

Thallium

0.092

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.4E-09

mg/kg-day

1.0E-05

mg/kg-day

0.00014

8.6E-09

mg/kg-day

1.0E-05

mg/kg-day

0.00086

Uranium

2.9

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.4E-08

mg/kg-day

2.0E-04

mg/kg-day

0.00022

2.7E-07

mg/kg-day

2.0E-04

mg/kg-day

0.0013

Vanadium

25

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.8E-07

mg/kg-day

5.0E-03

mg/kg-day

0.000075

2.3E-06

mg/kg-day

5.0E-03

mg/kg-day

0.00047

Metals Cancer Total

4E-07

Metals Noncancer Total

0.001

Metals Noncancer Total

0.009

Exposure Route Cancer Total

7E-07

Exposure Route Noncancer Total

0.001

Exposure Route Noncancer Total

0.009

Page 1 of 11


-------
Table C-5.5. Human Health Risk and Hazard Calculations - Arroyos on the Navajo Nation

Arroyos on the Navajo Nation - Kpp ei doo nahaazah dah (Difficult Access Open Space)

COPCa

EPCb

Units

Cancer
lntakec

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake0

Units

RfD/
RfCd

Units

Noncancer
Hazardf

Child
Noncancer
Intake0

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Child

Exposure Medium: Surface Soil (0-6 inches bgs



Exposure Route: External Exposure

Uranium-238

—

pCi/g

—

pCi/g

1.2E-10

risk/year pCi/g

—

—

—

—

—

—

—

—

—

—

—

Uranium-234

—

pCi/g

—

pCi/g

2.5E-10

risk/year pCi/g

—

—

—

—

—

—

—

—

—

—

—

Thorium-230

—

pCi/g

—

pCi/g

8.5E-10

risk/year pCi/g

—

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

1.3

pCi/g

3.0E-01

pCi/g

8.4E-06

risk/year pCi/g

2.5E-06

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

3E-06

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Exposure Route Cancer Total

3E-06

Exposure Route Noncancer Total

—

Exposure Route Noncancer Total

—

Exposure Route: Dermal Exposure

Aluminum

4,700

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

Arsenic

11

mg/kg

2.0E-07

mg/kg-day

1.5E+00

(mg/kg-day)"1

3.0E-07

1.4E-07

mg/kg-day

3.0E-04

mg/kg-day

0.00048

8.6E-07

mg/kg-day

3.0E-04

mg/kg-day

0.0029

Barium

74

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

Cadmium

0.064

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.1E-09

mg/kg-day

1.0E-04

mg/kg-day

0.000011

6.4E-09

mg/kg-day

1.0E-04

mg/kg-day

0.000064

Chromium

6.7

mg/kg

—

mg/kg-day

5.0E-01

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

Cobalt

4.0

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

Copper

5

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

Iron

12,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

Manganese

200

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

Molybdenum

0.81

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Selenium

1.5

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Thallium

0.092

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

Uranium

2.90

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

Vanadium

25

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Metals Cancer Total

3E-07

Metals Noncancer Total

0.0005

Metals Noncancer Total

0.003

Exposure Route Cancer Total

3E-07

Exposure Route Noncancer Total

0.0005

Exposure Route Noncancer Total

0.003

Page 2 of 11


-------
Table C-5.5. Human Health Risk and Hazard Calculations - Arroyos on the Navajo Nation

Arroyos on the Navajo Nation - Kpp ei doo nahaazah dah (Difficult Access Open Space)

COPCa

EPCb

Units

Cancer
lntakec

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake0

Units

RfD/
RfCd

Units

Noncancer
Hazardf

Child
Noncancer
Intake0

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Child

Exposure Medium: Surface Soil (0-6 inches bgs



Exposure Route: Inhalation of Particulates

Uranium-238

—

pCi/g

—

pCi

2.4E-08

risk/pCi

—

—

—

—

—

—

—

—

—

—

—

Uranium-234

—

pCi/g

—

pCi

2.8E-08

risk/pCi

—

—

—

—

—

—

—

—

—

—

—

Thorium-230

—

pCi/g

—

pCi

3.4E-08

risk/pCi

—

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

1.3

pCi/g

1.1E-01

pCi

5.9E-08

risk/pCi

6.7E-09

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

7E-09

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

4,700

mg/kg

--

ug/m3

—

(ug/m3y1

—

6.1E-07

mg/m3

5.0E-03

mg/m3

0.00012

6.1E-07

mg/m3

5.0E-03

mg/m3

0.00012

Arsenic

11

mg/kg

1.4E-06

ug/m3

4.3E-03

(ug/m3y1

6.1E-09

1.4E-09

mg/m3

1.5E-05

mg/m3

0.000095

1.4E-09

mg/m3

1.5E-05

mg/m3

0.000095

Barium

74

mg/kg

—

ug/m3

—

(ug/m3)"1

—

9.6E-09

mg/m3

5.0E-04

mg/m3

0.000019

9.6E-09

mg/m3

5.0E-04

mg/m3

0.000019

Cadmium

0.064

mg/kg

8.3E-09

ug/m3

1.8E-03

(ug/m3)"1

1.5E-11

8.3E-12

mg/m3

1.0E-05

mg/m3

0.00000083

8.3E-12

mg/m3

1.0E-05

mg/m3

0.00000083

Chromium

6.7

mg/kg

1.4E-06

ug/m3

8.4E-02

(ug/m3)"1

1.2E-07

8.7E-10

mg/m3

1.0E-04

mg/m3

0.0000087

8.7E-10

mg/m3

1.0E-04

mg/m3

0.0000087

Cobalt

4.0

mg/kg

5.2E-07

ug/m3

9.0E-03

(ug/m3)"1

4.7E-09

5.2E-10

mg/m3

6.0E-06

mg/m3

0.000087

5.2E-10

mg/m3

6.0E-06

mg/m3

0.000087

Copper

5

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

—

mg/m3

—

mg/m3

—

Iron

12,000

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

—

mg/m3

—

mg/m3

—

Manganese

200

mg/kg

—

ug/m3

—

(ug/m3)"1

—

2.6E-08

mg/m3

5.0E-05

mg/m3

0.00052

2.6E-08

mg/m3

5.0E-05

mg/m3

0.00052

Molybdenum

0.81

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.1E-10

mg/m3

2.0E-03

mg/m3

0.000000053

1.1E-10

mg/m3

2.0E-03

mg/m3

0.000000053

Selenium

1.5

mg/kg

—

ug/m3

—

(ug/m3)"1

—

2.0E-10

mg/m3

2.0E-02

mg/m3

0.000000010

2.0E-10

mg/m3

2.0E-02

mg/m3

0.000000010

Thallium

0.092

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

—

mg/m3

—

mg/m3

—

Uranium

2.90

mg/kg

—

ug/m3

—

(ug/m3)"1

—

3.8E-10

mg/m3

4.0E-05

mg/m3

0.0000094

3.8E-10

mg/m3

4.0E-05

mg/m3

0.0000094

Vanadium

25

mg/kg

—

ug/m3

—

(ug/m3)"1

—

3.3E-09

mg/m3

1.0E-04

mg/m3

0.000033

3.3E-09

mg/m3

1.0E-04

mg/m3

0.000033

Metals Cancer Total

1E-07

Metals Noncancer Total

0.0009

Metals Noncancer Total

0.0009

Exposure Route Cancer Total

1E-07

Exposure Route Noncancer Total

0.0009

Exposure Route Noncancer Total

0.0009

Exposure Medium: Surface Soil (0-6 inches bgs)

Exposure Route: Plant Consumption

Uranium-238

—

pCi/g

—

pCi/g

8.7E-11

risk/pCi/g

—

—

—

—

—

—

—

—

—

—

—

Uranium-234

—

pCi/g

—

pCi/g

9.6E-11

risk/pCi/g

—

—

—

—

—

—

—

—

—

—

—

Thorium-230

—

pCi/g

—

pCi/g

1.2E-10

risk/pCi/g

—

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

1.3

pCi/g

9.4E+03

pCi/g

3.7E-09

risk/pCi/g

3.5E-05

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

3E-05

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

4,700

mg/kg

--

mg/kg-day

—

(mg/kg-day)-1

—

3.7E-03

mg/kg-day

1.0E+00

mg/kg-day

0.0037

9.9E-03

mg/kg-day

1.0E+00

mg/kg-day

0.010

Arsenic

11

mg/kg

1.0E-05

mg/kg-day

1.5E+00

(mg/kg-dayy1

1.6E-05

9.1E-06

mg/kg-day

3.0E-04

mg/kg-day

0.030

2.4E-05

mg/kg-day

3.0E-04

mg/kg-day

0.081

Barium

74

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

9.6E-05

mg/kg-day

2.0E-01

mg/kg-day

0.00048

2.5E-04

mg/kg-day

2.0E-01

mg/kg-day

0.0013

Cadmium

0.064

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.9E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0019

5.0E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0050

Chromium

6.7

mg/kg

1.3E-05

mg/kg-day

5.0E-01

(mg/kg-day)"1

6.3E-06

5.4E-06

mg/kg-day

3.0E-03

mg/kg-day

0.0018

1.4E-05

mg/kg-day

3.0E-03

mg/kg-day

0.0048

Cobalt

4.0

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.4E-06

mg/kg-day

3.0E-04

mg/kg-day

0.015

1.2E-05

mg/kg-day

3.0E-04

mg/kg-day

0.039

Copper

5

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.0E-05

mg/kg-day

4.0E-02

mg/kg-day

0.0010

1.1E-04

mg/kg-day

4.0E-02

mg/kg-day

0.0027

Iron

12,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

--

9.5E-03

mg/kg-day

7.0E-01

mg/kg-day

0.014

2.5E-02

mg/kg-day

7.0E-01

mg/kg-day

0.036

Manganese

200

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.0E-03

mg/kg-day

2.4E-02

mg/kg-day

0.043

2.8E-03

mg/kg-day

2.4E-02

mg/kg-day

0.12

Molybdenum

0.81

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.1E-06

mg/kg-day

5.0E-03

mg/kg-day

0.00083

1.1E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0023

Selenium

1.5

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.7E-06

mg/kg-day

5.0E-03

mg/kg-day

0.00033

4.2E-06

mg/kg-day

5.0E-03

mg/kg-day

0.00084

Thallium

0.092

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.7E-08

mg/kg-day

1.0E-05

mg/kg-day

0.0067

1.8E-07

mg/kg-day

1.0E-05

mg/kg-day

0.018

Uranium

2.90

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.5E-06

mg/kg-day

2.0E-04

mg/kg-day

0.013

6.7E-06

mg/kg-day

2.0E-04

mg/kg-day

0.033

Vanadium

25

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.1E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0041

5.5E-05

mg/kg-day

5.0E-03

mg/kg-day

0.011

Metals Cancer Total

2E-05

Metals Noncancer Total

0.1

Metals Noncancer Total

0.4

Exposure Route Cancer Total

6E-05

Exposure Route Noncancer Total

0.1

Exposure Route Noncancer Total

0.4

Page 3 of 11


-------
Table C-5.5. Human Health Risk and Hazard Calculations - Arroyos on the Navajo Nation

Arroyos on the Navajo Nation - Kpp ei doo nahaazah dah (Difficult Access Open Space)

COPCa

EPCb

Units

Cancer
lntakec

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake0

Units

RfD/
RfCd

Units

Noncancer
Hazardf

Child
Noncancer
Intake0

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Child

Exposure Medium: Surface Soil (0-6 inches bgs



Exposure Route: Animal Consumption

Uranium-238

—

pCi/g

—

pCi/g

8.7E-11

risk/pCi/g

—

—

—

—

—

—

—

—

—

—

—

Uranium-234

—

pCi/g

—

pCi/g

9.6E-11

risk/pCi/g

—

—

—

—

—

—

—

—

—

—

—

Thorium-230

—

pCi/g

—

pCi/g

1.2E-10

risk/pCi/g

—

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

1.3

pCi/g

1.4E+02

pCi/g

3.7E-09

risk/pCi/g

5.3E-07

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

5E-07

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

4,700

mg/kg

--

mg/kg-day

—

(mg/kg-day)"1

—

3.4E-04

mg/kg-day

1.0E+00

mg/kg-day

0.00034

8.9E-04

mg/kg-day

1.0E+00

mg/kg-day

0.00089

Arsenic

11

mg/kg

1.3E-06

mg/kg-day

1.5E+00

(mg/kg-day)"1

2.0E-06

1.1E-06

mg/kg-day

3.0E-04

mg/kg-day

0.0037

3.0E-06

mg/kg-day

3.0E-04

mg/kg-day

0.0099

Barium

74

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

9.6E-07

mg/kg-day

2.0E-01

mg/kg-day

0.0000048

2.5E-06

mg/kg-day

2.0E-01

mg/kg-day

0.000013

Cadmium

0.064

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

7.0E-10

mg/kg-day

1.0E-04

mg/kg-day

0.0000070

1.8E-09

mg/kg-day

1.0E-04

mg/kg-day

0.000018

Chromium

6.7

mg/kg

4.2E-06

mg/kg-day

5.0E-01

(mg/kg-day)"1

2.1E-06

1.8E-06

mg/kg-day

3.0E-03

mg/kg-day

0.00061

4.9E-06

mg/kg-day

3.0E-03

mg/kg-day

0.0016

Cobalt

4.0

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.0E-06

mg/kg-day

3.0E-04

mg/kg-day

0.013

1.1E-05

mg/kg-day

3.0E-04

mg/kg-day

0.036

Copper

5

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.7E-06

mg/kg-day

4.0E-02

mg/kg-day

0.00012

1.3E-05

mg/kg-day

4.0E-02

mg/kg-day

0.00032

Iron

12,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.1E-02

mg/kg-day

7.0E-01

mg/kg-day

0.016

3.0E-02

mg/kg-day

7.0E-01

mg/kg-day

0.043

Manganese

200

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.8E-06

mg/kg-day

2.4E-02

mg/kg-day

0.00028

1.8E-05

mg/kg-day

2.4E-02

mg/kg-day

0.00075

Molybdenum

0.81

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.7E-07

mg/kg-day

5.0E-03

mg/kg-day

0.000075

9.7E-07

mg/kg-day

5.0E-03

mg/kg-day

0.00019

Selenium

1.5

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.3E-07

mg/kg-day

5.0E-03

mg/kg-day

0.000045

6.2E-07

mg/kg-day

5.0E-03

mg/kg-day

0.00012

Thallium

0.092

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.7E-07

mg/kg-day

1.0E-05

mg/kg-day

0.017

4.7E-07

mg/kg-day

1.0E-05

mg/kg-day

0.047

Uranium

2.90

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.1E-08

mg/kg-day

2.0E-04

mg/kg-day

0.00020

1.1E-07

mg/kg-day

2.0E-04

mg/kg-day

0.00054

Vanadium

25

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.0E-06

mg/kg-day

5.0E-03

mg/kg-day

0.00060

8.0E-06

mg/kg-day

5.0E-03

mg/kg-day

0.0016

Metals Cancer Total

4E-06

Metals Noncancer Total

0.05

Metals Noncancer Total

0.1

Exposure Route Cancer Total

5E-06

Exposure Route Noncancer Total

0.05

Exposure Route Noncancer Total

0.1

Exposure Medium: Surface Soil (0-6 inches bgs)

Exposure Route: Other Dine Lifeways Plant Ingestion

Uranium-238

—

pCi/g

—

pCi/g

8.7E-11

risk/pCi/g

—

—

—

—

—

—

—

—

—

—

—

Uranium-234

—

pCi/g

—

pCi/g

9.6E-11

risk/pCi/g

—

—

—

—

—

—

—

—

—

—

—

Thorium-230

—

pCi/g

—

pCi/g

1.2E-10

risk/pCi/g

—

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

1.3

pCi/g

7.5E+04

pCi/g

3.7E-09

risk/pCi/g

2.8E-04

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

3E-04

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

4,700

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.3E-02

mg/kg-day

1.0E+00

mg/kg-day

0.033

—

mg/kg-day

1.0E+00

mg/kg-day

—

Arsenic

11

mg/kg

7.7E-05

mg/kg-day

1.5E+00

(mg/kg-day)"1

1.2E-04

8.4E-05

mg/kg-day

3.0E-04

mg/kg-day

0.28

—

mg/kg-day

3.0E-04

mg/kg-day

—

Barium

74

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.0E-03

mg/kg-day

2.0E-01

mg/kg-day

0.0052

—

mg/kg-day

2.0E-01

mg/kg-day

—

Cadmium

0.064

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.4E-06

mg/kg-day

1.0E-04

mg/kg-day

0.024

—

mg/kg-day

1.0E-04

mg/kg-day

—

Chromium

6.7

mg/kg

5.7E-05

mg/kg-day

5.0E-01

(mg/kg-day)"1

2.9E-05

4.8E-05

mg/kg-day

3.0E-03

mg/kg-day

0.016

—

mg/kg-day

3.0E-03

mg/kg-day

—

Cobalt

4.0

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.4E-05

mg/kg-day

3.0E-04

mg/kg-day

0.15

—

mg/kg-day

3.0E-04

mg/kg-day

—

Copper

5

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.6E-04

mg/kg-day

4.0E-02

mg/kg-day

0.014

—

mg/kg-day

4.0E-02

mg/kg-day

—

Iron

12,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

--

8.4E-02

mg/kg-day

7.0E-01

mg/kg-day

0.12

—

mg/kg-day

7.0E-01

mg/kg-day

—

Manganese

200

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.4E-02

mg/kg-day

2.4E-02

mg/kg-day

0.57

—

mg/kg-day

2.4E-02

mg/kg-day

—

Molybdenum

0.81

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.5E-05

mg/kg-day

5.0E-03

mg/kg-day

0.011

—

mg/kg-day

5.0E-03

mg/kg-day

—

Selenium

1.5

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.7E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0033

—

mg/kg-day

5.0E-03

mg/kg-day

—

Thallium

0.092

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.7E-07

mg/kg-day

1.0E-05

mg/kg-day

0.057

—

mg/kg-day

1.0E-05

mg/kg-day

—

Uranium

2.90

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.3E-05

mg/kg-day

2.0E-04

mg/kg-day

0.12

—

mg/kg-day

2.0E-04

mg/kg-day

—

Vanadium

25

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.9E-04

mg/kg-day

5.0E-03

mg/kg-day

0.037

—

mg/kg-day

5.0E-03

mg/kg-day

—

Metals Cancer Total

1E-04

Metals Noncancer Total

1

Metals Noncancer Total

—

Exposure Route Cancer Total

4E-04

Exposure Route Noncancer Total

1

Exposure Route Noncancer Total

—

Page 4 of 11


-------
Table C-5.5. Human Health Risk and Hazard Calculations - Arroyos on the Navajo Nation

Arroyos on the Navajo Nation - Kpp ei doo nahaazah dah (Difficult Access Open Space)

COPCa

EPCb

Units

Cancer
lntakec

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake0

Units

RfD/
RfCd

Units

Noncancer
Hazardf

Child
Noncancer
Intake0

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Child

Exposure Medium: Surface Soil (0-6 inches bgs



Exposure Route: Other Dine Lifeways Plant Dermal

Aluminum

4,700

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

Arsenic

11

mg/kg

6.5E-06

mg/kg-day

1.5E+00

(mg/kg-day)"1

9.7E-06

7.0E-06

mg/kg-day

3.0E-04

mg/kg-day

0.023

—

mg/kg-day

3.0E-04

mg/kg-day

—

Barium

74

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

Cadmium

0.064

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.7E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0027

—

mg/kg-day

1.0E-04

mg/kg-day

—

Chromium

6.7

mg/kg

—

mg/kg-day

5.0E-01

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

Cobalt

4.0

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

Copper

5

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

Iron

12,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

Manganese

200

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

Molybdenum

0.81

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Selenium

1.5

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Thallium

0.092

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

Uranium

2.90

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

Vanadium

25

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Metals Cancer Total

1E-05

Metals Noncancer Total

0.03

Metals Noncancer Total

—

Exposure Route Cancer Total

1E-05

Exposure Route Noncancer Total

0.03

Exposure Route Noncancer Total

—

Exposure Medium: Surface Soil (0-6 inches bgs)

Exposure Route: Other Dine Lifeways Plant Inhalation

Uranium-238

—

pCi/g

—

pCi

2.4E-08

risk/pCi

—

—

—

—

—

—

—

—

—

—

—

Uranium-234

—

pCi/g

—

pCi

2.8E-08

risk/pCi

—

—

—

—

—

—

—

—

—

—

—

Thorium-230

—

pCi/g

—

pCi

3.4E-08

risk/pCi

—

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

1.3

pCi/g

8.1E+02

pCi

5.9E-08

risk/pCi

4.8E-05

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

5E-05

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

4,700

mg/kg

—

ug/m3

—

(ug/m3)"1

—

3.4E-04

mg/m3

5.0E-03

mg/m3

0.068

—

mg/m3

5.0E-03

mg/m3

—

Arsenic

11

mg/kg

7.8E-04

ug/m3

4.3E-03

(ug/m3)"1

3.4E-06

8.6E-07

mg/m3

1.5E-05

mg/m3

0.057

—

mg/m3

1.5E-05

mg/m3

—

Barium

74

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.0E-05

mg/m3

5.0E-04

mg/m3

0.021

—

mg/m3

5.0E-04

mg/m3

—

Cadmium

0.064

mg/kg

2.2E-05

ug/m3

1.8E-03

(ug/m3)"1

4.0E-08

2.4E-08

mg/m3

1.0E-05

mg/m3

0.0024

—

mg/m3

1.0E-05

mg/m3

—

Chromium

6.7

mg/kg

5.9E-04

ug/m3

8.4E-02

(ug/m3)"1

4.9E-05

5.0E-07

mg/m3

1.0E-04

mg/m3

0.0050

—

mg/m3

1.0E-04

mg/m3

—

Cobalt

4.0

mg/kg

4.0E-04

ug/m3

9.0E-03

(ug/m3)"1

3.6E-06

4.4E-07

mg/m3

6.0E-06

mg/m3

0.073

—

mg/m3

6.0E-06

mg/m3

—

Copper

5.1

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

—

mg/m3

—

mg/m3

—

Iron

12,000

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

—

mg/m3

—

mg/m3

—

Manganese

200

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.4E-04

mg/m3

5.0E-05

mg/m3

2.8

—

mg/m3

5.0E-05

mg/m3

—

Molybdenum

0.81

mg/kg

—

ug/m3

—

(ug/m3)"1

—

5.7E-07

mg/m3

2.0E-03

mg/m3

0.00028

—

mg/m3

2.0E-03

mg/m3

—

Selenium

1.5

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.7E-07

mg/m3

2.0E-02

mg/m3

0.0000083

—

mg/m3

2.0E-02

mg/m3

—

Thallium

0.092

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

—

mg/m3

—

mg/m3

—

Uranium

2.90

mg/kg

—

ug/m3

—

(ug/m3)"1

—

2.4E-07

mg/m3

4.0E-05

mg/m3

0.0060

—

mg/m3

4.0E-05

mg/m3

—

Vanadium

25

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.9E-06

mg/m3

1.0E-04

mg/m3

0.019

—

mg/m3

1.0E-04

mg/m3

—

Metals Cancer Total

6E-05

Metals Noncancer Total

3

Metals Noncancer Total

—

Exposure Route Cancer Total

1E-04

Exposure Route Noncancer Total

3

Exposure Route Noncancer Total

—

Surface Soil (0-6 inches bgs) Receptor Cancer Risk Total

6E-04

Receptor/Media Noncancer Hazard Total

5

Receptor/Media Noncancer Hazard Total

1

Page 5 of 11


-------
Table C-5.5. Human Health Risk and Hazard Calculations - Arroyos on the Navajo Nation

Arroyos on the Navajo Nation - Kpp ei doo nahaazah dah (Difficult Access Open Space)

COPCa

EPCb

Units

Cancer
lntakec

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake0

Units

RfD/
RfCd

Units

Noncancer
Hazardf

Child
Noncancer
Intake0

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Child

Exposure Medium: Subsurface Soil (0-72 inches bgs)

Exposure Route: Incidental Soil Ingestion

Uranium-238

—

pCi/g

—

pCi/g

1.3E-10

risk/pCi/g

—

—

—

—

—

—

—

—

—

—

—

Uranium-234

—

pCi/g

—

pCi/g

1.5E-10

risk/pCi/g

—

—

—

—

—

—

—

—

—

—

—

Thorium-230

—

pCi/g

—

pCi/g

1.7E-10

risk/pCi/g

—

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

1.5

pCi/g

5.1E+01

pCi/g

5.7E-09

risk/pCi/g

2.9E-07

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

3E-07

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

4,700

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

7.1E-05

mg/kg-day

1.0E+00

mg/kg-day

0.000071

4.4E-04

mg/kg-day

1.0E+00

mg/kg-day

0.00044

Arsenic

11

mg/kg

1.4E-07

mg/kg-day

1.5E+00

(mg/kg-day)"1

2.1E-07

1.0E-07

mg/kg-day

3.0E-04

mg/kg-day

0.00034

6.2E-07

mg/kg-day

3.0E-04

mg/kg-day

0.0021

Barium

75

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.1E-06

mg/kg-day

2.0E-01

mg/kg-day

0.0000056

7.0E-06

mg/kg-day

2.0E-01

mg/kg-day

0.000035

Cadmium

0.073

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.1E-09

mg/kg-day

1.0E-04

mg/kg-day

0.000011

6.8E-09

mg/kg-day

1.0E-04

mg/kg-day

0.000068

Chromium

6.7

mg/kg

3.9E-07

mg/kg-day

5.0E-01

(mg/kg-day)"1

1.9E-07

1.0E-07

mg/kg-day

3.0E-03

mg/kg-day

0.000034

6.2E-07

mg/kg-day

3.0E-03

mg/kg-day

0.00021

Cobalt

4.5

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.8E-08

mg/kg-day

3.0E-04

mg/kg-day

0.00023

4.2E-07

mg/kg-day

3.0E-04

mg/kg-day

0.0014

Copper

5.1

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

7.7E-08

mg/kg-day

4.0E-02

mg/kg-day

0.0000019

4.7E-07

mg/kg-day

4.0E-02

mg/kg-day

0.000012

Iron

15,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.3E-04

mg/kg-day

7.0E-01

mg/kg-day

0.00032

1.4E-03

mg/kg-day

7.0E-01

mg/kg-day

0.0020

Manganese

400

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.0E-06

mg/kg-day

2.4E-02

mg/kg-day

0.00025

3.7E-05

mg/kg-day

2.4E-02

mg/kg-day

0.0016

Molybdenum

0.81

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.2E-08

mg/kg-day

5.0E-03

mg/kg-day

0.0000024

7.5E-08

mg/kg-day

5.0E-03

mg/kg-day

0.000015

Selenium

1.5

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.3E-08

mg/kg-day

5.0E-03

mg/kg-day

0.0000045

1.4E-07

mg/kg-day

5.0E-03

mg/kg-day

0.000028

Thallium

0.092

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.4E-09

mg/kg-day

1.0E-05

mg/kg-day

0.00014

8.6E-09

mg/kg-day

1.0E-05

mg/kg-day

0.00086

Uranium

2.90

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.4E-08

mg/kg-day

2.0E-04

mg/kg-day

0.00022

2.7E-07

mg/kg-day

2.0E-04

mg/kg-day

0.0013

Vanadium

25

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.8E-07

mg/kg-day

5.0E-03

mg/kg-day

0.000075

2.3E-06

mg/kg-day

5.0E-03

mg/kg-day

0.00047

Metals Cancer Total

4E-07

Metals Noncancer Total

0.002

Metals Noncancer Total

0.01

Exposure Route Cancer Total

7E-07

Exposure Route Noncancer Total

0.002

Exposure Route Noncancer Total

0.01

Page 6 of 11


-------
Table C-5.5. Human Health Risk and Hazard Calculations - Arroyos on the Navajo Nation

Arroyos on the Navajo Nation - Kpp ei doo nahaazah dah (Difficult Access Open Space)

COPCa

EPCb

Units

Cancer
lntakec

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake0

Units

RfD/
RfCd

Units

Noncancer
Hazardf

Child
Noncancer
Intake0

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Child

Exposure Medium: Subsurface Soil (0-72 inches bgs)

Exposure Route: External Exposure

Uranium-238

—

pCi/g

—

pCi/g

1.2E-10

risk/year pCi/g

—

—

—

—

—

—

—

—

—

—

—

Uranium-234

—

pCi/g

—

pCi/g

2.5E-10

risk/year pCi/g

—

—

—

—

—

—

—

—

—

—

—

Thorium-230

—

pCi/g

—

pCi/g

8.5E-10

risk/year pCi/g

—

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

1.5

pCi/g

3.5E-01

pCi/g

8.4E-06

risk/year pCi/g

2.9E-06

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

3E-06

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Exposure Route Cancer Total

3E-06

Exposure Route Noncancer Total

—

Exposure Route Noncancer Total

—

Exposure Route: Dermal Exposure

Aluminum

4,700

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

Arsenic

11

mg/kg

2.0E-07

mg/kg-day

1.5E+00

(mg/kg-day)"1

3.0E-07

1.4E-07

mg/kg-day

3.0E-04

mg/kg-day

0.00048

8.6E-07

mg/kg-day

3.0E-04

mg/kg-day

0.0029

Barium

75

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

Cadmium

0.073

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.2E-09

mg/kg-day

1.0E-04

mg/kg-day

0.000012

7.3E-09

mg/kg-day

1.0E-04

mg/kg-day

0.00007

Chromium

6.7

mg/kg

—

mg/kg-day

5.0E-01

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

Cobalt

4.5

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

Copper

5.1

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

Iron

15,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

Manganese

400

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

Molybdenum

0.81

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Selenium

1.5

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Thallium

0.092

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

Uranium

2.90

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

Vanadium

25

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Metals Cancer Total

3E-07

Metals Noncancer Total

0.0005

Metals Noncancer Total

0.003

Exposure Route Cancer Total

3E-07

Exposure Route Noncancer Total

0.0005

Exposure Route Noncancer Total

0.003

Page 7 of 11


-------
Table C-5.5. Human Health Risk and Hazard Calculations - Arroyos on the Navajo Nation

Arroyos on the Navajo Nation - Kpp ei doo nahaazah dah (Difficult Access Open Space)

COPCa

EPCb

Units

Cancer
lntakec

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake0

Units

RfD/
RfCd

Units

Noncancer
Hazardf

Child
Noncancer
Intake0

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Child

Exposure Medium: Subsurface Soil (0-72 inches bgs)

Exposure Route: Inhalation of Particulates

Uranium-238

—

pCi/g

—

pCi

2.4E-08

risk/pCi

—

—

—

—

—

—

—

—

—

—

—

Uranium-234

—

pCi/g

—

pCi

2.8E-08

risk/pCi

—

—

—

—

—

—

—

—

—

—

—

Thorium-230

—

pCi/g

—

pCi

3.4E-08

risk/pCi

—

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

1.5

pCi/g

5.1E-04

pCi

5.9E-08

risk/pCi

3.0E-11

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

3E-11

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

4,700

mg/kg

--

ug/m3

—

(ug/m3y1

—

2.4E-09

mg/m3

5.0E-03

mg/m3

0.00000049

2.4E-09

mg/m3

5.0E-03

mg/m3

0.00000049

Arsenic

11

mg/kg

5.7E-09

ug/m3

4.3E-03

(ug/m3y1

2.5E-11

5.7E-12

mg/m3

1.5E-05

mg/m3

0.00000038

5.7E-12

mg/m3

1.5E-05

mg/m3

0.00000038

Barium

75

mg/kg

—

ug/m3

—

(ug/m3)"1

—

3.9E-11

mg/m3

5.0E-04

mg/m3

0.000000078

3.9E-11

mg/m3

5.0E-04

mg/m3

0.000000078

Cadmium

0.073

mg/kg

3.8E-11

ug/m3

1.8E-03

(ug/m3)"1

6.8E-14

3.8E-14

mg/m3

1.0E-05

mg/m3

0.0000000038

3.8E-14

mg/m3

1.0E-05

mg/m3

0.0000000038

Chromium

6.7

mg/kg

5.6E-09

ug/m3

8.4E-02

(ug/m3)"1

4.7E-10

3.5E-12

mg/m3

1.0E-04

mg/m3

0.000000035

3.5E-12

mg/m3

1.0E-04

mg/m3

0.000000035

Cobalt

4.5

mg/kg

2.3E-09

ug/m3

9.0E-03

(ug/m3)"1

2.1E-11

2.3E-12

mg/m3

6.0E-06

mg/m3

0.00000039

2.3E-12

mg/m3

6.0E-06

mg/m3

0.00000039

Copper

5

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

—

mg/m3

—

mg/m3

—

Iron

15,000

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

—

mg/m3

—

mg/m3

—

Manganese

400

mg/kg

—

ug/m3

—

(ug/m3)"1

—

2.1E-10

mg/m3

5.0E-05

mg/m3

0.0000042

2.1E-10

mg/m3

5.0E-05

mg/m3

0.0000042

Molybdenum

0.81

mg/kg

—

ug/m3

—

(ug/m3)"1

—

4.2E-13

mg/m3

2.0E-03

mg/m3

0.00000000021

4.2E-13

mg/m3

2.0E-03

mg/m3

0.00000000021

Selenium

1.5

mg/kg

—

ug/m3

—

(ug/m3)"1

—

7.8E-13

mg/m3

2.0E-02

mg/m3

0.000000000039

7.8E-13

mg/m3

2.0E-02

mg/m3

0.000000000039

Thallium

0.092

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

—

mg/m3

—

mg/m3

—

Uranium

2.90

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.5E-12

mg/m3

4.0E-05

mg/m3

0.000000038

1.5E-12

mg/m3

4.0E-05

mg/m3

0.000000038

Vanadium

25

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.3E-11

mg/m3

1.0E-04

mg/m3

0.00000013

1.3E-11

mg/m3

1.0E-04

mg/m3

0.00000013

Metals Cancer Total

5E-10

Metals Noncancer Total

0.000006

Metals Noncancer Total

0.000006

Exposure Route Cancer Total

5E-10

Exposure Route Noncancer Total

0.000006

Exposure Route Noncancer Total

0.000006

Exposure Medium: Subsurface Soil (0-72 inches bgs)

Exposure Route: Plant Consumption

Uranium-238

—

pCi/g

—

pCi/g

8.7E-11

risk/pCi/g

—

—

—

—

—

—

—

—

—

—

—

Uranium-234

—

pCi/g

—

pCi/g

9.6E-11

risk/pCi/g

—

—

—

—

—

—

—

—

—

—

—

Thorium-230

—

pCi/g

—

pCi/g

1.2E-10

risk/pCi/g

—

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

1.5

pCi/g

1.1E+04

pCi/g

3.7E-09

risk/pCi/g

4.0E-05

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

4E-05

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

4,700

mg/kg

--

mg/kg-day

—

(mg/kg-day)-1

—

3.7E-03

mg/kg-day

1.0E+00

mg/kg-day

0.0037

9.9E-03

mg/kg-day

1.0E+00

mg/kg-day

0.010

Arsenic

11

mg/kg

1.0E-05

mg/kg-day

1.5E+00

(mg/kg-dayy1

1.6E-05

9.1E-06

mg/kg-day

3.0E-04

mg/kg-day

0.030

2.4E-05

mg/kg-day

3.0E-04

mg/kg-day

0.081

Barium

75

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

9.8E-05

mg/kg-day

2.0E-01

mg/kg-day

0.00049

2.6E-04

mg/kg-day

2.0E-01

mg/kg-day

0.0013

Cadmium

0.073

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.1E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0021

5.7E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0057

Chromium

6.7

mg/kg

1.3E-05

mg/kg-day

5.0E-01

(mg/kg-day)"1

6.3E-06

5.4E-06

mg/kg-day

3.0E-03

mg/kg-day

0.0018

1.4E-05

mg/kg-day

3.0E-03

mg/kg-day

0.0048

Cobalt

4.5

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.0E-06

mg/kg-day

3.0E-04

mg/kg-day

0.017

1.3E-05

mg/kg-day

3.0E-04

mg/kg-day

0.044

Copper

5

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.0E-05

mg/kg-day

4.0E-02

mg/kg-day

0.0010

1.1E-04

mg/kg-day

4.0E-02

mg/kg-day

0.0027

Iron

15,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

--

1.2E-02

mg/kg-day

7.0E-01

mg/kg-day

0.017

3.2E-02

mg/kg-day

7.0E-01

mg/kg-day

0.045

Manganese

400

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.0E-03

mg/kg-day

2.4E-02

mg/kg-day

0.085

5.6E-03

mg/kg-day

2.4E-02

mg/kg-day

0.23

Molybdenum

0.81

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.1E-06

mg/kg-day

5.0E-03

mg/kg-day

0.00083

1.1E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0023

Selenium

1.5

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.7E-06

mg/kg-day

5.0E-03

mg/kg-day

0.00033

4.2E-06

mg/kg-day

5.0E-03

mg/kg-day

0.00084

Thallium

0.092

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

6.7E-08

mg/kg-day

1.0E-05

mg/kg-day

0.0067

1.8E-07

mg/kg-day

1.0E-05

mg/kg-day

0.018

Uranium

2.90

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.5E-06

mg/kg-day

2.0E-04

mg/kg-day

0.013

6.7E-06

mg/kg-day

2.0E-04

mg/kg-day

0.033

Vanadium

25

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.1E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0041

5.5E-05

mg/kg-day

5.0E-03

mg/kg-day

0.011

Metals Cancer Total

2E-05

Metals Noncancer Total

0.2

Metals Noncancer Total

0.5

Exposure Route Cancer Total

6E-05

Exposure Route Noncancer Total

0.2

Exposure Route Noncancer Total

0.5

Page 8 of 11


-------
Table C-5.5. Human Health Risk and Hazard Calculations - Arroyos on the Navajo Nation

Arroyos on the Navajo Nation - Kpp ei doo nahaazah dah (Difficult Access Open Space)

COPCa

EPCb

Units

Cancer
lntakec

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake0

Units

RfD/
RfCd

Units

Noncancer
Hazardf

Child
Noncancer
Intake0

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Child

Exposure Medium: Subsurface Soil (0-72 inches bgs)

Exposure Route: Animal Consumption

Uranium-238

—

pCi/g

—

pCi/g

8.7E-11

risk/pCi/g

—

—

—

—

—

—

—

—

—

—

—

Uranium-234

—

pCi/g

—

pCi/g

9.6E-11

risk/pCi/g

—

—

—

—

—

—

—

—

—

—

—

Thorium-230

—

pCi/g

—

pCi/g

1.2E-10

risk/pCi/g

—

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

1.5

pCi/g

1.7E+02

pCi/g

3.7E-09

risk/pCi/g

6.1E-07

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

6E-07

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

4,700

mg/kg

--

mg/kg-day

—

(mg/kg-day)"1

—

3.4E-04

mg/kg-day

1.0E+00

mg/kg-day

0.00034

8.9E-04

mg/kg-day

1.0E+00

mg/kg-day

0.00089

Arsenic

11

mg/kg

1.3E-06

mg/kg-day

1.5E+00

(mg/kg-day)"1

2.0E-06

1.1E-06

mg/kg-day

3.0E-04

mg/kg-day

0.0037

3.0E-06

mg/kg-day

3.0E-04

mg/kg-day

0.0099

Barium

75

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

9.8E-07

mg/kg-day

2.0E-01

mg/kg-day

0.0000049

2.6E-06

mg/kg-day

2.0E-01

mg/kg-day

0.000013

Cadmium

0.073

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

8.0E-10

mg/kg-day

1.0E-04

mg/kg-day

0.0000080

2.0E-09

mg/kg-day

1.0E-04

mg/kg-day

0.000020

Chromium

6.7

mg/kg

4.2E-06

mg/kg-day

5.0E-01

(mg/kg-day)"1

2.1E-06

1.8E-06

mg/kg-day

3.0E-03

mg/kg-day

0.00061

4.9E-06

mg/kg-day

3.0E-03

mg/kg-day

0.0016

Cobalt

4.5

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.5E-06

mg/kg-day

3.0E-04

mg/kg-day

0.015

1.2E-05

mg/kg-day

3.0E-04

mg/kg-day

0.041

Copper

5

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.7E-06

mg/kg-day

4.0E-02

mg/kg-day

0.00012

1.3E-05

mg/kg-day

4.0E-02

mg/kg-day

0.00032

Iron

15,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.4E-02

mg/kg-day

7.0E-01

mg/kg-day

0.020

3.8E-02

mg/kg-day

7.0E-01

mg/kg-day

0.054

Manganese

400

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.4E-05

mg/kg-day

2.4E-02

mg/kg-day

0.00057

3.6E-05

mg/kg-day

2.4E-02

mg/kg-day

0.0015

Molybdenum

0.81

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.7E-07

mg/kg-day

5.0E-03

mg/kg-day

0.000075

9.7E-07

mg/kg-day

5.0E-03

mg/kg-day

0.00019

Selenium

1.5

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.3E-07

mg/kg-day

5.0E-03

mg/kg-day

0.000045

6.2E-07

mg/kg-day

5.0E-03

mg/kg-day

0.00012

Thallium

0.092

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.7E-07

mg/kg-day

1.0E-05

mg/kg-day

0.017

4.7E-07

mg/kg-day

1.0E-05

mg/kg-day

0.047

Uranium

2.90

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.1E-08

mg/kg-day

2.0E-04

mg/kg-day

0.00020

1.1E-07

mg/kg-day

2.0E-04

mg/kg-day

0.00054

Vanadium

25

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.0E-06

mg/kg-day

5.0E-03

mg/kg-day

0.00060

8.0E-06

mg/kg-day

5.0E-03

mg/kg-day

0.0016

Metals Cancer Total

4E-06

Metals Noncancer Total

0.06

Metals Noncancer Total

0.2

Exposure Route Cancer Total

5E-06

Exposure Route Noncancer Total

0.06

Exposure Route Noncancer Total

0.2

Exposure Medium: Subsurface Soil (0-72 inches bgs)

Exposure Route: Other Dine Lifeways Plant Ingestion

Uranium-238

—

pCi/g

—

pCi/g

8.7E-11

risk/pCi/g

—

—

—

—

—

—

—

—

—

—

—

Uranium-234

—

pCi/g

—

pCi/g

9.6E-11

risk/pCi/g

—

—

—

—

—

—

—

—

—

—

—

Thorium-230

—

pCi/g

—

pCi/g

1.2E-10

risk/pCi/g

—

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

1.5

pCi/g

8.7E+04

pCi/g

3.7E-09

risk/pCi/g

3.2E-04

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

3E-04

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

4,700

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.3E-02

mg/kg-day

1.0E+00

mg/kg-day

0.033

—

mg/kg-day

1.0E+00

mg/kg-day

—

Arsenic

11

mg/kg

7.7E-05

mg/kg-day

1.5E+00

(mg/kg-day)"1

1.2E-04

8.4E-05

mg/kg-day

3.0E-04

mg/kg-day

0.28

—

mg/kg-day

3.0E-04

mg/kg-day

—

Barium

75

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.1E-03

mg/kg-day

2.0E-01

mg/kg-day

0.0053

—

mg/kg-day

2.0E-01

mg/kg-day

—

Cadmium

0.073

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.7E-06

mg/kg-day

1.0E-04

mg/kg-day

0.027

—

mg/kg-day

1.0E-04

mg/kg-day

—

Chromium

6.700

mg/kg

5.7E-05

mg/kg-day

5.0E-01

(mg/kg-day)"1

2.9E-05

4.8E-05

mg/kg-day

3.0E-03

mg/kg-day

0.016

—

mg/kg-day

3.0E-03

mg/kg-day

—

Cobalt

4.5

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.0E-05

mg/kg-day

3.0E-04

mg/kg-day

0.17

—

mg/kg-day

3.0E-04

mg/kg-day

—

Copper

5

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.6E-04

mg/kg-day

4.0E-02

mg/kg-day

0.014

—

mg/kg-day

4.0E-02

mg/kg-day

—

Iron

15,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

--

1.1E-01

mg/kg-day

7.0E-01

mg/kg-day

0.15

—

mg/kg-day

7.0E-01

mg/kg-day

—

Manganese

400

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.7E-02

mg/kg-day

2.4E-02

mg/kg-day

1.1

—

mg/kg-day

2.4E-02

mg/kg-day

—

Molybdenum

0.81

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.5E-05

mg/kg-day

5.0E-03

mg/kg-day

0.011

—

mg/kg-day

5.0E-03

mg/kg-day

—

Selenium

1.5

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.7E-05

mg/kg-day

5.0E-03

mg/kg-day

0.0033

—

mg/kg-day

5.0E-03

mg/kg-day

—

Thallium

0.092

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.7E-07

mg/kg-day

1.0E-05

mg/kg-day

0.057

—

mg/kg-day

1.0E-05

mg/kg-day

—

Uranium

2.90

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.3E-05

mg/kg-day

2.0E-04

mg/kg-day

0.12

—

mg/kg-day

2.0E-04

mg/kg-day

—

Vanadium

25

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.9E-04

mg/kg-day

5.0E-03

mg/kg-day

0.037

—

mg/kg-day

5.0E-03

mg/kg-day

—

Metals Cancer Total

1E-04

Metals Noncancer Total

2

Metals Noncancer Total

—

Exposure Route Cancer Total

5E-04

Exposure Route Noncancer Total

2

Exposure Route Noncancer Total

—

Page 9 of 11


-------
Table C-5.5. Human Health Risk and Hazard Calculations - Arroyos on the Navajo Nation

Arroyos on the Navajo Nation - Kpp ei doo nahaazah dah (Difficult Access Open Space)

COPCa

EPCb

Units

Cancer
lntakec

Units

Slope
Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake0

Units

RfD/
RfCd

Units

Noncancer
Hazardf

Child
Noncancer
Intake0

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Child

Exposure Medium: Subsurface Soil (0-72 inches bgs)

Exposure Route: Other Dine Lifeways Plant Dermal

Aluminum

4,700

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

Arsenic

11

mg/kg

6.5E-06

mg/kg-day

1.5E+00

(mg/kg-day)"1

9.7E-06

7.0E-06

mg/kg-day

3.0E-04

mg/kg-day

0.023

—

mg/kg-day

3.0E-04

mg/kg-day

—

Barium

75

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

Cadmium

0.073

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.1E-07

mg/kg-day

1.0E-04

mg/kg-day

0.0031

—

mg/kg-day

1.0E-04

mg/kg-day

—

Chromium

6.7

mg/kg

—

mg/kg-day

5.0E-01

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

Cobalt

4.5

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

Copper

5

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

Iron

15,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

Manganese

400

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

Molybdenum

0.81

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Selenium

1.5

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Thallium

0.092

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

Uranium

2.90

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

Vanadium

25

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Metals Cancer Total

1E-05

Metals Noncancer Total

0.03

Metals Noncancer Total

—

Exposure Route Cancer Total

1E-05

Exposure Route Noncancer Total

0.03

Exposure Route Noncancer Total

—

Exposure Medium: Subsurface Soil (0-72 inches bgs)

Exposure Route: Other Dine Lifeways Plant Inhalation

Uranium-238

—

pCi/g

—

pCi

2.4E-08

risk/pCi

—

—

—

—

—

—

—

—

—

—

—

Uranium-234

—

pCi/g

—

pCi

2.8E-08

risk/pCi

—

—

—

—

—

—

—

—

—

—

—

Thorium-230

—

pCi/g

—

pCi

3.4E-08

risk/pCi

—

—

—

—

—

—

—

—

—

—

—

Radium-226 in SE

1.5

pCi/g

9.3E+02

pCi

5.9E-08

risk/pCi

5.5E-05

—

—

—

—

—

—

—

—

—

—

Radionuclide Cancer Total

6E-05

Radionuclide Noncancer Total

—

Radionuclide Noncancer Total

—

Aluminum

4,700

mg/kg

—

ug/m3

—

(ug/m3)"1

—

3.4E-04

mg/m3

5.0E-03

mg/m3

0.068

—

mg/m3

5.0E-03

mg/m3

—

Arsenic

11

mg/kg

7.8E-04

ug/m3

4.3E-03

(ug/m3)"1

3.4E-06

8.6E-07

mg/m3

1.5E-05

mg/m3

0.057

—

mg/m3

1.5E-05

mg/m3

—

Barium

75

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.1E-05

mg/m3

5.0E-04

mg/m3

0.021

—

mg/m3

5.0E-04

mg/m3

—

Cadmium

0.073

mg/kg

2.6E-05

ug/m3

1.8E-03

(ug/m3)"1

4.6E-08

2.8E-08

mg/m3

1.0E-05

mg/m3

0.0028

—

mg/m3

1.0E-05

mg/m3

—

Chromium

6.7

mg/kg

5.9E-04

ug/m3

8.4E-02

(ug/m3)"1

4.9E-05

5.0E-07

mg/m3

1.0E-04

mg/m3

0.0050

—

mg/m3

1.0E-04

mg/m3

—

Cobalt

4.5

mg/kg

4.5E-04

ug/m3

9.0E-03

(ug/m3)"1

4.1E-06

5.0E-07

mg/m3

6.0E-06

mg/m3

0.083

—

mg/m3

6.0E-06

mg/m3

—

Copper

5

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

—

mg/m3

—

mg/m3

—

Iron

15,000

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

—

mg/m3

—

mg/m3

—

Manganese

400

mg/kg

—

ug/m3

—

(ug/m3)"1

—

2.8E-04

mg/m3

5.0E-05

mg/m3

5.6

—

mg/m3

5.0E-05

mg/m3

—

Molybdenum

0.81

mg/kg

—

ug/m3

—

(ug/m3)"1

—

5.7E-07

mg/m3

2.0E-03

mg/m3

0.00028

—

mg/m3

2.0E-03

mg/m3

—

Selenium

1.5

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.7E-07

mg/m3

2.0E-02

mg/m3

0.0000083

—

mg/m3

2.0E-02

mg/m3

—

Thallium

0.092

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

—

mg/m3

—

mg/m3

—

Uranium

2.90

mg/kg

—

ug/m3

—

(ug/m3)"1

—

2.4E-07

mg/m3

4.0E-05

mg/m3

0.0060

—

mg/m3

4.0E-05

mg/m3

—

Vanadium

25

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.9E-06

mg/m3

1.0E-04

mg/m3

0.019

—

mg/m3

1.0E-04

mg/m3

—

Metals Cancer Total

6E-05

Metals Noncancer Total

6

Metals Noncancer Total

—

Exposure Route Cancer Total

1E-04

Exposure Route Noncancer Total

6

Exposure Route Noncancer Total

—

Subsurface Soil (0-72 inches bgs) Receptor Cancer Risk Total

7E-04

Receptor/Media Noncancer Hazard Total

8

Receptor/Media Noncancer Hazard Total

0.7

Page 10 of 11


-------
Table C-5.5. Human Health Risk and Hazard Calculations - Arroyos on the Navajo Nation

Notes:

a COPCs are the constituents of interest with a maximum detected concentration exceeding the COPC screening level (see Table C-1).
b EPCs are provided on Table C-4.

c The intakes are the EPC multiplied by the exposure parameters and any applicable contaminant-specific inputs (see Table C-3 for exposure inputs, Table 4 of the NAUM risk assessment methodology [USEPA 2024b] report for contaminant-specific inputs,

and Appendix B of the NAUM risk assessment methodology [USEPA 2024b] report for equations).
d The toxicity values are provided in Table 4 of the NAUM risk assessment methodology (USEPA 2024b).

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,

COPC

EPC

mg/kg

|jg/m3
bgs

mg/kg-day
mg/m3

Not applicable
Microgram per cubic meter
Below ground surface
Contaminant of potential concern
Exposure point concentration
Milligram per kilogram
Milligram per kilogram per day
Milligram per cubic meter

pCi

pCi/g

RfC

RfD

SE

NAUM

USEPA

Navajo abandoned uranium mine
Picocurie

Picocurie per gram
Reference concentration
Reference dose
Secular equilbrium

U.S. Environmental Protection Agency

Reference:

U.S. Environmental Protection Agency (USEPA). 2024b. "Navajo Abandoned Uranium Mines Risk Assessment Methodology." Draft Final. March.

Page 11 of 11


-------
Table C-5.6. Human Health Risk and Hazard Calculations - Arroyos on United Nuclear Corporation Property

Arroyos on United Nuclear Corporation Property - UNC Outdoor Worker

COPCa

EPCb

Units

Cancer Intake0

Units

Slope Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Exposure Medium: Surface Soil (0-6 inches bgs)

Exposure Route: Incidental Soil In

gestion

Uranium-238

—

pCi/g

—

pCi/g

1.3E-10

risk/pCi/g

—

—

—

—

—

—

Uranium-234

—

pCi/g

—

pCi/g

1.5E-10

risk/pCi/g

—

—

—

—

—

—

Thorium-230

—

pCi/g

—

pCi/g

1.7E-10

risk/pCi/g

—

—

—

—

—

—

Radium-226 in SE

1.1

pCi/g

2.8E+02

pCi/g

5.7E-09

risk/pCi/g

1.6E-06

—

—

—

—

—

Radionuclide Cancer Total

2E-06

Radionuclide Noncancer Total

—

Aluminum

4,400

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.5E-03

mg/kg-day

1.0E+00

mg/kg-day

0.0015

Arsenic

4.6

mg/kg

3.4E-07

mg/kg-day

1.5E+00

(mg/kg-day)"1

5.1E-07

9.5E-07

mg/kg-day

3.0E-04

mg/kg-day

0.0032

Barium

48

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.6E-05

mg/kg-day

2.0E-01

mg/kg-day

0.000082

Cadmium

0.054

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.8E-08

mg/kg-day

1.0E-04

mg/kg-day

0.00018

Chromium

5.0

mg/kg

—

mg/kg-day

5.0E-01

(mg/kg-day)"1

—

1.7E-05

mg/kg-day

3.0E-03

mg/kg-day

0.0057

Cobalt

4.4

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.5E-06

mg/kg-day

3.0E-04

mg/kg-day

0.0050

Copper

4.7

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.6E-06

mg/kg-day

4.0E-02

mg/kg-day

0.000040

Iron

13,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

4.5E-03

mg/kg-day

7.0E-01

mg/kg-day

0.0064

Manganese

240

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

8.2E-05

mg/kg-day

2.4E-02

mg/kg-day

0.0034

Molybdenum

0.28

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

9.6E-08

mg/kg-day

5.0E-03

mg/kg-day

0.000019

Selenium

1.1

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.8E-07

mg/kg-day

5.0E-03

mg/kg-day

0.000075

Thallium

0.057

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.0E-08

mg/kg-day

1.0E-05

mg/kg-day

0.0020

Uranium

0.091

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.1E-08

mg/kg-day

2.0E-04

mg/kg-day

0.00016

Vanadium

0.53

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.8E-07

mg/kg-day

5.0E-03

mg/kg-day

0.000036

Metals Cancer Total

5E-07

Metals Noncancer Total

0.03

Exposure Route Cancer Total

2E-06

Exposure Route Noncancer Total

0.03

Page 1 of 6


-------
Table C-5.6. Human Health Risk and Hazard Calculations - Arroyos on United Nuclear Corporation Property

Arroyos on United Nuclear Corporation Property - UNC Outdoor Worker

COPCa

EPCb

Units

Cancer Intake0

Units

Slope Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Exposure Medium: Surface Soil (0-6 inches bgs)

Exposure Route: External Exposure

Uranium-238

—

pCi/g

—

pCi/g

1.2E-10

risk/year pCi/g

—

—

—

—

—

—

Uranium-234

—

pCi/g

—

pCi/g

2.5E-10

risk/year pCi/g

—

—

—

—

—

—

Thorium-230

—

pCi/g

—

pCi/g

8.5E-10

risk/year pCi/g

—

—

—

—

—

—

Radium-226 in SE

1.1

pCi/g

2.3E+00

pCi/g

8.4E-06

risk/year pCi/g

1.9E-05

—

—

—

—

—

Radionuclide Cancer Total

2E-05

Radionuclide Noncancer Total

—

Exposure Route Cancer Total

2E-05

Exposure Route Noncancer Total

—

Exposure Route: Dermal Exposure

Aluminum

4,400

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

Arsenic

4.6

mg/kg

7.1E-08

mg/kg-day

1.5E+00

(mg/kg-day)"1

1.1E-07

2.0E-07

mg/kg-day

3.0E-04

mg/kg-day

0.00067

Barium

48

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

Cadmium

0.054

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.1E-09

mg/kg-day

1.0E-04

mg/kg-day

0.000031

Chromium

5.0

mg/kg

—

mg/kg-day

5.0E-01

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

Cobalt

4.4

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

Copper

4.7

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

Iron

13,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

Manganese

240

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

Molybdenum

0.28

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Selenium

1.1

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Thallium

0.057

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

Uranium

0.091

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

Vanadium

0.53

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Metals Cancer Total

1E-07

Metals Noncancer Total

0.0007

Exposure Route Cancer Total

1E-07

Exposure Route Noncancer Total

0.0007

Page 2 of 6


-------
Table C-5.6. Human Health Risk and Hazard Calculations - Arroyos on United Nuclear Corporation Property

Arroyos on United Nuclear Corporation Property - UNC Outdoor Worker

COPCa

EPCb

Units

Cancer Intake0

Units

Slope Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Exposure Medium: Surface Soil (0-6 inches bgs)

Exposure Route: Inhalation of Particulates

Uranium-238

—

pCi/g

—

pCi

2.4E-08

risk/pCi

—

—

—

—

—

—

Uranium-234

—

pCi/g

—

pCi

2.8E-08

risk/pCi

—

—

—

—

—

—

Thorium-230

—

pCi/g

—

pCi

3.4E-08

risk/pCi

—

—

—

—

—

—

Radium-226 in SE

1.1

pCi/g

2.8E-03

pCi

5.9E-08

risk/pCi

1.6E-10

—

—

—

—

—

Radionuclide Cancer Total

2E-10

Radionuclide Noncancer Total

—

Aluminum

4,400

mg/kg

—

ug/m3

—

(ug/m3y1

—

6.1E-08

mg/m3

5.0E-03

mg/m3

0.000012

Arsenic

4.6

mg/kg

2.3E-08

ug/m3

4.3E-03

(ug/m3y1

9.8E-11

6.4E-11

mg/m3

1.5E-05

mg/m3

0.0000042

Barium

48

mg/kg

—

ug/m3

—

(ug/m3)"1

—

6.6E-10

mg/m3

5.0E-04

mg/m3

0.0000013

Cadmium

0.054

mg/kg

2.7E-10

ug/m3

1.8E-03

(ug/m3)"1

4.8E-13

7.5E-13

mg/m3

1.0E-05

mg/m3

0.000000075

Chromium

5.0

mg/kg

2.6E-09

ug/m3

8.4E-02

(ug/m3)"1

2.2E-10

1.2E-09

mg/m3

1.0E-04

mg/m3

0.000012

Cobalt

4.4

mg/kg

2.2E-08

ug/m3

9.0E-03

(ug/m3)"1

2.0E-10

6.1E-11

mg/m3

6.0E-06

mg/m3

0.000010

Copper

4.7

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

Iron

13,000

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

Manganese

240

mg/kg

—

ug/m3

—

(ug/m3)"1

—

3.3E-09

mg/m3

5.0E-05

mg/m3

0.000066

Molybdenum

0.28

mg/kg

—

ug/m3

—

(ug/m3)"1

—

3.9E-12

mg/m3

2.0E-03

mg/m3

0.0000000019

Selenium

1.1

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.5E-11

mg/m3

2.0E-02

mg/m3

0.00000000076

Thallium

0.057

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

Uranium

0.091

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.3E-12

mg/m3

4.0E-05

mg/m3

0.000000031

Vanadium

0.53

mg/kg

—

ug/m3

—

(ug/m3)"1

—

7.3E-12

mg/m3

1.0E-04

mg/m3

0.000000073

Metals Cancer Total

5E-10

Metals Noncancer Total

0.0001

Exposure Route Cancer Total

7E-10

Exposure Route Noncancer Total

0.0001

Surface Soil (0-6 inches bgs) Receptor Cancer Risk Total

2E-05

Receptor/Media Noncancer Hazard Total

0.03

Page 3 of 6


-------
Table C-5.6. Human Health Risk and Hazard Calculations - Arroyos on United Nuclear Corporation Property

Arroyos on United Nuclear Corporation Property - UNC Outdoor Worker

COPCa

EPCb

Units

Cancer Intake0

Units

Slope Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Exposure Medium: Subsurface Soil (0-72 inches bgs)

Exposure Route: Incidental Soil In

gestion

Uranium-238

—

pCi/g

—

pCi/g

1.3E-10

risk/pCi/g

—

—

—

—

—

—

Uranium-234

—

pCi/g

—

pCi/g

1.5E-10

risk/pCi/g

—

—

—

—

—

—

Thorium-230

—

pCi/g

—

pCi/g

1.7E-10

risk/pCi/g

—

—

—

—

—

—

Radium-226 in SE

1.1

pCi/g

2.8E+02

pCi/g

5.7E-09

risk/pCi/g

1.6E-06

—

—

—

—

—

Radionuclide Cancer Total

2E-06

Radionuclide Noncancer Total

—

Aluminum

4,700

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.6E-03

mg/kg-day

1.0E+00

mg/kg-day

0.0016

Arsenic

4.8

mg/kg

3.5E-07

mg/kg-day

1.5E+00

(mg/kg-day)"1

5.3E-07

9.9E-07

mg/kg-day

3.0E-04

mg/kg-day

0.0033

Barium

62

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.1E-05

mg/kg-day

2.0E-01

mg/kg-day

0.00011

Cadmium

0.055

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.9E-08

mg/kg-day

1.0E-04

mg/kg-day

0.00019

Chromium

5.0

mg/kg

—

mg/kg-day

5.0E-01

(mg/kg-day)"1

—

1.7E-05

mg/kg-day

3.0E-03

mg/kg-day

0.0057

Cobalt

4.4

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.5E-06

mg/kg-day

3.0E-04

mg/kg-day

0.0050

Copper

5.4

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

1.8E-06

mg/kg-day

4.0E-02

mg/kg-day

0.000046

Iron

15,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

5.1E-03

mg/kg-day

7.0E-01

mg/kg-day

0.0073

Manganese

280

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

9.6E-05

mg/kg-day

2.4E-02

mg/kg-day

0.0040

Molybdenum

0.28

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

9.6E-08

mg/kg-day

5.0E-03

mg/kg-day

0.000019

Selenium

1.1

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.8E-07

mg/kg-day

5.0E-03

mg/kg-day

0.000075

Thallium

0.059

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.0E-08

mg/kg-day

1.0E-05

mg/kg-day

0.0020

Uranium

0.091

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.1E-08

mg/kg-day

2.0E-04

mg/kg-day

0.00016

Vanadium

0.62

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

2.1E-07

mg/kg-day

5.0E-03

mg/kg-day

0.000042

Metals Cancer Total

5E-07

Metals Noncancer Total

0.03

Exposure Route Cancer Total

2E-06

Exposure Route Noncancer Total

0.03

Page 4 of 6


-------
Table C-5.6. Human Health Risk and Hazard Calculations - Arroyos on United Nuclear Corporation Property

Arroyos on United Nuclear Corporation Property - UNC Outdoor Worker

COPCa

EPCb

Units

Cancer Intake0

Units

Slope Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
Intake

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Exposure Medium: Subsurface Soil (0-72 inches bgs)

Exposure Route: External Exposure

Uranium-238

—

pCi/g

—

pCi/g

1.2E-10

risk/year pCi/g

—

—

—

—

—

—

Uranium-234

—

pCi/g

—

pCi/g

2.5E-10

risk/year pCi/g

—

—

—

—

—

—

Thorium-230

—

pCi/g

—

pCi/g

8.5E-10

risk/year pCi/g

—

—

—

—

—

—

Radium-226 in SE

1.1

pCi/g

2.3E+00

pCi/g

8.4E-06

risk/year pCi/g

1.9E-05

—

—

—

—

—

Radionuclide Cancer Total

2E-05

Radionuclide Noncancer Total

—

Exposure Route Cancer Total

2E-05

Exposure Route Noncancer Total

—

Exposure Route: Dermal Exposure

Aluminum

4,700

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E+00

mg/kg-day

—

Arsenic

4.8

mg/kg

7.4E-08

mg/kg-day

1.5E+00

(mg/kg-day)"1

1.1E-07

2.1E-07

mg/kg-day

3.0E-04

mg/kg-day

0.00069

Barium

62

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-01

mg/kg-day

—

Cadmium

0.055

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

3.2E-09

mg/kg-day

1.0E-04

mg/kg-day

0.000032

Chromium

5.0

mg/kg

—

mg/kg-day

5.0E-01

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-03

mg/kg-day

—

Cobalt

4.4

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

3.0E-04

mg/kg-day

—

Copper

5.4

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

4.0E-02

mg/kg-day

—

Iron

15,000

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

7.0E-01

mg/kg-day

—

Manganese

280

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.4E-02

mg/kg-day

—

Molybdenum

0.28

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Selenium

1.1

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Thallium

0.059

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

1.0E-05

mg/kg-day

—

Uranium

0.091

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

2.0E-04

mg/kg-day

—

Vanadium

0.62

mg/kg

—

mg/kg-day

—

(mg/kg-day)"1

—

—

mg/kg-day

5.0E-03

mg/kg-day

—

Metals Cancer Total

1E-07

Metals Noncancer Total

0.0007

Exposure Route Cancer Total

1E-07

Exposure Route Noncancer Total

0.0007

Page 5 of 6


-------
Table C-5.6. Human Health Risk and Hazard Calculations - Arroyos on United Nuclear Corporation Property

Arroyos on United Nuclear Corporation Property - UNC Outdoor Worker

COPCa

EPCb

Units

Cancer Intake0

Units

Slope Factor/
Unit Riskd

Units

Cancer
Risk6

Adult
Noncancer
lntakec

Units

RfD /
RfCd

Units

Noncancer
Hazardf

Adult

Exposure Medium: Subsurface Soil (0-72 inches bgs)

Exposure Route: Inhalation of Particulates

Uranium-238

—

pCi/g

—

pCi

2.4E-08

risk/pCi

—

—

—

—

—

—

Uranium-234

—

pCi/g

—

pCi

2.8E-08

risk/pCi

—

—

—

—

—

—

Thorium-230

—

pCi/g

—

pCi

3.4E-08

risk/pCi

—

—

—

—

—

—

Radium-226 in SE

1.1

pCi/g

2.8E-03

pCi

5.9E-08

risk/pCi

1.6E-10

—

—

—

—

—

Radionuclide Cancer Total

2E-10

Radionuclide Noncancer Total

—

Aluminum

4,700

mg/kg

—

ug/m3

—

(ug/m3y1

—

6.5E-08

mg/m3

5.0E-03

mg/m3

0.000013

Arsenic

4.8

mg/kg

2.4E-08

ug/m3

4.3E-03

(ug/m3y1

1.0E-10

6.6E-11

mg/m3

1.5E-05

mg/m3

0.0000044

Barium

62

mg/kg

—

ug/m3

—

(ug/m3)"1

—

8.6E-10

mg/m3

5.0E-04

mg/m3

0.0000017

Cadmium

0.055

mg/kg

2.7E-10

ug/m3

1.8E-03

(ug/m3)"1

4.9E-13

7.6E-13

mg/m3

1.0E-05

mg/m3

0.000000076

Chromium

5.0

mg/kg

2.6E-09

ug/m3

8.4E-02

(ug/m3)"1

2.2E-10

1.2E-09

mg/m3

1.0E-04

mg/m3

0.000012

Cobalt

4.4

mg/kg

2.2E-08

ug/m3

9.0E-03

(ug/m3)"1

2.0E-10

6.1E-11

mg/m3

6.0E-06

mg/m3

0.000010

Copper

5.4

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

Iron

15,000

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

Manganese

280

mg/kg

—

ug/m3

—

(ug/m3)"1

—

3.9E-09

mg/m3

5.0E-05

mg/m3

0.000077

Molybdenum

0.28

mg/kg

—

ug/m3

—

(ug/m3)"1

—

3.9E-12

mg/m3

2.0E-03

mg/m3

0.0000000019

Selenium

1.1

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.5E-11

mg/m3

2.0E-02

mg/m3

0.00000000076

Thallium

0.059

mg/kg

—

ug/m3

—

(ug/m3)"1

—

—

mg/m3

—

mg/m3

—

Uranium

0.091

mg/kg

—

ug/m3

—

(ug/m3)"1

—

1.3E-12

mg/m3

4.0E-05

mg/m3

0.000000031

Vanadium

0.62

mg/kg

—

ug/m3

—

(ug/m3)"1

—

8.6E-12

mg/m3

1.0E-04

mg/m3

0.000000086

Metals Cancer Total

5E-10

Metals Noncancer Total

0.0001

Exposure Route Cancer Total

7E-10

Exposure Route Noncancer Total

0.0001

Subsurface Soil (0-72 inches bgs) Receptor Cancer Risk Total

2E-05

Receptor/Media Noncancer Hazard Total

0.03

Notes:

a COPCs are the constituents of interest with a maximum detected concentration exceeding the COPC screening level (see Table C-1).
b EPCs are provided on Table C-4.

c The intakes are the EPC multiplied by the exposure parameters and any applicable contaminant-specific inputs (see Table C-3 for exposure inputs, Table 4 of the NAUM risk assessment methodology [USEPA 2024b] report for contaminant-specific inputs,

and Appendix B of the NAUM risk assessment methodology [USEPA 2024b] report for equations).
d The toxicity values are provided in Table 4 of the NAUM risk assessment methodology (USEPA 2024b).

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

Kerr-McGee

Kerr-McGee Corporation

SE

Secular equilbrium

mg/kg

Milligram per kilogram

UNC

United Nuclear Corporation

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). 2024b. "Navajo Abandoned Uranium Mines Risk Assessment Methodology." Draft Final. March.

Page 6 of 6


-------
Table C-6. Human Health Risk and Hazard Summary by Exposure Pathway

Church Rock Mine No. 1 - Kee'da'whn teeh (Full-Time Resident)

COPC

EPC

Units

Incidental Soil Ingestion

External Exposure /
Dermal Contact

Inhalation of Particulates

Plant Consumption

Animal Consumption

ODL Plant Ingestion

ODL Plant Dermal

ODL Plant Inhalation

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

Cancer
Risk

Adult
Hazard

Child
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

1.1

pCi/g

1.4E-06

-

-

7.0E-09

-

-

2.3E-09

-

-

6.8E-06

-

-

7.7E-06

-

-

3.1E-06

-

-

-

-

-

6.0E-06

-

-

3E-05

-

-

Uranium-234

1.2

pCi/g

1.7E-06

-

-

1.5E-08

-

-

2.9E-09

-

-

8.1E-06

-

-

9.3E-06

-

-

3.8E-06

-

-

-

-

-

7.7E-06

-

-

3E-05

-

-

Thorium-230

1.7

pCi/g

2.7E-06

-

-

7.3E-08

-

-

5.0E-09

-

-

3.6E-06

-

-

7.9E-09

-

-

2.0E-06

-

-

-

-

-

2.6E-06

-

-

1E-05

-

-

Radium-226 in SE

6.7

pCi/g

3.6E-04

-

-

2.9E-03

-

-

3.5E-08

-

-

2.7E-03

-

-

5.2E-03

-

-

1.5E-03

-

-

-

-

-

2.5E-04

-

-

1E-02

-

-

Aluminum

4,600

mg/kg

-

0.020

0.12

-

-

-

-

0.00012

0.00012

-

0.055

0.14

-

0.0032

0.0087

-

0.033

-

-

-

-

-

0.066

-

-

0.2

0.3

Arsenic

4.9

mg/kg

2.6E-05

0.042

0.25

1.5E-06

0.0025

0.015

2.7E-09

0.000042

0.000042

1.0E-04

0.21

0.56

8.1E-06

0.016

0.0425

5.2E-05

0.13

-

4.4E-06

0.011

-

1.5E-06

0.026

-

2E-04

0.4

0.9

Barium

110

mg/kg

-

0.0024

0.014

-

-

-

-

0.000029

0.000029

-

0.013

0.034

-

0.000072

0.00019

-

0.0083

-

-

-

-

-

0.033

-

-

0.06

0.05

Cadmium

0.14

mg/kg

-

0.0060

0.036

-

0.00028

0.0017

3.3E-11

0.0000018

0.0000018

-

0.083

0.22

-

0.0032

0.0084

-

0.056

-

-

0.0062

-

9.3E-08

0.0056

-

9E-08

0.2

0.3

Chromium

6.0

mg/kg

4.8E-05

0.0086

0.052

-

-

-

1.1E-07

0.0000078

0.0000078

8.4E-05

0.024

0.06

1.8E-05

0.0053

0.0141

2.6E-05

0.015

-

-

-

-

4.5E-05

0.0009

-

2E-04

0.1

0.1

Cobalt

6.1

mg/kg

-

0.087

0.53

-

-

-

7.1E-09

0.00013

0.00013

-

0.37

0.98

-

0.20

0.53

-

0.22

-

-

-

-

6.0E-06

0.12

-

6E-06

1

2

Copper

12

mg/kg

-

0.0013

0.0078

-

-

-

-

-

-

-

0.051

0.14

-

0.0027

0.0072

-

0.033

-

-

-

-

-

-

-

-

0.09

0.2

Iron

11,000

mg/kg

-

0.068

0.41

-

-

-

-

-

-

-

0.19

0.49

-

0.14

0.38

-

0.11

-

-

-

-

-

-

-

-

0.5

1

Manganese

160

mg/kg

-

0.029

0.17

-

-

-

-

0.00042

0.00042

-

0.73

1.9

-

0.0022

0.0059

-

0.49

-

-

-

-

-

2.3

-

-

4

2

Molybdenum

0.32

mg/kg

-

0.00028

0.0017

-

-

-

-

0.000000021

0.000000021

-

0.0070

0.019

-

0.00029

0.00077

-

0.0047

-

-

-

-

-

0.00012

-

-

0.01

0.02

Selenium

3.4

mg/kg

-

0.0029

0.018

-

-

-

-

0.000000022

0.000000022

-

0.012

0.033

-

0.052

0.14

-

0.0075

-

-

-

-

-

0.000019

-

-

0.08

0.2

Thallium

0.14

mg/kg

-

0.060

0.36

-

-

-

-

-

-

-

0.14

0.39

-

0.25

0.69

-

0.088

-

-

-

-

-

-

-

-

0.5

1

Uranium

7.3

mg/kg

-

0.16

0.95

-

-

-

-

0.000024

0.000024

-

0.47

1.3

-

0.0051

0.014

-

0.30

-

-

-

-

-

0.016

-

-

1.0

2

Vanadium

14

mg/kg

-

0.012

0.07

-

-

-

-

0.000018

0.000018

-

0.034

0.092

-

0.0031

0.0084

-

0.021

-

-

-

-

-

0.011

-

-

0.08

0.2

Exposure Pathway
Risk/Hazard Total

4E-04

0.5

3

3E-03

0.003

0.02

2E-07

0.0008

0.0008

3E-03

2

6

5E-03

0.7

2

2E-03

2

-

4E-06

0.02

--

3E-04

3

-

1E-02

8

10

Subsurface Soil (0-72 inches bgs)

Uranium-238

1.1

pCi/g

1.4E-06

-

-

7.0E-09

-

-

2.3E-09

-

-

6.8E-06

-

-

7.7E-06

-

-

3.1E-06

-

-

-

-

-

6.0E-06

-

-

3E-05

-

-

Uranium-234

1.2

pCi/g

1.7E-06

-

-

1.5E-08

-

-

2.9E-09

-

-

8.1E-06

-

-

9.3E-06

-

-

3.8E-06

-

-

-

-

-

7.7E-06

-

-

3E-05

-

-

Thorium-230

1.7

pCi/g

2.7E-06

-

-

7.3E-08

-

-

5.0E-09

-

-

3.6E-06

-

-

7.9E-09

-

-

2.0E-06

-

-

-

-

-

2.6E-06

-

-

1E-05

-

-

Radium-226 in SE

17

pCi/g

9.2E-04

-

-

7.3E-03

-

-

8.8E-08

-

-

6.9E-03

-

-

1.3E-02

-

-

3.8E-03

-

-

-

-

-

6.3E-04

-

-

3E-02

-

-

Aluminum

4,600

mg/kg

-

0.020

0.12

-

-

-

-

0.00012

0.00012

-

0.055

0.14

-

0.0032

0.0087

-

0.033

-

-

-

-

-

0.066

-

-

0.2

0.3

Arsenic

4.8

mg/kg

2.6E-05

0.042

0.24

1.5E-06

0.0024

0.015

2.7E-09

0.000042

0.000042

1.0E-04

0.21

0.54

7.9E-06

0.016

0.042

5.1E-05

0.12

-

4.3E-06

0.010

-

1.5E-06

0.025

-

2E-04

0.4

0.8

Barium

110

mg/kg

-

0.0024

0.014

-

-

-

-

0.000029

0.000029

-

0.013

0.03

-

0.000072

0.00019

-

0.0083

-

-

-

-

-

0.033

-

-

0.06

0.05

Cadmium

0.14

mg/kg

-

0.0060

0.036

-

0.00028

0.0017

3.3E-11

0.0000018

0.0000018

-

0.083

0.22

-

0.0032

0.0084

-

0.056

-

-

0.0062

-

9.3E-08

0.0056

-

9E-08

0.2

0.3

Chromium

6.0

mg/kg

4.8E-05

0.0086

0.052

-

-

-

1.1E-07

0.0000078

0.0000078

8.4E-05

0.024

0.06

1.8E-05

0.0053

0.0141

2.6E-05

0.015

-

-

-

-

4.5E-05

0.0009

-

2E-04

0.1

0.1

Cobalt

6.1

mg/kg

-

0.087

0.53

-

-

-

7.1E-09

0.00013

0.00013

-

0.37

0.98

-

0.20

0.53

-

0.22

-

-

-

-

6.0E-06

0.12

-

6E-06

1

2

Copper

12

mg/kg

-

0.0013

0.0078

-

-

-

-

-

-

-

0.051

0.14

-

0.0027

0.0072

-

0.033

-

-

-

-

-

-

-

-

0.09

0.2

Iron

11,000

mg/kg

-

0.068

0.41

-

-

-

-

-

-

-

0.19

0.49

-

0.14

0.38

-

0.11

-

-

-

-

-

-

-

-

0.5

1

Manganese

160

mg/kg

-

0.029

0.17

-

-

-

-

0.00042

0.00042

-

0.73

1.9

-

0.0022

0.0059

-

0.49

-

-

-

-

-

2.3

-

-

4

2

Molybdenum

0.32

mg/kg

-

0.00028

0.0017

-

-

-

-

0.000000021

0.000000021

-

0.0070

0.019

-

0.00029

0.00077

-

0.0047

-

-

-

-

-

0.00012

-

-

0.01

0.02

Selenium

3.1

mg/kg

-

0.0027

0.016

-

-

-

-

0.000000020

0.000000020

-

0.011

0.030

-

0.048

0.13

-

0.0068

-

-

-

-

-

0.000017

-

-

0.07

0.2

Thallium

0.14

mg/kg

-

0.060

0.36

-

-

-

-

-

-

-

0.14

0.39

-

0.25

0.69

-

0.088

-

-

-

-

-

-

-

-

0.5

1

Uranium

7.3

mg/kg

-

0.16

0.95

-

-

-

-

0.000024

0.000024

-

0.47

1.3

-

0.0051

0.014

-

0.30

-

-

-

-

-

0.016

-

-

1

2

Vanadium

14

mg/kg

-

0.012

0.073

-

-

-

-

0.000018

0.000018

-

0.034

0.092

-

0.0031

0.0084

-

0.021

-

-

-

-

-

0.011

-

-

0.08

0.2

Exposure Pathway
Risk/Hazard Total

1E-03

0.5

3

7E-03

0.003

0.02

2E-07

0.0008

0.0008

7E-03

2

6

1E-02

0.7

2

4E-03

2

-

4E-06

0.02

--

7E-04

3

-

3E-02

8

10

Page 1 of 6


-------
Table C-6. Human Health Risk and Hazard Summary by Exposure Pathway

Church Rock Mine No. 1 East - Kee'da'whn teeh (Full-Time Resident)

COPC

EPC

Units

Incidental Soil Ingestion

External Exposure /
Dermal Contact

Inhalation of Particulates

Plant Consumption

Animal Consumption

ODL Plant Ingestion

ODL Plant Dermal

ODL Plant Inhalation

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

Cancer
Risk

Adult
Hazard

Child
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

1.3

pCi/g

1.7E-06

-

-

8.2E-09

-

-

2.7E-09

-

-

8.0E-06

-

-

9.1E-06

-

-

3.7E-06

-

-

-

-

-

7.1E-06

-

-

3E-05

-

-

Uranium-234

1.4

pCi/g

2.0E-06

-

-

1.8E-08

-

-

3.4E-09

-

-

9.5E-06

-

-

1.1E-05

-

-

4.4E-06

-

-

-

-

-

9.0E-06

-

-

4E-05

-

-

Thorium-230

3.6

pCi/g

5.7E-06

-

-

1.6E-07

-

-

1.1E-08

-

-

7.7E-06

-

-

1.7E-08

-

-

4.2E-06

-

-

-

-

-

5.5E-06

-

-

2E-05

-

-

Radium-226 in SE

9.3

pCi/g

5.0E-04

-

-

4.0E-03

-

-

4.8E-08

-

-

3.8E-03

-

-

7.2E-03

-

-

2.1E-03

-

-

-

-

-

3.5E-04

-

-

2E-02

-

-

Aluminum

6,300

mg/kg

-

0.027

0.16

-

-

-

-

0.00016

0.00016

-

0.076

0.20

-

0.0044

0.0120

-

0.045

-

-

-

-

-

0.091

-

-

0.2

0.4

Arsenic

6.6

mg/kg

3.6E-05

0.057

0.33

2.1E-06

0.0033

0.020

3.7E-09

0.000057

0.000057

1.4E-04

0.29

0.75

1.1E-05

0.022

0.0572

7.0E-05

0.17

-

5.9E-06

0.014

-

2.0E-06

0.035

-

3E-04

0.6

1.0

Barium

160

mg/kg

-

0.0034

0.021

-

-

-

-

0.000042

0.000042

-

0.018

0.049

-

0.000104

0.00028

-

0.0120

-

-

-

-

-

0.048

-

-

0.08

0.07

Cadmium

0.13

mg/kg

-

0.0056

0.034

-

0.00026

0.0016

3.0E-11

0.0000017

0.0000017

-

0.077

0.21

-

0.0030

0.0078

-

0.052

-

-

0.0057

-

8.7E-08

0.0052

-

9E-08

0.1

0.3

Chromium

10

mg/kg

8.0E-05

0.0143

0.087

-

-

-

1.8E-07

0.000013

0.000013

1.4E-04

0.040

0.11

3.1E-05

0.0088

0.0235

4.4E-05

0.024

-

-

-

-

7.5E-05

0.0075

-

4E-04

0.1

0.2

Cobalt

6.9

mg/kg

-

0.099

0.60

-

-

-

8.1E-09

0.00015

0.00015

-

0.41

1.10

-

0.22

0.60

-

0.25

-

-

-

-

6.8E-06

0.14

-

7E-06

1

2

Copper

13

mg/kg

-

0.0014

0.0085

-

-

-

-

-

-

-

0.055

0.15

-

0.0029

0.0078

-

0.036

-

-

-

-

-

-

-

-

0.10

0.2

Iron

16,000

mg/kg

-

0.098

0.59

-

-

-

-

-

-

-

0.27

0.71

-

0.21

0.55

-

0.16

-

-

-

-

-

-

-

-

0.7

2

Manganese

200

mg/kg

-

0.036

0.22

-

-

-

-

0.00052

0.00052

-

0.92

2.4

-

0.0028

0.0074

-

0.61

-

-

-

-

-

2.9

-

-

4

3

Molybdenum

0.31

mg/kg

-

0.00027

0.0016

-

-

-

-

0.000000020

0.000000020

-

0.0068

0.018

-

0.00028

0.00074

-

0.0045

-

-

-

-

-

0.00011

-

-

0.01

0.02

Selenium

3.0

mg/kg

-

0.0026

0.016

-

-

-

-

0.000000020

0.000000020

-

0.011

0.029

-

0.046

0.13

-

0.0066

-

-

-

-

-

0.000017

-

-

0.07

0.2

Thallium

0.16

mg/kg

-

0.069

0.42

-

-

-

-

-

-

-

0.16

0.45

-

0.29

0.78

-

0.101

-

-

-

-

-

-

-

-

0.6

2

Uranium

3.6

mg/kg

-

0.08

0.47

-

-

-

-

0.000012

0.000012

-

0.23

0.6

-

0.0025

0.007

-

0.15

-

-

-

-

-

0.008

-

-

0.5

1

Vanadium

16

mg/kg

-

0.014

0.08

-

-

-

-

0.000021

0.000021

-

0.038

0.106

-

0.0035

0.0096

-

0.024

-

-

-

-

-

0.012

-

-

0.09

0.2

Exposure Pathway
Risk/Hazard Total

6E-04

0.5

3.0

4E-03

0.004

0.02

3E-07

0.001

0.001

4E-03

3

7

7E-03

0.8

2

2E-03

2

-

6E-06

0.02

--

5E-04

3

-

2E-02

8

10

Subsurface Soil (0-72 inches bgs)

Uranium-238

1.3

pCi/g

1.7E-06

-

-

8.2E-09

-

-

2.7E-09

-

-

8.0E-06

-

-

9.1E-06

-

-

3.7E-06

-

-

-

-

-

7.1E-06

-

-

3E-05

-

-

Uranium-234

1.4

pCi/g

2.0E-06

-

-

1.8E-08

-

-

3.4E-09

-

-

9.5E-06

-

-

1.1E-05

-

-

4.4E-06

-

-

-

-

-

9.0E-06

-

-

4E-05

-

-

Thorium-230

3.6

pCi/g

5.7E-06

-

-

1.6E-07

-

-

1.1E-08

-

-

7.7E-06

-

-

1.7E-08

-

-

4.2E-06

-

-

-

-

-

5.5E-06

-

-

2E-05

-

-

Radium-226 in SE

43

pCi/g

2.3E-03

-

-

1.8E-02

-

-

2.2E-07

-

-

1.7E-02

-

-

3.3E-02

-

-

9.5E-03

-

-

-

-

-

1.6E-03

-

-

8E-02

-

-

Aluminum

6,300

mg/kg

-

0.027

0.16

-

-

-

-

0.00016

0.00016

-

0.076

0.20

-

0.0044

0.012

-

0.045

-

-

-

-

-

0.091

-

-

0.2

0.4

Arsenic

6.3

mg/kg

3.4E-05

0.055

0.32

2.0E-06

0.0032

0.019

3.5E-09

0.000055

0.000055

1.3E-04

0.27

0.71

1.0E-05

0.021

0.055

6.7E-05

0.16

-

5.7E-06

0.014

-

2.0E-06

0.033

-

3E-04

0.6

1

Barium

160

mg/kg

-

0.0034

0.021

-

-

-

-

0.000042

0.000042

-

0.018

0.05

-

0.00010

0.00028

-

0.012

-

-

-

-

-

0.048

-

-

0.08

0.07

Cadmium

0.13

mg/kg

-

0.0056

0.034

-

0.00026

0.0016

3.0E-11

0.0000017

0.0000017

-

0.077

0.21

-

0.0030

0.0078

-

0.052

-

-

0.0057

-

8.7E-08

0.0052

-

9E-08

0.1

0.3

Chromium

10

mg/kg

8.0E-05

0.0143

0.087

-

-

-

1.8E-07

0.000013

0.000013

1.4E-04

0.040

0.11

3.1E-05

0.0088

0.0235

4.4E-05

0.024

-

-

-

-

7.5E-05

0.0075

-

4E-04

0.1

0.2

Cobalt

6.9

mg/kg

-

0.099

0.60

-

-

-

8.1E-09

0.00015

0.00015

-

0.41

1.1

-

0.22

0.60

-

0.25

-

-

-

-

6.8E-06

0.14

-

7E-06

1

2

Copper

13

mg/kg

-

0.0014

0.0085

-

-

-

-

-

-

-

0.055

0.15

-

0.0029

0.0078

-

0.036

-

-

-

-

-

-

-

-

0.1

0.2

Iron

16,000

mg/kg

-

0.098

0.59

-

-

-

-

-

-

-

0.27

0.71

-

0.21

0.55

-

0.16

-

-

-

-

-

-

-

-

0.7

2

Manganese

200

mg/kg

-

0.036

0.22

-

-

-

-

0.00052

0.00052

-

0.92

2.4

-

0.0028

0.0074

-

0.61

-

-

-

-

-

2.9

-

-

4

3

Molybdenum

0.51

mg/kg

-

0.00044

0.0027

-

-

-

-

0.000000033

0.000000033

-

0.011

0.030

-

0.00046

0.0012

-

0.0074

-

-

-

-

-

0.00019

-

-

0.02

0.03

Selenium

5.4

mg/kg

-

0.0046

0.028

-

-

-

-

0.000000035

0.000000035

-

0.019

0.052

-

0.083

0.23

-

0.012

-

-

-

-

-

0.000030

-

-

0.1

0.3

Thallium

0.16

mg/kg

-

0.069

0.42

-

-

-

-

-

-

-

0.16

0.45

-

0.29

0.78

-

0.10

-

-

-

-

-

-

-

-

0.6

2

Uranium

42

mg/kg

-

0.90

5.5

-

-

-

-

0.00014

0.00014

-

2.7

7.6

-

0.029

0.080

-

1.7

-

-

-

-

-

0.089

-

-

5

10

Vanadium

18

mg/kg

-

0.015

0.094

-

-

-

-

0.000023

0.000023

-

0.043

0.12

-

0.0040

0.011

-

0.027

-

-

-

-

-

0.014

-

-

0.10

0.2

Exposure Pathway
Risk/Hazard Total

2E-03

1

8

2E-02

0.003

0.02

4E-07

0.001

0.001

2E-02

5

14

3E-02

0.9

2

1E-02

3

-

6E-06

0.02

--

2E-03

3

-

8E-02

10

20

Page 2 of 6


-------
Table C-6. Human Health Risk and Hazard Summary by Exposure Pathway

Kerr-McGee Ponds on the Navajo Nation - Kee'da'whn teeh (Full-Time Resident)

COPC

EPC

Units

Incidental Soil Ingestion

External Exposure /
Dermal Contact

Inhalation of Particulates

Plant Consumption

Animal Consumption

ODL Plant Ingestion

ODL Plant Dermal

ODL Plant Inhalation

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

Cancer
Risk

Adult
Hazard

Child
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

1.1

pCi/g

1.4E-06

-

-

7.0E-09

-

-

2.3E-09

-

-

6.8E-06

-

-

7.7E-06

-

-

3.1E-06

-

-

-

-

-

6.0E-06

-

-

3E-05

-

-

Uranium-234

1.0

pCi/g

1.4E-06

-

-

1.3E-08

-

-

2.3E-09

-

-

6.6E-06

-

-

7.5E-06

-

-

3.1E-06

-

-

-

-

-

6.2E-06

-

-

2E-05

-

-

Thorium-230

2.0

pCi/g

3.2E-06

-

-

8.6E-08

-

-

5.9E-09

-

-

4.3E-06

-

-

9.3E-09

-

-

2.3E-06

-

-

-

-

-

3.1E-06

-

-

1E-05

-

-

Radium-226 in SE

9.3

pCi/g

5.0E-04

-

-

4.0E-03

-

-

4.8E-08

-

-

3.8E-03

-

-

7.2E-03

-

-

2.1E-03

-

-

-

-

-

3.5E-04

-

-

2E-02

-

-

Aluminum

6,900

mg/kg

-

0.030

0.18

-

-

-

-

0.00018

0.00018

-

0.083

0.21

-

0.0048

0.0131

-

0.049

-

-

-

-

-

0.099

-

-

0.3

0.4

Arsenic

5.9

mg/kg

3.2E-05

0.051

0.30

1.9E-06

0.0030

0.018

3.3E-09

0.000051

0.000051

1.2E-04

0.26

0.67

9.7E-06

0.019

0.0511

6.3E-05

0.15

-

5.3E-06

0.013

-

1.8E-06

0.031

-

2E-04

0.5

1

Barium

82

mg/kg

-

0.0018

0.011

-

-

-

-

0.000021

0.000021

-

0.009

0.025

-

0.000053

0.00014

-

0.0062

-

-

-

-

-

0.025

-

-

0.04

0.04

Cadmium

0.16

mg/kg

-

0.0069

0.042

-

0.00032

0.0019

3.7E-11

0.0000021

0.0000021

-

0.094

0.26

-

0.0037

0.0096

-

0.064

-

-

0.0070

-

1.1E-07

0.0064

-

1E-07

0.2

0.3

Chromium

8.2

mg/kg

6.6E-05

0.0118

0.071

-

-

-

1.5E-07

0.000011

0.000011

1.1E-04

0.033

0.09

2.5E-05

0.0072

0.0192

3.6E-05

0.020

-

-

-

-

6.1E-05

0.0061

-

3E-04

0.1

0.2

Cobalt

5.2

mg/kg

-

0.075

0.45

-

-

-

6.1E-09

0.00011

0.00011

-

0.31

0.83

-

0.17

0.45

-

0.19

-

-

-

-

5.1E-06

0.10

-

5E-06

0.8

2

Copper

11

mg/kg

-

0.0012

0.0072

-

-

-

-

-

-

-

0.047

0.12

-

0.0025

0.0066

-

0.030

-

-

-

-

-

-

-

-

0.08

0.1

Iron

15,000

mg/kg

-

0.092

0.56

-

-

-

-

-

-

-

0.26

0.66

-

0.20

0.51

-

0.15

-

-

-

-

-

-

-

-

0.7

2

Manganese

230

mg/kg

-

0.041

0.25

-

-

-

-

0.00060

0.00060

-

1.05

2.8

-

0.0032

0.0085

-

0.70

-

-

-

-

-

3.4

-

-

5

3

Molybdenum

0.55

mg/kg

-

0.00047

0.0029

-

-

-

-

0.000000036

0.000000036

-

0.0121

0.032

-

0.00050

0.00132

-

0.0080

-

-

-

-

-

0.00020

-

-

0.02

0.04

Selenium

2.9

mg/kg

-

0.0025

0.015

-

-

-

-

0.000000019

0.000000019

-

0.010

0.028

-

0.045

0.12

-

0.0064

-

-

-

-

-

0.000016

-

-

0.06

0.2

Thallium

0.15

mg/kg

-

0.065

0.39

-

-

-

-

-

-

-

0.15

0.42

-

0.27

0.74

-

0.095

-

-

-

-

-

-

-

-

0.6

2

Uranium

6.2

mg/kg

-

0.13

0.81

-

-

-

-

0.000020

0.000020

-

0.40

1.1

-

0.0043

0.012

-

0.26

-

-

-

-

-

0.013

-

-

0.8

2

Vanadium

17

mg/kg

-

0.015

0.09

-

-

-

-

0.000022

0.000022

-

0.041

0.112

-

0.0037

0.0102

-

0.026

-

-

-

-

-

0.013

-

-

0.1

0.2

Exposure Pathway
Risk/Hazard Total

6E-04

0.5

3

4E-03

0.003

0.02

2E-07

0.001

0.001

4E-03

3

7

7E-03

0.7

n

2E-03

o

-

5E-06

0.02

-

4E-04

4

-

2E-02

9

10

Subsurface Soil (0-66 inches bgs)

Uranium-238

1.1

pCi/g

1.4E-06

-

-

7.0E-09

-

-

2.3E-09

-

-

6.8E-06

-

-

7.7E-06

-

-

3.1E-06

-

-

-

-

-

6.0E-06

-

-

3E-05

-

-

Uranium-234

1.0

pCi/g

1.4E-06

-

-

1.3E-08

-

-

2.3E-09

-

-

6.6E-06

-

-

7.5E-06

-

-

3.1E-06

-

-

-

-

-

6.2E-06

-

-

2E-05

-

-

Thorium-230

2.0

pCi/g

3.2E-06

-

-

8.6E-08

-

-

5.9E-09

-

-

4.3E-06

-

-

9.3E-09

-

-

2.3E-06

-

-

-

-

-

3.1E-06

-

-

1E-05

-

-

Radium-226 in SE

9.3

pCi/g

5.0E-04

-

-

4.0E-03

-

-

4.8E-08

-

-

3.8E-03

-

-

7.2E-03

-

-

2.1E-03

-

-

-

-

-

3.5E-04

-

-

2E-02

-

-

Aluminum

6,900

mg/kg

-

0.030

0.18

-

-

-

-

0.00018

0.00018

-

0.083

0.21

-

0.0048

0.0131

-

0.049

-

-

-

-

-

0.099

-

-

0.3

0.4

Arsenic

5.9

mg/kg

3.2E-05

0.051

0.30

1.9E-06

0.0030

0.018

3.3E-09

0.000051

0.000051

1.2E-04

0.26

0.67

9.7E-06

0.019

0.051

6.3E-05

0.15

-

5.3E-06

0.013

-

1.8E-06

0.031

-

2E-04

0.5

1

Barium

82

mg/kg

-

0.0018

0.011

-

-

-

-

0.000021

0.000021

-

0.009

0.03

-

0.000053

0.00014

-

0.0062

-

-

-

-

-

0.025

-

-

0.04

0.04

Cadmium

0.16

mg/kg

-

0.0069

0.042

-

0.00032

0.0019

3.7E-11

0.0000021

0.0000021

-

0.094

0.26

-

0.0037

0.0096

-

0.064

-

-

0.0070

-

1.1E-07

0.0064

-

1E-07

0.2

0.3

Chromium

8.2

mg/kg

6.6E-05

0.0118

0.071

-

-

-

1.5E-07

0.000011

0.000011

1.1E-04

0.033

0.09

2.5E-05

0.0072

0.0192

3.6E-05

0.020

-

-

-

-

6.1E-05

0.0061

-

3E-04

0.1

0.2

Cobalt

5.2

mg/kg

-

0.075

0.45

-

-

-

6.1E-09

0.00011

0.00011

-

0.31

0.83

-

0.17

0.45

-

0.19

-

-

-

-

5.1E-06

0.10

-

5E-06

0.8

2

Copper

11

mg/kg

-

0.0012

0.0072

-

-

-

-

-

-

-

0.047

0.12

-

0.0025

0.0066

-

0.030

-

-

-

-

-

-

-

-

0.08

0.1

Iron

15,000

mg/kg

-

0.092

0.56

-

-

-

-

-

-

-

0.26

0.66

-

0.20

0.51

-

0.15

-

-

-

-

-

-

-

-

0.7

2

Manganese

230

mg/kg

-

0.041

0.25

-

-

-

-

0.00060

0.00060

-

1.05

2.8

-

0.0032

0.0085

-

0.70

-

-

-

-

-

3.4

-

-

5

3

Molybdenum

0.55

mg/kg

-

0.00047

0.0029

-

-

-

-

0.000000036

0.000000036

-

0.0121

0.032

-

0.00050

0.00132

-

0.0080

-

-

-

-

-

0.00020

-

-

0.02

0.04

Selenium

2.9

mg/kg

-

0.0025

0.015

-

-

-

-

0.000000019

0.000000019

-

0.010

0.028

-

0.045

0.12

-

0.0064

-

-

-

-

-

0.000016

-

-

0.06

0.2

Thallium

0.15

mg/kg

-

0.065

0.39

-

-

-

-

-

-

-

0.15

0.42

-

0.27

0.74

-

0.095

-

-

-

-

-

-

-

-

0.6

2

Uranium

6.2

mg/kg

-

0.13

0.81

-

-

-

-

0.000020

0.000020

-

0.40

1.1

-

0.0043

0.012

-

0.26

-

-

-

-

-

0.013

-

-

0.8

2

Vanadium

17

mg/kg

-

0.015

0.088

-

-

-

-

0.000022

0.000022

-

0.041

0.112

-

0.0037

0.0102

-

0.026

-

-

-

-

-

0.013

-

-

0.1

0.2

Exposure Pathway
Risk/Hazard Total

6E-04

0.5

3

4E-03

0.003

0.02

2E-07

0.001

0.001

4E-03

3

7

7E-03

0.7

n

2E-03

o

0

5E-06

0.020

0

4E-04

4

0

2E-02

9

10

Page 3 of 6


-------
Table C-6. Human Health Risk and Hazard Summary by Exposure Pathway

Kerr-McGee Ponds on United Nuclear Corporation Property - UNC Outdoor Worker

COPC

EPC

Units

Incidental Soil Ingestion

External Exposure /
Dermal Contact

Inhalation of Particulates

Plant Consumption

Animal Consumption

ODL Plant Ingestion

ODL Plant Dermal

ODL Plant Inhalation

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

Cancer
Risk

Adult
Hazard

Child
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

2.4

pCi/g

8.0E-08

--

--

6.1E-10

--

--

1.4E-10

~

--

--

--

--

--

--

--

--

--

--

--

~

~

--

--

--

8E-08

--

--

Uranium-234

2.4

pCi/g

8.9E-08

--

--

1.2E-09

~

~

1.7E-10

--

--

~

~

~

~

~

~

--

~

~

--

--

--

~

~

~

9E-08

~

--

Thorium-230

3.4

pCi/g

1.4E-07

--

--

5.9E-09

~

~

2.9E-10

~

~

~

~

~

--

--

--

~

~

~

~

~

~

~

~

~

1E-07

~

--

Radium-226 in SE

13.0

pCi/g

1.8E-05

~

»

2.2E-04

~

~

1.9E-09

~

~

~

~

~

~

~

~

~

~

~

~

~

~

»

»

--

2E-04

~

»

Aluminum

6,600

mg/kg

--

0.002

~

--

--

--

~

0.000018

~

--

--

--

~

~

~

--

--

--

~

~

~

~

~

~

--

0.002

~

Arsenic

6.0

mg/kg

6.6E-07

0.004

~

1.4E-07

0.0009

~

1.3E-10

0.0000055

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

8E-07

0.005

~

Barium

83

mg/kg

--

0.0001

~

--

~

~

--

0.0000023

--

~

~

~

~

~

~

~

~

~

--

--

--

~

~

~

--

0.0001

~

Cadmium

0.11

mg/kg

--

0.0004

~

~

0.00006

~

9.8E-13

0.00000015

~

~

~

~

--

--

--

~

~

~

~

~

~

~

~

~

1E-12

0.0004

~

Chromium

8.5

mg/kg

--

0.0097

~

~

~

~

3.8E-10

0.000020

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

--

4E-10

0.0100

~

Cobalt

5.2

mg/kg

»

0.006

»

»

»

--

2.3E-10

0.000012

~

--

--

--

~

~

~

--

--

--

~

~

~

~

~

~

2E-10

0.006

--

Copper

11

mg/kg

--

0.0001

~

~

~

~

~

--

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

--

0.00009

~

Iron

15,000

mg/kg

»

0.007

~

~

~

~

»

»

--

~

~

~

~

~

~

~

~

~

--

»

»

~

~

-

~

0.007

~

Manganese

220

mg/kg

--

0.003

~

~

~

~

~

0.000061

~

~

~

~

--

--

--

~

~

~

~

~

~

~

~

~

~

0.003

~

Molybdenum

0.57

mg/kg

»

0.00004

~

~

~

~

~

0.0000000039

~

~

~

~

~

~

~

~

~

~

~

~

~

»

»

--

~

0.00004

~

Selenium

4.0

mg/kg

--

0.0003

~

~

~

--

~

0.0000000028

~

--

--

--

~

~

~

--

--

--

~

~

~

~

~

~

--

0.0003

--

Thallium

0.14

mg/kg

»

0.005

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

0.005

~

Uranium

7.7

mg/kg

--

0.01

~

~

~

~

~

0.0000027

--

~

~

~

~

~

~

~

~

~

--

~

~

~

~

~

~

0.01

~

Vanadium

19

mg/kg

--

0.001

~

~

~

~

~

0.0000026

~

~

~

~

--

--

--

~

~

~

~

~

~

~

~

~

~

0.001

~

Exposure Pathway
Risk/Hazard Total

2E-05

0.05

--

2E-04

0.0009

-

3E-09

0.0001

-

-

-

-

-

-

-

--

-

-

-

--

--

--

--

-

2E-04

0.05

-

Subsurface Soil (0-72 inches bgs)

Uranium-238

52

pCi/g

1.7E-06

--

--

1.3E-08

--

--

3.1E-09

~

~

--

--

--

~

~

~

--

--

--

~

~

~

~

~

--

2E-06

--

--

Uranium-234

49

pCi/g

1.8E-06

--

~

2.5E-08

~

~

3.4E-09

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

2E-06

--

~

Thorium-230

3.4

pCi/g

1.4E-07

--

~

5.9E-09

~

~

2.9E-10

--

--

~

~

~

~

~

~

~

~

~

--

--

--

~

~

~

1E-07

--

~

Radium-226 in SE

12

pCi/g

1.7E-05

--

~

2.1E-04

~

~

1.8E-09

~

~

~

~

~

--

--

--

~

~

~

~

~

~

~

~

~

2E-04

--

~

Aluminum

6,600

mg/kg

--

0.002

~

--

~

~

--

0.000018

~

~

~

~

~

~

~

~

~

~

~

~

~

--

--

--

--

0.002

~

Arsenic

5.8

mg/kg

6.4E-07

0.004

»

1.3E-07

0.0008

--

1.2E-10

0.0000053

~

--

--

--

~

~

~

--

--

--

~

~

~

~

~

~

8E-07

0.005

--

Barium

75

mg/kg

--

0.0001

~

--

--

~

~

0.0000021

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

--

0.0001

~

Cadmium

0.093

mg/kg

»

0.0003

~

~

0.00005

~

8.3E-13

0.00000013

--

~

~

~

~

~

~

~

~

~

--

»

»

~

~

~

8E-13

0.0004

~

Chromium

8.1

mg/kg

--

0.0092

~

~

~

~

3.6E-10

0.000019

~

~

~

~

--

--

--

~

~

~

~

~

~

~

~

~

4E-10

0.0090

~

Cobalt

5.2

mg/kg

--

0.006

~

~

~

~

2.3E-10

0.000012

~

~

~

~

~

~

~

~

~

~

~

~

~

--

--

--

2E-10

0.006

~

Copper

10

mg/kg

--

0.0001

~

--

--

--

--

--

~

--

--

--

~

~

~

--

--

--

~

~

~

~

~

~

--

0.00008

--

Iron

15,000

mg/kg

--

0.007

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

0.007

~

Manganese

220

mg/kg

--

0.003

~

~

~

~

--

0.000061

--

~

~

~

~

~

~

~

~

~

--

~

~

~

~

~

~

0.003

~

Molybdenum

0.63

mg/kg

»

0.00004

~

~

~

~

~

0.0000000044

~

~

~

~

--

--

--

~

~

~

~

~

~

~

~

~

~

0.00004

~

Selenium

3.7

mg/kg

--

0.0003

~

~

~

~

~

0.0000000026

~

~

~

~

~

~

~

~

~

~

~

~

~

--

--

--

~

0.0003

~

Thallium

0.14

mg/kg

--

0.005

--

--

--

--

~

--

~

--

--

--

~

~

~

--

--

--

~

~

~

~

~

~

--

0.005

--

Uranium

25

mg/kg

--

0.04

~

~

~

~

~

0.0000086

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

0.04

~

Vanadium

18

mg/kg

--

0.001

~

~

~

~

--

0.0000025

--

~

~

~

~

~

~

~

~

~

--

--

--

~

~

~

~

0.001

~

Exposure Pathway
Risk/Hazard Total

2E-05

0.08

--

2E-04

0.0009

-

9E-09

0.0001

-

-

-

-

-

-

-

--

-

-

-

--

--

--

--

-

2E-04

0.08

-

Page 4 of 6


-------
Table C-6. Human Health Risk and Hazard Summary by Exposure Pathway

Arroyos on the Navajo Nation - Kqq ei doo nahaazah dah (Difficult Access Open Space)

COPC

EPC

Units

Incidental Soil Ingestion

External Exposure /
Dermal Contact

Inhalation of Particulates

Plant Consumption

Animal Consumption

ODL Plant Ingestion

ODL Plant Dermal

ODL Plant Inhalation

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

Cancer
Risk

Adult
Hazard

Child
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

-

pCi/g

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

Uranium-234

-

pCi/g

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

Thorium-230

-

pCi/g

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

Radium-226 in SE

1.3

pCi/g

2.5E-07

-

-

2.5E-06

-

-

6.7E-09

-

-

3.5E-05

-

-

5.3E-07

-

-

2.8E-04

-

-

-

-

-

4.8E-05

-

-

4E-04

-

-

Aluminum

4,700

mg/kg

-

0.000071

0.00044

-

-

-

-

0.00012

0.00012

-

0.0037

0.010

-

0.00034

0.00089

-

0.033

-

-

-

-

-

0.068

-

-

0.1

0.01

Arsenic

11

mg/kg

2.1E-07

0.00034

0.0021

3.0E-07

0.00048

0.0029

6.1E-09

0.00010

0.00010

1.6E-05

0.030

0.081

2.0E-06

0.0037

0.010

1.2E-04

0.28

-

0.000010

0.023

-

3.4E-06

0.057

-

1E-04

0.4

0.1

Barium

74

mg/kg

-

0.0000056

0.000034

-

-

-

-

0.000019

0.000019

-

0.00048

0.0013

-

0.0000048

0.000013

-

0.0052

-

-

-

-

-

0.021

-

-

0.03

0.001

Cadmium

0.064

mg/kg

-

0.000010

0.000060

-

0.000011

0.000064

1.5E-11

0.00000083

0.00000083

-

0.0019

0.0050

-

0.0000070

0.000018

-

0.024

-

-

0.0027

-

4.0E-08

0.0024

-

4E-08

0.03

0.005

Chromium

6.7

mg/kg

1.9E-07

0.000034

0.000208

-

-

-

1.2E-07

0.0000087

0.0000087

6.3E-06

0.0018

0.0048

2.1E-06

0.0006090

0.001624

2.9E-05

0.016

-

-

-

-

4.9E-05

0.0050

-

9E-05

0.02

0.007

Cobalt

4.0

mg/kg

-

0.00020

0.0012

-

-

-

4.7E-09

0.000087

0.000087

-

0.015

0.039

-

0.013

0.036

-

0.15

-

-

-

-

3.6E-06

0.073

-

4E-06

0.2

0.08

Copper

5.1

mg/kg

-

0.0000019

0.000012

-

-

-

-

-

-

-

0.0010

0.0027

-

0.00012

0.00032

-

0.014

-

-

-

-

-

-

-

-

0.02

0.003

Iron

12,000

mg/kg

-

0.00026

0.0016

-

-

-

-

-

-

-

0.014

0.036

-

0.016

0.043

-

0.12

-

-

-

-

-

-

-

-

0.2

0.08

Manganese

200

mg/kg

-

0.00013

0.00078

-

-

-

-

0.00052

0.00052

-

0.043

0.12

-

0.00028

0.00075

-

0.57

-

-

-

-

-

2.8

-

-

3

0.1

Molybdenum

0.81

mg/kg

-

0.0000024

0.000015

-

-

-

-

0.000000053

0.000000053

-

0.00083

0.0023

-

0.000075

0.00019

-

0.0110

-

-

-

-

-

0.00028

-

-

0.01

0.002

Selenium

1.5

mg/kg

-

0.0000045

0.000028

-

-

-

-

0.000000010

0.000000010

-

0.00033

0.00084

-

0.000045

0.00012

-

0.0033

-

-

-

-

-

0.0000083

-

-

0.004

0.001

Thallium

0.092

mg/kg

-

0.00014

0.00086

-

-

-

-

-

-

-

0.0067

0.018

-

0.017

0.047

-

0.057

-

-

-

-

-

-

-

-

0.08

0.07

Uranium

2.9

mg/kg

-

0.000218

0.00135

-

-

-

-

0.0000094

0.0000094

-

0.0126

0.0334

-

0.000203

0.00054

-

0.12

-

-

-

-

-

0.0060

-

-

0.10

0.040

Vanadium

25

mg/kg

-

0.000075

0.00047

-

-

-

-

0.000033

0.000033

-

0.0041

0.011

-

0.00060

0.0016

-

0.037

-

-

-

-

-

0.019

-

-

0.06

0.01

Exposure Pathway
Risk/Hazard Total

7E-07

0.001

0.009

3E-06

0.0005

0.003

1E-07

0.000895

0.000895

6E-05

0.1

0.4

5E-06

0.05

0.1

4E-04

1

-

1E-05

0.03

-

1E-04

3

-

6E-04

5

0.5

Subsurface Soil (0-36 inches bgs)

Uranium-238

-

pCi/g

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

Uranium-234

-

pCi/g

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

Thorium-230

-

pCi/g

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

Radium-226 in SE

1.5

pCi/g

2.9E-07

-

-

2.9E-06

-

-

3.0E-11

-

-

4.0E-05

-

-

6.1E-07

-

-

3.2E-04

-

-

-

-

-

5.5E-05

-

-

4E-04

-

-

Aluminum

4,700

mg/kg

-

0.000071

0.00044

-

-

-

-

0.00000049

0.00000049

-

0.0037

0.010

-

0.00034

0.00089

-

0.033

-

-

-

-

-

0.068

-

-

0.1

0.01

Arsenic

11

mg/kg

2.1E-07

0.00034

0.0021

3.0E-07

0.00048

0.0029

2.5E-11

0.00000038

0.00000038

1.6E-05

0.030

0.081

2.0E-06

0.0037

0.010

1.2E-04

0.28

-

0.000010

0.023

-

3.4E-06

0.057

-

1E-04

0.4

0.1

Barium

75

mg/kg

-

0.0000056

0.000035

-

-

-

-

0.000000078

0.000000078

-

0.00049

0.0013

-

0.0000049

0.000013

-

0.0053

-

-

-

-

-

0.021

-

-

0.03

0.001

Cadmium

0.073

mg/kg

-

0.000011

0.000068

-

0.000012

0.000073

6.8E-14

0.0000000038

0.0000000038

-

0.0021

0.0057

-

0.0000080

0.000020

-

0.027

-

-

0.0031

-

4.6E-08

0.0028

-

5E-08

0.03

0.006

Chromium

6.7

mg/kg

1.9E-07

0.000034

0.000208

-

-

-

4.7E-10

0.000000035

0.000000035

6.3E-06

0.0018

0.0048

2.1E-06

0.0006090

0.001624

2.9E-05

0.016

-

-

-

-

4.9E-05

0.0050

-

9E-05

0.02

0.007

Cobalt

4.5

mg/kg

-

0.00023

0.0014

-

-

-

2.1E-11

0.00000039

0.00000039

-

0.017

0.044

-

0.015

0.041

-

0.17

-

-

-

-

4.1E-06

0.083

-

4E-06

0.3

0.09

Copper

5.1

mg/kg

-

0.0000019

0.000012

-

-

-

-

-

-

-

0.0010

0.0027

-

0.00012

0.00032

-

0.014

-

-

-

-

-

-

-

-

0.02

0.003

Iron

15,000

mg/kg

-

0.00032

0.0020

-

-

-

-

-

-

-

0.017

0.045

-

0.020

0.054

-

0.15

-

-

-

-

-

-

-

-

0.2

0.1

Manganese

400

mg/kg

-

0.00025

0.0016

-

-

-

-

0.0000042

0.0000042

-

0.085

0.23

-

0.00057

0.0015

-

1.1

-

-

-

-

-

5.6

-

-

7

0.2

Molybdenum

0.81

mg/kg

-

0.0000024

0.000015

-

-

-

-

0.00000000021

0.00000000021

-

0.00083

0.0023

-

0.000075

0.00019

-

0.011

-

-

-

-

-

0.00028

-

-

0.01

0.002

Selenium

1.5

mg/kg

-

0.0000045

0.000028

-

-

-

-

0.000000000039

0.000000000039

-

0.00033

0.00084

-

0.000045

0.00012

-

0.0033

-

-

-

-

-

0.0000083

-

-

0.004

0.001

Thallium

0.092

mg/kg

-

0.00014

0.00086

-

-

-

-

-

-

-

0.0067

0.018

-

0.017

0.047

-

0.057

-

-

-

-

-

-

-

-

0.08

0.07

Uranium

2.9

mg/kg

-

0.000218

0.00135

-

-

-

-

0.0000000377

0.0000000377

-

0.0126

0.0334

-

0.000203

0.00054

-

0.117

-

-

-

-

-

0.0060

-

-

0.10

0.040

Vanadium

25

mg/kg

-

0.000075

0.00047

-

-

-

-

0.00000013

0.00000013

-

0.0041

0.011

-

0.00060

0.0016

-

0.037

-

-

-

-

-

0.019

-

-

0.06

0.01

Exposure Pathway
Risk/Hazard Total

7E-07

0.002

0.010

3E-06

0.0005

0.003

5E-10

0.000006

0.000006

6E-05

0.2

0.5

5E-06

0.06

CM

o

5E-04

o

-

1E-05

0.03

-

1E-04

6

-

6E-04

8

0.7

Page 5 of 6


-------
Table C-6. Human Health Risk and Hazard Summary by Exposure Pathway

Arroyos on United Nuclear Corporation Property - UNC Outdoor Worker

COPC

EPC

Units

Incidental Soil Ingestion

External Exposure /
Dermal Contact

Inhalation of Particulates

Plant Consumption

Animal Consumption

ODL Plant Ingestion

ODL Plant Dermal

ODL Plant Inhalation

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

Cancer
Risk

Adult
Hazard

Child
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

--

pCi/g

--

--

--

--

--

--

--

--

--

--

--

--

--

~

~

--

--

--

--

--

--

--

--

--

--

--

--

Uranium-234

--

pCi/g

--

~

--

--

~

~

--

~

--

~

~

~

--

--

--

~

~

~

--

~

~

~

~

~

--

~

--

Thorium-230

--

pCi/g

--

~

--

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

--

--

--

~

~

--

Radium-226 in SE

1.3E+00

pCi/g

1.6E-06

»

»

1.9E-05

»

--

1.6E-10

~

~

--

--

--

~

~

~

»

--

--

~

~

~

~

~

~

2E-05

--

-

Aluminum

4.7E+03

mg/kg

--

0.0015

~

--

~

~

~

0.000012

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

--

0.002

--

Arsenic

1.1E+01

mg/kg

5.1E-07

0.0032

~

1.1E-07

0.00067

~

9.8E-11

0.0000042

--

~

~

~

~

~

~

~

~

~

--

»

»

~

~

~

6E-07

0.004

»

Barium

7.4E+01

mg/kg

--

0.000082

~

~

~

~

--

0.0000013

~

~

~

~

--

--

--

~

~

~

~

~

~

~

~

~

~

0.00008

~

Cadmium

6.4E-02

mg/kg

--

0.00018

~

~

0.000031

~

4.8E-13

0.000000075

~

~

~

~

~

~

~

~

~

~

~

~

~

--

--

--

5E-13

0.0002

~

Chromium

6.7E+00

mg/kg

--

0.00571

--

--

~

--

2.2E-10

0.000012

~

--

--

--

~

~

~

~

--

--

~

~

~

~

~

~

2E-10

0.0060

~

Cobalt

4.0E+00

mg/kg

»

0.0050

-

~

~

~

2.0E-10

0.000010

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

2E-10

0.005

~

Copper

5.1E+00

mg/kg

--

0.000040

~

~

~

~

--

--

--

~

~

~

~

~

~

~

~

~

--

~

~

~

~

~

--

0.00004

~

Iron

1.2E+04

mg/kg

--

0.0064

~

~

~

~

~

»

~

~

~

~

--

--

--

~

~

~

~

~

~

~

~

~

~

0.006

~

Manganese

2.0E+02

mg/kg

--

0.0034

~

~

~

~

~

0.000066

~

~

~

~

~

~

~

~

~

~

~

~

~

--

--

--

~

0.003

~

Molybdenum

8.1E-01

mg/kg

»

0.000019

»

»

»

--

~

0.0000000019

~

--

--

--

~

~

~

»

--

--

~

~

~

~

~

~

--

0.00002

»

Selenium

1.5E+00

mg/kg

--

0.000075

~

~

~

~

~

0.00000000076

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

0.00008

~

Thallium

9.2E-02

mg/kg

»

0.0020

~

~

~

~

»

~

--

~

~

~

~

~

~

~

~

~

--

»

»

~

~

~

~

0.002

~

Uranium

2.9E+00

mg/kg

--

0.00016

~

~

~

~

~

0.000000031

~

~

~

~

--

--

--

~

~

~

~

~

~

~

~

~

~

0.0002

~

Vanadium

2.5E+01

mg/kg

--

0.000036

~

~

~

~

~

0.000000073

~

~

~

~

~

~

~

~

~

~

~

~

~

--

--

--

~

0.0000

~

Exposure Pathway
Risk/Hazard Total

2E-06

0.03

--

2E-05

0.0007

-

7E-10

0.00011

-

-

-

-

-

-

-

--

-

-

-

--

--

--

--

-

2E-05

0.03

--

Subsurface Soil (0-36 inches bgs)

Uranium-238

--

pCi/g

--

--

~

~

~

--

~

~

~

--

--

--

~

~

~

~

--

--

~

~

~

~

~

~

~

--

~

Uranium-234

--

pCi/g

--

--

~

~

~

~

~

--

--

~

~

~

~

~

~

~

~

~

--

~

~

~

~

~

~

--

~

Thorium-230

--

pCi/g

--

~

~

~

~

~

~

~

~

~

~

~

--

--

--

~

~

~

~

~

~

~

~

~

~

--

~

Radium-226 in SE

1.5E+00

pCi/g

1.6E-06

~

~

1.9E-05

~

~

1.6E-10

~

~

~

~

~

~

~

~

~

~

~

~

~

~

--

--

--

2E-05

~

~

Aluminum

4.7E+03

mg/kg

--

0.0016

--

--

--

--

~

0.000013

~

--

--

--

~

~

~

--

--

--

~

~

~

~

~

~

~

0.002

--

Arsenic

1.1E+01

mg/kg

5.3E-07

0.0033

~

1.1E-07

0.00069

~

1.0E-10

0.0000044

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

6E-07

0.004

~

Barium

7.5E+01

mg/kg

--

0.00011

~

~

~

~

--

0.0000017

--

~

~

~

~

~

~

~

~

~

--

--

--

~

~

~

~

0.0001

~

Cadmium

7.3E-02

mg/kg

»

0.00019

~

~

0.000032

~

4.9E-13

0.000000076

~

~

~

~

--

-

--

~

~

~

~

~

~

~

~

~

5E-13

0.0002

~

Chromium

6.7E+00

mg/kg

--

0.00571

~

~

~

~

2.2E-10

0.000011514

~

~

~

~

~

--

~

~

~

~

~

~

~

--

--

--

2E-10

0.0060

~

Cobalt

4.5E+00

mg/kg

»

0.0050

»

»

»

--

2.0E-10

0.000010

~

--

--

--

~

~

~

»

--

--

~

~

~

~

~

~

2E-10

0.005

»

Copper

5.1E+00

mg/kg

--

0.000046

~

~

~

~

~

--

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

0.00005

~

Iron

1.5E+04

mg/kg

~

0.0073

~

~

~

~

--

--

--

~

~

~

~

~

~

~

~

~

--

--

--

~

~

~

~

0.007

~

Manganese

4.0E+02

mg/kg

~

0.0040

~

~

~

~

~

0.000077

~

~

~

~

--

--

--

~

~

~

~

~

~

~

~

~

~

0.004

~

Molybdenum

8.1E-01

mg/kg

~

0.000019

~

~

~

~

~

0.0000000019

~

~

~

~

~

~

~

~

~

~

~

~

~

--

--

--

~

0.00002

~

Selenium

1.5E+00

mg/kg

--

0.000075

~

~

~

--

~

0.00000000076

~

--

--

--

~

~

~

~

--

--

~

~

~

~

~

~

--

0.00008

~

Thallium

9.2E-02

mg/kg

~

0.0020

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

~

0.002

~

Uranium

2.9E+00

mg/kg

~

0.00016

~

~

~

~

--

0.000000031

--

~

~

~

~

~

~

~

~

~

--

--

--

~

~

~

~

0.0002

~

Vanadium

2.5E+01

mg/kg

~

0.000042

~

~

~

~

~

0.000000086

~

~

~

~

--

--

--

~

~

~

~

~

~

~

~

~

~

0.00004

~

Exposure Pathway
Risk/Hazard Total

2E-06

0.03

--

2E-05

0.0007

-

7E-10

0.0001

-

-

-

-

-

-

-

--

-

-

-

--

--

--

--

-

2E-05

0.03

--

Notes:

Not applicable

bgs	Below ground surface

COPC	Contaminant of potential concern

EPC	Exposure point concentration

Kerr-McGee	Kerr-McGee Corporation

mg/kg	Milligram per kilogram

ODL	Other Dine Lifeways

pCi/g	Picocurie per gram

SE	Secular equilibrium

Page 6 of 6


-------
Table C-7: Human Health Risk and Hazard Summary and Identification of Candidate

Contaminants of Concern

Church Rock Mine No. 1 - Kee'da'whii teeh (Full-Time Resident)

COPC3

Units

Exposure Point
Concentration

Cancer
Riskbcd

Noncancer Hazardbd e f

Adult Child

Surface Soil (0-6 inches bgs)

Radionuclides9

Uranium-238

pCi/g

1.1

2.5E-05

—

--

Uranium-234

pCi/g

1.2

3.1E-05

—

--

Thorium-230

pCi/g

1.7

7.1E-05

—

--

Radium-226 in SE

pCi/g

6.7

1.3E-02

—

--

Radionuclide Total

1E-02

—

--

Metals h

Aluminum

mg/kg

4,600

--

0.18

0.27

Arsenic

mg/kg

4.9

2.0E-04

0.44

0.86

Barium

mg/kg

110

--

0.056

0.048

Cadmium

mg/kg

0.14

9.3E-08

0.16

0.27

Chromium

mg/kg

6.0

2.2E-04

0.054

0.13

Cobalt

mg/kg

6.10

6.0E-06

0.99

2.0

Copper

mg/kg

12

—

0.088

0.15

Iron

mg/kg

11,000

—

0.51

1.3

Manganese

mg/kg

160

—

3.6

2.1

Molybdenum

mg/kg

0.32

—

0.012

0.021

Selenium

mg/kg

3.4

—

0.075

0.19

Thallium

mg/kg

0.14

—

0.54

1.4

Uranium

mg/kg

7.3

—

0.96

2.3

Vanadium

mg/kg

14

—

0.080

0.17

Metal Total

4E-04

8

10

Cumulative Risk/Hazard Total

1E-02

8

10

Subsurface Soil (0-72 inches bgs)

Radionuclides9

Uranium-238

pCi/g

1.1

2.5E-05

—

"

Uranium-234

pCi/g

1.2

3.1E-05

—

"

Thorium-230

pCi/g

1.7

7.1E-05

—

"

Radium-226 in SE

pCi/g

17

3.3E-02

—

"

Radionuclide Total

3E-02

—

"

Metals h





Aluminum

mg/kg

4,600

--

0.18

0.27

Arsenic

mg/kg

4.8

1.9E-04

0.43

0.84

Barium

mg/kg

110

--

0.06

0.05

Cadmium

mg/kg

0.14

9.3E-08

0.16

0.27

Chromium

mg/kg

6.0

2.2E-04

0.054

0.13

Cobalt

mg/kg

6.1

6.0E-06

0.99

2.0

Copper

mg/kg

12

—

0.09

0.15

Iron

mg/kg

11,000

—

0.51

1.3

Manganese

mg/kg

160

—

3.59

2.1

Molybdenum

mg/kg

0.32

—

0.012

0.021

Selenium

mg/kg

3.1

—

0.068

0.18

Thallium

mg/kg

0.14

—

0.54

1.4

Uranium

mg/kg

7.3

—

0.96

2.3

Vanadium

mg/kg

14

—

0.08

0.17

Metal Total

4E-04

8

10

Cumulative Risk/Hazard Total

3E-02

8

10

Page 1 of 7


-------
Table C-7: Human Health Risk and Hazard Summary and Identification of Candidate

Contaminants of Concern

Church Rock Mine No. 1 East - Kee'da'whii teeh (Full-Time Resident)

COPC3

Units

Exposure Point
Concentration

Cancer
Riskbod

Noncancer Hazardb d 8

Adult Child

Surface Soil (0-6 inches bgs)

Radionuclides9

Uranium-238

pCi/g

1.3

3.0E-05

—

"

Uranium-234

pCi/g

1.4

3.6E-05

—

"

Thorium-230

pCi/g

3.6

2.3E-05

—

"

Radium-226 in SE

pCi/g

9.3

1.8E-02

—

"

Radionuclide Total

2E-02

—

"

Metals h

Aluminum

mg/kg

6,300

--

0.24

0.37

Arsenic

mg/kg

6.6

2.7E-04

0.59

1.2

Barium

mg/kg

160

--

0.082

0.070

Cadmium

mg/kg

0.13

8.7E-08

0.15

0.25

Chromium

mg/kg

10

3.7E-04

0.10

0.22

Cobalt

mg/kg

6.9

6.8E-06

1.1

2.3

Copper

mg/kg

13

—

0.10

0.16

Iron

mg/kg

16,000

—

0.74

1.9

Manganese

mg/kg

200

—

4.5

2.6

Molybdenum

mg/kg

0.31

—

0.012

0.020

Selenium

mg/kg

3.0

—

0.066

0.17

Thallium

mg/kg

0.16

—

0.62

1.6

Uranium

mg/kg

3.6

—

0.47

1.1

Vanadium

mg/kg

16

—

0.092

0.20

Metal Total

6E-04

8

10

Cumulative Risk/Hazard Total

2E-02

8

10

Subsurface Soil (0-72 inches bgs)

Radionuclides9

Uranium-238

pCi/g

1.3

3.0E-05

—

"

Uranium-234

pCi/g

1.4

3.6E-05

—

"

Thorium-230

pCi/g

3.6

2.3E-05

—

"

Radium-226 in SE

pCi/g

43

8.3E-02

—

"

Radionuclide Total

8E-02

—

"

Metals h

Aluminum

mg/kg

6,300

--

0.24

0.37

Arsenic

mg/kg

6.3

2.5E-04

0.56

1.1

Barium

mg/kg

160

--

0.082

0.070

Cadmium

mg/kg

0.13

8.7E-08

0.15

0.25

Chromium

mg/kg

10

3.7E-04

0.10

0.2

Cobalt

mg/kg

6.9

6.8E-06

1.1

2.3

Copper

mg/kg

13

—

0.10

0.16

Iron

mg/kg

16,000

—

0.74

1.9

Manganese

mg/kg

200

—

4.5

2.6

Molybdenum

mg/kg

0.51

—

0.020

0.033

Selenium

mg/kg

5.4

—

0.12

0.31

Thallium

mg/kg

0.16

—

0.62

1.6

Uranium

mg/kg

42

—

5.5

13

Vanadium

mg/kg

18

—

0.10

0.22

Metal Total

6E-04

10

20

Cumulative Risk/Hazard Total

8E-02

10

20

Page 2 of 7


-------
Table C-7: Human Health Risk and Hazard Summary and Identification of Candidate

Contaminants of Concern

Kerr-McGee Ponds on the Navajo Nation - Kee'da'whii teeh (Full-Time Resident)

COPC3

Units

Exposure Point
Concentration

Cancer
Riskbcd

Noncancer Hazardb d 8

Adult Child

Surface Soil (0-6 inches bgs)

Radionuclides9

Uranium-238

pCi/g

1.1

2.5E-05

—

--

Uranium-234

pCi/g

1.0

2.5E-05

—

--

Thorium-230

pCi/g

2.0

1.3E-05

—

--

Radium-226 in SE

pCi/g

9.3

1.8E-02

—

--

Radionuclide Total

2E-02

—

--

Metals h

Aluminum

mg/kg

6,900

--

0.27

0.41

Arsenic

mg/kg

5.9

2.4E-04

0.52

1.0

Barium

mg/kg

82

--

0.042

0.036

Cadmium

mg/kg

0.16

1.1E-07

0.18

0.31

Chromium

mg/kg

8.2

3.0E-04

0.078

0.18

Cobalt

mg/kg

5.2

5.2E-06

0.85

1.7

Copper

mg/kg

11

—

0.081

0.14

Iron

mg/kg

15,000

—

0.70

1.7

Manganese

mg/kg

230

-

5.2

3.0

Molybdenum

mg/kg

0.55

-

0.021

0.036

Selenium

mg/kg

2.9

—

0.064

0.16

Thallium

mg/kg

0.15

—

0.58

1.5

Uranium

mg/kg

6.2

—

0.81

1.9

Vanadium

mg/kg

17

—

0.10

0.21

Metal Total

5E-04

9

10

Cumulative Risk/Hazard Total

2E-02

9

10

Subsurface Soil (0-66 inches bgs)

Radionuclides9

Uranium-238

pCi/g

1.1

2.5E-05

—

"

Uranium-234

pCi/g

1.0

2.5E-05

—

"

Thorium-230

pCi/g

2.0

1.3E-05

—

"

Radium-226 in SE

pCi/g

9.3

1.8E-02

—

"

Radionuclide Total

2E-02

—

"

Metals h

Aluminum

mg/kg

6,900

--

0.27

0.41

Arsenic

mg/kg

5.9

2.4E-04

0.52

1.0

Barium

mg/kg

82

--

0.04

0.036

Cadmium

mg/kg

0.16

1.1E-07

0.18

0.31

Chromium

mg/kg

8.2

3.0E-04

0.078

0.18

Cobalt

mg/kg

5.2

5.2E-06

0.85

1.7

Copper

mg/kg

11

—

0.081

0.14

Iron

mg/kg

15,000

—

0.70

1.7

Manganese

mg/kg

230

—

5.2

3.0

Molybdenum

mg/kg

0.55

—

0.021

0.036

Selenium

mg/kg

2.9

—

0.064

0.16

Thallium

mg/kg

0.15

—

0.58

1.5

Uranium

mg/kg

6.2

—

0.81

1.9

Vanadium

mg/kg

17

—

0.10

0.21

Metal Total

5E-04

9

10

Cumulative Risk/Hazard Total

2E-02

9

10

Page 3 of 7


-------
Table C-7: Human Health Risk and Hazard Summary and Identification of Candidate

Contaminants of Concern

Kerr-McGee Ponds on United Nuclear Corporation Property

COPC3

Units

Exposure Point
Concentration

Cancer
RiskbGd

Noncancer Hazardb d 8

Adult Child

Surface Soil (0-6 inches bgs)

Radionuclides9

Uranium-238

pCi/g

2.4

8.1E-08

—

—

Uranium-234

pCi/g

2.4

9.0E-08

—

—

Thorium-230

pCi/g

3.4

1.5E-07

—

—

Radium-226 in SE

pCi/g

13

2.4E-04

—

—

Radionuclide Total

2E-04

—

—

Metals h

Aluminum

mg/kg

6,600

--

0.0023

--

Arsenic

mg/kg

6.0

8.0E-07

0.0050

—

Barium

mg/kg

83

—

0.00014

—

Cadmium

mg/kg

0.11

9.8E-13

0.0004

—

Chromium

mg/kg

8.5

3.8E-10

0.0097

—

Cobalt

mg/kg

5.2

2.3E-10

0.0059

—

Copper

mg/kg

11

—

0.000094

—

Iron

mg/kg

15,000

—

0.0073

—

Manganese

mg/kg

220

—

0.0032

—

Molybdenum

mg/kg

0.57

—

0.000039

—

Selenium

mg/kg

4.0

—

0.00027

—

Thallium

mg/kg

0.14

—

0.0048

—

Uranium

mg/kg

7.7

—

0.013

—

Vanadium

mg/kg

19

—

0.0013

—

Metal Total

8E-07

0.05

—

Cumulative Risk/Hazard Total

2E-04

0.05

—

Subsurface Soil (0-72 inches bgs)

Radionuclides9

Uranium-238

pCi/g

52

1.8E-06

—

—

Uranium-234

pCi/g

49

1.8E-06

—

—

Thorium-230

pCi/g

3.4

1.5E-07

—

—

Radium-226 in SE

pCi/g

12

2.2E-04

—

—

Radionuclide Total

2E-04

—

—

Metals h

Aluminum

mg/kg

6,600

--

0.0023

--

Arsenic

mg/kg

5.8

7.7E-07

0.0048

—

Barium

mg/kg

75

—

0.00013

—

Cadmium

mg/kg

0.093

8.3E-13

0.00037

—

Chromium

mg/kg

8.1

3.6E-10

0.0093

—

Cobalt

mg/kg

5.2

2.3E-10

0.0059

—

Copper

mg/kg

10

—

0.000084

—

Iron

mg/kg

15,000

—

0.0073

—

Manganese

mg/kg

220

—

0.0032

—

Molybdenum

mg/kg

0.63

—

0.000043

—

Selenium

mg/kg

3.7

—

0.00025

—

Thallium

mg/kg

0.14

—

0.0048

—

Uranium

mg/kg

25

—

0.043

—

Vanadium

mg/kg

18

—

0.0012

—

Metal Total

8E-07

0.08

—

Cumulative Risk/Hazard Total

2E-04

0.08

--

Page 4 of 7


-------
Table C-7: Human Health Risk and Hazard Summary and Identification of Candidate

Contaminants of Concern

Arroyos ori the Navajo Nation

COPCa

Units

Exposure Point
Concentration

Cancer
Riskbcd

Noncancer Hazardb d 8

Adult Child

Surface Soil (0-6 inches bgs)

Radionuclides9

Uranium-238

pCi/g

--

--

--

--

Uranium-234

pCi/g

--

--

--

--

Thorium-230

pCi/g

--

--

--

--

Radium-226 in SE

pCi/g

1.3

3.6E-04

—

--

Radionuclide Total

4E-04



--

Metals h

Aluminum

mg/kg

4,700

--

0.10

0.011

Arsenic

mg/kg

11

1.5E-04

0.39

0.096

Barium

mg/kg

74

--

0.026

0.0013

Cadmium

mg/kg

0.064

4.0E-08

0.031

0.0051

Chromium

mg/kg

6.7

8.7E-05

0.024

0.0066

Cobalt

mg/kg

4.0

3.6E-06

0.25

0.076

Copper

mg/kg

5.1

—

0.015

0.0030

Iron

mg/kg

12,000

—

0.15

0.080

Manganese

mg/kg

200

—

3.4

0.12

Molybdenum

mg/kg

0.81

—

0.012

0.0025

Selenium

mg/kg

1.5

—

0.0037

0.0010

Thallium

mg/kg

0.09

—

0.081

0.066

Uranium

mg/kg

2.9

—

0.14

0.035

Vanadium

mg/kg

25

—

0.061

0.013

Metal Total

2E-04

5

0.5

Cumulative Risk/Hazard Total

6E-04

5

0.5

Subsurface Soil (0-36 inches bgs)

Radionuclides9

Uranium-238

pCi/g

--

--

--

--

Uranium-234

pCi/g

--

--

--

--

Thorium-230

pCi/g

--

--

--

--

Radium-226 in SE

pCi/g

1.5

3.6E-04

—

--

Radionuclide Total

4E-04

—

--

Metals h

Aluminum

mg/kg

4,700

--

0.10

0.011

Arsenic

mg/kg

11

1.5E-04

0.39

0.095

Barium

mg/kg

75

--

0.027

0.001

Cadmium

mg/kg

0.073

4.6E-08

0.035

0.006

Chromium

mg/kg

6.7

8.7E-05

0.024

0.0066

Cobalt

mg/kg

4.5

4.1E-06

0.28

0.085

Copper

mg/kg

5.1

--

0.02

0.003

Iron

mg/kg

15,000

--

0.19

0.101

Manganese

mg/kg

400

--

6.82

0.236

Molybdenum

mg/kg

0.81

--

0.01

0.002

Selenium

mg/kg

1.5

--

0.00

0.001

Thallium

mg/kg

0.092

--

0.08

0.066

Uranium

mg/kg

2.9

--

0.14

0.035

Vanadium

mg/kg

25

--

0.06

0.013

Metal Total

2E-04

8

0.7

Cumulative Risk/Hazard Total

6E-04

8

0.7

Page 5 of 7


-------
Table C-7: Human Health Risk and Hazard Summary and Identification of Candidate

Contaminants of Concern

Arroyos on United Nuclear Corporation Property

COPCa

Units

Exposure Point
Concentration

Cancer
Riskbcd

Noncancer Hazardb d 8

Adult Child

Surface Soil (0-6 inches bgs)

Radionuclides 9

Uranium-238

pCi/g

--

—

—

—

Uranium-234

pCi/g

--

—

—

—

Thorium-230

pCi/g

--

—

—

—

Radium-226 in SE

pCi/g

1.1

2.0E-05

—

—

Radionuclide Total

2E-05



—

Metals h

Aluminum

mg/kg

4,400

—

0.0015

--

Arsenic

mg/kg

4.6

6.1E-07

0.0038

—

Barium

mg/kg

48

—

0.00008

—

Cadmium

mg/kg

0.054

4.8E-13

0.00022

—

Chromium

mg/kg

5.0

2.2E-10

0.0057

—

Cobalt

mg/kg

4.4

2.0E-10

0.0050

—

Copper

mg/kg

4.7

—

0.000040

—

Iron

mg/kg

13,000

—

0.0064

—

Manganese

mg/kg

240

—

0.0035

—

Molybdenum

mg/kg

0.28

—

0.000019

—

Selenium

mg/kg

1.1

—

0.000075

—

Thallium

mg/kg

0.057

—

0.0020

—

Uranium

mg/kg

0.091

—

0.00016

—

Vanadium

mg/kg

0.53

—

0.000036

—

Metal Total

6E-07

0.03

—

Cumulative Risk/Hazard Total

// Oh

0.03

--

Subsurface Soil (0-18 inches bgs)

Radionuclides9

Uranium-238

pCi/g

--

—

—

—

Uranium-234

pCi/g

--

—

—

—

Thorium-230

pCi/g

--

—

—

—

Radium-226 in SE

pCi/g

1.1

2.0E-05

—

—

Radionuclide Total

2E-05

—

—

Metals h

Aluminum

mg/kg

4,700

—

0.0015

--

Arsenic

mg/kg

4.8

6.4E-07

0.0038

—

Barium

mg/kg

62

—

0.000084

—

Cadmium

mg/kg

0.055

4.9E-13

0.00022

—

Chromium

mg/kg

5.0

2.2E-10

0.0057

—

Cobalt

mg/kg

4.4

2.0E-10

0.0050

—

Copper

mg/kg

5.4

—

0.000040

—

Iron

mg/kg

15,000

—

0.0064

—

Manganese

mg/kg

280

—

0.0035

—

Molybdenum

mg/kg

0.28

—

0.000019

—

Selenium

mg/kg

1.1

—

0.000075

—

Thallium

mg/kg

0.059

—

0.0020

—

Uranium

mg/kg

0.091

—

0.00016

—

Vanadium

mg/kg

0.62

—

0.000036

—

Metal Total

6E-07

0.03

—

Cumulative Risk/Hazard Total

2E-05

0.03

~

Page 6 of 7


-------
Table C-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 or equal to 1E-04 and less than 1 in 1 million [1E-06]).

b Bolded values are values greater than the target cancer risk of one in ten thousand (1E-04) or noncancer target
hazard of 1. Italicized values are within the USEPA's acceptable cancer risk range (cancer risk greater or equal to
1E-04 and less than 1E-06). 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. Target organ analyses were performed for any scenario-media combination with
a noncancer hazard greater than 1. If the target organ exceeds hazard index exceeds 1 but no individual COPC
has a hazard exceeding 1, the COPC contributing the highest amount of hazard was identified as a candidate
COC.

c Cancer risks are provided on Table C-5.1 through Table C-5.6.

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" (USEPA 2024b).

e Noncancer hazards are presented on Table C-5.1 through Table C-5.6.

f Thallium was retained as a candidate COC because the target organ analysis resulted in a hazard index of 3 for the dermal
target organ and thallium has the highest contribution to the target organ HI as follows:

Metal

Target Organ(s)

Adult Target Organ HI

Aluminum

Nervous

-

-

Nervous

4

Arsenic

Cardiovascular

Dermal

-

Dermal

1

Barium

Urinary

-

-

Urinary

2

Cadmium

Urinary

-

-

Gastrointestinal

1

Cobalt

Endocrine

-

-



Copper

Gastrointestinal

-

-

Child Target Organ HI

Iron

Gastrointestinal

-

-

Nervous

3

Manganese

Nervous

-

-

Dermal

3

Molybdenum

Urinary

-

-

Urinary

5

Selenium

Dermal

Hematologic

Nervous

Gastrointestinal

1

Thallium

Dermal

-

-





Uranium

Urinary

-

-





Vanadium

Urinary

Dermal

-





g For radionuclides, uranium-238 is assumed to be in secular equilibrium 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 secular equilibrium) will account for most of the risk from the uranium-238 decay chain.
" In the absence of speciated chromium data, chromium is evaluated using the assumption that it is 100 percent
hexavalent chromium (USEPA 2024b). No speciated chromium data are available.

-

Not applicable

bgs

Below ground surface

COC

Contaminant of concern

COPC

Contaminant of potential concern

EU

Exposure unit

HI

Hazard index

Kerr-McGee

Kerr-McGee Corporation

mg/kg

Milligram per kilogram

pCi/g

Picocurie per gram

SE

Secular equilbrium

USEPA

U.S. Environmental Protection Agency

Reference:

U.S. Environmental Protection Agency (USEPA). 2024b. "Navajo Abandoned Uranium Mines Risk Assessment
Methodology." Draft Final. March.

Page 7 of 7


-------
Table C-8. Ecological Risk Assessment Screening for Soil

Constituent of Interest3

Detection
Frequency13

Maximum
Detected
Concentration13

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) 8

Uranium-238

41 / 160

52.1

50

13,000

2,700

2,700

2,700

1,400

1,400

1,400

50

1.0

Yes

Uranium-234

24 / 24

49.4

44

12,000

2,800

2,800

2,800

1,400

1,400

1,400

44

1.1

Yes

Thorium-230

41 / 41

92

110

37,000

8,700

8,700

8,700

3,700

3,700

3,700

110

0.84

No

Radium-226 in SE
(Adjusted Radium-226)

797 / 797

468

5.0

240

15

15

15

6.0

6.0

6.0

5.0

94

Yes

Metals (mq/kq) f 9







Aluminum

126 / 126

9,600

NSL

NSL

NSL

NSL

NSL

NSL

NSL

NSL

NSL

NSL

No

Antimony

125 / 126

0.26

11

78

NSL

NSL

NSL

10

0.27

4.9

0.27

0.96

No

Arsenic

175 / 175

11

18

6J3

67

43

1,100

170

46

170

6.8

1.6

Yes

Barium

169 / 169

420

110

330

720

820

7.500

3,200

200

9,100

110

3.8

Yes

Beryllium

126 / 126

1.0

2j5

40

NSL

NSL

NSL

21

34

90

2.5

0.40

No

Cadmium

154 / 169

0.3

32

140

28

0.77

630

73

0.36

84

0.36

0.69

No

Chromium h

169 / 169

24

0.35

0.34

78

26

780

380

34

180

0.3

71

Yes

Cobalt

126 / 126

10

13

NSL

270

120

1,300

2,100

230

470

13

0.77

No

Copper

126 / 126

21

70

80

76

28

1,600

1,100

49

560

28

0.75

No

Iron

126 / 126

23,000

NSL

NSL

NSL

NSL

NSL

NSL

NSL

NSL

NSL

NSL

No

Lead

169 / 169

130

120

1,700

46

11

510

1,200

56

460

11

12

Yes

Manganese

126 / 126

400

220

450

4,300

4,300

650,000

5,300

4,000

6,200

220

1.8

Yes

Molybdenum IJ

165 / 175

1.8

2

NSL

18

15

90

635

4.8

64

2

0.90

No

Nickel

126 / 126

20

38

280

210

20

2,800

340

10

130

10

2.0

Yes

Selenium

170 / 175

37

0.52

4.1

2.2

1.2

83

2.7

0.63

2.8

0.52

71

Yes

Silver

29 / 169

0.19

560

NSL

69

4.2

930

1,500

14

990

4.2

0.045

No

Thallium

126 / 126

0.22

0.050

NSL


-------
Table C-8. Ecological Risk Assessment Screening for Soil

Notes (Continued):
bgs

Below ground surface

Contaminant of potential ecological concern
Ecological soil screening level

Environmental Risk from Ionizing Contaminants: Assessment and Management
Ecological screening level
Hazard quotient

Los Alamos National Laboratory

mg/kg

N3B

NOEC

Milligram per kilogram

Newport News Nuclear BWXT-Los Alamos, LLC
No observed effect concentration
No screening level
Picocurie per gram
Secular equilibrium

U.S. Environmental Protection Agency

COPEC
Eco-SSL
ERICA
ESL

NSL

pCi/g

SE

HQ
LANL

USEPA

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). 2023a. "Interim Ecological Soil Screening Level Documents." Accessed July 20. https://www.epa.gov/chemical-research/interim-ecological-soil-screening-level-documents.

USEPA. 2024b. "Navajo Abandoned Uranium Mines Risk Assessment Methodology." Draft Final. March.

Page 2 of 2


-------
Table C-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

Method®

Surface Soil (0-6 inches bgs)

Uranium-238

pCi/g

10 / 10

-

2.43

KMP-SS66-0000-0003-01

1.285

1.553

NP

1.6

UCL95

(14)

Uranium-234

pCi/g

10 / 10

-

2.43

KMP-SS50-0000-0003-01

1.299

1.628

N

1.6

UCL95

(2)

Thorium-230

pCi/g

10 / 10

-

3.57

CR1E-SS07-0000-0003-01

1.948

2.494

N

2.5

UCL95

(2)

Radium-226

pCi/g

375 / 375

-

86.3

CESS-041 (2-6)

4.93

5.859

NP

5.9

UCL95

(14)

Arsenic

mg/kg

108 / 108

-

11

KMP-12-00

5.453

5.663

G

5.7

UCL95

(6)

Barium

mg/kg

108 / 108

-

420

CR1E-SS15-0000-0003-01

84.68

93.64

NP

94

UCL95

(14)

Chromium

mg/kg

108 / 108

-

24

KMP-SS75-0000-0003-02

7.083

7.576

NP

7.6

UCL95

(14)

Lead

mg/kg

108 / 108

-

130

KM P-SS75-0000-0003-02

11.85

13.93

NP

14

UCL95

(14)

Manganese

mg/kg

85 / 85

-

310

KMP-SS77-0000-0003-01

184

191.5

N

190

UCL95

(2)

Nickel

mg/kg

85 / 85

-

20

CR1E-SS07-0000-0003-01

7.839

8.287

LN

8.3

UCL95

(14)

Selenium

mg/kg

118 / 118

-

21

KMP-17-00

2.569

3.004

NP

3.0

UCL95

(14)

Thallium

mg/kg

84 / 85

0

0.22

CR1E-SS12-0000-0003-01

0.129

0.135

G

0.14

UCL95

(7)

Uranium

mg/kg

164 / 164

-

61

RWPR-SS-002 (1.5-2)

5.071

6.24

LN

6.2

UCL95

(14)

Vanadium

mg/kg

108 / 108

-

41

KMP-17-00

15.75

16.61

NP

17

UCL95

(14)

Zinc

mg/kg

85 / 85

-

95

KMP-SS75-0000-0003-01

45.41

47.86

NP

48

UCL95

(14)

Page 1 of 3


-------
Table C-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

Method®

Subsurface Soil (0-72 inches bgs)

Uranium-238

pCi/g

14 / 14

-

51.5

KMP-SB28-0060-0066-01

4.842

12

NP

12

UCL95

(14)

Uranium-234

pCi/g

14 / 14

-

49.4

KM P-SB28-0060-0066-01

4.699

11.53

NP

12

UCL95

(14)

Thorium-230

pCi/g

14 / 14

-

3.57

CR1E-SS07-0000-0003-01

1.707

2.123

N

2.1

UCL95

(2)

Radium-226

pCi/g

683 / 683

-

468

C1LP-401 SS4 4.5-6

12.82

15.6

NP

16

UCL95

(14)

Arsenic

mg/kg

160 / 160

-

11

KMP-12-00

5.408

5.565

LN

5.6

UCL95

(14)

Barium

mg/kg

154 / 154

-

420

CR1E-SS15-0000-0003-01

78.08

84.27

NP

84

UCL95

(14)

Chromium

mg/kg

154 / 154

-

24

KMP-SS75-0000-0003-02

7.128

7.491

NP

7.5

UCL95

(14)

Lead

mg/kg

154 / 154

-

130

KM P-SS75-0000-0003-02

11.01

12.55

NP

13

UCL95

(14)

Manganese

mg/kg

115 / 115

-

400

KMA-SS02-0012-0018-01

194.3

201.5

LN

200

UCL95

(14)

Nickel

mg/kg

115 / 115

-

20

CR1E-SS07-0000-0003-01

7.787

8.138

LN

8.1

UCL95

(14)

Selenium

mg/kg

171 / 176

0

37

KMP-16-18

2.553

3.066

NP

3.1

UCL95

(15)

Thallium

mg/kg

113 / 115

0

0.22

CR1E-SS12-0000-0003-01

0.13

0.135

N

0.14

UCL95

(3)

Uranium

mg/kg

213 / 213

-

210

CELI-502 SS3 3-4.5

12.13

15.61

NP

16

UCL95

(14)

Vanadium

mg/kg

160 / 160

-

58

KMP-16-18

15.7

16.43

NP

16

UCL95

(14)

Zinc

mg/kg

115 / 115

-

95

KMP-SS75-0000-0003-01

43.6

45.5

NP

46

UCL95

(14)

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 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.
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 USEPA (2024b).

8 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 BCAUCL

(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%

BCAUCL







Page 2 of 3


-------
Table C-9. Exposure Point Concentrations for Ecological Risk Assessment

Notes (Continued):



BCA

Bias-corrected accelerated bootstrap method

bgs

Below ground surface

EPC

Exposure point concentration

G (data qualifier)

Sample density differs by more than 15% of the LCS density.

G (distribution)

Gamma distribution

H-UCL

UCL based upon Land's H-statistic

KM

Kaplan-Meier

LN

Lognormal distribution

M3

The requested MDC was not met, but the reported activity is greater than the reported MDC

N

Normal distribution

ND

Not detected

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). 2024b. "Navajo Abandoned Uranium Mines Risk Assessment Methodology." Draft Final. March.

Page 3 of 3


-------
Table C-10. Comparison of Individual Sample Results to Plant and Invertebrate NOECs

Sample ID

Sample
Depth
Bottom

COPEC3:

Uranium-
238

Uranium-
234

Thorium-
230

Radium-226 in
SE (Adjusted
Radium-226)

Aluminum

Antimony

Arsenic

Barium

Beryllium

Cadmium

Chromiumb

Cobalt

Copper

Iron

Lead

Manganese

Molybdenum

Nickel

Selenium

Silver

Thallium

Uranium

Vanadium

Zinc

Plant NOECc:

50

44

110

5.0

NSL

11

18

110

2.5

32

0.35

13

70

NSL

120

220

2

38

0.52

NSL

0.050

25

60

160

Soil Invertebrate
NOECc:

13,000

12,000

37,000

240

NSL

78

6.8

330

40

140

0.34

NSL

80

NSL

1,700

450

NSL

280

4.1

NSL

NSL

NSL

NSL

120

Units:

pCi/g

pCi/g

pCi/g

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

mg/kg

mg/kg

mg/kg

mg/kg

Church Rock Mine No. 1 - Surface Soil (0 - 6 inches bgs)

C1 LI-005.1 (0-6)

6



-

-

-

2.61

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-016.1 (0-6)

6



-

-

-

1.14

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-026.1 (0-6)

6



-

-

-

2.22

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-037.1 (0-6)

6



-

-

-

1.37

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LI-047.1 (0-2)

2



-

-

-

7.90

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-058.1 (0-6)

6



-

-

-

7.37

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LI-058.4 Dup

6



-

-

-

9.60

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LI-063.1 (0-6)

6



-

-

-

7.31

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-068.1 (0-6)

6



-

-

-

3.79

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-078.1 (0-6)

6



-

-

-

1.50

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-085.1 (0-6)

6



-

-

-

2.72

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-091.4 Dup

6



-

-

-

1.38

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-099.1 (0-6)

6



-

-

-

1.85

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-107.1 (0-6)

6



-

-

-

1.05

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-110.1 (0-6)

6



-

-

-

0.98

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LI-120.1 (0-6)

6



-

-

-

1.05

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-127.4 Dup

6



-

-

-

4.85

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-131.1 (0-6)

6



-

-

-

1.21

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-140.4 Dup

6



-

-

-

1.86

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-141.1 (0-6)

6



-

-

-

8.90

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LP-004.1 (0-6) Dup

6



-

-

-

1.35

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LP-009.1 (0-6)

6



-

-

-

47.10

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LP-015.1 (0-6)

6



-

-

-

35.80

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LP-019.1 (0-6)

6



-

-

-

4.90

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LP-020.1 (0-6)

6



-

-

-

26.60

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LP-026.1 (0-6)

6



-

-

-

12.50

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-031.1 (0-6)

6



-

-

-

2.23

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LP-037.1 (0-6) Dup

6



-

-

-

2.25

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-042.1 (0-6)

6



-

-

-

2.02

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LP-048.1 (0-6)

6



-

-

-

3.23

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LP-052.1 (0-6)

6



-

-

-

1.30

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LP-053.1 (0-6)

6



-

-

-

2.97

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LP-059.1 (0-6)

6



-

-

-

2.30

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LP-064.1 (0-6)

6



-

-

-

1.33

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LP-070.1 (0-6)

6



-

-

-

1.77

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LP-075.1 (0-6)

6



-

-

-

2.08

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-081.1 (0-6)

6



-

-

-

1.43

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LW-002.1 (0-6)

6



-

-

-

1.68

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LW-013.1 (0-6)

6



-

-

-

3.49

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LW-020.1 (0-6)

6



-

-

-

2.36

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LW-022.1 (0-6)

6



-

-

-

1.24

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LW-034.1 (0-6)

6



-

-

-

2.09

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LW-041.1 (0-6)

6



-

-

-

1.37

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LW-048.1 (0-6)

6



-

-

-

2.01

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LW-050.1 (0-6)

6



-

-

-

1.87

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LW-062.1 (0-6)

6



-

-

-

1.40

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LW-067.1 (0-6)

6



-

-

-

7.02

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LW-069.1 (0-6)

6



-

-

-

1.27

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LW-083.1 (0-6)

6



-

-

-

1.89

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LW-090.1 (0-6)

6



-

-

-

1.84

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LW-097.1 (0-6)

6



-

-

-

2.20

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LW-104.1 (0-6)

6



-

-

-

1.48

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1SS-026.1 (0-2)

2



-

-

-

26.90

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1SS-026.2 (2-6)

6



-

-

-

31.80

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1SS-041.1 (0-2) Dup

2



-

-

-

2.52

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1SS-041.2 (2-6)

6



-

-

-

1.55

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1SS-063A.1 (0-2)

2



-

-

-

41.20

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1SS-063A.2 (2-6)

6



-

-

-

8.40

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1SS-069.1 (0-2)

2



-

-

-

4.68

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1SS-069.2 (2-6)

6



-

-

-

1.81

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1SS-082.1 (0-2)

2



-

-

-

1.43

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1SS-082.2 (2-6)

6



-

-

-

1.17

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1SS-125.1 (0-2)

2



-

-

-

1.29

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CR1-SS05-0000-0003-01

3



-

-

-

-

3300

0.088

3.6

68

0.47

0.083

4

4.4

6.3

7900

8.7

120

0.15

4.7

1.1

0.058 U

0.098

1.5

11

35

CR1-SS06-0000-0003-01

3



-

-

-

-

5800

-

5.8

-

0.87

0.22

6.1

7.9

19

11000

17

150

0.42

9

1.9

0.1

0.2

-

14

70

Page 1 of 12


-------
Table C-10. Comparison of Individual Sample Results to Plant and Invertebrate NOECs

Sample ID

Sample
Depth
Bottom

COPEC3:

Uranium-
238

Uranium-
234

Thorium-
230

Radium-226 in
SE (Adjusted
Radium-226)

Aluminum

Antimony

Arsenic

Barium

Beryllium

Cadmium

Chromium13

Cobalt

Copper

Iron

Lead

Manganese

Molybdenum

Nickel

Selenium

Silver

Thallium

Uranium

Vanadium

Zinc

Plant NOECc:

50

44

110

5.0

NSL

11

18

110

2.5

32

0.35

13

70

NSL

120

220

2

38

0.52

NSL

0.050

25

60

160

Soil Invertebrate
NOECc:

13,000

12,000

37,000

240

NSL

78

6.8

330

40

140

0.34

NSL

80

NSL

1,700

450

NSL

280

4.1

NSL

NSL

NSL

NSL

120

Units:

pCi/g

pCi/g

pCi/g

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

mg/kg

mg/kg

mg/kg

mg/kg

CR1-SS06-0000-0003-02

3



-

-

-

1.9

-

0.19

-

86

-

-

-

-

-

-

-

-

-

-

-

-

-

2.7

-

-

CR1-SS07-0000-0003-01

3



-

-

-

2.87

4500

0.098

3.5

87

0.54

0.1

4.1

8

9.2

11000

10

170

0.18

5

1.2

0.06 U

0.15

4.6

11

41

CR1-SS08-0000-0003-01

3



-

-

-

3.13

4400

0.16

5.3

89

0.63

0.12

4.9

5.6

9.9

11000

10

170

0.29

6.5

1.7

0.058 U

0.14

3.2

13

43

CR1-SS09-0000-0003-01

3



-

-

-

8.6

5900

0.19

5.3

65

0.8

0.21

6.8

7

16

13000

15

160

0.37

9.2

3.2

0.072

0.16

9

17

61

CR1-SS10-0000-0003-01

3



0.82

0.81

0.86

1.23

3100

0.14

5.9

43

0.5

0.13

3.4

6.1

10

11000

11

140

0.28

5.9

1.3

0.062 U

0.13

1.4

12

45

CR1-SS11-0000-0003-01

3



-

-

-

1.29

4100

0.12

4.6

78

0.61

0.12

4.3

6.1

10

10000

10

150

0.25

6.2

1.8

0.058 U

0.12

1

12

45

CR1-SS12-0000-0003-01

3



-

-

-

1.16

3600

0.038

2.9

36

0.56

0.038 U

4.1

6.2

3.9

9900

7.2

150

0.16

6.5

1.2

0.057 U

0.067

1.6

12

52

CR1-SS13-0000-0003-01

3



-

-

-

2.25

4400

0.18

4.8

85

0.68

0.14

4.7

6.1

12

11000

11

160

0.34

7.2

1.6

0.059

0.13

4.6

13

47

CR1-SS14-0000-0003-01

3



-

-

-

-

3700

0.12

4.2

77

0.52

0.13

4

4.8

8

9200

9.1

140

0.21

5.2

1.3

0.065 U

0.14

1.5

12

38

CR1-SS15-0000-0003-01

3



1.02

0.91

1.71

2.29

-

-

-

-

-

0.1

-

-

5.9

-

-

-

-

-

-

0.058 U

0.094

-

-

38

CR1-SS15-0000-0003-02

3



-

-

-

-

4300

0.097

4.2

120

0.46

-

4.8

3.9

-

9400

7.8

130

0.32

4.6

1.2

-

-

1.8

12

-

CR1-SS16-0000-0003-01

3



1.12

1.21

1.46

1.73

4300

0.14

5

94

0.62

0.13

4.5

6

16

10000

10

160

0.27

6.5

1.4

0.059 U

0.14

1.7

12

42

CR1-SS17-0000-0003-01

3



-

-

-

0.82

2300

0.1

3.7

80

0.32

0.065

2.7

3.7

5

7300

6.9

120

0.19

3.9

0.79

0.057 U

0.1

0.61

8.6

27

CR1-SS18-0000-0003-01

3



-

-

-

1.33

3900

0.14

4.7

90

0.57

0.13

4.6

5.7

10

9200

10

150

0.23

6.4

1.3

0.057 U

0.11

1.2

12

41

CR1-SS19-0000-0003-01

3



-

-

-

18.20

3500

0.11

4.1

210

0.45

0.081

4.2

4.3

6.9

9200

7.7

190

0.39

5.1

4.5

0.057 U

0.097

CO
CO

15

38

CR1-SS20-0000-0003-01

3



-

-

-

1.19

2900

0.076

3.8

54

0.38

0.086

3

4.3

6.1

7800

7.7

100

0.18

4.2

1.1

0.057 U

0.093

1.1

9.3

32

CR1-SS21-0000-0003-01

3



-

-

-

2.27

7000

0.22

5.9

100

0.97

0.25

7.5

8.3

21

13000

18

180

0.4

11

2.1

0.1

0.21

3.1

17

70

CR1-SS22-0000-0003-01

3



-

-

-

-

-

0.13

5.3

110

-

0.14

-

6.4

-

12000

12

-

-

-

1.6

-

0.15

1.6

15

56

CR1-SS22-0000-0003-02

3



-

-

-

-

5900

-

-

-

0.71

-

12

-

14

-

-

180

0.53

CO
CO

-

0.076

-

-

-

-

CR1-SS23-0000-0003-01

3



-

-

-

1.54

5600

0.14

5.8

98

0.8

0.19

6

7.3

17

12000

14

180

0.27

9.6

1.8

0.081

0.18

1.2

15

62

CR1-SS24-0000-0003-01

3



-

-

-

19.20

6200

0.11

5.3

330

0.78

0.18

6.4

6.9

15

12000

14

200

0.35

8.7

4.4

0.09

0.17

21

19

62

CR1-SS25-0000-0003-01

3



-

-

-

2.94

4600

0.13

6.1

98

0.62

0.17

5.2

6.3

12

12000

11

200

0.34

7.2

1.9

0.065

0.13

1.9

15

60

CR1-SS26-0000-0003-01

3



-

-

-

28.50

4400

0.16

6.1

100

0.71

0.15

4.6

5.7

12

13000

12

170

0.61

7.4

9.5

0.062 U

0.15

55

20

48

CR1-SS27-0000-0003-01

3



-

-

-

4.68

3300

0.15

4.3

66

0.5

0.12

3.7

5

9.4

9800

8.9

140

0.27

5.7

2.7

0.059 U

0.097

4.9

13

43

CR1-SS28-0000-0003-01

3



-

-

-

28.00

3600

0.11

3.5

66

0.43

0.12

5.6

4

7.6

8400

11

130

0.26

6.8

14

0.062 U

0.089

20

20

37

CR1-SS29-0000-0003-01

3



-

-

-

3.21

4400

0.12

4.7

95

0.62

0.15

5.3

5.7

12

9600

11

170

0.27

7.6

1.7

0.058 U

0.11

3.4

13

47

CR1-SS30-0000-0003-01

3



-

-

-

2.12

4000

0.089

4.3

66

0.49

0.11

4.5

5.2

7.8

9300

9.1

140

0.2

6.1

1.4

0.061 U

0.11

1.6

11

49

CR1-SS31 -0000-0003-01

3



-

-

-

6.28

4600

0.078

3.6

41

0.44

0.11

6.2

3.4

5.7

10000

10

100

0.21

5.3

2.2

0.058 U

0.075

12

13

31

CR1-SS32-0000-0003-01

3



-

-

-

6.30

4200

0.13

4.1

83

0.57

0.13

13

6.3

12

9900

9.8

150

0.28

16

2.3

0.058 U

0.12

4.8

15

42

CR1-SS33-0000-0003-01

3



-

-

-

0.60

1400

0.055

3

63

0.2

0.051

2.3

2.5

3.2

5000

4.8

89

0.15

2.7

0.47

0.057 U

0.048

0.37

5.4

18

CR1-SS34-0000-0003-01

3



-

-

-

1.13

4800

0.14

5

86

0.62

0.12

5.2

5.8

11

11000

11

160

0.27

7.2

1.3

0.061

0.14

0.91

13

46

RWPR-SS-001 (0-6)

6



-

-

-

4.54

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

8.7

-

-

RWPR-SS-002 (0-6)

6



-

-

-

2.90

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

4.8

-

-

RWPR-SS-002 (1.5-2)

2



-

-

-

48.50

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

61

-

-

RWPR-SS-002 (2.5-3)

3



-

-

-

17.30

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

39

-

-

RWPR-SS-003 (0-2)

2



-

-

-

2.65

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

3.5

-

-

RWPR-SS-003 (2-5)

5



-

-

-

1.34

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

2.5

-

-

RWPR-SS-004 (0-6)

6



-

-

-

8.90

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

8.2

-

-

RWPR-SS-004 (1.5-2)

2



-

-

-

1.32

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

2.1

-

-

RWPR-SS-004 (2.5-3)

3



-

-

-

0.77

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

1.3

-

-

RWPR-SS-005 (0-2)

2



-

-

-

1.55

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

2.1

-

-

RWPR-SS-005 (2-6)

6



-

-

-

1.72

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

1.6

-

-

RWPR-SS-006 (0-6)

6



-

-

-

4.89

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

3.7

-

-

RWPR-SS-006 (1.5-1.9)

1.9



-

-

-

2.15

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

1.9

-

-

RWPR-SS-007 (0-6)

6



-

-

-

2.01

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

3

-

-

RWPR-SS-008 (0-6)

6



-

-

-

5.17

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

7.3

-

-

RWPR-SS-009 (0-6) C

6



-

-

-

2.09

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

1.7

-

-

RWPR-SS-009 (1.5-2)

2



-

-

-

0.56

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

0.82

-

-

RWPR-SS-009 (2.5-3)

3



-

-

-

0.76

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

0.6

-

-

RWPR-SS-010(0-6)

6



-

-

-

17.30

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

9.4

-

-

RWPR-SS-010 (1.5-2)

2



-

-

-

2.62

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

5.9

-

-

RWPR-SS-010(2.5-3)

3



-

-

-

1.62

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

2.4

-

-

RWPR-SS-011 (0-6)

6



-

-

-

3.73

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

2.8

-

-

RWPR-SS-011 (1.5-2)

2



-

-

-

0.96

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

0.97

-

-

RWPR-SS-011 (2.5-3)

3



-

-

-

0.63

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

0.68

-

-

RWPR-SS-012 (0-6)

6



-

-

-

12.2

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

10

-

-

RWPR-SS-012 (1.5-2)

2



-

-

-

2.08

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

2.6

-

-

RWPR-SS-012 (2.5-3)

3



-

-

-

1.12

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

2.2

-

-

RWPR-SS-014 (0-6)

6



-

-

-

3.56

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

3.3

-

-

RWPR-SS-014(1.5-2)

2



-

-

-

7.18

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

9

-

-

RWPR-SS-019 (0-2)

2



-

-

-

6.28

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

6.2

-

-

RWPR-SS-019 (0-6)

6



-

-

-

7.2

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

6.5

-

-

RWPR-SS-019 (1.5-2)

2



-

-

-

1.64

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

1.3

-

-

RWPR-SS-019 (2.5-3)

3



-

-

-

0.87

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

1.2

-

-

RWPR-SS-019 (2-6)

6



-

-

-

2.23

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

5

-

-

RWPR-SS-020 (0-6) C

6



-

-

-

18

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

4.2

-

-

Page 2 of 12


-------
Table C-10. Comparison of Individual Sample Results to Plant and Invertebrate NOECs

Sample ID

Sample
Depth
Bottom

COPEC3:

Uranium-
238

Uranium-
234

Thorium-
230

Radium-226 in
SE (Adjusted
Radium-226)

Aluminum

Antimony

Arsenic

Barium

Beryllium

Cadmium

Chromiumb

Cobalt

Copper

Iron

Lead

Manganese

Molybdenum

Nickel

Selenium

Silver

Thallium

Uranium

Vanadium

Zinc

Plant NOECc:

50

44

110

5.0

NSL

11

18

110

2.5

32

0.35

13

70

NSL

120

220

2

38

0.52

NSL

0.050

25

60

160

Soil Invertebrate
NOECc:

13,000

12,000

37,000

240

NSL

78

6.8

330

40

140

0.34

NSL

80

NSL

1,700

450

NSL

280

4.1

NSL

NSL

NSL

NSL

120

Units:

pCi/g

pCi/g

pCi/g

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

mg/kg

mg/kg

mg/kg

mg/kg

RWPR-SS-020 (1.5-2)

2



-

-

-

7.7

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

5.8

-

-

RWPR-SS-020 (2.5-3)

3



-

-

-

3.42

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

5.3

-

-

RWPR-SS-021 (0-2)

2



-

-

-

6.22

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

4.7

-

-

RWPR-SS-021 (1.5-2)

2



-

-

-

1.67

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

2.2

-

-

RWPR-SS-021 (2.5-3)

3



-

-

-

1.33

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

3

-

-

RWPR-SS-021 (2-6)

6



-

-

-

1.19

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

2.4

-

-

RWPR-SS-023 (0-6)

6



-

-

-

1.67

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

1.3

-

-

RWPR-SS-023 (1.5-2)

2



-

-

-

1.44

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

1.1

-

-

RWPR-SS-023 (2.5-3)

3



-

-

-

1.56

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

1.2

-

-

RWPR-SS-025 (0-6)

6



-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

0.61

-

-

RWPR-SS-025 (0-6) Dup

6



-

-

-

1.07

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

RWPR-SS-028 (0-6)

6



-

-

-

1.26

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

0.78

-

-

RWPR-SS-028 (1.5-2)

2



-

-

-

1.15

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

1.2

-

-

RWPR-SS-028 (2.5-3)

3



-

-

-

2.20

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

1.5

-

-

RWPR-SS-029 (0-6)

6



-

-

-

0.79

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

2.9

-

-

RWPR-SS-211 (0-6)

6



-

-

-

3.90

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

2.8

-

-

RWPR-SS-211 (1.5-2)

2



-

-

-

1.03

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

0.96

-

-

RWPR-SS-211 (2.5-3)

3



-

-

-

0.75

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

0.63

-

-

RWPR-SS-221 (0-2)

2



-

-

-

7.40

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

4.6

-

-

RWPR-SS-221 (1.5-2)

2



-

-

-

1.65

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

3.5

-

-

RWPR-SS-221 (2.5-3)

3



-

-

-

1.57

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

3

-

-

RWPR-SS-221 (2-6)

6



-

-

-

1.38

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

2.7

-

-

Frequency of Plant NOEC Exceedance:

0/3

0/3

0/3

34/146

0/30

0/30

0/30

3/30

0/30

0/30

30/30

0/30

0/30

0/30

0/30

0/30

0/30

0/30

29/30

0/30

29/30

3/86

0/30

0/30

Frequency of Soil Invertebrate NOEC Exceedance:

0/3

0/3

0/3

0/146

0/30

0/30

0/30

0/30

0/30

0/30

30/30

0/30

0/30

0/30

0/30

0/30

0/30

0/30

4/30

0/30

0/30

0/86

0/30

0/30

Frequency of Plant and Soil Invertebrate Exceedance:

0/3

0/3

0/3

34/146

0/30

0/30

0/30

3/30

0/30

0/30

30/30

0/30

0/30

0/30

0/30

0/30

0/30

0/30

29/30

0/30

29/30

3/86

0/30

0/30

Church Rock Mine No. 1 - Subsurface Soil (6 - 72 inches bgs) d

C1-1B008-5 (FD)

72



-

-

-

9.6

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1-BO01-5

72



-

-

-

0.868

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1-B003-5

72



-

-

-

2.86

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1-B006-5

72



-

-

-

0.59

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1-B007-5

72



-

-

-

16.3

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-005.2 (18-24)

24



-

-

-

1.9

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-005.3 (30-36)

36



-

-

-

1.63

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-016.2 (18-24)

24



-

-

-

5.23

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-016.3 (30-36)

36



-

-

-

2.88

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-026.2 (18-24)

24



-

-

-

4.71

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-026.3 (30-36)

36



-

-

-

1.98

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-037.2 (18-24)

24



-

-

-

3.89

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-037.4 Dup

36



-

-

-

5.36

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-047.2 (8-14) Dup

14



-

-

-

8.4

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-058.2 (9-15)

15



-

-

-

3.51

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-068.2 (10-16)

16



-

-

-

1.71

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-078.2 (14-20)

20



-

-

-

2.72

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-085.2 (18-24)

24



-

-

-

1.59

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-085.3 (30-36)

36



-

-

-

1.47

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-091.2 (18-24)

24



-

-

-

1.48

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-091.3 (30-36)

36



-

-

-

1.6

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-099.2 (18-24)

24



-

-

-

1.31

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LI-099.3 (30-36)

36



-

-

-

1.1

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-107.2 (18-24)

24



-

-

-

1.31

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-107.3 (30-36)

36



-

-

-

1.14

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-110.2 (18-24)

24



-

-

-

1.17

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-110.3 (30-36)

36



-

-

-

0.84

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LI-120.2 (18-24)

24



-

-

-

1.38

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LI-120.3 (30-36)

36



-

-

-

1.33

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LI-127.2 (18-24)

24



-

-

-

2.12

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LI-127.3 (30-36)

36



-

-

-

2.6

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-131.2 (18-24)

24



-

-

-

0.9

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-131.3 (30-36)

36



-

-

-

0.89

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LI-140.2 (18-24)

24



-

-

-

1.37

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LI-140.3 (30-36)

36



-

-

-

1.33

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-141.2 (18-24)

24



-

-

-

1.86

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-141.3 (30-36)

36



-

-

-

1.64

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-500SS1 0-1.5

18



-

-

-

10.2

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-500SS2 1.5-3

36



-

-

-

1.03

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-500SS3 3-4.5

54



-

-

-

1.62

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

Page 3 of 12


-------
Table C-10. Comparison of Individual Sample Results to Plant and Invertebrate NOECs

Sample ID

Sample
Depth
Bottom

COPEC3:

Uranium-
238

Uranium-
234

Thorium-
230

Radium-226 in
SE (Adjusted
Radium-226)

Aluminum

Antimony

Arsenic

Barium

Beryllium

Cadmium

Chromium13

Cobalt

Copper

Iron

Lead

Manganese

Molybdenum

Nickel

Selenium

Silver

Thallium

Uranium

Vanadium

Zinc

Plant NOECc:

50

44

110

5.0

NSL

11

18

110

2.5

32

0.35

13

70

NSL

120

220

2

38

0.52

NSL

0.050

25

60

160

Soil Invertebrate
NOECc:

13,000

12,000

37,000

240

NSL

78

6.8

330

40

140

0.34

NSL

80

NSL

1,700

450

NSL

280

4.1

NSL

NSL

NSL

NSL

120

Units:

pCi/g

pCi/g

pCi/g

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

mg/kg

mg/kg

mg/kg

mg/kg

C1LI-500SS4 4.5-6

72



-

-

-

2.09

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-501 SS1 0-1.5

18



-

-

-

5.51

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-501 SS10

72



-

-

-

-

-

-

3.6

-

-

-

-

-

-

-

-

-

1.1 U

-

0.53 U

-

-

-

11

-

C1LI-501 SS2 1.5-3

36



-

-

-

14.3

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-501 SS3 3-4.5

54



-

-

-

1.14

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LI-501 SS4 4.5-6

72



-

-

-

0.67

-

-

3.4

-

-

-

-

-

-

-

-

-

1 U

-

0.52 U

-

-

-

9.5

-

C1LP-004.2 (18-24)

24



-

-

-

62.6

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-004.3 (30-36)

36



-

-

-

45.5

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-009.2 (18-24)

24



-

-

-

13.5

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-009.3 (30-36)

36



-

-

-

6.89

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-015.2 (18-24)

24



-

-

-

7.45

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-015.3 (30-36)

36



-

-

-

4.62

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-019.2 (12-18)

18



-

-

-

1.15

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-020.2 (18-24)

24



-

-

-

29.9

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-020.3 (30-36)

36



-

-

-

29.2

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-020.4 (48-54) Dup

54



-

-

-

30

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-026.2 (18-24)

24



-

-

-

22.5

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-026.3 (30-36)

36



-

-

-

26.5

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-031.2 (18-24)

24



-

-

-

3.05

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-031.3 (30-36)

36



-

-

-

2.14

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-037.2 (16-22)

22



-

-

-

2.11

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-042.2 (18-24)

24



-

-

-

2.02

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-042.3 (30-36)

36



-

-

-

1.65

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-048.2 (18-24)

24



-

-

-

1.74

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-048.3 (30-36)

36



-

-

-

1.31

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-052.2 (18-24)

24



-

-

-

1.54

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-052.3 (30-36)

36



-

-

-

1.81

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-053.2 (18-24)

24



-

-

-

1.99

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LP-053.3 (30-36)

36



-

-

-

2.14

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LP-059.2 (18-24)

24



-

-

-

2.04

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LP-059.3 (30-36)

36



-

-

-

2.1

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LP-064.2 (18-24)

24



-

-

-

1.37

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LP-064.3 (30-36)

36



-

-

-

1.3

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LP-070.2 (18-24)

24



-

-

-

1.9

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LP-070.3 (30-36)

36



-

-

-

6.83

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LP-075.2 (18-24)

24



-

-

-

1.74

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LP-075.4 Dup

36



-

-

-

1.69

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-081.2 (18-24)

24



-

-

-

1.17

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-081.3 (30-36)

36



-

-

-

1.04

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-400SS1 0-1.5

18



-

-

-

2.15

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-400 SS2 1.5-3 Dup

36



-

-

-

31.3

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LP-400 SS3 3-4.5

54



-

-

-

2.4

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LP-400 SS4 4.5-6

72



-

-

-

2.04

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-401 SS1 0-1.5

18



-

-

-

8.2

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-401 SS2 1.5-3

36



-

-

-

18.5

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-401 SS3 3-4.5

54



-

-

-

30.7

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-401 SS4 4.5-6

72



-

-

-

468

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-402 DUP 402

72



-

-

-

14.9

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-402 SS1 0-1.5

18



-

-

-

2.2

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LP-402 SS2 1.5-3

36



-

-

-

1.98

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LP-402 SS3 3-4.5 Dup

54



-

-

-

3.29

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LP-402 SS4 4.5-6

72



-

-

-

16.2

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-403SS1 0-1.5

18



-

-

-

21.4

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-403 SS2 1.5-3 Dup

36



-

-

-

27.6

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-403 SS3 3-4.5

54



-

-

-

16

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LP-403 SS4 4.5-6

72



-

-

-

59.8

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-404SS1 0-1.5

18



-

-

-

2.66

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-404 SS2 1.5-3 Dup

36



-

-

-

1.78

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-404 SS3 3-4.5

54



-

-

-

2.92

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LP-404 SS4 4.5-6 Dup

72



-

-

-

2.08

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-405 SS1 0-1.5

18



-

-

-

1.65

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-405 SS2 1.5-3

36



-

-

-

1.57

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-405 SS3 3-4.5

54



-

-

-

1.35

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-405 SS4 4.5-6

72



-

-

-

1.44

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-406 SS1 0-1.5 Dup

18



-

-

-

1.18

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-406 SS2 1.5-3

36



-

-

-

1.54

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

Page 4 of 12


-------
Table C-10. Comparison of Individual Sample Results to Plant and Invertebrate NOECs

Sample ID

Sample
Depth
Bottom

COPEC3:

Uranium-
238

Uranium-
234

Thorium-
230

Radium-226 in
SE (Adjusted
Radium-226)

Aluminum

Antimony

Arsenic

Barium

Beryllium

Cadmium

Chromiumb

Cobalt

Copper

Iron

Lead

Manganese

Molybdenum

Nickel

Selenium

Silver

Thallium

Uranium

Vanadium

Zinc

Plant NOECc:

50

44

110

5.0

NSL

11

18

110

2.5

32

0.35

13

70

NSL

120

220

2

38

0.52

NSL

0.050

25

60

160

Soil Invertebrate
NOECc:

13,000

12,000

37,000

240

NSL

78

6.8

330

40

140

0.34

NSL

80

NSL

1,700

450

NSL

280

4.1

NSL

NSL

NSL

NSL

120

Units:

pCi/g

pCi/g

pCi/g

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

mg/kg

mg/kg

mg/kg

mg/kg

C1LP-406 SS3 3-4.5

54



-

-

-

1.62

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-406SS4 4.5-6

72



-

-

-

1.68

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-407 DUP 407

72



-

-

-

5.89

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-407 SS1 0-1.5

18



-

-

-

3.52

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-407 SS2 1.5-3

36



-

-

-

3.44

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-407 SS3 3-4.5

54



-

-

-

5.74

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-407 SS4 4.5-6

72



-

-

-

5.52

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-408 SS1 0-1.5

18



-

-

-

3.53

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-408 SS2 1.5-3

36



-

-

-

4.46

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-408 SS3 3-4.5

54



-

-

-

5.54

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-408 SS4 4.5-6

72



-

-

-

6.72

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-700 SS1 0-1.5

18



-

-

-

1.46

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-700 SS2 1.5-3 Dup

36



-

-

-

5.09

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-700 SS3 3-4.5

54



-

-

-

39.1

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-700 SS4 4.5-6

72



-

-

-

34.8

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-701 SS1 0-1.5

18



-

-

-

2.86

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-701 SS2 1.5-3

36



-

-

-

3.14

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-701 SS3 3-4.5

54



-

-

-

3.94

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-701 SS4 4.5-6

72



-

-

-

3.07

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-702 SS1 0-1.5

18



-

-

-

1.33

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-702 SS2 1.5-3

36



-

-

-

1.38

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-702 SS3 3-4.5

54



-

-

-

1.2

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LP-702 SS4 4.5-6

72



-

-

-

1.54

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-703SS1 0-1.5

18



-

-

-

1.28

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-703 SS2 1.5-3

36



-

-

-

1.14

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LP-703 SS3 3-4.5

54



-

-

-

1.13

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LP-703 SS4 4.5-6

72



-

-

-

1.2

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LW-002.2 (6-12)

12



-

-

-

1.36

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LW-013.2 (18-24)

24



-

-

-

31.1

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LW-013.4

36



-

-

-

38.7

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LW-020.2 (18-24)

24



-

-

-

99

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LW-020.3 (30-36)

36



-

-

-

189

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LW-022.2 (12-18) Dup

18



-

-

-

55.3

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LW-034.2 (18-24)

24



-

-

-

154

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LW-034.3 (30-36)

36



-

-

-

82

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LW-041.2 (12-18)

18



-

-

-

329

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LW-048.2 (12-18)

18



-

-

-

128

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LW-050.2 (18-24)

24



-

-

-

75.6

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LW-050.3 (30-36)

36



-

-

-

60.6

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LW-062.2 (18-24)

24



-

-

-

37.7

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LW-062.3 (30-36)

36



-

-

-

48.8

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LW-067.2 (18-24)

24



-

-

-

104

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LW-067.3 (30-36)

36



-

-

-

99

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LW-069.2 (18-24)

24



-

-

-

38.8

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1 LW-069.3 (30-36)

36



-

-

-

67.4

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LW-083.2 (8-14)

14



-

-

-

1.4

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LW-090.3 (30-36)

36



-

-

-

56.9

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LW-090.4 Dup

24



-

-

-

76.4

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LW-097.2 (18-24)

24



-

-

-

1.82

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LW-097.3 (30-36)

36



-

-

-

2.25

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1LW-104.2 (14-20)

20



-

-

-

1.31

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1SS-026.3 (12-18)

18



-

-

-

7.3

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1SS-041.3 (6-12)

12



-

-

-

2.05

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1SS-063A.3 (12-18)

18



-

-

-

1.6

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1SS-082.3 (18-24)

24



-

-

-

0.93

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

RWPR-SS-029 (6-9)

9



-

-

-

1.07

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

2.5

-

-

Frequency of Plant NOEC Exceedance:

0/0

0/0

0/0

58/161

0/0

0/0

0/2

0/0

0/0

0/0

0/0

0/0

0/0

0/0

0/0

0/0

0/2

0/0

0/2

0/0

0/0

0/1

0/2

0/0

Church Rock Mine No. 1 East - Surface Soil (0 - 6 inches bgs)

CELA-001 (0-2)

2



-

-

-

1.83

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-001 (2-6)

6



-

-

-

1.84

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-001 A. 1 (0-2")

2



-

-

-

1.60

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-004 (2-6) Dup

6



-

-

-

3.48

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-004.1 (0-2")

2



-

-

-

2.46

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-008 (2-6)

6



-

-

-

1.53

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-008.1 (0-2")

2



-

-

-

1.31

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-012 (2-6)

6



-

-

-

1.47

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

Page 5 of 12


-------
Table C-10. Comparison of Individual Sample Results to Plant and Invertebrate NOECs

Sample ID

Sample
Depth
Bottom

COPEC3:

Uranium-
238

Uranium-
234

Thorium-
230

Radium-226 in
SE (Adjusted
Radium-226)

Aluminum

Antimony

Arsenic

Barium

Beryllium

Cadmium

Chromiumb

Cobalt

Copper

Iron

Lead

Manganese

Molybdenum

Nickel

Selenium

Silver

Thallium

Uranium

Vanadium

Zinc

Plant NOECc:

50

44

110

5.0

NSL

11

18

110

2.5

32

0.35

13

70

NSL

120

220

2

38

0.52

NSL

0.050

25

60

160

Soil Invertebrate
NOECc:

13,000

12,000

37,000

240

NSL

78

6.8

330

40

140

0.34

NSL

80

NSL

1,700

450

NSL

280

4.1

NSL

NSL

NSL

NSL

120

Units:

pCi/g

pCi/g

pCi/g

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

mg/kg

mg/kg

mg/kg

mg/kg

CELA-012.1 (0-2")

2



-

-

-

2.24

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-016 (2-6)

6



-

-

-

2.61

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-016.1 (0-2")

2



-

-

-

4.93

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-020 (2-6)

6



-

-

-

1.35

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-020.1 (0-2")

2



-

-

-

1.69

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-024 (2-6)

6



-

-

-

1.71

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-024.1 (0-2")

2



-

-

-

1.26

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-027 (2-6)

6



-

-

-

2.01

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-027.1 (0-2")

2



-

-

-

2.24

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-031 (2-6)

6



-

-

-

2.63

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-031.1 (0-2")

2



-

-

-

2.34

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-035 (2-6)

6



-

-

-

1.63

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-035.1 (0-2")

2



-

-

-

1.96

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-039 (2-6)

6



-

-

-

3.19

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-039.1 (0-2")

2



-

-

-

2.21

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-043 (2-6)

6



-

-

-

75.60

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-043.1 (0-2")

2



-

-

-

5.00

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-047 (2-6)

6



-

-

-

3.17

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-047.1 (0-2")

2



-

-

-

2.62

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-051 (2-6)

6



-

-

-

2.68

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-051.1 (0-2")

2



-

-

-

3.17

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-054 (2-6)

6



-

-

-

1.67

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-054.1 (0-2")

2



-

-

-

1.64

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-058 (2-6)

6



-

-

-

3.08

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-058.1 (0-2")

2



-

-

-

37.80

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-062 (2-6)

6



-

-

-

2.14

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-062.1 (0-2") Dup

2



-

-

-

3.87

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-062.2

2



-

-

-

3.79

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-066 (2-6)

6



-

-

-

1.64

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-066.1 (0-2")

2



-

-

-

2.16

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-070 (2-6)

6



-

-

-

19.00

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-070.1 (0-2")

2



-

-

-

4.25

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-070.2

2



-

-

-

7.70

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-074 (2-6)

6



-

-

-

7.40

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-074.1 (0-2")

2



-

-

-

5.95

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CESS-037 (2-6)

6



-

-

-

1.48

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CESS-037.1 (0-2)

2



-

-

-

2.24

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CESS-041 (2-6)

6



-

-

-

86.30

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CESS-041.1 (0-2)

2



-

-

-

8.50

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CESS-060 (2-6)

6



-

-

-

4.34

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CESS-060.1 (0-2)

2



-

-

-

2.41

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CESS-069 (2-6)

6



-

-

-

2.27

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CESS-069.1 (0-2)

2



-

-

-

1.34

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CESS-070.1 (0-2)

2



-

-

-

1.60

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CR1E-SS05-0000-0003-01

3



-

-

-

1.59

6000

0.05

6.10

44.00

0.54

0.09

8.00

4.60

9.40

16000.00

10.00

120.00

0.36

9.80

1.40

0.06

0.20

1.00

12.00

46.00

CR1E-SS06-0000-0003-01

3



-

-

-

6.22

4700

0.04

4.50

68.00

0.42

0.05

8.50

4.50

7.70

12000.00

7.80

160.00

0.24

10.00

1.90

0.057 U

0.11

5.40

13.00

33.00

CR1E-SS07-0000-0003-01

3



1.27

1.35

3.57

3.21

-

0.07

-

-

0.42

-

22.00

-

8.40

11000.00

7.00

-

0.21

20.00

1.30

-

0.10

-

14.00

32.00

CR1E-SS07-0000-0003-02

3



-

-

-

-

4800

-

4.10

85.00

-

0.05

-

5.70

-

-

-

180.00

-

-

-

0.065 U

-

2.40

-

-

CR1E-SS08-0000-0003-01

3



-

-

-

1.76

5300

0.10

4.00

80.00

0.49

0.08

6.10

4.10

6.30

11000.00

8.10

140.00

0.24

5.70

1.20

0.058 U

0.10

2.60

14.00

40.00

CR1E-SS09-0000-0003-01

3



-

-

-

1.69

8000

0.06

8.00

72.00

0.66

0.09

8.50

6.90

13.00

21000.00

13.00

180.00

0.20

11.00

1.60

0.06

0.17

0.91

17.00

60.00

CR1E-SS10-0000-0003-01

3



-

-

-

1.67

8400

0.06

10.00

70.00

0.76

0.07

10.00

9.30

17.00

23000.00

16.00

190.00

0.23

13.00

1.80

0.08

0.20

1.00

18.00

65.00

CR1E-SS11-0000-0003-01

3



-

-

-

3.80

7400

0.09

6.50

86.00

0.62

0.14

10.00

6.40

14.00

17000.00

13.00

280.00

0.37

11.00

2.10

0.08

0.16

2.40

18.00

71.00

CR1E-SS12-0000-0003-01

3



-

-

-

1.59

7600

0.23

8.70

180.00

1.00

0.23

8.40

10.00

19.00

20000.00

18.00

290.00

0.40

13.00

3.10

0.09

0.22

1.90

23.00

80.00

CR1E-SS13-0000-0003-01

3



0.96

1.04

1.16

1.16

5100

0.10

5.70

100.00

0.72

0.15

5.10

6.80

12.00

12000.00

12.00

160.00

0.19

7.50

1.80

0.064 U

0.14

1.10

14.00

49.00

CR1E-SS14-0000-0003-01

3



-

-

-

1.50

4600

0.11

4.70

110.00

0.63

0.13

4.80

5.90

11.00

11000.00

11.00

160.00

0.25

7.40

5.00

0.058 U

0.13

5.30

13.00

47.00

CR1E-SS15-0000-0003-01

3



-

-

-

3.11

4600

0.13

4.80

420.00

0.65

0.14

5.70

6.10

11.00

11000.00

11.00

170.00

0.40

7.90

1.80

0.058 U

0.12

3.30

13.00

47.00

CR1E-SS16-0000-0003-01

3



-

-

-

4.58

4000

0.06

3.80

93.00

0.43

0.07

4.50

4.10

6.50

9700.00

7.50

140.00

0.19

5.30

2.50

0.059 U

0.08

3.30

12.00

36.00

CR1E-SS17-0000-0003-01

3



-

-

-

13.90

4600

0.10

4.90

78.00

0.56

0.12

5.50

5.90

9.80

12000.00

9.90

180.00

0.27

7.10

4.70

0.058 U

0.11

6.30

15.00

44.00

CR1E-SS18-0000-0003-01

3



-

-

-

1.81

4800

0.09

4.80

160.00

0.56

0.11

5.80

5.30

9.80

11000.00

9.70

180.00

0.21

7.20

1.60

0.059 U

0.11

1.40

13.00

45.00

CR1E-SS19-0000-0003-01

3



-

-

-

-

-

-

-

27.00

-

0.06

-

-

-

-

-

130.00

-

-

1.20

-

-

-

11.00

-

CR1E-SS19-0000-0003-02

3



-

-

-

1.39

4800

0.04

5.50

-

0.45

-

7.10

4.00

7.30

13000.00

8.30

-

0.38

8.00

-

0.059 U

0.16

0.87

-

36.00

Frequency of Plant NOEC Exceedance:

0/2

0/2

0/2

10/67

0/15

0/15

0/15

3/15

0/15

0/15

15/15

0/15

0/15

0/15

0/15

2/15

0/15

0/15

15/15

0/15

15/15

0/15

0/15

0/15

Frequency of Soil Invertebrate NOEC Exceedance:

0/2

0/2

0/2

0/67

0/15

0/15

3/15

1/15

0/15

0/15

15/15

0/15

0/15

0/15

0/15

0/15

0/15

0/15

2/15

0/15

0/15

0/15

0/15

0/15

Frequency of Plant and Soil Invertebrate Exceedance:

0/2

0/2

0/2

10/67

0/15

0/15

3/15

3/15

0/15

0/15

15/15

0/15

0/15

0/15

0/15

2/15

0/15

0/15

15/15

0/15

15/15

0/15

0/15

0/15

Page 6 of 12


-------
Table C-10. Comparison of Individual Sample Results to Plant and Invertebrate NOECs

Sample ID

Sample
Depth
Bottom

COPEC3:

Uranium-
238

Uranium-
234

Thorium-
230

Radium-226 in
SE (Adjusted
Radium-226)

Aluminum

Antimony

Arsenic

Barium

Beryllium

Cadmium

Chromiumb

Cobalt

Copper

Iron

Lead

Manganese

Molybdenum

Nickel

Selenium

Silver

Thallium

Uranium

Vanadium

Zinc

Plant NOECc:

50

44

110

5.0

NSL

11

18

110

2.5

32

0.35

13

70

NSL

120

220

2

38

0.52

NSL

0.050

25

60

160

Soil Invertebrate
NOECc:

13,000

12,000

37,000

240

NSL

78

6.8

330

40

140

0.34

NSL

80

NSL

1,700

450

NSL

280

4.1

NSL

NSL

NSL

NSL

120

Units:

pCi/g

pCi/g

pCi/g

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

mg/kg

mg/kg

mg/kg

mg/kg

Church Rock Mine No. 1 East - Subsurface Soil (6 - 72 inches bgs) d

C1E-1B002-5 (FD)

72



-

-

-

1.33

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1E-B001-5

72



-

-

-

0.674

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1E-B003-5

72



-

-

-

19.2

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1E-B004-5

72



-

-

-

1.02

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1E-B005-5

72



-

-

-

50

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

C1E-B006-5

72



-

-

-

0.932

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-001 (18-24)

24



-

-

-

1.34

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-001 (30-36)

36



-

-

-

1.49

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-004 (10-16)

16



-

-

-

1.65

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-008 DUP

18



-

-

-

3.56

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-012 (18-24)

24



-

-

-

1.18

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-012 (30-36)

36



-

-

-

1.13

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-016 (18-24)

24



-

-

-

96

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-016 (30-36)

36



-

-

-

74.2

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-020 (6-12)

12



-

-

-

1.52

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-024 (14-20)

20



-

-

-

1.28

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-027 (18-24)

24



-

-

-

112

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-027 (30-36)

36



-

-

-

81.3

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-031 (18-24)

24



-

-

-

71.9

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-031 (30-36)

36



-

-

-

151

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-035 (18-24)

24



-

-

-

352

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-035 (30-36)

36



-

-

-

103

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-039 (18-24)

24



-

-

-

194

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-039 (27-33)

33



-

-

-

429

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-043 (18-24)

24



-

-

-

363

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-043 (30-36)

36



-

-

-

35.8

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-047 (18-24)

24



-

-

-

59.5

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-047 (30-36)

36



-

-

-

123

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-051 (6-12)

12



-

-

-

89

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-054 (18-24)

24



-

-

-

83.3

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-054 (30-36)

36



-

-

-

65.5

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-058 DUP

24



-

-

-

261

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-062 (13-19)

19



-

-

-

3.7

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-066 (12-18)

18



-

-

-

45.3

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-070 (9-15)

15



-

-

-

2.67

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELA-074 (9-14)

14



-

-

-

3.67

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELI-502 DUP 502

54



-

-

-

90

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELI-502 SS1 0-1.5

18



-

-

-

25.5

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELI-502 SS2 1.5-3 Dup

24



-

-

-

232

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELI-502 SS3 3-4.5

54



-

-

-

97

-

-

2

-

-

-

-

-

-

-

-

-

1.1 U

-

0.53 U

-

-

210

11

-

CELI-502 SS4 4.5-6

72



-

-

-

8.1

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELI-502 SS9

54



-

-

-

-

-

-

2.8

-

-

-

-

-

-

-

-

-

1.8

-

23

-

-

-

28

-

CELI-503 SS1 0-1.5

18



-

-

-

14.5

-

-

6.2

-

-

-

-

-

-

-

-

-

1.1 U

-

2.7 U

-

-

73

18

-

CELI-503 SS2 1.5-3

36



-

-

-

1.24

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELI-503 SS3 3-4.5

54



-

-

-

1.03

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELI-503 SS4 4.5-6

72



-

-

-

1.22

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELI-503 SS5

18



-

-

-

-

-

-

7.2

-

-

-

-

-

-

-

-

-

1.3 U

-

3.2 U

-

-

-

21

-

CELP-409 SS1 0-1.5

18



-

-

-

2.57

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELP-409 SS2 1.5-3

36



-

-

-

2.05

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELP-409 SS3 3-4.5

54



-

-

-

1.6

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CELP-409 SS4 4.5-6

72



-

-

-

2.14

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CESS-037 (18-24)

24



-

-

-

1.2

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CESS-037 (24-30)

30



-

-

-

1.15

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CESS-041 (6-12)

12



-

-

-

16.9

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CESS-060 (18-24)

24



-

-

-

1.65

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CESS-060 (30-36)

36



-

-

-

2.39

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CESS-069 (18-24)

24



-

-

-

3.79

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CESS-069 (30-36)

36



-

-

-

2.9

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

Frequency of Plant NOEC Exceedance:

0/0

0/0

0/0

28/56

0/0

0/0

0/4

0/0

0/0

0/0

0/0

0/0

0/0

0/0

0/0

0/0

0/4

0/0

1/4

0/0

0/0

2/2

0/4

0/0

Page 7 of 12


-------
Table C-10. Comparison of Individual Sample Results to Plant and Invertebrate NOECs

Sample ID

Sample
Depth
Bottom

COPECa:

Uranium-
238

Uranium-
234

Thorium-
230

Radium-226 in
SE (Adjusted
Radium-226)

Aluminum

Antimony

Arsenic

Barium

Beryllium

Cadmium

Chromiumb

Cobalt

Copper

Iron

Lead

Manganese

Molybdenum

Nickel

Selenium

Silver

Thallium

Uranium

Vanadium

Zinc

Plant NOEC0:

50

44

110

5.0

NSL

11

18

110

2.5

32

0.35

13

70

NSL

120

220

2

38

0.52

NSL

0.050

25

60

160

Soil Invertebrate
NOEC0:

13,000

12,000

37,000

240

NSL

78

6.8

330

40

140

0.34

NSL

80

NSL

1,700

450

NSL

280

4.1

NSL

NSL

NSL

NSL

120

Units:

pCi/g

pCi/g

pCi/g

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

mg/kg

mg/kg

mg/kg

mg/kg

Kerr-McGee Ponds on the Navajo Nation - Surface Soil (0 - 6 inches bgs)

KMP-13-00

2



-

-

-

2.15

-

-

5.30

66.00

-

0.08

7.10

-

-

-

8.60

-

0.50

-

1.80

0.5 U

-

0.87

15.00

-

KMP-14-00

2



-

-

-

-

-

-

-

-

-

0.14

-

-

-

-

11.00

-

0.55

-

-

0.49 U

-

-

17.00

-

KMP-14D-00

2



-

-

-

8.21

-

-

5.60

78.00

-

-

8.20

-

-

-

-

-

-

-

2.90

-

-

1.30

-

-

KMP-SB44-0000-0006-01

6



-

-

-

9.30

6500

0.13

5.60

82.00

0.57

0.16

7.00

5.10

11.00

14000.00

13.00

230.00

0.42

7.90

2.40

0.062 U

0.15

6.20

15.00

44.00

KMP-SS49-0000-0003-01

3



-

-

-

4.00

-

0.09

-

-

-

0.09

-

-

-

-

-

-

0.36

-

-

-

-

1.40

-

-

KMP-SS49-0000-0003-02

3



-

-

-

-

6900

-

5.90

75.00

0.56



7.80

5.20

9.30

15000.00

11.00

220.00

-

8.40

1.90

0.059 U

0.15

-

16.00

45.00

KMP-SS74-0000-0003-01

3



1.13

0.97

2.04

2.80

5600

0.05

4.90

56.00

0.50

0.08

6.00

4.10

7.40

12000.00

9.30

190.00

0.35

6.80

1.40

0.059 U

0.12

0.94

12.00

36.00

Frequency of Plant NOEC Exceedance:

0/1

0/1

0/1

2/5

0/3

0/3

0/5

0/5

0/3

0/6

5/5

0/3

0/3

0/3

0/5

1/3

0/5

0/3

5/5

0/5

3/3

0/5

0/5

0/3

Frequency of Soil Invertebrate NOEC Exceedance:

0/1

0/1

0/1

0/5

0/3

0/3

0/5

0/5

0/3

0/6

5/5

0/3

0/3

0/3

0/5

0/3

0/5

0/3

0/5

0/5

0/3

0/5

0/5

0/3

Frequency of Plant and Soil Invertebrate Exceedance:

0/1

0/1

0/1

2/5

0/3

0/3

0/5

0/5

0/3

0/6

5/5

0/3

0/3

0/3

0/5

1/3

0/5

0/3

5/5

0/5

3/3

0/5

0/5

0/3

Kerr-McGee Ponds on the Navajo Nation - Subsurface Soil (6 - 72 inches bgs)d

KMP-SB43-0018-0024-01

24



-

-

-

2.13

6800

0.093

5.9

56

0.57

0.073

7.4

5.1

9

15000

10

210

0.37

7.8

1.3

0.06 U

0.14

3.8

14

41

KMP-SB45-0060-0066-01

66



-

-

-

1.46

6700

0.088

5.7

74

0.55

0.06

7

5.1

8.1

14000

9.5

220

0.36

7.7

1.2

0.06 U

0.14

0.64

14

39

Frequency of Plant NOEC Exceedance:

0/0

0/0

0/0

0/2

0/2

0/2

0/2

0/2

0/2

0/2

2/2

0/2

0/2

0/2

0/2

0/2

0/2

0/2

2/2

0/2

2/2

0/2

0/2

0/2

Kerr-McGee Ponds on United Nuclear Corporation Property - Surface Soil (0 - 6 inches bgs)

KMP-01 -00

2



-

-

-

3.06

-

-

6.90

87.00

-

0.12

8.70

-

-

-

12.00

-

0.69

-

2.70

0.53 U

-

2.60

21.00

-

KMP-02-00

2



-

-

-

1.41

-

-

5.20

140.00

-

0.12 U

7.10

-

-

-

8.30

-

0.52

-

1.60

0.5 U

-

9.70

16.00

-

KMP-03-00

2



-

-

-

8.32

-

-

4.50

55.00

-

0.08

6.60

-

-

-

8.60

-

1.3 U

-

3.10

0.53 U

-

3.50

16.00

-

KMP-04-00

2



-

-

-

2.67

-

-

7.00

90.00

-

0.12

9.50

-

-

-

13.00

-

0.57

-

1.80

0.21 U

-

1.30

21.00

-

KMP-05-00

2



-

-

-

2.92

-

-

4.70

50.00

-

0.07

7.30

-

-

-

8.50

-

1.3 U

-

1.80

0.52 U

-

1.40

17.00

-

KMP-06-00

2



-

-

-

2.22

-

-

4.50

51.00

-

0.12 U

6.90

-

-

-

7.70

-

0.52

-

2.00

0.49 U

-

2.80

16.00

-

KMP-07-00

2



-

-

-

6.45

-

-

9.20

100.00

-

0.14

12.00

-

-

-

17.00

-

0.65

-

3.30

0.58 U

-

2.90

26.00

-

KMP-08-00

2



-

-

-

5.36

-

-

4.80

55.00

-

0.07

6.80

-

-

-

10.00

-

1.2 U

-

2.60

0.49 U

-

2.10

17.00

-

KMP-09-00

2



-

-

-

7.42

-

-

5.30

65.00

-

0.09

8.30

-

-

-

9.90

-

0.93

-

5.00

0.56 U

-

13.00

22.00

-

KM P-10-00

2



-

-

-

7.77

-

-

5.20

92.00

-

0.10

6.90

-

-

-

8.90

-

0.51

-

3.60

0.51 U

-

4.20

18.00

-

KM P-15-00

2



-

-

-

22.84

-

-

5.00

73.00

-

0.13

7.80

-

-

-

11.00

-

0.65

-

6.60

0.51 U

-

13.00

23.00

-

KM P-16-00

2



-

-

-

6.67

-

-

-

89.00

-

-

9.90

-

-

-

14.00

-

-

-

3.80

-

-

3.60

-

-

KMP-16D-00

2



-

-

-

-

-

-

7.50

-

-

0.14

-

-

-

-

-

-

0.75

-

-

0.52 U

-

-

22.00

-

KMP-17-00

2



-

-

-

48.54

-

-

7.60

120.00

-

0.14

8.50

-

-

-

13.00

-

0.65

-

21.00

0.45 U

-

40.00

41.00

-

KM P-18-00

2



-

-

-

-

-

-

6.60

90.00

-

0.15

10.00

-

-

-

14.00

-

0.74

-

5.60

0.49 U

-

-

25.00

-

KMP-18D-00

2



-

-

-

16.44

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

13.00

-

-

KMP-19-00

2



-

-

-

26.04

-

-

5.30

74.00

-

0.08

7.20

-

-

-

10.00

-

0.70

-

8.80

0.46 U

-

18.00

26.00

-

KMP-20-00

2



-

-

-

13.70

-

-

5.70

74.00

-

0.10

8.00

-

-

-

11.00

-

0.61

-

6.20

0.5 U

-

12.00

22.00

-

KMP-21-00

2



-

-

-

4.43

-

-

4.90

52.00

-

0.06

7.00

-

-

-

8.70

-

0.54

-

2.50

0.45 U

-

4.80

17.00

-

KMP-22-00

2



-

-

-

4.35

-

-

4.90

51.00

-

0.12 U

7.00

-

-

-

8.10

-

1.2 U

-

2.00

0.48 U

-

3.50

16.00

-

KMP-23-00

2



-

-

-

3.73

-

-

6.00

63.00

-

0.11

7.60

-

-

-

9.60

-

0.80

-

1.90

0.51 U

-

2.80

18.00

-

KM P-S B27-0000-0006-01

6



1.17

1.11

0.94

1.27

7000

0.08

5.90

81.00

0.60

0.07

8.10

5.00

9.30

15000.00

10.00

200.00

0.41

8.70

1.30

0.059 U

0.17

1.50

14.00

40.00

KMP-SS45-0000-0003-01

3



-

-

-

1.14

4000

0.10

4.30

110.00

0.46

0.12

9.60

4.70

9.00

9300.00

8.10

-

0.24

11.00

0.97

0.057 U

0.10

0.99

11.00

33.00

KMP-SS45-0000-0003-02

3



-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

KM P-SS46-0000-0003-01

3



-

-

-

2.46

4900

0.04

4.10

75.00

0.41

0.08

5.90

4.00

7.20

11000.00

7.40

180.00

0.26

7.00

1.20

0.057 U

0.10

1.70

12.00

32.00

KMP-SS47-0000-0003-01

3



-

-

-

1.54

5100

0.05

4.40

63.00

0.44

0.08

5.80

4.20

6.40

12000.00

7.90

190.00

0.25

6.30

1.10

0.058 U

0.10

0.83

13.00

34.00

KM P-SS48-0000-0003-01

3



-

-

-

24.60

6000

0.09

5.30

52.00

0.49

0.09

6.70

4.40

7.70

13000.00

9.50

200.00

0.45

7.00

6.30

0.057 U

0.13

13.00

16.00

39.00

KM P-SS50-0000-0003-01

3



1.92

2.43

3.41

4.41

6300

0.05

5.40

58.00

0.54

0.09

6.90

4.60

8.00

14000.00

10.00

200.00

0.34

7.40

2.40

0.058 U

0.13

4.00

14.00

40.00

KMP-SS51 -0000-0003-01

3



-

-

-

1.66

6500

0.07

5.60

62.00

0.54

0.11

7.30

5.10

8.90

14000.00

11.00

210.00

0.29

7.80

1.40

0.057 U

0.13

1.20

14.00

43.00

KM P-SS52-0000-0003-01

3



-

-

-

2.47

6100

0.06

5.10

51.00

0.50

0.05

6.70

4.60

7.00

14000.00

8.50

180.00

0.37

7.20

1.30

0.057 U

0.12

3.30

13.00

37.00

KM P-SS53-0000-0003-01

3



-

-

-

0.89

5000

0.06

4.30

46.00

0.42

0.05

5.50

4.00

5.30

12000.00

7.20

180.00

0.28

5.90

0.99

0.057 U

0.09

0.61

13.00

31.00

KM P-SS54-0000-0003-01

3



-

-

-

7.60

7100

0.11

6.70

85.00

0.63

0.12

8.70

6.00

13.00

17000.00

12.00

230.00

0.44

10.00

1.90

0.06

0.15

2.20

16.00

51.00

KMP-SS55-0000-0003-01

3



-

-

-

8.30

8300

0.15

7.50

97.00

0.73

0.13

9.30

6.70

15.00

19000.00

15.00

270.00

0.55

11.00

2.80

0.09

0.18

5.90

19.00

59.00

KMP-SS56-0000-0003-01

3



-

-

-

6.57

5900

0.07

5.00

52.00

0.49

0.07

6.50

4.10

7.40

13000.00

9.10

200.00

0.46

6.70

2.20

0.058 U

0.12

5.10

14.00

38.00

KMP-SS57-0000-0003-01

3



-

-

-

12.00

7100

0.10

6.10

65.00

0.59

0.11

8.10

5.40

10.00

16000.00

12.00

210.00

0.58

8.40

3.30

0.058 U

0.14

5.90

17.00

48.00

KMP-SS58-0000-0003-01

3



-

-

-

7.80

6700

0.11

5.40

64.00

0.54

0.13

7.40

4.80

9.30

14000.00

11.00

220.00

0.38

7.40

2.50

0.057 U

0.12

2.60

15.00

43.00

KMP-SS59-0000-0003-01

3



-

-

-

12.00

7000

0.09

6.00

70.00

0.58

0.09

7.70

5.30

9.50

16000.00

11.00

220.00

0.46

8.30

3.50

0.057 U

0.14

19.00

17.00

47.00

KMP-SS60-0000-0003-01

3



-

-

-

8.80

6000

0.11

6.00

66.00

0.49

0.08

6.70

4.90

9.20

14000.00

10.00

190.00

0.61

7.70

3.00

0.058 U

0.12

5.60

15.00

43.00

KMP-SS61 -0000-0003-01

3



-

-

-

11.50

6300

0.10

5.40

70.00

0.52

0.11

7.10

4.60

8.80

14000.00

11.00

200.00

0.35

7.40

3.90

0.057 U

0.12

8.50

16.00

41.00

KMP-SS62-0000-0003-01

3



-

-

-

2.67

6300

0.10

5.10

59.00

0.51

0.09

7.00

4.40

7.90

14000.00

9.30

200.00

0.31

6.90

1.50

0.058 U

0.11

3.20

14.00

39.00

KMP-SS63-0000-0003-01

3



-

-

-

3.17

5900

0.07

4.80

50.00

0.50

0.08

6.60

4.30

7.10

13000.00

8.60

190.00

0.60

6.90

1.70

0.057 U

0.11

4.70

13.00

39.00

KMP-SS64-0000-0003-01

3



-

-

-

4.23

6100

0.09

5.00

52.00

0.50

0.07

6.90

4.50

7.70

14000.00

9.10

180.00

0.56

7.10

1.70

0.057 U

0.12

5.70

14.00

39.00

KMP-SS65-0000-0003-01

3



-

-

-

6.93

6100

0.08

5.20

57.00

0.49

0.08

6.90

4.60

8.20

14000.00

9.90

210.00

0.33

7.20

2.10

0.058 U

0.12

4.30

15.00

40.00

KMP-SS66-0000-0003-01

3



2.43

2.23

2.14

2.95

5800

0.06

4.80

49.00

0.47

0.06

6.20

4.20

6.50

13000.00

8.30

180.00

0.32

6.30

1.40

0.058 U

0.10

4.60

13.00

36.00

KMP-SS67-0000-0003-01

3



-

-

-

6.08

6900

0.08

6.20

99.00

0.56

0.10

7.90

5.50

11.00

16000.00

12.00

230.00

0.36

8.70

2.00

0.058 U

0.14

3.40

16.00

48.00

KMP-SS68-0000-0003-01

3



-

-

-

4.10

7500

0.07

6.90

91.00

0.60

0.08

8.30

6.00

11.00

17000.00

12.00

220.00

0.30

9.40

2.00

0.058 U

0.14

3.10

16.00

47.00

KMP-SS69-0000-0003-01

3



-

-

-

4.10

7500

0.07

6.50

74.00

0.62

0.13

8.40

5.70

11.00

17000.00

12.00

230.00

0.42

9.10

1.70

0.06

0.15

0.94

16.00

51.00

KMP-SS70-0000-0003-01

3



-

-

-

-

6400

0.05

6.10

59.00

0.51

0.07

7.10

5.30

9.20

15000.00

10.00

170.00

0.27

8.20

1.20

0.058 U

0.12

0.72

14.00

43.00

KMP-SS70-0000-0003-02

3



-

-

-

1.53

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

Page 8 of 12


-------
Table C-10. Comparison of Individual Sample Results to Plant and Invertebrate NOECs

Sample ID

Sample
Depth
Bottom

COPECa:

Uranium-
238

Uranium-
234

Thorium-
230

Radium-226 in
SE (Adjusted
Radium-226)

Aluminum

Antimony

Arsenic

Barium

Beryllium

Cadmium

Chromiumb

Cobalt

Copper

Iron

Lead

Manganese

Molybdenum

Nickel

Selenium

Silver

Thallium

Uranium

Vanadium

Zinc

Plant NOEC0:

50

44

110

5.0

NSL

11

18

110

2.5

32

0.35

13

70

NSL

120

220

2

38

0.52

NSL

0.050

25

60

160

Soil Invertebrate
NOEC0:

13,000

12,000

37,000

240

NSL

78

6.8

330

40

140

0.34

NSL

80

NSL

1,700

450

NSL

280

4.1

NSL

NSL

NSL

NSL

120

Units:

pCi/g

pCi/g

pCi/g

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

mg/kg

mg/kg

mg/kg

mg/kg

KMP-SS71 -0000-0003-01

3



-

-

-

12.90

6100

0.06

5.60

64.00

0.48

0.11

7.00

4.70

8.80

14000.00

11.00

200.00

0.41

7.50

2.90

0.057 U

0.12

1.40

15.00

43.00

KMP-SS72-0000-0003-01

3



-

-

-

2.09

6400

0.07

5.90

60.00

0.52

0.08

7.20

5.20

9.60

15000.00

10.00

200.00

0.30

8.10

1.30

0.058 U

0.12

0.70

14.00

47.00

KMP-SS73-0000-0003-01

3



-

-

-

4.90

6800

0.08

6.70

92.00

0.59

0.13

8.10

5.90

13.00

16000.00

13.00

230.00

0.42

9.60

1.90

0.07

0.14

1.20

16.00

53.00

KMP-SS75-0000-0003-01

3



-

-

-

68.10

5700

0.19

6.70

170.00

0.48

0.14

10.00

4.90

16.00

17000.00

37.00

240.00

1.40

9.10

9.10

0.058 U

0.14

19.00

36.00

95.00

KMP-SS75-0000-0003-02

3



-

-

-

57.90

5800

0.26

7.00

160.00

0.49

0.16

24.00

5.30

18.00

19000.00

130.00

230.00

1.60

9.40

7.80

0.058 U

0.15

25.00

33.00

90.00

KMP-SS76-0000-0003-01

3



-

-

-

6.17

7600

0.09

6.80

62.00

0.63

0.12

8.80

5.50

12.00

17000.00

14.00

230.00

0.45

9.50

2.20

0.07

0.18

1.30

16.00

53.00

KMP-SS77-0000-0003-01

3



-

-

-

5.82

7000

0.11

6.50

170.00

0.60

0.19

8.40

5.70

14.00

16000.00

16.00

310.00

0.46

9.30

2.00

0.07

0.16

1.40

16.00

55.00

KMP-SS78-0000-0003-01

3



1.01

0.93

2.19

2.97

5400

0.06

5.40

38.00

0.47

0.07

6.40

5.10

7.30

14000.00

9.20

210.00

0.40

7.50

1.20

0.058 U

0.15

0.72

12.00

39.00

KMP-SS79-0000-0003-01

3



-

-

-

7.30

6200

0.08

5.00

67.00

0.49

0.12

6.70

4.60

8.70

13000.00

11.00

230.00

0.33

7.10

2.20

0.058 U

0.11

4.50

14.00

39.00

Frequency of Plant NOEC Exceedance:

0/4

0/4

0/4

28/54

0/35

0/35

0/54

5/54

0/35

0/54

54/54

0/35

0/35

0/35

1/54

10/34

0/54

0/35

54/54

0/54

35/35

1/54

0/54

0/35

Frequency of Soil Invertebrate NOEC Exceedance:

0/4

0/4

0/4

0/54

0/35

0/35

8/54

0/54

0/35

0/54

54/54

0/35

0/35

0/35

0/54

0/34

0/54

0/35

9/54

0/54

0/35

0/54

0/54

0/35

Frequency of Plant and Soil Invertebrate Exceedance:

0/4

0/4

0/4

28/54

0/35

0/35

8/54

5/54

0/35

0/54

54/54

0/35

0/35

0/35

1/54

10/34

0/54

0/35

54/54

0/54

35/35

1/54

0/54

0/35

Kerr-McGee Ponds on United Nuclear Corporation Property - Subsurface Soil (6 - 72 inches bgs)d

KMP-16-18

24



-

-

-

143.1

-

-

5.1

190

-

0.11

8.1

-

-

-

11

-

1.4

-

37

0.52 U

-

110

58

-

KMP-16-36

42



-

-

-

1.7

-

-

5

51

-

0.12 U

7.5

-

-

-

8.3

-

0.63

-

1.4

0.48 U

-

37

16

-

KMP-17-18

24



-

-

-

8.3

-

-

4.9

55

-

0.12 U

7

-

-

-

7.6

-

0.64

-

3

0.46 U

-

130

17

-

KMP-17-36

42



-

-

-

3.4

-

-

4.7

43

-

0.12 U

6.9

-

-

-

7.3

-

0.58

-

2.3

0.47 U

-

58

16

-

KMP-18-18

24



-

-

-

1.9

-

-

4.5

43

-

0.11 U

7

-

-

-

7.2

-

0.75

-

1.4

0.45 U

-

24

16

-

KMP-18-36

42



-

-

-

1.3

-

-

4.7

43

-

0.13 U

7.7

-

-

-

8

-

0.65

-

1.7

0.5 U

-

38

16

-

KMP-19-18

24



-

-

-

3.1

-

-

5

62

-

0.13 U

7.7

-

-

-

9.1

-

0.79

-

3.3

0.53 U

-

60

18

-

KMP-19-36

42



-

-

-

1.7

-

-

5.3

55

-

0.13 U

7.4

-

-

-

7

-

0.67

-

2

0.5 U

-

32

17

-

KMP-20-18

24



-

-

-

2.3

-

-

4.2

74

-

0.13 U

8.6

-

-

-

6.7

-

0.69

-

1.6

0.5 U

-

22

17

-

KMP-20-36

42



-

-

-

1.3

-

-

7.5

69

-

0.076

7.4

-

-

-

12

-

1.1

-

1.5

0.5 U

-

32

17

-

KMP-21-18

24



-

-

-

3.2

-

-

4

41

-

0.076

5.9

-

-

-

6.4

-

0.76

-

1.6

0.46 U

-

35

13

-

KMP-21-36

42



-

-

-

1.6

-

-

5.3

57

-

0.067

8

-

-

-

8.9

-

0.75

-

2.1

0.5 U

-

22

17

-

KMP-22-18

24



-

-

-

1.1

-

-

5.3

47

-

0.062

7.8

-

-

-

8.5

-

0.51

-

1.7

0.19

-

4.3

16

-

KMP-22-36

42



-

-

-

0.9

-

-

4

40

-

0.12 U

5.8

-

-

-

6.4

-

1.2 U

-

1.4

0.5 U

-

0.77

13

-

KMP-23-18

24



-

-

-

1.3

-

-

4.9

51

-

0.077

7.8

-

-

-

7.9

-

1

-

1.3

0.51 U

-

44

16

-

KMP-23-36

42



-

-

-

1.3

-

-

4.9

54

-

0.13 U

8.2

-

-

-

8.2

-

1.3

-

1.5

0.52 U

-

52

16

-

KMP-SB24-0018-0024-01

24



-

-

-

0.98

6900

0.1

7

60

0.6

0.094

7.6

5.9

11

16000

12

220

0.4

9

1.4

0.066 U

0.15

2.2

15

46

KMP-SB24-0048-0054-01

54



1.22

1.33

1.22

1.56

9600

0.11

8.5

110

0.85

0.1

11

7.9

14

22000

15

300

0.53

12

1.8

0.11

0.21

1.1

20

60

KMP-SB25-0006-0012-01

12



-

-

-

1.81

5500

0.058

4.7

47

0.47

0.045

6.1

4.4

6.6

12000

7.7

180

0.67

6.5

1.5

0.06 U

0.11

23

13

32

KMP-SB25-0018-0024-01

24



-

-

-

0.92

6000

0.064

5.1

44

0.51

0.054

6.6

4.7

7.4

13000

8.2

190

0.47

6.9

1.1

0.062 U

0.12

60

13

35

KMP-SB26-0006-0012-01

12



1.33

1.06

1.13

1.16

8300

0.14

6.8

110

0.67

0.14

8.7

6

12

16000

13

270

0.48

9.7

1.5

0.067

0.17

5.9

17

48

KMP-SB26-0012-0018-01

18



-

-

-

-

-

0.11

6.5

-

0.63

0.12

8.4

5.7

11

16000

12

-

0.43

9.4

1.3

-

0.18

1.8

-

-

KMP-SB26-0012-0018-02

18



-

-

-

1.83

7700

-

-

90

-

-

-

-

-

-

-

250

-

-

-

0.066

-

-

16

46

KMP-SB27-0012-0018-01

18



-

-

-

1.17

8200

0.091

6.7

92

0.68

0.08

9

5.8

11

16000

11

230

0.41

9.7

1.5

0.069

0.18

0.8

16

46

KMP-SB28-0036-0042-01

42



-

-

-

0.93

5600

0.063

4.9

45

0.47

0.053

6.1

4.4

6.7

12000

7.9

170

1.7

6.5

1.1

0.061 U

0.11

180

12

32

KMP-SB28-0042-0048-01

48



-

-

-

0.93

6400

0.065

5.4

57

0.53

0.064

6.8

4.7

7.4

14000

8.6

200

1.4

7.3

1.1

0.061 U

0.13

190

13

36

KMP-SB28-0060-0066-01

66



51.5

49.4

1.1

-

5900

0.063

6.3

50

0.52

0.051

6.5

5.2

7.1

14000

00
00

190

-

7.2

1.2

0.06 U

0.13

160

13

35

KMP-SB28-0060-0066-02

66



-

-

-

0.95

-

-

-

-

-

-

-

-

-

-

-

-

0.38

-

-

-

-

-

-

-

KMP-SB29-0048-0054-01

54



-

-

-

0.82

-

0.063

-

60

-

-

5.6

4.1

-

-

-

-

0.39

-

1.1

0.059 U

0.1

0.59

13

31

KMP-SB29-0048-0054-02

54



-

-

-

-

5300

-

5

-

0.43

0.048

-

-

5.6

14000

7.4

310

-

6.1

-

-

-

-

-

-

KMP-SB30-0030-0036-01

36



-

-

-

0.78

5600

0.058

4.9

43

0.48

0.047

6.1

5.2

6.4

12000

7.9

170

1.2

6.6

2.9

0.058 U

0.12

0.86

12

32

KMP-SB31 -0060-0066-01

66



-

-

-

1.43

6900

0.057

6.3

59

0.61

0.061

7.8

5.7

9.8

16000

11

200

0.36

00
00

1.4

0.061

0.17

0.8

14

44

KMP-SB32-0060-0066-01

66



-

-

-

2.09

5500

0.049

5

46

0.46

0.051

8.2

4.3

7.2

12000

8.1

180

0.91

6.6

1.6

0.059 U

0.12

14

13

33

KMP-SB33-0054-0060-01

60



-

-

-

0.7

5600

0.043

5.1

44

0.47

0.05

6

4.5

6.8

13000

7.8

190

0.3

6.7

1.1

0.059 U

0.12

0.66

12

33

KMP-SB33-0060-0066-01

66



-

-

-

1.02

5000

0.042

4.6

35

0.43

0.044

7.7

4.3

6.6

12000

7.2

190

0.81

6.3

0.99

0.058 U

0.1

1.9

12

38

KMP-SB33-0066-0072-01

72



-

-

-

4.55

5500

0.046

4.9

47

0.44

0.052

6.6

4.3

7.2

12000

8.4

180

0.41

6.4

1.7

0.057 U

0.11

4

13

36

KMP-SB34-0048-0054-01

54



-

-

-

3.57

5400

0.05

4.8

41

0.45

0.05

6

4.3

6.9

12000

8.1

170

0.44

6.3

1.5

0.059 U

0.12

20

12

34

KMP-SB35-0006-0012-01

12



-

-

-

27.1

5400

0.1

5.3

65

0.44

0.11

5.8

4.2

7.6

12000

9.7

230

0.62

6.1

6.4

0.057 U

0.1

30

17

36

KMP-SB36-0030-0036-01

36



-

-

-

30.7

6100

0.074

5.5

51

0.5

0.065

6.7

4.7

8

13000

8.9

220

0.58

7.1

2.4

0.056 U

0.12

24

14

38

KMP-SB37-0066-0072-01

72



-

-

-

8.7

7000

0.099

6.2

58

0.57

0.07

7.5

5.4

9.5

15000

10

200

0.39

8.2

2

0.058 U

0.15

7.1

15

42

KMP-SB38-0006-0012-01

12



-

-

-

1.4

7200

0.11

6

69

0.55

0.094

7.5

5.9

9.8

16000

11

250

0.5

8.9

1.3

0.063 U

0.13

1.4

16

44

KMP-SB38-0036-0042-01

42



0.89

1.0

0.97

1.14

7900

0.11

6.8

83

0.6

0.079

8.6

6.3

11

17000

11

230

0.33

9.4

1.3

0.059 U

0.15

0.63

16

48

KMP-SB40-0054-0060-01

60



-

-

-

1.19

6400

0.07

5.1

55

0.51

0.06

6.6

4.5

7.2

13000

8

190

0.32

6.8

1.3

0.059 U

0.12

28

13

34

KMP-SB41 -0054-0060-01

60



-

-

-

1.48

7600

0.087

6

90

0.61

0.063

8

5.5

9.6

15000

10

240

0.41

8.6

1.3

0.061 U

0.16

0.76

15

43

KMP-SB42-0054-0060-01

60



-

-

-

1.05

7900

0.099

6.4

86

0.69

0.081

8.5

6.2

11

17000

11

240

0.39

9.3

1.4

0.061 U

0.17

1

17

47

Frequency of Plant NOEC Exceedance:

1/4

1/4

0/4

5/42

0/26

0/26

0/42

1/42

0/26

0/42

42/42

0/26

0/26

0/26

0/42

10/26

0/42

0/26

42/42

0/42

26/26

17/42

0/42

0/26

Page 9 of 12


-------
Table C-10. Comparison of Individual Sample Results to Plant and Invertebrate NOECs

Sample ID

Sample
Depth
Bottom

COPECa:

Uranium-

238

Uranium-
234

Thorium-
230

Radium-226 in
SE (Adjusted
Radium-226)

Aluminum

Antimony

Arsenic

Barium

Beryllium

Cadmium

Chromium15

Cobalt

Copper

Iron

Lead

Manganese

Molybdenum

Nickel

Selenium

Silver

Thallium

Uranium

Vanadium

Zinc

Plant NOECc:

50

44

110

5.0

NSL

11

18

110

2.5

32

0.35

13

70

NSL

120

220

2

38

0.52

NSL

0.050

25

60

160

Soil Invertebrate
NOECc:

13,000

12,000

37,000

240

NSL

78

6.8

330

40

140

0.34

NSL

80

NSL

1,700

450

NSL

280

4.1

NSL

NSL

NSL

NSL

120

Units:

pCi/g

pCi/g

pCi/g

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

mg/kg

mg/kg

mg/kg

mg/kg

Arroyos on Navajo Nation - Surface Soil (0 - 6 inches bgs)

CRPA-004.2 (2-6)

6



--

--

--

1.37

--

--

--

--

--

--

--

--

--

--

--

--

--

--

--

--

--

--

--

--

CRPA-005.1 (0-2)

2



-

-

-

1.10

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRPA-005.2 (2-6)

6



-

-

-

1.76

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRPA-006.1 (0-2)

2



-

-

-

1.84

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRPA-007.1 (0-2)

2



-

-

-

1.20

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRPA-007.2 (2-6)

6



-

-

-

1.43

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRPA-008.1 (0-2)

2



-

-

-

1.08

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRPA-009.1 (0-2)

2



-

-

-

1.20

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRPA-009.2 (2-6)

6



-

-

-

1.42

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRPA-010.1 (0-2)

2



-

-

-

1.23

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRPA-010.2 (2-6)

6



-

-

-

1.60

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRPA-011.2 (2-6)

6



-

-

-

0.92

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRPA-011.4

2



-

-

-

1.36

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRPA-012.1 (0-2)

2



-

-

-

1.29

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRPA-012.2 (2-6)

6



-

-

-

1.31

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRPA-013.1 (0-2)

2



-

-

-

1.22

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRPA-013.2 (2-6)

6



-

-

-

1.12

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRPA-014.1 (0-2)

2



-

-

-

1.79

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRPA-014.2 (2-6)

6



-

-

-

1.81

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRPA-U1.1 (0-2)

2



-

-

-

1.69

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRPA-U1.2 (2-6)

6



-

-

-

1.46

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-001.1 (0-2)

2



-

-

-

0.99

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-001.2 (2-6)

6



-

-

-

1.12

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-002.1 (0-2)

2



-

-

-

0.78

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-002.2 (2-6)

6



-

-

-

0.85

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-003.1 (0-2)

2



-

-

-

1.23

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-003.2 (2-6)

6



-

-

-

1.55

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-004.2 (2-6)

6



-

-

-

1.00

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-004.4

2



-

-

-

1.20

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-005.1 (0-2)

2



-

-

-

0.73

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-005.2 (2-6)

6



-

-

-

0.71

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-006.1 (0-2)

2



-

-

-

0.80

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-006.2 (2-6)

6



-

-

-

0.41

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-007.1 (0-2)

2



-

-

-

1.42

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-007.2 (2-6)

6



-

-

-

1.54

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-008.1 (0-2)

2



-

-

-

1.32

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-008.4

6



-

-

-

1.96

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-009.1 (0-2)

2



-

-

-

0.70

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-009.2 (2-4)

4



-

-

-

1.13

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-010.1 (0-2)

2



-

-

-

1.51

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-010.2 (2-6)

6



-

-

-

1.82

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-011.1 (0-2)

2



-

-

-

1.11

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-011.2 (2-6)

6



-

-

-

1.52

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-012.1 (0-2)

2



-

-

-

0.73

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-012.2 (2-6)

6



-

-

-

1.23

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-013.1 (0-2)

2



-

-

-

1.38

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-014.1 (0-2)

2



-

-

-

1.05

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-015.1 (0-2)

2



-

-

-

1.19

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-015.2 (2-6)

6



-

-

-

1.33

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-016.1 (0-2)

2



-

-

-

0.80

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-017.1 (0-2)

2



-

-

-

1.38

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-017.2 (2-6)

6



-

-

-

0.93

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-018.1 (0-2)

2



-

-

-

1.27

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-018.2 (2-6)

6



-

-

-

2.32

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-019.1 (0-2)

2



-

-

-

0.94

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-020.2 (2-6)

6



-

-

-

3.05

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-020.4

2



-

-

-

1.35

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-021.1 (0-2)

2



-

-

-

0.93

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-021.2 (2-6)

6



-

-

-

2.02

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-022.1 (0-2)

2



-

-

-

0.76

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-023.1 (0-2)

2



-

-

-

0.74

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-023.2 (2-6)

6



-

-

-

1.51

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-024.1 (0-2)

2



-

-

-

0.92

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-024.2 (2-6)

6



-

-

-

1.47

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-025.1 (0-2)

2



-

-

-

0.49

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

Page 10 of 12


-------
Table C-10. Comparison of Individual Sample Results to Plant and Invertebrate NOECs

Sample ID

Sample
Depth
Bottom

COPEC":

Uranium-

238

Uranium-
234

Thorium-
230

Radium-226 in
SE (Adjusted
Radium-226)

Aluminum

Antimony

Arsenic

Barium

Beryllium

Cadmium

Chromium15

Cobalt

Copper

Iron

Lead

Manganese

Molybdenum

Nickel

Selenium

Silver

Thallium

Uranium

Vanadium

Zinc

Plant NOEC":

50

44

110

5.0

NSL

11

18

110

2.5

32

0.35

13

70

NSL

120

220

2

38

0.52

NSL

0.050

25

60

160

Soil Invertebrate
NOEC":

13,000

12,000

37,000

240

NSL

78

6.8

330

40

140

0.34

NSL

80

NSL

1,700

450

NSL

280

4.1

NSL

NSL

NSL

NSL

120

Units:

pCi/g

pCi/g

pCi/g

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

mg/kg

mg/kg

mg/kg

mg/kg

CRUA-026.1 (0-2)

2



-

-

-

0.75

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-026.2 (2-6)

6



-

-

-

1.56

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-027.1 (0-2)

2



-

-

-

1.06

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-027.2 (2-6)

6



-

-

-

1.15

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-028.1 (0-2)

2



-

-

-

0.68

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-028.2 (2-6)

6



-

-

-

1.01

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-029.1 (0-2)

2



-

-

-

1.57

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-029.2 (2-6)

6



-

-

-

1.53

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-030.1 (0-2)

2



-

-

-

0.93

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-030.2 (2-6)

6



-

-

-

1.63

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-031.2 (2-6)

6



-

-

-

1.47

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-031.4

2



-

-

-

1.55

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-032.1 (0-2)

2



-

-

-

1.67

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-032.2 (2-6)

6



-

-

-

1.52

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-033.1 (0-2)

2



-

-

-

1.54

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-033.2 (2-6)

6



-

-

-

1.61

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-034.1 (0-2)

2



-

-

-

0.98

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-034.2 (2-6)

6



-

-

-

1.38

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-035.1 (0-2)

2



-

-

-

1.14

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-035.2 (2-6)

6



-

-

-

1.12

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-036.1 (0-2)

2



-

-

-

0.89

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-036.2 (2-6)

6



-

-

-

0.66

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

KMA-SS02-0000-0003-01

3



-

-

-

0.86

4700

0.04

4.40

59.00

0.38

0.05



4.00

5.10

12000.00

7.30

200.00

0.24

5.50

1.00

0.058 U

0.09

0.59

12.00

31.00

KMP-11-00

2



-

-

-

0.84

-

-

7.6

74.00

-

0.06

-

-

-

9.10

-

0.62

-

1.10

0.47 U

-

0.64

16.00

-

KM P-12-00

2



-

-

-

0.94

-

-

11

59.00

-

0.06

-

-

-

9.00

-

0.81

-

1.50

0.47 U

-

0.69

25.00

-

Frequency of Plant NOEC Exceedance:

0/0

0/0

0/0

0/90

0/1

0/1

0/3

0/3

0/1

0/3

3/3

0/1

0/1

0/1

0/3

0/1

0/3

0/1

3/3

0/3

1/1

0/3

0/3

0/1

Frequency of Soil Invertebrate NOEC Exceedance:

0/0

0/0

0/0

0/90

0/1

0/1

2/3

0/3

0/1

0/3

3/3

0/1

0/1

0/1

0/3

0/1

0/3

0/1

0/3

0/3

0/1

0/3

0/3

0/1

Frequency of Plant and Soil Invertebrate Exceedance:

0/0

0/0

0/0

0/90

0/1

0/1

2/3

0/3

0/1

0/3

3/3

0/1

0/1

0/1

0/3

0/1

0/3

0/1

3/3

0/3

1/1

0/3

0/3

0/1

Arroyos on Navajo Nation - Subsurface Soil (6 - 72 inches bgs)''

CRPA-003.3 (30-36)

36



--

--

--

1.2

--

--

--

--

--

--

--

--

--

--

--

--

--

--

--

--

--

--

--

--

CRPA-004.3 (7-13)

13



-

-

-

1.45

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRPA-005.3 (30-36)

36



-

-

-

2.66

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRPA-007.3 (6-12)

12



-

-

-

1.46

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRPA-010.3 (9-15)

15



-

-

-

1.95

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRPA-011.3 (15-21)

21



-

-

-

1.28

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRPA-012.3 (30-36)

36



-

-

-

1.21

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRPA-013.3 (30-36)

36



-

-

-

1.27

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRPA-U1.3 (14-20)

20



-

-

-

2.19

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-001.3 (14-20)

20



-

-

-

1.12

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-002.3 (13-19)

19



-

-

-

0.95

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-003.3 (6-11)

11



-

-

-

1.93

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-004.3 (14-20)

20



-

-

-

1.63

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-005.3 (30-36)

36



-

-

-

1.17

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-006.3 (30-36)

36



-

-

-

1.25

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-007.3 (6-12)

12



-

-

-

1.71

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-008.3 (18-24)

24



-

-

-

1.75

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-009.3 (16-22)

22



-

-

-

1.28

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-010.3 (30-36)

36



-

-

-

1.51

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-011.3 (30-36)

36



-

-

-

1.89

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-012.3 (30-36)

36



-

-

-

1.89

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-015.3 (30-36)

36



-

-

-

2.66

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-017.3 (30-36)

36



-

-

-

2.22

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-018.3 (30-36)

36



-

-

-

2.93

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-020.3 (30-36)

36



-

-

-

3.28

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-021.3 (30-36)

36



-

-

-

1.94

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-023.3 (30-36)

36



-

-

-

2.45

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-024.3 (30-36)

36



-

-

-

1.95

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-026.3 (30-36)

36



-

-

-

2.82

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-027.3 (30-36)

36



-

-

-

1.41

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-028.3 (30-36)

36



-

-

-

1.42

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-029.3 (30-36)

36



-

-

-

1.54

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-030.3 (6-12)

12



-

-

-

1.47

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-031.3 (30-36)

36



-

-

-

2

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-032.3 (30-36)

36



-

-

-

2.06

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-033.3 (30-36)

36



-

-

-

3.05

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-034.3 (30-36)

36



-

-

-

1.62

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

Page 11 of 12


-------
Table C-10. Comparison of Individual Sample Results to Plant and Invertebrate NOECs

Sample ID

Sample
Depth
Bottom

COPECa:

Uranium-

238

Uranium-
234

Thorium-
230

Radium-226 in
SE (Adjusted
Radium-226)

Aluminum

Antimony

Arsenic

Barium

Beryllium

Cadmium

Chromium15

Cobalt

Copper

Iron

Lead

Manganese

Molybdenum

Nickel

Selenium

Silver

Thallium

Uranium

Vanadium

Zinc

Plant NOECc:

50

44

110

5.0

NSL

11

18

110

2.5

32

0.35

13

70

NSL

120

220

2

38

0.52

NSL

0.050

25

60

160

Soil Invertebrate
NOECc:

13,000

12,000

37,000

240

NSL

78

6.8

330

40

140

0.34

NSL

80

NSL

1,700

450

NSL

280

4.1

NSL

NSL

NSL

NSL

120

Units:

pCi/g

pCi/g

pCi/g

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

mg/kg

mg/kg

mg/kg

mg/kg

CRUA-035.3 (30-36)

36



-

-

-

1.64

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-036.3 (30-36)

36



-

-

-

2.09

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

KMA-SS02-0012-0018-01

18



-

-

-

0.75

4200

0.064

5.6

75

0.39

0.073

4.5

4.5

5.1

15000

8

400

0.45

5.5

0.9

0.06 U

0.082

0.56

13

32

Frequency of Plant NOEC Exceedance:

0/0

0/0

0/0

0/40

0/1

0/1

0/1

0/1

0/1

0/1

1/1

0/1

0/1

0/1

0/1

1/1

0/1

0/1

1/1

0/1

1/1

0/1

0/1

0/1

Arroyos on United Nuclear Corporation Property- Surface Soil (0 - 6 inches bgs)

CRPA-001.1 (0-2)

2



--

--

--

0.79

--

--

--

--

--

--

--

--

--

--

--

--

--

--

--

--

--

--

--

--

CRPA-001.2 (2-6)

6



-

-

-

1.36

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRPA-002.1 (0-2)

2



-

-

-

1.07

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRPA-002.2 (2-6)

6



-

-

-

1.02

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRPA-003.1 (0-2)

2



-

-

-

0.84

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRPA-003.2 (2-6)

6



-

-

-

1.55

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-037.1 (0-2)

2



-

-

-

0.79

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-037.2 (2-6)

6



-

-

-

1.09

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-038.1 (0-2)

2



-

-

-

0.74

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-038.2 (2-6)

6



-

-

-

0.68

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-039.1 (0-2)

2



-

-

-

0.58

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-039.2 (2-6)

6



-

-

-

0.86

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

KMA-SS01 -0000-0003-01

3



-

-

-

0.85

4400

0.055

4.6

48

0.37

0.054



4.4

4.7

13000

7.5

240

0.28

5.5

1.3

0.057 U

0.09

0.53

12

30

Frequency of Plant NOEC Exceedance:

0/0

0/0

0/0

0/13

0/1

0/1

0/1

0/1

0/1

0/1

1/1

0/1

0/1

0/1

0/1

1/1

0/1

0/1

1/1

0/1

1/1

0/1

0/1

0/1

Frequency of Soil Invertebrate NOEC Exceedance:

0/0

0/0

0/0

0/13

0/1

0/1

0/1

0/1

0/1

0/1

1/1

0/1

0/1

0/1

0/1

0/1

0/1

0/1

0/1

0/1

0/1

0/1

0/1

0/1

Frequency of Plant and Soil Invertebrate Exceedance:

0/0

0/0

0/0

0/13

0/1

0/1

0/1

0/1

0/1

0/1

1/1

0/1

0/1

0/1

0/1

1/1

0/1

0/1

1/1

0/1

1/1

0/1

0/1

0/1

Arroyos on United Nuclear Corporation Property - Subsurface Soil (6 - 72 inches bgs) d

CRPA-001.3 (30-36)

36



--

--

--

1.17

--

--

--

--

--

--

--

--

--

--

--

--

--

--

--

--

-

--

--

--

CRPA-002.3 (30-36)

36



-

-

-

1.01

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRPA-003.3 (30-36)

36



-

-

-

1.2

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-037.3 (30-36)

36



-

-

-

1.83

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-038.3 (30-36)

36



-

-

-

0.69

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

CRUA-039.3 (30-36)

36



-

-

-

0.57

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

-

KMA-SS01-0012-0018-01

18



-

-

-

0.82

4700

0.067

4.8

62

0.4

0.055

5

3.9

5.4

15000

7.5

280

0.28

5.8

0.91

0.059 U

0.086

0.62

13

33

Frequency of Plant NOEC Exceedance:

0/0

0/0

0/0

0/7

0/1

0/1

0/1

0/1

0/1

0/1

1/1

0/1

0/1

0/1

0/1

1/1

0/1

0/1

1/1

0/1

1/1

0/1

0/1

0/1



Analvte Identified as Surface Soil Candidate COEC? 6

No

No

No

Yes (P)

No

No

Yes (I)

Yes (P/l)

No

No

Yes (P/l)

No

No

No

Yes (P)

Yes (P)

No

No

Yes (P/l)

No

Yes (P)

Yes (P)

No

No

Analvte Identified as Subsurface Soil Candidate COEC? 6

Yes (P)

Yes (P)

No

Yes (P)

No

No

No

Yes (P)

No

No

Yes (P)

No

No

No

No

Yes (P)

No

No

Yes (P)

No

Yes (P)

Yes (P)

No

No

Notes:

xceeds plant NOEC.

	 xceeds soil invertebrate NOEC.

|||||||||||||||||||^^	both soil invertebrate and plant NOECs.

a A constituent is included as a COPEC if the calculated SLERA HQ is equal to or greater than 1.0 (see Table C-8).

b In the absence of speciated chromium data, chromium is evaluated using the assumption that it is 100 percent hexavalent chromium (USEPA 2024b). No speciated chromium data are available. LANL chromium screening values are based on Cr(VI) (hexavalent chromium) for plants and invertebrates (Newport News Nuclear BWXT-Los Alamos, LLC. 2022).
c Screening levels for plants and invertebrates are NOECs (see Table C-8).

d Plants are exposed to surface and subsurface soil from 0 to 72 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.

6 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."

-

Not analyzed

bgs

Below ground surface

COEC

Contaminant of ecological concern

COPEC

Contaminant of potential ecological concern

HQ

Hazard quotient

mg/kg

Milligram per kilogram

NOEC

No observed effect concentration

NSL

No screening level

pCi/g

Picocurie per gram

Ra-226

Radium-226

SLERA

Screening-level ecological risk assessment

U

Not detected

USEPA

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). 2024b. "Navajo Abandoned Uranium Mines Risk Assessment Methodology." Draft Final. March.

Page 12 of 12


-------
Table C-11. Screening-Level Ecological Risk Assessment Refinement for Soil - Birds

Site-Wide

COPEC3

EPCb

Avian
Herbivore
NOEC0

Avian
Ground
Insectivore
NOEC0

Avian
Carnivore
NOEC0

Minimum
Avian
NOEC

Refined HQ
based on
Minimum
Avian NOECd

Include
Contaminant
as Candidate
COEC for
Birds?8

Surface Soil (0-6 inches bgs)

Radionuclides (pCi/q) '

Uranium-238

1.6

2,700

2,700

2,700

2,700

0.00059

No

Uranium-234

1.6

2,800

2,800

2,800

2,800

0.00057

No

Thorium-230

2.5

8,700

8,700

8,700

8,700

0.00029

No

Radium-226 in SE
(Adjusted Radium-226)

5.9

15

15

15

15

0.39

No

Metals (mg/kg)

Arsenic

5.7

67

43

1,100

43

0.13

No

Barium

94

720

820

7,500

720

0.13

No

Chromium 9

7.6

78

26

780

26

0.29

No

Lead

14

46

11

510

11

1.3

Yes

Manganese

190

4,300

4,300

650,000

4300

0.04

No

Nickel

8.3

210

20

2,800

20

0.42

No

Selenium

3.0

2.2

1.2

83

1.2

2.5

Yes

Thallium

0.14

6.9

4.5

48

4.5

0.03

No

Uranium

6.2

1,500

1,100

14,000

1100

0.01

No

Vanadium

17

13

7.8

140

7.8

2.2

Yes

Zinc

48

950

46

30,000

46

1.0

Yes

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 C-9.
cSee Table C-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 secular equilibrium. Site data for radium-226 are used to evaluate uranium-238 in SE.
g In the absence of speciated chromium data, chromium is evaluated using the assumption that it is 100 percent hexavalent
chromium (USEPA 2024b). No speciated chromium data are available. Eco-SSLs for hexavalent chromium are not available
for birds; therefore,Cr(lll) (trivalent chromium) Eco-SSLs were used (USEPA 2023a).

bgs

Below ground surface

mg/kg

Milligram per kilogram

COEC

Contaminant of ecological concern

NOEC

No observed effect concentration

COPEC

Contaminant of potential ecological concern

NSL

No screening level

Eco-SSL

Ecological soil screening level

pCi/g

Picocurie per gram

EPC

Exposure point concentration

SE

Secular equilibrium

ESL

Ecological screening level

USEPA

U.S. Environmental Protection

HQ

Hazard quotient



Agency

Page 1 of 2


-------
Table C-11. Screening-Level Ecological Risk Assessment Refinement for Soil - Birds

References:

U.S. Environmental Protection Agency (USEPA). 2023a. "Interim Ecological Soil Screening Level Documents." Accessed

July 20. https://www.epa.gov/chemical-research/interim-ecological-soil-screening-level-documents.

USEPA. 2024b. "Navajo Abandoned Uranium Mines Risk Assessment Methodology." Draft Final. March.

Page 2 of 2


-------
Table C-12. Screening-Level Ecological Risk Assessment Refinement for Soil - Mammals

Site-Wide





Mammalian

Mammalian

Ground
Insectivore
NOECc

Mammalian

Minimum
NOEC

Refined HQ
based on

Include
Contaminant

COPECa

EPCb

Herbivore
NOEC0

Carnivore
NOECc

Minimum
Mammalian

as Candidate
COEC for











NOECd

Mammals?8

Surface Soil (0-6 inches bgs)

Radionuclides (pCi/q) f

Uranium-238

1.6

1,400

1,400

1,400

1,400

0.0011

No

Uranium-234

1.6

1,400

1,400

1,400

1,400

0.0011

No

Thorium-230

2.5

3,700

3,700

3,700

3,700

0.0007

No

Radium-226 in SE
(Adjusted Radium-226)

5.9

6.0

6.0

6.0

6.0

0.98

No

Metals (mg/kg)

Arsenic

5.7

170

46

170

46

0.12

No

Barium

94

3,200

200

9,100

200

0.47

No

Chromium 9

7.6

380

34

180

34

0.22

No

Lead

14

1,200

56

460

56

0.25

No

Manganese

190

5,300

4,000

6,200

4,000

0.048

No

Nickel

8.3

340

10

130

10

0.83

No

Selenium

3.0

2.7

0.63

2.8

0.63

4.8

Yes

Thallium

0.14

1.2

0.42

5.0

0.42

0.33

No

Uranium

6.2

1,000

480

4,800

480

0.013

No

Vanadium

17

1,300

280

580

280.0

0.061

No

Zinc

48

6,800

79

10,000

79

0.61

No

Subsurface Soil (0-72 inches bgs



Radionuclides (pCi/g)

Uranium-238

12

1,400

1,400

1,400

1,400

0.0086

No

Uranium-234

12

1,400

1,400

1,400

1,400

0.0086

No

Thorium-230

2.1

3,700

3,700

3,700

3,700

0.00057

No

Radium-226 in SE
(Adjusted Radium-226)

16

6.0

6.0

6.0

6.0

2.7

Yes

Metals (mg/kg)

Arsenic

5.6

170

46

170

46

0.12

No

Barium

84

3,200

200

9,100

200

0.42

No

Chromium 9

7.5

380

34

180

34

0.22

No

Lead

13

1,200

56

460

56

0.23

No

Manganese

200

5,300

4,000

6,200

4,000

0.050

No

Molybdenum

0.52

635

4.8

64

4.8

0.11

No

Nickel

8.1

340

10

130

10

0.81

No

Selenium

3.1

2.7

0.63

2.8

0.63

4.9

Yes

Silver

0.094

1,500

14

990

14

0.0067

No

Thallium

0.14

1.2

0.42

5.0

0.42

0.33

No

Uranium

16

1,000

480

4,800

480

0.033

No

Vanadium

16

1,300

280

580

280.0

0.057

No

Zinc

46

6,800

79

10,000

79

0.58

No

Page 1 of 2


-------
Table C-12. Screening-Level Ecological Risk Assessment Refinement for Soil - Mammals

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 C-9.
cSee Table C-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.
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 secular equilibrium. Site data for radium-226 are used to evaluate uranium-238 in SE.
g In the absence of speciated chromium data, chromium is evaluated using the assumption that it is 100 percent hexavalent
chromium (USEPA 2024b). No speciated chromium data are available. Cr(lll) (trivalent chromium) Eco-SSLs were used for
mammals because the hexavalent chromium Eco-SSLs for mammals are higher than the trivalent chromium values
(USEPA 2023a).

bgs

Below ground surface

COPEC

Contaminant of potential ecological concern

Eco-SSL

Ecological soil screening level

HQ

Hazard quotient

LANL

Los Alamos National Laboratory

mg/kg

Milligram per kilogram

NA

Not applicable - receptor is not exposed to the subsurface depth interval

N3B

Newport News Nuclear BWXT-Los Alamos, LLC

NOEC

No observed effect concentration

NSL

No screening level

pCi/g

Picocurie per gram

SE

Secular equlibrium

USEPA

U.S. Environmental Protection Agency

References:

U.S. Environmental Protection Agency (USEPA). 2023a. "Interim Ecological Soil Screening Level Documents." Accessed

July 20. https://www.epa.gov/chemical-research/interim-ecological-soil-screening-level-documents.

USEPA. 2024b. "Navajo Abandoned Uranium Mines Risk Assessment Methodology." Draft Final. March.

Page 2 of 2


-------
ATTACHMENT C-l

DATA USED IN THE RISK ASSESSMENT


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1

C1 LI-047.1 (0-2)

12/14/2010

35.6665979

-108.501549

0

2

713R11

Ra-226

7.9 G

0.6

O

Q.

/g

CR1

C1 LI-047.1 (0-2) Dup

12/14/2010

35.6665979

-108.501549

0

2

713R11

Ra-226

7.9

0.6

O

Q.

/ g

CR1

C1SS-026.1 (0-2)

12/15/2010

35.6641373

-108.503343

0

2

713R11

Ra-226

26.9

0.6

O

Q.

/ g

CR1

C1SS-041.1 (0-2)

12/15/2010

35.6637671

-108.502242

0

2

713R11

Ra-226

1.42

0.8

O

Q.

/ g

CR1

C1SS-041.1 (0-2) Dup

12/15/2010

35.6637671

-108.502242

0

2

713R11

Ra-226

2.52

0.54

O

Q.

/ g

CR1

C1SS-063A.1 (0-2)

12/15/2010

35.6638077

-108.500865

0

2

713R11

Ra-226

41.2 G

0.8

O

Q.

/ g

CR1

C1SS-069.1 (0-2)

12/15/2010

35.6664561

-108.500366

0

2

713R11

Ra-226

4.68

0.41

O

Q.

/ g

CR1

C1SS-069.3 Dup

12/15/2010

35.6664561

-108.500366

0

2

713R11

Ra-226

3.7

0.54

O

Q.

/ g

CR1

C1SS-082.1 (0-2)

12/15/2010

35.6629857

-108.499478

0

2

713R11

Ra-226

1.43 G

0.39

O

Q.

/ g

CR1

C1SS-125.1 (0-2)

12/15/2010

35.665878

-108.497089

0

2

713R11

Ra-226

1.29 G

0.56

O

Q.

/g

CR1

RWPR-SS-003 (0-2)

10/8/2010

35.6660108

-108.504365

0

2

713R11

Ra-226

2.65 G

0.65

O

Q.

/g

CR1

RWPR-SS-005 (0-2)

10/8/2010

35.6658177

-108.504495

0

2

713R11

Ra-226

1.55

0.54

O

Q.

/g

CR1

RWPR-SS-019 (0-2)

10/8/2010

35.6646791

-108.504222

0

2

713R11

Ra-226

6.28 G

0.77

O

Q.

/g

CR1

RWPR-SS-021 (0-2)

10/6/2010

35.6644876

-108.504083

0

2

713R11

Ra-226

6.22

0.46

O

Q.

/g

CR1

RWPR-SS-221 (0-2)

10/6/2010

35.6644876

-108.504083

0

2

713R11

Ra-226

7.4 G

0.7

O

Q.

/g

CR1

RWPR-SS-003 (0-2)

10/8/2010

35.6660108

-108.504365

0

2

SW6020

URANIUM

3.5

11

mg/kg

CR1

RWPR-SS-005 (0-2)

10/8/2010

35.6658177

-108.504495

0

2

SW6020

URANIUM

2.1

10

mg/kg

CR1

RWPR-SS-019 (0-2)

10/8/2010

35.6646791

-108.504222

0

2

SW6020

URANIUM

6.2

11

mg/kg

CR1

RWPR-SS-021 (0-2)

10/6/2010

35.6644876

-108.504083

0

2

SW6020

URANIUM

4.7

11

mg/kg

CR1

RWPR-SS-221 (0-2)

10/6/2010

35.6644876

-108.504083

0

2

SW6020

URANIUM

4.6

12

mg/kg

CR1

CR1-SS05-0000-0003-01

5/19/2022

35.666713

-108.504141

0

3

SW6020

ALUMINUM

3300

15

mg/kg

CR1

CR1-SS06-0000-0003-01

5/19/2022

35.667094

-108.502536

0

3

SW6020

ALUMINUM

5800

16

mg/kg

CR1

CR1-SS06-0000-0003-02

5/19/2022

35.667094

-108.502536

0

3

SW6020

ALUMINUM

5000

15

mg/kg

CR1

CR1-SS07-0000-0003-01

5/19/2022

35.667085

-108.501729

0

3

SW6020

ALUMINUM

4500

16

mg/kg

CR1

CR1-SS08-0000-0003-01

5/19/2022

35.666503

-108.503201

0

3

SW6020

ALUMINUM

4400

15

mg/kg

CR1

CR1-SS09-0000-0003-01

5/19/2022

35.666327

-108.502514

0

3

SW6020

ALUMINUM

5900

15

mg/kg

CR1

CR1-SS10-0000-0003-01

5/19/2022

35.666522

-108.501608

0

3

SW6020

ALUMINUM

3100

16

mg/kg

CR1

CR1-SS11-0000-0003-01

5/19/2022

35.666126

-108.501314

0

3

SW6020

ALUMINUM

4100

15

mg/kg

CR1

CR1-SS12-0000-0003-01

5/19/2022

35.666314

-108.500988

0

3

SW6020

ALUMINUM

3600

15

mg/kg

CR1

CR1-SS13-0000-0003-01

5/19/2022

35.666176

-108.499679

0

3

SW6020

ALUMINUM

4400

15

mg/kg

CR1

CR1-SS14-0000-0003-01

5/19/2022

35.666944

-108.499149

0

3

SW6020

ALUMINUM

3700

17

mg/kg

CR1

CR1-SS15-0000-0003-01

5/18/2022

35.66634

-108.498

0

3

SW6020

ALUMINUM

4100

15

mg/kg

CR1

CR1-SS15-0000-0003-02

5/18/2022

35.66634

-108.498

0

3

SW6020

ALUMINUM

4300

15

mg/kg

CR1

CR1-SS16-0000-0003-01

5/18/2022

35.66598

-108.498

0

3

SW6020

ALUMINUM

4300

15

mg/kg

CR1

CR1-SS17-0000-0003-01

5/18/2022

35.665398

-108.498872

0

3

SW6020

ALUMINUM

2300

15

mg/kg

CR1

CR1-SS18-0000-0003-01

5/18/2022

35.665202

-108.499554

0

3

SW6020

ALUMINUM

3900

15

mg/kg

CR1

CR1-SS19-0000-0003-01

5/18/2022

35.665408

-108.500208

0

3

SW6020

ALUMINUM

3500

15

mg/kg

CR1

CR1-SS20-0000-0003-01

5/19/2022

35.664437

-108.499566

0

3

SW6020

ALUMINUM

2900

15

mg/kg

CR1

CR1-SS21 -0000-0003-01

5/19/2022

35.663695

-108.499566

0

3

SW6020

ALUMINUM

7000

16

mg/kg

CR1

CR1-SS22-0000-0003-01

5/19/2022

35.663664

-108.500468

0

3

SW6020

ALUMINUM

5600

15

mg/kg

CR1

CR1-SS22-0000-0003-02

5/19/2022

35.663664

-108.500468

0

3

SW6020

ALUMINUM

5900

15

mg/kg

CR1

CR1-SS23-0000-0003-01

5/19/2022

35.663755

-108.501126

0

3

SW6020

ALUMINUM

5600

17

mg/kg

Page 1 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1

CR1-SS24-0000-0003-01

5/19/2022

35.664237

-108.500743

0

3

SW6020

ALUMINUM

6200

16

mg/kg

CR1

CR1-SS25-0000-0003-01

5/19/2022

35.664474

-108.500594

0

3

SW6020

ALUMINUM

4600

16

mg/kg

CR1

CR1-SS26-0000-0003-01

5/19/2022

35.664639

-108.501293

0

3

SW6020

ALUMINUM

4400

16

mg/kg

CR1

CR1-SS27-0000-0003-01

5/19/2022

35.664035

-108.501678

0

3

SW6020

ALUMINUM

3300

15

mg/kg

CR1

CR1-SS28-0000-0003-01

5/19/2022

35.664057

-108.503308

0

3

SW6020

ALUMINUM

3600

16

mg/kg

CR1

CR1-SS29-0000-0003-01

5/19/2022

35.66443

-108.504

0

3

SW6020

ALUMINUM

4400

15

mg/kg

CR1

CR1-SS30-0000-0003-01

5/19/2022

35.665182

-108.504127

0

3

SW6020

ALUMINUM

4000

16

mg/kg

CR1

CR1-SS31 -0000-0003-01

5/19/2022

35.665752

-108.504261

0

3

SW6020

ALUMINUM

4600

15

mg/kg

CR1

CR1-SS32-0000-0003-01

5/19/2022

35.665946

-108.50414

0

3

SW6020

ALUMINUM

4200

15

mg/kg

CR1

CR1-SS33-0000-0003-01

5/19/2022

35.663477

-108.501566

0

3

SW6020

ALUMINUM

1400

15

mg/kg

CR1

CR1-SS34-0000-0003-01

5/19/2022

35.66306

-108.5

0

3

SW6020

ALUMINUM

4800

15

mg/kg

CR1

CR1-SS05-0000-0003-01

5/19/2022

35.666713

-108.504141

0

3

SW6020

ANTIMONY

0.088 J

0.1

mg/kg

CR1

CR1-SS06-0000-0003-01

5/19/2022

35.667094

-108.502536

0

3

SW6020

ANTIMONY

0.18

0.11

mg/kg

CR1

CR1-SS06-0000-0003-02

5/19/2022

35.667094

-108.502536

0

3

SW6020

ANTIMONY

0.19

0.1

mg/kg

CR1

CR1-SS07-0000-0003-01

5/19/2022

35.667085

-108.501729

0

3

SW6020

ANTIMONY

0.098 J

0.11

mg/kg

CR1

CR1-SS08-0000-0003-01

5/19/2022

35.666503

-108.503201

0

3

SW6020

ANTIMONY

0.16

0.1

mg/kg

CR1

CR1-SS09-0000-0003-01

5/19/2022

35.666327

-108.502514

0

3

SW6020

ANTIMONY

0.19

0.1

mg/kg

CR1

CR1-SS10-0000-0003-01

5/19/2022

35.666522

-108.501608

0

3

SW6020

ANTIMONY

0.14 J

0.11

mg/kg

CR1

CR1-SS11-0000-0003-01

5/19/2022

35.666126

-108.501314

0

3

SW6020

ANTIMONY

0.12

0.1

mg/kg

CR1

CR1-SS12-0000-0003-01

5/19/2022

35.666314

-108.500988

0

3

SW6020

ANTIMONY

0.038 J

0.1

mg/kg

CR1

CR1-SS13-0000-0003-01

5/19/2022

35.666176

-108.499679

0

3

SW6020

ANTIMONY

0.18

0.1

mg/kg

CR1

CR1-SS14-0000-0003-01

5/19/2022

35.666944

-108.499149

0

3

SW6020

ANTIMONY

0.12

0.11

mg/kg

CR1

CR1-SS15-0000-0003-01

5/18/2022

35.66634

-108.498

0

3

SW6020

ANTIMONY

0.082 J

0.1

mg/kg

CR1

CR1-SS15-0000-0003-02

5/18/2022

35.66634

-108.498

0

3

SW6020

ANTIMONY

0.097 J

0.1

mg/kg

CR1

CR1-SS16-0000-0003-01

5/18/2022

35.66598

-108.498

0

3

SW6020

ANTIMONY

0.14

0.1

mg/kg

CR1

CR1-SS17-0000-0003-01

5/18/2022

35.665398

-108.498872

0

3

SW6020

ANTIMONY

0.1

0.1

mg/kg

CR1

CR1-SS18-0000-0003-01

5/18/2022

35.665202

-108.499554

0

3

SW6020

ANTIMONY

0.14

0.1

mg/kg

CR1

CR1-SS19-0000-0003-01

5/18/2022

35.665408

-108.500208

0

3

SW6020

ANTIMONY

0.11

0.1

mg/kg

CR1

CR1-SS20-0000-0003-01

5/19/2022

35.664437

-108.499566

0

3

SW6020

ANTIMONY

0.076 J

0.1

mg/kg

CR1

CR1-SS21 -0000-0003-01

5/19/2022

35.663695

-108.499566

0

3

SW6020

ANTIMONY

0.22

0.1

mg/kg

CR1

CR1-SS22-0000-0003-01

5/19/2022

35.663664

-108.500468

0

3

SW6020

ANTIMONY

0.13

0.1

mg/kg

CR1

CR1-SS22-0000-0003-02

5/19/2022

35.663664

-108.500468

0

3

SW6020

ANTIMONY

0.11

0.1

mg/kg

CR1

CR1-SS23-0000-0003-01

5/19/2022

35.663755

-108.501126

0

3

SW6020

ANTIMONY

0.14

0.12

mg/kg

CR1

CR1-SS24-0000-0003-01

5/19/2022

35.664237

-108.500743

0

3

SW6020

ANTIMONY

0.11

0.11

mg/kg

CR1

CR1-SS25-0000-0003-01

5/19/2022

35.664474

-108.500594

0

3

SW6020

ANTIMONY

0.13

0.11

mg/kg

CR1

CR1-SS26-0000-0003-01

5/19/2022

35.664639

-108.501293

0

3

SW6020

ANTIMONY

0.16 J

0.11

mg/kg

CR1

CR1-SS27-0000-0003-01

5/19/2022

35.664035

-108.501678

0

3

SW6020

ANTIMONY

0.15

0.1

mg/kg

CR1

CR1-SS28-0000-0003-01

5/19/2022

35.664057

-108.503308

0

3

SW6020

ANTIMONY

0.11 J

0.11

mg/kg

CR1

CR1-SS29-0000-0003-01

5/19/2022

35.66443

-108.504

0

3

SW6020

ANTIMONY

0.12

0.1

mg/kg

CR1

CR1-SS30-0000-0003-01

5/19/2022

35.665182

-108.504127

0

3

SW6020

ANTIMONY

0.089 J

0.11

mg/kg

CR1

CR1-SS31 -0000-0003-01

5/19/2022

35.665752

-108.504261

0

3

SW6020

ANTIMONY

0.078 J

0.1

mg/kg

CR1

CR1-SS32-0000-0003-01

5/19/2022

35.665946

-108.50414

0

3

SW6020

ANTIMONY

0.13

0.1

mg/kg

Page 2 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1

CR1-SS33-0000-0003-01

5/19/2022

35.663477

-108.501566

0

3

SW6020

ANTIMONY

0.055 J

0.1

mg/kg

CR1

CR1-SS34-0000-0003-01

5/19/2022

35.66306

-108.5

0

3

SW6020

ANTIMONY

0.14

0.1

mg/kg

CR1

CR1-SS05-0000-0003-01

5/19/2022

35.666713

-108.504141

0

3

SW6020

ARSENIC

3.6

0.2

mg/kg

CR1

CR1-SS06-0000-0003-01

5/19/2022

35.667094

-108.502536

0

3

SW6020

ARSENIC

5.8

0.21

mg/kg

CR1

CR1-SS06-0000-0003-02

5/19/2022

35.667094

-108.502536

0

3

SW6020

ARSENIC

5.2

0.2

mg/kg

CR1

CR1-SS07-0000-0003-01

5/19/2022

35.667085

-108.501729

0

3

SW6020

ARSENIC

3.5

0.21

mg/kg

CR1

CR1-SS08-0000-0003-01

5/19/2022

35.666503

-108.503201

0

3

SW6020

ARSENIC

5.3

0.21

mg/kg

CR1

CR1-SS09-0000-0003-01

5/19/2022

35.666327

-108.502514

0

3

SW6020

ARSENIC

5.3

0.2

mg/kg

CR1

CR1-SS10-0000-0003-01

5/19/2022

35.666522

-108.501608

0

3

SW6020

ARSENIC

5.9

0.22

mg/kg

CR1

CR1-SS11-0000-0003-01

5/19/2022

35.666126

-108.501314

0

3

SW6020

ARSENIC

4.6

0.2

mg/kg

CR1

CR1-SS12-0000-0003-01

5/19/2022

35.666314

-108.500988

0

3

SW6020

ARSENIC

2.9

0.2

mg/kg

CR1

CR1-SS13-0000-0003-01

5/19/2022

35.666176

-108.499679

0

3

SW6020

ARSENIC

4.8

0.2

mg/kg

CR1

CR1-SS14-0000-0003-01

5/19/2022

35.666944

-108.499149

0

3

SW6020

ARSENIC

4.2

0.23

mg/kg

CR1

CR1-SS15-0000-0003-01

5/18/2022

35.66634

-108.498

0

3

SW6020

ARSENIC

4

0.2

mg/kg

CR1

CR1-SS15-0000-0003-02

5/18/2022

35.66634

-108.498

0

3

SW6020

ARSENIC

4.2

0.2

mg/kg

CR1

CR1-SS16-0000-0003-01

5/18/2022

35.66598

-108.498

0

3

SW6020

ARSENIC

5

0.21

mg/kg

CR1

CR1-SS17-0000-0003-01

5/18/2022

35.665398

-108.498872

0

3

SW6020

ARSENIC

3.7

0.2

mg/kg

CR1

CR1-SS18-0000-0003-01

5/18/2022

35.665202

-108.499554

0

3

SW6020

ARSENIC

4.7

0.2

mg/kg

CR1

CR1-SS19-0000-0003-01

5/18/2022

35.665408

-108.500208

0

3

SW6020

ARSENIC

4.1

0.2

mg/kg

CR1

CR1-SS20-0000-0003-01

5/19/2022

35.664437

-108.499566

0

3

SW6020

ARSENIC

3.8

0.2

mg/kg

CR1

CR1-SS21-0000-0003-01

5/19/2022

35.663695

-108.499566

0

3

SW6020

ARSENIC

5.9

0.21

mg/kg

CR1

CR1-SS22-0000-0003-01

5/19/2022

35.663664

-108.500468

0

3

SW6020

ARSENIC

5.3

0.2

mg/kg

CR1

CR1-SS22-0000-0003-02

5/19/2022

35.663664

-108.500468

0

3

SW6020

ARSENIC

5.1

0.2

mg/kg

CR1

CR1-SS23-0000-0003-01

5/19/2022

35.663755

-108.501126

0

3

SW6020

ARSENIC

5.8

0.23

mg/kg

CR1

CR1-SS24-0000-0003-01

5/19/2022

35.664237

-108.500743

0

3

SW6020

ARSENIC

5.3

0.21

mg/kg

CR1

CR1-SS25-0000-0003-01

5/19/2022

35.664474

-108.500594

0

3

SW6020

ARSENIC

6.1

0.22

mg/kg

CR1

CR1-SS26-0000-0003-01

5/19/2022

35.664639

-108.501293

0

3

SW6020

ARSENIC

6.1

0.22

mg/kg

CR1

CR1-SS27-0000-0003-01

5/19/2022

35.664035

-108.501678

0

3

SW6020

ARSENIC

4.3

0.21

mg/kg

CR1

CR1-SS28-0000-0003-01

5/19/2022

35.664057

-108.503308

0

3

SW6020

ARSENIC

3.5

0.22

mg/kg

CR1

CR1-SS29-0000-0003-01

5/19/2022

35.66443

-108.504

0

3

SW6020

ARSENIC

4.7

0.2

mg/kg

CR1

CR1-SS30-0000-0003-01

5/19/2022

35.665182

-108.504127

0

3

SW6020

ARSENIC

4.3

0.21

mg/kg

CR1

CR1-SS31 -0000-0003-01

5/19/2022

35.665752

-108.504261

0

3

SW6020

ARSENIC

3.6

0.2

mg/kg

CR1

CR1-SS32-0000-0003-01

5/19/2022

35.665946

-108.50414

0

3

SW6020

ARSENIC

4.1

0.2

mg/kg

CR1

CR1-SS33-0000-0003-01

5/19/2022

35.663477

-108.501566

0

3

SW6020

ARSENIC

3

0.2

mg/kg

CR1

CR1-SS34-0000-0003-01

5/19/2022

35.66306

-108.5

0

3

SW6020

ARSENIC

5

0.2

mg/kg

CR1

CR1-SS05-0000-0003-01

5/19/2022

35.666713

-108.504141

0

3

SW6020

BARIUM

68

0.51

mg/kg

CR1

CR1-SS06-0000-0003-01

5/19/2022

35.667094

-108.502536

0

3

SW6020

BARIUM

79

0.53

mg/kg

CR1

CR1-SS06-0000-0003-02

5/19/2022

35.667094

-108.502536

0

3

SW6020

BARIUM

86

0.51

mg/kg

CR1

CR1-SS07-0000-0003-01

5/19/2022

35.667085

-108.501729

0

3

SW6020

BARIUM

87

0.53

mg/kg

CR1

CR1-SS08-0000-0003-01

5/19/2022

35.666503

-108.503201

0

3

SW6020

BARIUM

89

0.51

mg/kg

CR1

CR1-SS09-0000-0003-01

5/19/2022

35.666327

-108.502514

0

3

SW6020

BARIUM

65

0.51

mg/kg

CR1

CR1-SS10-0000-0003-01

5/19/2022

35.666522

-108.501608

0

3

SW6020

BARIUM

43 J

0.55

mg/kg

Page 3 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1

CR1-SS11-0000-0003-01

5/19/2022

35.666126

-108.501314

0

3

SW6020

BARIUM

78

0.51

mg/kg

CR1

CR1-SS12-0000-0003-01

5/19/2022

35.666314

-108.500988

0

3

SW6020

BARIUM

36

0.5

mg/kg

CR1

CR1-SS13-0000-0003-01

5/19/2022

35.666176

-108.499679

0

3

SW6020

BARIUM

85

0.5

mg/kg

CR1

CR1-SS14-0000-0003-01

5/19/2022

35.666944

-108.499149

0

3

SW6020

BARIUM

77

0.57

mg/kg

CR1

CR1-SS15-0000-0003-01

5/18/2022

35.66634

-108.498

0

3

SW6020

BARIUM

97

0.5

mg/kg

CR1

CR1-SS15-0000-0003-02

5/18/2022

35.66634

-108.498

0

3

SW6020

BARIUM

120

0.5

mg/kg

CR1

CR1-SS16-0000-0003-01

5/18/2022

35.66598

-108.498

0

3

SW6020

BARIUM

94

0.51

mg/kg

CR1

CR1-SS17-0000-0003-01

5/18/2022

35.665398

-108.498872

0

3

SW6020

BARIUM

80

0.5

mg/kg

CR1

CR1-SS18-0000-0003-01

5/18/2022

35.665202

-108.499554

0

3

SW6020

BARIUM

90

0.5

mg/kg

CR1

CR1-SS19-0000-0003-01

5/18/2022

35.665408

-108.500208

0

3

SW6020

BARIUM

210

0.5

mg/kg

CR1

CR1-SS20-0000-0003-01

5/19/2022

35.664437

-108.499566

0

3

SW6020

BARIUM

54

0.5

mg/kg

CR1

CR1-SS21 -0000-0003-01

5/19/2022

35.663695

-108.499566

0

3

SW6020

BARIUM

100

0.52

mg/kg

CR1

CR1-SS22-0000-0003-01

5/19/2022

35.663664

-108.500468

0

3

SW6020

BARIUM

110

0.5

mg/kg

CR1

CR1-SS22-0000-0003-02

5/19/2022

35.663664

-108.500468

0

3

SW6020

BARIUM

110

0.51

mg/kg

CR1

CR1-SS23-0000-0003-01

5/19/2022

35.663755

-108.501126

0

3

SW6020

BARIUM

98

0.58

mg/kg

CR1

CR1-SS24-0000-0003-01

5/19/2022

35.664237

-108.500743

0

3

SW6020

BARIUM

330

0.53

mg/kg

CR1

CR1-SS25-0000-0003-01

5/19/2022

35.664474

-108.500594

0

3

SW6020

BARIUM

98

0.55

mg/kg

CR1

CR1-SS26-0000-0003-01

5/19/2022

35.664639

-108.501293

0

3

SW6020

BARIUM

100

0.54

mg/kg

CR1

CR1-SS27-0000-0003-01

5/19/2022

35.664035

-108.501678

0

3

SW6020

BARIUM

66

0.52

mg/kg

CR1

CR1-SS28-0000-0003-01

5/19/2022

35.664057

-108.503308

0

3

SW6020

BARIUM

66

0.55

mg/kg

CR1

CR1-SS29-0000-0003-01

5/19/2022

35.66443

-108.504

0

3

SW6020

BARIUM

95

0.51

mg/kg

CR1

CR1-SS30-0000-0003-01

5/19/2022

35.665182

-108.504127

0

3

SW6020

BARIUM

66

0.53

mg/kg

CR1

CR1-SS31-0000-0003-01

5/19/2022

35.665752

-108.504261

0

3

SW6020

BARIUM

41

0.51

mg/kg

CR1

CR1-SS32-0000-0003-01

5/19/2022

35.665946

-108.50414

0

3

SW6020

BARIUM

83

0.51

mg/kg

CR1

CR1-SS33-0000-0003-01

5/19/2022

35.663477

-108.501566

0

3

SW6020

BARIUM

63

0.5

mg/kg

CR1

CR1-SS34-0000-0003-01

5/19/2022

35.66306

-108.5

0

3

SW6020

BARIUM

86

0.51

mg/kg

CR1

CR1-SS05-0000-0003-01

5/19/2022

35.666713

-108.504141

0

3

SW6020

BERYLLIUM

0.47

0.051

mg/kg

CR1

CR1-SS06-0000-0003-01

5/19/2022

35.667094

-108.502536

0

3

SW6020

BERYLLIUM

0.87

0.053

mg/kg

CR1

CR1-SS06-0000-0003-02

5/19/2022

35.667094

-108.502536

0

3

SW6020

BERYLLIUM

0.75

0.051

mg/kg

CR1

CR1-SS07-0000-0003-01

5/19/2022

35.667085

-108.501729

0

3

SW6020

BERYLLIUM

0.54

0.053

mg/kg

CR1

CR1-SS08-0000-0003-01

5/19/2022

35.666503

-108.503201

0

3

SW6020

BERYLLIUM

0.63

0.051

mg/kg

CR1

CR1-SS09-0000-0003-01

5/19/2022

35.666327

-108.502514

0

3

SW6020

BERYLLIUM

0.8

0.051

mg/kg

CR1

CR1-SS10-0000-0003-01

5/19/2022

35.666522

-108.501608

0

3

SW6020

BERYLLIUM

0.5

0.055

mg/kg

CR1

CR1-SS11-0000-0003-01

5/19/2022

35.666126

-108.501314

0

3

SW6020

BERYLLIUM

0.61

0.051

mg/kg

CR1

CR1-SS12-0000-0003-01

5/19/2022

35.666314

-108.500988

0

3

SW6020

BERYLLIUM

0.56

0.05

mg/kg

CR1

CR1-SS13-0000-0003-01

5/19/2022

35.666176

-108.499679

0

3

SW6020

BERYLLIUM

0.68

0.05

mg/kg

CR1

CR1-SS14-0000-0003-01

5/19/2022

35.666944

-108.499149

0

3

SW6020

BERYLLIUM

0.52

0.057

mg/kg

CR1

CR1-SS15-0000-0003-01

5/18/2022

35.66634

-108.498

0

3

SW6020

BERYLLIUM

0.43

0.05

mg/kg

CR1

CR1-SS15-0000-0003-02

5/18/2022

35.66634

-108.498

0

3

SW6020

BERYLLIUM

0.46

0.05

mg/kg

CR1

CR1-SS16-0000-0003-01

5/18/2022

35.66598

-108.498

0

3

SW6020

BERYLLIUM

0.62

0.051

mg/kg

CR1

CR1-SS17-0000-0003-01

5/18/2022

35.665398

-108.498872

0

3

SW6020

BERYLLIUM

0.32

0.05

mg/kg

CR1

CR1-SS18-0000-0003-01

5/18/2022

35.665202

-108.499554

0

3

SW6020

BERYLLIUM

0.57

0.05

mg/kg

Page 4 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1

CR1-SS19-0000-0003-01

5/18/2022

35.665408

-108.500208

0

3

SW6020

BERYLLIUM

0.45

0.05

mg/kg

CR1

CR1-SS20-0000-0003-01

5/19/2022

35.664437

-108.499566

0

3

SW6020

BERYLLIUM

0.38

0.05

mg/kg

CR1

CR1-SS21 -0000-0003-01

5/19/2022

35.663695

-108.499566

0

3

SW6020

BERYLLIUM

0.97

0.052

mg/kg

CR1

CR1-SS22-0000-0003-01

5/19/2022

35.663664

-108.500468

0

3

SW6020

BERYLLIUM

0.69

0.05

mg/kg

CR1

CR1-SS22-0000-0003-02

5/19/2022

35.663664

-108.500468

0

3

SW6020

BERYLLIUM

0.71

0.051

mg/kg

CR1

CR1-SS23-0000-0003-01

5/19/2022

35.663755

-108.501126

0

3

SW6020

BERYLLIUM

0.8

0.058

mg/kg

CR1

CR1-SS24-0000-0003-01

5/19/2022

35.664237

-108.500743

0

3

SW6020

BERYLLIUM

0.78

0.053

mg/kg

CR1

CR1-SS25-0000-0003-01

5/19/2022

35.664474

-108.500594

0

3

SW6020

BERYLLIUM

0.62

0.055

mg/kg

CR1

CR1-SS26-0000-0003-01

5/19/2022

35.664639

-108.501293

0

3

SW6020

BERYLLIUM

0.71

0.054

mg/kg

CR1

CR1-SS27-0000-0003-01

5/19/2022

35.664035

-108.501678

0

3

SW6020

BERYLLIUM

0.5

0.052

mg/kg

CR1

CR1-SS28-0000-0003-01

5/19/2022

35.664057

-108.503308

0

3

SW6020

BERYLLIUM

0.43

0.055

mg/kg

CR1

CR1-SS29-0000-0003-01

5/19/2022

35.66443

-108.504

0

3

SW6020

BERYLLIUM

0.62

0.051

mg/kg

CR1

CR1-SS30-0000-0003-01

5/19/2022

35.665182

-108.504127

0

3

SW6020

BERYLLIUM

0.49

0.053

mg/kg

CR1

CR1-SS31 -0000-0003-01

5/19/2022

35.665752

-108.504261

0

3

SW6020

BERYLLIUM

0.44

0.051

mg/kg

CR1

CR1-SS32-0000-0003-01

5/19/2022

35.665946

-108.50414

0

3

SW6020

BERYLLIUM

0.57

0.051

mg/kg

CR1

CR1-SS33-0000-0003-01

5/19/2022

35.663477

-108.501566

0

3

SW6020

BERYLLIUM

0.2

0.05

mg/kg

CR1

CR1-SS34-0000-0003-01

5/19/2022

35.66306

-108.5

0

3

SW6020

BERYLLIUM

0.62

0.051

mg/kg

CR1

CR1-SS05-0000-0003-01

5/19/2022

35.666713

-108.504141

0

3

SW6020

CADMIUM

0.083 J

0.2

mg/kg

CR1

CR1-SS06-0000-0003-01

5/19/2022

35.667094

-108.502536

0

3

SW6020

CADMIUM

0.22

0.21

mg/kg

CR1

CR1-SS06-0000-0003-02

5/19/2022

35.667094

-108.502536

0

3

SW6020

CADMIUM

0.21

0.2

mg/kg

CR1

CR1-SS07-0000-0003-01

5/19/2022

35.667085

-108.501729

0

3

SW6020

CADMIUM

0.1 J

0.21

mg/kg

CR1

CR1-SS08-0000-0003-01

5/19/2022

35.666503

-108.503201

0

3

SW6020

CADMIUM

0.12 J

0.21

mg/kg

CR1

CR1-SS09-0000-0003-01

5/19/2022

35.666327

-108.502514

0

3

SW6020

CADMIUM

0.21

0.2

mg/kg

CR1

CR1-SS10-0000-0003-01

5/19/2022

35.666522

-108.501608

0

3

SW6020

CADMIUM

0.13 J

0.22

mg/kg

CR1

CR1-SS11-0000-0003-01

5/19/2022

35.666126

-108.501314

0

3

SW6020

CADMIUM

0.12 J

0.2

mg/kg

CR1

CR1-SS12-0000-0003-01

5/19/2022

35.666314

-108.500988

0

3

SW6020

CADMIUM

0.038 U

0.2

mg/kg

CR1

CR1-SS13-0000-0003-01

5/19/2022

35.666176

-108.499679

0

3

SW6020

CADMIUM

0.14 J

0.2

mg/kg

CR1

CR1-SS14-0000-0003-01

5/19/2022

35.666944

-108.499149

0

3

SW6020

CADMIUM

0.13 J

0.23

mg/kg

CR1

CR1-SS15-0000-0003-01

5/18/2022

35.66634

-108.498

0

3

SW6020

CADMIUM

0.1 J

0.2

mg/kg

CR1

CR1-SS15-0000-0003-02

5/18/2022

35.66634

-108.498

0

3

SW6020

CADMIUM

0.09 J

0.2

mg/kg

CR1

CR1-SS16-0000-0003-01

5/18/2022

35.66598

-108.498

0

3

SW6020

CADMIUM

0.13 J

0.21

mg/kg

CR1

CR1-SS17-0000-0003-01

5/18/2022

35.665398

-108.498872

0

3

SW6020

CADMIUM

0.065 J

0.2

mg/kg

CR1

CR1-SS18-0000-0003-01

5/18/2022

35.665202

-108.499554

0

3

SW6020

CADMIUM

0.13 J

0.2

mg/kg

CR1

CR1-SS19-0000-0003-01

5/18/2022

35.665408

-108.500208

0

3

SW6020

CADMIUM

0.081 J

0.2

mg/kg

CR1

CR1-SS20-0000-0003-01

5/19/2022

35.664437

-108.499566

0

3

SW6020

CADMIUM

0.086 J

0.2

mg/kg

CR1

CR1-SS21 -0000-0003-01

5/19/2022

35.663695

-108.499566

0

3

SW6020

CADMIUM

0.25

0.21

mg/kg

CR1

CR1-SS22-0000-0003-01

5/19/2022

35.663664

-108.500468

0

3

SW6020

CADMIUM

0.14 J

0.2

mg/kg

CR1

CR1-SS22-0000-0003-02

5/19/2022

35.663664

-108.500468

0

3

SW6020

CADMIUM

0.13 J

0.2

mg/kg

CR1

CR1-SS23-0000-0003-01

5/19/2022

35.663755

-108.501126

0

3

SW6020

CADMIUM

0.19 J

0.23

mg/kg

CR1

CR1-SS24-0000-0003-01

5/19/2022

35.664237

-108.500743

0

3

SW6020

CADMIUM

0.18 J

0.21

mg/kg

CR1

CR1-SS25-0000-0003-01

5/19/2022

35.664474

-108.500594

0

3

SW6020

CADMIUM

0.17 J

0.22

mg/kg

CR1

CR1-SS26-0000-0003-01

5/19/2022

35.664639

-108.501293

0

3

SW6020

CADMIUM

0.15 J

0.22

mg/kg

Page 5 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1

CR1-SS27-0000-0003-01

5/19/2022

35.664035

-108.501678

0

3

SW6020

CADMIUM

0.12 J

0.21

mg/kg

CR1

CR1-SS28-0000-0003-01

5/19/2022

35.664057

-108.503308

0

3

SW6020

CADMIUM

0.12 J

0.22

mg/kg

CR1

CR1-SS29-0000-0003-01

5/19/2022

35.66443

-108.504

0

3

SW6020

CADMIUM

0.15 J

0.2

mg/kg

CR1

CR1-SS30-0000-0003-01

5/19/2022

35.665182

-108.504127

0

3

SW6020

CADMIUM

0.11 J

0.21

mg/kg

CR1

CR1-SS31 -0000-0003-01

5/19/2022

35.665752

-108.504261

0

3

SW6020

CADMIUM

0.11 J

0.2

mg/kg

CR1

CR1-SS32-0000-0003-01

5/19/2022

35.665946

-108.50414

0

3

SW6020

CADMIUM

0.13 J

0.2

mg/kg

CR1

CR1-SS33-0000-0003-01

5/19/2022

35.663477

-108.501566

0

3

SW6020

CADMIUM

0.051 J

0.2

mg/kg

CR1

CR1-SS34-0000-0003-01

5/19/2022

35.66306

-108.5

0

3

SW6020

CADMIUM

0.12 J

0.2

mg/kg

CR1

CR1-SS05-0000-0003-01

5/19/2022

35.666713

-108.504141

0

3

SW6020

CHROMIUM

4

1

mg/kg

CR1

CR1-SS06-0000-0003-01

5/19/2022

35.667094

-108.502536

0

3

SW6020

CHROMIUM

6.1

1.1

mg/kg

CR1

CR1-SS06-0000-0003-02

5/19/2022

35.667094

-108.502536

0

3

SW6020

CHROMIUM

5.4

1

mg/kg

CR1

CR1-SS07-0000-0003-01

5/19/2022

35.667085

-108.501729

0

3

SW6020

CHROMIUM

4.1

1.1

mg/kg

CR1

CR1-SS08-0000-0003-01

5/19/2022

35.666503

-108.503201

0

3

SW6020

CHROMIUM

4.9

1

mg/kg

CR1

CR1-SS09-0000-0003-01

5/19/2022

35.666327

-108.502514

0

3

SW6020

CHROMIUM

6.8

1

mg/kg

CR1

CR1-SS10-0000-0003-01

5/19/2022

35.666522

-108.501608

0

3

SW6020

CHROMIUM

3.4

1.1

mg/kg

CR1

CR1-SS11-0000-0003-01

5/19/2022

35.666126

-108.501314

0

3

SW6020

CHROMIUM

4.3

1

mg/kg

CR1

CR1-SS12-0000-0003-01

5/19/2022

35.666314

-108.500988

0

3

SW6020

CHROMIUM

4.1

1

mg/kg

CR1

CR1-SS13-0000-0003-01

5/19/2022

35.666176

-108.499679

0

3

SW6020

CHROMIUM

4.7

1

mg/kg

CR1

CR1-SS14-0000-0003-01

5/19/2022

35.666944

-108.499149

0

3

SW6020

CHROMIUM

4

1.1

mg/kg

CR1

CR1-SS15-0000-0003-01

5/18/2022

35.66634

-108.498

0

3

SW6020

CHROMIUM

4.3

1

mg/kg

CR1

CR1-SS15-0000-0003-02

5/18/2022

35.66634

-108.498

0

3

SW6020

CHROMIUM

4.8

1

mg/kg

CR1

CR1-SS16-0000-0003-01

5/18/2022

35.66598

-108.498

0

3

SW6020

CHROMIUM

4.5

1

mg/kg

CR1

CR1-SS17-0000-0003-01

5/18/2022

35.665398

-108.498872

0

3

SW6020

CHROMIUM

2.7

1

mg/kg

CR1

CR1-SS18-0000-0003-01

5/18/2022

35.665202

-108.499554

0

3

SW6020

CHROMIUM

4.6

1

mg/kg

CR1

CR1-SS19-0000-0003-01

5/18/2022

35.665408

-108.500208

0

3

SW6020

CHROMIUM

4.2

1

mg/kg

CR1

CR1-SS20-0000-0003-01

5/19/2022

35.664437

-108.499566

0

3

SW6020

CHROMIUM

3

1

mg/kg

CR1

CR1-SS21 -0000-0003-01

5/19/2022

35.663695

-108.499566

0

3

SW6020

CHROMIUM

7.5

1

mg/kg

CR1

CR1-SS22-0000-0003-01

5/19/2022

35.663664

-108.500468

0

3

SW6020

CHROMIUM

11

1

mg/kg

CR1

CR1-SS22-0000-0003-02

5/19/2022

35.663664

-108.500468

0

3

SW6020

CHROMIUM

12

1

mg/kg

CR1

CR1-SS23-0000-0003-01

5/19/2022

35.663755

-108.501126

0

3

SW6020

CHROMIUM

6

1.2

mg/kg

CR1

CR1-SS24-0000-0003-01

5/19/2022

35.664237

-108.500743

0

3

SW6020

CHROMIUM

6.4

1.1

mg/kg

CR1

CR1-SS25-0000-0003-01

5/19/2022

35.664474

-108.500594

0

3

SW6020

CHROMIUM

5.2

1.1

mg/kg

CR1

CR1-SS26-0000-0003-01

5/19/2022

35.664639

-108.501293

0

3

SW6020

CHROMIUM

4.6

1.1

mg/kg

CR1

CR1-SS27-0000-0003-01

5/19/2022

35.664035

-108.501678

0

3

SW6020

CHROMIUM

3.7

1

mg/kg

CR1

CR1-SS28-0000-0003-01

5/19/2022

35.664057

-108.503308

0

3

SW6020

CHROMIUM

5.6

1.1

mg/kg

CR1

CR1-SS29-0000-0003-01

5/19/2022

35.66443

-108.504

0

3

SW6020

CHROMIUM

5.3

1

mg/kg

CR1

CR1-SS30-0000-0003-01

5/19/2022

35.665182

-108.504127

0

3

SW6020

CHROMIUM

4.5

1.1

mg/kg

CR1

CR1-SS31 -0000-0003-01

5/19/2022

35.665752

-108.504261

0

3

SW6020

CHROMIUM

6.2

1

mg/kg

CR1

CR1-SS32-0000-0003-01

5/19/2022

35.665946

-108.50414

0

3

SW6020

CHROMIUM

13

1

mg/kg

CR1

CR1-SS33-0000-0003-01

5/19/2022

35.663477

-108.501566

0

3

SW6020

CHROMIUM

2.3

1

mg/kg

CR1

CR1-SS34-0000-0003-01

5/19/2022

35.66306

-108.5

0

3

SW6020

CHROMIUM

5.2

1

mg/kg

CR1

CR1-SS05-0000-0003-01

5/19/2022

35.666713

-108.504141

0

3

SW6020

COBALT

4.4

0.51

mg/kg

Page 6 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1

CR1-SS06-0000-0003-01

5/19/2022

35.667094

-108.502536

0

3

SW6020

COBALT

7.9

0.53

mg/kg

CR1

CR1-SS06-0000-0003-02

5/19/2022

35.667094

-108.502536

0

3

SW6020

COBALT

7

0.51

mg/kg

CR1

CR1-SS07-0000-0003-01

5/19/2022

35.667085

-108.501729

0

3

SW6020

COBALT

8

0.53

mg/kg

CR1

CR1-SS08-0000-0003-01

5/19/2022

35.666503

-108.503201

0

3

SW6020

COBALT

5.6

0.51

mg/kg

CR1

CR1-SS09-0000-0003-01

5/19/2022

35.666327

-108.502514

0

3

SW6020

COBALT

7

0.51

mg/kg

CR1

CR1-SS10-0000-0003-01

5/19/2022

35.666522

-108.501608

0

3

SW6020

COBALT

6.1

0.55

mg/kg

CR1

CR1-SS11-0000-0003-01

5/19/2022

35.666126

-108.501314

0

3

SW6020

COBALT

6.1

0.51

mg/kg

CR1

CR1-SS12-0000-0003-01

5/19/2022

35.666314

-108.500988

0

3

SW6020

COBALT

6.2

0.5

mg/kg

CR1

CR1-SS13-0000-0003-01

5/19/2022

35.666176

-108.499679

0

3

SW6020

COBALT

6.1

0.5

mg/kg

CR1

CR1-SS14-0000-0003-01

5/19/2022

35.666944

-108.499149

0

3

SW6020

COBALT

4.8

0.57

mg/kg

CR1

CR1-SS15-0000-0003-01

5/18/2022

35.66634

-108.498

0

3

SW6020

COBALT

3.6

0.5

mg/kg

CR1

CR1-SS15-0000-0003-02

5/18/2022

35.66634

-108.498

0

3

SW6020

COBALT

3.9

0.5

mg/kg

CR1

CR1-SS16-0000-0003-01

5/18/2022

35.66598

-108.498

0

3

SW6020

COBALT

6

0.51

mg/kg

CR1

CR1-SS17-0000-0003-01

5/18/2022

35.665398

-108.498872

0

3

SW6020

COBALT

3.7

0.5

mg/kg

CR1

CR1-SS18-0000-0003-01

5/18/2022

35.665202

-108.499554

0

3

SW6020

COBALT

5.7

0.5

mg/kg

CR1

CR1-SS19-0000-0003-01

5/18/2022

35.665408

-108.500208

0

3

SW6020

COBALT

4.3

0.5

mg/kg

CR1

CR1-SS20-0000-0003-01

5/19/2022

35.664437

-108.499566

0

3

SW6020

COBALT

4.3

0.5

mg/kg

CR1

CR1-SS21 -0000-0003-01

5/19/2022

35.663695

-108.499566

0

3

SW6020

COBALT

8.3

0.52

mg/kg

CR1

CR1-SS22-0000-0003-01

5/19/2022

35.663664

-108.500468

0

3

SW6020

COBALT

6.4

0.5

mg/kg

CR1

CR1-SS22-0000-0003-02

5/19/2022

35.663664

-108.500468

0

3

SW6020

COBALT

6.4

0.51

mg/kg

CR1

CR1-SS23-0000-0003-01

5/19/2022

35.663755

-108.501126

0

3

SW6020

COBALT

7.3

0.58

mg/kg

CR1

CR1-SS24-0000-0003-01

5/19/2022

35.664237

-108.500743

0

3

SW6020

COBALT

6.9

0.53

mg/kg

CR1

CR1-SS25-0000-0003-01

5/19/2022

35.664474

-108.500594

0

3

SW6020

COBALT

6.3

0.55

mg/kg

CR1

CR1-SS26-0000-0003-01

5/19/2022

35.664639

-108.501293

0

3

SW6020

COBALT

5.7

0.54

mg/kg

CR1

CR1-SS27-0000-0003-01

5/19/2022

35.664035

-108.501678

0

3

SW6020

COBALT

5

0.52

mg/kg

CR1

CR1-SS28-0000-0003-01

5/19/2022

35.664057

-108.503308

0

3

SW6020

COBALT

4

0.55

mg/kg

CR1

CR1-SS29-0000-0003-01

5/19/2022

35.66443

-108.504

0

3

SW6020

COBALT

5.7

0.51

mg/kg

CR1

CR1-SS30-0000-0003-01

5/19/2022

35.665182

-108.504127

0

3

SW6020

COBALT

5.2

0.53

mg/kg

CR1

CR1-SS31-0000-0003-01

5/19/2022

35.665752

-108.504261

0

3

SW6020

COBALT

3.4

0.51

mg/kg

CR1

CR1-SS32-0000-0003-01

5/19/2022

35.665946

-108.50414

0

3

SW6020

COBALT

6.3

0.51

mg/kg

CR1

CR1-SS33-0000-0003-01

5/19/2022

35.663477

-108.501566

0

3

SW6020

COBALT

2.5

0.5

mg/kg

CR1

CR1-SS34-0000-0003-01

5/19/2022

35.66306

-108.5

0

3

SW6020

COBALT

5.8

0.51

mg/kg

CR1

CR1-SS05-0000-0003-01

5/19/2022

35.666713

-108.504141

0

3

SW6020

COPPER

6.3

2

mg/kg

CR1

CR1-SS06-0000-0003-01

5/19/2022

35.667094

-108.502536

0

3

SW6020

COPPER

19

2.1

mg/kg

CR1

CR1-SS06-0000-0003-02

5/19/2022

35.667094

-108.502536

0

3

SW6020

COPPER

16

2

mg/kg

CR1

CR1-SS07-0000-0003-01

5/19/2022

35.667085

-108.501729

0

3

SW6020

COPPER

9.2

2.1

mg/kg

CR1

CR1-SS08-0000-0003-01

5/19/2022

35.666503

-108.503201

0

3

SW6020

COPPER

9.9

2.1

mg/kg

CR1

CR1-SS09-0000-0003-01

5/19/2022

35.666327

-108.502514

0

3

SW6020

COPPER

16

2

mg/kg

CR1

CR1-SS10-0000-0003-01

5/19/2022

35.666522

-108.501608

0

3

SW6020

COPPER

10

2.2

mg/kg

CR1

CR1-SS11-0000-0003-01

5/19/2022

35.666126

-108.501314

0

3

SW6020

COPPER

10

2

mg/kg

CR1

CR1-SS12-0000-0003-01

5/19/2022

35.666314

-108.500988

0

3

SW6020

COPPER

3.9

2

mg/kg

CR1

CR1-SS13-0000-0003-01

5/19/2022

35.666176

-108.499679

0

3

SW6020

COPPER

12

2

mg/kg

Page 7 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1

CR1-SS14-0000-0003-01

5/19/2022

35.666944

-108.499149

0

3

SW6020

COPPER

8

2.3

mg/kg

CR1

CR1-SS15-0000-0003-01

5/18/2022

35.66634

-108.498

0

3

SW6020

COPPER

5.9

2

mg/kg

CR1

CR1-SS15-0000-0003-02

5/18/2022

35.66634

-108.498

0

3

SW6020

COPPER

5.9

2

mg/kg

CR1

CR1-SS16-0000-0003-01

5/18/2022

35.66598

-108.498

0

3

SW6020

COPPER

16

2.1

mg/kg

CR1

CR1-SS17-0000-0003-01

5/18/2022

35.665398

-108.498872

0

3

SW6020

COPPER

5

2

mg/kg

CR1

CR1-SS18-0000-0003-01

5/18/2022

35.665202

-108.499554

0

3

SW6020

COPPER

10

2

mg/kg

CR1

CR1-SS19-0000-0003-01

5/18/2022

35.665408

-108.500208

0

3

SW6020

COPPER

6.9

2

mg/kg

CR1

CR1-SS20-0000-0003-01

5/19/2022

35.664437

-108.499566

0

3

SW6020

COPPER

6.1

2

mg/kg

CR1

CR1-SS21 -0000-0003-01

5/19/2022

35.663695

-108.499566

0

3

SW6020

COPPER

21

2.1

mg/kg

CR1

CR1-SS22-0000-0003-01

5/19/2022

35.663664

-108.500468

0

3

SW6020

COPPER

13

2

mg/kg

CR1

CR1-SS22-0000-0003-02

5/19/2022

35.663664

-108.500468

0

3

SW6020

COPPER

14

2

mg/kg

CR1

CR1-SS23-0000-0003-01

5/19/2022

35.663755

-108.501126

0

3

SW6020

COPPER

17

2.3

mg/kg

CR1

CR1-SS24-0000-0003-01

5/19/2022

35.664237

-108.500743

0

3

SW6020

COPPER

15

2.1

mg/kg

CR1

CR1-SS25-0000-0003-01

5/19/2022

35.664474

-108.500594

0

3

SW6020

COPPER

12

2.2

mg/kg

CR1

CR1-SS26-0000-0003-01

5/19/2022

35.664639

-108.501293

0

3

SW6020

COPPER

12

2.2

mg/kg

CR1

CR1-SS27-0000-0003-01

5/19/2022

35.664035

-108.501678

0

3

SW6020

COPPER

9.4

2.1

mg/kg

CR1

CR1-SS28-0000-0003-01

5/19/2022

35.664057

-108.503308

0

3

SW6020

COPPER

7.6

2.2

mg/kg

CR1

CR1-SS29-0000-0003-01

5/19/2022

35.66443

-108.504

0

3

SW6020

COPPER

12

2

mg/kg

CR1

CR1-SS30-0000-0003-01

5/19/2022

35.665182

-108.504127

0

3

SW6020

COPPER

7.8

2.1

mg/kg

CR1

CR1-SS31 -0000-0003-01

5/19/2022

35.665752

-108.504261

0

3

SW6020

COPPER

5.7

2

mg/kg

CR1

CR1-SS32-0000-0003-01

5/19/2022

35.665946

-108.50414

0

3

SW6020

COPPER

12

2

mg/kg

CR1

CR1-SS33-0000-0003-01

5/19/2022

35.663477

-108.501566

0

3

SW6020

COPPER

3.2

2

mg/kg

CR1

CR1-SS34-0000-0003-01

5/19/2022

35.66306

-108.5

0

3

SW6020

COPPER

11

2

mg/kg

CR1

CR1-SS05-0000-0003-01

5/19/2022

35.666713

-108.504141

0

3

SW6020

IRON

7900

20

mg/kg

CR1

CR1-SS06-0000-0003-01

5/19/2022

35.667094

-108.502536

0

3

SW6020

IRON

11000

21

mg/kg

CR1

CR1-SS06-0000-0003-02

5/19/2022

35.667094

-108.502536

0

3

SW6020

IRON

10000

20

mg/kg

CR1

CR1-SS07-0000-0003-01

5/19/2022

35.667085

-108.501729

0

3

SW6020

IRON

11000

21

mg/kg

CR1

CR1-SS08-0000-0003-01

5/19/2022

35.666503

-108.503201

0

3

SW6020

IRON

11000

21

mg/kg

CR1

CR1-SS09-0000-0003-01

5/19/2022

35.666327

-108.502514

0

3

SW6020

IRON

13000

20

mg/kg

CR1

CR1-SS10-0000-0003-01

5/19/2022

35.666522

-108.501608

0

3

SW6020

IRON

11000

22

mg/kg

CR1

CR1-SS11-0000-0003-01

5/19/2022

35.666126

-108.501314

0

3

SW6020

IRON

10000

20

mg/kg

CR1

CR1-SS12-0000-0003-01

5/19/2022

35.666314

-108.500988

0

3

SW6020

IRON

9900

20

mg/kg

CR1

CR1-SS13-0000-0003-01

5/19/2022

35.666176

-108.499679

0

3

SW6020

IRON

11000

20

mg/kg

CR1

CR1-SS14-0000-0003-01

5/19/2022

35.666944

-108.499149

0

3

SW6020

IRON

9200

23

mg/kg

CR1

CR1-SS15-0000-0003-01

5/18/2022

35.66634

-108.498

0

3

SW6020

IRON

8600

20

mg/kg

CR1

CR1-SS15-0000-0003-02

5/18/2022

35.66634

-108.498

0

3

SW6020

IRON

9400

20

mg/kg

CR1

CR1-SS16-0000-0003-01

5/18/2022

35.66598

-108.498

0

3

SW6020

IRON

10000

21

mg/kg

CR1

CR1-SS17-0000-0003-01

5/18/2022

35.665398

-108.498872

0

3

SW6020

IRON

7300

20

mg/kg

CR1

CR1-SS18-0000-0003-01

5/18/2022

35.665202

-108.499554

0

3

SW6020

IRON

9200

20

mg/kg

CR1

CR1-SS19-0000-0003-01

5/18/2022

35.665408

-108.500208

0

3

SW6020

IRON

9200

20

mg/kg

CR1

CR1-SS20-0000-0003-01

5/19/2022

35.664437

-108.499566

0

3

SW6020

IRON

7800

20

mg/kg

CR1

CR1-SS21 -0000-0003-01

5/19/2022

35.663695

-108.499566

0

3

SW6020

IRON

13000

21

mg/kg

Page 8 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1

CR1-SS22-0000-0003-01

5/19/2022

35.663664

-108.500468

0

3

SW6020

IRON

12000

20

mg/kg

CR1

CR1-SS22-0000-0003-02

5/19/2022

35.663664

-108.500468

0

3

SW6020

IRON

12000

20

mg/kg

CR1

CR1-SS23-0000-0003-01

5/19/2022

35.663755

-108.501126

0

3

SW6020

IRON

12000

23

mg/kg

CR1

CR1-SS24-0000-0003-01

5/19/2022

35.664237

-108.500743

0

3

SW6020

IRON

12000

21

mg/kg

CR1

CR1-SS25-0000-0003-01

5/19/2022

35.664474

-108.500594

0

3

SW6020

IRON

12000

22

mg/kg

CR1

CR1-SS26-0000-0003-01

5/19/2022

35.664639

-108.501293

0

3

SW6020

IRON

13000

22

mg/kg

CR1

CR1-SS27-0000-0003-01

5/19/2022

35.664035

-108.501678

0

3

SW6020

IRON

9800

21

mg/kg

CR1

CR1-SS28-0000-0003-01

5/19/2022

35.664057

-108.503308

0

3

SW6020

IRON

8400

22

mg/kg

CR1

CR1-SS29-0000-0003-01

5/19/2022

35.66443

-108.504

0

3

SW6020

IRON

9600

20

mg/kg

CR1

CR1-SS30-0000-0003-01

5/19/2022

35.665182

-108.504127

0

3

SW6020

IRON

9300

21

mg/kg

CR1

CR1-SS31 -0000-0003-01

5/19/2022

35.665752

-108.504261

0

3

SW6020

IRON

10000

20

mg/kg

CR1

CR1-SS32-0000-0003-01

5/19/2022

35.665946

-108.50414

0

3

SW6020

IRON

9900

20

mg/kg

CR1

CR1-SS33-0000-0003-01

5/19/2022

35.663477

-108.501566

0

3

SW6020

IRON

5000

20

mg/kg

CR1

CR1-SS34-0000-0003-01

5/19/2022

35.66306

-108.5

0

3

SW6020

IRON

11000

20

mg/kg

CR1

CR1-SS05-0000-0003-01

5/19/2022

35.666713

-108.504141

0

3

SW6020

LEAD

8.7

0.2

mg/kg

CR1

CR1-SS06-0000-0003-01

5/19/2022

35.667094

-108.502536

0

3

SW6020

LEAD

17

0.21

mg/kg

CR1

CR1-SS06-0000-0003-02

5/19/2022

35.667094

-108.502536

0

3

SW6020

LEAD

14

0.2

mg/kg

CR1

CR1-SS07-0000-0003-01

5/19/2022

35.667085

-108.501729

0

3

SW6020

LEAD

10

0.21

mg/kg

CR1

CR1-SS08-0000-0003-01

5/19/2022

35.666503

-108.503201

0

3

SW6020

LEAD

10

0.21

mg/kg

CR1

CR1-SS09-0000-0003-01

5/19/2022

35.666327

-108.502514

0

3

SW6020

LEAD

15

0.2

mg/kg

CR1

CR1-SS10-0000-0003-01

5/19/2022

35.666522

-108.501608

0

3

SW6020

LEAD

11

0.22

mg/kg

CR1

CR1-SS11-0000-0003-01

5/19/2022

35.666126

-108.501314

0

3

SW6020

LEAD

10

0.2

mg/kg

CR1

CR1-SS12-0000-0003-01

5/19/2022

35.666314

-108.500988

0

3

SW6020

LEAD

7.2

0.2

mg/kg

CR1

CR1-SS13-0000-0003-01

5/19/2022

35.666176

-108.499679

0

3

SW6020

LEAD

11

0.2

mg/kg

CR1

CR1-SS14-0000-0003-01

5/19/2022

35.666944

-108.499149

0

3

SW6020

LEAD

9.1

0.23

mg/kg

CR1

CR1-SS15-0000-0003-01

5/18/2022

35.66634

-108.498

0

3

SW6020

LEAD

7.6

0.2

mg/kg

CR1

CR1-SS15-0000-0003-02

5/18/2022

35.66634

-108.498

0

3

SW6020

LEAD

7.8

0.2

mg/kg

CR1

CR1-SS16-0000-0003-01

5/18/2022

35.66598

-108.498

0

3

SW6020

LEAD

10

0.21

mg/kg

CR1

CR1-SS17-0000-0003-01

5/18/2022

35.665398

-108.498872

0

3

SW6020

LEAD

6.9

0.2

mg/kg

CR1

CR1-SS18-0000-0003-01

5/18/2022

35.665202

-108.499554

0

3

SW6020

LEAD

10

0.2

mg/kg

CR1

CR1-SS19-0000-0003-01

5/18/2022

35.665408

-108.500208

0

3

SW6020

LEAD

7.7

0.2

mg/kg

CR1

CR1-SS20-0000-0003-01

5/19/2022

35.664437

-108.499566

0

3

SW6020

LEAD

7.7

0.2

mg/kg

CR1

CR1-SS21-0000-0003-01

5/19/2022

35.663695

-108.499566

0

3

SW6020

LEAD

18

0.21

mg/kg

CR1

CR1-SS22-0000-0003-01

5/19/2022

35.663664

-108.500468

0

3

SW6020

LEAD

12

0.2

mg/kg

CR1

CR1-SS22-0000-0003-02

5/19/2022

35.663664

-108.500468

0

3

SW6020

LEAD

12

0.2

mg/kg

CR1

CR1-SS23-0000-0003-01

5/19/2022

35.663755

-108.501126

0

3

SW6020

LEAD

14

0.23

mg/kg

CR1

CR1-SS24-0000-0003-01

5/19/2022

35.664237

-108.500743

0

3

SW6020

LEAD

14

0.21

mg/kg

CR1

CR1-SS25-0000-0003-01

5/19/2022

35.664474

-108.500594

0

3

SW6020

LEAD

11

0.22

mg/kg

CR1

CR1-SS26-0000-0003-01

5/19/2022

35.664639

-108.501293

0

3

SW6020

LEAD

12

0.22

mg/kg

CR1

CR1-SS27-0000-0003-01

5/19/2022

35.664035

-108.501678

0

3

SW6020

LEAD

8.9

0.21

mg/kg

CR1

CR1-SS28-0000-0003-01

5/19/2022

35.664057

-108.503308

0

3

SW6020

LEAD

11

0.22

mg/kg

CR1

CR1-SS29-0000-0003-01

5/19/2022

35.66443

-108.504

0

3

SW6020

LEAD

11

0.2

mg/kg

Page 9 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1

CR1-SS30-0000-0003-01

5/19/2022

35.665182

-108.504127

0

3

SW6020

LEAD

9.1

0.21

mg/kg

CR1

CR1-SS31 -0000-0003-01

5/19/2022

35.665752

-108.504261

0

3

SW6020

LEAD

10

0.2

mg/kg

CR1

CR1-SS32-0000-0003-01

5/19/2022

35.665946

-108.50414

0

3

SW6020

LEAD

9.8

0.2

mg/kg

CR1

CR1-SS33-0000-0003-01

5/19/2022

35.663477

-108.501566

0

3

SW6020

LEAD

4.8

0.2

mg/kg

CR1

CR1-SS34-0000-0003-01

5/19/2022

35.66306

-108.5

0

3

SW6020

LEAD

11

0.2

mg/kg

CR1

CR1-SS05-0000-0003-01

5/19/2022

35.666713

-108.504141

0

3

SW6020

MANGANESE

120

0.76

mg/kg

CR1

CR1-SS06-0000-0003-01

5/19/2022

35.667094

-108.502536

0

3

SW6020

MANGANESE

150

0.79

mg/kg

CR1

CR1-SS06-0000-0003-02

5/19/2022

35.667094

-108.502536

0

3

SW6020

MANGANESE

150

0.77

mg/kg

CR1

CR1-SS07-0000-0003-01

5/19/2022

35.667085

-108.501729

0

3

SW6020

MANGANESE

170

0.79

mg/kg

CR1

CR1-SS08-0000-0003-01

5/19/2022

35.666503

-108.503201

0

3

SW6020

MANGANESE

170

0.77

mg/kg

CR1

CR1-SS09-0000-0003-01

5/19/2022

35.666327

-108.502514

0

3

SW6020

MANGANESE

160

0.76

mg/kg

CR1

CR1-SS10-0000-0003-01

5/19/2022

35.666522

-108.501608

0

3

SW6020

MANGANESE

140

0.82

mg/kg

CR1

CR1-SS11-0000-0003-01

5/19/2022

35.666126

-108.501314

0

3

SW6020

MANGANESE

150

0.76

mg/kg

CR1

CR1-SS12-0000-0003-01

5/19/2022

35.666314

-108.500988

0

3

SW6020

MANGANESE

150

0.75

mg/kg

CR1

CR1-SS13-0000-0003-01

5/19/2022

35.666176

-108.499679

0

3

SW6020

MANGANESE

160

0.76

mg/kg

CR1

CR1-SS14-0000-0003-01

5/19/2022

35.666944

-108.499149

0

3

SW6020

MANGANESE

140

0.85

mg/kg

CR1

CR1-SS15-0000-0003-01

5/18/2022

35.66634

-108.498

0

3

SW6020

MANGANESE

120

0.76

mg/kg

CR1

CR1-SS15-0000-0003-02

5/18/2022

35.66634

-108.498

0

3

SW6020

MANGANESE

130

0.75

mg/kg

CR1

CR1-SS16-0000-0003-01

5/18/2022

35.66598

-108.498

0

3

SW6020

MANGANESE

160

0.77

mg/kg

CR1

CR1-SS17-0000-0003-01

5/18/2022

35.665398

-108.498872

0

3

SW6020

MANGANESE

120

0.75

mg/kg

CR1

CR1-SS18-0000-0003-01

5/18/2022

35.665202

-108.499554

0

3

SW6020

MANGANESE

150

0.75

mg/kg

CR1

CR1-SS19-0000-0003-01

5/18/2022

35.665408

-108.500208

0

3

SW6020

MANGANESE

190

0.75

mg/kg

CR1

CR1-SS20-0000-0003-01

5/19/2022

35.664437

-108.499566

0

3

SW6020

MANGANESE

100

0.76

mg/kg

CR1

CR1-SS21-0000-0003-01

5/19/2022

35.663695

-108.499566

0

3

SW6020

MANGANESE

180

0.78

mg/kg

CR1

CR1-SS22-0000-0003-01

5/19/2022

35.663664

-108.500468

0

3

SW6020

MANGANESE

170

0.75

mg/kg

CR1

CR1-SS22-0000-0003-02

5/19/2022

35.663664

-108.500468

0

3

SW6020

MANGANESE

180

0.77

mg/kg

CR1

CR1-SS23-0000-0003-01

5/19/2022

35.663755

-108.501126

0

3

SW6020

MANGANESE

180

0.86

mg/kg

CR1

CR1-SS24-0000-0003-01

5/19/2022

35.664237

-108.500743

0

3

SW6020

MANGANESE

200

0.79

mg/kg

CR1

CR1-SS25-0000-0003-01

5/19/2022

35.664474

-108.500594

0

3

SW6020

MANGANESE

200

0.82

mg/kg

CR1

CR1-SS26-0000-0003-01

5/19/2022

35.664639

-108.501293

0

3

SW6020

MANGANESE

170

0.81

mg/kg

CR1

CR1-SS27-0000-0003-01

5/19/2022

35.664035

-108.501678

0

3

SW6020

MANGANESE

140

0.77

mg/kg

CR1

CR1-SS28-0000-0003-01

5/19/2022

35.664057

-108.503308

0

3

SW6020

MANGANESE

130

0.82

mg/kg

CR1

CR1-SS29-0000-0003-01

5/19/2022

35.66443

-108.504

0

3

SW6020

MANGANESE

170

0.77

mg/kg

CR1

CR1-SS30-0000-0003-01

5/19/2022

35.665182

-108.504127

0

3

SW6020

MANGANESE

140

0.8

mg/kg

CR1

CR1-SS31 -0000-0003-01

5/19/2022

35.665752

-108.504261

0

3

SW6020

MANGANESE

100

0.76

mg/kg

CR1

CR1-SS32-0000-0003-01

5/19/2022

35.665946

-108.50414

0

3

SW6020

MANGANESE

150

0.77

mg/kg

CR1

CR1-SS33-0000-0003-01

5/19/2022

35.663477

-108.501566

0

3

SW6020

MANGANESE

89

0.75

mg/kg

CR1

CR1-SS34-0000-0003-01

5/19/2022

35.66306

-108.5

0

3

SW6020

MANGANESE

160

0.76

mg/kg

CR1

CR1-SS05-0000-0003-01

5/19/2022

35.666713

-108.504141

0

3

SW6020

MOLYBDENUM

0.15 J

0.2

mg/kg

CR1

CR1-SS06-0000-0003-01

5/19/2022

35.667094

-108.502536

0

3

SW6020

MOLYBDENUM

0.42

0.21

mg/kg

CR1

CR1-SS06-0000-0003-02

5/19/2022

35.667094

-108.502536

0

3

SW6020

MOLYBDENUM

0.38

0.2

mg/kg

CR1

CR1-SS07-0000-0003-01

5/19/2022

35.667085

-108.501729

0

3

SW6020

MOLYBDENUM

0.18 J

0.21

mg/kg

Page 10 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1

CR1-SS08-0000-0003-01

5/19/2022

35.666503

-108.503201

0

3

SW6020

MOLYBDENUM

0.29

0.21

mg/kg

CR1

CR1-SS09-0000-0003-01

5/19/2022

35.666327

-108.502514

0

3

SW6020

MOLYBDENUM

0.37

0.2

mg/kg

CR1

CR1-SS10-0000-0003-01

5/19/2022

35.666522

-108.501608

0

3

SW6020

MOLYBDENUM

0.28

0.22

mg/kg

CR1

CR1-SS11-0000-0003-01

5/19/2022

35.666126

-108.501314

0

3

SW6020

MOLYBDENUM

0.25

0.2

mg/kg

CR1

CR1-SS12-0000-0003-01

5/19/2022

35.666314

-108.500988

0

3

SW6020

MOLYBDENUM

0.16 J

0.2

mg/kg

CR1

CR1-SS13-0000-0003-01

5/19/2022

35.666176

-108.499679

0

3

SW6020

MOLYBDENUM

0.34

0.2

mg/kg

CR1

CR1-SS14-0000-0003-01

5/19/2022

35.666944

-108.499149

0

3

SW6020

MOLYBDENUM

0.21 J

0.23

mg/kg

CR1

CR1-SS15-0000-0003-01

5/18/2022

35.66634

-108.498

0

3

SW6020

MOLYBDENUM

0.28

0.2

mg/kg

CR1

CR1-SS15-0000-0003-02

5/18/2022

35.66634

-108.498

0

3

SW6020

MOLYBDENUM

0.32

0.2

mg/kg

CR1

CR1-SS16-0000-0003-01

5/18/2022

35.66598

-108.498

0

3

SW6020

MOLYBDENUM

0.27

0.21

mg/kg

CR1

CR1-SS17-0000-0003-01

5/18/2022

35.665398

-108.498872

0

3

SW6020

MOLYBDENUM

0.19 J

0.2

mg/kg

CR1

CR1-SS18-0000-0003-01

5/18/2022

35.665202

-108.499554

0

3

SW6020

MOLYBDENUM

0.23

0.2

mg/kg

CR1

CR1-SS19-0000-0003-01

5/18/2022

35.665408

-108.500208

0

3

SW6020

MOLYBDENUM

0.39

0.2

mg/kg

CR1

CR1-SS20-0000-0003-01

5/19/2022

35.664437

-108.499566

0

3

SW6020

MOLYBDENUM

0.18 J

0.2

mg/kg

CR1

CR1-SS21 -0000-0003-01

5/19/2022

35.663695

-108.499566

0

3

SW6020

MOLYBDENUM

0.4

0.21

mg/kg

CR1

CR1-SS22-0000-0003-01

5/19/2022

35.663664

-108.500468

0

3

SW6020

MOLYBDENUM

0.49

0.2

mg/kg

CR1

CR1-SS22-0000-0003-02

5/19/2022

35.663664

-108.500468

0

3

SW6020

MOLYBDENUM

0.53

0.2

mg/kg

CR1

CR1-SS23-0000-0003-01

5/19/2022

35.663755

-108.501126

0

3

SW6020

MOLYBDENUM

0.27

0.23

mg/kg

CR1

CR1-SS24-0000-0003-01

5/19/2022

35.664237

-108.500743

0

3

SW6020

MOLYBDENUM

0.35

0.21

mg/kg

CR1

CR1-SS25-0000-0003-01

5/19/2022

35.664474

-108.500594

0

3

SW6020

MOLYBDENUM

0.34

0.22

mg/kg

CR1

CR1-SS26-0000-0003-01

5/19/2022

35.664639

-108.501293

0

3

SW6020

MOLYBDENUM

0.61 J

0.22

mg/kg

CR1

CR1-SS27-0000-0003-01

5/19/2022

35.664035

-108.501678

0

3

SW6020

MOLYBDENUM

0.27

0.21

mg/kg

CR1

CR1-SS28-0000-0003-01

5/19/2022

35.664057

-108.503308

0

3

SW6020

MOLYBDENUM

0.26

0.22

mg/kg

CR1

CR1-SS29-0000-0003-01

5/19/2022

35.66443

-108.504

0

3

SW6020

MOLYBDENUM

0.27

0.2

mg/kg

CR1

CR1-SS30-0000-0003-01

5/19/2022

35.665182

-108.504127

0

3

SW6020

MOLYBDENUM

0.2 J

0.21

mg/kg

CR1

CR1-SS31-0000-0003-01

5/19/2022

35.665752

-108.504261

0

3

SW6020

MOLYBDENUM

0.21

0.2

mg/kg

CR1

CR1-SS32-0000-0003-01

5/19/2022

35.665946

-108.50414

0

3

SW6020

MOLYBDENUM

0.28

0.2

mg/kg

CR1

CR1-SS33-0000-0003-01

5/19/2022

35.663477

-108.501566

0

3

SW6020

MOLYBDENUM

0.15 J

0.2

mg/kg

CR1

CR1-SS34-0000-0003-01

5/19/2022

35.66306

-108.5

0

3

SW6020

MOLYBDENUM

0.27

0.2

mg/kg

CR1

CR1-SS05-0000-0003-01

5/19/2022

35.666713

-108.504141

0

3

SW6020

NICKEL

4.7

2

mg/kg

CR1

CR1-SS06-0000-0003-01

5/19/2022

35.667094

-108.502536

0

3

SW6020

NICKEL

9

2.1

mg/kg

CR1

CR1-SS06-0000-0003-02

5/19/2022

35.667094

-108.502536

0

3

SW6020

NICKEL

8.1

2

mg/kg

CR1

CR1-SS07-0000-0003-01

5/19/2022

35.667085

-108.501729

0

3

SW6020

NICKEL

5

2.1

mg/kg

CR1

CR1-SS08-0000-0003-01

5/19/2022

35.666503

-108.503201

0

3

SW6020

NICKEL

6.5

2.1

mg/kg

CR1

CR1-SS09-0000-0003-01

5/19/2022

35.666327

-108.502514

0

3

SW6020

NICKEL

9.2

2

mg/kg

CR1

CR1-SS10-0000-0003-01

5/19/2022

35.666522

-108.501608

0

3

SW6020

NICKEL

5.9

2.2

mg/kg

CR1

CR1-SS11-0000-0003-01

5/19/2022

35.666126

-108.501314

0

3

SW6020

NICKEL

6.2

2

mg/kg

CR1

CR1-SS12-0000-0003-01

5/19/2022

35.666314

-108.500988

0

3

SW6020

NICKEL

6.5

2

mg/kg

CR1

CR1-SS13-0000-0003-01

5/19/2022

35.666176

-108.499679

0

3

SW6020

NICKEL

7.2

2

mg/kg

CR1

CR1-SS14-0000-0003-01

5/19/2022

35.666944

-108.499149

0

3

SW6020

NICKEL

5.2

2.3

mg/kg

CR1

CR1-SS15-0000-0003-01

5/18/2022

35.66634

-108.498

0

3

SW6020

NICKEL

4.2

2

mg/kg

CR1

CR1-SS15-0000-0003-02

5/18/2022

35.66634

-108.498

0

3

SW6020

NICKEL

4.6

2

mg/kg

Page 11 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1

CR1-SS16-0000-0003-01

5/18/2022

35.66598

-108.498

0

3

SW6020

NICKEL

6.5

2.1

mg/kg

CR1

CR1-SS17-0000-0003-01

5/18/2022

35.665398

-108.498872

0

3

SW6020

NICKEL

3.9

2

mg/kg

CR1

CR1-SS18-0000-0003-01

5/18/2022

35.665202

-108.499554

0

3

SW6020

NICKEL

6.4

2

mg/kg

CR1

CR1-SS19-0000-0003-01

5/18/2022

35.665408

-108.500208

0

3

SW6020

NICKEL

5.1

2

mg/kg

CR1

CR1-SS20-0000-0003-01

5/19/2022

35.664437

-108.499566

0

3

SW6020

NICKEL

4.2

2

mg/kg

CR1

CR1-SS21 -0000-0003-01

5/19/2022

35.663695

-108.499566

0

3

SW6020

NICKEL

11

2.1

mg/kg

CR1

CR1-SS22-0000-0003-01

5/19/2022

35.663664

-108.500468

0

3

SW6020

NICKEL

8.3

2

mg/kg

CR1

CR1-SS22-0000-0003-02

5/19/2022

35.663664

-108.500468

0

3

SW6020

NICKEL

00
CO

2

mg/kg

CR1

CR1-SS23-0000-0003-01

5/19/2022

35.663755

-108.501126

0

3

SW6020

NICKEL

9.6

2.3

mg/kg

CR1

CR1-SS24-0000-0003-01

5/19/2022

35.664237

-108.500743

0

3

SW6020

NICKEL

8.7

2.1

mg/kg

CR1

CR1-SS25-0000-0003-01

5/19/2022

35.664474

-108.500594

0

3

SW6020

NICKEL

7.2

2.2

mg/kg

CR1

CR1-SS26-0000-0003-01

5/19/2022

35.664639

-108.501293

0

3

SW6020

NICKEL

7.4

2.2

mg/kg

CR1

CR1-SS27-0000-0003-01

5/19/2022

35.664035

-108.501678

0

3

SW6020

NICKEL

5.7

2.1

mg/kg

CR1

CR1-SS28-0000-0003-01

5/19/2022

35.664057

-108.503308

0

3

SW6020

NICKEL

6.8

2.2

mg/kg

CR1

CR1-SS29-0000-0003-01

5/19/2022

35.66443

-108.504

0

3

SW6020

NICKEL

7.6

2

mg/kg

CR1

CR1-SS30-0000-0003-01

5/19/2022

35.665182

-108.504127

0

3

SW6020

NICKEL

6.1

2.1

mg/kg

CR1

CR1-SS31-0000-0003-01

5/19/2022

35.665752

-108.504261

0

3

SW6020

NICKEL

5.3

2

mg/kg

CR1

CR1-SS32-0000-0003-01

5/19/2022

35.665946

-108.50414

0

3

SW6020

NICKEL

16

2

mg/kg

CR1

CR1-SS33-0000-0003-01

5/19/2022

35.663477

-108.501566

0

3

SW6020

NICKEL

2.7

2

mg/kg

CR1

CR1-SS34-0000-0003-01

5/19/2022

35.66306

-108.5

0

3

SW6020

NICKEL

7.2

2

mg/kg

CR1

CR1-SS05-0000-0003-01

5/19/2022

35.666713

-108.504141

0

3

713R15

Ra-226

1.4

0.54

o

Q.

/ g

CR1

CR1-SS06-0000-0003-01

5/19/2022

35.667094

-108.502536

0

3

713R15

Ra-226

1.86 J

0.6

O

Q.

/g

CR1

CR1-SS06-0000-0003-02

5/19/2022

35.667094

-108.502536

0

3

713R15

Ra-226

1.9 J

0.63

pC

'g

CR1

CR1-SS07-0000-0003-01

5/19/2022

35.667085

-108.501729

0

3

713R15

Ra-226

2.87

0.52

pC

/g

CR1

CR1-SS08-0000-0003-01

5/19/2022

35.666503

-108.503201

0

3

713R15

Ra-226

3.13 J

0.48

o

Q.

/g

CR1

CR1-SS09-0000-0003-01

5/19/2022

35.666327

-108.502514

0

3

713R15

Ra-226

8.6 J

0.8

pC

/g

CR1

CR1-SS10-0000-0003-01

5/19/2022

35.666522

-108.501608

0

3

713R15

Ra-226

1.23

0.44

pC

/g

CR1

CR1-SS11-0000-0003-01

5/19/2022

35.666126

-108.501314

0

3

713R15

Ra-226

1.29

0.47

pC

/g

CR1

CR1-SS12-0000-0003-01

5/19/2022

35.666314

-108.500988

0

3

713R15

Ra-226

1.16

0.37

o

Q.

/g

CR1

CR1-SS13-0000-0003-01

5/19/2022

35.666176

-108.499679

0

3

713R15

Ra-226

2.25

0.55

pC

/g

CR1

CR1-SS14-0000-0003-01

5/19/2022

35.666944

-108.499149

0

3

713R15

Ra-226

1.42

0.37

pC

/g

CR1

CR1-SS15-0000-0003-01

5/18/2022

35.66634

-108.498

0

3

713R15

Ra-226

2.29

0.54

pC

/g

CR1

CR1-SS15-0000-0003-02

5/18/2022

35.66634

-108.498

0

3

713R15

Ra-226

2.27

0.44

o

Q.

/g

CR1

CR1-SS16-0000-0003-01

5/18/2022

35.66598

-108.498

0

3

713R15

Ra-226

1.73 J

0.32

pC

/g

CR1

CR1-SS17-0000-0003-01

5/18/2022

35.665398

-108.498872

0

3

713R15

Ra-226

0.82 J

0.44

pC

/g

CR1

CR1-SS18-0000-0003-01

5/18/2022

35.665202

-108.499554

0

3

713R15

Ra-226

1.33

0.52

pC

/g

CR1

CR1-SS19-0000-0003-01

5/18/2022

35.665408

-108.500208

0

3

713R15

Ra-226

18.2

0.5

o

Q.

/g

CR1

CR1-SS20-0000-0003-01

5/19/2022

35.664437

-108.499566

0

3

713R15

Ra-226

1.19

0.52

o

Q.

/g

CR1

CR1-SS21 -0000-0003-01

5/19/2022

35.663695

-108.499566

0

3

713R15

Ra-226

2.27 J

0.44

pC

/g

CR1

CR1-SS22-0000-0003-01

5/19/2022

35.663664

-108.500468

0

3

713R15

Ra-226

1.77 J

0.53

pC

/g

CR1

CR1-SS22-0000-0003-02

5/19/2022

35.663664

-108.500468

0

3

713R15

Ra-226

1.85 J

0.45

o

Q.

/g

CR1

CR1-SS23-0000-0003-01

5/19/2022

35.663755

-108.501126

0

3

713R15

Ra-226

1.54 J

0.34

o

Q.

/g

Page 12 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1

CR1-SS24-0000-0003-01

5/19/2022

35.664237

-108.500743

0

3

713R15

Ra-226

19.2 J

0.7

O

Q.

/g

CR1

CR1-SS25-0000-0003-01

5/19/2022

35.664474

-108.500594

0

3

713R15

Ra-226

2.94 J

0.48

O

Q.

/ g

CR1

CR1-SS26-0000-0003-01

5/19/2022

35.664639

-108.501293

0

3

713R15

Ra-226

28.5

0.8

pC

/g

CR1

CR1-SS27-0000-0003-01

5/19/2022

35.664035

-108.501678

0

3

713R15

Ra-226

4.68

0.53

pC

/g

CR1

CR1-SS28-0000-0003-01

5/19/2022

35.664057

-108.503308

0

3

713R15

Ra-226

28

0.8

o

Q.

/ g

CR1

CR1-SS29-0000-0003-01

5/19/2022

35.66443

-108.504

0

3

713R15

Ra-226

3.21

0.36

O

Q.

/ g

CR1

CR1-SS30-0000-0003-01

5/19/2022

35.665182

-108.504127

0

3

713R15

Ra-226

2.12

0.52

pC

/g

CR1

CR1-SS31 -0000-0003-01

5/19/2022

35.665752

-108.504261

0

3

713R15

Ra-226

6.28

0.49

pC

/g

CR1

CR1-SS32-0000-0003-01

5/19/2022

35.665946

-108.50414

0

3

713R15

Ra-226

6.3

0.5

o

Q.

/ g

CR1

CR1-SS33-0000-0003-01

5/19/2022

35.663477

-108.501566

0

3

713R15

Ra-226

0.6

0.38

O

Q.

/g

CR1

CR1-SS34-0000-0003-01

5/19/2022

35.66306

-108.5

0

3

713R15

Ra-226

1.13

0.41

pC

/g

CR1

CR1-SS05-0000-0003-01

5/19/2022

35.666713

-108.504141

0

3

SW6020

SELENIUM

1.1

1

mg/kg

CR1

CR1-SS06-0000-0003-01

5/19/2022

35.667094

-108.502536

0

3

SW6020

SELENIUM

1.9

1.1

mg/kg

CR1

CR1-SS06-0000-0003-02

5/19/2022

35.667094

-108.502536

0

3

SW6020

SELENIUM

1.6

1

mg/kg

CR1

CR1-SS07-0000-0003-01

5/19/2022

35.667085

-108.501729

0

3

SW6020

SELENIUM

1.2

1.1

mg/kg

CR1

CR1-SS08-0000-0003-01

5/19/2022

35.666503

-108.503201

0

3

SW6020

SELENIUM

1.7

1

mg/kg

CR1

CR1-SS09-0000-0003-01

5/19/2022

35.666327

-108.502514

0

3

SW6020

SELENIUM

3.2

1

mg/kg

CR1

CR1-SS10-0000-0003-01

5/19/2022

35.666522

-108.501608

0

3

SW6020

SELENIUM

1.3

1.1

mg/kg

CR1

CR1-SS11-0000-0003-01

5/19/2022

35.666126

-108.501314

0

3

SW6020

SELENIUM

1.8

1

mg/kg

CR1

CR1-SS12-0000-0003-01

5/19/2022

35.666314

-108.500988

0

3

SW6020

SELENIUM

1.2

1

mg/kg

CR1

CR1-SS13-0000-0003-01

5/19/2022

35.666176

-108.499679

0

3

SW6020

SELENIUM

1.6

1

mg/kg

CR1

CR1-SS14-0000-0003-01

5/19/2022

35.666944

-108.499149

0

3

SW6020

SELENIUM

1.3

1.1

mg/kg

CR1

CR1-SS15-0000-0003-01

5/18/2022

35.66634

-108.498

0

3

SW6020

SELENIUM

1.1

1

mg/kg

CR1

CR1-SS15-0000-0003-02

5/18/2022

35.66634

-108.498

0

3

SW6020

SELENIUM

1.2

1

mg/kg

CR1

CR1-SS16-0000-0003-01

5/18/2022

35.66598

-108.498

0

3

SW6020

SELENIUM

1.4

1

mg/kg

CR1

CR1-SS17-0000-0003-01

5/18/2022

35.665398

-108.498872

0

3

SW6020

SELENIUM

0.79 J

1

mg/kg

CR1

CR1-SS18-0000-0003-01

5/18/2022

35.665202

-108.499554

0

3

SW6020

SELENIUM

1.3

1

mg/kg

CR1

CR1-SS19-0000-0003-01

5/18/2022

35.665408

-108.500208

0

3

SW6020

SELENIUM

4.5

1

mg/kg

CR1

CR1-SS20-0000-0003-01

5/19/2022

35.664437

-108.499566

0

3

SW6020

SELENIUM

1.1

1

mg/kg

CR1

CR1-SS21-0000-0003-01

5/19/2022

35.663695

-108.499566

0

3

SW6020

SELENIUM

2.1

1

mg/kg

CR1

CR1-SS22-0000-0003-01

5/19/2022

35.663664

-108.500468

0

3

SW6020

SELENIUM

1.6

1

mg/kg

CR1

CR1-SS22-0000-0003-02

5/19/2022

35.663664

-108.500468

0

3

SW6020

SELENIUM

1.6

1

mg/kg

CR1

CR1-SS23-0000-0003-01

5/19/2022

35.663755

-108.501126

0

3

SW6020

SELENIUM

1.8

1.2

mg/kg

CR1

CR1-SS24-0000-0003-01

5/19/2022

35.664237

-108.500743

0

3

SW6020

SELENIUM

4.4

1.1

mg/kg

CR1

CR1-SS25-0000-0003-01

5/19/2022

35.664474

-108.500594

0

3

SW6020

SELENIUM

1.9

1.1

mg/kg

CR1

CR1-SS26-0000-0003-01

5/19/2022

35.664639

-108.501293

0

3

SW6020

SELENIUM

9.5

1.1

mg/kg

CR1

CR1-SS27-0000-0003-01

5/19/2022

35.664035

-108.501678

0

3

SW6020

SELENIUM

2.7

1

mg/kg

CR1

CR1-SS28-0000-0003-01

5/19/2022

35.664057

-108.503308

0

3

SW6020

SELENIUM

14

1.1

mg/kg

CR1

CR1-SS29-0000-0003-01

5/19/2022

35.66443

-108.504

0

3

SW6020

SELENIUM

1.7

1

mg/kg

CR1

CR1-SS30-0000-0003-01

5/19/2022

35.665182

-108.504127

0

3

SW6020

SELENIUM

1.4

1.1

mg/kg

CR1

CR1-SS31-0000-0003-01

5/19/2022

35.665752

-108.504261

0

3

SW6020

SELENIUM

2.2

1

mg/kg

CR1

CR1-SS32-0000-0003-01

5/19/2022

35.665946

-108.50414

0

3

SW6020

SELENIUM

2.3

1

mg/kg

Page 13 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1

CR1-SS33-0000-0003-01

5/19/2022

35.663477

-108.501566

0

3

SW6020

SELENIUM

0.47 J

1

mg/kg

CR1

CR1-SS34-0000-0003-01

5/19/2022

35.66306

-108.5

0

3

SW6020

SELENIUM

1.3

1

mg/kg

CR1

CR1-SS05-0000-0003-01

5/19/2022

35.666713

-108.504141

0

3

SW6020

SILVER

0.058 UJ

0.12

mg/kg

CR1

CR1-SS06-0000-0003-01

5/19/2022

35.667094

-108.502536

0

3

SW6020

SILVER

0.1 J

0.12

mg/kg

CR1

CR1-SS06-0000-0003-02

5/19/2022

35.667094

-108.502536

0

3

SW6020

SILVER

0.08 J

0.12

mg/kg

CR1

CR1-SS07-0000-0003-01

5/19/2022

35.667085

-108.501729

0

3

SW6020

SILVER

0.06 UJ

0.12

mg/kg

CR1

CR1-SS08-0000-0003-01

5/19/2022

35.666503

-108.503201

0

3

SW6020

SILVER

0.058 UJ

0.12

mg/kg

CR1

CR1-SS09-0000-0003-01

5/19/2022

35.666327

-108.502514

0

3

SW6020

SILVER

0.072 J

0.12

mg/kg

CR1

CR1-SS10-0000-0003-01

5/19/2022

35.666522

-108.501608

0

3

SW6020

SILVER

0.062 UJ

0.12

mg/kg

CR1

CR1-SS11-0000-0003-01

5/19/2022

35.666126

-108.501314

0

3

SW6020

SILVER

0.058 UJ

0.12

mg/kg

CR1

CR1-SS12-0000-0003-01

5/19/2022

35.666314

-108.500988

0

3

SW6020

SILVER

0.057 UJ

0.11

mg/kg

CR1

CR1-SS13-0000-0003-01

5/19/2022

35.666176

-108.499679

0

3

SW6020

SILVER

0.059 J

0.12

mg/kg

CR1

CR1-SS14-0000-0003-01

5/19/2022

35.666944

-108.499149

0

3

SW6020

SILVER

0.065 UJ

0.13

mg/kg

CR1

CR1-SS15-0000-0003-01

5/18/2022

35.66634

-108.498

0

3

SW6020

SILVER

0.058 UJ

0.12

mg/kg

CR1

CR1-SS15-0000-0003-02

5/18/2022

35.66634

-108.498

0

3

SW6020

SILVER

0.057 UJ

0.11

mg/kg

CR1

CR1-SS16-0000-0003-01

5/18/2022

35.66598

-108.498

0

3

SW6020

SILVER

0.059 UJ

0.12

mg/kg

CR1

CR1-SS17-0000-0003-01

5/18/2022

35.665398

-108.498872

0

3

SW6020

SILVER

0.057 UJ

0.11

mg/kg

CR1

CR1-SS18-0000-0003-01

5/18/2022

35.665202

-108.499554

0

3

SW6020

SILVER

0.057 UJ

0.11

mg/kg

CR1

CR1-SS19-0000-0003-01

5/18/2022

35.665408

-108.500208

0

3

SW6020

SILVER

0.057 UJ

0.11

mg/kg

CR1

CR1-SS20-0000-0003-01

5/19/2022

35.664437

-108.499566

0

3

SW6020

SILVER

0.057 UJ

0.11

mg/kg

CR1

CR1-SS21-0000-0003-01

5/19/2022

35.663695

-108.499566

0

3

SW6020

SILVER

0.1 J

0.12

mg/kg

CR1

CR1-SS22-0000-0003-01

5/19/2022

35.663664

-108.500468

0

3

SW6020

SILVER

0.071 J

0.11

mg/kg

CR1

CR1-SS22-0000-0003-02

5/19/2022

35.663664

-108.500468

0

3

SW6020

SILVER

0.076 J

0.12

mg/kg

CR1

CR1-SS23-0000-0003-01

5/19/2022

35.663755

-108.501126

0

3

SW6020

SILVER

0.081 J

0.13

mg/kg

CR1

CR1-SS24-0000-0003-01

5/19/2022

35.664237

-108.500743

0

3

SW6020

SILVER

0.09 J

0.12

mg/kg

CR1

CR1-SS25-0000-0003-01

5/19/2022

35.664474

-108.500594

0

3

SW6020

SILVER

0.065 J

0.13

mg/kg

CR1

CR1-SS26-0000-0003-01

5/19/2022

35.664639

-108.501293

0

3

SW6020

SILVER

0.062 U

0.12

mg/kg

CR1

CR1-SS27-0000-0003-01

5/19/2022

35.664035

-108.501678

0

3

SW6020

SILVER

0.059 U

0.12

mg/kg

CR1

CR1-SS28-0000-0003-01

5/19/2022

35.664057

-108.503308

0

3

SW6020

SILVER

0.062 U

0.12

mg/kg

CR1

CR1-SS29-0000-0003-01

5/19/2022

35.66443

-108.504

0

3

SW6020

SILVER

0.058 U

0.12

mg/kg

CR1

CR1-SS30-0000-0003-01

5/19/2022

35.665182

-108.504127

0

3

SW6020

SILVER

0.061 U

0.12

mg/kg

CR1

CR1-SS31 -0000-0003-01

5/19/2022

35.665752

-108.504261

0

3

SW6020

SILVER

0.058 U

0.12

mg/kg

CR1

CR1-SS32-0000-0003-01

5/19/2022

35.665946

-108.50414

0

3

SW6020

SILVER

0.058 U

0.12

mg/kg

CR1

CR1-SS33-0000-0003-01

5/19/2022

35.663477

-108.501566

0

3

SW6020

SILVER

0.057 U

0.11

mg/kg

CR1

CR1-SS34-0000-0003-01

5/19/2022

35.66306

-108.5

0

3

SW6020

SILVER

0.061 J

0.12

mg/kg

CR1

CR1-SS05-0000-0003-01

5/19/2022

35.666713

-108.504141

0

3

SW6020

THALLIUM

0.098

0.01

mg/kg

CR1

CR1-SS06-0000-0003-01

5/19/2022

35.667094

-108.502536

0

3

SW6020

THALLIUM

0.2

0.011

mg/kg

CR1

CR1-SS06-0000-0003-02

5/19/2022

35.667094

-108.502536

0

3

SW6020

THALLIUM

0.17

0.01

mg/kg

CR1

CR1-SS07-0000-0003-01

5/19/2022

35.667085

-108.501729

0

3

SW6020

THALLIUM

0.15

0.011

mg/kg

CR1

CR1-SS08-0000-0003-01

5/19/2022

35.666503

-108.503201

0

3

SW6020

THALLIUM

0.14

0.01

mg/kg

CR1

CR1-SS09-0000-0003-01

5/19/2022

35.666327

-108.502514

0

3

SW6020

THALLIUM

0.16

0.01

mg/kg

CR1

CR1-SS10-0000-0003-01

5/19/2022

35.666522

-108.501608

0

3

SW6020

THALLIUM

0.13

0.011

mg/kg

Page 14 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1

CR1-SS11-0000-0003-01

5/19/2022

35.666126

-108.501314

0

3

SW6020

THALLIUM

0.12

0.01

mg/kg

CR1

CR1-SS12-0000-0003-01

5/19/2022

35.666314

-108.500988

0

3

SW6020

THALLIUM

0.067

0.01

mg/kg

CR1

CR1-SS13-0000-0003-01

5/19/2022

35.666176

-108.499679

0

3

SW6020

THALLIUM

0.13

0.01

mg/kg

CR1

CR1-SS14-0000-0003-01

5/19/2022

35.666944

-108.499149

0

3

SW6020

THALLIUM

0.14

0.011

mg/kg

CR1

CR1-SS15-0000-0003-01

5/18/2022

35.66634

-108.498

0

3

SW6020

THALLIUM

0.094

0.01

mg/kg

CR1

CR1-SS15-0000-0003-02

5/18/2022

35.66634

-108.498

0

3

SW6020

THALLIUM

0.094

0.01

mg/kg

CR1

CR1-SS16-0000-0003-01

5/18/2022

35.66598

-108.498

0

3

SW6020

THALLIUM

0.14

0.01

mg/kg

CR1

CR1-SS17-0000-0003-01

5/18/2022

35.665398

-108.498872

0

3

SW6020

THALLIUM

0.1

0.01

mg/kg

CR1

CR1-SS18-0000-0003-01

5/18/2022

35.665202

-108.499554

0

3

SW6020

THALLIUM

0.11

0.01

mg/kg

CR1

CR1-SS19-0000-0003-01

5/18/2022

35.665408

-108.500208

0

3

SW6020

THALLIUM

0.097

0.01

mg/kg

CR1

CR1-SS20-0000-0003-01

5/19/2022

35.664437

-108.499566

0

3

SW6020

THALLIUM

0.093

0.01

mg/kg

CR1

CR1-SS21 -0000-0003-01

5/19/2022

35.663695

-108.499566

0

3

SW6020

THALLIUM

0.21

0.01

mg/kg

CR1

CR1-SS22-0000-0003-01

5/19/2022

35.663664

-108.500468

0

3

SW6020

THALLIUM

0.15

0.01

mg/kg

CR1

CR1-SS22-0000-0003-02

5/19/2022

35.663664

-108.500468

0

3

SW6020

THALLIUM

0.15

0.01

mg/kg

CR1

CR1-SS23-0000-0003-01

5/19/2022

35.663755

-108.501126

0

3

SW6020

THALLIUM

0.18

0.012

mg/kg

CR1

CR1-SS24-0000-0003-01

5/19/2022

35.664237

-108.500743

0

3

SW6020

THALLIUM

0.17

0.011

mg/kg

CR1

CR1-SS25-0000-0003-01

5/19/2022

35.664474

-108.500594

0

3

SW6020

THALLIUM

0.13

0.011

mg/kg

CR1

CR1-SS26-0000-0003-01

5/19/2022

35.664639

-108.501293

0

3

SW6020

THALLIUM

0.15

0.011

mg/kg

CR1

CR1-SS27-0000-0003-01

5/19/2022

35.664035

-108.501678

0

3

SW6020

THALLIUM

0.097

0.01

mg/kg

CR1

CR1-SS28-0000-0003-01

5/19/2022

35.664057

-108.503308

0

3

SW6020

THALLIUM

0.089

0.011

mg/kg

CR1

CR1-SS29-0000-0003-01

5/19/2022

35.66443

-108.504

0

3

SW6020

THALLIUM

0.11

0.01

mg/kg

CR1

CR1-SS30-0000-0003-01

5/19/2022

35.665182

-108.504127

0

3

SW6020

THALLIUM

0.11

0.011

mg/kg

CR1

CR1-SS31 -0000-0003-01

5/19/2022

35.665752

-108.504261

0

3

SW6020

THALLIUM

0.075

0.01

mg/kg

CR1

CR1-SS32-0000-0003-01

5/19/2022

35.665946

-108.50414

0

3

SW6020

THALLIUM

0.12

0.01

mg/kg

CR1

CR1-SS33-0000-0003-01

5/19/2022

35.663477

-108.501566

0

3

SW6020

THALLIUM

0.048

0.01

mg/kg

CR1

CR1-SS34-0000-0003-01

5/19/2022

35.66306

-108.5

0

3

SW6020

THALLIUM

0.14

0.01

mg/kg

CR1

CR1-SS05-0000-0003-01

5/19/2022

35.666713

-108.504141

0

3

SW6020

URANIUM

1.5

0.02

mg/kg

CR1

CR1-SS06-0000-0003-01

5/19/2022

35.667094

-108.502536

0

3

SW6020

URANIUM

2.6

0.021

mg/kg

CR1

CR1-SS06-0000-0003-02

5/19/2022

35.667094

-108.502536

0

3

SW6020

URANIUM

2.7

0.02

mg/kg

CR1

CR1-SS07-0000-0003-01

5/19/2022

35.667085

-108.501729

0

3

SW6020

URANIUM

4.6

0.021

mg/kg

CR1

CR1-SS08-0000-0003-01

5/19/2022

35.666503

-108.503201

0

3

SW6020

URANIUM

3.2

0.021

mg/kg

CR1

CR1-SS09-0000-0003-01

5/19/2022

35.666327

-108.502514

0

3

SW6020

URANIUM

9

0.02

mg/kg

CR1

CR1-SS10-0000-0003-01

5/19/2022

35.666522

-108.501608

0

3

SW6020

URANIUM

1.4

0.022

mg/kg

CR1

CR1-SS11-0000-0003-01

5/19/2022

35.666126

-108.501314

0

3

SW6020

URANIUM

1

0.02

mg/kg

CR1

CR1-SS12-0000-0003-01

5/19/2022

35.666314

-108.500988

0

3

SW6020

URANIUM

1.6

0.02

mg/kg

CR1

CR1-SS13-0000-0003-01

5/19/2022

35.666176

-108.499679

0

3

SW6020

URANIUM

4.6

0.02

mg/kg

CR1

CR1-SS14-0000-0003-01

5/19/2022

35.666944

-108.499149

0

3

SW6020

URANIUM

1.5

0.023

mg/kg

CR1

CR1-SS15-0000-0003-01

5/18/2022

35.66634

-108.498

0

3

SW6020

URANIUM

1.5

0.02

mg/kg

CR1

CR1-SS15-0000-0003-02

5/18/2022

35.66634

-108.498

0

3

SW6020

URANIUM

1.8

0.02

mg/kg

CR1

CR1-SS16-0000-0003-01

5/18/2022

35.66598

-108.498

0

3

SW6020

URANIUM

1.7

0.021

mg/kg

CR1

CR1-SS17-0000-0003-01

5/18/2022

35.665398

-108.498872

0

3

SW6020

URANIUM

0.61

0.02

mg/kg

CR1

CR1-SS18-0000-0003-01

5/18/2022

35.665202

-108.499554

0

3

SW6020

URANIUM

1.2

0.02

mg/kg

Page 15 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1

CR1-SS19-0000-0003-01

5/18/2022

35.665408

-108.500208

0

3

SW6020

URANIUM

00
CO

0.02

mg/kg

CR1

CR1-SS20-0000-0003-01

5/19/2022

35.664437

-108.499566

0

3

SW6020

URANIUM

1.1

0.02

mg/kg

CR1

CR1-SS21 -0000-0003-01

5/19/2022

35.663695

-108.499566

0

3

SW6020

URANIUM

3.1

0.021

mg/kg

CR1

CR1-SS22-0000-0003-01

5/19/2022

35.663664

-108.500468

0

3

SW6020

URANIUM

1.6

0.02

mg/kg

CR1

CR1-SS22-0000-0003-02

5/19/2022

35.663664

-108.500468

0

3

SW6020

URANIUM

1.6

0.02

mg/kg

CR1

CR1-SS23-0000-0003-01

5/19/2022

35.663755

-108.501126

0

3

SW6020

URANIUM

1.2

0.023

mg/kg

CR1

CR1-SS24-0000-0003-01

5/19/2022

35.664237

-108.500743

0

3

SW6020

URANIUM

21

0.021

mg/kg

CR1

CR1-SS25-0000-0003-01

5/19/2022

35.664474

-108.500594

0

3

SW6020

URANIUM

1.9

0.022

mg/kg

CR1

CR1-SS26-0000-0003-01

5/19/2022

35.664639

-108.501293

0

3

SW6020

URANIUM

55

0.022

mg/kg

CR1

CR1-SS27-0000-0003-01

5/19/2022

35.664035

-108.501678

0

3

SW6020

URANIUM

4.9

0.021

mg/kg

CR1

CR1-SS28-0000-0003-01

5/19/2022

35.664057

-108.503308

0

3

SW6020

URANIUM

20

0.022

mg/kg

CR1

CR1-SS29-0000-0003-01

5/19/2022

35.66443

-108.504

0

3

SW6020

URANIUM

3.4

0.02

mg/kg

CR1

CR1-SS30-0000-0003-01

5/19/2022

35.665182

-108.504127

0

3

SW6020

URANIUM

1.6

0.021

mg/kg

CR1

CR1-SS31 -0000-0003-01

5/19/2022

35.665752

-108.504261

0

3

SW6020

URANIUM

12

0.02

mg/kg

CR1

CR1-SS32-0000-0003-01

5/19/2022

35.665946

-108.50414

0

3

SW6020

URANIUM

4.8

0.02

mg/kg

CR1

CR1-SS33-0000-0003-01

5/19/2022

35.663477

-108.501566

0

3

SW6020

URANIUM

0.37

0.02

mg/kg

CR1

CR1-SS34-0000-0003-01

5/19/2022

35.66306

-108.5

0

3

SW6020

URANIUM

0.91

0.02

mg/kg

CR1

CR1-SS05-0000-0003-01

5/19/2022

35.666713

-108.504141

0

3

SW6020

VANADIUM

11

0.51

mg/kg

CR1

CR1-SS06-0000-0003-01

5/19/2022

35.667094

-108.502536

0

3

SW6020

VANADIUM

14

0.53

mg/kg

CR1

CR1-SS06-0000-0003-02

5/19/2022

35.667094

-108.502536

0

3

SW6020

VANADIUM

13

0.51

mg/kg

CR1

CR1-SS07-0000-0003-01

5/19/2022

35.667085

-108.501729

0

3

SW6020

VANADIUM

11

0.53

mg/kg

CR1

CR1-SS08-0000-0003-01

5/19/2022

35.666503

-108.503201

0

3

SW6020

VANADIUM

13

0.51

mg/kg

CR1

CR1-SS09-0000-0003-01

5/19/2022

35.666327

-108.502514

0

3

SW6020

VANADIUM

17

0.51

mg/kg

CR1

CR1-SS10-0000-0003-01

5/19/2022

35.666522

-108.501608

0

3

SW6020

VANADIUM

12

0.55

mg/kg

CR1

CR1-SS11-0000-0003-01

5/19/2022

35.666126

-108.501314

0

3

SW6020

VANADIUM

12

0.51

mg/kg

CR1

CR1-SS12-0000-0003-01

5/19/2022

35.666314

-108.500988

0

3

SW6020

VANADIUM

12

0.5

mg/kg

CR1

CR1-SS13-0000-0003-01

5/19/2022

35.666176

-108.499679

0

3

SW6020

VANADIUM

13

0.5

mg/kg

CR1

CR1-SS14-0000-0003-01

5/19/2022

35.666944

-108.499149

0

3

SW6020

VANADIUM

12

0.57

mg/kg

CR1

CR1-SS15-0000-0003-01

5/18/2022

35.66634

-108.498

0

3

SW6020

VANADIUM

11

0.5

mg/kg

CR1

CR1-SS15-0000-0003-02

5/18/2022

35.66634

-108.498

0

3

SW6020

VANADIUM

12

0.5

mg/kg

CR1

CR1-SS16-0000-0003-01

5/18/2022

35.66598

-108.498

0

3

SW6020

VANADIUM

12

0.51

mg/kg

CR1

CR1-SS17-0000-0003-01

5/18/2022

35.665398

-108.498872

0

3

SW6020

VANADIUM

8.6

0.5

mg/kg

CR1

CR1-SS18-0000-0003-01

5/18/2022

35.665202

-108.499554

0

3

SW6020

VANADIUM

12

0.5

mg/kg

CR1

CR1-SS19-0000-0003-01

5/18/2022

35.665408

-108.500208

0

3

SW6020

VANADIUM

15

0.5

mg/kg

CR1

CR1-SS20-0000-0003-01

5/19/2022

35.664437

-108.499566

0

3

SW6020

VANADIUM

9.3

0.5

mg/kg

CR1

CR1-SS21 -0000-0003-01

5/19/2022

35.663695

-108.499566

0

3

SW6020

VANADIUM

17

0.52

mg/kg

CR1

CR1-SS22-0000-0003-01

5/19/2022

35.663664

-108.500468

0

3

SW6020

VANADIUM

15

0.5

mg/kg

CR1

CR1-SS22-0000-0003-02

5/19/2022

35.663664

-108.500468

0

3

SW6020

VANADIUM

15

0.51

mg/kg

CR1

CR1-SS23-0000-0003-01

5/19/2022

35.663755

-108.501126

0

3

SW6020

VANADIUM

15

0.58

mg/kg

CR1

CR1-SS24-0000-0003-01

5/19/2022

35.664237

-108.500743

0

3

SW6020

VANADIUM

19

0.53

mg/kg

CR1

CR1-SS25-0000-0003-01

5/19/2022

35.664474

-108.500594

0

3

SW6020

VANADIUM

15

0.55

mg/kg

CR1

CR1-SS26-0000-0003-01

5/19/2022

35.664639

-108.501293

0

3

SW6020

VANADIUM

20

0.54

mg/kg

Page 16 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1

CR1-SS27-0000-0003-01

5/19/2022

35.664035

-108.501678

0

3

SW6020

VANADIUM

13

0.52

mg/kg

CR1

CR1-SS28-0000-0003-01

5/19/2022

35.664057

-108.503308

0

3

SW6020

VANADIUM

20

0.55

mg/kg

CR1

CR1-SS29-0000-0003-01

5/19/2022

35.66443

-108.504

0

3

SW6020

VANADIUM

13

0.51

mg/kg

CR1

CR1-SS30-0000-0003-01

5/19/2022

35.665182

-108.504127

0

3

SW6020

VANADIUM

11

0.53

mg/kg

CR1

CR1-SS31 -0000-0003-01

5/19/2022

35.665752

-108.504261

0

3

SW6020

VANADIUM

13

0.51

mg/kg

CR1

CR1-SS32-0000-0003-01

5/19/2022

35.665946

-108.50414

0

3

SW6020

VANADIUM

15

0.51

mg/kg

CR1

CR1-SS33-0000-0003-01

5/19/2022

35.663477

-108.501566

0

3

SW6020

VANADIUM

5.4

0.5

mg/kg

CR1

CR1-SS34-0000-0003-01

5/19/2022

35.66306

-108.5

0

3

SW6020

VANADIUM

13

0.51

mg/kg

CR1

CR1-SS05-0000-0003-01

5/19/2022

35.666713

-108.504141

0

3

SW6020

ZINC

35

10

mg/kg

CR1

CR1-SS06-0000-0003-01

5/19/2022

35.667094

-108.502536

0

3

SW6020

ZINC

70

11

mg/kg

CR1

CR1-SS06-0000-0003-02

5/19/2022

35.667094

-108.502536

0

3

SW6020

ZINC

62

10

mg/kg

CR1

CR1-SS07-0000-0003-01

5/19/2022

35.667085

-108.501729

0

3

SW6020

ZINC

41

11

mg/kg

CR1

CR1-SS08-0000-0003-01

5/19/2022

35.666503

-108.503201

0

3

SW6020

ZINC

43

10

mg/kg

CR1

CR1-SS09-0000-0003-01

5/19/2022

35.666327

-108.502514

0

3

SW6020

ZINC

61

10

mg/kg

CR1

CR1-SS10-0000-0003-01

5/19/2022

35.666522

-108.501608

0

3

SW6020

ZINC

45

11

mg/kg

CR1

CR1-SS11-0000-0003-01

5/19/2022

35.666126

-108.501314

0

3

SW6020

ZINC

45

10

mg/kg

CR1

CR1-SS12-0000-0003-01

5/19/2022

35.666314

-108.500988

0

3

SW6020

ZINC

52

10

mg/kg

CR1

CR1-SS13-0000-0003-01

5/19/2022

35.666176

-108.499679

0

3

SW6020

ZINC

47

10

mg/kg

CR1

CR1-SS14-0000-0003-01

5/19/2022

35.666944

-108.499149

0

3

SW6020

ZINC

38

11

mg/kg

CR1

CR1-SS15-0000-0003-01

5/18/2022

35.66634

-108.498

0

3

SW6020

ZINC

38

10

mg/kg

CR1

CR1-SS15-0000-0003-02

5/18/2022

35.66634

-108.498

0

3

SW6020

ZINC

34

10

mg/kg

CR1

CR1-SS16-0000-0003-01

5/18/2022

35.66598

-108.498

0

3

SW6020

ZINC

42

10

mg/kg

CR1

CR1-SS17-0000-0003-01

5/18/2022

35.665398

-108.498872

0

3

SW6020

ZINC

27

10

mg/kg

CR1

CR1-SS18-0000-0003-01

5/18/2022

35.665202

-108.499554

0

3

SW6020

ZINC

41

10

mg/kg

CR1

CR1-SS19-0000-0003-01

5/18/2022

35.665408

-108.500208

0

3

SW6020

ZINC

38

10

mg/kg

CR1

CR1-SS20-0000-0003-01

5/19/2022

35.664437

-108.499566

0

3

SW6020

ZINC

32

10

mg/kg

CR1

CR1-SS21-0000-0003-01

5/19/2022

35.663695

-108.499566

0

3

SW6020

ZINC

70

10

mg/kg

CR1

CR1-SS22-0000-0003-01

5/19/2022

35.663664

-108.500468

0

3

SW6020

ZINC

56

10

mg/kg

CR1

CR1-SS22-0000-0003-02

5/19/2022

35.663664

-108.500468

0

3

SW6020

ZINC

56

10

mg/kg

CR1

CR1-SS23-0000-0003-01

5/19/2022

35.663755

-108.501126

0

3

SW6020

ZINC

62

12

mg/kg

CR1

CR1-SS24-0000-0003-01

5/19/2022

35.664237

-108.500743

0

3

SW6020

ZINC

62

11

mg/kg

CR1

CR1-SS25-0000-0003-01

5/19/2022

35.664474

-108.500594

0

3

SW6020

ZINC

60

11

mg/kg

CR1

CR1-SS26-0000-0003-01

5/19/2022

35.664639

-108.501293

0

3

SW6020

ZINC

48

11

mg/kg

CR1

CR1-SS27-0000-0003-01

5/19/2022

35.664035

-108.501678

0

3

SW6020

ZINC

43

10

mg/kg

CR1

CR1-SS28-0000-0003-01

5/19/2022

35.664057

-108.503308

0

3

SW6020

ZINC

37

11

mg/kg

CR1

CR1-SS29-0000-0003-01

5/19/2022

35.66443

-108.504

0

3

SW6020

ZINC

47

10

mg/kg

CR1

CR1-SS30-0000-0003-01

5/19/2022

35.665182

-108.504127

0

3

SW6020

ZINC

49

11

mg/kg

CR1

CR1-SS31 -0000-0003-01

5/19/2022

35.665752

-108.504261

0

3

SW6020

ZINC

31

10

mg/kg

CR1

CR1-SS32-0000-0003-01

5/19/2022

35.665946

-108.50414

0

3

SW6020

ZINC

42

10

mg/kg

CR1

CR1-SS33-0000-0003-01

5/19/2022

35.663477

-108.501566

0

3

SW6020

ZINC

18

10

mg/kg

CR1

CR1-SS34-0000-0003-01

5/19/2022

35.66306

-108.5

0

3

SW6020

ZINC

46

10

mg/kg

CR1

RWPR-SS-001 (0-6)

10/6/2010

35.6661433

-108.504248

0

6

713R11

Ra-226

4.54 G

0.44

pCi/g

Page 17 of 92


-------
Attachment C-1. Data Used in the Risk Assessment











Sample

Sample













Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Top
Depth
(inches

Bottom
Depth
(inches

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit











bgs)

bgs)













CR1

RWPR-SS-002 (0-6)

10/6/2010

35.6661419

-108.503999

0

6

713R11

Ra-226

2.9 G

0.54

O

Q.

/g

CR1

C1 LI-005.1 (0-6)

12/14/2010

35.6663944

-108.503553

0

6

713R11

Ra-226

2.61 G

0.57

O

Q.

/ g

CR1

C1 LI-016.1 (0-6)

12/14/2010

35.6667753

-108.502749

0

6

713R11

Ra-226

1.14 G

0.49

O

Q.

/ g

CR1

C1 LI-026.1 (0-6)

12/14/2010

35.6669753

-108.50235

0

6

713R11

Ra-226

2.22 G

0.47

O

Q.

/ g

CR1

C1 LI-037.1 (0-6)

12/14/2010

35.6667797

-108.501957

0

6

713R11

Ra-226

1.37 G

0.48

O

Q.

/ g

CR1

C1 LI-058.1 (0-6)

12/14/2010

35.6660344

-108.500605

0

6

713R11

Ra-226

7.37

0.52

O

Q.

/ g

CR1

C1 LI-058.4 Dup

12/14/2010

35.6660344

-108.500605

0

6

713R11

Ra-226

9.6

0.7

O

Q.

/ g

CR1

C1 LI-063.1 (0-6)

12/13/2010

35.6656513

-108.500325

0

6

713R11

Ra-226

7.31

0.54

O

Q.

/g

CR1

C1 LI-068.1 (0-6)

12/13/2010

35.666229

-108.500202

0

6

713R11

Ra-226

3.79 G

0.49

O

Q.

/g

CR1

C1 LI-078.1 (0-6)

12/14/2010

35.6660362

-108.49979

0

6

713R11

Ra-226

1.5 G

0.41

O

Q.

/g

CR1

C1 LI-085.1 (0-6)

12/13/2010

35.6652767

-108.499514

0

6

713R11

Ra-226

2.72 G

0.59

O

Q.

/g

CR1

C1 LI-085.1 (0-6) Dup

12/13/2010

35.6652767

-108.499514

0

6

713R11

Ra-226

2.7 G

0.57

O

Q.

/g

CR1

C1LI-091.1 (0-6)

12/13/2010

35.665467

-108.499381

0

6

713R11

Ra-226

1.35 G

0.48

O

Q.

/g

CR1

C1LI-091.4 Dup

12/13/2010

35.665467

-108.499381

0

6

713R11

Ra-226

1.38 G

0.5

O

Q.

/g

CR1

C1 LI-099.1 (0-6)

12/13/2010

35.6664237

-108.499261

0

6

713R11

Ra-226

1.85

0.51

O

Q.

/g

CR1

C1LI-107.1 (0-6)

12/14/2010

35.6670014

-108.499118

0

6

713R11

Ra-226

1.05 G

0.47

O

Q.

/g

CR1

C1LI-110.1 (0-6)

12/14/2010

35.6660517

-108.498975

0

6

713R11

Ra-226

0.98 LT

0.47

O

Q.

/g

CR1

C1LI-120.1 (0-6)

12/13/2010

35.6652921

-108.49871

0

6

713R11

Ra-226

1.05 G

0.49

O

Q.

/g

CR1

C1LI-120.1 (0-6) Dup

12/13/2010

35.6652921

-108.49871

0

6

713R11

Ra-226

0.87 LT,G

0.54

O

Q.

/g

CR1

C1LI-127.1 (0-6)

12/14/2010

35.6658533

-108.498576

0

6

713R11

Ra-226

4.13

0.46

O

Q.

/g

CR1

C1LI-127.4 Dup

12/14/2010

35.6658533

-108.498576

0

6

713R11

Ra-226

4.85

0.58

O

Q.

/g

CR1

C1LI-131.1 (0-6)

12/13/2010

35.6652826

-108.49844

0

6

713R11

Ra-226

1.21 G

0.5

O

Q.

/g

CR1

C1LI-140.1 (0-6)

12/13/2010

35.66566

-108.498258

0

6

713R11

Ra-226

1.66 G

0.5

O

Q.

/g

CR1

C1LI-140.4 Dup

12/13/2010

35.66566

-108.498258

0

6

713R11

Ra-226

1.86 G

0.68

O

Q.

/g

CR1

C1LI-141.1 (0-6)

12/14/2010

35.6660451

-108.498177

0

6

713R11

Ra-226

8.9 G

0.6

O

Q.

/g

CR1

C1 LP-004.1 (0-6)

12/13/2010

35.664119

-108.502188

0

6

713R11

Ra-226

1.24 G

0.46

O

Q.

/ g

CR1

C1 LP-004.1 (0-6) Dup

12/13/2010

35.664119

-108.502188

0

6

713R11

Ra-226

1.35 G

0.54

O

Q.

/ g

CR1

C1 LP-009.1 (0-6)

12/13/2010

35.6639221

-108.501523

0

6

713R11

Ra-226

47.1 G

1

O

Q.

/ g

CR1

C1 LP-009.4 Dup

12/13/2010

35.6639221

-108.501523

0

6

713R11

Ra-226

42.7 M3,G

1.1

O

Q.

/ g

CR1

C1LP-015.1 (0-6)

12/13/2010

35.6639346

-108.501254

0

6

713R11

Ra-226

35.8 M3,G

1.2

O

Q.

/ g

CR1

C1LP-019.1 (0-6)

12/15/2010

35.6645068

-108.501124

0

6

713R11

Ra-226

4.9 G

0.6

O

Q.

/ g

CR1

C1 LP-020.1 (0-6)

12/13/2010

35.6639251

-108.500984

0

6

713R11

Ra-226

26.6

1

O

Q.

/ g

CR1

C1 LP-026.1 (0-6)

12/13/2010

35.6643085

-108.500718

0

6

713R11

Ra-226

12.5 G

0.7

O

Q.

/ g

CR1

C1LP-031.1 (0-6)

12/13/2010

35.6648889

-108.500588

0

6

713R11

Ra-226

2.23 G

0.62

O

Q.

/ g

CR1

C1 LP-037.1 (0-6)

12/13/2010

35.6645002

-108.500323

0

6

713R11

Ra-226

2.23 G

0.71

O

Q.

/ g

CR1

C1 LP-037.1 (0-6) Dup

12/13/2010

35.6645002

-108.500323

0

6

713R11

Ra-226

2.25 G

0.45

pC

/ g

CR1

C1 LP-042.1 (0-6)

12/13/2010

35.6646878

-108.500183

0

6

713R11

Ra-226

2.02 G

0.49

o

Q.

/ g

CR1

C1 LP-048.1 (0-6)

12/13/2010

35.6639283

-108.49991

0

6

713R11

Ra-226

3.23 G

0.79

O

Q.

/ g

CR1

C1 LP-052.1 (0-6)

12/13/2010

35.6637533

-108.499771

0

6

713R11

Ra-226

1.3 G

0.55

O

Q.

/g

CR1

C1 LP-053.1 (0-6)

12/13/2010

35.6641186

-108.499777

0

6

713R11

Ra-226

2.97 G

0.58

pC

/g

CR1

C1 LP-053.1 (0-6) Dup

12/13/2010

35.6641186

-108.499777

0

6

713R11

Ra-226

2.19 G

0.6

o

Q.

/g

CR1

C1 LP-059.1 (0-6)

12/13/2010

35.6646908

-108.499647

0

6

713R11

Ra-226

2.3 G

0.77

O

Q.

/g

Page 18 of 92


-------
Attachment C-1. Data Used in the Risk Assessment











Sample

Sample













Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Top
Depth
(inches

Bottom
Depth
(inches

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit











bgs)

bgs)













CR1

C1 LP-064.1 (0-6)

12/13/2010

35.6648619

-108.499507

0

6

713R11

Ra-226

1.33 G

0.62

O

Q.

/g

CR1

C1 LP-070.1 (0-6)

12/13/2010

35.6641079

-108.499235

0

6

713R11

Ra-226

1.77 G

0.57

O

Q.

/ g

CR1

C1 LP-075.1 (0-6)

12/13/2010

35.6646828

-108.499105

0

6

713R11

Ra-226

2.08 G

0.64

O

Q.

/ g

CR1

C1LP-081.1 (0-6)

12/13/2010

35.6643108

-108.498819

0

6

713R11

Ra-226

1.43

0.49

O

Q.

/ g

CR1

C1LP-081.1 (0-6) Dup

12/13/2010

35.6643108

-108.498819

0

6

713R11

Ra-226

1.43

0.41

O

Q.

/ g

CR1

C1 LW-002.1 (0-6)

12/16/2010

35.6661835

-108.503942

0

6

713R11

Ra-226

1.68 G

0.47

O

Q.

/ g

CR1

C1 LW-002.1 (0-6) Dup

12/16/2010

35.6661835

-108.503942

0

6

713R11

Ra-226

1.39 G

0.58

O

Q.

/ g

CR1

C1LW-013.1 (0-6)

12/14/2010

35.6652515

-108.503557

0

6

713R11

Ra-226

3.49

0.57

O

Q.

/ g

CR1

C1 LW-020.1 (0-6)

12/14/2010

35.6658232

-108.503512

0

6

713R11

Ra-226

2.36 G

0.61

O

Q.

/ g

CR1

C1 LW-022.1 (0-6)

12/15/2010

35.6644948

-108.503278

0

6

713R11

Ra-226

1.24

0.46

O

Q.

/ g

CR1

C1 LW-034.1 (0-6)

12/14/2010

35.6648644

-108.503012

0

6

713R11

Ra-226

2.09 G

0.62

O

Q.

/ g

CR1

C1LW-041.1 (0-6)

12/15/2010

35.6654339

-108.502875

0

6

713R11

Ra-226

1.37

0.36

O

Q.

/ g

CR1

C1LW-048.1 (0-6)

12/14/2010

35.6660088

-108.502742

0

6

713R11

Ra-226

2.01 G

0.48

O

Q.

/ g

CR1

C1 LW-050.1 (0-6)

12/14/2010

35.66468

-108.502583

0

6

713R11

Ra-226

1.87 G

0.64

O

Q.

/ g

CR1

C1 LW-062.1 (0-6)

12/14/2010

35.6650605

-108.502334

0

6

713R11

Ra-226

1.4

0.58

O

Q.

/ g

CR1

C1 LW-067.1 (0-6)

12/14/2010

35.6648745

-108.502187

0

6

713R11

Ra-226

7.02

0.41

O

Q.

/ g

CR1

C1 LW-069.1 (0-6)

12/14/2010

35.6656327

-108.502204

0

6

713R11

Ra-226

1.27 G

0.49

O

Q.

/ g

CR1

C1 LW-083.1 (0-6)

12/14/2010

35.6654455

-108.501778

0

6

713R11

Ra-226

1.89 G

0.49

O

Q.

/ g

CR1

C1 LW-090.1 (0-6)

12/14/2010

35.6656427

-108.501392

0

6

713R11

Ra-226

1.84 G

0.47

O

Q.

/ g

CR1

C1LW-097.1 (0-6)

12/14/2010

35.6654554

-108.500987

0

6

713R11

Ra-226

2.2 G

0.39

O

Q.

/ g

CR1

C1LW-104.1 (0-6)

12/14/2010

35.6656499

-108.500588

0

6

713R11

Ra-226

1.48 G

0.47

O

Q.

/ g

CR1

RWPR-SS-004 (0-6)

10/6/2010

35.6660068

-108.504092

0

6

713R11

Ra-226

8.9 G

0.6

O

Q.

/ g

CR1

RWPR-SS-006 (0-6)

10/8/2010

35.6658165

-108.504225

0

6

713R11

Ra-226

4.89 G

0.61

O

Q.

/g

CR1

RWPR-SS-007 (0-6)

10/8/2010

35.6656262

-108.504355

0

6

713R11

Ra-226

2.01 G

0.66

O

Q.

/g

CR1

RWPR-SS-008 (0-6)

10/8/2010

35.6656249

-108.504096

0

6

713R11

Ra-226

5.17 G

0.77

O

Q.

/g

CR1

RWPR-SS-010 (0-6)

10/6/2010

35.6654388

-108.503963

0

6

713R11

Ra-226

17.3 G

0.9

O

Q.

/g

CR1

RWPR-SS-011 (0-6)

10/7/2010

35.6652416

-108.504358

0

6

713R11

Ra-226

3.73 G

0.61

O

Q.

/g

CR1

RWPR-SS-011 (0-6) Dup

10/7/2010

35.6652416

-108.504358

0

6

713R11

Ra-226

3.54 G

0.5

O

Q.

/ g

CR1

RWPR-SS-012 (0-6)

10/7/2010

35.6652376

-108.504092

0

6

713R11

Ra-226

12.2 G

0.7

O

Q.

/ g

CR1

RWPR-SS-014 (0-6)

10/7/2010

35.6650555

-108.504222

0

6

713R11

Ra-226

3.56

0.55

O

Q.

/ g

CR1

RWPR-SS-019 (0-6)

10/7/2010

35.6646791

-108.504222

0

6

713R11

Ra-226

7.2 G

0.7

pC

/g

CR1

RWPR-SS-023 (0-6)

10/6/2010

35.6642878

-108.503953

0

6

713R11

Ra-226

1.67 G

0.48

pC

/g

CR1

RWPR-SS-025 (0-6)

10/8/2010

35.6640782

-108.504086

0

6

713R11

Ra-226

0.99 LT,G

0.37

o

Q.

/g

CR1

RWPR-SS-025 (0-6) Dup

10/8/2010

35.6640782

-108.504086

0

6

713R11

Ra-226

1.07 G

0.47

O

Q.

/g

CR1

RWPR-SS-211 (0-6)

10/7/2010

35.6652416

-108.504358

0

6

713R11

Ra-226

3.9 G

0.56

pC

/g

CR1

RWPR-SS-001 (0-6)

10/6/2010

35.6661433

-108.504248

0

6

SW6020

URANIUM

8.7

11

mg/kg

CR1

RWPR-SS-002 (0-6)

10/6/2010

35.6661419

-108.503999

0

6

SW6020

URANIUM

4.8

11

mg/kg

CR1

RWPR-SS-004 (0-6)

10/6/2010

35.6660068

-108.504092

0

6

SW6020

URANIUM

8.2

12

mg/kg

CR1

RWPR-SS-006 (0-6)

10/8/2010

35.6658165

-108.504225

0

6

SW6020

URANIUM

3.7

11

mg/kg

CR1

RWPR-SS-007 (0-6)

10/8/2010

35.6656262

-108.504355

0

6

SW6020

URANIUM

3

11

mg/kg

CR1

RWPR-SS-008 (0-6)

10/8/2010

35.6656249

-108.504096

0

6

SW6020

URANIUM

7.3

11

mg/kg

CR1

RWPR-SS-010 (0-6)

10/6/2010

35.6654388

-108.503963

0

6

SW6020

URANIUM

9.4

11

mg/kg

Page 19 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1

RWPR-SS-011 (0-6)

10/7/2010

35.6652416

-108.504358

0

6

SW6020

URANIUM

2.8

11

mg/kg

CR1

RWPR-SS-012 (0-6)

10/7/2010

35.6652376

-108.504092

0

6

SW6020

URANIUM

10

11

mg/kg

CR1

RWPR-SS-014 (0-6)

10/7/2010

35.6650555

-108.504222

0

6

SW6020

URANIUM

3.3

11

mg/kg

CR1

RWPR-SS-019 (0-6)

10/7/2010

35.6646791

-108.504222

0

6

SW6020

URANIUM

6.5

11

mg/kg

CR1

RWPR-SS-023 (0-6)

10/6/2010

35.6642878

-108.503953

0

6

SW6020

URANIUM

1.3

11

mg/kg

CR1

RWPR-SS-025 (0-6)

10/8/2010

35.6640782

-108.504086

0

6

SW6020

URANIUM

0.61

10

mg/kg

CR1

RWPR-SS-211 (0-6)

10/7/2010

35.6652416

-108.504358

0

6

SW6020

URANIUM

2.8

11

mg/kg

CR1

C1LI-500 SS1 0-1.5

5/3/2011

35.6668364

-108.502316

0

18

713R11

Ra-226

10.2 G

0.6

pC

/g

CR1

C1LI-501 SS1 0-1.5

5/3/2011

35.6665962

-108.502944

0

18

713R11

Ra-226

5.51 G

0.52

o

Q.

/g

CR1

C1LP-400 SS1 0-1.5

4/25/2011

35.6645408

-108.501319

0

18

713R11

Ra-226

2.15 G

0.57

O

Q.

/g

CR1

C1LP-401 SS1 0-1.5

4/25/2011

35.6640736

-108.501375

0

18

713R11

Ra-226

8.2

0.6

O

Q.

/g

CR1

C1LP-402 SS1 0-1.5

4/29/2011

35.6646723

-108.5003

0

18

713R11

Ra-226

2.2 G

0.5

O

Q.

/g

CR1

C1LP-403 SS1 0-1.5

4/29/2011

35.6640345

-108.500584

0

18

713R11

Ra-226

21.4 G

0.6

O

Q.

/g

CR1

C1LP-404 SS1 0-1.5

5/1/2011

35.664222

-108.499825

0

18

713R11

Ra-226

2.66 G

0.48

O

Q.

/g

CR1

C1LP-405 SS1 0-1.5

5/1/2011

35.6640588

-108.499182

0

18

713R11

Ra-226

1.65 G

0.66

O

Q.

/g

CR1

C1LP-406 SS1 0-1.5

5/1/2011

35.6654968

-108.499143

0

18

713R11

Ra-226

1.16 G

0.4

O

Q.

/g

CR1

C1LP-406 SS1 0-1.5 Dup

5/1/2011

35.6654968

-108.499143

0

18

713R11

Ra-226

1.18 G

0.43

O

Q.

/g

CR1

C1LP-407 SS1 0-1.5

5/2/2011

35.6658597

-108.498441

0

18

713R11

Ra-226

3.52 G

0.62

O

Q.

/g

CR1

C1LP-407 SS1 0-1.5 Dup

5/2/2011

35.6658597

-108.498441

0

18

713R11

Ra-226

3.23 G

0.48

O

Q.

/g

CR1

C1LP-408 SS1 0-1.5

5/2/2011

35.6661682

-108.498101

0

18

713R11

Ra-226

3.53 G

0.49

O

Q.

/g

CR1

C1LP-700 SS1 0-1.5

4/30/2011

35.663741

-108.500407

0

18

713R11

Ra-226

1.46 G

0.48

O

Q.

/g

CR1

C1LP-701 SS1 0-1.5

4/30/2011

35.6635129

-108.500075

0

18

713R11

Ra-226

2.86 G

0.66

O

Q.

/g

CR1

C1LP-702 SS1 0-1.5

4/30/2011

35.6633178

-108.499525

0

18

713R11

Ra-226

1.33

0.46

O

Q.

/g

CR1

C1LP-703 SS1 0-1.5

4/30/2011

35.6650352

-108.499164

0

18

713R11

Ra-226

1.28 G

0.47

O

Q.

/g

CR1

C1LP-703 SS1 0-1.5 Dup

4/30/2011

35.6650352

-108.499164

0

18

713R11

Ra-226

1.16 G

0.54

O

Q.

/g

CR1

RWPR-SS-006 (1.5-1.9)

10/8/2010

35.6658165

-108.504225

1.5

1.9

713R11

Ra-226

2.15

0.52

O

Q.

/g

CR1

RWPR-SS-006 (1.5-1.9)

10/8/2010

35.6658165

-108.504225

1.5

1.9

SW6020

URANIUM

1.9

11

mg/kg

CR1

RWPR-SS-002 (1.5-2)

10/6/2010

35.6661419

-108.503999

1.5

2

713R11

Ra-226

48.5 M3

1.2

o

Q.

/ g

CR1

RWPR-SS-004 (1.5-2)

10/6/2010

35.6660068

-108.504092

1.5

2

713R11

Ra-226

1.32

0.33

O

Q.

/ g

CR1

RWPR-SS-009 (1.5-2)

10/7/2010

35.6654374

-108.504225

1.5

2

713R11

Ra-226

0.56 LT

0.37

O

Q.

/g

CR1

RWPR-SS-010 (1.5-2)

10/6/2010

35.6654388

-108.503963

1.5

2

713R11

Ra-226

2.62

0.35

pC

'g

CR1

RWPR-SS-011 (1.5-2)

10/7/2010

35.6652416

-108.504358

1.5

2

713R11

Ra-226

0.96 LT

0.48

pC

/g

CR1

RWPR-SS-012 (1.5-2)

10/7/2010

35.6652376

-108.504092

1.5

2

713R11

Ra-226

2.08

0.48

o

Q.

/g

CR1

RWPR-SS-014 (1.5-2)

10/7/2010

35.6650555

-108.504222

1.5

2

713R11

Ra-226

7.18

0.56

O

Q.

/g

CR1

RWPR-SS-014 (1.5-2) Dup

10/7/2010

35.6650555

-108.504222

1.5

2

713R11

Ra-226

6.69

0.6

pC

'g

CR1

RWPR-SS-019 (1.5-2)

10/7/2010

35.6646791

-108.504222

1.5

2

713R11

Ra-226

1.64

0.48

pC

/g

CR1

RWPR-SS-020 (1.5-2)

10/7/2010

35.6646778

-108.50396

1.5

2

713R11

Ra-226

7.7

0.7

o

Q.

/g

CR1

RWPR-SS-021 (1.5-2)

10/6/2010

35.6644876

-108.504083

1.5

2

713R11

Ra-226

1.67 G

0.51

O

Q.

/g

CR1

RWPR-SS-023 (1.5-2)

10/6/2010

35.6642878

-108.503953

1.5

2

713R11

Ra-226

1.44 G

0.5

pC

/g

CR1

RWPR-SS-211 (1.5-2)

10/7/2010

35.6652416

-108.504358

1.5

2

713R11

Ra-226

1.03

0.43

pC

/g

CR1

RWPR-SS-221 (1.5-2)

10/6/2010

35.6644876

-108.504083

1.5

2

713R11

Ra-226

1.65 G

0.49

o

Q.

/g

CR1

RWPR-SS-002 (1.5-2)

10/6/2010

35.6661419

-108.503999

1.5

2

SW6020

URANIUM

61

10

mg/kg

Page 20 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1

RWPR-SS-004 (1.5-2)

10/6/2010

35.6660068

-108.504092

1.5

2

SW6020

URANIUM

2.1

10

mg/kg

CR1

RWPR-SS-009 (1.5-2)

10/7/2010

35.6654374

-108.504225

1.5

2

SW6020

URANIUM

0.82

10

mg/kg

CR1

RWPR-SS-010 (1.5-2)

10/6/2010

35.6654388

-108.503963

1.5

2

SW6020

URANIUM

5.9

10

mg/kg

CR1

RWPR-SS-011 (1.5-2)

10/7/2010

35.6652416

-108.504358

1.5

2

SW6020

URANIUM

0.97

10

mg/kg

CR1

RWPR-SS-012 (1.5-2)

10/7/2010

35.6652376

-108.504092

1.5

2

SW6020

URANIUM

2.6

10

mg/kg

CR1

RWPR-SS-014 (1.5-2)

10/7/2010

35.6650555

-108.504222

1.5

2

SW6020

URANIUM

9

10

mg/kg

CR1

RWPR-SS-019 (1.5-2)

10/7/2010

35.6646791

-108.504222

1.5

2

SW6020

URANIUM

1.3

10

mg/kg

CR1

RWPR-SS-020 (1.5-2)

10/7/2010

35.6646778

-108.50396

1.5

2

SW6020

URANIUM

5.8

11

mg/kg

CR1

RWPR-SS-021 (1.5-2)

10/6/2010

35.6644876

-108.504083

1.5

2

SW6020

URANIUM

2.2

11

mg/kg

CR1

RWPR-SS-023 (1.5-2)

10/6/2010

35.6642878

-108.503953

1.5

2

SW6020

URANIUM

1.1

11

mg/kg

CR1

RWPR-SS-211 (1.5-2)

10/7/2010

35.6652416

-108.504358

1.5

2

SW6020

URANIUM

0.96

10

mg/kg

CR1

RWPR-SS-221 (1.5-2)

10/6/2010

35.6644876

-108.504083

1.5

2

SW6020

URANIUM

3.5

11

mg/kg

CR1

RWPR-SS-003 (2-5)

10/8/2010

35.6660108

-108.504365

2

5

713R11

Ra-226

1.34 G

0.69

pCi/g

CR1

RWPR-SS-003 (2-5)

10/8/2010

35.6660108

-108.504365

2

5

SW6020

URANIUM

2.5

11

mg/kg

CR1

RWPR-SS-005 (2-6)

10/8/2010

35.6658177

-108.504495

2

6

713R11

Ra-226

1.72 G

0.72

pCi/g

CR1

RWPR-SS-019 (2-6)

10/8/2010

35.6646791

-108.504222

2

6

713R11

Ra-226

2.23 G

0.48

pCi/g

CR1

C1SS-026.2 (2-6)

12/15/2010

35.6641373

-108.503343

2

6

713R11

Ra-226

31.8

0.9

pCi/g

CR1

C1SS-026.2 (2-6) Dup

12/15/2010

35.6641373

-108.503343

2

6

713R11

Ra-226

28.4

0.9

pCi/g

CR1

C1SS-041.2 (2-6)

12/15/2010

35.6637671

-108.502242

2

6

713R11

Ra-226

1.55 G

0.43

pCi/g

CR1

C1SS-063A.2 (2-6)

12/15/2010

35.6638077

-108.500865

2

6

713R11

Ra-226

8.4 G

0.8

pCi/g

CR1

C1SS-069.2 (2-6)

12/15/2010

35.6664561

-108.500366

2

6

713R11

Ra-226

1.81

0.47

pCi/g

CR1

C1SS-082.2 (2-6)

12/15/2010

35.6629857

-108.499478

2

6

713R11

Ra-226

1.17 G

0.52

pCi/g

CR1

RWPR-SS-021 (2-6)

10/6/2010

35.6644876

-108.504083

2

6

713R11

Ra-226

1.19 G

0.55

pCi/g

CR1

RWPR-SS-221 (2-6)

10/6/2010

35.6644876

-108.504083

2

6

713R11

Ra-226

1.38 G

0.57

pCi/g

CR1

RWPR-SS-005 (2-6)

10/8/2010

35.6658177

-108.504495

2

6

SW6020

URANIUM

1.6

11

mg/kg

CR1

RWPR-SS-019 (2-6)

10/8/2010

35.6646791

-108.504222

2

6

SW6020

URANIUM

5

11

mg/kg

CR1

RWPR-SS-021 (2-6)

10/6/2010

35.6644876

-108.504083

2

6

SW6020

URANIUM

2.4

11

mg/kg

CR1

RWPR-SS-221 (2-6)

10/6/2010

35.6644876

-108.504083

2

6

SW6020

URANIUM

2.7

11

mg/kg

CR1

RWPR-SS-002 (2.5-3)

10/6/2010

35.6661419

-108.503999

2.5

3

713R11

Ra-226

17.3 G

1

o

Q.

/ g

CR1

RWPR-SS-004 (2.5-3)

10/6/2010

35.6660068

-108.504092

2.5

3

713R11

Ra-226

0.77 LT

0.49

O

Q.

/g

CR1

RWPR-SS-009 (2.5-3)

10/7/2010

35.6654374

-108.504225

2.5

3

713R11

Ra-226

0.76 LT

0.45

pC

Zg

CR1

RWPR-SS-010 (2.5-3)

10/6/2010

35.6654388

-108.503963

2.5

3

713R11

Ra-226

1.62

0.51

pC

/g

CR1

RWPR-SS-011 (2.5-3)

10/7/2010

35.6652416

-108.504358

2.5

3

713R11

Ra-226

0.63 LT

0.32

o

Q.

/ g

CR1

RWPR-SS-012 (2.5-3)

10/7/2010

35.6652376

-108.504092

2.5

3

713R11

Ra-226

1.12

0.49

O

Q.

/g

CR1

RWPR-SS-019 (2.5-3)

10/7/2010

35.6646791

-108.504222

2.5

3

713R11

Ra-226

0.87 LT

0.42

pC

/g

CR1

RWPR-SS-020 (2.5-3)

10/7/2010

35.6646778

-108.50396

2.5

3

713R11

Ra-226

3.42

0.52

pC

/g

CR1

RWPR-SS-021 (2.5-3)

10/6/2010

35.6644876

-108.504083

2.5

3

713R11

Ra-226

1.33 G

0.4

o

Q.

/g

CR1

RWPR-SS-023 (2.5-3)

10/6/2010

35.6642878

-108.503953

2.5

3

713R11

Ra-226

1.56

0.48

O

Q.

/g

CR1

RWPR-SS-211 (2.5-3)

10/7/2010

35.6652416

-108.504358

2.5

3

713R11

Ra-226

0.75 LT

0.42

pC

/g

CR1

RWPR-SS-221 (2.5-3)

10/6/2010

35.6644876

-108.504083

2.5

3

713R11

Ra-226

1.57

0.57

pC

/g

CR1

RWPR-SS-002 (2.5-3)

10/6/2010

35.6661419

-108.503999

2.5

3

SW6020

URANIUM

39

11

mg/kg

CR1

RWPR-SS-004 (2.5-3)

10/6/2010

35.6660068

-108.504092

2.5

3

SW6020

URANIUM

1.3

10

mg/kg

Page 21 of 92


-------
Attachment C-1. Data Used in the Risk Assessment











Sample

Sample













Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Top
Depth
(inches

Bottom
Depth
(inches

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit











bgs)

bgs)













CR1

RWPR-SS-009 (2.5-3)

10/7/2010

35.6654374

-108.504225

2.5

3

SW6020

URANIUM

0.6

11

mg/kg

CR1

RWPR-SS-010 (2.5-3)

10/6/2010

35.6654388

-108.503963

2.5

3

SW6020

URANIUM

2.4

10

mg/kg

CR1

RWPR-SS-011 (2.5-3)

10/7/2010

35.6652416

-108.504358

2.5

3

SW6020

URANIUM

0.68

10

mg/kg

CR1

RWPR-SS-012 (2.5-3)

10/7/2010

35.6652376

-108.504092

2.5

3

SW6020

URANIUM

2.2

10

mg/kg

CR1

RWPR-SS-019 (2.5-3)

10/7/2010

35.6646791

-108.504222

2.5

3

SW6020

URANIUM

1.2

10

mg/kg

CR1

RWPR-SS-020 (2.5-3)

10/7/2010

35.6646778

-108.50396

2.5

3

SW6020

URANIUM

5.3

10

mg/kg

CR1

RWPR-SS-021 (2.5-3)

10/6/2010

35.6644876

-108.504083

2.5

3

SW6020

URANIUM

3

11

mg/kg

CR1

RWPR-SS-023 (2.5-3)

10/6/2010

35.6642878

-108.503953

2.5

3

SW6020

URANIUM

1.2

11

mg/kg

CR1

RWPR-SS-211 (2.5-3)

10/7/2010

35.6652416

-108.504358

2.5

3

SW6020

URANIUM

0.63

10

mg/kg

CR1

RWPR-SS-221 (2.5-3)

10/6/2010

35.6644876

-108.504083

2.5

3

SW6020

URANIUM

3

11

mg/kg

CR1

C1 LW-002.2 (6-12)

12/16/2010

35.6661835

-108.503942

6

12

713R11

Ra-226

1.36

0.41

pC

'9

CR1

C1SS-041.3 (6-12)

12/15/2010

35.6637671

-108.502242

6

12

713R11

Ra-226

2.05

0.41

pC

/g

CR1

C1 LI-047.2 (8-14)

12/14/2010

35.6665979

-108.501549

8

14

713R11

Ra-226

7.7

0.5

o

Q.

/ g

CR1

C1 LI-047.2 (8-14) Dup

12/14/2010

35.6665979

-108.501549

8

14

713R11

Ra-226

8.4

0.6

O

Q.

/g

CR1

C1 LW-083.2 (8-14)

12/14/2010

35.6654455

-108.501778

8

14

713R11

Ra-226

1.4

0.37

O

Q.

/g

CR1

C1 LI-058.2 (9-15)

12/14/2010

35.6660344

-108.500605

9

15

713R11

Ra-226

3.51

0.39

O

Q.

/g

CR1

C1 LI-068.2 (10-16)

12/13/2010

35.666229

-108.500202

10

16

713R11

Ra-226

1.71

0.47

O

Q.

/g

CR1

C1LP-019.2 (12-18)

12/15/2010

35.6645068

-108.501124

12

18

713R11

Ra-226

1.15

0.37

O

Q.

/g

CR1

C1LW-022.2 (12-18)

12/15/2010

35.6644948

-108.503278

12

18

713R11

Ra-226

49.5 M3

1.1

O

Q.

/g

CR1

C1LW-022.2 (12-18) Dup

12/15/2010

35.6644948

-108.503278

12

18

713R11

Ra-226

55.3 M3

1.2

O

Q.

/g

CR1

C1LW-041.2 (12-18)

12/15/2010

35.6654339

-108.502875

12

18

713R11

Ra-226

329 M3

3

O

Q.

/g

CR1

C1LW-041.2 (12-18) Dup

12/15/2010

35.6654339

-108.502875

12

18

713R11

Ra-226

324 M3

3

O

Q.

/g

CR1

C1 LW-048.2 (12-18)

12/14/2010

35.6660088

-108.502742

12

18

713R11

Ra-226

128 M3,G

2

O

Q.

/g

CR1

C1SS-026.3 (12-18)

12/15/2010

35.6641373

-108.503343

12

18

713R11

Ra-226

7.3

0.66

O

Q.

/g

CR1

C1SS-063A.3 (12-18)

12/15/2010

35.6638077

-108.500865

12

18

713R11

Ra-226

1.6

0.38

O

Q.

/g

CR1

C1 LI-078.2 (14-20)

12/14/2010

35.6660362

-108.49979

14

20

713R11

Ra-226

2.72 G

0.64

O

Q.

/g

CR1

C1LW-104.2 (14-20)

12/14/2010

35.6656499

-108.500588

14

20

713R11

Ra-226

1.31

0.4

O

Q.

/g

CR1

C1 LP-037.2 (16-22)

12/13/2010

35.6645002

-108.500323

16

22

713R11

Ra-226

2.11

0.37

O

Q.

/g

CR1

C1 LP-037.2 (16-22) Dup

12/13/2010

35.6645002

-108.500323

16

22

713R11

Ra-226

1.96

0.45

O

Q.

/ g

CR1

C1 LI-005.2 (18-24)

12/14/2010

35.6663944

-108.503553

18

24

713R11

Ra-226

1.9

0.44

O

Q.

/ g

CR1

C1 LI-016.2 (18-24)

12/14/2010

35.6667753

-108.502749

18

24

713R11

Ra-226

5.23

0.57

O

Q.

/ g

CR1

C1 LI-026.2 (18-24)

12/14/2010

35.6669753

-108.50235

18

24

713R11

Ra-226

4.71

0.4

O

Q.

/g

CR1

C1 LI-037.2 (18-24)

12/14/2010

35.6667797

-108.501957

18

24

713R11

Ra-226

3.89

0.49

O

Q.

/g

CR1

C1 LI-085.2 (18-24)

12/13/2010

35.6652767

-108.499514

18

24

713R11

Ra-226

1.59 G

0.5

O

Q.

/g

CR1

C1LI-091.2 (18-24)

12/13/2010

35.665467

-108.499381

18

24

713R11

Ra-226

1.48 G

0.51

O

Q.

/g

CR1

C1 LI-099.2 (18-24)

12/13/2010

35.6664237

-108.499261

18

24

713R11

Ra-226

1.31

0.53

O

Q.

/g

CR1

C1 LI-099.4 Dup

12/13/2010

35.6664237

-108.499261

18

24

713R11

Ra-226

1.48

0.36

O

Q.

/g

CR1

C1LI-107.2 (18-24)

12/14/2010

35.6670014

-108.499118

18

24

713R11

Ra-226

1.31 G

0.56

O

Q.

/g

CR1

C1LI-107.4 Dup

12/14/2010

35.6670014

-108.499118

18

24

713R11

Ra-226

1.19 G

0.59

O

Q.

/g

CR1

C1LI-107.4 Dup2

12/14/2010

35.6670014

-108.499118

18

24

713R11

Ra-226

0.81 LT,G

0.57

O

Q.

/g

CR1

C1LI-110.2 (18-24)

12/14/2010

35.6660517

-108.498975

18

24

713R11

Ra-226

1.17

0.48

O

Q.

/g

CR1

C1LI-110.2 (18-24) Dup

12/14/2010

35.6660517

-108.498975

18

24

713R11

Ra-226

0.97 LT

0.39

O

Q.

/g

Page 22 of 92


-------
Attachment C-1. Data Used in the Risk Assessment











Sample

Sample













Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Top
Depth
(inches

Bottom
Depth
(inches

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit











bgs)

bgs)













CR1

C1LI-120.2 (18-24)

12/13/2010

35.6652921

-108.49871

18

24

713R11

Ra-226

1.38 G

0.55

O

Q.

/g

CR1

C1LI-127.2 (18-24)

12/14/2010

35.6658533

-108.498576

18

24

713R11

Ra-226

2.12

0.43

O

Q.

/ g

CR1

C1LI-131.2 (18-24)

12/13/2010

35.6652826

-108.49844

18

24

713R11

Ra-226

0.9 LT

0.39

O

Q.

/ g

CR1

C1LI-140.2 (18-24)

12/13/2010

35.66566

-108.498258

18

24

713R11

Ra-226

1.37

0.48

O

Q.

/ g

CR1

C1LI-141.2 (18-24)

12/14/2010

35.6660451

-108.498177

18

24

713R11

Ra-226

1.86 G

0.58

O

Q.

/ g

CR1

C1 LP-004.2 (18-24)

12/13/2010

35.664119

-108.502188

18

24

713R11

Ra-226

62.6 M3,G

1.3

O

Q.

/ g

CR1

C1 LP-009.2 (18-24)

12/13/2010

35.6639221

-108.501523

18

24

713R11

Ra-226

13.5

0.7

O

Q.

/ g

CR1

C1LP-015.2 (18-24)

12/13/2010

35.6639346

-108.501254

18

24

713R11

Ra-226

7.45

0.51

O

Q.

/ g

CR1

C1 LP-020.2 (18-24)

12/13/2010

35.6639251

-108.500984

18

24

713R11

Ra-226

29.9

0.7

O

Q.

/ g

CR1

C1 LP-026.2 (18-24)

12/13/2010

35.6643085

-108.500718

18

24

713R11

Ra-226

22.5

0.8

O

Q.

/ g

CR1

C1LP-031.2 (18-24)

12/13/2010

35.6648889

-108.500588

18

24

713R11

Ra-226

3.05

0.5

O

Q.

/ g

CR1

C1 LP-042.2 (18-24)

12/13/2010

35.6646878

-108.500183

18

24

713R11

Ra-226

2.02

0.4

pC

/ g

CR1

C1 LP-048.2 (18-24)

12/13/2010

35.6639283

-108.49991

18

24

713R11

Ra-226

1.74 G

0.45

o

Q.

/ g

CR1

C1 LP-052.2 (18-24)

12/13/2010

35.6637533

-108.499771

18

24

713R11

Ra-226

1.54

0.46

O

Q.

/ g

CR1

C1 LP-053.2 (18-24)

12/13/2010

35.6641186

-108.499777

18

24

713R11

Ra-226

1.99 G

0.42

O

Q.

/ g

CR1

C1 LP-053.4 Dup

12/13/2010

35.6641186

-108.499777

18

24

713R11

Ra-226

1.32

0.43

pC

/ g

CR1

C1 LP-059.2 (18-24)

12/13/2010

35.6646908

-108.499647

18

24

713R11

Ra-226

2.04 G

0.56

o

Q.

/ g

CR1

C1 LP-064.2 (18-24)

12/13/2010

35.6648619

-108.499507

18

24

713R11

Ra-226

1.37

0.35

O

Q.

/ g

CR1

C1 LP-070.2 (18-24)

12/13/2010

35.6641079

-108.499235

18

24

713R11

Ra-226

1.9

0.37

O

Q.

/ g

CR1

C1 LP-075.2 (18-24)

12/13/2010

35.6646828

-108.499105

18

24

713R11

Ra-226

1.74 G

0.47

pC

/ g

CR1

C1LP-081.2 (18-24)

12/13/2010

35.6643108

-108.498819

18

24

713R11

Ra-226

1.17

0.38

pC

/ g

CR1

C1LW-013.2 (18-24)

12/14/2010

35.6652515

-108.503557

18

24

713R11

Ra-226

31.1

0.9

o

Q.

/ g

CR1

C1 LW-020.2 (18-24)

12/14/2010

35.6658232

-108.503512

18

24

713R11

Ra-226

99 M3,G

2

O

Q.

/ g

CR1

C1 LW-034.2 (18-24)

12/14/2010

35.6648644

-108.503012

18

24

713R11

Ra-226

154 M3,G

1

pC

/ g

CR1

C1 LW-050.2 (18-24)

12/14/2010

35.66468

-108.502583

18

24

713R11

Ra-226

75.6 M3,G

1.5

pC

/ g

CR1

C1 LW-062.2 (18-24)

12/14/2010

35.6650605

-108.502334

18

24

713R11

Ra-226

37.7 G

0.8

o

Q.

/ g

CR1

C1LW-067.2 (18-24)

12/14/2010

35.6648745

-108.502187

18

24

713R11

Ra-226

104

1

O

Q.

/ g

CR1

C1 LW-067.2 (18-24) Dup

12/14/2010

35.6648745

-108.502187

18

24

713R11

Ra-226

102 M3

2

O

Q.

/ g

CR1

C1LW-069.2 (18-24)

12/14/2010

35.6656327

-108.502204

18

24

713R11

Ra-226

38.8

1

O

Q.

/ g

CR1

C1LW-090.2 (18-24)

12/14/2010

35.6656427

-108.501392

18

24

713R11

Ra-226

67.8 M3

1.1

O

Q.

/g

CR1

C1LW-090.4 Dup

12/14/2010

35.6656427

-108.501392

18

24

713R11

Ra-226

76.4 M3

1.2

O

Q.

/g

CR1

C1 LW-097.2 (18-24)

12/14/2010

35.6654554

-108.500987

18

24

713R11

Ra-226

1.82

0.43

O

Q.

/g

CR1

C1SS-082.3 (18-24)

12/15/2010

35.6629857

-108.499478

18

24

713R11

Ra-226

0.93 LT

0.42

O

Q.

/g

CR1

C1LI-500 SS2 1.5-3

5/3/2011

35.6668364

-108.502316

18

36

713R11

Ra-226

1.03

0.51

O

Q.

/g

CR1

C1LI-501 SS2 1.5-3

5/3/2011

35.6665962

-108.502944

18

36

713R11

Ra-226

14.3

0.5

O

Q.

/g

CR1

C1LP-400 SS2 1.5-3

4/25/2011

35.6645408

-108.501319

18

36

713R11

Ra-226

28.7

1

O

Q.

/g

CR1

C1LP-400 SS2 1.5-3 Dup

4/25/2011

35.6645408

-108.501319

18

36

713R11

Ra-226

31.3

0.8

O

Q.

/g

CR1

C1LP-401 SS2 1.5-3

4/25/2011

35.6640736

-108.501375

18

36

713R11

Ra-226

18.5 G

0.8

O

Q.

/g

CR1

C1LP-402 SS2 1.5-3

4/29/2011

35.6646723

-108.5003

18

36

713R11

Ra-226

1.98

0.56

O

Q.

/g

CR1

C1LP-403 SS2 1.5-3

4/29/2011

35.6640345

-108.500584

18

36

713R11

Ra-226

24.3 G

0.7

O

Q.

/g

CR1

C1LP-403 SS2 1.5-3 Dup

4/29/2011

35.6640345

-108.500584

18

36

713R11

Ra-226

27.6 G

0.8

O

Q.

/g

CR1

C1LP-404 SS2 1.5-3

5/1/2011

35.664222

-108.499825

18

36

713R11

Ra-226

1.54 G

0.65

O

Q.

/g

Page 23 of 92


-------
Attachment C-1. Data Used in the Risk Assessment











Sample

Sample













Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Top
Depth
(inches

Bottom
Depth
(inches

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit











bgs)

bgs)













CR1

C1LP-404 SS2 1.5-3 Dup

5/1/2011

35.664222

-108.499825

18

36

713R11

Ra-226

1.78

0.43

O

Q.

/g

CR1

C1LP-405 SS2 1.5-3

5/1/2011

35.6640588

-108.499182

18

36

713R11

Ra-226

1.57

0.38

O

Q.

/ g

CR1

C1LP-406 SS2 1.5-3

5/1/2011

35.6654968

-108.499143

18

36

713R11

Ra-226

1.54 G

0.44

O

Q.

/ g

CR1

C1LP-407 SS2 1.5-3

5/2/2011

35.6658597

-108.498441

18

36

713R11

Ra-226

3.44 G

0.5

O

Q.

/ g

CR1

C1LP-408 SS2 1.5-3

5/2/2011

35.6661682

-108.498101

18

36

713R11

Ra-226

4.46 G

0.53

O

Q.

/ g

CR1

C1LP-700 SS2 1.5-3

4/30/2011

35.663741

-108.500407

18

36

713R11

Ra-226

4.8

0.49

O

Q.

/ g

CR1

C1LP-700 SS2 1.5-3 Dup

4/30/2011

35.663741

-108.500407

18

36

713R11

Ra-226

5.09

0.49

O

Q.

/g

CR1

C1LP-701 SS2 1.5-3

4/30/2011

35.6635129

-108.500075

18

36

713R11

Ra-226

3.14 G

0.48

O

Q.

/g

CR1

C1LP-702 SS2 1.5-3

4/30/2011

35.6633178

-108.499525

18

36

713R11

Ra-226

1.38 G

0.59

O

Q.

/g

CR1

C1LP-703 SS2 1.5-3

4/30/2011

35.6650352

-108.499164

18

36

713R11

Ra-226

1.14 G

0.58

O

Q.

/g

CR1

C1 LI-005.3 (30-36)

12/14/2010

35.6663944

-108.503553

30

36

713R11

Ra-226

1.63

0.48

O

Q.

/ g

CR1

C1LI-016.3 (30-36)

12/14/2010

35.6667753

-108.502749

30

36

713R11

Ra-226

2.88

0.39

pC

/ g

CR1

C1 LI-026.3 (30-36)

12/14/2010

35.6669753

-108.50235

30

36

713R11

Ra-226

1.98

0.55

o

Q.

/g

CR1

C1 LI-037.3 (30-36)

12/14/2010

35.6667797

-108.501957

30

36

713R11

Ra-226

4.71

0.57

O

Q.

/g

CR1

C1 LI-037.4 Dup

12/14/2010

35.6667797

-108.501957

30

36

713R11

Ra-226

5.36

0.48

O

Q.

/g

CR1

C1 LI-085.3 (30-36)

12/13/2010

35.6652767

-108.499514

30

36

713R11

Ra-226

1.47

0.52

O

Q.

/g

CR1

C1LI-091.3 (30-36)

12/13/2010

35.665467

-108.499381

30

36

713R11

Ra-226

1.6 G

0.63

O

Q.

/g

CR1

C1 LI-099.3 (30-36)

12/13/2010

35.6664237

-108.499261

30

36

713R11

Ra-226

1.1

0.42

O

Q.

/g

CR1

C1LI-107.3 (30-36)

12/14/2010

35.6670014

-108.499118

30

36

713R11

Ra-226

1.14 G

0.58

O

Q.

/g

CR1

C1LI-110.3 (30-36)

12/14/2010

35.6660517

-108.498975

30

36

713R11

Ra-226

0.84 LT

0.35

O

Q.

/g

CR1

C1 LI-120.3 (30-36)

12/13/2010

35.6652921

-108.49871

30

36

713R11

Ra-226

1.33 G

0.48

O

Q.

/g

CR1

C1 LI-127.3 (30-36)

12/14/2010

35.6658533

-108.498576

30

36

713R11

Ra-226

2.6

0.48

O

Q.

/g

CR1

C1LI-131.3 (30-36)

12/13/2010

35.6652826

-108.49844

30

36

713R11

Ra-226

0.89 LT

0.43

O

Q.

/g

CR1

C1 LI-140.3 (30-36)

12/13/2010

35.66566

-108.498258

30

36

713R11

Ra-226

1.33

0.39

O

Q.

/g

CR1

C1LI-141.3 (30-36)

12/14/2010

35.6660451

-108.498177

30

36

713R11

Ra-226

1.64

0.5

O

Q.

/g

CR1

C1 LP-004.3 (30-36)

12/13/2010

35.664119

-108.502188

30

36

713R11

Ra-226

45.5 M3

1.1

O

Q.

/ g

CR1

C1 LP-009.3 (30-36)

12/13/2010

35.6639221

-108.501523

30

36

713R11

Ra-226

6.89

0.52

O

Q.

/ g

CR1

C1LP-015.3 (30-36)

12/13/2010

35.6639346

-108.501254

30

36

713R11

Ra-226

4.62

0.43

O

Q.

/ g

CR1

C1 LP-020.3 (30-36)

12/13/2010

35.6639251

-108.500984

30

36

713R11

Ra-226

29.2

0.7

O

Q.

/g

CR1

C1 LP-026.3 (30-36)

12/13/2010

35.6643085

-108.500718

30

36

713R11

Ra-226

26.5

0.7

O

Q.

/g

CR1

C1LP-031.3 (30-36)

12/13/2010

35.6648889

-108.500588

30

36

713R11

Ra-226

2.14

0.4

O

Q.

/g

CR1

C1 LP-042.3 (30-36)

12/13/2010

35.6646878

-108.500183

30

36

713R11

Ra-226

1.65 G

0.41

O

Q.

/g

CR1

C1 LP-048.3 (30-36)

12/13/2010

35.6639283

-108.49991

30

36

713R11

Ra-226

1.31

0.44

O

Q.

/g

CR1

C1 LP-052.3 (30-36)

12/13/2010

35.6637533

-108.499771

30

36

713R11

Ra-226

1.81

0.57

O

Q.

/g

CR1

C1 LP-053.3 (30-36)

12/13/2010

35.6641186

-108.499777

30

36

713R11

Ra-226

2.14

0.57

O

Q.

/g

CR1

C1 LP-059.3 (30-36)

12/13/2010

35.6646908

-108.499647

30

36

713R11

Ra-226

2.1 G

0.58

O

Q.

/g

CR1

C1 LP-064.3 (30-36)

12/13/2010

35.6648619

-108.499507

30

36

713R11

Ra-226

1.3 G

0.49

O

Q.

/g

CR1

C1 LP-070.3 (30-36)

12/13/2010

35.6641079

-108.499235

30

36

713R11

Ra-226

6.83

0.59

O

Q.

/g

CR1

C1 LP-075.3 (30-36)

12/13/2010

35.6646828

-108.499105

30

36

713R11

Ra-226

1.48 G

0.49

O

Q.

/g

CR1

C1 LP-075.4 Dup

12/13/2010

35.6646828

-108.499105

30

36

713R11

Ra-226

1.69

0.47

O

Q.

/g

CR1

C1LP-081.3 (30-36)

12/13/2010

35.6643108

-108.498819

30

36

713R11

Ra-226

1.04

0.44

O

Q.

/g

CR1

C1LW-013.3 (30-36)

12/14/2010

35.6652515

-108.503557

30

36

713R11

Ra-226

38.6

0.8

O

Q.

/g

Page 24 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1

C1LW-013.4

12/14/2010

35.6652515

-108.503557

30

36

713R11

Ra-226

38.7

0.9

O

Q.

/g

CR1

C1LW-013.4 Dup

12/14/2010

35.6652515

-108.503557

30

36

713R11

Ra-226

37.5

0.7

O

Q.

/ g

CR1

C1 LW-020.3 (30-36)

12/14/2010

35.6658232

-108.503512

30

36

713R11

Ra-226

189 M3,G

2

O

Q.

/ g

CR1

C1 LW-034.3 (30-36)

12/14/2010

35.6648644

-108.503012

30

36

713R11

Ra-226

82 M3,G

1.4

O

Q.

/ g

CR1

C1 LW-050.3 (30-36)

12/14/2010

35.66468

-108.502583

30

36

713R11

Ra-226

60.6 M3

1.2

O

Q.

/ g

CR1

C1 LW-062.3 (30-36)

12/14/2010

35.6650605

-108.502334

30

36

713R11

Ra-226

48.8 G

0.9

O

Q.

/ g

CR1

C1 LW-067.3 (30-36)

12/14/2010

35.6648745

-108.502187

30

36

713R11

Ra-226

99 M3,G

1

O

Q.

/ g

CR1

C1 LW-067.4

12/14/2010

35.6648745

-108.502187

30

36

713R11

Ra-226

98 M3,G

2

O

Q.

/ g

CR1

C1LW-067.4 Dup

12/14/2010

35.6648745

-108.502187

30

36

713R11

Ra-226

97 M3

1

O

Q.

/ g

CR1

C1 LW-069.3 (30-36)

12/14/2010

35.6656327

-108.502204

30

36

713R11

Ra-226

67.4 M3

1.2

O

Q.

/ g

CR1

C1 LW-090.3 (30-36)

12/14/2010

35.6656427

-108.501392

30

36

713R11

Ra-226

56.9

0.9

O

Q.

/ g

CR1

C1 LW-097.3 (30-36)

12/14/2010

35.6654554

-108.500987

30

36

713R11

Ra-226

2.25

0.42

O

Q.

/ g

CR1

C1LI-500 SS3 3-4.5

5/3/2011

35.6668364

-108.502316

36

54

713R11

Ra-226

1.62 G

0.62

O

Q.

/ g

CR1

C1LI-501 DUP 501

5/3/2011

35.6665962

-108.502944

36

54

713R11

Ra-226

1.07

0.32

O

Q.

/ g

CR1

C1LI-501 SS3 3-4.5

5/3/2011

35.6665962

-108.502944

36

54

713R11

Ra-226

1.14

0.4

O

Q.

/ g

CR1

C1LP-400 SS3 3-4.5

4/25/2011

35.6645408

-108.501319

36

54

713R11

Ra-226

2.4

0.54

O

Q.

/g

CR1

C1LP-401 SS3 3-4.5

4/25/2011

35.6640736

-108.501375

36

54

713R11

Ra-226

30.7 G

0.9

O

Q.

/g

CR1

C1LP-402 SS3 3-4.5

4/29/2011

35.6646723

-108.5003

36

54

713R11

Ra-226

3.15 G

0.44

O

Q.

/g

CR1

C1LP-402 SS3 3-4.5 Dup

4/29/2011

35.6646723

-108.5003

36

54

713R11

Ra-226

3.29

0.43

O

Q.

/g

CR1

C1LP-403 SS3 3-4.5

4/29/2011

35.6640345

-108.500584

36

54

713R11

Ra-226

16 G

0.8

O

Q.

/g

CR1

C1LP-404 SS3 3-4.5

5/1/2011

35.664222

-108.499825

36

54

713R11

Ra-226

2.92

0.4

O

Q.

/g

CR1

C1LP-405 SS3 3-4.5

5/1/2011

35.6640588

-108.499182

36

54

713R11

Ra-226

1.35 G

0.47

O

Q.

/g

CR1

C1LP-406 SS3 3-4.5

5/1/2011

35.6654968

-108.499143

36

54

713R11

Ra-226

1.62 G

0.49

O

Q.

/g

CR1

C1LP-407 SS3 3-4.5

5/2/2011

35.6658597

-108.498441

36

54

713R11

Ra-226

5.74

0.44

O

Q.

/g

CR1

C1LP-408 SS3 3-4.5

5/2/2011

35.6661682

-108.498101

36

54

713R11

Ra-226

5.54 G

0.54

O

Q.

/g

CR1

C1LP-700 SS3 3-4.5

4/30/2011

35.663741

-108.500407

36

54

713R11

Ra-226

39.1 G

0.9

O

Q.

/ g

CR1

C1LP-701 SS3 3-4.5

4/30/2011

35.6635129

-108.500075

36

54

713R11

Ra-226

3.94 G

0.52

O

Q.

/ g

CR1

C1LP-702 SS3 3-4.5

4/30/2011

35.6633178

-108.499525

36

54

713R11

Ra-226

1.2

0.43

O

Q.

/g

CR1

C1LP-703 SS3 3-4.5

4/30/2011

35.6650352

-108.499164

36

54

713R11

Ra-226

1.13 G

0.5

O

Q.

/g

CR1

C1LP-703 SS3 3-4.5 Dup

4/30/2011

35.6650352

-108.499164

36

54

713R11

Ra-226

1.13

0.41

O

Q.

/g

CR1

C1 LP-020.4 (48-54)

12/13/2010

35.6639251

-108.500984

48

54

713R11

Ra-226

29.1

0.9

O

Q.

/ g

CR1

C1 LP-020.4 (48-54) Dup

12/13/2010

35.6639251

-108.500984

48

54

713R11

Ra-226

30

1

O

Q.

/ g

CR1

C1LI-501 SS10

5/3/2011

35.6665962

-108.502944

54

72

SW6010

ARSENIC

3.6

1.1

mg/kg

CR1

C1LI-501 SS4 4.5-6

5/3/2011

35.6665962

-108.502944

54

72

SW6010

ARSENIC

3.4

1

mg/kg

CR1

C1LI-501 SS10

5/3/2011

35.6665962

-108.502944

54

72

SW6010

MOLYBDENUM

1.1 U

1.1

mg/kg

CR1

C1LI-501 SS4 4.5-6

5/3/2011

35.6665962

-108.502944

54

72

SW6010

MOLYBDENUM

1 U

1

mg/kg

CR1

C1-1B008-5 (FD)

7/17/2015

35.6646504

-108.49905

54

72

Unknown

Ra-226

9.6

Unknown

pCi/g

CR1

C1-B001-5

7/13/2015

35.6660711

-108.503664

54

72

Unknown

Ra-226

0.868

Unknown

pCi/g

CR1

C1-B003-5

7/14/2015

35.6659976

-108.502431

54

72

Unknown

Ra-226

2.86

Unknown

pCi/g

CR1

C1-B006-5

7/17/2015

35.6648266

-108.50078

54

72

Unknown

Ra-226

0.59

Unknown

pCi/g

CR1

C1-B007-5

7/17/2015

35.6643482

-108.5006

54

72

Unknown

Ra-226

16.3

Unknown

pCi/g

CR1

C1-B008-5

7/17/2015

35.6646504

-108.49905

54

72

Unknown

Ra-226

1.9

Unknown

pCi/g

Page 25 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1

C1LI-500 SS4 4.5-6

5/3/2011

35.6668364

-108.502316

54

72

713R11

Ra-226

2.09 G

0.43

O

Q.

/g

CR1

C1LI-501 SS4 4.5-6

5/3/2011

35.6665962

-108.502944

54

72

713R11

Ra-226

0.67 LT

0.41

O

Q.

/g

CR1

C1LP-400 SS4 4.5-6

4/25/2011

35.6645408

-108.501319

54

72

713R11

Ra-226

2.04

0.58

O

Q.

/ g

CR1

C1LP-401 SS4 4.5-6

4/25/2011

35.6640736

-108.501375

54

72

713R11

Ra-226

468 M3,G

3

O

Q.

/ g

CR1

C1LP-402 DUP 402

4/29/2011

35.6646723

-108.5003

54

72

713R11

Ra-226

14.9 G

0.5

O

Q.

/ g

CR1

C1LP-402 SS4 4.5-6

4/29/2011

35.6646723

-108.5003

54

72

713R11

Ra-226

16.2

0.6

O

Q.

/ g

CR1

C1LP-403 SS4 4.5-6

4/29/2011

35.6640345

-108.500584

54

72

713R11

Ra-226

59.8 M3,G

1.1

O

Q.

/ g

CR1

C1LP-404 SS4 4.5-6

5/1/2011

35.664222

-108.499825

54

72

713R11

Ra-226

1.84 G

0.58

O

Q.

/ g

CR1

C1LP-404 SS4 4.5-6 Dup

5/1/2011

35.664222

-108.499825

54

72

713R11

Ra-226

2.08 G

0.46

O

Q.

/g

CR1

C1LP-405 SS4 4.5-6

5/1/2011

35.6640588

-108.499182

54

72

713R11

Ra-226

1.44 G

0.63

O

Q.

/g

CR1

C1LP-406 SS4 4.5-6

5/1/2011

35.6654968

-108.499143

54

72

713R11

Ra-226

1.68 G

0.45

O

Q.

/g

CR1

C1LP-407 DUP 407

5/2/2011

35.6658597

-108.498441

54

72

713R11

Ra-226

5.89

0.61

O

Q.

/g

CR1

C1LP-407 SS4 4.5-6

5/2/2011

35.6658597

-108.498441

54

72

713R11

Ra-226

5.52

0.57

O

Q.

/g

CR1

C1LP-408 SS4 4.5-6

5/2/2011

35.6661682

-108.498101

54

72

713R11

Ra-226

6.72 G

0.64

O

Q.

/g

CR1

C1LP-408 SS4 4.5-6 Dup

5/2/2011

35.6661682

-108.498101

54

72

713R11

Ra-226

6.6 G

0.73

O

Q.

/g

CR1

C1LP-700 SS4 4.5-6

4/30/2011

35.663741

-108.500407

54

72

713R11

Ra-226

34.8 M3

1

O

Q.

/g

CR1

C1LP-701 SS4 4.5-6

4/30/2011

35.6635129

-108.500075

54

72

713R11

Ra-226

3.07 G

0.57

O

Q.

/g

CR1

C1LP-702 SS4 4.5-6

4/30/2011

35.6633178

-108.499525

54

72

713R11

Ra-226

1.54 G

0.46

O

Q.

/g

CR1

C1LP-703 SS4 4.5-6

4/30/2011

35.6650352

-108.499164

54

72

713R11

Ra-226

1.2 G

0.54

O

Q.

/g

CR1

C1LI-501 SS10

5/3/2011

35.6665962

-108.502944

54

72

SW6010

SELENIUM

0.53 U

0.53

mg/kg

CR1

C1LI-501 SS4 4.5-6

5/3/2011

35.6665962

-108.502944

54

72

SW6010

SELENIUM

0.52 U

0.52

mg/kg

CR1

C1LI-501 SS10

5/3/2011

35.6665962

-108.502944

54

72

SW6010

VANADIUM

11

1.1

mg/kg

CR1

C1LI-501 SS4 4.5-6

5/3/2011

35.6665962

-108.502944

54

72

SW6010

VANADIUM

9.5

1

mg/kg

CR1E

CELA-001 (0-2)

5/6/2011

35.6649477

-108.490897

0

2

713R11

Ra-226

1.83 G

0.53

o

Q.

/ g

CR1E

CELA-001A.1 (0-2")

12/15/2010

35.6649422

-108.490893

0

2

713R11

Ra-226

1.6

0.54

O

Q.

/g

CR1E

CELA-004.1 (0-2")

12/15/2010

35.6645728

-108.490624

0

2

713R11

Ra-226

2.46

0.49

O

Q.

/g

CR1E

CELA-008.1 (0-2")

12/15/2010

35.6647603

-108.490491

0

2

713R11

Ra-226

1.31

0.49

O

Q.

/ g

CR1E

CELA-012.1 (0-2")

12/15/2010

35.6662795

-108.490503

0

2

713R11

Ra-226

2.24 G

0.53

O

Q.

/ g

CR1E

CELA-016.1 (0-2")

12/15/2010

35.6660879

-108.490371

0

2

713R11

Ra-226

4.93

0.63

O

Q.

/ g

CR1E

CELA-020.1 (0-2")

12/15/2010

35.6655228

-108.490225

0

2

713R11

Ra-226

1.69

0.45

O

Q.

/ g

CR1E

CELA-024.1 (0-2")

12/15/2010

35.6653285

-108.490085

0

2

713R11

Ra-226

1.26

0.59

pC

/g

CR1E

CELA-027.1 (0-2")

12/15/2010

35.6664685

-108.490101

0

2

713R11

Ra-226

2.24

0.41

pC

/g

CR1E

CELA-031.1 (0-2")

12/15/2010

35.6662824

-108.489968

0

2

713R11

Ra-226

2.34

0.43

o

Q.

/ g

CR1E

CELA-035.1 (0-2")

12/15/2010

35.6660909

-108.489832

0

2

713R11

Ra-226

1.96

0.66

O

Q.

/ g

CR1E

CELA-039.1 (0-2")

12/15/2010

35.6662839

-108.489699

0

2

713R11

Ra-226

2.21

0.38

pC

/g

CR1E

CELA-043.1 (0-2")

12/15/2010

35.6664715

-108.489566

0

2

713R11

Ra-226

5 G

0.57

pC

/g

CR1E

CELA-047.1 (0-2")

12/15/2010

35.6666673

-108.489429

0

2

713R11

Ra-226

2.62 G

0.42

o

Q.

/ g

CR1E

CELA-051.1 (0-2")

12/15/2010

35.6659187

-108.489157

0

2

713R11

Ra-226

3.17 G

0.49

O

Q.

/ g

CR1E

CELA-054.1 (0-2")

12/15/2010

35.6661008

-108.489024

0

2

713R11

Ra-226

1.64

0.47

pC

/g

CR1E

CELA-058.1 (0-2")

12/15/2010

35.6666674

-108.488891

0

2

713R11

Ra-226

37.8 G

1

pC

/g

CR1E

CELA-062.1 (0-2")

12/15/2010

35.6662953

-108.488622

0

2

713R11

Ra-226

3.73 G

0.55

o

Q.

/ g

CR1E

CELA-062.1 (0-2") Dup

12/15/2010

35.6662953

-108.488622

0

2

713R11

Ra-226

3.87 G

0.48

O

Q.

/ g

Page 26 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1E

CELA-062.2

12/15/2010

35.6662953

-108.488622

0

2

713R11

Ra-226

3.79 G

0.44

O

Q.

/g

CR1E

CELA-066.1 (0-2")

12/15/2010

35.6668592

-108.488485

0

2

713R11

Ra-226

2.16

0.47

O

Q.

/ g

CR1E

CELA-066.1 (0-2") Dup

12/15/2010

35.6668592

-108.488485

0

2

713R11

Ra-226

1.68

0.46

pC

/g

CR1E

CELA-070.1 (0-2")

12/15/2010

35.6668607

-108.488216

0

2

713R11

Ra-226

4.25 G

0.88

pC

/g

CR1E

CELA-070.2

12/15/2010

35.6668607

-108.488216

0

2

713R11

Ra-226

7.7 G

0.6

o

Q.

/ g

CR1E

CELA-074.1 (0-2")

12/15/2010

35.667244

-108.487956

0

2

713R11

Ra-226

5.95 G

0.56

O

Q.

/ g

CR1E

CESS-037.1 (0-2)

12/15/2010

35.6650409

-108.489423

0

2

713R11

Ra-226

2.24

0.45

pC

/g

CR1E

CESS-041.1 (0-2)

12/15/2010

35.6654512

-108.489254

0

2

713R11

Ra-226

8.5 G

0.9

pC

/g

CR1E

CESS-041.2

12/15/2010

35.6654512

-108.489254

0

2

713R11

Ra-226

8.1 G

0.8

o

Q.

/ g

CR1E

CESS-060.1 (0-2)

12/15/2010

35.6664792

-108.488135

0

2

713R11

Ra-226

2.41

0.39

O

Q.

/ g

CR1E

CESS-069.1 (0-2)

12/15/2010

35.6672442

-108.487414

0

2

713R11

Ra-226

1.34

0.44

pC

/g

CR1E

CESS-070.1 (0-2)

12/15/2010

35.6640557

-108.490229

0

2

713R11

Ra-226

1.6

0.37

pC

/g

CR1E

CR1E-SS05-0000-0003-01

5/19/2022

35.664557

-108.489454

0

3

SW6020

ALUMINUM

6000

15

mg/kg

CR1E

CR1E-SS06-0000-0003-01

5/19/2022

35.665434

-108.488911

0

3

SW6020

ALUMINUM

4700

15

mg/kg

CR1E

CR1E-SS07-0000-0003-01

5/19/2022

35.665828

-108.488623

0

3

SW6020

ALUMINUM

4700

15

mg/kg

CR1E

CR1E-SS07-0000-0003-02

5/19/2022

35.665828

-108.488623

0

3

SW6020

ALUMINUM

4800

17

mg/kg

CR1E

CR1E-SS08-0000-0003-01

5/19/2022

35.666966

-108.488662

0

3

SW6020

ALUMINUM

5300

15

mg/kg

CR1E

CR1E-SS09-0000-0003-01

5/19/2022

35.664733

-108.49064

0

3

SW6020

ALUMINUM

8000

15

mg/kg

CR1E

CR1E-SS10-0000-0003-01

5/19/2022

35.665086

-108.490244

0

3

SW6020

ALUMINUM

8400

16

mg/kg

CR1E

CR1E-SS11-0000-0003-01

5/19/2022

35.665393

-108.489297

0

3

SW6020

ALUMINUM

7400

15

mg/kg

CR1E

CR1E-SS12-0000-0003-01

5/19/2022

35.665819

-108.490253

0

3

SW6020

ALUMINUM

7600

15

mg/kg

CR1E

CR1E-SS13-0000-0003-01

5/19/2022

35.666222

-108.490271

0

3

SW6020

ALUMINUM

5100

17

mg/kg

CR1E

CR1E-SS14-0000-0003-01

5/19/2022

35.666028

-108.489317

0

3

SW6020

ALUMINUM

4600

15

mg/kg

CR1E

CR1E-SS15-0000-0003-01

5/19/2022

35.666507

-108.489822

0

3

SW6020

ALUMINUM

4600

15

mg/kg

CR1E

CR1E-SS16-0000-0003-01

5/19/2022

35.666619

-108.488931

0

3

SW6020

ALUMINUM

4000

15

mg/kg

CR1E

CR1E-SS17-0000-0003-01

5/19/2022

35.66629

-108.489

0

3

SW6020

ALUMINUM

4600

15

mg/kg

CR1E

CR1E-SS18-0000-0003-01

5/19/2022

35.667002

-108.488124

0

3

SW6020

ALUMINUM

4800

15

mg/kg

CR1E

CR1E-SS19-0000-0003-01

5/19/2022

35.664622

-108.490056

0

3

SW6020

ALUMINUM

4500

15

mg/kg

CR1E

CR1E-SS19-0000-0003-02

5/19/2022

35.664622

-108.490056

0

3

SW6020

ALUMINUM

4800

16

mg/kg

CR1E

CR1E-SS05-0000-0003-01

5/19/2022

35.664557

-108.489454

0

3

SW6020

ANTIMONY

0.051 J

0.1

mg/kg

CR1E

CR1E-SS06-0000-0003-01

5/19/2022

35.665434

-108.488911

0

3

SW6020

ANTIMONY

0.039 J

0.1

mg/kg

CR1E

CR1E-SS07-0000-0003-01

5/19/2022

35.665828

-108.488623

0

3

SW6020

ANTIMONY

0.069 J

0.1

mg/kg

CR1E

CR1E-SS07-0000-0003-02

5/19/2022

35.665828

-108.488623

0

3

SW6020

ANTIMONY

0.056 J

0.11

mg/kg

CR1E

CR1E-SS08-0000-0003-01

5/19/2022

35.666966

-108.488662

0

3

SW6020

ANTIMONY

0.1

0.1

mg/kg

CR1E

CR1E-SS09-0000-0003-01

5/19/2022

35.664733

-108.49064

0

3

SW6020

ANTIMONY

0.055 J

0.1

mg/kg

CR1E

CR1E-SS10-0000-0003-01

5/19/2022

35.665086

-108.490244

0

3

SW6020

ANTIMONY

0.058 J

0.1

mg/kg

CR1E

CR1E-SS11-0000-0003-01

5/19/2022

35.665393

-108.489297

0

3

SW6020

ANTIMONY

0.085 J

0.1

mg/kg

CR1E

CR1E-SS12-0000-0003-01

5/19/2022

35.665819

-108.490253

0

3

SW6020

ANTIMONY

0.23

0.1

mg/kg

CR1E

CR1E-SS13-0000-0003-01

5/19/2022

35.666222

-108.490271

0

3

SW6020

ANTIMONY

0.1 J

0.11

mg/kg

CR1E

CR1E-SS14-0000-0003-01

5/19/2022

35.666028

-108.489317

0

3

SW6020

ANTIMONY

0.11

0.1

mg/kg

CR1E

CR1E-SS15-0000-0003-01

5/19/2022

35.666507

-108.489822

0

3

SW6020

ANTIMONY

0.13

0.1

mg/kg

CR1E

CR1E-SS16-0000-0003-01

5/19/2022

35.666619

-108.488931

0

3

SW6020

ANTIMONY

0.064 J

0.1

mg/kg

Page 27 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1E

CR1E-SS17-0000-0003-01

5/19/2022

35.66629

-108.489

0

3

SW6020

ANTIMONY

0.097 J

0.1

mg/kg

CR1E

CR1E-SS18-0000-0003-01

5/19/2022

35.667002

-108.488124

0

3

SW6020

ANTIMONY

0.091 J

0.1

mg/kg

CR1E

CR1E-SS19-0000-0003-01

5/19/2022

35.664622

-108.490056

0

3

SW6020

ANTIMONY

0.031 UJ

0.1

mg/kg

CR1E

CR1E-SS19-0000-0003-02

5/19/2022

35.664622

-108.490056

0

3

SW6020

ANTIMONY

0.038 J

0.1

mg/kg

CR1E

CR1E-SS05-0000-0003-01

5/19/2022

35.664557

-108.489454

0

3

SW6020

ARSENIC

6.1

0.2

mg/kg

CR1E

CR1E-SS06-0000-0003-01

5/19/2022

35.665434

-108.488911

0

3

SW6020

ARSENIC

4.5

0.2

mg/kg

CR1E

CR1E-SS07-0000-0003-01

5/19/2022

35.665828

-108.488623

0

3

SW6020

ARSENIC

3.9

0.2

mg/kg

CR1E

CR1E-SS07-0000-0003-02

5/19/2022

35.665828

-108.488623

0

3

SW6020

ARSENIC

4.1

0.23

mg/kg

CR1E

CR1E-SS08-0000-0003-01

5/19/2022

35.666966

-108.488662

0

3

SW6020

ARSENIC

4

0.2

mg/kg

CR1E

CR1E-SS09-0000-0003-01

5/19/2022

35.664733

-108.49064

0

3

SW6020

ARSENIC

8

0.2

mg/kg

CR1E

CR1E-SS10-0000-0003-01

5/19/2022

35.665086

-108.490244

0

3

SW6020

ARSENIC

10

0.21

mg/kg

CR1E

CR1E-SS11-0000-0003-01

5/19/2022

35.665393

-108.489297

0

3

SW6020

ARSENIC

6.5

0.2

mg/kg

CR1E

CR1E-SS12-0000-0003-01

5/19/2022

35.665819

-108.490253

0

3

SW6020

ARSENIC

8.7

0.2

mg/kg

CR1E

CR1E-SS13-0000-0003-01

5/19/2022

35.666222

-108.490271

0

3

SW6020

ARSENIC

5.7

0.22

mg/kg

CR1E

CR1E-SS14-0000-0003-01

5/19/2022

35.666028

-108.489317

0

3

SW6020

ARSENIC

4.7

0.2

mg/kg

CR1E

CR1E-SS15-0000-0003-01

5/19/2022

35.666507

-108.489822

0

3

SW6020

ARSENIC

4.8

0.2

mg/kg

CR1E

CR1E-SS16-0000-0003-01

5/19/2022

35.666619

-108.488931

0

3

SW6020

ARSENIC

3.8

0.21

mg/kg

CR1E

CR1E-SS17-0000-0003-01

5/19/2022

35.66629

-108.489

0

3

SW6020

ARSENIC

4.9

0.2

mg/kg

CR1E

CR1E-SS18-0000-0003-01

5/19/2022

35.667002

-108.488124

0

3

SW6020

ARSENIC

4.8

0.21

mg/kg

CR1E

CR1E-SS19-0000-0003-01

5/19/2022

35.664622

-108.490056

0

3

SW6020

ARSENIC

5

0.2

mg/kg

CR1E

CR1E-SS19-0000-0003-02

5/19/2022

35.664622

-108.490056

0

3

SW6020

ARSENIC

5.5

0.21

mg/kg

CR1E

CR1E-SS05-0000-0003-01

5/19/2022

35.664557

-108.489454

0

3

SW6020

BARIUM

44

0.51

mg/kg

CR1E

CR1 E-SS06-0000-0003-01

5/19/2022

35.665434

-108.488911

0

3

SW6020

BARIUM

68

0.5

mg/kg

CR1E

CR1 E-SS07-0000-0003-01

5/19/2022

35.665828

-108.488623

0

3

SW6020

BARIUM

77

0.51

mg/kg

CR1E

CR1 E-SS07-0000-0003-02

5/19/2022

35.665828

-108.488623

0

3

SW6020

BARIUM

85

0.57

mg/kg

CR1E

CR1 E-SS08-0000-0003-01

5/19/2022

35.666966

-108.488662

0

3

SW6020

BARIUM

80

0.51

mg/kg

CR1E

CR1 E-SS09-0000-0003-01

5/19/2022

35.664733

-108.49064

0

3

SW6020

BARIUM

72

0.5

mg/kg

CR1E

CR1E-SS10-0000-0003-01

5/19/2022

35.665086

-108.490244

0

3

SW6020

BARIUM

70

0.52

mg/kg

CR1E

CR1E-SS11-0000-0003-01

5/19/2022

35.665393

-108.489297

0

3

SW6020

BARIUM

86

0.51

mg/kg

CR1E

CR1E-SS12-0000-0003-01

5/19/2022

35.665819

-108.490253

0

3

SW6020

BARIUM

180

0.51

mg/kg

CR1E

CR1E-SS13-0000-0003-01

5/19/2022

35.666222

-108.490271

0

3

SW6020

BARIUM

100

0.56

mg/kg

CR1E

CR1E-SS14-0000-0003-01

5/19/2022

35.666028

-108.489317

0

3

SW6020

BARIUM

110

0.51

mg/kg

CR1E

CR1E-SS15-0000-0003-01

5/19/2022

35.666507

-108.489822

0

3

SW6020

BARIUM

420

0.51

mg/kg

CR1E

CR1E-SS16-0000-0003-01

5/19/2022

35.666619

-108.488931

0

3

SW6020

BARIUM

93

0.52

mg/kg

CR1E

CR1E-SS17-0000-0003-01

5/19/2022

35.66629

-108.489

0

3

SW6020

BARIUM

78

0.51

mg/kg

CR1E

CR1E-SS18-0000-0003-01

5/19/2022

35.667002

-108.488124

0

3

SW6020

BARIUM

160

0.52

mg/kg

CR1E

CR1E-SS19-0000-0003-01

5/19/2022

35.664622

-108.490056

0

3

SW6020

BARIUM

27

0.5

mg/kg

CR1E

CR1E-SS19-0000-0003-02

5/19/2022

35.664622

-108.490056

0

3

SW6020

BARIUM

20

0.52

mg/kg

CR1E

CR1E-SS05-0000-0003-01

5/19/2022

35.664557

-108.489454

0

3

SW6020

BERYLLIUM

0.54

0.051

mg/kg

CR1E

CR1E-SS06-0000-0003-01

5/19/2022

35.665434

-108.488911

0

3

SW6020

BERYLLIUM

0.42

0.05

mg/kg

CR1E

CR1E-SS07-0000-0003-01

5/19/2022

35.665828

-108.488623

0

3

SW6020

BERYLLIUM

0.42

0.051

mg/kg

CR1E

CR1E-SS07-0000-0003-02

5/19/2022

35.665828

-108.488623

0

3

SW6020

BERYLLIUM

0.42

0.057

mg/kg

Page 28 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1E

CR1E-SS08-0000-0003-01

5/19/2022

35.666966

-108.488662

0

3

SW6020

BERYLLIUM

0.49

0.051

mg/kg

CR1E

CR1E-SS09-0000-0003-01

5/19/2022

35.664733

-108.49064

0

3

SW6020

BERYLLIUM

0.66

0.05

mg/kg

CR1E

CR1E-SS10-0000-0003-01

5/19/2022

35.665086

-108.490244

0

3

SW6020

BERYLLIUM

0.76

0.052

mg/kg

CR1E

CR1E-SS11-0000-0003-01

5/19/2022

35.665393

-108.489297

0

3

SW6020

BERYLLIUM

0.62

0.051

mg/kg

CR1E

CR1E-SS12-0000-0003-01

5/19/2022

35.665819

-108.490253

0

3

SW6020

BERYLLIUM

1

0.051

mg/kg

CR1E

CR1E-SS13-0000-0003-01

5/19/2022

35.666222

-108.490271

0

3

SW6020

BERYLLIUM

0.72

0.056

mg/kg

CR1E

CR1E-SS14-0000-0003-01

5/19/2022

35.666028

-108.489317

0

3

SW6020

BERYLLIUM

0.63

0.051

mg/kg

CR1E

CR1E-SS15-0000-0003-01

5/19/2022

35.666507

-108.489822

0

3

SW6020

BERYLLIUM

0.65

0.051

mg/kg

CR1E

CR1E-SS16-0000-0003-01

5/19/2022

35.666619

-108.488931

0

3

SW6020

BERYLLIUM

0.43

0.052

mg/kg

CR1E

CR1E-SS17-0000-0003-01

5/19/2022

35.66629

-108.489

0

3

SW6020

BERYLLIUM

0.56

0.051

mg/kg

CR1E

CR1E-SS18-0000-0003-01

5/19/2022

35.667002

-108.488124

0

3

SW6020

BERYLLIUM

0.56

0.052

mg/kg

CR1E

CR1E-SS19-0000-0003-01

5/19/2022

35.664622

-108.490056

0

3

SW6020

BERYLLIUM

0.44

0.05

mg/kg

CR1E

CR1E-SS19-0000-0003-02

5/19/2022

35.664622

-108.490056

0

3

SW6020

BERYLLIUM

0.45

0.052

mg/kg

CR1E

CR1E-SS05-0000-0003-01

5/19/2022

35.664557

-108.489454

0

3

SW6020

CADMIUM

0.087 J

0.2

mg/kg

CR1E

CR1E-SS06-0000-0003-01

5/19/2022

35.665434

-108.488911

0

3

SW6020

CADMIUM

0.049 J

0.2

mg/kg

CR1E

CR1E-SS07-0000-0003-01

5/19/2022

35.665828

-108.488623

0

3

SW6020

CADMIUM

0.05 J

0.2

mg/kg

CR1E

CR1E-SS07-0000-0003-02

5/19/2022

35.665828

-108.488623

0

3

SW6020

CADMIUM

0.052 J

0.23

mg/kg

CR1E

CR1E-SS08-0000-0003-01

5/19/2022

35.666966

-108.488662

0

3

SW6020

CADMIUM

0.075 J

0.2

mg/kg

CR1E

CR1E-SS09-0000-0003-01

5/19/2022

35.664733

-108.49064

0

3

SW6020

CADMIUM

0.088 J

0.2

mg/kg

CR1E

CR1E-SS10-0000-0003-01

5/19/2022

35.665086

-108.490244

0

3

SW6020

CADMIUM

0.071 J

0.21

mg/kg

CR1E

CR1E-SS11-0000-0003-01

5/19/2022

35.665393

-108.489297

0

3

SW6020

CADMIUM

0.14 J

0.2

mg/kg

CR1E

CR1E-SS12-0000-0003-01

5/19/2022

35.665819

-108.490253

0

3

SW6020

CADMIUM

0.23

0.2

mg/kg

CR1E

CR1E-SS13-0000-0003-01

5/19/2022

35.666222

-108.490271

0

3

SW6020

CADMIUM

0.15 J

0.22

mg/kg

CR1E

CR1E-SS14-0000-0003-01

5/19/2022

35.666028

-108.489317

0

3

SW6020

CADMIUM

0.13 J

0.2

mg/kg

CR1E

CR1E-SS15-0000-0003-01

5/19/2022

35.666507

-108.489822

0

3

SW6020

CADMIUM

0.14 J

0.2

mg/kg

CR1E

CR1E-SS16-0000-0003-01

5/19/2022

35.666619

-108.488931

0

3

SW6020

CADMIUM

0.072 J

0.21

mg/kg

CR1E

CR1E-SS17-0000-0003-01

5/19/2022

35.66629

-108.489

0

3

SW6020

CADMIUM

0.12 J

0.2

mg/kg

CR1E

CR1E-SS18-0000-0003-01

5/19/2022

35.667002

-108.488124

0

3

SW6020

CADMIUM

0.11 J

0.21

mg/kg

CR1E

CR1E-SS19-0000-0003-01

5/19/2022

35.664622

-108.490056

0

3

SW6020

CADMIUM

0.061 J

0.2

mg/kg

CR1E

CR1E-SS19-0000-0003-02

5/19/2022

35.664622

-108.490056

0

3

SW6020

CADMIUM

0.056 J

0.21

mg/kg

CR1E

CR1E-SS05-0000-0003-01

5/19/2022

35.664557

-108.489454

0

3

SW6020

CHROMIUM

8

1

mg/kg

CR1E

CR1E-SS06-0000-0003-01

5/19/2022

35.665434

-108.488911

0

3

SW6020

CHROMIUM

8.5

1

mg/kg

CR1E

CR1E-SS07-0000-0003-01

5/19/2022

35.665828

-108.488623

0

3

SW6020

CHROMIUM

22

1

mg/kg

CR1E

CR1E-SS07-0000-0003-02

5/19/2022

35.665828

-108.488623

0

3

SW6020

CHROMIUM

21

1.1

mg/kg

CR1E

CR1E-SS08-0000-0003-01

5/19/2022

35.666966

-108.488662

0

3

SW6020

CHROMIUM

6.1

1

mg/kg

CR1E

CR1E-SS09-0000-0003-01

5/19/2022

35.664733

-108.49064

0

3

SW6020

CHROMIUM

8.5

1

mg/kg

CR1E

CR1E-SS10-0000-0003-01

5/19/2022

35.665086

-108.490244

0

3

SW6020

CHROMIUM

10

1

mg/kg

CR1E

CR1E-SS11-0000-0003-01

5/19/2022

35.665393

-108.489297

0

3

SW6020

CHROMIUM

10

1

mg/kg

CR1E

CR1E-SS12-0000-0003-01

5/19/2022

35.665819

-108.490253

0

3

SW6020

CHROMIUM

8.4

1

mg/kg

CR1E

CR1E-SS13-0000-0003-01

5/19/2022

35.666222

-108.490271

0

3

SW6020

CHROMIUM

5.1

1.1

mg/kg

CR1E

CR1E-SS14-0000-0003-01

5/19/2022

35.666028

-108.489317

0

3

SW6020

CHROMIUM

4.8

1

mg/kg

CR1E

CR1E-SS15-0000-0003-01

5/19/2022

35.666507

-108.489822

0

3

SW6020

CHROMIUM

5.7

1

mg/kg

Page 29 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1E

CR1E-SS16-0000-0003-01

5/19/2022

35.666619

-108.488931

0

3

SW6020

CHROMIUM

4.5

1

mg/kg

CR1E

CR1E-SS17-0000-0003-01

5/19/2022

35.66629

-108.489

0

3

SW6020

CHROMIUM

5.5

1

mg/kg

CR1E

CR1E-SS18-0000-0003-01

5/19/2022

35.667002

-108.488124

0

3

SW6020

CHROMIUM

5.8

1

mg/kg

CR1E

CR1E-SS19-0000-0003-01

5/19/2022

35.664622

-108.490056

0

3

SW6020

CHROMIUM

6.8

1

mg/kg

CR1E

CR1E-SS19-0000-0003-02

5/19/2022

35.664622

-108.490056

0

3

SW6020

CHROMIUM

7.1

1

mg/kg

CR1E

CR1E-SS05-0000-0003-01

5/19/2022

35.664557

-108.489454

0

3

SW6020

COBALT

4.6

0.51

mg/kg

CR1E

CR1E-SS06-0000-0003-01

5/19/2022

35.665434

-108.488911

0

3

SW6020

COBALT

4.5

0.5

mg/kg

CR1E

CR1E-SS07-0000-0003-01

5/19/2022

35.665828

-108.488623

0

3

SW6020

COBALT

4.6

0.51

mg/kg

CR1E

CR1E-SS07-0000-0003-02

5/19/2022

35.665828

-108.488623

0

3

SW6020

COBALT

5.7

0.57

mg/kg

CR1E

CR1E-SS08-0000-0003-01

5/19/2022

35.666966

-108.488662

0

3

SW6020

COBALT

4.1

0.51

mg/kg

CR1E

CR1E-SS09-0000-0003-01

5/19/2022

35.664733

-108.49064

0

3

SW6020

COBALT

6.9

0.5

mg/kg

CR1E

CR1E-SS10-0000-0003-01

5/19/2022

35.665086

-108.490244

0

3

SW6020

COBALT

9.3

0.52

mg/kg

CR1E

CR1E-SS11-0000-0003-01

5/19/2022

35.665393

-108.489297

0

3

SW6020

COBALT

6.4

0.51

mg/kg

CR1E

CR1E-SS12-0000-0003-01

5/19/2022

35.665819

-108.490253

0

3

SW6020

COBALT

10

0.51

mg/kg

CR1E

CR1E-SS13-0000-0003-01

5/19/2022

35.666222

-108.490271

0

3

SW6020

COBALT

6.8

0.56

mg/kg

CR1E

CR1E-SS14-0000-0003-01

5/19/2022

35.666028

-108.489317

0

3

SW6020

COBALT

5.9

0.51

mg/kg

CR1E

CR1E-SS15-0000-0003-01

5/19/2022

35.666507

-108.489822

0

3

SW6020

COBALT

6.1

0.51

mg/kg

CR1E

CR1E-SS16-0000-0003-01

5/19/2022

35.666619

-108.488931

0

3

SW6020

COBALT

4.1

0.52

mg/kg

CR1E

CR1E-SS17-0000-0003-01

5/19/2022

35.66629

-108.489

0

3

SW6020

COBALT

5.9

0.51

mg/kg

CR1E

CR1E-SS18-0000-0003-01

5/19/2022

35.667002

-108.488124

0

3

SW6020

COBALT

5.3

0.52

mg/kg

CR1E

CR1E-SS19-0000-0003-01

5/19/2022

35.664622

-108.490056

0

3

SW6020

COBALT

3.8

0.5

mg/kg

CR1E

CR1E-SS19-0000-0003-02

5/19/2022

35.664622

-108.490056

0

3

SW6020

COBALT

4

0.52

mg/kg

CR1E

CR1E-SS05-0000-0003-01

5/19/2022

35.664557

-108.489454

0

3

SW6020

COPPER

9.4

2

mg/kg

CR1E

CR1E-SS06-0000-0003-01

5/19/2022

35.665434

-108.488911

0

3

SW6020

COPPER

7.7

2

mg/kg

CR1E

CR1E-SS07-0000-0003-01

5/19/2022

35.665828

-108.488623

0

3

SW6020

COPPER

8.4

2

mg/kg

CR1E

CR1E-SS07-0000-0003-02

5/19/2022

35.665828

-108.488623

0

3

SW6020

COPPER

8.1

2.3

mg/kg

CR1E

CR1E-SS08-0000-0003-01

5/19/2022

35.666966

-108.488662

0

3

SW6020

COPPER

6.3

2

mg/kg

CR1E

CR1E-SS09-0000-0003-01

5/19/2022

35.664733

-108.49064

0

3

SW6020

COPPER

13

2

mg/kg

CR1E

CR1E-SS10-0000-0003-01

5/19/2022

35.665086

-108.490244

0

3

SW6020

COPPER

17

2.1

mg/kg

CR1E

CR1E-SS11-0000-0003-01

5/19/2022

35.665393

-108.489297

0

3

SW6020

COPPER

14

2

mg/kg

CR1E

CR1E-SS12-0000-0003-01

5/19/2022

35.665819

-108.490253

0

3

SW6020

COPPER

19

2

mg/kg

CR1E

CR1E-SS13-0000-0003-01

5/19/2022

35.666222

-108.490271

0

3

SW6020

COPPER

12

2.2

mg/kg

CR1E

CR1E-SS14-0000-0003-01

5/19/2022

35.666028

-108.489317

0

3

SW6020

COPPER

11

2

mg/kg

CR1E

CR1E-SS15-0000-0003-01

5/19/2022

35.666507

-108.489822

0

3

SW6020

COPPER

11

2

mg/kg

CR1E

CR1E-SS16-0000-0003-01

5/19/2022

35.666619

-108.488931

0

3

SW6020

COPPER

6.5

2.1

mg/kg

CR1E

CR1E-SS17-0000-0003-01

5/19/2022

35.66629

-108.489

0

3

SW6020

COPPER

9.8

2

mg/kg

CR1E

CR1E-SS18-0000-0003-01

5/19/2022

35.667002

-108.488124

0

3

SW6020

COPPER

9.8

2.1

mg/kg

CR1E

CR1E-SS19-0000-0003-01

5/19/2022

35.664622

-108.490056

0

3

SW6020

COPPER

6.8

2

mg/kg

CR1E

CR1E-SS19-0000-0003-02

5/19/2022

35.664622

-108.490056

0

3

SW6020

COPPER

7.3

2.1

mg/kg

CR1E

CR1E-SS05-0000-0003-01

5/19/2022

35.664557

-108.489454

0

3

SW6020

IRON

16000

20

mg/kg

CR1E

CR1E-SS06-0000-0003-01

5/19/2022

35.665434

-108.488911

0

3

SW6020

IRON

12000

20

mg/kg

CR1E

CR1E-SS07-0000-0003-01

5/19/2022

35.665828

-108.488623

0

3

SW6020

IRON

11000

20

mg/kg

Page 30 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1E

CR1E-SS07-0000-0003-02

5/19/2022

35.665828

-108.488623

0

3

SW6020

IRON

11000

23

mg/kg

CR1E

CR1E-SS08-0000-0003-01

5/19/2022

35.666966

-108.488662

0

3

SW6020

IRON

11000

20

mg/kg

CR1E

CR1E-SS09-0000-0003-01

5/19/2022

35.664733

-108.49064

0

3

SW6020

IRON

21000

20

mg/kg

CR1E

CR1E-SS10-0000-0003-01

5/19/2022

35.665086

-108.490244

0

3

SW6020

IRON

23000

21

mg/kg

CR1E

CR1E-SS11-0000-0003-01

5/19/2022

35.665393

-108.489297

0

3

SW6020

IRON

17000

20

mg/kg

CR1E

CR1E-SS12-0000-0003-01

5/19/2022

35.665819

-108.490253

0

3

SW6020

IRON

20000

20

mg/kg

CR1E

CR1E-SS13-0000-0003-01

5/19/2022

35.666222

-108.490271

0

3

SW6020

IRON

12000

22

mg/kg

CR1E

CR1E-SS14-0000-0003-01

5/19/2022

35.666028

-108.489317

0

3

SW6020

IRON

11000

20

mg/kg

CR1E

CR1E-SS15-0000-0003-01

5/19/2022

35.666507

-108.489822

0

3

SW6020

IRON

11000

20

mg/kg

CR1E

CR1E-SS16-0000-0003-01

5/19/2022

35.666619

-108.488931

0

3

SW6020

IRON

9700

21

mg/kg

CR1E

CR1E-SS17-0000-0003-01

5/19/2022

35.66629

-108.489

0

3

SW6020

IRON

12000

20

mg/kg

CR1E

CR1E-SS18-0000-0003-01

5/19/2022

35.667002

-108.488124

0

3

SW6020

IRON

11000

21

mg/kg

CR1E

CR1E-SS19-0000-0003-01

5/19/2022

35.664622

-108.490056

0

3

SW6020

IRON

12000

20

mg/kg

CR1E

CR1E-SS19-0000-0003-02

5/19/2022

35.664622

-108.490056

0

3

SW6020

IRON

13000

21

mg/kg

CR1E

CR1E-SS05-0000-0003-01

5/19/2022

35.664557

-108.489454

0

3

SW6020

LEAD

10

0.2

mg/kg

CR1E

CR1E-SS06-0000-0003-01

5/19/2022

35.665434

-108.488911

0

3

SW6020

LEAD

7.8

0.2

mg/kg

CR1E

CR1E-SS07-0000-0003-01

5/19/2022

35.665828

-108.488623

0

3

SW6020

LEAD

7

0.2

mg/kg

CR1E

CR1E-SS07-0000-0003-02

5/19/2022

35.665828

-108.488623

0

3

SW6020

LEAD

6.9

0.23

mg/kg

CR1E

CR1E-SS08-0000-0003-01

5/19/2022

35.666966

-108.488662

0

3

SW6020

LEAD

8.1

0.2

mg/kg

CR1E

CR1E-SS09-0000-0003-01

5/19/2022

35.664733

-108.49064

0

3

SW6020

LEAD

13

0.2

mg/kg

CR1E

CR1E-SS10-0000-0003-01

5/19/2022

35.665086

-108.490244

0

3

SW6020

LEAD

16

0.21

mg/kg

CR1E

CR1E-SS11-0000-0003-01

5/19/2022

35.665393

-108.489297

0

3

SW6020

LEAD

13

0.2

mg/kg

CR1E

CR1E-SS12-0000-0003-01

5/19/2022

35.665819

-108.490253

0

3

SW6020

LEAD

18

0.2

mg/kg

CR1E

CR1E-SS13-0000-0003-01

5/19/2022

35.666222

-108.490271

0

3

SW6020

LEAD

12

0.22

mg/kg

CR1E

CR1E-SS14-0000-0003-01

5/19/2022

35.666028

-108.489317

0

3

SW6020

LEAD

11

0.2

mg/kg

CR1E

CR1E-SS15-0000-0003-01

5/19/2022

35.666507

-108.489822

0

3

SW6020

LEAD

11

0.2

mg/kg

CR1E

CR1E-SS16-0000-0003-01

5/19/2022

35.666619

-108.488931

0

3

SW6020

LEAD

7.5

0.21

mg/kg

CR1E

CR1E-SS17-0000-0003-01

5/19/2022

35.66629

-108.489

0

3

SW6020

LEAD

9.9

0.2

mg/kg

CR1E

CR1E-SS18-0000-0003-01

5/19/2022

35.667002

-108.488124

0

3

SW6020

LEAD

9.7

0.21

mg/kg

CR1E

CR1E-SS19-0000-0003-01

5/19/2022

35.664622

-108.490056

0

3

SW6020

LEAD

7.9

0.2

mg/kg

CR1E

CR1E-SS19-0000-0003-02

5/19/2022

35.664622

-108.490056

0

3

SW6020

LEAD

8.3

0.21

mg/kg

CR1E

CR1E-SS05-0000-0003-01

5/19/2022

35.664557

-108.489454

0

3

SW6020

MANGANESE

120

0.76

mg/kg

CR1E

CR1E-SS06-0000-0003-01

5/19/2022

35.665434

-108.488911

0

3

SW6020

MANGANESE

160

0.76

mg/kg

CR1E

CR1E-SS07-0000-0003-01

5/19/2022

35.665828

-108.488623

0

3

SW6020

MANGANESE

150

0.76

mg/kg

CR1E

CR1E-SS07-0000-0003-02

5/19/2022

35.665828

-108.488623

0

3

SW6020

MANGANESE

180

0.85

mg/kg

CR1E

CR1E-SS08-0000-0003-01

5/19/2022

35.666966

-108.488662

0

3

SW6020

MANGANESE

140

0.76

mg/kg

CR1E

CR1E-SS09-0000-0003-01

5/19/2022

35.664733

-108.49064

0

3

SW6020

MANGANESE

180

0.75

mg/kg

CR1E

CR1E-SS10-0000-0003-01

5/19/2022

35.665086

-108.490244

0

3

SW6020

MANGANESE

190

0.79

mg/kg

CR1E

CR1E-SS11-0000-0003-01

5/19/2022

35.665393

-108.489297

0

3

SW6020

MANGANESE

280

0.76

mg/kg

CR1E

CR1E-SS12-0000-0003-01

5/19/2022

35.665819

-108.490253

0

3

SW6020

MANGANESE

290

0.76

mg/kg

CR1E

CR1E-SS13-0000-0003-01

5/19/2022

35.666222

-108.490271

0

3

SW6020

MANGANESE

160

0.84

mg/kg

CR1E

CR1E-SS14-0000-0003-01

5/19/2022

35.666028

-108.489317

0

3

SW6020

MANGANESE

160

0.76

mg/kg

Page 31 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1E

CR1E-SS15-0000-0003-01

5/19/2022

35.666507

-108.489822

0

3

SW6020

MANGANESE

170

0.77

mg/kg

CR1E

CR1E-SS16-0000-0003-01

5/19/2022

35.666619

-108.488931

0

3

SW6020

MANGANESE

140

0.77

mg/kg

CR1E

CR1E-SS17-0000-0003-01

5/19/2022

35.66629

-108.489

0

3

SW6020

MANGANESE

180

0.76

mg/kg

CR1E

CR1E-SS18-0000-0003-01

5/19/2022

35.667002

-108.488124

0

3

SW6020

MANGANESE

180

0.77

mg/kg

CR1E

CR1E-SS19-0000-0003-01

5/19/2022

35.664622

-108.490056

0

3

SW6020

MANGANESE

130

0.76

mg/kg

CR1E

CR1E-SS19-0000-0003-02

5/19/2022

35.664622

-108.490056

0

3

SW6020

MANGANESE

120

0.78

mg/kg

CR1E

CR1E-SS05-0000-0003-01

5/19/2022

35.664557

-108.489454

0

3

SW6020

MOLYBDENUM

0.36

0.2

mg/kg

CR1E

CR1E-SS06-0000-0003-01

5/19/2022

35.665434

-108.488911

0

3

SW6020

MOLYBDENUM

0.24

0.2

mg/kg

CR1E

CR1E-SS07-0000-0003-01

5/19/2022

35.665828

-108.488623

0

3

SW6020

MOLYBDENUM

0.21

0.2

mg/kg

CR1E

CR1E-SS07-0000-0003-02

5/19/2022

35.665828

-108.488623

0

3

SW6020

MOLYBDENUM

0.21 J

0.23

mg/kg

CR1E

CR1E-SS08-0000-0003-01

5/19/2022

35.666966

-108.488662

0

3

SW6020

MOLYBDENUM

0.24

0.2

mg/kg

CR1E

CR1E-SS09-0000-0003-01

5/19/2022

35.664733

-108.49064

0

3

SW6020

MOLYBDENUM

0.2

0.2

mg/kg

CR1E

CR1E-SS10-0000-0003-01

5/19/2022

35.665086

-108.490244

0

3

SW6020

MOLYBDENUM

0.23

0.21

mg/kg

CR1E

CR1E-SS11-0000-0003-01

5/19/2022

35.665393

-108.489297

0

3

SW6020

MOLYBDENUM

0.37

0.2

mg/kg

CR1E

CR1E-SS12-0000-0003-01

5/19/2022

35.665819

-108.490253

0

3

SW6020

MOLYBDENUM

0.4

0.2

mg/kg

CR1E

CR1E-SS13-0000-0003-01

5/19/2022

35.666222

-108.490271

0

3

SW6020

MOLYBDENUM

0.19 J

0.22

mg/kg

CR1E

CR1E-SS14-0000-0003-01

5/19/2022

35.666028

-108.489317

0

3

SW6020

MOLYBDENUM

0.25

0.2

mg/kg

CR1E

CR1E-SS15-0000-0003-01

5/19/2022

35.666507

-108.489822

0

3

SW6020

MOLYBDENUM

0.4

0.2

mg/kg

CR1E

CR1E-SS16-0000-0003-01

5/19/2022

35.666619

-108.488931

0

3

SW6020

MOLYBDENUM

0.19 J

0.21

mg/kg

CR1E

CR1E-SS17-0000-0003-01

5/19/2022

35.66629

-108.489

0

3

SW6020

MOLYBDENUM

0.27

0.2

mg/kg

CR1E

CR1E-SS18-0000-0003-01

5/19/2022

35.667002

-108.488124

0

3

SW6020

MOLYBDENUM

0.21

0.21

mg/kg

CR1E

CR1E-SS19-0000-0003-01

5/19/2022

35.664622

-108.490056

0

3

SW6020

MOLYBDENUM

0.34

0.2

mg/kg

CR1E

CR1E-SS19-0000-0003-02

5/19/2022

35.664622

-108.490056

0

3

SW6020

MOLYBDENUM

0.38

0.21

mg/kg

CR1E

CR1E-SS05-0000-0003-01

5/19/2022

35.664557

-108.489454

0

3

SW6020

NICKEL

9.8

2

mg/kg

CR1E

CR1E-SS06-0000-0003-01

5/19/2022

35.665434

-108.488911

0

3

SW6020

NICKEL

10

2

mg/kg

CR1E

CR1E-SS07-0000-0003-01

5/19/2022

35.665828

-108.488623

0

3

SW6020

NICKEL

20

2

mg/kg

CR1E

CR1E-SS07-0000-0003-02

5/19/2022

35.665828

-108.488623

0

3

SW6020

NICKEL

20

2.3

mg/kg

CR1E

CR1E-SS08-0000-0003-01

5/19/2022

35.666966

-108.488662

0

3

SW6020

NICKEL

5.7

2

mg/kg

CR1E

CR1E-SS09-0000-0003-01

5/19/2022

35.664733

-108.49064

0

3

SW6020

NICKEL

11

2

mg/kg

CR1E

CR1E-SS10-0000-0003-01

5/19/2022

35.665086

-108.490244

0

3

SW6020

NICKEL

13

2.1

mg/kg

CR1E

CR1E-SS11-0000-0003-01

5/19/2022

35.665393

-108.489297

0

3

SW6020

NICKEL

11

2

mg/kg

CR1E

CR1E-SS12-0000-0003-01

5/19/2022

35.665819

-108.490253

0

3

SW6020

NICKEL

13

2

mg/kg

CR1E

CR1E-SS13-0000-0003-01

5/19/2022

35.666222

-108.490271

0

3

SW6020

NICKEL

7.5

2.2

mg/kg

CR1E

CR1E-SS14-0000-0003-01

5/19/2022

35.666028

-108.489317

0

3

SW6020

NICKEL

7.4

2

mg/kg

CR1E

CR1E-SS15-0000-0003-01

5/19/2022

35.666507

-108.489822

0

3

SW6020

NICKEL

7.9

2

mg/kg

CR1E

CR1E-SS16-0000-0003-01

5/19/2022

35.666619

-108.488931

0

3

SW6020

NICKEL

5.3

2.1

mg/kg

CR1E

CR1E-SS17-0000-0003-01

5/19/2022

35.66629

-108.489

0

3

SW6020

NICKEL

7.1

2

mg/kg

CR1E

CR1E-SS18-0000-0003-01

5/19/2022

35.667002

-108.488124

0

3

SW6020

NICKEL

7.2

2.1

mg/kg

CR1E

CR1E-SS19-0000-0003-01

5/19/2022

35.664622

-108.490056

0

3

SW6020

NICKEL

7.4

2

mg/kg

CR1E

CR1E-SS19-0000-0003-02

5/19/2022

35.664622

-108.490056

0

3

SW6020

NICKEL

8

2.1

mg/kg

CR1E

CR1E-SS05-0000-0003-01

5/19/2022

35.664557

-108.489454

0

3

713R15

Ra-226

1.59

0.56

pCi/g

CR1E

CR1E-SS06-0000-0003-01

5/19/2022

35.665434

-108.488911

0

3

713R15

Ra-226

6.22

0.5

pCi/g

Page 32 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1E

CR1E-SS07-0000-0003-01

5/19/2022

35.665828

-108.488623

0

3

713R15

Ra-226

3.21

0.48

O

Q.

/g

CR1E

CR1E-SS07-0000-0003-02

5/19/2022

35.665828

-108.488623

0

3

713R15

Ra-226

3.12

0.38

O

Q.

/ g

CR1E

CR1E-SS08-0000-0003-01

5/19/2022

35.666966

-108.488662

0

3

713R15

Ra-226

1.76

0.54

pC

/g

CR1E

CR1E-SS09-0000-0003-01

5/19/2022

35.664733

-108.49064

0

3

713R15

Ra-226

1.69 J

0.51

pC

/g

CR1E

CR1E-SS10-0000-0003-01

5/19/2022

35.665086

-108.490244

0

3

713R15

Ra-226

1.67 J

0.34

o

Q.

/ g

CR1E

CR1E-SS11-0000-0003-01

5/19/2022

35.665393

-108.489297

0

3

713R15

Ra-226

3.8 J

0.68

O

Q.

/ g

CR1E

CR1E-SS12-0000-0003-01

5/19/2022

35.665819

-108.490253

0

3

713R15

Ra-226

1.59

0.43

pC

/g

CR1E

CR1E-SS13-0000-0003-01

5/19/2022

35.666222

-108.490271

0

3

713R15

Ra-226

1.16

0.48

pC

/g

CR1E

CR1E-SS14-0000-0003-01

5/19/2022

35.666028

-108.489317

0

3

713R15

Ra-226

1.5 J

0.54

o

Q.

/ g

CR1E

CR1E-SS15-0000-0003-01

5/19/2022

35.666507

-108.489822

0

3

713R15

Ra-226

3.11

0.46

O

Q.

/ g

CR1E

CR1E-SS16-0000-0003-01

5/19/2022

35.666619

-108.488931

0

3

713R15

Ra-226

4.58

0.62

pC

/g

CR1E

CR1E-SS17-0000-0003-01

5/19/2022

35.66629

-108.489

0

3

713R15

Ra-226

13.9

0.6

pC

/g

CR1E

CR1E-SS18-0000-0003-01

5/19/2022

35.667002

-108.488124

0

3

713R15

Ra-226

1.81

0.29

o

Q.

/ g

CR1E

CR1E-SS19-0000-0003-01

5/19/2022

35.664622

-108.490056

0

3

713R15

Ra-226

1.37

0.37

O

Q.

/ g

CR1E

CR1E-SS19-0000-0003-02

5/19/2022

35.664622

-108.490056

0

3

713R15

Ra-226

1.39

0.43

pC

/ g

CR1E

CR1E-SS05-0000-0003-01

5/19/2022

35.664557

-108.489454

0

3

SW6020

SELENIUM

1.4

1

mg/kg

CR1E

CR1E-SS06-0000-0003-01

5/19/2022

35.665434

-108.488911

0

3

SW6020

SELENIUM

1.9

1

mg/kg

CR1E

CR1E-SS07-0000-0003-01

5/19/2022

35.665828

-108.488623

0

3

SW6020

SELENIUM

1.3

1

mg/kg

CR1E

CR1E-SS07-0000-0003-02

5/19/2022

35.665828

-108.488623

0

3

SW6020

SELENIUM

1.1

1.1

mg/kg

CR1E

CR1E-SS08-0000-0003-01

5/19/2022

35.666966

-108.488662

0

3

SW6020

SELENIUM

1.2

1

mg/kg

CR1E

CR1E-SS09-0000-0003-01

5/19/2022

35.664733

-108.49064

0

3

SW6020

SELENIUM

1.6

1

mg/kg

CR1E

CR1E-SS10-0000-0003-01

5/19/2022

35.665086

-108.490244

0

3

SW6020

SELENIUM

1.8

1

mg/kg

CR1E

CR1E-SS11-0000-0003-01

5/19/2022

35.665393

-108.489297

0

3

SW6020

SELENIUM

2.1

1

mg/kg

CR1E

CR1E-SS12-0000-0003-01

5/19/2022

35.665819

-108.490253

0

3

SW6020

SELENIUM

3.1

1

mg/kg

CR1E

CR1E-SS13-0000-0003-01

5/19/2022

35.666222

-108.490271

0

3

SW6020

SELENIUM

1.8

1.1

mg/kg

CR1E

CR1E-SS14-0000-0003-01

5/19/2022

35.666028

-108.489317

0

3

SW6020

SELENIUM

5

1

mg/kg

CR1E

CR1E-SS15-0000-0003-01

5/19/2022

35.666507

-108.489822

0

3

SW6020

SELENIUM

1.8

1

mg/kg

CR1E

CR1E-SS16-0000-0003-01

5/19/2022

35.666619

-108.488931

0

3

SW6020

SELENIUM

2.5

1

mg/kg

CR1E

CR1E-SS17-0000-0003-01

5/19/2022

35.66629

-108.489

0

3

SW6020

SELENIUM

4.7

1

mg/kg

CR1E

CR1E-SS18-0000-0003-01

5/19/2022

35.667002

-108.488124

0

3

SW6020

SELENIUM

1.6

1

mg/kg

CR1E

CR1E-SS19-0000-0003-01

5/19/2022

35.664622

-108.490056

0

3

SW6020

SELENIUM

1.2

1

mg/kg

CR1E

CR1E-SS19-0000-0003-02

5/19/2022

35.664622

-108.490056

0

3

SW6020

SELENIUM

1.2

1

mg/kg

CR1E

CR1E-SS05-0000-0003-01

5/19/2022

35.664557

-108.489454

0

3

SW6020

SILVER

0.06 J

0.12

mg/kg

CR1E

CR1E-SS06-0000-0003-01

5/19/2022

35.665434

-108.488911

0

3

SW6020

SILVER

0.057 U

0.11

mg/kg

CR1E

CR1E-SS07-0000-0003-01

5/19/2022

35.665828

-108.488623

0

3

SW6020

SILVER

0.058 U

0.12

mg/kg

CR1E

CR1E-SS07-0000-0003-02

5/19/2022

35.665828

-108.488623

0

3

SW6020

SILVER

0.065 U

0.13

mg/kg

CR1E

CR1E-SS08-0000-0003-01

5/19/2022

35.666966

-108.488662

0

3

SW6020

SILVER

0.058 U

0.12

mg/kg

CR1E

CR1E-SS09-0000-0003-01

5/19/2022

35.664733

-108.49064

0

3

SW6020

SILVER

0.063 J

0.11

mg/kg

CR1E

CR1E-SS10-0000-0003-01

5/19/2022

35.665086

-108.490244

0

3

SW6020

SILVER

0.081 J

0.12

mg/kg

CR1E

CR1E-SS11-0000-0003-01

5/19/2022

35.665393

-108.489297

0

3

SW6020

SILVER

0.076 J

0.12

mg/kg

CR1E

CR1E-SS12-0000-0003-01

5/19/2022

35.665819

-108.490253

0

3

SW6020

SILVER

0.089 J

0.12

mg/kg

CR1E

CR1E-SS13-0000-0003-01

5/19/2022

35.666222

-108.490271

0

3

SW6020

SILVER

0.064 U

0.13

mg/kg

Page 33 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1E

CR1E-SS14-0000-0003-01

5/19/2022

35.666028

-108.489317

0

3

SW6020

SILVER

0.058 U

0.12

mg/kg

CR1E

CR1E-SS15-0000-0003-01

5/19/2022

35.666507

-108.489822

0

3

SW6020

SILVER

0.058 U

0.12

mg/kg

CR1E

CR1E-SS16-0000-0003-01

5/19/2022

35.666619

-108.488931

0

3

SW6020

SILVER

0.059 U

0.12

mg/kg

CR1E

CR1E-SS17-0000-0003-01

5/19/2022

35.66629

-108.489

0

3

SW6020

SILVER

0.058 U

0.12

mg/kg

CR1E

CR1E-SS18-0000-0003-01

5/19/2022

35.667002

-108.488124

0

3

SW6020

SILVER

0.059 U

0.12

mg/kg

CR1E

CR1E-SS19-0000-0003-01

5/19/2022

35.664622

-108.490056

0

3

SW6020

SILVER

0.057 U

0.11

mg/kg

CR1E

CR1E-SS19-0000-0003-02

5/19/2022

35.664622

-108.490056

0

3

SW6020

SILVER

0.059 U

0.12

mg/kg

CR1E

CR1E-SS05-0000-0003-01

5/19/2022

35.664557

-108.489454

0

3

SW6020

THALLIUM

0.2

0.01

mg/kg

CR1E

CR1E-SS06-0000-0003-01

5/19/2022

35.665434

-108.488911

0

3

SW6020

THALLIUM

0.11

0.01

mg/kg

CR1E

CR1E-SS07-0000-0003-01

5/19/2022

35.665828

-108.488623

0

3

SW6020

THALLIUM

0.1

0.01

mg/kg

CR1E

CR1E-SS07-0000-0003-02

5/19/2022

35.665828

-108.488623

0

3

SW6020

THALLIUM

0.093

0.011

mg/kg

CR1E

CR1E-SS08-0000-0003-01

5/19/2022

35.666966

-108.488662

0

3

SW6020

THALLIUM

0.099

0.01

mg/kg

CR1E

CR1E-SS09-0000-0003-01

5/19/2022

35.664733

-108.49064

0

3

SW6020

THALLIUM

0.17

0.01

mg/kg

CR1E

CR1E-SS10-0000-0003-01

5/19/2022

35.665086

-108.490244

0

3

SW6020

THALLIUM

0.2

0.01

mg/kg

CR1E

CR1E-SS11-0000-0003-01

5/19/2022

35.665393

-108.489297

0

3

SW6020

THALLIUM

0.16

0.01

mg/kg

CR1E

CR1E-SS12-0000-0003-01

5/19/2022

35.665819

-108.490253

0

3

SW6020

THALLIUM

0.22

0.01

mg/kg

CR1E

CR1E-SS13-0000-0003-01

5/19/2022

35.666222

-108.490271

0

3

SW6020

THALLIUM

0.14

0.011

mg/kg

CR1E

CR1E-SS14-0000-0003-01

5/19/2022

35.666028

-108.489317

0

3

SW6020

THALLIUM

0.13

0.01

mg/kg

CR1E

CR1E-SS15-0000-0003-01

5/19/2022

35.666507

-108.489822

0

3

SW6020

THALLIUM

0.12

0.01

mg/kg

CR1E

CR1E-SS16-0000-0003-01

5/19/2022

35.666619

-108.488931

0

3

SW6020

THALLIUM

0.084

0.01

mg/kg

CR1E

CR1E-SS17-0000-0003-01

5/19/2022

35.66629

-108.489

0

3

SW6020

THALLIUM

0.11

0.01

mg/kg

CR1E

CR1E-SS18-0000-0003-01

5/19/2022

35.667002

-108.488124

0

3

SW6020

THALLIUM

0.11

0.01

mg/kg

CR1E

CR1E-SS19-0000-0003-01

5/19/2022

35.664622

-108.490056

0

3

SW6020

THALLIUM

0.14

0.01

mg/kg

CR1E

CR1E-SS19-0000-0003-02

5/19/2022

35.664622

-108.490056

0

3

SW6020

THALLIUM

0.16

0.01

mg/kg

CR1E

CR1E-SS05-0000-0003-01

5/19/2022

35.664557

-108.489454

0

3

SW6020

URANIUM

1

0.02

mg/kg

CR1E

CR1E-SS06-0000-0003-01

5/19/2022

35.665434

-108.488911

0

3

SW6020

URANIUM

5.4

0.02

mg/kg

CR1E

CR1E-SS07-0000-0003-01

5/19/2022

35.665828

-108.488623

0

3

SW6020

URANIUM

2.3

0.02

mg/kg

CR1E

CR1E-SS07-0000-0003-02

5/19/2022

35.665828

-108.488623

0

3

SW6020

URANIUM

2.4

0.023

mg/kg

CR1E

CR1E-SS08-0000-0003-01

5/19/2022

35.666966

-108.488662

0

3

SW6020

URANIUM

2.6

0.02

mg/kg

CR1E

CR1E-SS09-0000-0003-01

5/19/2022

35.664733

-108.49064

0

3

SW6020

URANIUM

0.91

0.02

mg/kg

CR1E

CR1E-SS10-0000-0003-01

5/19/2022

35.665086

-108.490244

0

3

SW6020

URANIUM

1

0.021

mg/kg

CR1E

CR1E-SS11-0000-0003-01

5/19/2022

35.665393

-108.489297

0

3

SW6020

URANIUM

2.4

0.02

mg/kg

CR1E

CR1E-SS12-0000-0003-01

5/19/2022

35.665819

-108.490253

0

3

SW6020

URANIUM

1.9

0.02

mg/kg

CR1E

CR1E-SS13-0000-0003-01

5/19/2022

35.666222

-108.490271

0

3

SW6020

URANIUM

1.1

0.022

mg/kg

CR1E

CR1E-SS14-0000-0003-01

5/19/2022

35.666028

-108.489317

0

3

SW6020

URANIUM

5.3

0.02

mg/kg

CR1E

CR1E-SS15-0000-0003-01

5/19/2022

35.666507

-108.489822

0

3

SW6020

URANIUM

3.3

0.02

mg/kg

CR1E

CR1E-SS16-0000-0003-01

5/19/2022

35.666619

-108.488931

0

3

SW6020

URANIUM

3.3

0.021

mg/kg

CR1E

CR1E-SS17-0000-0003-01

5/19/2022

35.66629

-108.489

0

3

SW6020

URANIUM

6.3

0.02

mg/kg

CR1E

CR1E-SS18-0000-0003-01

5/19/2022

35.667002

-108.488124

0

3

SW6020

URANIUM

1.4

0.021

mg/kg

CR1E

CR1E-SS19-0000-0003-01

5/19/2022

35.664622

-108.490056

0

3

SW6020

URANIUM

0.83

0.02

mg/kg

CR1E

CR1E-SS19-0000-0003-02

5/19/2022

35.664622

-108.490056

0

3

SW6020

URANIUM

0.87

0.021

mg/kg

CR1E

CR1E-SS05-0000-0003-01

5/19/2022

35.664557

-108.489454

0

3

SW6020

VANADIUM

12

0.51

mg/kg

Page 34 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1E

CR1E-SS06-0000-0003-01

5/19/2022

35.665434

-108.488911

0

3

SW6020

VANADIUM

13

0.5

mg/kg

CR1E

CR1E-SS07-0000-0003-01

5/19/2022

35.665828

-108.488623

0

3

SW6020

VANADIUM

14

0.51

mg/kg

CR1E

CR1E-SS07-0000-0003-02

5/19/2022

35.665828

-108.488623

0

3

SW6020

VANADIUM

13

0.57

mg/kg

CR1E

CR1E-SS08-0000-0003-01

5/19/2022

35.666966

-108.488662

0

3

SW6020

VANADIUM

14

0.51

mg/kg

CR1E

CR1E-SS09-0000-0003-01

5/19/2022

35.664733

-108.49064

0

3

SW6020

VANADIUM

17

0.5

mg/kg

CR1E

CR1E-SS10-0000-0003-01

5/19/2022

35.665086

-108.490244

0

3

SW6020

VANADIUM

18

0.52

mg/kg

CR1E

CR1E-SS11-0000-0003-01

5/19/2022

35.665393

-108.489297

0

3

SW6020

VANADIUM

18

0.51

mg/kg

CR1E

CR1E-SS12-0000-0003-01

5/19/2022

35.665819

-108.490253

0

3

SW6020

VANADIUM

23

0.51

mg/kg

CR1E

CR1E-SS13-0000-0003-01

5/19/2022

35.666222

-108.490271

0

3

SW6020

VANADIUM

14

0.56

mg/kg

CR1E

CR1E-SS14-0000-0003-01

5/19/2022

35.666028

-108.489317

0

3

SW6020

VANADIUM

13

0.51

mg/kg

CR1E

CR1E-SS15-0000-0003-01

5/19/2022

35.666507

-108.489822

0

3

SW6020

VANADIUM

13

0.51

mg/kg

CR1E

CR1E-SS16-0000-0003-01

5/19/2022

35.666619

-108.488931

0

3

SW6020

VANADIUM

12

0.52

mg/kg

CR1E

CR1E-SS17-0000-0003-01

5/19/2022

35.66629

-108.489

0

3

SW6020

VANADIUM

15

0.51

mg/kg

CR1E

CR1E-SS18-0000-0003-01

5/19/2022

35.667002

-108.488124

0

3

SW6020

VANADIUM

13

0.52

mg/kg

CR1E

CR1E-SS19-0000-0003-01

5/19/2022

35.664622

-108.490056

0

3

SW6020

VANADIUM

11

0.5

mg/kg

CR1E

CR1E-SS19-0000-0003-02

5/19/2022

35.664622

-108.490056

0

3

SW6020

VANADIUM

11

0.52

mg/kg

CR1E

CR1E-SS05-0000-0003-01

5/19/2022

35.664557

-108.489454

0

3

SW6020

ZINC

46

10

mg/kg

CR1E

CR1E-SS06-0000-0003-01

5/19/2022

35.665434

-108.488911

0

3

SW6020

ZINC

33

10

mg/kg

CR1E

CR1E-SS07-0000-0003-01

5/19/2022

35.665828

-108.488623

0

3

SW6020

ZINC

32

10

mg/kg

CR1E

CR1E-SS07-0000-0003-02

5/19/2022

35.665828

-108.488623

0

3

SW6020

ZINC

31

11

mg/kg

CR1E

CR1E-SS08-0000-0003-01

5/19/2022

35.666966

-108.488662

0

3

SW6020

ZINC

40

10

mg/kg

CR1E

CR1E-SS09-0000-0003-01

5/19/2022

35.664733

-108.49064

0

3

SW6020

ZINC

60

10

mg/kg

CR1E

CR1E-SS10-0000-0003-01

5/19/2022

35.665086

-108.490244

0

3

SW6020

ZINC

65

10

mg/kg

CR1E

CR1E-SS11-0000-0003-01

5/19/2022

35.665393

-108.489297

0

3

SW6020

ZINC

71

10

mg/kg

CR1E

CR1E-SS12-0000-0003-01

5/19/2022

35.665819

-108.490253

0

3

SW6020

ZINC

80

10

mg/kg

CR1E

CR1E-SS13-0000-0003-01

5/19/2022

35.666222

-108.490271

0

3

SW6020

ZINC

49

11

mg/kg

CR1E

CR1E-SS14-0000-0003-01

5/19/2022

35.666028

-108.489317

0

3

SW6020

ZINC

47

10

mg/kg

CR1E

CR1E-SS15-0000-0003-01

5/19/2022

35.666507

-108.489822

0

3

SW6020

ZINC

47

10

mg/kg

CR1E

CR1E-SS16-0000-0003-01

5/19/2022

35.666619

-108.488931

0

3

SW6020

ZINC

36

10

mg/kg

CR1E

CR1 E-SS17-0000-0003-01

5/19/2022

35.66629

-108.489

0

3

SW6020

ZINC

44

10

mg/kg

CR1E

CR1E-SS18-0000-0003-01

5/19/2022

35.667002

-108.488124

0

3

SW6020

ZINC

45

10

mg/kg

CR1E

CR1E-SS19-0000-0003-01

5/19/2022

35.664622

-108.490056

0

3

SW6020

ZINC

35

10

mg/kg

CR1E

CR1E-SS19-0000-0003-02

5/19/2022

35.664622

-108.490056

0

3

SW6020

ZINC

36

10

mg/kg

CR1E

CELI-503 SS1 0-1.5

5/5/2011

35.6670417

-108.488182

0

18

SW6010

ARSENIC

6.2

1.1

mg/kg

CR1E

CELI-503 SS5

5/5/2011

35.6670417

-108.488182

0

18

SW6010

ARSENIC

7.2

1.3

MG/KG

CR1E

CELI-503 SS1 0-1.5

5/5/2011

35.6670417

-108.488182

0

18

SW6010

MOLYBDENUM

1.1 U

1.1

mg/kg

CR1E

CELI-503 SS5

5/5/2011

35.6670417

-108.488182

0

18

SW6010

MOLYBDENUM

1.3 U

1.3

mg/kg

CR1E

CELI-502 SS1 0-1.5

5/5/2011

35.6670954

-108.488555

0

18

713R11

Ra-226

25.5 G

0.7

pCi/g

CR1E

CELI-503 SS1 0-1.5

5/5/2011

35.6670417

-108.488182

0

18

713R11

Ra-226

14.5

0.6

pCi/g

CR1E

CELP-409 SS1 0-1.5

5/4/2011

35.6657679

-108.489458

0

18

713R11

Ra-226

2.57 G

0.66

pCi/g

CR1E

CELI-503 SS1 0-1.5

5/5/2011

35.6670417

-108.488182

0

18

SW6010

SELENIUM

2.7 U

2.7

mg/kg

CR1E

CELI-503 SS5

5/5/2011

35.6670417

-108.488182

0

18

SW6010

SELENIUM

3.2 U

3.2

mg/kg

Page 35 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1E

CELI-503 SS1 0-1.5

5/5/2011

35.6670417

-108.488182

0

18

SW6020

URANIUM

73

110

mg/kg

CR1E

CELI-503 SS1 0-1.5

5/5/2011

35.6670417

-108.488182

0

18

SW6010

VANADIUM

18

5.4

mg/kg

CR1E

CELI-503 SS5

5/5/2011

35.6670417

-108.488182

0

18

SW6010

VANADIUM

21

6.5

mg/kg

CR1E

CELA-001 (2-6)

5/6/2011

35.6649477

-108.490897

2

6

713R11

Ra-226

1.84 G

0.65

pC

/g

CR1E

CELA-004 (2-6)

5/6/2011

35.6645728

-108.490624

2

6

713R11

Ra-226

3.07

0.57

o

Q.

/g

CR1E

CELA-004 (2-6) Dup

5/6/2011

35.6645728

-108.490624

2

6

713R11

Ra-226

3.48

0.37

O

Q.

/g

CR1E

CELA-008 (2-6)

5/6/2011

35.6647603

-108.490491

2

6

713R11

Ra-226

1.53 G

0.44

pC

'g

CR1E

CELA-008 (2-6) Dup

5/6/2011

35.6647603

-108.490491

2

6

713R11

Ra-226

1.43 G

0.53

pC

/g

CR1E

CELA-012 (2-6)

5/4/2011

35.6662795

-108.490503

2

6

713R11

Ra-226

1.47

0.43

o

Q.

/g

CR1E

CELA-016 (2-6)

5/4/2011

35.6660879

-108.490371

2

6

713R11

Ra-226

2.61

0.37

O

Q.

/g

CR1E

CELA-020 (2-6)

5/6/2011

35.6655228

-108.490225

2

6

713R11

Ra-226

1.35

0.39

pC

'g

CR1E

CELA-024 (2-6)

5/6/2011

35.6653285

-108.490085

2

6

713R11

Ra-226

1.71 G

0.63

pC

/g

CR1E

CELA-027 (2-6)

5/4/2011

35.6664685

-108.490101

2

6

713R11

Ra-226

2.01

0.47

o

Q.

/g

CR1E

CELA-031 (2-6)

5/4/2011

35.6662824

-108.489968

2

6

713R11

Ra-226

2.63 G

0.67

O

Q.

/g

CR1E

CELA-035 (2-6)

5/4/2011

35.6660909

-108.489832

2

6

713R11

Ra-226

1.63

0.54

pC

'g

CR1E

CELA-039 (2-6)

5/4/2011

35.6662839

-108.489699

2

6

713R11

Ra-226

3.19 G

0.59

pC

/g

CR1E

CELA-043 (2-6)

5/4/2011

35.6664715

-108.489566

2

6

713R11

Ra-226

75.6

0.9

o

Q.

/g

CR1E

CELA-047 (2-6)

5/4/2011

35.6666673

-108.489429

2

6

713R11

Ra-226

3.17 G

0.59

O

Q.

/g

CR1E

CELA-051 (2-6)

5/6/2011

35.6659187

-108.489157

2

6

713R11

Ra-226

2.68 G

0.56

pC

/g

CR1E

CELA-054 (2-6)

5/6/2011

35.6661008

-108.489024

2

6

713R11

Ra-226

1.67 G

0.49

pC

/g

CR1E

CELA-058 (2-6)

5/5/2011

35.6666674

-108.488891

2

6

713R11

Ra-226

3.08 G

0.67

o

Q.

/g

CR1E

CELA-062 (2-6)

5/5/2011

35.6662953

-108.488622

2

6

713R11

Ra-226

2.14 G

0.54

O

Q.

/g

CR1E

CELA-066 (2-6)

5/5/2011

35.6668592

-108.488485

2

6

713R11

Ra-226

1.64 G

0.48

pC

/g

CR1E

CELA-070 (2-6)

5/5/2011

35.6668607

-108.488216

2

6

713R11

Ra-226

19 G

0.7

pC

/g

CR1E

CELA-074 (2-6)

5/5/2011

35.667244

-108.487956

2

6

713R11

Ra-226

7.4 G

0.7

o

Q.

/g

CR1E

CELA-074 DUP

5/5/2011

35.667244

-108.487956

2

6

713R11

Ra-226

6.86 G

0.71

pC

/g

CR1E

CESS-037 (2-6)

5/6/2011

35.6650409

-108.489423

2

6

713R12

Ra-226

1.48 G

0.36

pC

'g

CR1E

CESS-041 (2-6)

5/6/2011

35.6654512

-108.489254

2

6

713R12

Ra-226

86.3 M3,G

1.6

pC

/g

CR1E

CESS-060 (2-6)

5/6/2011

35.6664792

-108.488135

2

6

713R12

Ra-226

4.34 G

0.53

o

Q.

/ g

CR1E

CESS-069 (2-6)

5/6/2011

35.6672442

-108.487414

2

6

713R11

Ra-226

2.27 G

0.5

pC

/g

CR1E

CELA-020 (6-12)

5/6/2011

35.6655228

-108.490225

6

12

713R11

Ra-226

1.52 G

0.47

pC

'g

CR1E

CELA-051 (6-12)

5/6/2011

35.6659187

-108.489157

6

12

713R11

Ra-226

89 M3,G

2

pC

/g

CR1E

CESS-041 (6-12)

5/6/2011

35.6654512

-108.489254

6

12

713R12

Ra-226

16.9

0.6

o

Q.

/ g

CR1E

CELA-074 (9-14)

5/5/2011

35.667244

-108.487956

9

14

713R11

Ra-226

3.67 G

0.52

pC

Zg

CR1E

CELA-070 (9-15)

5/5/2011

35.6668607

-108.488216

9

15

713R11

Ra-226

2.67 G

0.46

pC

'g

CR1E

CELA-004 (10-16)

5/6/2011

35.6645728

-108.490624

10

16

713R11

Ra-226

1.65 G

0.59

pC

/g

CR1E

CELA-008 (12-18)

5/6/2011

35.6647603

-108.490491

12

18

713R11

Ra-226

3.03 G

0.64

o

Q.

/g

CR1E

CELA-008 DUP

5/6/2011

35.6647603

-108.490491

12

18

713R11

Ra-226

3.56 G

0.52

o

Q.

/g

CR1E

CELA-066 (12-18)

5/5/2011

35.6668592

-108.488485

12

18

713R11

Ra-226

45.3 M3,G

1

pC

/g

CR1E

CELA-062 (13-19)

5/5/2011

35.6662953

-108.488622

13

19

713R11

Ra-226

3.7 G

0.74

pC

/g

CR1E

CELA-024 (14-20)

5/6/2011

35.6653285

-108.490085

14

20

713R11

Ra-226

1.28 G

0.44

o

Q.

/g

CR1E

CELA-001 (18-24)

5/6/2011

35.6649477

-108.490897

18

24

713R11

Ra-226

1.34

0.45

o

Q.

/g

Page 36 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1E

CELA-012 (18-24)

5/4/2011

35.6662795

-108.490503

18

24

713R11

Ra-226

1.18

0.54

O

Q.

/g

CR1E

CELA-016 (18-24)

5/4/2011

35.6660879

-108.490371

18

24

713R11

Ra-226

96 M3,G

1

O

Q.

/g

CR1E

CELA-027 (18-24)

5/4/2011

35.6664685

-108.490101

18

24

713R11

Ra-226

112 M3

1

pC

'g

CR1E

CELA-031 (18-24)

5/4/2011

35.6662824

-108.489968

18

24

713R11

Ra-226

71.9 G

1

pC

/g

CR1E

CELA-031 (18-24) Dup

5/4/2011

35.6662824

-108.489968

18

24

713R11

Ra-226

71

0.8

o

Q.

/g

CR1E

CELA-035 (18-24)

5/4/2011

35.6660909

-108.489832

18

24

713R11

Ra-226

352 M3

2

O

Q.

/g

CR1E

CELA-039 (18-24)

5/4/2011

35.6662839

-108.489699

18

24

713R11

Ra-226

194 M3

2

pC

'g

CR1E

CELA-043 (18-24)

5/4/2011

35.6664715

-108.489566

18

24

713R11

Ra-226

363 M3,G

3

pC

/g

CR1E

CELA-047 (18-24)

5/4/2011

35.6666673

-108.489429

18

24

713R11

Ra-226

59.5 M3

1.2

o

Q.

/g

CR1E

CELA-047 (18-24) Dup

5/4/2011

35.6666673

-108.489429

18

24

713R11

Ra-226

58.9

0.9

O

Q.

/g

CR1E

CELA-054 (18-24)

5/6/2011

35.6661008

-108.489024

18

24

713R11

Ra-226

83.3 M3

1.1

pC

'g

CR1E

CELA-058 (18-24)

5/5/2011

35.6666674

-108.488891

18

24

713R11

Ra-226

260 M3,G

3

pC

/g

CR1E

CELA-058 DUP

5/5/2011

35.6666674

-108.488891

18

24

713R11

Ra-226

261 M3,G

3

o

Q.

/g

CR1E

CELI-502 SS2 1.5-3 Dup

5/5/2011

35.6670954

-108.488555

18

24

713R11

Ra-226

232 M3,G

2

O

Q.

/g

CR1E

CESS-037 (18-24)

5/5/2011

35.6650409

-108.489423

18

24

713R12

Ra-226

1.2 G

0.48

pC

/g

CR1E

CESS-060 (18-24)

5/6/2011

35.6664792

-108.488135

18

24

713R12

Ra-226

1.65 G

0.51

pC

/g

CR1E

CESS-069 (18-24)

5/6/2011

35.6672442

-108.487414

18

24

713R11

Ra-226

3.79 G

0.61

o

Q.

/g

CR1E

CELI-502 SS2 1.5-3

5/5/2011

35.6670954

-108.488555

18

36

713R11

Ra-226

220 M3,G

1

O

Q.

/g

CR1E

CELI-503 SS2 1.5-3

5/5/2011

35.6670417

-108.488182

18

36

713R11

Ra-226

1.24

0.5

pC

/g

CR1E

CELP-409 SS2 1.5-3

5/4/2011

35.6657679

-108.489458

18

36

713R11

Ra-226

2.05 G

0.48

pC

/g

CR1E

CESS-037 (24-30)

5/5/2011

35.6650409

-108.489423

24

30

713R12

Ra-226

1.15 G

0.54

o

Q.

/g

CR1E

CELA-039 (27-33)

5/4/2011

35.6662839

-108.489699

27

33

713R11

Ra-226

429 M3

2

O

Q.

/g

CR1E

CELA-001 (30-36)

5/6/2011

35.6649477

-108.490897

30

36

713R11

Ra-226

1.49

0.39

pC

/g

CR1E

CELA-012 (30-36)

5/4/2011

35.6662795

-108.490503

30

36

713R11

Ra-226

1.13 G

0.5

pC

/g

CR1E

CELA-016 (30-36)

5/4/2011

35.6660879

-108.490371

30

36

713R11

Ra-226

74.2 M3,G

1.1

o

Q.

/g

CR1E

CELA-027 (30-36)

5/4/2011

35.6664685

-108.490101

30

36

713R11

Ra-226

81.3 M3

1.1

pC

/g

CR1E

CELA-031 (30-36)

5/4/2011

35.6662824

-108.489968

30

36

713R11

Ra-226

151 M3,G

2

pC

/g

CR1E

CELA-031 (30-36) Dup

5/4/2011

35.6662824

-108.489968

30

36

713R11

Ra-226

128 M3,G

2

pC

/g

CR1E

CELA-035 (30-36)

5/4/2011

35.6660909

-108.489832

30

36

713R11

Ra-226

103 M3

1

o

Q.

/g

CR1E

CELA-043 (30-36)

5/4/2011

35.6664715

-108.489566

30

36

713R11

Ra-226

35.8 M3

1

pC

/g

CR1E

CELA-047 (30-36)

5/4/2011

35.6666673

-108.489429

30

36

713R11

Ra-226

123 M3,G

1

pC

/g

CR1E

CELA-054 (30-36)

5/6/2011

35.6661008

-108.489024

30

36

713R11

Ra-226

65.5 M3

1.2

pC

/g

CR1E

CESS-060 (30-36)

5/6/2011

35.6664792

-108.488135

30

36

713R12

Ra-226

2.39 G

0.51

o

Q.

/g

CR1E

CESS-060 (30-36) Dup

5/6/2011

35.6664792

-108.488135

30

36

713R12

Ra-226

1.78 G

0.55

pC

/g

CR1E

CESS-069 (30-36)

5/6/2011

35.6672442

-108.487414

30

36

713R12

Ra-226

2.9 G

0.47

pc

/g

CR1E

CELI-502 SS3 3-4.5

5/5/2011

35.6670954

-108.488555

36

54

SW6010

ARSENIC

2

1.1

mg/kg

CR1E

CELI-502 SS9

5/5/2011

35.6670954

-108.488555

36

54

SW6010

ARSENIC

2.8

1.1

mg/kg

CR1E

CELI-502 SS3 3-4.5

5/5/2011

35.6670954

-108.488555

36

54

SW6010

MOLYBDENUM

1.1 U

1.1

mg/kg

CR1E

CELI-502 SS9

5/5/2011

35.6670954

-108.488555

36

54

SW6010

MOLYBDENUM

1.8

1.1

mg/kg

CR1E

CELI-502 DUP 502

5/5/2011

35.6670954

-108.488555

36

54

713R11

Ra-226

90 M3,G

1

pCi/g

CR1E

CELI-502 SS3 3-4.5

5/5/2011

35.6670954

-108.488555

36

54

713R11

Ra-226

97 M3,G

2

pCi/g

CR1E

CELI-503 SS3 3-4.5

5/5/2011

35.6670417

-108.488182

36

54

713R11

Ra-226

1.03 G

0.6

pCi/g

Page 37 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

CR1E

CELP-409 SS3 3-4.5

5/4/2011

35.6657679

-108.489458

36

54

713R11

Ra-226

1.6 G

0.47

pCi/g

CR1E

CELI-502 SS3 3-4.5

5/5/2011

35.6670954

-108.488555

36

54

SW6010

SELENIUM

0.53 U

0.53

mg/kg

CR1E

CELI-502 SS9

5/5/2011

35.6670954

-108.488555

36

54

SW6010

SELENIUM

23

0.53

mg/kg

CR1E

CELI-502 SS3 3-4.5

5/5/2011

35.6670954

-108.488555

36

54

SW6020

URANIUM

210

1100

mg/kg

CR1E

CELI-502 SS3 3-4.5

5/5/2011

35.6670954

-108.488555

36

54

SW6010

VANADIUM

11

1.1

mg/kg

CR1E

CELI-502 SS9

5/5/2011

35.6670954

-108.488555

36

54

SW6010

VANADIUM

28

1.1

mg/kg

CR1E

C1E-1B002-5 (FD)

7/19/2015

35.6663025

-108.489642

54

72

Unknown

Ra-226

1.33

Unknown

pCi/g

CR1E

C1E-B001-5

7/18/2015

35.6658978

-108.49003

54

72

Unknown

Ra-226

0.674

Unknown

pCi/g

CR1E

C1E-B002-5

7/19/2015

35.6663025

-108.489642

54

72

Unknown

Ra-226

1.23

Unknown

pCi/g

CR1E

C1E-B003-5

7/19/2015

35.6665262

-108.489713

54

72

Unknown

Ra-226

19.2

Unknown

pCi/g

CR1E

C1E-B004-5

7/19/2015

35.6666309

-108.488707

54

72

Unknown

Ra-226

1.02

Unknown

pCi/g

CR1E

C1E-B005-5

7/18/2015

35.6660932

-108.48908

54

72

Unknown

Ra-226

50

Unknown

pCi/g

CR1E

C1E-B006-5

7/18/2015

35.6655495

-108.489476

54

72

Unknown

Ra-226

0.932

Unknown

pCi/g

CR1E

CELI-502 SS4 4.5-6

5/5/2011

35.6670954

-108.488555

54

72

713R11

Ra-226

8.1 G

0.7

pCi/g

CR1E

CELI-503 SS4 4.5-6

5/5/2011

35.6670417

-108.488182

54

72

713R11

Ra-226

1.22

0.37

pCi/g

CR1E

CELP-409 DUP 409

5/4/2011

35.6657679

-108.489458

54

72

713R11

Ra-226

1.98 G

0.48

pCi/g

CR1E

CELP-409 SS4 4.5-6

5/4/2011

35.6657679

-108.489458

54

72

713R11

Ra-226

2.14 G

0.68

pCi/g

KMP NN

KMP-13-00

7/19/2017

35.660042

-108.490344

0

2

Unknown

ARSENIC

5.3

Unknown

mg/kg

KMP NN

KMP-14-00

7/19/2017

35.659959

-108.488751

0

2

Unknown

ARSENIC

5.2

Unknown

mg/kg

KMP NN

KMP-14D-00

7/19/2017

35.659959

-108.488751

0

2

Unknown

ARSENIC

5.6

Unknown

mg/kg

KMP NN

KMP-13-00

7/19/2017

35.660042

-108.490344

0

2

Unknown

BARIUM

66

Unknown

mg/kg

KMP NN

KMP-14-00

7/19/2017

35.659959

-108.488751

0

2

Unknown

BARIUM

73

Unknown

mg/kg

KMP NN

KMP-14D-00

7/19/2017

35.659959

-108.488751

0

2

Unknown

BARIUM

78

Unknown

mg/kg

KMP NN

KMP-13-00

7/19/2017

35.660042

-108.490344

0

2

Unknown

CADMIUM

0.078 J

Unknown

mg/kg

KMP NN

KMP-14-00

7/19/2017

35.659959

-108.488751

0

2

Unknown

CADMIUM

0.14

Unknown

mg/kg

KMP NN

KMP-14D-00

7/19/2017

35.659959

-108.488751

0

2

Unknown

CADMIUM

0.12

Unknown

mg/kg

KMP NN

KMP-13-00

7/19/2017

35.660042

-108.490344

0

2

Unknown

CHROMIUM

7.1

Unknown

mg/kg

KMP NN

KMP-14-00

7/19/2017

35.659959

-108.488751

0

2

Unknown

CHROMIUM

7.5

Unknown

mg/kg

KMP NN

KMP-14D-00

7/19/2017

35.659959

-108.488751

0

2

Unknown

CHROMIUM

8.2

Unknown

mg/kg

KMP NN

KMP-13-00

7/19/2017

35.660042

-108.490344

0

2

Unknown

LEAD

8.6

Unknown

mg/kg

KMP NN

KMP-14-00

7/19/2017

35.659959

-108.488751

0

2

Unknown

LEAD

11

Unknown

mg/kg

KMP NN

KMP-14D-00

7/19/2017

35.659959

-108.488751

0

2

Unknown

LEAD

11

Unknown

mg/kg

KMP NN

KMP-13-00

7/19/2017

35.660042

-108.490344

0

2

Unknown

MOLYBDENUM

0.5

Unknown

mg/kg

KMP NN

KMP-14-00

7/19/2017

35.659959

-108.488751

0

2

Unknown

MOLYBDENUM

0.55 J

Unknown

mg/kg

KMP NN

KMP-14D-00

7/19/2017

35.659959

-108.488751

0

2

Unknown

MOLYBDENUM

0.53 J

Unknown

mg/kg

KMP NN

KMP-13-00

7/19/2017

35.660042

-108.490344

0

2

Unknown

Ra-226

2.15

Unknown

mg/kg

KMP NN

KMP-14-00

7/19/2017

35.659959

-108.488751

0

2

Unknown

Ra-226

5.88

Unknown

mg/kg

KMP NN

KMP-14D-00

7/19/2017

35.659959

-108.488751

0

2

Unknown

Ra-226

8.21

Unknown

mg/kg

KMP NN

KMP-13-00

7/19/2017

35.660042

-108.490344

0

2

Unknown

SELENIUM

1.8

Unknown

mg/kg

KMP NN

KMP-14-00

7/19/2017

35.659959

-108.488751

0

2

Unknown

SELENIUM

2.5

Unknown

mg/kg

KMP NN

KMP-14D-00

7/19/2017

35.659959

-108.488751

0

2

Unknown

SELENIUM

2.9

Unknown

mg/kg

KMP NN

KMP-13-00

7/19/2017

35.660042

-108.490344

0

2

Unknown

SILVER

0.5 U

Unknown

mg/kg

Page 38 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMP NN

KMP-14-00

7/19/2017

35.659959

-108.488751

0

2

Unknown

SILVER

0.49 U

Unknown

mg/kg

KMP NN

KMP-14D-00

7/19/2017

35.659959

-108.488751

0

2

Unknown

SILVER

0.45 U

Unknown

mg/kg

KMP NN

KMP-13-00

7/19/2017

35.660042

-108.490344

0

2

Unknown

URANIUM

0.87

Unknown

mg/kg

KMP NN

KMP-14-00

7/19/2017

35.659959

-108.488751

0

2

Unknown

URANIUM

1.1

Unknown

mg/kg

KMP NN

KMP-14D-00

7/19/2017

35.659959

-108.488751

0

2

Unknown

URANIUM

1.3

Unknown

mg/kg

KMP NN

KMP-13-00

7/19/2017

35.660042

-108.490344

0

2

Unknown

VANADIUM

15

Unknown

mg/kg

KMP NN

KMP-14-00

7/19/2017

35.659959

-108.488751

0

2

Unknown

VANADIUM

17

Unknown

mg/kg

KMP NN

KMP-14D-00

7/19/2017

35.659959

-108.488751

0

2

Unknown

VANADIUM

17

Unknown

mg/kg

KMP NN

KM P-SS49-0000-0003-01

5/19/2022

35.659839

-108.491057

0

3

SW6020

ALUMINUM

6200

15

mg/kg

KMP NN

KMP-SS49-0000-0003-02

5/19/2022

35.659839

-108.491057

0

3

SW6020

ALUMINUM

6900

15

mg/kg

KMP NN

KMP-SS74-0000-0003-01

5/19/2022

35.659863

-108.488353

0

3

SW6020

ALUMINUM

5600

15

mg/kg

KMP NN

KM P-SS49-0000-0003-01

5/19/2022

35.659839

-108.491057

0

3

SW6020

ANTIMONY

0.09 J

0.1

mg/kg

KMP NN

KMP-SS49-0000-0003-02

5/19/2022

35.659839

-108.491057

0

3

SW6020

ANTIMONY

0.065 J

0.1

mg/kg

KMP NN

KMP-SS74-0000-0003-01

5/19/2022

35.659863

-108.488353

0

3

SW6020

ANTIMONY

0.046 J

0.1

mg/kg

KMP NN

KM P-SS49-0000-0003-01

5/19/2022

35.659839

-108.491057

0

3

SW6020

ARSENIC

5.4

0.2

mg/kg

KMP NN

KMP-SS49-0000-0003-02

5/19/2022

35.659839

-108.491057

0

3

SW6020

ARSENIC

5.9

0.21

mg/kg

KMP NN

KMP-SS74-0000-0003-01

5/19/2022

35.659863

-108.488353

0

3

SW6020

ARSENIC

4.9

0.21

mg/kg

KMP NN

KM P-SS49-0000-0003-01

5/19/2022

35.659839

-108.491057

0

3

SW6020

BARIUM

66

0.51

mg/kg

KMP NN

KMP-SS49-0000-0003-02

5/19/2022

35.659839

-108.491057

0

3

SW6020

BARIUM

75

0.52

mg/kg

KMP NN

KMP-SS74-0000-0003-01

5/19/2022

35.659863

-108.488353

0

3

SW6020

BARIUM

56

0.52

mg/kg

KMP NN

KM P-SS49-0000-0003-01

5/19/2022

35.659839

-108.491057

0

3

SW6020

BERYLLIUM

0.52

0.051

mg/kg

KMP NN

KMP-SS49-0000-0003-02

5/19/2022

35.659839

-108.491057

0

3

SW6020

BERYLLIUM

0.56

0.052

mg/kg

KMP NN

KMP-SS74-0000-0003-01

5/19/2022

35.659863

-108.488353

0

3

SW6020

BERYLLIUM

0.5

0.052

mg/kg

KMP NN

KM P-SS49-0000-0003-01

5/19/2022

35.659839

-108.491057

0

3

SW6020

CADMIUM

0.089 J

0.2

mg/kg

KMP NN

KMP-SS49-0000-0003-02

5/19/2022

35.659839

-108.491057

0

3

SW6020

CADMIUM

0.085 J

0.21

mg/kg

KMP NN

KMP-SS74-0000-0003-01

5/19/2022

35.659863

-108.488353

0

3

SW6020

CADMIUM

0.082 J

0.21

mg/kg

KMP NN

KM P-SS49-0000-0003-01

5/19/2022

35.659839

-108.491057

0

3

SW6020

CHROMIUM

7.3

1

mg/kg

KMP NN

KMP-SS49-0000-0003-02

5/19/2022

35.659839

-108.491057

0

3

SW6020

CHROMIUM

7.8

1

mg/kg

KMP NN

KMP-SS74-0000-0003-01

5/19/2022

35.659863

-108.488353

0

3

SW6020

CHROMIUM

6

1

mg/kg

KMP NN

KM P-SS49-0000-0003-01

5/19/2022

35.659839

-108.491057

0

3

SW6020

COBALT

4.6

0.51

mg/kg

KMP NN

KMP-SS49-0000-0003-02

5/19/2022

35.659839

-108.491057

0

3

SW6020

COBALT

5.2

0.52

mg/kg

KMP NN

KMP-SS74-0000-0003-01

5/19/2022

35.659863

-108.488353

0

3

SW6020

COBALT

4.1

0.52

mg/kg

KMP NN

KM P-SS49-0000-0003-01

5/19/2022

35.659839

-108.491057

0

3

SW6020

COPPER

8.3

2

mg/kg

KMP NN

KMP-SS49-0000-0003-02

5/19/2022

35.659839

-108.491057

0

3

SW6020

COPPER

9.3

2.1

mg/kg

KMP NN

KMP-SS74-0000-0003-01

5/19/2022

35.659863

-108.488353

0

3

SW6020

COPPER

7.4

2.1

mg/kg

KMP NN

KM P-SS49-0000-0003-01

5/19/2022

35.659839

-108.491057

0

3

SW6020

IRON

14000

20

mg/kg

KMP NN

KMP-SS49-0000-0003-02

5/19/2022

35.659839

-108.491057

0

3

SW6020

IRON

15000

21

mg/kg

KMP NN

KMP-SS74-0000-0003-01

5/19/2022

35.659863

-108.488353

0

3

SW6020

IRON

12000

21

mg/kg

KMP NN

KMP-SS49-0000-0003-01

5/19/2022

35.659839

-108.491057

0

3

SW6020

LEAD

9.8

0.2

mg/kg

KMP NN

KMP-SS49-0000-0003-02

5/19/2022

35.659839

-108.491057

0

3

SW6020

LEAD

11

0.21

mg/kg

KMP NN

KMP-SS74-0000-0003-01

5/19/2022

35.659863

-108.488353

0

3

SW6020

LEAD

9.3

0.21

mg/kg

KMP NN

KM P-SS49-0000-0003-01

5/19/2022

35.659839

-108.491057

0

3

SW6020

MANGANESE

200

0.77

mg/kg

Page 39 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMP NN

KMP-SS49-0000-0003-02

5/19/2022

35.659839

-108.491057

0

3

SW6020

MANGANESE

220

0.77

mg/kg

KMP NN

KMP-SS74-0000-0003-01

5/19/2022

35.659863

-108.488353

0

3

SW6020

MANGANESE

190

0.77

mg/kg

KMP NN

KM P-SS49-0000-0003-01

5/19/2022

35.659839

-108.491057

0

3

SW6020

MOLYBDENUM

0.36

0.2

mg/kg

KMP NN

KMP-SS49-0000-0003-02

5/19/2022

35.659839

-108.491057

0

3

SW6020

MOLYBDENUM

0.33

0.21

mg/kg

KMP NN

KMP-SS74-0000-0003-01

5/19/2022

35.659863

-108.488353

0

3

SW6020

MOLYBDENUM

0.35

0.21

mg/kg

KMP NN

KM P-SS49-0000-0003-01

5/19/2022

35.659839

-108.491057

0

3

SW6020

NICKEL

7.7

2

mg/kg

KMP NN

KMP-SS49-0000-0003-02

5/19/2022

35.659839

-108.491057

0

3

SW6020

NICKEL

8.4

2.1

mg/kg

KMP NN

KMP-SS74-0000-0003-01

5/19/2022

35.659863

-108.488353

0

3

SW6020

NICKEL

6.8

2.1

mg/kg

KMP NN

KM P-SS49-0000-0003-01

5/19/2022

35.659839

-108.491057

0

3

713R15

Ra-226

4

0.49

mg/kg

KMP NN

KMP-SS49-0000-0003-02

5/19/2022

35.659839

-108.491057

0

3

713R15

Ra-226

3.78

0.47

pCi/g

KMP NN

KMP-SS74-0000-0003-01

5/19/2022

35.659863

-108.488353

0

3

713R15

Ra-226

2.8

0.44

mg/kg

KMP NN

KM P-SS49-0000-0003-01

5/19/2022

35.659839

-108.491057

0

3

SW6020

SELENIUM

1.7

1

mg/kg

KMP NN

KMP-SS49-0000-0003-02

5/19/2022

35.659839

-108.491057

0

3

SW6020

SELENIUM

1.9

1

mg/kg

KMP NN

KMP-SS74-0000-0003-01

5/19/2022

35.659863

-108.488353

0

3

SW6020

SELENIUM

1.4

1

mg/kg

KMP NN

KM P-SS49-0000-0003-01

5/19/2022

35.659839

-108.491057

0

3

SW6020

SILVER

0.058 U

0.12

mg/kg

KMP NN

KMP-SS49-0000-0003-02

5/19/2022

35.659839

-108.491057

0

3

SW6020

SILVER

0.059 U

0.12

mg/kg

KMP NN

KMP-SS74-0000-0003-01

5/19/2022

35.659863

-108.488353

0

3

SW6020

SILVER

0.059 U

0.12

mg/kg

KMP NN

KM P-SS49-0000-0003-01

5/19/2022

35.659839

-108.491057

0

3

SW6020

THALLIUM

0.13

0.01

mg/kg

KMP NN

KMP-SS49-0000-0003-02

5/19/2022

35.659839

-108.491057

0

3

SW6020

THALLIUM

0.15

0.01

mg/kg

KMP NN

KMP-SS74-0000-0003-01

5/19/2022

35.659863

-108.488353

0

3

SW6020

THALLIUM

0.12

0.01

mg/kg

KMP NN

KM P-SS49-0000-0003-01

5/19/2022

35.659839

-108.491057

0

3

SW6020

URANIUM

1.4

0.02

mg/kg

KMP NN

KMP-SS49-0000-0003-02

5/19/2022

35.659839

-108.491057

0

3

SW6020

URANIUM

1.4

0.021

mg/kg

KMP NN

KMP-SS74-0000-0003-01

5/19/2022

35.659863

-108.488353

0

3

SW6020

URANIUM

0.94

0.021

mg/kg

KMP NN

KM P-SS49-0000-0003-01

5/19/2022

35.659839

-108.491057

0

3

SW6020

VANADIUM

14

0.51

mg/kg

KMP NN

KMP-SS49-0000-0003-02

5/19/2022

35.659839

-108.491057

0

3

SW6020

VANADIUM

16

0.52

mg/kg

KMP NN

KMP-SS74-0000-0003-01

5/19/2022

35.659863

-108.488353

0

3

SW6020

VANADIUM

12

0.52

mg/kg

KMP NN

KM P-SS49-0000-0003-01

5/19/2022

35.659839

-108.491057

0

3

SW6020

ZINC

42

10

mg/kg

KMP NN

KMP-SS49-0000-0003-02

5/19/2022

35.659839

-108.491057

0

3

SW6020

ZINC

45

10

mg/kg

KMP NN

KMP-SS74-0000-0003-01

5/19/2022

35.659863

-108.488353

0

3

SW6020

ZINC

36

10

mg/kg

KMP NN

KM P-S B44-0000-0006-01

6/8/2022

35.659847

-108.490914

0

6

SW6020

ALUMINUM

6500

16

mg/kg

KMP NN

KM P-S B44-0000-0006-01

6/8/2022

35.659847

-108.490914

0

6

SW6020

ANTIMONY

0.13

0.11

mg/kg

KMP NN

KM P-S B44-0000-0006-01

6/8/2022

35.659847

-108.490914

0

6

SW6020

ARSENIC

5.6

0.22

mg/kg

KMP NN

KM P-S B44-0000-0006-01

6/8/2022

35.659847

-108.490914

0

6

SW6020

BARIUM

82

0.55

mg/kg

KMP NN

KM P-S B44-0000-0006-01

6/8/2022

35.659847

-108.490914

0

6

SW6020

BERYLLIUM

0.57

0.055

mg/kg

KMP NN

KM P-S B44-0000-0006-01

6/8/2022

35.659847

-108.490914

0

6

SW6020

CADMIUM

0.16 J

0.22

mg/kg

KMP NN

KM P-S B44-0000-0006-01

6/8/2022

35.659847

-108.490914

0

6

SW6020

CHROMIUM

7

1.1

mg/kg

KMP NN

KM P-S B44-0000-0006-01

6/8/2022

35.659847

-108.490914

0

6

SW6020

COBALT

5.1

0.55

mg/kg

KMP NN

KM P-S B44-0000-0006-01

6/8/2022

35.659847

-108.490914

0

6

SW6020

COPPER

11

2.2

mg/kg

KMP NN

KM P-SB44-0000-0006-01

6/8/2022

35.659847

-108.490914

0

6

SW6020

IRON

14000

22

mg/kg

KMP NN

KM P-S B44-0000-0006-01

6/8/2022

35.659847

-108.490914

0

6

SW6020

LEAD

13

0.22

mg/kg

KMP NN

KM P-SB44-0000-0006-01

6/8/2022

35.659847

-108.490914

0

6

SW6020

MANGANESE

230

0.82

mg/kg

KMP NN

KM P-SB44-0000-0006-01

6/8/2022

35.659847

-108.490914

0

6

SW6020

MOLYBDENUM

0.42

0.22

mg/kg

Page 40 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMP NN

KM P-S B44-0000-0006-01

6/8/2022

35.659847

-108.490914

0

6

SW6020

NICKEL

7.9

2.2

mg/kg

KMP NN

KM P-S B44-0000-0006-01

6/8/2022

35.659847

-108.490914

0

6

713R15

Ra-226

9.3 J

0.8

mg/kg

KMP NN

KM P-S B44-0000-0006-01

6/8/2022

35.659847

-108.490914

0

6

SW6020

SELENIUM

2.4

1.1

mg/kg

KMP NN

KM P-S B44-0000-0006-01

6/8/2022

35.659847

-108.490914

0

6

SW6020

SILVER

0.062 U

0.12

mg/kg

KMP NN

KM P-S B44-0000-0006-01

6/8/2022

35.659847

-108.490914

0

6

SW6020

THALLIUM

0.15

0.011

mg/kg

KMP NN

KM P-S B44-0000-0006-01

6/8/2022

35.659847

-108.490914

0

6

SW6020

URANIUM

6.2

0.022

mg/kg

KMP NN

KM P-S B44-0000-0006-01

6/8/2022

35.659847

-108.490914

0

6

SW6020

VANADIUM

15

0.55

mg/kg

KMP NN

KM P-S B44-0000-0006-01

6/8/2022

35.659847

-108.490914

0

6

SW6020

ZINC

44

11

mg/kg

KMP NN

KMP-SB43-0018-0024-01

6/8/2022

35.659847

-108.491192

18

24

SW6020

ALUMINUM

6800

16

mg/kg

KMP NN

KMP-SB43-0018-0024-01

6/8/2022

35.659847

-108.491192

18

24

SW6020

ANTIMONY

0.093 J

0.1

mg/kg

KMP NN

KMP-SB43-0018-0024-01

6/8/2022

35.659847

-108.491192

18

24

SW6020

ARSENIC

5.9

0.21

mg/kg

KMP NN

KMP-SB43-0018-0024-01

6/8/2022

35.659847

-108.491192

18

24

SW6020

BARIUM

56

0.52

mg/kg

KMP NN

KMP-SB43-0018-0024-01

6/8/2022

35.659847

-108.491192

18

24

SW6020

BERYLLIUM

0.57

0.052

mg/kg

KMP NN

KMP-SB43-0018-0024-01

6/8/2022

35.659847

-108.491192

18

24

SW6020

CADMIUM

0.073 J

0.21

mg/kg

KMP NN

KMP-SB43-0018-0024-01

6/8/2022

35.659847

-108.491192

18

24

SW6020

CHROMIUM

7.4

1

mg/kg

KMP NN

KMP-SB43-0018-0024-01

6/8/2022

35.659847

-108.491192

18

24

SW6020

COBALT

5.1

0.52

mg/kg

KMP NN

KMP-SB43-0018-0024-01

6/8/2022

35.659847

-108.491192

18

24

SW6020

COPPER

9

2.1

mg/kg

KMP NN

KMP-SB43-0018-0024-01

6/8/2022

35.659847

-108.491192

18

24

SW6020

IRON

15000

21

mg/kg

KMP NN

KMP-SB43-0018-0024-01

6/8/2022

35.659847

-108.491192

18

24

SW6020

LEAD

10

0.21

mg/kg

KMP NN

KMP-SB43-0018-0024-01

6/8/2022

35.659847

-108.491192

18

24

SW6020

MANGANESE

210

0.78

mg/kg

KMP NN

KMP-SB43-0018-0024-01

6/8/2022

35.659847

-108.491192

18

24

SW6020

MOLYBDENUM

0.37

0.21

mg/kg

KMP NN

KMP-SB43-0018-0024-01

6/8/2022

35.659847

-108.491192

18

24

SW6020

NICKEL

7.8

2.1

mg/kg

KMP NN

KMP-SB43-0018-0024-01

6/8/2022

35.659847

-108.491192

18

24

713R15

Ra-226

2.13 J

0.61

mg/kg

KMP NN

KMP-SB43-0018-0024-01

6/8/2022

35.659847

-108.491192

18

24

SW6020

SELENIUM

1.3

1

mg/kg

KMP NN

KMP-SB43-0018-0024-01

6/8/2022

35.659847

-108.491192

18

24

SW6020

SILVER

0.06 U

0.12

mg/kg

KMP NN

KMP-SB43-0018-0024-01

6/8/2022

35.659847

-108.491192

18

24

SW6020

THALLIUM

0.14

0.01

mg/kg

KMP NN

KMP-SB43-0018-0024-01

6/8/2022

35.659847

-108.491192

18

24

SW6020

URANIUM

3.8

0.021

mg/kg

KMP NN

KMP-SB43-0018-0024-01

6/8/2022

35.659847

-108.491192

18

24

SW6020

VANADIUM

14

0.52

mg/kg

KMP NN

KMP-SB43-0018-0024-01

6/8/2022

35.659847

-108.491192

18

24

SW6020

ZINC

41

10

mg/kg

KMP NN

KM P-S B45-0060-0066-01

6/8/2022

35.659847

-108.490637

60

66

SW6020

ALUMINUM

6700

16

mg/kg

KMP NN

KM P-S B45-0060-0066-01

6/8/2022

35.659847

-108.490637

60

66

SW6020

ANTIMONY

0.088 J

0.11

mg/kg

KMP NN

KM P-S B45-0060-0066-01

6/8/2022

35.659847

-108.490637

60

66

SW6020

ARSENIC

5.7

0.21

mg/kg

KMP NN

KM P-S B45-0060-0066-01

6/8/2022

35.659847

-108.490637

60

66

SW6020

BARIUM

74

0.53

mg/kg

KMP NN

KM P-S B45-0060-0066-01

6/8/2022

35.659847

-108.490637

60

66

SW6020

BERYLLIUM

0.55

0.053

mg/kg

KMP NN

KM P-S B45-0060-0066-01

6/8/2022

35.659847

-108.490637

60

66

SW6020

CADMIUM

0.06 J

0.21

mg/kg

KMP NN

KM P-S B45-0060-0066-01

6/8/2022

35.659847

-108.490637

60

66

SW6020

CHROMIUM

7

1.1

mg/kg

KMP NN

KM P-S B45-0060-0066-01

6/8/2022

35.659847

-108.490637

60

66

SW6020

COBALT

5.1

0.53

mg/kg

KMP NN

KM P-S B45-0060-0066-01

6/8/2022

35.659847

-108.490637

60

66

SW6020

COPPER

8.1

2.1

mg/kg

KMP NN

KM P-S B45-0060-0066-01

6/8/2022

35.659847

-108.490637

60

66

SW6020

IRON

14000

21

mg/kg

KMP NN

KM P-S B45-0060-0066-01

6/8/2022

35.659847

-108.490637

60

66

SW6020

LEAD

9.5

0.21

mg/kg

KMP NN

KM P-S B45-0060-0066-01

6/8/2022

35.659847

-108.490637

60

66

SW6020

MANGANESE

220

0.79

mg/kg

KMP NN

KM P-S B45-0060-0066-01

6/8/2022

35.659847

-108.490637

60

66

SW6020

MOLYBDENUM

0.36

0.21

mg/kg

Page 41 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMP NN

KM P-S B45-0060-0066-01

6/8/2022

35.659847

-108.490637

60

66

SW6020

NICKEL

7.7

2.1

mg/kg

KMP NN

KM P-S B45-0060-0066-01

6/8/2022

35.659847

-108.490637

60

66

713R15

Ra-226

1.46 J

0.61

mg/kg

KMP NN

KM P-S B45-0060-0066-01

6/8/2022

35.659847

-108.490637

60

66

SW6020

SELENIUM

1.2

1.1

mg/kg

KMP NN

KM P-S B45-0060-0066-01

6/8/2022

35.659847

-108.490637

60

66

SW6020

SILVER

0.06 U

0.12

mg/kg

KMP NN

KM P-S B45-0060-0066-01

6/8/2022

35.659847

-108.490637

60

66

SW6020

THALLIUM

0.14

0.011

mg/kg

KMP NN

KM P-S B45-0060-0066-01

6/8/2022

35.659847

-108.490637

60

66

SW6020

URANIUM

0.64

0.021

mg/kg

KMP NN

KM P-S B45-0060-0066-01

6/8/2022

35.659847

-108.490637

60

66

SW6020

VANADIUM

14

0.53

mg/kg

KMP NN

KM P-S B45-0060-0066-01

6/8/2022

35.659847

-108.490637

60

66

SW6020

ZINC

39

11

mg/kg

KMP UNC

KMP-01-00

7/18/2017

35.659423

-108.492172

0

2

Unknown

ARSENIC

6.9

Unknown

mg/kg

KMP UNC

KMP-02-00

7/18/2017

35.659438

-108.491379

0

2

Unknown

ARSENIC

5.2

Unknown

mg/kg

KMP UNC

KMP-03-00

7/18/2017

35.65946

-108.490578

0

2

Unknown

ARSENIC

4.5

Unknown

mg/kg

KMP UNC

KMP-04-00

7/18/2017

35.65878

-108.49234

0

2

Unknown

ARSENIC

7

Unknown

mg/kg

KMP UNC

KMP-05-00

7/18/2017

35.658795

-108.491547

0

2

Unknown

ARSENIC

4.7

Unknown

mg/kg

KMP UNC

KMP-06-00

7/18/2017

35.658817

-108.490746

0

2

Unknown

ARSENIC

4.5

Unknown

mg/kg

KMP UNC

KMP-07-00

7/18/2017

35.658175

-108.492052

0

2

Unknown

ARSENIC

9.2

Unknown

mg/kg

KMP UNC

KMP-08-00

7/18/2017

35.65819

-108.491259

0

2

Unknown

ARSENIC

4.8

Unknown

mg/kg

KMP UNC

KMP-09-00

7/18/2017

35.658213

-108.490459

0

2

Unknown

ARSENIC

5.3

Unknown

mg/kg

KMP UNC

KMP-10-00

7/18/2017

35.65764

-108.490873

0

2

Unknown

ARSENIC

5.2

Unknown

mg/kg

KMP UNC

KMP-15-00

7/18/2017

35.659695

-108.491137

0

2

Unknown

ARSENIC

5

Unknown

mg/kg

KMP UNC

KMP-16-00

7/18/2017

35.658292

-108.491842

0

2

Unknown

ARSENIC

7.2

Unknown

mg/kg

KMP UNC

KMP-16D-00

7/18/2017

35.658292

-108.491842

0

2

Unknown

ARSENIC

7.5

Unknown

mg/kg

KMP UNC

KMP-17-00

7/19/2017

35.658397

-108.491778

0

2

Unknown

ARSENIC

7.6

Unknown

mg/kg

KMP UNC

KMP-18-00

7/19/2017

35.658584

-108.491524

0

2

Unknown

ARSENIC

6.6

Unknown

mg/kg

KMP UNC

KMP-18D-00

7/19/2017

35.658584

-108.491524

0

2

Unknown

ARSENIC

6.5

Unknown

mg/kg

KMP UNC

KMP-19-00

7/19/2017

35.65865

-108.491373

0

2

Unknown

ARSENIC

5.3

Unknown

mg/kg

KMP UNC

KMP-20-00

7/19/2017

35.658809

-108.491224

0

2

Unknown

ARSENIC

5.7

Unknown

mg/kg

KMP UNC

KMP-21-00

7/19/2017

35.658901

-108.491165

0

2

Unknown

ARSENIC

4.9

Unknown

mg/kg

KMP UNC

KMP-22-00

7/19/2017

35.658405

-108.490563

0

2

Unknown

ARSENIC

4.9

Unknown

mg/kg

KMP UNC

KMP-23-00

7/18/2017

35.658984

-108.490548

0

2

Unknown

ARSENIC

6

Unknown

mg/kg

KMP UNC

KMP-01-00

7/18/2017

35.659423

-108.492172

0

2

Unknown

BARIUM

87

Unknown

mg/kg

KMP UNC

KMP-02-00

7/18/2017

35.659438

-108.491379

0

2

Unknown

BARIUM

140

Unknown

mg/kg

KMP UNC

KMP-03-00

7/18/2017

35.65946

-108.490578

0

2

Unknown

BARIUM

55

Unknown

mg/kg

KMP UNC

KMP-04-00

7/18/2017

35.65878

-108.49234

0

2

Unknown

BARIUM

90

Unknown

mg/kg

KMP UNC

KMP-05-00

7/18/2017

35.658795

-108.491547

0

2

Unknown

BARIUM

50

Unknown

mg/kg

KMP UNC

KMP-06-00

7/18/2017

35.658817

-108.490746

0

2

Unknown

BARIUM

51

Unknown

mg/kg

KMP UNC

KMP-07-00

7/18/2017

35.658175

-108.492052

0

2

Unknown

BARIUM

100

Unknown

mg/kg

KMP UNC

KMP-08-00

7/18/2017

35.65819

-108.491259

0

2

Unknown

BARIUM

55

Unknown

mg/kg

KMP UNC

KMP-09-00

7/18/2017

35.658213

-108.490459

0

2

Unknown

BARIUM

65

Unknown

mg/kg

KMP UNC

KMP-10-00

7/18/2017

35.65764

-108.490873

0

2

Unknown

BARIUM

92

Unknown

mg/kg

KMP UNC

KMP-15-00

7/18/2017

35.659695

-108.491137

0

2

Unknown

BARIUM

73

Unknown

mg/kg

KMP UNC

KMP-16-00

7/18/2017

35.658292

-108.491842

0

2

Unknown

BARIUM

89

Unknown

mg/kg

KMP UNC

KMP-16D-00

7/18/2017

35.658292

-108.491842

0

2

Unknown

BARIUM

86

Unknown

mg/kg

Page 42 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KMP-17-00

7/19/2017

35.658397

-108.491778

0

2

Unknown

BARIUM

120

Unknown

mg/kg

KMPUNC

KMP-18-00

7/19/2017

35.658584

-108.491524

0

2

Unknown

BARIUM

90

Unknown

mg/kg

KMP UNC

KMP-18D-00

7/19/2017

35.658584

-108.491524

0

2

Unknown

BARIUM

89

Unknown

mg/kg

KMP UNC

KMP-19-00

7/19/2017

35.65865

-108.491373

0

2

Unknown

BARIUM

74

Unknown

mg/kg

KMP UNC

KMP-20-00

7/19/2017

35.658809

-108.491224

0

2

Unknown

BARIUM

74

Unknown

mg/kg

KMP UNC

KMP-21-00

7/19/2017

35.658901

-108.491165

0

2

Unknown

BARIUM

52

Unknown

mg/kg

KMP UNC

KMP-22-00

7/19/2017

35.658405

-108.490563

0

2

Unknown

BARIUM

51

Unknown

mg/kg

KMP UNC

KMP-23-00

7/18/2017

35.658984

-108.490548

0

2

Unknown

BARIUM

63

Unknown

mg/kg

KMP UNC

KMP-01-00

7/18/2017

35.659423

-108.492172

0

2

Unknown

CADMIUM

0.12 J

Unknown

mg/kg

KMP UNC

KMP-02-00

7/18/2017

35.659438

-108.491379

0

2

Unknown

CADMIUM

0.12 U

Unknown

mg/kg

KMP UNC

KMP-03-00

7/18/2017

35.65946

-108.490578

0

2

Unknown

CADMIUM

0.075 J

Unknown

mg/kg

KMP UNC

KMP-04-00

7/18/2017

35.65878

-108.49234

0

2

Unknown

CADMIUM

0.12 J

Unknown

mg/kg

KMP UNC

KMP-05-00

7/18/2017

35.658795

-108.491547

0

2

Unknown

CADMIUM

0.072 J

Unknown

mg/kg

KMP UNC

KMP-06-00

7/18/2017

35.658817

-108.490746

0

2

Unknown

CADMIUM

0.12 U

Unknown

mg/kg

KMP UNC

KMP-07-00

7/18/2017

35.658175

-108.492052

0

2

Unknown

CADMIUM

0.14

Unknown

mg/kg

KMP UNC

KMP-08-00

7/18/2017

35.65819

-108.491259

0

2

Unknown

CADMIUM

0.069 J

Unknown

mg/kg

KMP UNC

KMP-09-00

7/18/2017

35.658213

-108.490459

0

2

Unknown

CADMIUM

0.087 J

Unknown

mg/kg

KMP UNC

KMP-10-00

7/18/2017

35.65764

-108.490873

0

2

Unknown

CADMIUM

0.096 J

Unknown

mg/kg

KMP UNC

KMP-15-00

7/18/2017

35.659695

-108.491137

0

2

Unknown

CADMIUM

0.13

Unknown

mg/kg

KMP UNC

KMP-16-00

7/18/2017

35.658292

-108.491842

0

2

Unknown

CADMIUM

0.12

Unknown

mg/kg

KMP UNC

KMP-16D-00

7/18/2017

35.658292

-108.491842

0

2

Unknown

CADMIUM

0.14

Unknown

mg/kg

KMP UNC

KMP-17-00

7/19/2017

35.658397

-108.491778

0

2

Unknown

CADMIUM

0.14

Unknown

mg/kg

KMP UNC

KMP-18-00

7/19/2017

35.658584

-108.491524

0

2

Unknown

CADMIUM

0.15

Unknown

mg/kg

KMP UNC

KMP-18D-00

7/19/2017

35.658584

-108.491524

0

2

Unknown

CADMIUM

0.14

Unknown

mg/kg

KMP UNC

KMP-19-00

7/19/2017

35.65865

-108.491373

0

2

Unknown

CADMIUM

0.08 J

Unknown

mg/kg

KMP UNC

KMP-20-00

7/19/2017

35.658809

-108.491224

0

2

Unknown

CADMIUM

0.098 J

Unknown

mg/kg

KMP UNC

KMP-21-00

7/19/2017

35.658901

-108.491165

0

2

Unknown

CADMIUM

0.059 J

Unknown

mg/kg

KMP UNC

KMP-22-00

7/19/2017

35.658405

-108.490563

0

2

Unknown

CADMIUM

0.12 U

Unknown

mg/kg

KMP UNC

KMP-23-00

7/18/2017

35.658984

-108.490548

0

2

Unknown

CADMIUM

0.11 J

Unknown

mg/kg

KMP UNC

KMP-01-00

7/18/2017

35.659423

-108.492172

0

2

Unknown

CHROMIUM

8.7

Unknown

mg/kg

KMP UNC

KMP-02-00

7/18/2017

35.659438

-108.491379

0

2

Unknown

CHROMIUM

7.1

Unknown

mg/kg

KMP UNC

KMP-03-00

7/18/2017

35.65946

-108.490578

0

2

Unknown

CHROMIUM

6.6

Unknown

mg/kg

KMP UNC

KMP-04-00

7/18/2017

35.65878

-108.49234

0

2

Unknown

CHROMIUM

9.5

Unknown

mg/kg

KMP UNC

KMP-05-00

7/18/2017

35.658795

-108.491547

0

2

Unknown

CHROMIUM

7.3

Unknown

mg/kg

KMP UNC

KMP-06-00

7/18/2017

35.658817

-108.490746

0

2

Unknown

CHROMIUM

6.9

Unknown

mg/kg

KMP UNC

KMP-07-00

7/18/2017

35.658175

-108.492052

0

2

Unknown

CHROMIUM

12

Unknown

mg/kg

KMP UNC

KMP-08-00

7/18/2017

35.65819

-108.491259

0

2

Unknown

CHROMIUM

6.8

Unknown

mg/kg

KMP UNC

KMP-09-00

7/18/2017

35.658213

-108.490459

0

2

Unknown

CHROMIUM

8.3

Unknown

mg/kg

KMP UNC

KMP-10-00

7/18/2017

35.65764

-108.490873

0

2

Unknown

CHROMIUM

6.9

Unknown

mg/kg

KMP UNC

KMP-15-00

7/18/2017

35.659695

-108.491137

0

2

Unknown

CHROMIUM

7.8

Unknown

mg/kg

KMP UNC

KMP-16-00

7/18/2017

35.658292

-108.491842

0

2

Unknown

CHROMIUM

9.9

Unknown

mg/kg

KMP UNC

KMP-16D-00

7/18/2017

35.658292

-108.491842

0

2

Unknown

CHROMIUM

9.8

Unknown

mg/kg

Page 43 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KMP-17-00

7/19/2017

35.658397

-108.491778

0

2

Unknown

CHROMIUM

8.5

Unknown

mg/kg

KMPUNC

KMP-18-00

7/19/2017

35.658584

-108.491524

0

2

Unknown

CHROMIUM

10

Unknown

mg/kg

KMP UNC

KMP-18D-00

7/19/2017

35.658584

-108.491524

0

2

Unknown

CHROMIUM

9.5

Unknown

mg/kg

KMP UNC

KMP-19-00

7/19/2017

35.65865

-108.491373

0

2

Unknown

CHROMIUM

7.2

Unknown

mg/kg

KMP UNC

KMP-20-00

7/19/2017

35.658809

-108.491224

0

2

Unknown

CHROMIUM

8

Unknown

mg/kg

KMP UNC

KMP-21-00

7/19/2017

35.658901

-108.491165

0

2

Unknown

CHROMIUM

7

Unknown

mg/kg

KMP UNC

KMP-22-00

7/19/2017

35.658405

-108.490563

0

2

Unknown

CHROMIUM

7

Unknown

mg/kg

KMP UNC

KMP-23-00

7/18/2017

35.658984

-108.490548

0

2

Unknown

CHROMIUM

7.6

Unknown

mg/kg

KMP UNC

KMP-01-00

7/18/2017

35.659423

-108.492172

0

2

Unknown

LEAD

12

Unknown

mg/kg

KMP UNC

KMP-02-00

7/18/2017

35.659438

-108.491379

0

2

Unknown

LEAD

8.3

Unknown

mg/kg

KMP UNC

KMP-03-00

7/18/2017

35.65946

-108.490578

0

2

Unknown

LEAD

8.6

Unknown

mg/kg

KMP UNC

KMP-04-00

7/18/2017

35.65878

-108.49234

0

2

Unknown

LEAD

13

Unknown

mg/kg

KMP UNC

KMP-05-00

7/18/2017

35.658795

-108.491547

0

2

Unknown

LEAD

8.5

Unknown

mg/kg

KMP UNC

KMP-06-00

7/18/2017

35.658817

-108.490746

0

2

Unknown

LEAD

7.7

Unknown

mg/kg

KMP UNC

KMP-07-00

7/18/2017

35.658175

-108.492052

0

2

Unknown

LEAD

17

Unknown

mg/kg

KMP UNC

KMP-08-00

7/18/2017

35.65819

-108.491259

0

2

Unknown

LEAD

10

Unknown

mg/kg

KMP UNC

KMP-09-00

7/18/2017

35.658213

-108.490459

0

2

Unknown

LEAD

9.9

Unknown

mg/kg

KMP UNC

KMP-10-00

7/18/2017

35.65764

-108.490873

0

2

Unknown

LEAD

8.9

Unknown

mg/kg

KMP UNC

KMP-15-00

7/18/2017

35.659695

-108.491137

0

2

Unknown

LEAD

11

Unknown

mg/kg

KMP UNC

KMP-16-00

7/18/2017

35.658292

-108.491842

0

2

Unknown

LEAD

14

Unknown

mg/kg

KMP UNC

KMP-16D-00

7/18/2017

35.658292

-108.491842

0

2

Unknown

LEAD

13

Unknown

mg/kg

KMP UNC

KMP-17-00

7/19/2017

35.658397

-108.491778

0

2

Unknown

LEAD

13

Unknown

mg/kg

KMP UNC

KMP-18-00

7/19/2017

35.658584

-108.491524

0

2

Unknown

LEAD

14

Unknown

mg/kg

KMP UNC

KMP-18D-00

7/19/2017

35.658584

-108.491524

0

2

Unknown

LEAD

14

Unknown

mg/kg

KMP UNC

KMP-19-00

7/19/2017

35.65865

-108.491373

0

2

Unknown

LEAD

10

Unknown

mg/kg

KMP UNC

KMP-20-00

7/19/2017

35.658809

-108.491224

0

2

Unknown

LEAD

11

Unknown

mg/kg

KMP UNC

KMP-21-00

7/19/2017

35.658901

-108.491165

0

2

Unknown

LEAD

8.7

Unknown

mg/kg

KMP UNC

KMP-22-00

7/19/2017

35.658405

-108.490563

0

2

Unknown

LEAD

8.1

Unknown

mg/kg

KMP UNC

KMP-23-00

7/18/2017

35.658984

-108.490548

0

2

Unknown

LEAD

9.6

Unknown

mg/kg

KMP UNC

KMP-01-00

7/18/2017

35.659423

-108.492172

0

2

Unknown

MOLYBDENUM

0.69 J

Unknown

mg/kg

KMP UNC

KMP-02-00

7/18/2017

35.659438

-108.491379

0

2

Unknown

MOLYBDENUM

0.52 J

Unknown

mg/kg

KMP UNC

KMP-03-00

7/18/2017

35.65946

-108.490578

0

2

Unknown

MOLYBDENUM

1.3 U

Unknown

mg/kg

KMP UNC

KMP-04-00

7/18/2017

35.65878

-108.49234

0

2

Unknown

MOLYBDENUM

0.57

Unknown

mg/kg

KMP UNC

KMP-05-00

7/18/2017

35.658795

-108.491547

0

2

Unknown

MOLYBDENUM

1.3 U

Unknown

mg/kg

KMP UNC

KMP-06-00

7/18/2017

35.658817

-108.490746

0

2

Unknown

MOLYBDENUM

0.52 J

Unknown

mg/kg

KMP UNC

KMP-07-00

7/18/2017

35.658175

-108.492052

0

2

Unknown

MOLYBDENUM

0.65 J

Unknown

mg/kg

KMP UNC

KMP-08-00

7/18/2017

35.65819

-108.491259

0

2

Unknown

MOLYBDENUM

1.2 U

Unknown

mg/kg

KMP UNC

KMP-09-00

7/18/2017

35.658213

-108.490459

0

2

Unknown

MOLYBDENUM

0.93 J

Unknown

mg/kg

KMP UNC

KMP-10-00

7/18/2017

35.65764

-108.490873

0

2

Unknown

MOLYBDENUM

0.51 J

Unknown

mg/kg

KMP UNC

KMP-15-00

7/18/2017

35.659695

-108.491137

0

2

Unknown

MOLYBDENUM

0.65 J

Unknown

mg/kg

KMP UNC

KMP-16-00

7/18/2017

35.658292

-108.491842

0

2

Unknown

MOLYBDENUM

0.64 J

Unknown

mg/kg

KMP UNC

KMP-16D-00

7/18/2017

35.658292

-108.491842

0

2

Unknown

MOLYBDENUM

0.75 J

Unknown

mg/kg

Page 44 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KMP-17-00

7/19/2017

35.658397

-108.491778

0

2

Unknown

MOLYBDENUM

0.65 J

Unknown

mg/kg

KMPUNC

KMP-18-00

7/19/2017

35.658584

-108.491524

0

2

Unknown

MOLYBDENUM

0.74 J

Unknown

mg/kg

KMP UNC

KMP-18D-00

7/19/2017

35.658584

-108.491524

0

2

Unknown

MOLYBDENUM

0.7 J

Unknown

mg/kg

KMP UNC

KMP-19-00

7/19/2017

35.65865

-108.491373

0

2

Unknown

MOLYBDENUM

0.7 J

Unknown

mg/kg

KMP UNC

KMP-20-00

7/19/2017

35.658809

-108.491224

0

2

Unknown

MOLYBDENUM

0.61 J

Unknown

mg/kg

KMP UNC

KMP-21-00

7/19/2017

35.658901

-108.491165

0

2

Unknown

MOLYBDENUM

0.54 J

Unknown

mg/kg

KMP UNC

KMP-22-00

7/19/2017

35.658405

-108.490563

0

2

Unknown

MOLYBDENUM

1.2 U

Unknown

mg/kg

KMP UNC

KMP-23-00

7/18/2017

35.658984

-108.490548

0

2

Unknown

MOLYBDENUM

0.8 J

Unknown

mg/kg

KMP UNC

KMP-01-00

7/18/2017

35.659423

-108.492172

0

2

Unknown

Ra-226

3.06

Unknown

o

Q.

/ g

KMP UNC

KMP-02-00

7/18/2017

35.659438

-108.491379

0

2

Unknown

Ra-226

1.41

Unknown

O

Q.

/g

KMP UNC

KMP-03-00

7/18/2017

35.65946

-108.490578

0

2

Unknown

Ra-226

8.32

Unknown

pC

Zg

KMP UNC

KMP-04-00

7/18/2017

35.65878

-108.49234

0

2

Unknown

Ra-226

2.67

Unknown

pC

/g

KMP UNC

KMP-05-00

7/18/2017

35.658795

-108.491547

0

2

Unknown

Ra-226

2.92

Unknown

o

Q.

/g

KMP UNC

KMP-06-00

7/18/2017

35.658817

-108.490746

0

2

Unknown

Ra-226

2.22

Unknown

O

Q.

/g

KMP UNC

KMP-07-00

7/18/2017

35.658175

-108.492052

0

2

Unknown

Ra-226

6.45

Unknown

pC

/g

KMP UNC

KMP-08-00

7/18/2017

35.65819

-108.491259

0

2

Unknown

Ra-226

5.36

Unknown

pC

/g

KMP UNC

KMP-09-00

7/18/2017

35.658213

-108.490459

0

2

Unknown

Ra-226

7.42

Unknown

o

Q.

/g

KMP UNC

KMP-10-00

7/18/2017

35.65764

-108.490873

0

2

Unknown

Ra-226

7.77

Unknown

O

Q.

/g

KMP UNC

KMP-15-00

7/18/2017

35.659695

-108.491137

0

2

Unknown

Ra-226

22.84

Unknown

pC

/g

KMP UNC

KMP-16-00

7/18/2017

35.658292

-108.491842

0

2

Unknown

Ra-226

6.67

Unknown

pC

/g

KMP UNC

KMP-16D-00

7/18/2017

35.658292

-108.491842

0

2

Unknown

Ra-226

4.71

Unknown

o

Q.

/g

KMP UNC

KMP-17-00

7/19/2017

35.658397

-108.491778

0

2

Unknown

Ra-226

48.54

Unknown

O

Q.

/g

KMP UNC

KMP-18-00

7/19/2017

35.658584

-108.491524

0

2

Unknown

Ra-226

15.38

Unknown

pC

/g

KMP UNC

KMP-18D-00

7/19/2017

35.658584

-108.491524

0

2

Unknown

Ra-226

16.44

Unknown

pC

/g

KMP UNC

KMP-19-00

7/19/2017

35.65865

-108.491373

0

2

Unknown

Ra-226

26.04

Unknown

o

Q.

/g

KMP UNC

KMP-20-00

7/19/2017

35.658809

-108.491224

0

2

Unknown

Ra-226

13.7

Unknown

O

Q.

/g

KMP UNC

KMP-21-00

7/19/2017

35.658901

-108.491165

0

2

Unknown

Ra-226

4.43

Unknown

pC

/g

KMP UNC

KMP-22-00

7/19/2017

35.658405

-108.490563

0

2

Unknown

Ra-226

4.35

Unknown

pC

/g

KMP UNC

KMP-23-00

7/18/2017

35.658984

-108.490548

0

2

Unknown

Ra-226

3.73

Unknown

o

Q.

/g

KMP UNC

KMP-01-00

7/18/2017

35.659423

-108.492172

0

2

Unknown

SELENIUM

2.7

Unknown

mg/kg

KMP UNC

KMP-02-00

7/18/2017

35.659438

-108.491379

0

2

Unknown

SELENIUM

1.6

Unknown

mg/kg

KMP UNC

KMP-03-00

7/18/2017

35.65946

-108.490578

0

2

Unknown

SELENIUM

3.1

Unknown

mg/kg

KMP UNC

KMP-04-00

7/18/2017

35.65878

-108.49234

0

2

Unknown

SELENIUM

1.8

Unknown

mg/kg

KMP UNC

KMP-05-00

7/18/2017

35.658795

-108.491547

0

2

Unknown

SELENIUM

1.8

Unknown

mg/kg

KMP UNC

KMP-06-00

7/18/2017

35.658817

-108.490746

0

2

Unknown

SELENIUM

2

Unknown

mg/kg

KMP UNC

KMP-07-00

7/18/2017

35.658175

-108.492052

0

2

Unknown

SELENIUM

3.3

Unknown

mg/kg

KMP UNC

KMP-08-00

7/18/2017

35.65819

-108.491259

0

2

Unknown

SELENIUM

2.6

Unknown

mg/kg

KMP UNC

KMP-09-00

7/18/2017

35.658213

-108.490459

0

2

Unknown

SELENIUM

5

Unknown

mg/kg

KMP UNC

KMP-10-00

7/18/2017

35.65764

-108.490873

0

2

Unknown

SELENIUM

3.6

Unknown

mg/kg

KMP UNC

KMP-15-00

7/18/2017

35.659695

-108.491137

0

2

Unknown

SELENIUM

6.6

Unknown

mg/kg

KMP UNC

KMP-16-00

7/18/2017

35.658292

-108.491842

0

2

Unknown

SELENIUM

3.8

Unknown

mg/kg

KMP UNC

KMP-16D-00

7/18/2017

35.658292

-108.491842

0

2

Unknown

SELENIUM

3.7

Unknown

mg/kg

Page 45 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KMP-17-00

7/19/2017

35.658397

-108.491778

0

2

Unknown

SELENIUM

21

Unknown

mg/kg

KMPUNC

KMP-18-00

7/19/2017

35.658584

-108.491524

0

2

Unknown

SELENIUM

5.6

Unknown

mg/kg

KMP UNC

KMP-18D-00

7/19/2017

35.658584

-108.491524

0

2

Unknown

SELENIUM

5.5

Unknown

mg/kg

KMP UNC

KMP-19-00

7/19/2017

35.65865

-108.491373

0

2

Unknown

SELENIUM

00
CO

Unknown

mg/kg

KMP UNC

KMP-20-00

7/19/2017

35.658809

-108.491224

0

2

Unknown

SELENIUM

6.2

Unknown

mg/kg

KMP UNC

KMP-21-00

7/19/2017

35.658901

-108.491165

0

2

Unknown

SELENIUM

2.5

Unknown

mg/kg

KMP UNC

KMP-22-00

7/19/2017

35.658405

-108.490563

0

2

Unknown

SELENIUM

2

Unknown

mg/kg

KMP UNC

KMP-23-00

7/18/2017

35.658984

-108.490548

0

2

Unknown

SELENIUM

1.9

Unknown

mg/kg

KMP UNC

KMP-01-00

7/18/2017

35.659423

-108.492172

0

2

Unknown

SILVER

0.53 U

Unknown

mg/kg

KMP UNC

KMP-02-00

7/18/2017

35.659438

-108.491379

0

2

Unknown

SILVER

0.5 U

Unknown

mg/kg

KMP UNC

KMP-03-00

7/18/2017

35.65946

-108.490578

0

2

Unknown

SILVER

0.53 U

Unknown

mg/kg

KMP UNC

KMP-04-00

7/18/2017

35.65878

-108.49234

0

2

Unknown

SILVER

0.21 U

Unknown

mg/kg

KMP UNC

KMP-05-00

7/18/2017

35.658795

-108.491547

0

2

Unknown

SILVER

0.52 U

Unknown

mg/kg

KMP UNC

KMP-06-00

7/18/2017

35.658817

-108.490746

0

2

Unknown

SILVER

0.49 U

Unknown

mg/kg

KMP UNC

KMP-07-00

7/18/2017

35.658175

-108.492052

0

2

Unknown

SILVER

0.58 U

Unknown

mg/kg

KMP UNC

KMP-08-00

7/18/2017

35.65819

-108.491259

0

2

Unknown

SILVER

0.49 U

Unknown

mg/kg

KMP UNC

KMP-09-00

7/18/2017

35.658213

-108.490459

0

2

Unknown

SILVER

0.56 U

Unknown

mg/kg

KMP UNC

KMP-10-00

7/18/2017

35.65764

-108.490873

0

2

Unknown

SILVER

0.51 U

Unknown

mg/kg

KMP UNC

KMP-15-00

7/18/2017

35.659695

-108.491137

0

2

Unknown

SILVER

0.51 U

Unknown

mg/kg

KMP UNC

KMP-16-00

7/18/2017

35.658292

-108.491842

0

2

Unknown

SILVER

0.5 U

Unknown

mg/kg

KMP UNC

KMP-16D-00

7/18/2017

35.658292

-108.491842

0

2

Unknown

SILVER

0.52 U

Unknown

mg/kg

KMP UNC

KMP-17-00

7/19/2017

35.658397

-108.491778

0

2

Unknown

SILVER

0.45 U

Unknown

mg/kg

KMP UNC

KMP-18-00

7/19/2017

35.658584

-108.491524

0

2

Unknown

SILVER

0.49 U

Unknown

mg/kg

KMP UNC

KMP-18D-00

7/19/2017

35.658584

-108.491524

0

2

Unknown

SILVER

0.46 U

Unknown

mg/kg

KMP UNC

KMP-19-00

7/19/2017

35.65865

-108.491373

0

2

Unknown

SILVER

0.46 U

Unknown

mg/kg

KMP UNC

KMP-20-00

7/19/2017

35.658809

-108.491224

0

2

Unknown

SILVER

0.5 U

Unknown

mg/kg

KMP UNC

KMP-21-00

7/19/2017

35.658901

-108.491165

0

2

Unknown

SILVER

0.45 U

Unknown

mg/kg

KMP UNC

KMP-22-00

7/19/2017

35.658405

-108.490563

0

2

Unknown

SILVER

0.48 U

Unknown

mg/kg

KMP UNC

KMP-23-00

7/18/2017

35.658984

-108.490548

0

2

Unknown

SILVER

0.51 U

Unknown

mg/kg

KMP UNC

KMP-01-00

7/18/2017

35.659423

-108.492172

0

2

Unknown

URANIUM

2.6

Unknown

mg/kg

KMP UNC

KMP-02-00

7/18/2017

35.659438

-108.491379

0

2

Unknown

URANIUM

9.7

Unknown

mg/kg

KMP UNC

KMP-03-00

7/18/2017

35.65946

-108.490578

0

2

Unknown

URANIUM

3.5

Unknown

mg/kg

KMP UNC

KMP-04-00

7/18/2017

35.65878

-108.49234

0

2

Unknown

URANIUM

1.3

Unknown

mg/kg

KMP UNC

KMP-05-00

7/18/2017

35.658795

-108.491547

0

2

Unknown

URANIUM

1.4

Unknown

mg/kg

KMP UNC

KMP-06-00

7/18/2017

35.658817

-108.490746

0

2

Unknown

URANIUM

2.8

Unknown

mg/kg

KMP UNC

KMP-07-00

7/18/2017

35.658175

-108.492052

0

2

Unknown

URANIUM

2.9

Unknown

mg/kg

KMP UNC

KMP-08-00

7/18/2017

35.65819

-108.491259

0

2

Unknown

URANIUM

2.1

Unknown

mg/kg

KMP UNC

KMP-09-00

7/18/2017

35.658213

-108.490459

0

2

Unknown

URANIUM

13

Unknown

mg/kg

KMP UNC

KMP-10-00

7/18/2017

35.65764

-108.490873

0

2

Unknown

URANIUM

4.2

Unknown

mg/kg

KMP UNC

KMP-15-00

7/18/2017

35.659695

-108.491137

0

2

Unknown

URANIUM

13

Unknown

mg/kg

KMP UNC

KMP-16-00

7/18/2017

35.658292

-108.491842

0

2

Unknown

URANIUM

3.6

Unknown

mg/kg

KMP UNC

KMP-16D-00

7/18/2017

35.658292

-108.491842

0

2

Unknown

URANIUM

3.1

Unknown

mg/kg

Page 46 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KMP-17-00

7/19/2017

35.658397

-108.491778

0

2

Unknown

URANIUM

40

Unknown

mg/kg

KMPUNC

KMP-18-00

7/19/2017

35.658584

-108.491524

0

2

Unknown

URANIUM

11

Unknown

mg/kg

KMP UNC

KMP-18D-00

7/19/2017

35.658584

-108.491524

0

2

Unknown

URANIUM

13

Unknown

mg/kg

KMP UNC

KMP-19-00

7/19/2017

35.65865

-108.491373

0

2

Unknown

URANIUM

18

Unknown

mg/kg

KMP UNC

KMP-20-00

7/19/2017

35.658809

-108.491224

0

2

Unknown

URANIUM

12

Unknown

mg/kg

KMP UNC

KMP-21-00

7/19/2017

35.658901

-108.491165

0

2

Unknown

URANIUM

4.8

Unknown

mg/kg

KMP UNC

KMP-22-00

7/19/2017

35.658405

-108.490563

0

2

Unknown

URANIUM

3.5

Unknown

mg/kg

KMP UNC

KMP-23-00

7/18/2017

35.658984

-108.490548

0

2

Unknown

URANIUM

2.8

Unknown

mg/kg

KMP UNC

KMP-01-00

7/18/2017

35.659423

-108.492172

0

2

Unknown

VANADIUM

21

Unknown

mg/kg

KMP UNC

KMP-02-00

7/18/2017

35.659438

-108.491379

0

2

Unknown

VANADIUM

16

Unknown

mg/kg

KMP UNC

KMP-03-00

7/18/2017

35.65946

-108.490578

0

2

Unknown

VANADIUM

16

Unknown

mg/kg

KMP UNC

KMP-04-00

7/18/2017

35.65878

-108.49234

0

2

Unknown

VANADIUM

21

Unknown

mg/kg

KMP UNC

KMP-05-00

7/18/2017

35.658795

-108.491547

0

2

Unknown

VANADIUM

17

Unknown

mg/kg

KMP UNC

KMP-06-00

7/18/2017

35.658817

-108.490746

0

2

Unknown

VANADIUM

16

Unknown

mg/kg

KMP UNC

KMP-07-00

7/18/2017

35.658175

-108.492052

0

2

Unknown

VANADIUM

26

Unknown

mg/kg

KMP UNC

KMP-08-00

7/18/2017

35.65819

-108.491259

0

2

Unknown

VANADIUM

17

Unknown

mg/kg

KMP UNC

KMP-09-00

7/18/2017

35.658213

-108.490459

0

2

Unknown

VANADIUM

22

Unknown

mg/kg

KMP UNC

KMP-10-00

7/18/2017

35.65764

-108.490873

0

2

Unknown

VANADIUM

18

Unknown

mg/kg

KMP UNC

KMP-15-00

7/18/2017

35.659695

-108.491137

0

2

Unknown

VANADIUM

23

Unknown

mg/kg

KMP UNC

KMP-16-00

7/18/2017

35.658292

-108.491842

0

2

Unknown

VANADIUM

23

Unknown

mg/kg

KMP UNC

KMP-16D-00

7/18/2017

35.658292

-108.491842

0

2

Unknown

VANADIUM

22

Unknown

mg/kg

KMP UNC

KMP-17-00

7/19/2017

35.658397

-108.491778

0

2

Unknown

VANADIUM

41

Unknown

mg/kg

KMP UNC

KMP-18-00

7/19/2017

35.658584

-108.491524

0

2

Unknown

VANADIUM

25

Unknown

mg/kg

KMP UNC

KMP-18D-00

7/19/2017

35.658584

-108.491524

0

2

Unknown

VANADIUM

24

Unknown

mg/kg

KMP UNC

KMP-19-00

7/19/2017

35.65865

-108.491373

0

2

Unknown

VANADIUM

26

Unknown

mg/kg

KMP UNC

KMP-20-00

7/19/2017

35.658809

-108.491224

0

2

Unknown

VANADIUM

22

Unknown

mg/kg

KMP UNC

KMP-21-00

7/19/2017

35.658901

-108.491165

0

2

Unknown

VANADIUM

17

Unknown

mg/kg

KMP UNC

KMP-22-00

7/19/2017

35.658405

-108.490563

0

2

Unknown

VANADIUM

16

Unknown

mg/kg

KMP UNC

KMP-23-00

7/18/2017

35.658984

-108.490548

0

2

Unknown

VANADIUM

18

Unknown

mg/kg

KMP UNC

KMP-SS45-0000-0003-01

5/19/2022

35.659562

-108.493833

0

3

SW6020

ALUMINUM

4000

15

mg/kg

KMP UNC

KMP-SS45-0000-0003-02

5/19/2022

35.659562

-108.493833

0

3

SW6020

ALUMINUM

4000

15

mg/kg

KMP UNC

KMP-SS46-0000-0003-01

5/19/2022

35.659453

-108.493003

0

3

SW6020

ALUMINUM

4900

15

mg/kg

KMP UNC

KMP-SS47-0000-0003-01

5/19/2022

35.659543

-108.49221

0

3

SW6020

ALUMINUM

5100

15

mg/kg

KMP UNC

KM P-SS48-0000-0003-01

5/19/2022

35.659648

-108.491281

0

3

SW6020

ALUMINUM

6000

15

mg/kg

KMP UNC

KMP-SS50-0000-0003-01

5/19/2022

35.6595

-108.491

0

3

SW6020

ALUMINUM

6300

15

mg/kg

KMP UNC

KM P-SS51-0000-0003-01

5/19/2022

35.65919

-108.491

0

3

SW6020

ALUMINUM

6500

15

mg/kg

KMP UNC

KM P-SS52-0000-0003-01

5/19/2022

35.659169

-108.491722

0

3

SW6020

ALUMINUM

6100

15

mg/kg

KMP UNC

KMP-SS53-0000-0003-01

5/19/2022

35.659201

-108.492371

0

3

SW6020

ALUMINUM

5000

15

mg/kg

KMP UNC

KM P-SS54-0000-0003-01

5/19/2022

35.658712

-108.492621

0

3

SW6020

ALUMINUM

7100

15

mg/kg

KMP UNC

KMP-SS55-0000-0003-01

5/19/2022

35.658793

-108.492026

0

3

SW6020

ALUMINUM

8300

16

mg/kg

KMP UNC

KM P-SS56-0000-0003-01

5/19/2022

35.658831

-108.491366

0

3

SW6020

ALUMINUM

5900

15

mg/kg

KMP UNC

KMP-SS57-0000-0003-01

5/19/2022

35.658672

-108.491525

0

3

SW6020

ALUMINUM

7100

15

mg/kg

Page 47 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KMP-SS58-0000-0003-01

5/19/2022

35.65853

-108.492

0

3

SW6020

ALUMINUM

6700

15

mg/kg

KMPUNC

KMP-SS59-0000-0003-01

5/19/2022

35.658334

-108.491827

0

3

SW6020

ALUMINUM

7000

15

mg/kg

KMP UNC

KM P-SS60-0000-0003-01

5/19/2022

35.658129

-108.492013

0

3

SW6020

ALUMINUM

6000

15

mg/kg

KMP UNC

KM P-SS61 -0000-0003-01

5/19/2022

35.657958

-108.491301

0

3

SW6020

ALUMINUM

6300

15

mg/kg

KMP UNC

KM P-SS62-0000-0003-01

5/19/2022

35.658355

-108.491208

0

3

SW6020

ALUMINUM

6300

15

mg/kg

KMP UNC

KM P-SS63-0000-0003-01

5/19/2022

35.658917

-108.490612

0

3

SW6020

ALUMINUM

5900

15

mg/kg

KMP UNC

KM P-SS64-0000-0003-01

5/19/2022

35.658394

-108.49068

0

3

SW6020

ALUMINUM

6100

15

mg/kg

KMP UNC

KM P-SS65-0000-0003-01

5/19/2022

35.658535

-108.490274

0

3

SW6020

ALUMINUM

6100

15

mg/kg

KMP UNC

KM P-SS66-0000-0003-01

5/19/2022

35.658093

-108.490734

0

3

SW6020

ALUMINUM

5800

15

mg/kg

KMP UNC

KMP-SS67-0000-0003-01

5/19/2022

35.658057

-108.490414

0

3

SW6020

ALUMINUM

6900

15

mg/kg

KMP UNC

KM P-SS68-0000-0003-01

5/19/2022

35.65776

-108.491

0

3

SW6020

ALUMINUM

7500

15

mg/kg

KMP UNC

KMP-SS69-0000-0003-01

5/19/2022

35.65736

-108.492

0

3

SW6020

ALUMINUM

7500

15

mg/kg

KMP UNC

KMP-SS70-0000-0003-01

5/19/2022

35.657343

-108.490976

0

3

SW6020

ALUMINUM

6400

15

mg/kg

KMP UNC

KMP-SS70-0000-0003-02

5/19/2022

35.657343

-108.490976

0

3

SW6020

ALUMINUM

5900

15

mg/kg

KMP UNC

KM P-SS71-0000-0003-01

5/19/2022

35.656666

-108.491638

0

3

SW6020

ALUMINUM

6100

15

mg/kg

KMP UNC

KMP-SS72-0000-0003-01

5/19/2022

35.656683

-108.49091

0

3

SW6020

ALUMINUM

6400

15

mg/kg

KMP UNC

KMP-SS73-0000-0003-01

5/19/2022

35.658117

-108.493493

0

3

SW6020

ALUMINUM

6800

15

mg/kg

KMP UNC

KMP-SS75-0000-0003-01

5/19/2022

35.659492

-108.489461

0

3

SW6020

ALUMINUM

5700

15

mg/kg

KMP UNC

KMP-SS75-0000-0003-02

5/19/2022

35.659492

-108.489461

0

3

SW6020

ALUMINUM

5800

15

mg/kg

KMP UNC

KMP-SS76-0000-0003-01

5/19/2022

35.659031

-108.489527

0

3

SW6020

ALUMINUM

7600

15

mg/kg

KMP UNC

KMP-SS77-0000-0003-01

5/19/2022

35.658484

-108.488991

0

3

SW6020

ALUMINUM

7000

15

mg/kg

KMP UNC

KMP-SS78-0000-0003-01

5/19/2022

35.658169

-108.487842

0

3

SW6020

ALUMINUM

5400

15

mg/kg

KMP UNC

KMP-SS79-0000-0003-01

5/19/2022

35.658754

-108.491022

0

3

SW6020

ALUMINUM

6200

15

mg/kg

KMP UNC

KMP-SS45-0000-0003-01

5/19/2022

35.659562

-108.493833

0

3

SW6020

ANTIMONY

0.1

0.099

mg/kg

KMP UNC

KMP-SS45-0000-0003-02

5/19/2022

35.659562

-108.493833

0

3

SW6020

ANTIMONY

0.096 J

0.1

mg/kg

KMP UNC

KM P-SS46-0000-0003-01

5/19/2022

35.659453

-108.493003

0

3

SW6020

ANTIMONY

0.041 J

0.1

mg/kg

KMP UNC

KMP-SS47-0000-0003-01

5/19/2022

35.659543

-108.49221

0

3

SW6020

ANTIMONY

0.048 J

0.1

mg/kg

KMP UNC

KMP-SS48-0000-0003-01

5/19/2022

35.659648

-108.491281

0

3

SW6020

ANTIMONY

0.094 J

0.1

mg/kg

KMP UNC

KMP-SS50-0000-0003-01

5/19/2022

35.6595

-108.491

0

3

SW6020

ANTIMONY

0.054 J

0.1

mg/kg

KMP UNC

KM P-SS51-0000-0003-01

5/19/2022

35.65919

-108.491

0

3

SW6020

ANTIMONY

0.07 J

0.1

mg/kg

KMP UNC

KMP-SS52-0000-0003-01

5/19/2022

35.659169

-108.491722

0

3

SW6020

ANTIMONY

0.057 J

0.1

mg/kg

KMP UNC

KMP-SS53-0000-0003-01

5/19/2022

35.659201

-108.492371

0

3

SW6020

ANTIMONY

0.058 J

0.1

mg/kg

KMP UNC

KMP-SS54-0000-0003-01

5/19/2022

35.658712

-108.492621

0

3

SW6020

ANTIMONY

0.11

0.1

mg/kg

KMP UNC

KMP-SS55-0000-0003-01

5/19/2022

35.658793

-108.492026

0

3

SW6020

ANTIMONY

0.15

0.1

mg/kg

KMP UNC

KM P-SS56-0000-0003-01

5/19/2022

35.658831

-108.491366

0

3

SW6020

ANTIMONY

0.066 J

0.1

mg/kg

KMP UNC

KMP-SS57-0000-0003-01

5/19/2022

35.658672

-108.491525

0

3

SW6020

ANTIMONY

0.1 J

0.1

mg/kg

KMP UNC

KMP-SS58-0000-0003-01

5/19/2022

35.65853

-108.492

0

3

SW6020

ANTIMONY

0.11

0.1

mg/kg

KMP UNC

KMP-SS59-0000-0003-01

5/19/2022

35.658334

-108.491827

0

3

SW6020

ANTIMONY

0.092 J

0.1

mg/kg

KMP UNC

KM P-SS60-0000-0003-01

5/19/2022

35.658129

-108.492013

0

3

SW6020

ANTIMONY

0.11

0.1

mg/kg

KMP UNC

KM P-SS61 -0000-0003-01

5/19/2022

35.657958

-108.491301

0

3

SW6020

ANTIMONY

0.1

0.1

mg/kg

KMP UNC

KM P-SS62-0000-0003-01

5/19/2022

35.658355

-108.491208

0

3

SW6020

ANTIMONY

0.1 J

0.1

mg/kg

KMP UNC

KM P-SS63-0000-0003-01

5/19/2022

35.658917

-108.490612

0

3

SW6020

ANTIMONY

0.071 J

0.1

mg/kg

Page 48 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KM P-SS64-0000-0003-01

5/19/2022

35.658394

-108.49068

0

3

SW6020

ANTIMONY

0.088 J

0.1

mg/kg

KMPUNC

KM P-SS65-0000-0003-01

5/19/2022

35.658535

-108.490274

0

3

SW6020

ANTIMONY

0.075 J

0.1

mg/kg

KMP UNC

KM P-SS66-0000-0003-01

5/19/2022

35.658093

-108.490734

0

3

SW6020

ANTIMONY

0.064 J

0.1

mg/kg

KMP UNC

KMP-SS67-0000-0003-01

5/19/2022

35.658057

-108.490414

0

3

SW6020

ANTIMONY

0.079 J

0.1

mg/kg

KMP UNC

KM P-SS68-0000-0003-01

5/19/2022

35.65776

-108.491

0

3

SW6020

ANTIMONY

0.066 J

0.1

mg/kg

KMP UNC

KM P-SS69-0000-0003-01

5/19/2022

35.65736

-108.492

0

3

SW6020

ANTIMONY

0.071 J

0.1

mg/kg

KMP UNC

KMP-SS70-0000-0003-01

5/19/2022

35.657343

-108.490976

0

3

SW6020

ANTIMONY

0.052 J

0.1

mg/kg

KMP UNC

KMP-SS70-0000-0003-02

5/19/2022

35.657343

-108.490976

0

3

SW6020

ANTIMONY

0.047 J

0.1

mg/kg

KMP UNC

KM P-SS71-0000-0003-01

5/19/2022

35.656666

-108.491638

0

3

SW6020

ANTIMONY

0.061 J

0.1

mg/kg

KMP UNC

KMP-SS72-0000-0003-01

5/19/2022

35.656683

-108.49091

0

3

SW6020

ANTIMONY

0.069 J

0.1

mg/kg

KMP UNC

KMP-SS73-0000-0003-01

5/19/2022

35.658117

-108.493493

0

3

SW6020

ANTIMONY

0.084 J

0.1

mg/kg

KMP UNC

KMP-SS75-0000-0003-01

5/19/2022

35.659492

-108.489461

0

3

SW6020

ANTIMONY

0.19

0.1

mg/kg

KMP UNC

KMP-SS75-0000-0003-02

5/19/2022

35.659492

-108.489461

0

3

SW6020

ANTIMONY

0.26

0.1

mg/kg

KMP UNC

KMP-SS76-0000-0003-01

5/19/2022

35.659031

-108.489527

0

3

SW6020

ANTIMONY

0.093 J

0.1

mg/kg

KMP UNC

KMP-SS77-0000-0003-01

5/19/2022

35.658484

-108.488991

0

3

SW6020

ANTIMONY

0.11

0.1

mg/kg

KMP UNC

KMP-SS78-0000-0003-01

5/19/2022

35.658169

-108.487842

0

3

SW6020

ANTIMONY

0.058 J

0.1

mg/kg

KMP UNC

KMP-SS79-0000-0003-01

5/19/2022

35.658754

-108.491022

0

3

SW6020

ANTIMONY

0.083 J

0.1

mg/kg

KMP UNC

KMP-SS45-0000-0003-01

5/19/2022

35.659562

-108.493833

0

3

SW6020

ARSENIC

4.3

0.2

mg/kg

KMP UNC

KMP-SS45-0000-0003-02

5/19/2022

35.659562

-108.493833

0

3

SW6020

ARSENIC

4.2

0.2

mg/kg

KMP UNC

KMP-SS46-0000-0003-01

5/19/2022

35.659453

-108.493003

0

3

SW6020

ARSENIC

4.1

0.2

mg/kg

KMP UNC

KMP-SS47-0000-0003-01

5/19/2022

35.659543

-108.49221

0

3

SW6020

ARSENIC

4.4

0.2

mg/kg

KMP UNC

KMP-SS48-0000-0003-01

5/19/2022

35.659648

-108.491281

0

3

SW6020

ARSENIC

5.3

0.2

mg/kg

KMP UNC

KMP-SS50-0000-0003-01

5/19/2022

35.6595

-108.491

0

3

SW6020

ARSENIC

5.4

0.2

mg/kg

KMP UNC

KM P-SS51-0000-0003-01

5/19/2022

35.65919

-108.491

0

3

SW6020

ARSENIC

5.6

0.2

mg/kg

KMP UNC

KMP-SS52-0000-0003-01

5/19/2022

35.659169

-108.491722

0

3

SW6020

ARSENIC

5.1

0.2

mg/kg

KMP UNC

KMP-SS53-0000-0003-01

5/19/2022

35.659201

-108.492371

0

3

SW6020

ARSENIC

4.3

0.2

mg/kg

KMP UNC

KMP-SS54-0000-0003-01

5/19/2022

35.658712

-108.492621

0

3

SW6020

ARSENIC

6.7

0.2

mg/kg

KMP UNC

KMP-SS55-0000-0003-01

5/19/2022

35.658793

-108.492026

0

3

SW6020

ARSENIC

7.5

0.21

mg/kg

KMP UNC

KM P-SS56-0000-0003-01

5/19/2022

35.658831

-108.491366

0

3

SW6020

ARSENIC

5

0.2

mg/kg

KMP UNC

KM P-SS57-0000-0003-01

5/19/2022

35.658672

-108.491525

0

3

SW6020

ARSENIC

6.1

0.2

mg/kg

KMP UNC

KM P-SS58-0000-0003-01

5/19/2022

35.65853

-108.492

0

3

SW6020

ARSENIC

5.4

0.2

mg/kg

KMP UNC

KM P-SS59-0000-0003-01

5/19/2022

35.658334

-108.491827

0

3

SW6020

ARSENIC

6

0.2

mg/kg

KMP UNC

KM P-SS60-0000-0003-01

5/19/2022

35.658129

-108.492013

0

3

SW6020

ARSENIC

6

0.2

mg/kg

KMP UNC

KM P-SS61-0000-0003-01

5/19/2022

35.657958

-108.491301

0

3

SW6020

ARSENIC

5.4

0.2

mg/kg

KMP UNC

KM P-SS62-0000-0003-01

5/19/2022

35.658355

-108.491208

0

3

SW6020

ARSENIC

5.1

0.2

mg/kg

KMP UNC

KM P-SS63-0000-0003-01

5/19/2022

35.658917

-108.490612

0

3

SW6020

ARSENIC

4.8

0.2

mg/kg

KMP UNC

KM P-SS64-0000-0003-01

5/19/2022

35.658394

-108.49068

0

3

SW6020

ARSENIC

5

0.2

mg/kg

KMP UNC

KMP-SS65-0000-0003-01

5/19/2022

35.658535

-108.490274

0

3

SW6020

ARSENIC

5.2

0.2

mg/kg

KMP UNC

KM P-SS66-0000-0003-01

5/19/2022

35.658093

-108.490734

0

3

SW6020

ARSENIC

4.8

0.2

mg/kg

KMP UNC

KMP-SS67-0000-0003-01

5/19/2022

35.658057

-108.490414

0

3

SW6020

ARSENIC

6.2

0.2

mg/kg

KMP UNC

KMP-SS68-0000-0003-01

5/19/2022

35.65776

-108.491

0

3

SW6020

ARSENIC

6.9

0.2

mg/kg

KMP UNC

KMP-SS69-0000-0003-01

5/19/2022

35.65736

-108.492

0

3

SW6020

ARSENIC

6.5

0.2

mg/kg

Page 49 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KM P-SS70-0000-0003-01

5/19/2022

35.657343

-108.490976

0

3

SW6020

ARSENIC

6.1

0.2

mg/kg

KMPUNC

KMP-SS70-0000-0003-02

5/19/2022

35.657343

-108.490976

0

3

SW6020

ARSENIC

5.6

0.2

mg/kg

KMP UNC

KM P-SS71 -0000-0003-01

5/19/2022

35.656666

-108.491638

0

3

SW6020

ARSENIC

5.6

0.2

mg/kg

KMP UNC

KM P-SS72-0000-0003-01

5/19/2022

35.656683

-108.49091

0

3

SW6020

ARSENIC

5.9

0.2

mg/kg

KMP UNC

KMP-SS73-0000-0003-01

5/19/2022

35.658117

-108.493493

0

3

SW6020

ARSENIC

6.7

0.2

mg/kg

KMP UNC

KM P-SS75-0000-0003-01

5/19/2022

35.659492

-108.489461

0

3

SW6020

ARSENIC

6.7

0.2

mg/kg

KMP UNC

KMP-SS75-0000-0003-02

5/19/2022

35.659492

-108.489461

0

3

SW6020

ARSENIC

7

0.2

mg/kg

KMP UNC

KMP-SS76-0000-0003-01

5/19/2022

35.659031

-108.489527

0

3

SW6020

ARSENIC

6.8

0.2

mg/kg

KMP UNC

KMP-SS77-0000-0003-01

5/19/2022

35.658484

-108.488991

0

3

SW6020

ARSENIC

6.5

0.2

mg/kg

KMP UNC

KM P-SS78-0000-0003-01

5/19/2022

35.658169

-108.487842

0

3

SW6020

ARSENIC

5.4

0.2

mg/kg

KMP UNC

KMP-SS79-0000-0003-01

5/19/2022

35.658754

-108.491022

0

3

SW6020

ARSENIC

5

0.2

mg/kg

KMP UNC

KM P-SS45-0000-0003-01

5/19/2022

35.659562

-108.493833

0

3

SW6020

BARIUM

110

0.5

mg/kg

KMP UNC

KMP-SS45-0000-0003-02

5/19/2022

35.659562

-108.493833

0

3

SW6020

BARIUM

98

0.5

mg/kg

KMP UNC

KM P-SS46-0000-0003-01

5/19/2022

35.659453

-108.493003

0

3

SW6020

BARIUM

75

0.5

mg/kg

KMP UNC

KMP-SS47-0000-0003-01

5/19/2022

35.659543

-108.49221

0

3

SW6020

BARIUM

63

0.51

mg/kg

KMP UNC

KM P-SS48-0000-0003-01

5/19/2022

35.659648

-108.491281

0

3

SW6020

BARIUM

52

0.5

mg/kg

KMP UNC

KMP-SS50-0000-0003-01

5/19/2022

35.6595

-108.491

0

3

SW6020

BARIUM

58

0.51

mg/kg

KMP UNC

KM P-SS51-0000-0003-01

5/19/2022

35.65919

-108.491

0

3

SW6020

BARIUM

62

0.5

mg/kg

KMP UNC

KM P-SS52-0000-0003-01

5/19/2022

35.659169

-108.491722

0

3

SW6020

BARIUM

51

0.5

mg/kg

KMP UNC

KMP-SS53-0000-0003-01

5/19/2022

35.659201

-108.492371

0

3

SW6020

BARIUM

46

0.5

mg/kg

KMP UNC

KM P-SS54-0000-0003-01

5/19/2022

35.658712

-108.492621

0

3

SW6020

BARIUM

85

0.51

mg/kg

KMP UNC

KMP-SS55-0000-0003-01

5/19/2022

35.658793

-108.492026

0

3

SW6020

BARIUM

97

0.52

mg/kg

KMP UNC

KMP-SS56-0000-0003-01

5/19/2022

35.658831

-108.491366

0

3

SW6020

BARIUM

52

0.51

mg/kg

KMP UNC

KMP-SS57-0000-0003-01

5/19/2022

35.658672

-108.491525

0

3

SW6020

BARIUM

65

0.51

mg/kg

KMP UNC

KMP-SS58-0000-0003-01

5/19/2022

35.65853

-108.492

0

3

SW6020

BARIUM

64

0.5

mg/kg

KMP UNC

KMP-SS59-0000-0003-01

5/19/2022

35.658334

-108.491827

0

3

SW6020

BARIUM

70

0.5

mg/kg

KMP UNC

KMP-SS60-0000-0003-01

5/19/2022

35.658129

-108.492013

0

3

SW6020

BARIUM

66

0.51

mg/kg

KMP UNC

KM P-SS61 -0000-0003-01

5/19/2022

35.657958

-108.491301

0

3

SW6020

BARIUM

70

0.5

mg/kg

KMP UNC

KMP-SS62-0000-0003-01

5/19/2022

35.658355

-108.491208

0

3

SW6020

BARIUM

59

0.51

mg/kg

KMP UNC

KM P-SS63-0000-0003-01

5/19/2022

35.658917

-108.490612

0

3

SW6020

BARIUM

50

0.5

mg/kg

KMP UNC

KM P-SS64-0000-0003-01

5/19/2022

35.658394

-108.49068

0

3

SW6020

BARIUM

52

0.5

mg/kg

KMP UNC

KM P-SS65-0000-0003-01

5/19/2022

35.658535

-108.490274

0

3

SW6020

BARIUM

57

0.5

mg/kg

KMP UNC

KM P-SS66-0000-0003-01

5/19/2022

35.658093

-108.490734

0

3

SW6020

BARIUM

49

0.51

mg/kg

KMP UNC

KM P-SS67-0000-0003-01

5/19/2022

35.658057

-108.490414

0

3

SW6020

BARIUM

99

0.51

mg/kg

KMP UNC

KM P-SS68-0000-0003-01

5/19/2022

35.65776

-108.491

0

3

SW6020

BARIUM

91

0.51

mg/kg

KMP UNC

KM P-SS69-0000-0003-01

5/19/2022

35.65736

-108.492

0

3

SW6020

BARIUM

74

0.5

mg/kg

KMP UNC

KM P-SS70-0000-0003-01

5/19/2022

35.657343

-108.490976

0

3

SW6020

BARIUM

59

0.51

mg/kg

KMP UNC

KMP-SS70-0000-0003-02

5/19/2022

35.657343

-108.490976

0

3

SW6020

BARIUM

54

0.5

mg/kg

KMP UNC

KM P-SS71-0000-0003-01

5/19/2022

35.656666

-108.491638

0

3

SW6020

BARIUM

64

0.5

mg/kg

KMP UNC

KMP-SS72-0000-0003-01

5/19/2022

35.656683

-108.49091

0

3

SW6020

BARIUM

60

0.51

mg/kg

KMP UNC

KMP-SS73-0000-0003-01

5/19/2022

35.658117

-108.493493

0

3

SW6020

BARIUM

92

0.51

mg/kg

KMP UNC

KMP-SS75-0000-0003-01

5/19/2022

35.659492

-108.489461

0

3

SW6020

BARIUM

170

0.51

mg/kg

Page 50 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KMP-SS75-0000-0003-02

5/19/2022

35.659492

-108.489461

0

3

SW6020

BARIUM

160

0.51

mg/kg

KMPUNC

KMP-SS76-0000-0003-01

5/19/2022

35.659031

-108.489527

0

3

SW6020

BARIUM

62

0.51

mg/kg

KMP UNC

KMP-SS77-0000-0003-01

5/19/2022

35.658484

-108.488991

0

3

SW6020

BARIUM

170

0.51

mg/kg

KMP UNC

KM P-SS78-0000-0003-01

5/19/2022

35.658169

-108.487842

0

3

SW6020

BARIUM

38

0.51

mg/kg

KMP UNC

KMP-SS79-0000-0003-01

5/19/2022

35.658754

-108.491022

0

3

SW6020

BARIUM

67

0.51

mg/kg

KMP UNC

KM P-SS45-0000-0003-01

5/19/2022

35.659562

-108.493833

0

3

SW6020

BERYLLIUM

0.46

0.05

mg/kg

KMP UNC

KMP-SS45-0000-0003-02

5/19/2022

35.659562

-108.493833

0

3

SW6020

BERYLLIUM

0.45

0.05

mg/kg

KMP UNC

KM P-SS46-0000-0003-01

5/19/2022

35.659453

-108.493003

0

3

SW6020

BERYLLIUM

0.41

0.05

mg/kg

KMP UNC

KMP-SS47-0000-0003-01

5/19/2022

35.659543

-108.49221

0

3

SW6020

BERYLLIUM

0.44

0.051

mg/kg

KMP UNC

KM P-SS48-0000-0003-01

5/19/2022

35.659648

-108.491281

0

3

SW6020

BERYLLIUM

0.49

0.05

mg/kg

KMP UNC

KMP-SS50-0000-0003-01

5/19/2022

35.6595

-108.491

0

3

SW6020

BERYLLIUM

0.54

0.051

mg/kg

KMP UNC

KM P-SS51-0000-0003-01

5/19/2022

35.65919

-108.491

0

3

SW6020

BERYLLIUM

0.54

0.05

mg/kg

KMP UNC

KM P-SS52-0000-0003-01

5/19/2022

35.659169

-108.491722

0

3

SW6020

BERYLLIUM

0.5

0.05

mg/kg

KMP UNC

KMP-SS53-0000-0003-01

5/19/2022

35.659201

-108.492371

0

3

SW6020

BERYLLIUM

0.42

0.05

mg/kg

KMP UNC

KM P-SS54-0000-0003-01

5/19/2022

35.658712

-108.492621

0

3

SW6020

BERYLLIUM

0.63

0.051

mg/kg

KMP UNC

KMP-SS55-0000-0003-01

5/19/2022

35.658793

-108.492026

0

3

SW6020

BERYLLIUM

0.73

0.052

mg/kg

KMP UNC

KM P-SS56-0000-0003-01

5/19/2022

35.658831

-108.491366

0

3

SW6020

BERYLLIUM

0.49

0.051

mg/kg

KMP UNC

KMP-SS57-0000-0003-01

5/19/2022

35.658672

-108.491525

0

3

SW6020

BERYLLIUM

0.59

0.051

mg/kg

KMP UNC

KMP-SS58-0000-0003-01

5/19/2022

35.65853

-108.492

0

3

SW6020

BERYLLIUM

0.54

0.05

mg/kg

KMP UNC

KMP-SS59-0000-0003-01

5/19/2022

35.658334

-108.491827

0

3

SW6020

BERYLLIUM

0.58

0.05

mg/kg

KMP UNC

KMP-SS60-0000-0003-01

5/19/2022

35.658129

-108.492013

0

3

SW6020

BERYLLIUM

0.49

0.051

mg/kg

KMP UNC

KM P-SS61-0000-0003-01

5/19/2022

35.657958

-108.491301

0

3

SW6020

BERYLLIUM

0.52

0.05

mg/kg

KMP UNC

KMP-SS62-0000-0003-01

5/19/2022

35.658355

-108.491208

0

3

SW6020

BERYLLIUM

0.51

0.051

mg/kg

KMP UNC

KMP-SS63-0000-0003-01

5/19/2022

35.658917

-108.490612

0

3

SW6020

BERYLLIUM

0.5

0.05

mg/kg

KMP UNC

KMP-SS64-0000-0003-01

5/19/2022

35.658394

-108.49068

0

3

SW6020

BERYLLIUM

0.5

0.05

mg/kg

KMP UNC

KMP-SS65-0000-0003-01

5/19/2022

35.658535

-108.490274

0

3

SW6020

BERYLLIUM

0.49

0.05

mg/kg

KMP UNC

KMP-SS66-0000-0003-01

5/19/2022

35.658093

-108.490734

0

3

SW6020

BERYLLIUM

0.47

0.051

mg/kg

KMP UNC

KMP-SS67-0000-0003-01

5/19/2022

35.658057

-108.490414

0

3

SW6020

BERYLLIUM

0.56

0.051

mg/kg

KMP UNC

KMP-SS68-0000-0003-01

5/19/2022

35.65776

-108.491

0

3

SW6020

BERYLLIUM

0.6

0.051

mg/kg

KMP UNC

KMP-SS69-0000-0003-01

5/19/2022

35.65736

-108.492

0

3

SW6020

BERYLLIUM

0.62

0.05

mg/kg

KMP UNC

KM P-SS7 0-0000-0003-01

5/19/2022

35.657343

-108.490976

0

3

SW6020

BERYLLIUM

0.51

0.051

mg/kg

KMP UNC

KM P-SS7 0-0000-0003-02

5/19/2022

35.657343

-108.490976

0

3

SW6020

BERYLLIUM

0.47

0.05

mg/kg

KMP UNC

KMP-SS71-0000-0003-01

5/19/2022

35.656666

-108.491638

0

3

SW6020

BERYLLIUM

0.48

0.05

mg/kg

KMP UNC

KM P-SS72-0000-0003-01

5/19/2022

35.656683

-108.49091

0

3

SW6020

BERYLLIUM

0.52

0.051

mg/kg

KMP UNC

KMP-SS73-0000-0003-01

5/19/2022

35.658117

-108.493493

0

3

SW6020

BERYLLIUM

0.59

0.051

mg/kg

KMP UNC

KM P-SS75-0000-0003-01

5/19/2022

35.659492

-108.489461

0

3

SW6020

BERYLLIUM

0.48

0.051

mg/kg

KMP UNC

KMP-SS75-0000-0003-02

5/19/2022

35.659492

-108.489461

0

3

SW6020

BERYLLIUM

0.49

0.051

mg/kg

KMP UNC

KMP-SS76-0000-0003-01

5/19/2022

35.659031

-108.489527

0

3

SW6020

BERYLLIUM

0.63

0.051

mg/kg

KMP UNC

KMP-SS77-0000-0003-01

5/19/2022

35.658484

-108.488991

0

3

SW6020

BERYLLIUM

0.6

0.051

mg/kg

KMP UNC

KM P-SS78-0000-0003-01

5/19/2022

35.658169

-108.487842

0

3

SW6020

BERYLLIUM

0.47

0.051

mg/kg

KMP UNC

KMP-SS79-0000-0003-01

5/19/2022

35.658754

-108.491022

0

3

SW6020

BERYLLIUM

0.49

0.051

mg/kg

KMP UNC

KM P-SS45-0000-0003-01

5/19/2022

35.659562

-108.493833

0

3

SW6020

CADMIUM

0.12 J

0.2

mg/kg

Page 51 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KMP-SS45-0000-0003-02

5/19/2022

35.659562

-108.493833

0

3

SW6020

CADMIUM

0.1 J

0.2

mg/kg

KMPUNC

KM P-SS46-0000-0003-01

5/19/2022

35.659453

-108.493003

0

3

SW6020

CADMIUM

0.075 J

0.2

mg/kg

KMP UNC

KMP-SS47-0000-0003-01

5/19/2022

35.659543

-108.49221

0

3

SW6020

CADMIUM

0.076 J

0.2

mg/kg

KMP UNC

KM P-SS48-0000-0003-01

5/19/2022

35.659648

-108.491281

0

3

SW6020

CADMIUM

0.088 J

0.2

mg/kg

KMP UNC

KMP-SS50-0000-0003-01

5/19/2022

35.6595

-108.491

0

3

SW6020

CADMIUM

0.093 J

0.2

mg/kg

KMP UNC

KM P-SS51-0000-0003-01

5/19/2022

35.65919

-108.491

0

3

SW6020

CADMIUM

0.11 J

0.2

mg/kg

KMP UNC

KM P-SS52-0000-0003-01

5/19/2022

35.659169

-108.491722

0

3

SW6020

CADMIUM

0.048 J

0.2

mg/kg

KMP UNC

KMP-SS53-0000-0003-01

5/19/2022

35.659201

-108.492371

0

3

SW6020

CADMIUM

0.048 J

0.2

mg/kg

KMP UNC

KM P-SS54-0000-0003-01

5/19/2022

35.658712

-108.492621

0

3

SW6020

CADMIUM

0.12 J

0.2

mg/kg

KMP UNC

KMP-SS55-0000-0003-01

5/19/2022

35.658793

-108.492026

0

3

SW6020

CADMIUM

0.13 J

0.21

mg/kg

KMP UNC

KM P-SS56-0000-0003-01

5/19/2022

35.658831

-108.491366

0

3

SW6020

CADMIUM

0.067 J

0.2

mg/kg

KMP UNC

KMP-SS57-0000-0003-01

5/19/2022

35.658672

-108.491525

0

3

SW6020

CADMIUM

0.11 J

0.2

mg/kg

KMP UNC

KMP-SS58-0000-0003-01

5/19/2022

35.65853

-108.492

0

3

SW6020

CADMIUM

0.13 J

0.2

mg/kg

KMP UNC

KMP-SS59-0000-0003-01

5/19/2022

35.658334

-108.491827

0

3

SW6020

CADMIUM

0.093 J

0.2

mg/kg

KMP UNC

KM P-SS60-0000-0003-01

5/19/2022

35.658129

-108.492013

0

3

SW6020

CADMIUM

0.075 J

0.2

mg/kg

KMP UNC

KM P-SS61 -0000-0003-01

5/19/2022

35.657958

-108.491301

0

3

SW6020

CADMIUM

0.11 J

0.2

mg/kg

KMP UNC

KM P-SS62-0000-0003-01

5/19/2022

35.658355

-108.491208

0

3

SW6020

CADMIUM

0.085 J

0.2

mg/kg

KMP UNC

KM P-SS63-0000-0003-01

5/19/2022

35.658917

-108.490612

0

3

SW6020

CADMIUM

0.082 J

0.2

mg/kg

KMP UNC

KM P-SS64-0000-0003-01

5/19/2022

35.658394

-108.49068

0

3

SW6020

CADMIUM

0.065 J

0.2

mg/kg

KMP UNC

KM P-SS65-0000-0003-01

5/19/2022

35.658535

-108.490274

0

3

SW6020

CADMIUM

0.083 J

0.2

mg/kg

KMP UNC

KM P-SS66-0000-0003-01

5/19/2022

35.658093

-108.490734

0

3

SW6020

CADMIUM

0.06 J

0.2

mg/kg

KMP UNC

KMP-SS67-0000-0003-01

5/19/2022

35.658057

-108.490414

0

3

SW6020

CADMIUM

0.1 J

0.2

mg/kg

KMP UNC

KM P-SS68-0000-0003-01

5/19/2022

35.65776

-108.491

0

3

SW6020

CADMIUM

0.083 J

0.2

mg/kg

KMP UNC

KM P-SS69-0000-0003-01

5/19/2022

35.65736

-108.492

0

3

SW6020

CADMIUM

0.13 J

0.2

mg/kg

KMP UNC

KM P-SS70-0000-0003-01

5/19/2022

35.657343

-108.490976

0

3

SW6020

CADMIUM

0.073 J

0.2

mg/kg

KMP UNC

KMP-SS70-0000-0003-02

5/19/2022

35.657343

-108.490976

0

3

SW6020

CADMIUM

0.063 J

0.2

mg/kg

KMP UNC

KM P-SS71 -0000-0003-01

5/19/2022

35.656666

-108.491638

0

3

SW6020

CADMIUM

0.11 J

0.2

mg/kg

KMP UNC

KM P-SS72-0000-0003-01

5/19/2022

35.656683

-108.49091

0

3

SW6020

CADMIUM

0.079 J

0.2

mg/kg

KMP UNC

KMP-SS73-0000-0003-01

5/19/2022

35.658117

-108.493493

0

3

SW6020

CADMIUM

0.13 J

0.2

mg/kg

KMP UNC

KM P-SS75-0000-0003-01

5/19/2022

35.659492

-108.489461

0

3

SW6020

CADMIUM

0.14 J

0.2

mg/kg

KMP UNC

KMP-SS75-0000-0003-02

5/19/2022

35.659492

-108.489461

0

3

SW6020

CADMIUM

0.16 J

0.2

mg/kg

KMP UNC

KMP-SS76-0000-0003-01

5/19/2022

35.659031

-108.489527

0

3

SW6020

CADMIUM

0.12 J

0.2

mg/kg

KMP UNC

KMP-SS77-0000-0003-01

5/19/2022

35.658484

-108.488991

0

3

SW6020

CADMIUM

0.19 J

0.2

mg/kg

KMP UNC

KM P-SS78-0000-0003-01

5/19/2022

35.658169

-108.487842

0

3

SW6020

CADMIUM

0.071 J

0.2

mg/kg

KMP UNC

KMP-SS79-0000-0003-01

5/19/2022

35.658754

-108.491022

0

3

SW6020

CADMIUM

0.12 J

0.2

mg/kg

KMP UNC

KM P-SS45-0000-0003-01

5/19/2022

35.659562

-108.493833

0

3

SW6020

CHROMIUM

9.6

0.99

mg/kg

KMP UNC

KMP-SS45-0000-0003-02

5/19/2022

35.659562

-108.493833

0

3

SW6020

CHROMIUM

8.4

1

mg/kg

KMP UNC

KM P-SS46-0000-0003-01

5/19/2022

35.659453

-108.493003

0

3

SW6020

CHROMIUM

5.9

1

mg/kg

KMP UNC

KMP-SS47-0000-0003-01

5/19/2022

35.659543

-108.49221

0

3

SW6020

CHROMIUM

5.8

1

mg/kg

KMP UNC

KM P-SS48-0000-0003-01

5/19/2022

35.659648

-108.491281

0

3

SW6020

CHROMIUM

6.7

1

mg/kg

KMP UNC

KMP-SS50-0000-0003-01

5/19/2022

35.6595

-108.491

0

3

SW6020

CHROMIUM

6.9

1

mg/kg

KMP UNC

KM P-SS51-0000-0003-01

5/19/2022

35.65919

-108.491

0

3

SW6020

CHROMIUM

7.3

1

mg/kg

Page 52 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KM P-SS52-0000-0003-01

5/19/2022

35.659169

-108.491722

0

3

SW6020

CHROMIUM

6.7

1

mg/kg

KMPUNC

KMP-SS53-0000-0003-01

5/19/2022

35.659201

-108.492371

0

3

SW6020

CHROMIUM

5.5

1

mg/kg

KMP UNC

KM P-SS54-0000-0003-01

5/19/2022

35.658712

-108.492621

0

3

SW6020

CHROMIUM

8.7

1

mg/kg

KMP UNC

KMP-SS55-0000-0003-01

5/19/2022

35.658793

-108.492026

0

3

SW6020

CHROMIUM

9.3

1

mg/kg

KMP UNC

KM P-SS56-0000-0003-01

5/19/2022

35.658831

-108.491366

0

3

SW6020

CHROMIUM

6.5

1

mg/kg

KMP UNC

KMP-SS57-0000-0003-01

5/19/2022

35.658672

-108.491525

0

3

SW6020

CHROMIUM

8.1

1

mg/kg

KMP UNC

KMP-SS58-0000-0003-01

5/19/2022

35.65853

-108.492

0

3

SW6020

CHROMIUM

7.4

1

mg/kg

KMP UNC

KMP-SS59-0000-0003-01

5/19/2022

35.658334

-108.491827

0

3

SW6020

CHROMIUM

7.7

1

mg/kg

KMP UNC

KM P-SS60-0000-0003-01

5/19/2022

35.658129

-108.492013

0

3

SW6020

CHROMIUM

6.7

1

mg/kg

KMP UNC

KM P-SS61 -0000-0003-01

5/19/2022

35.657958

-108.491301

0

3

SW6020

CHROMIUM

7.1

1

mg/kg

KMP UNC

KM P-SS62-0000-0003-01

5/19/2022

35.658355

-108.491208

0

3

SW6020

CHROMIUM

7

1

mg/kg

KMP UNC

KM P-SS63-0000-0003-01

5/19/2022

35.658917

-108.490612

0

3

SW6020

CHROMIUM

6.6

1

mg/kg

KMP UNC

KM P-SS64-0000-0003-01

5/19/2022

35.658394

-108.49068

0

3

SW6020

CHROMIUM

6.9

1

mg/kg

KMP UNC

KM P-SS65-0000-0003-01

5/19/2022

35.658535

-108.490274

0

3

SW6020

CHROMIUM

6.9

1

mg/kg

KMP UNC

KM P-SS66-0000-0003-01

5/19/2022

35.658093

-108.490734

0

3

SW6020

CHROMIUM

6.2

1

mg/kg

KMP UNC

KMP-SS67-0000-0003-01

5/19/2022

35.658057

-108.490414

0

3

SW6020

CHROMIUM

7.9

1

mg/kg

KMP UNC

KM P-SS68-0000-0003-01

5/19/2022

35.65776

-108.491

0

3

SW6020

CHROMIUM

8.3

1

mg/kg

KMP UNC

KMP-SS69-0000-0003-01

5/19/2022

35.65736

-108.492

0

3

SW6020

CHROMIUM

8.4

1

mg/kg

KMP UNC

KMP-SS70-0000-0003-01

5/19/2022

35.657343

-108.490976

0

3

SW6020

CHROMIUM

7.1

1

mg/kg

KMP UNC

KMP-SS70-0000-0003-02

5/19/2022

35.657343

-108.490976

0

3

SW6020

CHROMIUM

6.7

1

mg/kg

KMP UNC

KM P-SS71-0000-0003-01

5/19/2022

35.656666

-108.491638

0

3

SW6020

CHROMIUM

7

1

mg/kg

KMP UNC

KMP-SS72-0000-0003-01

5/19/2022

35.656683

-108.49091

0

3

SW6020

CHROMIUM

7.2

1

mg/kg

KMP UNC

KMP-SS73-0000-0003-01

5/19/2022

35.658117

-108.493493

0

3

SW6020

CHROMIUM

8.1

1

mg/kg

KMP UNC

KMP-SS75-0000-0003-01

5/19/2022

35.659492

-108.489461

0

3

SW6020

CHROMIUM

10 J

1

mg/kg

KMP UNC

KMP-SS75-0000-0003-02

5/19/2022

35.659492

-108.489461

0

3

SW6020

CHROMIUM

24 J

1

mg/kg

KMP UNC

KMP-SS76-0000-0003-01

5/19/2022

35.659031

-108.489527

0

3

SW6020

CHROMIUM

00
CO

1

mg/kg

KMP UNC

KMP-SS77-0000-0003-01

5/19/2022

35.658484

-108.488991

0

3

SW6020

CHROMIUM

8.4

1

mg/kg

KMP UNC

KMP-SS78-0000-0003-01

5/19/2022

35.658169

-108.487842

0

3

SW6020

CHROMIUM

6.4

1

mg/kg

KMP UNC

KMP-SS79-0000-0003-01

5/19/2022

35.658754

-108.491022

0

3

SW6020

CHROMIUM

6.7

1

mg/kg

KMP UNC

KMP-SS45-0000-0003-01

5/19/2022

35.659562

-108.493833

0

3

SW6020

COBALT

4.7

0.5

mg/kg

KMP UNC

KMP-SS45-0000-0003-02

5/19/2022

35.659562

-108.493833

0

3

SW6020

COBALT

4.6

0.5

mg/kg

KMP UNC

KM P-SS46-0000-0003-01

5/19/2022

35.659453

-108.493003

0

3

SW6020

COBALT

4

0.5

mg/kg

KMP UNC

KMP-SS47-0000-0003-01

5/19/2022

35.659543

-108.49221

0

3

SW6020

COBALT

4.2

0.51

mg/kg

KMP UNC

KMP-SS48-0000-0003-01

5/19/2022

35.659648

-108.491281

0

3

SW6020

COBALT

4.4

0.5

mg/kg

KMP UNC

KMP-SS50-0000-0003-01

5/19/2022

35.6595

-108.491

0

3

SW6020

COBALT

4.6

0.51

mg/kg

KMP UNC

KM P-SS51-0000-0003-01

5/19/2022

35.65919

-108.491

0

3

SW6020

COBALT

5.1

0.5

mg/kg

KMP UNC

KM P-SS52-0000-0003-01

5/19/2022

35.659169

-108.491722

0

3

SW6020

COBALT

4.6

0.5

mg/kg

KMP UNC

KMP-SS53-0000-0003-01

5/19/2022

35.659201

-108.492371

0

3

SW6020

COBALT

4

0.5

mg/kg

KMP UNC

KM P-SS54-0000-0003-01

5/19/2022

35.658712

-108.492621

0

3

SW6020

COBALT

6

0.51

mg/kg

KMP UNC

KMP-SS55-0000-0003-01

5/19/2022

35.658793

-108.492026

0

3

SW6020

COBALT

6.7

0.52

mg/kg

KMP UNC

KM P-SS56-0000-0003-01

5/19/2022

35.658831

-108.491366

0

3

SW6020

COBALT

4.1

0.51

mg/kg

KMP UNC

KMP-SS57-0000-0003-01

5/19/2022

35.658672

-108.491525

0

3

SW6020

COBALT

5.4

0.51

mg/kg

Page 53 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KMP-SS58-0000-0003-01

5/19/2022

35.65853

-108.492

0

3

SW6020

COBALT

4.8

0.5

mg/kg

KMPUNC

KMP-SS59-0000-0003-01

5/19/2022

35.658334

-108.491827

0

3

SW6020

COBALT

5.3

0.5

mg/kg

KMP UNC

KM P-SS60-0000-0003-01

5/19/2022

35.658129

-108.492013

0

3

SW6020

COBALT

4.9

0.51

mg/kg

KMP UNC

KM P-SS61 -0000-0003-01

5/19/2022

35.657958

-108.491301

0

3

SW6020

COBALT

4.6

0.5

mg/kg

KMP UNC

KM P-SS62-0000-0003-01

5/19/2022

35.658355

-108.491208

0

3

SW6020

COBALT

4.4

0.51

mg/kg

KMP UNC

KM P-SS63-0000-0003-01

5/19/2022

35.658917

-108.490612

0

3

SW6020

COBALT

4.3

0.5

mg/kg

KMP UNC

KM P-SS64-0000-0003-01

5/19/2022

35.658394

-108.49068

0

3

SW6020

COBALT

4.5

0.5

mg/kg

KMP UNC

KM P-SS65-0000-0003-01

5/19/2022

35.658535

-108.490274

0

3

SW6020

COBALT

4.6

0.5

mg/kg

KMP UNC

KM P-SS66-0000-0003-01

5/19/2022

35.658093

-108.490734

0

3

SW6020

COBALT

4.2

0.51

mg/kg

KMP UNC

KMP-SS67-0000-0003-01

5/19/2022

35.658057

-108.490414

0

3

SW6020

COBALT

5.5

0.51

mg/kg

KMP UNC

KM P-SS68-0000-0003-01

5/19/2022

35.65776

-108.491

0

3

SW6020

COBALT

6

0.51

mg/kg

KMP UNC

KMP-SS69-0000-0003-01

5/19/2022

35.65736

-108.492

0

3

SW6020

COBALT

5.7

0.5

mg/kg

KMP UNC

KMP-SS70-0000-0003-01

5/19/2022

35.657343

-108.490976

0

3

SW6020

COBALT

5.3

0.51

mg/kg

KMP UNC

KMP-SS70-0000-0003-02

5/19/2022

35.657343

-108.490976

0

3

SW6020

COBALT

4.9

0.5

mg/kg

KMP UNC

KM P-SS71-0000-0003-01

5/19/2022

35.656666

-108.491638

0

3

SW6020

COBALT

4.7

0.5

mg/kg

KMP UNC

KMP-SS72-0000-0003-01

5/19/2022

35.656683

-108.49091

0

3

SW6020

COBALT

5.2

0.51

mg/kg

KMP UNC

KMP-SS73-0000-0003-01

5/19/2022

35.658117

-108.493493

0

3

SW6020

COBALT

5.9

0.51

mg/kg

KMP UNC

KMP-SS75-0000-0003-01

5/19/2022

35.659492

-108.489461

0

3

SW6020

COBALT

4.9

0.51

mg/kg

KMP UNC

KMP-SS75-0000-0003-02

5/19/2022

35.659492

-108.489461

0

3

SW6020

COBALT

5.3

0.51

mg/kg

KMP UNC

KMP-SS76-0000-0003-01

5/19/2022

35.659031

-108.489527

0

3

SW6020

COBALT

5.5

0.51

mg/kg

KMP UNC

KMP-SS77-0000-0003-01

5/19/2022

35.658484

-108.488991

0

3

SW6020

COBALT

5.7

0.51

mg/kg

KMP UNC

KMP-SS78-0000-0003-01

5/19/2022

35.658169

-108.487842

0

3

SW6020

COBALT

5.1

0.51

mg/kg

KMP UNC

KMP-SS79-0000-0003-01

5/19/2022

35.658754

-108.491022

0

3

SW6020

COBALT

4.6

0.51

mg/kg

KMP UNC

KMP-SS45-0000-0003-01

5/19/2022

35.659562

-108.493833

0

3

SW6020

COPPER

9

2

mg/kg

KMP UNC

KMP-SS45-0000-0003-02

5/19/2022

35.659562

-108.493833

0

3

SW6020

COPPER

00
CO

2

mg/kg

KMP UNC

KM P-SS46-0000-0003-01

5/19/2022

35.659453

-108.493003

0

3

SW6020

COPPER

7.2

2

mg/kg

KMP UNC

KMP-SS47-0000-0003-01

5/19/2022

35.659543

-108.49221

0

3

SW6020

COPPER

6.4

2

mg/kg

KMP UNC

KMP-SS48-0000-0003-01

5/19/2022

35.659648

-108.491281

0

3

SW6020

COPPER

7.7

2

mg/kg

KMP UNC

KMP-SS50-0000-0003-01

5/19/2022

35.6595

-108.491

0

3

SW6020

COPPER

8

2

mg/kg

KMP UNC

KM P-SS51-0000-0003-01

5/19/2022

35.65919

-108.491

0

3

SW6020

COPPER

8.9

2

mg/kg

KMP UNC

KMP-SS52-0000-0003-01

5/19/2022

35.659169

-108.491722

0

3

SW6020

COPPER

7

2

mg/kg

KMP UNC

KMP-SS53-0000-0003-01

5/19/2022

35.659201

-108.492371

0

3

SW6020

COPPER

5.3

2

mg/kg

KMP UNC

KMP-SS54-0000-0003-01

5/19/2022

35.658712

-108.492621

0

3

SW6020

COPPER

13

2

mg/kg

KMP UNC

KMP-SS55-0000-0003-01

5/19/2022

35.658793

-108.492026

0

3

SW6020

COPPER

15

2.1

mg/kg

KMP UNC

KM P-SS56-0000-0003-01

5/19/2022

35.658831

-108.491366

0

3

SW6020

COPPER

7.4

2

mg/kg

KMP UNC

KMP-SS57-0000-0003-01

5/19/2022

35.658672

-108.491525

0

3

SW6020

COPPER

10

2

mg/kg

KMP UNC

KMP-SS58-0000-0003-01

5/19/2022

35.65853

-108.492

0

3

SW6020

COPPER

9.3

2

mg/kg

KMP UNC

KMP-SS59-0000-0003-01

5/19/2022

35.658334

-108.491827

0

3

SW6020

COPPER

9.5

2

mg/kg

KMP UNC

KM P-SS60-0000-0003-01

5/19/2022

35.658129

-108.492013

0

3

SW6020

COPPER

9.2

2

mg/kg

KMP UNC

KM P-SS61 -0000-0003-01

5/19/2022

35.657958

-108.491301

0

3

SW6020

COPPER

00
CO

2

mg/kg

KMP UNC

KM P-SS62-0000-0003-01

5/19/2022

35.658355

-108.491208

0

3

SW6020

COPPER

7.9

2

mg/kg

KMP UNC

KM P-SS63-0000-0003-01

5/19/2022

35.658917

-108.490612

0

3

SW6020

COPPER

7.1

2

mg/kg

Page 54 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KM P-SS64-0000-0003-01

5/19/2022

35.658394

-108.49068

0

3

SW6020

COPPER

7.7

2

mg/kg

KMPUNC

KM P-SS65-0000-0003-01

5/19/2022

35.658535

-108.490274

0

3

SW6020

COPPER

8.2

2

mg/kg

KMP UNC

KM P-SS66-0000-0003-01

5/19/2022

35.658093

-108.490734

0

3

SW6020

COPPER

6.5

2

mg/kg

KMP UNC

KMP-SS67-0000-0003-01

5/19/2022

35.658057

-108.490414

0

3

SW6020

COPPER

11

2

mg/kg

KMP UNC

KM P-SS68-0000-0003-01

5/19/2022

35.65776

-108.491

0

3

SW6020

COPPER

11

2

mg/kg

KMP UNC

KM P-SS69-0000-0003-01

5/19/2022

35.65736

-108.492

0

3

SW6020

COPPER

11

2

mg/kg

KMP UNC

KMP-SS70-0000-0003-01

5/19/2022

35.657343

-108.490976

0

3

SW6020

COPPER

9.2

2

mg/kg

KMP UNC

KMP-SS70-0000-0003-02

5/19/2022

35.657343

-108.490976

0

3

SW6020

COPPER

8.1

2

mg/kg

KMP UNC

KM P-SS71-0000-0003-01

5/19/2022

35.656666

-108.491638

0

3

SW6020

COPPER

00
CO

2

mg/kg

KMP UNC

KMP-SS72-0000-0003-01

5/19/2022

35.656683

-108.49091

0

3

SW6020

COPPER

9.6

2

mg/kg

KMP UNC

KMP-SS73-0000-0003-01

5/19/2022

35.658117

-108.493493

0

3

SW6020

COPPER

13

2

mg/kg

KMP UNC

KMP-SS75-0000-0003-01

5/19/2022

35.659492

-108.489461

0

3

SW6020

COPPER

16

2

mg/kg

KMP UNC

KMP-SS75-0000-0003-02

5/19/2022

35.659492

-108.489461

0

3

SW6020

COPPER

18

2

mg/kg

KMP UNC

KMP-SS76-0000-0003-01

5/19/2022

35.659031

-108.489527

0

3

SW6020

COPPER

12

2

mg/kg

KMP UNC

KMP-SS77-0000-0003-01

5/19/2022

35.658484

-108.488991

0

3

SW6020

COPPER

14

2

mg/kg

KMP UNC

KMP-SS78-0000-0003-01

5/19/2022

35.658169

-108.487842

0

3

SW6020

COPPER

7.3

2

mg/kg

KMP UNC

KMP-SS79-0000-0003-01

5/19/2022

35.658754

-108.491022

0

3

SW6020

COPPER

8.7

2

mg/kg

KMP UNC

KMP-SS45-0000-0003-01

5/19/2022

35.659562

-108.493833

0

3

SW6020

IRON

9300

20

mg/kg

KMP UNC

KMP-SS45-0000-0003-02

5/19/2022

35.659562

-108.493833

0

3

SW6020

IRON

9000

20

mg/kg

KMP UNC

KMP-SS46-0000-0003-01

5/19/2022

35.659453

-108.493003

0

3

SW6020

IRON

11000

20

mg/kg

KMP UNC

KMP-SS47-0000-0003-01

5/19/2022

35.659543

-108.49221

0

3

SW6020

IRON

12000

20

mg/kg

KMP UNC

KMP-SS48-0000-0003-01

5/19/2022

35.659648

-108.491281

0

3

SW6020

IRON

13000

20

mg/kg

KMP UNC

KMP-SS50-0000-0003-01

5/19/2022

35.6595

-108.491

0

3

SW6020

IRON

14000

20

mg/kg

KMP UNC

KM P-SS51-0000-0003-01

5/19/2022

35.65919

-108.491

0

3

SW6020

IRON

14000

20

mg/kg

KMP UNC

KM P-SS52-0000-0003-01

5/19/2022

35.659169

-108.491722

0

3

SW6020

IRON

14000

20

mg/kg

KMP UNC

KMP-SS53-0000-0003-01

5/19/2022

35.659201

-108.492371

0

3

SW6020

IRON

12000

20

mg/kg

KMP UNC

KMP-SS54-0000-0003-01

5/19/2022

35.658712

-108.492621

0

3

SW6020

IRON

17000

20

mg/kg

KMP UNC

KMP-SS55-0000-0003-01

5/19/2022

35.658793

-108.492026

0

3

SW6020

IRON

19000

21

mg/kg

KMP UNC

KMP-SS56-0000-0003-01

5/19/2022

35.658831

-108.491366

0

3

SW6020

IRON

13000

20

mg/kg

KMP UNC

KMP-SS57-0000-0003-01

5/19/2022

35.658672

-108.491525

0

3

SW6020

IRON

16000

20

mg/kg

KMP UNC

KMP-SS58-0000-0003-01

5/19/2022

35.65853

-108.492

0

3

SW6020

IRON

14000

20

mg/kg

KMP UNC

KMP-SS59-0000-0003-01

5/19/2022

35.658334

-108.491827

0

3

SW6020

IRON

16000

20

mg/kg

KMP UNC

KMP-SS60-0000-0003-01

5/19/2022

35.658129

-108.492013

0

3

SW6020

IRON

14000

20

mg/kg

KMP UNC

KM P-SS61-0000-0003-01

5/19/2022

35.657958

-108.491301

0

3

SW6020

IRON

14000

20

mg/kg

KMP UNC

KM P-SS62-0000-0003-01

5/19/2022

35.658355

-108.491208

0

3

SW6020

IRON

14000

20

mg/kg

KMP UNC

KM P-SS63-0000-0003-01

5/19/2022

35.658917

-108.490612

0

3

SW6020

IRON

13000

20

mg/kg

KMP UNC

KMP-SS64-0000-0003-01

5/19/2022

35.658394

-108.49068

0

3

SW6020

IRON

14000

20

mg/kg

KMP UNC

KMP-SS65-0000-0003-01

5/19/2022

35.658535

-108.490274

0

3

SW6020

IRON

14000

20

mg/kg

KMP UNC

KMP-SS66-0000-0003-01

5/19/2022

35.658093

-108.490734

0

3

SW6020

IRON

13000

20

mg/kg

KMP UNC

KMP-SS67-0000-0003-01

5/19/2022

35.658057

-108.490414

0

3

SW6020

IRON

16000

20

mg/kg

KMP UNC

KMP-SS68-0000-0003-01

5/19/2022

35.65776

-108.491

0

3

SW6020

IRON

17000

20

mg/kg

KMP UNC

KMP-SS69-0000-0003-01

5/19/2022

35.65736

-108.492

0

3

SW6020

IRON

17000

20

mg/kg

Page 55 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KM P-SS70-0000-0003-01

5/19/2022

35.657343

-108.490976

0

3

SW6020

IRON

15000

20

mg/kg

KMPUNC

KMP-SS70-0000-0003-02

5/19/2022

35.657343

-108.490976

0

3

SW6020

IRON

14000

20

mg/kg

KMP UNC

KM P-SS71 -0000-0003-01

5/19/2022

35.656666

-108.491638

0

3

SW6020

IRON

14000

20

mg/kg

KMP UNC

KM P-SS72-0000-0003-01

5/19/2022

35.656683

-108.49091

0

3

SW6020

IRON

15000

20

mg/kg

KMP UNC

KMP-SS73-0000-0003-01

5/19/2022

35.658117

-108.493493

0

3

SW6020

IRON

16000

20

mg/kg

KMP UNC

KM P-SS75-0000-0003-01

5/19/2022

35.659492

-108.489461

0

3

SW6020

IRON

17000

20

mg/kg

KMP UNC

KMP-SS75-0000-0003-02

5/19/2022

35.659492

-108.489461

0

3

SW6020

IRON

19000

20

mg/kg

KMP UNC

KMP-SS76-0000-0003-01

5/19/2022

35.659031

-108.489527

0

3

SW6020

IRON

17000

20

mg/kg

KMP UNC

KMP-SS77-0000-0003-01

5/19/2022

35.658484

-108.488991

0

3

SW6020

IRON

16000

20

mg/kg

KMP UNC

KM P-SS78-0000-0003-01

5/19/2022

35.658169

-108.487842

0

3

SW6020

IRON

14000

20

mg/kg

KMP UNC

KMP-SS79-0000-0003-01

5/19/2022

35.658754

-108.491022

0

3

SW6020

IRON

13000

20

mg/kg

KMP UNC

KM P-SS45-0000-0003-01

5/19/2022

35.659562

-108.493833

0

3

SW6020

LEAD

8.1

0.2

mg/kg

KMP UNC

KMP-SS45-0000-0003-02

5/19/2022

35.659562

-108.493833

0

3

SW6020

LEAD

8.1

0.2

mg/kg

KMP UNC

KM P-SS46-0000-0003-01

5/19/2022

35.659453

-108.493003

0

3

SW6020

LEAD

7.4

0.2

mg/kg

KMP UNC

KMP-SS47-0000-0003-01

5/19/2022

35.659543

-108.49221

0

3

SW6020

LEAD

7.9

0.2

mg/kg

KMP UNC

KM P-SS48-0000-0003-01

5/19/2022

35.659648

-108.491281

0

3

SW6020

LEAD

9.5

0.2

mg/kg

KMP UNC

KMP-SS50-0000-0003-01

5/19/2022

35.6595

-108.491

0

3

SW6020

LEAD

10

0.2

mg/kg

KMP UNC

KM P-SS51-0000-0003-01

5/19/2022

35.65919

-108.491

0

3

SW6020

LEAD

11

0.2

mg/kg

KMP UNC

KM P-SS52-0000-0003-01

5/19/2022

35.659169

-108.491722

0

3

SW6020

LEAD

8.5

0.2

mg/kg

KMP UNC

KMP-SS53-0000-0003-01

5/19/2022

35.659201

-108.492371

0

3

SW6020

LEAD

7.2

0.2

mg/kg

KMP UNC

KM P-SS54-0000-0003-01

5/19/2022

35.658712

-108.492621

0

3

SW6020

LEAD

12

0.2

mg/kg

KMP UNC

KMP-SS55-0000-0003-01

5/19/2022

35.658793

-108.492026

0

3

SW6020

LEAD

15

0.21

mg/kg

KMP UNC

KMP-SS56-0000-0003-01

5/19/2022

35.658831

-108.491366

0

3

SW6020

LEAD

9.1

0.2

mg/kg

KMP UNC

KMP-SS57-0000-0003-01

5/19/2022

35.658672

-108.491525

0

3

SW6020

LEAD

12

0.2

mg/kg

KMP UNC

KMP-SS58-0000-0003-01

5/19/2022

35.65853

-108.492

0

3

SW6020

LEAD

11

0.2

mg/kg

KMP UNC

KMP-SS59-0000-0003-01

5/19/2022

35.658334

-108.491827

0

3

SW6020

LEAD

11

0.2

mg/kg

KMP UNC

KMP-SS60-0000-0003-01

5/19/2022

35.658129

-108.492013

0

3

SW6020

LEAD

10

0.2

mg/kg

KMP UNC

KM P-SS61 -0000-0003-01

5/19/2022

35.657958

-108.491301

0

3

SW6020

LEAD

11

0.2

mg/kg

KMP UNC

KMP-SS62-0000-0003-01

5/19/2022

35.658355

-108.491208

0

3

SW6020

LEAD

9.3

0.2

mg/kg

KMP UNC

KM P-SS63-0000-0003-01

5/19/2022

35.658917

-108.490612

0

3

SW6020

LEAD

8.6

0.2

mg/kg

KMP UNC

KM P-SS64-0000-0003-01

5/19/2022

35.658394

-108.49068

0

3

SW6020

LEAD

9.1

0.2

mg/kg

KMP UNC

KM P-SS65-0000-0003-01

5/19/2022

35.658535

-108.490274

0

3

SW6020

LEAD

9.9

0.2

mg/kg

KMP UNC

KM P-SS66-0000-0003-01

5/19/2022

35.658093

-108.490734

0

3

SW6020

LEAD

8.3

0.2

mg/kg

KMP UNC

KM P-SS67-0000-0003-01

5/19/2022

35.658057

-108.490414

0

3

SW6020

LEAD

12

0.2

mg/kg

KMP UNC

KM P-SS68-0000-0003-01

5/19/2022

35.65776

-108.491

0

3

SW6020

LEAD

12

0.2

mg/kg

KMP UNC

KM P-SS69-0000-0003-01

5/19/2022

35.65736

-108.492

0

3

SW6020

LEAD

12

0.2

mg/kg

KMP UNC

KM P-SS70-0000-0003-01

5/19/2022

35.657343

-108.490976

0

3

SW6020

LEAD

10

0.2

mg/kg

KMP UNC

KMP-SS70-0000-0003-02

5/19/2022

35.657343

-108.490976

0

3

SW6020

LEAD

9.4

0.2

mg/kg

KMP UNC

KM P-SS71-0000-0003-01

5/19/2022

35.656666

-108.491638

0

3

SW6020

LEAD

11

0.2

mg/kg

KMP UNC

KMP-SS72-0000-0003-01

5/19/2022

35.656683

-108.49091

0

3

SW6020

LEAD

10

0.2

mg/kg

KMP UNC

KMP-SS73-0000-0003-01

5/19/2022

35.658117

-108.493493

0

3

SW6020

LEAD

13

0.2

mg/kg

KMP UNC

KMP-SS75-0000-0003-01

5/19/2022

35.659492

-108.489461

0

3

SW6020

LEAD

37 J

0.2

mg/kg

Page 56 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KMP-SS75-0000-0003-02

5/19/2022

35.659492

-108.489461

0

3

SW6020

LEAD

130 J

0.2

mg/kg

KMPUNC

KMP-SS76-0000-0003-01

5/19/2022

35.659031

-108.489527

0

3

SW6020

LEAD

14

0.2

mg/kg

KMP UNC

KMP-SS77-0000-0003-01

5/19/2022

35.658484

-108.488991

0

3

SW6020

LEAD

16

0.2

mg/kg

KMP UNC

KM P-SS78-0000-0003-01

5/19/2022

35.658169

-108.487842

0

3

SW6020

LEAD

9.2

0.2

mg/kg

KMP UNC

KMP-SS79-0000-0003-01

5/19/2022

35.658754

-108.491022

0

3

SW6020

LEAD

11

0.2

mg/kg

KMP UNC

KM P-SS45-0000-0003-01

5/19/2022

35.659562

-108.493833

0

3

SW6020

MANGANESE

160

0.75

mg/kg

KMP UNC

KMP-SS45-0000-0003-02

5/19/2022

35.659562

-108.493833

0

3

SW6020

MANGANESE

180

0.75

mg/kg

KMP UNC

KM P-SS46-0000-0003-01

5/19/2022

35.659453

-108.493003

0

3

SW6020

MANGANESE

180

0.75

mg/kg

KMP UNC

KMP-SS47-0000-0003-01

5/19/2022

35.659543

-108.49221

0

3

SW6020

MANGANESE

190

0.76

mg/kg

KMP UNC

KM P-SS48-0000-0003-01

5/19/2022

35.659648

-108.491281

0

3

SW6020

MANGANESE

200

0.75

mg/kg

KMP UNC

KMP-SS50-0000-0003-01

5/19/2022

35.6595

-108.491

0

3

SW6020

MANGANESE

200

0.76

mg/kg

KMP UNC

KM P-SS51-0000-0003-01

5/19/2022

35.65919

-108.491

0

3

SW6020

MANGANESE

210

0.75

mg/kg

KMP UNC

KM P-SS52-0000-0003-01

5/19/2022

35.659169

-108.491722

0

3

SW6020

MANGANESE

180

0.75

mg/kg

KMP UNC

KMP-SS53-0000-0003-01

5/19/2022

35.659201

-108.492371

0

3

SW6020

MANGANESE

180

0.75

mg/kg

KMP UNC

KM P-SS54-0000-0003-01

5/19/2022

35.658712

-108.492621

0

3

SW6020

MANGANESE

230

0.76

mg/kg

KMP UNC

KMP-SS55-0000-0003-01

5/19/2022

35.658793

-108.492026

0

3

SW6020

MANGANESE

270

0.78

mg/kg

KMP UNC

KMP-SS56-0000-0003-01

5/19/2022

35.658831

-108.491366

0

3

SW6020

MANGANESE

200

0.76

mg/kg

KMP UNC

KMP-SS57-0000-0003-01

5/19/2022

35.658672

-108.491525

0

3

SW6020

MANGANESE

210

0.77

mg/kg

KMP UNC

KMP-SS58-0000-0003-01

5/19/2022

35.65853

-108.492

0

3

SW6020

MANGANESE

220

0.75

mg/kg

KMP UNC

KMP-SS59-0000-0003-01

5/19/2022

35.658334

-108.491827

0

3

SW6020

MANGANESE

220

0.76

mg/kg

KMP UNC

KMP-SS60-0000-0003-01

5/19/2022

35.658129

-108.492013

0

3

SW6020

MANGANESE

190

0.76

mg/kg

KMP UNC

KM P-SS61 -0000-0003-01

5/19/2022

35.657958

-108.491301

0

3

SW6020

MANGANESE

200

0.75

mg/kg

KMP UNC

KMP-SS62-0000-0003-01

5/19/2022

35.658355

-108.491208

0

3

SW6020

MANGANESE

200

0.76

mg/kg

KMP UNC

KM P-SS63-0000-0003-01

5/19/2022

35.658917

-108.490612

0

3

SW6020

MANGANESE

190

0.75

mg/kg

KMP UNC

KM P-SS64-0000-0003-01

5/19/2022

35.658394

-108.49068

0

3

SW6020

MANGANESE

180

0.75

mg/kg

KMP UNC

KM P-SS65-0000-0003-01

5/19/2022

35.658535

-108.490274

0

3

SW6020

MANGANESE

210

0.76

mg/kg

KMP UNC

KM P-SS66-0000-0003-01

5/19/2022

35.658093

-108.490734

0

3

SW6020

MANGANESE

180

0.76

mg/kg

KMP UNC

KM P-SS67-0000-0003-01

5/19/2022

35.658057

-108.490414

0

3

SW6020

MANGANESE

230

0.76

mg/kg

KMP UNC

KM P-SS68-0000-0003-01

5/19/2022

35.65776

-108.491

0

3

SW6020

MANGANESE

220

0.77

mg/kg

KMP UNC

KM P-SS69-0000-0003-01

5/19/2022

35.65736

-108.492

0

3

SW6020

MANGANESE

230

0.75

mg/kg

KMP UNC

KMP-SS70-0000-0003-01

5/19/2022

35.657343

-108.490976

0

3

SW6020

MANGANESE

170

0.76

mg/kg

KMP UNC

KMP-SS70-0000-0003-02

5/19/2022

35.657343

-108.490976

0

3

SW6020

MANGANESE

160

0.75

mg/kg

KMP UNC

KM P-SS71 -0000-0003-01

5/19/2022

35.656666

-108.491638

0

3

SW6020

MANGANESE

200

0.75

mg/kg

KMP UNC

KMP-SS72-0000-0003-01

5/19/2022

35.656683

-108.49091

0

3

SW6020

MANGANESE

200

0.76

mg/kg

KMP UNC

KMP-SS73-0000-0003-01

5/19/2022

35.658117

-108.493493

0

3

SW6020

MANGANESE

230

0.76

mg/kg

KMP UNC

KM P-SS75-0000-0003-01

5/19/2022

35.659492

-108.489461

0

3

SW6020

MANGANESE

240

0.76

mg/kg

KMP UNC

KMP-SS75-0000-0003-02

5/19/2022

35.659492

-108.489461

0

3

SW6020

MANGANESE

230

0.76

mg/kg

KMP UNC

KMP-SS76-0000-0003-01

5/19/2022

35.659031

-108.489527

0

3

SW6020

MANGANESE

230

0.76

mg/kg

KMP UNC

KMP-SS77-0000-0003-01

5/19/2022

35.658484

-108.488991

0

3

SW6020

MANGANESE

310

0.76

mg/kg

KMP UNC

KMP-SS78-0000-0003-01

5/19/2022

35.658169

-108.487842

0

3

SW6020

MANGANESE

210

0.76

mg/kg

KMP UNC

KMP-SS79-0000-0003-01

5/19/2022

35.658754

-108.491022

0

3

SW6020

MANGANESE

230

0.76

mg/kg

KMP UNC

KMP-SS45-0000-0003-01

5/19/2022

35.659562

-108.493833

0

3

SW6020

MOLYBDENUM

0.24

0.2

mg/kg

Page 57 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KMP-SS45-0000-0003-02

5/19/2022

35.659562

-108.493833

0

3

SW6020

MOLYBDENUM

0.24

0.2

mg/kg

KMPUNC

KM P-SS46-0000-0003-01

5/19/2022

35.659453

-108.493003

0

3

SW6020

MOLYBDENUM

0.26

0.2

mg/kg

KMP UNC

KMP-SS47-0000-0003-01

5/19/2022

35.659543

-108.49221

0

3

SW6020

MOLYBDENUM

0.25

0.2

mg/kg

KMP UNC

KM P-SS48-0000-0003-01

5/19/2022

35.659648

-108.491281

0

3

SW6020

MOLYBDENUM

0.45

0.2

mg/kg

KMP UNC

KMP-SS50-0000-0003-01

5/19/2022

35.6595

-108.491

0

3

SW6020

MOLYBDENUM

0.34 J

0.2

mg/kg

KMP UNC

KM P-SS51-0000-0003-01

5/19/2022

35.65919

-108.491

0

3

SW6020

MOLYBDENUM

0.29

0.2

mg/kg

KMP UNC

KM P-SS52-0000-0003-01

5/19/2022

35.659169

-108.491722

0

3

SW6020

MOLYBDENUM

0.37

0.2

mg/kg

KMP UNC

KMP-SS53-0000-0003-01

5/19/2022

35.659201

-108.492371

0

3

SW6020

MOLYBDENUM

0.28

0.2

mg/kg

KMP UNC

KM P-SS54-0000-0003-01

5/19/2022

35.658712

-108.492621

0

3

SW6020

MOLYBDENUM

0.44

0.2

mg/kg

KMP UNC

KMP-SS55-0000-0003-01

5/19/2022

35.658793

-108.492026

0

3

SW6020

MOLYBDENUM

0.55

0.21

mg/kg

KMP UNC

KM P-SS56-0000-0003-01

5/19/2022

35.658831

-108.491366

0

3

SW6020

MOLYBDENUM

0.46

0.2

mg/kg

KMP UNC

KMP-SS57-0000-0003-01

5/19/2022

35.658672

-108.491525

0

3

SW6020

MOLYBDENUM

0.58

0.2

mg/kg

KMP UNC

KMP-SS58-0000-0003-01

5/19/2022

35.65853

-108.492

0

3

SW6020

MOLYBDENUM

0.38

0.2

mg/kg

KMP UNC

KMP-SS59-0000-0003-01

5/19/2022

35.658334

-108.491827

0

3

SW6020

MOLYBDENUM

0.46

0.2

mg/kg

KMP UNC

KMP-SS60-0000-0003-01

5/19/2022

35.658129

-108.492013

0

3

SW6020

MOLYBDENUM

0.61

0.2

mg/kg

KMP UNC

KM P-SS61-0000-0003-01

5/19/2022

35.657958

-108.491301

0

3

SW6020

MOLYBDENUM

0.35

0.2

mg/kg

KMP UNC

KM P-SS62-0000-0003-01

5/19/2022

35.658355

-108.491208

0

3

SW6020

MOLYBDENUM

0.31

0.2

mg/kg

KMP UNC

KMP-SS63-0000-0003-01

5/19/2022

35.658917

-108.490612

0

3

SW6020

MOLYBDENUM

0.6

0.2

mg/kg

KMP UNC

KM P-SS64-0000-0003-01

5/19/2022

35.658394

-108.49068

0

3

SW6020

MOLYBDENUM

0.56

0.2

mg/kg

KMP UNC

KMP-SS65-0000-0003-01

5/19/2022

35.658535

-108.490274

0

3

SW6020

MOLYBDENUM

0.33

0.2

mg/kg

KMP UNC

KM P-SS66-0000-0003-01

5/19/2022

35.658093

-108.490734

0

3

SW6020

MOLYBDENUM

0.32 J

0.2

mg/kg

KMP UNC

KMP-SS67-0000-0003-01

5/19/2022

35.658057

-108.490414

0

3

SW6020

MOLYBDENUM

0.36

0.2

mg/kg

KMP UNC

KMP-SS68-0000-0003-01

5/19/2022

35.65776

-108.491

0

3

SW6020

MOLYBDENUM

0.3

0.2

mg/kg

KMP UNC

KMP-SS69-0000-0003-01

5/19/2022

35.65736

-108.492

0

3

SW6020

MOLYBDENUM

0.42

0.2

mg/kg

KMP UNC

KMP-SS70-0000-0003-01

5/19/2022

35.657343

-108.490976

0

3

SW6020

MOLYBDENUM

0.27

0.2

mg/kg

KMP UNC

KMP-SS70-0000-0003-02

5/19/2022

35.657343

-108.490976

0

3

SW6020

MOLYBDENUM

0.24

0.2

mg/kg

KMP UNC

KM P-SS71 -0000-0003-01

5/19/2022

35.656666

-108.491638

0

3

SW6020

MOLYBDENUM

0.41

0.2

mg/kg

KMP UNC

KMP-SS72-0000-0003-01

5/19/2022

35.656683

-108.49091

0

3

SW6020

MOLYBDENUM

0.3

0.2

mg/kg

KMP UNC

KMP-SS73-0000-0003-01

5/19/2022

35.658117

-108.493493

0

3

SW6020

MOLYBDENUM

0.42

0.2

mg/kg

KMP UNC

KMP-SS75-0000-0003-01

5/19/2022

35.659492

-108.489461

0

3

SW6020

MOLYBDENUM

1.4

0.2

mg/kg

KMP UNC

KMP-SS75-0000-0003-02

5/19/2022

35.659492

-108.489461

0

3

SW6020

MOLYBDENUM

1.6

0.2

mg/kg

KMP UNC

KMP-SS76-0000-0003-01

5/19/2022

35.659031

-108.489527

0

3

SW6020

MOLYBDENUM

0.45

0.2

mg/kg

KMP UNC

KMP-SS77-0000-0003-01

5/19/2022

35.658484

-108.488991

0

3

SW6020

MOLYBDENUM

0.46

0.2

mg/kg

KMP UNC

KMP-SS78-0000-0003-01

5/19/2022

35.658169

-108.487842

0

3

SW6020

MOLYBDENUM

0.4

0.2

mg/kg

KMP UNC

KMP-SS79-0000-0003-01

5/19/2022

35.658754

-108.491022

0

3

SW6020

MOLYBDENUM

0.33

0.2

mg/kg

KMP UNC

KM P-SS45-0000-0003-01

5/19/2022

35.659562

-108.493833

0

3

SW6020

NICKEL

11

2

mg/kg

KMP UNC

KMP-SS45-0000-0003-02

5/19/2022

35.659562

-108.493833

0

3

SW6020

NICKEL

10

2

mg/kg

KMP UNC

KM P-SS46-0000-0003-01

5/19/2022

35.659453

-108.493003

0

3

SW6020

NICKEL

7

2

mg/kg

KMP UNC

KMP-SS47-0000-0003-01

5/19/2022

35.659543

-108.49221

0

3

SW6020

NICKEL

6.3

2

mg/kg

KMP UNC

KM P-SS48-0000-0003-01

5/19/2022

35.659648

-108.491281

0

3

SW6020

NICKEL

7

2

mg/kg

KMP UNC

KMP-SS50-0000-0003-01

5/19/2022

35.6595

-108.491

0

3

SW6020

NICKEL

7.4

2

mg/kg

KMP UNC

KM P-SS51-0000-0003-01

5/19/2022

35.65919

-108.491

0

3

SW6020

NICKEL

7.8

2

mg/kg

Page 58 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KM P-SS52-0000-0003-01

5/19/2022

35.659169

-108.491722

0

3

SW6020

NICKEL

7.2

2

mg/kg

KMPUNC

KMP-SS53-0000-0003-01

5/19/2022

35.659201

-108.492371

0

3

SW6020

NICKEL

5.9

2

mg/kg

KMP UNC

KM P-SS54-0000-0003-01

5/19/2022

35.658712

-108.492621

0

3

SW6020

NICKEL

10

2

mg/kg

KMP UNC

KMP-SS55-0000-0003-01

5/19/2022

35.658793

-108.492026

0

3

SW6020

NICKEL

11

2.1

mg/kg

KMP UNC

KM P-SS56-0000-0003-01

5/19/2022

35.658831

-108.491366

0

3

SW6020

NICKEL

6.7

2

mg/kg

KMP UNC

KMP-SS57-0000-0003-01

5/19/2022

35.658672

-108.491525

0

3

SW6020

NICKEL

8.4

2

mg/kg

KMP UNC

KMP-SS58-0000-0003-01

5/19/2022

35.65853

-108.492

0

3

SW6020

NICKEL

7.4

2

mg/kg

KMP UNC

KMP-SS59-0000-0003-01

5/19/2022

35.658334

-108.491827

0

3

SW6020

NICKEL

8.3

2

mg/kg

KMP UNC

KM P-SS60-0000-0003-01

5/19/2022

35.658129

-108.492013

0

3

SW6020

NICKEL

7.7

2

mg/kg

KMP UNC

KM P-SS61 -0000-0003-01

5/19/2022

35.657958

-108.491301

0

3

SW6020

NICKEL

7.4

2

mg/kg

KMP UNC

KM P-SS62-0000-0003-01

5/19/2022

35.658355

-108.491208

0

3

SW6020

NICKEL

6.9

2

mg/kg

KMP UNC

KM P-SS63-0000-0003-01

5/19/2022

35.658917

-108.490612

0

3

SW6020

NICKEL

6.9

2

mg/kg

KMP UNC

KM P-SS64-0000-0003-01

5/19/2022

35.658394

-108.49068

0

3

SW6020

NICKEL

7.1

2

mg/kg

KMP UNC

KM P-SS65-0000-0003-01

5/19/2022

35.658535

-108.490274

0

3

SW6020

NICKEL

7.2

2

mg/kg

KMP UNC

KM P-SS66-0000-0003-01

5/19/2022

35.658093

-108.490734

0

3

SW6020

NICKEL

6.3

2

mg/kg

KMP UNC

KMP-SS67-0000-0003-01

5/19/2022

35.658057

-108.490414

0

3

SW6020

NICKEL

8.7

2

mg/kg

KMP UNC

KM P-SS68-0000-0003-01

5/19/2022

35.65776

-108.491

0

3

SW6020

NICKEL

9.4

2

mg/kg

KMP UNC

KMP-SS69-0000-0003-01

5/19/2022

35.65736

-108.492

0

3

SW6020

NICKEL

9.1

2

mg/kg

KMP UNC

KMP-SS70-0000-0003-01

5/19/2022

35.657343

-108.490976

0

3

SW6020

NICKEL

8.2

2

mg/kg

KMP UNC

KMP-SS70-0000-0003-02

5/19/2022

35.657343

-108.490976

0

3

SW6020

NICKEL

7.6

2

mg/kg

KMP UNC

KM P-SS71-0000-0003-01

5/19/2022

35.656666

-108.491638

0

3

SW6020

NICKEL

7.5

2

mg/kg

KMP UNC

KMP-SS72-0000-0003-01

5/19/2022

35.656683

-108.49091

0

3

SW6020

NICKEL

8.1

2

mg/kg

KMP UNC

KMP-SS73-0000-0003-01

5/19/2022

35.658117

-108.493493

0

3

SW6020

NICKEL

9.6

2

mg/kg

KMP UNC

KMP-SS75-0000-0003-01

5/19/2022

35.659492

-108.489461

0

3

SW6020

NICKEL

9.1

2

mg/kg

KMP UNC

KMP-SS75-0000-0003-02

5/19/2022

35.659492

-108.489461

0

3

SW6020

NICKEL

9.4

2

mg/kg

KMP UNC

KMP-SS76-0000-0003-01

5/19/2022

35.659031

-108.489527

0

3

SW6020

NICKEL

9.5

2

mg/kg

KMP UNC

KMP-SS77-0000-0003-01

5/19/2022

35.658484

-108.488991

0

3

SW6020

NICKEL

9.3

2

mg/kg

KMP UNC

KMP-SS78-0000-0003-01

5/19/2022

35.658169

-108.487842

0

3

SW6020

NICKEL

7.5

2

mg/kg

KMP UNC

KMP-SS79-0000-0003-01

5/19/2022

35.658754

-108.491022

0

3

SW6020

NICKEL

7.1

2

mg/kg

KMP UNC

KMP-SS45-0000-0003-01

5/19/2022

35.659562

-108.493833

0

3

713R15

Ra-226

1.14

0.41

pC

'9

KMP UNC

KMP-SS45-0000-0003-02

5/19/2022

35.659562

-108.493833

0

3

713R15

Ra-226

1.09

0.44

pC

<9

KMP UNC

KM P-SS46-0000-0003-01

5/19/2022

35.659453

-108.493003

0

3

713R15

Ra-226

2.46 J

0.44

pC

/g

KMP UNC

KMP-SS47-0000-0003-01

5/19/2022

35.659543

-108.49221

0

3

713R15

Ra-226

1.54

0.48

o

Q.

/g

KMP UNC

KMP-SS48-0000-0003-01

5/19/2022

35.659648

-108.491281

0

3

713R15

Ra-226

24.6

0.8

pC

'g

KMP UNC

KMP-SS50-0000-0003-01

5/19/2022

35.6595

-108.491

0

3

713R15

Ra-226

4.41

0.53

pC

/g

KMP UNC

KM P-SS51-0000-0003-01

5/19/2022

35.65919

-108.491

0

3

713R15

Ra-226

1.66

0.39

pC

/g

KMP UNC

KM P-SS52-0000-0003-01

5/19/2022

35.659169

-108.491722

0

3

713R15

Ra-226

2.47

0.59

o

Q.

/ g

KMP UNC

KMP-SS53-0000-0003-01

5/19/2022

35.659201

-108.492371

0

3

713R15

Ra-226

0.89 J

0.43

o

Q.

/ g

KMP UNC

KM P-SS54-0000-0003-01

5/19/2022

35.658712

-108.492621

0

3

713R15

Ra-226

7.6 J

1.1

pC

Zg

KMP UNC

KMP-SS55-0000-0003-01

5/19/2022

35.658793

-108.492026

0

3

713R15

Ra-226

8.3 J

0.7

pC

/g

KMP UNC

KM P-SS56-0000-0003-01

5/19/2022

35.658831

-108.491366

0

3

713R15

Ra-226

6.57 J

0.5

o

Q.

/g

KMP UNC

KMP-SS57-0000-0003-01

5/19/2022

35.658672

-108.491525

0

3

713R15

Ra-226

12 J

0.9

o

Q.

/g

Page 59 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KMP-SS58-0000-0003-01

5/19/2022

35.65853

-108.492

0

3

713R15

Ra-226

7.8

0.6

O

Q.

/g

KMPUNC

KMP-SS59-0000-0003-01

5/19/2022

35.658334

-108.491827

0

3

713R15

Ra-226

12

0.5

O

Q.

/g

KMP UNC

KM P-SS60-0000-0003-01

5/19/2022

35.658129

-108.492013

0

3

713R15

Ra-226

00
CO

0.7

pC

'g

KMP UNC

KM P-SS61-0000-0003-01

5/19/2022

35.657958

-108.491301

0

3

713R15

Ra-226

11.5

0.7

pC

/g

KMP UNC

KM P-SS62-0000-0003-01

5/19/2022

35.658355

-108.491208

0

3

713R15

Ra-226

2.67

0.46

o

Q.

/ g

KMP UNC

KM P-SS63-0000-0003-01

5/19/2022

35.658917

-108.490612

0

3

713R15

Ra-226

3.17

0.46

O

Q.

/ g

KMP UNC

KM P-SS64-0000-0003-01

5/19/2022

35.658394

-108.49068

0

3

713R15

Ra-226

4.23 J

0.39

pC

/g

KMP UNC

KM P-SS65-0000-0003-01

5/19/2022

35.658535

-108.490274

0

3

713R15

Ra-226

6.93

0.72

pC

/g

KMP UNC

KM P-SS66-0000-0003-01

5/19/2022

35.658093

-108.490734

0

3

713R15

Ra-226

2.95

0.48

o

Q.

/ g

KMP UNC

KMP-SS67-0000-0003-01

5/19/2022

35.658057

-108.490414

0

3

713R15

Ra-226

6.08 J

0.69

O

Q.

/ g

KMP UNC

KM P-SS68-0000-0003-01

5/19/2022

35.65776

-108.491

0

3

713R15

Ra-226

4.1

0.62

pC

/g

KMP UNC

KMP-SS69-0000-0003-01

5/19/2022

35.65736

-108.492

0

3

713R15

Ra-226

4.1 J

0.57

pC

/g

KMP UNC

KMP-SS70-0000-0003-01

5/19/2022

35.657343

-108.490976

0

3

713R15

Ra-226

1.35 J

0.44

o

Q.

/g

KMP UNC

KMP-SS70-0000-0003-02

5/19/2022

35.657343

-108.490976

0

3

713R15

Ra-226

1.53

0.51

O

Q.

/g

KMP UNC

KM P-SS71-0000-0003-01

5/19/2022

35.656666

-108.491638

0

3

713R15

Ra-226

12.9 J

0.7

pC

/g

KMP UNC

KMP-SS72-0000-0003-01

5/19/2022

35.656683

-108.49091

0

3

713R15

Ra-226

2.09 J

0.31

pC

/g

KMP UNC

KMP-SS73-0000-0003-01

5/19/2022

35.658117

-108.493493

0

3

713R15

Ra-226

4.9 J

0.69

o

Q.

/g

KMP UNC

KMP-SS75-0000-0003-01

5/19/2022

35.659492

-108.489461

0

3

713R15

Ra-226

68.1 M3

1.1

O

Q.

/g

KMP UNC

KMP-SS75-0000-0003-02

5/19/2022

35.659492

-108.489461

0

3

713R15

Ra-226

57.9 M3

1

pC

/g

KMP UNC

KMP-SS76-0000-0003-01

5/19/2022

35.659031

-108.489527

0

3

713R15

Ra-226

6.17 J

0.5

pC

/g

KMP UNC

KMP-SS77-0000-0003-01

5/19/2022

35.658484

-108.488991

0

3

713R15

Ra-226

5.82 J

0.74

o

Q.

/g

KMP UNC

KMP-SS78-0000-0003-01

5/19/2022

35.658169

-108.487842

0

3

713R15

Ra-226

2.97 J

0.39

O

Q.

/g

KMP UNC

KMP-SS79-0000-0003-01

5/19/2022

35.658754

-108.491022

0

3

713R15

Ra-226

7.3

0.7

pC

/g

KMP UNC

KMP-SS45-0000-0003-01

5/19/2022

35.659562

-108.493833

0

3

SW6020

SELENIUM

0.97 J

0.99

mg/kg

KMP UNC

KMP-SS45-0000-0003-02

5/19/2022

35.659562

-108.493833

0

3

SW6020

SELENIUM

0.97 J

1

mg/kg

KMP UNC

KM P-SS46-0000-0003-01

5/19/2022

35.659453

-108.493003

0

3

SW6020

SELENIUM

1.2

1

mg/kg

KMP UNC

KMP-SS47-0000-0003-01

5/19/2022

35.659543

-108.49221

0

3

SW6020

SELENIUM

1.1

1

mg/kg

KMP UNC

KMP-SS48-0000-0003-01

5/19/2022

35.659648

-108.491281

0

3

SW6020

SELENIUM

6.3

1

mg/kg

KMP UNC

KMP-SS50-0000-0003-01

5/19/2022

35.6595

-108.491

0

3

SW6020

SELENIUM

2.4

1

mg/kg

KMP UNC

KM P-SS51-0000-0003-01

5/19/2022

35.65919

-108.491

0

3

SW6020

SELENIUM

1.4

1

mg/kg

KMP UNC

KMP-SS52-0000-0003-01

5/19/2022

35.659169

-108.491722

0

3

SW6020

SELENIUM

1.3

1

mg/kg

KMP UNC

KMP-SS53-0000-0003-01

5/19/2022

35.659201

-108.492371

0

3

SW6020

SELENIUM

0.99 J

1

mg/kg

KMP UNC

KMP-SS54-0000-0003-01

5/19/2022

35.658712

-108.492621

0

3

SW6020

SELENIUM

1.9

1

mg/kg

KMP UNC

KMP-SS55-0000-0003-01

5/19/2022

35.658793

-108.492026

0

3

SW6020

SELENIUM

2.8

1

mg/kg

KMP UNC

KM P-SS56-0000-0003-01

5/19/2022

35.658831

-108.491366

0

3

SW6020

SELENIUM

2.2

1

mg/kg

KMP UNC

KMP-SS57-0000-0003-01

5/19/2022

35.658672

-108.491525

0

3

SW6020

SELENIUM

3.3

1

mg/kg

KMP UNC

KMP-SS58-0000-0003-01

5/19/2022

35.65853

-108.492

0

3

SW6020

SELENIUM

2.5

1

mg/kg

KMP UNC

KMP-SS59-0000-0003-01

5/19/2022

35.658334

-108.491827

0

3

SW6020

SELENIUM

3.5

1

mg/kg

KMP UNC

KM P-SS60-0000-0003-01

5/19/2022

35.658129

-108.492013

0

3

SW6020

SELENIUM

3

1

mg/kg

KMP UNC

KM P-SS61 -0000-0003-01

5/19/2022

35.657958

-108.491301

0

3

SW6020

SELENIUM

3.9

1

mg/kg

KMP UNC

KM P-SS62-0000-0003-01

5/19/2022

35.658355

-108.491208

0

3

SW6020

SELENIUM

1.5

1

mg/kg

KMP UNC

KM P-SS63-0000-0003-01

5/19/2022

35.658917

-108.490612

0

3

SW6020

SELENIUM

1.7

1

mg/kg

Page 60 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KM P-SS64-0000-0003-01

5/19/2022

35.658394

-108.49068

0

3

SW6020

SELENIUM

1.7

1

mg/kg

KMPUNC

KM P-SS65-0000-0003-01

5/19/2022

35.658535

-108.490274

0

3

SW6020

SELENIUM

2.1

1

mg/kg

KMP UNC

KM P-SS66-0000-0003-01

5/19/2022

35.658093

-108.490734

0

3

SW6020

SELENIUM

1.4

1

mg/kg

KMP UNC

KMP-SS67-0000-0003-01

5/19/2022

35.658057

-108.490414

0

3

SW6020

SELENIUM

2

1

mg/kg

KMP UNC

KM P-SS68-0000-0003-01

5/19/2022

35.65776

-108.491

0

3

SW6020

SELENIUM

2

1

mg/kg

KMP UNC

KM P-SS69-0000-0003-01

5/19/2022

35.65736

-108.492

0

3

SW6020

SELENIUM

1.7

1

mg/kg

KMP UNC

KMP-SS70-0000-0003-01

5/19/2022

35.657343

-108.490976

0

3

SW6020

SELENIUM

1.2

1

mg/kg

KMP UNC

KMP-SS70-0000-0003-02

5/19/2022

35.657343

-108.490976

0

3

SW6020

SELENIUM

1.2

1

mg/kg

KMP UNC

KM P-SS71-0000-0003-01

5/19/2022

35.656666

-108.491638

0

3

SW6020

SELENIUM

2.9

1

mg/kg

KMP UNC

KMP-SS72-0000-0003-01

5/19/2022

35.656683

-108.49091

0

3

SW6020

SELENIUM

1.3

1

mg/kg

KMP UNC

KMP-SS73-0000-0003-01

5/19/2022

35.658117

-108.493493

0

3

SW6020

SELENIUM

1.9

1

mg/kg

KMP UNC

KMP-SS75-0000-0003-01

5/19/2022

35.659492

-108.489461

0

3

SW6020

SELENIUM

9.1

1

mg/kg

KMP UNC

KMP-SS75-0000-0003-02

5/19/2022

35.659492

-108.489461

0

3

SW6020

SELENIUM

7.8

1

mg/kg

KMP UNC

KMP-SS76-0000-0003-01

5/19/2022

35.659031

-108.489527

0

3

SW6020

SELENIUM

2.2

1

mg/kg

KMP UNC

KMP-SS77-0000-0003-01

5/19/2022

35.658484

-108.488991

0

3

SW6020

SELENIUM

2

1

mg/kg

KMP UNC

KMP-SS78-0000-0003-01

5/19/2022

35.658169

-108.487842

0

3

SW6020

SELENIUM

1.2

1

mg/kg

KMP UNC

KMP-SS79-0000-0003-01

5/19/2022

35.658754

-108.491022

0

3

SW6020

SELENIUM

2.2

1

mg/kg

KMP UNC

KMP-SS45-0000-0003-01

5/19/2022

35.659562

-108.493833

0

3

SW6020

SILVER

0.057 U

0.11

mg/kg

KMP UNC

KMP-SS45-0000-0003-02

5/19/2022

35.659562

-108.493833

0

3

SW6020

SILVER

0.057 U

0.11

mg/kg

KMP UNC

KM P-SS46-0000-0003-01

5/19/2022

35.659453

-108.493003

0

3

SW6020

SILVER

0.057 U

0.11

mg/kg

KMP UNC

KMP-SS47-0000-0003-01

5/19/2022

35.659543

-108.49221

0

3

SW6020

SILVER

0.058 U

0.12

mg/kg

KMP UNC

KMP-SS48-0000-0003-01

5/19/2022

35.659648

-108.491281

0

3

SW6020

SILVER

0.057 U

0.11

mg/kg

KMP UNC

KMP-SS50-0000-0003-01

5/19/2022

35.6595

-108.491

0

3

SW6020

SILVER

0.058 U

0.12

mg/kg

KMP UNC

KM P-SS51-0000-0003-01

5/19/2022

35.65919

-108.491

0

3

SW6020

SILVER

0.057 U

0.11

mg/kg

KMP UNC

KMP-SS52-0000-0003-01

5/19/2022

35.659169

-108.491722

0

3

SW6020

SILVER

0.057 U

0.11

mg/kg

KMP UNC

KMP-SS53-0000-0003-01

5/19/2022

35.659201

-108.492371

0

3

SW6020

SILVER

0.057 U

0.11

mg/kg

KMP UNC

KMP-SS54-0000-0003-01

5/19/2022

35.658712

-108.492621

0

3

SW6020

SILVER

0.062 J

0.12

mg/kg

KMP UNC

KMP-SS55-0000-0003-01

5/19/2022

35.658793

-108.492026

0

3

SW6020

SILVER

0.088 J

0.12

mg/kg

KMP UNC

KMP-SS56-0000-0003-01

5/19/2022

35.658831

-108.491366

0

3

SW6020

SILVER

0.058 U

0.12

mg/kg

KMP UNC

KMP-SS57-0000-0003-01

5/19/2022

35.658672

-108.491525

0

3

SW6020

SILVER

0.058 U

0.12

mg/kg

KMP UNC

KMP-SS58-0000-0003-01

5/19/2022

35.65853

-108.492

0

3

SW6020

SILVER

0.057 U

0.11

mg/kg

KMP UNC

KMP-SS59-0000-0003-01

5/19/2022

35.658334

-108.491827

0

3

SW6020

SILVER

0.057 U

0.11

mg/kg

KMP UNC

KMP-SS60-0000-0003-01

5/19/2022

35.658129

-108.492013

0

3

SW6020

SILVER

0.058 U

0.12

mg/kg

KMP UNC

KM P-SS61-0000-0003-01

5/19/2022

35.657958

-108.491301

0

3

SW6020

SILVER

0.057 U

0.11

mg/kg

KMP UNC

KM P-SS62-0000-0003-01

5/19/2022

35.658355

-108.491208

0

3

SW6020

SILVER

0.058 U

0.12

mg/kg

KMP UNC

KM P-SS63-0000-0003-01

5/19/2022

35.658917

-108.490612

0

3

SW6020

SILVER

0.057 U

0.11

mg/kg

KMP UNC

KM P-SS64-0000-0003-01

5/19/2022

35.658394

-108.49068

0

3

SW6020

SILVER

0.057 U

0.11

mg/kg

KMP UNC

KM P-SS65-0000-0003-01

5/19/2022

35.658535

-108.490274

0

3

SW6020

SILVER

0.058 U

0.12

mg/kg

KMP UNC

KM P-SS66-0000-0003-01

5/19/2022

35.658093

-108.490734

0

3

SW6020

SILVER

0.058 U

0.12

mg/kg

KMP UNC

KMP-SS67-0000-0003-01

5/19/2022

35.658057

-108.490414

0

3

SW6020

SILVER

0.058 U

0.12

mg/kg

KMP UNC

KM P-SS68-0000-0003-01

5/19/2022

35.65776

-108.491

0

3

SW6020

SILVER

0.058 U

0.12

mg/kg

KMP UNC

KMP-SS69-0000-0003-01

5/19/2022

35.65736

-108.492

0

3

SW6020

SILVER

0.057 J

0.11

mg/kg

Page 61 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KM P-SS70-0000-0003-01

5/19/2022

35.657343

-108.490976

0

3

SW6020

SILVER

0.058 U

0.12

mg/kg

KMPUNC

KMP-SS70-0000-0003-02

5/19/2022

35.657343

-108.490976

0

3

SW6020

SILVER

0.057 U

0.11

mg/kg

KMP UNC

KM P-SS71 -0000-0003-01

5/19/2022

35.656666

-108.491638

0

3

SW6020

SILVER

0.057 U

0.11

mg/kg

KMP UNC

KM P-SS72-0000-0003-01

5/19/2022

35.656683

-108.49091

0

3

SW6020

SILVER

0.058 U

0.12

mg/kg

KMP UNC

KMP-SS73-0000-0003-01

5/19/2022

35.658117

-108.493493

0

3

SW6020

SILVER

0.072 J

0.12

mg/kg

KMP UNC

KM P-SS75-0000-0003-01

5/19/2022

35.659492

-108.489461

0

3

SW6020

SILVER

0.058 U

0.12

mg/kg

KMP UNC

KMP-SS75-0000-0003-02

5/19/2022

35.659492

-108.489461

0

3

SW6020

SILVER

0.058 U

0.12

mg/kg

KMP UNC

KMP-SS76-0000-0003-01

5/19/2022

35.659031

-108.489527

0

3

SW6020

SILVER

0.073 J

0.12

mg/kg

KMP UNC

KMP-SS77-0000-0003-01

5/19/2022

35.658484

-108.488991

0

3

SW6020

SILVER

0.066 J

0.12

mg/kg

KMP UNC

KM P-SS78-0000-0003-01

5/19/2022

35.658169

-108.487842

0

3

SW6020

SILVER

0.058 U

0.12

mg/kg

KMP UNC

KMP-SS79-0000-0003-01

5/19/2022

35.658754

-108.491022

0

3

SW6020

SILVER

0.058 U

0.12

mg/kg

KMP UNC

KM P-SS45-0000-0003-01

5/19/2022

35.659562

-108.493833

0

3

SW6020

THALLIUM

0.097

0.0099

mg/kg

KMP UNC

KMP-SS45-0000-0003-02

5/19/2022

35.659562

-108.493833

0

3

SW6020

THALLIUM

0.095

0.01

mg/kg

KMP UNC

KM P-SS46-0000-0003-01

5/19/2022

35.659453

-108.493003

0

3

SW6020

THALLIUM

0.096

0.01

mg/kg

KMP UNC

KMP-SS47-0000-0003-01

5/19/2022

35.659543

-108.49221

0

3

SW6020

THALLIUM

0.1

0.01

mg/kg

KMP UNC

KM P-SS48-0000-0003-01

5/19/2022

35.659648

-108.491281

0

3

SW6020

THALLIUM

0.13

0.01

mg/kg

KMP UNC

KMP-SS50-0000-0003-01

5/19/2022

35.6595

-108.491

0

3

SW6020

THALLIUM

0.13

0.01

mg/kg

KMP UNC

KM P-SS51-0000-0003-01

5/19/2022

35.65919

-108.491

0

3

SW6020

THALLIUM

0.13

0.01

mg/kg

KMP UNC

KM P-SS52-0000-0003-01

5/19/2022

35.659169

-108.491722

0

3

SW6020

THALLIUM

0.12

0.01

mg/kg

KMP UNC

KMP-SS53-0000-0003-01

5/19/2022

35.659201

-108.492371

0

3

SW6020

THALLIUM

0.093

0.01

mg/kg

KMP UNC

KM P-SS54-0000-0003-01

5/19/2022

35.658712

-108.492621

0

3

SW6020

THALLIUM

0.15

0.01

mg/kg

KMP UNC

KMP-SS55-0000-0003-01

5/19/2022

35.658793

-108.492026

0

3

SW6020

THALLIUM

0.18

0.01

mg/kg

KMP UNC

KM P-SS56-0000-0003-01

5/19/2022

35.658831

-108.491366

0

3

SW6020

THALLIUM

0.12

0.01

mg/kg

KMP UNC

KMP-SS57-0000-0003-01

5/19/2022

35.658672

-108.491525

0

3

SW6020

THALLIUM

0.14

0.01

mg/kg

KMP UNC

KMP-SS58-0000-0003-01

5/19/2022

35.65853

-108.492

0

3

SW6020

THALLIUM

0.12

0.01

mg/kg

KMP UNC

KMP-SS59-0000-0003-01

5/19/2022

35.658334

-108.491827

0

3

SW6020

THALLIUM

0.14

0.01

mg/kg

KMP UNC

KM P-SS60-0000-0003-01

5/19/2022

35.658129

-108.492013

0

3

SW6020

THALLIUM

0.12

0.01

mg/kg

KMP UNC

KM P-SS61 -0000-0003-01

5/19/2022

35.657958

-108.491301

0

3

SW6020

THALLIUM

0.12

0.01

mg/kg

KMP UNC

KM P-SS62-0000-0003-01

5/19/2022

35.658355

-108.491208

0

3

SW6020

THALLIUM

0.11

0.01

mg/kg

KMP UNC

KM P-SS63-0000-0003-01

5/19/2022

35.658917

-108.490612

0

3

SW6020

THALLIUM

0.11

0.01

mg/kg

KMP UNC

KM P-SS64-0000-0003-01

5/19/2022

35.658394

-108.49068

0

3

SW6020

THALLIUM

0.12

0.01

mg/kg

KMP UNC

KM P-SS65-0000-0003-01

5/19/2022

35.658535

-108.490274

0

3

SW6020

THALLIUM

0.12

0.01

mg/kg

KMP UNC

KM P-SS66-0000-0003-01

5/19/2022

35.658093

-108.490734

0

3

SW6020

THALLIUM

0.1

0.01

mg/kg

KMP UNC

KMP-SS67-0000-0003-01

5/19/2022

35.658057

-108.490414

0

3

SW6020

THALLIUM

0.14

0.01

mg/kg

KMP UNC

KM P-SS68-0000-0003-01

5/19/2022

35.65776

-108.491

0

3

SW6020

THALLIUM

0.14

0.01

mg/kg

KMP UNC

KM P-SS69-0000-0003-01

5/19/2022

35.65736

-108.492

0

3

SW6020

THALLIUM

0.15

0.01

mg/kg

KMP UNC

KM P-SS70-0000-0003-01

5/19/2022

35.657343

-108.490976

0

3

SW6020

THALLIUM

0.12

0.01

mg/kg

KMP UNC

KMP-SS70-0000-0003-02

5/19/2022

35.657343

-108.490976

0

3

SW6020

THALLIUM

0.11

0.01

mg/kg

KMP UNC

KM P-SS71 -0000-0003-01

5/19/2022

35.656666

-108.491638

0

3

SW6020

THALLIUM

0.12

0.01

mg/kg

KMP UNC

KM P-SS72-0000-0003-01

5/19/2022

35.656683

-108.49091

0

3

SW6020

THALLIUM

0.12

0.01

mg/kg

KMP UNC

KMP-SS73-0000-0003-01

5/19/2022

35.658117

-108.493493

0

3

SW6020

THALLIUM

0.14

0.01

mg/kg

KMP UNC

KM P-SS75-0000-0003-01

5/19/2022

35.659492

-108.489461

0

3

SW6020

THALLIUM

0.14

0.01

mg/kg

Page 62 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KMP-SS75-0000-0003-02

5/19/2022

35.659492

-108.489461

0

3

SW6020

THALLIUM

0.15

0.01

mg/kg

KMPUNC

KMP-SS76-0000-0003-01

5/19/2022

35.659031

-108.489527

0

3

SW6020

THALLIUM

0.18

0.01

mg/kg

KMP UNC

KMP-SS77-0000-0003-01

5/19/2022

35.658484

-108.488991

0

3

SW6020

THALLIUM

0.16

0.01

mg/kg

KMP UNC

KM P-SS78-0000-0003-01

5/19/2022

35.658169

-108.487842

0

3

SW6020

THALLIUM

0.15

0.01

mg/kg

KMP UNC

KMP-SS79-0000-0003-01

5/19/2022

35.658754

-108.491022

0

3

SW6020

THALLIUM

0.11

0.01

mg/kg

KMP UNC

KM P-SS45-0000-0003-01

5/19/2022

35.659562

-108.493833

0

3

SW6020

URANIUM

0.99

0.02

mg/kg

KMP UNC

KMP-SS45-0000-0003-02

5/19/2022

35.659562

-108.493833

0

3

SW6020

URANIUM

0.88

0.02

mg/kg

KMP UNC

KM P-SS46-0000-0003-01

5/19/2022

35.659453

-108.493003

0

3

SW6020

URANIUM

1.7

0.02

mg/kg

KMP UNC

KMP-SS47-0000-0003-01

5/19/2022

35.659543

-108.49221

0

3

SW6020

URANIUM

0.83

0.02

mg/kg

KMP UNC

KM P-SS48-0000-0003-01

5/19/2022

35.659648

-108.491281

0

3

SW6020

URANIUM

13

0.02

mg/kg

KMP UNC

KMP-SS50-0000-0003-01

5/19/2022

35.6595

-108.491

0

3

SW6020

URANIUM

4

0.02

mg/kg

KMP UNC

KM P-SS51-0000-0003-01

5/19/2022

35.65919

-108.491

0

3

SW6020

URANIUM

1.2

0.02

mg/kg

KMP UNC

KM P-SS52-0000-0003-01

5/19/2022

35.659169

-108.491722

0

3

SW6020

URANIUM

3.3

0.02

mg/kg

KMP UNC

KMP-SS53-0000-0003-01

5/19/2022

35.659201

-108.492371

0

3

SW6020

URANIUM

0.61

0.02

mg/kg

KMP UNC

KM P-SS54-0000-0003-01

5/19/2022

35.658712

-108.492621

0

3

SW6020

URANIUM

2.2

0.02

mg/kg

KMP UNC

KMP-SS55-0000-0003-01

5/19/2022

35.658793

-108.492026

0

3

SW6020

URANIUM

5.9

0.021

mg/kg

KMP UNC

KMP-SS56-0000-0003-01

5/19/2022

35.658831

-108.491366

0

3

SW6020

URANIUM

5.1

0.02

mg/kg

KMP UNC

KMP-SS57-0000-0003-01

5/19/2022

35.658672

-108.491525

0

3

SW6020

URANIUM

5.9

0.02

mg/kg

KMP UNC

KMP-SS58-0000-0003-01

5/19/2022

35.65853

-108.492

0

3

SW6020

URANIUM

2.6

0.02

mg/kg

KMP UNC

KMP-SS59-0000-0003-01

5/19/2022

35.658334

-108.491827

0

3

SW6020

URANIUM

19

0.02

mg/kg

KMP UNC

KMP-SS60-0000-0003-01

5/19/2022

35.658129

-108.492013

0

3

SW6020

URANIUM

5.6

0.02

mg/kg

KMP UNC

KM P-SS61 -0000-0003-01

5/19/2022

35.657958

-108.491301

0

3

SW6020

URANIUM

8.5

0.02

mg/kg

KMP UNC

KMP-SS62-0000-0003-01

5/19/2022

35.658355

-108.491208

0

3

SW6020

URANIUM

3.2

0.02

mg/kg

KMP UNC

KMP-SS63-0000-0003-01

5/19/2022

35.658917

-108.490612

0

3

SW6020

URANIUM

4.7

0.02

mg/kg

KMP UNC

KM P-SS64-0000-0003-01

5/19/2022

35.658394

-108.49068

0

3

SW6020

URANIUM

5.7

0.02

mg/kg

KMP UNC

KM P-SS65-0000-0003-01

5/19/2022

35.658535

-108.490274

0

3

SW6020

URANIUM

4.3

0.02

mg/kg

KMP UNC

KM P-SS66-0000-0003-01

5/19/2022

35.658093

-108.490734

0

3

SW6020

URANIUM

4.6

0.02

mg/kg

KMP UNC

KM P-SS67-0000-0003-01

5/19/2022

35.658057

-108.490414

0

3

SW6020

URANIUM

3.4

0.02

mg/kg

KMP UNC

KM P-SS68-0000-0003-01

5/19/2022

35.65776

-108.491

0

3

SW6020

URANIUM

3.1

0.02

mg/kg

KMP UNC

KM P-SS69-0000-0003-01

5/19/2022

35.65736

-108.492

0

3

SW6020

URANIUM

0.94

0.02

mg/kg

KMP UNC

KMP-SS70-0000-0003-01

5/19/2022

35.657343

-108.490976

0

3

SW6020

URANIUM

0.72

0.02

mg/kg

KMP UNC

KMP-SS70-0000-0003-02

5/19/2022

35.657343

-108.490976

0

3

SW6020

URANIUM

0.63

0.02

mg/kg

KMP UNC

KM P-SS71 -0000-0003-01

5/19/2022

35.656666

-108.491638

0

3

SW6020

URANIUM

1.4

0.02

mg/kg

KMP UNC

KMP-SS72-0000-0003-01

5/19/2022

35.656683

-108.49091

0

3

SW6020

URANIUM

0.7

0.02

mg/kg

KMP UNC

KMP-SS73-0000-0003-01

5/19/2022

35.658117

-108.493493

0

3

SW6020

URANIUM

1.2

0.02

mg/kg

KMP UNC

KM P-SS75-0000-0003-01

5/19/2022

35.659492

-108.489461

0

3

SW6020

URANIUM

19

0.02

mg/kg

KMP UNC

KMP-SS75-0000-0003-02

5/19/2022

35.659492

-108.489461

0

3

SW6020

URANIUM

25

0.02

mg/kg

KMP UNC

KMP-SS76-0000-0003-01

5/19/2022

35.659031

-108.489527

0

3

SW6020

URANIUM

1.3

0.02

mg/kg

KMP UNC

KMP-SS77-0000-0003-01

5/19/2022

35.658484

-108.488991

0

3

SW6020

URANIUM

1.4

0.02

mg/kg

KMP UNC

KMP-SS78-0000-0003-01

5/19/2022

35.658169

-108.487842

0

3

SW6020

URANIUM

0.72

0.02

mg/kg

KMP UNC

KMP-SS79-0000-0003-01

5/19/2022

35.658754

-108.491022

0

3

SW6020

URANIUM

4.5

0.02

mg/kg

KMP UNC

KMP-SS45-0000-0003-01

5/19/2022

35.659562

-108.493833

0

3

SW6020

VANADIUM

11

0.5

mg/kg

Page 63 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KMP-SS45-0000-0003-02

5/19/2022

35.659562

-108.493833

0

3

SW6020

VANADIUM

11

0.5

mg/kg

KMPUNC

KM P-SS46-0000-0003-01

5/19/2022

35.659453

-108.493003

0

3

SW6020

VANADIUM

12

0.5

mg/kg

KMP UNC

KMP-SS47-0000-0003-01

5/19/2022

35.659543

-108.49221

0

3

SW6020

VANADIUM

13

0.51

mg/kg

KMP UNC

KM P-SS48-0000-0003-01

5/19/2022

35.659648

-108.491281

0

3

SW6020

VANADIUM

16

0.5

mg/kg

KMP UNC

KMP-SS50-0000-0003-01

5/19/2022

35.6595

-108.491

0

3

SW6020

VANADIUM

14

0.51

mg/kg

KMP UNC

KM P-SS51-0000-0003-01

5/19/2022

35.65919

-108.491

0

3

SW6020

VANADIUM

14

0.5

mg/kg

KMP UNC

KM P-SS52-0000-0003-01

5/19/2022

35.659169

-108.491722

0

3

SW6020

VANADIUM

13

0.5

mg/kg

KMP UNC

KMP-SS53-0000-0003-01

5/19/2022

35.659201

-108.492371

0

3

SW6020

VANADIUM

13

0.5

mg/kg

KMP UNC

KM P-SS54-0000-0003-01

5/19/2022

35.658712

-108.492621

0

3

SW6020

VANADIUM

16

0.51

mg/kg

KMP UNC

KMP-SS55-0000-0003-01

5/19/2022

35.658793

-108.492026

0

3

SW6020

VANADIUM

19

0.52

mg/kg

KMP UNC

KMP-SS56-0000-0003-01

5/19/2022

35.658831

-108.491366

0

3

SW6020

VANADIUM

14

0.51

mg/kg

KMP UNC

KMP-SS57-0000-0003-01

5/19/2022

35.658672

-108.491525

0

3

SW6020

VANADIUM

17

0.51

mg/kg

KMP UNC

KMP-SS58-0000-0003-01

5/19/2022

35.65853

-108.492

0

3

SW6020

VANADIUM

15

0.5

mg/kg

KMP UNC

KMP-SS59-0000-0003-01

5/19/2022

35.658334

-108.491827

0

3

SW6020

VANADIUM

17

0.5

mg/kg

KMP UNC

KMP-SS60-0000-0003-01

5/19/2022

35.658129

-108.492013

0

3

SW6020

VANADIUM

15

0.51

mg/kg

KMP UNC

KM P-SS61 -0000-0003-01

5/19/2022

35.657958

-108.491301

0

3

SW6020

VANADIUM

16

0.5

mg/kg

KMP UNC

KMP-SS62-0000-0003-01

5/19/2022

35.658355

-108.491208

0

3

SW6020

VANADIUM

14

0.51

mg/kg

KMP UNC

KM P-SS63-0000-0003-01

5/19/2022

35.658917

-108.490612

0

3

SW6020

VANADIUM

13

0.5

mg/kg

KMP UNC

KM P-SS64-0000-0003-01

5/19/2022

35.658394

-108.49068

0

3

SW6020

VANADIUM

14

0.5

mg/kg

KMP UNC

KM P-SS65-0000-0003-01

5/19/2022

35.658535

-108.490274

0

3

SW6020

VANADIUM

15

0.5

mg/kg

KMP UNC

KM P-SS66-0000-0003-01

5/19/2022

35.658093

-108.490734

0

3

SW6020

VANADIUM

13

0.51

mg/kg

KMP UNC

KM P-SS67-0000-0003-01

5/19/2022

35.658057

-108.490414

0

3

SW6020

VANADIUM

16

0.51

mg/kg

KMP UNC

KM P-SS68-0000-0003-01

5/19/2022

35.65776

-108.491

0

3

SW6020

VANADIUM

16

0.51

mg/kg

KMP UNC

KMP-SS69-0000-0003-01

5/19/2022

35.65736

-108.492

0

3

SW6020

VANADIUM

16

0.5

mg/kg

KMP UNC

KMP-SS70-0000-0003-01

5/19/2022

35.657343

-108.490976

0

3

SW6020

VANADIUM

14

0.51

mg/kg

KMP UNC

KMP-SS70-0000-0003-02

5/19/2022

35.657343

-108.490976

0

3

SW6020

VANADIUM

13

0.5

mg/kg

KMP UNC

KM P-SS71 -0000-0003-01

5/19/2022

35.656666

-108.491638

0

3

SW6020

VANADIUM

15

0.5

mg/kg

KMP UNC

KMP-SS72-0000-0003-01

5/19/2022

35.656683

-108.49091

0

3

SW6020

VANADIUM

14

0.51

mg/kg

KMP UNC

KMP-SS73-0000-0003-01

5/19/2022

35.658117

-108.493493

0

3

SW6020

VANADIUM

16

0.51

mg/kg

KMP UNC

KMP-SS75-0000-0003-01

5/19/2022

35.659492

-108.489461

0

3

SW6020

VANADIUM

36

0.51

mg/kg

KMP UNC

KMP-SS75-0000-0003-02

5/19/2022

35.659492

-108.489461

0

3

SW6020

VANADIUM

33

0.51

mg/kg

KMP UNC

KMP-SS76-0000-0003-01

5/19/2022

35.659031

-108.489527

0

3

SW6020

VANADIUM

16

0.51

mg/kg

KMP UNC

KMP-SS77-0000-0003-01

5/19/2022

35.658484

-108.488991

0

3

SW6020

VANADIUM

16

0.51

mg/kg

KMP UNC

KM P-SS78-0000-0003-01

5/19/2022

35.658169

-108.487842

0

3

SW6020

VANADIUM

12

0.51

mg/kg

KMP UNC

KMP-SS79-0000-0003-01

5/19/2022

35.658754

-108.491022

0

3

SW6020

VANADIUM

14

0.51

mg/kg

KMP UNC

KM P-SS45-0000-0003-01

5/19/2022

35.659562

-108.493833

0

3

SW6020

ZINC

33

9.9

mg/kg

KMP UNC

KMP-SS45-0000-0003-02

5/19/2022

35.659562

-108.493833

0

3

SW6020

ZINC

32

10

mg/kg

KMP UNC

KM P-SS46-0000-0003-01

5/19/2022

35.659453

-108.493003

0

3

SW6020

ZINC

32

10

mg/kg

KMP UNC

KMP-SS47-0000-0003-01

5/19/2022

35.659543

-108.49221

0

3

SW6020

ZINC

34

10

mg/kg

KMP UNC

KMP-SS48-0000-0003-01

5/19/2022

35.659648

-108.491281

0

3

SW6020

ZINC

39

10

mg/kg

KMP UNC

KMP-SS50-0000-0003-01

5/19/2022

35.6595

-108.491

0

3

SW6020

ZINC

40

10

mg/kg

KMP UNC

KM P-SS51-0000-0003-01

5/19/2022

35.65919

-108.491

0

3

SW6020

ZINC

43

10

mg/kg

Page 64 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KM P-SS52-0000-0003-01

5/19/2022

35.659169

-108.491722

0

3

SW6020

ZINC

37

10

mg/kg

KMPUNC

KMP-SS53-0000-0003-01

5/19/2022

35.659201

-108.492371

0

3

SW6020

ZINC

31

10

mg/kg

KMP UNC

KM P-SS54-0000-0003-01

5/19/2022

35.658712

-108.492621

0

3

SW6020

ZINC

51

10

mg/kg

KMP UNC

KMP-SS55-0000-0003-01

5/19/2022

35.658793

-108.492026

0

3

SW6020

ZINC

59

10

mg/kg

KMP UNC

KM P-SS56-0000-0003-01

5/19/2022

35.658831

-108.491366

0

3

SW6020

ZINC

38

10

mg/kg

KMP UNC

KMP-SS57-0000-0003-01

5/19/2022

35.658672

-108.491525

0

3

SW6020

ZINC

48

10

mg/kg

KMP UNC

KMP-SS58-0000-0003-01

5/19/2022

35.65853

-108.492

0

3

SW6020

ZINC

43

10

mg/kg

KMP UNC

KMP-SS59-0000-0003-01

5/19/2022

35.658334

-108.491827

0

3

SW6020

ZINC

47

10

mg/kg

KMP UNC

KMP-SS60-0000-0003-01

5/19/2022

35.658129

-108.492013

0

3

SW6020

ZINC

43

10

mg/kg

KMP UNC

KM P-SS61-0000-0003-01

5/19/2022

35.657958

-108.491301

0

3

SW6020

ZINC

41

10

mg/kg

KMP UNC

KMP-SS62-0000-0003-01

5/19/2022

35.658355

-108.491208

0

3

SW6020

ZINC

39

10

mg/kg

KMP UNC

KMP-SS63-0000-0003-01

5/19/2022

35.658917

-108.490612

0

3

SW6020

ZINC

39

10

mg/kg

KMP UNC

KMP-SS64-0000-0003-01

5/19/2022

35.658394

-108.49068

0

3

SW6020

ZINC

39

10

mg/kg

KMP UNC

KMP-SS65-0000-0003-01

5/19/2022

35.658535

-108.490274

0

3

SW6020

ZINC

40

10

mg/kg

KMP UNC

KMP-SS66-0000-0003-01

5/19/2022

35.658093

-108.490734

0

3

SW6020

ZINC

36

10

mg/kg

KMP UNC

KMP-SS67-0000-0003-01

5/19/2022

35.658057

-108.490414

0

3

SW6020

ZINC

48

10

mg/kg

KMP UNC

KMP-SS68-0000-0003-01

5/19/2022

35.65776

-108.491

0

3

SW6020

ZINC

47

10

mg/kg

KMP UNC

KMP-SS69-0000-0003-01

5/19/2022

35.65736

-108.492

0

3

SW6020

ZINC

51

10

mg/kg

KMP UNC

KMP-SS70-0000-0003-01

5/19/2022

35.657343

-108.490976

0

3

SW6020

ZINC

43

10

mg/kg

KMP UNC

KM P-SS70-0000-0003-02

5/19/2022

35.657343

-108.490976

0

3

SW6020

ZINC

39

10

mg/kg

KMP UNC

KM P-SS71-0000-0003-01

5/19/2022

35.656666

-108.491638

0

3

SW6020

ZINC

43

10

mg/kg

KMP UNC

KM P-SS72-0000-0003-01

5/19/2022

35.656683

-108.49091

0

3

SW6020

ZINC

47

10

mg/kg

KMP UNC

KM P-SS73-0000-0003-01

5/19/2022

35.658117

-108.493493

0

3

SW6020

ZINC

53

10

mg/kg

KMP UNC

KM P-SS75-0000-0003-01

5/19/2022

35.659492

-108.489461

0

3

SW6020

ZINC

95

10

mg/kg

KMP UNC

KM P-SS75-0000-0003-02

5/19/2022

35.659492

-108.489461

0

3

SW6020

ZINC

90

10

mg/kg

KMP UNC

KM P-SS76-0000-0003-01

5/19/2022

35.659031

-108.489527

0

3

SW6020

ZINC

53

10

mg/kg

KMP UNC

KMP-SS77-0000-0003-01

5/19/2022

35.658484

-108.488991

0

3

SW6020

ZINC

55

10

mg/kg

KMP UNC

KMP-SS78-0000-0003-01

5/19/2022

35.658169

-108.487842

0

3

SW6020

ZINC

39

10

mg/kg

KMP UNC

KMP-SS79-0000-0003-01

5/19/2022

35.658754

-108.491022

0

3

SW6020

ZINC

39

10

mg/kg

KMP UNC

KMP-SB27-0000-0006-01

6/3/2022

35.659216

-108.489648

0

6

SW6020

ALUMINUM

7000

16

mg/kg

KMP UNC

KMP-SB27-0000-0006-01

6/3/2022

35.659216

-108.489648

0

6

SW6020

ANTIMONY

0.081 J

0.1

mg/kg

KMP UNC

KMP-SB27-0000-0006-01

6/3/2022

35.659216

-108.489648

0

6

SW6020

ARSENIC

5.9

0.21

mg/kg

KMP UNC

KMP-SB27-0000-0006-01

6/3/2022

35.659216

-108.489648

0

6

SW6020

BARIUM

81

0.52

mg/kg

KMP UNC

KMP-SB27-0000-0006-01

6/3/2022

35.659216

-108.489648

0

6

SW6020

BERYLLIUM

0.6

0.052

mg/kg

KMP UNC

KM P-SB27-0000-0006-01

6/3/2022

35.659216

-108.489648

0

6

SW6020

CADMIUM

0.07 J

0.21

mg/kg

KMP UNC

KM P-SB27-0000-0006-01

6/3/2022

35.659216

-108.489648

0

6

SW6020

CHROMIUM

8.1

1

mg/kg

KMP UNC

KM P-SB27-0000-0006-01

6/3/2022

35.659216

-108.489648

0

6

SW6020

COBALT

5

0.52

mg/kg

KMP UNC

KM P-SB27-0000-0006-01

6/3/2022

35.659216

-108.489648

0

6

SW6020

COPPER

9.3

2.1

mg/kg

KMP UNC

KMP-SB27-0000-0006-01

6/3/2022

35.659216

-108.489648

0

6

SW6020

IRON

15000

21

mg/kg

KMP UNC

KM P-SB27-0000-0006-01

6/3/2022

35.659216

-108.489648

0

6

SW6020

LEAD

10

0.21

mg/kg

KMP UNC

KMP-SB27-0000-0006-01

6/3/2022

35.659216

-108.489648

0

6

SW6020

MANGANESE

200

0.78

mg/kg

KMP UNC

KMP-SB27-0000-0006-01

6/3/2022

35.659216

-108.489648

0

6

SW6020

MOLYBDENUM

0.41

0.21

mg/kg

Page 65 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KM P-SB27-0000-0006-01

6/3/2022

35.659216

-108.489648

0

6

SW6020

NICKEL

8.7

2.1

mg/kg

KMPUNC

KM P-SB27-0000-0006-01

6/3/2022

35.659216

-108.489648

0

6

713R15

Ra-226

1.27

0.4

pCi/g

KMP UNC

KM P-SB27-0000-0006-01

6/3/2022

35.659216

-108.489648

0

6

SW6020

SELENIUM

1.3

1

mg/kg

KMP UNC

KM P-SB27-0000-0006-01

6/3/2022

35.659216

-108.489648

0

6

SW6020

SILVER

0.059 U

0.12

mg/kg

KMP UNC

KM P-SB27-0000-0006-01

6/3/2022

35.659216

-108.489648

0

6

SW6020

THALLIUM

0.17

0.01

mg/kg

KMP UNC

KM P-SB27-0000-0006-01

6/3/2022

35.659216

-108.489648

0

6

SW6020

URANIUM

1.5

0.021

mg/kg

KMP UNC

KM P-SB27-0000-0006-01

6/3/2022

35.659216

-108.489648

0

6

SW6020

VANADIUM

14

0.52

mg/kg

KMP UNC

KM P-SB27-0000-0006-01

6/3/2022

35.659216

-108.489648

0

6

SW6020

ZINC

40

10

mg/kg

KMP UNC

KMP-SB25-0006-0012-01

6/3/2022

35.659242

-108.491829

6

12

SW6020

ALUMINUM

5500

16

mg/kg

KMP UNC

KMP-SB26-0006-0012-01

6/3/2022

35.659916

-108.49061

6

12

SW6020

ALUMINUM

8300

16

mg/kg

KMP UNC

KMP-SB35-0006-0012-01

6/3/2022

35.658326

-108.491719

6

12

SW6020

ALUMINUM

5400

15

mg/kg

KMP UNC

KMP-SB38-0006-0012-01

6/3/2022

35.657432

-108.490829

6

12

SW6020

ALUMINUM

7200

17

mg/kg

KMP UNC

KMP-SB25-0006-0012-01

6/3/2022

35.659242

-108.491829

6

12

SW6020

ANTIMONY

0.058 J

0.1

mg/kg

KMP UNC

KMP-SB26-0006-0012-01

6/3/2022

35.659916

-108.49061

6

12

SW6020

ANTIMONY

0.14

0.11

mg/kg

KMP UNC

KMP-SB35-0006-0012-01

6/3/2022

35.658326

-108.491719

6

12

SW6020

ANTIMONY

0.1

0.1

mg/kg

KMP UNC

KMP-SB38-0006-0012-01

6/3/2022

35.657432

-108.490829

6

12

SW6020

ANTIMONY

0.11 J

0.11

mg/kg

KMP UNC

KMP-SB25-0006-0012-01

6/3/2022

35.659242

-108.491829

6

12

SW6020

ARSENIC

4.7

0.21

mg/kg

KMP UNC

KMP-SB26-0006-0012-01

6/3/2022

35.659916

-108.49061

6

12

SW6020

ARSENIC

6.8

0.22

mg/kg

KMP UNC

KMP-SB35-0006-0012-01

6/3/2022

35.658326

-108.491719

6

12

SW6020

ARSENIC

5.3

0.2

mg/kg

KMP UNC

KMP-SB38-0006-0012-01

6/3/2022

35.657432

-108.490829

6

12

SW6020

ARSENIC

6

0.22

mg/kg

KMP UNC

KMP-SB25-0006-0012-01

6/3/2022

35.659242

-108.491829

6

12

SW6020

BARIUM

47

0.52

mg/kg

KMP UNC

KMP-SB26-0006-0012-01

6/3/2022

35.659916

-108.49061

6

12

SW6020

BARIUM

110

0.55

mg/kg

KMP UNC

KMP-SB35-0006-0012-01

6/3/2022

35.658326

-108.491719

6

12

SW6020

BARIUM

65

0.5

mg/kg

KMP UNC

KMP-SB38-0006-0012-01

6/3/2022

35.657432

-108.490829

6

12

SW6020

BARIUM

69

0.55

mg/kg

KMP UNC

KMP-SB25-0006-0012-01

6/3/2022

35.659242

-108.491829

6

12

SW6020

BERYLLIUM

0.47

0.052

mg/kg

KMP UNC

KMP-SB26-0006-0012-01

6/3/2022

35.659916

-108.49061

6

12

SW6020

BERYLLIUM

0.67

0.055

mg/kg

KMP UNC

KMP-SB35-0006-0012-01

6/3/2022

35.658326

-108.491719

6

12

SW6020

BERYLLIUM

0.44

0.05

mg/kg

KMP UNC

KMP-SB38-0006-0012-01

6/3/2022

35.657432

-108.490829

6

12

SW6020

BERYLLIUM

0.55

0.055

mg/kg

KMP UNC

KMP-SB25-0006-0012-01

6/3/2022

35.659242

-108.491829

6

12

SW6020

CADMIUM

0.045 J

0.21

mg/kg

KMP UNC

KMP-SB26-0006-0012-01

6/3/2022

35.659916

-108.49061

6

12

SW6020

CADMIUM

0.14 J

0.22

mg/kg

KMP UNC

KMP-SB35-0006-0012-01

6/3/2022

35.658326

-108.491719

6

12

SW6020

CADMIUM

0.11 J

0.2

mg/kg

KMP UNC

KMP-SB38-0006-0012-01

6/3/2022

35.657432

-108.490829

6

12

SW6020

CADMIUM

0.094 J

0.22

mg/kg

KMP UNC

KMP-SB25-0006-0012-01

6/3/2022

35.659242

-108.491829

6

12

SW6020

CHROMIUM

6.1

1

mg/kg

KMP UNC

KMP-SB26-0006-0012-01

6/3/2022

35.659916

-108.49061

6

12

SW6020

CHROMIUM

8.7

1.1

mg/kg

KMP UNC

KMP-SB35-0006-0012-01

6/3/2022

35.658326

-108.491719

6

12

SW6020

CHROMIUM

5.8

1

mg/kg

KMP UNC

KMP-SB38-0006-0012-01

6/3/2022

35.657432

-108.490829

6

12

SW6020

CHROMIUM

7.5

1.1

mg/kg

KMP UNC

KMP-SB25-0006-0012-01

6/3/2022

35.659242

-108.491829

6

12

SW6020

COBALT

4.4

0.52

mg/kg

KMP UNC

KMP-SB26-0006-0012-01

6/3/2022

35.659916

-108.49061

6

12

SW6020

COBALT

6

0.55

mg/kg

KMP UNC

KMP-SB35-0006-0012-01

6/3/2022

35.658326

-108.491719

6

12

SW6020

COBALT

4.2

0.5

mg/kg

KMP UNC

KM P-SB38-0006-0012-01

6/3/2022

35.657432

-108.490829

6

12

SW6020

COBALT

5.9

0.55

mg/kg

KMP UNC

KM P-SB25-0006-0012-01

6/3/2022

35.659242

-108.491829

6

12

SW6020

COPPER

6.6

2.1

mg/kg

KMP UNC

KMP-SB26-0006-0012-01

6/3/2022

35.659916

-108.49061

6

12

SW6020

COPPER

12

2.2

mg/kg

Page 66 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KMP-SB35-0006-0012-01

6/3/2022

35.658326

-108.491719

6

12

SW6020

COPPER

7.6

2

mg/kg

KMPUNC

KMP-SB38-0006-0012-01

6/3/2022

35.657432

-108.490829

6

12

SW6020

COPPER

9.8

2.2

mg/kg

KMP UNC

KMP-SB25-0006-0012-01

6/3/2022

35.659242

-108.491829

6

12

SW6020

IRON

12000

21

mg/kg

KMP UNC

KMP-SB26-0006-0012-01

6/3/2022

35.659916

-108.49061

6

12

SW6020

IRON

16000

22

mg/kg

KMP UNC

KMP-SB35-0006-0012-01

6/3/2022

35.658326

-108.491719

6

12

SW6020

IRON

12000

20

mg/kg

KMP UNC

KMP-SB38-0006-0012-01

6/3/2022

35.657432

-108.490829

6

12

SW6020

IRON

16000

22

mg/kg

KMP UNC

KMP-SB25-0006-0012-01

6/3/2022

35.659242

-108.491829

6

12

SW6020

LEAD

7.7

0.21

mg/kg

KMP UNC

KMP-SB26-0006-0012-01

6/3/2022

35.659916

-108.49061

6

12

SW6020

LEAD

13

0.22

mg/kg

KMP UNC

KMP-SB35-0006-0012-01

6/3/2022

35.658326

-108.491719

6

12

SW6020

LEAD

9.7

0.2

mg/kg

KMP UNC

KMP-SB38-0006-0012-01

6/3/2022

35.657432

-108.490829

6

12

SW6020

LEAD

11

0.22

mg/kg

KMP UNC

KMP-SB25-0006-0012-01

6/3/2022

35.659242

-108.491829

6

12

SW6020

MANGANESE

180

0.78

mg/kg

KMP UNC

KMP-SB26-0006-0012-01

6/3/2022

35.659916

-108.49061

6

12

SW6020

MANGANESE

270

0.82

mg/kg

KMP UNC

KMP-SB35-0006-0012-01

6/3/2022

35.658326

-108.491719

6

12

SW6020

MANGANESE

230

0.76

mg/kg

KMP UNC

KMP-SB38-0006-0012-01

6/3/2022

35.657432

-108.490829

6

12

SW6020

MANGANESE

250

0.83

mg/kg

KMP UNC

KMP-SB25-0006-0012-01

6/3/2022

35.659242

-108.491829

6

12

SW6020

MOLYBDENUM

0.67

0.21

mg/kg

KMP UNC

KMP-SB26-0006-0012-01

6/3/2022

35.659916

-108.49061

6

12

SW6020

MOLYBDENUM

0.48

0.22

mg/kg

KMP UNC

KMP-SB35-0006-0012-01

6/3/2022

35.658326

-108.491719

6

12

SW6020

MOLYBDENUM

0.62

0.2

mg/kg

KMP UNC

KMP-SB38-0006-0012-01

6/3/2022

35.657432

-108.490829

6

12

SW6020

MOLYBDENUM

0.5

0.22

mg/kg

KMP UNC

KMP-SB25-0006-0012-01

6/3/2022

35.659242

-108.491829

6

12

SW6020

NICKEL

6.5

2.1

mg/kg

KMP UNC

KMP-SB26-0006-0012-01

6/3/2022

35.659916

-108.49061

6

12

SW6020

NICKEL

9.7

2.2

mg/kg

KMP UNC

KMP-SB35-0006-0012-01

6/3/2022

35.658326

-108.491719

6

12

SW6020

NICKEL

6.1

2

mg/kg

KMP UNC

KMP-SB38-0006-0012-01

6/3/2022

35.657432

-108.490829

6

12

SW6020

NICKEL

8.9

2.2

mg/kg

KMP UNC

KMP-SB25-0006-0012-01

6/3/2022

35.659242

-108.491829

6

12

713R15

Ra-226

1.81 J

0.44

pCi/g

KMP UNC

KMP-SB26-0006-0012-01

6/3/2022

35.659916

-108.49061

6

12

713R15

Ra-226

1.16 J

0.57

pCi/g

KMP UNC

KMP-SB35-0006-0012-01

6/3/2022

35.658326

-108.491719

6

12

713R15

Ra-226

27.1 J

0.8

pCi/g

KMP UNC

KMP-SB38-0006-0012-01

6/3/2022

35.657432

-108.490829

6

12

713R15

Ra-226

1.4 J

0.59

pCi/g

KMP UNC

KMP-SB25-0006-0012-01

6/3/2022

35.659242

-108.491829

6

12

SW6020

SELENIUM

1.5

1

mg/kg

KMP UNC

KMP-SB26-0006-0012-01

6/3/2022

35.659916

-108.49061

6

12

SW6020

SELENIUM

1.5

1.1

mg/kg

KMP UNC

KMP-SB35-0006-0012-01

6/3/2022

35.658326

-108.491719

6

12

SW6020

SELENIUM

6.4

1

mg/kg

KMP UNC

KMP-SB38-0006-0012-01

6/3/2022

35.657432

-108.490829

6

12

SW6020

SELENIUM

1.3

1.1

mg/kg

KMP UNC

KMP-SB25-0006-0012-01

6/3/2022

35.659242

-108.491829

6

12

SW6020

SILVER

0.06 U

0.12

mg/kg

KMP UNC

KMP-SB26-0006-0012-01

6/3/2022

35.659916

-108.49061

6

12

SW6020

SILVER

0.067 J

0.12

mg/kg

KMP UNC

KMP-SB35-0006-0012-01

6/3/2022

35.658326

-108.491719

6

12

SW6020

SILVER

0.057 UJ

0.11

mg/kg

KMP UNC

KMP-SB38-0006-0012-01

6/3/2022

35.657432

-108.490829

6

12

SW6020

SILVER

0.063 UJ

0.13

mg/kg

KMP UNC

KMP-SB25-0006-0012-01

6/3/2022

35.659242

-108.491829

6

12

SW6020

THALLIUM

0.11

0.01

mg/kg

KMP UNC

KM P-SB26-0006-0012-01

6/3/2022

35.659916

-108.49061

6

12

SW6020

THALLIUM

0.17

0.011

mg/kg

KMP UNC

KM P-SB35-0006-0012-01

6/3/2022

35.658326

-108.491719

6

12

SW6020

THALLIUM

0.1

0.01

mg/kg

KMP UNC

KM P-SB38-0006-0012-01

6/3/2022

35.657432

-108.490829

6

12

SW6020

THALLIUM

0.13

0.011

mg/kg

KMP UNC

KMP-SB25-0006-0012-01

6/3/2022

35.659242

-108.491829

6

12

SW6020

URANIUM

23

0.021

mg/kg

KMP UNC

KMP-SB26-0006-0012-01

6/3/2022

35.659916

-108.49061

6

12

SW6020

URANIUM

5.9

0.022

mg/kg

KMP UNC

KMP-SB35-0006-0012-01

6/3/2022

35.658326

-108.491719

6

12

SW6020

URANIUM

30

0.02

mg/kg

KMP UNC

KMP-SB38-0006-0012-01

6/3/2022

35.657432

-108.490829

6

12

SW6020

URANIUM

1.4

0.022

mg/kg

Page 67 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KMP-SB25-0006-0012-01

6/3/2022

35.659242

-108.491829

6

12

SW6020

VANADIUM

13

0.52

mg/kg

KMPUNC

KMP-SB26-0006-0012-01

6/3/2022

35.659916

-108.49061

6

12

SW6020

VANADIUM

17

0.55

mg/kg

KMP UNC

KMP-SB35-0006-0012-01

6/3/2022

35.658326

-108.491719

6

12

SW6020

VANADIUM

17

0.5

mg/kg

KMP UNC

KMP-SB38-0006-0012-01

6/3/2022

35.657432

-108.490829

6

12

SW6020

VANADIUM

16

0.55

mg/kg

KMP UNC

KMP-SB25-0006-0012-01

6/3/2022

35.659242

-108.491829

6

12

SW6020

ZINC

32

10

mg/kg

KMP UNC

KMP-SB26-0006-0012-01

6/3/2022

35.659916

-108.49061

6

12

SW6020

ZINC

48

11

mg/kg

KMP UNC

KMP-SB35-0006-0012-01

6/3/2022

35.658326

-108.491719

6

12

SW6020

ZINC

36

10

mg/kg

KMP UNC

KMP-SB38-0006-0012-01

6/3/2022

35.657432

-108.490829

6

12

SW6020

ZINC

44

11

mg/kg

KMP UNC

KMP-SB26-0012-0018-01

6/3/2022

35.659916

-108.49061

12

18

SW6020

ALUMINUM

7600

16

mg/kg

KMP UNC

KMP-SB26-0012-0018-02

6/3/2022

35.659916

-108.49061

12

18

SW6020

ALUMINUM

7700

16

mg/kg

KMP UNC

KMP-SB27-0012-0018-01

6/3/2022

35.659216

-108.489648

12

18

SW6020

ALUMINUM

8200

16

mg/kg

KMP UNC

KMP-SB26-0012-0018-01

6/3/2022

35.659916

-108.49061

12

18

SW6020

ANTIMONY

0.11

0.1

mg/kg

KMP UNC

KMP-SB26-0012-0018-02

6/3/2022

35.659916

-108.49061

12

18

SW6020

ANTIMONY

0.099 J

0.11

mg/kg

KMP UNC

KMP-SB27-0012-0018-01

6/3/2022

35.659216

-108.489648

12

18

SW6020

ANTIMONY

0.091 J

0.11

mg/kg

KMP UNC

KMP-SB26-0012-0018-01

6/3/2022

35.659916

-108.49061

12

18

SW6020

ARSENIC

6.5

0.21

mg/kg

KMP UNC

KMP-SB26-0012-0018-02

6/3/2022

35.659916

-108.49061

12

18

SW6020

ARSENIC

6.5

0.21

mg/kg

KMP UNC

KMP-SB27-0012-0018-01

6/3/2022

35.659216

-108.489648

12

18

SW6020

ARSENIC

6.7

0.21

mg/kg

KMP UNC

KMP-SB26-0012-0018-01

6/3/2022

35.659916

-108.49061

12

18

SW6020

BARIUM

85

0.52

mg/kg

KMP UNC

KMP-SB26-0012-0018-02

6/3/2022

35.659916

-108.49061

12

18

SW6020

BARIUM

90

0.53

mg/kg

KMP UNC

KMP-SB27-0012-0018-01

6/3/2022

35.659216

-108.489648

12

18

SW6020

BARIUM

92

0.53

mg/kg

KMP UNC

KMP-SB26-0012-0018-01

6/3/2022

35.659916

-108.49061

12

18

SW6020

BERYLLIUM

0.63

0.052

mg/kg

KMP UNC

KMP-SB26-0012-0018-02

6/3/2022

35.659916

-108.49061

12

18

SW6020

BERYLLIUM

0.63

0.053

mg/kg

KMP UNC

KMP-SB27-0012-0018-01

6/3/2022

35.659216

-108.489648

12

18

SW6020

BERYLLIUM

0.68

0.053

mg/kg

KMP UNC

KMP-SB26-0012-0018-01

6/3/2022

35.659916

-108.49061

12

18

SW6020

CADMIUM

0.12 J

0.21

mg/kg

KMP UNC

KMP-SB26-0012-0018-02

6/3/2022

35.659916

-108.49061

12

18

SW6020

CADMIUM

0.1 J

0.21

mg/kg

KMP UNC

KMP-SB27-0012-0018-01

6/3/2022

35.659216

-108.489648

12

18

SW6020

CADMIUM

0.08 J

0.21

mg/kg

KMP UNC

KMP-SB26-0012-0018-01

6/3/2022

35.659916

-108.49061

12

18

SW6020

CHROMIUM

8.4

1

mg/kg

KMP UNC

KMP-SB26-0012-0018-02

6/3/2022

35.659916

-108.49061

12

18

SW6020

CHROMIUM

8.4

1.1

mg/kg

KMP UNC

KMP-SB27-0012-0018-01

6/3/2022

35.659216

-108.489648

12

18

SW6020

CHROMIUM

9

1.1

mg/kg

KMP UNC

KMP-SB26-0012-0018-01

6/3/2022

35.659916

-108.49061

12

18

SW6020

COBALT

5.7

0.52

mg/kg

KMP UNC

KMP-SB26-0012-0018-02

6/3/2022

35.659916

-108.49061

12

18

SW6020

COBALT

5.7

0.53

mg/kg

KMP UNC

KMP-SB27-0012-0018-01

6/3/2022

35.659216

-108.489648

12

18

SW6020

COBALT

5.8

0.53

mg/kg

KMP UNC

KMP-SB26-0012-0018-01

6/3/2022

35.659916

-108.49061

12

18

SW6020

COPPER

11

2.1

mg/kg

KMP UNC

KMP-SB26-0012-0018-02

6/3/2022

35.659916

-108.49061

12

18

SW6020

COPPER

11

2.1

mg/kg

KMP UNC

KMP-SB27-0012-0018-01

6/3/2022

35.659216

-108.489648

12

18

SW6020

COPPER

11

2.1

mg/kg

KMP UNC

KMP-SB26-0012-0018-01

6/3/2022

35.659916

-108.49061

12

18

SW6020

IRON

16000

21

mg/kg

KMP UNC

KMP-SB26-0012-0018-02

6/3/2022

35.659916

-108.49061

12

18

SW6020

IRON

16000

21

mg/kg

KMP UNC

KMP-SB27-0012-0018-01

6/3/2022

35.659216

-108.489648

12

18

SW6020

IRON

16000

21

mg/kg

KMP UNC

KMP-SB26-0012-0018-01

6/3/2022

35.659916

-108.49061

12

18

SW6020

LEAD

12

0.21

mg/kg

KMP UNC

KMP-SB26-0012-0018-02

6/3/2022

35.659916

-108.49061

12

18

SW6020

LEAD

12

0.21

mg/kg

KMP UNC

KMP-SB27-0012-0018-01

6/3/2022

35.659216

-108.489648

12

18

SW6020

LEAD

11

0.21

mg/kg

KMP UNC

KMP-SB26-0012-0018-01

6/3/2022

35.659916

-108.49061

12

18

SW6020

MANGANESE

240

0.78

mg/kg

Page 68 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KMP-SB26-0012-0018-02

6/3/2022

35.659916

-108.49061

12

18

SW6020

MANGANESE

250

0.79

mg/kg

KMPUNC

KMP-SB27-0012-0018-01

6/3/2022

35.659216

-108.489648

12

18

SW6020

MANGANESE

230

0.79

mg/kg

KMP UNC

KMP-SB26-0012-0018-01

6/3/2022

35.659916

-108.49061

12

18

SW6020

MOLYBDENUM

0.43

0.21

mg/kg

KMP UNC

KMP-SB26-0012-0018-02

6/3/2022

35.659916

-108.49061

12

18

SW6020

MOLYBDENUM

0.41

0.21

mg/kg

KMP UNC

KMP-SB27-0012-0018-01

6/3/2022

35.659216

-108.489648

12

18

SW6020

MOLYBDENUM

0.41

0.21

mg/kg

KMP UNC

KMP-SB26-0012-0018-01

6/3/2022

35.659916

-108.49061

12

18

SW6020

NICKEL

9.4

2.1

mg/kg

KMP UNC

KMP-SB26-0012-0018-02

6/3/2022

35.659916

-108.49061

12

18

SW6020

NICKEL

9.4

2.1

mg/kg

KMP UNC

KMP-SB27-0012-0018-01

6/3/2022

35.659216

-108.489648

12

18

SW6020

NICKEL

9.7

2.1

mg/kg

KMP UNC

KMP-SB26-0012-0018-01

6/3/2022

35.659916

-108.49061

12

18

713R15

Ra-226

1.32 J

0.33

pCi/g

KMP UNC

KMP-SB26-0012-0018-02

6/3/2022

35.659916

-108.49061

12

18

713R15

Ra-226

1.83 J

0.86

pCi/g

KMP UNC

KMP-SB27-0012-0018-01

6/3/2022

35.659216

-108.489648

12

18

713R15

Ra-226

1.17 J

0.49

pCi/g

KMP UNC

KMP-SB26-0012-0018-01

6/3/2022

35.659916

-108.49061

12

18

SW6020

SELENIUM

1.3

1

mg/kg

KMP UNC

KMP-SB26-0012-0018-02

6/3/2022

35.659916

-108.49061

12

18

SW6020

SELENIUM

1.3

1.1

mg/kg

KMP UNC

KMP-SB27-0012-0018-01

6/3/2022

35.659216

-108.489648

12

18

SW6020

SELENIUM

1.5

1.1

mg/kg

KMP UNC

KMP-SB26-0012-0018-01

6/3/2022

35.659916

-108.49061

12

18

SW6020

SILVER

0.063 J

0.12

mg/kg

KMP UNC

KMP-SB26-0012-0018-02

6/3/2022

35.659916

-108.49061

12

18

SW6020

SILVER

0.066 J

0.12

mg/kg

KMP UNC

KMP-SB27-0012-0018-01

6/3/2022

35.659216

-108.489648

12

18

SW6020

SILVER

0.069 J

0.12

mg/kg

KMP UNC

KMP-SB26-0012-0018-01

6/3/2022

35.659916

-108.49061

12

18

SW6020

THALLIUM

0.18

0.01

mg/kg

KMP UNC

KMP-SB26-0012-0018-02

6/3/2022

35.659916

-108.49061

12

18

SW6020

THALLIUM

0.18

0.011

mg/kg

KMP UNC

KMP-SB27-0012-0018-01

6/3/2022

35.659216

-108.489648

12

18

SW6020

THALLIUM

0.18

0.011

mg/kg

KMP UNC

KMP-SB26-0012-0018-01

6/3/2022

35.659916

-108.49061

12

18

SW6020

URANIUM

1.8

0.021

mg/kg

KMP UNC

KMP-SB26-0012-0018-02

6/3/2022

35.659916

-108.49061

12

18

SW6020

URANIUM

1.6

0.021

mg/kg

KMP UNC

KMP-SB27-0012-0018-01

6/3/2022

35.659216

-108.489648

12

18

SW6020

URANIUM

0.8

0.021

mg/kg

KMP UNC

KMP-SB26-0012-0018-01

6/3/2022

35.659916

-108.49061

12

18

SW6020

VANADIUM

15

0.52

mg/kg

KMP UNC

KMP-SB26-0012-0018-02

6/3/2022

35.659916

-108.49061

12

18

SW6020

VANADIUM

16

0.53

mg/kg

KMP UNC

KMP-SB27-0012-0018-01

6/3/2022

35.659216

-108.489648

12

18

SW6020

VANADIUM

16

0.53

mg/kg

KMP UNC

KMP-SB26-0012-0018-01

6/3/2022

35.659916

-108.49061

12

18

SW6020

ZINC

45

10

mg/kg

KMP UNC

KMP-SB26-0012-0018-02

6/3/2022

35.659916

-108.49061

12

18

SW6020

ZINC

46

11

mg/kg

KMP UNC

KMP-SB27-0012-0018-01

6/3/2022

35.659216

-108.489648

12

18

SW6020

ZINC

46

11

mg/kg

KMP UNC

KMP-SB24-0018-0024-01

6/3/2022

35.658718

-108.492772

18

24

SW6020

ALUMINUM

6900

17

mg/kg

KMP UNC

KMP-SB25-0018-0024-01

6/3/2022

35.659242

-108.491829

18

24

SW6020

ALUMINUM

6000

16

mg/kg

KMP UNC

KMP-SB24-0018-0024-01

6/3/2022

35.658718

-108.492772

18

24

SW6020

ANTIMONY

0.1 J

0.12

mg/kg

KMP UNC

KMP-SB25-0018-0024-01

6/3/2022

35.659242

-108.491829

18

24

SW6020

ANTIMONY

0.064 J

0.11

mg/kg

KMP UNC

KMP-16-18

7/18/2017

35.658292

-108.491842

18

24

Unknown

ARSENIC

5.1

Unknown

mg/kg

KMP UNC

KMP-17-18

7/19/2017

35.658397

-108.491778

18

24

Unknown

ARSENIC

4.9

Unknown

mg/kg

KMP UNC

KMP-18-18

7/19/2017

35.658584

-108.491524

18

24

Unknown

ARSENIC

4.5

Unknown

mg/kg

KMP UNC

KMP-19-18

7/19/2017

35.65865

-108.491373

18

24

Unknown

ARSENIC

5

Unknown

mg/kg

KMP UNC

KMP-20-18

7/19/2017

35.658809

-108.491224

18

24

Unknown

ARSENIC

4.2

Unknown

mg/kg

KMP UNC

KMP-21-18

7/19/2017

35.658901

-108.491165

18

24

Unknown

ARSENIC

4

Unknown

mg/kg

KMP UNC

KMP-22-18

7/19/2017

35.658405

-108.490563

18

24

Unknown

ARSENIC

5.3

Unknown

mg/kg

KMP UNC

KMP-23-18

7/18/2017

35.658984

-108.490548

18

24

Unknown

ARSENIC

4.9

Unknown

mg/kg

KMP UNC

KMP-SB24-0018-0024-01

6/3/2022

35.658718

-108.492772

18

24

SW6020

ARSENIC

7

0.23

mg/kg

Page 69 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KMP-SB25-0018-0024-01

6/3/2022

35.659242

-108.491829

18

24

SW6020

ARSENIC

5.1

0.22

mg/kg

KMPUNC

KMP-16-18

7/18/2017

35.658292

-108.491842

18

24

Unknown

BARIUM

190

Unknown

mg/kg

KMP UNC

KMP-17-18

7/19/2017

35.658397

-108.491778

18

24

Unknown

BARIUM

55

Unknown

mg/kg

KMP UNC

KMP-18-18

7/19/2017

35.658584

-108.491524

18

24

Unknown

BARIUM

43

Unknown

mg/kg

KMP UNC

KMP-19-18

7/19/2017

35.65865

-108.491373

18

24

Unknown

BARIUM

62

Unknown

mg/kg

KMP UNC

KMP-20-18

7/19/2017

35.658809

-108.491224

18

24

Unknown

BARIUM

74

Unknown

mg/kg

KMP UNC

KMP-21-18

7/19/2017

35.658901

-108.491165

18

24

Unknown

BARIUM

41

Unknown

mg/kg

KMP UNC

KMP-22-18

7/19/2017

35.658405

-108.490563

18

24

Unknown

BARIUM

47

Unknown

mg/kg

KMP UNC

KMP-23-18

7/18/2017

35.658984

-108.490548

18

24

Unknown

BARIUM

51

Unknown

mg/kg

KMP UNC

KMP-SB24-0018-0024-01

6/3/2022

35.658718

-108.492772

18

24

SW6020

BARIUM

60

0.58

mg/kg

KMP UNC

KMP-SB25-0018-0024-01

6/3/2022

35.659242

-108.491829

18

24

SW6020

BARIUM

44

0.55

mg/kg

KMP UNC

KMP-SB24-0018-0024-01

6/3/2022

35.658718

-108.492772

18

24

SW6020

BERYLLIUM

0.6

0.058

mg/kg

KMP UNC

KMP-SB25-0018-0024-01

6/3/2022

35.659242

-108.491829

18

24

SW6020

BERYLLIUM

0.51

0.055

mg/kg

KMP UNC

KMP-16-18

7/18/2017

35.658292

-108.491842

18

24

Unknown

CADMIUM

0.11 J

Unknown

mg/kg

KMP UNC

KMP-17-18

7/19/2017

35.658397

-108.491778

18

24

Unknown

CADMIUM

0.12 U

Unknown

mg/kg

KMP UNC

KMP-18-18

7/19/2017

35.658584

-108.491524

18

24

Unknown

CADMIUM

0.11 U

Unknown

mg/kg

KMP UNC

KMP-19-18

7/19/2017

35.65865

-108.491373

18

24

Unknown

CADMIUM

0.13 U

Unknown

mg/kg

KMP UNC

KMP-20-18

7/19/2017

35.658809

-108.491224

18

24

Unknown

CADMIUM

0.13 U

Unknown

mg/kg

KMP UNC

KMP-21-18

7/19/2017

35.658901

-108.491165

18

24

Unknown

CADMIUM

0.076 J

Unknown

mg/kg

KMP UNC

KMP-22-18

7/19/2017

35.658405

-108.490563

18

24

Unknown

CADMIUM

0.062

Unknown

mg/kg

KMP UNC

KMP-23-18

7/18/2017

35.658984

-108.490548

18

24

Unknown

CADMIUM

0.077 J

Unknown

mg/kg

KMP UNC

KMP-SB24-0018-0024-01

6/3/2022

35.658718

-108.492772

18

24

SW6020

CADMIUM

0.094 J

0.23

mg/kg

KMP UNC

KMP-SB25-0018-0024-01

6/3/2022

35.659242

-108.491829

18

24

SW6020

CADMIUM

0.054 J

0.22

mg/kg

KMP UNC

KMP-16-18

7/18/2017

35.658292

-108.491842

18

24

Unknown

CHROMIUM

8.1

Unknown

mg/kg

KMP UNC

KMP-17-18

7/19/2017

35.658397

-108.491778

18

24

Unknown

CHROMIUM

7

Unknown

mg/kg

KMP UNC

KMP-18-18

7/19/2017

35.658584

-108.491524

18

24

Unknown

CHROMIUM

7

Unknown

mg/kg

KMP UNC

KMP-19-18

7/19/2017

35.65865

-108.491373

18

24

Unknown

CHROMIUM

7.7

Unknown

mg/kg

KMP UNC

KMP-20-18

7/19/2017

35.658809

-108.491224

18

24

Unknown

CHROMIUM

8.6

Unknown

mg/kg

KMP UNC

KMP-21-18

7/19/2017

35.658901

-108.491165

18

24

Unknown

CHROMIUM

5.9

Unknown

mg/kg

KMP UNC

KMP-22-18

7/19/2017

35.658405

-108.490563

18

24

Unknown

CHROMIUM

7.8

Unknown

mg/kg

KMP UNC

KMP-23-18

7/18/2017

35.658984

-108.490548

18

24

Unknown

CHROMIUM

7.8

Unknown

mg/kg

KMP UNC

KM P-SB24-0018-0024-01

6/3/2022

35.658718

-108.492772

18

24

SW6020

CHROMIUM

7.6

1.2

mg/kg

KMP UNC

KM P-SB25-0018-0024-01

6/3/2022

35.659242

-108.491829

18

24

SW6020

CHROMIUM

6.6

1.1

mg/kg

KMP UNC

KMP-SB24-0018-0024-01

6/3/2022

35.658718

-108.492772

18

24

SW6020

COBALT

5.9

0.58

mg/kg

KMP UNC

KMP-SB25-0018-0024-01

6/3/2022

35.659242

-108.491829

18

24

SW6020

COBALT

4.7

0.55

mg/kg

KMP UNC

KMP-SB24-0018-0024-01

6/3/2022

35.658718

-108.492772

18

24

SW6020

COPPER

11

2.3

mg/kg

KMP UNC

KMP-SB25-0018-0024-01

6/3/2022

35.659242

-108.491829

18

24

SW6020

COPPER

7.4

2.2

mg/kg

KMP UNC

KMP-SB24-0018-0024-01

6/3/2022

35.658718

-108.492772

18

24

SW6020

IRON

16000

23

mg/kg

KMP UNC

KMP-SB25-0018-0024-01

6/3/2022

35.659242

-108.491829

18

24

SW6020

IRON

13000

22

mg/kg

KMP UNC

KMP-16-18

7/18/2017

35.658292

-108.491842

18

24

Unknown

LEAD

11

Unknown

mg/kg

KMP UNC

KMP-17-18

7/19/2017

35.658397

-108.491778

18

24

Unknown

LEAD

7.6

Unknown

mg/kg

KMP UNC

KMP-18-18

7/19/2017

35.658584

-108.491524

18

24

Unknown

LEAD

7.2

Unknown

mg/kg

Page 70 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KMP-19-18

7/19/2017

35.65865

-108.491373

18

24

Unknown

LEAD

9.1

Unknown

mg/kg

KMPUNC

KMP-20-18

7/19/2017

35.658809

-108.491224

18

24

Unknown

LEAD

6.7

Unknown

mg/kg

KMP UNC

KMP-21-18

7/19/2017

35.658901

-108.491165

18

24

Unknown

LEAD

6.4

Unknown

mg/kg

KMP UNC

KMP-22-18

7/19/2017

35.658405

-108.490563

18

24

Unknown

LEAD

8.5

Unknown

mg/kg

KMP UNC

KMP-23-18

7/18/2017

35.658984

-108.490548

18

24

Unknown

LEAD

7.9

Unknown

mg/kg

KMP UNC

KMP-SB24-0018-0024-01

6/3/2022

35.658718

-108.492772

18

24

SW6020

LEAD

12

0.23

mg/kg

KMP UNC

KMP-SB25-0018-0024-01

6/3/2022

35.659242

-108.491829

18

24

SW6020

LEAD

8.2

0.22

mg/kg

KMP UNC

KMP-SB24-0018-0024-01

6/3/2022

35.658718

-108.492772

18

24

SW6020

MANGANESE

220

0.86

mg/kg

KMP UNC

KMP-SB25-0018-0024-01

6/3/2022

35.659242

-108.491829

18

24

SW6020

MANGANESE

190

0.82

mg/kg

KMP UNC

KMP-16-18

7/18/2017

35.658292

-108.491842

18

24

Unknown

MOLYBDENUM

1.4

Unknown

mg/kg

KMP UNC

KMP-17-18

7/19/2017

35.658397

-108.491778

18

24

Unknown

MOLYBDENUM

0.64 J

Unknown

mg/kg

KMP UNC

KMP-18-18

7/19/2017

35.658584

-108.491524

18

24

Unknown

MOLYBDENUM

0.75 J

Unknown

mg/kg

KMP UNC

KMP-19-18

7/19/2017

35.65865

-108.491373

18

24

Unknown

MOLYBDENUM

0.79 J

Unknown

mg/kg

KMP UNC

KMP-20-18

7/19/2017

35.658809

-108.491224

18

24

Unknown

MOLYBDENUM

0.69 J

Unknown

mg/kg

KMP UNC

KMP-21-18

7/19/2017

35.658901

-108.491165

18

24

Unknown

MOLYBDENUM

0.76 J

Unknown

mg/kg

KMP UNC

KMP-22-18

7/19/2017

35.658405

-108.490563

18

24

Unknown

MOLYBDENUM

0.51 J

Unknown

mg/kg

KMP UNC

KMP-23-18

7/18/2017

35.658984

-108.490548

18

24

Unknown

MOLYBDENUM

1 J

Unknown

mg/kg

KMP UNC

KMP-SB24-0018-0024-01

6/3/2022

35.658718

-108.492772

18

24

SW6020

MOLYBDENUM

0.4

0.23

mg/kg

KMP UNC

KMP-SB25-0018-0024-01

6/3/2022

35.659242

-108.491829

18

24

SW6020

MOLYBDENUM

0.47

0.22

mg/kg

KMP UNC

KMP-SB24-0018-0024-01

6/3/2022

35.658718

-108.492772

18

24

SW6020

NICKEL

9

2.3

mg/kg

KMP UNC

KMP-SB25-0018-0024-01

6/3/2022

35.659242

-108.491829

18

24

SW6020

NICKEL

6.9

2.2

mg/kg

KMP UNC

KMP-16-18

7/18/2017

35.658292

-108.491842

18

24

Unknown

Ra-226

143.1

Unknown

pCi/g

KMP UNC

KMP-17-18

7/19/2017

35.658397

-108.491778

18

24

Unknown

Ra-226

8.3

Unknown

pCi/g

KMP UNC

KMP-18-18

7/19/2017

35.658584

-108.491524

18

24

Unknown

Ra-226

1.9

Unknown

pCi/g

KMP UNC

KMP-19-18

7/19/2017

35.65865

-108.491373

18

24

Unknown

Ra-226

3.1

Unknown

pCi/g

KMP UNC

KMP-20-18

7/19/2017

35.658809

-108.491224

18

24

Unknown

Ra-226

2.3

Unknown

pCi/g

KMP UNC

KMP-21-18

7/19/2017

35.658901

-108.491165

18

24

Unknown

Ra-226

3.2

Unknown

pCi/g

KMP UNC

KMP-22-18

7/19/2017

35.658405

-108.490563

18

24

Unknown

Ra-226

1.1

Unknown

pCi/g

KMP UNC

KMP-23-18

7/18/2017

35.658984

-108.490548

18

24

Unknown

Ra-226

1.3

Unknown

pCi/g

KMP UNC

KMP-SB24-0018-0024-01

6/3/2022

35.658718

-108.492772

18

24

713R15

Ra-226

0.98 J

0.54

pCi/g

KMP UNC

KMP-SB25-0018-0024-01

6/3/2022

35.659242

-108.491829

18

24

713R15

Ra-226

0.92 J

0.38

pCi/g

KMP UNC

KMP-16-18

7/18/2017

35.658292

-108.491842

18

24

Unknown

SELENIUM

37

Unknown

mg/kg

KMP UNC

KMP-17-18

7/19/2017

35.658397

-108.491778

18

24

Unknown

SELENIUM

3

Unknown

mg/kg

KMP UNC

KMP-18-18

7/19/2017

35.658584

-108.491524

18

24

Unknown

SELENIUM

1.4

Unknown

mg/kg

KMP UNC

KMP-19-18

7/19/2017

35.65865

-108.491373

18

24

Unknown

SELENIUM

3.3

Unknown

mg/kg

KMP UNC

KMP-20-18

7/19/2017

35.658809

-108.491224

18

24

Unknown

SELENIUM

1.6

Unknown

mg/kg

KMP UNC

KMP-21-18

7/19/2017

35.658901

-108.491165

18

24

Unknown

SELENIUM

1.6

Unknown

mg/kg

KMP UNC

KMP-22-18

7/19/2017

35.658405

-108.490563

18

24

Unknown

SELENIUM

1.7

Unknown

mg/kg

KMP UNC

KMP-23-18

7/18/2017

35.658984

-108.490548

18

24

Unknown

SELENIUM

1.3

Unknown

mg/kg

KMP UNC

KMP-SB24-0018-0024-01

6/3/2022

35.658718

-108.492772

18

24

SW6020

SELENIUM

1.4

1.2

mg/kg

KMP UNC

KMP-SB25-0018-0024-01

6/3/2022

35.659242

-108.491829

18

24

SW6020

SELENIUM

1.1 J

1.1

mg/kg

KMP UNC

KMP-16-18

7/18/2017

35.658292

-108.491842

18

24

Unknown

SILVER

0.52 U

Unknown

mg/kg

Page 71 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KMP-17-18

7/19/2017

35.658397

-108.491778

18

24

Unknown

SILVER

0.46 U

Unknown

mg/kg

KMPUNC

KMP-18-18

7/19/2017

35.658584

-108.491524

18

24

Unknown

SILVER

0.45 U

Unknown

mg/kg

KMP UNC

KMP-19-18

7/19/2017

35.65865

-108.491373

18

24

Unknown

SILVER

0.53 U

Unknown

mg/kg

KMP UNC

KMP-20-18

7/19/2017

35.658809

-108.491224

18

24

Unknown

SILVER

0.5 U

Unknown

mg/kg

KMP UNC

KMP-21-18

7/19/2017

35.658901

-108.491165

18

24

Unknown

SILVER

0.46 U

Unknown

mg/kg

KMP UNC

KMP-22-18

7/19/2017

35.658405

-108.490563

18

24

Unknown

SILVER

0.19

Unknown

mg/kg

KMP UNC

KMP-23-18

7/18/2017

35.658984

-108.490548

18

24

Unknown

SILVER

0.51 U

Unknown

mg/kg

KMP UNC

KMP-SB24-0018-0024-01

6/3/2022

35.658718

-108.492772

18

24

SW6020

SILVER

0.066 U

0.13

mg/kg

KMP UNC

KMP-SB25-0018-0024-01

6/3/2022

35.659242

-108.491829

18

24

SW6020

SILVER

0.062 U

0.12

mg/kg

KMP UNC

KMP-SB24-0018-0024-01

6/3/2022

35.658718

-108.492772

18

24

SW6020

THALLIUM

0.15

0.012

mg/kg

KMP UNC

KMP-SB25-0018-0024-01

6/3/2022

35.659242

-108.491829

18

24

SW6020

THALLIUM

0.12

0.011

mg/kg

KMP UNC

KMP-16-18

7/18/2017

35.658292

-108.491842

18

24

Unknown

URANIUM

110

Unknown

mg/kg

KMP UNC

KMP-17-18

7/19/2017

35.658397

-108.491778

18

24

Unknown

URANIUM

130

Unknown

mg/kg

KMP UNC

KMP-18-18

7/19/2017

35.658584

-108.491524

18

24

Unknown

URANIUM

24

Unknown

mg/kg

KMP UNC

KMP-19-18

7/19/2017

35.65865

-108.491373

18

24

Unknown

URANIUM

60

Unknown

mg/kg

KMP UNC

KMP-20-18

7/19/2017

35.658809

-108.491224

18

24

Unknown

URANIUM

22

Unknown

mg/kg

KMP UNC

KMP-21-18

7/19/2017

35.658901

-108.491165

18

24

Unknown

URANIUM

35

Unknown

mg/kg

KMP UNC

KMP-22-18

7/19/2017

35.658405

-108.490563

18

24

Unknown

URANIUM

4.3

Unknown

mg/kg

KMP UNC

KMP-23-18

7/18/2017

35.658984

-108.490548

18

24

Unknown

URANIUM

44

Unknown

mg/kg

KMP UNC

KMP-SB24-0018-0024-01

6/3/2022

35.658718

-108.492772

18

24

SW6020

URANIUM

2.2

0.023

mg/kg

KMP UNC

KMP-SB25-0018-0024-01

6/3/2022

35.659242

-108.491829

18

24

SW6020

URANIUM

60

0.022

mg/kg

KMP UNC

KMP-16-18

7/18/2017

35.658292

-108.491842

18

24

Unknown

VANADIUM

58

Unknown

mg/kg

KMP UNC

KMP-17-18

7/19/2017

35.658397

-108.491778

18

24

Unknown

VANADIUM

17

Unknown

mg/kg

KMP UNC

KMP-18-18

7/19/2017

35.658584

-108.491524

18

24

Unknown

VANADIUM

16

Unknown

mg/kg

KMP UNC

KMP-19-18

7/19/2017

35.65865

-108.491373

18

24

Unknown

VANADIUM

18

Unknown

mg/kg

KMP UNC

KMP-20-18

7/19/2017

35.658809

-108.491224

18

24

Unknown

VANADIUM

17

Unknown

mg/kg

KMP UNC

KMP-21-18

7/19/2017

35.658901

-108.491165

18

24

Unknown

VANADIUM

13

Unknown

mg/kg

KMP UNC

KMP-22-18

7/19/2017

35.658405

-108.490563

18

24

Unknown

VANADIUM

16

Unknown

mg/kg

KMP UNC

KMP-23-18

7/18/2017

35.658984

-108.490548

18

24

Unknown

VANADIUM

16

Unknown

mg/kg

KMP UNC

KMP-SB24-0018-0024-01

6/3/2022

35.658718

-108.492772

18

24

SW6020

VANADIUM

15

0.58

mg/kg

KMP UNC

KMP-SB25-0018-0024-01

6/3/2022

35.659242

-108.491829

18

24

SW6020

VANADIUM

13

0.55

mg/kg

KMP UNC

KMP-SB24-0018-0024-01

6/3/2022

35.658718

-108.492772

18

24

SW6020

ZINC

46

12

mg/kg

KMP UNC

KMP-SB25-0018-0024-01

6/3/2022

35.659242

-108.491829

18

24

SW6020

ZINC

35

11

mg/kg

KMP UNC

KMP-SB30-0030-0036-01

6/4/2022

35.65856

-108.49066

30

36

SW6020

ALUMINUM

5600

15

mg/kg

KMP UNC

KM P-S B36-0030-0036-01

6/3/2022

35.658143

-108.491879

30

36

SW6020

ALUMINUM

6100

15

mg/kg

KMP UNC

KM P-S B30-0030-0036-01

6/4/2022

35.65856

-108.49066

30

36

SW6020

ANTIMONY

0.058 J

0.1

mg/kg

KMP UNC

KM P-S B36-0030-0036-01

6/3/2022

35.658143

-108.491879

30

36

SW6020

ANTIMONY

0.074 J

0.099

mg/kg

KMP UNC

KM P-S B30-0030-0036-01

6/4/2022

35.65856

-108.49066

30

36

SW6020

ARSENIC

4.9

0.21

mg/kg

KMP UNC

KM P-S B36-0030-0036-01

6/3/2022

35.658143

-108.491879

30

36

SW6020

ARSENIC

5.5

0.2

mg/kg

KMP UNC

KM P-S B30-0030-0036-01

6/4/2022

35.65856

-108.49066

30

36

SW6020

BARIUM

43

0.51

mg/kg

KMP UNC

KM P-S B36-0030-0036-01

6/3/2022

35.658143

-108.491879

30

36

SW6020

BARIUM

51

0.49

mg/kg

KMP UNC

KM P-S B30-0030-0036-01

6/4/2022

35.65856

-108.49066

30

36

SW6020

BERYLLIUM

0.48

0.051

mg/kg

Page 72 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KM P-S B36-0030-0036-01

6/3/2022

35.658143

-108.491879

30

36

SW6020

BERYLLIUM

0.5

0.049

mg/kg

KMPUNC

KM P-S B30-0030-0036-01

6/4/2022

35.65856

-108.49066

30

36

SW6020

CADMIUM

0.047 J

0.21

mg/kg

KMP UNC

KM P-S B36-0030-0036-01

6/3/2022

35.658143

-108.491879

30

36

SW6020

CADMIUM

0.065 J

0.2

mg/kg

KMP UNC

KM P-S B30-0030-0036-01

6/4/2022

35.65856

-108.49066

30

36

SW6020

CHROMIUM

6.1

1

mg/kg

KMP UNC

KM P-S B36-0030-0036-01

6/3/2022

35.658143

-108.491879

30

36

SW6020

CHROMIUM

6.7

0.99

mg/kg

KMP UNC

KM P-S B30-0030-0036-01

6/4/2022

35.65856

-108.49066

30

36

SW6020

COBALT

5.2

0.51

mg/kg

KMP UNC

KM P-S B36-0030-0036-01

6/3/2022

35.658143

-108.491879

30

36

SW6020

COBALT

4.7

0.49

mg/kg

KMP UNC

KM P-S B30-0030-0036-01

6/4/2022

35.65856

-108.49066

30

36

SW6020

COPPER

6.4

2.1

mg/kg

KMP UNC

KM P-S B36-0030-0036-01

6/3/2022

35.658143

-108.491879

30

36

SW6020

COPPER

8

2

mg/kg

KMP UNC

KM P-S B30-0030-0036-01

6/4/2022

35.65856

-108.49066

30

36

SW6020

IRON

12000

21

mg/kg

KMP UNC

KM P-S B36-0030-0036-01

6/3/2022

35.658143

-108.491879

30

36

SW6020

IRON

13000

20

mg/kg

KMP UNC

KM P-S B30-0030-0036-01

6/4/2022

35.65856

-108.49066

30

36

SW6020

LEAD

7.9

0.21

mg/kg

KMP UNC

KM P-S B36-0030-0036-01

6/3/2022

35.658143

-108.491879

30

36

SW6020

LEAD

8.9

0.2

mg/kg

KMP UNC

KM P-S B30-0030-0036-01

6/4/2022

35.65856

-108.49066

30

36

SW6020

MANGANESE

170

0.77

mg/kg

KMP UNC

KM P-S B36-0030-0036-01

6/3/2022

35.658143

-108.491879

30

36

SW6020

MANGANESE

220

0.74

mg/kg

KMP UNC

KM P-S B30-0030-0036-01

6/4/2022

35.65856

-108.49066

30

36

SW6020

MOLYBDENUM

1.2

0.21

mg/kg

KMP UNC

KM P-S B36-0030-0036-01

6/3/2022

35.658143

-108.491879

30

36

SW6020

MOLYBDENUM

0.58

0.2

mg/kg

KMP UNC

KM P-S B30-0030-0036-01

6/4/2022

35.65856

-108.49066

30

36

SW6020

NICKEL

6.6

2.1

mg/kg

KMP UNC

KM P-S B36-0030-0036-01

6/3/2022

35.658143

-108.491879

30

36

SW6020

NICKEL

7.1

2

mg/kg

KMP UNC

KM P-S B30-0030-0036-01

6/4/2022

35.65856

-108.49066

30

36

713R15

Ra-226

0.78 J

0.39

pCi/g

KMP UNC

KM P-S B36-0030-0036-01

6/3/2022

35.658143

-108.491879

30

36

713R15

Ra-226

30.7

1

pCi/g

KMP UNC

KM P-S B30-0030-0036-01

6/4/2022

35.65856

-108.49066

30

36

SW6020

SELENIUM

2.9

1

mg/kg

KMP UNC

KM P-S B36-0030-0036-01

6/3/2022

35.658143

-108.491879

30

36

SW6020

SELENIUM

2.4

0.99

mg/kg

KMP UNC

KM P-S B30-0030-0036-01

6/4/2022

35.65856

-108.49066

30

36

SW6020

SILVER

0.058 U

0.12

mg/kg

KMP UNC

KM P-S B36-0030-0036-01

6/3/2022

35.658143

-108.491879

30

36

SW6020

SILVER

0.056 UJ

0.11

mg/kg

KMP UNC

KM P-S B30-0030-0036-01

6/4/2022

35.65856

-108.49066

30

36

SW6020

THALLIUM

0.12

0.01

mg/kg

KMP UNC

KM P-S B36-0030-0036-01

6/3/2022

35.658143

-108.491879

30

36

SW6020

THALLIUM

0.12

0.0099

mg/kg

KMP UNC

KM P-S B30-0030-0036-01

6/4/2022

35.65856

-108.49066

30

36

SW6020

URANIUM

0.86

0.021

mg/kg

KMP UNC

KM P-S B36-0030-0036-01

6/3/2022

35.658143

-108.491879

30

36

SW6020

URANIUM

24

0.02

mg/kg

KMP UNC

KM P-S B30-0030-0036-01

6/4/2022

35.65856

-108.49066

30

36

SW6020

VANADIUM

12

0.51

mg/kg

KMP UNC

KM P-S B36-0030-0036-01

6/3/2022

35.658143

-108.491879

30

36

SW6020

VANADIUM

14

0.49

mg/kg

KMP UNC

KM P-S B30-0030-0036-01

6/4/2022

35.65856

-108.49066

30

36

SW6020

ZINC

32

10

mg/kg

KMP UNC

KM P-S B36-0030-0036-01

6/3/2022

35.658143

-108.491879

30

36

SW6020

ZINC

38

9.9

mg/kg

KMP UNC

KM P-S B28-0036-0042-01

6/4/2022

35.658964

-108.490576

36

42

SW6020

ALUMINUM

5600

16

mg/kg

KMP UNC

KM P-S B38-0036-0042-01

6/3/2022

35.657432

-108.490829

36

42

SW6020

ALUMINUM

7900

15

mg/kg

KMP UNC

KM P-S B28-0036-0042-01

6/4/2022

35.658964

-108.490576

36

42

SW6020

ANTIMONY

0.063 J

0.11

mg/kg

KMP UNC

KM P-S B38-0036-0042-01

6/3/2022

35.657432

-108.490829

36

42

SW6020

ANTIMONY

0.11 J

0.1

mg/kg

KMP UNC

KMP-16-36

7/18/2017

35.658292

-108.491842

36

42

Unknown

ARSENIC

5

Unknown

mg/kg

KMP UNC

KMP-17-36

7/19/2017

35.658397

-108.491778

36

42

Unknown

ARSENIC

4.7

Unknown

mg/kg

KMP UNC

KMP-18-36

7/19/2017

35.658584

-108.491524

36

42

Unknown

ARSENIC

4.7

Unknown

mg/kg

KMP UNC

KMP-19-36

7/19/2017

35.65865

-108.491373

36

42

Unknown

ARSENIC

5.3

Unknown

mg/kg

KMP UNC

KMP-20-36

7/19/2017

35.658809

-108.491224

36

42

Unknown

ARSENIC

7.5

Unknown

mg/kg

Page 73 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KMP-21-36

7/19/2017

35.658901

-108.491165

36

42

Unknown

ARSENIC

5.3

Unknown

mg/kg

KMPUNC

KMP-22-36

7/19/2017

35.658405

-108.490563

36

42

Unknown

ARSENIC

4

Unknown

mg/kg

KMP UNC

KMP-23-36

7/18/2017

35.658984

-108.490548

36

42

Unknown

ARSENIC

4.9

Unknown

mg/kg

KMP UNC

KM P-S B28-0036-0042-01

6/4/2022

35.658964

-108.490576

36

42

SW6020

ARSENIC

4.9

0.21

mg/kg

KMP UNC

KM P-S B38-0036-0042-01

6/3/2022

35.657432

-108.490829

36

42

SW6020

ARSENIC

6.8

0.21

mg/kg

KMP UNC

KMP-16-36

7/18/2017

35.658292

-108.491842

36

42

Unknown

BARIUM

51

Unknown

mg/kg

KMP UNC

KMP-17-36

7/19/2017

35.658397

-108.491778

36

42

Unknown

BARIUM

43

Unknown

mg/kg

KMP UNC

KMP-18-36

7/19/2017

35.658584

-108.491524

36

42

Unknown

BARIUM

43

Unknown

mg/kg

KMP UNC

KMP-19-36

7/19/2017

35.65865

-108.491373

36

42

Unknown

BARIUM

55

Unknown

mg/kg

KMP UNC

KMP-20-36

7/19/2017

35.658809

-108.491224

36

42

Unknown

BARIUM

69

Unknown

mg/kg

KMP UNC

KMP-21-36

7/19/2017

35.658901

-108.491165

36

42

Unknown

BARIUM

57

Unknown

mg/kg

KMP UNC

KMP-22-36

7/19/2017

35.658405

-108.490563

36

42

Unknown

BARIUM

40

Unknown

mg/kg

KMP UNC

KMP-23-36

7/18/2017

35.658984

-108.490548

36

42

Unknown

BARIUM

54

Unknown

mg/kg

KMP UNC

KMP-SB28-0036-0042-01

6/4/2022

35.658964

-108.490576

36

42

SW6020

BARIUM

45

0.53

mg/kg

KMP UNC

KMP-SB38-0036-0042-01

6/3/2022

35.657432

-108.490829

36

42

SW6020

BARIUM

83

0.52

mg/kg

KMP UNC

KMP-SB28-0036-0042-01

6/4/2022

35.658964

-108.490576

36

42

SW6020

BERYLLIUM

0.47

0.053

mg/kg

KMP UNC

KMP-SB38-0036-0042-01

6/3/2022

35.657432

-108.490829

36

42

SW6020

BERYLLIUM

0.6

0.052

mg/kg

KMP UNC

KMP-16-36

7/18/2017

35.658292

-108.491842

36

42

Unknown

CADMIUM

0.12 U

Unknown

mg/kg

KMP UNC

KMP-17-36

7/19/2017

35.658397

-108.491778

36

42

Unknown

CADMIUM

0.12 U

Unknown

mg/kg

KMP UNC

KMP-18-36

7/19/2017

35.658584

-108.491524

36

42

Unknown

CADMIUM

0.13 U

Unknown

mg/kg

KMP UNC

KMP-19-36

7/19/2017

35.65865

-108.491373

36

42

Unknown

CADMIUM

0.13 U

Unknown

mg/kg

KMP UNC

KMP-20-36

7/19/2017

35.658809

-108.491224

36

42

Unknown

CADMIUM

0.076 J

Unknown

mg/kg

KMP UNC

KMP-21-36

7/19/2017

35.658901

-108.491165

36

42

Unknown

CADMIUM

0.067 J

Unknown

mg/kg

KMP UNC

KMP-22-36

7/19/2017

35.658405

-108.490563

36

42

Unknown

CADMIUM

0.12 U

Unknown

mg/kg

KMP UNC

KMP-23-36

7/18/2017

35.658984

-108.490548

36

42

Unknown

CADMIUM

0.13 U

Unknown

mg/kg

KMP UNC

KMP-SB28-0036-0042-01

6/4/2022

35.658964

-108.490576

36

42

SW6020

CADMIUM

0.053 J

0.21

mg/kg

KMP UNC

KMP-SB38-0036-0042-01

6/3/2022

35.657432

-108.490829

36

42

SW6020

CADMIUM

0.079 J

0.21

mg/kg

KMP UNC

KMP-16-36

7/18/2017

35.658292

-108.491842

36

42

Unknown

CHROMIUM

7.5

Unknown

mg/kg

KMP UNC

KMP-17-36

7/19/2017

35.658397

-108.491778

36

42

Unknown

CHROMIUM

6.9

Unknown

mg/kg

KMP UNC

KMP-18-36

7/19/2017

35.658584

-108.491524

36

42

Unknown

CHROMIUM

7.7

Unknown

mg/kg

KMP UNC

KMP-19-36

7/19/2017

35.65865

-108.491373

36

42

Unknown

CHROMIUM

7.4

Unknown

mg/kg

KMP UNC

KMP-20-36

7/19/2017

35.658809

-108.491224

36

42

Unknown

CHROMIUM

7.4

Unknown

mg/kg

KMP UNC

KMP-21-36

7/19/2017

35.658901

-108.491165

36

42

Unknown

CHROMIUM

8

Unknown

mg/kg

KMP UNC

KMP-22-36

7/19/2017

35.658405

-108.490563

36

42

Unknown

CHROMIUM

5.8

Unknown

mg/kg

KMP UNC

KMP-23-36

7/18/2017

35.658984

-108.490548

36

42

Unknown

CHROMIUM

8.2

Unknown

mg/kg

KMP UNC

KM P-SB28-0036-0042-01

6/4/2022

35.658964

-108.490576

36

42

SW6020

CHROMIUM

6.1

1.1

mg/kg

KMP UNC

KM P-SB38-0036-0042-01

6/3/2022

35.657432

-108.490829

36

42

SW6020

CHROMIUM

8.6

1

mg/kg

KMP UNC

KM P-SB28-0036-0042-01

6/4/2022

35.658964

-108.490576

36

42

SW6020

COBALT

4.4

0.53

mg/kg

KMP UNC

KM P-SB38-0036-0042-01

6/3/2022

35.657432

-108.490829

36

42

SW6020

COBALT

6.3

0.52

mg/kg

KMP UNC

KMP-SB28-0036-0042-01

6/4/2022

35.658964

-108.490576

36

42

SW6020

COPPER

6.7

2.1

mg/kg

KMP UNC

KM P-SB38-0036-0042-01

6/3/2022

35.657432

-108.490829

36

42

SW6020

COPPER

11

2.1

mg/kg

KMP UNC

KM P-SB28-0036-0042-01

6/4/2022

35.658964

-108.490576

36

42

SW6020

IRON

12000

21

mg/kg

Page 74 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KM P-S B38-0036-0042-01

6/3/2022

35.657432

-108.490829

36

42

SW6020

IRON

17000

21

mg/kg

KMPUNC

KMP-16-36

7/18/2017

35.658292

-108.491842

36

42

Unknown

LEAD

8.3

Unknown

mg/kg

KMP UNC

KMP-17-36

7/19/2017

35.658397

-108.491778

36

42

Unknown

LEAD

7.3

Unknown

mg/kg

KMP UNC

KMP-18-36

7/19/2017

35.658584

-108.491524

36

42

Unknown

LEAD

8

Unknown

mg/kg

KMP UNC

KMP-19-36

7/19/2017

35.65865

-108.491373

36

42

Unknown

LEAD

7

Unknown

mg/kg

KMP UNC

KMP-20-36

7/19/2017

35.658809

-108.491224

36

42

Unknown

LEAD

12

Unknown

mg/kg

KMP UNC

KMP-21-36

7/19/2017

35.658901

-108.491165

36

42

Unknown

LEAD

8.9

Unknown

mg/kg

KMP UNC

KMP-22-36

7/19/2017

35.658405

-108.490563

36

42

Unknown

LEAD

6.4

Unknown

mg/kg

KMP UNC

KMP-23-36

7/18/2017

35.658984

-108.490548

36

42

Unknown

LEAD

8.2

Unknown

mg/kg

KMP UNC

KMP-SB28-0036-0042-01

6/4/2022

35.658964

-108.490576

36

42

SW6020

LEAD

7.9

0.21

mg/kg

KMP UNC

KMP-SB38-0036-0042-01

6/3/2022

35.657432

-108.490829

36

42

SW6020

LEAD

11

0.21

mg/kg

KMP UNC

KMP-SB28-0036-0042-01

6/4/2022

35.658964

-108.490576

36

42

SW6020

MANGANESE

170

0.8

mg/kg

KMP UNC

KMP-SB38-0036-0042-01

6/3/2022

35.657432

-108.490829

36

42

SW6020

MANGANESE

230

0.77

mg/kg

KMP UNC

KMP-16-36

7/18/2017

35.658292

-108.491842

36

42

Unknown

MOLYBDENUM

0.63 J

Unknown

mg/kg

KMP UNC

KMP-17-36

7/19/2017

35.658397

-108.491778

36

42

Unknown

MOLYBDENUM

0.58 J

Unknown

mg/kg

KMP UNC

KMP-18-36

7/19/2017

35.658584

-108.491524

36

42

Unknown

MOLYBDENUM

0.65 J

Unknown

mg/kg

KMP UNC

KMP-19-36

7/19/2017

35.65865

-108.491373

36

42

Unknown

MOLYBDENUM

0.67 J

Unknown

mg/kg

KMP UNC

KMP-20-36

7/19/2017

35.658809

-108.491224

36

42

Unknown

MOLYBDENUM

1.1 J

Unknown

mg/kg

KMP UNC

KMP-21-36

7/19/2017

35.658901

-108.491165

36

42

Unknown

MOLYBDENUM

0.75 J

Unknown

mg/kg

KMP UNC

KMP-22-36

7/19/2017

35.658405

-108.490563

36

42

Unknown

MOLYBDENUM

1.2 U

Unknown

mg/kg

KMP UNC

KMP-23-36

7/18/2017

35.658984

-108.490548

36

42

Unknown

MOLYBDENUM

1.3

Unknown

mg/kg

KMP UNC

KMP-SB28-0036-0042-01

6/4/2022

35.658964

-108.490576

36

42

SW6020

MOLYBDENUM

1.7

0.21

mg/kg

KMP UNC

KMP-SB38-0036-0042-01

6/3/2022

35.657432

-108.490829

36

42

SW6020

MOLYBDENUM

0.33 J

0.21

mg/kg

KMP UNC

KMP-SB28-0036-0042-01

6/4/2022

35.658964

-108.490576

36

42

SW6020

NICKEL

6.5

2.1

mg/kg

KMP UNC

KMP-SB38-0036-0042-01

6/3/2022

35.657432

-108.490829

36

42

SW6020

NICKEL

9.4

2.1

mg/kg

KMP UNC

KMP-16-36

7/18/2017

35.658292

-108.491842

36

42

Unknown

Ra-226

1.7

Unknown

pCi/g

KMP UNC

KMP-17-36

7/19/2017

35.658397

-108.491778

36

42

Unknown

Ra-226

3.4

Unknown

pCi/g

KMP UNC

KMP-18-36

7/19/2017

35.658584

-108.491524

36

42

Unknown

Ra-226

1.3

Unknown

pCi/g

KMP UNC

KMP-19-36

7/19/2017

35.65865

-108.491373

36

42

Unknown

Ra-226

1.7

Unknown

pCi/g

KMP UNC

KMP-20-36

7/19/2017

35.658809

-108.491224

36

42

Unknown

Ra-226

1.3

Unknown

pCi/g

KMP UNC

KMP-21-36

7/19/2017

35.658901

-108.491165

36

42

Unknown

Ra-226

1.6

Unknown

pCi/g

KMP UNC

KMP-22-36

7/19/2017

35.658405

-108.490563

36

42

Unknown

Ra-226

0.9

Unknown

pCi/g

KMP UNC

KMP-23-36

7/18/2017

35.658984

-108.490548

36

42

Unknown

Ra-226

1.3

Unknown

pCi/g

KMP UNC

KM P-S B28-0036-0042-01

6/4/2022

35.658964

-108.490576

36

42

713R15

Ra-226

0.93 J

0.39

pCi/g

KMP UNC

KM P-S B38-0036-0042-01

6/3/2022

35.657432

-108.490829

36

42

713R15

Ra-226

1.14 J

0.45

pCi/g

KMP UNC

KMP-16-36

7/18/2017

35.658292

-108.491842

36

42

Unknown

SELENIUM

1.4

Unknown

mg/kg

KMP UNC

KMP-17-36

7/19/2017

35.658397

-108.491778

36

42

Unknown

SELENIUM

2.3

Unknown

mg/kg

KMP UNC

KMP-18-36

7/19/2017

35.658584

-108.491524

36

42

Unknown

SELENIUM

1.7

Unknown

mg/kg

KMP UNC

KMP-19-36

7/19/2017

35.65865

-108.491373

36

42

Unknown

SELENIUM

2

Unknown

mg/kg

KMP UNC

KMP-20-36

7/19/2017

35.658809

-108.491224

36

42

Unknown

SELENIUM

1.5

Unknown

mg/kg

KMP UNC

KMP-21-36

7/19/2017

35.658901

-108.491165

36

42

Unknown

SELENIUM

2.1

Unknown

mg/kg

KMP UNC

KMP-22-36

7/19/2017

35.658405

-108.490563

36

42

Unknown

SELENIUM

1.4

Unknown

mg/kg

Page 75 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KMP-23-36

7/18/2017

35.658984

-108.490548

36

42

Unknown

SELENIUM

1.5

Unknown

mg/kg

KMPUNC

KM P-S B28-0036-0042-01

6/4/2022

35.658964

-108.490576

36

42

SW6020

SELENIUM

1.1 J

1.1

mg/kg

KMP UNC

KM P-S B38-0036-0042-01

6/3/2022

35.657432

-108.490829

36

42

SW6020

SELENIUM

1.3

1

mg/kg

KMP UNC

KMP-16-36

7/18/2017

35.658292

-108.491842

36

42

Unknown

SILVER

0.48 U

Unknown

mg/kg

KMP UNC

KMP-17-36

7/19/2017

35.658397

-108.491778

36

42

Unknown

SILVER

0.47 U

Unknown

mg/kg

KMP UNC

KMP-18-36

7/19/2017

35.658584

-108.491524

36

42

Unknown

SILVER

0.5 U

Unknown

mg/kg

KMP UNC

KMP-19-36

7/19/2017

35.65865

-108.491373

36

42

Unknown

SILVER

0.5 U

Unknown

mg/kg

KMP UNC

KMP-20-36

7/19/2017

35.658809

-108.491224

36

42

Unknown

SILVER

0.5 U

Unknown

mg/kg

KMP UNC

KMP-21-36

7/19/2017

35.658901

-108.491165

36

42

Unknown

SILVER

0.5 U

Unknown

mg/kg

KMP UNC

KMP-22-36

7/19/2017

35.658405

-108.490563

36

42

Unknown

SILVER

0.5 U

Unknown

mg/kg

KMP UNC

KMP-23-36

7/18/2017

35.658984

-108.490548

36

42

Unknown

SILVER

0.52 U

Unknown

mg/kg

KMP UNC

KM P-S B28-0036-0042-01

6/4/2022

35.658964

-108.490576

36

42

SW6020

SILVER

0.061 U

0.12

mg/kg

KMP UNC

KM P-S B38-0036-0042-01

6/3/2022

35.657432

-108.490829

36

42

SW6020

SILVER

0.059 UJ

0.12

mg/kg

KMP UNC

KM P-S B28-0036-0042-01

6/4/2022

35.658964

-108.490576

36

42

SW6020

THALLIUM

0.11

0.011

mg/kg

KMP UNC

KM P-SB38-0036-0042-01

6/3/2022

35.657432

-108.490829

36

42

SW6020

THALLIUM

0.15

0.01

mg/kg

KMP UNC

KMP-16-36

7/18/2017

35.658292

-108.491842

36

42

Unknown

URANIUM

37

Unknown

mg/kg

KMP UNC

KMP-17-36

7/19/2017

35.658397

-108.491778

36

42

Unknown

URANIUM

58

Unknown

mg/kg

KMP UNC

KMP-18-36

7/19/2017

35.658584

-108.491524

36

42

Unknown

URANIUM

38

Unknown

mg/kg

KMP UNC

KMP-19-36

7/19/2017

35.65865

-108.491373

36

42

Unknown

URANIUM

32

Unknown

mg/kg

KMP UNC

KMP-20-36

7/19/2017

35.658809

-108.491224

36

42

Unknown

URANIUM

32

Unknown

mg/kg

KMP UNC

KMP-21-36

7/19/2017

35.658901

-108.491165

36

42

Unknown

URANIUM

22

Unknown

mg/kg

KMP UNC

KMP-22-36

7/19/2017

35.658405

-108.490563

36

42

Unknown

URANIUM

0.77

Unknown

mg/kg

KMP UNC

KMP-23-36

7/18/2017

35.658984

-108.490548

36

42

Unknown

URANIUM

52

Unknown

mg/kg

KMP UNC

KM P-SB28-0036-0042-01

6/4/2022

35.658964

-108.490576

36

42

SW6020

URANIUM

180

0.021

mg/kg

KMP UNC

KM P-SB38-0036-0042-01

6/3/2022

35.657432

-108.490829

36

42

SW6020

URANIUM

0.63

0.021

mg/kg

KMP UNC

KMP-16-36

7/18/2017

35.658292

-108.491842

36

42

Unknown

VANADIUM

16

Unknown

mg/kg

KMP UNC

KMP-17-36

7/19/2017

35.658397

-108.491778

36

42

Unknown

VANADIUM

16

Unknown

mg/kg

KMP UNC

KMP-18-36

7/19/2017

35.658584

-108.491524

36

42

Unknown

VANADIUM

16

Unknown

mg/kg

KMP UNC

KMP-19-36

7/19/2017

35.65865

-108.491373

36

42

Unknown

VANADIUM

17

Unknown

mg/kg

KMP UNC

KMP-20-36

7/19/2017

35.658809

-108.491224

36

42

Unknown

VANADIUM

17

Unknown

mg/kg

KMP UNC

KMP-21-36

7/19/2017

35.658901

-108.491165

36

42

Unknown

VANADIUM

17

Unknown

mg/kg

KMP UNC

KMP-22-36

7/19/2017

35.658405

-108.490563

36

42

Unknown

VANADIUM

13

Unknown

mg/kg

KMP UNC

KMP-23-36

7/18/2017

35.658984

-108.490548

36

42

Unknown

VANADIUM

16

Unknown

mg/kg

KMP UNC

KM P-S B28-0036-0042-01

6/4/2022

35.658964

-108.490576

36

42

SW6020

VANADIUM

12

0.53

mg/kg

KMP UNC

KM P-S B38-0036-0042-01

6/3/2022

35.657432

-108.490829

36

42

SW6020

VANADIUM

16

0.52

mg/kg

KMP UNC

KM P-S B28-0036-0042-01

6/4/2022

35.658964

-108.490576

36

42

SW6020

ZINC

32

11

mg/kg

KMP UNC

KM P-S B38-0036-0042-01

6/3/2022

35.657432

-108.490829

36

42

SW6020

ZINC

48

10

mg/kg

KMP UNC

KM P-S B28-0042-0048-01

6/4/2022

35.658964

-108.490576

42

48

SW6020

ALUMINUM

6400

16

mg/kg

KMP UNC

KM P-S B28-0042-0048-01

6/4/2022

35.658964

-108.490576

42

48

SW6020

ANTIMONY

0.065 J

0.11

mg/kg

KMP UNC

KM P-S B28-0042-0048-01

6/4/2022

35.658964

-108.490576

42

48

SW6020

ARSENIC

5.4

0.21

mg/kg

KMP UNC

KM P-S B28-0042-0048-01

6/4/2022

35.658964

-108.490576

42

48

SW6020

BARIUM

57

0.53

mg/kg

KMP UNC

KM P-S B28-0042-0048-01

6/4/2022

35.658964

-108.490576

42

48

SW6020

BERYLLIUM

0.53

0.053

mg/kg

Page 76 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KM P-S B28-0042-0048-01

6/4/2022

35.658964

-108.490576

42

48

SW6020

CADMIUM

0.064 J

0.21

mg/kg

KMPUNC

KM P-S B28-0042-0048-01

6/4/2022

35.658964

-108.490576

42

48

SW6020

CHROMIUM

6.8

1.1

mg/kg

KMP UNC

KM P-S B28-0042-0048-01

6/4/2022

35.658964

-108.490576

42

48

SW6020

COBALT

4.7

0.53

mg/kg

KMP UNC

KM P-S B28-0042-0048-01

6/4/2022

35.658964

-108.490576

42

48

SW6020

COPPER

7.4

2.1

mg/kg

KMP UNC

KM P-S B28-0042-0048-01

6/4/2022

35.658964

-108.490576

42

48

SW6020

IRON

14000

21

mg/kg

KMP UNC

KM P-S B28-0042-0048-01

6/4/2022

35.658964

-108.490576

42

48

SW6020

LEAD

8.6

0.21

mg/kg

KMP UNC

KM P-S B28-0042-0048-01

6/4/2022

35.658964

-108.490576

42

48

SW6020

MANGANESE

200

0.8

mg/kg

KMP UNC

KM P-S B28-0042-0048-01

6/4/2022

35.658964

-108.490576

42

48

SW6020

MOLYBDENUM

1.4

0.21

mg/kg

KMP UNC

KM P-S B28-0042-0048-01

6/4/2022

35.658964

-108.490576

42

48

SW6020

NICKEL

7.3

2.1

mg/kg

KMP UNC

KM P-S B28-0042-0048-01

6/4/2022

35.658964

-108.490576

42

48

713R15

Ra-226

0.93 J

0.44

pCi/g

KMP UNC

KM P-S B28-0042-0048-01

6/4/2022

35.658964

-108.490576

42

48

SW6020

SELENIUM

1.1

1.1

mg/kg

KMP UNC

KM P-S B28-0042-0048-01

6/4/2022

35.658964

-108.490576

42

48

SW6020

SILVER

0.061 U

0.12

mg/kg

KMP UNC

KM P-S B28-0042-0048-01

6/4/2022

35.658964

-108.490576

42

48

SW6020

THALLIUM

0.13

0.011

mg/kg

KMP UNC

KM P-S B28-0042-0048-01

6/4/2022

35.658964

-108.490576

42

48

SW6020

URANIUM

190

0.021

mg/kg

KMP UNC

KM P-S B28-0042-0048-01

6/4/2022

35.658964

-108.490576

42

48

SW6020

VANADIUM

13

0.53

mg/kg

KMP UNC

KM P-S B28-0042-0048-01

6/4/2022

35.658964

-108.490576

42

48

SW6020

ZINC

36

11

mg/kg

KMP UNC

KM P-S B24-0048-0054-01

6/3/2022

35.658718

-108.492772

48

54

SW6020

ALUMINUM

9600

16

mg/kg

KMP UNC

KM P-S B29-0048-0054-01

6/4/2022

35.65859

-108.490409

48

54

SW6020

ALUMINUM

5000

15

mg/kg

KMP UNC

KMP-SB29-0048-0054-02

6/4/2022

35.65859

-108.490409

48

54

SW6020

ALUMINUM

5300

15

mg/kg

KMP UNC

KM P-S B34-0048-0054-01

6/3/2022

35.658631

-108.491402

48

54

SW6020

ALUMINUM

5400

16

mg/kg

KMP UNC

KM P-S B24-0048-0054-01

6/3/2022

35.658718

-108.492772

48

54

SW6020

ANTIMONY

0.11 J

0.11

mg/kg

KMP UNC

KM P-S B29-0048-0054-01

6/4/2022

35.65859

-108.490409

48

54

SW6020

ANTIMONY

0.063 J

0.1

mg/kg

KMP UNC

KMP-SB29-0048-0054-02

6/4/2022

35.65859

-108.490409

48

54

SW6020

ANTIMONY

0.058 J

0.1

mg/kg

KMP UNC

KM P-S B34-0048-0054-01

6/3/2022

35.658631

-108.491402

48

54

SW6020

ANTIMONY

0.05 J

0.1

mg/kg

KMP UNC

KM P-S B24-0048-0054-01

6/3/2022

35.658718

-108.492772

48

54

SW6020

ARSENIC

8.5

0.21

mg/kg

KMP UNC

KM P-S B29-0048-0054-01

6/4/2022

35.65859

-108.490409

48

54

SW6020

ARSENIC

4.9

0.21

mg/kg

KMP UNC

KMP-SB29-0048-0054-02

6/4/2022

35.65859

-108.490409

48

54

SW6020

ARSENIC

5

0.2

mg/kg

KMP UNC

KM P-S B34-0048-0054-01

6/3/2022

35.658631

-108.491402

48

54

SW6020

ARSENIC

4.8

0.21

mg/kg

KMP UNC

KM P-S B24-0048-0054-01

6/3/2022

35.658718

-108.492772

48

54

SW6020

BARIUM

110

0.54

mg/kg

KMP UNC

KM P-S B29-0048-0054-01

6/4/2022

35.65859

-108.490409

48

54

SW6020

BARIUM

60

0.51

mg/kg

KMP UNC

KMP-SB29-0048-0054-02

6/4/2022

35.65859

-108.490409

48

54

SW6020

BARIUM

55

0.51

mg/kg

KMP UNC

KM P-S B34-0048-0054-01

6/3/2022

35.658631

-108.491402

48

54

SW6020

BARIUM

41

0.52

mg/kg

KMP UNC

KM P-S B24-0048-0054-01

6/3/2022

35.658718

-108.492772

48

54

SW6020

BERYLLIUM

0.85

0.054

mg/kg

KMP UNC

KM P-S B29-0048-0054-01

6/4/2022

35.65859

-108.490409

48

54

SW6020

BERYLLIUM

0.42

0.051

mg/kg

KMP UNC

KMP-SB29-0048-0054-02

6/4/2022

35.65859

-108.490409

48

54

SW6020

BERYLLIUM

0.43

0.051

mg/kg

KMP UNC

KMP-SB34-0048-0054-01

6/3/2022

35.658631

-108.491402

48

54

SW6020

BERYLLIUM

0.45

0.052

mg/kg

KMP UNC

KMP-SB24-0048-0054-01

6/3/2022

35.658718

-108.492772

48

54

SW6020

CADMIUM

0.1 J

0.21

mg/kg

KMP UNC

KMP-SB29-0048-0054-01

6/4/2022

35.65859

-108.490409

48

54

SW6020

CADMIUM

0.043 J

0.21

mg/kg

KMP UNC

KMP-SB29-0048-0054-02

6/4/2022

35.65859

-108.490409

48

54

SW6020

CADMIUM

0.048 J

0.2

mg/kg

KMP UNC

KMP-SB34-0048-0054-01

6/3/2022

35.658631

-108.491402

48

54

SW6020

CADMIUM

0.05 J

0.21

mg/kg

KMP UNC

KMP-SB24-0048-0054-01

6/3/2022

35.658718

-108.492772

48

54

SW6020

CHROMIUM

11

1.1

mg/kg

KMP UNC

KMP-SB29-0048-0054-01

6/4/2022

35.65859

-108.490409

48

54

SW6020

CHROMIUM

5.6

1

mg/kg

Page 77 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KMP-SB29-0048-0054-02

6/4/2022

35.65859

-108.490409

48

54

SW6020

CHROMIUM

5.6

1

mg/kg

KMPUNC

KM P-S B34-0048-0054-01

6/3/2022

35.658631

-108.491402

48

54

SW6020

CHROMIUM

6

1

mg/kg

KMP UNC

KM P-S B24-0048-0054-01

6/3/2022

35.658718

-108.492772

48

54

SW6020

COBALT

7.9

0.54

mg/kg

KMP UNC

KM P-S B29-0048-0054-01

6/4/2022

35.65859

-108.490409

48

54

SW6020

COBALT

4.1

0.51

mg/kg

KMP UNC

KMP-SB29-0048-0054-02

6/4/2022

35.65859

-108.490409

48

54

SW6020

COBALT

3.9

0.51

mg/kg

KMP UNC

KM P-S B34-0048-0054-01

6/3/2022

35.658631

-108.491402

48

54

SW6020

COBALT

4.3

0.52

mg/kg

KMP UNC

KM P-S B24-0048-0054-01

6/3/2022

35.658718

-108.492772

48

54

SW6020

COPPER

14

2.1

mg/kg

KMP UNC

KM P-S B29-0048-0054-01

6/4/2022

35.65859

-108.490409

48

54

SW6020

COPPER

5.5

2.1

mg/kg

KMP UNC

KMP-SB29-0048-0054-02

6/4/2022

35.65859

-108.490409

48

54

SW6020

COPPER

5.6

2

mg/kg

KMP UNC

KM P-S B34-0048-0054-01

6/3/2022

35.658631

-108.491402

48

54

SW6020

COPPER

6.9

2.1

mg/kg

KMP UNC

KM P-S B24-0048-0054-01

6/3/2022

35.658718

-108.492772

48

54

SW6020

IRON

22000

21

mg/kg

KMP UNC

KM P-S B29-0048-0054-01

6/4/2022

35.65859

-108.490409

48

54

SW6020

IRON

13000

21

mg/kg

KMP UNC

KMP-SB29-0048-0054-02

6/4/2022

35.65859

-108.490409

48

54

SW6020

IRON

14000

20

mg/kg

KMP UNC

KM P-S B34-0048-0054-01

6/3/2022

35.658631

-108.491402

48

54

SW6020

IRON

12000

21

mg/kg

KMP UNC

KM P-S B24-0048-0054-01

6/3/2022

35.658718

-108.492772

48

54

SW6020

LEAD

15

0.21

mg/kg

KMP UNC

KM P-S B29-0048-0054-01

6/4/2022

35.65859

-108.490409

48

54

SW6020

LEAD

7.3

0.21

mg/kg

KMP UNC

KMP-SB29-0048-0054-02

6/4/2022

35.65859

-108.490409

48

54

SW6020

LEAD

7.4

0.2

mg/kg

KMP UNC

KM P-S B34-0048-0054-01

6/3/2022

35.658631

-108.491402

48

54

SW6020

LEAD

8.1

0.21

mg/kg

KMP UNC

KM P-S B24-0048-0054-01

6/3/2022

35.658718

-108.492772

48

54

SW6020

MANGANESE

300

0.8

mg/kg

KMP UNC

KM P-S B29-0048-0054-01

6/4/2022

35.65859

-108.490409

48

54

SW6020

MANGANESE

290

0.77

mg/kg

KMP UNC

KMP-SB29-0048-0054-02

6/4/2022

35.65859

-108.490409

48

54

SW6020

MANGANESE

310

0.77

mg/kg

KMP UNC

KM P-S B34-0048-0054-01

6/3/2022

35.658631

-108.491402

48

54

SW6020

MANGANESE

170

0.78

mg/kg

KMP UNC

KM P-S B24-0048-0054-01

6/3/2022

35.658718

-108.492772

48

54

SW6020

MOLYBDENUM

0.53 J

0.21

mg/kg

KMP UNC

KM P-S B29-0048-0054-01

6/4/2022

35.65859

-108.490409

48

54

SW6020

MOLYBDENUM

0.39

0.21

mg/kg

KMP UNC

KMP-SB29-0048-0054-02

6/4/2022

35.65859

-108.490409

48

54

SW6020

MOLYBDENUM

0.34

0.2

mg/kg

KMP UNC

KM P-S B34-0048-0054-01

6/3/2022

35.658631

-108.491402

48

54

SW6020

MOLYBDENUM

0.44

0.21

mg/kg

KMP UNC

KM P-S B24-0048-0054-01

6/3/2022

35.658718

-108.492772

48

54

SW6020

NICKEL

12

2.1

mg/kg

KMP UNC

KM P-S B29-0048-0054-01

6/4/2022

35.65859

-108.490409

48

54

SW6020

NICKEL

5.9

2.1

mg/kg

KMP UNC

KMP-SB29-0048-0054-02

6/4/2022

35.65859

-108.490409

48

54

SW6020

NICKEL

6.1

2

mg/kg

KMP UNC

KM P-S B34-0048-0054-01

6/3/2022

35.658631

-108.491402

48

54

SW6020

NICKEL

6.3

2.1

mg/kg

KMP UNC

KM P-S B24-0048-0054-01

6/3/2022

35.658718

-108.492772

48

54

713R15

Ra-226

1.56 J

0.53

pCi/g

KMP UNC

KM P-S B29-0048-0054-01

6/4/2022

35.65859

-108.490409

48

54

713R15

Ra-226

0.82 J

0.48

pCi/g

KMP UNC

KMP-SB29-0048-0054-02

6/4/2022

35.65859

-108.490409

48

54

713R15

Ra-226

0.8 J

0.44

pCi/g

KMP UNC

KM P-S B34-0048-0054-01

6/3/2022

35.658631

-108.491402

48

54

713R15

Ra-226

3.57

0.47

pCi/g

KMP UNC

KM P-S B24-0048-0054-01

6/3/2022

35.658718

-108.492772

48

54

SW6020

SELENIUM

1.8

1.1

mg/kg

KMP UNC

KM P-S B29-0048-0054-01

6/4/2022

35.65859

-108.490409

48

54

SW6020

SELENIUM

1.1

1

mg/kg

KMP UNC

KMP-SB29-0048-0054-02

6/4/2022

35.65859

-108.490409

48

54

SW6020

SELENIUM

0.98 J

1

mg/kg

KMP UNC

KM P-S B34-0048-0054-01

6/3/2022

35.658631

-108.491402

48

54

SW6020

SELENIUM

1.5

1

mg/kg

KMP UNC

KM P-S B24-0048-0054-01

6/3/2022

35.658718

-108.492772

48

54

SW6020

SILVER

0.11 J

0.12

mg/kg

KMP UNC

KMP-SB29-0048-0054-01

6/4/2022

35.65859

-108.490409

48

54

SW6020

SILVER

0.059 U

0.12

mg/kg

KMP UNC

KMP-SB29-0048-0054-02

6/4/2022

35.65859

-108.490409

48

54

SW6020

SILVER

0.058 U

0.12

mg/kg

KMP UNC

KMP-SB34-0048-0054-01

6/3/2022

35.658631

-108.491402

48

54

SW6020

SILVER

0.059 U

0.12

mg/kg

Page 78 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KM P-S B24-0048-0054-01

6/3/2022

35.658718

-108.492772

48

54

SW6020

THALLIUM

0.21

0.011

mg/kg

KMPUNC

KM P-S B29-0048-0054-01

6/4/2022

35.65859

-108.490409

48

54

SW6020

THALLIUM

0.1

0.01

mg/kg

KMP UNC

KMP-SB29-0048-0054-02

6/4/2022

35.65859

-108.490409

48

54

SW6020

THALLIUM

0.1

0.01

mg/kg

KMP UNC

KM P-S B34-0048-0054-01

6/3/2022

35.658631

-108.491402

48

54

SW6020

THALLIUM

0.12

0.01

mg/kg

KMP UNC

KM P-S B24-0048-0054-01

6/3/2022

35.658718

-108.492772

48

54

SW6020

URANIUM

1.1

0.021

mg/kg

KMP UNC

KM P-S B29-0048-0054-01

6/4/2022

35.65859

-108.490409

48

54

SW6020

URANIUM

0.59

0.021

mg/kg

KMP UNC

KMP-SB29-0048-0054-02

6/4/2022

35.65859

-108.490409

48

54

SW6020

URANIUM

0.58

0.02

mg/kg

KMP UNC

KM P-S B34-0048-0054-01

6/3/2022

35.658631

-108.491402

48

54

SW6020

URANIUM

20

0.021

mg/kg

KMP UNC

KM P-S B24-0048-0054-01

6/3/2022

35.658718

-108.492772

48

54

SW6020

VANADIUM

20

0.54

mg/kg

KMP UNC

KM P-S B29-0048-0054-01

6/4/2022

35.65859

-108.490409

48

54

SW6020

VANADIUM

13

0.51

mg/kg

KMP UNC

KMP-SB29-0048-0054-02

6/4/2022

35.65859

-108.490409

48

54

SW6020

VANADIUM

13

0.51

mg/kg

KMP UNC

KM P-S B34-0048-0054-01

6/3/2022

35.658631

-108.491402

48

54

SW6020

VANADIUM

12

0.52

mg/kg

KMP UNC

KM P-S B24-0048-0054-01

6/3/2022

35.658718

-108.492772

48

54

SW6020

ZINC

60

11

mg/kg

KMP UNC

KM P-S B29-0048-0054-01

6/4/2022

35.65859

-108.490409

48

54

SW6020

ZINC

31

10

mg/kg

KMP UNC

KMP-SB29-0048-0054-02

6/4/2022

35.65859

-108.490409

48

54

SW6020

ZINC

31

10

mg/kg

KMP UNC

KM P-S B34-0048-0054-01

6/3/2022

35.658631

-108.491402

48

54

SW6020

ZINC

34

10

mg/kg

KMP UNC

KM P-S B33-0054-0060-01

6/3/2022

35.658445

-108.491212

54

60

SW6020

ALUMINUM

5600

16

mg/kg

KMP UNC

KM P-S B41-0054-0060-01

6/4/2022

35.659569

-108.491192

54

60

SW6020

ALUMINUM

7600

16

mg/kg

KMP UNC

KM P-S B42-0054-0060-01

6/8/2022

35.659569

-108.492026

54

60

SW6020

ALUMINUM

7900

16

mg/kg

KMP UNC

KM P-S B33-0054-0060-01

6/3/2022

35.658445

-108.491212

54

60

SW6020

ANTIMONY

0.043 J

0.1

mg/kg

KMP UNC

KM P-S B41-0054-0060-01

6/4/2022

35.659569

-108.491192

54

60

SW6020

ANTIMONY

0.087 J

0.11

mg/kg

KMP UNC

KM P-S B42-0054-0060-01

6/8/2022

35.659569

-108.492026

54

60

SW6020

ANTIMONY

0.099 J

0.11

mg/kg

KMP UNC

KM P-S B33-0054-0060-01

6/3/2022

35.658445

-108.491212

54

60

SW6020

ARSENIC

5.1

0.21

mg/kg

KMP UNC

KM P-S B41-0054-0060-01

6/4/2022

35.659569

-108.491192

54

60

SW6020

ARSENIC

6

0.21

mg/kg

KMP UNC

KM P-S B42-0054-0060-01

6/8/2022

35.659569

-108.492026

54

60

SW6020

ARSENIC

6.4

0.21

mg/kg

KMP UNC

KM P-S B33-0054-0060-01

6/3/2022

35.658445

-108.491212

54

60

SW6020

BARIUM

44

0.52

mg/kg

KMP UNC

KM P-S B41-0054-0060-01

6/4/2022

35.659569

-108.491192

54

60

SW6020

BARIUM

90

0.53

mg/kg

KMP UNC

KM P-S B42-0054-0060-01

6/8/2022

35.659569

-108.492026

54

60

SW6020

BARIUM

86

0.54

mg/kg

KMP UNC

KM P-S B33-0054-0060-01

6/3/2022

35.658445

-108.491212

54

60

SW6020

BERYLLIUM

0.47

0.052

mg/kg

KMP UNC

KM P-S B41-0054-0060-01

6/4/2022

35.659569

-108.491192

54

60

SW6020

BERYLLIUM

0.61

0.053

mg/kg

KMP UNC

KM P-S B42-0054-0060-01

6/8/2022

35.659569

-108.492026

54

60

SW6020

BERYLLIUM

0.69

0.054

mg/kg

KMP UNC

KM P-S B33-0054-0060-01

6/3/2022

35.658445

-108.491212

54

60

SW6020

CADMIUM

0.05 J

0.21

mg/kg

KMP UNC

KM P-S B41-0054-0060-01

6/4/2022

35.659569

-108.491192

54

60

SW6020

CADMIUM

0.063 J

0.21

mg/kg

KMP UNC

KM P-S B42-0054-0060-01

6/8/2022

35.659569

-108.492026

54

60

SW6020

CADMIUM

0.081 J

0.21

mg/kg

KMP UNC

KM P-S B33-0054-0060-01

6/3/2022

35.658445

-108.491212

54

60

SW6020

CHROMIUM

6

1

mg/kg

KMP UNC

KM P-S B41-0054-0060-01

6/4/2022

35.659569

-108.491192

54

60

SW6020

CHROMIUM

8

1.1

mg/kg

KMP UNC

KM P-S B42-0054-0060-01

6/8/2022

35.659569

-108.492026

54

60

SW6020

CHROMIUM

8.5

1.1

mg/kg

KMP UNC

KM P-S B33-0054-0060-01

6/3/2022

35.658445

-108.491212

54

60

SW6020

COBALT

4.5

0.52

mg/kg

KMP UNC

KM P-SB41 -0054-0060-01

6/4/2022

35.659569

-108.491192

54

60

SW6020

COBALT

5.5

0.53

mg/kg

KMP UNC

KM P-SB42-0054-0060-01

6/8/2022

35.659569

-108.492026

54

60

SW6020

COBALT

6.2

0.54

mg/kg

KMP UNC

KMP-SB33-0054-0060-01

6/3/2022

35.658445

-108.491212

54

60

SW6020

COPPER

6.8

2.1

mg/kg

KMP UNC

KM P-SB41 -0054-0060-01

6/4/2022

35.659569

-108.491192

54

60

SW6020

COPPER

9.6

2.1

mg/kg

Page 79 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KM P-S B42-0054-0060-01

6/8/2022

35.659569

-108.492026

54

60

SW6020

COPPER

11

2.1

mg/kg

KMPUNC

KM P-S B33-0054-0060-01

6/3/2022

35.658445

-108.491212

54

60

SW6020

IRON

13000

21

mg/kg

KMP UNC

KM P-S B41-0054-0060-01

6/4/2022

35.659569

-108.491192

54

60

SW6020

IRON

15000

21

mg/kg

KMP UNC

KM P-S B42-0054-0060-01

6/8/2022

35.659569

-108.492026

54

60

SW6020

IRON

17000

21

mg/kg

KMP UNC

KM P-S B33-0054-0060-01

6/3/2022

35.658445

-108.491212

54

60

SW6020

LEAD

7.8

0.21

mg/kg

KMP UNC

KM P-S B41-0054-0060-01

6/4/2022

35.659569

-108.491192

54

60

SW6020

LEAD

10

0.21

mg/kg

KMP UNC

KM P-S B42-0054-0060-01

6/8/2022

35.659569

-108.492026

54

60

SW6020

LEAD

11

0.21

mg/kg

KMP UNC

KM P-S B33-0054-0060-01

6/3/2022

35.658445

-108.491212

54

60

SW6020

MANGANESE

190

0.78

mg/kg

KMP UNC

KM P-S B41-0054-0060-01

6/4/2022

35.659569

-108.491192

54

60

SW6020

MANGANESE

240

0.8

mg/kg

KMP UNC

KM P-S B42-0054-0060-01

6/8/2022

35.659569

-108.492026

54

60

SW6020

MANGANESE

240

0.81

mg/kg

KMP UNC

KM P-S B33-0054-0060-01

6/3/2022

35.658445

-108.491212

54

60

SW6020

MOLYBDENUM

0.3

0.21

mg/kg

KMP UNC

KM P-S B41-0054-0060-01

6/4/2022

35.659569

-108.491192

54

60

SW6020

MOLYBDENUM

0.41

0.21

mg/kg

KMP UNC

KM P-S B42-0054-0060-01

6/8/2022

35.659569

-108.492026

54

60

SW6020

MOLYBDENUM

0.39

0.21

mg/kg

KMP UNC

KM P-S B33-0054-0060-01

6/3/2022

35.658445

-108.491212

54

60

SW6020

NICKEL

6.7

2.1

mg/kg

KMP UNC

KM P-S B41-0054-0060-01

6/4/2022

35.659569

-108.491192

54

60

SW6020

NICKEL

8.6

2.1

mg/kg

KMP UNC

KM P-S B42-0054-0060-01

6/8/2022

35.659569

-108.492026

54

60

SW6020

NICKEL

9.3

2.1

mg/kg

KMP UNC

KM P-S B33-0054-0060-01

6/3/2022

35.658445

-108.491212

54

60

713R15

Ra-226

0.7 J

0.44

pCi/g

KMP UNC

KM P-S B41-0054-0060-01

6/4/2022

35.659569

-108.491192

54

60

713R15

Ra-226

1.48 J

0.54

pCi/g

KMP UNC

KM P-S B42-0054-0060-01

6/8/2022

35.659569

-108.492026

54

60

713R15

Ra-226

1.05 J

0.5

pCi/g

KMP UNC

KM P-S B33-0054-0060-01

6/3/2022

35.658445

-108.491212

54

60

SW6020

SELENIUM

1.1

1

mg/kg

KMP UNC

KM P-S B41-0054-0060-01

6/4/2022

35.659569

-108.491192

54

60

SW6020

SELENIUM

1.3

1.1

mg/kg

KMP UNC

KM P-S B42-0054-0060-01

6/8/2022

35.659569

-108.492026

54

60

SW6020

SELENIUM

1.4

1.1

mg/kg

KMP UNC

KM P-S B33-0054-0060-01

6/3/2022

35.658445

-108.491212

54

60

SW6020

SILVER

0.059 U

0.12

mg/kg

KMP UNC

KM P-S B41-0054-0060-01

6/4/2022

35.659569

-108.491192

54

60

SW6020

SILVER

0.061 U

0.12

mg/kg

KMP UNC

KM P-S B42-0054-0060-01

6/8/2022

35.659569

-108.492026

54

60

SW6020

SILVER

0.061 U

0.12

mg/kg

KMP UNC

KM P-S B33-0054-0060-01

6/3/2022

35.658445

-108.491212

54

60

SW6020

THALLIUM

0.12

0.01

mg/kg

KMP UNC

KM P-S B41-0054-0060-01

6/4/2022

35.659569

-108.491192

54

60

SW6020

THALLIUM

0.16

0.011

mg/kg

KMP UNC

KM P-S B42-0054-0060-01

6/8/2022

35.659569

-108.492026

54

60

SW6020

THALLIUM

0.17

0.011

mg/kg

KMP UNC

KM P-S B33-0054-0060-01

6/3/2022

35.658445

-108.491212

54

60

SW6020

URANIUM

0.66

0.021

mg/kg

KMP UNC

KM P-S B41-0054-0060-01

6/4/2022

35.659569

-108.491192

54

60

SW6020

URANIUM

0.76

0.021

mg/kg

KMP UNC

KM P-S B42-0054-0060-01

6/8/2022

35.659569

-108.492026

54

60

SW6020

URANIUM

1

0.021

mg/kg

KMP UNC

KM P-S B33-0054-0060-01

6/3/2022

35.658445

-108.491212

54

60

SW6020

VANADIUM

12

0.52

mg/kg

KMP UNC

KM P-S B41-0054-0060-01

6/4/2022

35.659569

-108.491192

54

60

SW6020

VANADIUM

15

0.53

mg/kg

KMP UNC

KM P-S B42-0054-0060-01

6/8/2022

35.659569

-108.492026

54

60

SW6020

VANADIUM

17

0.54

mg/kg

KMP UNC

KM P-S B33-0054-0060-01

6/3/2022

35.658445

-108.491212

54

60

SW6020

ZINC

33

10

mg/kg

KMP UNC

KM P-S B41-0054-0060-01

6/4/2022

35.659569

-108.491192

54

60

SW6020

ZINC

43

11

mg/kg

KMP UNC

KM P-S B42-0054-0060-01

6/8/2022

35.659569

-108.492026

54

60

SW6020

ZINC

47

11

mg/kg

KMP UNC

KM P-S B28-0060-0066-01

6/4/2022

35.658964

-108.490576

60

66

SW6020

ALUMINUM

5900

16

mg/kg

KMP UNC

KMP-SB28-0060-0066-02

6/4/2022

35.658964

-108.490576

60

66

SW6020

ALUMINUM

5900

16

mg/kg

KMP UNC

KM P-SB31-0060-0066-01

6/4/2022

35.658122

-108.490535

60

66

SW6020

ALUMINUM

6900

16

mg/kg

KMP UNC

KM P-S B32-0060-0066-01

6/4/2022

35.658833

-108.491113

60

66

SW6020

ALUMINUM

5500

15

mg/kg

KMP UNC

KM P-S B33-0060-0066-01

6/3/2022

35.658445

-108.491212

60

66

SW6020

ALUMINUM

5000

15

mg/kg

Page 80 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KM P-S B28-0060-0066-01

6/4/2022

35.658964

-108.490576

60

66

SW6020

ANTIMONY

0.063 J

0.11

mg/kg

KMPUNC

KMP-SB28-0060-0066-02

6/4/2022

35.658964

-108.490576

60

66

SW6020

ANTIMONY

0.063 J

0.11

mg/kg

KMP UNC

KM P-SB31-0060-0066-01

6/4/2022

35.658122

-108.490535

60

66

SW6020

ANTIMONY

0.057 J

0.1

mg/kg

KMP UNC

KM P-S B32-0060-0066-01

6/4/2022

35.658833

-108.491113

60

66

SW6020

ANTIMONY

0.049 J

0.1

mg/kg

KMP UNC

KM P-S B33-0060-0066-01

6/3/2022

35.658445

-108.491212

60

66

SW6020

ANTIMONY

0.042 J

0.1

mg/kg

KMP UNC

KM P-S B28-0060-0066-01

6/4/2022

35.658964

-108.490576

60

66

SW6020

ARSENIC

6.3

0.21

mg/kg

KMP UNC

KMP-SB28-0060-0066-02

6/4/2022

35.658964

-108.490576

60

66

SW6020

ARSENIC

5.3

0.21

mg/kg

KMP UNC

KM P-SB31-0060-0066-01

6/4/2022

35.658122

-108.490535

60

66

SW6020

ARSENIC

6.3

0.21

mg/kg

KMP UNC

KM P-S B32-0060-0066-01

6/4/2022

35.658833

-108.491113

60

66

SW6020

ARSENIC

5

0.21

mg/kg

KMP UNC

KM P-S B33-0060-0066-01

6/3/2022

35.658445

-108.491212

60

66

SW6020

ARSENIC

4.6

0.21

mg/kg

KMP UNC

KM P-S B28-0060-0066-01

6/4/2022

35.658964

-108.490576

60

66

SW6020

BARIUM

50

0.53

mg/kg

KMP UNC

KMP-SB28-0060-0066-02

6/4/2022

35.658964

-108.490576

60

66

SW6020

BARIUM

49

0.53

mg/kg

KMP UNC

KM P-SB31-0060-0066-01

6/4/2022

35.658122

-108.490535

60

66

SW6020

BARIUM

59

0.52

mg/kg

KMP UNC

KM P-S B32-0060-0066-01

6/4/2022

35.658833

-108.491113

60

66

SW6020

BARIUM

46

0.51

mg/kg

KMP UNC

KM P-S B33-0060-0066-01

6/3/2022

35.658445

-108.491212

60

66

SW6020

BARIUM

35

0.51

mg/kg

KMP UNC

KM P-S B28-0060-0066-01

6/4/2022

35.658964

-108.490576

60

66

SW6020

BERYLLIUM

0.52

0.053

mg/kg

KMP UNC

KMP-SB28-0060-0066-02

6/4/2022

35.658964

-108.490576

60

66

SW6020

BERYLLIUM

0.5

0.053

mg/kg

KMP UNC

KM P-SB31-0060-0066-01

6/4/2022

35.658122

-108.490535

60

66

SW6020

BERYLLIUM

0.61

0.052

mg/kg

KMP UNC

KM P-S B32-0060-0066-01

6/4/2022

35.658833

-108.491113

60

66

SW6020

BERYLLIUM

0.46

0.051

mg/kg

KMP UNC

KM P-S B33-0060-0066-01

6/3/2022

35.658445

-108.491212

60

66

SW6020

BERYLLIUM

0.43

0.051

mg/kg

KMP UNC

KM P-S B28-0060-0066-01

6/4/2022

35.658964

-108.490576

60

66

SW6020

CADMIUM

0.051 J

0.21

mg/kg

KMP UNC

KMP-SB28-0060-0066-02

6/4/2022

35.658964

-108.490576

60

66

SW6020

CADMIUM

0.051 J

0.21

mg/kg

KMP UNC

KM P-SB31-0060-0066-01

6/4/2022

35.658122

-108.490535

60

66

SW6020

CADMIUM

0.061 J

0.21

mg/kg

KMP UNC

KM P-S B32-0060-0066-01

6/4/2022

35.658833

-108.491113

60

66

SW6020

CADMIUM

0.051 J

0.21

mg/kg

KMP UNC

KM P-S B33-0060-0066-01

6/3/2022

35.658445

-108.491212

60

66

SW6020

CADMIUM

0.044 J

0.21

mg/kg

KMP UNC

KM P-S B28-0060-0066-01

6/4/2022

35.658964

-108.490576

60

66

SW6020

CHROMIUM

6.5

1.1

mg/kg

KMP UNC

KMP-SB28-0060-0066-02

6/4/2022

35.658964

-108.490576

60

66

SW6020

CHROMIUM

6.4

1.1

mg/kg

KMP UNC

KM P-SB31-0060-0066-01

6/4/2022

35.658122

-108.490535

60

66

SW6020

CHROMIUM

7.8

1

mg/kg

KMP UNC

KM P-S B32-0060-0066-01

6/4/2022

35.658833

-108.491113

60

66

SW6020

CHROMIUM

8.2

1

mg/kg

KMP UNC

KM P-S B33-0060-0066-01

6/3/2022

35.658445

-108.491212

60

66

SW6020

CHROMIUM

7.7

1

mg/kg

KMP UNC

KM P-S B28-0060-0066-01

6/4/2022

35.658964

-108.490576

60

66

SW6020

COBALT

5.2

0.53

mg/kg

KMP UNC

KMP-SB28-0060-0066-02

6/4/2022

35.658964

-108.490576

60

66

SW6020

COBALT

5

0.53

mg/kg

KMP UNC

KM P-SB31-0060-0066-01

6/4/2022

35.658122

-108.490535

60

66

SW6020

COBALT

5.7

0.52

mg/kg

KMP UNC

KM P-S B32-0060-0066-01

6/4/2022

35.658833

-108.491113

60

66

SW6020

COBALT

4.3

0.51

mg/kg

KMP UNC

KM P-S B33-0060-0066-01

6/3/2022

35.658445

-108.491212

60

66

SW6020

COBALT

4.3

0.51

mg/kg

KMP UNC

KM P-S B28-0060-0066-01

6/4/2022

35.658964

-108.490576

60

66

SW6020

COPPER

7.1

2.1

mg/kg

KMP UNC

KMP-SB28-0060-0066-02

6/4/2022

35.658964

-108.490576

60

66

SW6020

COPPER

7.1

2.1

mg/kg

KMP UNC

KM P-SB31-0060-0066-01

6/4/2022

35.658122

-108.490535

60

66

SW6020

COPPER

9.8

2.1

mg/kg

KMP UNC

KM P-S B32-0060-0066-01

6/4/2022

35.658833

-108.491113

60

66

SW6020

COPPER

7.2

2.1

mg/kg

KMP UNC

KM P-S B33-0060-0066-01

6/3/2022

35.658445

-108.491212

60

66

SW6020

COPPER

6.6

2.1

mg/kg

KMP UNC

KM P-S B28-0060-0066-01

6/4/2022

35.658964

-108.490576

60

66

SW6020

IRON

14000

21

mg/kg

KMP UNC

KMP-SB28-0060-0066-02

6/4/2022

35.658964

-108.490576

60

66

SW6020

IRON

13000

21

mg/kg

Page 81 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KM P-SB31-0060-0066-01

6/4/2022

35.658122

-108.490535

60

66

SW6020

IRON

16000

21

mg/kg

KMPUNC

KM P-S B32-0060-0066-01

6/4/2022

35.658833

-108.491113

60

66

SW6020

IRON

12000

21

mg/kg

KMP UNC

KM P-S B33-0060-0066-01

6/3/2022

35.658445

-108.491212

60

66

SW6020

IRON

12000

21

mg/kg

KMP UNC

KM P-S B28-0060-0066-01

6/4/2022

35.658964

-108.490576

60

66

SW6020

LEAD

00
CO

0.21

mg/kg

KMP UNC

KMP-SB28-0060-0066-02

6/4/2022

35.658964

-108.490576

60

66

SW6020

LEAD

8.3

0.21

mg/kg

KMP UNC

KM P-SB31-0060-0066-01

6/4/2022

35.658122

-108.490535

60

66

SW6020

LEAD

11

0.21

mg/kg

KMP UNC

KM P-S B32-0060-0066-01

6/4/2022

35.658833

-108.491113

60

66

SW6020

LEAD

8.1

0.21

mg/kg

KMP UNC

KM P-S B33-0060-0066-01

6/3/2022

35.658445

-108.491212

60

66

SW6020

LEAD

7.2

0.21

mg/kg

KMP UNC

KM P-S B28-0060-0066-01

6/4/2022

35.658964

-108.490576

60

66

SW6020

MANGANESE

190

0.79

mg/kg

KMP UNC

KMP-SB28-0060-0066-02

6/4/2022

35.658964

-108.490576

60

66

SW6020

MANGANESE

180

0.79

mg/kg

KMP UNC

KM P-SB31-0060-0066-01

6/4/2022

35.658122

-108.490535

60

66

SW6020

MANGANESE

200

0.79

mg/kg

KMP UNC

KM P-S B32-0060-0066-01

6/4/2022

35.658833

-108.491113

60

66

SW6020

MANGANESE

180

0.77

mg/kg

KMP UNC

KM P-S B33-0060-0066-01

6/3/2022

35.658445

-108.491212

60

66

SW6020

MANGANESE

190

0.77

mg/kg

KMP UNC

KM P-S B28-0060-0066-01

6/4/2022

35.658964

-108.490576

60

66

SW6020

MOLYBDENUM

0.37

0.21

mg/kg

KMP UNC

KMP-SB28-0060-0066-02

6/4/2022

35.658964

-108.490576

60

66

SW6020

MOLYBDENUM

0.38

0.21

mg/kg

KMP UNC

KM P-SB31-0060-0066-01

6/4/2022

35.658122

-108.490535

60

66

SW6020

MOLYBDENUM

0.36

0.21

mg/kg

KMP UNC

KM P-S B32-0060-0066-01

6/4/2022

35.658833

-108.491113

60

66

SW6020

MOLYBDENUM

0.91

0.21

mg/kg

KMP UNC

KM P-S B33-0060-0066-01

6/3/2022

35.658445

-108.491212

60

66

SW6020

MOLYBDENUM

0.81

0.21

mg/kg

KMP UNC

KM P-S B28-0060-0066-01

6/4/2022

35.658964

-108.490576

60

66

SW6020

NICKEL

7.2

2.1

mg/kg

KMP UNC

KMP-SB28-0060-0066-02

6/4/2022

35.658964

-108.490576

60

66

SW6020

NICKEL

7

2.1

mg/kg

KMP UNC

KM P-SB31-0060-0066-01

6/4/2022

35.658122

-108.490535

60

66

SW6020

NICKEL

00
CO

2.1

mg/kg

KMP UNC

KM P-S B32-0060-0066-01

6/4/2022

35.658833

-108.491113

60

66

SW6020

NICKEL

6.6

2.1

mg/kg

KMP UNC

KM P-S B33-0060-0066-01

6/3/2022

35.658445

-108.491212

60

66

SW6020

NICKEL

6.3

2.1

mg/kg

KMP UNC

KM P-S B28-0060-0066-01

6/4/2022

35.658964

-108.490576

60

66

713R15

Ra-226

0.88 J

0.32

pCi/g

KMP UNC

KMP-SB28-0060-0066-02

6/4/2022

35.658964

-108.490576

60

66

713R15

Ra-226

0.95 J

0.48

pCi/g

KMP UNC

KM P-SB31-0060-0066-01

6/4/2022

35.658122

-108.490535

60

66

713R15

Ra-226

1.43 J

0.47

pCi/g

KMP UNC

KM P-S B32-0060-0066-01

6/4/2022

35.658833

-108.491113

60

66

713R15

Ra-226

2.09

0.51

pCi/g

KMP UNC

KM P-S B33-0060-0066-01

6/3/2022

35.658445

-108.491212

60

66

713R15

Ra-226

1.02

0.37

pCi/g

KMP UNC

KM P-S B28-0060-0066-01

6/4/2022

35.658964

-108.490576

60

66

SW6020

SELENIUM

1.2

1.1

mg/kg

KMP UNC

KMP-SB28-0060-0066-02

6/4/2022

35.658964

-108.490576

60

66

SW6020

SELENIUM

1.1

1.1

mg/kg

KMP UNC

KM P-SB31-0060-0066-01

6/4/2022

35.658122

-108.490535

60

66

SW6020

SELENIUM

1.4

1

mg/kg

KMP UNC

KM P-S B32-0060-0066-01

6/4/2022

35.658833

-108.491113

60

66

SW6020

SELENIUM

1.6

1

mg/kg

KMP UNC

KM P-S B33-0060-0066-01

6/3/2022

35.658445

-108.491212

60

66

SW6020

SELENIUM

0.99 J

1

mg/kg

KMP UNC

KM P-S B28-0060-0066-01

6/4/2022

35.658964

-108.490576

60

66

SW6020

SILVER

0.06 U

0.12

mg/kg

KMP UNC

KMP-SB28-0060-0066-02

6/4/2022

35.658964

-108.490576

60

66

SW6020

SILVER

0.06 U

0.12

mg/kg

KMP UNC

KM P-SB31-0060-0066-01

6/4/2022

35.658122

-108.490535

60

66

SW6020

SILVER

0.061 J

0.12

mg/kg

KMP UNC

KM P-S B32-0060-0066-01

6/4/2022

35.658833

-108.491113

60

66

SW6020

SILVER

0.059 U

0.12

mg/kg

KMP UNC

KM P-S B33-0060-0066-01

6/3/2022

35.658445

-108.491212

60

66

SW6020

SILVER

0.058 U

0.12

mg/kg

KMP UNC

KM P-S B28-0060-0066-01

6/4/2022

35.658964

-108.490576

60

66

SW6020

THALLIUM

0.13

0.011

mg/kg

KMP UNC

KM P-SB28-0060-0066-02

6/4/2022

35.658964

-108.490576

60

66

SW6020

THALLIUM

0.13

0.011

mg/kg

KMP UNC

KM P-SB31 -0060-0066-01

6/4/2022

35.658122

-108.490535

60

66

SW6020

THALLIUM

0.17

0.01

mg/kg

KMP UNC

KM P-SB32-0060-0066-01

6/4/2022

35.658833

-108.491113

60

66

SW6020

THALLIUM

0.12

0.01

mg/kg

Page 82 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KM P-S B33-0060-0066-01

6/3/2022

35.658445

-108.491212

60

66

SW6020

THALLIUM

0.1

0.01

mg/kg

KMPUNC

KM P-S B28-0060-0066-01

6/4/2022

35.658964

-108.490576

60

66

SW6020

URANIUM

160

0.021

mg/kg

KMP UNC

KMP-SB28-0060-0066-02

6/4/2022

35.658964

-108.490576

60

66

SW6020

URANIUM

150

0.021

mg/kg

KMP UNC

KM P-SB31-0060-0066-01

6/4/2022

35.658122

-108.490535

60

66

SW6020

URANIUM

0.8

0.021

mg/kg

KMP UNC

KM P-S B32-0060-0066-01

6/4/2022

35.658833

-108.491113

60

66

SW6020

URANIUM

14

0.021

mg/kg

KMP UNC

KM P-S B33-0060-0066-01

6/3/2022

35.658445

-108.491212

60

66

SW6020

URANIUM

1.9

0.021

mg/kg

KMP UNC

KM P-S B28-0060-0066-01

6/4/2022

35.658964

-108.490576

60

66

SW6020

VANADIUM

13

0.53

mg/kg

KMP UNC

KMP-SB28-0060-0066-02

6/4/2022

35.658964

-108.490576

60

66

SW6020

VANADIUM

12

0.53

mg/kg

KMP UNC

KM P-SB31-0060-0066-01

6/4/2022

35.658122

-108.490535

60

66

SW6020

VANADIUM

14

0.52

mg/kg

KMP UNC

KM P-S B32-0060-0066-01

6/4/2022

35.658833

-108.491113

60

66

SW6020

VANADIUM

13

0.51

mg/kg

KMP UNC

KM P-S B33-0060-0066-01

6/3/2022

35.658445

-108.491212

60

66

SW6020

VANADIUM

12

0.51

mg/kg

KMP UNC

KM P-S B28-0060-0066-01

6/4/2022

35.658964

-108.490576

60

66

SW6020

ZINC

35

11

mg/kg

KMP UNC

KMP-SB28-0060-0066-02

6/4/2022

35.658964

-108.490576

60

66

SW6020

ZINC

35

11

mg/kg

KMP UNC

KM P-SB31-0060-0066-01

6/4/2022

35.658122

-108.490535

60

66

SW6020

ZINC

44

10

mg/kg

KMP UNC

KM P-S B32-0060-0066-01

6/4/2022

35.658833

-108.491113

60

66

SW6020

ZINC

33

10

mg/kg

KMP UNC

KM P-S B33-0060-0066-01

6/3/2022

35.658445

-108.491212

60

66

SW6020

ZINC

38

10

mg/kg

KMP UNC

KM P-S B40-0054-0060-01

6/4/2022

35.659292

-108.49147

65

60

SW6020

ALUMINUM

6400

15

mg/kg

KMP UNC

KM P-S B40-0054-0060-01

6/4/2022

35.659292

-108.49147

65

60

SW6020

ANTIMONY

0.07 J

0.1

mg/kg

KMP UNC

KM P-S B40-0054-0060-01

6/4/2022

35.659292

-108.49147

65

60

SW6020

ARSENIC

5.1

0.21

mg/kg

KMP UNC

KM P-S B40-0054-0060-01

6/4/2022

35.659292

-108.49147

65

60

SW6020

BARIUM

55

0.52

mg/kg

KMP UNC

KM P-S B40-0054-0060-01

6/4/2022

35.659292

-108.49147

65

60

SW6020

BERYLLIUM

0.51

0.052

mg/kg

KMP UNC

KM P-S B40-0054-0060-01

6/4/2022

35.659292

-108.49147

65

60

SW6020

CADMIUM

0.06 J

0.21

mg/kg

KMP UNC

KM P-S B40-0054-0060-01

6/4/2022

35.659292

-108.49147

65

60

SW6020

CHROMIUM

6.6

1

mg/kg

KMP UNC

KM P-S B40-0054-0060-01

6/4/2022

35.659292

-108.49147

65

60

SW6020

COBALT

4.5

0.52

mg/kg

KMP UNC

KM P-S B40-0054-0060-01

6/4/2022

35.659292

-108.49147

65

60

SW6020

COPPER

7.2

2.1

mg/kg

KMP UNC

KM P-S B40-0054-0060-01

6/4/2022

35.659292

-108.49147

65

60

SW6020

IRON

13000

21

mg/kg

KMP UNC

KM P-S B40-0054-0060-01

6/4/2022

35.659292

-108.49147

65

60

SW6020

LEAD

8

0.21

mg/kg

KMP UNC

KM P-S B40-0054-0060-01

6/4/2022

35.659292

-108.49147

65

60

SW6020

MANGANESE

190

0.77

mg/kg

KMP UNC

KM P-S B40-0054-0060-01

6/4/2022

35.659292

-108.49147

65

60

SW6020

MOLYBDENUM

0.32

0.21

mg/kg

KMP UNC

KM P-S B40-0054-0060-01

6/4/2022

35.659292

-108.49147

65

60

SW6020

NICKEL

6.8

2.1

mg/kg

KMP UNC

KM P-S B40-0054-0060-01

6/4/2022

35.659292

-108.49147

65

60

713R15

Ra-226

1.19

0.37

pCi/g

KMP UNC

KM P-S B40-0054-0060-01

6/4/2022

35.659292

-108.49147

65

60

SW6020

SELENIUM

1.3

1

mg/kg

KMP UNC

KM P-S B40-0054-0060-01

6/4/2022

35.659292

-108.49147

65

60

SW6020

SILVER

0.059 U

0.12

mg/kg

KMP UNC

KM P-S B40-0054-0060-01

6/4/2022

35.659292

-108.49147

65

60

SW6020

THALLIUM

0.12

0.01

mg/kg

KMP UNC

KM P-S B40-0054-0060-01

6/4/2022

35.659292

-108.49147

65

60

SW6020

URANIUM

28

0.021

mg/kg

KMP UNC

KM P-S B40-0054-0060-01

6/4/2022

35.659292

-108.49147

65

60

SW6020

VANADIUM

13

0.52

mg/kg

KMP UNC

KM P-S B40-0054-0060-01

6/4/2022

35.659292

-108.49147

65

60

SW6020

ZINC

34

10

mg/kg

KMP UNC

KM P-SB33-0066-0072-01

6/3/2022

35.658445

-108.491212

66

72

SW6020

ALUMINUM

5500

15

mg/kg

KMP UNC

KM P-SB37-0066-0072-01

6/3/2022

35.657957

-108.491269

66

72

SW6020

ALUMINUM

7000

15

mg/kg

KMP UNC

KM P-SB33-0066-0072-01

6/3/2022

35.658445

-108.491212

66

72

SW6020

ANTIMONY

0.046 J

0.1

mg/kg

KMP UNC

KM P-SB37-0066-0072-01

6/3/2022

35.657957

-108.491269

66

72

SW6020

ANTIMONY

0.099 J

0.1

mg/kg

KMP UNC

KM P-SB33-0066-0072-01

6/3/2022

35.658445

-108.491212

66

72

SW6020

ARSENIC

4.9

0.2

mg/kg

Page 83 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

KMPUNC

KM P-S B37-0066-0072-01

6/3/2022

35.657957

-108.491269

66

72

SW6020

ARSENIC

6.2

0.21

mg/kg

KMPUNC

KM P-S B33-0066-0072-01

6/3/2022

35.658445

-108.491212

66

72

SW6020

BARIUM

47

0.5

mg/kg

KMP UNC

KM P-S B37-0066-0072-01

6/3/2022

35.657957

-108.491269

66

72

SW6020

BARIUM

58

0.51

mg/kg

KMP UNC

KM P-S B33-0066-0072-01

6/3/2022

35.658445

-108.491212

66

72

SW6020

BERYLLIUM

0.44

0.05

mg/kg

KMP UNC

KM P-S B37-0066-0072-01

6/3/2022

35.657957

-108.491269

66

72

SW6020

BERYLLIUM

0.57

0.051

mg/kg

KMP UNC

KM P-S B33-0066-0072-01

6/3/2022

35.658445

-108.491212

66

72

SW6020

CADMIUM

0.052 J

0.2

mg/kg

KMP UNC

KM P-S B37-0066-0072-01

6/3/2022

35.657957

-108.491269

66

72

SW6020

CADMIUM

0.07 J

0.21

mg/kg

KMP UNC

KM P-S B33-0066-0072-01

6/3/2022

35.658445

-108.491212

66

72

SW6020

CHROMIUM

6.6

1

mg/kg

KMP UNC

KM P-S B37-0066-0072-01

6/3/2022

35.657957

-108.491269

66

72

SW6020

CHROMIUM

7.5

1

mg/kg

KMP UNC

KM P-S B33-0066-0072-01

6/3/2022

35.658445

-108.491212

66

72

SW6020

COBALT

4.3

0.5

mg/kg

KMP UNC

KM P-S B37-0066-0072-01

6/3/2022

35.657957

-108.491269

66

72

SW6020

COBALT

5.4

0.51

mg/kg

KMP UNC

KM P-S B33-0066-0072-01

6/3/2022

35.658445

-108.491212

66

72

SW6020

COPPER

7.2

2

mg/kg

KMP UNC

KM P-S B37-0066-0072-01

6/3/2022

35.657957

-108.491269

66

72

SW6020

COPPER

9.5

2.1

mg/kg

KMP UNC

KM P-S B33-0066-0072-01

6/3/2022

35.658445

-108.491212

66

72

SW6020

IRON

12000

20

mg/kg

KMP UNC

KM P-S B37-0066-0072-01

6/3/2022

35.657957

-108.491269

66

72

SW6020

IRON

15000

21

mg/kg

KMP UNC

KM P-S B33-0066-0072-01

6/3/2022

35.658445

-108.491212

66

72

SW6020

LEAD

8.4

0.2

mg/kg

KMP UNC

KM P-S B37-0066-0072-01

6/3/2022

35.657957

-108.491269

66

72

SW6020

LEAD

10

0.21

mg/kg

KMP UNC

KM P-S B33-0066-0072-01

6/3/2022

35.658445

-108.491212

66

72

SW6020

MANGANESE

180

0.75

mg/kg

KMP UNC

KM P-S B37-0066-0072-01

6/3/2022

35.657957

-108.491269

66

72

SW6020

MANGANESE

200

0.77

mg/kg

KMP UNC

KM P-S B33-0066-0072-01

6/3/2022

35.658445

-108.491212

66

72

SW6020

MOLYBDENUM

0.41

0.2

mg/kg

KMP UNC

KM P-S B37-0066-0072-01

6/3/2022

35.657957

-108.491269

66

72

SW6020

MOLYBDENUM

0.39

0.21

mg/kg

KMP UNC

KM P-S B33-0066-0072-01

6/3/2022

35.658445

-108.491212

66

72

SW6020

NICKEL

6.4

2

mg/kg

KMP UNC

KM P-S B37-0066-0072-01

6/3/2022

35.657957

-108.491269

66

72

SW6020

NICKEL

8.2

2.1

mg/kg

KMP UNC

KM P-S B33-0066-0072-01

6/3/2022

35.658445

-108.491212

66

72

713R15

Ra-226

4.55

0.52

pCi/g

KMP UNC

KM P-S B37-0066-0072-01

6/3/2022

35.657957

-108.491269

66

72

713R15

Ra-226

8.7 J

0.6

pCi/g

KMP UNC

KM P-S B33-0066-0072-01

6/3/2022

35.658445

-108.491212

66

72

SW6020

SELENIUM

1.7

1

mg/kg

KMP UNC

KM P-S B37-0066-0072-01

6/3/2022

35.657957

-108.491269

66

72

SW6020

SELENIUM

2

1

mg/kg

KMP UNC

KM P-S B33-0066-0072-01

6/3/2022

35.658445

-108.491212

66

72

SW6020

SILVER

0.057 U

0.11

mg/kg

KMP UNC

KM P-S B37-0066-0072-01

6/3/2022

35.657957

-108.491269

66

72

SW6020

SILVER

0.058 UJ

0.12

mg/kg

KMP UNC

KM P-S B33-0066-0072-01

6/3/2022

35.658445

-108.491212

66

72

SW6020

THALLIUM

0.11

0.01

mg/kg

KMP UNC

KM P-S B37-0066-0072-01

6/3/2022

35.657957

-108.491269

66

72

SW6020

THALLIUM

0.15

0.01

mg/kg

KMP UNC

KM P-S B33-0066-0072-01

6/3/2022

35.658445

-108.491212

66

72

SW6020

URANIUM

4

0.02

mg/kg

KMP UNC

KM P-S B37-0066-0072-01

6/3/2022

35.657957

-108.491269

66

72

SW6020

URANIUM

7.1

0.021

mg/kg

KMP UNC

KM P-S B33-0066-0072-01

6/3/2022

35.658445

-108.491212

66

72

SW6020

VANADIUM

13

0.5

mg/kg

KMP UNC

KM P-S B37-0066-0072-01

6/3/2022

35.657957

-108.491269

66

72

SW6020

VANADIUM

15

0.51

mg/kg

KMP UNC

KM P-S B33-0066-0072-01

6/3/2022

35.658445

-108.491212

66

72

SW6020

ZINC

36

10

mg/kg

KMP UNC

KM P-S B37-0066-0072-01

6/3/2022

35.657957

-108.491269

66

72

SW6020

ZINC

42

10

mg/kg

Arroyo NN

KMP-11-00

7/18/2017

35.660042

-108.491651

0

2

Unknown

ARSENIC

7.6

Unknown

mg/kg

Arroyo NN

KMP-11D-00

7/18/2017

35.660042

-108.491651

0

2

Unknown

ARSENIC

6.4

Unknown

mg/kg

Arroyo NN

KMP-12-00

7/18/2017

35.660276

-108.49119

0

2

Unknown

ARSENIC

11

Unknown

mg/kg

Arroyo NN

KMP-11-00

7/18/2017

35.660042

-108.491651

0

2

Unknown

BARIUM

74

Unknown

mg/kg

Arroyo NN

KMP-11 D-00

7/18/2017

35.660042

-108.491651

0

2

Unknown

BARIUM

59

Unknown

mg/kg

Page 84 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

Arroyo NN

KMP-12-00

7/18/2017

35.660276

-108.49119

0

2

Unknown

BARIUM

59

Unknown

mg/kg

Arroyo NN

KMP-11-00

7/18/2017

35.660042

-108.491651

0

2

Unknown

CADMIUM

0.063 J

Unknown

mg/kg

Arroyo NN

KMP-11D-00

7/18/2017

35.660042

-108.491651

0

2

Unknown

CADMIUM

0.12 U

Unknown

mg/kg

Arroyo NN

KMP-12-00

7/18/2017

35.660276

-108.49119

0

2

Unknown

CADMIUM

0.064 J

Unknown

mg/kg

Arroyo NN

KMP-11-00

7/18/2017

35.660042

-108.491651

0

2

Unknown

CHROMIUM

5.5

Unknown

mg/kg

Arroyo NN

KMP-11 D-00

7/18/2017

35.660042

-108.491651

0

2

Unknown

CHROMIUM

5.5

Unknown

mg/kg

Arroyo NN

KMP-12-00

7/18/2017

35.660276

-108.49119

0

2

Unknown

CHROMIUM

6.7

Unknown

mg/kg

Arroyo NN

KMP-11-00

7/18/2017

35.660042

-108.491651

0

2

Unknown

LEAD

9.1

Unknown

mg/kg

Arroyo NN

KMP-11 D-00

7/18/2017

35.660042

-108.491651

0

2

Unknown

LEAD

7.8

Unknown

mg/kg

Arroyo NN

KMP-12-00

7/18/2017

35.660276

-108.49119

0

2

Unknown

LEAD

9

Unknown

mg/kg

Arroyo NN

KMP-11-00

7/18/2017

35.660042

-108.491651

0

2

Unknown

MOLYBDENUM

0.62 J

Unknown

mg/kg

Arroyo NN

KMP-11 D-00

7/18/2017

35.660042

-108.491651

0

2

Unknown

MOLYBDENUM

0.52 J

Unknown

mg/kg

Arroyo NN

KMP-12-00

7/18/2017

35.660276

-108.49119

0

2

Unknown

MOLYBDENUM

0.81 J

Unknown

mg/kg

Arroyo NN

CRPA-004.1 (0-2)

12/11/2010

35.6609489

-108.492682

0

2

713R11

Ra-226

1.2 G

0.46

o

Q.

/ g

Arroyo NN

CRPA-005.1 (0-2)

12/11/2010

35.6609379

-108.492681

0

2

713R11

Ra-226

1.1 G

0.52

pC

'g

Arroyo NN

CRPA-006.1 (0-2)

12/11/2010

35.6608914

-108.492634

0

2

713R11

Ra-226

1.84 G

0.65

pC

/g

Arroyo NN

CRPA-007.1 (0-2)

12/11/2010

35.663502

-108.489999

0

2

713R11

Ra-226

1.2 G

0.43

o

Q.

/ g

Arroyo NN

CRPA-007.1 (0-2) Dup

12/11/2010

35.663502

-108.489999

0

2

713R11

Ra-226

1.33 G

0.51

o

Q.

/ g

Arroyo NN

CRPA-008.1 (0-2)

12/11/2010

35.6634773

-108.489992

0

2

713R11

Ra-226

1.08 G

0.57

pC

/g

Arroyo NN

CRPA-009.1 (0-2)

12/11/2010

35.6634691

-108.489992

0

2

713R11

Ra-226

1.2 G

0.39

pC

/g

Arroyo NN

CRPA-010.1 (0-2)

12/11/2010

35.6652361

-108.488896

0

2

713R11

Ra-226

1.23 G

0.57

o

Q.

/ g

Arroyo NN

CRPA-011.1 (0-2)

12/11/2010

35.6652059

-108.488889

0

2

713R11

Ra-226

1.23 G

0.45

o

Q.

/ g

Arroyo NN

CRPA-011.4 Dup

12/11/2010

35.6652059

-108.488889

0

2

713R11

Ra-226

1.36 G

0.48

pC

/g

Arroyo NN

CRPA-012.1 (0-2)

12/11/2010

35.6652252

-108.488869

0

2

713R11

Ra-226

1.29 G

0.53

pC

/g

Arroyo NN

CRPA-013.1 (0-2)

12/11/2010

35.6658514

-108.488413

0

2

713R11

Ra-226

1.22 G

0.62

o

Q.

/ g

Arroyo NN

CRPA-014.1 (0-2)

12/11/2010

35.6667842

-108.487636

0

2

713R11

Ra-226

1.79 G

0.57

pC

/g

Arroyo NN

CRPA-U1.1 (0-2)

12/11/2010

35.6675871

-108.486484

0

2

713R11

Ra-226

1.69 G

0.46

pC

Zg

Arroyo NN

CRPA-U1.4 Dup

12/11/2010

35.6675871

-108.486484

0

2

713R11

Ra-226

1.43 G

0.66

pC

/g

Arroyo NN

CRUA-001.1 (0-2)

12/9/2010

35.6657521

-108.510332

0

2

713R11

Ra-226

0.99 LT

0.35

o

Q.

/g

Arroyo NN

CRUA-002.1 (0-2)

12/9/2010

35.6657302

-108.510318

0

2

713R11

Ra-226

0.78 LT

0.34

pC

/g

Arroyo NN

CRUA-003.1 (0-2)

12/9/2010

35.665741

-108.510352

0

2

713R11

Ra-226

1.23 G

0.46

pC

/g

Arroyo NN

CRUA-003.1 (0-2) Dup

12/9/2010

35.665741

-108.510352

0

2

713R11

Ra-226

1.1

0.36

pC

/g

Arroyo NN

CRUA-004.1 (0-2)

12/9/2010

35.6654039

-108.509221

0

2

713R11

Ra-226

1.14

0.38

o

Q.

/g

Arroyo NN

CRUA-004.4 Dup

12/9/2010

35.6654039

-108.509221

0

2

713R11

Ra-226

1.2

0.41

pC

/g

Arroyo NN

CRUA-005.1 (0-2)

12/9/2010

35.6654016

-108.509154

0

2

713R11

Ra-226

0.66 LT

0.47

pC

/g

Arroyo NN

CRUA-005.1 (0-2) Dup

12/9/2010

35.6654016

-108.509154

0

2

713R11

Ra-226

0.73 LT

0.39

pC

/g

Arroyo NN

CRUA-006.1 (0-2)

12/9/2010

35.6653931

-108.509191

0

2

713R11

Ra-226

0.8 LT

0.37

o

Q.

/g

Arroyo NN

CRUA-007.1 (0-2)

12/9/2010

35.6639899

-108.50663

0

2

713R11

Ra-226

1.42 G

0.6

o

Q.

/g

Arroyo NN

CRUA-008.1 (0-2)

12/9/2010

35.663979

-108.506614

0

2

713R11

Ra-226

1.32

0.42

pC

/g

Arroyo NN

CRUA-009.1 (0-2)

12/9/2010

35.6639815

-108.506644

0

2

713R11

Ra-226

0.7 LT

0.47

pC

/g

Arroyo NN

CRUA-010.1 (0-2)

12/10/2010

35.6643344

-108.505448

0

2

713R11

Ra-226

1.51

0.31

o

Q.

/g

Arroyo NN

CRUA-011.1 (0-2)

12/10/2010

35.66437

-108.505462

0

2

713R11

Ra-226

1.11

0.44

o

Q.

/g

Page 85 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

Arroyo NN

CRUA-012.1 (0-2)

12/10/2010

35.664389

-108.505499

0

2

713R11

Ra-226

0.73 LT

0.34

O

Q.

/g

Arroyo NN

CRUA-012.1 (0-2) Dup

12/10/2010

35.664389

-108.505499

0

2

713R11

Ra-226

0.62 LT.TI

0.48

O

Q.

/ g

Arroyo NN

CRUA-013.1 (0-2)

12/10/2010

35.6640912

-108.504221

0

2

713R11

Ra-226

1.38 G

0.39

pC

/g

Arroyo NN

CRUA-014.1 (0-2)

12/10/2010

35.6641022

-108.504221

0

2

713R11

Ra-226

1.05 G

0.52

pC

/g

Arroyo NN

CRUA-015.1 (0-2)

12/10/2010

35.664094

-108.504211

0

2

713R11

Ra-226

1.19

0.42

o

Q.

/ g

Arroyo NN

CRUA-016.1 (0-2)

12/10/2010

35.663831

-108.503098

0

2

713R11

Ra-226

0.8 LT,G

0.36

O

Q.

/ g

Arroyo NN

CRUA-016.1 (0-2) Dup

12/10/2010

35.663831

-108.503098

0

2

713R11

Ra-226

0.79 LT.TI

0.44

pC

/g

Arroyo NN

CRUA-017.1 (0-2)

12/10/2010

35.6638339

-108.503071

0

2

713R11

Ra-226

1.38

0.49

pC

/g

Arroyo NN

CRUA-017.1 (0-2) Dup

12/10/2010

35.6638339

-108.503071

0

2

713R11

Ra-226

1.07

0.47

o

Q.

/ g

Arroyo NN

CRUA-018.1 (0-2)

12/10/2010

35.66382

-108.503091

0

2

713R11

Ra-226

1.27 G

0.48

O

Q.

/ g

Arroyo NN

CRUA-019.1 (0-2)

12/10/2010

35.6636112

-108.502116

0

2

713R11

Ra-226

0.94 LT,G

0.55

pC

/g

Arroyo NN

CRUA-020.1 (0-2)

12/10/2010

35.663644

-108.502137

0

2

713R11

Ra-226

0.79 LT

0.43

pC

/g

Arroyo NN

CRUA-020.4 Dup

12/10/2010

35.663644

-108.502137

0

2

713R11

Ra-226

1.35

0.41

o

Q.

/ g

Arroyo NN

CRUA-021.1 (0-2)

12/10/2010

35.6636112

-108.502113

0

2

713R11

Ra-226

0.93 LT

0.46

O

Q.

/ g

Arroyo NN

CRUA-022.1 (0-2)

12/10/2010

35.6637156

-108.501114

0

2

713R11

Ra-226

0.75 LT,G

0.42

pC

/g

Arroyo NN

CRUA-022.1 (0-2) Dup

12/10/2010

35.6637156

-108.501114

0

2

713R11

Ra-226

0.76 LT,G

0.49

pC

/g

Arroyo NN

CRUA-023.1 (0-2)

12/10/2010

35.66371

-108.501141

0

2

713R11

Ra-226

0.67 LT.TI

0.41

o

Q.

/ g

Arroyo NN

CRUA-023.1 (0-2) Dup

12/10/2010

35.66371

-108.501141

0

2

713R11

Ra-226

0.74 LT

0.44

O

Q.

/ g

Arroyo NN

CRUA-024.1 (0-2)

12/10/2010

35.6637129

-108.501114

0

2

713R11

Ra-226

0.92 LT

0.45

pC

/g

Arroyo NN

CRUA-025.1 (0-2)

12/10/2010

35.6630845

-108.499984

0

2

713R11

Ra-226

0.49 LT,G,TI

0.46

pC

/g

Arroyo NN

CRUA-026.1 (0-2)

12/10/2010

35.6631118

-108.500015

0

2

713R11

Ra-226

0.75 LT,G

0.54

o

Q.

/ g

Arroyo NN

CRUA-027.1 (0-2)

12/10/2010

35.6631202

-108.499988

0

2

713R11

Ra-226

1.06

0.43

O

Q.

/ g

Arroyo NN

CRUA-028.1 (0-2)

12/10/2010

35.6628508

-108.499528

0

2

713R11

Ra-226

0.68 LT,G

0.59

pC

/g

Arroyo NN

CRUA-029.1 (0-2)

12/10/2010

35.66287

-108.499521

0

2

713R11

Ra-226

1.57

0.36

pC

/g

Arroyo NN

CRUA-030.1 (0-2)

12/10/2010

35.662884

-108.499488

0

2

713R11

Ra-226

0.93 LT,G

0.3

o

Q.

/ g

Arroyo NN

CRUA-031.1 (0-2)

12/10/2010

35.6621985

-108.499236

0

2

713R11

Ra-226

1.37

0.44

pC

/g

Arroyo NN

CRUA-031.4 Dup

12/10/2010

35.6621985

-108.499236

0

2

713R11

Ra-226

1.55

0.44

pC

Zg

Arroyo NN

CRUA-032.1 (0-2)

12/10/2010

35.6621878

-108.499192

0

2

713R11

Ra-226

1.67

0.43

pC

/g

Arroyo NN

CRUA-032.1 (0-2) Dup

12/10/2010

35.6621878

-108.499192

0

2

713R11

Ra-226

1.3

0.37

o

Q.

/ g

Arroyo NN

CRUA-033.1 (0-2)

12/10/2010

35.6622016

-108.499186

0

2

713R11

Ra-226

1.54 G

0.53

pC

Zg

Arroyo NN

CRUA-034.1 (0-2)

12/10/2010

35.660668

-108.498294

0

2

713R11

Ra-226

0.98 LT,G

0.43

pC

/g

Arroyo NN

CRUA-034.1 (0-2) Dup

12/10/2010

35.660668

-108.498294

0

2

713R11

Ra-226

0.74 LT

0.44

pC

/g

Arroyo NN

CRUA-035.1 (0-2)

12/10/2010

35.6606763

-108.498291

0

2

713R11

Ra-226

1.14

0.42

o

Q.

/ g

Arroyo NN

CRUA-036.1 (0-2)

12/10/2010

35.6606681

-108.498278

0

2

713R11

Ra-226

0.89 LT

0.36

pC

Zg

Arroyo NN

KMP-11-00

7/18/2017

35.660042

-108.491651

0

2

Unknown

Ra-226

0.84

Unknown

pC

/g

Arroyo NN

KMP-11D-00

7/18/2017

35.660042

-108.491651

0

2

Unknown

Ra-226

0.81 J

Unknown

pC

/g

Arroyo NN

KMP-12-00

7/18/2017

35.660276

-108.49119

0

2

Unknown

Ra-226

0.94

Unknown

o

Q.

/ g

Arroyo NN

KMP-11-00

7/18/2017

35.660042

-108.491651

0

2

Unknown

SELENIUM

1.1 J

Unknown

mg/kg

Arroyo NN

KMP-11 D-00

7/18/2017

35.660042

-108.491651

0

2

Unknown

SELENIUM

1.1 J

Unknown

mg/kg

Arroyo NN

KMP-12-00

7/18/2017

35.660276

-108.49119

0

2

Unknown

SELENIUM

1.5

Unknown

mg/kg

Arroyo NN

KMP-11-00

7/18/2017

35.660042

-108.491651

0

2

Unknown

SILVER

0.46 U

Unknown

mg/kg

Arroyo NN

KMP-11 D-00

7/18/2017

35.660042

-108.491651

0

2

Unknown

SILVER

0.47 U

Unknown

mg/kg

Page 86 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

Arroyo NN

KMP-12-00

7/18/2017

35.660276

-108.49119

0

2

Unknown

SILVER

0.47 U

Unknown

mg/kg

Arroyo NN

KMP-11-00

7/18/2017

35.660042

-108.491651

0

2

Unknown

URANIUM

0.64

Unknown

mg/kg

Arroyo NN

KMP-11D-00

7/18/2017

35.660042

-108.491651

0

2

Unknown

URANIUM

0.57

Unknown

mg/kg

Arroyo NN

KMP-12-00

7/18/2017

35.660276

-108.49119

0

2

Unknown

URANIUM

0.69

Unknown

mg/kg

Arroyo NN

KMP-11-00

7/18/2017

35.660042

-108.491651

0

2

Unknown

VANADIUM

16

Unknown

mg/kg

Arroyo NN

KMP-11 D-00

7/18/2017

35.660042

-108.491651

0

2

Unknown

VANADIUM

16

Unknown

mg/kg

Arroyo NN

KMP-12-00

7/18/2017

35.660276

-108.49119

0

2

Unknown

VANADIUM

25

Unknown

mg/kg

Arroyo NN

KMA-SS02-0000-0003-01

5/19/2022

35.660713

-108.490604

0

3

SW6020

ALUMINUM

4700

15

mg/kg

Arroyo NN

KMA-SS02-0000-0003-01

5/19/2022

35.660713

-108.490604

0

3

SW6020

ANTIMONY

0.042 J

0.1

mg/kg

Arroyo NN

KMA-SS02-0000-0003-01

5/19/2022

35.660713

-108.490604

0

3

SW6020

ARSENIC

4.4

0.2

mg/kg

Arroyo NN

KMA-SS02-0000-0003-01

5/19/2022

35.660713

-108.490604

0

3

SW6020

BARIUM

59

0.51

mg/kg

Arroyo NN

KMA-SS02-0000-0003-01

5/19/2022

35.660713

-108.490604

0

3

SW6020

BERYLLIUM

0.38

0.051

mg/kg

Arroyo NN

KMA-SS02-0000-0003-01

5/19/2022

35.660713

-108.490604

0

3

SW6020

CADMIUM

0.045 J

0.2

mg/kg

Arroyo NN

KMA-SS02-0000-0003-01

5/19/2022

35.660713

-108.490604

0

3

SW6020

CHROMIUM

5.1

1

mg/kg

Arroyo NN

KMA-SS02-0000-0003-01

5/19/2022

35.660713

-108.490604

0

3

SW6020

COBALT

4

0.51

mg/kg

Arroyo NN

KMA-SS02-0000-0003-01

5/19/2022

35.660713

-108.490604

0

3

SW6020

COPPER

5.1

2

mg/kg

Arroyo NN

KMA-SS02-0000-0003-01

5/19/2022

35.660713

-108.490604

0

3

SW6020

IRON

12000

20

mg/kg

Arroyo NN

KMA-SS02-0000-0003-01

5/19/2022

35.660713

-108.490604

0

3

SW6020

LEAD

7.3

0.2

mg/kg

Arroyo NN

KMA-SS02-0000-0003-01

5/19/2022

35.660713

-108.490604

0

3

SW6020

MANGANESE

200

0.76

mg/kg

Arroyo NN

KMA-SS02-0000-0003-01

5/19/2022

35.660713

-108.490604

0

3

SW6020

MOLYBDENUM

0.24

0.2

mg/kg

Arroyo NN

KMA-SS02-0000-0003-01

5/19/2022

35.660713

-108.490604

0

3

SW6020

NICKEL

5.5

2

mg/kg

Arroyo NN

KMA-SS02-0000-0003-01

5/19/2022

35.660713

-108.490604

0

3

713R15

Ra-226

0.86 J

0.33

pCi/g

Arroyo NN

KMA-SS02-0000-0003-01

5/19/2022

35.660713

-108.490604

0

3

SW6020

SELENIUM

1

1

mg/kg

Arroyo NN

KMA-SS02-0000-0003-01

5/19/2022

35.660713

-108.490604

0

3

SW6020

SILVER

0.058 U

0.12

mg/kg

Arroyo NN

KMA-SS02-0000-0003-01

5/19/2022

35.660713

-108.490604

0

3

SW6020

THALLIUM

0.092

0.01

mg/kg

Arroyo NN

KMA-SS02-0000-0003-01

5/19/2022

35.660713

-108.490604

0

3

SW6020

URANIUM

0.59

0.02

mg/kg

Arroyo NN

KMA-SS02-0000-0003-01

5/19/2022

35.660713

-108.490604

0

3

SW6020

VANADIUM

12

0.51

mg/kg

Arroyo NN

KMA-SS02-0000-0003-01

5/19/2022

35.660713

-108.490604

0

3

SW6020

ZINC

31

10

mg/kg

Arroyo NN

RWPR-SS-028 (0-6)

10/8/2010

35.6638706

-108.503384

0

6

713R11

Ra-226

1.26 G

0.54

pCi/g

Arroyo NN

RWPR-SS-029 (0-6)

10/7/2010

35.6639114

-108.503943

0

6

713R11

Ra-226

0.79 LT,G

0.53

pCi/g

Arroyo NN

RWPR-SS-028 (0-6)

10/8/2010

35.6638706

-108.503384

0

6

SW6020

URANIUM

0.78

11

mg/kg

Arroyo NN

RWPR-SS-029 (0-6)

10/7/2010

35.6639114

-108.503943

0

6

SW6020

URANIUM

2.9

10

mg/kg

Arroyo NN

RWPR-SS-028 (1.5-2)

10/8/2010

35.6638706

-108.503384

1.5

2

713R11

Ra-226

1.15

0.43

pCi/g

Arroyo NN

RWPR-SS-028 (1.5-2)

10/8/2010

35.6638706

-108.503384

1.5

2

SW6020

URANIUM

1.2

10

mg/kg

Arroyo NN

CRUA-009.2 (2-4)

12/9/2010

35.6639815

-108.506644

2

4

713R11

Ra-226

1.13 G

0.6

pCi/g

Arroyo NN

CRPA-004.2 (2-6)

12/11/2010

35.6609489

-108.492682

2

6

713R11

Ra-226

1.37 G

0.67

pCi/g

Arroyo NN

CRPA-005.2 (2-6)

12/11/2010

35.6609379

-108.492681

2

6

713R11

Ra-226

1.76 G

0.5

pCi/g

Arroyo NN

CRPA-007.2 (2-6)

12/11/2010

35.663502

-108.489999

2

6

713R11

Ra-226

1.43 G

0.62

pCi/g

Arroyo NN

CRPA-007.2 (2-6) Dup

12/11/2010

35.663502

-108.489999

2

6

713R11

Ra-226

1.21 G

0.56

pCi/g

Arroyo NN

CRPA-009.2 (2-6)

12/11/2010

35.6634691

-108.489992

2

6

713R11

Ra-226

1.42 G

0.54

pCi/g

Arroyo NN

CRPA-010.2 (2-6)

12/11/2010

35.6652361

-108.488896

2

6

713R11

Ra-226

1.6 G

0.66

pCi/g

Arroyo NN

CRPA-011.2 (2-6)

12/11/2010

35.6652059

-108.488889

2

6

713R11

Ra-226

0.92 LT,G

0.74

pCi/g

Page 87 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

Arroyo NN

CRPA-012.2 (2-6)

12/11/2010

35.6652252

-108.488869

2

6

713R11

Ra-226

1.31 G

0.7

O

Q.

/g

Arroyo NN

CRPA-013.2 (2-6)

12/11/2010

35.6658514

-108.488413

2

6

713R11

Ra-226

1.12 G

0.59

O

Q.

/ g

Arroyo NN

CRPA-014.2 (2-6)

12/11/2010

35.6667842

-108.487636

2

6

713R11

Ra-226

1.81 G

0.47

pC

/g

Arroyo NN

CRPA-U1.2 (2-6)

12/11/2010

35.6675871

-108.486484

2

6

713R11

Ra-226

1.46 G

0.65

pC

/g

Arroyo NN

CRUA-001.2 (2-6)

12/9/2010

35.6657521

-108.510332

2

6

713R11

Ra-226

1.12 G

0.42

o

Q.

/ g

Arroyo NN

CRUA-002.2 (2-6)

12/9/2010

35.6657302

-108.510318

2

6

713R11

Ra-226

0.85 LT,G

0.46

O

Q.

/g

Arroyo NN

CRUA-003.2 (2-6)

12/9/2010

35.665741

-108.510352

2

6

713R11

Ra-226

1.55 G

0.62

pC

/g

Arroyo NN

CRUA-004.2 (2-6)

12/9/2010

35.6654039

-108.509221

2

6

713R11

Ra-226

1 G

0.53

pC

/g

Arroyo NN

CRUA-005.2 (2-6)

12/9/2010

35.6654016

-108.509154

2

6

713R11

Ra-226

0.71 LT,G

0.35

o

Q.

/g

Arroyo NN

CRUA-006.2 (2-6)

12/9/2010

35.6653931

-108.509191

2

6

713R11

Ra-226

0.41 LT,G

0.33

O

Q.

/g

Arroyo NN

CRUA-007.2 (2-6)

12/9/2010

35.6639899

-108.50663

2

6

713R11

Ra-226

1.54 G

0.69

pC

/g

Arroyo NN

CRUA-008.2 (2-6)

12/9/2010

35.663979

-108.506614

2

6

713R11

Ra-226

1.67

0.48

pC

/g

Arroyo NN

CRUA-008.4 Dup

12/9/2010

35.663979

-108.506614

2

6

713R11

Ra-226

1.96

0.54

o

Q.

/g

Arroyo NN

CRUA-010.2 (2-6)

12/10/2010

35.6643344

-108.505448

2

6

713R11

Ra-226

1.82 G

0.48

O

Q.

/g

Arroyo NN

CRUA-011.2 (2-6)

12/10/2010

35.66437

-108.505462

2

6

713R11

Ra-226

1.52

0.5

pC

/g

Arroyo NN

CRUA-012.2 (2-6)

12/10/2010

35.664389

-108.505499

2

6

713R11

Ra-226

1.23

0.39

pC

/g

Arroyo NN

CRUA-015.2 (2-6)

12/10/2010

35.664094

-108.504211

2

6

713R11

Ra-226

1.33

0.41

o

Q.

/g

Arroyo NN

CRUA-017.2 (2-6)

12/10/2010

35.6638339

-108.503071

2

6

713R11

Ra-226

0.93 LT

0.43

O

Q.

/g

Arroyo NN

CRUA-018.2 (2-6)

12/10/2010

35.66382

-108.503091

2

6

713R11

Ra-226

2.32 G

0.67

pC

/g

Arroyo NN

CRUA-020.2 (2-6)

12/10/2010

35.663644

-108.502137

2

6

713R11

Ra-226

3.05

0.52

pC

/g

Arroyo NN

CRUA-021.2 (2-6)

12/10/2010

35.6636112

-108.502113

2

6

713R11

Ra-226

2.02 G

0.48

o

Q.

/g

Arroyo NN

CRUA-023.2 (2-6)

12/10/2010

35.66371

-108.501141

2

6

713R11

Ra-226

1.51

0.46

O

Q.

/g

Arroyo NN

CRUA-024.2 (2-6)

12/10/2010

35.6637129

-108.501114

2

6

713R11

Ra-226

1.47

0.42

pC

/g

Arroyo NN

CRUA-026.2 (2-6)

12/10/2010

35.6631118

-108.500015

2

6

713R11

Ra-226

1.56 G

0.59

pC

/g

Arroyo NN

CRUA-026.4 Dup

12/10/2010

35.6631118

-108.500015

2

6

713R11

Ra-226

1.26 G

0.43

o

Q.

/g

Arroyo NN

CRUA-027.2 (2-6)

12/10/2010

35.6631202

-108.499988

2

6

713R11

Ra-226

1.15 G

0.37

pC

/g

Arroyo NN

CRUA-028.2 (2-6)

12/10/2010

35.6628508

-108.499528

2

6

713R11

Ra-226

1.01 G

0.52

pC

/g

Arroyo NN

CRUA-029.2 (2-6)

12/10/2010

35.66287

-108.499521

2

6

713R11

Ra-226

1.53

0.49

pC

/g

Arroyo NN

CRUA-030.2 (2-6)

12/10/2010

35.662884

-108.499488

2

6

713R11

Ra-226

1.63

0.32

o

Q.

/g

Arroyo NN

CRUA-031.2 (2-6)

12/10/2010

35.6621985

-108.499236

2

6

713R11

Ra-226

1.47

0.39

pC

/g

Arroyo NN

CRUA-032.2 (2-6)

12/10/2010

35.6621878

-108.499192

2

6

713R11

Ra-226

1.52

0.39

pC

/g

Arroyo NN

CRUA-033.2 (2-6)

12/10/2010

35.6622016

-108.499186

2

6

713R11

Ra-226

1.61 G

0.53

pC

/g

Arroyo NN

CRUA-034.2 (2-6)

12/10/2010

35.660668

-108.498294

2

6

713R11

Ra-226

1.38

0.46

o

Q.

/g

Arroyo NN

CRUA-034.2 (2-6) Dup

12/10/2010

35.660668

-108.498294

2

6

713R11

Ra-226

0.82 LT

0.44

pC

/g

Arroyo NN

CRUA-035.2 (2-6)

12/10/2010

35.6606763

-108.498291

2

6

713R11

Ra-226

1.12 G

0.46

pC

/g

Arroyo NN

CRUA-036.2 (2-6)

12/10/2010

35.6606681

-108.498278

2

6

713R11

Ra-226

0.66 LT

0.44

pC

/g

Arroyo NN

RWPR-SS-028 (2.5-3)

10/8/2010

35.6638706

-108.503384

2.5

3

713R11

Ra-226

2.2

0.46

o

Q.

/ g

Arroyo NN

RWPR-SS-028 (2.5-3)

10/8/2010

35.6638706

-108.503384

2.5

3

SW6020

URANIUM

1.5

10

mg/kg

Arroyo NN

RWPR-SS-029 (6-9)

10/7/2010

35.6639114

-108.503943

6

9

713R11

Ra-226

1.07

0.53

pCi/g

Arroyo NN

RWPR-SS-029 (6-9)

10/7/2010

35.6639114

-108.503943

6

9

SW6020

URANIUM

2.5

11

mg/kg

Arroyo NN

CRUA-003.3 (6-11)

12/9/2010

35.665741

-108.510352

6

11

713R11

Ra-226

1.93 G

0.6

pCi/g

Arroyo NN

CRPA-007.3 (6-12)

12/11/2010

35.663502

-108.489999

6

12

713R11

Ra-226

1.46 G

0.46

pCi/g

Page 88 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

Arroyo NN

CRUA-007.3 (6-12)

12/9/2010

35.6639899

-108.50663

6

12

713R11

Ra-226

1.71 G

0.58

pCi/g

Arroyo NN

CRUA-030.3 (6-12)

12/10/2010

35.662884

-108.499488

6

12

713R11

Ra-226

1.39

0.33

pCi/g

Arroyo NN

CRUA-030.3 (6-12) Dup

12/10/2010

35.662884

-108.499488

6

12

713R11

Ra-226

1.47

0.46

pCi/g

Arroyo NN

CRPA-004.3 (7-13)

12/11/2010

35.6609489

-108.492682

7

13

713R11

Ra-226

1.45 G

0.47

pCi/g

Arroyo NN

CRPA-010.3 (9-15)

12/11/2010

35.6652361

-108.488896

9

15

713R11

Ra-226

1.95 G

0.52

pCi/g

Arroyo NN

KMA-SS02-0012-0018-01

5/19/2022

35.660713

-108.490604

12

18

SW6020

ALUMINUM

4200

16

mg/kg

Arroyo NN

KMA-SS02-0012-0018-01

5/19/2022

35.660713

-108.490604

12

18

SW6020

ANTIMONY

0.064 J

0.1

mg/kg

Arroyo NN

KMA-SS02-0012-0018-01

5/19/2022

35.660713

-108.490604

12

18

SW6020

ARSENIC

5.6

0.21

mg/kg

Arroyo NN

KMA-SS02-0012-0018-01

5/19/2022

35.660713

-108.490604

12

18

SW6020

BARIUM

75

0.52

mg/kg

Arroyo NN

KMA-SS02-0012-0018-01

5/19/2022

35.660713

-108.490604

12

18

SW6020

BERYLLIUM

0.39

0.052

mg/kg

Arroyo NN

KMA-SS02-0012-0018-01

5/19/2022

35.660713

-108.490604

12

18

SW6020

CADMIUM

0.073 J

0.21

mg/kg

Arroyo NN

KMA-SS02-0012-0018-01

5/19/2022

35.660713

-108.490604

12

18

SW6020

CHROMIUM

4.5

1

mg/kg

Arroyo NN

KMA-SS02-0012-0018-01

5/19/2022

35.660713

-108.490604

12

18

SW6020

COBALT

4.5

0.52

mg/kg

Arroyo NN

KMA-SS02-0012-0018-01

5/19/2022

35.660713

-108.490604

12

18

SW6020

COPPER

5.1

2.1

mg/kg

Arroyo NN

KMA-SS02-0012-0018-01

5/19/2022

35.660713

-108.490604

12

18

SW6020

IRON

15000

21

mg/kg

Arroyo NN

KMA-SS02-0012-0018-01

5/19/2022

35.660713

-108.490604

12

18

SW6020

LEAD

8

0.21

mg/kg

Arroyo NN

KMA-SS02-0012-0018-01

5/19/2022

35.660713

-108.490604

12

18

SW6020

MANGANESE

400

0.79

mg/kg

Arroyo NN

KMA-SS02-0012-0018-01

5/19/2022

35.660713

-108.490604

12

18

SW6020

MOLYBDENUM

0.45

0.21

mg/kg

Arroyo NN

KMA-SS02-0012-0018-01

5/19/2022

35.660713

-108.490604

12

18

SW6020

NICKEL

5.5

2.1

mg/kg

Arroyo NN

KMA-SS02-0012-0018-01

5/19/2022

35.660713

-108.490604

12

18

713R15

Ra-226

0.75 J

0.35

pCi/g

Arroyo NN

KMA-SS02-0012-0018-01

5/19/2022

35.660713

-108.490604

12

18

SW6020

SELENIUM

0.9 J

1

mg/kg

Arroyo NN

KMA-SS02-0012-0018-01

5/19/2022

35.660713

-108.490604

12

18

SW6020

SILVER

0.06 U

0.12

mg/kg

Arroyo NN

KMA-SS02-0012-0018-01

5/19/2022

35.660713

-108.490604

12

18

SW6020

THALLIUM

0.082

0.01

mg/kg

Arroyo NN

KMA-SS02-0012-0018-01

5/19/2022

35.660713

-108.490604

12

18

SW6020

URANIUM

0.56

0.021

mg/kg

Arroyo NN

KMA-SS02-0012-0018-01

5/19/2022

35.660713

-108.490604

12

18

SW6020

VANADIUM

13

0.52

mg/kg

Arroyo NN

KMA-SS02-0012-0018-01

5/19/2022

35.660713

-108.490604

12

18

SW6020

ZINC

32

10

mg/kg

Arroyo NN

CRUA-002.3 (13-19)

12/9/2010

35.6657302

-108.510318

13

19

713R11

Ra-226

0.95 LT

0.55

pC

'9

Arroyo NN

CRPA-U1.3 (14-20)

12/11/2010

35.6675871

-108.486484

14

20

713R11

Ra-226

2.19 G

0.61

pC

/g

Arroyo NN

CRUA-001.3 (14-20)

12/9/2010

35.6657521

-108.510332

14

20

713R11

Ra-226

1.12 G

0.44

o

Q.

/g

Arroyo NN

CRUA-004.3 (14-20)

12/9/2010

35.6654039

-108.509221

14

20

713R11

Ra-226

1.63 G

0.39

pC

'g

Arroyo NN

CRPA-011.3 (15-21)

12/11/2010

35.6652059

-108.488889

15

21

713R11

Ra-226

1.28 G

0.64

pC

/g

Arroyo NN

CRUA-009.3 (16-22)

12/9/2010

35.6639815

-108.506644

16

22

713R11

Ra-226

1.28 G

0.39

pC

/g

Arroyo NN

CRUA-008.3 (18-24)

12/9/2010

35.663979

-108.506614

18

24

713R11

Ra-226

1.75 G

0.56

o

Q.

/g

Arroyo NN

CRPA-005.3 (30-36)

12/11/2010

35.6609379

-108.492681

30

36

713R11

Ra-226

2.66 G

0.58

pC

/g

Arroyo NN

CRPA-012.3 (30-36)

12/11/2010

35.6652252

-108.488869

30

36

713R11

Ra-226

1.21 G

0.57

pC

/g

Arroyo NN

CRPA-013.3 (30-36)

12/11/2010

35.6658514

-108.488413

30

36

713R11

Ra-226

1.27 G

0.57

pC

/g

Arroyo NN

CRPA-013.3 (30-36) Dup

12/11/2010

35.6658514

-108.488413

30

36

713R11

Ra-226

1.06 G

0.65

o

Q.

/g

Arroyo NN

CRUA-005.3 (30-36)

12/9/2010

35.6654016

-108.509154

30

36

713R11

Ra-226

1.17

0.5

o

Q.

/g

Arroyo NN

CRUA-006.3 (30-36)

12/9/2010

35.6653931

-108.509191

30

36

713R11

Ra-226

1.25 G

0.56

pC

/g

Arroyo NN

CRUA-010.3 (30-36)

12/10/2010

35.6643344

-108.505448

30

36

713R11

Ra-226

1.51 G

0.48

pC

/g

Arroyo NN

CRUA-010.3 (30-36) Dup

12/10/2010

35.6643344

-108.505448

30

36

713R11

Ra-226

1.27

0.48

o

Q.

/g

Arroyo NN

CRUA-011.3 (30-36)

12/10/2010

35.66437

-108.505462

30

36

713R11

Ra-226

1.89 G

0.45

o

Q.

/g

Page 89 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

Arroyo NN

CRUA-012.3 (30-36)

12/10/2010

35.664389

-108.505499

30

36

713R11

Ra-226

1.89 G

0.44

O

Q.

/g

Arroyo NN

CRUA-015.3 (30-36)

12/10/2010

35.664094

-108.504211

30

36

713R11

Ra-226

2.66 G

0.5

O

Q.

/ g

Arroyo NN

CRUA-015.4 Dup

12/10/2010

35.664094

-108.504211

30

36

713R11

Ra-226

2.59 G

0.52

pC

/g

Arroyo NN

CRUA-017.3 (30-36)

12/10/2010

35.6638339

-108.503071

30

36

713R11

Ra-226

2.22

0.46

pC

/g

Arroyo NN

CRUA-018.3 (30-36)

12/10/2010

35.66382

-108.503091

30

36

713R11

Ra-226

2.93 G

0.49

o

Q.

/ g

Arroyo NN

CRUA-020.3 (30-36)

12/10/2010

35.663644

-108.502137

30

36

713R11

Ra-226

3.28 G

0.65

O

Q.

/ g

Arroyo NN

CRUA-021.3 (30-36)

12/10/2010

35.6636112

-108.502113

30

36

713R11

Ra-226

1.94 G

0.52

pC

/g

Arroyo NN

CRUA-023.3 (30-36)

12/10/2010

35.66371

-108.501141

30

36

713R11

Ra-226

2.45

0.43

pC

/g

Arroyo NN

CRUA-024.3 (30-36)

12/10/2010

35.6637129

-108.501114

30

36

713R11

Ra-226

1.95 G

0.43

o

Q.

/ g

Arroyo NN

CRUA-026.3 (30-36)

12/10/2010

35.6631118

-108.500015

30

36

713R11

Ra-226

2.82 G

0.54

O

Q.

/ g

Arroyo NN

CRUA-027.3 (30-36)

12/10/2010

35.6631202

-108.499988

30

36

713R11

Ra-226

1.41 G

0.4

pC

/g

Arroyo NN

CRUA-028.3 (30-36)

12/10/2010

35.6628508

-108.499528

30

36

713R11

Ra-226

1.42 G

0.43

pC

/g

Arroyo NN

CRUA-029.3 (30-36)

12/10/2010

35.66287

-108.499521

30

36

713R11

Ra-226

1.54

0.45

o

Q.

/ g

Arroyo NN

CRUA-031.3 (30-36)

12/10/2010

35.6621985

-108.499236

30

36

713R11

Ra-226

2

0.57

O

Q.

/ g

Arroyo NN

CRUA-032.3 (30-36)

12/10/2010

35.6621878

-108.499192

30

36

713R11

Ra-226

2.06

0.46

pC

/g

Arroyo NN

CRUA-033.3 (30-36)

12/10/2010

35.6622016

-108.499186

30

36

713R11

Ra-226

3.05 G

0.64

pC

/g

Arroyo NN

CRUA-034.3 (30-36)

12/10/2010

35.660668

-108.498294

30

36

713R11

Ra-226

1.62

0.45

o

Q.

/ g

Arroyo NN

CRUA-035.3 (30-36)

12/10/2010

35.6606763

-108.498291

30

36

713R11

Ra-226

1.64

0.44

O

Q.

/ g

Arroyo NN

CRUA-036.3 (30-36)

12/10/2010

35.6606681

-108.498278

30

36

713R11

Ra-226

2.09 G

0.54

pC

/g

Arroyo UNC

CRPA-001.1 (0-2)

12/11/2010

35.6565449

-108.496193

0

2

713R11

Ra-226

0.79 LT

0.44

pC

/g

Arroyo UNC

CRPA-001.1 (0-2) Dup

12/11/2010

35.6565449

-108.496193

0

2

713R11

Ra-226

0.59 LT

0.46

o

Q.

/ g

Arroyo UNC

CRPA-002.1 (0-2)

12/11/2010

35.6565366

-108.4962

0

2

713R11

Ra-226

1.07 G

0.37

O

Q.

/ g

Arroyo UNC

CRPA-002.1 (0-2) Dup

12/11/2010

35.6565366

-108.4962

0

2

713R11

Ra-226

0.72 LT.TI

0.43

pC

/g

Arroyo UNC

CRPA-003.1 (0-2)

12/11/2010

35.6565341

-108.496166

0

2

713R11

Ra-226

0.84 LT.TI

0.56

pC

/g

Arroyo UNC

CRUA-037.1 (0-2)

12/10/2010

35.6566466

-108.496686

0

2

713R11

Ra-226

0.79 LT

0.48

o

Q.

/ g

Arroyo UNC

CRUA-038.1 (0-2)

12/10/2010

35.6566744

-108.496632

0

2

713R11

Ra-226

0.74 LT

0.31

pC

/g

Arroyo UNC

CRUA-039.1 (0-2)

12/10/2010

35.6566965

-108.496605

0

2

713R11

Ra-226

0.58 LT,G,TI

0.5

pc

/g

Arroyo UNC

KMA-SS01-0000-0003-01

5/19/2022

35.659642

-108.493534

0

3

SW6020

ALUMINUM

4400

15

mg/kg

Arroyo UNC

KMA-SS01-0000-0003-01

5/19/2022

35.659642

-108.493534

0

3

SW6020

ANTIMONY

0.055 J

0.099

mg/kg

Arroyo UNC

KMA-SS01-0000-0003-01

5/19/2022

35.659642

-108.493534

0

3

SW6020

ARSENIC

4.6

0.2

mg/kg

Arroyo UNC

KMA-SS01-0000-0003-01

5/19/2022

35.659642

-108.493534

0

3

SW6020

BARIUM

48

0.5

mg/kg

Arroyo UNC

KMA-SS01-0000-0003-01

5/19/2022

35.659642

-108.493534

0

3

SW6020

BERYLLIUM

0.37

0.05

mg/kg

Arroyo UNC

KMA-SS01-0000-0003-01

5/19/2022

35.659642

-108.493534

0

3

SW6020

CADMIUM

0.054 J

0.2

mg/kg

Arroyo UNC

KMA-SS01-0000-0003-01

5/19/2022

35.659642

-108.493534

0

3

SW6020

CHROMIUM

4.9

0.99

mg/kg

Arroyo UNC

KMA-SS01-0000-0003-01

5/19/2022

35.659642

-108.493534

0

3

SW6020

COBALT

4.4

0.5

mg/kg

Arroyo UNC

KMA-SS01-0000-0003-01

5/19/2022

35.659642

-108.493534

0

3

SW6020

COPPER

4.7

2

mg/kg

Arroyo UNC

KMA-SS01-0000-0003-01

5/19/2022

35.659642

-108.493534

0

3

SW6020

IRON

13000

20

mg/kg

Arroyo UNC

KMA-SS01-0000-0003-01

5/19/2022

35.659642

-108.493534

0

3

SW6020

LEAD

7.5

0.2

mg/kg

Arroyo UNC

KMA-SS01-0000-0003-01

5/19/2022

35.659642

-108.493534

0

3

SW6020

MANGANESE

240

0.74

mg/kg

Arroyo UNC

KMA-SS01-0000-0003-01

5/19/2022

35.659642

-108.493534

0

3

SW6020

MOLYBDENUM

0.28

0.2

mg/kg

Arroyo UNC

KMA-SS01-0000-0003-01

5/19/2022

35.659642

-108.493534

0

3

SW6020

NICKEL

5.5

2

mg/kg

Arroyo UNC

KMA-SS01-0000-0003-01

5/19/2022

35.659642

-108.493534

0

3

713R15

Ra-226

0.85 J

0.4

pCi/g

Page 90 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Exposure
Unit

Sample ID

Sample
Date

Latitude

Longitude

Sample
Top
Depth
(inches
bgs)

Sample
Bottom
Depth
(inches
bgs)

Analytical
Method

Analyte

Result and
Qualifier

Reporting
Limit

Unit

Arroyo UNC

KMA-SS01-0000-0003-01

5/19/2022

35.659642

-108.493534

0

3

SW6020

SELENIUM

1.3

0.99

mg/kg

Arroyo UNC

KMA-SS01-0000-0003-01

5/19/2022

35.659642

-108.493534

0

3

SW6020

SILVER

0.057 U

0.11

mg/kg

Arroyo UNC

KMA-SS01-0000-0003-01

5/19/2022

35.659642

-108.493534

0

3

SW6020

THALLIUM

0.091

0.0099

mg/kg

Arroyo UNC

KMA-SS01-0000-0003-01

5/19/2022

35.659642

-108.493534

0

3

SW6020

URANIUM

0.53

0.02

mg/kg

Arroyo UNC

KMA-SS01-0000-0003-01

5/19/2022

35.659642

-108.493534

0

3

SW6020

VANADIUM

12

0.5

mg/kg

Arroyo UNC

KMA-SS01-0000-0003-01

5/19/2022

35.659642

-108.493534

0

3

SW6020

ZINC

30

9.9

mg/kg

Arroyo UNC

CRPA-001.2 (2-6)

12/11/2010

35.6565449

-108.496193

2

6

713R11

Ra-226

1.36 G

0.55

pCi/g

Arroyo UNC

CRPA-002.2 (2-6)

12/11/2010

35.6565366

-108.4962

2

6

713R11

Ra-226

1.02 G

0.6

pCi/g

Arroyo UNC

CRPA-003.2 (2-6)

12/11/2010

35.6565341

-108.496166

2

6

713R11

Ra-226

1.55 G

0.52

pCi/g

Arroyo UNC

CRUA-037.2 (2-6)

12/10/2010

35.6566466

-108.496686

2

6

713R11

Ra-226

1.09 G

0.54

pCi/g

Arroyo UNC

CRUA-037.4 Dup

12/10/2010

35.6566466

-108.496686

2

6

713R11

Ra-226

0.77 LT,G

0.46

pCi/g

Arroyo UNC

CRUA-038.2 (2-6)

12/10/2010

35.6566744

-108.496632

2

6

713R11

Ra-226

0.68 LT

0.49

pCi/g

Arroyo UNC

CRUA-039.2 (2-6)

12/10/2010

35.6566965

-108.496605

2

6

713R11

Ra-226

0.86 LT,G,TI

0.5

pCi/g

Arroyo UNC

KMA-SS01 -0012-0018-01

5/19/2022

35.659642

-108.493534

12

18

SW6020

ALUMINUM

4700

16

mg/kg

Arroyo UNC

KMA-SS01 -0012-0018-01

5/19/2022

35.659642

-108.493534

12

18

SW6020

ANTIMONY

0.067 J

0.1

mg/kg

Arroyo UNC

KMA-SS01 -0012-0018-01

5/19/2022

35.659642

-108.493534

12

18

SW6020

ARSENIC

4.8

0.21

mg/kg

Arroyo UNC

KMA-SS01 -0012-0018-01

5/19/2022

35.659642

-108.493534

12

18

SW6020

BARIUM

62

0.52

mg/kg

Arroyo UNC

KMA-SS01 -0012-0018-01

5/19/2022

35.659642

-108.493534

12

18

SW6020

BERYLLIUM

0.4

0.052

mg/kg

Arroyo UNC

KMA-SS01 -0012-0018-01

5/19/2022

35.659642

-108.493534

12

18

SW6020

CADMIUM

0.055 J

0.21

mg/kg

Arroyo UNC

KMA-SS01 -0012-0018-01

5/19/2022

35.659642

-108.493534

12

18

SW6020

CHROMIUM

5

1

mg/kg

Arroyo UNC

KMA-SS01 -0012-0018-01

5/19/2022

35.659642

-108.493534

12

18

SW6020

COBALT

3.9

0.52

mg/kg

Arroyo UNC

KMA-SS01 -0012-0018-01

5/19/2022

35.659642

-108.493534

12

18

SW6020

COPPER

5.4

2.1

mg/kg

Arroyo UNC

KMA-SS01 -0012-0018-01

5/19/2022

35.659642

-108.493534

12

18

SW6020

IRON

15000

21

mg/kg

Arroyo UNC

KMA-SS01 -0012-0018-01

5/19/2022

35.659642

-108.493534

12

18

SW6020

LEAD

7.5

0.21

mg/kg

Arroyo UNC

KMA-SS01 -0012-0018-01

5/19/2022

35.659642

-108.493534

12

18

SW6020

MANGANESE

280

0.78

mg/kg

Arroyo UNC

KMA-SS01 -0012-0018-01

5/19/2022

35.659642

-108.493534

12

18

SW6020

MOLYBDENUM

0.28

0.21

mg/kg

Arroyo UNC

KMA-SS01 -0012-0018-01

5/19/2022

35.659642

-108.493534

12

18

SW6020

NICKEL

5.8

2.1

mg/kg

Arroyo UNC

KMA-SS01 -0012-0018-01

5/19/2022

35.659642

-108.493534

12

18

713R15

Ra-226

0.82 J

0.61

pCi/g

Arroyo UNC

KMA-SS01 -0012-0018-01

5/19/2022

35.659642

-108.493534

12

18

SW6020

SELENIUM

0.91 J

1

mg/kg

Arroyo UNC

KMA-SS01 -0012-0018-01

5/19/2022

35.659642

-108.493534

12

18

SW6020

SILVER

0.059 U

0.12

mg/kg

Arroyo UNC

KMA-SS01 -0012-0018-01

5/19/2022

35.659642

-108.493534

12

18

SW6020

THALLIUM

0.086

0.01

mg/kg

Arroyo UNC

KMA-SS01 -0012-0018-01

5/19/2022

35.659642

-108.493534

12

18

SW6020

URANIUM

0.62

0.021

mg/kg

Arroyo UNC

KMA-SS01 -0012-0018-01

5/19/2022

35.659642

-108.493534

12

18

SW6020

VANADIUM

13

0.52

mg/kg

Arroyo UNC

KMA-SS01 -0012-0018-01

5/19/2022

35.659642

-108.493534

12

18

SW6020

ZINC

33

10

mg/kg

Arroyo UNC

CRPA-001.3 (30-36)

12/11/2010

35.6565449

-108.496193

30

36

713R11

Ra-226

1.17 G

0.61

pC

'9

Arroyo UNC

CRPA-001.4 Dup

12/11/2010

35.6565449

-108.496193

30

36

713R11

Ra-226

0.96 LT,G

0.53

pC

/g

Arroyo UNC

CRPA-002.3 (30-36)

12/11/2010

35.6565366

-108.4962

30

36

713R11

Ra-226

1.01 G

0.55

o

Q.

/g

Arroyo UNC

CRPA-003.3 (30-36)

12/11/2010

35.6565341

-108.496166

30

36

713R11

Ra-226

1.2 G

0.45

O

Q.

/ g

Arroyo UNC

CRUA-037.3 (30-36)

12/10/2010

35.6566466

-108.496686

30

36

713R11

Ra-226

1.83 G

0.36

pC

/g

Arroyo UNC

CRUA-038.3 (30-36)

12/10/2010

35.6566744

-108.496632

30

36

713R11

Ra-226

0.69 LT,G

0.5

pC

/g

Arroyo UNC

CRUA-039.3 (30-36)

12/10/2010

35.6566965

-108.496605

30

36

713R11

Ra-226

0.57 LT,G

0.51

o

Q.

/g

Page 91 of 92


-------
Attachment C-1. Data Used in the Risk Assessment

Notes:

bgs	Below ground surface

CR1	Quivira Church Rock Mine No. 1

CR1E	Quivira Church Rock Mine No. 1 East

G	Sample density differs by more than 15 percent of the laboratory control sample density

J	Estimated concentration

Kerr-McGee Kerr-McGee Corporation

KMP	Kerr-McGee Ponds

LT	Less than

M3	The requested minimum detectable concentration was not met, but the reported activity is greater than the reported minimum detectable concentration

mg/kg	Milligram per kilogram

NN	Navajo Nation

pCi/g	Picocurie per gram

Ra-226	Radium-226

Tl	Nuclide identification is tentative

U	Not detected

UJ	Not detected; the detection limit is estimated

UNC	United Nuclear Corporation

Page 92 of 92


-------
APPENDIX D

ENVIRONMENTAL METRICS ANALYSIS


-------
Table D-1. Environmental Metrics Assessment Summary

Alternative

Energy Use1

Air
Pollutants2

Water Use3

Water
Quality
Impacts4

Ecosystem
Impact5

Materials6

Overall
Greenness
Score7

Alternative 1: No Action

8

8

8

8

8

8

48

Alternative 2: Consolidate and Cap All Waste On Site.

5

5

4

4

5

5

28

Alternative 3: Dispose of All Mine Waste Off Site at
Red Rock Disposal Facility.

3

3

2

3

4

6

21

Alternative 4: Dispose of All Mine Waste Off Site at
RCRA C or LLRW Facility.

1

1

1

1

1

6

11

Notes:

A rating system of 1 through 8 is used where 8 is best and 1 is worst.

Total energy use and percentage of renewable energy

2	Air pollutants and greenhouse gas emissions

3	Water use

4	Impacts on water resources

5	Protecting ecosystem services

6	Materials management and waste reduction

7	Overall greenneess score was calculated by summing the score in each of the six core elements.
LLRW Low-level radioactive waste

RCRA	Resource Conservation and Recovery Act

Page 1 of 1


-------
Table D-2. Estimated Risk of Injuries and Fatalities and Greenhouse Gas Emissions from Onsite and Offsite Trucking

Alternative

Truckloads of
Waste

Miles Round Trip
to Transport
Waste

Truckloads of
Offsite Fill

Miles Round Trip to
Import Fill and
Cover

Water Truck
Mileage

Total Miles

Estimated Injuries
from Offsite
Trucking1

Estimated Fatalities
from Offsite
Trucking1

Estimated Greenhouse
Gas Emissions from
Offsite Trucking2
(metric tons C02e)

1: No Action

0

0

0

0

0

0

0

0

0

2: Consolidate and Cap All Mine Waste On
Site

57,140

6

22,370

5

236,600

691,290

0.224

0.0104

1,200

3: Dispose of All Mine Waste Off Site at Red
Rocks Disposal Facility

76,180

88

18,330

5

266,900

7,062,390

2.29

0.1066

12,500

4: Dispose of All Mine Waste Off Site at a
RCRA C or LLRW Facility

76,180

1,250

18,330

5

987,900

96,304,550

31.20

1.4542

170,900

Notes:



















1 A rate of 32.4 injuries and 1.51 fatalities per 100 million large truck miles traveled was calculated as shown below using data from 2011 to 2020 from the National Center for Statistics and Analysis (2022).













Injury Rate per

Fatality Rate per











People Killed in

Number of Large



100 Million Large-

100 Million Large-











Crashes Involving

Trucks Involved in

Large-Truck Miles

Truck-Miles

Truck-Miles









Year

Large Trucks

Injuries

Traveled (millions)

Traveled

Traveled









2011

3,633

62,534

267,594

23.37

1.36









2012

3,825

76,621

269,207

28.46

1.42









2013

3,921

73,089

275,017

26.58

1.43









2014

3,749

88,473

279,132

31.70

1.34









2015

4,075

87,307

279,844

31.20

1.46









2016

4,562

102,080

287,895

35.46

1.58









2017

4,805

106,733

297,593

35.87

1.61









2018

4,909

112,253

304,864

36.82

1.61









2019

5,033

118,527

300,050

39.50

1.68









2020

4,842

106,902

302,141

35.38

1.60















32.43 injuries per 100 million miles traveled









Average from 201

1 - 2020



1.51 fatalities per 100 million miles traveled







2 Metric tons of C02e per large truck mile traveled was calculated as shown below using data and methods from the U.S. Environmental Protection Agency (2022) Greenhouse Gases Equivalencies Calculator. Carbon dioxide emissions per gallon of

diesel fuel was obtained from the U.S. Energy Information Administration (2022). Mileage for combination trucks (Classification Types 8-13) was obtained from Federal Highway Administration (2018) highway statistics based on 2012 and 2013 data.

22.38 lb C02/gallon diesel fuel X

1 C02e

X

1

0.001775

metric tons C02e

2,205 lb C02/metric ton C02

0.986 C02

5.8 miles/gallon

miles traveled

C02e Carbon dioxide equivalent

LLRW Low-level radioactive waste

RCRA Resource Conservation and Recovery Act

References:

Federal Flighway Administration. 2018. "Annual Vehicle Distance Traveled in Miles and Related Data - 2013 by Flighway Category and Vehicle Type: Table M-1Revised May. https://www.fhwa.dot.gov/policyinformation/statistics/2013/vm1 .cfm.
National Center for Statistics and Analysis. 2022. "Large Trucks: 2020 Data." Traffic Safety Facts. Report No. DOT FIS 813 286. National Flighway Traffic Safety Administration. April. https://crashstats.nhtsa.dot.gov/Api/Public/ViewPublication/813286.
U.S. Energy Information Administration. 2022. "Frequently Asked Questions: Flow Much Carbon Dioxide Is Produced from U.S. Gasoline and Diesel Fuel Consumption?" Last updated May 10. https://www.eia.gov/tools/faqs/faq.php?id=307&t=11.
U.S. Environmental Protection Agency. 2022. "Greenhouse Gases Equivalencies Calculator - Calculations and References." Last updated June 23. https://www.epa.gov/energy/greenhouse-gases-equivalencies-calculator-calculations-and-references.

Page 1 of 1


-------
APPENDIX E
COST ANALYSIS


-------
Table E-1. Alternative 2

Cost Estimate Summary

Site: Quivira Tronox Mines Site











Location: Navajo Nation, New Mexico











Phase: Feasibility Study (-30% to +50%)





Alternative 2. Consolidate and Cap All Mine Waste On Site

Base Year: 2023











Date: August 2023











Direct Capital Costs

Description



Quantity

Unit

Unit Cost

Total Cost

Field Overhead and Oversight Costs:

Field Overhead and Oversight



35

Months

36,715.18

$1,285,000

Mobilization/Demobilization



8

Each

54,148.02

$433,200

Travel, Lodgingand Per Diem



525

Ea Person per MO

5,505

$2,890,100

Voluntary Alternative Housing



1

Lump Sum

2,000,000

$2,000,000

SUBTOTAL









$6,608,000

General Site Work Costs:

Fence Construction/Repair - Equipment Storage Area



1,000

LF

$28.24

$28,200

Clearing and Grubbing



63

AC

$1,331.54

$83,700

Land Surveying



63

AC

$697.34

$43,800

SUBTOTAL









$156,000

Earthwork Costs:

Excavation of Mine Waste (Excavate and Load into Trucks)



1,005,500

BCY

$2.16

$2,173,900

Excavation of Mine Waste - Dozer Scraping (25% of Volume, In Addition to Excavator)

251,375

BCY

$2.68

$673,700

General Backfill from Off-Site (Import, Place, Compact)



109,951

LCY

$30.69

$3,374,800

General Backfill from On-Site (Import, Place, Compact)



256,551

LCY

$12.11

$3,107,400

Soil Cap



64,533

CCY

$34.10

$2,200,800

Site Restoration



63

AC

$23,807.26

$1,496,500

Erosion and Sediment Control



251

AC-YR

$735.10

$184,800

Dust Control



696

Day

$7,907.84

$5,502,000

Pipeline Arroyo Sloping, Armoring, and Road Rebuilding



1

Lump Sum

$293,147.53

$293,148

Shaft Closure



2

Each

$109,522.20

$219,044

Adit Closure



2

Each

$50,000

$100,000

SUBTOTAL









$19,326,000

Transportation and Disposal Costs:

Hauling to CR-2, Placing, Compaction, and Covering



1,256,875

LCY

$11.52

$14,479,200

Dust Control



667

Day

$7,907.84

$5,277,500

SUBTOTAL









$19,756,700

Total Direct Capital Costs (Rounded to Nearest $1,000)









$45,847,000

Indirect Capital Costs

Description



%





Total Cost

Permitting/Planning/lnstitutional Controls



4%





$1,254,712

Professional/Tech. - Project Management



5%





$1,568,390

Professional/Tech. - Remedial Design



5%





$1,568,390

Professional/Tech. - Construction Mgmt.



6%





$1,882,068

Total Indirect Capital Costs (Rounded to Nearest $1,000)









$6,274,000

Total Capital Costs

Description



%





Total Cost

Subtotal Capital Costs









$52,121,000

Contingency Allowance



15%





$7,758,150

Total Capital Cost (Rounded to Nearest $1,000)









$59,879,000

Maintenance Costs

Description



%





Total Cost

Present Worth of 10, 30, and 100 Years Maintenance Costs Depending on
to the Nearest $1,000)

Activity (Rounded

7.0%





$1,377,000

Contingency Allowance (25%)



25%





$344,300

Total Present Worth Maintenance Costs (Rounded to Nearest $1,000)









$1,721,000

Total Cost (Rounded to Nearest $1,000)









$61,600,000

Notes:

xl.25 Expansion Factor Used for all LCY quantities
x0.9 Compaction Factor Used for all CCY quantities

AC

Acre

BCY

Bank Cubic Yard

CCY

Compacted Cubic Yard

CF

Cubic Foot

EA

Each

LCY

Loose Cubic Yard

LF

Linear Foot

MO

Month

YR

Year

Page 1 of 1


-------
Table E-2. Alternative 2 Cost Estimating Assumptions

Alternative 2 Assumptions

Mobilization/Demobilization



Total Time (Days)

3

Clearing and Grubbing



Total Acres

63



Daily Output

4



Total Clearing Time (Days)

16

Hauling



Total Material (CY)

1,321,408



Daily Output (CY/trip)

22



Trip/Day/Truck

15



# of Trucks

6



Total Time (Days)

667

Site Restoration



Total Area (Acres)

63



Volume per Acre of Imported Borrow (CY/Acre)

807



Daily Output for Importing Borrow (CY/Day/Dozer)

1,000



# of Dozers

4



Total Site Restoration Time (Days)

13

Inspection and Maintenance



Total Cap and Restoration Area Requiring Regrading (SY)

48,400



Total Cap and Restoration Area Requiring Hydroseeding Revegetation (SY)

304,242



Duration of Inspection & Maintenance of Cap (years)

100



Duration of Inspection & Maintenance of Restored Excavation Areas (years)

30



Present Worth Interest Rate (%)

7.0%



Area of repository cap requiring regrading each year (0-10) (%)

10%



Area of repository cap requiring regrading each year (10-30) (%)

5%



Area of repository cap requiring revegetation each year (0-10)(%)

25%



Area of repository cap requiring revegetation each year (10-30)(%)

10%



Areas not capped of requiring regrading each year (0-10) (%)

10%



Areas not capped of requiring regrading each year (10-30) (%)

5%



Areas not capped requiring revegetation each year (0-10) (%)

25%



Areas not capped requiring revegetation each year (10-30) (%)

10%



Equipment mobilization cost for annual maintenance ($)

666

Total Job Duration (Excluding Maintenance)



Working Days (Assume 240 days/year)

699



Working Months

35



Actual 9 Months (Assume 180 working days/year) to Account for Weather

47



Working Years

2.9



Actual Years (Assume 180 working days/year)

3.9



Total Job Duration

4 Years

Notes:





CY Cubic Yard





MO Month





SY Square Yard





Page 1 of 1


-------
Table E-3. Alternative 3

Cost Estimate Summary

Site: Quivira Tronox Mines Site









Location: Navajo Nation, New Mexico
Phase: Feasibility Study (-30% to +50%)
Base Year: 2023



Alternative 3. Dispose of All Mine Waste Off Site at Red Rock
Disposal Facility

Date: August 2023









Direct Capital Costs

Description

Quantity

Unit

Unit Cost

Total Cost

Field Overhead and Oversight Costs:

Field Overhead and Oversight

42

MO

36,715

$1,542,000

Mobilization/Demobilization

10

EA

54,148

$541,500

Travel, Lodgingand Per Diem

630

Ea Person per MO

5,505

$3,468,200

Voluntary Alternative Housing

1

Lump Sum

2,000,000

$2,000,000

SUBTOTAL







$7,552,000

General Site Work Costs:

Fence Construction/Repair - Equipment Storage Area

1,000

LF

$28.24

$28,200

Clearingand Grubbing

63

AC

$1,332

$83,700

Land Surveying

63

AC

$697

$43,800

SUBTOTAL







$156,000

Earthwork Costs:

Excavation of Mine Waste (Excavate and Load into Trucks)

1,005,500

BCY

$2.16

$2,173,900

Excavation of Mine Waste - Dozer Scraping (25% of Volume, In Addition to Excavator) 251,375

BCY

$2.68

$673,700

General Backfill from Off-Site (Import, Place, Compact)

109,951

LCY

$30.69

$3,374,800

General Backfill from On-Site (Import, Place, Compact)

256,551

LCY

$12.11

$3,107,400

Site Restoration

63

AC

$23,807

$1,496,500

Erosion and Sediment Control

314

AC-YR

$735

$231,000

Dust Control

822

Day

$3,954

$3,249,600

Shaft Closure

2

Each

$109,522

$219,000

Adit Closure

2

Each

$50,000

$100,000

SUBTOTAL







$14,626,000

Transportation and Disposal Costs:

Hauling to Red Rocks Disposal Facility

1,256,875

LCY

$12.90

$16,213,700

Disposal of Contaminated Soil - Red Rocks Disposal Facility

1,256,875

LCY

$82.50

$103,692,200

Dust Control

793

Day

$7,908

$6,274,700

SUBTOTAL







$126,180,600

Total Direct Capital Costs (Rounded to Nearest $1,000)







$148,515,000

Indirect Capital Costs

Description

%





Total Cost

Permitting/Planning/lnstitutional Controls

4%





$1,792,912

Professional/Technician - Project Management

5%





$2,241,140

Professional/Technician - Remedial Design

5%





$2,241,140

Professional/Technician - Construction Management.

6%





$2,689,368

Total Indirect Capital Costs (Rounded to Nearest $1,000)







$8,965,000

Total Capital Costs

Description

%





Total Cost

Subtotal Capital Costs







$157,480,000

Contingency Allowance

15%





$23,622,000

Total Capital Cost (Rounded to Nearest $1,000)







$181,102,000

Maintenance Costs

Description







Total Cost

Present Worth of 10 and 30 Years Maintenance Costs Depending
the Nearest $1,000)

on Activity (Rounded to





$1,148,000

Contingency Allowance

25%





$287,000

Total Present Worth Maintenance Costs (Rounded to Nearest $1,000)







$1,435,000

Total Cost (Rounded to Nearest $1,000)







$182,537,000

xl.25 Expansion Factor Used for all LCY quantities
x0.9 Compaction Factor Used for all CCY quantities

AC

Acre

BCY

Bank Cubic Yard

CCY

Compacted Cubic Yard

CF

Cubic Foot

EA

Each

LCY

Loose Cubic Yard

LF

Linear Foot

MO

Month

YR

Year

Page 1 of 1


-------
Table E-4. Alternative 3 Cost Estimating Assumptions

Alternative 3 Assumptions

Mobilization/Demobilization



Total Time (Days)

3.00

Clearing and Grubbing



Total Acres

63



Daily Output

4



Total Clearing Time (Days)

15.7

Hauling



Total Material (CY)

1,256,875



Daily Output (CY/trip)

17



Trip/Day/Truck

4



# of Trucks

24



Total Time (Days)

793

Site Restoration



Total Area (Acres)

63



Volume per Acre of Imported Borrow (CY/Acre)

807



Daily Output for Importing Borrow (CY/Day/Dozer)

1,000



# of Dozers

4



Total Site Restoration Time (Days)

12.7

Inspection and Maintenance



Total Restored Excavation Area Requiring Regrading (SY)

304,242



Total Restored Excavation Area Requiring Hydroseeding Revegetation (SY)

304,242



Duration of Inspection & Maintenance of Restored Excavation Areas (years)

30



Present Worth Interest Rate (%)

7.0%



Areas requiring regrading each year (0-10) (%)

10%



Areas requiring regrading each year (10-30) (%)

5%



Areas requiring revegetation each year (0-10) (%)

25%



Areas requiring revegetation each year (10-30) (%)

10%



Equipment mobilization cost for annual maintenance ($)

666

Total Job Duration (Excluding Maintenance)



Working Days (Assume 240 days/year)

825



Working Months

42



Actual 9 Months (Assume 180 working days/year) to Account for Weather

56



Working Years

3.4



Actual Years (Assume 180 working days/year)

4.6



Total Job Duration

4 Years 7 Months

Notes:





CY Cubic Yard





MO Month





SY Square Yard





Page 1 of 1


-------
Table E-5. Alternative 4

Cost Estimate Summary

Site: Quivira Tronox Mines Site











Location: Navajo Nation, New Mexico





Alternative 4. Dispose of All Mine Waste Off Site at a Resource

Phase: Feasibility Study (-30% to +50%)





Conservation and Recovery Act C or Low-Level Radioactive Waste

Base Year: 2023







Facility



Date: August 2023











Direct Capital Costs

Description



Quantity

Unit

Unit Cost

Total Cost

Field Overhead and Oversight Costs:

Field Overhead and Oversight



154

MO

36,715

$5,654,100

Mobilization/Demobilization



36

EA

54,148

$1,949,300

Travel, Lodgingand Per Diem



2,310

Ea Person per MO

5,505

$12,716,600

Voluntary Alternative Housing



1

Lump Sum

2,000,000

$2,000,000

SUBTOTAL









$22,320,000

General Site Work Costs:

Fence Construction/Repair - Equipment Storage Area



1,000

LF

$28.24

$28,200

Clearingand Grubbing



63

AC

$1,332

$83,700

Land Surveying



63

AC

$697

$43,800

SUBTOTAL









$156,000

Earthwork Costs:

Excavation of Mine Waste (Excavate and Load into Trucks)



1,005,500

BCY

$2.16

$2,173,900

Excavation of Mine Waste - Dozer Scraping (25% of Volume, In Addition to Excavator) 251,375

BCY

$2.68

$673,700

General Backfill from Off-Site (Import, Place, Compact)



109,951

LCY

$30.69

$3,374,800

General Backfill from On-Site (Import, Place, Compact)



256,551

LCY

$12.11

$3,107,400

Site Restoration



63

AC

$23,807

$1,496,500

Erosion and Sediment Control



1,131

AC-YR

$735

$831,800

Dust Control



3,075

Day

$3,954

$12,159,700

Shaft Closure



2

EA

$109,522

$219,000

Adit Closure



2

EA

$50,000

$100,000

SUBTOTAL









$24,137,000

Transportation and Disposal Costs:











Hauling to Clean Harbors Facility, Deer Trail, CO



1,256,875

LCY

$180

$226,237,500

Disposal Contaminated Soil at Clean Harbors Facility, Deer Trail, CO

1,256,875

LCY

$105

$131,971,900

Dust Control



3,047

Day

$7,908

$24,094,900

SUBTOTAL









$382,304,300

Total Direct Capital Costs (Rounded to Nearest $1,000)









$428,917,000

Indirect Capital Costs

Description



%





Total Cost

Permitting/Planning/lnstitutional Controls



4%





$11,877,804

Professional/Technician - Project Management



5%





$14,847,255

Professional/Technician - Remedial Design



5%





$14,847,255

Professional/Technician - Construction Management



6%





$17,816,706

Total Indirect Capital Costs (Rounded to Nearest $1,000)









$59,389,000

Total Capital Costs

Description



%





Total Cost

Subtotal Capital Costs









$488,306,000

Contingency Allowance



15%





$73,245,900

Total Capital Cost (Rounded to Nearest $1,000)









$561,552,000

Maintenance Costs

Description



%





Total Cost

Present Worth of 10 and 30 Years Maintenance Costs Depending
the Nearest $1,000)

on Activity (Rounded to





$1,148,000

Contingency Allowance



25%





$287,000

Total Present Worth Maintenance Costs (Rounded to Nearest $1,000)







$1,435,000

Total Cost (Rounded to Nearest $1,000)









$562,987,000

Notes:

xl.25 Expansion Factor Used for all LCY quantities
x0.9 Compaction Factor Used for all CCY quantities

AC

Acre

BCY

Bank Cubic Yard

CCY

Compacted Cubic Yard

CF

Cubic Foot

EA

Each

LCY

Loose Cubic Yard

LF

Linear Foot

MO

Month

YR

Year

Page 1 of 1


-------
Table E-6. Alternative 4 Cost Estimating Assumptions

Alternative 4 Assumptions

Mobilization/Demobilization



Total Time (Days)

3.00

Clearing and Grubbing



Total Acres

63



Daily Output

4



Total Clearing Time (Days)

15.7

Hauling



Total Material (CY)

1,256,875



Daily Output (CY/trip)

25



Trip/Day/Truck

17



Total Time (Days)

3,047

Site Restoration



Total Area (Acres)

63



Volume per Acre of Imported Borrow (CY/Acre)

807



Daily Output for Importing Borrow (CY/Day/Dozer)

1,000



# of Dozers

4



Total Site Restoration Time (Days)

12.7

Inspection and Maintenance



Total Restored Excavation Area Requiring Regrading (SY)

304,242



Total Restored Excavation Area Requiring Hydroseeding Revegetation (SY)

304,242



Duration of Inspection & Maintenance of Restored Excavation Areas (years)

30



Present Worth Interest Rate (%)

7.0%



Areas requiring regrading each year (0-10) (%)

10%



Areas requiring regrading each year (10-30) (%)

5%



Areas requiring revegetation each year (0-10) (%)

25%



Areas requiring revegetation each year (10-30) (%)

10%



Equipment mobilization cost for annual maintenance ($)

666

Total Job Duration (Excluding Maintenance)



Working Days (Assume 240 days/year)

3,079



Working Months

154



Actual 9 Months (Assume 180 working days/year) to Account for Weather

205



Working Years

12.8



Actual Years (Assume 180 working days/year)

17.1



Total Job Duration

17 Years 1 Month

Notes:





CY Cubic Yard





MO Month





SY Square Yard





Page 1 of 1


-------
Table E-7. Unit Cost Breakdown

Cost Item

Cost Source

Unit Cost

Unit

Description

Support Structures





$264.86



Office trailer, furnished, rent per month, 32 foot x 8 foot,

015213200350







excluding hookups

Storage Boxes

015213201250

$95.73

Month

Storage boxes, rent per month, 20 foot x 8 foot

Field Office Lights/HVAC

015213400160

$177.57

Month

Field office expense, field office lights & HVAC

Telephone/internet

015213400140

$95.23

Month

Field office expense, telephone bill; average bill/month, incl.





long distance

Portable Toilets

015433406410

$220.92

Month

Rent toilet portable chemical

Field Office Equipment

015213400100

$248.99

Month

Field office expense, office equipment rental, average

Field Office Supplies

015213400120

$98.70

Month

Field office expense, office supplies, average

Trash

Engineering Estimate

$435.00

Month

No markup









1 @ $l,250/month MultiRAE Pro Pumped 10.6 electron volt

Air Monitoring Equipment Rental CR-1

Vendor Quote

$1,975.00

Month

and 1 @ $725/month SKC Particulate Monitor (Field









Environmental Instruments published quote)









1 @ $l,250/month MultiRAE Pro Pumped 10.6 electron volt

Air Monitoring Equipment Rental CR-1E

Vender Quote

$1,975.00

Month

and 1 @ $725/month SKC Particulate Monitor (Field









Environmental Instruments published quote)

Rental trucks 4-wheel drive

015433407200

$1,578.00

Month

Rent truck pickup 3/4 ton 4 wheel drive

4-wheel drive truck fuel

Engineering Estimate

$1,792.00

Month

No markup (Weeks x 4 = Months)

Rental cars

Vendor Quote

$1,505.00

Month

Weeks x 4 = Months

Rental car fuel

Engineering Estimate

$916.36

Month

No markup (Weeks x 4 = Months)

Submersible Pump (Month)

015433404700

$520.74

Month

Rent pump submersible electric 2 inch diameter, 120 GPM

Truck Scales (Month)

Engineering Estimate

$200.00

Month

No markup





$20.00



No markup. 432 hours/ month. Looks like they assumed 6-14

Security - Night Watchman

Engineering Estimate





hour shifts and 1-24 hour shift per week for 4 weeks.

Voluntary Alternative Housing

Per USEPA direction

$2,000,000.00

Lump Sum



Mobilization/Demobilization

Mobilization/Demobilization of

015436501300

$284.87

Each

Mobilization or demobilization, delivery charge for equipment,

Trailers/Storage Boxes

hauled on 3 ton capacity towed trailer. 50 mile roundtrip.

Temporary Electric Connect/Disconnect



$3,379.81



Meter center, main circuit breaker, rainproof, Single Phase, 3

262713102240

Each





Wire, 120/240 Volt, 400 Ampere

Large Equipment

015436501600

$2,598.31

Each

Mobilization or demobilization, delivery charge for equipment,

Mobilization/Demobilization

hauled on 50-ton capacity towed trailer. 50 miles roundtrip.

Small Equipment



$665.88



Mobilization or demobilization, delivery charge for equipment,

015436501400





hauled on 20-ton capacity towed trailer. 50 miles roundtrip.

Travel, Lodging, and Per Diem

Travel/Airfare

Engineering Estimate

$350.00

Month

1.5 trips per month @ $350

Lodging and Per Diem

CONUS Rate

$166.00

Day

CONUS rate for Gallup, NM as of 10/2023

Fence Construction/Repair









Fence, chain link industrial, galvanized steel, 3 strands barb

Fence Construction/Repair

323113200200

$28.24

LF

wire, 2 inch posts @ 10 foot on center, 9 gauge wire, 6 foot









high, Schedule 40, includes excavation, & concrete

Clearing and Grubbing





$1,331.54



Selective clearing, brush, light clearing, with dozer, ball and



311313100300









chain, excludes removal offsite

Land Surveying

Topographical Survey, Average

22113090050

$697.34

Acre

Topographical surveying, conventional, average

Excavation of Mine Waste

Excavate, place in stockpile (no utilities)



$2.16



Excavator, hydraulic, crawler mtd., 4.5 CY capacity = 340

312316435700

BCY





CY/hour. Add 15% for loading into trucks. 2720 CY/Day





$2.68



Dozer, open site, sand and gravel, 460 HP dozer, 150 foot haul,

Excavating - Dozer

312316465530

BCY





assuming 25% of waste requiring dozer

General Backfill from Off-Site









Material only, bank run gravel + Delivery charge, minimum 20

Import Borrow Soil, includes delivery

312323150020 + 312323151800 S27.54

LCY







tons, 1 hour round trip, add. B34B Crew. Assume 1.5 tons/CY









Spread dumped material, no compaction by dozer +

Place/compact backfill/cover material

312323170020 + 312323235600 $3.15

LCY

Compaction sheepsfoot or wobbly wheel roller, 6 inch lifts, 2









passes

Page 1 of 4


-------
Table E-7. Unit Cost Breakdown

Cost Item

Cost Source

Unit Cost

Unit

Description

General Backfill from On-Site

Excavate, place in stockpile (no utilities)
Load stockpiles to trucks

Off-road truck, 22 CY, 10 MPH, 2 mile
cycle

312316465530
312316435700

312323205110

$2.68
$2.16

$4.12

BCY

Place/compact backfill/cover material 312323170020 + 312323235600 $3.15

Excavating, bulk, dozer, open site, bank measure, sand and
gravel, 460 HP dozer, 150 foot haul
Excavator, hydraulic, crawler mtd., 4.5 CY capacity = 340
CY/hour. Add 15% for loading into trucks. 2,720 CY/Day
Cycle hauling(wait, load, travel, unload or dump & return) time
per cycle, excavated or borrow, loose cubic yards, 15 minute
load/wait/unload, 22 CY truck, cycle 2 mile, 10 MPH, excludes
loading equipment. Daily Output 374 LCY/Day
Spread dumped material, no compaction by dozer +

Compaction sheepsfoot or wobbly wheel roller, 6 inch lifts, 2
passes	

On-Site Transportation

Hauling to CR-2

312323205110

$8.37

Place/compact backfill/cover material 312323170020 + 312323235600 $3.15

Cycle hauling (wait, load, travel, unload or dump & return)
time per cycle, excavated or borrow, loose cubic yards, 15
minute load/wait/unload, 22 CY truck, cycle 4 mile, 15 MPH,
excludes loading equipment. Added the difference between
the 2 mile cycle and the 4 mile cycle to get a 10 mile cycle to
get 6 miles round trip

Spread dumped material, no compaction by dozer +
Compaction sheepsfoot or wobbly wheel roller, 6 inch lifts, 2
passes	

Transporting Waste from CR-1E to CR-1

On-road truck, 20 CY, 10 MPH, 4 mile
cycle

312323204040

Place/compact backfill/cover material 312323170020 + 312323235600

$3.51

$3.15

LCY

Cycle hauling (wait, load, travel, unload or dump & return)
time per cycle, excavated or borrow, loose cubic yards, 15
minute load/wait/unload, 20 CY truck, cycle 4 miles, 25 MPH,
excludes loading equipment. 380 CY/Day
Spread dumped material, no compaction by dozer +
Compaction sheepsfoot or wobbly wheel roller, 6 inch lifts, 2
passes	

Site Restoration

Import Borrow Soil, includes delivery 312323150020 + 312323151800 $20.49

Place/compact vegetative layer 312323170020 + 312323235600

Hydroseeding

Fine Grading
Rough Grading

329219145400
312213200280

$3.15

$56.01

$0.22
$5,269.30

LCY

LCY

MSF

SY
SF

Material only, bank run gravel + Delivery charge, minimum 20
tons, 1 hour round trip, add. B34B Crew. Assume 1.5 tons/CY.
1,000 CY/Day

Spread dumped material, no compaction by dozer +
Compaction sheepsfoot or wobbly wheel roller, 6 inch lifts, 2
passes

Seeding athletic fields, seeding utility mix with mulch and
fertilizer, 7 pounds per MSF, hydro or air seeding

cost per 100,000 SF

Erosion and Sediment Control

Silt Fence, Polypropylene, 3-ft High	312514161000

Straw waddles	312514160600

$2.75
$3.94

LF
LF

Synthetic erosion control, silt fence, install and remove, 3 feet
high.

Straw in polymeric netting, biodegradable log

Dust Control

Dust Control, Heavy

312323202510

$1,976.96 Truck/Day Crew B59,1 truck/trailer and 1 driver.

Unnamed Arroyo #2 Sloping and Armoring

Excavate, place in stockpile (no utilities)

Boulders loaded on truck
Haul boulders

Place riprap

312316465400

312316302800
312316305420

313713100200

$5.51

$19.90
$7.63

$41.02

BCY

LCY
LCY

Excavating, bulk, dozer, open site, bank measure, sand and
gravel, 300 HP dozer, 300 foot haul
Boulders under 1/2 CY, loaded on truck, no hauling
Haul boulders, 25 ton off-highway dump, 2 mile round trip
Rip-rap and rock lining, random, broken stone, 18 inch
minimum thickness, machine placed for slope protection, not
grouted. Unit given in SY, multiply by 18 inches to get volume
unit cost.	

Page 2 of 4


-------
Table E-7. Unit Cost Breakdown

Cost Item

Cost Source

Unit Cost

Unit

Description

Pipeline Arroyo Sloping, Armoring, and Road Rebuilding

Excavate, place in stockpile (no utilities)

312316465400

$5.51

BCY

Excavating, bulk, dozer, open site, bank measure, sand and
gravel, 300 HP dozer, 300 foot haul

Boulders loaded on truck

312316302800

$19.90

BCY

Boulders under 1/2 CY, loaded on truck, no hauling

Haul boulders

312316305420

$7.63

LCY

Haul boulders, 25 ton off-highway dump, 2 mile round trip
Rip-rap and rock lining, random, broken stone, 18 inch

Place riprap

313713100200

$41.02

LCY

minimum thickness, machine placed for slope protection, not
grouted. Unit given in SY, multiply by 18 inches to get volume
unit cost.

Base course drainage layers, aggregate base course for

Road Base

321123231513

$37.11

CCY

roadways and large paved areas, alternate method to figure
base course, crushed stone, compacted, 3/4 inch, 12 inch deep

Gravel

015523500050

$8.76

SY

Temporary, roads, gravel fill, 4 inch gravel depth, excl surfacing

Road Grading

340113100310

$565.90

Mile

Maintenance grading of roadways, roadway, 4 passes, 3 MPH

Import and Install Geotextile Fabric

Mirafi 160N/O Orange Nonwoven

Vender Quote, ACF West

$1.81

SY

Import and place Mirafi 160N/O Orange Nonwoven Geotextile

Geotextile Fabric

Geosynthetics

Fabric

Shaft Closure

Excavation

312316130050

$8.57

BCY

Excavating trench or continuous footing, common earth, 3/8 CY
excavator, 1 foot to 4 foot deep

Concrete Delivered

33113350150

$131.10

CY

Heavyweight concrete delivered 2000 psi

Forming

31113456150

$134.85

Each

12 foot x 12 foot footing form

Placing Concrete

33113704350

$25.71

CY

Place, level and consolidate, over 10 CY pumped



Hauling of Off-Site Licensed Facility



Hauling to Clean Harbors Facility, Deer

312323204114

$180.00

LCY

600 loaded miles x $5/loaded mile = $3,000 per trip /25 tons

Trail, Colorado

per trip = $120 per ton x 1.5 tons/CY = $180/LCY

Hauling to Red Rocks Disposal Facility

312323204114

$12.90

LCY

43 loaded miles x $5/loaded mile = $215 per trip/25 tons per
trip = $8.6 per ton x 1.5 tons/CY = $12.90/LCY

Disposal of Contaminated Soil at Licensed Facility

Disposal Contaminated Soil - Clean
Harbors Facility, DeerTrail, Colorado

Quote for disposal at DeerTrail,







Colorado - September 2020
(includes tax and fees)

$105.00

LCY

Price does not include hauling. $70/Ton, assume 1.5 tons/CY.

Disposal Contaminated Soil - Red Rocks

Quote for Disposal at Red Rocks

$82.50

LCY

Assumed price ($55/ton). Landfill quoted between $53 and

Disposal Facility

Disposal Facility - January 2022

$58/ton.

Transport to and Place Material at Off-Site Location









Spread dumped material, no compaction by dozer +

Place/compact backfill/cover material

312323170020 + 312323235600

$3.15

LCY

Compaction sheepsfoot or wobbly wheel roller, 6 inch lifts, 2
passes

Top Liner

HDPE Liner

Southwest Linings in Bernalillo,
New Mexico

$0.60

SF

Early 2020 estimate

Drainage Geonet

Southwest Linings in Bernalillo,
New Mexico

$0.40

SF

Early 2020 estimate

Soil Cap









Material only, bank run gravel + Delivery charge, minimum 20

Import Borrow Soil, includes delivery

312323150020 + 312323151800

$27.54

LCY

tons, 1 hour round trip, add. B34B Crew. Assume 1.5 tons/CY.
130 Ton/Day/Truck

Spread dumped material, no compaction by dozer +

Place/compact borrow

312323170020 + 312323235600

$3.15

LCY

Compaction sheepsfoot or wobbly wheel roller, 6 inch lifts, 2
passes. 1,000 LCY/Day/Truck

Excavation of Off-Site Repository

Excavate, place in stockpile (no utilities)

312316465400

$5.51

BCY

Excavating, bulk, dozer, open site, bank measure, sand and
gravel, 300 HP dozer, 300 foot haul

Soil Cap at Off-Site Repository









Spread dumped material, no compaction by dozer +

Place/compact borrow

312323170020 + 312323235600

$3.15

LCY

Compaction sheepsfoot or wobbly wheel roller, 6 inch lifts, 2
passes. 1,000 LCY/Dav/Truck

Page 3 of 4


-------
Table E-7. Unit Cost Breakdown

Cost Item

Cost Source

Unit Cost

Unit

Description

Rock Armoring on Benches

Boulders drilled and blasted

312316302900

32.07

LCY

Drilling and blasting rock, boulders, drilled and blasted

Loading

312316302800

19.9

LCY

Boulders under 1/2 CY, loaded on truck, no hauling

Hauling

312316305460

5.02

LCY

Drilling and blasting rock, 25 ton off-highway dump, 4 mile
round trip, haul boulders

Rip-rap and rock lining, random, broken stone, 18 inch

Riprap/Placing

313712100200

$82.03

SY

minimum thickness, machine placed for slope protection, not
grouted.

Fence Maintenance

Fence Inspection

Engineers Estimate

$110.00

Hour



Fence Repair

Engineers Estimate

$2.42

LF







O&M





Hydroseeding

329219145400

$56.01

MSF

Seeding athletic fields, seeding utility mix with mulch and
fertilizer, 7 pounds per MSF, hydro or air seeding

Riprap

Actual 2023 Cost

$40.00

ton

Cost from 2023 Quivira construction

Small Equipment

015436501400

$717.03

Each

Mobilization or demobilization, delivery charge for equipment,
hauled on 20-ton capacity towed trailer. 50 miles roundtrip.

Fine Grading

312213200280

$0.22

SY



Lawn Mower

015433403407

$2,546.58

Week

146.58 per week 40 hours per week operator $60/hour

Straw waddles

312514160600

$3.94

LF

Straw in polymeric netting, biodegradable log

Topographical Survey, Average

22113090050

$697.34

Acre

Topographical surveying, conventional, average

Notes:









BCY = Bank cubic yard

HDPE = High-density polyethylene



MPH = Mile per hour

CY = Cubic Yard

HP = Horse power





MSF = Thousand square foot

CCY = Compacted cubic yard

HVAC = Heating, ventilation, and air conditioning



psi = Pound per square inch

CONUS = Continental United States

LCY = Loose cubic yard





SF = Square foot

GPM = Gallon per minute

LF = Linear foot





SY = Square yard

Page 4 of 4


-------
Table E-8. Derived Costs

Cost Item

Unit Cost

Unit

Qty

Derived Unit Cost

Unit

Support Structures

Trailers

$264.86

Month

2

$529.72

Month

Storage Boxes

$95.73

Month

2

$191.46

Month

Field Office Lights/Heating/Air Conditioning

$177.57

Month

1

$177.57

Month

Telephone/internet

$95.23

Month

1

$95.23

Month

Portable Toilets

$220.92

Month

4

$883.68

Month

Field Office Equipment

$248.99

Month

1

$248.99

Month

Field Office Supplies

$98.70

Month

1

$98.70

Month

Trash

$435.00

Month

1

$435.00

Month

Air Monitoring Equipment Rental CR-1

$1,975.00

Month

1

$1,975.00

Month

Air Monitoring Equipment Rental CR-1E

$1,975.00

Month

1

$1,975.00

Month

Rental trucks 4-wheel drive

$1,578.00

Month

4

$6,312.00

Month

4-wheel drive truck fuel

$1,792.00

Month

4

$7,168.00

Month

Rental cars

$1,505.00

Month

3

$4,515.00

Month

Rental car fuel

$916.36

Month

3

$2,749.09

Month

Submersible Pump (Month)

$520.74

Month

1

$520.74

Month

Truck Scales (Month)

$200.00

Month

1

$200.00

Month

Security - Night Watchman

$20.00

Hour

432

$8,640.00

Month







Subtotal

$36,715.18

Month

Voluntary Alternative Housing

$2,000,000.00

Lump Sum

1

$2,000,000.00

Lump Sum

Mobilization/Demobilization

Mobilization/Demobilization of Trailers/Storage Boxes

$284.87

Each

4

$1,139.48

Each

Temporary Electric Connect/Disconnect

$3,379.81

Each

1

$3,379.81

Each

Large Equipment Mobilization/Demobilization

$2,598.31

Each

15

$38,974.65

Each

Small Equipment

$665.88

Each

16

$10,654.08

Each







Subtotal

$54,148.02

Each

Travel, Lodging, and Per Diem

Travel/Airfare

$350.00

Month

1.5

$525.00

Month

Lodging and Per Diem

$166.00

Day

30

$4,980.00

Month







Subtotal

$5,505.00

Month

Fence Construction/Repair

Fence Construction/Repair

$28.24

LF

1

$28.24

LF







Subtotal

$28.24

LF

Clearing and Grubbing

Clear and Grub

$1,331.54

Acre

1

$1,331.54

Acre







Subtotal

$1,331.54

Acre

Land Surveying

Land surveying, Mob/Demob

$697.34

Acre

1

$697.34

Lump Sum







Subtotal

$697.34

Lump Sum

Excavation of Mine Waste

Excavate, place in stockpile (no utilities)

$2.16

BCY

1

$2.16

BCY

Load stockpiles to trucks

$2.68

BCY

1

$2.68

BCY







Subtotal

$4.84

BCY

General Backfill from Off-Site

Import Borrow Soil, includes delivery

$27.54

LCY

1

$27.54

LCY

Place/compact backfill/cover material

$3.15

LCY

1

$3.15

LCY







Subtotal

$30.69

LCY

General Backfill from On-Site

Excavate, place in stockpile (no utilities)

$2.68

BCY

1

$2.68

BCY

Load stockpiles to trucks

$2.16

BCY

1

$2.16

BCY

Off-road truck, 22 CY, 10 MPH, 2 mile cycle

$4.12

LCY

1

$4.12

LCY

Place/compact backfill/cover material

$3.15

LCY

1

$3.15

LCY







Subtotal

$12.11

LCY

Page 1 of 3


-------
Table E-8. Derived Costs

Cost Item

Unit Cost

Unit

Qty

Derived Unit Cost

Unit

On-Site Transportation

Hauling to CR-2

$8.37

LCY

l

$8.37

LCY

Place/compact backfill/cover material

$3.15

LCY

l

$3.15

LCY





Subtotal CR-2

$11.52

LCY

Site Restoration

Import Borrow Soil, includes delivery

$20.49

LCY

806.67

$16,531.29

Acre

Place/compact vegetative layer

$3.15

LCY

806.67

$2,541.00

Acre

Hydroseeding

$56.01

MSF

43.56

$2,439.80

Acre

Rough Grading

$52.69

MSF

43.56

$2,295.18

Acre







Subtotal

$23,807.26

Acre

Erosion and Sediment Control

Silt Fence, Polypropylene, 3-foot High

$2.75

LF

210

$577.50

Acre

Straw Waddles

$3.94

LF

40

$157.60

Acre







Subtotal

$735.10

Acre

Dust Control On-Site Alternative

Dust Control, Heavy

$1,976.96

Truck/Day

4

$7,907.84

Day







Subtotal

$7,907.84

Day

Dust Control Off-Site Alternatives

Dust Control, Heavy

$1,976.96

BCY

2

$3,953.92

Day







Subtotal

$3,953.92

Day

Unnamed Arroyo #2 Sloping and Armoring

Excavate, place in stockpile (no utilities)

$5.51

BCY

3700

$20,387.00



Boulders loaded on truck

$19.90

LCY

2500

$49,750.00



Haul boulders

$7.63

LCY

2500

$19,075.00



Place riprap

$41.02

LCY

2500

$102,537.50









Subtotal

$191,749.50

Lump Sum

Pipeline Arroyo Sloping, Armoring, and Road Rebuilding

Excavate, place in stockpile (no utilities)

$5.51

BCY

3700

$20,387.00



Boulders loaded on truck

$19.90

LCY

2500

$49,750.00



Haul boulders

$7.63

LCY

2500

$19,075.00



Place riprap

$41.02

LCY

2500

$102,537.50



Road Base

$37.11

CCY

370

$13,744.44



Gravel

$8.76

SY

10000

$87,600.00



Road Grading

$565.90

Mile

0.09

$53.59











$293,147.53

Lump Sum

Shaft Closure

Excavation

$8.57

BCY

20

$171.40



Concrete Delivered

$131.10

CY

230

$30,153.00



Forming

$134.85

Each

2

$269.70



Placing Concrete

$25.71

CY

230

$5,913.30









Subtotal

$36,507.40



Complexity and Remoteness Multiplier





3

$109,522.20

Each

Adit Closure

Lump sum assumption

$50,000.00

Each

1

$50,000.00











$50,000.00

Each

Hauling to Off-Site Licensed Facility

Hauling to Clean Harbors Facility, Deer Trail, Colorado

$180.00

LCY

1

$180.00

LCY

Hauling to Red Rocks Disposal Facility

$12.90

LCY

1

$12.90

LCY

Disposal of Contaminated Soil at Licensed Facility

Disposal Contaminated Soil - Clean Harbors Facility, Deer

$105.00

LCY

1

$105.00

LCY

Trail, Colorado







Disposal Contaminated Soil - Red Rocks Disposal Facility

$82.50

LCY

1

$82.50

LCY

Page 2 of 3


-------
Table E-8. Derived Costs

Cost Item

Unit Cost

Unit

Qty

Derived Unit Cost

Unit

Transport to and Place Material at Off-Site Location

Hauling to CR-2

$8.37

LCY

l

$8.37

LCY

Place/compact backfill/cover material

$3.15

LCY

l

$3.15

LCY







Subtotal

$11.52

LCY

Soil Cap

Import Borrow Soil, includes delivery

$27.54

LCY

1.11

$30.60

CCY

Place/compact borrow

$3.15

LCY

1.11

$3.50

CCY







Subtotal

$34.10

CCY

Rock Armoring on Benches

Boulders drilled and blasted

$32.07

LCY

1

$32.07

LCY

Loading

$19.90

LCY

1

$19.90

LCY

Hauling

$5.02

LCY

1

$5.02

LCY

Riprap/Placing

$82.03

SY

1

$82.03

LCY







Subtotal

$139.02

LCY

Fence Maintenance

Fence Inspection

$110.00

Hour

10

$1,100.00

Event

Fence Repair

$2.42

LF

250

$605.00

Event







Subtotal

$1,705.00

Event

Maintenance

Revegetation (30 years)











Hydroseeding

56.01

MSF

43.56

$2,439.80

Acre

Small Equipment

717.03

Each

1

$717.03

Year

Regrading/Erosion Control (10 years)











Small Equipment

717.03

Each

1

$717.03

Year

Fine Grading

0.22

SY

1

$0.22

SY

Riprap

40

ton

500

$20,000.00

year

Silt Fence, Polypropylene, 3-foot High

$2.75

LF

210

$577.50

Acre

Straw Waddles

$3.94

LF

40

$157.60

Acre

Cap Weed Control (30 years)











Lawn Mower

2546.58

Week

0.5

$1,273.29

Year

Inspection/Vegetation Survey (30 years)











Topographical Survey, Average

697.34

Acre

62.86

$43,834.79

Year

Notes:

BCY = Bank cubic yard	LF = Linear foot	X1.25 Expansion Factor Used for LCY quantities

CY = Cubic yard	MPH = Mile per hour	X0.9 Compaction Factor Used for CCY quantities

CCY = Compacted cubic yard	MSF = Thousand square foot

LCY = Loose cubic yard	SY = Square yard

Page 3 of 3


-------
Table E-9. Derived Quantities

Region

Areas Outside Capped Waste Piles
Requiring Restoration (AC)

General Backfill Volume (BCY)

Soil Cap
Volume (BCY)

Off-Site Disposal Volumes
(BCY)

On Site Transport
Volumes (BCY)

Onsite

Red Rocks

KCKA or
LLRW

Onsite

Red Rocks

KCKA or
LLRW

Onsite

Red Rocks

RCRA or LLRW

Onsite

Cover on Waste Pile (Footprint)

Outer Perimeter

East Side Toe

East Side

Western Toe

Southern Toe

Pond 1

Pond 1A

Unreclaimed Pond
Pond 3
Pond 2

Lower Pond 5 Hotspot
Lower Pond 5 Hotspot
Lower Pond 6c
Lower Pond 6b

20.93

20.93

20.93

135,095

135,095

135,095



33,771.92

33,771.92

33,771.92

7.31

7.31

7.31

11,798

11,798

11,798



11,797.64

11,797.64

11,797.64

1.52

1.52

1.52

3,671

3,671

3,671



3,670.82

3,670.82

3,670.82

1.65

1.65

1.65

5,334

5,334

5,334



5,334.33

5,334.33

5,334.33

1.63

1.63

1.63

3,955

3,955

3,955



3,954.83

3,954.83

3,954.83

1.88

1.88

1.88

12,150

12,150

12,150



12,150.04

12,150.04

12,150.04

0.62

0.62

0.62

13,950

13,950

13,950



13,950.07

13,950.07

13,950.07

0.15

0.15

0.15

1,959

1,959

1,959



1,959.14

1,959.14

1,959.14

1.95

1.95

1.95

21,978

21,978

21,978



21,978.13

21,978.13

21,978.13

0.23

0.23

0.23

3,671

3,671

3,671



3,671.59

3,671.59

3,671.59

0.21

0.21

0.21

6,587

6,587

6,587



6,587.37

6,587.37

6,587.37

0.07

0.07

0.07

795

795

795



794.57

794.57

794.57

0.06

0.06

0.06

3,934

3,934

3,934



393.39

393.39

393.39

0.30

0.30

0.30

3,361

3,361

3,361



3,360.84

3,360.84

3,360.84

0.22

0.22

0.22

2,438

2,438

2,438



2,438.37

2,438.37

2,438.37

CR-1 Existing Waste Pile















803,325.00

803,325.00

803,325.00

CR-1 Total

38.73

38.73

38.73

230,676

230,676

230,676



929,200

929,200

929,200

North Industrial
Hotspot
Surface 1
Surface 2
Surface 3
Surface 4
Outer Perimeter

0.50

0.50

0.50

2,015

2,015

2,015



2,014.76

2,014.76

2,014.76

0.05

0.05

0.05

427

427

427



426.65

426.65

426.65

0.06

0.06

0.06

141

141

141



140.83

140.83

140.83

3.80

3.80

3.80

9,207

9,207

9,207



9,206.78

9,206.78

9,206.78

0.02

0.02

0.02

51

51

51



49.92

49.92

49.92

0.01

0.01

0.01

28

28

28



28.40

28.40

28.40

4.46

4.46

4.46

7,202

7,202

7,202



7,201.56

7,201.56

7,201.56

CR-1E Existing Waste Piles

2.55

2.55

2.55

16,456

16,456

16,456



30,168

30,168

30,168

CR-1E Total

11.5

11.5

11.5

35,526

35,526

35,526



49,300

49,300

49,300

KMP UNC Hotspot
KMP UNC Hotspot 4ft
KMP UNC Hotspot 6 ft
KMP UNC Hotspot 6 ft
KMP UNC Perimeter
KMP NN Perimeter
KMP NN Hotspot

0.00

0.00

0.00

-

-

-



-

-

-

1.01

1.01

1.01

6,531.01

6,531.01

6,531.01



6,531.01

6,531.01

6,531.01

0.07

0.07

0.07

642.49

642.49

642.49



642.49

642.49

642.49

0.08

0.08

0.08

817.47

817.47

817.47



817.47

817.47

817.47

9.42

9.42

9.42

15,201.34

15,201.34

15,201.34



15,201.34

15,201.34

15,201.34

1.84

1.84

1.84

2,973.26

2,973.26

2,973.26



2,973.24

2,973.24

2,973.24

0.26

0.26

0.26

834.07

834.07

834.07



834.12

834.12

834.12

Kerr McGee Pond Total

12.7

12.7

12.7

26,999.64

26,999.64

26,999.64



27,000

27,000

27,000

Cap Area (acres)













10







Total Quantities

62.9

62.9

62.9

293,202

293,202

293,202

64,533

1,005,500

1,005,500

1,005,500

Truckloads

2120

2120

2120

18,330

18,330

18,330

4,040

76,180

76,180

57,140

Page 1 of 2


-------
Table E-9. Derived Quantities

Riprap Volume



LF

11.3 FT Slope

LF

8.49 FT
Slope

Total SF

SY

CY

(Assuming
3ft Depth)

CR-1

8,245

93,169

0

0

93,169

10,352

10,352

CR-1E

3,516

39,731

2,146

18,220

57,950

6,439

6,439

Canyon Repository Area

10.00 ACRES

Riprap Volume (LCY)

Alternative 2

10,352

Alternative 3

16,971

Alternative 4

16,971

Off Site Truckloads Site Restoration

Alternative 2

24,490

Alternative 3

96,630

Alternative 4

96,630

Notes:
BCY
CY
LF

LLRW

Bank cubic yard
Cubic yard
Linear foot

Low-level radioactive waste

RCRA	Resource Conservation and Recovery Act

SF	Square foot

SY	Square yard

Page 2 of 2


-------
Table E-10. Inspection and Maintenance Breakdown

Percent Revegetation (0-10 years):

25%

Percent Revegetation (10-30 years):

10%

Percent Regrading (0-10 years):

10%

Percent Regrading (10-30 years):

5%

Percent Erosion Control:

10%

Total Site Area Square Yards:

304,242

CR-2 Cap Area Square yards:

48,400



Alternative 2

All Alternatives

Duration

Activity

Cap Only

Entire Site

10 years Maintenance

Revegetation (Square Yards)

12,100

76,061

Regrading (Square Yards)

35,264

30,424

30 years Maintenance

Erosion Control (Acre)

1

6

100 years Maintenance

Inspection

12,100

76,061

Present Value Calculations

Years (n)

5

4.100197436

Interest (i)

0.07



Years (n)

10

7.023581541

Interest (i)

0.07



Years (n)

30

12.40904118

Interest (i)

0.07



Years (n)

100

14.26925071

Interest (i)

0.07



Quivira Present Worth of Maintenance - 7%





Alternative 2
Cap Only

Entire Site for All
Alternatives

Alternative 2
Total

0 to 10 years
Maintenance

Revegetation

$46,335

$279,496

$325,831

Regrading/Erosion Control

$27,192.52

$66,724.98

$93,917

10 to 30 years
Maintenance

Revegetation

$31,165

$199,210

$230,375

Regrading/Erosion Control

$24,021.44

$58,943.79

$82,965

0 to 30 years
Maintenance

Site Inspection

$0.00

$543,947.74

$543,948

0 to 100 years
Maintenance

Cap Inspection

$99,505.19

$0.00

$99,505

Total Maintenance



$228,219

$1,148,322

$1,376,542

Page 1 of 2


-------
Table E-10. Inspection and Maintenance Breakdown
	Assumptions	

1% Interest Rate

Offsite Cap Area based on percentage of overall repository capacity needed for Quivira
Assuming 10% of repository cap will require regrading/erosion control each year (0-10)
Assuming 5% of repository cap will require regrading/erosion control each year (10-30)
Assuming 25% of repository cap will require revegetation each year (0-10)

Assuming 10% of repository cap will require revegetation each year (10-30)

Assuming 10% of areas not capped will require regrading/erosion control each year (0-10)
Assuming 5% of areas not capped will require regrading/erosion control each year (10-30)
Assuming 25% of areas not capped will require revegetation each year (0-10)

Assuming 10% of areas not capped will require revegetation each year (10-30)

$717.03 - Equipment mobilization cost for annual maintenance
500 tons riprap per year, $40/ton

Page 2 of 2


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APPENDIX F

POST-RESTORATION VISUALIZATIONS


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EXISTING CONDITIONS - CR-1

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PROPOSED RECLAMATION - CR-1

Conceptual CR-1 Repository
Post-Removal Action

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TETRATECH


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Conceptual Canyon Repository
Post-Removal Action

TETRATECH


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