REMOVAL SITE EVALUATION REPORT
Babbitt Ranches, LLC - Milestone Hawaii
Stewardship Project
(Section 9 Lease Abandoned Uranium Mine)
CERCLA Docket No. 2016-13
Preparedfor:
U.S. Environmental Protection Agency
Region IX
Mail Code SFD-6-2
75 Hawthorne St.
San Francisco, CA 94105
Prepared by:
1
A Engineering Analytics, Inc.
1
\J\i
Engineering Analytics, Inc.
1600 Specht Point Road, Suite 209
Fort Collins, Colorado 80525
(970) 488-3111
Project No. 110704
March 18, 2021
Rev. 1.2
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
TITLE AND APPROVAL PAGE
Title:
Removal Site Evaluation Report, Babbitt Ranches, LLC - Milestone
Hawaii Stewardship Project (Section 9 Lease Abandoned Uranium Mine)
CERCLA Docket No. 2016-13
Prepared by:
Engineering Analytics, Inc.
1600 Specht Point Road #209
Fort Collins, CO 80525
(970)488-3111
Integral Consulting, Inc.
45 Exchange Street, Suite 200
Portland, ME 04101
(970) 231-1160
Environmental Restoration Group, Inc.
8809 Washington St. NE, Suite 150
Albuquerque, New Mexico 87113
(505) 298-4224
Date: 2/18/2021
Program Manager:
Chuck Howe
QA Management Team Lead:
Toby Wright
EPA Region IX Project Manager/OSC:
Estrella Armijo
Signature.
Date
Signature
4/1/2021
Date
4/1/2021
Signature: ESTRELLA
ARMIJO
Date
Digitally signed by ESTRELLA
ARMIJO
Date: 2021.03.24 15:45:45
-07'00'
Under penalty of law, I certify that to the best of my knowledge, after appropriate
inquiries of all relevant persons involved in the preparation of the report, the information
submitted is true, accurate, and complete. I am aware that there are significant penalties
for submitting false information, including the possibility of fine andjxapijsonment for
knowing violations. ^
Characterization Project Manager: Signature:
Jason Andrews
Date 4/1/2021
March 18, 2021
Rev. 1.2
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Site Name/Project: Babbitt Ranches, LLC - Milestone Hawaii Stewardship Project,
Section 9 Lease Abandoned Uranium Mine
Site Location: Section 9, Township 27 North, Range 10 East of the Gila and Salt
River Base and Meridian near Cameron, Coconino County,
Arizona
Approval Entity: EPA Region IX
March 18, 2021
Rev. 1.2
ii
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
DISTRIBUTION LIST
Doc ii in en t
Recipients
Title
()r<>;ini/;ilion
Telephone
Nil in her
K-mjiil Address
Billy Cordasco
President and General Manager
Babbitt Ranches, LLC
(928) 774-6199
cobarVvbabbittranchcs.com
Chuck Howe
Program Manager
C2 Environmental, LLC
(928) 310-6898
chowe@c2-env.com
Dan Overton
Principal Engineer
Engineering Analytics, Inc.
(970) 488-3111
do ve rto n a c nga nalvtics.com
Jason Andrews
Characterization Project Manager
Engineering Analytics, Inc.
(970) 488-3111
jandrews@enganalytics.com
Mike Schierman
Radiological Team Lead
H3 Environmental, LLC
(505) 312-6401
mikeschicrmanVv,ergo ffice.com
Chuck Fan-
Radiological Team Review Lead
ERG Inc.
(505) 298-4224
Chuck Fa xx a c rgo ffice.com
Bruce Marshall
Characterization Team Lead
Engineering Analytics, Inc.
(720) 708-8329
bmarshall@enganalytics.com
John Samuelian
Risk Assessment Team Lead
Integral Consulting, Inc.
(207) 874-9000
j samuelian@integral-corp. com
Toby Wright
OA Management Team Lead
Wright Environmental Services, Inc.
(970) 231-1160
wrightenv@gmail.com
Estrella Armijo
Remedial Project Manager/OSC
EPA Region IX
(415) 972-3859
Armij o .Estrella@epa.gov
Jerry Helton
Manager
Arizona Department of Environmental
Quality
(602) 542-2578
helton.jerry@azdeq.gov
Bruce Campbell
Environmental Program Specialist
Arizona State Land Department
(602) 542-2578
bcampbell@azland. gov
Eric Zielske
Hazmat Lead
BLM - AZ State Office
(602) 653-6283
zielske@blm.gov
Matthew Plis
Environmental Engineering
Abandoned Mines and Hazmat
Coordinator
BLM - Lower Sonoran Field Office
(623) 580-5518
mplis@blm.gov
James Anderson
Realty Coordinator
BLM - Lower Sonoran Field Office
(623) 580-5500
jvanders@blm.gov
Harrison Karr
Principal Attorney
Navajo Nation Department of Justice
(928) 871-6347
hkarr@nndoj .org
Brian Curley-
Chambers
Attorney Candidate
Navajo Nation Department of Justice
(928) 871-6347
bcchambers@nndoj. org
Dariel Yazzie
Program Supervisor
Navajo Nation Environmental
Protection Agency - Superfund
Program
(928) 871-7692
darielyazzie@navajo-nsn.gov
Tennille Begay
Remedial Project Manager
Navajo Nation Environmental
Protection Agency - Superfund
Program
(928) 551-3877
tbbegay@navajo-nen.gov
March 18, 2021
Rev. 1.2
iii
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
DOCUMENT REVISION TRACKING
Date Approved
Rev. No.
Prepared By
Approvals
Revision Description
QA
Project
0.0
EA, ERG,
Integral
1.0
EA, ERG,
Integral
Response to August 25,
2020 EPA comments
1.1
EA, Integral
Response to Oct 28,
2020 and December 14,
2020 EPA comments
1.2
EA, Integral
Response to Feb 19 and
March 8, 2021 EPA
comments
March 18, 2021
Rev. 1.2
iv
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
TABLE OF CONTENTS
TITLE AND APPROVAL PAGE i
DISTRIBUTION LIST iii
DOCUMENT REVISION TRACKING iv
ACRONYMS xxiii
EXECUTIVE SUMMARY 1
1.0 INTRODUCTION 4
1.1 Purpose and Objectives 4
1.2 Initial Evaluation 4
1.3 Work Completed Under Current AOC 5
2.0 SITE SETTING 9
2.1 Site Location 9
2.2 Site History 11
2.2.1 Land Ownership Hi story 11
2.2.2 Mining History 11
2.3 Current Conditions 15
2.4 Ecological Conditions 16
2.5 Geologic Setting 17
2.6 Physical Conceptual Site Model 18
2.6.1 AUM 457 18
2.6.2 AUM 458 19
2.6.3 AUM 459 20
3.0 INVESTIGATION WORK PLANS 21
3.1 Site Mapping 21
3.1.1 Desktop Survey 21
3.1.2 BSA Selection 21
3.1.3 Field Reconnaissance 22
3.2 Gamma Radiation Survey 23
3.2.1 BSA Gamma Survey 23
3.2.2 Transect Gamma Survey 23
March 18, 2021 v Engineering Analytics, Inc.
Rev. 1.2
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
3.3 Concrete Surface Activity Survey 24
3.4 BSA Sediment and Soil Sampling 24
3.5 Surface and Subsurface Soils and Sediment Sampling 24
4.0 FIELD INVESTIGATION 26
4.1 Desktop Survey 26
4.2 BSA Selection 26
4.3 Field Reconnaissance 26
4.4 Gamma Survey 27
4.4.1 BSA Scanning 27
4.4.2 Area of Potential Effect Scanning 27
4.4.2.1 APE Scanning 2017 27
4.4.2.2 APE Scanning 2020 28
4.4.3 Concrete Surface Activity Measurements 29
4.4.4 Subsurface Gamma Profiling 29
4.5 Soil Sampling 30
4.5.1 Surface Soil Sampling 30
4.5.1.1 2017 Data Collection 30
4.5.1.2 2018 Data Set Supplement 31
4.5.2 Subsurface Soil Sampling 32
5.0 ANALYSES AND RESULTS 33
5.1 Laboratory Data Validation 33
5.1.1 2017 Data Set 33
5.1.2 2019 Data Set 35
5.2 Correlation Study Results 36
5.2.1 Surface Correlation Results 36
5.2.1.1 Radium-226 36
5.2.1.2 High-Pressurized Ion Chamber and Gamma Count Rate Correlations 37
5.2.1.3 Metals Correlation 37
5.2.2 Subsurface Correlation Results 38
5.3 Background Study Area Pooling 39
Rev. 1.2
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
5.4 Delineation of Investigation Level 40
5.5 TENORM Identification 41
5.6 Potential Material Migration 41
5.6.1 Potential Material Migration from AUM 457 41
5.6.1.1 Northern Drainage 42
5.6.1.2 Pond Area 42
5.6.1.3 UpgraderArea 42
5.6.1.4 Bedrock Ridge West of AUM 457 42
5.6.2 Potential Material Migration from AUM 458 43
5.6.2.1 Within AUM 458 43
5.6.2.2 Outside of AUM 458 43
5.6.2.3 Ridge South of AUM 458 43
5.6.2.4 Drainage Southeast of AUM 458 44
5.6.3 Potential Material Migration from AUM 459 44
5.6.3.1 Drainage North from AUM 459 44
5.6.3.2 Drainage Northwest of AUM 459 45
5.6.3.3 Potential Migration Summary 45
6.0 HUMAN HEALTH STREAMLINED RISK EVALUATION 46
6.1 HHSRE Conceptual Site Model Development 46
6.2 Evaluated Receptors 46
6.3 Exposure Pathways and Scenarios 47
6.4 Receptors and Exposure Assumptions 47
6.5 Identification of HHSRE PCOCs 48
6.6 Exposure Point Concentrations for HHSRE 48
6.7 Exposure Assessment 50
6.7.1 Area C orrecti on F actors 51
6.7.2 Soil Grain Size Analyses 51
6.8 Chemical Uptake Factors 51
6.9 Toxicity Benchmarks 51
6.10 Human Health Risk Characterization Approach 52
Rev. 1.2
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
6.11 Non-Radiological Human Health Risks 52
6.12 Radiological Human Health Risks 53
6.13 Receptor Specific Risks 53
6.13.1 On-Site Worker 53
6.13.2 Long Term Adult Recreator - 24 years of Exposure 54
6.13.3 Child Recreator - 2 years of Exposure 55
6.13.4 Combined Child and Long Term Adult Recreator - 26 Years of Exposure 56
6.14 HHSRE Uncertainty Analysis Approach 56
6.14.1 Representativeness of sampling 56
6.14.2 Receptor selection and representativeness 57
6.14.2.1 Uncertainty Assessment - Short Term Adult Recreator (1 year of Exposure) 57
6.14.3 Comparison of Average and UCL Concentrations as EPCs and Effects on
Calculated Risks 58
6.14.4 Spatial Averaging 58
6.14.5 Area C orrecti on F actors 58
6.14.6 Off-Site Transport of Site Soils in Air 58
6.14.7 Assessment of Effects of Ra-226 Soils Collected from Depth 59
6.15 Summary of HHSRE Results 61
7.0 ECOLOGICAL STREAMLINED RISK EVALUATION 63
7.1 Ecological Setting 63
7.2 EcoSRE Conceptual Site Models 64
7.3 Evaluated Receptors 65
7.4 Identification of EcoSRE PCOCs 66
7.5 Exposure Point Concentrations for EcoSRE 66
7.6 Exposure Assessment 67
7.6.1 Exposure Calculations and Exposure Assumptions for Assessing Non-Radiological
Risks 6 8
7.6.2 Exposure Calculations and Exposure Assumptions for Assessing Radiological Risks
69
7.7 Non-Radiological Toxicity Benchmarks 70
March 18, 2021 viii Engineering Analytics, Inc.
Rev. 1.2
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
1.1.1 Toxicity Benchmarks for the Assessment of Vegetation Effects 70
7.7.2 Toxicity Benchmarks for the Assessment of Effects on Mammalian and Avian
Species 70
7.8 Radiological Benchmarks 72
7.9 Ecological Risk Characterization Approach 73
7.9.1 Plants 74
7.9.2 Herbivorous bird: Mourning dove 75
7.9.3 Herbivorous mammal: Deer mouse 75
7.9.4 Insectivorous bird: American kestrel 76
7.9.5 Insectivorous bird: Rock wren 77
7.9.6 Insectivorous mammal: Desert shrew 77
7.9.7 Omnivorous mammal: Coyote 78
7.9.8 Carnivorous bird: Golden eagle 78
7.9.9 Assessment of Potential Receptor Risks in the LCR Under Wet Conditions 79
7.10 EcoSRE Uncertainty Analysis 80
7.10.1 Representativeness of sampling 80
7.10.2 Receptor selection and representativeness 80
7.10.3 Conservatism from use of chemical uptake models to estimate prey and forage
PCOC concentrations 81
7.10.4 Comparison of non-radiological and radiological risk results to those generated by
the LANL EcoRisk model (LANL, 2017a) 81
7.10.5 Development of non-radiological benchmarks (i.e., TRV) 81
7.11 Summary of EcoSRE Results 82
8.0 PROPOSED RISK BASED ACTION LEVEL 84
9.0 REPOSITORY AND WASTE VOLUMES 89
9.1 CHARACTERIZATION OF PITS 89
9.1.1 AUM 457 89
9.1.2 AUM 458 89
9.1.3 Summary of Pit Capacity 90
9.2 WASTE VOLUMES 90
Rev. 1.2
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
9.2.1 Volumes Above IL 90
9.2.1.1 Volume Above IL - NW Quadrant 91
9.2.1.2 Volume Above IL - NE Quadrant 91
9.2.1.3 Volume Above IL - SW Quadrant 91
9.2.1.4 Volume Above IL - SE Quadrant 91
9.2.2 Volume Above Proposed Risk Based Action Levels 92
10.0 SUMMARY AND CONCLUSIONS 93
11.0 REFERENCES 95
March 18, 2021
Rev. 1.2
X
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
LIST OF TABLES
Table 4-1 Summary Statistics for Gamma Count Rates (cpm) in the Background Study
Areas
Table 4-2 Survey Instruments for Transect Gamma Survey
Table 4-3 Survey Instruments for the Concrete Survey
Table 4-4 Soil and Sediment Sample Location Rationale
Table 4-5 Survey Instruments for Subsurface Gamma Profiling
Table 4-6 Analytes and Methods for Surface Soil and Sediment Samples
Table 4-7 Summary Statistics for Activity Concentrations of Radium-226 (pCi/g) in
Samples of Surface Soils Obtained in the Background Study
Table 4-8 Summary Statistics for Concentrations of Arsenic (mg/kg) in Samples of Surface
Soils Obtained in the Background Study
Table 4-9 Summary Statistics for Concentrations of Mercury (mg/kg) in Samples of Surface
Soils Obtained in the Background Study
Table 4-10 Summary Statistics for Concentrations of Molybdenum (mg/kg) in Samples of
Surface Soils Obtained in the Background Study
Table 4-11 Summary Statistics for Concentrations of Selenium (mg/kg) in Samples of
Surface Soils Obtained in the Background Study
Table 4-12 Summary Statistics for Concentrations of Uranium (mg/kg) in Samples of Surface
Soils Obtained in the Background Study
Table 4-13 Summary Statistics for Concentrations of Vanadium (mg/kg) in Samples of
Surface Soils Obtained in the Background Study
Table 4-14 Summary Statistics for Constituents (n=ll) for the Drainage BSA #2 (2107 and
2018 Data Set)
Table 5-1 Data Validation Assessment of Relevant Field Data for Phase II Background Soil
Sampling
Table 5-2 Data Validation Assessment of Analytical Lab Data for Phase II Background Soil
Sampling
Table 5-3 Data Validation Assessment of Relevant Field Data for Phase III Soil Sampling
March 18, 2021
Rev. 1.2
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 5-4 Data Validation Assessment of Analytical Lab Data for Phase III Background
Soil Sampling
Table 5-5 Description of Measurement Type and Analytic Technique/Equipment used for
the Phase II Correlation Study
Table 5-6 Gamma Count Rates and Associated Activity Concentrations of Radium-226 in
Samples of Surface Soils obtained in the Phase II Correlation Study
Table 5-7 Co-Located: Soil Radium-226 Activity Concentrations, Static Gamma Count
Rate, and Exposure Rate Measurements
Table 5-8 Adjusted r2 Values for Regression of Non-Radiological Constituents on Ra-226, a
surrogate for Gamma Data
Table 5-9 Summary of Soil Sample Results
Table 5-10 ANOVA Table for Ordinary Least Square (OLS) Regression of Net Shielded
Gamma on Ra-226 for the Complete Correlation Data Set
Table 5-11 Outlying Data Points Excluded From the Second OLS Regression
Table 5-12 ANOVA Table for OLS Regression of Net Shielded Gamma on Ra-226 for the
Second Correlation Data Set
Table 5-13 ANOVA Table for OLS Regression of Ra-226 on Arsenic Soil Concentrations for
the Second Correlation Data Set
Table 5-14 ANOVA Table for OLS Regression of Ra-226 on Mercury Soil Concentrations
for the Second Correlation Data Set
Table 5-15 ANOVA Table for OLS Regression of Ra-226 on Molybdenum Soil
Concentrations for the Second Correlation Data Set
Table 5-16 ANOVA Table for OLS Regression of Ra-226 on Selenium Soil Concentrations
for the Second Correlation Data Set
Table 5-17 ANOVA Table for OLS Regression of Ra-226 on Uranium Soil Concentrations
for the Second Correlation Data Set
Table 5-18 ANOVA Table for OLS Regression of Ra-226 on Vanadium Soil Concentrations
for the Second Correlation Data Set
Table 5-19 Summary Statistics for Metals and Radiological Constituents in the Correlation
Data Set
March 18, 2021
Rev. 1.2
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 5-20 Adjusted r2 Values for Regression of Ra-226 on Metals and Net Shielded Static
Gamma Count Rate
Table 5-21 Result (p-value) of the SDC Test on Ra-226 Soil Activity Concentrations within
each BSA
Table 5-22 Investigation Level for Each of the Pooled BSAs
Table 6-1 Summary of HHSRE Soil Exposure Point Concentrations by Evaluated Area
Table 6-2 HHSRE Evaluation Areas and Assigned EPA Risk Calculator Area Correlation
Factors
Table 6-3 Summary of Grain Size Analysis of Soils
Table 6-4a Non-cancer HQ Results and Cancer Risk Results for Individual Non-Radiological
and Radiological PCOCs - On-Site Workers
Table 6-4b Non-cancer HI Results and Sum Cancer Risk Results for Non-Radiological and
Radiological PCOCs - On-Site Workers
Table 6-5a Non-cancer HQ Results and Cancer Risk Results for Individual Non-Radiological
and Radiological PCOCs - Adult Recreator Based on 24 Years of Exposure
Table 6-5b Non-cancer HI Results and Sum Cancer Risk Results for Non-Radiological and
Radiological PCOCs - Adult Recreator Based on 24 Years of Exposure
Table 6-6a Non-cancer HQ Results and Cancer Risk Results for Individual Non-Radiological
and Radiological PCOCs - Child Recreator
Table 6-6b Non-cancer HI Results and Sum Cancer Risk Results for Non-Radiological and
Radiological PCOCs - Child Recreator
Table 6-7a Non-cancer HQ Results and Cancer Risk Results for Individual Non-Radiological
and Radiological PCOCs - Combined Adult and Child Recreator
Table 6-7b Non-cancer HI Results and Sum Cancer Risk Results for Non-Radiological and
Radiological PCOCs - Combined Adult and Child Recreator
Table 6-8a Uncertainty Assessment - Non-cancer HQ Results and Cancer Risk Results for
Individual Non-Radiological and Radiological PCOCs - Adult Recreator Based
on 1 Year of Exposure
Table 6-8b Uncertainty Assessment - Non-cancer HI Results and Sum Cancer Risk Results
for Non-Radiological and Radiological PCOCs - Adult Recreator Based on 1
Year of Exposure
March 18, 2021
Rev. 1.2
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-9 Uncertainty Assessment - Relative Contributions of Ingestion, Dermal Contact,
and Inhalation Pathways to Total Risks
Table 6-10 Uncertainty Assessment - Comparison of HHSRE Soil Exposure Point
Concentrations for Ra-226 for Soil Depths of Zero to 6 Inches and Zero to 12
Inches and Calculated Risks to Adult Recreators
Table 6-1 la Summary of HHSRE Non-Radiological PCOC HQ Results for All Evaluated
Receptors and Areas
Table 6-1 lb Summary of HHSRE Arsenic and Ra-226 Cancer Risk Results for All Evaluated
Receptors and Areas
Table 7-1 Summary of EcoSRE Soil Exposure Point Concentrations by Evaluated Area and
Receptor Group
Table 7-2 Summary of Calculated EcoSRE Exposure Point Concentrations for Plants,
Invertebrates and Small Mammals by Evaluated Area and Receptor Group
Table 7-3a Summary of Non-Radiological and Radiological Ecological Screening Levels for
Soils Based on Plant Toxicity
Table 7-3b Summary of Non-Radiological TRVs for Mammalian and Avian Receptors
Table 7-4 HQ Results for Upland and Riparian Area Exposures to Non-Radiological and
Radiological PCOCs - Vegetation
Table 7-5a HQ Results for Riparian Area Exposures to Non-Radiological PCOCs -
Herbivorous Bird (Mourning Dove)
Table 7-5b HQ Results for Riparian Area Exposures to Radiological PCOC (Ra-226) -
Herbivorous Bird (Mourning Dove)
Table 7-6a HQ Results for Upland and Riparian Area Exposures to Non-Radiological PCOCs
- Herbivorous Mammal (Deer Mouse)
Table 7-6b HQ Results for Upland and Riparian Area Exposures to Radiological PCOC
(Ra-226) - Herbivorous Mammal (Deer Mouse)
Table 7-7a HQ Results for Upland Area Exposures to Non-Radiological PCOCs -
Insectivorous Bird (American Kestrel)
Table 7-7b HQ Results for Upland Area Exposures to Radiological PCOC (Ra-226) -
Insectivorous Bird (American Kestrel)
Table 7-8a HQ Results for Upland Area Exposures to Non-Radiological PCOCs -
Insectivorous Bird (Rock Wren)
March 18, 2021
Rev. 1.2
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-8b HQ Results for Upland Area Exposure to Radiological PCOC (Ra-226) -
Insectivorous Bird (Rock Wren)
Table 7-9a HQ Results for Upland and Riparian Area Exposures to Non-Radiological PCOCs
- Insectivorous Mammal (Desert Shrew)
Table 7-9b HQ Results for Upland and Riparian Area Exposures to Radiological PCOC
(Ra-226) - Insectivorous Mammal (Desert Shrew)
Table 7-10a HQ Results for Riparian Area Exposures to Non-Radiological PCOCs -
Omnivorous Mammal (Coyote)
Table 7-10b HQ Results for Riparian Area Exposure to Radiological PCOC (Ra-226) -
Omnivorous Mammal (Coyote)
Table 7-1 la HQ Results for Upland Area Exposures to Non-Radiological PCOCs -
Carnivorous Bird (Golden Eagle)
Table 7-1 lb HQ Results for Upland Area Exposures to Radiological PCOC - Carnivorous
Bird (Golden Eagle)
Table 7-12 Evaluation of Potential Risks to Spadefoot Toad from LCR Channel Sample
Results under the Wet Scenario
Table 7-13 Uncertainty Assessment of Receptor Selection - HQ Results for Upland and
Riparian Area Exposures to Non-Radiological and Radiological PCOCs by Soil
Invertebrates
Table 7-14 Uncertainty Assessment - Comparison of Ra-266 ssESLs to LANL (2017a) ESLs
of Similar Species
Table 7-15a Summary of EcoSRE HQ Results for All Evaluated Receptors and
Non-Radiological PCOCs
Table 7-15b Summary of EcoSRE HQ Results for All Evaluated Receptors and Radiological
PCOCs
Table 8-la Comparison of Human Health Risk Based Action Levels for Radium-226 and
Daughter Products in Soils to Comparable Ecological Receptor Risk Based
Action Levels
Table 8-lb Comparison of Human Health Risk Based Action Levels for Non-Radiological
PCOCs in Soils to Comparable Ecological Receptor Risk Based Action Levels
Table 9-1 Potential Pit Capacities
Table 9-2 Horizontal Correlations Between Exposure Rate and Static Gamma County Rate
Table 9-3 Vertical Correlations Between Exposure Rate and Ra-226 Concentrations in Soil
Table 9-4 Waste Volumes
March 18, 2021
Rev. 1.2
XV
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
LIST OF FIGURES
Figure 1-1
Site Location
Figure 1-2
AUM 457 PCOC Soils Concentrations
Figure 1-3
AUM 458 PCOC Soils Concentrations
Figure 1-4
AUM 459 PCOC Soils Concentrations
Figure 2-1
Site Location and Proposed Area of Potential Effect for Phase III Work
Figure 2-2
Weston Gamma Survey Data, AUM 457
Figure 2-3
Weston Gamma Survey Data, AUM 458
Figure 2-4
Weston Gamma Survey Data, AUM 459
Figure 2-5
Site Geology
Figure 2-6
Physical Conceptual Site Model for the Area of Potential Effect
Figure 2-7
Physical Conceptual Site Model for AUM 457
Figure 2-8
Physical Conceptual Site Model for AUMs 458 and 459
Figure 3-1
Locations of Proposed BSAs and Other Mine Related Disturbances
Figure 4-1
Gamma Scan Results for Alluvial BSA #1
Figure 4-2
Gamma Scan Results for Alluvial BSA #2
Figure 4-3
Gamma Scan Results for Drainage BSA #2
Figure 4-4
Gamma Scan Results for Terrace BSA #1
Figure 4-5
Gamma Scan Results for EPA QTer BRA
Figure 4-6
Gamma Scan Results for Little Colorado River BSA
Figure 4-7
Gamma Scan Results for Terrace BSA #2
Figure 4-8
Results of Mobile Gamma Scan Survey
March 18, 2021
Rev. 1.2
xvi
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Figure 4-9 Results of Mobile Gamma Scan Survey NE Quadrant
Figure 4-10 Results of Mobile Gamma Scan Survey NW Quadrant
Figure 4-11 Results of Mobile Gamma Scan Survey SE Quadrant
Figure 4-12 Results of Mobile Gamma Scan Survey SW Quadrant
Figure 4-13 Additional Scanning, AUM 457 (CPM), NE Quadrant
Figure 4-14 Additional Scanning Area, AUM 458 (CPM), SE Quadrant
Figure 4-15 Results of Mobile Gamma Scan Survey (CPM)
Figure 4-16 Results of Mobile Gamma Scan Survey (CPM), NW Quadrant
Figure 4-17 Results of Mobile Gamma Scan Survey (CPM), NE Quadrant
Figure 4-18 Results of Mobile Gamma Scan Survey (CPM), SE Quadrant
Figure 4-19 Results of Mobile Gamma Scan Survey (CPM), SW Quadrant
Figure 4-20 Boxplot Showing Alpha Surface Activity by Survey Group
Figure 4-21 Boxplot Showing Beta Surface Activity by Survey Group
Figure 4-22 Test Pit Locations and Maximum Gamma Readings
Figure 4-23 Test Pit Locations with Results of Gamma Survey (Compared to IL), NE
Quadrant
Figure 4-24 Test Pit Locations in Area of AUM 457
Figure 4-25 Test Pit Locations with Results of Gamma Scan Survey (Compared to IL), SE
Quadrant
Figure 4-26 Test Pit Locations in Area of AUMs 458 and 459
Figure 4-27 Test Pit Locations with Results of Gamma Scan Survey (Compared to IL), SW
Quadrant
Figure 4-28 Test Pit Locations with Results of Gamma Scan Survey (Compared to IL), NW
Quadrant
Figure 4-29 Boxplot Showing Soil Concentration of Radium-226 by Background Study Area
March 18, 2021
Rev. 1.2
XV/'/'
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Figure 4-30 Terrace BSA #2 Radium-226 Concentrations
Figure 4-31 Alluvial BSA #1 Radium-226 Concentrations
Figure 4-32 Alluvial BSA #2 Radium-226 Concentrations
Figure 4-33 EPA QTer Radium-226 Concentrations
Figure 4-34 Drainage BSA #2 Radium-226 Concentrations
Figure 4-35 Terrace BSA #1 Radium-226 Concentrations
Figure 4-36 Little Colorado River BSA Radium-226 Concentrations
Figure 4-37 Boxplot Showing Soil Concentrations of Arsenic by Background Study Area
Figure 4-38 Boxplot Showing Soil Concentrations of Mercury by Background Study Area
Figure 4-39 Boxplot Showing Soil Concentrations of Molybdenum by Background Study
Area
Figure 4-40 Boxplot Showing Soil Concentrations of Selenium by Background Study Area
Figure 4-41 Boxplot Showing Soil Concentrations of Uranium by Background Study Area
Figure 4-42 Boxplot Showing Soil Concentrations of Vanadium by Background Study Area
Figure 4-43 Terrace BSA #2 Metals Concentrations
Figure 4-44 Alluvial BSA #1 Metals Concentrations
Figure 4-45 Alluvial BSA #2 Metals Concentrations
Figure 4-46 EPA QTer BRA Metals Concentrations
Figure 4-47 Drainage Basin #2 Metals Concentrations
Figure 4-48 Terrace BSA #1 Metals Concentrations
Figure 4-49 Little Colorado River BSA Metals Concentrations
Figure 4-50 Boxplot Showing Soil Concentrations for Drainage BSA #2
Figure 5-1 Correlation Between Horizontal Gamma Survey Correlation Data and Soil
Radium Activity Concentration
March 18, 2021
Rev. 1.2
XV/'/'/'
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Figure 5-2 Correlation Between the Upper 95% Confidence Interval of the Mean Horizontal
Gamma Survey Response and Soil Radium Activity Concentration
Figure 5-3 Correlation Between High-Pressurized Ion Chamber Exposure Rate and Mean
Vertical Gamma Survey Response
Figure 5-4 Correlation Between Soil Radium-226 Activity Concentration and High-
Pressurized Ion Chamber Exposure Rate
Figure 5-5 Exposure Rate for the Entire APE
Figure 5-6 Correlation Between Radium-226 and Arsenic
Figure 5-7 Correlation Between Radium-226 and Gamma Count Rate
Figure 5-8 Correlation Between Radium-226 and Mercury
Figure 5-9 Correlation Between Radium-226 and Molybdenum
Figure 5-10 Correlation Between Radium-226 and Selenium
Figure 5-11 Correlation Between Radium-226 and Uranium
Figure 5-12 Correlation Between Radium-226 and Vanadium
Figure 5-13 Correlation Between Radium-226 and Gamma Count Rate With Outliers
Removed
Figure 5-14 Location of BSA Application Areas
Figure 5-15 Map of TENORM v NORM
Figure 5-16 Map of TENORM v NORM for NW Quadrant
Figure 5-17 Map of TENORM v NORM for NE Quadrant
Figure 5-18 Map of TENORM v NORM for SW Quadrant
Figure 5-19 Map of TENORM v NORM for SE Quadrant
Figure 5-20 Gamma Concentrations in Drainage Areas
Figure 9-1 AUM 457 LiDAR Data
March 18, 2021 xix Engineering Analytics, Inc.
Rev. 1.2
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Figure 9-2 AUM 457 Conceptual Repository Design, Channel Cover Surface
Figure 9-3 AUM 457 Conceptual Repository Design, Mound Cover Surface
Figure 9-4 AUM 458 LiDAR Data
Figure 9-5 AUM 458 Conceptual Repository Design, Channel Cover Surface
Figure 9-6 AUM 458 Conceptual Repository Design, Mound Cover Surface
Figure 9-7 AUM 458 Conceptual Repository Design, Raised Mound Cover Surface
Figure 9-8 Results of Mobile Gamma Scan Survey Above IL with Test Pit Locations
Figure 9-9 Results of Mobile Gamma Scan Survey Above IL with Test Pit Locations, NW
Quadrant
Figure 9-10 Results of Mobile Gamma Scan Survey Above IL with Test Pit Locations, NE
Quadrant
Figure 9-11 Volume Estimate Above IL at AUM 457
Figure 9-12 Results of Mobile Gamma Scan Survey Above IL with Test Pit Locations, SW
Quadrant
Figure 9-13 Volume Estimate Above IL at AUM 458
Figure 9-14 Results of Mobile Gamma Scan Survey Above IL with Test Pit Locations, SE
Quadrant
Figure 9-15 Risk Based Results of Mobile Gamma Scan Survey Above 160 pCi/g and Test Pit
Locations
Figure 9-16 Risk Based Results of Mobile Gamma Scan Survey Above 160 pCi/g, NW
Quadrant
Figure 9-17 Risk Based Results of Mobile Gamma Scan Survey Above 160 pCi/g, NE
Quadrant
Figure 9-18 Volume Estimate Above 160 pCi/g at AUM 457
Figure 9-19 Risk Based Results of Mobile Gamma Scan Survey Above 160 pCi/g, SW
Quadrant
March 18, 2021 xx Engineering Analytics, Inc.
Rev. 1.2
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Figure 9-20 Volume Estimate Above 160 pCi/g at AUM 458
Figure 9-21 Risk Based Results of Mobile Gamma Scan Survey Above 160 pCi/g, SE
Quadrant
Figure 9-22 Risk Based Results of Mobile Gamma Scan Survey and Volume Estimate Above
12 pCi/g and Test Pit Locations
Figure 9-23 Risk Based Results of Mobile Gamma Scan Survey and Volume Estimate Above
12 pCi/g, NW Quadrant
Figure 9-24 Risk Based Results of Mobile Gamma Scan Survey and Volume Estimate Above
12 pCi/g, NE Quadrant
Figure 9-25 Risk Based Results of Mobile Gamma Scan Survey and Volume Estimate Above
12 pCi/g, SW Quadrant
Figure 9-26 Risk Based Results of Mobile Gamma Scan Survey and Volume Estimate Above
12 pCi/g, SE Quadrant
Figure 9-27 Risk Based Results of Mobile Gamma Scan Surveys Comparing Above 12 pCi/g
and Above 160 pCi/g and Test Pit Locations
Figure 9-28 Risk Based Results of Mobile Gamma Scan Surveys Comparing Above 12 pCi/g
and Above 160 pCi/g and Test Pit Locations, NE Quadrant
Figure 9-29 Risk Based Results of Mobile Gamma Scan Surveys Comparing Above 12 pCi/g
and Above 160 pCi/g and Test Pit Locations, SE Quadrant
LIST OF APPENDICES
Appendix A Weston Solutions (2012) Preliminary Assessment
Appendix B Weston Solutions (2014) Site Inspection Report
Appendix C EPA Technical Memorandum (2016b), Identification of Section 9 Lease
Abandoned Uranium Mine Site Background
Appendix D Approved QMP
Appendix E Approved DMP
March 18, 2021 xxi Engineering Analytics, Inc.
Rev. 1.2
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Appendix F
Approved QAPP
Appendix G
Approved Phase I Work Plan
Approved H
Approved Phase II Field Sampling Plan
Appendix I
Approved Phase II Work Plan
Appendix J
Approved Phase II Summary Report
Appendix K
Approved Phase III Field Sampling Plan
Appendix L
Approved Phase III Work Plan
Appendix M
Approved Phase III Summary Report
March 18, 2021
Rev. 1.2
xxii
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
ACRONYMS
95UCL 95% Upper Confidence Limit
ACF Area C orrecti on F actor
ADD Average Daily Dose
ADEQ Arizona Department of Environmental Quality
AOC Administrative Settlement Agreement and Order on Consent
ANOVA Analysis of Variance
APE Area of Potential Effect
AUF Area Use Factor
AUM Abandoned Uranium Mine
BCG Biota Concentration Guide
BLM U.S. Bureau of Land Management
BOR U.S. Bureau of Reclamation
BRA Background Reference Area
BSA Background Study Area
BTF Biota Transfer Factor
CERCLA Comprehensive Environmental Response, Compensation, and Liability Act
CERCLIS Comprehensive Environmental Response, Compensation, and Liability
Information System
cpm Counts per Minute
cps Counts per Second
CSF Cancer Slope Factor
CSM Conceptual Site Model
CY Cubic Yards
DCF Dose Conversion Factor
DMP Data Management Plan
DOE Department of Energy
DQO Data Quality Objective
DSC Dwass, Steel, Critchlow test
ECio Concentration that causes an effect in 10% of organisms
EC20 Concentration that causes an effect in 20% of organisms
EcoCSM Ecological Conceptual Site Model
EcoSRE Ecological Streamlined Risk Evaluation
EcoSSL Ecological Soil Screening Level
EECA Engineering Evaluation/Cost Analysis
EPA U.S. Environmental Protection Agency
EPC Exposure Point Concentration
ERB Equipment Rinsate Blank
ESL Ecological Screening Level
FSP Field Sampling Plan
GIS Geographic Information System
HASP Health and Safety Plan
HHSRE Human Health Streamlined Risk Evaluation
HI Hazard Index
March 18, 2021 xxiii Engineering Analytics, Inc.
Rev. 1.2
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
HQ
Hazard Quotient
HQloael
Hazard Quotient based on the TRVloael
HQnoael
Hazard Quotient based on the TRVnoael
IL
Investigation Level (IL for Ra-226 is 1.24 above background)
ILCR
Incremental Lifetime Cancer Risk
LADD
Lifetime Average Daily Dose
LCR
Little Colorado River
LiDAR
Light Detection and Ranging
LOAEL
Lowest Observed Adverse Effect Level
MARS SIM
Multi-Agency Survey and Site Investigation Manual
MDCscan
Scanning Minimum Detectable Concentration
MDL
Minimum Detectable Limit
mg/kg
Milligrams per Kilogram
MQO
Measurement Quality Objective
n
Number of Samples
NAMLRP
Navajo Abandoned Mine Land Reclamation Program
NNEPA
Navajo Nation Environmental Protection Agency
NOAEL
No Observed Adverse Effect Level
NORM
Naturally Occurring Radioactive Material
OLS
Ordinary Least Squared
OSWER
Office of Solid Waste and Emergency Response (Now OLEM: Office of Land
and Emergency Management)
PA
Preliminary Assessment
pCi/g
PicoCuries per Gram
PCOC
Potential Contaminants of Concern (defined in the 2016 AOC as Ra-226,
uranium, arsenic, molybdenum, mercury, selenium and vanadium)
HPIC
High-Pressurized Ion Chamber
PNEC
Probable No Effect Concentration
ppmdw
Parts per Million, dry weight
PRG
Preliminary Remediation Goal
QA
Quality Assurance
QC
Quality Control
QAPP
Quality Assurance Project Plan
QMP
Quality Management Plan
r2
Coefficient of Determination
Ra-226
Radium 226, a specific isotope of the element radium
rbAL
Risk Based Action Level
RfD
Reference Dose
RME
Reasonable Maximum Exposure
RSE
Removal Site Evaluation
SF
Slope Factor
SI
Site Inspection
ssESL
Site-specific Ecological Screening Level
SQuiRT
NOAA Screening Quick Reference Tables
SUF
Seasonal Use Factor
March 18, 2021
Rev. 1.2
xx iv
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
TENORM
Technologically Enhanced Naturally Occurring Radioactive Material
TF
Transfer Factor
tpd
Tons per Day
TRV
Toxicity Reference Value
TRVloael
Toxicity Reference Value based on the LOAEL value
TRVnoael
Toxicity Reference Value based on the NOAEL value
UCL
Upper Confidence Limit
USACE
United States Army Corps of Engineers
UTL
Upper Tolerance Limit
March 18, 2021
Rev. 1.2
XXV
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
EXECUTIVE SUMMARY
This Removal Site Evaluation (RSE) Report documents the methods, results, and evaluation of
the tasks outlined in response to Administrative Settlement Agreement and Order on Consent
(AOC) (EPA, 2016a). The AOC (EPA, 2016a) included these three phases of work:
• Phase I: Cultural Resources Surveys, Biological Survey and Signage.
• Phase II: Background Determination, Gamma Survey, and Soil Correlation.
• Phase III: Removal Site Evaluation, Vertical Profiling, Risk Evaluation, and
Removal Volume Calculations.
This RSE Report consolidates and summarizes the results of the respective work plans, summary
reports, and analysis.
The project area is located in the Little Colorado River (LCR) Valley in Coconino County,
Arizona (Figure 1-1). The Site falls within the boundary of the CO Bar Ranch, which is owned
and operated by the Respondent, headquartered in Flagstaff, Arizona. Section 9 is owned by the
Respondent. A portion of Section 10 on CO Bar Ranch (i.e., the portion west of the LCR) is
owned by the Bureau of Land Management (BLM) and leased by the Respondent. The Navajo
Nation surrounds this general area and is located approximately 10 miles to the west of Section
9, one mile to the north of Section 9, and is on the adjacent Section 10 on the east side of the
LCR. The Navajo Nation owns the eastern majority of Section 10 with the LCR floodplain as the
dividing feature between ownership in Section 10. The land to the south is a mix of federal,
state, and private owners. The project Site is not currently used by the Respondent for any
purposes involving livestock or human activity. There are no structures or facilities present
within the project Site related to any Respondent operations.
Field activities in support of completion of the phases of work included site mapping, gamma
radiation scanning, concrete surface activity surveying, surface soil sampling, and subsurface soil
sampling.
The lateral extent of soils characterized as technologically enhanced naturally occurring
radioactive material (TENORM) presented in the Phase II Summary Report (dated August 9,
2018; approved August 17, 2019 [EA, 2018a]) which exceeded the investigation level (IL)
within the Area of Potential Effect (APE) along with the vertical profiling results were used to
develop the volume estimate of TENORM above the IL:
• The IL for radium-226 (Ra-226) is 1.24 picoCurie per gram (pCi/g) above background
(AOC, Appendix A, Section 1.3)
• The resulting IL was calculated for three landforms within the APE:
o Little Colorado River (LCR) (2.76 pCi/g)
o Drainage (6.07 pCi/g)
o Alluvial (6.59 pCi/g)
• The estimated volume of TENORM material exceeding the IL within the APE is 31,550
cubic yards (CY).
March 18, 2021
Rev. 1.2
1
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Conceptual on-Site repository designs were developed for Abandoned Uranium Mine
(AUM) 457 and AUM 458:
• The pit at AUM 457 has an estimated capacity of 1,560 CY.
• The pit at AUM 458 has an estimated capacity of 5,670 CY.
The potential risks to human health and geological receptors were developed from exposure to
seven potential contaminants of concern (PCOCs). Potential cancer risks to humans were
evaluated for arsenic and Ra-226. Potential non-cancer risks were evaluated for arsenic,
mercury, molybdenum, selenium, uranium, and vanadium. Potential cancer risks to arsenic in
soils were evaluated in the context of EPA's acceptable risk range of lxlO"6 to lxlO"4.
Additionally, in accordance with the approved Phase III Work Plan (EA, 2019c), potential
radiological cancer risks were evaluated in the context of the lxlO"4 risk. This is comparable to
the 12 mrem/year acceptable dose level per OSWER Directive No. 9200.4-18 (EPA 1997a;
3xl0"4). Non-cancer human health and ecological risks are evaluated in the context of a single
risk value.
The results of the Human Health Streamline Risk Evaluation (HHSRE) determined:
• All potential cancer risks are below or within the Environmental Protection Agency's
(EPA) acceptable risk range, except for Ra-226 in AUM 458.
• All potential non-cancer risks are below EPA's acceptable risk value.
The results of the Ecological Streamlined Risk Evaluation (EcoSRE) determined:
• All potential risks for the receptors to Ra-226 in Site soils for all evaluated areas are
below EPA's acceptable risk value.
• All potential risks for receptors to non-radiological PCOCs are below the EPA acceptable
risk value for the non-radiological across all receptors and evaluated areas except for
molybdenum in soils in AUM 458 to plants and small mammals.
• All potential risks for larger mammals to non-radiological PCOCs are below EPA's
acceptable risk value.
Risk based action level (rbAL) volume estimate:
• The calculated Ra-226 rbAL varies by the evaluated receptor and exposure scenarios.
For longer-term exposures (i.e., recreator exposures of 24 years for adult or combined
adult and child recreator exposures of 26 years), the rbALs range from 12 to 13 pCi/g.
• The ecological Ra-226 rbAL is 160 pCi/g, based on protection of small mammals (desert
shrew) and birds (rock wren).
• The volume of TENORM estimated to exceed the IL is 31,550 CY. The calculated
volume of material above the rbAL of 12 pCi/g is 10,036 CY and the calculated volume
of material above the rbAL of 160 pCi/g is 942 CY.
This report has been informed by 128 interagency meetings during the past 46 months. The
HHSRE analyses demonstrate that all results occur within the EPA acceptable risk range, except
for Ra-226 in soils from individual AUMs. The EcoSRE analyses demonstrate all of the results
occur within EPA acceptable risk range, except molybdenum. A total 942 CY of TENORM is
March 18, 2021
Rev. 1.2
2
Engineering Analytics, Inc.
-------
Babbitt Ranches, LLC
Removal Site Evaluation Report Milestone Hawaii Stewardship Project
above the rbAL value of 160 pCi/g. The property is deed restricted. Entry upon the property is
prohibited pursuant to the deed restriction recorded in Coconino County and is in violation of
Arizona trespass law.
March 18, 2021
Rev. 1.2
3
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
1.0 INTRODUCTION
Babbitt Ranches, LLC and C.O. Bar Inc. (Respondent) through its land use ethic, conservation
practices, and scientific ventures, is committed to its role as landowner and land steward, and as
such is dedicated to treating the land and its communities with utmost respect, and participating
with ecological processes. Babbitt Ranches voluntarily entered into an Administrative
Settlement Agreement and Order on Consent (AOC) on October 25, 2016 with the U.S.
Environmental Protection Agency (EPA) to perform an interim removal action, including a
removal site evaluation (RSE), related to historic uranium mining activities on land currently
owned by Respondent (the "Milestone Hawaii Stewardship Project" or "Project") located in
Section 9, Township 27 North, Range 10 East of the Gila and Salt River Base and Meridian, near
Cameron, Coconino County, Arizona (the "Site") (Figure 1-1). The AOC (EPA, 2016a)
included three phases of work:
• Phase I: Cultural Resources Surveys, Biological Survey and Signage.
• Phase II: Background Determination, Gamma Survey, and Soil Correlation.
• Phase III: Removal Site Evaluation, Vertical Profiling, Risk Evaluation, and
Removal Volume Calculations.
This RSE Report consolidates and summarizes the preceding three phases of data collection and
analysis.
1.1 Purpose and Objectives
The purpose of this report is to present the results of the RSE and all supporting documentation
from the three phases of work listed above. The objective of this report is to fulfill the
requirement for a Final RSE and Completion Report set out in Section 5.3 of the Scope of Work
for Removal Site Evaluation AOC (EPA, 2016a).
1.2 Initial Evaluation
Weston Solutions, Inc. (Weston) published a Preliminary Assessment (PA) report related to the
legacy uranium production activities on the Site for the EPA in 2012 (Weston, 2012). Field
activities performed by Weston in 2010 in support of the PA were limited to a reconnaissance
and a low density (widely spaced transects) gamma radiation survey of the Site. Specific
information regarding the instrumentation used to perform the gamma radiation survey or the
survey protocol is not provided in Weston (2012). The EPA indicated that the detector height
used was 1 meter (3 feet) above ground surface. The PA reported in that the Hazard Ranking
System factors for the Site include uranium waste rock generated during mining, surface water
from the Site flows into the Little Colorado River, no active drinking water wells within four
miles of the site, and no schools, daycare centers, or occupied residences on Site or within 200
feet of the Site. As presented in the Phase III Work Plan the nearest residence is about 5.1 miles
from the Site. The Weston PA is provided in Appendix A.
March 18, 2021
Rev. 1.2
4
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Weston performed a follow-up Site Inspection (SI) of the Site for the EPA, publishing their
results in 2014 (Weston, 2014). The SI field activities performed by Weston in support of the SI
included the following:
• Additional (mobile) gamma radiation survey over a larger area than in the PA.
• Stationary (static) gamma radiation measurements.
• Soil sampling both of presumed "source" and "background" areas. Soils samples were
collected of surficial material (0 to 6-inch depth) and, in some cases, soil samples were
also collected from deeper horizons (6 to 12-inch depth and 12 to 18-inch depth).
• Sediment sampling in drainages, depressions within mined areas, and the riparian
corridor adjacent to the Little Colorado River (LCR). Sediment samples were collected
from surficial material only.
• A wetlands evaluation.
Select chemistry and activity data in soils and sediments at the Site from the SI (Weston, 2014) is
illustrated on Figures 1-2, 1-3, and 1-4. Additional information on the concentrations of metals,
metalloids, and radionuclides in soils and sediments is available in the SI Report (Weston, 2014).
Weston (2014) reported using a 2-inch by 2-inch sodium iodide detector to perform the gamma
survey, taking measurements at one-second intervals. The "field-of-view" of the detector was
estimated by Weston (2014) to be a circle one-meter (3.3 feet) in diameter and was reported to be
1 meter (3 feet) above ground surface in Appendix H of the Weston report (2014).
The SI report presented Hazard Ranking System factors of contaminated soil from historic
mining that have the presence of U-238, Ra-226, arsenic, lead, mercury, and molybdenum.
Weston also reports that contaminate soil appears to have migrated into the western reaches of
the Little Colorado River. The Weston SI is provided in Appendix B.
Weston and EPA personnel performed additional background reconnaissance at the Site on July
21, 2016 and proposed background reference areas in their memo dated October 26, 2016 (EPA,
2016b). The EPA memo is provided in Appendix C.
1.3 Work Completed Under Current AOC
The AOC (EPA, 2016a) involved three phases of work including Phase I Cultural Resources
Surveys, Biological Survey and Signage; Phase II Background Determination and Gamma
Survey; and Phase III Removal Site Evaluation. Numerous documents have been prepared in
support of the three phases of work. This RSE Report is supported by these additional Project
documents:
• Health and Safety Plan (HASP) (EA, 2016)
• Quality Management Plan (QMP) (EA, 2017b)
• Data Management Plan (DMP) (EA, 2017c)
• Quality Assurance Project Plan (QAPP) (EA, 2017f)
• Phase I Work Plan (EA, 2017a)
March 18, 2021
Rev. 1.2
5
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
• Phase II Field Sampling Plan (FSP) (EA, 2017d)
• Phase II Work Plan (EA, 2017e)
• Phase II Summary Report (EA, 2018a)
• Phase III Field Sampling Plan (EA, 2018b)
• Phase III Work Plan (EA, 2019c)
• Phase III Summary Report (EA, 2020)
The Health and Safety Plan (HASP) was prepared to address procedures for project health and
safety. The plan included basic safety procedures to follow while on site, emergency room
directions, field activities and equipment description, an analysis of site and project hazards and
hazard mitigation plans, training requirements, medical surveillance requirements, personal
protective equipment, exposure monitoring, site evacuation procedures, decontamination
procedures, and job safety analyses.
The Quality Management Plan (QMP) was prepared to support the activities completed under the
AOC. The objective of the quality program was to ensure an appropriate level of team technical
expertise related to AUM site characterization and restoration, and to ensure sufficient and
appropriate data and information to support defensible decision making for the Project. The
QMP describes the quality program and related systems, which are structured to support the
program objectives. The QMP also describes the policies and systems for implementing and
assessing the effectiveness of the quality program. The QMP was prepared in accordance with
the U.S. Environmental Protection Agency (EPA) document entitled, EPA Requirements for
Quality Management Plans, EPA QA/R-2 (EPA, 2001), and is compliant with ASQ/ANSI
E4:2014 Quality Management Systems for Environmental Information and Technology
Programs (ASQ, 2014). The approved QMP is provided in Appendix D.
The Data Management Plan (DMP) was intended for use with all data collection work associated
with the Milestone Hawaii Stewardship Project under the current AOC. The DMP provided
guidance associated with data collection, processing, reporting, and storage for sampling,
analysis, monitoring, and other efforts to ensure that data collected was consistent and complete
within the Site activities. The DMP included data types, formats, data management processes,
data quality checks, and end-use products appropriate for supporting the Milestone Hawaii
Stewardship Project. The approved DMP is provided in Appendix E.
The Quality Assurance Project Plan (QAPP) established the quality assurance requirements for
environmental and engineering data collection to be implemented pursuant to the AOC (EPA,
2016a). The purpose of the QAPP was to provide guidance regarding the manner in which
quality assurance (QA) and quality control (QC) procedures were applied to produce data that
are scientifically valid, of documented quality, and legally defensible. Specific elements
required in the QAPP included: project management, measurement data acquisition, assessment
and oversight, data review and verification, and usability. The approved QAPP is provided in
Appendix F.
The purpose of the Phase I Work Plan was to provide a plan and approach for installation of
bilingual (English and Navajo) warning signs at the Project site. The objective of the Phase I
Work Plan was to install sufficient signage to inform those that might access the Site of the
March 18, 2021
Rev. 1.2
6
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
potential hazards that may be present. The approved Phase I Work Plan is provided in Appendix
G.
The objective of the Phase II Field Sampling Plan (FSP) was to provide guidance to field
personnel by defining the number, type, and location of samples to be collected; the type of
analyses to be performed on these samples; and the rationale behind the sampling design and
analytical program. The Phase II FSP covered work to be performed under Phase II as defined in
Appendix A of the AOC (EPA, 2016a). The approved Phase II FSP is provided in Appendix H.
Specifically, the Phase II FSP covered the following Phase II tasks:
• The Background Study.
• The Transect Gamma Survey.
• Soil Sampling for Gamma Survey - Soil Concentration Correlation Study.
The Phase II Work Plan covered work to be performed under Phase II as defined in Appendix A
of the AOC (EPA, 2016a). The approved Phase II Work Plan is provided in Appendix I.
Phase II consisted of the following four tasks:
1. The Background (desktop) Study, which identified potential background study areas and,
once these areas were approved by the EPA, established background levels in soils and
sediments for gamma emissions and potential contaminants of concern (PCOCs) in areas
not impacted by technologically enhanced naturally occurring radioactive material
(TENORM).
2. The Transect Gamma Survey, which supported defining the lateral extent of those areas
impacted by mine-related TENORM as well as the magnitude of the gamma emissions
within the mine-related TENORM impacted areas.
3. Soil Sampling for Gamma Scan - Soil Concentration Correlation Study, which had the
goal of establishing mathematical relationships to accurately estimate PCOC levels in
soils and sediments based on their gamma radiation level.
4. Summary Report, which summarized the Phase II results and provided the raw data
generated by the work.
The Phase II Summary Report documented the methods, results, and evaluation of the Phase II
tasks. The approved Phase II Summary Report is provided in Appendix J. The report provided a
detailed discussion of:
• The background data population statistics.
• A site-wide map of the predicted gamma radiation exposure rates.
• The correlations between the PCOCs and gamma emission rate.
• Deviations from the Phase II Work Plan.
Phase III of the Project consisted of the following four tasks as defined in Section 2.3 of
Appendix A to the AOC (EPA, 2016a):
1. Characterization of surface, subsurface soils, and sediment.
2. Characterization (volume) of pits.
March 18, 2021
Rev. 1.2
7
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
3. Streamlined risk evaluations.
4. Waste volumes.
The Phase III FSP covered characterization of the surface and subsurface soils and sediments
The Phase III FSP (EA, 2018b) was specific to Phase III work as listed above. Data required to
characterize the volume of the mining pits was completed in 2016 with the collection of high
resolution Light Detection and Ranging (LiDAR) topographic data for the Site. In addition to
the Phase III field investigation, limited field work was performed as a continuation of sampling
originated under Phase II. The approved Phase III FSP is provided in Appendix K.
The Phase III Work Plan (EA, 2019c) was specific to the performance of the Phase III work
items as defined in Appendix A of the AOC (EPA, 2016a) and listed above. The approved Phase
III Work Plan is provided in Appendix L.
The Phase III Summary Report (EA, 2020) documented the methods, results, and evaluation of
the tasks outlined in the Phase III Work Plan (approved on September 13, 2019). The approved
Phase III Summary Report is provided in Appendix M. The Phase III Summary Report provided
a detailed discussion of:
• Vertical profile of soils above investigation level (IL).
• Conceptual on-Site pit volume estimates.
• Human Health Streamlined Risk Evaluations.
• Ecological Streamlined Risk Evaluation.
• Development of volume estimates above the risk based action level (rbAL) and IL.
March 18, 2021
Rev. 1.2
8
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
2.0 SITE SETTING
2.1 Site Location
The project area is located in the Little Colorado River (LCR) Valley in Coconino County,
Arizona (Figure 1-1). Areas affected by historical uranium mining west of the LCR on Section 9
and Section 10 of Township 27 North, Range 10 East of the Gila and Salt River Base and
Meridian comprise the Site (Figure 2-1). The Site falls within the boundary of the CO Bar
Ranch, which is owned and operated by the Respondent, headquartered in Flagstaff, Arizona.
Section 9 is owned by the Respondent. A portion of Section 10 on CO Bar Ranch (i.e., the
portion west of the LCR) is owned by the Bureau of Land Management (BLM) Reclamation and
leased by the Respondent. The Navajo Nation surrounds this general area and is located
approximately 10 miles to the west of Section 9, one mile to the north of Section 9, and is on the
adjacent Section 10 on the east side. The Navajo Nation owns the eastern majority of Section 10
with the LCR floodplain as the dividing feature between ownership in Section 10. The project
Site is not currently used by the Respondent for any purposes involving livestock or human
activity. There are no structures or facilities present within the project Site related to any
Respondent operations.
The Arizona Department of Environmental Quality (ADEQ) conducted a uranium site discovery
project in 2007 (ADEQ, 2007) to identify potential uranium mining impacts in Arizona that
might warrant further investigation. This project identified the Section 9 Lease sites. Also, in
2007 the United States Army Corps of Engineers (USACE), EPA, the Navajo Nation
Environmental Protection Agency (NNEPA), and the Navajo Abandoned Mine Land
Reclamation Program (NAMLRP) issued an AUM Geographic Information System (GIS) Report
compiling the findings from earlier investigations of the uranium mining operations throughout
the Navajo Nation; the Section 9 Lease sites were identified in the report. The U.S.
Environmental Protection Agency (EPA) has identified three abandoned uranium mines (AUMs)
that potentially affect the Site: AUM 457, AUM 458, and AUM 459. These are shown on Figure
2-1.
The Site is defined in Section III of the AOC as:
"Site " shall mean and include the Section 9 Lease Mine, including Section 9 of Township 27
North, Range 10 East, including the areas depicted in Appendix A, and other areas where
hazardous substances from Section 9 have been deposited, stored, disposed of, placed, or
otherwise came to be located on Section 10 of Township 27 North, Range 10 East.
The EPA included the Site in the Comprehensive Environmental Response, Compensation, and
Liability Information System (CERCLIS) on October 10, 2011 as EPA ID No. NNN000909110
(Weston, 2012).
The three AUMs that potentially affect the Site have been described by the EPA in the AOC as
follows:
• Abandoned Uranium Mine ("AUM") AUM 457 comprises approximately 16.5 acres,
is located on the western banks of the Little Colorado River, and is the northern most
of the three mining areas investigated by EPA as the "Section 9 Lease Site. " A UM
March 18, 2021
Rev. 1.2
9
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
457 is characterized by a former borrow pit, a former pond, and the remnants of
facilities which former operators claimed could upgrade uranium ore, including a
clearly visible foundation and partially intact walls. Un-reclaimed mining-related
uranium waste rock, and various wood/metal mining-related debris are present within
the footprint of AUM 457. ... A portion of AUM 457 extends east of the boundary of
Section 9 onto Section 10, which is owned by the United States. ...
• AUM 458 comprises approximately 9.3 acres, is located approximately 0.25 miles
west of the Little Colorado River, and is the most central of the three mining areas,
approximately 0.5 miles south of AUM 457 and 1,000 feet northwest of AUM 459.
AUM 458 is characterized by a centralized recessed pit/depression with standing
water and vegetation, surrounded by un-reclaimed mining-related uranium waste
rock, and various wood/metal mining-related debris. ...
• AUM 459 comprises approximately 13.3 acres, is located approximately 1,000 feet
west of the Little Colorado River1, and is the southern most of the three mining areas,
approximately 1,000 feet southeast of AUM 458 and 0.75 miles south of AUM 457.
AUM 459 is characterized by the presence of three pit areas each surrounded by un-
reclaimed mining-related uranium waste rock, and various wood/metal mining-related
debris. Most, and possibly all, of AUM 459 is located south of the boundary of Section
9 on property owned by the State.
In addition to the mining features and structures contained within the "approximate mining
areas" associated with AUMs 457 and 458, and materials that have come to be located in Section
9 from mining operations in AUM 459 as established by the EPA, Appendix A to the AOC
includes these additional "Areas to be Addressed":
• Areas of technologically enhanced naturally occurring radioactive material
(TENORM) in the immediate vicinity of the AUMs (step-out areas) at the discretion
of the EPA.
• Mine haul roads and shoulders (as defined in EPA, 2016a).
• Little Colorado River riparian corridor (as defined in EPA, 2016a).
• Drainages (as defined in EPA, 2016a).
The currently proposed Area of Potential Effect (APE) is illustrated on Figure 2-1. The APE is
the area anticipated to have been impacted or that may be impacted by investigation activities.
For purposes of this Project, the eastern Site boundary has been established as 5 meters (15 feet)
west of the centerline of the Little Colorado River (further defined as USGS 1969 mapping).
Figure 2-1 also presents the approximate boundaries of the mining areas as defined by Weston
(2012) and background study areas (BSAs).
1 The Little Colorado River channel changes with time and the distances provided from the AOC are for reference
only.
March 18, 2021
Rev. 1.2
10
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
2.2 Site History
2.2.1 Land Ownership History
The land ownership history has been described by the EPA in the AOC as follows:
• From August 6, 1912 through June 20, 1960, Section 9 was owned sequentially by
Babbitt Bros. Lands, Inc. (1921-1954) and CO Bar Livestock Company (1954-1960),
subsidiaries of Babbitt Brothers Trading Company, a precursor to Babbitt Ranches LLC.
• On June 20, 1960, CO Bar Livestock Company sold Section 9 in an installment sale,
conveying title to Arizona Title Guarantee and Trust Company, as Trustee for John and
Carolyn D. Haynes, George B. and Mary Cady, and B. T. Investment Corporation. CO
Bar Livestock carried back a portion of the purchase price.
• ... On November 23, 1971, Arizona Title and Trust Company conveyed title of Section 9
back to CO Bar Livestock Company. Through subsequent transactions between related
entities, Respondent C.O. Bar, Inc. became the owner.
2.2.2 Mining History
The mining history has been described by the EPA in the AOC as follows:
• Uranium was first reported in the Cameron area in 1950, and mining ceased by 1963.
Mining occurred on Section 9 from 1957 to 1962. In 1957, Arrowhead Uranium, a
subsidiary of Rare Metals Corporation of America ("Rare Metals"), leased the rights to
Section 9 from CO Bar Livestock Company, and began an open pit mining operation. In
the first year, Rare Metals shipped 17.95 tons of low grade ore from the Site to the Rare
Metals Mill in Tuba City and paid royalties to CO Bar Livestock Company. By 1958
Rare Metals ceased mining operations at the Site, and C.L. Rankin acquired the lease
from CO Bar Livestock Company. C.L. Rankin shipped 87.21 tons of low grade ore in
1958, and 234.32 tons of low grade ore in 1959.
• In 1959, Murchison Ventures, Inc. ("Murchison Ventures"), owned by John Milton
Addison and others, acquired the lease of Section 9. Murchison Ventures built a small
processing plant known as a "Benson Upgrader " in the northeast part of Section 9, near
one of the former pits (AUM 457). Murchison Ventures claimed the Benson Upgrader
would separate the waste rock from previous mining activities into a "sellable " higher
grade slime fraction and a lower grade sand fraction. Murchison Ventures sent a
shipment of 10.76 tons of upgraded ore to the Tuba City Mill in 1959. In 1960,
Murchison Ventures modified the plant and sent another shipment of 11.31 tons of ore to
the mill. John Milton Addison was adjudicated bankrupt on June 27, I960.2 On this
date, all funds and assets—including the mining lease for the east half of Section 9—of
John Milton Addison and various corporate entities with which he was affiliated came
under the jurisdiction of the United States District Court for the Northern District of
Texas (Dallas). In 1961, John Milton Addison, along with six associates, was (SIC)
convicted offraud, conspiracy, and federal security violations related to the upgrading
operation.
1 SECv. John Milton Addison, Murchison Ventures, etal., 194 FSupp. 709 (N.D. Tex., 1961), Page 714.
March 18, 2021
Rev. 1.2
11
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
• In October 1960, a group of Addison's investors incorporated as Milestone Hawaii to
assume control over the Murchison Ventures operation on Section 9. As noted above, this
was after the title to Section 9 was conveyed to Arizona Title and Trust Company in June
1960. During the summer of 1961, Milestone Hawaii demolished the original Benson
Upgrader on Section 9 and replaced it with a larger upgrader, and in March 1962
shipped 23.93 tons of low-grade material to the Tuba City Mill.
• Mining operations ceased at the Site in 1961; no known mining activities have been
performed at the Site since. While operational, the Atomic Energy Commission estimated
the uranium ore production volume at the Section 9 Lease Mine, which included all three
AUMs, as 386 tons [AUMs 457 and 458 are located on Section 9 and AUM 459 is
located on Arizona state land].
The Benson Upgrader operations were run by John Milton Addison (Chenoweth, 1993). It was
stated that the Benson Upgrader could treat 1,000-1,500 tons per day of ore material averaging
0.01-0.03% U3O8 and produce 200-300 tons per day of ore material containing 0.25-0.30%
U3O8 (Chenoweth, 1993).
A 10.76 ton shipment identified as having originated from the CO Bar Livestock Company lease
that averaged 0.16% U3O8 was shipped to the Tuba City Mill (Chenoweth, 1993).
On December 4, 1959, the trial of John Addison began for theft and violating Texas state
securities laws in San Antonio; Addison was acquitted.
In April 1960 the Benson Upgrader was modified and another ore shipment from the Murchison
Ventures Mill was sent to Tuba City. This 11.31ton shipment averaged 0.16% U3O8
(Chenoweth, 1993).
On May 17, 1960, in a federal action for fraud Addison was indicted by a federal grand jury in
Fort Worth, TX, on charges alleging fraud, conspiracy, and violations of federal securities
regulations.
On June 15, 1960, fourteen employees at "Cameron Millsite" (i.e., Benson Upgrader) were
forced to attend a 7-hour-long meeting by Addison and held there by an armed security guard
force. Addison was charged with false imprisonment.
On June 20, 1960, CO Bar relinquished ownership of Section 9. Arizona Title Guarantee and
Trust Company assumed a warranty deed as Trustee from CO Bar Livestock Company.
On June 24, 1960, the Arizona Daily Sun reported that on June 23, 1960 Addison and 22 others
were arraigned in Flagstaff on a charge of false imprisonment of 14 men at the upgrader site on
June 15, 1960.
In June 1960 Murchison Ventures reorganized itself into Milestone Hawaii, Inc. (Chenoweth,
1993). Milestone Hawaii, Inc. was not incorporated until October 10, 1960.
March 18, 2021
Rev. 1.2
12
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
In July 1960 a Texas bankruptcy Court held John Milton Addison's company to be bankrupt
(United Sates Court of Appeals Firth Circuit, 1967).
The Arizona Daily Sun reported on August 22, 1960 that Addison's false imprisonment trial
began in Flagstaff against Addison et al.
The Arizona Daily Sun reported on August 24, 1960 that, " William J. Rochelle, Dallas lawyer
and co-receiver in Addison's federal bankruptcy case, reported this Tuesday to creditors.
Rochelle, who was named a trustee in the case, appeared as creditors met for the first time with
bankruptcy referee Elmore Whitehurst. Whitehurst continued the hearing until Sept. 19 when
Addison didn 7 appear to answer further questions about his assets. Addison currently is on trial
at Flagstaff".
The Arizona Daily Sun reported on August 31, 1960 that on August 30, 1960, Addison et al.
were acquitted of false imprisonment charges. Addison said he wanted to get the upgrader in
production as soon as possible at the company site near Cameron, the scene of the alleged
imprisonment of the 14 men on June 15.
The Arizona Daily Sun reported on May 27, 1961 that on October 10, 1960, Milestone Hawaii,
Inc. formed - assets and operations of Milestone Hawaii were subordinated to Wm. J. Rochelle,
Jr, the bankruptcy trustee for Milestone Hawaii. A Notice of Incorporation was published for
Milestone Hawaii. ARTICLE IX of the Incorporating documents stated: Each and every
stockholder shall be advised that the assets of this corporation and the operation of this
corporation, shall be subordinate to the directives of the Trustee [William Rochelle Jr.] in the
bankrupt estate of John Milton Addison, aforesaid, and if in the opinion of said Trustee it is
unwise for this corporation to exist, and the same shall be terminated prior to the payment of the
claims in the said bankrupt estate, then such termination shall be final and neither the officers,
directors, or the stockholders shall have any grievances against said Trustee nor shall any of the
stockholders have the right to any suit or grievance against any or all of the directors and
officers of this corporation. "
The Arizona Daily Sun reported on February 1, 1961 that on January 31, 1961, Trustee Wm. J.
Rochelle, Jr. assumed control of the Murchison leases and assets. Addison turned over [leases]
to a lawyer for trustee William J. Rochelle, Jr. bankruptcy estate's trustee, a Dallas bankruptcy
attorney with Weil, Gotshal and Manges. Addison delivered [the leases] in compliance with a
court order, clearing the way for a new non-Addison corporation to take over the operation. "We
have now agreed to the terms of a lease agreement, " said Rochelle, "and we will submit it to the
court and the creditors for approval." "The new company, Milestone Hawaii Inc., put up
$150,000 before Rochelle would consider its proposal. All stockholders in Milestone live in
Hawaii. They will operate the mining properties and the Benson upgrader, a device which
Addison claims permits profitable mining of otherwise worthless uranium ore. NO PROFIT will
be taken out of the new company until Addison's $2 million in debts to creditors and lenders is
repaid with interest," Rochelle said.
March 18, 2021
Rev. 1.2
13
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
On February 17, 1961, Addison and six associates were convicted in a Texas court of mail fraud,
conspiracy, and Federal security-law violations (Chenoweth, 1993). Addison purported to own
patent rights to the Benson Upgrader, which, with at a total investment cost of $65,000, would
produce profits of $86,000 a day and, by upgrading low-grade uranium, would replace a 13
million dollar uranium mill. He represented that he and his associates owned a uranium mine
containing 2Vi million dollars of uranium. (United States of America, Appellant v. William J.
Rochelle, Jr., Trustee in Bankruptcy for John Milton Addison, 384 F.2d 748 [5th Cir. 1967]).
In SEC v. Addison the United States District Court Northern District of Texas, Dallas Division,
June 2, 1961, the court found that Benson Upgraders were unproven and unprofitable.
Addison was sentenced to serve 15 years and pay fines totaling $36,000. See, John Milton
Addisonv. United States, 317F.2d 808 (5th Cir. 1963). Addison was released on parole in 1971.
The San Antonio Light reported on August 7, 1961 that the original Benson Upgrader was
dismantled by Milestone Hawaii. "Uranium upgrader has been dismantled', see letter from
Naoji Yamagata to San Antonio newspaper and replaced by a new upgrader. "Initialproduction
of concentrates will be on the order of 50 tons" Yamagata reported. 'Milestone Hawaii is
erecting a completely new, modern plant at the old site near Cameron," the letter said. "The new
concentrator will treat large low-grade ore reserves on private, public and Navajo Indian land
within economic hauling distance of the mill site. " The corporation was formed earlier this year
by a group of independent Hawaiian investors to lease the assets of Addison's bankrupt estate.
"The company expects to raise the tonnage to 100 tons daily by early 1962. We expect to
produce about 1 ton of concentrate for each 10 tons of ore treated."
In September 1961, the original Benson Upgrader was replaced with larger one by Milestone
Hawaii. Milestone Hawaii officials all reside in Honolulu:
President - Naoji Yamagata
Secretary - Johnny Sakaki
Manager - Leon K. Sterling Jr.
According to Travis P. Lane's Weekly Report TPL WR 9-16-61, the company dismantled the
original Benson upgrader constructed by Murchison Ventures and built a much larger and more
elaborate one on the same site. Plant design and construction were under the supervision of Page
Blakemore. Mining was to be performed on contract by Cameron Mining Co. Properties
included sections leased from the CO Bar Livestock Co. (Babbitt) and a section owned by
Blakemore. The lands to be worked first were all at or near the plant site. It was anticipated that
plant feed would run 0.06-0.07% U3O8 and upgraded product 0.50-0.60% U3O8 and that the
plant would handle around 700 tons per day (tpd). (Travis P. Lane Weekly Report TPL WR 9-
16-61 - Item in Arizona Department of Mines and Mineral Resources Mining Collection).
On November 3, 1961, Chenoweth visited the Milestone Hawaii upgrader and talked with Leon
Sterlin and Page Blakemore. Chenoweth was told that the new upgrader "Will get feed from
Section 9 and Section 16 where he has a lease." (Chenoweth notes, 2012). Blakemore had
leases to both the Grub #14 area and part of AUM 459 area between August and December 1961.
March 18, 2021
Rev. 1.2
14
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Neither Sterling nor Milestone Hawaii had any leases in Section 16. Leon Sterlin referred to "a
section owned by Blakemore," which is problematic because Blakemore was an operator and
contractor, not a property owner.
On March 8, 1962, Chenoweth again visited the Milestone upgrader. Chenoweth states that the
"Plant was crushing a small stockpile of material left by Murchison" (Chenoweth notes, 2012).
According to Chenoweth (1993), in March 1962 Milestone Hawaii shipped 23.93 tons of ore that
averaged 0.10% U3O8; material that was processed for this shipment came from shallow pits in
T27N R10E, Sections 9 and 16 and was labeled Milestone No.l. The upgraded material came
from T27N R10E, Sections 9 and 16 (Nos. 71 [Section 9 lease] and 83 [Grub #14 in SW quarter-
section of Section 16]) (Chenoweth 1993). According to Chenoweth (2012), "The 23.93 tons of
material shipped in 1962 came from processing waste material left on Section 9 and from an old
pit on Sectionl6, an AZ State Lease." (Chenoweth notes 2012). The shipment went to the Tuba
City Mill.
In May 1962, the Tuba City Mill operated by Rare Metals was closed. (Chenoweth, 1993).
In July 1962, Rare Metals merged with El Paso Natural Gas Co. (Chenoweth, 1993).
On May 28, 1963 the Lease, which had been under the supervision and control of the Bankruptcy
Trustee, Wm. J. Rochelle, Jr., was released back to Milestone Hawaii. The release was signed by
William J. Rochelle, Jr., Trustee in Bankruptcy for John Milton Addison.
On November 23, 1971 CO Bar regained ownership of Section 9 because Arizona Title
Insurance Company defaulted on its note held as security by CO Bar Livestock Company. CO
Bar Livestock reassumed the warranty deed from Arizona Title Insurance Company.
In his 1993 report, Chenoweth stated in Table 8 that a total of 361.55 tons of ore were delivered
to the Tuba City Mill from Section 9 (not including 23.59 tons from Milestone No.l) at an
average of 0.12% U3O8. The shipments cited above total only 127.32 tons, so 234.32 tons of ore
shipped to the mill from Section 9 are unaccounted for in Chenoweth's text. Chenoweth in his
2012 notes identifies a shipment by Rankin in 1959 of 234.32 tons, which is consistent with the
total ore shipped.
2.3 Current Conditions
The three AUMs (457, 458, and 459) within and adjacent to Section 9 are described as follows:
• AUM 457 is primarily located on Section 9 but does extend eastward onto Section 10.
The western portion of Section 10 from the boundary with Section 9 to the Little
Colorado River is owned by the U.S. BLM.
• AUM 458 is located wholly within Section 9.
March 18, 2021
Rev. 1.2
15
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
• AUM 459 is located wholly within Section 16, which is owned by the State of Arizona.
Erosional depositions from AUM 459 waste material has encroached onto the very
southern portion of Section 9 within the bottom of the drainage.
The Navajo Nation surrounds this general area to the west, north, and east. The eastern majority
of Section 10 is on the Navajo Nation with the centerline of the Little Colorado River as the
dividing feature between the BLM land and the Navajo Nation Land for Section 10. The Little
Colorado River (LCR) floodplain transects Section 10 in a south-north orientation. The LCR
flows to the north in this area. Dry drainages (e.g., arroyos, washes) originate within Section 9
and drain eastward, terminating at the LCR floodplain. A playa is located west-southwest of
AUM 457.
Shallow mine pits (less than 20 feet deep), waste rock piles, mine access haul roads, and concrete
foundations and walls of former mine structures reside on the ground surface in areas where
mining took place in Section 9. The gamma radiation level collected by Weston (2014) is
provided on Figures 2-2, 2-3, and 2-4. Data for select metals, metalloids and radionuclides are
included on Figures 1-2, 1-3, and 1-4.
Section 9 has been deed restricted as of July 22, 2019. Entry upon the property is prohibited
pursuant to the deed restriction recorded in Coconino County and is in violation of Arizona
trespass law. The deed restriction does not allow any future use of Section 9 with the exception
of maintenance of the main access road and inspection of the property. Signs have been posted
on Section 9 to notify potential trespassers that the section is deed restricted. The deed
restriction is provided in the Phase III Summary Report provided in Attachment M.
As discussed in Section 6.0 and based on the current conditions the following human receptors
were evaluated:
• On-Site Adult Worker
• Long Term Adult Recreator (24 years of exposure)
• Child Recreator (2 years of exposure)
• Combined Long Term Adult and Child Recreator (26 years of exposure)
2.4 Ecological Conditions
SWCA Environmental Consultants (SWCA) summarized the land use and ecological setting of
the Site as part of their biological resources survey (SWCA, 2016). The climate at the Site is
very dry, with temperatures below freezing in the winter (average minimum approximately 21°F)
and very hot in the summer (average maximum temperature of approximately 97°F). The
average monthly precipitation ranges from 0.33 to 0.91 inch with an annual total of 5.7 inches.
There are two named watercourses on or near the Site: an ephemeral reach of the Little Colorado
River (LCR) along the eastern boundary of the Site and Mays Wash located on the south side of
the Site. On average, the LCR channel is dry three months of the year. The nearest perennial
surface water with any hydrological connection to the Site is the lowest reach of the LCR, which
begins approximately 58 miles downstream of AUM 457.
March 18, 2021
Rev. 1.2
16
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
There is vegetation in the riparian habitats along the LCR and Mays Wash, and within drainages
and depressions in the upland areas. Vegetation in these areas is degraded by non-native,
invasive species including tamarisk. Most of the upland areas are sparsely vegetated by native
(e.g., snakeweed, shadscale) and non-native species (e.g., camelthorn). There are only a few
cottonwood trees in the area.
As presented in Section 7.0 the following ecological receptors were evaluated:
In the upland areas (e.g., the AUMs) under the Dry and Wet Condition Scenarios the following
receptors were evaluated:
• Plants
• Insectivorous mammal: Desert shrew
• Insectivorous bird: Rock wren
• Herbivorous mammal: Deer mouse
• Insectivorous bird: American kestrel
• Carnivorous bird: Golden eagle
In the riparian areas (e.g., along the LCR) Dry
receptors were evaluated:
• Plants
• Insectivorous mammal: Desert shrew
• Insectivorous bird: Rock wren
• Herbivorous mammal: Deer mouse
• Herbivorous bird: Mourning dove
• Omnivorous mammal: Coyote
• Carnivorous bird: Golden eagle
and Wet Condition Scenarios the following
2.5 Geologic Setting
The Geologic Map of the Cameron Quadrangle (Billingsley et al., 2007) was reviewed to
determine the general site geology. The mapped units are shown on Figure 2-5. According to the
geologic map, the following Quaternary-aged geologic materials are present at the Site:
1. Terrace deposits (Qgy)
2. Playa deposits (Qps)
3. Alluvial deposits in the Site drainages and in the Little Colorado River floodplain (Qs and
Qf)
4. Alluvial fan and eolian deposits (Qay and Qae)
5. Dune sand and valley fill (Qd and Qv)
In the background determination memo from the EPA (2016b), the alluvial deposits (numbers 2-
5) were grouped together as Qal. They included the floodplain, stream, Holocene fluvial, and
dune deposits. This grouping of the Playa deposits, Alluvial deposits, Alluvial Fan, and Dune
sand and valley fill as Quaternary Alluvium (Qal) was determined to be appropriate and was
used for the Project.
March 18, 2021
Rev. 1.2
17
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
In addition, both mineralized and unmineralized outcrops of the Chinle Formation (Petrified
Forest [TRcp] and Shinarump members [TRcs]) are present at the Site. Uranium mineralization
occurs in a thin zone of the Shinarump member where exposed in the mine pits in the AUMs
(EPA, 2016b). Outcrops are considered naturally occurring radioactive material (NORM).
As part of the Background Study for the Phase II work, a Desktop Survey (EA, 2018a) was
completed. The Desktop Survey was used to scope the areal extent of the Background Study. As
part of the Desktop Survey, aerial photographs along with the geologic map (Billingsley et al.,
2007) were used to confirm the locations and areal extent of the dominant geological/pedological
units potentially impacted by uranium operations at the Site. In general, the geology noted in the
Billingsley et al. (2007) map matches what is shown in the aerial photographs. However,
supplementary geologic mapping in the vicinity of AUMs 457 and 458 was completed as part of
the Field Reconnaissance portion of the Background Study. The results of this supplementary
mapping are presented in the Phase II Summary Report (provided as Appendix J to this report).
The additional geological mapping was needed in the areas of the AUMs and Background Study
Areas (BSAs) to account for local inaccuracies of the existing Billingsley et al. (2007) geologic
mapping.
The geologic mapping from Billingsley et al. (2007) was also overlain over the aerial
radiological survey that was completed in 1997 (Bechtel Nevada, 2001). There does not seem to
be a strong correlation in the Project area between the radiological survey results and the
geologic units.
2.6 Physical Conceptual Site Model
The three EPA-identified AUMs (457, 458, and 459) within and adjacent to Section 9 along with
other Site features are shown on Figure 2-6. Site details for each AUM are discussed below.
2.6.1 AUM 457
Figure 2-7 presents the EPA-identified AUM boundary, EPA-identified drainage area boundary,
EPA-identified "Wetland 3," EPA-identified road centerline and buffer, and other mine related
disturbances for AUM 457. These mine related features include mine pits, the upgrader area,
and other areas of mine waste. AUM 457 was accessed by a set of roads over which ore was
hauled to off-site uranium mills. Aside from the primary site access road, numerous tracks have
been left by vehicles traveling the area over many decades, not all of which relate to mining
activity. Mining activities at AUM 457 included excavation of shallow mine pits from which ore
was removed, and the generation of waste rock piles where overburden, gangue, and low-grade
mineralized rock was moved and stockpiled (waste rock areas). Ore removed from AUM 457
pits or delivered from other Section 9 Lease AUM pits was stockpiled on the bluff west of the
LCR floodplain area (ore stockpile area).
The upgrader system was installed east of the ore stockpiles off the bluff to take advantage of the
elevation difference and use the gravity-driven potential energy to assist the hydraulic sorting of
the ores by the upgrader (upgrader area). Granular and liquid waste from the upgrader was
discharged to the land surface west of the LCR. The upgrader area currently includes concrete
foundation walls and on-grade slabs, though essentially all the metal and wooden components of
March 18, 2021
Rev. 1.2
18
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
the system have been removed. Some wood and metal scrap from mine related structures remain
littered across the Site.
Figure 2-7 shows four areas (Northern Drainage, Pond Area, Upgrader Area, Bedrock Ridge
West of AUM 457) with indication of the general flow direction of surface water near AUM 457.
The Northern Drainage flows from the playa area towards the Little Colorado River. This
drainage has only minimal sources of mining wastes, and has no indication of historic transport
of mine waste above IL levels into Section 10. Material migration is not considered likely for
this drainage area. The Pond Area shows that drainage from the pond berm is directed into the
pond. This drainage is self-contained and material migration is not considered likely for this
drainage area. The Upgrader Area drains from the upgrader to the east towards the LCR. There
is evidence of erosion from the upgrader area down the drainage to the bank of the LCR in
Section 10. The depth of the alluvial deposit from this erosion varies from 1 foot to 5 feet in the
drainage. The Bedrock Ridge drainage shown Figure 2-7 shows drainage to the west off of the
ridge west of the upgrader to the Playa. There has been no indication of historic transport of
mine waste above IL into the LCR from this drainage area. A more detailed discussion of the
material migration and flow from these drainages is provided in more detail in Section 5.6.1.
2.6.2 AUM 458
Figure 2-8 presents the EPA-identified AUM boundary, EPA-identified drainage area boundary,
EPA-identified drainage network, EPA-identified road centerline and buffer, and other mine
related disturbances for AUM 458. Based on the maps included in the AOC, AUM 458 was
accessed by a single mine road from the north, ore was hauled either directly to a mill or to the
upgrader at AUM 457 over this road. Aside from the primary site access road, numerous blade
cuts and tracks have been left by mining activity. Mining activities at AUM 458 included the
excavation of shallow mine pits from which ore was removed, and generation of mine waste.
Ore removed from AUM 458 pits was stockpiled and either hauled directly to a mill or to the
upgrader at AUM 457. TENORM may be present along haul roads as ore may have spilled along
the road alignments during transport. There is also the potential that the haul roads may have
been cut through outcrops that have gamma readings above the statistical background average.
General traffic unrelated to mining activities may also have dislodged rock that contains
uranium.
Review of Figure 2-8 shows four areas (within AUM 458, outside AUM 458, ridge south of
AUM 458, drainage south of AUM 458) with the general direction of surface water flow
indicated. Figure 2-8 indicates that drainage from the inside of the pit is directed to the bottom
of the pit. Potential flow is from the crest of the pit into the pit bottom. This drainage is self-
contained and material migration is not considered likely for this drainage area. The area outside
of the pit capture area, but within AUM 458 boundary is shown on Figure 2-8. This area flows
radially away from the pit capture area. The surface gamma surveys outside of the pit capture
area are generally less than two times IL as shown on Figure 4-14. There is evidence of erosion
from the area, gamma survey data indicate the material has not historically migrated very far,
and thus the potential for off-Site contamination is low. There is an area of exploration along the
ridge south of AUM 458. The runoff from this ridge generally flows to either the west or east.
There is limited evidence of erosion from this area to the west and east. However, the gamma
surveys in the NORM areas surrounding this feature are below the IL as shown on Figure 4-14.
March 18, 2021
Rev. 1.2
19
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Therefore, while there is evidence of erosion from the area, gamma survey data indicate the
material has not historically migrated very far, and thus the potential for off-Site contamination
is low. There is a large drainage south and east of AUM 458. This drainage flows from the west
in an easterly direction to the LCR. The drainage flows between AUM 458 and AUM 459 as
shown on Figure 2-8. There is an area that is up to two times the IL in the finger drainage
immediately north of AUM 458, however, downgradient of this area the gamma levels are below
IL. Therefore, while there is evidence of erosion from the area, gamma survey data indicate the
material has not historically migrated very far, and thus the potential for off-Site contamination
is low. A more detailed discussion of the material migration and flow from these drainages is
provided in more detail in Section 5.6.2
2.6.3 AUM 459
Figure 2-8 presents the EPA-identified AUM boundary, EPA-identified drainage area boundary,
EPA-identified drainage network, EPA-identified road centerline and buffer, and other mine
related disturbances for AUM 459. Figure 2-8 includes the portion of AUM 459 within the
Section 9 Lease site and not the portion within adjacent Section 16. Pursuant to the AOC, mine
related features to be addressed in this and subsequent phases of work are limited to a single
mine access road and a section of drainage that is downgradient from Section 16 mining
disturbances. Inspection of Site imagery indicates that there are no visible mining-related
disturbances related to AUM 459 in Section 9 other than the mine access road. The Weston SI
Report (Weston, 2014) identified the northern extent of AUM 459 as extending into Section 9.
Ore removed from AUM 459 pits in Section 16 was either hauled directly to a mill or to the
upgrader located at AUM 457.
Review of Figure 2-8 shows two areas (drainage north from AUM 459, drainage northwest from
AUM 459) with the general direction of surface water flow indicated. The drainage that flows
northeast from AUM 459 to the LCR combines with two additional drainages before they enter
the LCR floodplain as shown on Figure 2-8. There is evidence of erosion from AUM 459 into
the drainage in Section 9. The material decreases in gamma values from the AUM 459 boundary
downgradient to the road, but remains above the IL the entire distance. The alluvium below the
road is below the IL until it enters the LCR floodplain. There is the potential for this elevated
material to migrate into the LCR floodplain during larger storm events. There is a large drainage
northwest of AUM 459. This drainage flows from the west in a northerly direction to the LCR.
The drainage flows between AUM-458 and AUM 459 as shown on Figure 2-8. The surface
gamma surveys of the drainage southeast and downgradient of the AUM 458 area are shown on
Figure 4-11 and show the gamma levels below IL. While there is evidence of erosion from the
area, gamma survey data indicate the material has not historically migrated very far, and thus the
potential for off-site contamination is low. A more detailed discussion of the material migration
and flow from these drainages is provided in more detail in Section 5.6.2
March 18, 2021
Rev. 1.2
20
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
3.0 INVESTIGATION WORK PLANS
The three phases of work included in the AOC (EPA, 2016a) were Phase I: Cultural Resources
Surveys, Biological Survey and Signage; Phase II: Background Determination and Gamma
Scanning; and Phase III: Removal Site Evaluation. As required by the AOC, prior to initiating
work on each phase a Work Plan was developed for EPA review and approval. The Phase I, II,
and III Work Plans (EA, 2017a, 2017e, 2019c) are included with this report as Appendices G, I,
and L. Field activities in support of completion of the phases of work included site mapping,
gamma radiation scanning, concrete surface activity surveying, surface soil sampling, and
subsurface soil sampling. This section outlines the field sampling methods used for the field
work performed for the Site. Field sampling methods are further defined in the Phase II (EA,
2017d) and Phase III (EA, 2018b) Field Sampling Plans which are included with this report as
Appendices D and K, respectively.
3.1 Site Mapping
Site mapping was conducted to inform the first task in the Phase II work - the Background
Study. The purpose of the Background Study was to identify potential background study areas
(BSAs) and, once these areas were approved by the EPA, establish background levels in soils
and sediments for gamma emissions and preliminary descriptive statistics for PCOCs in areas not
impacted by TENORM. The background levels are intended to support establishing
investigation levels (IL), as defined in Section 1.3 of the SOW. Per the Phase II Work Plan, the
background study was divided into the following subtasks:
• Desktop survey
• Background study area (BSA) selection
• Field reconnaissance and gamma scan
3.1.1 Desktop Survey
The following data and information sources were reviewed during the Desktop Survey:
• Aerial photography (various sources).
• Topographic mapping (various sources).
• Historic aerial radiometric data (Bechtel Nevada, 2001).
• Gamma survey data from the prior investigations (Weston, 2012 and 2014).
• Analytical data from soil samples collected in the SI investigation (Weston, 2014).
• Geologic mapping (USGS, 2007).
• Soils mapping (Soil Conservation Service, 1983).
3.1.2 BSA Selection
The BSAs for soil sampling were selected with the general intent of being considered
appropriate background reference areas (BRAs) such that the background data collected from the
BSA is reasonable and appropriate if not entirely sufficient for use as background when
assessing Final Status Surveys data. The Desktop Survey included selecting BSAs for the
alluvial and terrace deposits. In addition, BSAs were selected for drainage areas and the LCR
corridor. It was determined that while the geology in these areas is similar to the overall
March 18, 2021
Rev. 1.2
21
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
geology, the depositional characteristics are such that these areas should have a representative
BSA also.
In conformance with the Phase II Work Plan, provided in Appendix I of this report, the following
criteria were considered during the Desktop Survey to identify potential BSAs:
• Geological materials in the BSA shall have similar physical, chemical, geological,
radiological, and biological characteristics as encountered in the AUM and likely step-out
areas being evaluated per the Multi-Agency Survey and Site Investigation Manual
(MARSSIM) Section 4.5 (EPA, 2000), as determined by appropriate experts.
• The BSA shall be selected with the objective that the radioactivity present in a BSA
would be ideally the same as the comparable geological material in the AUM and likely
step-out areas had they never been contaminated, per MARSSIM Section 4.5 (EPA,
2000), as determined by appropriate radiological experts.
• The BSAs shall not be potentially contaminated by Site activities and shall not be part of
the AUM and likely step-out areas being evaluated. Therefore, BSAs shall be upwind
and upgradient of the AUM and likely step-out areas being evaluated.
• It is the project goal to find appropriate BSAs with no anthropogenic disturbance or
TENORM. If no appropriate undisturbed BSA can be located, a BSA with disturbance
that is demonstrably not mining related and is upwind may be selected as a reasonable
BSA location.
• BSAs should be selected for each geologic unit or material anticipated in the AUM and
within the likely step-out areas being evaluated.
• BSAs shall be void of culturally sensitive locations.
• BSAs shall be contiguous 0.5 acre areas or other appropriate sizes.
3.1.3 Field Reconnaissance
After the Desktop Survey was completed, a Field Reconnaissance was performed from
September 12-14, 2017, in general conformance with the guidance provided in the Phase II Work
Plan (EA, 2017e). The field reconnaissance included representatives from EA, C2
Environmental, EPA staff, and Weston Solutions (EPA-Contractor). During the field
reconnaissance, the BSA boundaries were adjusted to avoid anthropogenic disturbance and to
better align with selected geologic features. These field adjustments were agreed to by all
present in the field.
In addition to confirmation of the BSA locations, the field reconnaissance was also used to
confirm locations of mining-related TENORM and to perform geologic mapping of AUM 457
and AUM 458.
March 18, 2021
Rev. 1.2
22
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
3.2 Gamma Radiation Survey
3.2.1 BSA Gamma Survey
The seven background study areas discussed in the Desktop Survey section along with the "Qter
BRA" proposed by the EPA (EPA, 2016b) were characterized (Figure 3-1). The BSAs were
selected for study because they are unimpacted by mining and are generally representative of
Site conditions within the Area of Potential Effect (APE). Figure 3-1 depicts the selected and
approved BSA locations. Characterization of the BSAs consisted of:
• A scanning gamma radiation (gamma) survey, which occurred October 19-25, 2017.
• Soil samples and static gamma measurements, collected October 24-27, 2017 (discussed
in Section 3.4).
Environmental Restoration Group, Inc. (ERG) conducted a mobile gamma survey of each BSA
using a Model 44-20 three-inch by three-inch sodium-iodide detector paired with either a
Ludlum Model 4612 multi-zone single channel analyzer or a Model 2221 ratemeter. The AOC
SOW (paragraph 1.3) required a scanning minimum detectable concentration (MDCscan) of half
of the IL for radium-226 (Ra-226) in soil of 1.24 pCi/g plus background with the gamma
detector. A background of 1 pCi/g was assumed. A Ludlum model 44-20 detector was required
since the more commonly used Ludlum model 44-10 is not sensitive enough to meet this
requirement. This is in agreement with the approved Phase II Workplan. The instruments were
function-checked before and after each day of use using a cesium-137 radiological check source.
The Model 4612 array's single channel analyzer was operated in open mode, without a region of
interest, thus the reported result is a true gross gamma count.
The responses of instruments used for more than one day were tracked for consistency over the
course of the gamma survey. Tracking proceeded as follows: prior to use in the field, ten initial
quality control (QC) function check values were recorded for each instrument and each
subsequent function check was compared to a range of the instrument's initial QC ten count
average plus or minus 20 percent. Most of the function check results were within 10% of the
established baseline, and none exceeded the 20% limit specified in the workplan. On a few dates,
instrument high voltages were adjusted to provide a check that the potentiometer was functioning
within its tolerance. Instrument calibration and function check forms are included in the Phase II
Summary Report provided in Appendix J of this report.
The gamma survey in the BSAs was conducted using the method described in Section 5.1.2 of
the Phase II Work Plan (EA, 2017e). During gamma scanning of the BSAs no signs of
disturbance were noted. The BSA locations showed no signs of alteration of conditions from
those seen and discussed with the EPA and Weston during the site field reconnaissance. The
results of the BSA gamma survey are discussed in Section 4.0.
3.2.2 Transect Gamma Survey
The purpose of the transect gamma survey was to characterize the range of gamma radiation
levels in areas impacted by Section 9 Lease mining. Mine related disturbances were identified
during the desktop and field reconnaissance portions of the background study. The gamma
transect scanning was used in delineating the areal extent of mining-related TENORM at the
March 18, 2021
Rev. 1.2
23
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Site. To achieve this objective, GPS-based gamma-ray scans (gamma survey) were conducted
over the Areas to be Addressed as presented in the Scope of Work provided in the Phase II Work
Plan (EA, 2017e). The gamma scanning trends were used for the delineation. The areas were
divided into the following four types of features:
• Transect gamma survey of AUM areas.
• Handheld gamma survey of upgrader foundation.
• Transect gamma survey of EPA drainage areas.
• Transect gamma survey of other mine related disturbance.
Details of survey methods are provided in the Phase II Work Plan (provided as Appendix I of
this report) and discussed in Section 4.4.
3.3 Concrete Surface Activity Survey
An upgrader foundation is located in AUM 457 as discussed in Section 2.6. The upgrader
foundation was surveyed on November 6-7, 2017 using direct (static) measurements to quantify
alpha and beta surface activity per unit area. Static measurements were made on one-meter
square grids of accessible floor and wall surfaces.
3.4 BSA Sediment and Soil Sampling
Soil and sediment samples were collected from BSAs to define background levels of the PCOCs.
Soil and sediment samples were collected from the upper 15 cm (0 to 6 inches) of these
materials. Samples were collected from October 24-27, 2017, and additional samples were
collected from December 3-6, 2018.
The Phase II Work Plan (provided as Appendix I to this report) contains a memorandum that
describes the technical basis for the estimated number of background samples to be collected
from the BSAs for sample adequacy. The discussion of the sample collection and results is
presented in Section 4.5.
The soil and sediment samples were collected, described and documented as outlined in the Field
Sampling Plan (provided as Appendix H to this report). Static gamma survey readings (single
point readings) were collected at each BSA soil/sediment sample location.
3.5 Surface and Subsurface Soils and Sediment Sampling
Phase III of the Project included characterization of surface, subsurface, and sediment for the
Site. The field investigation for this work was conducted at the Site from December 3 through
December 6, 2018. The Field Investigation was performed in general conformance with the
guidance provided in the Phase III Work Plan (EA, 2019c) and was intended to complete Task 1
(Characterization of Surface, Subsurface Soils, and Sediment) as presented in Section 5.0 of the
Phase III Work Plan. The Phase III Work Plan was approved in two parts. Sections 1.0 through
5.3 and Sections 5.6 to 9.0 were approved on November 16, 2018. The Field Investigation was
performed under the guidance of those approved sections. The remaining sections (5.4 and 5.5)
were approved on September 13, 2019.
March 18, 2021
Rev. 1.2
24
Engineering Analytics, Inc.
-------
Babbitt Ranches, LLC
Removal Site Evaluation Report Milestone Hawaii Stewardship Project
The Field Investigation program that was conducted at the Site generally included excavation of
test pits and collection of soil and sediment samples with depth. The investigation is described in
Section 4.4.4.
March 18, 2021
Rev. 1.2
25
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
4.0 FIELD INVESTIGATION
4.1 Desktop Survey
A Desktop Survey was completed as part of the Background Study. The complete results of the
Desktop Survey are included in Appendix A of the Phase II Summary Report (EA, 2018). The
objective of the Desktop Survey was to support robust scoping of the Phase II Background Study
and Transect Gamma Scan Study. This objective was met by using the available information to
identify distribution of the geological materials present at the Site, describe the estimated extent
of mining-related disturbances at the Site, review the Background Reference Areas (BRAs)
proposed by the EPA (2016b), and develop potential BSAs to evaluate in the field. To complete
the objectives, relevant data sources and information were reviewed, including aerial
photographs, geologic and soils mapping, historic aerial radiometric data, previous site
assessments, and topographic and LiDAR data.
4.2 BSA Selection
One objective of the Desktop Survey was to select BSAs for each of the dominant
geological/pedological units identified at the Site for gamma scanning and soil sampling. The
BSAs for soil sampling were selected with the general intent of meeting the requirements of the
Multi-Agency Survey and Site Investigation Manual (MARSSIM) (EPA, 2000) to be considered
as appropriate Background Reference Areas (BRAs). Thus, the background data collected from
the BSA is reasonable and appropriate if not entirely sufficient for use as background when
assessing Final Status Surveys data. The Desktop Survey included selecting BSAs for the
alluvial and terrace deposits. In addition, BSAs were selected for drainage areas and the LCR
corridor. It was determined that while the geology in these areas is similar to the overall
geology, the depositional characteristics are such that these areas should have a representative
BSA also.
In addition, on October 26, 2016, the EPA issued a technical memorandum identifying potential
background reference areas (BRAs) for the Site (EPA, 2016b). Consequently, although the
background areas are called BRAs in EPA report (2016b) and BSAs in this report both are
consistent with the eventual selection of BRAs. The EPA proposed BRAs consisted of one
Terrace deposit location ("Qter BRA"), one Shinarump Member location ("TRcs BRA"), and
one location in alluvial deposits ("Qal BRA").
The BSAs from the Desktop Survey are presented on Figure 3-1.
4.3 Field Reconnaissance
The Field Reconnaissance was performed to meet the following objectives:
1. Confirmation of proposed BSA locations.
2. Confirmation of mining-related TENORM.
3. Geologic mapping of AUM 457 and 458.
During the Desktop Survey, seven potential BSA locations were selected: two in the alluvial
deposits, two in the terrace deposits, two in the drainage areas, and one in the LCR deposits.
During the Field Reconnaissance from September 12 through 14, 2017, all seven sites were
visited and observed along with two of the EPA proposed BRAs. The EPA alluvial BRA was not
March 18, 2021
Rev. 1.2
26
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
accessible due to dense vegetation and was therefore not visited during the Field
Reconnaissance. New sites were proposed in the Field Reconnaissance report Appendix A of the
Phase II Summary Report (provided as Appendix J to this report) along with justification for
their location. One of the drainage areas (Drainage #1 BSA) was removed from analyses due to
concern by the EPA for the potential TENORM impacted material in the BSA area. Gamma
scanning was performed and soil samples were collected from Drainage #1 BSA at the EA
team's choosing to help quantify the soils that contribute to the drainage in question. The data
collected from Drainage #1 BSA was included in this report for completeness. However, it was
not used in any calculations or to draw any conclusions presented in this report. The locations of
the BSAs are shown on Figure 3-1. Gamma scanning included the seven sites along with a
slightly modified Qter BRA location as proposed by the EPA (2016b). Site features identified at
each AUM are provided on Figures 2-6 through 2-8. In addition, geologic mapping was
performed for AUMs 457 and 458 and is presented on Figure 2-5.
4.4 Gamma Survey
4.4.1 BSA Scanning
A summary of the gamma count rate within each BSA is presented in Table 4-1. BSA gamma
surveys were completed October 19-25, 2017. The gamma count rates ranged from
19,679-89,067 counts per minute (cpm). However, at the request of the EPA some gamma count
rates at the edge of the BSA were removed from the BSA areas due to concern that these areas
might have been impacted by mineralization or TENORM. Thus, the resulting range of gamma
count rates is 19,679-56,560 cpm. The removal of these data points is discussed in the
memorandum provided in Appendix C of the Phase II Summary Report (provided as Appendix J
to this report). The results of the gamma survey for each approved BSA are shown on
Figures 4-1 through 4-7. A detailed review of the collected data was completed and potential
outliers were reviewed for potential removal from the data set. It was concluded that there were
no data outliers. A complete statistical analysis of the soil and mobile gamma data, including
identification of potential outliers, is provided in Appendix C of the Phase II Summary Report
(provided as Appendix J to this report).
4.4.2 Area of Potential Effect Scanning
4.4.2.1 APE Scanning 2017
A GPS-based gamma survey was conducted across the entire APE intermittently between
October 16, 2017 and November 11, 2017. Results of the mobile gamma survey are shown on
Figures 4-8 through 4-12. Figures 4-15 through 4-19 present the results in counts per minute.
The transect spacing for the gamma survey was varied per area as follows:
• Three-foot transects within the AUM boundaries (100 percent coverage).
• Six-foot transects within the mine disturbance areas.
• Twelve-foot transects within the drainage areas; or throughout the thalweg with 12-foot
transects out to an elevation change of no less than two feet if the thalweg could be
visibly verified.
March 18, 2021
Rev. 1.2
27
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
• Fifteen-meter (approximately 45 feet) transects within the remaining non-surveyed area
of the APE. The decision was made on November 6, 2017 to complete 15-meter
transects within the remaining APE regardless of potential step-out thresholds.
• All areas were surveyed at a speed between 0.5 to 1.0 meters (approximately 1.5 to 3
feet) per second, with the detector approximately 0.5 meter above the ground surface.
The array scanning surveys were conducted using three Ludlum Model 44-20 three-inch by
three-inch sodium-iodide high-energy detectors paired with a Ludlum Model 4612 multi-zone
single channel analyzer. The backpack scanning surveys were conducted using a Ludlum Model
44-20 paired with a Ludlum Model 2221 ratemeter single channel analyzer. Table 4-2 lists the
radiological instrumentation used in the gamma survey by model and serial number. The Model
4612 single channel analyzers were operated in open mode, without a region of interest, thus the
reported result is a true gross gamma count.
The responses of instruments used for more than one day were tracked for consistency over the
course of the gamma survey. To demonstrate consistency, instruments were function-checked
before and after each day of use using a cesium-137 radiological check source. Tracking
proceeded as follows: prior to use in the field, ten initial quality control (QC) function check
values were recorded for each instrument and each subsequent function check was compared to a
range of the instrument's initial QC 10 count average plus or minus 20 percent of the net detector
response. Most of the function check results were within 10% of the established baseline, and
none exceeded the 20% limit specified in the workplan. On a few dates, instrument high voltages
were adjusted to provide a check that the potentiometer was functioning within its tolerance.
Instrument calibration and function check forms are included in Appendix B of the Phase II
Summary Report (provided as Appendix J to this report).
4.4.2.2 APE Scanning 2020
The equipment used to perform scanning during the Phase II field work could not quantify
gamma count rates above 999,960, which is less than upper end of the material that was
encountered at the Site. Thus, additional gamma scanning within the AUM was conducted on
March 10, 2020 to obtain measurements of gamma above the previous upper limit. The
additional gamma scanning followed the procedures and protocols approved in the Phase II
Work Plan dated September 6, 2017 (provided as Appendix I to this report). Gamma scanning
was completed consistent with Section 5.2.1 and 5.1.4 of the Phase II Work Plan. Ludlum Model
44-20 3-inch by 3-inch sodium iodide high energy gamma-radiation detectors, coupled to a
Ludlum Model 2221 with firmware version 26102N13 that provides counts per minute (cpm) and
counts per second (cps) output, as presented in Table 4-2. Count rate and scaler (counts
integrated over second) data were collected every second. All areas were surveyed at a
walkover speed between 0.5 to 1.0 meters per second, with the detector approximately 0.5
meter above the ground surface. Field personnel walked through the supplemental scanning
areas carrying the GPS and ratemeter instrumentation in a backpack while holding the detector.
As described in the Phase II Work Plan, this scanning protocol results in a scanning minimum
detectable concentration (MDCscan) of approximately 1 picocurie per gram (pCi/g), which meets
the required MDCscan of half the IL, as specified in Section 1.3 of the SOW. The results of the
horizontal scanning are shown on Figures 4-13 and 4-14. Instrument calibration and function
March 18, 2021
Rev. 1.2
28
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
check forms are provided in Appendix H of the Phase III Summary Report (provided as
Appendix M to this report).
4.4.3 Concrete Surface Activity Measurements
The survey of the upgrader foundation consisted of direct (static) measurements of alpha and
beta surface activity per unit area collected on November 6-7, 2017. Static measurements were
made on one-meter square grids of accessible floor and wall surfaces. The measurements were
made using Ludlum Model 43-93 detectors paired with Ludlum Model 2360 ratemeter/scalers.
Table 4-3 describes the instrumentation used for the survey. All static measurements were made
in the center of an area no greater than one square meter. At the end of the count, the alpha and
beta measurement were recorded and the scanning area was photographed.
ERG classified the locations to be surveyed into 13 groups: Bottom Wall (BW), Cement Box
(CB), Highest Slab (HS), Lower Block (LB), Lower Slab (LS), Rear Slab (RS), Small Corridor
(SC), Small Wall (SW), Top Northern Slab (TNS), Top Slab (TS), Upper Wall (UW), Upper
West Block (UWB), and West Wall (WW). Results of the upgrader foundation survey and
photographs of the corresponding grid locations are presented in Appendix H of the Phase II
Summary Report (provided as Appendix J to this report).
Figures 4-20 and 4-21 are Tukey-style boxplots of surface activity per unit area (alpha and beta,
respectively) classified by the survey group.
Surface of the concrete is an initial screen and not a final status survey for free release. Babbitt
Ranches is cognizant that the upgrader remnants are related to former mining activities. The
deed restriction prohibits entry onto the Site. In furtherance of this prohibition No Trespassing
signs have bene posted and Babbitt Supports removal of the upgrader remnants. A final
determination on the status of the upgrade remnants will be made in consultation with EPA.
Thus, no further characterization of the upgrader foundation is warranted at this time.
4.4.4 Subsurface Gamma Profiling
The test pit gamma scanning was completed from December 3 through December 6, 2018. The
test pit excavation and gamma survey generally included the following tasks:
• Excavation of test pits with hand auger and/or backhoe at 21 locations.
• Collection of soil and sediment samples at 6 inch intervals.
• Quantification of gamma emissions of each 6 inch soil fraction.
• Determination of the contact between disturbed material and the underlying undisturbed
material.
• Determination of samples for analyses of PCOCs and delivery of the samples to ALS
Environmental Laboratories (ALS) in Fort Collins, Colorado for analyses.
• Geotechnical analyses of grain size for use in the Streamlined Human Health Risk
Evaluation.
Sample location selection rationale are presented in Table 4-4. The locations of the test pits with
the gamma survey results are shown on Figures 4-22 through 4-28. These test pits were
excavated in 6-inch intervals to a depth ranging from 0 to 7 feet to expose the surface and
March 18, 2021
Rev. 1.2
29
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
subsurface soils, and sediments. Test pits TP-10 and TP-13 were excluded due to the presence of
bedrock at the surface. A letter report, dated February 28, 2019, documenting the field
investigation was provided to the EPA (EA, 2019b). The EPA issued an e-mail response on May
22, 2019 indicating that they had no questions or comments regarding the field memo. The letter
report is provided in Appendix B of the Phase III Summary Report (provided as Appendix M to
this report).
Consistent with the approved Phase III Work Plan, the gamma emissions of each 6-inch fraction
were quantified at the surface using a 60-second static measurement on a 1 liter Marinelli beaker
of soil, using a shielded Ludlum 44-10 2-inch by 2-inch sodium iodide detector coupled with a
Ludlum Model 2221 scaler/ratemeter. The 2-inch by 2-inch sodium iodide detector was selected
for its compatibility with the Project's Marinelli beakers and shield. Samples were typically
counted within one hour after collection. No spectral analysis was conducted in the field. Table
4-5 lists the radiological instrumentation used to make the gamma measurements by model and
serial number. Instrument calibration and function check forms are included in Appendix C of
the Phase III Summary Report (provided as Appendix M to this report). A summary of the
gamma measurements is presented in Appendix B of the Phase III Summary Report (provided as
Appendix M to this report). The maximum gamma emission rate for each test pit is presented on
Figure 4-17.
4.5 Soil Sampling
4.5.1 Surface Soil Sampling
4.5.1.1 2017 Data Collection
ERG conducted soil sampling on the Site in support of the transect gamma scanning and
background studies as described in the Phase II Work Plan (EA, 2017e). This work was
performed under the guidance and requirements provided in the Phase II Field Sampling Plan
(FSP) and Quality Assurance Project Plan (QAPP) (provided as Appendices H and F,
respectively, to this report). Weston Solutions (EPA-contractor) was present in the field during
sample collection to provide oversight. Soil and sediment grab samples were collected from the
top 15 cm of material (0-6 inches) throughout each of the seven BSAs on October 24-27, 2017.
Samples were collected on a triangular grid starting from a random coordinate (EA, 2018a). The
soil samples were successfully collected at the selected locations and no adjustments were
needed to account for vegetation or other debris. ALS in Fort Collins, Colorado analyzed the soil
samples for Ra-226 and six other PCOCs as presented in Table 4-4. This is consistent with the
approved Phase II Work Plan. The soil sample results are provided in Appendix D of the Phase II
Summary Report (provided as Appendix J to this report). Tables of soil and static gamma data
are provided in Appendix E of the Phase II Summary Report (provided as Appendix J to this
report). A complete statistical analysis of the soil and mobile gamma data, including
identification of potential outliers, is provided in Appendix C of the Phase II Summary Report
(provided as Appendix J to this report).
The number of samples collected in each BSA and summary of the Ra-226 analytic results are
presented in Table 4-7. Figure 4-29 depicts the Ra-226 soil sampling data in a Tukey-style
boxplot. The concentrations of Ra-226 within the BSAs range from 0.55 to 5.43 picocuries per
March 18, 2021
Rev. 1.2
30
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
gram (pCi/g). The Ra-226 concentrations for each soil sample location within the BSAs are
shown on Figures 4-30 through 4-36.
The soil samples were also analyzed for arsenic, mercury, molybdenum, selenium, uranium, and
vanadium. The analytical results are summarized in Tables 4-8 through 4-13 and Tukey-style
boxplots for each metal are shown on Figures 4-37 through 4-42. The metals results for each soil
sample location within the BSAs are shown Figures 4-43 through 4-49.
A direct gamma measurement was also made at each soil sample location. ERG used a Ludlum
Model 44-20 3-inch x 3-inch Nal (Tl) scintillation detector (serial #271435) paired with a Model
2221 ratemeter/scaler (serial #051517N) for making direct measurements of gamma activity.
The instruments were function-checked before and after each day of use using a cesium-137
radiological check source.
4.5.1.2 2018 Data Set Supplement
Additional BSA soil samples were collected in 2018 to supplement the soil samples collected
as part of the Phase II work. These soil samples were collected in conjunction with the Phase III
field work and consisted of the following:
1. The collection of additional soil/sediment samples with analysis of PCOCs to further
evaluate the relationship between the metals/metalloids and Ra-226, using gamma count
rate as a surrogate for Ra-226. Those samples were collected from the test pits and the
results are discussed in Section 5.0.
2. The collection and analysis of additional soil/sediment samples in the Alluvial BSA #1
and Drainage BSA #2 pools to complete the characterization of PCOCs for these BSAs.
The field team, with EPA concurrence, determined that additional samples from Alluvial
BSA#1 could not be collected in a representative area, thereby forgoing additional sample
collection. Five additional samples (D207 through D211) were collected from Drainage BSA #2
at locations independent of those selected in Phase II. The original and additional sample
locations in the Drainage BSA #2 are shown on Figure 4-34. These additional samples,
combined with the samples collection in Phase II, will meet the number of samples proposed in
the Phase II Work Plan (EA, 2017e).
Soil samples were collected from the upper 6 inches (0 to 6 inches) of the planned background
sampling locations and described and documented according to the requirements of the Phase III
Field Sampling Plan (provided as Appendix K to this report). The additional sample locations in
Drainage BSA #2 were laid out on a random-start triangular grid using Visual Sample Plan.
Combining the Phase II and Phase III samples results in 11 samples total from Drainage BSA #2.
This total number of samples is enough to statistically determine the PCOC populations in these
two BSAs. The overall approach for this assessment was to aggregate the background data into
meaningful data populations based on geological material type or lithology, and estimate the
number of background data samples needed for the objective that the average concentration that
accurately represents the true background average to within ± 20% at the 95% confidence level
per NUREG-5849 (NRC, 1992) as presented in the Phase II Work Plan provided in Appendix I
of this report
March 18, 2021
Rev. 1.2
31
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
A summary of analytical results for the Drainage BSA #2 samples from Phases II and III is
presented in Table 4-14. Figure 4-50 depicts soil concentrations for PCOCs in Tukey-style
boxplots. The concentrations of Ra-226 within Drainage BSA #2 ranged from 0.94 to 1.71
picocuries per gram (pCi/g). The samples used as original sample data are identified in Table 2
the Phase III Soil Sample Data Verification and Validation Technical Memorandum (Appendix
D. 1) of the Phase III Summary Report (provided as Appendix M to this report).
A direct gamma measurement was also made at each Drainage BSA #2 sample location. ERG
used a Ludlum Model 44-10 2-inch by 2-inch Nal (Tl) scintillation detector (serial #PR355764)
paired with a Model 2221 ratemeter/scaler (serial #262347) for making direct measurements of
gamma activity. The instruments were function-checked before and after each day of use with a
cesium-137 radiological check source. For radionuclides, all laboratory-reported values were
used to calculate background summary statistics. For metals data sets with values not reported
above the reporting limit (non-detects), the minimum detectable limit (MDL) was reported as the
sample result to calculate background summary statistics.
4.5.2 Subsurface Soil Sampling
Following the gamma analysis discussed in Section 4.4.4, the soil from each sampled interval
was placed in a new clean individual sample jar, supplied by ALS, for shipment to EA's office.
Forty-four discrete samples were determined to be representative of the range of gamma count
rates obtained in the field and were submitted to the lab for testing. A discussion of this
approach is provided in Appendix B of the Phase III Summary Report (provided as Appendix M
to this report).
Four samples were tested for grain size distribution for use in the Human Health Streamlined
Risk Evaluation (HHSRE). These samples were TP-2 0-0.5 feet, TP-6 0.5-1.2 feet, TP-16 0.5-
1.0 feet, and TP-18 0-0.5 feet and the results are provided in Appendix B of the Phase III
Summary Report (provided as Appendix M to this report). The samples analyzed from a depth
of 0 to 0.5 feet have the potential for dust inhalation. The locations were selected to provide
spatial distribution across the Site. They were also selected to reflect the type of material that
may be encountered. TP-2 was located in native alluvium at the northern end of the Site. TP-6
is located in the upgrader discharge material. TP-16 is located in a typical drainage. TP-18 is
located in the TENORM at AUM 457. Although there were some differences in the relative
amounts of percent sand and percent fines, all four samples were classified as fine sand.
Interpretation of these results in the context of HHSRE exposure pathways is provided in
Section 6.7.2.
March 18, 2021
Rev. 1.2
32
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
5.0 ANALYSES AND RESULTS
5.1 Laboratory Data Validation
This section discusses the Level IV data validation results for soil samples collected during the
Phase II and Phase III field investigations. Section 5.1.2 of the Quality Assurance Project Plan
(QAPP) (provided as Appendix F to this report) specified that a Level IV data validation would
be completed on 10% of the data packages and a Level II data validation would be completed on
the remaining 90% of the sample results.
As described in Section 5 of the Project QAPP, the purpose of the data review, verification and
validation is to document that the specified data requirements (sampling and analytical) defined
in the Phase II Work Plan, FSP and QAPP were completed. The process of data verification
assesses data completeness of recorded data and answers the question: "Were the specified
sampling or analysis procedure requirements followed to produce the data?" Whereas, data
validation is a process that evaluates compliance with method, procedure, and contract
requirements, as well as quality objectives developed in measurement performance criteria. Data
validation answers the question: "Have all quality issues been resolved, and does the data meet
the required quality measurement performance criteria?" Data review, verification and
validation procedures are provided in SOP-QA-100 (Exhibit C.l of the QAPP).
Field records are reviewed to assess compliance with requirements specified in the Phase II
Work Plan, the FSP and the QAPP, including assessment of these items:
• Samples correctly identified.
• Laboratory receipt of sample documented.
• Required field data collected and acceptable.
• Sample preservation requirements met.
• Required sampling procedures were followed.
• Required QC samples were collected.
• Custody records are complete.
5.1.1 2017 Data Set
The 2017 data set consisted of samples collected from the Background Study Areas (BSAs)
during the Phase II investigation. The EA team collected 101 soil samples (92 originals and 9
field duplicates) and generated nine aqueous equipment rinsate blank (ERB) samples during the
field investigations. All samples were shipped to ALS in Fort Collins, Colorado for analyses.
One (original) soil sample container broke in shipment; consequently, analytical data are
available from 100 soil samples (91 originals and 9 field duplicates). ALS reported the data
from these samples in four work orders numbered:
• 1711413
• 1711418
• 1711420
• 1711421
March 18, 2021
Rev. 1.2
33
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
The Level IV data packages are provided in Appendix G.l of the Phase II Summary Report
(provided as Appendix J to this report).
ERG conducted Level IV data validation (Ra-226 and gross alpha only) for one of these data
packages (Work Order Number 1711413). This meets the requirement of 10% Level IV
reporting and validation in the QAPP. Work Order Number 1711413 consists of data for the
following samples.
• 24 background soil samples
• Two correlation samples
• Two field rinsate samples (water)
• Two duplicate soil samples
Validation of field generated radiometric data included assessing if minimum detectable activity
criteria were met and identified any obvious spurious measurements. In addition, field logs and
records were reviewed for any notes of unanticipated field conditions, anomalous equipment
function, or anomalous readings.
ERG conducted Level II data validation on 100% of Ra-226 soil sample results and concluded
that the data met the measurement quality objectives (MQOs) specified in the project QAPP.
The data validation summary memo for radionuclides is provided in Appendix G.l of the Phase
II Summary Report (provided as Appendix J to this report). Table 5-1 provides the data
validation assessment of the relevant field data for background soil sampling. The validation of
radiological analytical data identified that all field QA requirements were met with the exception
of two items. First, the COC for one sample shipment was not signed though samples were
confirmed to have remained in the custody of the sampler and a custody seal placed on the
shipping container was intact upon receipt by the lab. Second, it was identified that all field
rinsate samples were not preserved in the field and were preserved by lab but after the 5 days
specified by the EPA Method 900.0. This preservation method was not identified in the QAPP
or FSP. Lack of preservation was deemed unlikely to affect the analytical results since this is a
low level field rinsate sample. Consequently, no data qualifiers were assigned for Work Order
Number 1711413 as part of the ERG data validation.
As described in the QAPP (provided as Appendix F to this report), ALS provided Level IV data
packages for the Phase II soil samples. EA completed a Level IV data validation on 11% of the
non-radionuclide data packages by randomly selecting two or three samples from each of the
four data packages (11 total samples). For these 11 samples a detailed review of field and
laboratory documentation, standards used, maintenance performed, evaluation of field and
laboratory QC sample results, and recalculation of the concentrations published by ALS was
conducted. EA performed a Level II data validation on the remaining 89% of the data (89
samples), reviewing field and laboratory documentation, and evaluating field and laboratory QC
sample results. Table 5-2 provides the data validation assessment of analytical laboratory non-
radionuclide data for background soil sampling.
March 18, 2021
Rev. 1.2
34
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
The EPA Quality Assurance Section completed a review of the data usability. The EPA Quality
Assurance Section requested that the rinsate sample data be rejected and that "all environmental
data should be flagged as "J" accompanied by an explanatory comment that there is no usable
rinsate quality control sample." The EPA also indicated that "there is presumptive and
corroborating evidence that the environmental sample data were not biased due to cross-
contamination. " The results of the EPA review were provided in a memorandum dated April 5,
2018, which is provided in Appendix G.3 of the Phase II Summary Report (provided as
Appendix J to this report). Based on the EPA comments, the EA team has agreed to qualify the
rinsate data with "R" (rejected) and flag the other laboratory results as "J" to identify that the
rinsate data could not definitively confirm that absence of cross contamination between samples.
5.1.2 2019 Data Set
This section discusses the Level IV data validation results for soil samples collected during the
Phase III investigation. The EA team submitted 59 soil samples (49 originals and 10 field
duplicates), seven aqueous ERB, and one field blank of the water used to collect the ERB to ALS
in Fort Collins, Colorado for analyses. Analytical data are available for all samples in Appendix
E of the Phase III Summary Report (provided as Appendix M to this report). ALS reported the
data from these samples in a single batch numbered 1812316. The Level IV data package for
batch number 1812316 is provided in Appendix D.2 of the Phase III Summary Report (provided
as Appendix M to this report).
Environmental Restoration Group, Inc. (ERG) conducted Level IV data validation (Ra-226 and
gross alpha only) for the single laboratory data package (ALS batch no. 1812316) (ERG, 2019).
This exceeds the requirement of 10% Level IV reporting and validation in the QAPP. Batch
number 1812316 consists of data for the following samples.
• 5 background soil samples
• 44 correlation soil samples
• 10 field duplicate soil samples
• Seven field rinsate samples (water), plus one field blank of the rinsate water
Validation of field generated radiometric data included assessing whether minimum detectable
activity criteria were met and identification of any obvious spurious measurements. In addition,
field logs and records were reviewed for any notes of unanticipated field conditions, anomalous
equipment function, or anomalous readings.
The data validation summary memo for radionuclides is provided in Appendix D.3 of the Phase
III Summary Report. Table 5-3 provides the data validation assessment of the relevant field data.
The validation of radiological analytical data identified that all field QA requirements were met
except for three errors affecting COC forms:
1. Sample dates and times on laboratory COC forms were not completed. Individual sample
IDs indicate the date of sampling.
2. Background soil samples were collected over two sample jars to ensure adequate sample
volume. Instead of indicating on the COC that each jar was part of a set of two jars
March 18, 2021
Rev. 1.2
35
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
representing a single sample location, the jars were listed individually on the COCs and
logged in by the laboratory as separate samples. In effect, each jar was inadvertently
requested to be independently analyzed by ALS, with the result that each background
sample has its own field duplicate.
The intentional field duplicate collected at location D207 was also inadvertently
duplicated, resulting in four independent analyses for location D207.
3. Eight of the twelve background samples (D207, D207-DUP, D208, D209, D209-DUP,
D210, D210-DUP, D211) did not have their sample IDs properly recorded. These
samples omitted the leading "D" required before the sample number specified by
Section 3.3 of the Phase III Field Sampling Plan: Sample Identification and Labeling
(provided as Appendix K to this report). The omitted "D" does not affect the sample
traceability since other unique identifiers within the sample IDs differentiate samples
from each other.
These errors do not compromise data integrity or the ability to properly identify and track
samples. Field and laboratory results were determined to meet project data quality objectives
(DQOs), as defined in the project QAPP, for radiological analyses. Consequently, no data
qualifiers were assigned for batch number 1812316 as a result of ERG's data validation.
As described in the QAPP, ALS provided Level IV data packages for the Phase III soil samples.
EA completed a Level IV data validation on 10% of the non-radionuclide data packages by
randomly selecting six samples from the data package (EA, 2019a). For these six samples, EA
conducted a detailed review of field and laboratory documentation, standards used, maintenance
performed, evaluation of field and laboratory QC sample results, and recalculation of the
concentrations published by ALS. EA performed a Level II data validation on the remaining
soils data (5 samples), reviewing field and laboratory documentation, and evaluating field and
laboratory QC sample results.
The data validation summary memo for metals is provided in Appendix D.l of the Phase III
Summary Report (provided as Appendix M to this report). Table 5-4 provides the data
validation assessment of analytical laboratory data for soil sampling. Based on EA's review, all
data were accepted as reported by ALS without further qualification except arsenic results from
ALS "Prep Batch" IP 190109-5. EA qualified the arsenic results for these 20 samples (Lab ID
Nos. 1812316-26 through -48) as estimated ("J") based on low matrix spike/matrix spike
duplicate results.
5.2 Correlation Study Results
5.2.1 Surface Correlation Results
5.2.1.1 Radium-226
ERG established correlations via regression modelling of Ra-226 soil concentrations, exposure
rate, and static or scanning gamma count rate (as appropriate) via co-located measurements at 10
sites throughout the investigation area. The types of measurements and equipment used are
described in Table 5-5. These correlation locations are depicted cartographically on Figure 3-1.
One soil sample, collected from correlation location 10, was broken in-transit to the independent
March 18, 2021
Rev. 1.2
36
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
laboratory. Because of the loss of sample integrity, location 10 was excluded from the analyses
described below. In total, nine correlation points were used in the regression models.
Per the Phase II Work Plan (EA, 2017e), correlation soil samples were collected using a
five-point composite sampling technique on November 6-7, 2017. Samples were analyzed for
Ra-226 by ALS in Fort Collins, Colorado by EPA method 901.1m. The analytical results were
correlated with average gamma-survey data collected within the composited area, consisting of a
10 by 10 meter grid centered on the correlation location, using simple linear regression. Table 5-
6 presents the gamma survey summary statistics and associated Ra-226 soil data. The different
number of gamma measurements within each correlation location is a function of four factors: 1)
the required transect spacing at the correlation location; 2) the speed of scanning; 3) the presence
or absence of objects and geological or topographical features which had to be navigated; and 4)
the exact spatial geometry of the template used to compute the spatially-averaged gamma count
rate. The distributions and coefficient of variation (CV) within each grid are appropriate and the
central limit theorem says that the sample number (n) is adequate to characterize the mean in all
cases. Figures 5-1 and 5-2 present the regression model results. The model showed good
correlation between the two variables, with an adjusted coefficient of determination (r2) value of
0.894, which exceeded the study DQO of r2 > 0.8. Additional statistical analysis of the soil
regression model is provided in Appendix C of the Phase II Summary Report (provided as
Appendix J to this report). These correlations allow for an estimation of Ra-226 concentrations
in soils. The correlation is valid for the same data collection method under the same conditions
as the correlation locations. If the data collection method changes or the conditions of the site
change, then the correlation may need to be updated to provide a reasonable estimate of the
radium concentrations in soil.
5.2.1.2 High-Pressurized Ion Chamber and Gamma Count Rate Correlations
Two correlations were established using data from the high-pressurized ion chamber (HPIC):
• A correlation between exposure rate and static gamma count rate.
• A correlation between exposure rate and Ra-226 concentration in soil.
These correlations were established using simple linear regression using the software JMP 13.2.1
and verified in R (x64 v 3.4.3), Version J3.2. J. SAS Institute Inc., Caiy, NC, 1989-2007.
Table 5-7 presents the data used to build the regression models, including: HPIC exposure rate,
soil Ra-226 concentration, and static gamma count rate. Figures 5-3 and 5-4 depict the result of
exposure rate regressed on static gamma count rate and exposure rate regressed on Ra-226
concentration in soil, respectively. Both regressions show good correlation and exceed the DQO
of r2 > 0.8. The exposure rate is shown on Figure 5-5
5.2.1.3 Metals Correlation
ERG also performed linear regression analysis to evaluate whether non-radiological constituents
(arsenic, mercury, molybdenum, selenium, uranium, and vanadium) in the nine samples were
significantly correlated with Ra-226 (a surrogate for gamma count rate). Separate models were
run for each metal constituent in both the BSA and correlation sample pools presented in
Section 5.3.
March 18, 2021
Rev. 1.2
37
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
A significant correlation between a metal and gamma-survey data in the BSA data pool could
indicate a stoichiometric relationship between mineral constituents in undisturbed soils. A
significant correlation between a metal and mobile gamma data in the correlation pool could
indicate a mine process that concentrated and/or co-located metals (e.g., the presence of a waste
rock pile). However, none of the analyzed metals appears to be significantly correlated with the
Ra-226 data (i.e., the observed adjusted r2 values were less than the DQO of 0.8). Table 5-8
reports the adjusted r2 values for each of the constituents, analyzed by pool.
During the Phase III evaluation the soil sampling results from the samples collected in areas with
known mine-related material were used to more robustly investigate potential correlations
between gamma-survey data and metal constituents as discussed in the following section.
5.2.2 Subsurface Correlation Results
The objective of this task was to develop mathematical correlations between:
1. Ra-226 concentrations in soil and net shielded static gamma count rate, as measured on a
1 liter Marinelli beaker of the same soil, and
2. Ra-226 concentrations and concentrations of arsenic, mercury, molybdenum, selenium,
uranium, and vanadium in soil.
The test pit correlation soil and sediment samples represent a subset of the individual samples
collected from the test pits. Test pit correlation populations vary in size due to the exclusion of
U flagged metals data and also because one sample, from TP-14, did not have an associated
representative ambient gamma measurement and therefore it was not possible to calculate a net
shielded static gamma measurement to correlate with the concentration of Ra-226 in soil. If the
analyte was analyzed for but not detected a "U" is entered. For samples, negative values are
reported as non-detects.
Soil samples were analyzed by ALS for Ra-226, arsenic, mercury, molybdenum, selenium,
uranium, and vanadium by the methods described in Table 4-6. The analytical results are
provided in Table 5-9 for the correlation populations of each metal and Ra-226.
Analytical data were received from ALS on January 22, 2019. Statistical correlations were
computed following the protocol described in the Phase III Field Sampling Plan (provided as
Appendix K to this report). Ordinary least squares regression was used to relate soil
concentrations of Ra-226 to net shielded gamma count rate and other constituents of interest
(arsenic, mercury, molybdenum, selenium, uranium, and vanadium). The resulting analysis of
variance (ANOVA) table is presented as Tables 5-10 through 5-18. The resulting mean
regression is plotted on Figures 5-6 through 5-12. Assuming that a standard linear regression
analysis describes the relationship between the dependent variable and the independent variable
(Ra-226), for the purposes of this project an r2 value of greater than or equal to 0.8 was required
to define a meaningful site-specific correlation. This metric for r2 is consistent with that
described in the Phase II Work Plan (EA, 2017e). Error bars on the correlation plots represent
the 95% confidence level uncertainty for radionuclides and ± 20% for metals. The grey banded
region on the correlation plots represent the 95% prediction interval of the regression model.
March 18, 2021
Rev. 1.2
38
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
The summary statistics for metals and radiological constituents in the correlation population is
provided in Table 5-19. Table 5-20 reports the adjusted r2 values for each of the constituents.
Correlations of Ra-226 to all metal PCOCs did not meet the project DQO of an adjusted r2 value
of 0.8 or greater. The summary ANOVA statistics for each of these correlations are contained in
Tables 5-13 through 5-19. The correlations are displayed graphically on Figure 5-6, and
Figure 5-8 through Figure 5-12. All correlations of Ra-226 to metals exclude U flagged data, if
any. Because the presence or absence of Ra-226 in soil/sediment does not reliably and
quantifiably correlate to the presence of metal PCOCs, it is not possible to use the concentration
of Ra-226 in soil/sediment as a surrogate for the presence or absence of a metal PCOC.
The initial statistical model relating the concentration of Ra-226 in soil/sediment to static gamma
count rate did not meet the project DQO for adjusted r2 (adjusted r2 > 0.8) for the complete
correlation data set (n=43). The summary analysis of variance (ANOVA) statistics for the
correlation are displayed in Table 5-10 and the correlation is displayed graphically on Figure 5-7.
However, as discussed in Section 5.0 of the Phase II Summary Report (provided as Appendix J
to this report), two of the collected samples were identified as outliers and removed from the
second correlation data set. Although a review of the laboratory analytical data and field notes
from the associated samples did not identify any irregularities with sampling or analysis for these
two samples, these two points were removed from the data set and a second Ra-226 to gamma
regression model (n=41) was developed. These outlying data points were also excluded from all
Ra-226 to metal regression analyses. The ANOVA table for the second Ra-226 to gamma
regression (n=41) is presented in Table 5-12. The resulting mean regression is presented on
Figure 5-13. Figure 5-13 presents a standard linear regression analysis that describes the
relationship between the dependent variable and the independent variable (Ra-226) with the
outliers removed.
With the outlying data points removed, the statistical model relating concentration of Ra-226 in
soil/sediment to static gamma count rate met the project DQO for a correlation (adjusted r2 value
> 0.8). Based on this analysis, it is appropriate to use the correlation between soil/sediment
concentration of Ra-226 and gamma radiation count rate to estimate the depth of TENORM
exceeding the IL in the Project area, and to use this depth information to estimate removal
volumes as an input to an alternatives analysis.
5.3 Background Study Area Pooling
To determine whether all of the BSA soil data could be pooled to calculate an upper tolerance
limit (UTL) for background Ra-226 Site-wide, a non-parametric Dwass, Steel, Critchlow (DSC)
test was performed on soil Ra-226 concentrations using the software R x64 v 3.5.0. The DSC test
evaluates the distribution of each sub-population within the study against all other sub-
population distributions to determine which, if any, sub-populations differ significantly (i.e. ,P<
0.05). The results of this test are given in Table 5-21. A statistical comparison of the pooling
using the complete and censored data set is available in Appendix F of the Phase II Summary
Report (provided as Appendix J to this report). The censored data set was developed at the
request of EPA to remove data that the EPA felt was potentially impacted by mineralization or
TENORM.
March 18, 2021
Rev. 1.2
39
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
While useful, the pairwise test can only serve as a guide for pooling BSAs, as the transitive
property is not inviolate when making statistical comparisons between populations. The
following conclusions were drawn from the DSC test result:
1. The Little Colorado River BSA is significantly different from most other BSAs
(p < 0.05). As presented on Figure 3-1, the LCR BSA is located in the active river
channel and may contain sediments from upgradient sources. Thus, it is anticipated that
the soil sediments in this location change with time as the river flows.
2. The Alluvial #1 and #2, Qter BRA, and Terrace #1 and #2 BSAs are not significantly
different from each other.
3. The Drainage BSA #2 is different from most other BSAs.
Based on the pairwise results, it was evaluated whether it would be possible to pool the BSAs
into three groups: Little Colorado River (LCR); Drainage #2; and Alluvial (consisting of
Alluvial #1 and #2, Qter BRA, and Terrace #1 and #2 BSAs). A second pairwise DWS test was
carried out on the pooled data, and each of these three pools is significantly different from the
other (p < 0.001). Therefore, the three proposed pools of BSA data represent three distinct data
sets and are proposed to be treated as three distinct background areas.
The area to which each BSA would apply was determined by examining similarities between the
sites. Drainage #2 BSA was taken to be representative of the EPA-identified Site drainages and
drainage areas bounding the LCR, as identified via the spatial extent of water-loving vegetative
communities on Site orthophotos. The LCR pool was taken to be the active channel of the LCR,
as depicted on Site orthophotos. The Alluvial pool was used for all remaining areas at the Site.
5.4 Delineation of Investigation Level
To delineate the investigation level (IL) for the horizontal gamma survey, it was necessary to
determine which BSA would represent specific portions of the Site. The three pooled BSAs
represent:
• Little Colorado River floodplain.
• Drainages upgradient of the LCR.
• Other locations/Alluvial.
The extent of the LCR floodplain was defined and discussed in Section 4.2. The background
radiological conditions within this area are assumed to be similar to the LCR BSA. To define the
spatial extent of drainage areas, the EPA-derived polygon depicting drainages was extended to
connect the system to the LCR polygon. Background radiological conditions and the
depositional environment within this area are similar to the Drainage BSA #2. The remainder of
the Site was classified as "Other," represented by the Alluvial #1 and #2 BSAs, Terrace #1 and
#2 BSAs, and EPA QTer BRA. The pooled background areas are presented on Figure 5-14.
Figure 5-14 shows the pooled locations where each of the three background concentrations for
Ra-226 have been applied. A statistical comparison of the pooling using the complete and
censored data set is available in Appendix F of the Phase II Summary Report (provided as
March 18, 2021
Rev. 1.2
40
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Appendix J to this report). The censored data set was developed at the request of EPA to remove
data that the EPA felt was potentially impacted by mineralization or TENORM.
The investigation level for the Site is defined as the 95% upper tolerance limit (UTL) for the
gamma survey results for the relevant pooled BSA plus the gamma count rate corresponding to
1.24 pCi/g of Ra-226. The correlation relationship between Ra-226 established in Section 5.2
was used to convert 1.24 pCi/g of Ra-226 to a gamma count rate (3,612 cpm). Specifically, the
equation on Figure 5-2, which represents the upper 95% prediction limit for Ra-226 at a given
gamma count rate was used.
The lowest Ra-226 concentration in the correlation data set was 1.41 ± 0.24 pCi/g; 1.24 pCi/g
(the concentration used to calculate the IL) is within the range of analytical uncertainty of the
correlation study's lowest value. Furthermore, the use of the 95% upper prediction limit of the
correlation to establish the IL provides a conservative estimate of the gamma count rate
corresponding to 1.24 pCi/g. The uncertainty associated with extrapolating the linear regression
beyond the lowest concentration of 1.41 ± 0.24 to 1.24 pCi/g is negligible when considering the
analytical error of the laboratory and the conservative use of the 95% upper prediction limit.
The ILs for each of the pooled BSAs are presented in Table 5-22. These investigation levels,
together with the gamma scanning data described in Section 4.4.2, were used to develop the
binning shown on Figures 4-8 through 4-12.
5.5 TENORM Identification
The delineation of TENORM versus naturally occurring radioactive material (NORM) was
completed for the gamma survey data points. The results of the TENORM delineation are shown
on Figures 5-15 through 5-19. The delineation of TENORM was based upon a review of aerial
photography, topographic features, which were delineated through field verification during the
field reconnaissance discussed in Section 4.3 and Appendix A of the Phase II Summary Report
(provided as Appendix J to this report). The use of aerial photography combined with knowledge
of the Site allowed for the delineation of TENORM in areas of surface disturbance. Areas that
were above the IL and topographically downgradient of an area that contained TENORM, which
was above the IL, were considered to be TENORM (e.g., EPA-defined drainages). Data points
above the IL that were not related to surface disturbance areas above the IL or connected by
drainage pathways to areas that were above the IL were not considered TENORM.
5.6 Potential Material Migration
This section has been developed to evaluate possible past movement of material within and off
the Site due rain events and erosion. A qualitative evaluation was completed using the gamma
data and site topography to look for potential migration of material. This is discussed in more
detail in the following section.
5.6.1 Potential Material Migration from A UM 45 7
Review of Figure 2-7 shows four areas with indication of the general flow direction of surface
water near AUM 457. These four areas are discussed below in north to south order.
March 18, 2021
Rev. 1.2
41
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
5.6.1.1 Northern Drainage
Review of the northern drainage shown on Figure 2-7 indicates that the drainage north of the pit
area flows from the playa area towards the Little Colorado River. The drainage goes through a
dam breach immediately west of the Section 9/Section 10 border. Potential flow into this area
would be from the Playa to the west, the pit to the south and the dozer pushes from historic
investigation from the north. Figure 4-9 shows that gamma surface surveys are at or below IL
near the other mine related disturbance area. Figure 5-20 shows the gamma scan results for the
defined drainages in cpm. The gamma scan results indicate that there are decreasing
concentrations as the drainage approaches the LCR. Generally, readings above IL end
approximately 300 feet west of the LCR. Additionally, soils excavated from Test Pit 2, shown
on Figures 4-23 and 4-24, in the drainage have Ra-226 levels ranging from 2.69 to 2.82 pCi/g,
which is below the IL of 2.95 pCi/g for drainages. This area does not show signs of surface
erosion into the drainage area from the pit area as the surface of the pit area is exposed bedrock.
Thus, this drainage has only marginal sources of mining wastes, and has no indication of historic
transport of mine waste above IL levels into Section 10. Material migration is not considered
likely for this drainage area.
5.6.1.2 Pond Area
The Pond Area is shown on Figure 2-7 and indicates that drainage from the pond berm is
directed into the pond. Potential flow is from the crest of the berm into the impoundment. The
surface surveys on Figure 4-9 show surface soils elevated to higher than 3 IL mainly in the
southwest portion of the impoundment. Test Pits 4 and 6 were excavated from within the Pond
Area as shown on Figures 4-23 and 4-24. These test pits had Ra-226 levels ranging from 1.61 to
5.92 pCi/g; some of the Ra-226 levels are above the IL value of 4.96 pCi/g. This drainage is
self-contained and material migration is not considered possible for this drainage area.
5.6.1.3 UpgraderArea
The drainage to the east of the upgrader area is shown on Figure 2-7. This area drains from three
paths around the upgrader to the east towards the LCR. The area exits to the west of LCR just
north of the Wetland 3 area shown on Figure 2-7. Surface gamma surveys show areas greater
than 3 IL in the drainages below the stockpile and upgrader, however, the southernmost finger of
the drainage area has gamma surveys below 1 IL as shown on Figure 4-9. Figure 5-20 shows the
gamma scan results for the defined drainages in counts per minute cpm. The gamma scan results
indicate that there are decreasing concentrations as the drainage approaches the LCR. Test Pits 7,
8, and 9 were excavated in this drainage as shown on Figures 4-23 and 4-24. Test Pits 7 and 8
have Ra-226 levels above IL in the upper one foot. Test Pit 9 has Ra-226 levels above IL to a
depth of 5 feet. Test Pit 9 encountered gravel at a depth of 5 feet that is likely not from the
upgrader area, and native soils at a depth of 7 feet. There is evidence of erosion from the
upgrader area down the drainage to the bank of the LCR in Section 10. The depth of the alluvial
deposit from this erosion varies from 1 foot to 5 feet in the drainage. However, once the
drainage intersects the LCR, the alluvium from the Site will be difficult to distinguish from the
LCR alluvium being transported down the LCR from locations upgradient from the Site.
5.6.1.4 Bedrock Ridge West of AUM 457
Figure 2-7 shows drainage to the west off of the ridge west of the upgrader. Figure 4-9 shows
this area is NORM material and is generally below IL. Direction of flow from this area would be
March 18, 2021
Rev. 1.2
42
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
to the Playa. The Playa then drains north and reaches the Northern Drainage as discussed above.
Flow is then out the drainage to the east towards the LCR. Gamma readings drop to IL or below
approximately 300 feet west of the LCR. There has been no indication of historic transport of
mine waste above IL into the LCR from this drainage area.
5.6.2 Potential Material Migration from A UM 458
Review of Figure 2-8 shows four areas with the general direction of surface water flow indicated.
These four areas are discussed below.
5.6.2.1 Within AUM 458
AUM 458 is shown on Figure 2-8. The figure indicates that drainage from the inside of the pit is
directed to the bottom of the pit. Potential flow is from the crest of the pit into the pit bottom.
The no indication of surface water flow leaving the pit was observed during EA's site visits. As
discussed in Section 9.1.2 the pit depth ranged from 18 to 30 feet. The surface gamma surveys
in the AUM 458 area show that a majority of the surface material is more than three times higher
than IL as shown on Figure 4-12. Test Pits 18, 19 and 20 were excavated inside the pit drainage
area as shown on Figures 4-26 and 4-27. The soils in Test Pit 18 were below the Ra-226
background levels. The soils in Test Pit 19 were above the Ra-226 background levels, but these
soils are limited to depth of approximately 1 foot due to shallow bedrock. The soils in Test Pit
20 were above the Ra-226 background levels. There is evidence of erosion from the pit walls
and dozer pushes into the bottom of the pit. This drainage is self-contained and material
migration is not considered likely for this drainage area.
5.6.2.2 Outside of AUM 458
The area outside of the pit capture area, but within AUM 458 boundary is shown on Figure 2-8.
This area flows radially away from the pit capture area. The surface gamma surveys outside of
the pit capture area are generally less than two times IL as shown on Figure 4-12. Test Pit 21
was excavated in this area at the location shown on Figures 4-26 and 4-27, and shows Ra-226
higher than IL. However, the gamma surveys in the NORM area outside of the AUM 458
boundary are less than IL as shown on Figures 4-11 and 4-12. There is limited evidence of
erosion from the areas outside of the pit capture zone, however, the migration of this material is
limited in nature, and gamma surveys of the NORM area surrounding the AUM 458 boundary
show only a small area above IL west of AUM 458.Material farther to the north along the
drainage is below IL as shown on Figure 4-12. Therefore, while there is evidence of erosion from
the area, gamma survey data indicate the material has not historically migrated very far, and thus
the potential for off-Site contamination is low.
5.6.2.3 Ridge South of AUM 458
There is an area of exploration along the ridge south of AUM 458 that is identified on
Figure 2-8. The runoff from this ridge generally flows to either the west or east. The surface
gamma surveys of the area are shown on Figure 4-12 and show the gamma levels to be 1 to 2
times the IL. Figure 5-20 shows the gamma scan results for the EPA identified drainage in cpm.
The gamma scan results indicate that there are decreasing concentrations from the ridge line
towards the east, towards Mays Wash. Test Pit 22 is located in this drainage basin as shown on
Figures 4-26 and 4-27, and shows Ra-226 to range from 2.69 to 4.14 which exceeds the IL of
2.95 for drainage basins. There is limited evidence of erosion from this area to the west and east.
March 18, 2021
Rev. 1.2
43
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
However, the gamma surveys in the NORM areas surrounding this feature are below the IL as
shown on Figure 4-12. Therefore, while there is evidence of erosion from the area, gamma
survey data indicate the material has not historically migrated very far, and thus the potential for
off-Site contamination is low.
5.6.2.4 Drainage Southeast of AUM 458
There is a large drainage south and east of AUM 458. This drainage flows from the west in an
easterly direction to the LCR. The drainage flows between AUM 458 and AUM 459 as shown
on Figure 2-8. A finger of the drainage also originates north of AUM 458. The surface gamma
surveys of the drainage southeast and downgradient of the AUM 458 area are shown on
Figure 4-11 and show the gamma levels below IL. There is an area that is up to two times the IL
in the finger drainage immediately north of AUM 458, however, downgradient of this area the
gamma levels are below IL. Figure 5-20 shows the gamma scan results for the defined drainages
in cpm. The gamma scan results indicate that there are decreasing concentrations as the drainage
approaches the LCR. Test Pit 16 is in the drainage downgradient of AUM 458 and shown on
Figures 4-26 and 4-27, and has Ra-226 readings of 1.2 and 1.23 which are below the IL value of
2.95 for drainages. Therefore, while there is evidence of erosion from the area, gamma survey
data indicate the material has not historically migrated very far, and thus the potential for off-Site
contamination is low.
5.6.3 Potential Material Migration from A UM 459
Review of Figure 2-8 shows two areas with the general direction of surface water flow indicated.
As presented in 2.6.3, no visible mining-related disturbances related to AUM 459 in Section 9
other than the mine access road. Thus, TENORM on Section 9 likely migrated on site from
Section 16. These two areas are discussed below.
5.6.3.1 Drainage North from AUM 459
There is a drainage that flows northeast from AUM 459 to the LCR. This drainage combines
with two additional drainages before they enter the LCR floodplain as shown on Figure 2-8. The
gamma survey data shown on Figure 4-11 indicate that the area where erosion from AUM 459
enters the drainage near the Section 9/Section 16 boundary is two to three times higher than the
IL. These values drop to 1 to 2 times IL at the AUM 459 boundary, but remain at that elevated
level until the drainage intersects the road approximately 650 feet north of the AUM 459
boundary. Further downgradient of the road the gamma surveys are less than the IL as shown on
Figure 4-11, indicating that the material is not currently migrating into the LCR floodplain.
Figure 5-20 shows the gamma scan results for the defined drainages in cpm. The gamma scan
results indicate that there are decreasing concentrations as the drainage approaches the LCR. Test
Pit 23 is in the AUM 459 boundary, just north of the Section 9/16 boundary, as shown on
Figures 4-22 and 4-26. The Ra-226 values in Test Pit 23 range from 15.9 to 19.7 pCi/g and are
above the IL value of 2.95 indicating that erosion of the material from AUM 459 is occurring
into the drainage. There is evidence of erosion from AUM 459 into the drainage in Section 9.
The material decreases in gamma values from the AUM 459 boundary downgradient to the road,
but remains above the IL the entire distance. The alluvium below the road is below the IL until it
enters the LCR floodplain. There is the potential for this elevated material to migrate into the
LCR floodplain during larger storm events. However, once in the LCR it would be difficult to
March 18, 2021
Rev. 1.2
44
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
distinguish from materials that were generated upgradient of the Site and transported down the
LCR from locations upgradient from the Site.
5.6.3.2 Drainage Northwest of AUM 459
There is a large drainage northwest of AUM 459 as discussed in Section 5.6.2.4 above. This
drainage flows from the west in an easterly direction to the LCR. The drainage flows between
AUM-458 and AUM 459 as shown on Figure 2-8. The surface gamma surveys of the drainage
southeast and downgradient of the AUM 458 area are shown on Figure 4-11 and show the
gamma levels below IL. Figure 5-20 shows the gamma scan results for the defined drainages in
cpm. The gamma scan results indicate that there are decreasing concentrations as the drainage
approaches the LCR. Test Pit 16 is in the drainage, as shown on Figures 4-26 and 4-27,
downgradient of AUM 458 and has Ra-226 readings of 1.2 and 1.23 which are below the IL
value of 2.95 for drainages. This drainage merges with the Drainage North from AUM 459, as
described in Section 5.6.3.1 above, at the LCR floodplain. While there is evidence of erosion
from the area, gamma survey data indicate the material has not historically migrated very far,
and thus the potential for off-site contamination is low.
5.6.3.3 Potential Migration Summary
Based on review of the Site topography, gamma survey and soil analytical results there is the
potential for migration from the Site to the LCR from two areas: The Upgrader Area at AUM
457, and the Drainage North of AUM 459, based on current Site conditions.
March 18, 2021
Rev. 1.2
45
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
6.0 HUMAN HEALTH STREAMLINED RISK EVALUATION
The Human Health Streamlined Risk Evaluation (HHSRE) provides information needed to
establish the potential contaminants of concern (PCOCs), calculate risk to potential current and
future receptors under current Site conditions. The HHSRE is used in conjunction with the
Ecological Streamlined Risk Evaluation [EcoSRE] to develop proposed action levels for P COCs
that will be protective for users under the current and planned future use at the Site, considering
any recorded covenants restricting the use of the land. The assessment of potential human health
risks for the non-radionuclide chemicals follow accepted EPA CERCLA requirements for
conducting human health risk assessments (e.g., EPA, 1989). The potential human health non-
radiological and radiological risks are calculated using the EPA on-line preliminary remediation
goals (PRG) calculators adjusted to using site-specific exposure assumptions. Appendix Table
Fl-1 of the Phase III Summary Report (provided as Appendix M to this report) summarizes the
variances from the Phase III Work Plan.
6.1 HHSRE Conceptual Site Model Development
The preliminary conceptual models for areas of potential human and ecological effects were
developed in the Phase II Summary Report (provided as Appendix J to this report) for the AUMs
and nearby areas. The PCOCs are derived from mining-related ore and waste rock that have
been excavated from the near-surface uranium deposits and dispersed into the local environment.
The principal potential Site-wide exposure pathways are ingestion and dermal contact with
contaminated soils, inhalation of dust, and exposure to ionizing radiation. Separate risk
calculations were prepared to reflect dry and wet conditions at the Site. The Dry Conditions
Scenario is the more common environmental condition at the Site, allowing contact with soils at
any location on the Site, including the dry Little Colorado River (LCR) channel bed. The Wet
Conditions Scenario is relevant when water is present (flowing or stagnant) in the LCR channel,
which precludes contact with the bed materials, as well as potential Site access from the east.
6.2 Evaluated Receptors
Given the streamlined nature of the HHSRE and the deed restriction that prohibits all future uses
of the section with the exception of maintaining the access road, exhaustive analysis of all
potential receptors and exposure pathways was not warranted. A copy of the deed restriction is
provided in Appendix A of the Phase III Summary Report (provided as Appendix M to this
report). The selection of receptors for the HHSRE was discussed in the Phase III Work Plan, and
includes the following five receptor groups or activities:
• On-Site Adult Worker
• Long Term Adult Recreator (24 years of exposure)
• Child Recreator (2 years of exposure)
• Combined Long Term Adult and Child Recreator (26 years of exposure)
Receptors that were not directly evaluated in the HHSRE include residents (adult, adolescents
and children), off-site workers, and off-site trespasser/ranchers (adult). The rationale for
excluding these receptors was presented in the Phase III Work Plan, and is reproduced in
Appendix Table F2-1 of the Phase III Summary Report (provided as Appendix M to this report).
March 18, 2021
Rev. 1.2
46
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Additional information regarding the exposure assumptions for each of these receptors is
provided in Section 6.4.
6.3 Exposure Pathways and Scenarios
The evaluation of complete and incomplete exposure pathways for human receptors was
provided in the Phase III Work Plan (provided as Appendix L to this report) as part of the
Conceptual Site Models (CSMs). The CSMs were developed using Dry and Wet Condition
Scenarios, defined below:
• Dry Condition Scenario: The exposure pathways evaluated for this scenario included
external (e.g., gamma radiation), inhalation of dust, dermal contact, and ingestion of soils
and the dry LCR channel bed sediments.
• Wet Condition Scenario: In the wet scenario is it assumed that no direct or indirect
contact occurs for the evaluated receptors to the submerged LCR streambed sediments.
External (e.g., gamma radiation), inhalation of dust, dermal contact, and ingestion of soils
from the remainder of the Site were assessed for the evaluated receptors.
A separate risk analysis for exposure to radon gas was not evaluated because there are no intact
buildings at the Site to accumulate the radon gas and any released radon would rapidly dissipate
in outdoor air (ATSDR, 2012)3. Section 9, which is owned by Babbitt Ranches, has also been
deed restricted so that no future use of the section is permitted including the construction of any
buildings or other structures. A copy of the deed restriction is provided in Appendix A of the
Phase III Summary Report (provided as Appendix M to this report).
Human health risk assessments typically also include evaluation of current and potential site
activities to provide guidance for site risk management. Present-use scenarios reflect those that
are occurring or can occur under current conditions. For this Site the only known activity is
limited to occasional visits by Site Workers, although there is some evidence of unauthorized use
of the property. Recreational use is commonly examined for U.S. Bureau of Land Management
(BLM) sites and was also examined at this Site. It is anticipated that future uses at the Site will
be similar to those under current conditions. Section 9 has also been deed restricted so that no
future use of the section is permitted with the exception of maintaining the access road.
6.4 Receptors and Exposure Assumptions
The potential exposures that were evaluated in the HHSRE include direct (On-Site) exposure for
(1) On-Site Workers; (2) Long Term Adult Recreator - 24 years; (4) Child Recreator - 2 years;
and (5) Combined Child and Adult Recreator - 26 years. The exposure assumptions used in the
HHSRE are consistent with those presented in the Phase III Work Plan and are provided by
receptor group in Appendix F of the Phase III Summary Report (provided as Appendix M to this
report). These were developed using standard sources, such as EPA's Exposure Factors
Handbook (EPA, 2011), the more recent updates from EPA (EPA, 2014), and also Site-specific
information on Babbitt worker activities. The derivation of the assumptions for Babbitt workers
(that includes ranch laborers and cowboys located within 10 miles of Section 9) was provided in
3 The radon isotopes Rn-218 and Rn-222 are included in the Ra-226 risk calculations since they are daughter
products of Ra-226 decay.
March 18, 2021
Rev. 1.2
47
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
the Phase III Work Plan (provided as Appendix L to this report) and supporting data are
presented and additional data summaries are provided in Appendix F4-lb of the Phase III
Summary Report (provided as Appendix M to this report). The Appendix F4-lb table
summarizes information for key parameters (e.g., employment duration, cumulative duration of
all visits over employment period) for (a) Babbitt workers that have actually visited the Site, and
(b) Babbitt workers that have visited or could be assigned to visit the Site. The cumulative hours
visited has a Reasonable Maximum Exposure (RME; equivalent to maximum in this case) value
of 6 hours for either workers who have visited the Site or workers who have been assigned to
visit the Site. Therefore, this value represents an upper end of the cumulative exposure over the
entire employment period for all potential Site workers. No non-field Babbitt employees were
included in the exposure assumption development since they have no potential to visit the Site.
Babbitt Ranches does not actively ranch this land nor will they in the future due to the deed
restrictions. Entry upon the property and any use of the property beyond that permitted in the
deed restriction is prohibited and is trespass under Arizona law.
The Phase III Work Plan also discussed potential indirect (Off-Site) exposure, such as
wind-borne migration of dust from the AUMs to the Little Colorado River floodplain for
receptors in the Little Colorado River floodplain. These exposure pathways include inhalation
exposures to wind-borne dusts released from the AUMs and incidental contact (ingestion) with
wind-borne dusts that deposit in the floodplain area. The EPA PRG Calculator includes an
estimate of exposure from suspended particulates. These results were used in lieu of using an air
deposition model in the uncertainty assessment in Section 6.14.
EPA calculates potential risks for adult and child separately and also as an "aggregated
individual" i.e., exposure assumptions for the child and adult are age-weighted and combined as
a single receptor. The HHSRE presented results for the separate age groups and aggregate
individual.
6.5 Identification of HHSRE PCOCs
The AOC identified the PCOCs, which are the same for both the HHSRE and the EcoSRE.
These include the following: arsenic, mercury, molybdenum, selenium, uranium, vanadium, and
Ra-226. Potential human health risks associated with mercury exposure were based on the
toxicity of inorganic mercury, given that the evaluated exposure source is soils, and mercury is
more likely to be in the inorganic form in soils.
6.6 Exposure Point Concentrations for HHSRE
The analytical data collected as part of the Phase II and III field programs were used to develop
the Exposure Point Concentrations (EPCs). Prior to calculating the EPCs the samples with field
duplicates were averaged. In those cases where one but not both of the sample-duplicate pairs
was detected, the detected result was used as the sample result. This occurred with some of the
selenium and molybdenum sample results.
EPCs that were used in the HHSRE represent the 95% upper confidence limit (95UCL) of the
mean concentration of each PCOC. These 95UCLs were calculated using EPA-developed
ProUCL software (version 5.1; Singh and Singh 2015; EPA, 2016d). This software provides
March 18, 2021
Rev. 1.2
48
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
information on summary statistics (e.g., detection frequencies, ranges of detected results, means),
assesses the distributions of the data (e.g., normal, lognormal, gamma), and calculates the
Kaplan-Meier mean values (when the detection frequencies are less than 100%). The UCLs
recommended by the software were used except in the cases where there was insufficient data to
use the statistical analysis (such as from a small number of collected samples) or where the
recommended UCL was greater than the maximum observed concentration. In these cases the
maximum detected value was used.
Surface soil samples, defined as samples collected from a depth interval of 0 to 6 inches (or
equivalently, 0 to 15 cm) were used for the EPC calculations since this depth interval has the
greatest potential for exposure under current or future use conditions. For the evaluation of
Ra-226, exposure could also occur (from radiological emissions) from greater depths. Most of
the radium soils data (119 of 150 samples; 80%) were collected from a depth of 0 to 6 inches
with 12 additional samples collected from a depth of 6 to 12 inches (the remaining 19 samples
were collected from depth up to 4 feet from ground surface). The samples collected from 6 to 12
inches included two locations in AUM 457, four locations in AUM 458, one location in AUM
459, three test pit samples, one test pit drain sample, and one sample from the mine related
disturbance area. Given that the 6 to 12 inch interval does not cover all areas of the Site, the
effect on EPCs and calculated risks for radium exposure between the 0 to 6 inch and 0 to 12 inch
interval will be evaluated in the uncertainty assessment.
HHSRE EPCs were calculated for the individual PCOCs using the following areas and scenarios:
• Area of Potential Effect (APE) With AUMs - wet and dry scenarios
• APE Less AUMs - wet and dry scenarios
• Outside of APE - same values for wet or dry scenarios
• Individual AUMs (AUM 457, 458, and 459) - same values for wet or dry scenarios for
AUM 457; AUM 458 and 459 are dry scenario only
• LCR Channel Bed - dry scenario only
Results from the background areas were evaluated as part of the "Outside of APE" area and were
not subtracted from the results of the soil samples collected from the APE. The assessment of
the individual AUMs was added as an assessment area after submission and approval of the
Phase III Work Plan with the concurrence of EPA and Babbitt Ranches. Separate EPCs were
developed for the wet and dry scenarios for the APE with AUMs and APE less AUMs because in
both cases the APE extends into the LCR channel bed. The Outside of APE and individual
AUMs assessment represent both wet and dry scenarios because these are outside of the LCR
channel bed.
The soil EPCs by PCOC and evaluated area are shown in Table 6-1. Additional summary
information for each of the EPCs and the associated ProUCL outputs are provided in
Appendix Table F3-2 and F3-3 of the Phase III Summary Report (provided as Appendix M to
this report). Some of the recommended UCLs from ProUCL were not used because they
exceeded the maximum detected concentration (e.g., molybdenum in AUM 458). In these cases,
the maximum detected concentration was used as the UCL value. These are identified on
Appendix Table F3-2 of the Phase III Summary Report (provided as Appendix M to this report).
March 18, 2021
Rev. 1.2
49
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
A cross-tabulation of the soil Sample IDs and the evaluation area assignments is provided in
Appendix Table F3-1 of the Phase III Summary Report (provided as Appendix M to this report).
EPCs for all of the PCOCs and all evaluated areas of the Site were developed with the exception
of selenium, which was not detected in any of the samples collected from the LCR channel bed
or AUM 459. The detection limit range in the samples from this area was 0.06 to 0.28 parts per
million dry weight (ppmdw) and 0.05 to 0.05 ppmdw, respectively. This PCOC was excluded
from the assessment of these evaluated areas of the Site.
Spatial averaging methods were not used for the HHSRE EPC development. This is discussed
further in the uncertainty assessment.
6.7 Exposure Assessment
The exposure pathways that were evaluated for the three receptors listed in the Phase III Work
Plan are ingestion of soils, dermal contact with soils (non-radiological PCOCs only), inhalation
of dust, and exposure to ionizing radiation.
The objective of the exposure assessment is to estimate the type, magnitude, frequency, and
duration of exposures for complete exposure pathways via intake equations. If the exposure
occurs over time, the total exposure can be divided by the time period of interest to obtain an
average exposure rate (e.g., mg/kg-day). The general equation for estimating a time-weighted
average intake is:
EPC x IR X EF x ED X Bf
Intake =
BW x AT
where:
EPC =
chemical concentration at the exposure point (e.g., milligrams per
kilogram [mg/kg] sediment)
IR
intake rate (e.g., milligrams per day [mg/day])
EF
exposure frequency (days/year)
ED
exposure duration (years)
Bf
bioavailability factor
BW =
body weight of exposed individual (kg)
AT
averaging time (period over which exposure is averaged, usually measured
in days)
Standard data sources were identified for this information (e.g., EPA, 2011) as well as other
relevant literature sources and Site-specific and regionally relevant information. The exposure
assumptions by receptor are provided in Appendix Table F4 series of the Phase III Summary
Report (provided as Appendix M to this report).
The same exposure assumptions were used for the radiological and non-radiological risk
calculations. Inputs for chemical risk assessments calculate exposures and risks on an equivalent
March 18, 2021
Rev. 1.2
50
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
daily basis, for both the non-radiological and radiological EPA on-line calculators. The risks
associated with radiological PCOC (i.e., Ra-226 and daughter products in secular equilibrium)
were evaluated using the on-line EPA Radiological PRG Risk Calculator4, while the risks for the
non-radiological PCOCs are evaluated using the ORNL RAIS Contaminated Media (Risk)
Calculator5.
6.7.1 Area Correction Factors
The Area Correction Factor (ACF) is used by the EPA radiological PRG calculator to adjust for
the finite size of the exposure area relative to the "infinite" source assumed when the dose
coefficients were developed for Federal Guidance Reports 12 and 13 (Bellamy et al., 2014). The
EPA radiological PRG calculator only allows for select areas to be used for Area Correction
Factors. To achieve consistency between different aspects of the risk evaluations the area of each
Site area was rounded to the closest of these pre-established values. This rounded area was then
used for all other area entry inputs in the PRG calculators, both radiological and non-radiological
risk calculations, for consistency. The actual and selected area for each Site area is displayed in
Table 6-2. Some of the Site areas (e.g., APE with AUMs) are considerable larger than the largest
selectable option in the PRG model range. To keep the risk evaluation within the EPA model
bounds the largest selectable area was chosen, which was 1,000,000 m2 or approximately 250
acres. Two sites, AUM 458 and LCR, were assigned ACFs of 100,000 m2 or approximately 25
acres. These sites were later determined to be smaller than 25 acres but use of a larger Area
Correction Factor in these cases was used for conservatism. ACFs are also used to calculate
climatic conditions, volatilization factors, and wind driven particulate emission factors.
6.7.2 Soil Grain Size Analyses
As discussed in Section 4.4.2, four soil sample locations were analyzed for grain size distribution
to assess the potential for wind entrainment. The sample-specific grain size and hydrometer
analyses are provided in Appendix B of the Phase III Summary Report (provided as Appendix M
to this report) and key parameters are summarized in Table 6-3. Given that all four samples,
which represented different portions of the Site, had similar grain size characteristics (i.e., were
all classified as fine sands) it is not anticipated that there would be significant differences across
the Site for the potential for wind erosion.
6.8 Chemical Uptake Factors
For the HHSRE, the non-radiological PCOC-specific uptake factors from the Phase III Work
Plan were used. These are shown in Appendix Table F4-3 of the Phase III Summary Report.
6.9 Toxicity Benchmarks
The toxicity benchmarks presented in the Phase III Work Plan were updated to reflect those from
the EPA on-line risk tool used for the HHSRE. These are shown in Appendix Table F4-4a for
non-radiological PCOCs and Appendix Table F4-4c of the Phase III Summary Report (provided
as Appendix M to this report) for Ra-226 (and daughter products). Appendix Table F4-4b of the
4 Accessed from this URL: https://epa-prgs.ornl.gov/cgi-bin/radionuclides/rprg_search
5 Available from this URL: https://rais.ornl.gov/cgi-bin/prg/RISK_search?select=chem
March 18, 2021
Rev. 1.2
51
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Phase III Summary Report summarizes the target organ or systems, and the basis for the non-
radiological non-cancer toxicity values.
6.10 Human Health Risk Characterization Approach
Risk characterization is the step in the risk assessment process that combines the results of the
exposure assessment and the toxicity assessment for each PCOC to estimate the potential for
cancer and non-cancer human health risks from chronic or subchronic exposure to that
constituent. The methodology to estimate potential cumulative non-cancer and cancer risks from
Site-related PCOCs is summarized below.
6.11 Non-Radiological Human Health Risks
For PCOCs that are evaluated for non-carcinogenic effects, the estimated average daily doses
(ADDs) calculated for each exposure route considered for each PCOC are compared to reference
doses (RfDs). The following formula is used to estimate the potential non-carcinogenic risk for
HQ = hazard quotient (unitless)
ADD = average daily dose of PCOC (mg/kg-day)
RfD = reference dose (mg/kg-day)
When the Hazard Quotient (HQ) for a given constituent and pathway does not exceed one, the
RfD has not been exceeded, and the non-cancer health effects are below levels of regulatory
concern as a result of potential exposure to that constituent via that pathway. The HQs for each
constituent are summed to yield the Hazard Index (HI) for that pathway. A Total HI is then
calculated for each exposure medium by summing the pathway-specific HI values. A Total HI
value that does not exceed one is below levels of regulatory concern for the receptor's potential
exposure to PCOCs in the environmental medium evaluated. The non-radiological PCOCs have
overlapping target organs or effects (see Appendix Table F4-4b of the Phase III Summary
Report). Consequently, the total HI represents the sum of the HI values across all of the non-
radiological PCOCs rather than calculating target organ- or effect-specific HI values.
For the evaluation of the potential cancer risk associated with exposure to a PCOC, the toxicity
factor (Cancer Slope Factor [CSF] for non-radiologicals) is multiplied by the lifetime average
daily dose (LADD) calculated for that chemical through each exposure pathway, as shown in the
equation below.
each PCOC:
HQ = ADD -h RfD
where:
ILCR = CSF x LADD
where:
ILCR
CSF
LADD
incremental lifetime cancer risk (no units)
cancer slope factor (l/[mg/kg-day])
calculated potential lifetime average daily dose of PCOC (mg/kg-day)
March 18, 2021
Rev. 1.2
52
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
For potential excess lifetime cancer risks, EPA's acceptable risk range is between one-in-ten-
thousand and one-in-a-million (1 x 10"4 to 1 x 10"6). For exposures to multiple carcinogens, EPA
(1989) has required that the upper bound cancer risks for all PCOCs in all exposure pathways for
a given receptor be summed to derive a total cancer risk:
Total cancer risk = X cancer risk for each PCOC
As presented in Section 6.7, the non-radiological human health risks are evaluated using the
ORNL RAIS Contaminated Media (Risk) Calculator. This calculator utilizes the methodology
above to calculate both non-cancer and cancer risks. Risks were initially calculated for all
receptors using the soil UCL EPC values. The risks based on the mean soil PCOC
concentrations were calculated based on the ratios of the mean and UCL soil concentrations and
the UCL risk results.
6.12 Radiological Human Health Risks
As presented in Section 6.7, the risks associated with radiological PCOCs were evaluated using
the on-line EPA Radiological PRG Risk Calculator6. A similar equation to that for the ILCR is
used but the CSF is replaced with the radionuclide-specific Slope Factor (SF). Potential
radiological cancer risks were evaluated in the context of the upper end of EPA's acceptable risk
range of lxlO"6 to lxlO"4, and in addition were compared to the 12 mrem/year acceptable dose
level per OSWER Directive No. 9200.4-18 (EPA 1997a; 3xl0"4), in accordance with the
approved Phase III Work Plan (EA, 2019c). The standard output of this program includes a
tabulation of the media- and radionuclide-specific EPC, dose calculations, and cancer risk
results, as well as external dose calculations. The risks from exposure to Ra-226 assumed that
Ra-226 was in secular equilibrium with its daughter products.
Risks were initially calculated for all receptors using the soil UCL EPC values. The risk based
on the mean soil Ra-226 concentrations were calculated based on the ratios of the mean and UCL
soil concentrations and the UCL risk results.
6.13 Receptor Specific Risks
This section summarizes the potential non-cancer and cancer risks by receptor. Each receptor
summary includes results for all of the evaluated areas. The output from the on-line EPA
calculators are provided in native Excel formats as part of the Appendix Table F5 series of the
Phase III Summary Report.
6.13.1 On-Site Worker
The non-radiological cancer and non-cancer risk values for the individual PCOCs are shown in
Table 6-4a and the HI values (sum of all HQ values) and sum of cancer risks are shown in
Table 6-4b.
All of the cancer risks from exposure to arsenic were below 1 x 10"6, the lower end of EPA's
acceptable cancer risk range, indicating that the potential cancer risk from this non-radiological
6 Accessed from this URL: https://epa-prgs.ornl.gov/cgi-bin/radionuclides/rprg_search
March 18, 2021
Rev. 1.2
53
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
PCOC in soils from any area of the Site for this receptor was below the level of regulatory
concern. All of the HQ values were below one for the non-radiological PCOCs, indicating that
the potential risks from exposure to the PCOCs by this receptor group from any area of the Site
were below the level of regulatory concern.
The Ra-226 Site-specific soil EPCs were used as inputs to the EPA online calculator and the risk
results are also shown in Table 6-4a. All of the cancer risks from exposure to Ra-226 and its
associated daughter products in soils were on the order of 1 x 10"8 or smaller based on the UCL
EPC values for all of the evaluated portions of the Site. The calculated risks were at least two
orders of magnitude lower than 1 x 10"6, the lower end of EPA's acceptable cancer risk range,
and at least four orders of magnitude lower than the 1 x 10"4 threshold from OSWER Directive
No. 9200.4-18 (EPA 1997a). The Ra-226 risk values are well below the level of regulatory
concern for this receptor group from the evaluated portions of the Site.
The HI values (sum of non-radiological PCOC HQ value) were less than one and the sum of the
cancer risks (sum of arsenic and Ra-226 risks) were also less than 1 x 10"6 indicating potential
risks across the PCOCs for this receptor for all of the evaluated areas were below the levels of
regulatory concern.
Outputs for both the radiological and non-radiological EPA calculators for this scenario are
located in Appendix Table F5 series of the Phase III Summary Report (provided as Appendix M
to this report).
6.13.2 Long Term Adult Recreator — 24 years of Exposure
This scenario is based on an exposure duration of 24 years by a Long Term Adult Recreator.
Use of the Site by a Long Term Adult Recreator is prohibited under the deed restriction and is a
trespass under Arizona law. The non-radiological cancer and non-cancer risk values for the
individual PCOCs are shown in Table 6-5a and the HI values (sum of all HQ values) and sum of
cancer risks are shown in Table 6-5b.
All of the cancer risks from exposure to arsenic were below 1 x 10"6, the lower end of EPA's
acceptable cancer risk range, indicating that the potential cancer risk from this non-radiological
PCOC in soils from any area of the Site for this receptor was below the level of regulatory
concern. All of the HQ values were below one for the non-radiological PCOCs, indicating that
the potential risk from exposure to the PCOCs by this receptor from any area of the Site were
below the level of regulatory concern.
The Ra-226 Site-specific soil EPCs were used as inputs to the EPA online calculator and the risk
results are also shown in Table 6-5a. All of the cancer risks from exposure to Ra-226 (and its
associated daughter products) in soils are below or within the EPA acceptable cancer risk range
(i.e., less than or equal to lxlO"4 risk), and were below the OSWER risk value, across the
evaluated areas, except for AUM 458 (UCL and mean EPC). The calculated risk (2xl0"4) using
the average Ra-226 soil level in AUM 458 (22.1 pCi/g) was less than the 12 mrem/year
acceptable dose level per OSWER Directive No. 9200.4-18 (EPA 1997a; 3xl0"4). The calculated
risk (6xl0"4) using the UCL Ra-226 soil level in AUM 458 (73.9 pCi/g) was greater than the 12
mrem/year acceptable dose level.
March 18, 2021
Rev. 1.2
54
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-5b summarizes the HI values (non-radiological PCOCs only) and the sum of the cancer
risks (arsenic plus Ra-226). The HI values were less than one for all of the evaluated portions of
the Site. The sum of the cancer risks were the same (after rounding) to the Ra-226 only results
because the arsenic cancer risks are two to three orders of magnitude lower than the Ra-226 risks
and did not significantly change the combined cancer risks.
Outputs for both the radiological and non-radiological EPA calculators for this scenario are
provided in Appendix Table F5 series of the Phase III Summary Report (provided as Appendix
M to this report).
6.13.3 Child Recreator — 2 years of Exposure
This scenario assesses potential risks to a child that accompanies an adult recreator. Use of the
Site by a Child Recreator is likewise prohibited by the deed restriction and is a trespass under
Arizona law. The non-radiological cancer and non-cancer risk values for the individual PCOCs
are shown in Table 6-6a and the HI values (sum of all HQ values) and sum of cancer risks are
shown in Table 6-6b.
All of the cancer risks from exposure to arsenic were below 1 x 10"6, the lower end of EPA's
acceptable cancer risk range, and therefore the potential cancer risk from this non-radiological
PCOC in soils from any area of the Site for this receptor was below the level of regulatory
concern. All of the HQ values were below one for the non-radiological PCOCs, indicating that
the potential risk from exposure to the PCOCs by this receptor from any area of the Site were
below the level of regulatory concern.
The Ra-226 Site-specific soil EPCs were used as inputs to the EPA online calculator and the risk
results are also shown in Table 6-6a. All of the cancer risks from exposure to Ra-226 (and its
associated daughter products) in soils were below or within EPA's acceptable risk range (i.e.,
less than or equal to lxl0"4 risk), and were below the OSWER risk value based on the average or
UCL EPC values for all of the evaluated portions of the Site. Therefore, the Ra-226 risk values
were below the level of regulatory concern for this receptor from the evaluated portions of the
Site.
Table 6-6b summarizes the HI values (sum of non-radiological PCOC HQ values) and the sum
of the cancer risks (arsenic plus Ra-226). The HI values were less than one for all of the
evaluated portions of the Site. The HI values (non-radiological PCOCs only) were less than one
and the sum of the cancer risks (non-radiological and radiological) were below or within the
acceptable risk range of regulatory concern for this receptor group from the evaluated portions of
the Site.
Outputs for both the radiological and non-radiological EPA calculators for this scenario are
provided in Appendix Table F5 series of the Phase III Summary Report (provided as Appendix
M to this report).
March 18, 2021
Rev. 1.2
55
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
6.13.4 Combined Child and Long Term Adult Recreator — 26 Years of Exposure
In this scenario an individual was assumed to have spent 2 years visiting the Site as a child and
24 years as an adult, each of which is prohibited under the deed restriction and in violation of
Arizona law. The non-radiological cancer and non-cancer risk values for the individual PCOCs
are shown in Table 6-7a and the HI values (sum of all HQ values) and sum of cancer risks are
shown in Table 6-7b.
All of the cancer risks from exposure to arsenic were below 1 x 10"6, the lower end of EPA's
acceptable cancer risk range, and therefore the potential cancer risk from this non-radiological
PCOC in soils from any area of the Site for this receptor was below the level of regulatory
concern. All of the HQ values were below one for the non-radiological PCOCs, indicating that
the potential risk from exposure to the PCOCs by this receptor from any area of the Site were
below the level of regulatory concern.
The Ra-226 Site-specific soil EPCs were used as inputs to the EPA online calculator and the risk
results are also shown in Table 6-8a. All of the cancer risks from exposure to Ra-226 (and its
associated daughter products) in soils were below or within the EPA acceptable cancer risk range
(i.e., less than or equal to lxlO"4 risk), and were below the OSWER risk value, for all of the
evaluated portions of the Site, except AUM 458. The calculated risk (2x10"4) using the average
Ra-226 soil level in AUM 458 (22.1 pCi/g) was less than the 12 mrem/year acceptable dose level
per OSWER Directive No. 9200.4-18 (EPA 1997a; 3xl0"4). The calculated risk (6xl0"4) using
the UCL Ra-226 soil level in AUM 458 (73.9 pCi/g) was greater than the 12 mrem/year
acceptable dose level.
Table 6-8b summarizes the HI values (sum of non-radiological PCOC HQ values) and the sum
of the cancer risks (arsenic plus Ra-226). The HI values were less than one for all of the
evaluated portions of the Site. The sum of the cancer risks were the same (after rounding) to the
Ra-226 only results because the arsenic cancer risks are two to three orders of magnitude lower
than the Ra-226 risks and did not significantly change the combined cancer risks.
Outputs for both the radiological and non-radiological EPA calculators for this scenario are
provided in Appendix Table F5 series of the Phase III Summary Report (provided as Appendix
M to this report).
6.14 HHSRE Uncertainty Analysis Approach
The section discusses the HHSRE risk characterization and will also include a discussion of the
quantitative and qualitative uncertainty of the HHSRE risk characterization.
6.14.1 Representativeness of sampling
The adequacy of the sampling strategies to characterize site conditions is a potential source of
uncertainty. The Phase II and III sampling program was biased towards the assessment of Site
features within and outside of the APE. Consequently, the PCOC soil concentrations would be
biased high and represent an upper end estimate of a Site-wide average or UCL soil
concentration. This is a reasonable approach in conducting a streamlined assessment to
minimize the potential for missing potential areas that may cause potential risks.
March 18, 2021
Rev. 1.2
56
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
6.14.2 Receptor selection and representativeness
Assessment of all potential human health receptors is not warranted for an HHSRE, which
focuses on receptors that are more likely to be exposed to Site media. Although camping and
related recreational activities are prohibited under the deed restriction, trespass under Arizona
law and unlikely to occur at the Site, adult and child recreators were used to represent potentially
highly conservative exposures by non-worker receptors that may visit the Site. Thus, although a
receptor such as a trespasser was not explicitly evaluated, the long term recreator has an
exposure profile that would yield more conservative risks than in these other receptors. An
adult recreator with one year of exposure of transient recreational use at the site was evaluated
and presented in Section 6.14.2.1. This was assumed to be comparable to a site trespasser.
The HHSRE also conservatively assumed that all of the exposures would occur at specific areas
(e.g., the recreator would always camp at AUM 458). This is unlikely to occur on any portion of
the Site due to lack of attractive features but would yield a highly conservative estimate of the
potential risks.
6.14.2.1 Uncertainty Assessment - Short Term Adult Recreator (1 year of Exposure)
This scenario is based on an exposure duration of 1 year, reflective of a transient recreational use
of the Site. Use of the Site by a Short Term Adult Recreator is prohibited by the deed restriction
and is a trespass under Arizona law. The non-radiological cancer and non-cancer risk values for
the individual PCOCs are shown in Table 6-8a and the HI values (sum of all HQ values) and sum
of cancer risks are shown in Table 6-8b.
All of the cancer risks from exposure to arsenic were below 1 x 10"6, the lower end of EPA's
acceptable cancer risk range, and therefore the potential cancer risk from this non-radiological
PCOC in soils from any area of the Site for this receptor was below the level of regulatory
concern. All of the HQ values were below one for the non-radiological PCOCs, indicating that
the potential risk from exposure to the PCOCs by this receptor from any area of the Site were
below the level of regulatory concern.
The Ra-226 Site-specific soil EPCs were used as inputs to the EPA online calculator and the risk
results are also shown in Table 6-8a. All of the cancer risks from exposure to Ra-226 (and
associated daughter products) in soils were below or within the EPA acceptable risk range (i.e.,
less than or equal to lxl0"4 risk), and were below the OSWER risk value based on the average or
UCL EPC values for all of the evaluated portions of the Site. Therefore, the Ra-226 risk values
were below the level of regulatory concern for this receptor from the evaluated portions of the
Site.
Table 6-8b summarizes the HI values (sum of non-radiological PCOC HQ values) and the sum
of the cancer risks (arsenic plus Ra-226). The HI values were less than one for all of the
evaluated portions of the Site. The sum of the cancer risks were below or within the acceptable
risk range of regulatory concern for this receptor group from the evaluated portions of the Site.
March 18, 2021
Rev. 1.2
57
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Outputs for both the radiological and non-radiological EPA calculators for this scenario are
provided in Appendix Table F5 series of the Phase III Summary Report (provided as Appendix
M to this report).
6.14.3 Comparison of Average and UCL Concentrations as EPCs and Effects on
Calculated Risks
The risk summary tables show the risks calculated using both the mean and UCL values, which
provides bounds for the potential risks. The mean values provide a lower bound of the potential
risks while the UCL represents an upper bound of the potential mean values. For a given
receptor, the calculated risks are proportional to the EPC values. The risks calculating using
either the mean or UCL values were below or within EPA acceptable risk limits for all PCOCs,
all evaluated areas, and all evaluated receptors, except for Ra-226 in soils at the individual
AUMs. As an example, using the combined adult and child recreator (Table 6-8a), for AUM 457
the average Ra-226 cancer risk was within EPA's acceptable risk range while the UCL cancer
risks were at the upper end of EPA's acceptable risk range. For AUM 458, potential cancer risks
using either the average or the UCL were greater than EPA's acceptable risk range. For AUM
459, where the average and UCL EPCs were the same (only a single sample was collected) the
potential cancer risks were at the upper end of EPA's acceptable risk range.
6.14.4 Spatial Averaging
The potential to assess risks using the Site-wide spatial average was included as a possible
method for consideration for EPC development in the Phase III Work Plan. Such an approach is
useful for the assessment of larger sites, particularly when there is the potential for contact with
media randomly across the Site. The HHSRE was structured to evaluate specific exposure areas
(although it is assumed that contact with media is random within each of these areas). Spatial
averaging methods typically yield more representative area-wide exposure estimates which are
often lower than those calculated using conventional unweighted EPC methods. Therefore, use
of the latter would yield upper bound estimates of the risks.
6.14.5 Area Correction Factors
As discussed in Section 6.7.1, the Area Correction Factors are used to adjust for the finite size of
the exposure area relative to the "infinite" source assumed for radiological risk assessments. An
ACF of 25 acres was assigned to two of the evaluated areas - AUM 458 and LCR channel area -
although both are smaller than this area (Table 6-2). The areas of AUM 458 and LCR Channel
are 14.4 and 14.5 acres, respectability. Using a smaller ACF results in a slight reduction (less
than 5%) of the calculated risks (due to reduction in external dosing). For example, the
calculated risks for a site worker at AUM 458 using the UCL EPCs would reduce from 2.8xl0"9
to 2.7xl0"9 when the ACF is adjusted from 25 acres to 14.4 acres (there would be no difference
with rounded to one significant digit). The larger ACF was retained for conservatism.
6.14.6 Off-Site Transport of Site Soils in Air
An assessment of off-site transport of Site soils in air was included in the Phase III Work Plan.
RESRAD-Offsite was originally intended to be used to predict the off-site media concentrations.
However, the PRG calculator includes an estimate exposure related to particulate emissions into
March 18, 2021
Rev. 1.2
58
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
the overlying air and inhalation of these suspended solids. Such exposures would be the largest
in the evaluated areas and would dissipate (resulting in lower potential risks) the further one
moves from the evaluated area. Inhalation exposures were a very minor component of the Site
risks. For example, Table 6-9 compares the ingestion, dermal contact (for the non-radionuclide
PCOCs), inhalation risks, or external exposures (for Ra-226) to the total risks at AUM 458 for all
of the PCOCs. This AUM was selected because it had some of the higher PCOC UCL values.
Results shown are for the adult recreator and 24 years of exposure. When inhalation is not the
sole exposure route (as was the case for mercury) it contributes well below 0.04% to the total
risk. Given that this pathway represents a de minimis at the evaluated area it is unlikely to
represent a major exposure pathway if any soils migrate off-site.
Review of the EPCs (Table 6-1) further suggests there is not a large amount of off-site transport
of soils from the Site. The LCR channel samples have some of the lowest PCOC concentrations
relative to other evaluated areas of the Site.
6.14.7 Assessment of Effects of Ra-226 Soils Collectedfrom Depth
Surface soils (defined as samples collected from a depth of 0 to 6 inches) were used for the risk
characterization. However, radiological emissions from Ra-226 from soils collected from a
depth of one foot also represent a potential source of exposure. Most of the radium soils data
(119 of 150 samples; 80%) were collected from a depth of 0 to 6 inches with 12 additional
samples collected from a depth of 6 to 12 inches. This portion of the uncertainty assessment
compares the effects on EPCs and calculated risks to adult recreators from Ra-226 exposures for
the 0 to 6 inch and 0 to 12 inch depth intervals.
The EPCs and calculated cancer risks for a long term adult recreator (e.g., 14 days per year for
24 years) for each of the evaluated areas is provided in Table 6-10. Additional summary
information for the 0 to 12 inch Ra-226 EPCs is provided in Appendix Table F7-la of the Phase
III Summary Report (provided as Appendix M to this report). Table F7-lb lists the additional
soil samples from the 6 to 12 inch depth interval that were depth averaged with their
corresponding surface soil depth. The supporting ProUCL calculations for the 0 to 12 inch depth
interval are provided in Appendix Table F7-2 of the Phase III Summary Report (provided as
Appendix M to this report). A brief summary of the changes in the Ra-226 EPC concentrations
and risks to the adult recreator by the addition of the 6-12 inch depth samples is discussed below:
• APE Area with AUMs (Dry Scenario): Seven samples from 6-12 inch depth were
averaged with the corresponding 0-6 inch depth sample from this location, plus there
were two additional samples (Drain-TP2 and MRD-TP1) which were not collected from
the 0-6 inch depth. This increased the number of results from 62 to 65 from this area.
The addition of these samples increased the mean (from 5.18 to 6.19 pCi/g) and the
95UCL (from 10.9 to 13.4 pCi/g). This resulted in a slight increase in the calculated risk
based on the average EPC, but this was still within EPA's acceptable risk range. The
calculated risk based on the UCL EPC also increased and was at the upper end of EPA's
acceptable risk range (after rounding).
• APE Area with AUMs (Wet Scenario): Seven samples from 6-12 inch depth were
averaged with the corresponding 0-6 inch depth sample from this location, plus there
March 18, 2021
Rev. 1.2
59
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
were two additional samples (Drain-TP2 and MRD-TP1) which were not collected from
the 0-6 inch depth. This increased the number of results from 50 to 55 from this area.
The addition of these samples increased the mean (from 6.21 to 7.31 pCi/g) and the
95UCL (from 13.2 to 15.7 pCi/g). This resulted in a slight increase in the calculated risk
based on the average EPC, but this was still within EPA's acceptable risk range. The
calculated risk based on the UCL EPC was unchanged (after rounding) and was at the
upper end of but within EPA's acceptable risk range.
• APE Area Less AUMs (Dry Scenario): One sample from 6-12 inch depth (TP-15) was
averaged with the corresponding 0-6 inch depth sample from this location, plus there
were two additional samples (Drain-TP2 and MRD-TP1) which were not collected from
the 0-6 inch depth. This increased the number of results from 45 to 47 from this area.
The addition of these samples increased the mean (from 2.48 to 3.10 pCi/g) and the
95UCL (from 2.93 to 6.00 pCi/g). Different UCL types were identified by ProUCL with
the addition of the deeper samples. This resulted in a slight increase in the calculated risk
based on the average EPC and approximate doubling based on the UCL EPC. However,
all cancer risks were still within EPA's acceptable risk range.
• APE Area Less AUMs (Wet Scenario): One sample from 6-12 inch depth (TP-15) was
averaged with the corresponding 0-6 inch depth sample from this location, plus there
were two additional samples (Drain-TP2 and MRD-TP1) which were not collected from
the 0-6 inch depth. This increased the number of results from 33 to 35 from this area.
The addition of these samples increased the mean (from 3.05 to 3.85 pCi/g) and the
95UCL (from 3.56 to 7.59 pCi/g). Different UCL types were identified by ProUCL with
the addition of the deeper samples. This resulted in a slight increase in the calculated risk
based on the average EPC and approximate doubling based on the UCL EPC. However,
all cancer risks were still within EPA's acceptable risk range.
• Outside of APE Area (Wet and Dry Scenarios): No change in EPCs or calculated risks
since there were no additional samples from 6-12 inch depth. The cancer risks based on
the average or UCL EPCs were all within EPA's acceptable risk range.
• APE 457 (Wet and Dry Scenarios): Two samples from 6-12 inch depth were averaged
with the corresponding 0-6 inch depth sample from these locations. The addition of these
samples decreased the mean (from 7.67 to 7.34 pCi/g) and decreased the 95UCL (from
15.8 to 14.9 pCi/g). The cancer risks based on the average or UCL EPCs were
unchanged (after rounding).
• APE 458 (Dry Scenario Only): Three samples from 6-12 inch depth were averaged with
the corresponding 0-6 inch depth sample from these locations, plus one additional sample
(from TP 18) which was not collected from the 0-6 inch depth. This increased the number
of results from 5 to 6 from this area. The addition of this sample increased the mean
(from 22.1 to 26.4 pCi/g) and the 95UCL (from 73.9 to 100 pCi/g). The 95UCL values
for both the 0 to 6 inch and 0 to 12 inch depth intervals were the maximum detected value
since in both cases the recommended 95UCL exceeded the maximum detected amount.
The cancer risks based on the average EPCs were unchanged (after rounding), while the
cancer risks based on the 95UCL EPCs increased (from 6 x 10"4 to 8 x 10"4). Risks based
on the average and UCL EPCs were both above the upper end of EPA's acceptable risk
range.
March 18, 2021
Rev. 1.2
60
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
• APE 459 (Dry Scenario Only): One sample from 6-12 inch depth was averaged with the
corresponding 0 to 6 inch depth sample result (average of sample-duplicate pair) from
this location. The mean and 95UCL EPCs slightly increased (from 15.0 to 17.3 pCi/g) by
the addition of the deeper sample but there was no change in the calculated risks after
rounding. Risks based on the average and UCL EPCs were within EPA's acceptable risk
range.
• LCR Channel Area (Dry Scenario): No change in EPCs or calculated risks since there
were no additional samples collected from 6-12 inch depth. The cancer risks based on
the average or UCL EPCs were all within EPA's acceptable risk range.
In summary, there were increases in the soil mean and 95UCL EPCs for some of the evaluated
areas, a decrease in the soil mean and 95UCL EPCs for one evaluated area, and no change in the
soil mean and 95UCL EPCs for two areas, with the addition of the samples collected from 6 to
12 inches. The calculated risks were all less than or within EPA's acceptable risk range.
Therefore, the assessment of potential risks based on the 0 to 6 inch depth interval soil results (a
larger data set) is representative of the potential risk at the Site.
6.15 Summary of HHSRE Results
Tables 6-1 la and 6-1 lb graphically summarize the individual PCOC HHSRE Non-Cancer (HQ)
Results and the HHSRE Cancer Risk Results (respectively) for All Evaluated Receptors and
Areas. For the non-cancer risk results (Table 6-1 la) the following color coding was used:
• HQ values less than or equal to one = green.
• HQ values between one and 10 = yellow.
• HQ values greater than ten = red.
For the cancer risks (Table 6-1 lb) the following color coding was used:
• Cancer risks less than or equal to 1 x 10"4 = green.
• Cancer risks greater than 1 x 10"4 = red.
Risk results using both the UCL and mean EPC values are reported. The tables show all of the
non-cancer and cancer risk results are coded green, indicating risks from the individual non-
radiological PCOCs across the evaluated receptors and areas are below levels or within the
acceptable risk range of regulatory concern.
Potential human health cancer risks from exposure to Ra-226 (and daughter products) in soils are
below or within EPA's acceptable risk range for some of the receptors and the evaluated areas,
except for the individual AUM 458. The potential risks from exposures to soils from the AUMs
were below or within the acceptable risk range for site workers, and child recreators (2-year
exposure duration). Potential cancer risks for exposure to AUM soils by long term adult
recreators (24 years) and combined adult and child recreators (combined 26 years of exposure)
varied depending on the whether the average or UCL soil values were used. Cancer risks for
these two longer-term recreators were within EPA's acceptable risk range for AUM 457 when
the average soil EPC was used but was above the upper limit of EPA's acceptable risk range for
the UCL soil values in AUM 458. The calculated risks were slightly higher for the combined
March 18, 2021
Rev. 1.2
61
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
adult and child recreators (combined 26 years of exposure) relative to the adult recreators (24
years).
The exposure pathways for human receptors included in this report were based on Babbitt
Ranches, LLC and BLM current land usage. Current and future use of Babbitt land has been
restricted and limited as set forth below:
• Section 9 is private property owned by Babbitt Ranches LLC that has been Deed
Restricted.
• No active cattle operations or other active land use is permitted on Section 9, except as
specified in the Deed Restriction discussed in Appendix A of the Phase III Summary
Report (provided as Appendix M to this report).
• Entry onto Section 9 is a trespass under Arizona law and is also prohibited by the Deed
Restriction.
The assumptions used for the human receptor exposure pathways represent our best judgment
based on the information available at the time of preparation of this report. Navajo cultural
values were not considered as part of the exposure pathways for human receptors in the above
scenarios as there are not currently inputs reflective of these practices available for the PRG
calculator. These inputs are being developed. Should additional information become available
from the BLM, State, or other sources, prior to conclusion of this AOC, we will review and
consider that information and modify our analyses accordingly. We provide this information
regarding the development of these inputs as a reference point for future readers of this report.
March 18, 2021
Rev. 1.2
62
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
7.0 ECOLOGICAL STREAMLINED RISK EVALUATION
The assessment of potential ecological risks for the non-radionuclide chemicals follows accepted
EPA CERCLA requirements for conducting ecological risk assessments (e.g., EPA 1997b, 1998,
1999) and the potential ecological risks for the radionuclides were evaluated following the
methodology from the Los Alamos National Laboratory (LANL, 2017a) ECORISK tool.
7.1 Ecological Setting
SWCA Environmental Consultants (SWCA) summarized the land use and ecological setting of
the Site as part of their biological resources survey (SWCA, 2016). A copy of the SWCA (2016)
report is provided in Appendix Attachment G.l of the Phase III Summary Report (provided as
Appendix M to this report). The key ecological setting relevant to the Ecological Streamlined
Risk Evaluation (EcoSRE) is as follows.
• Climate at the Site is very dry, with temperatures below freezing in the winter (average
minimum approximately 21°F) and very hot in the summer (average maximum
temperature of approximately 97°F). For the available period of record (1962 to 1992) at
nearby Cameron, Arizona7 the average monthly precipitation ranges from 0.33 to 0.91
inch with an annual total of 5.7 inches. Average monthly total snowfall in the winter
ranges from 0.1 to 0.7 inch, with an annual total of 1.9 inches.
• There are two named watercourses on or near the Site: an ephemeral reach of the Little
Colorado River (LCR) along the eastern boundary of the Site and Mays Wash located on
the south side of the Site. At the time of the biological survey (August 2016), there was
no aquatic vegetation in the dry channel of the LCR (SWCA, 2016). There were a small
number of shallow pools of standing water in the LCR that were remnants of recent
thunderstorms. The shallow pools had no evidence of aquatic life. On average, the LCR
channel is dry three months of the year (range: one to eight months). No standing pools
were observed during the Phase II (completed September 12-17 and October 24-27,
2017) or Phase III (completed December 3-6, 2018) field work. The nearest perennial
surface water with any hydrological connection to the Site is the lowest reach of the LCR,
which begins approximately 58 miles downstream of AUM 457.
• At AUMs 457 and 458 Weston (2014) reported the presence of wetland habitats.
Wetland scientists from SWCA visited the areas identified as wetlands in July and
September 2014. Their evaluation was reported in SWCA (2016) and they did not
observe wetland hydrology, hydric soils, obligate wetland vegetation, or other wetland
organisms at either AUM. Furthermore, no wetland hydrology or obligate wetland
vegetation was observed anywhere on the Site, although two facultative species (tamarisk
and camelthorn) were observed at AUM 457, as well as throughout the LCR floodplain,
in Mays Wash, and at several upland locations. The site conditions observed by SWCA
were consistent with the observed conditions during the Phase II and III field work.
7 Available from https://wrcc.dri.edu/cgi-bin/cliMAIN.pl7azcame
March 18, 2021
Rev. 1.2
63
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
As indicated in the SWCA (2016) report with regard to wetlands, "SWCA's failure to
find wetland indicators at either AUM 457 or AUM 458 raises the question of how the
EPA evaluation and the SWCA evaluation of the same sites using the same protocol could
come to opposite conclusions. We cannot answer that question definitively, but the EPA's
evaluation in early August 2013 and SWCA's evaluation in late July and early September
2014 were conducted at roughly the same time of year but under vastly different
hydrological conditions."
• There are ephemeral drainage ways and some small "pocket" areas in the upland area
where precipitation can accumulate. The latter are associated with some of the AUMs.
• There is vegetation in the riparian habitats along the LCR and Mays Wash, and within
drainages and depressions in the upland areas. Vegetation in these areas is degraded by
non-native, invasive species including tamarisk. The tamarisk has been defoliated by
tamarisk leaf beetles. Most of the upland areas are sparsely vegetated by native (e.g.,
snakeweed, shadscale) and non-native species (e.g., camelthorn). There are only a few
cottonwood trees in the area.
• AUMs 457 and 458 are located in the upland portion of the Site, although a small portion
of AUM 457 is within the riparian buffer of the LCR. AUM 459 is located on Section 16
and material from AUM 459 has migrated onto Section 9. Generally, the substrates in
these areas consist of poorly sorted fluvial gravel, pebbles, and cobbles partly
consolidated in a matrix of mud and sand cemented with calcium and gypsum. There are
competent outcrops scattered throughout the Site and near/within the AUMs, some of
which have been disturbed from historical mining operations.
Representative photographs of the typical upland and riparian habitats of the Site are provided in
Tables 2 and 3 of the SWCA (2016) report. A list of the known or expected terrestrial fauna that
may use the Site is provided in Table 4 of SWCA (2016).
7.2 EcoSRE Conceptual Site Models
Two potential Ecological CSMs (EcoCSMs) were developed for the Site and presented in the
Phase III Work Plan (provided as Appendix L to this report). One represents the more typical
"dry" conditions when there is little to no water present in the LCR, and the other when flowing
or standing water is present in the LCR.
The Dry Conditions Scenario is the more common environmental condition at the Site. Potential
exposure areas include the upland areas (where the AUMs are located), the riparian buffer along
the LCR dry channel, and the LCR dry channel.
The Wet Conditions Scenario is relevant when water is present (flowing or stagnant) in the LCR
channel. The water flow of the LCR near the Site is ephemeral, as evidenced by the discharges
March 18, 2021
Rev. 1.2
64
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
at USGS Gage Station 09402000 near Cameron, about 10 miles north of the Site (Figure l-l)8.
No surface water was available for collection during the Phase II or prior field investigations.
Potential representative receptors that were evaluated under "wet" LCR conditions are
amphibians for direct contact (surface water), and insectivorous birds for indirect contact based
on consumption of emergent insects.
7.3 Evaluated Receptors
Given the streamlined nature of the EcoSRE, exhaustive analysis of all potential receptors in a
food chain is not warranted. Rather, the focus is on receptors that are representative of the lower
and upper trophic level feeding guilds that may be present in the evaluated areas. The receptors
proposed in the Phase III Work Plan were evaluated in the EcoSRE.
In the upland areas (e.g., the AUMs) under the Dry and Wet Condition Scenarios the following
receptors were evaluated:
• Plants
• Insectivorous mammal: Desert shrew
• Insectivorous bird: Rock wren
• Herbivorous mammal: Deer mouse
• Insectivorous bird: American kestrel
• Carnivorous bird: Golden eagle
In the riparian areas (e.g., along the LCR) Dry and Wet Condition Scenarios the following
receptors were evaluated:
• Plants
• Insectivorous mammal: Desert shrew
• Insectivorous bird: Rock wren
• Herbivorous mammal: Deer mouse
• Herbivorous bird: Mourning dove
• Omnivorous mammal: Coyote
• Carnivorous bird: Golden eagle
As noted in SWCA (2016), the habitats at the Site are not ideal for many of these receptors. For
example, the golden eagle (which is on the Navajo Endangered Species List) may prey on small
mammals at the Site but the sparse vegetation cover and defoliated tamarisk does not provide
ideal habitat for small mammals.
The EcoSRE also semi-quantitatively evaluates the following two receptors that may use the
LCR under the Wet Conditions Scenario:
• Amphibian: Spadefoot toad
8 Data was summarized for the period of October 1, 2018 to October 1, 2019. This flow pattern during this period
was consistent with the median flows for the last 70 years. Data was accessed from this link:
https://waterdata.usgs.gov/nwis/uv?site_no=09402000
March 18, 2021
Rev. 1.2
65
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
• Insectivorous bird: Rock wren
The rock wren is used to represent insectivorous birds that may prey on emergent aquatic insects
when water is present in the LCR.
7.4 Identification of EcoSRE PCOCs
The AOC identified the PCOCs; these are the same for both the HHSRE and the EcoSRE. These
include the following: arsenic, mercury, molybdenum, selenium, uranium, vanadium, and
Ra-226. Risks associated with mercury exposure were based on the toxicity of methylmercury
rather than on inorganic mercury. This is a conservative assumption that overestimates the
potential risk to this PCOC associated with soil ingestion, given that mercury is more likely to be
in the inorganic form in soils.
7.5 Exposure Point Concentrations for EcoSRE
The analytical data collected as part of the Phase II and III field programs were used to develop
the exposure point concentrations (EPCs). As was done for the HHSRE, prior to calculating the
EPCs the samples with field duplicates were averaged. In those cases where one but not both of
the sample-duplicate pairs was detected, the detected result was used as the sample result. This
occurred with some of the selenium and molybdenum sample results.
In an EcoSRE both the average and UCL media concentrations are used as EPCs to provide
bounding estimates on the potential risks that can be useful for overall Site risk management.
EPA's ProUCL software (version 5.1.02) was used to calculate the EPCs (EPA, 2016c).
The areas that were proposed for each evaluation in the Phase III work were the following:
• Site-wide (upland terrestrial only)
• Background study areas (BSAs) (river and upland)
• Riparian habitat along the LCR
• LCR dried sediment bed (based on prior reports)
In order to be consistent with the HHSRE, which evaluated exposures based on the APE, the
EcoSRE assessment areas were adjusted to the following, incorporating the upland and riparian
habitats at the Site:
• Upland Receptors - APE With AUMs
• Upland Receptors - APE Less AUMs
• Upland Receptors - Outside of APE
• Upland Receptors - Individual AUMs
• Riparian Receptors - Riparian Buffer Area within APE
The assessment of the individual AUMs was added to the EcoSRE after submission and approval
of the Phase III Work Plan with the concurrence of EPA and Babbitt Ranches. There were no
soil samples collected as part of the Phase II and III investigations from the riparian buffer areas
outside of the APE. Therefore, this subarea was not evaluated in the EcoSRE.
March 18, 2021
Rev. 1.2
66
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
The soil EPCs by PCOC and evaluated area are shown in Table 7-1. Additional summary
information for each of the EPCs and the associated ProUCL outputs are provided in
Appendix G, Tables G2-2 and G2-3 of the Phase III Summary Report (provided as Appendix M
to this report), respectively. Some of the recommended UCLs from ProUCL were not used
because they exceeded the maximum detected concentration (e.g., molybdenum in AUM 458).
In these cases, the maximum detected concentration was used as the UCL value. These are
identified on Appendix Table G2-2 of the Phase III Summary Report (provided as Appendix M
to this report). A cross-tabulation of the soil Sample IDs and the evaluation area assignments is
provided in Appendix Table G2-1 of the Phase III Summary Report (provided as Appendix M to
this report).
EPCs for all of the PCOCs and all evaluated areas of the Site were developed with the exception
of selenium, which was not detected in any of the samples collected from the Riparian Buffer
Area within the APE or the Upland Individual AUM 459. The detection limit range in the
samples from the Riparian Buffer within the APE ranged from 0.06 to 0.28 ppmdw and the
detection limit for the single sample from AUM 459 was 0.05 ppmdw. This PCOC was excluded
from the assessment of these evaluated areas of the Site.
Spatial averaging methods were not used for the EcoSRE EPC development. This is discussed
further in the uncertainty assessment in Section 7.10.
7.6 Exposure Assessment
The primary exposure pathway assessed was indirect contact (i.e., consumption of forage or
prey). Uptake of evaluated PCOCs into forage (e.g., plants) or prey (e.g., insects) is based on
literature values. No Site-specific analytical data for forage or prey (e.g., insects) have been
collected as part of the Phase II and III field investigation.
The general formula to calculate PCOC concentrations in the different biota that serve as prey or
forage for higher trophic level organisms uses the following equation:
Concbiota = ConcSoii x BTF
Where the Concbiota is the biota concentration (on a dry or wet weight basis), the Concsoii is the
soil (or sediment) concentration (typically on a dry weight basis), and the BTF is the biota
transfer factor. BTFs represent the ratio of the chemical concentration in the biota and the
chemical concentration in the soil or sediment. Two types of BTFs are typically reported in the
literature:
• BTFww-dw: This form is the wet weight biota concentration divided by the dry weight soil
or sediment concentration, and has units of kgdw/kgww.
• BTFdw-dw: This form is the dry weight biota concentration divided by the dry weight soil
or sediment concentration, and has units of kgdw/kgdw.
Appendix Table G2-3 of the Phase III Summary Report (provided as Appendix M to this report)
summarizes the BTF values that were used to calculate the plant and forage PCOC
concentrations. The Phase III Summary Report BTF values were based on literature values, such
March 18, 2021
Rev. 1.2
67
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
as the regressions developed by Sample et al. (1998) to estimate uptake from soils by small
mammals across different feeding guilds (omnivore, herbivore, and insectivore). For the
EcoSRE, these values were replaced with those from LANL (2017a). For the non-radionuclide
metals the BTF unit for non-radionuclides is tissue mg/kgdw per unit mg/kgdw in soil, while the
BTF unit for Ra-226 is tissue pCi/gww per pCi/gdw in soil. The estimated Ra-226 tissue
concentration is converted to equivalent dry weight basis using a moisture content of 68%.
The plant, soil invertebrate, and small mammal EPCs by PCOC and evaluated area are shown in
Table 7-2. These were calculated from the mean and UCL soil values using the corresponding
BTF values from Appendix Table G2-3 of the Phase III Summary Report (provided as Appendix
M to this report).
7.6.1 Exposure Calculations and Exposure Assumptions for Assessing Non-Radiological
Risks
The general equation used to estimate the non-radiological PCOC average daily dose (ADD) for
these receptors is shown below:
ADD (mg/kgbw - day) =
(Cw x IRw) + (Csx IRs) + ^"(Cd x Fr x I Rcl,)
: SUF x AUF
BW
Where,
ADD = average daily dose (mg/kgbw-day)
Cw = concentration of PCOC in unfiltered surface water (mg/L)
Cs = concentration of PCOC in soil/sediment (mg/kgdw)
Cdi = concentration of PCOC in diet item (i) (mg/kgdw)
Fr; = fraction of diet comprised of diet item (i) (unitless)
IRw = ingestion rate of surface water (liters per day [1/day])
IRs = ingestion rate of soil/sediment (kilograms (dry weight) per day
[kgdw/day])
IRdi = ingestion rate of diet item (i) (dry weight) (kgdw/day)
AUF = area use factor (unitless)
SUF = seasonal use factor (unitless)
BW = body weight (kilograms [kg]).
The exposure assumptions for assessing non-radiological risks are provided by receptors in
Appendix Table G3-1 of the Phase III Summary Report (provided as Appendix M to this report).
These were all based on standard data sources (e.g., EPA, 1993; Nagy, 1987; Sample and Suter,
1994)9. These assumptions were consistent with those from the Phase III Work Plan, with the
addition of the assessment area-specific Area Use Factors (AUFs). The AUFs are based on the
areal coverages of the assessed areas, the habitat information from SWCA (2016), and receptor
9 The Nagy (1987) allometric equations, which were cited in the Wildlife Exposure Factors Handbook (EPA 1993),
were preferred over the more recent Nagy (2001) publication since the latter did not include any information for the
four receptors that used the Food Ingestion Rate allometric equations (mourning dove, rock wren, coyote, and
golden eagle) or relevant surrogate species.
March 18, 2021
Rev. 1.2
68
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
home range information from the published literature. The areal extents of each of the evaluated
areas are shown in Appendix Table G3-2 of the Phase III Summary Report (provided as
Appendix M to this report). These areas were generated using ArcGIS.
7.6.2 Exposure Calculations and Exposure Assumptions for Assessing Radiological
Risks
For the assessment of potential radiological risks from Ra-226 exposure, the equation used to
develop soil Ecological Screening Levels (ESLs) from LANL (2017a) was modified to include
the receptor-specific AUF and SUF values. The general equation10 is shown below.
TRV
ssESL —
((IRsoii-dw+(ET( TF^fwxIR^fw))xTFbioodxRtxDCFint^fW) + DCFext) * AUF * SUF)
Where,
ssESL
TRV
IRsoil-dw
TFi
IRi-fw
TFblood
Rt
DCFint-fw
DCFext
AUF
SUF
BW
site-specific ecological screening level for soil (pCi/g)
toxicity reference value, no-observed-adverse-effect level (NOAEL)
and lowest-observed-adverse-effect level (LOAEL) based (rad/d)
ingestion rate of soil (kilograms (dry weight) per day [kgdw/day])
transfer factor of diet item (i) (pCi/g [fresh weight] per pCi/g [dry
soil])
ingestion rate of diet item (i) (g [fresh weight] per g body weight per
day)
transfer factor to blood (unitless)
retention time (days)
internal dose conversion factor (rad/d per pCi/g [fresh tissue])
external dose conversion factor assuming either 180 or 360 degrees of
exposure (rad/d per pCi/g [dry soil])
area use factor (unitless)
seasonal use factor (unitless)
body weight (kilograms [kg]).
Ground-dwelling or foraging receptors (e.g., shrews) use DCFext based on 360 degrees of
exposure while most avian receptors use DCFext based on 180 degrees of exposure.
The exposure assumptions for assessing radiological risks are provided by receptor in
Appendix G Table G3-3 of the Phase III Summary Report (provided as Appendix M to this
report). LANL (2017a) uses the beef transfer factor (TF beef fw) for all species exposed via the
diet, including non-carnivorous species such as herbivorous birds, to calculate the transfer factor
from blood to tissues (TF blood). The latter is calculated as the product of the food ingestion
10 Some of the variable names have been modified from the LANL (2017a) equation here for clarity. The original
LANL variable names are provided in the input assumption table.
March 18, 2021
Rev. 1.2
69
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
rate (I_food_fw), body weight, and TF_beef_fw. The associated User's Manual (LANL, 2017b)
does not include an explanation of why a beef transfer term is used to calculate the blood transfer
factor for herbivorous species. Therefore, Appendix G Table G3-3 of the Phase III Summary
Report (provided as Appendix M to this report) includes the TFbeeffw for all of the evaluated
receptors exposed via the food chain.
7.7 Non-Radiological Toxicity Benchmarks
Non-radiological toxicity benchmarks were used to assess potential risks to plants, and avian and
mammalian species. Soil screening levels were used to assess potential effects on vegetation.
For the remaining receptors Toxicity Reference Values (TRVs) were used. Changes in the TRVs
relative to the Phase III Work Plan are listed in Appendix G Table Gl-1 of the Phase III
Summary Report (provided as Appendix M to this report).
7.7.1 Toxicity Benchmarks for the Assessment of Vegetation Effects
Toxicity benchmarks for the assessment of potential impact on vegetation were not provided in
the Phase III Work Plan but are shown in Table 7-3a. The soil Ecological Screening Levels
(ESLs) for the evaluation of "Generic Plants" from the LANL (2017a) ECORISK Database were
used for this assessment. Vegetation ESLs were available for all PCOCs except for
molybdenum, which had no ESL value. M-EMS (2014) reviewed molybdenum toxicity to
support the development of soil quality guidelines for this metal. Table C-3 from their report
compiled total soil concentrations that represented ECio and EC2011 toxicity benchmarks for
growth-related endpoints (e.g., shoot length) in a variety of plants. The EC10 and EC20 values
were considered comparable to NOAEL and LOAEL values (respectively) and are provided in
Appendix G Table G6-2 of the Phase III Summary Report (provided as Appendix M to this
report). The geometric means of the NOAEL and LOAEL soil concentrations were 15 and 73
mg/kgdw, respectively. These values are within the range of the 10th and 90th percentiles for
site-specific probable no effect concentration (PNEC) values in European agricultural soil of
10.7 and 168 mg/kg (Oorts et al., 2016).
7.7.2 Toxicity Benchmarks for the Assessment of Effects on Mammalian and Avian
Species
Section 5.5.7 of the Phase III Work Plan presented the methodology to derive the toxicity
benchmark for the ecological receptors. The principal data sources for the avian and mammalian
TRVs are the Ecological Soil Screening Level (EcoSSL) documents and Sample et al. (1996);
these were supplemented by the screening TRVs reported in LANL (2017a). The NOAEL and
LOAEL values representing growth, reproduction, and survival effects endpoints were compiled
from these studies and are presented in Appendix G Table G4 series and Table G5 series of the
Phase III Summary Report (provided as Appendix M to this report) for the mammalian and avian
receptors, respectively. The data were summarized two ways:
• The "Bounded TRV Summary" values were based on studies that reported both NOAEL
and LOAEL values.
11 EC10 and EC20 are the effective concentrations that reflect toxicity at 10 and 20%, respectively, of the control.
March 18, 2021
Rev. 1.2
70
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
• The "All TRV Summary" values were calculated across all studies whether they
represented bounded NOAEL and LOAEL values, or reported NOAEL or LOAEL values
only.
As discussed in the Phase III Work Plan, those studies that report both NOAEL and LOAEL
values (i.e., bounded NOAEL and LOAEL values) were preferred when deriving TRVs across
multiple studies. The mammalian and avian TRVs are discussed below.
Mammalian TRVs
The mammalian TRVs for the non-radionuclide PCOCs are summarized in Table 7-3b and
Appendix G Table G4-1 of the Phase III Summary Report (provided as Appendix M to this
report). The following is a summary of the selected TRVnoael and TRVloael values for the
non-radiological PCOCs.
• Arsenic. The TRVnoael and TRVloael values for arsenic were the geometric means of
four bounded NOAEL and LOAEL results in mice from the EcoSSL document (EPA,
2005a) and were applied to all small mammal receptors. These were body weight scaled
for the larger mammalian receptors.
• Mercury (inorganic and methyl): The TRVnoael values for mercury (inorganic and
methyl) replaced the value from the Phase III Work Plan, and were applied to all
mammals without body weight scaling. LANL (2017a) did not report a TRVloael value
for mercury PCOCs.
• Molybdenum: The molybdenum TRVnoael and TRVloael values for small mammals
were updated based on data reported for rats in ATSDR (2017). These were body-weight
scaled for the larger mammalian receptors. LANL (2017a) did not report mammalian
TRVs for molybdenum.
• Selenium: The TRVnoael and TRVloael values for selenium were the geometric means
of 27 bounded NOAEL and LOAEL results in mice and hamsters from the EcoSSL
document (EPA, 2007) and were applied to all small mammal receptors. These were
body weight scaled for the larger mammalian receptors.
• Uranium: The TRVnoael value for uranium from LANL (2017a) replaced the value from
the Phase III Work Plan, and was applied to all mammals without body weight scaling.
LANL (2017a) did not report TRVloael values for uranium PCOCs.
• Vanadium: The TRVnoaf.t. and TRVloael values for vanadium were the geometric means
of three bounded NOAEL and LOAEL results in mice from the EcoSSL document (EPA,
2005b) and were applied to all small mammal receptors. These were body weight scaled
for the larger mammalian receptors.
The supporting calculations for the derivation of the TRVnoael and TRVloael values are
provided in the Appendix G Table G4 series of the Phase III Summary Report (provided as
Appendix M to this report).
March 18, 2021
Rev. 1.2
71
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Avian TRYs
The avian TRVs for the non-radionuclide PCOCs are summarized in Table 7-3b and Appendix G
Table G5-1 of the Phase III Summary Report (provided as Appendix M to this report). The
following is a summary of the selected TRVnoael and TRVloael values for the non-radiological
PCOCs.
• Arsenic. TRVs were developed using unbounded results from the EcoSSL document
(EPA, 2005a). The TRVnoael was the geometric mean of eight NOAEL values and the
TRVloael was the geometric mean five LOAEL values. There were no bounded
NOAEL and LOAEL values available from this data source.
• Mercury (inorganic): The TRVnoael and TRVloael values for mercury (inorganic) were
from Hill and Schaffner (1976), as cited by Sample et al. (1996).
• Mercury (methyl)'. TRVs were developed using unbounded results from a literature
review. The TRVnoael was the geometric mean of three NOAEL values and the
TRVloael was the geometric mean of six LOAEL values. Results are compiled in
Appendix G Table G5-2b of the Phase III Summary Report (provided as Appendix M to
this report).
• Molybdenum: TRVs for molybdenum were not available from the EPA/EcoSSL. The
TRVnoael used was from a study by Stafford et al (2016). A TRVloael could not be
derived from this study.
• Selenium: The avian TRVnoael and TRVloael values for selenium were the geometric
means of 45 bounded NOAEL and LOAEL results in multiple avian species (American
kestrel, black-crowned night-heron, chicken, duck, Japanese quail, and screech owl) from
the EcoSSL document (EPA, 2007) and supplemented with the LANL (2017a) TRVs.
• Uranium'. The uranium avian TRVnoael and TRVloael values from LANL (2017a) were
used as reported.
• Vanadium: The avian TRVnoael and TRVloael values for vanadium were the geometric
means of 58 bounded NOAEL and LOAEL results in multiple avian species (chicken,
duck, screech owl, and Japanese quail) from the EcoSSL document (EPA, 2005b) and
supplemented with the LANL (2017a) TRVs.
The supporting calculations are provided in the Appendix G Table G5-2 series of the Phase III
Summary Report (provided as Appendix M to this report).
7.8 Radiological Benchmarks
Radiological benchmarks were used to assess potential risks to plants, and avian and mammalian
species. Ra-226 is used as a surrogate to assess potential radiological effects of uranium since
Ra-226 contributes approximately 97 percent of the total risk in the U-238 decay chain.
March 18, 2021
Rev. 1.2
72
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
LANL (2017a) includes NOAEL and LOAEL based TRVs for all organisms of 0.1 and 1.0 rad/d,
respectively. DOE (2002) has developed Biota Concentration Guides (BCGs) for assessing
potential impacts to ecological receptors. These are radionuclide-specific, but are based on the
following exposure thresholds (Yu, 2012): 1 rad/d for terrestrial plants and 0.1 rad/d for
terrestrial animals. The latter is comparable to the TRVnoael from LANL (2017a). The DOE
dose criteria are for protection of the biota population rather than individuals.
The EcoSRE assessment of potential Ra-226 risks based on the LANL (2017a) method uses the
NOAEL and LOAEL values of 0.1 and 1.0 rad/d, respectively.
7.9 Ecological Risk Characterization Approach
The hazard quotient approach was used to assess potential non-radiological and radiological
risks. HQ was calculated using the following equation:
p
HQ =
TRV
Where:
HQ = Hazard quotient
E = Estimated exposure
TRV = Toxicity reference value for the PCOC
Units used for exposure estimates and for the TRV may vary among lines of evidence, but must
be the same for the numerator and denominator in the HQ equation. ESLs replace TRV in this
equation when screening values are used for the comparisons.
An HQ greater than one indicates that exposure is greater than the toxicological benchmark, and
the interpretation of this finding depends in part on the benchmark that is used. An HQ>1 that
uses a LOAEL-based TRV is often interpreted as indicating a greater potential for risk than HQs
that use a NOAEL-based TRV. Unless the NOAEL and LOAEL TRVs are accompanied by an
exposure-response analysis, it is unclear what effect level corresponds with the HQ and,
therefore, if an incremental change in HQ translates into a meaningful change in the likelihood or
magnitude of effect.
For this EcoSRE, NOAEL- and LOAEL-based HQs (i.e., HQnoael and HQloael) are calculated
to provide a relative risk range to support the risk characterization. The magnitude of HQs does
not necessarily indicate the potential for effects, since these are calculated from NOAEL- or
LOAEL-based TRVs. The dose-response curves from chemical exposures are frequently not
linear, which is not reflected in the NOAEL- or LOAEL-based TRVs. EPA has not identified a
method of evaluating the magnitude of HQs relevant to the degree of risk to individuals or
populations, and only recognizes whether an HQ is greater or less than "1." Also, risks that fall
between the NOAEL and LOAEL may or may not be linked to adverse effects at the population
or individual level, depending on chemical of interest and TRV that is used. Nonetheless, the
relative magnitudes of the HQ values can guide the interpretation of the risk results, particularly
when based on the LOAEL TRVs. Therefore, the following descriptors are used to interpret HQ
results:
March 18, 2021
Rev. 1.2
73
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
• If the HQnoael is less than or equal to one, no adverse ecological effect for the receptor
population is expected to occur as a result of exposure to the PCOC.
• If the HQnoael is greater than one but the LOAEL HQ is less than or equal to one, then
the potential for adverse ecological effect to a receptor population is considered low.
• If the HQloael is greater than one then there is potential for population level effects.
The HQ results are presented by receptor and then an overall synopsis follows below.
7.9.1 Plants
The PCOC EPCs in soils, plant toxicity benchmarks, and the associated HQ values are shown in
Table 7-4. The key results are summarized below:
• Upland - APE with AUMs: The HQnoael and HQloael values based on either the
average or UCL concentrations were all below one, except for the molybdenum HQnoael
value using the UCL which was above one. Although the molybdenum HQ value was
greater than one the soil UCL value (36.7 mg/kgdw) was within the range of NOAEL
values used to derive the TRVnoael (5 to 70 mg/kgdw) and was also within the PNEC
range (10.7 to 168 mg/kgdw; Oorts et al., 2016).
The vanadium HQloael value using the UCL rounds to 1 but the calculated value was
below one (0.95).
• Uyland - APE Less AUMs: The HQnoael and HQloael values based on either the
average or UCL concentrations were all below one, except for the vanadium HQnoael
which was slightly above one (calculated value was 1.1) using the UCL soil
concentration. The HQloael values for both the average and UCL concentrations were
less than one.
• Upland - Outside of APE: The HQnoael and HQloael values based on either the average
or UCL concentrations were all below one.
• Upland - AUM 457: The HQnoael and HQloael values based on either the average or
UCL concentrations were all below one, except for the molybdenum HQnoael value
using the UCL soil concentration which was slightly above one (calculated value was
1.7). The HQloael values for both the average and UCL concentrations were less than
one.
• Upland - AUM 458: The HQnoael and HQloael values based on either the average or
UCL concentrations were all below one for mercury, selenium and vanadium in soils.
The non-radiological PCOCs values were greater than one for molybdenum and uranium,
with the largest relative HQ values for molybdenum. The Ra-226 HQloael value was
slightly above one (actual value was 1.4) when the UCL soil concentration was
evaluated. The HQloael values were all below one, except for molybdenum using either
the mean or UCL soil concentrations. These results indicate some potential for impacts
to plants at AUM 458 due to molybdenum content of the soils.
• Upland - A UM 459: The HQnoael and HQloael values based on either the average or
UCL concentrations were all below one except for the molybdenum HQnoael values
which were greater than one. All of the HQloael values were less than one.
March 18, 2021
Rev. 1.2
74
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
• Riparian - Riparian Buffer Area within APE: The HQnoael and HQloael values based
on either the average or UCL concentrations were all below one.
Based on these results it is not anticipated that there would be any impact to vegetation related to
the PCOC concentrations in soils from any portion of the Site, except possibly from
molybdenum in AUM 458. The geometric means of the soil NOAEL and LOAEL values for
plant toxicity of molybdenum were used as the TRVs (Appendix G Table G6-2). Although the
observed molybdenum mean and UCL soil concentrations (98.8 and 350 mg/kgdw) were above
the TRVloael, they are within the range of the LOAEL values (5 to 3,900 mg/kgdw) indicating
these exceedances of the TRVs may not reflect a measurable risk. SWCA (2016) reported that
there is sparse vegetative cover (less than 10% spatial coverage) at this AUM and the densest
vegetation was observed growing in a small depression at the bottom of the pit12. This is
consistent with the conditions observed during the Phase II and III field work. The substrate at
AUM 458 predominantly consists of waste rock piles and other mining debris which would limit
the establishment of plants in this area.
7.9.2 Herbivorous bird: Mourning dove
The mourning dove is used as the representative species for herbivorous birds that may forage in
the riparian areas of the Site. This receptor was not evaluated in the upland portions of the Site.
The non-radiological EPCs in soils and diet (vegetation), calculated ADD, and the HQ values are
shown in Table 7-5a. The HQnoael and HQloael values were less than one for the riparian areas
of the Site, using either the average or UCL soil concentrations. These results indicate any
potential risk from exposure to the non-radiological PCOCs to this receptor group from the
riparian areas of the Site is below levels of regulatory concern.
The Ra-226 soil EPCs were compared to the Site-specific ESL (ssESL) NOAEL and LOAEL
values in Table 7-5b. The HQnoael and HQloael values were less than one for the riparian areas
of the Site, using either the average or UCL soil concentrations. These results indicate any
potential risk from exposure to Ra-226 in soils to this receptor group from the riparian areas of
the Site is below levels of regulatory concern.
7.9.3 Herbivorous mammal: Deer mouse
The deer mouse is used as the representative species for herbivorous mammal that may forage in
the upland and riparian areas of the Site. The non-radiological EPCs in soils and diet
(vegetation), calculated ADD, and the HQ values are shown in Table 7-6a. The key results are
summarized below:
• Upland - APE with AUMs: The HQnoael and HQloael values based on either the
average or UCL concentrations were all below one.
• Upland - APE Less AUMs: The HQnoael and HQloael values based on either the
average or UCL concentrations were all below one.
• Upland - Outside of APE: The HQnoael and HQloael values based on either the
12 Photographs of AUM 458 are provided in Table 2 of SWCA (2016)
March 18, 2021
Rev. 1.2
75
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
average or UCL concentrations were all below one.
• Uyland - A UM 457: The HQnoael and HQloael values based on either the average or
UCL concentrations were all below one.
• Upland - A UM 458: The HQnoael and HQloael values based on either the average or
UCL concentrations were all below one for arsenic, mercury, selenium, uranium and
vanadium. The molybdenum HQnoael value using either the average or UCL
concentrations were above one. The molybdenum HQloael value using the average
concentration was below one, whereas the molybdenum HQloael value using the UCL
was greater than one.
• Upland - A UM 459\ The HQnoael and HQloael values based on either the average or
UCL concentrations were all below one except for the molybdenum HQnoael values
which was slightly greater than one (actual value was 1.1). All of the HQloael values
were less than one.
• Riparian - Riparian Buffer Area within APE: The HQnoael and HQloael values based
on either the average or UCL concentrations were all below one.
These results indicate any potential risk from exposure to the non-radiological PCOCs to this
receptor group from the evaluated areas of the Site were below the regulatory level, except
potentially from molybdenum in soils for this receptor group at AUM 458 only. Although the
molybdenum HQloael was greater than one, it may not be significant since the upper range of
the LOAEL values was approximately 6.5 times larger than the geometric mean value used as
the TRV (Appendix G Table G4-3c of the Phase III Summary Report).
The Ra-226 soil EPCs were compared to the ssESL NOAEL and LOAEL values in Table 7-6b.
The HQnoael and HQloael values were less than one for all evaluated areas, indicating any
potential risk from exposure to Ra-226 in soils to this receptor group from any portion of the
Site, including the individual AUMs, were below the regulatory level.
7.9.4 Insectivorous bird: American kestrel
The American kestrel is used as the representative species for insectivorous birds that may forage
in the upland areas of the Site. This receptor was not evaluated in the riparian areas. The
non-radiological EPCs in soils, calculated ADD, and the HQ values are shown in Table 7-7a.
The HQnoael and HQloael values were less than one for all evaluated areas of the Site,
including the AUMs, using either the average or UCL soil concentrations. These results indicate
any potential risk from exposure to the non-radiological PCOCs to this receptor group from the
upland areas of the Site were below the regulatory level.
The Ra-226 soil EPCs were compared to the ssESL NOAEL and LOAEL values in Table 7-7b.
The HQnoael and HQloael values were less than one for all evaluated areas of the Site,
including the AUMs, using either the average or UCL soil concentrations. These results indicate
March 18, 2021
Rev. 1.2
76
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
any potential risk from exposure to the Ra-226 to this receptor group from any location at the
Site were below the regulatory level.
7.9.5 Insectivorous bird: Rock wren
The rock wren is used as the representative species for insectivorous birds that may forage in the
upland and riparian areas of the Site. The non-radiological EPCs in soils, calculated ADD, and
the HQ values are shown in Table 7-8a. The non-radiological PCOC HQnoael and HQloael
values were less than one for all evaluated areas of the Site, including the AUMs, using either the
average or UCL soil concentrations. These results indicate any potential risk from exposure to
the non-radiological PCOCs to this receptor group from the evaluated areas of the Site were
below the regulatory level.
The Ra-226 soil EPCs were compared to the ssESL NOAEL and LOAEL values in Table 7-8b.
The HQnoael and HQloael values were less than one for all evaluated areas, except for the
HQnoael using the UCL soil concentration in AUM 458 which was slightly above one (actual
value was 1.6). The Ra-226 HQnoael result is not considered significant since the HQloael
values were all below one for both the average and UCL soil concentrations.
7.9.6 Insectivorous mammal: Desert shrew
The desert shrew is used as the representative species for insectivorous mammal that may forage
in the upland and riparian areas of the Site. The non-radiological EPCs in soils, plants, and
invertebrates, calculated ADD, and the HQ values are shown in Table 7-9a. They key results are
summarized below:
• Upland - APE with AUMs: The HQnoael and HQloael values based on either the
average or UCL concentrations were all below one.
• Upland - APE Less AUMs: The HQnoael and HQloael values based on either the
average or UCL concentrations were all below one.
• Upland - Outside of APE: The HQnoael and HQloael values based on either the
average or UCL concentrations were all below one.
• Upland - A UM 457: The HQnoael and HQloael values based on either the average or
UCL concentrations were all below one.
• Upland - A UM 458: The HQnoael and HQloael values based on either the average or
UCL concentrations were all below one for arsenic, mercury, selenium, uranium and
vanadium. The molybdenum HQnoael value using either the average or UCL
concentrations were above one. The molybdenum HQloael value using the average
concentration was below one, whereas the molybdenum HQloael value using the UCL
was greater than one.
• Upland - A UM 459: The HQnoael and HQloael values based on either the average or
UCL concentrations were all below one.
March 18, 2021
Rev. 1.2
77
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
• Riparian - Riparian Buffer Area within APE: The HQnoael and HQloael values based
on either the average or UCL concentrations were all below one.
These results indicate any potential risk from exposure to non-radiological PCOCs in soils to this
receptor group from any of the evaluated portions of the Site were below the regulatory level,
except for molybdenum at AUM 458. Although the molybdenum HQloael was greater than
one, it may not be significant since the upper range of the LOAEL values was approximately 6.5
times larger than the geometric mean value used as the TRV (Appendix G Table G4-3c of the
Phase III Summary Report).
The Ra-226 soil EPCs were compared to the ssESL NOAEL and LOAEL values in Table 7-9b.
The HQnoael and HQloael values were less than one for all evaluated areas, including the
individual AUMs, indicating any potential risk from exposure to Ra-226 in soils to this receptor
group from the evaluated any portion of the Site were below the regulatory level.
7.9.7 Omnivorous mammal: Coyote
The coyote is used as the representative species for omnivorous mammals that may forage in the
riparian areas of the Site. This receptor was not evaluated in the upland portions of the Site. The
non-radiological EPCs in soils and diet, calculated ADD, and the HQ values are shown in
Table 7-10a. The HQnoael and HQloael values were less than one for the evaluated areas of the
Site, using either the average or UCL soil concentrations. These results indicate any potential
risk from exposure to the non-radiological PCOCs to this receptor group from the Site is below
the level of regulatory concern.
The Ra-226 soil EPCs were compared to the ssESL NOAEL and LOAEL values in Table 7-10b.
The HQnoael and HQloael values were less than one indicating any potential risk from exposure
to Ra-226 in soils to this receptor group from the evaluated portion of the Site is below the level
of regulatory concern.
7.9.8 Carnivorous bird: Golden eagle
The golden eagle is used as the representative species for carnivorous birds that may forage in
the upland and riparian areas of the Site. The non-radiological EPCs in soils and diet, calculated
ADD, and the HQ values are shown in Table 7-1 la. The HQnoael and HQloael values were
less than one for all evaluated areas of the Site, including the AUMs, using either the average or
UCL soil concentrations. These results indicate any potential risk from exposure to the
non-radiological PCOCs to this receptor group from the Site is below the level of regulatory
concern.
The Ra-226 soil EPCs were compared to the ssESL NOAEL and LOAEL values in Table 7-1 lb.
The HQnoael and HQloael values were less than one for all evaluated areas, including the
AUMs, indicating any potential risk from exposure to Ra-226 in soils to this receptor group from
any portion of the Site is below levels of regulatory concern.
March 18, 2021
Rev. 1.2
78
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
7.9.9 Assessment of Potential Receptor Risks in the LCR Under Wet Conditions
The following receptors are evaluated semi-quantitatively in the LCR under the Wet Conditions
Scenario:
• Amphibian: Spadefoot toad
• Insectivorous bird: Rock wren
Given the ephemeral nature of water in the LCR, it is likely that exposure to insectivorous birds
to emergent aquatic insects will occur only when water is present in the LCR.
Amphibians
The spadefoot toad is the representative amphibian receptor that may use the LCR under wet
conditions. This species buries itself in soft substrates and emerges to breed in the temporary
ponds created by the heavy runoff, such as during the summer monsoons.
There were no surface water samples collected as part of the Phase II and III field programs
therefore this assessment focuses on comparison to sediment benchmarks. Sediment benchmarks
have not been developed to assess risks to amphibians or reptiles, except for some specific
chemicals (e.g., total PCBs). However, sediment benchmarks for protection of aquatic
organisms can be used as a surrogate for the assessment of burrowing amphibians, such as the
spadefoot toad.
Table 7-12 compares the mean and UCL values from samples collected from the LCR channel -
used as a surrogate for sediments from the LCR channel - to sediment benchmarks. There were
multiple data sources for the sediment benchmarks The NOAEL and LOAEL values for arsenic,
mercury, selenium, and uranium were from LANL (2017a) for aquatic community organisms
and the values for Ra-226 were also from LANL (2017a) for all aquatic organisms. An alternate
Ra-226 NOAEL benchmark from DOE (2002) was also used. LANL (2017a) did not have any
NOAEL or LOAEL sediment criteria for molybdenum or vanadium. The molybdenum values
were the Dutch Ministry target and intervention values for sediments reported in Friday (1998,
2005). The vanadium NOAEL value was from the NOAA Screening Quick Reference Tables
(SQuiRT)13 and represented background values for sediments. None of the observed mean or
UCL values in sediments were greater than these benchmarks. Therefore, it is not anticipated
that there would be any impacts to amphibians from PCOCs in the LCR channel under the Wet
Scenario.
Insectivorous Birds
The rock wren is the representative insectivorous bird receptor that may use the LCR under wet
conditions. Potential risks to the rock wren from exposure to solids in the upland and riparian
areas of the Site were presented in Section 7.9.5. When water is present in the LCR, this species
may also prey on emergent insects that were exposed to PCOCs present in the LCR channel
substrate. Assuming the BTF-invertebrate values used for the Dry Conditions scenario would
also apply to the potential uptake by emergent insects from the LCR channel area, a qualitative
13 Available from https://response.restoration.noaa.gov/sites/default/files/SQuiRTs.pdf
March 18, 2021
Rev. 1.2
79
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
assessment of the potential rock wren risks under the wet scenario can be obtained by comparing
the EPC from the channel area only to the EPCs from the remainder of the Site (Table 9-1 and
Appendix G Table G2-2 of the Phase III Summary Report). The EPCs from the channel area are
much lower than reported from the other portions of the Site. Given that the latter showed no HQ
values above one, it is likely that there are not any potential risks to the rock wren (and other
insectivorous birds) that may opportunistically feed on emergent insects under the LCR Wet
Conditions and that potential risk is below the level of regulatory concern.
7.10 EcoSRE Uncertainty Analysis
This section discusses the EcoSRE risk characterization and includes a discussion of the
quantitative and qualitative uncertainty of the EcoSRE risk characterization.
7.10.1 Representativeness of sampling
The Phase II and III sampling program was biased towards the assessment of Site features within
and outside of the APE. Consequently, the soils PCOC concentrations would be biased high and
represent upper end estimates of a Site-wide average or UCL soil concentration. This is
reasonable for a streamlined assessment to minimize the potential for missing potential areas that
may cause potential risks.
In their Site Inspection Report, Weston (2014) reported radionuclide and non-radionuclide
results from five sediment samples collected along the edge of the LCR proximal to the AUMs
(some background samples were also collected at other locations). The Phase II and III field
programs collected additional soil samples from the dry channel of the LCR. During both field
efforts no surface water was available for collection. USGS collects data on discharge and gage
height for the LCR near Cameron, AZ (USGS Gage 09402000) but no chemical parameters.
SWCA (2016) reported that the LCR surface water (when present) exhibits poor water quality
due to high suspended solids and dissolved salts. Therefore, assessment from surface water
could not be performed as part of the EcoSRE.
A literature review showed that there was no LCR biota data available near the Site. Andrews et
al. (1995) collected fish and birds for metals and radionuclide analyses (but not Ra-226) from
multiple stations in the Puerco River and Little Colorado River in August 1993. Their most
downstream station (Station 7) was located approximately 30 km south of Cameron, upstream of
the Site, but was designated an "observation site" rather than a "collection site" because it was
"xeric and/or depauperate of species available for collection" at the time of their survey. Review
of the USGS gage station data from August 1993 shows a spike of discharge near the end of
August but virtually no flow prior to that period. The actual survey dates were not reported by
the authors to verify whether they were present at the station during the no flow period.
7.10.2 Receptor selection and representativeness
As discussed earlier, evaluation of all potential receptors in a food chain is not warranted for an
EcoSRE, which focuses on receptors that are representative of the lower and upper trophic level
feeding guilds that may be present in the evaluated areas. The receptors proposed in the Phase
III Work Plan were evaluated in the EcoSRE. The selected receptors represent a cross-section of
feeding guilds across the habitats at the Site. The addition of the spadefoot toad for the LCR wet
March 18, 2021
Rev. 1.2
80
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
scenario also reflects potential risks that may occur under intermittent wet conditions at the Site.
The latter showed that risks are unlikely to this species because the LCR bed concentrations were
all below screening benchmarks.
At the request of EPA, soil results from the evaluated areas were also compared to the screening
benchmarks for earthworms, which were used as surrogate for soil invertebrates such as insects.
ESLs were available for five PCOCs from LANL (2017a) and the molybdenum ESL (LOAEL
only) was derived from information provided for springtails (Folsomia Candida) and two
earthworm species (Eisenia andrei and Enchytraeus crypticus) in M-EMS (2014; Appendix G
Table G7-1 of the Phase III Summary Report). No invertebrate ESLs were available for
vanadium which was not evaluated further. The available ESLs were compared to the mean and
UCL soil values in Table 7-13. There were several HQnoael values greater than one calculated
using the UCL soil concentrations, but most of the HQloael values were less than one with
exception of soils from AUM 458. Therefore, although soil invertebrates were not originally
selected as a receptor group, their results are generally consistent with the conclusions from the
plant assessment (Table 7-4).
7.10.3 Conservatism from use of chemical uptake models to estimate prey and forage
PCOC concentrations
PCOC analytical results of forage (i.e., plants) and prey items were not available for the
EcoSRE, which instead relied upon literature BTF values. These uptake factors do not account
for soil characteristics or similar factors that may reduce the bioavailability of the PCOC. Use of
BTF values is generally considered to be a conservative approach, and is appropriate for the
streamlined process of an EcoSRE.
7.10.4 Comparison of non-radiological and radiological risk results to those generated by
the LANL EcoRisk model (LANL, 2017a)
The LANL (2017a) methodology was used to assess potential risks from Ra-226 exposure. The
default exposure assumptions were modified to reflect those of the evaluated receptors at the
Site, and the receptor- and evaluation area-specific AUFs were additional variables in the
calculations of the ssESLs. Table 7-14 compares the ssESLs to the ESLs from LANL (2017a)
for similar species. With the exception of the coyote that has a large home range (and therefore
small AUFs), the ssESLs were very similar to the ESLs from LANL (2017a). ESLs are not
adjusted to AUFs. Therefore, development and use of ssESLs does not result in any undue
uncertainty for the risk characterization.
7.10.5 Development of non-radiological benchmarks (i.e., TRV)
Several of the proposed non-radiological PCOC TRVs from the Phase III Work Plan were
updated for the EcoSRE. This was predominantly due to the addition of the LANL (2017a)
TRVs. The small mammal molybdenum TRVnoael and TRVloael values were updated from
the values presented in the Phase III Work Plan (which were based on a single mouse study)14
following review of rat data from ATSDR (2017). These values were used as calculated for the
14 The molybdenum TRVnoael and TRVloael values from the Phase III Work Plan were 0.26 and 2.6 mg/kg-day,
respectively.
March 18, 2021
Rev. 1.2
81
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
assessment of potential molybdenum risks for all small mammals and were body weight scaled
to assess potential risks to coyote. Body weight scaling of the rat TRVnoael and TRVloael
values could have been used to develop the small mammal TRVs. It is noteworthy that the body
scaled TRVnoael and TRVloael values are larger for the mouse (11 and 33 mg/kg-day,
respectively) than those for the rat (Appendix G Table G4-2 of the Phase III Summary Report),
indicating more conservatism in the risk characterization when the latter are used. Most of the
molybdenum toxicological studies using mice have focused on inhalation exposures (ATSDR,
2017). ATSDR (2017) developed NOAEL of 5.3 and LOAEL of 11 mg/kg-day based on
reproductive endpoint (abnormalities in mouse oocytes) from the study by Zhang et al (2013).
These values are larger than those proposed in the Phase III Work Plan, but consistent with the
TRVnoael and TRVloael values developed based on rat data. Given these results use of the rat
TRVs as a surrogate for all small mammals would not unduly misrepresent the potential toxicity
of molybdenum to the evaluated small mammal receptors at the Site.
The non-radiological PCOC TRVs were based on a mixture of bounded and unbounded NOAEL
and LOAEL results. This was PCOC specific and varied based on the availability of data. As
discussed in the Phase III Work Plan, preference was made to use bounded values, although
unbounded values were used in several cases (e.g., avian TRVs for arsenic and methylmercury).
The avian arsenic TRVs can be used as an example when the unbounded NOAEL and LOAEL
values were used. This was required in this case because there were no bounded NOAEL and
LOAEL values available from EcoSSL (EPA 2005a) and LANL (2017a). The mammalian
arsenic TRVs are an example where the geometric means of the bounded values were used rather
than the unbounded values. There were four unbounded values but seven unbounded NOAELs
and 13 bounded LOAELs, which yielded geometric mean values of 4.57 and 3.89 mg/kg-day,
respectively. It is counterintuitive to use a LOAEL that is smaller than the NOAEL.
Consequently, the bounded NOAEL and LOAEL values were used to assess potential arsenic
risks to small mammals even though it was based on a smaller data set.
7.11 Summary of EcoSRE Results
Tables 7-15a and 7-15b graphically summarize the EcoSRE HQnoael and HQloael results for
the non-radiological PCOCs and radiological PCOC (respectively) across all receptors and
evaluated areas. For both tables the following color coding was used:
• HQ values less than or equal to one = green.
• HQ values between one and 10 = yellow.
• HQ values greater than ten = red.
Risk results using both the mean and UCL EPC values are reported. Review of Table 7-15a
shows the following:
• Most of the HQ values for plants were coded green, indicating the HQ values were below
the regulatory limit. As discussed in Section 7.9.1, exceptions were molybdenum in
several of the areas (APE with AUMs, AUM 457, AUM 458 and AUM 459), and
vanadium in one evaluated area (APE outside of the AUMs). As discussed in Section
7.9.1, the molybdenum soil concentrations in AUM 458 were within the range of the
LOAEL values indicating these exceedances of the TRVs may not reflect a measurable
risk above the levels of regulatory concern. The vanadium HQnoael was only slightly
March 18, 2021
Rev. 1.2
82
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
above one using the UCL soil concentration and is not considered to be significant given
that the HQloael values were both below the level of regulatory concern. Local substrate
quality may be more important for the establishment of plants in this AUM than PCOC
concentrations in the soil.
• Most of the HQ values for small mammals (deer mouse, desert shrew) were coded green,
except for molybdenum in AUM 458 and 459. The molybdenum HQnoael results from
deer mouse exposure to soils in AUM 459 are not considered significant since the
HQloael values were all below one. These results suggest some potential for risk above
EPA's level of regulatory concern to molybdenum in soils for small mammals at AUM
458 only. Although as discussed in Sections 7.9.3 and 7.9.6 the molybdenum HQloael
results may not be significant since the upper range of the LOAEL values was
approximately 6.5 times larger than the geometric mean value used as the TRV.
HQ values for the large mammal (coyote) were all coded green, indicating the HQ values
were below the level of regulatory concern from exposure to the assessed areas.
• Risks for all of the avian species, which includes the golden eagle, were coded green
indicating any potential risk from any the non-radiological PCOCs across the Site were
below the regulatory limit.
As shown in Table 7-15b, all of the Ra-226 HQloael values were coded green, indicating any
potential risks to the receptors across the evaluated areas to this radiological PCOC the HQ
values were below the regulatory limit. The HQnoael values were also coded green for all
receptors except for plants and rock wrens when using the UCL soil concentration for Ra-226 in
AUM 458. Risks using the average Ra-226 soil concentration were coded green for plants and
rock wrens.
Overall, most of the potential ecological risk above the level of regulatory concern is associated
with exposure to soils in AUM 458 but this is restricted to plants and small mammals only.
Larger mammals and all avian species do not have any calculated HQ values greater than one
from exposure to Site soils and thus were below EPA's level of regulatory concern.
March 18, 2021
Rev. 1.2
83
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
8.0 PROPOSED RISK BASED ACTION LEVEL
In accordance with the AOC (EPA, 2016a), the methodologies and assumptions used by the
HHSRE (and the EcoSRE) were used to "... calculate proposed action levels for (P )COCs that
will be protective for users under the current and planned future use at the Site. " The more
conservative (i.e., lower) of the PCOC-specific HHSRE or EcoSRE risk based action levels
(rbALs) were used to calculate "...the volumes (sic) of contaminates soil and sediment with
concentrations above the screen levels and with concentrations above the proposed risk based
action levels" (EPA, 2016a). Development of Action Levels for future remediation were not part
of the AOC or this RSE.
The HHSRE provides information needed to establish the potential contaminants of concern
(PCOCs), and calculate risk to potential current and future receptors under current Site
conditions, taking into consideration any recorded covenants restricting the use of the land. The
HHSRE showed potential cancer and non-cancer risks for the non-radiological PCOCs were less
than the levels of regulatory concern and hence acceptable to the EPA for the evaluated human
receptors at the Site. Potential human health cancer risks from exposure to Ra-226 (and daughter
products) were below or within the acceptable risk range for On-Site Workers, and Child
Recreators (2-year exposure duration). Risks for longer term Adult Recreators (24 years) and
Combined Adult and Child Recreators (combined 26 years of exposure) were below or within
the acceptable EPA cancer risk range (i.e., range less than or equal to lxlO"6 to lxlO"4 risk), and
were below the OSWER risk value (i.e., 3xl0"4), for all areas of the Site except for AUM 458.
The highest relative risks are calculated for exposures at AUM 458.
Given these results, the following approach was used to develop the rbALs for the Site:
• Acceptable soil concentrations at the three acceptable cancer risk levels (i.e., 1 x 10"6,
1 x 10"5 and 1 x 10"4) and a non-cancer risk level of one (i.e., HQ of one) were calculated
for each PCOC using the input soil UCL value for AUM 458 (73.9 pCi/g) and the risk
results for all the evaluated receptors. The AUM 458 area showed the largest risk relative
to the other evaluated areas.
• The human-health based rbALs were then compared to the soil concentrations back
calculated to HQnoael or HQloael of one for the ecological receptors to determine
whether they would be equally protective. Risks to the ecological receptors vary by their
AUF values. Therefore, only the rock wren and desert shrew were used to assess the
suitability of the human health rbAL values since they have AUF of one for all of the
evaluated portions of the Site (except for AUM 459) and had the lowest ssESL values for
Ra-226. AUM 459 was excluded because the AUFs were below one for both the desert
shrew and rock wren in this area (see Appendix G Table G3-1 of the Phase III Summary
Report).
March 18, 2021
Rev. 1.2
84
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
• To estimate the soil concentrations that would achieve HQnoael or HQloael values of
one for the desert shrew and rock wren15, regression lines were fit to the HQ and soil
EPC values. Separate calculations were performed for the NOAEL and LOAEL based
values due to the different TRVs used to calculate the HQ values. The regression lines
were linear and all exhibited good fit (r2 value > 0.93). The input values (mean and UCL
soil values and HQ results for the two receptors) and the regression equation slope and
intercept values are shown in Appendix F Table F6-2a and F6-2b of the Phase III
Summary Report (provided as Appendix M to this report).
These rbAL values are based on the exposure assumptions used to assess the human and
non-human receptors that may utilize the Site. The values are shown in Table 8-la for Ra-226
and Table 8-lb for the non-radiological PCOCs. Supporting calculations are provided in
Appendix F Table F6 series of the Phase III Summary Report (provided as Appendix M to this
report). The proposed rbALs are discussed below:
• Ra-226: The Ra-226 human health rbAL values, which include daughter products (under
secular equilibrium), were calculated for each of the following receptor groups and
scenarios for the risk levels of 1 x 10"6 to 1 x 10"4 using the EPCs and risk results for
AUM 458 (Table 8-la).
In the discussion below, the calculated Ra-226 rbALs were compared to the soil result for
samples collected Outside of the APE, which can be considered regional background
levels for Ra-226 in soils (Appendix F Table F3-2 in the Phase III Summary Report).
The mean Ra-226 in these soils was 1.99 pCi/g with an overall range of 1.04 to 3.72
pCi/g. Ra-226 was detected in all of the samples collected Outside of the APE Area.
o On-Site Worker (Section 6.13.1) - The potential rbALs ranged from 170 to 17,000
pCi/g across the risk levels of 1 x 10"6 to 1 x 10"4. These were all greater than the
Ra-226 values for soils Outside of the APE Area.
o Long Term Adult Recreator (14 days per year, 24 years of exposure;
Section 6.13.2): The potential rbALs ranged from 0.13 to 13 pCi/g across the risk
levels of 1 x 10"6 to 1 x 10"4. The rbAL values for risk levels of 1 x 10"6 and
1 x 10"5 are below the Ra-226 values for soils Outside of the APE Area.
o Child Recreator (14 days per year, 2 year of exposure; Section 6.13.4): The
potential rbALs ranged from 1.5 to 150 pCi/g across the risk levels of 1 x 10"6 to
1 x 10"4. The rbAL value for the risk levels of 1 x 10"6 is below the values for
soils Outside of the APE.
o Combined Child and Long Term Adult Recreator (14 days per year, 2 years as
child and 24 years as adult; Section 6.13.5): The potential rbALs ranged from
15 Although the rock wren did not have any HQ values greater than one it was included in the development of the
proposed rbALs to generate values for avian species.
March 18, 2021
Rev. 1.2
85
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
0.12 to 12 pCi/g across the risk levels of 1 x 10"6 to 1 x 10"4 The rbAL values for
risk levels of 1 x 10"6 and 1 x 10"5 are below the values for soils Outside of the
APE.
For the ecological receptors the NOAEL ssESL values ranged from 47 to 540 pCi/g and
the LOAEL ssESL values ranged from 470 to 5,400 pCi/g. The geometric mean of the
NOAEL values was 159 pCi/g. The latter value (rounded to 160 pCi/g) is the proposed
ecological rbAL. As shown in Table 8-la, for one of the evaluated human health
receptors (On-Site Worker), the ecological rbAL would be more protective than the
human health based rbAL for Ra-226.
The human health and ecological rbALs for non-radiological PCOCs are provided in Table 8-lb
and are summarized below.
• Arsenic: The arsenic input soil UCL value for AUM 458 (27.7 mg/kg), the three
acceptable cancer risk levels (i.e., 1 x 10"6, 1 x 10"5 and 1 x 10"4) and a non-cancer risk
HQ value of one was used to develop the rbALs for this PCOC. The human health rbAL
values ranged from 31 to 130,000 mg/kg for the risk levels of 1 x 10"6 to 1 x 10"4 and had
a non-cancer risk level of 790 to 8,600 mg/kg (across all receptors except the Site
Workers). For the ecological receptors the backcalculated NOAEL values ranged from
55 to 140 mg/kg and the LOAEL based value ranged from 120 to 360 mg/kg. The
geometric mean of the NOAEL values was 88 mg/kg. The latter value (rounded to 90
mg/kg) is the proposed ecological rbAL. This would be protective of all evaluated
human health receptors (potential cancer risk would be greater than lxlO"6, but less than
1 x 10"5) and is also below the LOAEL based risk values for the two ecological receptors.
The proposed arsenic rbAL is greater than the mean (3.0 mg/kg) and range of results (1 to
5 mg/kg) for soils Outside of the APE (Appendix F Table F3-2 of the Phase III Summary
Report), which is considered regional background. Arsenic was detected in all of the
Outside of the APE soil samples.
• Mercury: The mercury input soil UCL value for AUM 458 (0.17 mg/kg) and an HQ
value of one was used to develop the rbALs for this PCOC. The human health rbAL
value was 450 mg/kg to 910 (across all receptors except the Site Workers). For the
ecological receptors the backcalculated NOAEL values ranged from 0.25 to 1.3 mg/kg
and the LOAEL based value was 1.1 mg/kg (a mercury LOAEL was not calculated for
the desert shrew). The geometric mean of the NOAEL values was 0.57 mg/kg. The
latter value (rounded to 0.6 mg/kg) is the proposed ecological rbAL. This would be
protective of all evaluated human health receptors and still below the LOAEL based risk
value for the avian ecological receptors.
The proposed mercury rbAL is greater than the mean (0.0103 mg/kg) and range of results
(0.00017 to 0.02 mg/kg) for soils Outside of the APE (Appendix F Table F3-2 of the
Phase III Summary Report), which is considered regional background. Mercury was
detected in all but one of these soil samples (detection limit of 0.0000595 mg/kg).
March 18, 2021
Rev. 1.2
86
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
• Molybdenum: The molybdenum input soil UCL value for AUM 458 (350 mg/kg) and an
HQ value of one was used to develop the rbALs for this PCOC. The human health rbAL
value was 8,900 to 100,000 mg/kg (across all receptors except the Site Workers). For the
ecological receptors the backcalculated NOAEL values ranged from 37 to 1,400 mg/kg
and the single LOAEL based value was 120 mg/kg (a molybdenum LOAEL was not
calculated for the rock wren). The geometric mean of the NOAEL values was 228 mg/kg,
which is rounded to 230 mg/kg as the proposed ecological rbAL. This would be
protective of all evaluated human health receptors.
The proposed molybdenum rbAL is greater than the mean (0.254 mg/kg) and range of
detections (0.0705 to 1.04 mg/kg) for soils Outside of the APE (Appendix F Table F3-2
of the Phase III Summary Report), which is considered regional background.
Molybdenum was detected in 59% of these samples (24 of 41 samples) with a detection
limit range of 0.17 to 0.19 mg/kg.
• Selenium: The selenium input soil UCL value for AUM 458 (0.518 mg/kg) and an HQ
value of one was used to develop the rbALs for this PCOC. The human health rbAL
value was 8,900 to 100,000 mg/kg (across all receptors except the Site Workers). For the
ecological receptors the backcalculated NOAEL values ranged from 3.2 to 4.3 mg/kg and
the LOAEL values ranged from 7.6 to 9.1 mg/kg. The geometric mean of the NOAEL
values was 3.7 mg/kg, which is the proposed ecological rbAL. This would be protective
of all evaluated human health receptors.
The proposed selenium rbAL is greater than the mean (0.173 mg/kg) and range of
detections (0.27 to 0.69 mg/kg) for soils Outside of the APE (Appendix F Table F3-2 of
the Phase III Summary Report), which is considered regional background. Selenium was
detected in 27% of these samples (11 of 41 samples) with a detection limit range of
0.0495 to 0.48 mg/kg.
• Uranium: The uranium input soil UCL value for AUM 458 (86.2 mg/kg) and an HQ
value of one was used to develop the rbALs for this PCOC. The human health rbAL
value was 360 to 4,200 mg/kg (across all receptors except the Site Workers). For the
ecological receptors the backcalculated NOAEL values ranged from 450 to 7,500 mg/kg
and the LOAEL value was 57,000 mg/kg. The geometric mean of the NOAEL values
was 1,602 mg/kg. It is proposed that the human health value of 360 mg/kg be used as the
rbAL. It will be protective of the evaluated ecological receptors.
The proposed uranium rbAL is greater than the mean (2.54 mg/kg) and range of
detections (0.930 to 9.55 mg/kg) for soils Outside of the APE (Appendix F Table F3-2 of
the Phase III Summary Report), which is considered regional background. Uranium was
detected in all of these samples.
• Vanadium: The vanadium input soil UCL value for AUM 458 (17.6 mg/kg) and an HQ
value of one was used to develop the rbALs for this PCOC. The human health rbAL
value was 9,000 to 100,000 mg/kg (across all receptors except the Site Workers). For the
ecological receptors the backcalculated NOAEL values ranged from 77 to 11,020 mg/kg
March 18, 2021
Rev. 1.2
87
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
and the LOAEL values ranged from 160 to 220 mg/kg. The geometric mean of the
NOAEL values was 95 mg/kg, which is the proposed rbAL. This would be protective of
all evaluated human health receptors.
The proposed vanadium rbAL is greater than the mean (43.2 mg/kg) and range of
detections (13 to 88 mg/kg) for soils Outside of the APE (Appendix F Table F3-2 of the
Phase III Summary Report), which is considered regional background. Vanadium was
detected in all of these samples.
The rbALs are used to estimate waste volumes above these values in the next section.
March 18, 2021
Rev. 1.2
88
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
9.0 REPOSITORY AND WASTE VOLUMES
9.1 CHARACTERIZATION OF PITS
Page 4 of Appendix A of the Administrative Settlement Agreement and Order on Consent
(AOC) (EPA 2016a) states: "Respondents shall measure and calculate volumes of mining pits to
estimate their capacity to receive mining wastesEA used high resolution Light Detection and
Ranging (LiDAR) topographic data collected at the Site in 2016 to develop volumes of the mine
pits associated with AUM 457 and AUM 458. The LiDAR data was collected under the
direction of Arizona licensed land surveyor (Maser, 2020). Conceptual layouts were prepared
for various options for use of the AUM 457 and AUM 458 pits as mining waste repositories.
9.1.1 AUM 457
The LiDAR data for AUM 457 is presented on Figure 9-1. The pit at AUM 457 is
approximately 6 feet deep on the east and west sides, 4 feet deep on the south side, and daylights
into the drainage towards the north. The bottom of the pit slopes at approximately 2.5% from
south to north. Two conceptual disposal layouts were prepared tying the top of a proposed cover
into the side slopes on the west, south, and east sides of the pit and sloping to the north at 2%.
The cover options were a layout with a 5H:1V slope on the north face tying into a 2% cover
grade. The repository was assumed to have a 3 feet minimum cover thickness.
One option was prepared assuming a concave downward surface down the middle of the
impoundment. This option was named the "Channel Cover Surface" and is presented on
Figure 9-2. This option results in a total volume of 4,470 cubic yards (CY), with 3,130 CY
required for the cover and 1,340 CY remaining for waste disposal.
A second option was prepared assuming a convex upward surface down the middle of the
impoundment. This option was named the "Mound Cover Surface" and is presented on
Figure 9-3. This option results in a total volume of 4,630 CY, with 3,070 CY required for the
cover and 1,560 CY remaining for waste disposal.
9.1.2 AUM 458
The LiDAR data for AUM 458 is presented on Figure 9-4. The pit at AUM 458 is
approximately 18 feet deep on the north and east sides, 30 feet deep on the south side and
daylights into the drainage towards the west. The bottom of the pit is relatively flat. Three
conceptual disposal layouts were prepared tying the top of a proposed cover into the side slopes
on the north, east and south sides of the pit and sloping to the west at 2%. The cover options
were prepared with a 2% cover grade. The repository was assumed to have a 3 feet minimum
cover thickness.
One option was prepared assuming a concave downward surface down the middle of the
impoundment. This option was named the "Channel Cover Surface" and is presented on
Figure 9-5. This option results in a total volume of 2,770 CY, with 2,030 CY required for the
cover and 740 CY remaining for waste disposal.
March 18, 2021
Rev. 1.2
89
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
A second option was prepared assuming a convex upward surface down the middle of the
impoundment. This option was named the "Mound Cover Surface" and is presented on
Figure 9-6. This option results in a total volume of 2,820 CY, with 2,020 CY required for the
cover and 800 CY remaining for waste disposal.
A third option was prepared assuming a convex upward surface mounded in the middle with
5H:1V side slopes. This option was named the "Raised Mound Cover Surface" and is presented
on Figure 9-7. This option results in a total volume of 9,370 CY, with 3,700 CY required for the
cover and 5,670 CY remaining for waste disposal.
9.1.3 Summary of Pit Capacity
EA prepared conceptual repository designs to determine the capacity of pits AUM 457 and 458
to receive mining wastes. With a convex upward mounded repository design AUM 458 could
hold approximately 5,670 CY of removal material. With a convex upward surface down the
middle of the impoundment the repository design at AUM 457 could hold approximately 1,560
CY of removal material. The potential pit capacities are summarized in Table 9-1.
9.2 WASTE VOLUMES
Page 5 of Appendix A of the Administrative Settlement Agreement and Order on Consent
(AOC) (EPA, 2016a) states: "Waste Volumes: Respondents shall calculate the volumes of
contaminated soil and sediment with concentrations above the screening levels and with
concentrations above the proposed risk based action levels. " This section of the report presents
analyses to determine the volumes of contaminated soils above the investigation level
(IL)/screening levels and the risk based action levels. Since the requirement is to calculate
volumes of contaminated soils, only the soils deemed as TENORM on Figures 5-14 through 5-18
were used to determine volumes. The soils designated as NORM were not included in the
volume estimates.
9.2.1 Volumes Above IL
The investigation levels for 1) horizontal correlations between exposure rate and static gamma
count rate, and 2) vertical correlations between exposure rate and Ra-226 concentration in soil
were discussed in Section 5.0 of this report. The correlation data are presented in Appendix B of
the Phase III Summary Report (provided as Appendix M to this report). The horizontal and
vertical correlations are summarized in Tables 9-2 and 9-3, respectively. The correlations were
performed for the LCR, Drainage, and Alluvial Pooled Areas presented on Figure 5-13.
For the purpose of determining volumes in a desktop survey the mean correlation was used to
determine a reasonable estimate of quantities. The goal of the volume estimate is not to estimate
a conservative estimate, rather to estimate a most reasonable estimate for future use in an
engineering evaluation/cost analysis (EECA) study.
Based upon the areas of TENORM, the mean horizontal correlation between IL and static
gamma count rate for the pooled areas, and the static gamma count rates, the areas that exceeded
IL for the surface horizontal surveys were determined. The areas that exceed the IL are
presented on Figure 9-8. This data is sub-divided into four quadrants for further discussion in
March 18, 2021
Rev. 1.2
90
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
the report, and to allow the data to be analyzed at a larger scale. The volume of material that
exceed IL is 31,500 CY as shown presented on Figure 9-8. As defined in this report and the
AOC, the IL is 1.24 pCi/g above background and has not been defined as a cleanup level. A
summary of the waste volumes is provided in Table 9-4.
9.2.1.1 Volume Above IL - NW Quadrant
The areas that exceed the horizontal IL for the NW Quadrant are shown on Figure 9-9, as well as
the test pit locations in the dozer push area. Based on the field investigation, soil sampling, and
the vertical (test pit) correlations, the samples that exceeded the IL in Test Pit 1 reached a depth
of 3 feet. This material was identified as material imported to the Site and disposed of in the
dozer push area. Thus, the dozer push area that exceeded the horizontal IL was assumed to have
a depth of 3 feet for the volume estimate. Other areas that exceeded the horizontal IL in the NW
Quadrant are limited to surface soils sitting on top of bedrock and were assumed to have a depth
of 0 to 2 inches with an average depth of 1 inch. The areas and depths for the NW Quadrant are
presented on Figure 9-9. The volume of material that exceeds IL in this quadrant is 4,087 CY.
9.2.1.2 Volume Above IL - NE Quadrant
The areas that exceed the horizontal IL and the location of the test pits for the NE Quadrant are
shown on Figure 9-10. The NE Quadrant contains AUM 457 and its related features consisting
of the pit, pond, concrete slabs, waste rock piles, and upgrader foundations as shown on
Figure 4-1. Based on the field investigation, soil sampling, the vertical (test pit) correlations, the
aerial photography, and the Site topography, the areas that exceed the IL are shown on
Figure 9-11. The estimated depth of soils that exceed IL are also shown on Figures 9-10 and 9-
11. In general, the depth of soils above IL are estimated to be 1 foot for the slabs, 7 to 10 feet for
the waste rock piles, 5 feet for the upgrader, 2.5 feet for the ponds, up to 5.5 feet for the drainage
below the upgrader, 0.3 feet for the pit, and 0 to 2 inches with an average of one inch for the
remaining soils that are on top of near surface bedrock. The volume of material that exceeds IL
in this quadrant is 10,209 CY as shown on Figure 9-11.
9.2.1.3 Volume Above IL - SW Quadrant
The areas that exceed the horizontal IL and the location of the test pits for the SW Quadrant are
shown on Figure 9-12. The SW Quadrant contains AUM 458 and its related features consisting
of the pit, roads cuts, and dozer pushes as shown on Figure 4-2. Based on the field investigation,
soil sampling, the vertical (test pit) correlations, the aerial photography, and the site topography,
the areas that exceed the IL are shown on Figure 9-13. The estimated depths of the soils that
exceed IL are also shown on Figures 9-12 and 9-13. In general, the depth of soils above IL are
estimated to be 1 foot for the bottom of the pit, 1.5 feet for the road to the south, 5 feet for the
dozer push areas, 1.5 feet for the alluvial areas to the east of the dozer push, and 0 to 2 inches,
with an average of 1 inch for the remaining soils that are on top of near surface bedrock and
excavated pit faces. The volume of material that exceeds IL in this quadrant is 7,818 CY as
shown on Figure 9-13.
9.2.1.4 Volume Above IL - SE Quadrant
The areas that exceed the horizontal IL and the locations of the test pits for the SE Quadrant are
shown on Figure 9-14. The SE Quadrant is north of the off-Site pit area located in AUM 459.
Based on the field investigation, soil sampling and the vertical (test pit) correlations, the samples
March 18, 2021
Rev. 1.2
91
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
that exceeded the IL are shown on Figure 9-14. In general, the depths of soils above IL are
estimated to be 1 foot in the alluvium at the location of TP-15, 1 foot in the area of TP-17, and 3
feet in the alluvium drainage below AUM 459 (TP-23). Other areas that exceeded the horizontal
IL in the SE Quadrant are limited to surface soils sitting on top of bedrock and were assumed to
have a depth of 0 to 2 inches with an average of 1 inch. The areas and depths for the SE
Quadrant are presented on Figure 9-15. The volume of material that exceeds IL in this quadrant
is 9,436 CY as shown on Figure 9-14.
9.2.2 Volume Above Proposed Risk Based Action Levels
The rbALs are presented in Section 8.0 of this report. The rbAL for Ra-226 for the receptors
presented in Section 6.13 was determined to range from 12 pCi/g (Long Term Adult Recreator
and Child) to 160 pCi/g (On-Site Worker). The approved Phase II (horizontal) correlation
between gamma count rate and Ra-226 concentration in soil was used to estimate the
concentration of Ra-226 in supplemental gamma survey areas. The extents of TENORM gamma
survey data that is potentially above the rbAL of 160 pCi/g for Ra-226 are shown on Figures 9-
15 through 9-21. Areas with Ra-226 readings above the rbAL of 160 pCi/g are located within
AUM 457 and 458. AUM 457 is located in the northeast area of the site and AUM 458 is located
in the southwest area of the site. The volume of material above the rbAL of 160 pCi/g at AUM
457 was calculated to be 940 cubic yards and is presented on Figure 9-18. The depths of
excavation ranged from one inch to 10 feet at AUM 457. The volume of material above the
rbAL of 160 pCi/g at AUM 458 was calculated to be 2 cubic yards and is presented on
Figure 9-20. The area above the rbAL of 160 pCi/g at AUM 458 are located in outcrop areas and
thus an excavation depth of one inch was assumed.
The extents of TENORM gamma survey data that is potentially above the rbAL of 12 pCi/g for
Ra-226 are shown on Figures 9-22 through 9-26. The volume of material above the rbAL of 12
pCi/g was calculated to be 10,036 cubic yards and is presented on Figures 9-23 through 9-26.
The depths of excavation ranged from one inch to 10 feet.
The lateral extents and calculated volumes for the rbAL of 160 pCi/g and 12 pCi/g area shown
on Figures 9-27 through 9-29. The there is no material calculated to be on Section 10 above the
rbAL of 160 pCi/g. The amount of material above the rbAL of 12 pCi/g on Section 10 was
calculated to be 634 cubic yards.
The depths of excavation that were used to calculate volumes for the material above the IL were
also used to determine the depths of excavation for the material above the rbAL. Thus, the
depths used to determine the volumes above the rbAL are conservative.
March 18, 2021
Rev. 1.2
92
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
10.0 SUMMARY AND CONCLUSIONS
This RSE report presents the results of all the work completed under the AOC (EPA, 2016a)
including the streamlined risk evaluations, and material volume estimates above the IL and risk-
based action levels. This RSE meets the requirements presented in the AOC.
The HHSRE showed that the non-cancer risks from the non-radiological PCOCs in soils were
below the level of regulatory concern and the cancer risks from arsenic and Ra-226 in soils were
below the levels or within acceptable range of regulatory concern for all of the evaluated
receptors and evaluated portions of the Site, except for Ra-226 at AUM 458. Based on the UCL
soil concentrations, the latter showed calculated risks above lxlO"4 and also above the OSWER
Directive 9200.4-18 value of 3xl0"4 for the two of the three recreational receptors (adult only and
combined adult plus child) but not for the other evaluated receptor (child recreator and site
worker).
The EcoSRE showed that the potential risks were below EPA's level of regulatory concern for
nearly all of the non-radiological PCOCs and Ra-226 to birds or mammals that utilize the
evaluated portions of the Site. The exceptions were for molybdenum exposures to plants, and
small mammals in AUM 458. For plants, molybdenum had HQnoael and HQloael values above
one using either the mean or UCL concentrations across most of the evaluated Site area
(exception was the riparian area), and an HQloael above one using the UCL soil concentration
from AUM 458 only. However, this was likely not significant given that mean and UCL soil
concentrations were within the range of the LOAEL values used to derive the TRV.
Furthermore, the substrate (i.e., soil types and precipitation) particularly in the AUMs, would
limit the establishment of plants in these areas. For the small herbivorous and insectivorous
mammals (deer mouse and desert shrew, respectively) the UCL soil concentrations for
molybdenum showed HQnoael and HQloael values above one for AUM 458 only. Calculated
risks from the other AUMs and evaluated areas were all below the regulatory level of concern.
The risk based action levels are presented in Section 8.0 of this report. The rbAL for Ra-226 for
the receptors presented in Section 6.13 was determined to range from 12 pCi/g (Long Term
Adult Recreator and Child) to 160 pCi/g (On-Site Worker). The extent of gamma survey data
that is potentially above the rbAL for Ra-226 is shown on Figures 9-17 through 9-27. A
summary of the volume of material based on the rbAL is provided below.
• The volume of material above the rbAL 160 pCi/g in the northeast quadrant (Figure 9-17)
at AUM 457 was calculated to be 940 cubic yards and is presented on Figure 9-18. The
there is no material calculated to be on Section 10 above the rbAL of 160 pCi/g.
• The volume of material above the rbAL 12 pCi/g in the northeast quadrant (AUM 457)
was calculated to be 2,688 cubic yards and is presented on Figure 9-24. The amount of
material above the rbAL of 12 pCi/g on Section 10 was calculated to be 634 cubic yards.
• No material above the rbAl of 160 pCi/g was encountered in the southeast quadrant as
presented on Figure 9-21
• The volume of material above the rbAL 12 pCi/g in the southeast quadrant was calculated
to be 647 cubic yards and it presented on Figure 9-26.
• The volume of material above the rbAL 160 pCi/g in the southwest quadrant (Figure 9-
19) at AUM 458 was calculated to be 2 cubic yards and is presented on Figure 9-20.
March 18, 2021
Rev. 1.2
93
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
• The volume of material above the rbAL 12 pCi/g in the southwest quadrant (AUM 458)
was calculated to be 5,535 cubic yards and is presented on Figure 9-25.
• No material above the rbAl of 160 pCi/g was encountered in the northwest as presented
on Figure 9-16
• The volume of material above the rbAL 12 pCi/g in the northwest quadrant was
calculated to be 1,166 cubic yards and is presented on Figure 9-23.
The depths of excavation that were used to calculate volumes for the material above the IL were
also used to determine the depths of excavation for the material above the rbAL. Thus, the
depths used to determine the volumes above the rbAL are conservative.
March 18, 2021
Rev. 1.2
94
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
11.0 REFERENCES
Agency for Toxic Substances and Disease Registry (ATSDR). 2012. Toxicological Profile for
Radon. US Department of Health and Human Services. May. Available from
https://www.atsdr.cdc.gov/toxprofiles/tpl45.pdf
Agency for Toxic Substances and Disease Registry (ATSDR). 2017. Toxicological Profile for
Molybdenum. Draft for Comment. April. U.S. Department of Health and Human
Services. Available from https://www.atsdr.cdc.gov/ToxProfiles/tp212.pdf
American Society for Quality (ASQ). 2014. Quality Management Systems for Environmental
Information and Technology Programs - Requirements with Guidance for Use.
ASQ/ANSI E4:2014. February.
Andrews, B.J., K.A. King, and D.L. Baker. 1995. Radionuclides and trace elements in fish and
wildlife of the Puerco and Little Colorado Rivers. U.S. Fish and Wildlife Service,
Phoenix Ecological Services Field Office, Arizona. Available from
https://www.fws.gov/southwest/es/arizona/Documents/ECReports/RadionuclidesAZ.pdf
Arizona Daily Sun. 1960a. http://www.newspapers.com/newspage/66475481/. June 24.
Arizona Daily Sun. 1960b. http://newspaperarchive.com/us/arizona/flagstaff/arizona-dailv-
sun/1960/08-22/. August 22
Arizona Daily Sun. 1960c. http://www.newspapers.com/newspage/66477355/. August 24.
Arizona Daily Sun. 1960d http://www.newspapers.com/newspage/66477563/. August 31.
Arizona Daily Sun. 1961. http://www.newspapers.com/newspage/16782363/ February 1.
Arizona Daily Sun. 1967. http://www.newspapers.com/newspage/68739286/. May 27
Arizona Department of Environmental Quality (ADEQ). 2007. Uranium Site Discovery Project,
Phoenix, AZ. September 12.
Bechtel Nevada. 2001. An Aerial Radiological Survey of Abandoned Uranium Mines in the
Navajo Nation. Survey conducted in Arizona, New Mexico and Utah for the U.S.
Environmental Protection Agency by the U.S. Department of Energy under IAG DW
8955235-01-5. DOE/NV/11718-602. August.
Bellamy, M., L. Finklea, F. Dolislager and K. Eckerman. 2014. Area Correction Factors for
Contaminated Soil for Use in Risk and Dose Assessment Models. ORNL/TM-2013/00.
Oak Ridge National Laboratory. September. Available from https://epa-
sdcc.ornl.gov/ACF FINAL.pdf
March 18, 2021
Rev. 1.2
95
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Billingsley, G.H., Priest, S.S., and Felger, T.J. 2007. Geologic Map of the Cameron 30' x 60'
Quadrangle, Coconino County, Northern Arizona, USGS Scientific Investigations Map
(SIM) 2977. Scale 1:100,000.
Chenoweth, William L. 1993. Geology and Production History of the Uranium Ore Deposits in
the Cameron Area, Coconino County, Arizona. Arizona Geological Survey, Contributed
Report 93-B. August.
Chenoweth, William L. 2012. Section 9 Lease Analysis and Field Notes. September 1.
Engineering Analytics, Inc. (EA). 2016. Project Health and Safety Plan, Babbitt Ranch Hawaii
Milestone Project. October 21.
Engineering Analytics, Inc. (EA). 2017a. Signage Work Plan, Phase I Work, Babbitt Ranches,
LLC - Milestone Hawaii Stewardship Project (Section 9 Lease Abandoned Uranium
Mine) Rev. 5.1. May 3.
Engineering Analytics, Inc. (EA). 2017b. Quality Management Plan, Babbitt Ranches, LLC -
Milestone Hawaii Stewardship Project (Section 9 Lease Abandoned Uranium Mine). Rev
2.0. May 9.
Engineering Analytics, Inc. (EA). 2017c. Data Management Plan, Babbitt Ranches, LLC -
Milestone Hawaii Stewardship Project (Section 9 Lease Abandoned Uranium Mine).
Rev. 3.0. June 15.
Engineering Analytics, Inc. (EA). 2017d. Field Sampling Plan, Phase II Work, Babbitt Ranches,
LLC - Milestone Hawaii Stewardship Project (Section 9 Lease Abandoned Uranium
Mine). September 1.
Engineering Analytics, Inc. (EA). 2017e. Transection Gamma Scan and Background Study Work
Plan Phase II Work, Babbitt Ranches, LLC - Milestone Hawaii Stewardship Project
(Section 9 Lease Abandoned Uranium Mine). Rev. 3.1. September 6.
Engineering Analytics, Inc. (EA). 2017f. Quality Assurance Project Plan, Babbitt Ranches, LLC
- Milestone Hawaii Stewardship Project (Section 9 Lease Abandoned Uranium Mine).
Rev. 3.2. October 4.
Engineering Analytics, Inc. (EA). 2018a. Summary Report for Phase II Work, Babbitt Ranches,
LLC - Milestone Hawaii Stewardship Project (Section 9 Lease Abandoned Uranium
Mine). Rev. 2.1. August 9.
Engineering Analytics, Inc. (EA). 2018b. Field Sampling Plan, Phase III Work, Babbitt Ranches,
LLC - Milestone Hawaii Stewardship Project (Section 9 Lease Abandoned Uranium
Mine). Rev. 1.2. November 7.
March 18, 2021
Rev. 1.2
96
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Engineering Analytics, Inc. (EA). 2019a. Phase III Soil Sample Data Verification and Validation
(Metals data), Babbitt Ranches, LLC Milestone Hawaii Stewardship Project (Section 9
Lease Abandoned Uranium Mine). February 25.
Engineering Analytics, Inc. (EA). 2019b. Summary of Phase III Field Investigation for
Characterization of Surface, Subsurface Soils and Sediment, Babbitt Ranches, LLC -
Milestone Hawaii Stewardship Project, Section 9 Lease Abandoned Uranium Mine,
Coconino County, Arizona. February 28.
Engineering Analytics, Inc. (EA). 2019c. Phase III Work Plan, Babbitt Ranches, LLC -
Milestone Hawaii Stewardship Project (Section 9 Lease Abandoned Uranium Mine).
Rev. 1.9. September 13.
Engineering Analytics, Inc. (EA). 2020. Summary Report for Phase III, Babbitt Ranches, LLC -
Milestone Hawaii Stewardship Project (Section 9 Lease Abandoned Uranium Mine).
Rev 1.4. June 12.
Environmental Restoration Group, Inc. (ERG). 2019. Level IV Data Validation Results for
Radium-226 in Soil Collected from Background Study Areas and Test Pits of the
Milestone Hawaii Stewardship Project. April 12.
Friday, G.P. 1998. Ecological screening values for surface water, sediment, and soil. WSRC-
TR-98-00110. Westinghouse Savannah River Company. Available from
https://www.osti.gov/servlets/purl/4764/MmZPPiLA.pdf
Friday, G.P. 2005. Ecological Screening Values for Surface Water, Sediment and Soil: 2005
Update. Savannah River National Laboratory. WSRC-TR-2004-00227. August.
Available from https://www.osti.gov/biblio/881510
Los Alamos National Laboratory (LANL). 2017a. ECORISK Database Release 4.1. September.
Available from https://www.intellusnm.com/documents/document-
library.cfc?method=retrieveLanlFile&nodeId=ce92dc7b-ddb7-464d-bd59-
17c9d99d658e&fileName=ECORISK_Database_R4.1 .zip
Los Alamos National Laboratory (LANL). 2017b. ECORISK Database User Guide, Revision 1.
September. LA-UR-17-263 76. ESHID-602538. Available from
https://www.intellusnm.com/documents/document-
library.cfc?method=retrieveLanlFile&nodeId=l 1019
Maser. 2016. Babbitt Rach Milestone Hawaii LiDAR data. Collected November 15th and 16th.
Maser. 2020. Memorandum, Babbitt Rach Milestone Hawaii Memorandum of Record MC
Project No. 160003028A. January 20.
March 18, 2021
Rev. 1.2
97
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Millennium EMS Solutions Ltd (M-EMS). 2014. Proposed Soil Quality Guidelines,
Molybdenum, Environmental and Human Health Effects. Report prepared for Petroleum
Technology Alliance Canada. May.
Nagy, K.A. 1987. Field metabolic rate and food requirement scaling in mammals and birds. Eco.
Monogr. 57: 111-128.
Nagy, K. 2001. Food requirements of wild animals: Predictive equations for free-living
mammals, reptiles, and birds. Nutrition Abstracts and Reviews, Series B 71, 21R-31R.
Nuclear Regulatory Commission (NRC). 1992. Manual for Conducting Radiological Surveys in
Support of License Termination. NUREG/CR - 5849; ORAU - 92/C57. 1992.
Oorts, K., E. Smolders, S.P. McGrath, C.A.M. van Gestel, M.J. McLaughlin and S. Carey. 2016.
Derivation of ecological standards for risk assessment of molybdate in soil. Environ.
Chem. 13:168-180
Sample, B.E. and G.W. Suter II. 1994. Estimating Exposure of Terrestrial Wildlife to
Contaminants. Oak Ridge National Laboratory. September. ES/ER/TM-125. Available
from https://rais.ornl. gov/documents/tm 125.pdf
Sample, B.E., D.M. Opresko, and G.W. Suter II. 1996. Toxicological benchmarks for wildlife:
1996 Revision. ES/ER/TM-86/R3. Oak Ridge National Laboratory.
Sample, B.E., J.J. Beauchamp, R.A. Efroymson, and G. W. Suter II. 1998. Development and
Validation of Bioaccumulation Models for Small Mammals. February. ES/ER/TM-219.
Oak Ridge National Laboratory. Available from
http s: //rai s. ornl. gov/documents/tm219. pdf
San Antonio Light. 1961. http://newspaperarchive.com/us/texas/san-antonio/san-antonio-
light/1961/08-07/page-12. August 7
Singh, A. and A.K. Singh. 2015. ProUCL Version 5.1. Technical Guide Statistical Software for
Environmental Applications for Data Sets with and without Nondetect Observations.
Prepared for USEPA ORD Site Characterization and Monitoring Technical Support
Center. EPA/600/R-07/041. Available from www.epa.gov/sites/production/files/2016-
05/documents/proucl 5.1 tech-guide.pdf.
Soil Conservation Service, 1983. Soil Survey of Coconino County Area Arizona, Central Part.
U.S. Department of Agriculture in cooperation with the Arizona Agricultural Experiment
Station, August, 212 p.
Stafford, J.M., C.E. Lambert, J.A. Zyskowski, C.L. Engfehr, O.J. Fletcher, S.L. Clark, A.
Tiwary, C.M. Guide, and B.E. Sample. 2016. Dietary toxicity of soluble and insoluble
March 18, 2021
Rev. 1.2
98
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
molybdenum to northern bobwhite quail (Colinus virginianus). Ecotoxicology. 25: 291-
301.
SWCA Environmental Consultants (SWCA). 2016. Biological Resources Survey, Babbitt
Ranches Milestone Hawaii Reclamation Project (Section 9 Lease AUM Removal
Action), Coconino County, Arizona. Report prepared for Babbitt Ranches, LLC.
December.
United States Court of Appeals Firth Circuit. 1967. 384F.2d 748, United States of America,
Appellant v. William J. Rochelle Fr., Trustee in Bankruptcy for John Milton Addison,
Bankrupt, Appellee. No. 23923. October 20.
U.S. Department of Energy (DOE). 2002. A Graded Approach for Evaluating Radiation Doses
to Aquatic and Terrestrial Biota. DOE-STD-1153-2002. July. Available from
https ://www. standards. doe, gov/ standards-documents/1100/1153 - AStd-2002
U.S. Environmental Protection Agency (EPA). 1989. Risk Assessment Guidance for Superfund.
Volume I: Human Health Evaluation Manual (Part A). Interim Final. EPA/540/1-89/002.
U.S. Environmental Protection Agency, Office of Emergency and Remedial Response.
December. Available from https://www.epa.gov/sites/production/files/2015-
09/documents/rags_a.pdf
U.S. Environmental Protection Agency (EPA). 1993. Wildlife Exposure Factors Handbook.
EPA/600/R-93/187. Available from
http://oaspub.epa.gov/eims/eimscomm.getfile?p_download_id=489605. U.S.
Environmental Protection Agency, Office Research and Development. December.
U.S. Environmental Protection Agency (EPA). 1997a. Memorandum: Establishment of Cleanup
Levels for CERCLA Sites with Radioactive Contamination. OSWER Directive No.
9200.4-18. 22 August. Available from https://semspub.epa.gov/work/HQ/176331.pdf
U.S. Environmental Protection Agency (EPA). 1997b. Ecological Risk Assessment Guidance
for Superfund: Process for Designing and Conducting Ecological Risk Assessments.
EPA 540-R-97-006. Available from
www.epa.gov/oswer/riskassessment/ecorisk/ecorisk.htm. U.S. Environmental Protection
Agency, Office of Solid Waste and Emergency Response. June.
U.S. Environmental Protection Agency (EPA). 1998. Guidelines for ecological risk assessment.
63FR26845. EPA/630/R-95/002F. Available from
http://oaspub.epa.gov/eims/eimscomm.getfile?p_download_id=36512. U.S.
Environmental Protection Agency. May.
U.S. Environmental Protection Agency (EPA). 1999. Issuance of Final Guidance: Ecological
Risk Assessment and Risk Management Principles for Superfund Sites. OSWER
Directive 9285.7-28P. Office of Solid Waste and Emergency Response, 7 October.
March 18, 2021
Rev. 1.2
99
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
U.S. Environmental Protection Agency (EPA). 2000. Multi-Agency Radiation Survey and Site
Investigation Manual (MARSSIM), EPA 402-R-97-016, Rev. 1, NUREG-1557, Rev. 1,
DOE/EH-0624. Rev. 1. August.
U.S. Environmental Protection Agency (EPA). 2001. EPA Requirements for Quality
Management Plans, EPA QA/R-2. EPA/240/B-01/002. March 2001 (Reissued May
2006).
U.S. Environmental Protection Agency (EPA). 2005a. Ecological soil screening levels for
arsenic. Interim Final. OSWER Directive 9285.7-62. Available from
https://rais.ornl.gov/documents/eco-ssl_arsenic.pdf. U.S. Environmental Protection
Agency. March.
U.S. Environmental Protection Agency (EPA). 2005b. Ecological soil screening levels for
vanadium. Interim Final. OSWER Directive 9285.7-75. Available from
https://rais.ornl.gov/documents/eco-ssl_vanadium.pdf. U.S. Environmental Protection
Agency. April.
U.S. Environmental Protection Agency (EPA). 2007. Ecological soil screening levels for
selenium. Interim Final. OSWER Directive 9285.7-72. Available from
www.epa.gov/ecotox/ecossl/pdf/eco-ssl_selenium.pdf. U.S. Environmental Protection
Agency.
U.S. Environmental Protection Agency (EPA). 2011. Exposure Factors Handbook: 2011
Edition. EPA/600/R-09/052F. U.S. Environmental Protection Agency, National Center
for Environmental Assessment, Office of Research and Development. September.
Available from http://ofmpub.epa.gov/eims/eimscomm.getfile7p download id=522996
U.S. Environmental Protection Agency (EPA). 2014. Human Health Evaluation Manual,
Supplemental Guidance: Updated of Standard Default Exposure Factors. OSWER
Directive 9200.1-120. Office of Solid Waste and Emergency Response. 6 February, 9
November 2015 update. Available from
https ://rai s. ornl .gov/documents/O S WER_Directive_9200.1 -
120_ExposureF actors_corrected2. pdf
U.S. Environmental Protection Agency (EPA). 2016a. Administrative Settlement Agreement and
Order on Consent in the matter of Section 9 Lease Mine Site, Arizona, entered into
between the EPA Region IX and Babbitt Ranches, LLC. October 25.
U.S. Environmental Protection Agency (EPA). 2016b. Identification of Section 9 Lease
Abandoned Uranium Mine Sites Background Reference Areas. October 26.
U.S. Environmental Protection Agency (EPA). 2016c. ProUCL Version 5.1.00 Statistical
Software for Environmental Applications for Data Sets with and without Nondetect
Observations. EPA/600/R-07/041. May.
March 18, 2021
Rev. 1.2
100
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
U.S. Environmental Protection Agency (EPA). 2016d. ProUCL Version 5.1.002 software. June
20 Update. Available from https://www.epa.gov/land-research/proucl-software
Weston Solutions, Inc. (Weston). 2012. Preliminary Assessment, Section 9 Lease Abandoned
Uranium Mine, Coconino County, Arizona, EPA ID No. NNN000909110. Report
prepared for the EPA Region 9. November.
Weston Solutions, Inc. (Weston). 2014. Site Inspection Report, Section 9 Lease Abandoned
Uranium Mine, Coconino County, Arizona, EPA ID No. NNN000909110. Report
prepared for the EPA Region 9. June.
Yu, C. 2012. RESRAD Family of Codes — A Suite of Tools for Environmental Radiological
Dose Assessment. Presented at the Environmental Radiological Assistance Directory
Web Conference, June 27, 2012. Available from
https://www.energy.gov/sites/prod/files/2014/03/fl4/resrad codes erad iune 2012-
Charlie%20Yu.pdf
Zhang Y-L, F-J Liu, X-L Chen, Z-Q Zhang, R-Z Shu, X-L Yu, X-W Zhai, L-J Jin, X-G Ma, Q
Qi and Z-J Liu. 2013. Dual effects of molybdenum on mouse oocyte quality and ovarian
oxidative stress. Syst Biol Reprod Med 59(6):312-318.
March 18, 2021
Rev. 1.2
101
Engineering Analytics, Inc.
-------
TABLES
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 4-1 Summary Statistics for Gamma Count Rates (cpm) in the Background Study Areas
Background
Study Area
Number of
Measurements
Minimum
Maximum
Mean
Median
Standard
Deviation
Relative
Standard
Deviation (%)
Alluvial BSA #1
2,046
39,595
50,613
45,668
45,595
1,649
3.61
Alluvial BSA #2
3,715
37,744
51,925
44,771
44,753
2,250
5.03
Drainage BSA #2
1,632
34,110
52,957
39,586
39,363
2,279
5.76
Little Colorado
River BSA
3,641
19,679
30,180
23,190
22,983
1,372
5.92
EPA "Qter BRA"
1,432
33,106
45,860
38,676
38,612
1,877
4.85
Terrace BSA #1
1,567
32,658
56,560
40,191
39,481
3,728
9.27
Terrace BSA #2
1,169
36,168
48,685
41,106
41,089
1,744
4.24
cpm = counts per minute
All measurements were collected using a Ludlum model 44-20, a 3x3 inch sodium iodide detector.
March 18, 2021
Rev. 1.2
T-l
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 4-2 Survey Instruments for Transect Gamma Survey
System
Identifier1
Channel
Date Range Used
Ludlum Detector
Ludlum Ratemeter
Model
Serial Number
Model
Serial Number
3
1
10/18/17-10/23/17
44-20
PR269980
4612
291488
3
2
10/18/17-10/23/17
44-20
PR269985
4612
291488
3
3
10/18/17-10/23/17
44-20
051517N
4612
291488
10
-
11/08/17- 11/09/17
44-20
PR269985
2221
271435
11
-
10/20/17- 11/09/17
44-20
PR262403
2221
218564
12
-
10/17/17-11/08/17
44-20
051517N
2221
271435
12(2)
-
11/07/17- 11/09/17
44-20
051517S
2221
149940
13(2)
-
10/19/17-10/27/17
44-20
051517S
2221
149940
16
-
03/10/20
44-20
042911F2
2221
176952
'The identifier is used to distinguish the instrument pair used for specific measurements.
2 The system identifier is only specific to the data logger used to collect the GPS gamma walkover data. During the demob and remob between
10/27/2017 and 11/06/2017 a different data logger was put into circulation and paired with the same 2221/44-20 pair.
March 18, 2021
Rev. 1.2
T-2
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 4-3 Survey Instrumentation used for the Concrete Survey
Date Range Used
Ludlum Detector
Ludlum Ratemeter
Model
Serial Number
Model
Serial Number
11/06/17
43-93
PR298426
2360
184965
11/06/17- 11/07/17
43-93
PR339054
2360
215279
11/06/17- 11/09/17
43-93
PR199838
2360
278586
March 18, 2021
Rev. 1.2
T-3
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 4-4 Soil and Sediment Sample Location Rationale
Test Pit ID
Rationale
Selection Criteria
TP-1
Excavation to determine the depth of impacted material in
the dozer push area at the north of the site.
General location in the TENORM area. Professional
judgment used.
TP-2
Excavation in the EPA identified drainage north of AUM
457 to determine the depth of impacted material.
General location in center of the Drainage area where
sediments are anticipated to be the deepest.
Professional judgment used.
TP-3
Excavation in TENORM area within AUM 457 to
determine the depth of impacted material.
Pit at the north of AUM 457. Professional judgment
used.
TP-4
Excavation in bottom of the pond area within AUM 457 to
determine the depth of impacted material.
Center of the pond where sediments are anticipated to
be the deepest. Professional judgment used.
TP-5
Excavation in TENORM area within AUM 457 to
determine the depth of impacted material.
West side of AUM 457 in TENORM area.
Professional judgment used.
TP-6
Excavation in berm around the pond area within AUM
457 to determine the depth of impacted material.
Top of the berm around the pond area. Professional
judgment used.
TP-7
Excavation in the drainage downgradient of the up-grader
foundation within AUM 457 to determine the depth of
impacted material.
Area is directly downgradient of the upgrader and
anticipated to the area of deepest sediment.
Professional judgment used.
TP-8
Excavation in the drainage downgradient of the up-grader
foundation within AUM 457 to determine the depth of
impacted material.
Area is directly downgradient of the upgrader and
anticipated to the area of deepest sediment.
Professional judgment used.
TP-9
Excavation in at the northwestern edge of Wetlands Area
3 and downgradient of the up-grader foundation within
AUM 457 to determine the depth of impacted material.
Area is directly downgradient of the upgrader and
anticipated to the area of deepest sediment.
Professional judgment used.
TP-10
Excavation in the TENORM area within AUM 457 to
determine the depth of impacted material.
Access road to AUM 457. Professional judgment used.
Location may be adjusted to account for field
conditions.
TP-11
Excavation in at the western edge of Wetlands Area 3.
Test pit is provided to bound Wetlands Area 3.
Professional judgment used.
March 18, 2021
Rev. 1.2
T-4
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 4-5 Survey Instruments for Subsurface Gamma Profiling
Ludlum Detector
Ludlum Ratemeter/Data Logger
Date
Range
Used
Notes
Model
Serial
Number
Model
Serial Number
43-93
PR299677
2360
215282
12/3/18
12/4/18
Used to prepare sample shipment.
43-93
PR292138
2360
277007
12/5/18
12/6/18
Used to prepare sample shipment.
19
180310
N/A
12/3/18
12/6/18
Used to prepare sample shipment.
44-10
PR355764
2221
262347
12/3/18
12/6/18
Used to quantify static shielded gamma
count rate of trench samples.
'The identifier is used to distinguish the instrument pair used for specific measurements.
March 18, 2021
Rev. 1.2
T-5
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 4-6 Analytes and Methods for Surface Soil and Sediment Samples
Analyte
Group
Analyte1
Analytical
Method2
Anticipated
Concentration
Range
Method
Detection
Limit3
Laboratory
CRQL3
Metals
and
Metalloids
Arsenic
EPA 6020
2-250 mg/kg
0.0036 mg/kg
0.2 mg/kg
Mercury
EPA 747IB
0.01-10 mg/kg
0.00005 mg/kg
0.033 mg/kg
Molybdenum
EPA 6010
5-2000 mg/kg
0.47 mg/kg
1.0 mg/kg
Selenium
EPA 6010
2-50 mg/kg
0.3 mg/kg
0.5 mg/kg
Uranium
EPA 6020
0.1-350 mg/kg
0.0018 mg/kg
0.01 mg/kg
Vanadium
EPA 6010
10-400 mg/kg
0.2 mg/kg
1.0 mg/kg
Radionuclides
Ra-226
EPA 901.1M
0.5-1,000 pCi/g
NA
0.25 pCi/g
'The Potential Contaminants of Concern (PCOCs) are identified in Section 1.2 of Appendix A to the AOC (EPA, 2016a).
2EPA Method 6010 and 6020 analyses require digestion via EPA Method 3050B.
3CRQL = Contract Required Quantitation Limit. Depending upon sample matrix, the actual sample detection limit may vary.
March 18, 2021
Rev. 1.2
T-6
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 4-7 Summary Statistics for Concentrations of Ra-226 (pCi/g) in Samples of Surface Soils Obtained in the
Background Study
Background Study Area
Number of
Samples
Minimum
Maximum
Mean
Median
Standard
Deviation
Alluvial BSA #1
7
1.57
3.59
2.54
2.44
0.67
Alluvial BSA #2
15
1.63
5.43
2.73
2.69
0.94
Drainage BSA #2
6
1.04
1.71
1.27
1.21
0.24
Little Colorado River
BSA
11
0.55
1.26
0.85
0.83
0.2
EPA "Qter BRA"
10
1.52
2.98
1.99
1.87
0.4
Terrace #1
10
1.33
2.64
2.03
1.95
0.38
Terrace #2
10
2.05
3.72
2.4
2.25
0.49
pCi/g = picocuries per gram
March 18, 2021
Rev. 1.2
T-7
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 4-8 Summary Statistics for Concentrations of Arsenic (mg/kg) in Samples of Surface Soils Obtained in the
Background Study
Background Study Area
Number of
Samples
Minimum
Maximum
Mean
Median
Standard
Deviation
Alluvial BSA #1
7
2.30
2.90
2.54
2.50
0.21
Alluvial BSA #2
15
2.80
3.70
3.36
3.40
0.30
Drainage BSA #2
6
2.90
3.50
3.20
3.20
0.24
Little Colorado River
BSA
11
1.50
2.40
1.90
1.90
0.29
EPA "Qter BRA"
10
3.00
5.00
4.05
4.25
0.70
Terrace BSA #1
10
1.00
3.40
2.09
2.10
0.84
Terrace BSA #2
10
1.80
4.90
2.88
2.80
0.80
mg/kg = milligrams per kilogram
For the sample results reported as below the MDL, the sample's MDL was used to calculate the summary statistics.
March 18, 2021
Rev. 1.2
T-8
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 4-9 Summary Statistics for Concentrations of Mercury (mg/kg) in Samples of Surface Soils Obtained in the
Background Study
Background Study Area
Number of
Samples
Minimum
Maximum
Mean
Median
Standard
Deviation
Alluvial BSA #1
7
0.0054
0.017
0.0081
0.0066
0.0040
Alluvial BSA #2
15
0.0039
0.01
0.00656
0.0065
0.0017
Drainage BSA #2
6
0.0041
0.009
0.00633
0.0058
0.00202
Little Colorado River
BSA
11
0.0014
0.0052
0.0035
0.0038
0.00111
EPA "Qter BRA"
10
0.011
0.019
0.0158
0.016
0.00249
Terrace BSA #1
10
0.0048
0.02
0.0112
0.011
0.00403
Terrace BSA #2
10
0.0059
0.011
0.00936
0.0098
0.00169
mg/kg = milligrams per kilogram
For the sample results reported as below the MDL, the sample's MDL was used to calculate the summary statistics.
March 18, 2021
Rev. 1.2
T-9
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 4-10 Summary Statistics for Concentrations of Molybdenum (mg/kg) in Samples of Surface Soils Obtained in the
Background Study
Background Study Area
Number of
Samples
Minimum
Maximum
Mean
Median
Standard
Deviation
Alluvial BSA #1
7
0.18
0.63
0.39
0.42
0.17
Alluvial BSA #2
15
0.18
0.59
0.294
0.24
0.13
Drainage BSA #2
6
0.17
0.36
0.215
0.18
0.0731
Little Colorado River BSA
11
0.18
0.25
0.199
0.19
0.0207
EPA "Qter BRA"
10
0.18
0.34
0.216
0.19
0.0604
Terrace #1
10
0.17
0.54
0.254
0.19
0.113
Terrace #2
10
0.18
0.53
0.365
0.35
0.105
mg/kg = milligrams per kilogram
For the sample results reported as below the MDL, the sample's MDL was used to calculate the summary statistics.
March 18, 2021
Rev. 1.2
T-10
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 4-11 Summary Statistics for Concentrations of Selenium (mg/kg) in Samples of Surface Soils Obtained in the
Background Study
Background Study Area
Number of
Samples
Minimum
Maximum
Mean
Median
Standard
Deviation
Alluvial BSA #1
7
0.24
0.63
0.33
0.28
0.14
Alluvial BSA #2
15
0.23
1.9
0.545
0.44
0.454
Drainage BSA#2
6
0.22
0.68
0.37
0.29
0.187
Little Colorado River
BSA
11
0.23
0.28
0.248
0.24
0.016
EPA "Qter BRA"
10
0.23
0.51
0.342
0.26
0.126
Terrace BSA #1
10
0.23
0.69
0.344
0.24
0.162
Terrace BSA #2
10
0.23
0.47
0.265
0.245
0.0725
mg/kg = milligrams per kilogram
For the sample results reported as below the MDL, the sample's MDL was used to calculate the summary statistics.
March 18, 2021
Rev. 1.2
T-ll
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 4-12 Summary Statistics for Concentrations of Uranium (mg/kg) in Samples of Surface Soils Obtained in the
Background Study
Background Study Area
Number of
Samples
Minimum
Maximum
Mean
Median
Standard
Deviation
Alluvial BSA #1
7
2.3
3.0
2.6
2.6
0.23
Alluvial BSA #2
15
1.9
3.9
2.69
2.6
0.53
Drainage BSA #2
6
0.93
1.5
1.27
1.3
0.21
Little Colorado River
BSA
11
0.47
0.76
0.63
0.66
0.09
EPA "Qter BRA"
10
1.8
3.5
2.23
2.15
0.5
Terrace BSA #1
10
1.2
2.3
1.68
1.65
0.35
Terrace BSA #2
10
3.1
5.4
3.99
4
0.68
mg/kg = milligrams per kilogram
For the sample results reported as below the MDL, the sample's MDL was used to calculate the summary statistics.
March 18, 2021
Rev. 1.2
T-12
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 4-13 Summary Statistics for Concentrations of Vanadium (mg/kg) in Samples of Surface Soils Obtained in the
Background Study
Background Study Area
Number of
Samples
Minimum
Maximum
Mean
Median
Standard
Deviation
Alluvial BSA #1
7
59
85
70.7
68
9.2
Alluvial BSA #2
15
58
90
71.2
70
9.6
Drainage BSA #2
6
31
35
33.5
34
1.8
Little Colorado River
BSA
11
11
17
13.18
13
2.0
EPA "Qter BRA"
10
60
88
69.6
70
8.4
Terrace BSA #1
10
13
41
24.8
21
8.9
Terrace BSA #2
10
22
46
38.7
40
7.1
mg/kg = milligrams per kilogram
For the sample results reported as below the MDL, the sample's MDL was used to calculate the summary statistics.
March 18, 2021
Rev. 1.2
T-13
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 4-14 Summary Statistics for Constituents (n=ll) for the Drainage BSA #2 (2017 and 2018 Data Set)
Constituent
Unit
Minimum
Maximum
Mean
Median
Standard
Deviation
Arsenic
mg/kg
2.0
3.5
2.8
2.9
0.5
Mercury
mg/kg
0.00006
0.009
0.0036
0.0041
0.0035
Molybdenum
mg/kg
0.04
0.36
0.18
0.18
0.09
Ra-226
pCi/g
0.94
1.71
1.22
1.19
0.2
Selenium
mg/kg
0.049
0.68
0.23
0.22
0.21
Uranium
mg/kg
0.91
1.5
1.2
1.2
0.20
Vanadium
mg/kg
28.0
35.0
32.2
32.0
2.3
mg/kg = milligrams per kilogram
pCi/g = picocuries per gram
For the sample results reported as below the MDL, the sample's MDL was used to calculate the summary statistics.
March 18, 2021
Rev. 1.2
T-14
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 5-1 Data Validation Assessment of Relevant Field Data for Phase II Background Soil Sampling
Validation
Requirement
Met?
Validation
Requirement
Supplemental
Requirements
Qualifiers
Samples Affected
Comments
I. Relevant Field Data Review
Yes
All data components
are present.
Including the COCs,
copy of field logbook
or other field notes.
None
No
The internal COC is
complete with
respect to all
required form
entries.
A complete and
accurate custody log
is recorded.
None
All samples in batch #1711413
The COC field "Relinquished by" is empty. The relinquisher Sam
Patemiti was contacted and confirmed that the samples never left his
custody until the samples were received by FedEx. Furthermore, Mr.
Patemiti applied a custody seal to the shipping container that arrived
intact. Hie COCs in every other batch were signed. This was
confirmed by the "Condition of Sample Upon Receipt" Form provided
by ALS Labs.
No
The internal COC is
complete with
respect to all
required form
entries.
Field data and
sample preservation
information.
None
BGS-T110-0-10-102617Rin,
BGS-D105-0-15-102617Rin
BGS-T110-0-10-102617Rin and BGS-D105-0-15-102617Rin, both
field rinsate samples, were unpreserved. These rinsate samples should
have been preserved with nitric acid or delivered to the laboratory
within 5 days of collection in accordance with EPA Method 900.0.
This preservation method was not identified in the QAPP or FSP. Lack
of preservation is unlikely to affect result since this is a low level field
rinsate sample.
Yes
Identification of
requested analyses.
None
Yes
References to any
special or non-
routine sampling,
handling, or analysis
requirements.
None
N/A
Any attached
supporting records
containing additional
sample relevant
information.
Only the COC was submitted to the laboratory.
March 18, 2021
Rev. 1.2
T-15
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 5-1 Data Validation Assessment of Relevant Field Data for Phase II Background Soil Sampling (Continued)
Y;ili(l;ilii>ll
Ki'(|iiiivnu'iil
Mil?
Y;ili(l;iliiill
ki'(|iiiiviiU'iil
Sii|)|)k'iiH'iil;il
Ki'(|iiimiK'iils
Qll;ililli'l's
S;iiii|)k's AITiik'd
Cum iiii-ii Is
1. Ki'kviinl I k-Id l);il;i Ri-\ ii-u
Sample collection
was complete and
followed the QAPP,
applicable FSP,
SOP, or work plan.
None
All samples in batch #1711413
There was an addition implemented to the soil sample nomenclature
to account for multiple BSAs. This addition was approved by the
Radiological Technical Team Lead, Mike Schierman. Please refer to
Tyler Alecksen's logbook dated 11/16 for further detail.
Equipment Rinsate
Blank
There is at least one
blank for every 20
samples or one on
each day.
None
The concentration of
the blank is less than
or equal to the
required detection
limit.
R
BGS-T110-0-10-102617Rin,
BGS-D105-0-15-102617Rin
Based on discussion with EPA, the all rinsate samples were qualified
with "R" (rejected) due to deviations of preservation from EPA
Method 900.0
Field Duplicate
At least one duplicate
sample was collected
per 20 samples or
one per sampling
event, which ever was
more frequent.
None
The duplicate
samples were a split
of one of the original
samples.
None
March 18, 2021
Rev. 1.2
T-16
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 5-1 Data Validation Assessment of Relevant Field Data for Phase II Background Soil Sampling (Continued)
Validation
Requirement
Met?
Validation
Requirement
Supplemental
Requirements
Qualifiers
Samples Affected
Comments
I. Relevant Field Data Review
Yes
Field Duplicate
When the average of
the analytical results
(the duplicate pairs)
is greater than or
equal to the UBGR,
(x > 0.5), the relative
percent difference
(RPD) must be less
than 127% for
samples from
Background Study
Areas.
None
BGS-D105-0-15-102617S,
BGS-D105-0-15-102617Dup;
BGS-T110-0-10-102617S,
BGS-T110-0-10-102617Dup.
All field duplicates in batch #1711413 originated in Background
Study Areas. All duplicates averages were greater than 0.5 pCi/g and
met their respective Measurement Quality Objective for precision.
March 18, 2021
Rev. 1.2
T-17
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 5-2 Data Validation Assessment of Analytical Lab Data for Phase II Background Soil Sampling
Validation
Requirement Met?
Validation
Requirement
Supplemental
Requirements
Qualifiers
Samples Affected
Comments
Yes
Holding Times
Met?
Was the lab in compliance
with the prescribed holding
time allowance of 6
months.
None
All samples
Mercury was analyzed on the same day the
soils samples were extracted.
Yes
Condition of
Samples Upon
Receipt
Was the custody seal on the
shipping container intact?
None
All samples
All details were provided by ALS labs in the
"Condition of Sample Upon" receipt form. In
batch 1711418, sample 458-3-0-15-110617S
was broken upon arrival.
Was the received COC in
agreement with samples
received?
Was there sufficient sample
for the requested analysis?
Were all sample containers
received intact?
Yes
Appropriate
Methods
All analytical laboratory
procedures for this project
shall use EPA approved
methods in accordance
with the OAPP / FSP.
J
All samples
Soil samples for Mo, Se, V, As and U extracted via
SW846 Method 3050. Mo, Se and V analyzed via
SW846 Method 6010. As and U analyzed via
SW846 Method 6020. Hg extracted and analyzed
via SW846 Method 7471.
Due to rejection of rinstae blank data resulting
from improper rinstae sample preservation, it
was agreed that all analytical data weould be
qualified with "J" to identify that the absence
of cross contamination between samples could
not be completely verified.
Yes
Calibration Okay
Laboratory instrument
calibration methods and
frequency will be
performed per the
laboratory's
None
All samples
Documentation of calibration included in reports.
Expiration dates of standards okay. All ICV/CCV
standard results within control limits. Several ICP
ICB/CCB samples reported slight negative values
or values just above the MDL, but less than the
CRDL.
March 18, 2021
Rev. 1.2
T-18
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 5-2 Data Validation Assessment of Analytical Lab Data for Phase II Background Soil Sampling (Continued)
Validation
Requirement Met?
Validation
Requirement
Supplemental
Requirements
Qualifiers
Samples Affected
Comments
Yes
Method Blanks
(MB)
OA manual and SOPs.
None
All Samples
V, As and U not present any of the 7 MBs. Mo
reported as negative value in 1 of 7 MBs. Se
reported just above MDL in 2 of 7 MBs. Hg
reported as negative in 5 of 7 MBs and just above
MDL in 2 of 7 MBs. All positive values < CRQL.
Yes
Lab Control
Samples (LCS)
At least one LCS is
analyzed per every 20
samples in a batch.
None
All Samples
Frequency requirement met.
Are the recovery limits met
(75% to 125%).
None
All Samples
All LCS results within control limits.
Partially
Spikes Recovery
Limits Met
The matrix spike control
limits are 75%-125%
Recovery
and \RPD\ <20%unless
otherwise
specified by the laboratory.
U in 30
samples in
Prep Batches
IP171221-2
and -5
qualified as
estimated
("J").
Qualification
for Mo in one
sample
changed from
U to U.T.
All Samples
All 6 MS/MSD pairs for V, As and Hg within
control limits. One MS/MSD pair for Mo and Se
outside of control limits. Two of six MS/MSD pairs
exhibited uranium values outside of control limits.
March 18, 2021
Rev. 1.2
T-19
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 5-2 Data Validation Assessment of Analytical Lab Data for Phase II Background Soil Sampling (Continued)
Validation
Requirement Met?
Validation
Requirement
Supplemental
Requirements
Qualifiers
Samples Affected
Comments
N/A
Total Propagated
Uncertainty
The TPIJfor each sample
falls below the maximum
acceptable TPUfor Ra-226
Not applicable for metals analyses.
Yes
Laboratory
Duplicates
If both results > 5x CRDL,
\RPD\ <20%
All samples.
Se, V and As within control limits of all six
laboratory duplicates. Mo and U within control
limits in 5 of 6 laboratory duplicates each.
Yes
Reporting
Limits/Quantitation
Limits Met
All analytical results exceed
the CROL.
All Samples
Mo okay. MDLs of As and V above Project MDL
in a few samples, but metals concentrations above
MDL. MDL of U above Project MDL in all
samples, but U concentrations above MDL. MDL
for Se in 4 samples above Project MDL and values
for these 4 samples reported below MDL ("U").
Yes
Completeness
Completeness is assessed by
the ratio of fully usable data
points to the total number of
data points. The ratio must
exceed 95%.
All samples
101 samples and 6 metals for 606 total data points.
One sample container broke in transit (-6). No
sample values rejected. Completeness = 600/606 =
99%.
March 18, 2021
Rev. 1.2
T-20
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 5-3 Data Validation Assessment of Relevant Field Data for Phase III Soil Sampling
Data
Data Quality
Indicator
Sample or
Measurement
Validation Requirement
Validation
Result
Comments
Logs
All
components of
data are
present
--
COCs, field logbooks, field
notes are present
PASS
COCs
complete and
accurate
--
Complete and accurate
custody log
FAIL
Errors found in dates and times of some
samples. Sample traceability unaffected.
Field
Sample
collection
complete
All
Samples collected according to
QAPP, FSP, SOPs, and/or
Work Plan
PASS
SOPs
followed
All
Field guidance follows SOP
PASS
Preservation
met
All
Samples preserved according
to QAPP and/or FSP
PASS
Equipment
Blanks Clean
Rinsates
Blank nuclide concentrations
are below quantitation level
FAIL
Drain-TP16-RINSE-120318 contained
detectable gross a.
Field
Duplicates
FPD / RD /
AD
Field
duplicates
At least one duplicate sample
collected per 20 samples or
one per sampling event,
whichever was more frequent
PASS
March 18, 2021
Rev. 1.2
T-21
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 5-4 Data Validation Assessment of Analytical Lab Data for Phase III Background Soil Sampling
Data
Data Quality
Indicator
Sample or
Measurement
Validation Requirement
Validation
Result
Comments
Holding Times
Met
All
Sample hold times meet QAPP
and/or FSP requirements
PASS
Appropriate
Methods
All
Procedures use EPA approved
methods in accordance with the
QAPP and/or FSP
PASS
Lab
Calibration OK
-
The laboratory followed
calibration procedures
PASS
Blanks Clean
Blanks
Laboratory blanks are below
quantitation level
PASS
Detectable concentrations were measured for gross a, but
no validation requirements exist.
For the metals analyses performed via ICP, negative results
were reported for several calibration blank and method
blanks. However, a bias was determined not to be present.
March 18, 2021
Rev. 1.2
T-22
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 5-4 Data Validation Assessment of Analytical Lab Data for Phase III Background Soil Sampling (Continued)
Data
Data Quality
Indicator
Sample or
Measurement
Validation Requirement
Validation
Result
Comments
Lab Control
Samples (LCS)
Recovery Limit
Met
LCS/QC
Standards
%D < control limit of 81%
PASS
Spikes
Recovery
Limits criteria
met
Matrix
Spikes/Matrix
Spike
Duplicates
(Metals only)
The matrix spike control limits
are 75%-125% Recovery and
RPD <20% unless otherwise
specified by the laboratory
PARTIALLY
The results for the arsenic matrix spike/matrix spike
duplicate samples 1812316-26MS and 1812316-26MSD
were below the lower control limit. EA will qualify the
arsenic results from the Project samples associated with QC
samples 1812316-26MS and 1812316-26MSD (ALS "Prep
Batch" IP190109-5) as estimated ("J" qualifier).
Duplicate RPD
/RD/AD
Laboratory
duplicates
At least one LCS is analyzed per
20 samples in a batch
PASS
Sample volumes were insufficient to allow preparation of a
duplicate. Duplicate analysis of Samples 1812316-5, -29,
and -53 performed in lieu of a prepared duplicate.
Reporting
Limits /
Quantitation
Limits Met
All
Analytical results exceed
quantitation limits
PASS
Many Minimum Detectable Concentrations (MDCs) are
above the requested MDC but meet the acceptance criteria
for uncertainty.
March 18, 2021
Rev. 1.2
T-23
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 5-4 Data Validation Assessment of Analytical Lab Data for Phase III Background Soil Sampling (Continued)
Data
Data Quality
Indicator
Sample or
Measurement
Validation Requirement
Validation
Result
Comments
Accuracy /
Bias
LCS/QC
Standards
%D < control limit of 81%
PASS
Accuracy /
Bias /
Sensitivity-
Contamination
Matrix Blanks
Analyte control limit of ±0.45
pCi/g
PASS
Sample and
Analytical
Potential
TENORM
Precision
Lab
Duplicates
RPD <113% for x > UBGR,
or AD < 2.54 pCi/g for x <
UBGR
PASS
Precision
Field
Duplicates
RPD < 113% for x > UBGR,
or AD < 2.54 pCi/g for x <
UBGR
PASS
Completeness
All Data
Usable data > 95% all data
PASS
Total
Propagated
Uncertainty
(TPU) "
--
TPU < calculated TPU limit
PASS
March 18, 2021
Rev. 1.2
T-24
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 5-4 Data Validation Assessment of Analytical Lab Data for Phase III Background Soil Sampling (Continued)
Data
Data Quality
Indicator
Sample or
Measurement
Validation Requirement
Validation
Result
Comments
Sample and
Analytical
Background
Study Areas
Accuracy/Bias
LCS/QC
Standards
%D < control limit of 81%
PASS
Accuracy /
Bias /
Sensitivity-
Contamination
Matrix Blanks
Control limit of ±0.45 pCi/g
PASS
Precision
Lab
Duplicates
RPD < 127% for x > UBGR,
or AD < 2.54 pCi/g for x <
UBGR
PASS
Precision
Field
Duplicates
RPD < 127% for x > UBGR,
or AD < 2.54 pCi/g for x <
UBGR
PASS
Completeness
All Data
Usable data >95% all data
PASS
Total
Propagated
Uncertainty
--
TPU < calculated TPU limit
PASS
March 18, 2021
Rev. 1.2
T-25
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 5-5 Description of Measurement Type and Analytic Technique/Equipment used for the Phase II Correlation Study
Measurement Type
Report Unit
Equipment Used
Exposure Rate
|jR/hr
High Pressure Ionization Chamber
Reuter-Stokes
Serial #1000992
Soil Ra-226 Concentration
pCi/g
Laboratory Analysis
EPA 901.1m
Static Gamma Count Rate
cpm
44-20 3x3" Nal(Tl) Serial #051517N
Ludlum Model 2221 Ratemeter (serial# 271435)
44-20 3x3" Nal(Tl) Serial # PR262403
Ludlum Model 2221 Ratemeter Serial # 218564
Dynamic Gamma Count Rate
cpm
44-20 3x3" Nal(Tl) Serial # 051517S
Ludlum Model 2221 Ratemeter Serial # 149940
44-20 3x3" Nal(Tl) Serial # 051517N
Ludlum Model 2221 Ratemeter Serial # 271435
March 18, 2021
Rev. 1.2
T-26
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 5-6 Gamma Count Rates and Associated Concentrations of Ra-226 in Samples of Surface Soils obtained in the Phase II Correlation Study
Location
n
(>ami
Mean
la C ount Kale
.Minimum
(cpm)
.Maximum
Standard
Deviation
Relative
Standard
Deviation (%)
Result
Ka-226 (p('i/g
Krror ±2rr
MDI.
Correlation 1
72
33,100
29,586
38,192
1,537
4.64
1.94
0.31
0.33
Correlation 2
153
37,874
35,780
40,725
893
2.36
1.41
0.24
0.33
Correlation 3
218
77,951
62,393
87,956
4,428
5.68
6.97
0.89
0.43
Correlation 4
124
49,756
45,496
53,788
1,636
3.29
2.21
0.32
0.28
Correlation 5
103
56,257
51,027
60,530
1,807
3.21
3.75
0.50
0.29
Correlation 6
131
64,745
60,283
71,365
2,092
3.23
3.55
0.48
0.35
Correlation 7
115
81,035
70,248
94,754
5,734
7.08
6.32
0.78
0.27
Correlation 8
140
103,936
83,616
113,894
5,252
5.05
11.4
1.40
0.50
Correlation 9
166
144,964
127,087
176,490
8,357
5.76
11.9
1.40
0.40
cpm = counts per minute
MDL = method detection limit
n = number of samples
pCi/g = picocuries per gram
a = standard deviation
March 18, 2021
Rev. 1.2
T-27
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 5-7 Co-Located: Soil Ra-226 Concentrations, Static Gamma Count Rate, and Exposure Rate Measurements
Location
Ra-226 Result
(pCi/g)
Ra-226 Error
±2o
(pCi/g)
Ra-226 MDL
(PCi/g)
Exposure rate
(|jR/hr)
Static gamma
count rate (cpm)
Correlation 1
1.94
0.31
0.33
12.3
29,562
Correlation 2
1.41
0.24
0.33
14.1
38,949
Correlation 3
6.97
0.89
0.43
24.1
81,318
Correlation 4
2.21
0.32
0.28
15.0
44,924
Correlation 5
3.75
0.50
0.29
17.1
51,691
Correlation 6
3.55
0.48
0.35
18.8
66,269
Correlation 7
6.32
0.78
0.27
24.0
92,741
Correlation 8
11.4
1.40
0.50
26.6
95,872
Correlation 9
11.9
1.40
0.40
38.1
136,766
cpm = counts per minute
MDL = method detection limit
pCi/g = picocuries per gram
a = standard deviation
l_iR/hr = micro-Roentgens per hour
March 18, 2021
Rev. 1.2
T-28
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 5-8 Adjusted r2 Values for Regression of Non-Radiological Constituents on Ra-226, a surrogate for Gamma Data
Pool
Constituent
Adjusted r2
BSA
Arsenic
0.11
BSA
Mercury
0.09
BSA
Molybdenum
0.19
BSA
Selenium
0.009
BSA
Uranium
0.46
BSA
Vanadium
0.37
Correlation
Arsenic
0.65
Correlation
Mercury
0.69
Correlation
Molybdenum
0.75
Correlation
Selenium
-0.14
Correlation
Uranium
0.54
Correlation
Vanadium
0.22
March 18, 2021
Rev. 1.2
T-29
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 5-9 Summary of Soil Sample Results
TEST
PIT/Sample
ID
Location
Depth
Sample
Date
Sample
Type
Constituent
Ra-226
pCi/g
Mercury
(mg/kg)
Arsenic
(mg/kg)
Uranium
(mg/kg)
Molybdenum
(mg/kg)
Selenium
(mg/kg)
Vanadium
(mg/kg)
TP14
AUM 457
o
p
L/i
12/03/18
Soil
2.94
0.00006
0.94
1.4
0.58
0.32
4
TP14-DUP
AUM 457
o
p
L/i
12/03/18
Soil
2.93
0.000057
0.97
1.4
0.55
0.051
3.6
TP15
AUM 457
0.5 - 1
12/06/18
Soil
7.54
0.026
6.6
5.7
6.7
0.055
9.2
TP15
AUM 457
o
p
L/i
12/06/18
Soil
8.2
0.02
9.9
6.7
30
0.054
15
TP3
AUM 457
o
p
L/i
12/04/18
Soil
12.1
0.015
14
8
35
0.092
27
TP3-DUP
AUM 457
o
p
12/04/18
Soil
12.5
0.018
17
19
25
0.054
24
TP4
AUM 457
2-2.5
12/04/18
Soil
5.92
0.0095
2.4
5.6
4.3
0.053
29
TP4
AUM 457
3 -3.5
12/04/18
Soil
2.46
0.00006
2
3.4
2.8
0.054
22
TP 5
AUM 457
0.5 - 1
12/04/18
Soil
1.93
0.000064
2.4
2
1.4
0.18
39
TP 5
AUM 457
o
p
L/i
12/04/18
Soil
3
0.000064
2.6
4.5
3.6
0.055
39
TP6
AUM 457
o
p
12/04/18
Soil
1.76
0.000058
2
2.7
3
0.26
27
TP6
AUM 457
1 - 1.5
12/04/18
Soil
1.61
0.000061
1.8
1.6
0.71
0.048
32
RINSE
AUM 457
N/A
12/04/18
Water
Gross Alpha 0.67 pCi/L
RINSE
AUM 457
N/A
12/04/18
Water
Gross Beta 1.2 pCi/L
TP18
AUM 458
0.5 - 1
12/05/18
Soil
14
0.071
19
15
72
0.74
12
TP18
AUM 458
2-2.5
12/05/18
Soil
4.08
0.017
5.3
6.8
12
0.052
13
TP19
AUM 458
0.5 - 1
12/05/18
Soil
126
0.54
55
140
820
0.46
13
TP19
AUM 458
o
p
L/i
12/05/18
Soil
73.9
0.21
30
110
350
0.53
17
TP20
AUM 458
0.5 - 1
12/05/18
Soil
24.1
0.16
30
44
160
0.21
8.1
TP20
AUM 458
o
p
12/05/18
Soil
6.18
0.1
18
12
22
0.14
17
TP20
AUM 458
1 - 1.5
12/05/18
Soil
19.8
0.26
39
42
130
0.7
7.9
TP21
AUM 458
0.5 - 1
12/05/18
Soil
5.64
0.074
23
8.3
23
0.3
19
TP21
AUM 458
o
p
L/i
12/05/18
Soil
6.88
0.04
8.5
9.3
14
0.049
12
RINSE
AUM 458
N/A
12/05/18
Water
Gross Alpha 0.6 pCi/L
RINSE
AUM 458
N/A
12/05/18
Water
Gross Beta -0.1 pCi/L
TP23
AUM 459
0.5 - 1
12/06/18
Soil
19.7
0.032
8.2
15
55
0.17
9.8
TP23
AUM 459
o
p
12/06/18
Soil
15.9
0.019
7.1
8.3
52
0.047
6.7
TP23-DUP
AUM 459
o
p
12/06/18
Soil
14
0.0069
7.4
9.7
38
0.053
5.5
TP23
AUM 459
2.5-3
12/06/18
Soil
10.1
0.02
8.3
8.9
28
0.056
13
207
BGS
o
p
12/05/18
Soil
1.26
0.000061
2.4
1.1
0.037
0.054
33
207-DUP
BGS
o
p
12/05/18
Soil
1.14
0.000059
2.4
1.2
0.049
0.053
29
208
BGS
o
p
12/05/18
Soil
0.94
0.000061
2.4
0.91
0.14
0.055
31
209
BGS
o
p
L/i
12/05/18
Soil
1.19
0.000061
2.2
1
0.26
0.049
31
209
BGS
o
p
12/05/18
Soil
1.22
0.000058
2.2
1.1
0.27
0.05
30
210
BGS
o
p
12/05/18
Soil
1.28
0.00017
2.3
1.2
0.079
0.052
30
March 18, 2021
Rev. 1.2
T-30
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 5-9 Summary of Soil Sample Results (Continued)
TEST
PIT/Sample
ID
Location
Depth
Sample
Date
Sample
Type
Constituent
Ra-226
pCi/g
Mercury
(mg/kg)
Arsenic
(mg/kg)
Uranium
(mg/kg)
Molybdenum
(mg/kg)
Selenium
(mg/kg)
Vanadium
(mg/kg)
210
BGS
o
p
L/i
12/05/18
Soil
1.37
0.000057
2.6
1.3
0.062
0.052
32
211
BGS
o
p
L/i
12/05/18
Soil
1.29
0.0013
2
1.4
0.19
0.051
28
D207
BGS
o
p
L/i
12/05/18
Soil
1.14
0.000061
2.4
1.1
0.077
0.053
30
D207
BGS
o
p
L/i
12/05/18
Soil
1.07
0.00006
2.2
1.2
0.18
0.05
31
D208
BGS
o
p
L/i
12/05/18
Soil
1.24
0.000061
2.3
0.97
0.062
0.053
31
D211
BGS
o
p
L/i
12/05/18
Soil
1.3
0.000061
2
1.5
0.19
0.048
28
TP16
Drain
o
p
L/i
12/03/18
Soil
1.23
0.000058
1.7
1.3
0.27
0.051
24
TP16
Drain
1 - 1.5
12/03/18
Soil
1.2
0.000062
2
1.3
0.2
0.052
29
TP16
RINSE
N/A
12/03/18
Water
Gross Alpha 13.6 pCi/L
TP16
RINSE
N/A
12/03/18
Water
Gross Beta 4.8 pCi/L
TP2
Drain
0.5 - 1
12/04/18
Soil
2.82
0.0065
3.7
3.4
3.5
0.051
41
TP2
Drain
1 - 1.5
12/04/18
Soil
2.69
0.0012
3.4
3.9
2.1
0.058
42
TP 7
Drain
o
p
L/i
12/04/18
Soil
5.71
0.000062
2.7
6
18
0.12
19
TP 7
Drain
1 - 1.5
12/04/18
Soil
1.69
0.000058
1.7
3.6
7.9
0.15
17
TP 8
Drain
0.5 - 1
12/04/18
Soil
31.3
0.028
12
21
53
0.23
23
TP 8
Drain
o
p
L/i
12/04/18
Soil
37.5
0.019
6.3
14
37
0.32
25
TP 8
Drain
2.5-3
12/04/18
Soil
1.76
0.000059
2.2
2.8
6.5
0.057
21
TP11
LCR
2-2.5
12/03/18
Soil
1.81
0.0099
2.4
1.5
0.77
0.061
23
TP12
LCR
o
p
12/03/18
Soil
1.48
0.000071
2.4
1.8
0.71
0.06
25
TP12
LCR
1 - 1.5
12/03/18
Soil
1.86
0.0089
2.6
2
0.71
0.056
26
TP9
LCR
2-2.5
12/03/18
Soil
58.2
0.17
10
28
78
0.047
16
TP9
LCR
3 -3.5
12/03/18
Soil
55.7
0.16
7.9
37
34
0.074
21
TP9
LCR
4.5 - 5
12/03/18
Soil
7.37
0.028
3.6
16
18
0.063
22
TP9
RINSE
N/A
12/03/18
Water
Gross Alpha 2.1 pCi/L
TP9
RINSE
N/A
12/03/18
Water
Gross Beta 6.9 pCi/L
TP9
RINSE
N/A
12/04/18
Water
Gross Alpha 1.5 pCi/L
TP9
RINSE
N/A
12/04/18
Water
Gross Beta -0.8 pCi/L
TP17
ROAD
o
p
L/i
12/06/18
Soil
8.7
0.0027
8.2
11
27
0.054
20
TP17
ROAD
2-2.5
12/06/18
Soil
1.64
0.000062
2
3.9
13
0.047
21
TP17
RINSE
N/A
12/06/18
Water
Gross Alpha 1.6 pCi/L
TP17
RINSE
N/A
12/06/18
Water
Gross Beta 0 pCi/L
TP22
AUM 458
o
p
12/05/18
Soil
2.69
0.065
2.1
2.7
0.2
0.054
13
TP22
AUM 458
1 - 1.5
12/05/18
Soil
4.14
0.082
2.4
3.9
0.37
0.17
8.4
TP1
MRD
0.5 - 1
12/05/18
Soil
31.6
0.081
1.3
45
8
0.054
16
TP1
MRD
1.5-2
12/05/18
Soil
71.8
0.33
1.7
180
0.84
0.35
21
March 18, 2021
Rev. 1.2
T-31
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 5-9 Summary of Soil Sample Results (Continued)
Tl ST
PIT/Sam pie
II)
Location
Dcplli
Sample
Dale
Sample
Type
Ua-226
p('i/g
Mercury
(m«/k«)
Arsenic
(m«/k«)
(onslilu
I railium
(m«/k«)
fill
Molybdenum
(m«/k«)
Selenium
(m«/k«)
Vanadium
(m«/k«)
TP1
MRD
2.5-3
12/05/18
Soil
3.94
0.002
0.92
21
1.5
0.052
49
TP1
MRD
N/A
12/05/18
Water
Gross Alpha 0.9 pCi/L
TP1
MRD
N/A
12/05/18
Water
Gross Beta 0.7 pCi/L
BLANK
NULL
N/A
12/03/18
Water
Gross Alpha 1.2 pCi/L
BLANK
NULL
N/A
12/03/18
Water
Gross Beta -0.7 pCi/L
Notes:
AUM = Abandoned Uranium Mine, Drain = EPA Defined Drainage, BGS = Background Sample, RINSE = Sample Rinsate, BLANK = Sample Blank, LCR = Little Colorado
River, MRD = Mine Related Disturbance, DUP = Sample Duplicate
March 18, 2021
Rev. 1.2
T-32
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 5-10 ANOVA Table for Ordinary Least Square (OLS) Regression of Net Shielded Gamma on Ra-226 for the
Complete Correlation Data Set (n=43)
Estimate
Std.Error
t-value
Pr (>|t|)
Intercept
-1.33
2.73
-0.49
0.628
Net Shielded
Gamma (counts
per 60 sec)
0.00359
0.000354
10.143
9.65 x 10"13
Residual standard error: 3244 on 41 degrees of freedom
Multiple r-squared: 0.715 Adjusted r-squared: 0.7081
F-statistic: 102.9 on 1 and 41 DF p-value: 9.651 x 10~13
Table 5-11 Outlying Data Points Excluded From the Second OLS Regression
Test
Pit ID
Depth
Interval
(inches)
Sample ID
Date
Collected
Time
Collected
Ra-226
Result
(pCi/g)
Net
Gamma1
(counts per
60 sec)
TP-1
18-24
MRD-TP1-1.5-
2.0-120518
12/5/2018
08:41
71.8
30360
TP-19
6-12
458-TP19-0.5-
1.0-120518
12/5/2018
15:09
126
15102
1 Shielded static 60-second count with a Ludlum 44-10/2221
Table 5-12 ANOVA Table for OLS Regression of Net Shielded Gamma on Ra-226 for the Second Correlation Data Set
(n=41)
Estimate
Std. Error
t-value
Pr (>|t|)
Intercept
-3.02
1.15
-2.62
0.0125
Net Shielded
Gamma (counts
per 60 sec)
0.00378
0.000196
19.331
< 2.2 x 10"16
Residual standard error: 1334 on 39 degrees of freedom
Multiple r-squared: 0.9055 Adjusted r-squared: 0.9031
F-statistic: 373.7 on 1 and 39 DF p-value: < 2.2 x 10~16
March 18, 2021
Rev. 1.2
T-33
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 5-13 ANOVA Table for OLS Regression of Ra-226 on Arsenic Soil Concentrations for the Second Correlation Data
Set (n=41)
Estimate
Std.Error
t-value
Pr (>|t|)
Intercept
5.26
3.09
1.70
0.0964
Arsenic
0.000905
0.000265
3.41
0.00149
Residual standard error: 15.05 on 40 degrees of freedom
Multiple r-squared: 0.226 Adjusted r-squared: 0.206
F-statistic: 11.65 on 1 and 40 DF p-value: 0.00149
Table 5-14 ANOVA Table for OLS Regression of Ra-226 on Mercury Soil Concentrations for the Second Correlation Data
Set (n=41)
Estimate
Std.Error
t-value
P.- (>|t|)
Intercept
6.17
3.60
1.72
0.0978
Mercury
176
39.8
4.42
0.000145
Residual standard error: 14.5 on 27 degrees of freedom
Multiple r-squared: 0.420 Adjusted r-squared: 0.398
F-statistic: 19.5 on 1 and 27 DF p-value: 0.000148
Table 5-15 ANOVA Table for OLS Regression of Ra-226 on Molybdenum Soil Concentrations for the Second Correlation
Data Set (n=41)
Estimate
Std.Error
t-value
Pr (>|t|)
Intercept
5.84
2.03
2.88
0.0063
Molybdenum
0.203
0.0299
6.80
3.62 x 10"8
Residual standard error: 11.65 on 40 degrees of freedom
Multiple r-squared: 0.536 Adjusted r-squared: 0.524
F-statistic: 46.2 on 1 and 40 DF p-value: 3.62 x 10~8
March 18, 2021
Rev. 1.2
T-34
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 5-16 ANOVA Table for OLS Regression of Ra-226 on Selenium Soil Concentrations for the Second Correlation Data
Set (n=41)
Estimate
Std.Error
t-value
Pr (>|t|)
Intercept
10.6
7.45
1.43
0.171
Selenium
26.5
23.3
1.14
0.271
Residual standard error: 19.8 on 17 degrees of freedom
Multiple r-squared: 0.0709 Adjusted r-squared: 0.0162
F-statistic: 1.30 on 1 and 17 DF p-value: 0.271
Table 5-17 ANOVA Table for OLS Regression of Ra-226 on Uranium Soil Concentrations for the Second Correlation Data
Set (n=41)
Estimate
Std.Error
t-value
Pr (>|t|)
Intercept
2.70
1.78
1.52
0.136
Uranium
7.23 x 10"4
7.64 x 10"5
9.46
9.41 x 10"12
Residual standard error: 9.51 on 40 degrees of freedom
Multiple r-squared: 0.691 Adjusted r-squared: 0.683
F-statistic: 89.4 on 1 and 40 DF p-value 9.41 x 10~12
Table 5-18 ANOVA Table for OLS Regression of Ra-226 on Vanadium Soil Concentrations for the Second Correlation
Data Set (n=41)
Estimate
Std.Error
t-value
Pr (>|t|)
Intercept
20.0
5.84
3.43
0.00141
Vanadium
-0.373
0.250
-1.49
0.144
Residual standard error: 16.6 on 40 degrees of freedom
Multiple r-squared: 0.0527 Adjusted r-squared: 0.0290
F-statistic: 2.23 on 1 and 40 DF p-value: 0.144
March 18, 2021
Rev. 1.2
T-35
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 5-19 Summary Statistics for Metals and Radiological Constituents in the Correlation Data Set
Constituent
Unit
n1
Minimum
Maximum
Mean
Median
Standard
Deviation
Number of
non-detects
Arsenic
mg/kg
41
0.92
55
8.62
3.5
11.27
0
Mercury
mg/kg
41
0.000058
0.54
0.06
0.018
0.11
13
Molybdenum
mg/kg
41
0.2
820
48.6
10
133.1
0
Ra-226
pCi/g
41
1.2
126
16.1
10
25.3
0
Selenium
mg/kg
41
0.047
0.74
0.16
0.059
0.17
23
Uranium
mg/kg
41
1.3
180
19.83
6.75
36.55
0
Vanadium
mg/kg
41
4
49
20.8
20.5
10.2
0
mg/kg = milligrams per kilogram
pCi/g = picocuries per gram
1 The correlation population excludes two outliers and U-flagged data, if any.
March 18, 2021
Rev. 1.2
T-36
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 5-20 Adjusted r2 Values for Regression of Ra-226 on Metals and Net Shielded Static Gamma Count Rate
Independent Variable
Dependent Variable
n
Adjusted
r2
Ra-226
Arsenic
42
0.21
Ra-226
Mercury
29
0.40
Ra-226
Molybdenum
42
0.52
Ra-226
Selenium
19
0.016
Ra-226
Uranium
43
0.68
Ra-226
Vanadium
42
0.029
Net shielded static
gamma count rate
Ra-226
43
0.71
Net shielded static
gamma count rate
Ra-226
41
0.90
Table 5-21 Result (p-value) of the DSC Test on Ra-226 Soil Concentrations within each BSA
Background Study
Area
Alluvial #1
Alluvial #2
Drainage #2
Little
Colorado
River
Qter BRA
Terrace #1
Alluvial #2
1.00
-
-
-
-
-
Drainage #2
0.065
0.011
-
-
-
-
Little Colorado River
0.0089
0.00037
0.073
-
-
-
March 18, 2021
Rev. 1.2
T-37
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 5-21 Result (p-value) of the DSC Test on Ra-226 Soil Concentrations within each BSA (Continued)
Background Study
Area
Alluvial #1
Alluvial #2
Drainage #2
Little
Colorado
River
Qter BRA
Terrace #1
Qter BRA
0.51
0.14
0.038
0.0021
-
-
Terrace #1
0.64
0.30
0.038
0.0021
1.00
-
Terrace #2
0.99
1.00
0.020
0.0021
0.13
0.49
Table 5-22 Investigation Levels for Each of the Pooled BSAs
Pooled BSA
95% Gamma UTL
(cpm)
IL (cpm)
Alluvial BSA #1 and # 2, Terrace BSA #1
and #2, EPA "Qter BRA"
48,212
51,824
Drainage BSA # 2
43,564
47,176
Little Colorado River BSA
26,053
29,665
cpm = counts per minute
IL is calculated as 3,612 cpm (equivalent to 1.24 pCi/g, as described in Section 5.4) plus the 95% gamma UTL.
March 18, 2021
Rev. 1.2
T-38
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-1 Summary of HHSRE Soil Exposure Point Concentrations by Evaluated Area
Evaluated
Area
PCOCs
Units
Freq of
Detection
Mean or
KM
Mean
Distribution Type
Recommended
UCL95 of the
Mean
Comment
APE with
AUMs
(Dry
Scenario)
Arsenic
mg/kg
62/62
4.66
No discernible
7.65
Mercury
mg/kg
56/62
0.0168
No discernible
0.0353
Molybdenum
mg/kg
45/62
11.4
No discernible
36.7
Ra-226
pCi/g
62/62
5.18
No discernible
10.9
Selenium
mg/kg
25/62
0.231
Gamma
0.316
a
Uranium
mg/kg
62/62
6.89
No discernible
15.8
Vanadium
mg/kg
62/62
42.3
No discernible
57.2
APE with
AUMs
(Wet
Scenario)
Arsenic
mg/kg
50/50
5.30
No discernible
8.91
Mercury
mg/kg
45/50
0.020
No discernible
0.0426
Molybdenum
mg/kg
43/50
14.1
No discernible
58.7
Ra-226
pCi/g
50/50
6.21
No discernible
13.2
Selenium
mg/kg
25/50
0.272
Gamma
0.373
Uranium
mg/kg
50/50
8.38
No discernible
19.3
Vanadium
mg/kg
50/50
49.0
No discernible
64.9
APE Less
AUMs
(Dry
Scenario)
Arsenic
mg/kg
45/45
3.00
No discernible
3.41
b
Mercury
mg/kg
42/45
0.00773
No discernible
0.0141
Molybdenum
mg/kg
28/45
1.58
No discernible
5.43
Ra-226
pCi/g
45/45
2.48
Gamma
2.93
Selenium
mg/kg
18/45
0.253
Approximate Gamma
0.38
a
Uranium
mg/kg
45/45
2.74
No discernible
4.33
Vanadium
mg/kg
45/45
48.23
No discernible
66.9
March 18, 2021
Rev. 1.2
T-39
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-1 Summary of HHSRE Soil Exposure Point Concentrations by Evaluated Area (Continued)
Evaluated
Area
PCOCs
Units
Freq of
Detection
Mean or
KM
Mean
Distribution Type
Recommended
UCL 95 of the
Mean
Comment
APE Less
AUMs
(Wet
Scenario)
Arsenic
mg/kg
33/33
3.37
No discernible
3.89
Mercury
mg/kg
31/33
0.00937
No discernible
0.0177
Molybdenum
mg/kg
26/33
2.066
No discernible
7.27
Ra-226
pCi/g
33/33
3.054
No discernible
3.56
Selenium
mg/kg
18/33
0.326
Approximate Gamma
0.510
Uranium
mg/kg
33/33
3.47
No discernible
4.24
Vanadium
mg/kg
33/33
60.6
No discernible
78.2
Outside of
APE
(Wet and Dry
Scenario)
Arsenic
mg/kg
41/41
2.97
Normal
3.23
Mercury
mg/kg
40/41
0.0103
Normal
0.0116
Molybdenum
mg/kg
24/41
0.254
Gamma
0.338
a
Ra-226
pCi/g
41/41
1.988
Approximate Normal
2.141
Selenium
mg/kg
11/41
0.173
Normal
0.231
Uranium
mg/kg
41/41
2.54
Lognormal
2.92
Vanadium
mg/kg
41/41
43.23
Normal
48.17
AUM 457
(Wet and Dry
Scenario)
Arsenic
mg/kg
11/11
4.45
Approximate
Lognormal
6.57
Mercury
mg/kg
8/11
0.0118
Normal
0.0171
Molybdenum
mg/kg
11/11
10.4
Gamma
24.39
Ra-226
pCi/g
11/11
7.67
Gamma
15.75
Selenium
mg/kg
4/12
0.115
Normal
0.168
Uranium
mg/kg
11/11
6.46
Gamma
9.74
Vanadium
mg/kg
11/11
33.6
Normal
38.18
March 18, 2021
Rev. 1.2
T-40
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-1 Summary of HHSRE Soil Exposure Point Concentrations by Evaluated Area (Continued)
Evaluated
Area
PCOCs
Units
Freq of
Detection
Mean or
KM
Mean
Distribution Type
Recommended
UCL 95 of the
Mean
Comment
AUM 458
(Dry Scenario
Only)
Arsenic
mg/kg
5/5
19.5
Normal
27.7
Mercury
mg/kg
5/5
0.11
Normal
0.17
Molybdenum
mg/kg
5/5
95.8
Gamma
350
c
Ra-226
pCi/g
5/5
22.05
Approximate
Lognormal
73.9
c
Selenium
mg/kg
3/5
0.267
Normal
0.518
Uranium
mg/kg
5/5
44.9
Normal
86.2
Vanadium
mg/kg
5/5
15
No discernible
17
c
AUM 459
(Dry Scenario
Only)
Arsenic
mg/kg
1/1
7.25
-
7.25
d
Mercury
mg/kg
1/1
0.01295
-
0.01295
d
Molybdenum
mg/kg
1/1
45
-
45
d
Ra-226
pCi/g
1/1
14.95
-
14.95
d
Selenium
mg/kg
0/1
ND
-
ND
Uranium
mg/kg
1/1
9.00
-
9.00
d
Vanadium
mg/kg
1/1
6.1
-
6.1
d
March 18, 2021
Rev. 1.2
T-41
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-1 Summary of HHSRE Soil Exposure Point Concentrations by Evaluated Area (Continued)
Kvaluated
Area
PCOCs
1 nils
l;re(| of
Deled ion
Mean or
KM
Mean
Distribution Type
Recommended
I CI. 95 of the
Mean
Comment
LCR Channel
Area (Dry
Scenario
Only)
Arsenic
mg/kg
12/12
1.96
Normal
2.12
Mercury
mg/kg
11/12
0.00322
Normal
0.00397
Molybdenum
mg/kg
2/12
0.23
No discernible
0.490
Ra-226
pCi/g
12/12
0.915
Normal
1.05
Selenium
mg/kg
0/12
ND
-
-
Uranium
mg/kg
12/12
0.725
No discernible
0.921
a
Vanadium
mg/kg
12/12
14.2
Approximate Gamma
16.5
Notes:
Arsenic and uranium were reported by the laboratory with unit of |ig/kg but were converted to unit of mg/kg (by dividing by 1,000) in this table
and for all risk calculations.
When detection frequency is 100% the arithmetic mean is reported, otherwise the mean calculated using the Kaplan-Meier method is reported.
All calculations performed using EPA software ProUCL (v 5.1) (EPA, 2016c). Additional summary information and the associated ProUCL output
are provided in Appendix Table F2-2 and F2-3 of the Phase III Summary Report (Appendix M).
ND = not detected
UCL = upper confidence limit
a Two UCLs were suggested by ProUCL and the larger of the two was reported here and used for risk calculations.
b Three UCLs were suggested by ProUCL and the larger of the three was reported here and used for risk calculations.
0 Recommended UCL exceeded the maximum detection. Latter was used as the UCL value.
d No output from ProUCL because single sample collected from this area. Used detected result as mean and UCL value.
March 18, 2021
Rev. 1.2
T-42
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-2 HHSRE Evaluation Areas and Assigned EPA Risk Calculator Area Correction Factors
HHSRE Evaluation
Areas
Scenario
Estimated
Area (m2)
Equivalent Area
(acres)
Assigned Areas for
EPA Risk Calculator
(acres)
APE Area with
AUMsa
Dry
2,027,027
501
250b
Wet
1,750,663
433
250b
APE Area Less
AUMs a
Dry
1,702,713
421
250b
Wet
1,426,349
352
250b
Outside of APE
Dry
1,948,320
481
250b
Wet
1,948,320
481
250b
AUM 457
Dry
102,531
25.3
25
Wet
99,570
24.6
25
AUM 458
Dry
58,269
14.4
25
AUM 459a
Dry
82,298
20.3
25
LCR Channel Area
Dry
58,869
14.5
25
Notes:
Estimated areas were calculated using ArcGIS from Figure 2-1 - Site Location and Proposed Area of Potential Effect.
The non-rad PRG uses acres in calculation of Particulate Emission Factor (Wind Driven) and similar terms such as
volatilization rates (which is relevant to the assessment of mercury). The rad PRG uses areas in both nf and also in acres,
depending on the parameter. Areas (in m2) are used for rad PRG Equations and Parameters (e.g., gamma emission
calculations) but areas (in acres) are used to calculate particulate emissions. For consistency, areas in acres were used for
all calculations.
a Only includes portion of AUM 459 that falls inside of APE (1,357 m2)
bThe maximum acreage for the non-rad and rad-PRG calculator is 250 acres (equivalent to approximately 1,000,000 m2).
March 18, 2021
Rev. 1.2
T-43
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-3 Summary of Grain Size Analyses of Soils
Sample ID and Description of Sampling Location
TP2-0.0-0.5
TP6-0.5-1.01
TP16-0.5-1.01
TP18-0.0-0.5
General
Parameter
Native
Upgrader
Typical
TENORM
Group
Alluvium
(northern
end of the
Site)
Discharge
Material
Property
Drainage
at AUM 457
% Gravel
%Coarse
Gravel
0
0
0
0
%Fine Gravel
0.1
1.1
0.4
8.6
%Sand
%Coarse Sand
0.2
0.6
1.0
2.4
%Medium
15.5
21.7
28.3
18.0
Sand
%Fine Sand
70.6
57.9
51.3
44.0
%Fines
%ClaV
1.8
0
0
1.4
%Silt
11.8
18.7
19.0
25.6
Description
Fine sand
Fine sand
Fine sand
Fine sand
March 18, 2021
Rev. 1.2
T-44
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-4a Non-cancer HQ Results and Cancer Risk Results for Individual Non-Radiological and Radiological PCOCs -
On-Site Workers
Evaluated
Area
PCOCs
Units
Soil EPC Values
Hazard Quotient
Carcinogenic
Risk
UCL
Mean
UCL
Mean
UCL
Mean
APE with
AUMs
(Dry
Scenario)
Arsenic
mg/kg
7.65E+00
4.66E+00
1E-06
8E-07
3E-10
2E-10
Mercury
mg/kg
3.53E-02
1.68E-02
3E-08
1E-08
—
—
Molybdenum
mg/kg
3.67E+01
1.14E+01
5E-07
2E-07
—
—
Ra-226
pCi/g
1.09E+01
5.18E+00
—
—
6E-08
3E-08
Selenium
mg/kg
3.16E-01
2.31E-01
5E-09
3E-09
—
—
Uranium
mg/kg
1.58E+01
6.89E+00
6E-06
2E-06
—
—
Vanadium
mg/kg
5.72E+01
4.23E+01
8E-07
6E-07
—
—
APE Area
with
AUMs
(Wet
Scenario)
Arsenic
mg/kg
8.91E+00
5.30E+00
2E-06
9E-07
3E-10
2E-10
Mercury
mg/kg
4.26E-02
2.00E-02
3E-08
2E-08
—
—
Molybdenum
mg/kg
5.87E+01
1.41E+01
8E-07
2E-07
—
—
Ra-226
pCi/g
1.32E+01
6.21E+00
—
—
8E-08
4E-08
Selenium
mg/kg
3.73E-01
2.72E-01
5E-09
4E-09
—
—
Uranium
mg/kg
1.93E+01
8.38E+00
7E-06
3E-06
—
—
Vanadium
mg/kg
6.49E+01
4.90E+01
9E-07
7E-07
—
—
APE Less
AUMs
(Dry
Scenario)
Arsenic
mg/kg
3.41E+00
3.00E+00
6E-07
5E-07
1E-10
1E-10
Mercury
mg/kg
1.41E-02
7.73E-03
1E-08
6E-09
—
—
Molybdenum
mg/kg
5.43E+00
1.58E+00
8E-08
2E-08
—
—
Ra-226
pCi/g
2.93E+00
2.48E+00
—
—
2E-08
1E-08
Selenium
mg/kg
3.77E-01
2.53E-01
5E-09
4E-09
—
—
Uranium
mg/kg
4.33E+00
2.74E+00
2E-06
1E-06
—
—
Vanadium
mg/kg
6.69E+01
4.82E+01
1E-06
7E-07
—
—
March 18, 2021
Rev. 1.2
T-45
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-4a Non-cancer HQ Results and Cancer Risk Results for Individual Non-Radiological and Radiological PCOCs -
On-Site Workers (Continued)
Evaluated
Area
PCOCs
Units
Soil EPC Values
Hazard Quotient
Carcinogenic
Risk
UCL
Mean
UCL
Mean
UCL
Mean
APE Less
AUMs
(Wet
Scenario)
Arsenic
mg/kg
3.89E+00
3.37E+00
7E-07
6E-07
2E-10
IE-10
Mercury
mg/kg
1.77E-02
9.37E-03
1E-08
7E-09
—
—
Molybdenum
mg/kg
7.27E+00
2.07E+00
1E-07
3E-08
—
—
Ra-226
pCi/g
3.56E+00
3.05E+00
—
—
2E-08
2E-08
Selenium
mg/kg
5.10E-01
3.26E-01
7E-09
5E-09
—
—
Uranium
mg/kg
4.24E+00
3.47E+00
2E-06
1E-06
—
—
Vanadium
mg/kg
7.82E+01
6.06E+01
1E-06
9E-07
—
—
Outside of
APE (Wet
and Dry
Scenario)
Arsenic
mg/kg
3.23E+00
2.97E+00
6E-07
5E-07
IE-10
IE-10
Mercury
mg/kg
1.16E-02
1.03E-02
9E-09
8E-09
—
—
Molybdenum
mg/kg
3.38E-01
2.54E-01
5E-09
4E-09
—
—
Ra-226
pCi/g
2.14E+00
1.99E+00
—
—
1E-08
1E-08
Selenium
mg/kg
2.31E-01
1.73E-01
3E-09
2E-09
—
—
Uranium
mg/kg
2.92E+00
2.54E+00
1E-06
9E-07
—
—
Vanadium
mg/kg
4.82E+01
4.32E+01
7E-07
6E-07
—
—
AUM 457
(Wet and
Dry
Scenario)
Arsenic
mg/kg
6.57E+00
4.45E+00
1E-06
8E-07
3E-10
2E-10
Mercury
mg/kg
1.71E-02
1.18E-02
9E-09
6E-09
—
—
Molybdenum
mg/kg
2.44E+01
1.04E+01
4E-07
1E-07
—
—
Ra-226
pCi/g
1.58E+01
7.67E+00
—
—
9E-08
4E-08
Selenium
mg/kg
1.68E-01
1.15E-01
2E-09
2E-09
—
—
Uranium
mg/kg
9.74E+00
6.46E+00
4E-06
2E-06
—
—
Vanadium
mg/kg
3.82E+01
3.36E+01
5E-07
5E-07
—
~
March 18, 2021
Rev. 1.2
T-46
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-4a Non-cancer HQ Results and Cancer Risk Results for Individual Non-Radiological and Radiological PCOCs -
Evaluated
Area
PCOCs
Units
Soil EPC Values
Hazard Quotient
Carcinogenic
Risk
UCL
Mean
UCL
Mean
UCL
Mean
Arsenic
mg/kg
2.77E+01
1.95E+01
5E-06
3E-06
1E-09
8E-10
AUM 458
(Dry
Scenario
Only)
Mercury
mg/kg
1.70E-01
1.10E-01
9E-08
6E-08
-
-
Molybdenum
mg/kg
3.50E+02
9.58E+01
5E-06
1E-06
-
-
Ra-226
pCi/g
7.39E+01
2.21E+01
-
—
4E-07
1E-07
Selenium
mg/kg
5.18E-01
2.67E-01
7E-09
4E-09
-
-
Uranium
mg/kg
8.62E+01
4.49E+01
3E-05
2E-05
-
-
Vanadium
mg/kg
1.76E+01
1.50E+01
3E-07
2E-07
-
-
Arsenic
mg/kg
7.25E+00
7.25E+00
1E-06
1E-06
3E-10
3E-10
AUM 459
Mercury
mg/kg
1.30E-02
1.30E-02
7E-09
7E-09
-
-
(Dry
Molybdenum
mg/kg
4.50E+01
4.50E+01
6E-07
6E-07
-
-
Scenario
Ra-226
pCi/g
1.50E+01
1.50E+01
-
-
9E-08
9E-08
Only)
Selenium
mg/kg
ND
ND
-
-
-
-
Uranium
mg/kg
9.00E+00
9.00E+00
3E-06
3E-06
-
-
Vanadium
mg/kg
6.10E+00
6.10E+00
9E-08
9E-08
-
-
LCR
Arsenic
mg/kg
2.12E+00
1.96E+00
4E-07
3E-07
8E-11
8E-11
Channel
Mercury
mg/kg
3.97E-03
3.22E-03
2E-09
2E-09
-
-
Area
Molybdenum
mg/kg
4.90E-01
2.30E-01
7E-09
3E-09
-
-
(Dry
Ra-226
pCi/g
1.05E+00
9.15E-01
-
-
6E-09
5E-09
Scenario
Selenium
mg/kg
ND
ND
-
-
-
-
Only)
Uranium
mg/kg
9.21E-01
7.25E-01
3E-07
3E-07
-
-
Vanadium
mg/kg
1.65E+01
1.42E+01
2E-07
2E-07
-
-
Notes: Arsenic and uranium were reported by the laboratory with unit of |ig/kg but were converted to unit of mg/kg (by dividing by 1,000) in this
table and for all risk calculations Supporting calculations provided in Appendix F of the Phase III Summary Report (Appendix M).
A dash indicates calculation was not required.
Hazard Quotient (HQ) values less than one are below levels of regulatory concern.
Cancer risk values below or within EPA acceptable range of 1E-6 and 1E-4 are not of regulatory concern.
March 18, 2021
Rev. 1.2
T-47
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-4b Non-cancer HI Results and Sum Cancer Risk Results for Non-Radiological
and Radiological PCOCs - On-Site Workers
Evaluated Area
Hazart
Index
Sum Cancer Risk
UCL
Mean
UCL
Mean
APE with AUMs
(Dry Scenario)
8E-06
4E-06
6E-08
3E-08
APE with AUMs
(Wet Scenario)
1E-05
5E-06
8E-08
4E-08
APE Less AUMs
(Dry Scenario)
3E-06
2E-06
2E-08
1E-08
APE Less AUMs
(Wet Scenario)
3E-06
3E-06
2E-08
2E-08
Outside of APE
(Wet and Dry
Scenario)
2E-06
2E-06
1E-08
1E-08
AUM 457
(Wet and Dry
Scenario)
6E-06
4E-06
9E-08
4E-08
AUM 458
(Wet and Dry
Scenario)
4E-05
2E-05
4E-08
1E-07
AUM 459
(Wet and Dry
Scenario)
5E-06
5E-06
9E-08
9E-08
LCR Channel
Area
(Dry Scenario
Only)
9E-07
8E-07
6E-09
5E-09
Notes:
Hazard Index (HI) is sum of individual PCOC HQ values.
HI values less than one indicate are below regulatory concern.
Sum of cancer risk values below or within EPA acceptable range of 1E-6 and 1E-4 are
not of regulatory concern.
March 18, 2021
Rev. 1.2
T-48
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-5a Non-cancer HQ Results and Cancer Risk Results for Individual Non-Radiological and Radiological PCOCs -
Adult Recreator Based on 24 Years of Exposure
Evaluated
Area
PCOCs
Units
Soil EPC Values
Hazard
Quotient
Carcinogenic
Risk
UCL
Mean
UCL
Mean
UCL
Mean
APE with
AUMs
(Dry
Scenario)
Arsenic
mg/kg
7.65E+00
4.66E+00
9.E-04
5.E-04
l.E-07
8.E-08
Mercury
mg/kg
3.53E-02
1.68E-02
5.E-05
3.E-05
—
—
Molybdenum
mg/kg
3.67E+01
1.14E+01
4.E-04
l.E-04
—
—
Ra-226
pCi/g
1.09E+01
5.18E+00
—
—
9E-05
4E-05
Selenium
mg/kg
3.16E-01
2.31E-01
3.E-06
2.E-06
—
—
Uranium
mg/kg
1.58E+01
6.89E+00
4.E-03
2.E-03
—
—
Vanadium
mg/kg
5.72E+01
4.23E+01
5.E-04
4.E-04
—
—
APE with
AUMs
(Wet
Scenario)
Arsenic
mg/kg
8.91E+00
5.30E+00
l.E-03
6.E-04
2.E-07
9.E-08
Mercury
mg/kg
4.26E-02
2.00E-02
6.E-05
3.E-05
—
—
Molybdenum
mg/kg
5.87E+01
1.41E+01
6.E-04
l.E-04
—
—
Ra-226
pCi/g
1.32E+01
6.21E+00
—
—
1E-04
5E-05
Selenium
mg/kg
3.73E-01
2.72E-01
4.E-06
3.E-06
—
—
Uranium
mg/kg
1.93E+01
8.38E+00
5.E-03
2.E-03
—
—
Vanadium
mg/kg
6.49E+01
4.90E+01
6.E-04
5.E-04
—
—
APE Less
AUMs
(Dry
Scenario)
Arsenic
mg/kg
3.41E+00
3.00E+00
4.E-04
3.E-04
6.E-08
5.E-08
Mercury
mg/kg
1.41E-02
7.73E-03
2.E-05
l.E-05
—
—
Molybdenum
mg/kg
5.43E+00
1.58E+00
5.E-05
2.E-05
—
—
Ra-226
pCi/g
2.93E+00
2.48E+00
—
—
2E-05
2E-05
Selenium
mg/kg
3.77E-01
2.53E-01
4.E-06
2.E-06
—
—
Uranium
mg/kg
4.33E+00
2.74E+00
l.E-03
7.E-04
—
—
Vanadium
mg/kg
6.69E+01
4.82E+01
6.E-04
5.E-04
—
—
March 18, 2021
Rev. 1.2
T-49
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-5a Non-cancer HQ Results and Cancer Risk Results for Individual Non-Radiological and Radiological PCOCs -
Adult Recreator Based on 24 Years of Exposure (Continued)
Evaluated
Area
PCOCs
Units
Soil EPC Values
Haz
Quot
ard
ient
Carcino
Ris
genie
UCL
Mean
UCL
Mean
UCL
Mean
APE Less
AUMs
(Wet
Scenario)
Arsenic
mg/kg
3.89E+00
3.37E+00
5.E-04
4.E-04
7.E-08
6.E-08
Mercury
mg/kg
1.77E-02
9.37E-03
3.E-05
l.E-05
—
—
Molybdenum
mg/kg
7.27E+00
2.07E+00
7.E-05
2.E-05
—
—
Ra-226
pCi/g
3.56E+00
3.05E+00
—
—
3E-05
2E-05
Selenium
mg/kg
5.10E-01
3.26E-01
5.E-06
3.E-06
—
—
Uranium
mg/kg
4.24E+00
3.47E+00
l.E-03
8.E-04
—
—
Vanadium
mg/kg
7.82E+01
6.06E+01
7.E-04
6.E-04
—
—
Outside
of APE
(Wet and
Dry
Scenario)
Arsenic
mg/kg
3.23E+00
2.97E+00
4.E-04
3.E-04
6.E-08
5.E-08
Mercury
mg/kg
1.16E-02
1.03E-02
2.E-05
2.E-05
—
—
Molybdenum
mg/kg
3.38E-01
2.54E-01
3.E-06
2.E-06
—
—
Ra-226
pCi/g
2.14E+00
1.99E+00
—
—
2E-05
2E-05
Selenium
mg/kg
2.31E-01
1.73E-01
2.E-06
2.E-06
—
—
Uranium
mg/kg
9.74E+00
6.46E+00
7.E-04
6.E-04
—
—
Vanadium
mg/kg
4.82E+01
4.32E+01
5.E-04
4.E-04
—
—
AUM 457
(Wet and
Dry
Scenario)
Arsenic
ug/kg
6.57E+03
4.45E+03
8.E-04
5.E-04
l.E-07
8.E-08
Mercury
mg/kg
1.71E-02
1.18E-02
2.E-05
l.E-05
—
—
Molybdenum
mg/kg
2.44E+01
1.04E+01
8.E-05
3.E-05
—
—
Ra-226
pCi/g
1.58E+01
7.67E+00
—
—
1E-04
6E-05
Selenium
mg/kg
1.68E-01
1.15E-01
2.E-06
l.E-06
—
—
Uranium
ug/kg
9.74E+03
6.46E+03
2.E-03
2.E-03
—
—
Vanadium
mg/kg
3.82E+01
3.36E+01
4.E-04
3.E-04
—
—
March 18, 2021
Rev. 1.2
T-50
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-5a Non-cancer HQ Results and Cancer Risk Results for Individual Non-Radiological and Radiological PCOCs -
Adult Recreator Based on 24 Years of Exposure (Continued)
Evaluated
PCOCs
Units
Soil EPC Values
Hazard
Carcinogenic
Area
Quol
ient
Risk
UCL
Mean
UCL
Mean
UCL
Mean
Arsenic
mg/kg
2.77E+01
1.95E+01
3.E-03
2.E-03
5.E-07
3.E-07
AUM 458
(Dry
Scenario
Only)
Mercury
mg/kg
1.70E-01
1.10E-01
2.E-04
l.E-04
-
-
Molybdenum
mg/kg
1.03E+03
9.58E+01
3.E-03
3.E-04
-
-
Ra-226
pCi/g
7.39E+01
2.21E+01
-
-
6E-04
2E-04
Selenium
mg/kg
5.18E-01
2.67E-01
5.E-06
3.E-06
-
-
Uranium
mg/kg
8.62E+01
4.49E+01
2.E-02
l.E-02
-
-
Vanadium
mg/kg
1.76E+01
1.50E+01
2.E-04
l.E-04
-
-
Arsenic
mg/kg
7.25E+00
7.25E+00
8.E-04
8.E-04
l.E-07
l.E-07
AUM 459
(Dry
Scenario
Only)
Mercury
mg/kg
1.30E-02
1.30E-02
l.E-05
l.E-05
-
-
Molybdenum
mg/kg
4.50E+01
4.50E+01
l.E-04
l.E-04
-
-
Ra-226
pCi/g
1.50E+01
1.50E+01
-
-
1E-04
1E-04
Selenium
mg/kg
ND
ND
-
-
-
-
Uranium
mg/kg
9.00E+00
9.00E+00
2.E-03
2.E-03
-
-
Vanadium
mg/kg
6.10E+00
6.10E+00
6.E-05
6.E-05
-
-
LCR
Channel
Area
(Dry
Scenario
Only)
Arsenic
mg/kg
2.12E+00
1.96E+00
2.E-04
2.E-04
4.E-08
4.E-08
Mercury
mg/kg
3.97E-03
3.22E-03
4.E-06
4.E-06
-
-
Molybdenum
mg/kg
4.90E-01
2.30E-01
2.E-06
8.E-07
-
-
Ra-226
pCi/g
1.05E+00
9.15E-01
-
-
8E-06
7E-06
Selenium
mg/kg
—
ND
-
-
-
-
Uranium
mg/kg
9.21E-01
7.25E-01
2.E-04
2.E-04
-
-
Vanadium
mg/kg
1.65E+01
1.42E+01
2.E-04
l.E-04
-
-
Notes: Arsenic and uranium were reported by the laboratory with unit of |ig/kg but were converted to unit of mg/kg (by dividing by 1,000) in this
table and for all risk calculations. Supporting calculations provided in Appendix F of the Phase III Summary Report (Appendix M).
A dash indicates calculation was not required.
Hazard Quotient (HQ) values less than one are below regulatory concern.
Cancer risk values below or within EPA acceptable range of 1E-6 and 1E-4 are not of regulatory concern.
March 18, 2021
Rev. 1.2
T-51
Engineering Analytics, Inc.
-------
Phase III Summary Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-5b Non-cancer HI Results and Sum Cancer Risk Results for Non-Radiological
and Radiological PCOCs - Adult Recreator Based on 24 Years of Exposure
Evaluated Area
Hazard Index
Sum Cancer
Risk
UCL
Mean
UCL
Mean
APE with AUMs
(Dry Scenario)
6E-03
3E-03
9E-05
4E-05
APE with AUMs
(Wet Scenario)
7E-03
3E-03
1E-04
5E-05
APE Less AUMs
(Dry Scenario Only)
2E-03
1E-03
2E-05
2E-05
APE Less AUMs
(Wet Scenario)
2E-03
2E-03
3E-05
2E-05
Outside of APE
(Wet and Dry
Scenario)
2E-03
1E-03
2E-05
2E-05
AUM 457
(Wet and Dry
Scenario)
4E-03
2E-03
1E-04
6E-05
AUM 458
(Wet and Dry
Scenario)
3E-02
1E-02
6E-04
2E-04
AUM 459
(Wet and Dry
Scenario)
3E-03
3E-03
1E-04
1E-04
LCR Channel Area
(Dry Scenario Only)
6E-04
5E-04
8E-06
7E-06
Notes:
Hazard Index (HI) is sum of individual PCOC HQ values.
HI values less than one are below regulatory concern.
Sum of cancer risk values below or within EPA acceptable range of 1E-6
and 1E-4 are not of regulatory concern.
March 18, 2021
Rev. 1.2
T-52
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-6a Non-cancer HQ Results and Cancer Risk Results for Individual Non-Radiological and Radiological PCOCs -
Child Recreator
Evaluated
Area
PCOCs
Units
Soil EPC Values
Haz
Quoi
ard
tient
Carcinogenic
Risk
UCL
Mean
UCL
Mean
UCL
Mean
APE with
AUMs
(Dry
Scenario)
Arsenic
mg/kg
7.65E+00
4.66E+00
9E-03
5E-03
1E-07
7E-08
Mercury
mg/kg
3.53E-02
1.68E-02
5E-05
3E-05
-
-
Molybdenum
mg/kg
3.67E+01
1.14E+01
4E-03
1E-03
-
-
Ra-226
pCi/g
1.09E+01
5.18E+00
-
-
7E-06
4E-06
Selenium
mg/kg
3.16E-01
2.31E-01
3E-05
2E-05
-
-
Uranium
mg/kg
1.58E+01
6.89E+00
4E-02
2E-02
-
-
Vanadium
mg/kg
5.72E+01
4.23E+01
6E-03
4E-03
-
-
APE with
AUMs
(Wet
Scenario)
Arsenic
mg/kg
8.91E+00
5.30E+00
1E-02
6E-03
1E-07
8E-08
Mercury
mg/kg
4.26E-02
2.00E-02
6E-05
3E-05
-
-
Molybdenum
mg/kg
5.87E+01
1.41E+01
6E-03
1E-03
-
-
Ra-226
pCi/g
1.32E+01
6.21E+00
-
-
9E-06
4E-06
Selenium
mg/kg
3.73E-01
2.72E-01
4E-05
3E-05
-
-
Uranium
mg/kg
1.93E+01
8.38E+00
5E-02
2E-02
-
-
Vanadium
mg/kg
6.49E+01
4.90E+01
7E-03
5E-03
-
-
APE Less
AUMs
(Dry
Scenario)
Arsenic
mg/kg
3.41E+00
3.00E+00
4E-03
3E-03
5E-08
4E-08
Mercury
mg/kg
1.41E-02
7.73E-03
2E-05
1E-05
-
-
Molybdenum
mg/kg
5.43E+00
1.58E+00
6E-04
2E-04
-
-
Ra-226
pCi/g
2.93E+00
2.48E+00
-
-
2E-06
2E-06
Selenium
mg/kg
3.77E-01
2.53E-01
4E-05
3E-05
-
-
Uranium
mg/kg
4.33E+00
2.74E+00
1E-02
7E-03
-
-
Vanadium
mg/kg
6.69E+01
4.82E+01
7E-03
5E-03
-
-
March 18, 2021
Rev. 1.2
T-53
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-6a Non-cancer HQ Results and Cancer Risk Results for Individual Non-Radiological and Radiological PCOCs -
Child Recreator (Continued)
Evaluated
Area
PCOCs
Units
Soil EPC Values
Hazard
Quotient
Carcinogenic
Risk
UCL
Mean
UCL
Mean
UCL
Mean
Arsenic
mg/kg
3.89E+00
3.37E+00
4E-03
4E-03
6E-08
5E-08
APE Less
AUMs
(Wet
Scenario)
Mercury
mg/kg
1.77E-02
9.37E-03
3E-05
1E-05
-
-
Molybdenum
mg/kg
7.27E+00
2.07E+00
7E-04
2E-04
-
-
Ra-226
pCi/g
3.56E+00
3.05E+00
-
-
2E-06
2E-06
Selenium
mg/kg
5.10E-01
3.26E-01
5E-05
3E-05
-
-
Uranium
mg/kg
4.24E+00
3.47E+00
1E-02
9E-03
-
-
Vanadium
mg/kg
7.82E+01
6.06E+01
8E-03
6E-03
-
-
Arsenic
mg/kg
3.23E+00
2.97E+00
4E-03
3E-03
5E-08
4E-08
Outside
Mercury
mg/kg
1.16E-02
1.03E-02
2E-05
2E-05
-
-
of APE
Molybdenum
mg/kg
3.38E-01
2.54E-01
3E-05
3E-05
-
-
(Wet and
Ra-226
pCi/g
2.14E+00
1.99E+00
-
-
1E-06
1E-06
Dry
Selenium
mg/kg
2.31E-01
1.73E-01
2E-05
2E-05
-
-
Scenario)
Uranium
mg/kg
2.92E+00
2.54E+00
7E-03
6E-03
-
-
Vanadium
mg/kg
4.82E+01
4.32E+01
5E-03
4E-03
-
-
March 18, 2021
Rev. 1.2
T-54
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-6a Non-cancer HQ Results and Cancer Risk Results for Individual Non-Radiological and Radiological PCOCs -
Child Recreator (Continued)
Hazard
Carcinogenic
Evaluated
PCOCs
Units
Soil EPC Values
Quotient
Risk
Area
Evaluated Area
Units
UCL
Mean
UCL
Mean
UCL
Mean
Arsenic
mg/kg
6.57E+00
4.45E+00
8E-03
5E-03
1E-07
7E-08
AUM 457
(Wet and
Dry
Scenario)
Mercury
mg/kg
1.71E-02
1.18E-02
2E-05
1E-05
-
-
Molybdenum
mg/kg
2.44E+01
1.04E+01
2E-03
1E-03
-
-
Ra-226
pCi/g
1.58E+01
7.67E+00
-
-
1E-05
5E-06
Selenium
mg/kg
1.68E-01
1.15E-01
2E-05
1E-05
-
-
Uranium
mg/kg
9.74E+00
6.46E+00
2E-02
2E-02
-
-
Vanadium
mg/kg
3.82E+01
3.36E+01
4E-03
3E-03
-
-
Arsenic
mg/kg
2.77E+01
1.95E+01
3E-02
2E-02
4E-07
3E-07
AUM 458
(Dry
Scenario
Only)
Mercury
mg/kg
1.70E-01
1.10E-01
2E-04
1E-04
-
-
Molybdenum
mg/kg
3.50E+02
9.58E+01
4E-02
1E-02
-
-
Ra-226
pCi/g
7.39E+01
2.21E+01
-
-
5E-05
2E-05
Selenium
mg/kg
5.18E-01
2.67E-01
5E-05
3E-05
-
-
Uranium
mg/kg
8.62E+01
4.49E+01
2E-01
1E-01
-
-
Vanadium
mg/kg
1.76E+01
1.50E+01
2E-03
2E-03
-
-
Arsenic
mg/kg
7.25E+00
7.25E+00
8E-03
8E-03
1E-07
1E-07
AUM 459
(Dry
Scenario
Only)
Mercury
mg/kg
1.30E-02
1.30E-02
1E-05
1E-05
-
-
Molybdenum
mg/kg
4.50E+01
4.50E+01
5E-03
5E-03
-
-
Ra-226
pCi/g
1.50E+01
1.50E+01
-
-
1E-06
1E-06
Selenium
mg/kg
ND
ND
-
-
-
-
Uranium
mg/kg
9.00E+00
9.00E+00
2E-02
2E-02
-
-
Vanadium
mg/kg
6.10E+00
6.10E+00
6E-04
6E-04
-
-
March 18, 2021
Rev. 1.2
T-55
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-6a Non-cancer HQ Results and Cancer Risk Results for Individual Non-Radiological and Radiological PCOCs -
Child Recreator (Continued)
Evaluated
Area
PCOCs
Units
Soil EPC Values
Hazard
Quotient
Carcinogenic
Risk
Evaluated Area
Units
LCR
Channel
Area
(Dry
Scenario
Only)
Arsenic
mg/kg
2.12E+00
1.96E+00
2E-03
2E-03
3E-08
3E-08
Mercury
mg/kg
3.97E-03
3.22E-03
4E-06
4E-06
-
-
Molybdenum
mg/kg
4.90E-01
2.30E-01
5E-05
2E-05
-
-
Ra-226
pCi/g
1.05E+00
9.15E-01
-
-
7E-07
6E-07
Selenium
mg/kg
ND
ND
-
-
-
-
Uranium
mg/kg
9.21E-01
7.25E-01
2E-03
2E-03
-
-
Vanadium
mg/kg
1.65E+01
1.42E+01
2E-03
1E-03
-
-
Notes:
Arsenic and uranium were reported by the laboratory with unit of |ig/kg but were converted to unit of mg/kg (by dividing by 1,000) in this table and
for all risk calculations.
Supporting calculations provided in Appendix F of the Phase III Summary Report (provided as Appendix M to this report).
A dash indicates calculation was not required.
Hazard Quotient (HQ) values less than are below levels of regulatory concern.
Cancer risk values below or within EPA acceptable range of 1E-6 and 1E-4 are not of regulatory concern.
ND = Not detected
March 18, 2021
Rev. 1.2
T-56
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-6b Non-cancer HI Results and Sum Cancer Risk Results for Non-Radiological
and Radiological PCOCs - Child Recreator
Evaluated Area
Hazard Index
Sum Cancer
Risk
UCL
Mean
UCL
Mean
APE with AUMs
(Dry Scenario)
6E-02
3E-02
7E-06
4E-06
APE with AUMs
(Wet Scenario)
7E-02
3E-02
9E-06
4E-06
APE Less AUMs
(Dry Scenario)
2E-02
2E-02
2E-06
2E-06
APE Less AUMs
(Wet Scenario)
2E-02
2E-02
2E-06
2E-06
Outside of APE
(Wet and Dry
Scenario)
2E-02
1E-02
1E-06
1E-06
AUM 457
(Wet and Dry
Scenario)
4E-02
3E-02
1E-05
5E-06
AUM 458
(Wet and Dry
Scenario)
3E-01
1E-01
5E-05
1E-05
AUM 459
(Wet and Dry
Scenario)
4E-02
4E-02
1E-05
1E-05
LCR Channel Area
(Dry Scenario Only)
7E-03
6E-03
7E-07
6E-07
Notes:
Hazard Index (HI) is sum of individual PCOC HQ values.
HI values less than one are below levels of regulatory concern.
Sum of cancer risk values below or within EPA acceptable risk range of
1E-6 and 1E-4 are not of regulatory concern.
March 18, 2021
Rev. 1.2
T-57
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-7a Non-cancer HQ Results and Cancer Risk Results for Non-Radiological and Radiological PCOCs - Combined
Adult and Child Recreator
Evaluated
Area
PCOCs
Units
Soil EPC Values
Hazard Quotient
Carcinogenic
Risk
UCL
Mean
UCL
Mean
UCL
Mean
Arsenic
mg/kg
7.65E+00
4.66E+00
1E-02
6E-03
3E-07
2E-07
APE
Mercury
mg/kg
3.53E-02
1.68E-02
1E-04
5E-05
-
-
with
Molybdenum
mg/kg
3.67E+01
1.14E+01
4E-03
1E-03
-
-
AUMs
Ra-226
pCi/g
1.09E+01
5.18E+00
-
-
9E-05
4E-05
(Dry
Selenium
mg/kg
3.16E-01
2.31E-01
4E-05
3E-05
-
-
Scenario)
Uranium
mg/kg
1.58E+01
6.89E+00
4E-02
2E-02
-
-
Vanadium
mg/kg
5.72E+01
4.23E+01
6E-03
5E-03
-
-
Arsenic
mg/kg
8.91E+00
5.30E+00
1E-02
7E-03
3E-07
2E-07
APE
Mercury
mg/kg
4.26E-02
2.00E-02
1E-04
6E-05
-
-
with
Molybdenum
mg/kg
5.87E+01
1.41E+01
7E-03
2E-03
-
-
AUMs
Ra-226
pCi/g
1.32E+01
6.21E+00
-
-
1E-04
5E-05
(Wet
Selenium
mg/kg
3.73E-01
2.72E-01
4E-05
3E-05
-
-
Scenario)
Uranium
mg/kg
1.93E+01
8.38E+00
5E-02
2E-02
-
-
Vanadium
mg/kg
6.49E+01
4.90E+01
7E-03
5E-03
-
-
Arsenic
mg/kg
3.41E+00
3.00E+00
4E-03
4E-03
1E-07
1E-07
APE
Mercury
mg/kg
1.41E-02
7.73E-03
4E-05
2E-05
-
-
Less
Molybdenum
mg/kg
5.43E+00
1.58E+00
6E-04
2E-04
-
-
AUMs
Ra-226
pCi/g
2.93E+00
2.48E+00
-
-
3E-05
2E-05
(Dry
Selenium
mg/kg
3.77E-01
2.53E-01
4E-05
3E-05
-
-
Scenario)
Uranium
mg/kg
4.33E+00
2.74E+00
1E-02
8E-03
-
-
Vanadium
mg/kg
6.69E+01
4.82E+01
7E-03
5E-03
-
-
March 18, 2021
Rev. 1.2
T-58
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-7a Non-cancer HQ Results and Cancer Risk Results for Non-Radiological and Radiological PCOCs - Combined
Adult and Child Recreator (Continued)
Evaluated
Area
PCOCs
Units
Soil EPC Values
Hazard Quotient
Carcinogenic
Risk
UCL
Mean
UCL
Mean
UCL
Mean
APE Less
AUMs
(Wet
Scenario)
Arsenic
mg/kg
3.89E+00
3.37E+00
5E-03
4E-03
1E-07
1E-07
Mercury
mg/kg
1.77E-02
9.37E-03
5E-05
3E-05
-
-
Molybdenum
mg/kg
7.27E+00
2.07E+00
8E-04
2E-04
-
-
Ra-226
pCi/g
3.56E+00
3.05E+00
-
-
3E-05
3E-05
Selenium
mg/kg
5.10E-01
3.26E-01
6E-05
4E-05
-
-
Uranium
mg/kg
4.24E+00
3.47E+00
1E-02
1E-02
-
-
Vanadium
mg/kg
7.82E+01
6.06E+01
9E-03
7E-03
-
-
Outside
of APE
(Wet and
Dry
Scenario)
Arsenic
mg/kg
3.23E+00
2.97E+00
4E-03
4E-03
1E-07
1E-07
Mercury
mg/kg
1.16E-02
1.03E-02
3E-05
3E-05
-
-
Molybdenum
mg/kg
3.38E-01
2.54E-01
4E-05
3E-05
-
-
Ra-226
pCi/g
2.14E+00
1.99E+00
-
-
2E-05
2E-05
Selenium
mg/kg
2.31E-01
1.73E-01
3E-05
2E-05
-
-
Uranium
mg/kg
2.92E+00
2.54E+00
8E-03
7E-03
-
-
Vanadium
mg/kg
4.82E+01
4.32E+01
5E-03
5E-03
-
-
AUM 457
(Wet and
Dry
Scenario)
Arsenic
mg/kg
6.57E+00
4.45E+00
8E-03
6E-03
2E-07
1E-07
Mercury
mg/kg
1.71E-02
1.18E-02
4E-05
3E-05
-
-
Molybdenum
mg/kg
2.44E+01
1.04E+01
3E-03
1E-03
-
-
Ra-226
pCi/g
1.58E+01
7.67E+00
-
-
1E-04
6E-05
Selenium
mg/kg
1.68E-01
1.15E-01
2E-05
1E-05
-
-
Uranium
mg/kg
9.74E+00
6.46E+00
3E-02
2E-02
-
-
Vanadium
mg/kg
3.82E+01
3.36E+01
4E-03
4E-03
-
-
March 18, 2021
Rev. 1.2
T-59
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-7a Non-cancer HQ Results and Cancer Risk Results for Non-Radiological and Radiological PCOCs - Combined
Adult and Child Recreator (Continued)
Evaluated
Area
PCOCs
Units
Soil EPC Values
Hazard Quotient
Carcinogenic
Risk
UCL
Mean
UCL
Mean
UCL
Mean
AUM 458
(Dry
Scenario
Only)
Arsenic
mg/kg
2.77E+01
1.95E+01
3E-02
2E-02
9E-07
6E-07
Mercury
mg/kg
1.70E-01
1.10E-01
4E-04
2E-04
-
-
Molybdenum
mg/kg
3.50E+02
9.58E+01
1E-01
1E-02
-
-
Ra-226
pCi/g
7.39E+01
2.21E+01
-
-
6E-04
2E-04
Selenium
mg/kg
5.18E-01
2.67E-01
6E-05
3E-05
-
-
Uranium
mg/kg
8.62E+01
4.49E+01
2E-01
1E-01
-
-
Vanadium
mg/kg
1.76E+01
1.50E+01
2E-03
2E-03
-
-
AUM 459
(Dry
Scenario
Only)
Arsenic
mg/kg
7.25E+00
7.25E+00
9E-03
9E-03
2E-07
2E-07
Mercury
mg/kg
1.30E-02
1.30E-02
3E-05
3E-05
-
-
Molybdenum
mg/kg
4.50E+01
4.50E+01
5E-03
5E-03
-
-
Ra-226
pCi/g
1.50E+01
1.50E+01
-
-
1E-04
1E-04
Selenium
mg/kg
ND
ND
-
-
-
-
Uranium
mg/kg
9.00E+00
9.00E+03
3E-02
3E-02
-
-
Vanadium
mg/kg
6.10E+00
6.10E+00
7E-04
7E-04
-
-
LCR
Channel
Area
(Dry
Scenario
Only)
Arsenic
mg/kg
2.12E+00
1.96E+00
3E-03
2E-03
7E-08
6E-08
Mercury
mg/kg
3.97E-03
3.22E-03
9E-06
7E-06
-
-
Molybdenum
mg/kg
4.90E-01
2.30E-01
5E-05
2E-05
-
-
Ra-226
pCi/g
1.05E+00
9.15E-01
-
-
9E-06
8E-06
Selenium
mg/kg
ND
ND
-
-
-
-
Uranium
mg/kg
9.21E-01
7.25E-01
3E-03
2E-03
-
-
Vanadium
mg/kg
1.65E+01
1.42E+01
2E-03
2E-03
-
-
Notes: Supporting calculations provided in Appendix F of the Phase III Summary Report (provided as Appendix M to this report).
A dash indicates calculation was not required.
Hazard Quotient (HQ) values less than one are below level of regulatory concern.
Cancer risk values below or within EPA acceptable range of 1E-6 and 1E-4 are not of regulatory concern.
ND = Not detected.
March 18, 2021
Rev. 1.2
T-60
Engineering Analytics, Inc.
-------
Removal Site Evaluation
Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-7b Non-cancer HI Results and Sum Cancer Risk Results for Non-Radiological
and Radiological PCOCs - Combined Adult and Child Recreator
Evaluated Area
Hazart
Index
Sum Cancer Risk
UCL
Mean
UCL
Mean
APE with AUMs
(Dry Scenario)
6E-02
3E-02
9E-05
4E-05
APE with AUMs
(Wet Scenario)
8E-02
4E-02
1E-04
5E-05
APE Less AUMs
(Dry Scenario)
2E-02
2E-02
3E-05
2E-05
APE Less AUMs
(Wet Scenario)
3E-02
2E-02
3E-05
3E-05
Outside of APE
(Wet and Dry
Scenario)
2E-02
2E-02
2E-05
2E-05
AUM 457
(Wet and Dry
Scenario)
4E-02
3E-02
1E-04
6E-05
AUM 458
(Wet and Dry
Scenario)
4E-01
2E-01
6E-04
2E-04
AUM 459
(Wet and Dry
Scenario)
4E-02
4E-02
1E-04
1E-04
LCR Channel Area
(Dry Scenario Only)
7E-03
6E-03
9E-06
8E-06
Notes:
Hazard Index (HI) is sum of individual PCOC HQ values.
HI values less than one below levels of regulatory concern.
Sum of cancer risk values below or within EPA acceptable range of 1E-6 and
1E-4 are not of regulatory concern.
March 18, 2021
Rev. 1.2
T-61
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-8a Uncertainty Assessment - Non-cancer HQ Results and Cancer Risk Results for Individual Non-Radiological and Radiological PCOCs - Adult Recreator Based on 1 Year of Exposure
Evaluated Area
PCOCs
Units
Soil EPC Values
Hazard Quotient
Carcinogenic
Risk
UCL
Mean
UCL
Mean
UCL
Mean
APE with AUMs
(Dry Scenario)
Arsenic
mg/kg
7.65E+00
4.66E+00
9E-04
5E-04
6E-09
3E-09
Mercury
mg/kg
3.53E-02
1.68E-02
5E-05
3E-05
-
-
Molybdenum
mg/kg
3.67E+01
1.14E+01
4E-04
1E-04
-
-
Ra-226
pCi/g
1.09E+01
5.18E+00
-
-
4E-06
2E-06
Selenium
mg/kg
3.16E-01
2.31E-01
3E-06
2E-06
-
-
Uranium
mg/kg
1.58E+01
6.89E+00
4E-03
2E-03
-
-
Vanadium
mg/kg
5.72E+01
4.23E+01
5E-04
4E-04
-
-
APE with AUMs
(Wet Scenario)
Arsenic
mg/kg
8.91E+00
5.30E+00
1E-03
6E-04
7E-09
4E-09
Mercury
mg/kg
4.26E-02
2.00E-02
6E-05
3E-05
-
-
Molybdenum
mg/kg
5.87E+01
1.41E+01
6E-04
1E-04
-
-
Ra-226
pCi/g
1.32E+01
6.21E+00
-
-
4E-06
2E-06
Selenium
mg/kg
3.73E-01
2.72E-01
4E-06
3E-06
-
-
Uranium
mg/kg
1.93E+01
8.38E+00
5E-03
2E-03
-
-
Vanadium
mg/kg
6.49E+01
4.90E+01
6E-04
5E-04
-
-
APE Less AUMs
(Dry Scenario)
Arsenic
mg/kg
3.41E+00
3.00E+00
4E-04
3E-04
3E-09
2E-09
Mercury
mg/kg
1.41E-02
7.73E-03
2E-05
1E-05
-
-
Molybdenum
mg/kg
5.43E+00
1.58E+00
5E-05
2E-05
-
-
Ra-226
pCi/g
2.93E+00
2.48E+00
-
-
1E-06
8E-07
Selenium
mg/kg
3.77E-01
2.53E-01
4E-06
2E-06
—
—
Uranium
mg/kg
4.33E+00
2.74E+00
1E-03
7E-04
—
—
Vanadium
mg/kg
6.69E+01
4.82E+01
6E-04
5E-04
—
—
March 18, 2021
Rev. 1.2
T-62
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-8a Uncertainty Assessment - Non-cancer HQ Results and Cancer Risk Results for Individual Non-Radiological and Radiological PCOCs - Adult Recreator Based on 1 Year of Exposure (Continued)
Evaluated Area
PCOCs
Units
Soil EPC Values
Hazard Quotient
Carcinogenic
Risk
Units
UCL
Mean
UCL
Mean
UCL
Mean
APE Less AUMs
(Wet Scenario)
Arsenic
mg/kg
3.89E+00
3.37E+00
5E-04
4E-04
3E-09
3E-09
Mercury
mg/kg
1.77E-02
9.37E-03
3E-05
1E-05
-
-
Molybdenum
mg/kg
7.27E+00
2.07E+00
7E-05
2E-05
-
-
Ra-226
pCi/g
3.56E+00
3.05E+00
-
-
1E-06
1E-06
Selenium
mg/kg
5.10E-01
3.26E-01
5E-06
3E-06
-
-
Uranium
mg/kg
4.24E+00
3.47E+00
1E-03
8E-04
-
-
Vanadium
mg/kg
7.82E+01
6.06E+01
7E-04
6E-04
-
-
Outside of APE
(Wet and Dry
Scenario)
Arsenic
mg/kg
3.23E+00
2.97E+00
4E-04
3E-04
2E-09
2E-09
Mercury
mg/kg
1.16E-02
1.03E-02
2E-05
2E-05
-
-
Molybdenum
mg/kg
3.38E-01
2.54E-01
3E-06
2E-06
-
-
Ra-226
pCi/g
2.14E+00
1.99E+00
-
-
7E-07
7E-07
Selenium
mg/kg
2.31E-01
1.73E-01
2E-06
2E-06
-
-
Uranium
mg/kg
2.92E+00
2.54E+00
7E-04
6E-04
-
-
Vanadium
mg/kg
4.82E+01
4.32E+01
5E-04
4E-04
-
-
AUM 457
(Wet and Dry
Scenario)
Arsenic
mg/kg
6.57E+00
4.45E+00
8E-04
5E-04
5E-09
3E-09
Mercury
mg/kg
1.71E-02
1.18E-02
2E-05
1E-05
-
-
Molybdenum
mg/kg
2.44E+01
1.04E+01
2E-04
1E-04
-
-
Ra-226
pCi/g
1.58E+01
7.67E+00
-
-
5E-06
3E-06
Selenium
mg/kg
1.68E-01
1.15E-01
2E-06
1E-06
-
-
Uranium
mg/kg
9.74E+00
6.46E+00
2E-03
2E-03
-
-
Vanadium
mg/kg
3.82E+01
3.36E+01
4E-04
3E-04
-
-
March 18, 2021
Rev. 1.2
T-63
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-8a Uncertainty Assessment - Non-cancer HQ Results and Cancer Risk Results for Individual Non-Radiological and Radiological PCOCs - Adult Recreator Based on 1 Year of Exposure (Continued)
Evaluated Area
PCOCs
Units
Soil EPC Values
Hazard Quotient
Carcinogenic
Risk
Units
UCL
Mean
UCL
Mean
UCL
Mean
AUM 458
(Dry Scenario
Only)
Arsenic
mg/kg
2.77E+01
1.95E+01
3E-03
2E-03
2E-08
1E-08
Mercury
mg/kg
1.70E-01
1.10E-01
2E-04
1E-04
-
-
Molybdenum
mg/kg
3.50E+02
9.58E+01
3E-03
9E-04
-
-
Ra-226
pCi/g
7.39E+01
2.21E+01
-
-
2E-05
7E-06
Selenium
mg/kg
5.18E-01
2.67E-01
5E-06
3E-06
-
-
Uranium
mg/kg
8.62E+01
4.49E+01
2E-02
1E-02
-
-
Vanadium
mg/kg
1.76E+01
1.50E+01
2E-04
1E-04
-
-
AUM 459
(Dry Scenario
Only)
Arsenic
mg/kg
7.25E+00
7.25E+00
8E-04
8E-04
5E-09
5E-09
Mercury
mg/kg
1.30E-02
1.30E-02
1E-05
1E-05
-
-
Molybdenum
mg/kg
4.50E+01
4.50E+01
4E-04
4E-04
-
-
Ra-226
pCi/g
1.50E+01
1.50E+01
-
-
5E-06
5E-06
Selenium
mg/kg
ND
ND
-
-
-
-
Uranium
mg/kg
9.00E+00
9.00E+00
2E-03
2E-03
-
-
Vanadium
mg/kg
6.10E+00
6.10E+00
6E-05
6E-05
-
-
LCR Channel
Area
(Dry Scenario
Only)
Arsenic
mg/kg
2.12E+00
1.96E+00
2E-04
2E-04
2E-09
1E-09
Mercury
mg/kg
3.97E-03
3.22E-03
4E-06
4E-06
-
-
Molybdenum
mg/kg
4.90E-01
2.30E-01
5E-06
2E-06
-
-
Ra-226
pCi/g
1.05E+00
9.15E-01
-
-
3E-07
3E-07
Selenium
mg/kg
ND
ND
-
-
-
-
Uranium
mg/kg
9.21E-01
7.25E-01
2E-04
2E-04
-
-
Vanadium
mg/kg
1.65E+01
1.42E+01
2E-04
1E-04
-
-
Notes: Arsenic and uranium were reported by the laboratory with unit of |ig/kg but were converted to unit of mg/kg (by dividing by 1,000) in this table and for
all risk calculations. Supporting calculations provided in Appendix F of the Phase III Summary Report. A dash indicates calculation was not required.
Hazard Quotient (HQ) values less than one are below levels of regulatory concern. Cancer risk values below or within EPA acceptable range of 1E-6 and
1E-4 are not of regulatory concern. ND = Not detected.
March 18, 2021
Rev. 1.2
T-64
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-8b Uncertainty Assessment - Non-cancer HI Results and Sum Cancer Risk Results for Non-Radiological and Radiological PCOCs - Adult Recreator Based on 1 Year of Exposure
Kvalualed Area
II a/art
ICL
1 Index
Mean
Sum (
Ui
ICL
ancer
sk
Mean
APE with AUMs
(Dry Scenario)
6E-03
3E-03
4E-06
2E-06
APE with AUMs
(Wet Scenario)
7E-03
3E-03
4E-06
2E-06
APE Less AUMs
(Dry Scenario)
2E-03
1E-03
1E-06
8E-07
APE Less AUMs
(Wet Scenario)
2E-03
2E-03
1E-06
1E-06
Outside of APE
(Wet and Dry
Scenario)
2E-03
1E-03
7E-07
7E-07
AUM 457
(Wet and Dry
Scenario)
4E-03
3E-03
5E-06
2E-06
AUM 458
(Wet and Dry
Scenario)
3E-02
1E-02
2E-05
7E-06
AUM 459
(Wet and Dry
Scenario)
4E-03
4E-03
5E-06
5E-06
LCR Channel Area
(Dry Scenario Only)
6E-04
5E-04
3E-07
3E-07
Notes:
Hazard Index (HI) is sum of individual PCOC HQ values.
HI values less than one are below levels of regulatory concern.
Sum of cancer risk values below or within EPA acceptable range of 1E-6
and 1E-4 are not of regulatory concern.
March 18, 2021
Rev. 1.2
T-65
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-9 Uncertainty Assessment - Relative Contributions of Ingestion, Dermal Contact, and Inhalation Pathways to Total Risks
.Non-Cancer Uisks
Cancer Uisk
Scenario
i:p(
1 IQmiiii
%IIQ
from
Inhalation
Uisk
(total)
% Uisk
from
Inhalation
PCOC
a I (1.
Ingestion
Dermal
Inhalation
a I (1.
Ingestion
Dermal
Inhalation
Kxtcrnal
a I (1.
AUM 458
(Dry
Scenario
Only)
Arsenic
2.77E+01
2.7E-03
5.6E-04
7.0E-08
3.2E-03
0.0022%
4.1E-07
8.7E-08
1.5E-12
5.0E-07
0.00031%
Mercury
1.70E-01
1.9E-04
1.9E-04
—
Molybdenum
3.50E+02
3.4E-03
3.4E-03
—
Ra-226
7.39E+01
—
—
1.4E-05
2.9E-11
5.6E-04
5.7E-04
0.0000051%
Selenium
5.18E-01
5.0E-06
9.8E-13
5.0E-06
0.000020%
Uranium
8.62E+01
2.1E-02
8.1E-08
2.1E-02
0.000392%
Vanadium
1.76E+01
1.7E-04
6.6E-09
1.7E-04
0.003946%
Notes:
Non-radionuclide EPCs converted to mg/kg for this table. Ra-226 soil concentration has unit of pCi/g and the risks reflect all daughter products.
Risk results shown are for long term adult recreator.
Values are shown to two significant digits to better display differences.
A dash (—) indicates calculation not required.
March 18, 2021
Rev. 1.2
T-66
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-10 Uncertainty Assessment - Comparison of HHSRE Soil Exposure Point Concentrations for Ra-226 for Soil
Depths of Zero to 6 Inches and Zero to 12 Inches and Calculated Risks to Adult Recreators
Soil Depth Interval Zero to Six Inches
Soil Depth Interval Zero to Twelve Inches
Receptor Group
and Evaluated
Area
EPC
Mean
EPC
UCL
Mean
Cancer
Risk
UCL
Cancer
Risk
EPC
Mean
EPC
UCL
Mean
Cancer
Risk
UCL
Cancer
Risk
APE Area with
AUMs
(Dry Scenario)
5.18
10.9
4E-05
9E-05
6.19
13.4
5E-05
1E-04
APE Area with
AUMs
(Wet Scenario)
6.21
13.2
5E-05
1E-04
7.31
15.7
6E-05
1E-04
APE Area Less
AUMs
(Dry Scenario)
2.48
2.93
2E-05
2E-05
3.1
6
2E-05
5E-05
APE Area Less
AUMs
(Wet Scenario)
3.05
3.56
2E-05
3E-05
3.85
7.59
3E-05
6E-05
Outside of APE
(Wet and Dry
Scenario)
1.99
2.14
2E-05
2E-05
1.99
2.14
2E-05
2E-05
AUM 457
(Wet and Dry
Scenario)
7.67
15.8
6E-05
1E-04
7.34
14.9
6E-05
1E-04
AUM 458
(Dry Scenario
Only)
22.1
73.9
2E-04
6E-04
26.4
100
2E-04
8E-04
AUM 459
(Dry Scenario
Only)
15
15
1E-04
1E-04
17.3
17.3
1E-04
1E-04
LCR Channel
Area
(Dry Scenario
Only)
0.915
1.04
7E-06
8E-06
0.915
1.04
7E-06
8E-06
Notes:
Ra-226 concentration unit is pCi/g.
Recreator risks are based on 24 years of exposure.
EPCs and cancer risks for surface samples collected from 0 to 6 inches are from Table 6-5b.
Risks are calculated assuming concentrations are at the surface for conservatism.
March 18, 2021
Rev. 1.2
T-67
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-lla Summary of HHSRE Non-Radiological PCOC HQ Results for All Evaluated
Receptors and Areas
On-Site Workers
(Table 6-4a)
Adult Recreator,
ED of 24 years
(Table 6-5a)
Child Recreator
(Table 6-6a)
Combined Adult and
Child Recreator
(Table 6-7a)
Evaluated Area
PCOCs
o
3
O
3
O
3
O
3
APE Area with
Arsenic
©
©
©
©
©
©
©
•
AUMs
Mercury
©
©
©
©
•
•
©
•
(Dry Scenario)
Molybdenum
©
©
©
©
•
•
©
•
Selenium
©
©
©
©
©
•
©
©
Uranium
©
o
©
©
•
©
©
©
Vanadium
©
©
©
©
©
©
•
•
APE Area with
Arsenic
©
•
©
©
•
•
•
•
AUMs
Mercury
©
•
*
•
•
©
©
©
(Wet Scenario)
Molybdenum
•
©
©
•
•
©
©
•
Selenium
•
•
©
•
•
©
©
©
Uranium
©
•
©
•
•
©
•
•
Vanadium
•
•
©
©
©
•
•
©
APE Area Less
Arsenic
•
•
•
•
•
•
•
•
AUMs
Mercury
©
•
©
•
©
©
•
©
(Dry Scenario Only)
Molybdenum
©
©
©
©
©
©
•
©
Selenium
©
©
©
©
©
©
©
©
Uranium
©
©
©
©
•
©
©
©
Vanadium
©
©
©
©
•
©
©
©
APE Area Less
Arsenic
•
•
©
©
©
©
©
•
AUMs
Mercury
©
©
©
©
©
•
•
•
(Wet Scenario)
Molybdenum
©
©
©
©
©
©
©
•
Selenium
©
©
©
©
©
©
©
©
Uranium
©
©
©
©
©
©
©
©
Vanadium
©
©
©
©
©
©
©
©
Outside of APE Area
Arsenic
•
•
©
©
©
©
©
•
(Wet and Dry
Mercury
•
©
©
©
©
©
©
©
Scenario)
Molybdenum
©
©
©
©
©
©
©
•
Selenium
•
©
©
©
©
•
•
•
Uranium
©
©
©
©
©
©
©
©
Vanadium
©
©
©
©
•
©
©
©
AUM 457
Arsenic
•
©
•
©
•
•
©
•
(Wet and Dry
Mercury
©
©
©
•
©
©
©
©
Scenario)
Molybdenum
©
©
<§>
©
©
•
•
©
Selenium
•
©
©
©
•
©
©
©
Uranium
©
©
•
•
•
©
•
©
Vanadium
•
•
©
©
•
•
•
•
AUM 458
Arsenic
•
•
•
•
•
•
•
•
(Dry Scenario Only)
Mercury
©
©
©
•
•
©
•
•
Molybdenum
©
©
©
•
•
©
©
•
Selenium
©
©
©
©
©
©
©
©
Uranium
©
©
©
©
•
•
•
©
Vanadium
©
©
©
©
©
©
©
©
AUM 459
Arsenic
•
©
©
©
•
©
•
•
(Dry Scenario Only)
Mercury
©
©
©
©
©
©
©
©
Molybdenum
©
©
©
©
©
•
©
©
Selenium
ND
ND
ND
ND
ND
ND
ND
ND
Uranium
©
©
©
©
©
©
©
©
Vanadium
©
©
©
©
©
©
©
•
Arsenic
©
Q
Q
©
©
©
LCR Channel Area
(Dry Scenario Only)
Mercury
Molybdenum
©
©
©
©
•
©
©
©
©
©
~
©
©
©
©
©
Selenium
ND
ND
ND
ND
ND
ND
ND
ND
Uranium
©
©
©
©
©
•
©
©
Vanadium
©
•
©
©
©
©
•
•
Notes:
Color coding: green = HQ ? 1; yellow = HQ > 1 and HQ ? 10; red = HQ > 10.
ND = Not detected
UCL = upper confidence limit of the mean
March 18, 2021
Rev. 1.2
T-68
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 6-llb Summary of HHSRE Arsenic and Ra-226 Cancer Risk Results for All Evaluated Receptors and Areas
On-Site Workers
(Table 6-4a)
O
D
(0
Adult Recreator, ED of
24 years
(Table 6-5a)
O
Child Recreator
(Table 6-6a)
Combined Adult and
Child Recreator
(Table 6-7a)
O
3
at
e
APE Area with AUMs
(Dry Scenario)
Arsenic
Radium-226
APE Area with AUMs
(Wet Scenario)
Arsenic
Radium-226
APE Area Less AUMs
(Dry Scenario Only)
Arsenic
Radium-226
APE Area Less AUMs
(Wet Scenario)
Arsenic
Radium-226
Outside of APE Area
(Wet and Dry Scenario)
Arsenic
Radium-226
AUM 457
(Wet and Dry Scenario)
Arsenic
Radium-226
AUM 458
(Dry Scenario Only)
Arsenic
Radium-226
AUM 459
(Dry Scenario Only)
Arsenic
Radium-226
LCR Channel Area
(Dry Scenario Only)
Arsenic
Radium-226
Notes:
Color coding: green = cancer risk 1x104; red = cancer risk > IxlO4
UCL = upper confidence limit of the mean
March 18, 2021
Rev. 1.2
T-69
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
March 18, 2021 T-70
Rev. 1.2
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-1 Summary of EcoSRE Soil Exposure Point Concentrations by Evaluated Area and Receptor Group
Receptor
Group and
Mean
Evaluated
Freq of
or KM
Recommended
Area
PCOCs
Units
Detection
Mean
Distribution Type
UCL
Comment
Arsenic
mg/kg
62/62
4.66
No discernible
7.65
Upland
Receptors -
APE Area
with AUMs
Mercury
mg/kg
56/62
0.0168
No discernible
0.0353
Molybdenum
mg/kg
45/62
11.4
No discernible
36.7
Ra-226
pCi/g
62/62
5.18
No discernible
10.9
Selenium
mg/kg
25/62
0.231
Gamma
0.316
a
Uranium
mg/kg
62/62
6.89
No discernible
15.8
Vanadium
mg/kg
62/62
42.3
No discernible
57.2
Arsenic
mg/kg
45/45
3.00
No discernible
3.41
b
Mercury
mg/kg
42/45
0.00773
No discernible
0.0141
Upland
Molybdenum
mg/kg
28/45
1.58
No discernible
5.43
Receptors -
Ra-226
pCi/g
45/45
2.48
Gamma
2.93
APE Area
Less AUMs
Selenium
mg/kg
18/45
0.253
Approximate
Gamma
0.38
a
Uranium
mg/kg
45/45
2.74
No discernible
4.33
Vanadium
mg/kg
45/45
48.23
No discernible
66.9
Arsenic
mg/kg
41/41
2.97
Normal
3.23
Upland
Receptors -
Outside of
APE
Mercury
mg/kg
40/41
0.0103
Normal
0.0116
Molybdenum
mg/kg
24/41
0.254
Gamma
0.338
a
Ra-226
pCi/g
41/41
1.988
Approximate Normal
2.141
Selenium
mg/kg
11/41
0.173
Normal
0.231
Uranium
mg/kg
41/41
2.54
Lognormal
2.92
Vanadium
mg/kg
41/41
43.23
Normal
48.17
March 18, 2021
Rev. 1.2
T-71
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-1 Summary of EcoSRE Soil Exposure Point Concentrations by Evaluated Area and Receptor Group (Continued)
Receptor
Group and
Mean
Evaluated
Freq of
or KM
Recommended
Area
PCOCs
Units
Detection
Mean
Distribution Type
UCL
Comment
Arsenic
mg/kg
11/11
4.45
Approximate
Lognormal
6.57
Upland
Receptors -
APE 457
Mercury
mg/kg
8/11
0.0118
Normal
0.0171
Molybdenum
mg/kg
11/11
10.4
Gamma
24.39
Ra-226
pCi/g
11/11
7.67
Gamma
15.75
Selenium
mg/kg
4/12
0.115
Normal
0.168
Uranium
mg/kg
11/11
6.46
Gamma
9.74
Vanadium
mg/kg
11/11
33.6
Normal
38.2
Arsenic
mg/kg
5/5
19.5
Normal
27.7
Mercury
mg/kg
5/5
0.110
Normal
0.170
Upland
Receptors -
APE 458
Molybdenum
mg/kg
5/5
95.8
Gamma
350
c
Ra-226
pCi/g
5/5
22.1
Approximate
Lognormal
73.9
c
Selenium
mg/kg
3/5
0.267
Normal
0.518
Uranium
mg/kg
5/5
44.9
Normal
86.2
Vanadium
mg/kg
5/5
15.0
No discernible
17.0
c
Arsenic
mg/kg
1/1
7.25
___
7.25
d
Mercury
mg/kg
1/1
0.01295
___
0.01295
d
Upland
Molybdenum
mg/kg
1/1
45.0
___
45.0
d
Receptors -
Ra-226
pCi/g
1/1
14.95
___
14.95
d
APE 459
Selenium
mg/kg
0/1
ND
___
ND
Uranium
mg/kg
1/1
9.00
___
9.00
d
Vanadium
mg/kg
1/1
6.1
—
6.1
d
March 18, 2021
Rev. 1.2
T-72
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-1 Summary of EcoSRE Soil Exposure Point Concentrations by Evaluated Area and Receptor Group (Continued)
Ueceptor
Group and
Mean
Kvalualed
l-'req of
or KM
Recommended
Area
PCOCs
1 nils
Deled ion
Mean
Distribution Type
1 CI.
Comment
Arsenic
mg/kg
12/12
1.96
Normal
2.12
Riparian
Receptors -
Riparian
Buffer Area
within APE
Mercury
mg/kg
11/12
0.00322
Normal
0.00397
Molybdenum
mg/kg
2/12
0.230
No discernible
0.490
Ra-226
pCi/g
12/12
0.915
Normal
1.05
Selenium
mg/kg
0/12
ND
___
___
Uranium
mg/kg
12/12
0.725
No discernible
0.921
a
Vanadium
mg/kg
12/12
14.2
Approximate
Gamma
16.5
Notes:
Arsenic and uranium were reported by the laboratory with unit of |ig/kg but were converted to unit of mg/kg (by dividing by 1,000) in this
table and for all risk calculations.
When detection frequency is 100% the arithmetic mean is reported, otherwise the mean calculated using the Kaplan-Meier method is
reported.
All calculations performed using EPA software ProUCL (v 5.1). Additional summary information and the associated ProUCL output are
provided in Appendix Tables G3-2 and G3-3 of the Phase III Summary Report (provided as Appendix M to this report).
ND = not detected
a Two UCLs were suggested by ProUCL and the larger of the two were reported here and used for risk calculations.
b Three UCLs were suggested by ProUCL and the larger of the three was reported here and used for risk calculations.
0 Recommended UCL exceeded the maximum detection. Latter was used as the UCL value.
d No output from ProUCL because single sample collected from this area. Used detected result as UCL value.
March 18, 2021
Rev. 1.2
T-73
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-2 Summary of Calculated EcoSRE Exposure Point Concentrations for Plants, Invertebrates and Small Mammals
by Evaluated Area and Receptor Group
Calculated Media <
Concentrations Using
Jiota Transfer Factors
Receptor Group
and Evaluated
Area
PCOCs
Units
Plants
Soil
Invertebrates
Small Mammals
Mean
UCL
Mean
UCL
Mean
UCL
Upland Receptors -
APE Area with
AUMs
Arsenic
mg/kg
(dry)
0.220
0.361
1.10
1.81
0.00138
0.00226
Mercury
mg/kg
(dry)
0.0111
0.0234
0.00790
0.0166
0.00101
0.00212
Molybdenum
mg/kg
(dry)
4.58
14.68
5.49
17.62
0.00273
0.00877
Ra-226
pCi/g
(wet)
0.28
0.593
10.94
23.0
0.0897
0.189
Selenium
mg/kg
(dry)
0.162
0.221
0.229
0.313
0.00148
0.00203
Uranium
mg/kg
(dry)
0.834
1.92
0.228
0.523
0.00010
0.00023
Vanadium
mg/kg
(dry)
0.232
0.315
1.78
2.40
0.00803
0.0109
March 18, 2021
Rev. 1.2
T-74
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-2 Summary of Calculated EcoSRE Exposure Point Concentrations for Plants, Invertebrates and Small Mammals by
Evaluated Area and Receptor Group (Continued)
Calculated Media <
Concentrations Using
Jiota Transfer Factors
Receptor Group
and Evaluated
Area
PCOCs
Units
Plants
Soil
Invertebrates
Small Mammals
Mean
UCL
Mean
UCL
Mean
UCL
Upland Receptors -
APE Area Less
AUMs
Arsenic
mg/kg
(dry)
0.142
0.161
0.708
0.804
0.000887
0.00101
Mercury
mg/kg
(dry)
0.00512
0.0093
0.00363
0.0066
0.000464
0.00085
Molybdenum
mg/kg
(dry)
0.630
2.170
0.756
2.60
0.000377
0.00130
Ra-226
pCi/g
(wet)
0.135
0.160
5.24
6.19
0.0430
0.0507
Selenium
mg/kg
(dry)
0.177
0.264
0.250
0.373
0.00162
0.00242
Uranium
mg/kg
(dry)
0.331
0.524
0.090
0.143
0.0000397
0.0000628
Vanadium
mg/kg
(dry)
0.265
0.368
2.03
2.81
0.00916
0.0127
Upland Receptors -
Outside of APE
Arsenic
mg/kg
(dry)
0.140
0.152
0.701
0.763
0.00088
0.00096
Mercury
mg/kg
(dry)
0.00683
0.00769
0.00484
0.00545
0.000618
0.000696
Molybdenum
mg/kg
(dry)
0.102
0.135
0.122
0.162
0.0000607
0.0000808
Ra-226
pCi/g
(wet)
0.108
0.116
4.19
4.52
0.0344
0.0370
Selenium
mg/kg
(dry)
0.121
0.162
0.171
0.229
0.00111
0.00148
March 18, 2021
Rev. 1.2
T-75
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-2
Summary of Calculated EcoSRE Exposure Point Concentrations for Plants, Invertebrates and Small
Calculated Media <
Concentrations Using
Jiota Transfer Factors
Receptor Group
and Evaluated
Area
PCOCs
Units
Plants
Soil
Invertebrates
Small Mammals
Mean
UCL
Mean
UCL
Mean
UCL
Uranium
ug/kg (dry)
0.307
0.354
0.084
0.096
0.0000368
0.0000424
Vanadium
mg/kg
(dry)
0.238
0.265
1.82
2.02
0.00821
0.00915
Upland Receptors -
APE 457
Arsenic
mg/kg
(dry)
0.21
0.31
1.05
1.55
0.001
0.002
Mercury
mg/kg
(dry)
0.00782
0.0113
0.00555
0.00804
0.000708
0.00103
Molybdenum
mg/kg
(dry)
4.152
9.756
4.982
11.707
0.00248
0.00583
Ra-226
pCi/g
(wet)
0.417
0.857
16.2
33.2
0.133
0.272
Selenium
mg/kg
(dry)
0.081
0.118
0.114
0.166
0.00074
0.00108
Uranium
mg/kg
(dry)
0.782
1.18
0.213
0.321
0.0001
0.0001
Vanadium
mg/kg
(dry)
0.185
0.210
1.41
1.60
0.00638
0.00725
Upland Receptors -
APE 458
Arsenic
mg/kg
(dry)
1
1
5
7
0.006
0.008
Mercury
mg/kg
(dry)
0.07293
0.11271
0.05170
0.07990
0.0066
0.0102
Molybdenum
mg/kg
(dry)
38.3
140
46.0
168
0.0229
0.084
March 18, 2021
Rev. 1.2
T-76
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-2 Summary of Calculated EcoSRE Exposure Point Concentrations for Plants, Invertebrates and Small Mammals
Calculated Media <
Concentrations Using
Jiota Transfer Factors
Receptor Group
and Evaluated
Area
PCOCs
Units
Plants
Soil
Invertebrates
Small Mammals
Mean
UCL
Mean
UCL
Mean
UCL
Ra-226
pCi/g
(wet)
1.20
4.02
46.53
155.9
0.3815
1.2785
Selenium
mg/kg
(dry)
0.187
0.363
0.264
0.513
0.00171
0.00333
Uranium
mg/kg
(dry)
5.43
10.4
1.48
2.84
0.0007
0.0012
Vanadium
mg/kg
(dry)
0.083
0.094
0.63
0.71
0.00285
0.00323
Upland Receptors -
APE 459
Arsenic
mg/kg
(dry)
0
0
2
2
0.002
0.002
Mercury
mg/kg
(dry)
0.00859
0.00859
0.00609
0.00609
0.000777
0.000777
Molybdenum
mg/kg
(dry)
18.0
18.0
21.6
21.6
0.0108
0.0108
Ra-226
pCi/g
(wet)
0.813
0.813
31.5
31.5
0.259
0.259
Selenium
mg/kg
(dry)
ND
ND
ND
ND
ND
ND
Uranium
mg/kg
(dry)
1.089
1.089
0.297
0.297
0.000131
0.000131
Vanadium
mg/kg
(dry)
0.034
0.034
0.26
0.26
0.00116
0.00116
March 18, 2021
Rev. 1.2
T-77
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-2
Summary of Calculated EcoSRE Exposure Point Concentrations for Plants, Invertebrates and Small Mammals
Calculated Media <
Concentrations Using
Jiota Transfer Factors
Receptor Group
and Evaluated
Area
PCOCs
Units
Plants
Soil
Invertebrates
Small Mammals
Mean
UCL
Mean
UCL
Mean
UCL
Riparian Receptors
- Riparian Buffer
Area within APE
Arsenic
mg/kg
(dry)
0.1
0
0
1
0.001
0.001
Mercury
mg/kg
(dry)
0.00213
0.00263
0.00151
0.00187
0.000193
0.000238
Molybdenum
mg/kg
(dry)
0.092
0.196
0.110
0.235
0.000055
0.000117
Ra-226
pCi/g
(wet)
0.0498
0.057
1.93
2.21
0.0158
0.0181
Selenium
mg/kg
(dry)
ND
ND
ND
ND
ND
ND
Uranium
mg/kg
(dry)
0.088
0.111
0.024
0.030
0.0000105
0.0000134
Vanadium
mg/kg
(dry)
0.078
0.091
0.595
0.694
0.00269
0.00314
Notes:
Media concentrations calculated as product of soil EPCs and analyte-specific BTFs.
ND = not detected.
March 18, 2021
Rev. 1.2
T-78
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-3a Summary of Non-Radiological and Radiological Ecological Screening Levels for Soils Based on Plant Toxicity
ESL values
PCOCs
Units
NOAEL
LOAEL
Source
Arsenic
mg/kg
18
91
LANL (2017a)
Mercury
mg/kg
34
64
LANL (2017a)
Molybdenum
mg/kg
15
73
M-EMS (2014)
Ra-226
pCi/g
54
540
LANL (2017a)
Selenium
mg/kg
0.52
3
LANL (2017a)
Uranium
mg/kg
25
250
LANL (2017a)
Vanadium
mg/kg
60
80
LANL (2017a)
Notes:
LANL (2017a) did not report an ESL for molybdenum. See
Appendix Table G6-2 of the Phase III Summary Report (provided
as Appendix M to this report) for derivation of molybdenum plant
NOAEL and LOAEL values.
March 18, 2021
Rev. 1.2
T-79
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-3b Summary of Non-Radiological TRVs for Mammalian and Avian Receptors
Mammalian Receptors
Deer Mouse
Shrew
Coyote
1»(()(
TUY\o\i:i
TUYi o\i:i
TUY\oai:i
TUYi o\i:i
TUY\oai:i
TUYi o\i:i
Arsenic
1.01E+01
2.55E+01
1.01E+01
2.55E+01
1.86E+00
4.14E+00
Mercury, inorganic
1.41E+01
NR
1.41E+01
NR
1.41E+01
NC
Mercury, methyl
1.60E-01
NR
1.60E-01
NR
1.60E-01
NC
Molybdenum
4.39E+00
1.49E+01
4.39E+00
1.49E+01
2.48E+00
7.38E+00
Selenium
9.15E-01
2.00E+00
9.15E-01
2.00E+00
2.05E-01
4.46E-01
Uranium
1.50E+01
NR
1.50E+01
NR
1.50E+01
NC
Vanadium
4.16E+00
8.31E+00
4.16E+00
8.31E+00
9.30E-01
1.86E+00
Avian Receptors
Mourning Dove
American Kestrel
Rock Wren
Golden Eagle
PCOC
TRVnoael
TRVloael
TRVnoael
TRVloael
TRVnoael
TRVloael
TRVnoael
TRVloael
Arsenic
3.62E+00
7.65E+00
3.62E+00
7.65E+00
3.62E+00
7.65E+00
3.62E+00
7.65E+00
Mercury, inorganic
4.50E-01
9.00E-01
4.50E-01
9.00E-01
4.50E-01
9.00E-01
4.50E-01
9.00E-01
Mercury, methyl
3.16E-02
1.40E-01
3.16E-02
1.40E-01
3.16E-02
1.40E-01
3.16E-02
1.40E-01
Molybdenum
5.45E+02
NR
5.45E+02
NR
5.45E+02
NR
5.45E+02
NR
Selenium
8.32E-01
1.99E+00
8.32E-01
1.99E+00
8.32E-01
1.99E+00
8.32E-01
1.99E+00
Uranium
7.80E+01
7.80E+02
7.80E+01
7.80E+02
7.80E+01
7.80E+02
7.80E+01
7.80E+02
Vanadium
1.24E+00
2.62E+00
1.24E+00
2.62E+00
1.24E+00
2.62E+00
1.24E+00
2.62E+00
Notes:
The TRV unit is mg/kg-day.
See Appendix Table G4 series and G5 series of the Phase III Summary Report (App M) for additional details on the derivation of the mammalian and avian TRVs.
NR = Not reported
March 18, 2021
Rev. 1.2
T-80
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-4 HQ Results for Upland and Riparian Area Exposures to Non-Radiological and Radiological PCOCs -
Vegetation
Receptor Group
and Evaluated
Area
PCOCs
Soil EPC Values
Plant ESL values
HQnoael
HQloael
Mean
UCL
NOAEL
LOAEL
Mean
UCL
Mean
UCL
Upland - APE
Area with
AUMs
Arsenic
4.66E+00
7.65E+00
1.80E+01
9.10E+01
3.E-01
4.E-01
5.E-02
8.E-02
Mercury
1.68E-02
3.53E-02
3.40E+01
6.40E+01
5.E-04
l.E-03
3.E-04
6.E-04
Molybdenum
1.14E+01
3.67E+01
1.47E+01
7.34E+01
8.E-01
2.E+00
2.E-01
5.E-01
Ra-226
5.18E+00
1.09E+01
5.40E+01
5.40E+02
l.E-01
2.E-01
l.E-02
2.E-02
Selenium
2.31E-01
3.16E-01
5.20E-01
3.00E+00
4.E-01
6.E-01
8.E-02
l.E-01
Uranium
6.89E+00
1.58E+01
2.50E+01
2.50E+02
3.E-01
6.E-01
3.E-02
6.E-02
Vanadium
4.23E+01
5.72E+01
6.00E+01
8.00E+01
7.E-01
1.E+00
5.E-01
7.E-01
Upland - APE
Area Less
AUMs
Arsenic
3.00E+00
3.41E+00
1.80E+01
9.10E+01
2.E-01
2.E-01
3.E-02
4.E-02
Mercury
7.73E-03
1.41E-01
3.40E+01
6.40E+01
2.E-04
4.E-03
l.E-04
2.E-03
Molybdenum
1.58E+00
5.43E+00
1.47E+01
7.34E+01
l.E-01
4.E-01
2.E-02
7.E-02
Ra-226
2.48E+00
2.93E+00
5.40E+01
5.40E+02
5.E-02
5.E-02
5.E-03
5.E-03
Selenium
2.53E-01
3.77E-01
5.20E-01
3.00E+00
5.E-01
7.E-01
8.E-02
l.E-01
Uranium
2.74E+00
4.33E+00
2.50E+01
2.50E+02
l.E-01
2.E-01
l.E-02
2.E-02
Vanadium
4.82E+01
6.69E+01
6.00E+01
8.00E+01
8.E-01
1.E+00
6.E-01
8.E-01
Upland -
Outside of APE
Arsenic
2.97E+00
3.23E+00
1.80E+01
9.10E+01
2.E-01
2.E-01
3.E-02
4.E-02
Mercury
1.03E-02
1.16E-02
3.40E+01
6.40E+01
3.E-04
3.E-04
2.E-04
2.E-04
Molybdenum
2.54E-01
3.38E-01
1.47E+01
7.34E+01
2.E-02
2.E-02
3.E-03
5.E-03
Ra-226
1.99E+00
2.14E+00
5.40E+01
5.40E+02
4.E-02
4.E-02
4.E-03
4.E-03
Selenium
1.73E-01
2.31E-01
5.20E-01
3.00E+00
3.E-01
4.E-01
6.E-02
8.E-02
Uranium
2.54E+00
2.92E+00
2.50E+01
2.50E+02
l.E-01
l.E-01
l.E-02
l.E-02
Vanadium
4.32E+01
4.82E+01
6.00E+01
8.00E+01
7.E-01
8.E-01
5.E-01
6.E-01
March 18, 2021
Rev. 1.2
T-81
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-4 HQ Results for Upland and Riparian Area Exposures to Non-Radiological and Radiological PCOCs - Vegetation
(Continued)
Receptor Group
and Evaluated
Area
PCOCs
Soil EPC Values
Plant ESL values
HQnoael
HQloael
Mean
UCL
NOAEL
LOAEL
Mean
UCL
Mean
UCL
Upland
Receptors -
APE 457
Arsenic
4.45E+00
6.57E+00
1.80E+01
9.10E+01
2.E-01
4.E-01
5.E-02
7.E-02
Mercury
1.18E-02
1.71E-02
3.40E+01
6.40E+01
3.E-04
5.E-04
2.E-04
3.E-04
Molybdenum
1.04E+01
2.44E+01
1.47E+01
7.34E+01
7.E-01
2.E+00
l.E-01
3.E-01
Ra-226
7.67E+00
1.58E+01
5.40E+01
5.40E+02
l.E-01
3.E-01
l.E-02
3.E-02
Selenium
1.15E-01
1.68E-01
5.20E-01
3.00E+00
2.E-01
3.E-01
4.E-02
6.E-02
Uranium
6.46E+00
9.74E+00
2.50E+01
2.50E+02
3.E-01
4.E-01
3.E-02
4.E-02
Vanadium
3.36E+01
3.82E+01
6.00E+01
8.00E+01
6.E-01
6.E-01
4.E-01
5.E-01
Upland
Receptors -
APE 458
Arsenic
1.95E+01
2.77E+01
1.80E+01
9.10E+01
1.E+00
2.E+00
2.E-01
3.E-01
Mercury
1.10E-01
1.70E-01
3.40E+01
6.40E+01
3.E-03
5.E-03
2.E-03
3.E-03
Molybdenum
9.58E+01
3.50E+02
1.47E+01
7.34E+01
6.E+00
2.E+01
1.E+00
5.E+00
Ra-226
2.21E+01
7.39E+01
5.40E+01
5.40E+02
4.E-01
1.E+00
4.E-02
l.E-01
Selenium
2.67E-01
5.18E-01
5.20E-01
3.00E+00
5.E-01
1.E+00
9.E-02
2.E-01
Uranium
4.49E+01
8.62E+01
2.50E+01
2.50E+02
2.E+00
3.E+00
2.E-01
3.E-01
Vanadium
1.50E+01
1.70E+01
6.00E+01
8.00E+01
3.E-01
3.E-01
2.E-01
2.E-01
Upland
Receptors -
APE 459
Arsenic
7.25E+00
7.25E+00
1.80E+01
9.10E+01
4.E-01
4.E-01
8.E-02
8.E-02
Mercury
1.30E-02
1.30E-02
3.40E+01
6.40E+01
4.E-04
4.E-04
2.E-04
2.E-04
Molybdenum
4.50E+01
4.50E+01
1.47E+01
7.34E+01
3.E+00
3.E+00
6.E-01
6.E-01
Ra-226
1.50E+01
1.50E+01
5.40E+01
5.40E+02
3.E-01
3.E-01
3.E-02
3.E-02
Selenium
ND
ND
5.20E-01
3.00E+00
ND
ND
ND
ND
Uranium
9.00E+00
9.00E+00
2.50E+01
2.50E+02
4.E-01
4.E-01
4.E-02
4.E-02
Vanadium
6.10E+00
6.10E+00
6.00E+01
8.00E+01
l.E-01
l.E-01
8.E-02
8.E-02
March 18, 2021
Rev. 1.2
T-82
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-4 HQ Results for Upland and Riparian Area Exposures to Non-Radiological and Radiological PCOCs - Vegetation
(Continued)
Receptor Group
and Evaluated
Area
PCOCs
Soil EPC Values
Plant ESL values
HQnoael
HQloael
Mean
UCL
NOAEL
LOAEL
Mean
UCL
Mean
UCL
Riparian -
Riparian Buffer
Area within
APE
Arsenic
1.96E+00
2.12E+00
1.80E+01
9.10E+01
l.E-01
l.E-01
2.E-02
2.E-02
Mercury
3.22E-03
3.97E-03
3.40E+01
6.40E+01
9.E-05
l.E-04
5.E-05
6.E-05
Molybdenum
2.30E-01
4.90E-01
1.47E+01
7.34E+01
2.E-02
3.E-02
3.E-03
7.E-03
Ra-226
9.15E-01
1.05E+00
5.40E+01
5.40E+02
2.E-02
2.E-02
2.E-03
2.E-03
Selenium
ND
ND
5.20E-01
3.00E+00
—
—
—
—
Uranium
7.25E-01
9.21E-01
2.50E+01
2.50E+02
3.E-02
4.E-02
3.E-03
4.E-03
Vanadium
1.42E+01
1.65E+01
6.00E+01
8.00E+01
2.E-01
3.E-01
2.E-01
2.E-01
Notes:
Non-radiological concentration unit is mg/kgdw. Ra-226 concentration unit is pCi/gdw.
See Appendix Table G2 series of the Phase III Summary Report (provided as Appendix M to this report) for additional details regarding the calculation of EPC
values.
ESL values were for "Generic Plants" from LANL (2017a), except for molybdenum which had no ESL value from this source. Alternate source was used (see
Appendix Tables G6-1 and G6-2 of the Phase III Summary Report [Appendix M]).
HQ values less than one are below levels of regulatory concern.
HQ values greater than one are highlighted.
ND = Not detected
March 18, 2021
Rev. 1.2
T-83
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-5a HQ Results for Riparian Area Exposures to Non-Radiological PCOCs - Herbivorous Bird (Mourning Dove)
Receptor
Group and
Evaluated
Area
PCOCs
Soil EPC Values
(mg/kgdw)
Diet EP<
(mg /
2 Values
kgdw)
AI
(mg/k
)D
2-day)
HQnoael
HQloael
Mean
UCL
Mean
UCL
Mean
UCL
Mean
UCL
Mean
UCL
Riparian -
Riparian
Buffer Area
within APE
Arsenic
2.00E+00
2.10E+00
9.30E-02
1.00E-01
8.6.E-04
9.3.E-04
2.4.E-04
2.6.E-04
1.1E-04
1.2E-04
Mercury
3.20E-03
4.00E-03
2.10E-03
2.60E-03
1.4.E-05
1.8.E-05
4.6.E-04
5.6.E-04
1.0E-04
1.3E-04
Molybdenum
2.30E-01
4.90E-01
9.20E-02
2.00E-01
6.3.E-04
1.3.E-03
1.2.E-06
2.5.E-06
NC
NC
Selenium
ND
ND
ND
ND
—
—
—
—
—
—
Uranium
7.20E-01
9.20E-01
8.80E-02
1.10E-01
6.7.E-04
8.5.E-04
8.6.E-06
l.l.E-05
8.6E-07
1.1E-06
Vanadium
1.40E+01
1.70E+01
7.80E-02
9.10E-02
2.4.E-03
2.8.E-03
1.9.E-03
2.2.E-03
9.0E-04
1.1E-03
Notes:
See Appendix Table G3 series of the Phase III Summary Report (provided as Appendix M to this report) for additional details regarding the calculation of EPC values.
This receptor was not evaluated in the upland portions of the Site.
HQ values less than one are below levels of regulatory concern.
ND = Not detected
UCL = Upper Confidence Limit of the mean
EPC = Exposure Point Concentration
-- = Not applicable
Table 7-5b HQ Results for Riparian Area Exposures to Radiological PCOC (Ra-226) - Herbivorous Bird (Mourning Dove)
Receptor Group and
Evaluated Area
PCOCs
Soil EPC Values
(pCi/gdw)
ssESL Values
(pCi/gdw)
HQnoael
HQloael
Mean
UCL
NOAEL
LOAEL
Mean
UCL
Mean
UCL
Riparian - Riparian
Buffer Area within
APE
Ra-226
9.15E-01
1.05E+00
3.9E+03
3.9E+04
2.E-04
3.E-04
2.E-05
3.E-05
Notes:
See Appendix Table G3 series of the Phase III Summary Report (provided as Appendix M to this report) for additional details regarding the calculation of EPC
values.
ssESL values account for receptor AUF and SUF values. See Appendix Tables G6-3 and G6-4 of the Phase III Summary Report (Appendix M) for additional details.
This receptor was not evaluated in the upland portions of the Site.
ssESL = site-specific ecological screening levels
UCL = Upper Confidence Limit of the mean
EPC = Exposure Point Concentration
March 18, 2021
Rev. 1.2
T-84
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-6a HQ Results for Upland and Riparian Area Exposures to Non-Radiological PCOCs - Herbivorous Mammal (Deer Mouse)
Receptor Group
and Evaluated Area
PCOCs
Soil EPC Values
(mg/kgdw)
Diet EP<
(mg /
I! Values
kgdw)
AI
(mg/k
)D
2-day)
HQnoael
HQloael
Mean
UCL
Mean
UCL
Mean
UCL
Mean
UCL
Mean
UCL
Upland - APE Area
with AUMs
Arsenic
4.70E+00
7.60E+00
2.20E-01
3.60E-01
7.8.E-02
1.3.E-01
8E-03
1E-02
3.E-03
5.E-03
Mercury
1.70E-02
3.50E-02
1.10E-02
2.30E-02
2.9.E-03
6.0.E-03
2E-02
4E-02
NC
NC
Molybdenum
1.10E+01
3.70E+01
4.60E+00
1.50E+01
1.2.E+00
3.9.E+00
3E-01
9E-01
8.E-02
3.E-01
Selenium
2.30E-01
3.20E-01
1.60E-01
2.20E-01
4.2.E-02
5.7.E-02
5E-02
6E-02
2.E-02
3.E-02
Uranium
6.90E+00
1.60E+01
8.30E-01
1.90E+00
2.4.E-01
5.6.E-01
2E-02
4E-02
NC
NC
Vanadium
4.20E+01
5.70E+01
2.30E-01
3.10E-01
2.7.E-01
3.6.E-01
7E-02
9E-02
3.E-02
4.E-02
Upland - APE Area
Less AUMs
Arsenic
3.00E+00
3.40E+00
1.40E-01
1.60E-01
5.0.E-02
5.7.E-02
5E-03
6E-03
2.E-03
2.E-03
Mercury
7.70E-03
1.40E-02
5.10E-03
9.30E-03
1.3.E-03
2.4.E-03
8E-03
2E-02
NC
NC
Molybdenum
1.60E+00
5.40E+00
6.30E-01
2.20E+00
1.7.E-01
5.7.E-01
4E-02
1E-01
l.E-02
4.E-02
Selenium
2.50E-01
3.80E-01
1.80E-01
2.60E-01
4.6.E-02
6.8.E-02
5E-02
7E-02
2.E-02
3.E-02
Uranium
2.70E+00
4.30E+00
3.30E-01
5.20E-01
9.6.E-02
1.5.E-01
6E-03
1E-02
NC
NC
Vanadium
4.80E+01
6.70E+01
2.70E-01
3.70E-01
3.1.E-01
4.3.E-01
7E-02
1E-01
4.E-02
5.E-02
Upland - Outside of
APE
Arsenic
3.00E+00
3.20E+00
1.40E-01
1.50E-01
5.0.E-02
5.4.E-02
5E-03
5E-03
2.E-03
2.E-03
Mercury
1.00E-02
1.20E-02
6.80E-03
7.70E-03
1.8.E-03
2.0.E-03
1E-02
1E-02
NC
NC
Molybdenum
2.50E-01
3.40E-01
1.00E-01
1.40E-01
2.7.E-02
3.5.E-02
6E-03
8E-03
2.E-03
2.E-03
Selenium
1.70E-01
2.30E-01
1.20E-01
1.60E-01
3.1.E-02
4.2.E-02
3E-02
5E-02
2.E-02
2.E-02
Uranium
2.50E+00
2.90E+00
3.10E-01
3.50E-01
8.9.E-02
1.0.E-01
6E-03
7E-03
NC
NC
Vanadium
4.30E+01
4.80E+01
2.40E-01
2.60E-01
2.8.E-01
3.1.E-01
7E-02
7E-02
3.E-02
4.E-02
Upland Receptors -
AUM 457
Arsenic
4.40E+00
6.60E+00
2.10E-01
3.10E-01
7.5.E-02
l.l.E-01
7E-03
1E-02
3.E-03
4.E-03
Mercury
1.20E-02
1.70E-02
7.80E-03
1.10E-02
2.0.E-03
2.9.E-03
1E-02
2E-02
—
—
Molybdenum
1.00E+01
2.40E+01
4.20E+00
9.80E+00
1.1.E+00
2.6.E+00
3E-01
6E-01
7.E-02
2.E-01
Selenium
1.20E-01
1.70E-01
8.00E-02
1.20E-01
2.1.E-02
3.0.E-02
2E-02
3E-02
l.E-02
2.E-02
Uranium
6.50E+00
9.70E+00
7.80E-01
1.20E+00
2.3.E-01
3.4.E-01
2E-02
2E-02
—
—
Vanadium
3.40E+01
3.80E+01
1.80E-01
2.10E-01
2.1.E-01
2.4.E-01
5E-02
6E-02
3.E-02
3.E-02
Upland Receptors -
AUM 458
Arsenic
2.00E+01
2.80E+01
9.20E-01
1.30E+00
3.3.E-01
4.7.E-01
3E-02
5E-02
l.E-02
2.E-02
Mercury
1.10E-01
1.70E-01
7.30E-02
1.10E-01
1.9.E-02
2.9.E-02
1E-01
2E-01
—
—
Molybdenum
9.60E+01
3.50E+02
3.80E+01
1.40E+02
1.0.E+01
3.7.E+01
2E+00
8E+00
7.E-01
3.E+00
Selenium
2.70E-01
5.20E-01
1.90E-01
3.60E-01
4.8.E-02
9.3.E-02
5E-02
1E-01
2.E-02
5.E-02
Uranium
4.50E+01
8.60E+01
5.40E+00
1.00E+01
1.6.E+00
3.0.E+00
1E-01
2E-01
—
—
Vanadium
1.50E+01
1.70E+01
8.20E-02
9.40E-02
9.6.E-02
l.l.E-01
2E-02
3E-02
l.E-02
l.E-02
Upland Receptors -
AUM 459
Arsenic
7.20E+00
7.20E+00
3.40E-01
3.40E-01
1.2.E-01
1.2.E-01
1E-02
1E-02
5.E-03
5.E-03
Mercury
1.30E-02
1.30E-02
8.60E-03
8.60E-03
2.2.E-03
2.2.E-03
1E-02
1E-02
—
—
Molybdenum
4.50E+01
4.50E+01
1.80E+01
1.80E+01
4.7.E+00
4.7.E+00
1E+00
1E+00
3.E-01
3.E-01
Selenium
ND
ND
ND
ND
—
—
—
—
—
—
Uranium
9.00E+00
9.00E+00
1.10E+00
1.10E+00
3.2.E-01
3.2.E-01
2E-02
2E-02
—
—
Vanadium
6.10E+00
6.10E+00
3.40E-02
3.40E-02
3.9.E-02
3.9.E-02
9E-03
9E-03
5.E-03
5.E-03
March 18, 2021
Rev. 1.2
T-85
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-6a HQ Results for Upland and Riparian Area Exposures to Non-Radiological PCOCs - Herbivorous Mammal (Deer Mouse) (Continued)
Ueeeplor (iroup
and Kvalualed Area
PCOCs
Soil i:pc
(ill"/
Mean
Values
v«
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-6b HQ Results for Upland and Riparian Area Exposures to Radiological PCOC (Ra-226) - Herbivorous Mammal (Deer Mouse)
Ueceplor Group
and Kvalualed
Area
PCOCs
soil i: pc
(p( i
Mean
Values
/g.lH )
I ( L
ssl.SI.
(pC i
NOAKI.
Values
/g.lH )
I.OAKI.
IIQn
Mean
ou.i
I (1.
IIQi
Mean
1 CI.
Upland - APE
Area with
AUMs
Ra-226
5.18E+00
1.09E+01
5.40E+02
5.40E+03
l.E-02
2.E-02
l.E-03
2.E-03
Upland - APE
Area Less
AUMs
Ra-226
2.48E+00
2.93E+00
5.40E+02
5.40E+03
5.E-03
5.E-03
5.E-04
5.E-04
Upland -
Outside of APE
Ra-226
1.99E+00
2.14E+00
5.40E+02
5.40E+03
4.E-03
4.E-03
4.E-04
4.E-04
Upland - AUM
457
Ra-226
7.67E+00
1.58E+01
5.40E+02
5.40E+03
l.E-02
3.E-02
l.E-03
3.E-03
Upland - AUM
458
Ra-226
2.21E+01
7.39E+01
5.40E+02
5.40E+03
4.E-02
l.E-01
4.E-03
l.E-02
Upland - AUM
459
Ra-226
1.50E+01
1.50E+01
5.40E+02
5.40E+03
3.E-02
3.E-02
3.E-03
3.E-03
Riparian -
Riparian Buffer
Area within
APE
Ra-226
9.15E-01
1.05E+00
5.40E+02
5.40E+03
2.E-03
2.E-03
2.E-04
2.E-04
Notes:
See Appendix Table G3 series of the Phase III Summary Report (provided as Appendix M to this report) for additional details regarding the calculation of EPC
values.
ssESL values account for receptor AUF and SUF values. See Appendix Tables G6-3 and G6-4 of the Phase III Summary Report (Appendix M) for additional
details.
HQ values less than one are below levels of regulatory concern.
ssESL = site-specific ecological screening levels for soils
UCL = Upper Confidence Limit of the mean
March 18, 2021
Rev. 1.2
T-87
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-7a HQ Results for Upland Area Exposures to Non-Radiological PCOCs - Insectivorous Bird (American Kestrel)
Receptor
Group and
Evaluated
Area
PCOCs
Soil EP(
(mg /
2 Values
kgdw)
Diet EP<
(mg /
2 Values
kgdw)
ADD
(mg/kg-day)
HQnoael
HQloael
Mean
UCL
Mean
UCL
Mean
UCL
Mean
UCL
Mean
UCL
Upland - APE
Area with
AUMs
Arsenic
4.70E+00
7.60E+00
1.10E+00
1.80E+00
1.70E-01
2.80E-01
5.E-02
8.E-02
2.E-02
4.E-02
Mercury
1.70E-02
3.50E-02
7.90E-03
1.70E-02
1.20E-03
2.50E-03
4.E-02
8.E-02
9.E-03
2.E-02
Molybdenum
1.10E+01
3.70E+01
5.50E+00
1.80E+01
8.20E-01
2.60E+00
2.E-03
5.E-03
NC
NC
Selenium
2.30E-01
3.20E-01
2.30E-01
3.10E-01
3.40E-02
4.60E-02
4.E-02
6.E-02
2.E-02
2.E-02
Uranium
6.90E+00
1.60E+01
2.30E-01
5.20E-01
5.30E-02
1.20E-01
7.E-04
2.E-03
7.E-05
2.E-04
Vanadium
4.20E+01
5.70E+01
1.80E+00
2.40E+00
3.80E-01
5.10E-01
3.E-01
4.E-01
l.E-01
2.E-01
Upland - APE
Area Less
AUMs
Arsenic
3.00E+00
3.40E+00
7.10E-01
8.00E-01
1.10E-01
1.30E-01
3.E-02
4.E-02
l.E-02
2.E-02
Mercury
7.70E-03
1.40E-02
3.60E-03
6.60E-03
5.50E-04
9.90E-04
2.E-02
3.E-02
4.E-03
7.E-03
Molybdenum
1.60E+00
5.40E+00
7.60E-01
2.60E+00
1.10E-01
3.90E-01
2.E-04
7.E-04
NC
NC
Selenium
2.50E-01
3.80E-01
2.50E-01
3.70E-01
3.70E-02
5.50E-02
4.E-02
7.E-02
2.E-02
3.E-02
Uranium
2.70E+00
4.30E+00
9.00E-02
1.40E-01
2.10E-02
3.30E-02
3.E-04
4.E-04
3.E-05
4.E-05
Vanadium
4.80E+01
6.70E+01
2.00E+00
2.80E+00
4.30E-01
6.00E-01
4.E-01
5.E-01
2.E-01
2.E-01
Upland -
Outside of
APE
Arsenic
3.00E+00
3.20E+00
7.00E-01
7.60E-01
1.10E-01
1.20E-01
3.E-02
3.E-02
l.E-02
2.E-02
Mercury
1.00E-02
1.20E-02
4.80E-03
5.50E-03
7.30E-04
8.20E-04
2.E-02
3.E-02
5.E-03
6.E-03
Molybdenum
2.50E-01
3.40E-01
1.20E-01
1.60E-01
1.80E-02
2.40E-02
3.E-05
5.E-05
NC
NC
Selenium
1.70E-01
2.30E-01
1.70E-01
2.30E-01
2.50E-02
3.40E-02
3.E-02
4.E-02
l.E-02
2.E-02
Uranium
2.50E+00
2.90E+00
8.40E-02
9.60E-02
1.90E-02
2.20E-02
3.E-04
3.E-04
3.E-05
3.E-05
Vanadium
4.30E+01
4.80E+01
1.80E+00
2.00E+00
3.90E-01
4.30E-01
3.E-01
4.E-01
2.E-01
2.E-01
Upland
Receptors -
AUM 457
Arsenic
4.40E+00
6.60E+00
1.10E+00
1.60E+00
2.20E-02
3.30E-02
6.E-03
9.E-03
3.E-03
4.E-03
Mercury
1.20E-02
1.70E-02
5.50E-03
8.00E-03
1.10E-04
1.60E-04
4.E-03
5.E-03
8.E-04
l.E-03
Molybdenum
1.00E+01
2.40E+01
5.00E+00
1.20E+01
1.00E-01
2.40E-01
2.E-04
4.E-04
NC
NC
Selenium
1.20E-01
1.70E-01
1.10E-01
1.70E-01
2.30E-03
3.30E-03
3.E-03
4.E-03
l.E-03
2.E-03
Uranium
6.50E+00
9.70E+00
2.10E-01
3.20E-01
6.70E-03
1.00E-02
9.E-05
l.E-04
9.E-06
l.E-05
Vanadium
3.40E+01
3.80E+01
1.40E+00
1.60E+00
4.10E-02
4.70E-02
3.E-02
4.E-02
2.E-02
2.E-02
Upland
Receptors -
AUM 458
Arsenic
2.00E+01
2.80E+01
4.60E+00
6.50E+00
5.60E-02
7.90E-02
2.E-02
2.E-02
7.E-03
l.E-02
Mercury
1.10E-01
1.70E-01
5.20E-02
8.00E-02
6.00E-04
9.30E-04
2.E-02
3.E-02
4.E-03
7.E-03
Molybdenum
9.60E+01
3.50E+02
4.60E+01
1.70E+02
5.40E-01
2.00E+00
l.E-03
4.E-03
NC
NC
Selenium
2.70E-01
5.20E-01
2.60E-01
5.10E-01
3.00E-03
5.90E-03
4.E-03
7.E-03
2.E-03
3.E-03
Uranium
4.50E+01
8.60E+01
1.50E+00
2.80E+00
2.70E-02
5.10E-02
3.E-04
7.E-04
3.E-05
7.E-05
Vanadium
1.50E+01
1.70E+01
6.30E-01
7.10E-01
1.00E-02
1.20E-02
8.E-03
l.E-02
4.E-03
0.0045
March 18, 2021
Rev. 1.2
T-88
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-7a HQ Results for Upland Area Exposures to Non-Radiological PCOCs - Insectivorous Bird (American Kestrel) (Continued)
Receptor
Group and
Evaluated
Area
PCOCs
Soil EP(
(mg /
2 Values
kgdw)
Diet EP<
(mg /
2 Values
kgdw)
ADD
(mg/kg-day)
HQnoael
HQloael
Mean
UCL
Mean
UCL
Mean
UCL
Mean
UCL
Mean
UCL
Upland
Receptors -
AUM 459
Arsenic
7.20E+00
7.20E+00
1.70E+00
1.70E+00
4.80E-04
4.80E-04
l.E-04
l.E-04
6.E-05
6.E-05
Mercury
1.30E-02
1.30E-02
6.10E-03
6.10E-03
1.70E-06
1.70E-06
5.E-05
5.E-05
l.E-05
l.E-05
Molybdenum
4.50E+01
4.50E+01
2.20E+01
2.20E+01
5.90E-03
5.90E-03
l.E-05
l.E-05
NC
NC
Selenium
ND
ND
ND
ND
—
—
—
—
—
—
Uranium
9.00E+00
9.00E+00
3.00E-01
3.00E-01
1.20E-04
1.20E-04
2.E-06
2.E-06
2.E-07
2.E-07
Vanadium
6.10E+00
6.10E+00
2.60E-01
2.60E-01
9.90E-05
9.90E-05
8.E-05
8.E-05
4.E-05
4.E-05
Notes:
See Appendix Table G3 series of the Phase III Summary Report (provided as Appendix M to this report) for additional details regarding the calculation of EPC values.
HQ values less than one are below levels of regulatory concern.
This receptor was not evaluated in the riparian portion of the Site.
ADD = average daily dose
EPC = exposure point concentrations
ND = Not detected
NC = Not calculated (TRVloael not available)
UCL = upper confidence limit of the mean
-- = Not applicable
March 18, 2021
Rev. 1.2
T-89
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-7b HQ Results for Upland Area Exposures to Radiological PCOC (Ra-226) - Insectivorous Bird (American Kestrel)
Ueceplor (iroup
and Kvalualed
Area
PCOCs
soil i:p(
(p('i
Mean
Values
/«.l« )
1 CI.
ssKSI.
(p( i
NOAI.I.
Values
/g.lH )
I.OAI.I.
IIQn
Mean
ou.i
1 CI.
IIQi
Mean
1 CI.
Upland - APE
Area with AUMs
Ra-226
5.18E+00
1.09E+01
9.1E+02
9.1E+03
6.E-03
l.E-02
6.E-04
l.E-03
Upland - APE
Area Less AUMs
Ra-226
2.48E+00
2.93E+00
9.1E+02
9.1E+03
3.E-03
3.E-03
3.E-04
3.E-04
Upland - Outside
of APE
Ra-226
1.99E+00
2.14E+00
9.1E+02
9.1E+03
2.E-03
2.E-03
2.E-04
2.E-04
Upland - AUM
457
Ra-226
7.67E+00
1.58E+01
9.1E+02
9.1E+03
8.E-03
2.E-02
8.E-04
2.E-03
Upland - AUM
458
Ra-226
2.21E+01
7.39E+01
9.1E+02
9.1E+03
2.E-02
8.E-02
2.E-03
8.E-03
Upland - AUM
459
Ra-226
1.50E+01
1.50E+01
9.1E+02
9.1E+03
2.E-02
2.E-02
2.E-03
2.E-03
Notes:
See Appendix Table G3 series of the Phase III Summary Report (provided as Appendix M to this report) for additional details regarding the calculation of EPC
values.
ssESL values account for receptor AUF and SUF values. See Appendix Tables G6-3 and G6-4 of the Phase III Summary Report for additional details.
HQ values less than one are below levels of regulatory concern.
This receptor was not evaluated in the riparian portion of the Site.
ssESL = site-specific ecological screening levels for soils
UCL = Upper Confidence Limit of the mean
March 18, 2021
Rev. 1.2
T-90
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-8a HQ Results for Upland Area Exposures to Non-Radiological PCOCs - Insectivorous Bird (Rock Wren)
Receptor
Group and
Evaluated
Area
PCOCs
Soil EP(
(mg /
^ Values
kgdw)
Diet EP<
(mg /
I! Values
kgdw)
AI
(mg/k
)D
2-day)
HQnoael
HQloael
Mean
UCL
Mean
UCL
Mean
UCL
Mean
UCL
Mean
UCL
Upland - APE
Area with
AUMs
Arsenic
4.70E+00
7.60E+00
1.10E+00
1.80E+00
3.1E-01
5.1E-01
9.E-02
l.E-01
4.E-02
7.E-02
Mercury
1.70E-02
3.50E-02
7.90E-03
1.70E-02
2.1E-03
4.5E-03
7.E-02
l.E-01
2.E-02
3.E-02
Molybdenum
1.10E+01
3.70E+01
5.50E+00
1.80E+01
1.5E+00
4.8E+00
3.E-03
9.E-03
NC
NC
Selenium
2.30E-01
3.20E-01
2.30E-01
3.10E-01
6.1E-02
8.3E-02
7.E-02
l.E-01
3.E-02
4.E-02
Uranium
6.90E+00
1.60E+01
2.30E-01
5.20E-01
9.5E-02
2.2E-01
l.E-03
3.E-03
l.E-04
3.E-04
Vanadium
4.20E+01
5.70E+01
1.80E+00
2.40E+00
6.8E-01
9.3E-01
6.E-01
8.E-01
3.E-01
4.E-01
Upland - APE
Area Less
AUMs
Arsenic
3.00E+00
3.40E+00
7.10E-01
8.00E-01
2.0E-01
2.3E-01
6.E-02
6.E-02
3.E-02
3.E-02
Mercury
7.70E-03
1.40E-02
3.60E-03
6.60E-03
9.9E-04
1.8E-03
3.E-02
6.E-02
7.E-03
l.E-02
Molybdenum
1.60E+00
5.40E+00
7.60E-01
2.60E+00
2.1E-01
7.1E-01
4.E-04
l.E-03
NC
NC
Selenium
2.50E-01
3.80E-01
2.50E-01
3.70E-01
6.7E-02
9.9E-02
8.E-02
l.E-01
3.E-02
5.E-02
Uranium
2.70E+00
4.30E+00
9.00E-02
1.40E-01
3.8E-02
6.0E-02
5.E-04
8.E-04
5.E-05
8.E-05
Vanadium
4.80E+01
6.70E+01
2.00E+00
2.80E+00
7.8E-01
1.1E+00
6.E-01
9.E-01
3.E-01
4.E-01
Upland -
Outside of
APE
Arsenic
3.00E+00
3.20E+00
7.00E-01
7.60E-01
2.0E-01
2.2E-01
6.E-02
6.E-02
3.E-02
3.E-02
Mercury
1.00E-02
1.20E-02
4.80E-03
5.50E-03
1.3E-03
1.5E-03
4.E-02
5.E-02
9.E-03
l.E-02
Molybdenum
2.50E-01
3.40E-01
1.20E-01
1.60E-01
3.3E-02
4.4E-02
6.E-05
8.E-05
NC
NC
Selenium
1.70E-01
2.30E-01
1.70E-01
2.30E-01
4.6E-02
6.1E-02
6.E-02
7.E-02
2.E-02
3.E-02
Uranium
2.50E+00
2.90E+00
8.40E-02
9.60E-02
3.5E-02
4.0E-02
5.E-04
5.E-04
5.E-05
5.E-05
Vanadium
4.30E+01
4.80E+01
1.80E+00
2.00E+00
7.0E-01
7.8E-01
6.E-01
6.E-01
3.E-01
3.E-01
Upland
Receptors -
AUM 457
Arsenic
4.40E+00
6.60E+00
1.10E+00
1.60E+00
3.0E-01
4.4E-01
8.E-02
l.E-01
4.E-02
6.E-02
Mercury
1.20E-02
1.70E-02
5.50E-03
8.00E-03
1.5E-03
2.2E-03
5.E-02
7.E-02
l.E-02
2.E-02
Molybdenum
1.00E+01
2.40E+01
5.00E+00
1.20E+01
1.4E+00
3.2E+00
3.E-03
6.E-03
NC
NC
Selenium
1.20E-01
1.70E-01
1.10E-01
1.70E-01
3.0E-02
4.4E-02
4.E-02
5.E-02
2.E-02
2.E-02
Uranium
6.50E+00
9.70E+00
2.10E-01
3.20E-01
8.9E-02
1.3E-01
l.E-03
2.E-03
l.E-04
2.E-04
Vanadium
3.40E+01
3.80E+01
1.40E+00
1.60E+00
5.4E-01
6.2E-01
4.E-01
5.E-01
2.E-01
2.E-01
Upland
Receptors -
AUM 458
Arsenic
2.00E+01
2.80E+01
4.60E+00
6.50E+00
1.3E+00
1.8E+00
4.E-01
5.E-01
2.E-01
2.E-01
Mercury
1.10E-01
1.70E-01
5.20E-02
8.00E-02
1.4E-02
2.2E-02
5.E-01
7.E-01
l.E-01
2.E-01
Molybdenum
9.60E+01
3.50E+02
4.60E+01
1.70E+02
1.2E+01
4.6E+01
2.E-02
3.E-01
NC
NC
Selenium
2.70E-01
5.20E-01
2.60E-01
5.10E-01
7.0E-02
1.4E-01
8.E-02
2.E-01
4.E-02
7.E-02
Uranium
4.50E+01
8.60E+01
1.50E+00
2.80E+00
6.2E-01
1.2E+00
8.E-03
2.E-02
8.E-04
2.E-03
Vanadium
1.50E+01
1.70E+01
6.30E-01
7.10E-01
2.4E-01
2.7E-01
2.E-01
2.E-01
9.E-02
l.E-01
March 18, 2021
Rev. 1.2
T-91
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-8a HQ Results for Upland Area Exposures to Non-Radiological PCOCs - Insectivorous Bird (Rock Wren) (Continued)
Receptor
Group and
Evaluated
Area
PCOCs
Soil EP(
(mg /
^ Values
kgdw)
Diet EP<
(mg /
I! Values
kgdw)
AI
(mg/k
)D
2-day)
HQnoael
HQloael
Mean
UCL
Mean
UCL
Mean
UCL
Mean
UCL
Mean
UCL
Upland
Receptors -
AUM 459
Arsenic
7.20E+00
7.20E+00
1.70E+00
1.70E+00
1.2E-01
1.2E-01
3.E-02
3.E-02
2.E-02
2.E-02
Mercury
1.30E-02
1.30E-02
6.10E-03
6.10E-03
4.2E-04
4.2E-04
l.E-02
l.E-02
3.E-03
3.E-03
Molybdenum
4.50E+01
4.50E+01
2.20E+01
2.20E+01
1.5E+00
1.5E+00
3.E-03
3.E-03
NC
NC
Selenium
ND
ND
ND
ND
—
—
—
—
—
—
Uranium
9.00E+00
9.00E+00
3.00E-01
3.00E-01
3.2E-02
3.2E-02
4.E-04
4.E-04
4.E-05
4.E-05
Vanadium
6.10E+00
6.10E+00
2.60E-01
2.60E-01
2.5E-02
2.5E-02
2.E-02
2.E-02
l.E-02
l.E-02
Riparian -
Riparian
Buffer Area
within APE
Arsenic
2.00E+00
2.10E+00
4.60E-01
5.00E-01
1.3E-01
1.4E-01
4.E-02
4.E-02
2.E-02
2.E-02
Mercury
3.20E-03
4.00E-03
1.50E-03
1.90E-03
4.1E-04
5.1E-04
l.E-02
2.E-02
3.E-03
4.E-03
Molybdenum
2.30E-01
4.90E-01
1.10E-01
2.40E-01
3.0E-02
6.4E-02
6.E-05
l.E-04
NC
NC
Selenium
ND
ND
ND
ND
—
—
—
—
—
—
Uranium
7.20E-01
9.20E-01
2.40E-02
3.00E-02
1.0E-02
1.3E-02
l.E-04
2.E-04
l.E-05
2.E-05
Vanadium
1.40E+01
1.70E+01
6.00E-01
6.90E-01
2.3E-01
2.7E-01
2.E-01
2.E-01
9.E-02
l.E-01
Notes:
See Appendix Table G3 series of the Phase III Summary Report (provided as Appendix M to this report) for additional details regarding the calculation of EPC values.
HQ values less than one are below levels of regulatory concern.
ADD = average daily dose
EPC = exposure point concentrations
ND = Not detected
NC = Not calculated (TRVloael not available)
UCL = upper confidence limit of the mean
-- = Not applicable
March 18, 2021
Rev. 1.2
T-92
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-8b HQ Results for Upland area Exposures to Radiological PCOC (Ra-226) - Insectivorous Bird (Rock Wren)
Ueceplor (iroup
and Kvalualed
Area
PCOCs
soil i:p(
(p( i
Mean
Values
/g.lH )
1 CI.
ssKSI.
(p( i
NOAKI.
Values
/«.l« )
I.OAKI.
IIQn
Mean
ou.i
I (1.
IIQi
Mean
1 CI.
Upland - APE
Area with
AUMs
Ra-226
5.18E+00
1.09E+01
4.70E+01
4.70E+02
l.E-01
2.E-01
l.E-02
2.E-02
Upland - APE
Area Less
AUMs
Ra-226
2.48E+00
2.93E+00
4.70E+01
4.70E+02
5.E-02
6.E-02
5.E-03
6.E-03
Upland -
Outside of APE
Ra-226
1.99E+00
2.14E+00
4.70E+01
4.70E+02
4.E-02
5.E-02
4.E-03
5.E-03
Upland - AUM
457
Ra-226
7.67E+00
1.58E+01
4.70E+01
4.70E+02
2.E-01
3.E-01
2.E-02
3.E-02
Upland - AUM
458
Ra-226
2.21E+01
7.39E+01
4.70E+01
4.70E+02
5.E-01
2.E+00
5.E-02
2.E-01
Upland - AUM
459
Ra-226
1.50E+01
1.50E+01
4.70E+01
4.70E+02
3.E-01
3.E-01
3.E-02
3.E-02
Riparian -
Riparian Buffer
Area within
APE
Ra-226
9.15E-01
1.05E+00
4.70E+01
4.70E+02
2.E-02
2.E-02
2.E-03
2.E-03
Notes:
See Appendix Table G3 series for additional details regarding the calculation of EPC values.
ssESL values account for receptor AUF and SUF values. See Appendix Tables 16-3 and 16-4 of the Phase III Summary Report (provided as Appendix M to this
report) for additional details.
HQ values less than one are below levels of regulatory concern.
HQ values greater than one are highlighted.
ssESL = site-specific ecological screening levels for soils
UCL = Upper Confidence Limit of the mean
March 18, 2021
Rev. 1.2
T-93
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-9a HQ Results for Upland and Riparian Area Exposures to Non-Radiological PCOCs - Insectivorous Mammal (Desert Shrew)
Receptor
Group and
Evaluated
Area
PCOCs
Soil EPC Values
(mg/kgdw)
Plant EPC Values
(mg/kgdw)
Inverteb
Val
(mg /
rate EPC
ues
kgdw)
ADD
HQnoael
HQloael
Mean
UCL
Mean
UCL
Mean
UCL
Mean
UCL
Mean
UCL
Mean
UCL
Upland -
APE with
AUMs
Arsenic
4.70E+00
7.60E+00
2.20E-01
3.60E-01
1.10E+00
1.80E+00
3.30E-01
5.40E-01
3.E-02
5.E-02
l.E-02
2.E-02
Mercury
1.70E-02
3.50E-02
1.10E-02
2.30E-02
7.90E-03
1.70E-02
2.00E-03
4.30E-03
l.E-02
3.E-02
NC
NC
Molybdenum
1.10E+01
3.70E+01
4.60E+00
1.50E+01
5.50E+00
1.80E+01
1.40E+00
4.40E+00
3.E-01
1.E+00
9.E-02
3.E-01
Selenium
2.30E-01
3.20E-01
1.60E-01
2.20E-01
2.30E-01
3.10E-01
5.10E-02
6.90E-02
6.E-02
8.E-02
3.E-02
4.E-02
Uranium
6.90E+00
1.60E+01
8.30E-01
1.90E+00
2.30E-01
5.20E-01
2.30E-01
5.30E-01
2.E-02
4.E-02
NC
NC
Vanadium
4.20E+01
5.70E+01
2.30E-01
3.10E-01
1.80E+00
2.40E+00
1.40E+00
1.90E+00
3.E-01
5.E-01
2.E-01
2.E-01
Upland -
APE Less
AUMs
Arsenic
3.00E+00
3.40E+00
1.40E-01
1.60E-01
7.10E-01
8.00E-01
2.10E-01
2.40E-01
2.E-02
2.E-02
8.E-03
9.E-03
Mercury
7.70E-03
1.40E-02
5.10E-03
9.30E-03
3.60E-03
6.60E-03
9.30E-04
1.70E-03
6.E-03
l.E-02
NC
NC
Molybdenum
1.60E+00
5.40E+00
6.30E-01
2.20E+00
7.60E-01
2.60E+00
1.90E-01
6.50E-01
4.E-02
2.E-01
l.E-02
4.E-02
Selenium
2.50E-01
3.80E-01
1.80E-01
2.60E-01
2.50E-01
3.70E-01
5.50E-02
8.30E-02
6.E-02
9.E-02
3.E-02
4.E-02
Uranium
2.70E+00
4.30E+00
3.30E-01
5.20E-01
9.00E-02
1.40E-01
9.10E-02
1.40E-01
6.E-03
l.E-02
NC
NC
Vanadium
4.80E+01
6.70E+01
2.70E-01
3.70E-01
2.00E+00
2.80E+00
1.60E+00
2.30E+00
4.E-01
5.E-01
2.E-01
3.E-01
Upland -
Outside of
APE
Arsenic
3.00E+00
3.20E+00
1.40E-01
1.50E-01
7.00E-01
7.60E-01
2.10E-01
2.30E-01
2.E-02
2.E-02
8.E-03
9.E-03
Mercury
1.00E-02
1.20E-02
6.80E-03
7.70E-03
4.80E-03
5.50E-03
1.20E-03
1.40E-03
8.E-03
9.E-03
NC
NC
Molybdenum
2.50E-01
3.40E-01
1.00E-01
1.40E-01
1.20E-01
1.60E-01
3.00E-02
4.10E-02
7.E-03
9.E-03
2.E-03
3.E-03
Selenium
1.70E-01
2.30E-01
1.20E-01
1.60E-01
1.70E-01
2.30E-01
3.80E-02
5.10E-02
4.E-02
6.E-02
2.E-02
3.E-02
Uranium
2.50E+00
2.90E+00
3.10E-01
3.50E-01
8.40E-02
9.60E-02
8.40E-02
9.70E-02
6.E-03
7.E-03
NC
NC
Vanadium
4.30E+01
4.80E+01
2.40E-01
2.60E-01
1.80E+00
2.00E+00
1.50E+00
1.60E+00
4.E-01
4.E-01
2.E-01
2.E-01
Upland
Receptors -
AUM 457
Arsenic
4.40E+00
6.60E+00
2.10E-01
3.10E-01
1.10E+00
1.60E+00
3.10E-01
4.60E-01
3.E-02
5.E-02
l.E-02
2.E-02
Mercury
1.20E-02
1.70E-02
7.80E-03
1.10E-02
5.50E-03
8.00E-03
1.40E-03
2.10E-03
9.E-03
l.E-02
NC
NC
Molybdenum
1.00E+01
2.40E+01
4.20E+00
9.80E+00
5.00E+00
1.20E+01
1.20E+00
2.90E+00
3.E-01
7.E-01
8.E-02
2.E-01
Selenium
1.20E-01
1.70E-01
8.00E-02
1.20E-01
1.10E-01
1.70E-01
2.50E-02
3.70E-02
3.E-02
4.E-02
l.E-02
2.E-02
Uranium
6.50E+00
9.70E+00
7.80E-01
1.20E+00
2.10E-01
3.20E-01
2.10E-01
3.20E-01
l.E-02
2.E-02
NC
NC
Vanadium
3.40E+01
3.80E+01
1.80E-01
2.10E-01
1.40E+00
1.60E+00
1.10E+00
1.30E+00
3.E-01
3.E-01
l.E-01
2.E-01
Upland
Receptors -
AUM 458
Arsenic
2.00E+01
2.80E+01
9.20E-01
1.30E+00
4.60E+00
6.50E+00
1.40E+00
2.00E+00
l.E-01
2.E-01
5.E-02
8.E-02
Mercury
1.10E-01
1.70E-01
7.30E-02
1.10E-01
5.20E-02
8.00E-02
1.30E-02
2.10E-02
8.E-02
l.E-01
NC
NC
Molybdenum
9.60E+01
3.50E+02
3.80E+01
1.40E+02
4.60E+01
1.70E+02
1.10E+01
4.20E+01
3.E+00
l.E+01
8.E-01
3.E+00
Selenium
2.70E-01
5.20E-01
1.90E-01
3.60E-01
2.60E-01
5.10E-01
5.80E-02
1.10E-01
6.E-02
l.E-01
3.E-02
6.E-02
Uranium
4.50E+01
8.60E+01
5.40E+00
1.00E+01
1.50E+00
2.80E+00
1.50E+00
2.90E+00
l.E-01
2.E-01
NC
NC
Vanadium
1.50E+01
1.70E+01
8.20E-02
9.40E-02
6.30E-01
7.10E-01
5.10E-01
5.70E-01
l.E-01
l.E-01
6.E-02
7.E-02
March 18, 2021
Rev. 1.2
T-94
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-9a HQ Results for Upland and Riparian Area Exposures to Non-Radiological PCOCs - Insectivorous Mammal (Desert Shrew) (Continued)
Receptor
Group and
Evaluated
Area
PCOCs
Soil EPC Values
(mg/kgdw)
Plant EPC Values
(mg/kgdw)
Inverteb
Val
(mg /
rate EPC
ues
kgdw)
ADD
HQnoael
HQloael
Mean
UCL
Mean
UCL
Mean
UCL
Mean
UCL
Mean
UCL
Mean
UCL
Upland
Receptors -
AUM 459
Arsenic
7.20E+00
7.20E+00
3.40E-01
3.40E-01
1.70E+00
1.70E+00
1.80E-01
1.80E-01
2.E-02
2.E-02
7.E-03
7.E-03
Mercury
1.30E-02
1.30E-02
8.60E-03
8.60E-03
6.10E-03
6.10E-03
5.40E-04
5.40E-04
3.E-03
3.E-03
NC
NC
Molybdenum
4.50E+01
4.50E+01
1.80E+01
1.80E+01
2.20E+01
2.20E+01
1.90E+00
1.90E+00
4.E-01
4.E-01
l.E-01
l.E-01
Selenium
ND
ND
ND
ND
—
—
—
—
—
—
—
—
Uranium
9.00E+00
9.00E+00
1.10E+00
1.10E+00
3.00E-01
3.00E-01
1.00E-01
1.00E-01
7.E-03
7.E-03
NC
NC
Vanadium
6.10E+00
6.10E+00
3.40E-02
3.40E-02
2.60E-01
2.60E-01
7.20E-02
7.20E-02
2.E-02
2.E-02
9.E-03
9.E-03
Riparian -
Riparian
Buffer Area
within APE
Arsenic
2.00E+00
2.10E+00
9.30E-02
1.00E-01
4.60E-01
5.00E-01
2.60E-02
2.80E-02
3.E-03
3.E-03
l.E-03
l.E-03
Mercury
3.20E-03
4.00E-03
2.10E-03
2.60E-03
1.50E-03
1.90E-03
7.30E-05
8.90E-05
5.E-04
6.E-04
NC
NC
Molybdenum
2.30E-01
4.90E-01
9.20E-02
2.00E-01
1.10E-01
2.40E-01
5.20E-03
1.10E-02
l.E-03
3.E-03
4.E-04
7.E-04
Selenium
ND
ND
ND
ND
—
—
—
—
—
—
—
—
Uranium
7.20E-01
9.20E-01
8.80E-02
1.10E-01
2.40E-02
3.00E-02
4.50E-03
5.70E-03
3.E-04
4.E-04
NC
NC
Vanadium
1.40E+01
1.70E+01
7.80E-02
9.10E-02
6.00E-01
6.90E-01
8.90E-02
1.00E-01
2.E-02
3.E-02
l.E-02
l.E-02
Notes:
See Appendix Table G3 series of the Phase III Summary Report (provided as Appendix M to this report) for additional details regarding the calculation of EPC values.
HQ values less than one are below levels of regulatory concern.
HQ values greater than one are highlighted.
ADD = average daily dose
EPC = exposure point concentrations
ND = Not detected
NC = Not calculated (TRVloael not available)
UCL = upper confidence limit of the mean
-- = Not applicable
March 18, 2021
Rev. 1.2
T-95
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-9b HQ Results for Upland and Riparian Area Exposures to Radiological PCOC (Ra-226) - Insectivorous Mammal
(Desert Shrew)
Receptor Group
and Evaluated
Area
PCOCs
Soil EPC Values
(pCi/gdw)
ssESL Values
(pCi/gdw)
HQnoael
HQloael
Mean
UCL
NOAEL
LOAEL
Mean
UCL
Mean
UCL
Upland - APE
with AUMs
Ra-226
5.18E+00
1.09E+01
5.90E+02
5.90E+03
9.E-03
2.E-02
9.E-04
2.E-03
Upland - APE
Less AUMs
Ra-226
2.48E+00
2.93E+00
5.90E+02
5.90E+03
4.E-03
5.E-03
4.E-04
5.E-04
Upland -
Outside of APE
Ra-226
1.99E+00
2.14E+00
5.90E+02
5.90E+03
3.E-03
4.E-03
3.E-04
4.E-04
Upland - AUM
457
Ra-226
7.67E+00
1.58E+01
5.90E+02
5.90E+03
l.E-02
3.E-02
l.E-03
3.E-03
Upland - AUM
458
Ra-226
2.21E+01
7.39E+01
5.90E+02
5.90E+03
4.E-02
l.E-01
4.E-03
l.E-02
Upland - AUM
459
Ra-226
1.50E+01
1.50E+01
5.90E+02
5.90E+03
3.E-02
3.E-02
3.E-03
3.E-03
Riparian -
Riparian Buffer
Area within
APE
Ra-226
9.15E-01
1.05E+00
5.90E+02
5.90E+03
2.E-03
2.E-03
2.E-04
2.E-04
Notes:
See Appendix Table G3 series for additional details regarding the calculation of EPC values.
ssESL values account for receptor AUF and SUF values. See Appendix Tables G6-3 and G6-4 of the Phase III Summary Report (provided as Appendix M to
this report) for additional details.
HQ values less than one indicate no significant risk.
ssESL = site-specific ecological screening levels for soils
UCL = Upper Confidence Limit of the mean
March 18, 2021
Rev. 1.2
T-96
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-10a HQ Results for Riparian Area Exposures to Non-Radiological PCOCs - Omnivorous Mammal (Coyote)
Receptor
Group and
Evaluated
Area
PCOCs
Soil EPC Values
(mg/kgdw)
Diet EPC Values
(mg/kgdw)
ADD
HQnoael
HQloael
Mean
UCL
Mean
UCL
Mean
UCL
Mean
UCL
Mean
UCL
Riparian -
Riparian
Buffer Area
within APE
Arsenic
2.00E+00
2.10E+00
5.80E-04
6.30E-04
1.50E-05
1.60E-05
8.E-06
9.E-06
4.E-06
4.E-06
Mercury
3.20E-03
4.00E-03
1.90E-04
2.40E-04
9.70E-08
1.20E-07
6.E-07
8.E-07
NC
NC
Molybdenum
2.30E-01
4.90E-01
5.50E-05
1.20E-04
1.80E-06
3.70E-06
7.E-07
2.E-06
2.E-07
5.E-07
Selenium
ND
ND
ND
ND
—
—
—
—
—
—
Uranium
7.20E-01
9.20E-01
1.10E-05
1.30E-05
5.50E-06
7.00E-06
4.E-07
5.E-07
NC
NC
Vanadium
1.40E+01
1.70E+01
2.70E-03
3.10E-03
1.10E-04
1.30E-04
l.E-04
l.E-04
6.E-05
7.E-05
Notes:
See Appendix Table G3 series of the Phase III Summary Report (provided as Appendix M to this report) for additional details regarding the calculation of EPC values.
HQ values less than one are below levels of regulatory concern.
This receptor was not evaluated in the upland portions of the Site.
ADD = average daily dose
EPC = exposure point concentrations
ND = Not detected
NC = Not calculated (TRVloael not available)
UCL = upper confidence limit of the mean
-- = Not applicable
March 18, 2021
Rev. 1.2
T-97
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-10b HQ Results for Riparian Area Exposure to Radiological PCOC (Ra-226) - Omnivorous Mammal (Coyote)
Receptor Group
and Evaluated
Area
PCOCs
Soil EPC Values
(pCi/gdw)
ssESL Values
(pCi/gdw)
HQnoael
HQloael
Mean
UCL
NOAEL
LOAEL
Mean
UCL
Mean
UCL
Riparian -
Riparian Buffer
Area within APE
Ra-226
9.15E-
01
1.05E+00
2.80E+04
2.80E+05
3.E-05
4.E-05
3.E-06
4.E-06
Notes:
See Appendix Table G3 series of the Phase III Summary Report (provided as Appendix M to this report) for additional details regarding the calculation of EPC values.
ssESL values account for receptor AUF and SUF values. See Appendix Tables G6-3 and G6-4 of the Phase III Summary Report for additional details.
HQ values less than one are below levels of regulatory concern.
This receptor was not evaluated in the upland portions of the Site.
ssESL = site-specific ecological screening levels for soils
UCL = Upper Confidence Limit of the mean
March 18, 2021
Rev. 1.2
T-98
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-lla HQ Results for Upland Area Exposures to Non-Radiological PCOCs - Carnivorous Bird (Golden Eagle)
Receptor
Group and
Evaluated
Area
PCOCs
Soil EPC Values
(mg/kgdw)
Diet EPC Values
(mg/kgdw)
ADD
HQnoael
HQloael
Mean
UCL
Mean
UCL
Mean
UCL
Mean
UCL
Mean
UCL
Upland - APE
with AUMs
Arsenic
4.70E+00
7.60E+00
1.40E-03
2.30E-03
2.8.E-08
4.7.E-08
8.E-09
l.E-08
4.E-09
6.E-09
Mercury
1.70E-02
3.50E-02
1.00E-03
2.10E-03
2.1.E-08
4.4.E-08
7.E-07
l.E-06
2.E-07
3.E-07
Molybdenum
1.10E+01
3.70E+01
2.70E-03
8.80E-03
5.6.E-08
1.8.E-07
l.E-10
3.E-10
NC
NC
Selenium
2.30E-01
3.20E-01
1.50E-03
2.00E-03
3.1.E-08
4.2.E-08
4.E-08
5.E-08
2.E-08
2.E-08
Uranium
6.90E+00
1.60E+01
1.00E-04
2.30E-04
2.1.E-09
4.7.E-09
3.E-11
6.E-11
3.E-12
6.E-12
Vanadium
4.20E+01
5.70E+01
8.00E-03
1.10E-02
1.7.E-07
2.2.E-07
l.E-07
2.E-07
6.E-08
9.E-08
Upland - APE
Less AUMs
Arsenic
3.00E+00
3.40E+00
8.90E-04
1.00E-03
1.7.E-08
1.9.E-08
5.E-09
5.E-09
2.E-09
3.E-09
Mercury
7.70E-03
1.40E-02
4.60E-04
8.50E-04
8.7.E-09
1.6.E-08
3.E-07
5.E-07
6.E-08
l.E-07
Molybdenum
1.60E+00
5.40E+00
3.80E-04
1.30E-03
7.1.E-09
2.4.E-08
l.E-11
5.E-11
NC
NC
Selenium
2.50E-01
3.80E-01
1.60E-03
2.40E-03
3.1.E-08
4.6.E-08
4.E-08
6.E-08
2.E-08
2.E-08
Uranium
2.70E+00
4.30E+00
4.00E-05
6.30E-05
7.5.E-10
1.2.E-09
l.E-11
2.E-11
l.E-12
2.E-12
Vanadium
4.80E+01
6.70E+01
9.20E-03
1.30E-02
1.7.E-07
2.4.E-07
l.E-07
2.E-07
7.E-08
9.E-08
Upland -
Outside of
APE
Arsenic
3.00E+00
3.20E+00
8.80E-04
9.60E-04
2.4.E-08
2.6.E-08
7.E-09
7.E-09
3.E-09
3.E-09
Mercury
1.00E-02
1.20E-02
6.20E-04
7.00E-04
1.7.E-08
1.9.E-08
5.E-07
6.E-07
l.E-07
l.E-07
Molybdenum
2.50E-01
3.40E-01
6.10E-05
8.10E-05
1.6.E-09
2.2.E-09
3.E-12
4.E-12
NC
NC
Selenium
1.70E-01
2.30E-01
1.10E-03
1.50E-03
3.0.E-08
4.0.E-08
4.E-08
5.E-08
2.E-08
2.E-08
Uranium
2.50E+00
2.90E+00
3.70E-05
4.20E-05
9.9.E-10
l.l.E-09
l.E-11
2.E-11
l.E-12
2.E-12
Vanadium
4.30E+01
4.80E+01
8.20E-03
9.20E-03
2.2.E-07
2.5.E-07
2.E-07
2.E-07
9.E-08
9.E-08
Upland
Receptors -
AUM 457
Arsenic
4.40E+00
6.60E+00
1.30E-03
1.90E-03
1.5.E-09
2.2.E-09
4.E-10
6.E-10
2.E-10
3.E-10
Mercury
1.20E-02
1.70E-02
7.10E-04
1.00E-03
8.0.E-10
1.2.E-09
3.E-08
4.E-08
6.E-09
8.E-09
Molybdenum
1.00E+01
2.40E+01
2.50E-03
5.80E-03
2.8.E-09
6.6.E-09
5.E-12
l.E-11
NC
NC
Selenium
1.20E-01
1.70E-01
7.40E-04
1.10E-03
8.4.E-10
1.2.E-09
l.E-09
2.E-09
4.E-10
6.E-10
Uranium
6.50E+00
9.70E+00
9.40E-05
1.40E-04
l.l.E-10
1.6.E-10
l.E-12
2.E-12
l.E-13
2.E-13
Vanadium
3.40E+01
3.80E+01
6.40E-03
7.30E-03
7.3.E-09
8.2.E-09
6.E-09
7.E-09
3.E-09
3.E-09
March 18, 2021
Rev. 1.2
T-99
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-lla HQ Results for Upland Area Exposures to Non-Radiological PCOCs - Carnivorous Bird (Golden Eagle) (Continued)
Receptor
Group and
Evaluated
Area
PCOCs
Soil EPC Values
(mg/kgdw)
Diet EPC Values
(mg/kgdw)
ADD
HQnoael
HQloael
Mean
UCL
Mean
UCL
Mean
UCL
Mean
UCL
Mean
UCL
Upland
Receptors -
AUM 458
Arsenic
2.00E+01
2.80E+01
5.80E-03
8.20E-03
3.7.E-09
5.3.E-09
l.E-09
2.E-09
5.E-10
7.E-10
Mercury
1.10E-01
1.70E-01
6.60E-03
1.00E-02
4.3.E-09
6.6.E-09
l.E-07
2.E-07
3.E-08
5.E-08
Molybdenum
9.60E+01
3.50E+02
2.30E-02
8.40E-02
1.5.E-08
5.4.E-08
3.E-11
l.E-10
NC
NC
Selenium
2.70E-01
5.20E-01
1.70E-03
3.30E-03
l.l.E-09
2.1.E-09
l.E-09
3.E-09
6.E-10
l.E-09
Uranium
4.50E+01
8.60E+01
6.50E-04
1.20E-03
4.2.E-10
8.1.E-10
5.E-12
l.E-11
5.E-13
l.E-12
Vanadium
1.50E+01
1.70E+01
2.80E-03
3.20E-03
1.8.E-09
2.1.E-09
2.E-09
2.E-09
7.E-10
8.E-10
Upland
Receptors -
AUM 459
Arsenic
7.20E+00
7.20E+00
2.10E-03
2.10E-03
3.2.E-11
3.2.E-11
9.E-12
9.E-12
4.E-12
4.E-12
Mercury
1.30E-02
1.30E-02
7.80E-04
7.80E-04
1.2.E-11
1.2.E-11
4.E-10
4.E-10
8.E-11
8.E-11
Molybdenum
4.50E+01
4.50E+01
1.10E-02
1.10E-02
1.6.E-10
1.6.E-10
3.E-13
3.E-13
NC
NC
Selenium
ND
ND
ND
ND
—
—
—
—
—
—
Uranium
9.00E+00
9.00E+00
1.30E-04
1.30E-04
2.0.E-12
2.0.E-12
3.E-14
3.E-14
3.E-15
3.E-15
Vanadium
6.10E+00
6.10E+00
1.20E-03
1.20E-03
1.7.E-11
1.7.E-11
l.E-11
l.E-11
7.E-12
7.E-12
Riparian -
Riparian
Buffer Area
within APE
Arsenic
2.00E+00
2.10E+00
5.80E-04
6.30E-04
9.0.E-10
9.7.E-10
3.E-10
3.E-10
l.E-10
l.E-10
Mercury
3.20E-03
4.00E-03
1.90E-04
2.40E-04
3.0.E-10
3.7.E-10
l.E-08
l.E-08
2.E-09
3.E-09
Molybdenum
2.30E-01
4.90E-01
5.50E-05
1.20E-04
8.5.E-11
1.8.E-10
2.E-13
3.E-13
NC
NC
Selenium
ND
ND
ND
ND
—
—
—
—
—
—
Uranium
7.20E-01
9.20E-01
1.10E-05
1.30E-05
1.6.E-11
2.1.E-11
2.E-13
3.E-13
2.E-14
3.E-14
Vanadium
1.40E+01
1.70E+01
2.70E-03
3.10E-03
4.2.E-09
4.9.E-09
3.E-09
4.E-09
2.E-09
2.E-09
Notes:
See Appendix Table G3 series of the Phase III Summary Report (provided as Appendix M to this report) for additional details regarding the calculation of EPC values.
HQ values less than one are below levels of regulatory concern.
ADD = average daily dose
EPC = exposure point concentrations
ND = Not detected
NC = Not calculated (TRVloael not available)
UCL = upper confidence limit of the mean
-- = Not applicable
March 18, 2021
Rev. 1.2
T-100
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-llb HQ Results for Upland Area Exposures to Radiological PCOC (Ra-226) - Carnivorous Bird (Golden Eagle)
Receptor Group
and Evaluated
Area
PCOCs
Soil EPC Values
(pCi/gdw)
ssESL Values
(pCi/gdw)
HQnoael
HQloael
Mean
UCL
NOAEL
LOAEL
Mean
UCL
Mean
UCL
Upland - APE
with AUMs
Ra-226
5.18E+00
1.09E+01
1.10E+06
1.10E+07
5.E-06
l.E-05
5.E-07
l.E-06
Upland - APE
Less AUMs
Ra-226
2.48E+00
2.93E+00
1.20E+06
1.20E+07
2.E-06
2.E-06
2.E-07
2.E-07
Upland -
Outside of APE
Ra-226
1.99E+00
2.14E+00
8.40E+05
8.40E+06
2.E-06
3.E-06
2.E-07
3.E-07
Upland - AUM
457
Ra-226
7.67E+00
1.58E+01
1.99E+07
1.99E+08
4.E-07
8.E-07
4.E-08
8.E-08
Upland - AUM
458
Ra-226
2.21E+01
7.39E+01
3.51E+07
3.51E+08
6.E-07
2.E-06
6.E-08
2.E-07
Upland - AUM
459
Ra-226
1.50E+01
1.50E+01
1.51E+09
1.51E+10
l.E-08
l.E-08
l.E-09
l.E-09
Riparian -
Riparian Buffer
Area within
APE
Ra-227
9.15E-01
1.05E+00
1.50E+07
1.50E+08
6.E-08
7.E-08
6.E-09
7.E-09
Notes:
See Appendix Table G2 series for additional details regarding the calculation of EPC values.
ssESL values account for receptor AUF and SUF values. See Appendix Tables G6-3 and G6-4 of the Phase III Summary Report (provided as Appendix M to
this report) for additional details.
HQ values less than one are below levels of regulatory concern.
ssESL = site-specific ecological screening levels for soils
UCL = Upper Confidence Limit of the mean
March 18, 2021
Rev. 1.2
T-101
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-12 Evaluation of Potential Risks to Spadefoot Toad from LCR Channel Sample Results under the Wet Scenario
PCOCs
Riparian Area
Samples
Sediment Criteria
Units
Mean
UCL
NOAEL
LOAEL
Source
Arsenic
mg/kgdw
1.96E+00
2.12E+00
9.70E+00
3.30E+01
a
Mercury
mg/kgdw
3.22E-03
3.97E-03
1.80E-01
1.00E+00
a
Molybdenum
mg/kgdw
2.30E-01
4.90E-01
1.00E+01
2.00E+02
b
Selenium
mg/kgdw
ND
ND
7.20E-01
2.90E+00
a
Uranium
mg/kgdw
7.25E-01
9.21E-01
1.00E+02
1.00E+03
a
Vanadium
mg/kgdw
1.42E+01
1.65E+01
5.00E+01
NR
c
Ra-226
pCi/gdw
9.15E-01
1.05E+00
5.00E+01
NR
d
1.40E+03
1.40E+04
e
Notes:
Sediment benchmarks were derived from different sources.
ND = Not detected
NR = Not reported
a Values from LANL (2017a) for Aquatic community organisms - sediment
b Values shown are the Dutch Ministry target and intervention values for molybdenum in sediments reported
in Friday (1998).
0 Value from NOAA SQuIRT, background value for sediments.
d DOE (2002)
e Values from LANL (2017a) for Aquatic organisms - sediment
March 18, 2021
Rev. 1.2
T-102
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-13 Uncertainty Assessment of Receptor Selection - HQ Results for Upland and Riparian Area Exposures to
Non-Radiological and Radiological PCOCs by Soil Invertebrates
Receptor Group
and Evaluated
Area
PCOCs
Soil EPC Values
Earthworm ESLs
HQnoael
HQloael
Mean
UCL
NOAEL
LOAEL
Mean
UCL
Mean
UCL
Upland - APE
Area with
AUMs
Arsenic
4.66E+00
7.65E+00
6.80E+00
6.80E+01
7.E-01
1.E+00
7.E-02
l.E-01
Mercury
1.68E-02
3.53E-02
5.00E-02
5.00E-01
3.E-01
7.E-01
3.E-02
7.E-02
Molybdenum
1.14E+01
3.67E+01
NR
2.15E+02
NR
NR
5.E-02
2.E-01
Ra-226
5.18E+00
1.09E+01
1.50E+00
1.50E+01
3.E+00
7.E+00
3.E-01
7.E-01
Selenium
2.31E-01
3.16E-01
4.10E+00
4.10E+01
6.E-02
8.E-02
6.E-03
8.E-03
Uranium
6.89E+00
1.58E+01
1.10E+03
1.10E+04
6.E-03
l.E-02
6.E-04
l.E-03
Vanadium
4.23E+01
5.72E+01
NR
NR
—
—
-
—
—
Upland - APE
Area Less
AUMs
Arsenic
3.00E+00
3.41E+00
6.80E+00
6.80E+01
4.E-01
5.E-01
4.E-02
5.E-02
Mercury
7.73E-03
1.41E-01
5.00E-02
5.00E-01
2.E-01
3.E+00
2.E-02
3.E-01
Molybdenum
1.58E+00
5.43E+00
NR
2.15E+02
NR
NR
7.E-03
3.E-02
Ra-226
2.48E+00
2.93E+00
1.50E+00
1.50E+01
2.E+00
2.E+00
2.E-01
2.E-01
Selenium
2.53E-01
3.77E-01
4.10E+00
4.10E+01
6.E-02
9.E-02
6.E-03
9.E-03
Uranium
2.74E+00
4.33E+00
1.10E+03
1.10E+04
2.E-03
4.E-03
2.E-04
4.E-04
Vanadium
4.82E+01
6.69E+01
NR
NR
—
—
-
—
—
March 18, 2021
Rev. 1.2
T-103
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-13 Uncertainty Assessment of Receptor Selection - HQ Results for Upland and Riparian Area Exposures to
Non-Radiological and Radiological PCOCs by Soil Invertebrates (Continued)
Ueceplor Group
and Kvalualed
Area
PCOCs
soil i:p(
Mean
Values
1 CI.
Karlhwo
NOAKL
rm KSI.s
I.OAKI.
IIQn
Mean
< > \ i: i
1 CI.
IIQi
Mean
OU.I
1 CI.
Upland -
Outside of APE
Arsenic
2.97E+00
3.23E+00
6.80E+00
6.80E+01
4.E-01
5.E-01
4.E-02
5.E-02
Mercury
1.03E-02
1.16E-02
5.00E-02
5.00E-01
2.E-01
2.E-01
2.E-02
2.E-02
Molybdenum
2.54E-01
3.38E-01
NR
2.15E+02
NR
NR
l.E-03
2.E-03
Ra-226
1.99E+00
2.14E+00
1.50E+00
1.50E+01
l.E+00
l.E+00
l.E-01
l.E-01
Selenium
1.73E-01
2.31E-01
4.10E+00
4.10E+01
4.E-02
6.E-02
4.E-03
6.E-03
Uranium
2.54E+00
2.92E+00
1.10E+03
1.10E+04
2.E-03
3.E-03
2.E-04
3.E-04
Vanadium
4.32E+01
4.82E+01
NR
NR
—
—
-
—
—
Upland
Receptors -
APE 457
Arsenic
4.45E+00
6.57E+00
6.80E+00
6.80E+01
7.E-01
l.E+00
7.E-02
l.E-01
Mercury
1.18E-02
1.71E-02
5.00E-02
5.00E-01
2.E-01
3.E-01
2.E-02
3.E-02
Molybdenum
1.04E+01
2.44E+01
NR
2.15E+02
XR
XR
5.E-02
l.E-01
Ra-226
7.67E+00
1.58E+01
1.50E+00
1.50E+01
5 1- mi
i n in
5.E-01
1 11 mi
Selenium
1.15E-01
1.68E-01
4.10E+00
4.10E+01
3.E-02
4.E-02
3.E-03
4.E-03
Uranium
6.46E+00
9.74E+00
1.10E+03
1.10E+04
6.E-03
9.E-03
6.E-04
9.E-04
Vanadium
3.36E+01
3.82E+01
NR
NR
—
—
-
—
—
Upland
Receptors -
APE 458
Arsenic
1.95E+01
2.77E+01
6.80E+00
6.80E+01
3n mi
4n mi
3.E-01
4.E-01
Mercury
1.10E-01
1.70E-01
5.00E-02
5.00E-01
:.i ; do
3n mi
2.E-01
3.E-01
Molybdenum
9.58E+01
1.03E+03
NR
2.15E+02
NR
\R
4 ll-Dl
5 11 i)i)
Ra-226
2.21E+01
7.39E+01
1.50E+00
1.50E+01
i n in
5 11 i) 1
1 11 mi
5 11 i)i)
Selenium
2.67E-01
5.18E-01
4.10E+00
4.10E+01
7 11-1)2
1 ll-Dl
7.E-03
l.E-02
Uranium
4.49E+01
8.62E+01
1.10E+03
1.10E+04
4.E-02
8.E-02
4.E-03
8.E-03
March 18, 2021
Rev. 1.2
T-104
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-13 Uncertainty Assessment of Receptor Selection - HQ Results for Upland and Riparian Area Exposures to
Non-Radiological and Radiological PCOCs by Soil Invertebrates (Continued)
Receptor Group
and Evaluated
Area
PCOCs
Soil EPC Values
Earthworm ESLs
HQnoael
HQloael
Mean
UCL
NOAEL
LOAEL
Mean
UCL
Mean
UCL
Vanadium
1.50E+01
1.76E+01
NR
NR
—
—
-
—
—
Upland
Receptors -
APE 459
Arsenic
7.25E+00
7.25E+00
6.80E+00
6.80E+01
1.E+00
1.E+00
l.E-01
l.E-01
Mercury
1.30E-02
1.30E-02
5.00E-02
5.00E-01
3.E-01
3.E-01
3.E-02
3.E-02
Molybdenum
4.50E+01
4.50E+01
NR
2.15E+02
NR
NR
2.E-01
2.E-01
Ra-226
1.50E+01
1.50E+01
1.50E+00
1.50E+01
l.E+01
l.E+01
1.E+00
1.E+00
Selenium
ND
ND
4.10E+00
4.10E+01
ND
ND
ND
ND
Uranium
9.00E+00
9.00E+00
1.10E+03
1.10E+04
8.E-03
8.E-03
8.E-04
8.E-04
Vanadium
6.10E+00
6.10E+00
NR
NR
—
—
-
—
—
Riparian -
Riparian Buffer
Area within
APE
Arsenic
1.96E+00
2.12E+00
6.80E+00
6.80E+01
3.E-01
3.E-01
3.E-02
3.E-02
Mercury
3.22E-03
3.97E-03
5.00E-02
5.00E-01
6.E-02
8.E-02
6.E-03
8.E-03
Molybdenum
2.30E-01
4.90E-01
NR
2.15E+02
NR
NR
l.E-03
2.E-03
Ra-226
9.15E-01
1.05E+00
1.50E+00
1.50E+01
6.E-01
7.E-01
6.E-02
7.E-02
Selenium
ND
ND
4.10E+00
4.10E+01
—
—
—
—
Uranium
7.25E-01
9.21E-01
1.10E+03
1.10E+04
7.E-04
8.E-04
7.E-05
8.E-05
Vanadium
1.42E+01
1.65E+01
NR
NR
—
—
-
—
—
Notes:
Non-radiological concentration unit is mg/kgdw. Ra-226 concentration unit is pCi/gdw. See Appendix Table G2 series of the Phase III Summary Report (provided
as Appendix M to this report) for additional details regarding the calculation of EPC values. ESL values were for earthworms (except for molybdenum) and
assumed applicable to all terrestrial invertebrates (e.g., insects). See Appendix Table G7 series of the Phase III Summary Report for additional information.
HQ values less than one is below regulatory risk level. HQ values greater than one are highlighted. ND = Not detected. NR = Not reported
March 18, 2021
Rev. 1.2
T-105
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-14 Uncertainty Assessment - Comparison of Ra-226 ssESLs to LANL (2017a) ESLs of Similar Species
Babbitt Site
LANL (2017a) Model
ssESL Values
(pCi/gdw)
LANL ESL Values
(pCi/gdw)
Babbitt Receptor
Evaluated Area
NOAEL
LOAEL
LANL Receptor
NOAEL
LOAEL
Deer Mouse
All evaluated areas
540
5,400
Deer Mouse
380
3,800
American
Kestrel
Upland areas only
910
9,100
American Kestrel
870
8,700
Desert Shrew
All evaluated areas
590
5,900
Montane Shrew
510
5,100
Coyote
Riparian areas only
28,000
280,000
Gray Fox
370
3,700
Note:
The Coyote ssESL accounts for the AUF which is not included in the Gray Fox LANL ESL calculation.
The LANL ESL values uses different (though similar) exposure assumptions and TRVs compared to those used to develop the ssESLs.
The "Evaluated Area" refers to those portions of the Site where exposures to PCOCs were assessed.
March 18, 2021
Rev. 1.2
T-106
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-15a Summary of EcoSRE HQ Results for All Evaluated Receptors and
Evaluated Area
PCOCs
Arsenic
Mercury
Upland - APE Area Molybdenum
with AUMs
Selenium
Uranium
Vanadium
Arsenic
Mercury
Upland - APE Area Molybdenum
Less AUMs
Selenium
Uranium
Vanadium
Arsenic
Mercury
Upland - Outside of Molybdenum
APE Area Selenium
Uranium
Vanadium
Arsenic
Mercury
Upland Receptors - Molybdenum
AUM 457 Selenium
Uranium
Vanadium
Arsenic
Mercury
Upland Receptors - Molybdenum
AUM 458
Selenium
Uranium
Vanadium
Arsenic
Mercury
Upland Receptors - Molybdenum
AUM 459
Selenium
Uranium
Vanadium
Riparian - Riparian
Buffer Area within
APE
Arsenic
Mercury
Molybdenum
Selenium
_Ur anium
Vanadium
Plants
HQnoael
HQloael
ND
ND
J
B
ND
ND
ND
ND
Mourning Dove
HQnoael
HQloael
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
ND
NR
NR
ND
J
B
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
ND
NR
NR
ND
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
ND
NR
NR
NC
ND
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
ND
NR
NR
NC
ND
Deer Mouse
HQnoael
HQloael
ND
ND
J
B
ND
ND
NC
NC
NC
NC
NC
NC
ND
NC
ND
NC
NC
NC
NC
NC
NC
NC
ND
NC
ND
NC
Non-Radiologica
American
Kestrel
HQnoael
HQloael
ND
ND
J
B
ND
ND
NC
NC
NC
NC
NC
NC
ND
NC
ND
NC
NC
NC
NC
NC
NC
NC
ND
NC
ND
NC
PCOCs
Rock
Wren
HQnoael
HQloael
ND
ND
J
B
ND
ND
TS h-}
i B
NC
NC
NC
NC
NC
NC
ND
NC
ND
NC
NC
NC
NC
NC
NC
ND
NC
ND
Desert
Shrew
HQnoael
HQloael
TS l-J
i B
ND
ND
ND
ND
TS h-}
i B
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
ND
NC
NC
ND
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
NC
ND
NC
NC
ND
NC
Coyote
HQnoael
HQloael
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
ND
J
B
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
ND
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NC
ND
NC
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NR
NC
ND
NC
Golden
Eagle
HQnoael
ND
ND
J
B
ND
ND
Notes:
Color coding: green = HQ less than one; yellow = HQ between one and ten; red = HQ greater than 10.
ND = Not detected
NC = Not calculated (TRVloael n°t avaliable)
NR = Not reported. Receptor not evaluated in this area.
UCL=upper confidence limit of the mean
— = Not applicable
HQloael
NC
NC
NC
NC
NC
NC
ND
NC
ND
NC
NC
NC
NC
NC
NC
ND
NC
ND
March 18, 2021
Rev. 1.2
T-107
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 7-15b Summary of EcoSRE HQ Results for All Evaluated Receptors and Radiological PCOCs
l'l suits
Mourning Dove
Door Mouse
American
Kestrel
Rock
Wren
Desert
Shrew
Coyote
Golden
Ksiglc
Kviiluiitcd Area PCOCs
IIQnoakl
HQlOAEL
IIQnoakl
HQloael
IIQnoakl
HQloael
IIQnoakl
HQloael
IIQnoakl
HQloael
IIQnoakl
HQloael
IIQnoakl
HQloael
IIQnoakl
HQloael
s 1
« hJ
U
« U5
s
u U
S &
« J
— u
§ P
s
— u
§ P
« J
§
c >
C5 J
§ p
u u
S £3
s
« J
§ U)
« l-J
§ P
« J
§ U1
s i
« hJ
S p
s
— u
§
« J
§
C -i
« J
v {j
§ *3
« J
S p
s
S
Upland - APE Area with
AUMs
Radium-226
NR
NR
NR
NR
NR
NR
NR
NR
Upland - APE Area Less
AUMs
Radium-226
NR
NR
NR
NR
NR
NR
NR
NR
Upland - Outside of APE
Area
Radium-226
NR
NR
NR
NR
NR
NR
NR
NR
Upland Receptors - AUM
457
Radium-226
NR
NR
NR
NR
NR
NR
NR
NR
Upland Receptors - AUM
458
Radium-226
NR
NR
NR
NR
NR
NR
NR
NR
Upland Receptors - AUM
459
Radium-226
¦
NR
NR
NR
NR
NR
NR
NR
NR
Riparian - Riparian Buffer
Area within APE
Radium-226
NR
NR
NR
NR
Notes:
Color coding: green =HQ less than one; yellow = HQ between one and ten; red =HQ greater than 10.
ND = Not detected
NC = Not calculated (TRVLoael not available)
NR = Not reported. Receptor not evaluated in this area.
UCL = upper confidence limit of the mean
— = Not applicable
March 18, 2021
Rev. 1.2
T-108
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 8-la Comparison of Human Health Risk Based Action Levels for Ra-226 and Daughter Products in Soils to Comparable Ecological Receptor Risk Based Action Levels
AI M 45S IIIISKI. Risks
I In niiiii llciillh Rcccplor
iind Scenario
Risk
I > |>C
I ( I.
( ;incci
Risk
Assochilcd
iiiisri:
Tsihle
11iiin;i 11 I lo;ilIII rhAl.s ill
DilTcrcnl Risk Thresholds
11-0(. 11.-05 11.-04
R;i-22f> ssl-'.SI.s :il HQ of Oik* iind lor l-'.colo^iciil
Rcccplors wiili At I \;ilucs oI'Oiio
Rock
\\ rcii
NOAI.I.
Rock
\\ roil
I.OA 1.1.
Dcscrl
Shrew
NOAI.I.
Dcscrl
Shrew
I.OA I'. I.
(iCOIllCilll
I'.colo^iciil
NOAII.s
Poicul i:il
rhAI.
On-Site Workers
Long Term Recreator -
Adult Only
(14 days per year, 24 years
as adult)
Long Term Recreator -
Child Only
(14 days per year; 2 years
as child)
Long Term Recreator -
Adult and Child
(14 days per year; 2 years
as child, 24 years as adult)
C
C
C
c
7.39E+01
7.39E+01
7.39E+01
7.39E+01
4.2E-07
5.7E-04
4.9E-05
6.2E-04
6-4a
6-5a
6-7a
6-8a
170 1,700 17,000
0.13
1.5
0.12
1.3
15
1.2
13
150
12
47
47
47
47
470
470
470
470
540
540
540
540
5,400
5,400
5,400
5,400
159
159
159
159
Notes:
The rbAL soil units are pCi/g.
The rbALs were back-calculated from the radium cancer risks (shown to two significant figures) for AUM 458, which had the highest relative risk of the evaluated areas.
Ra-226 rbAL values include daughter products.
The "Long Term Recreator - Adult and Child" receptor group is comparable to the BLM screening receptor scenario.
rbAL values are rounded to two significant digits.
Risk Type: C = cancer risk
March 18, 2021
Rev. 1.2
T-109
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 8-lb Comparison of Human Health Risk Based Action Levels for Non-Radiological PCOCs in Soils to Comparable Ecological Receptor Risk Based Action Levels
Human Health rbALs at Different Risk Non-Rad Soil Cone - Non-Rad Soil Cone -
AUM 458 HHSRE Risks
Thresholds
Wren
Shrew
Human Health Receptor
Cancer
HHSRE
Geomean
Proposed
and Scenario
PCOCs
Risk Type
UCL
HQ
Risk
Table
1E-06
1E-05 1E-04
HQ=1
@HQnoael:
= 1 @HQ|_OAEL=
1 @HQnoael-1
@HQ[_oael-1
NOAELs
rbAL
Site Workers
Arsenic
C
2.77E+01
—
1.1E-09
64a
25,000
250,000 (a)
...
55
120
140
360
87.7
90
Arsenic, Inorganic
NC
2.77E+01
4.8E-06
—
64a
—
—
(a)
55
120
140
360
87.7
90
Mercury (elemental)
NC
1.70E-01
9.4E-08
—
64a
—
—
(a)
0.25
1.1
1.3
NC
0.57
0.6
Molybdenum
NC
3.50E+02
5.0E-06
—
64a
—
...
(a)
1,400
NC
37
120
228
230
Selenium
NC
5.18E-01
7.5E-09
—
64a
—
...
(a)
3.2
7.6
4.3
9.1
3.71
4
Uranium (Soluble Salts)
NC
8.62E+01
3.1E-05
—
64a
—
—
(a)
5,700
57,000
450
NC
1,602
360
Vanadium and Compounds
NC
1.76E+01
2.5E-07
—
64 a
—
_ —
(a)
77
160
110
220
92.0
92
Long-Term Recreator -
Arsenic
C
2.77E+01
5.0E-07
6-5 a
56
560 5,600
_.
55
120
140
360
87.7
90
Adult Only
Arsenic. Inorganic
NC
2.77E+01
3.2E-03
_
6-5 a
—
_
8,600
55
120
140
360
87.7
90
(14 days per year. 24
Mercury (elemental)
NC
1.70E-01
1.9E-04
6-5 a
—
_. _
910
0.25
1.1
1.3
NC
0.57
0.6
years)
Molybdenum
NC
3.50E+02
3.4E-03
6-5 a
__
100.000
1,400
NC
37
120
228
230
Selenium
NC
5.18E-01
5.0E-06
...
6-5 a
100.000
3.2
7.6
4.3
9.1
3.71
4
Uranium (Soluble Salts)
NC
8.S2E+01
2.1E-02
6-5 a
—
— —
4,200
5,700
57.000
450
NC
1,602
360
Vanadium and Compounds
NC
1.76E+01
1.7E-04
—
6-5 a
—
_. _
100.000
77
160
110
220
92.0
92
Long-Term Recreator-
Arsenic
C
2.77E+01
—
4.1E-07
6-6 a
68
680 6.800
...
55
120
140
360
87.7
90
Child Only
Arsenic. Inorganic
NC
2.77E+01
3.2E-02
—
6-6a
—
...
870
55
120
140
360
87.7
90
(14 days per year: 2
Mercury (elemental)
NC
1.70E-01
1.9E-04
—
6-6a
—
...
910
0.25
1.1
1.3
NC
0.57
0.6
years as child)
Molybdenum
NC
3.50E+02
3.6E-02
—
6-6a
—
...
9,800
1,400
NC
37
120
228
230
Selenium
NC
5.18E-01
5.3E-05
—
6-6a
—
...
9.800
3.2
7.6
4.3
9.1
3.71
4
Uranium (Soluble Salts)
NC
8.62E+01
2.2E-01
—
6-6 a
—
...
390
5,700
57,000
450
NC
1,602
360
Vanadium and Compounds
NC
1.76E+01
1.8E-03
—
6-6 a
—
— —
9,800
77
160
110
220
92.0
92
Long-Term Recreator-
Adult and Child
Arsenic
C
2.77E+01
—
9.0E-07
6-7a
31
310 3,100
—
55
120
140
360
87.7
90
Arsenic, Inorganic
NC
2.77E+01
3.5E-02
—
6-7a
—
— —
790
55
120
140
360
87.7
90
(14 days per year; 2
Mercury (elemental)
NC
1.70E-01
3.7E-04
—
6-7a
—
— —
450
0.25
1.1
1.3
NC
0.57
0.6
years as child. 24 years
Molybdenum
NC
3.50E+02
3.9E-02
6-7a
—
—
8,900
1,400
NC
37
120
228
230
as adult)
Selenium
NC
5.18E-01
5.8E-05
6-7a
—
— —
8,900
3.2
7.6
4.3
9.1
3.71
4
Uranium (Soluble Salts)
NC
8.62E+01
2.4E-01
6-7a
—
— —
360
5,700
57.000
450
NC
1,602
360
Vanadium and Compounds
NC
1.76E+01
2.0E-03
—
6-7a
—
—
9.000
77
160
110
220
92.0
92
Notes:
The rbAL soil units are mg/kg.3w.
The rbALs were back-calculated from the risks for AUM 458. which had the highest relative risk of the evaluated areas
The "Long-Term Recreator - Adult and Child" receptor group is comparable to the BLM screening receptor scenario.
Risk Type: C = cancer risk, NC = non-cancer
NC = Not calculated. TRVLoael was not available for molybdenum in this speces.
rbAL values are rounded to two significant digits.
(a) rbAL value exceeds 1,000.000 mg/kg.
March 18, 2021
Rev. 1.2
T-110
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 9-1 Potential Pit Capacities
Cover Option
AUM 457
(CY)
AUM 458
(CY)
Channel Cover
1,340
740
Mound Cover
1,560
800
Raised Mound Cover
NA
5,670
Table 9-2 Horizonal Correlations Between Exposure Rate and Static Gamma Count
Rate
HORIZONTAL CORRE1
LATIO
N
Pool
Background
pCi/g
IL
pCi/g
gamma - mean
cpm(1)
gamma - 95 LPL
cpm
Drainage
1.71
2.95
48419
19004
Alluvial
3.72
4.96
67169
37096
LCR
1.26
2.5
44221
14953
Notes:
'The gamma measurement for the horizontal correlation was a scanning measurement performed using an unshielded
3-inch by 3-inchNaI(Tl) detector
Table 9-3 Vertical Correlations Between Exposure Rate and Ra-266 Concentrations in
Soil
VERTICAL CORRELATION
Background
IL
NET gamma - mean
NET gamma - 95
LPL
Pool
pCi/g
pCi/g
cpm(1-2)
cpm
Drainage
1.71
2.95
1828
-941
Alluvial
3.72
4.96
2307
-458
LCR
1.26
2.5
1721
-1049
Notes:
'The gamma measurement for the vertical correlation was a static measurement performed using a shielded 2-inch by
2-inch Nal(Tl) detector
2The second correlation data set (n=41) regression was used to develop the vertical correlation
March 18, 2021
Rev. 1.2
T-lll
Engineering Analytics, Inc.
-------
Removal Site Evaluation Report
Babbitt Ranches, LLC
Milestone Hawaii Stewardship Project
Table 9-4 Waste Volumes
Quadrant
Volume
Above IL(1)
(CY)
Volume
Above
160 pCi/g(2)
(CY)
Volume
Above
12 pCi/g(3)
(CY)
NW
4,087
0
1,166
NE
10,209
0
2,688
SW
7,818
940
5,535
SE
9,436
2
647
TOTAL
31,550
942
10,036
Notes:1 Investigation Level (IL) for Ra-226 is 1.24 above background as presented in Table 9-2.
(Drainage = 2.95 pCi/g, Alluvial = 4.96 pCi/g, LCR = 2.5 pCi/g) and presented on Figures 9-9 through 9-15.
2 Risk Based Action Level (rbAL) for On-Site Worker (Section 8.0; Table 8-la)
3 rbAL for Long Term Adult Recreator and Child (Section 8.0; Table 8.1a)
March 18, 2021
Rev. 1.2
T-112
Engineering Analytics, Inc.
-------
FIGURES
-------
¦PHOENIX
TUCSON
SCALE IN MILES
H O P I
\ ™ INDIA
RESERVATION
LAND
(APPROX)jK"
NAVAJO
NATION
LAND
(APPROX)
FLAGSTAFF
SCALE IN MILES
Engineering Analytics, Inc. FIGURE 1-1
SITE LOCATION
BABBITT RANCHES
-------
Figure 3-7 • Soil Analytical Results
(Arsenic, Lead, Molybdenum, Mercury,
Radium-236 and Uraniurn-238)
AUM 457
Navajo Nation • Arizona
i Sample Locations
Sample Exceedances
2xSD
pra**/! Waste Fife
| 1 Waste Area
~ Site Boundary
AnrtflteilJRiiMtti to - 6'»
Arsenic: 3,9
U«d; 11
Molybdenum: 12
Mercury: 0.016
Radium-226: 1 79
Uranium-238: 3 29
Section 9
Section 10
Analytical Results (0 • 6 in bos)
Amnio 83
Lead: 40
Molybdenum: 420
Mercury: 0.3!
Radium-236: 158
Uranium-238: 76.1
Analytical Results 10 - 6 in baa)
Arsenic; 7.3
Lead: 10
Molybden um: 61
Mercury: 0 024
Radium-226: 30.1
Uranium-238; 7,53
Analytical Results t0 - 6 in
Arsenic: 3.1
bead: 12
Molybdenum. 9,0
Mercury: 0 021
Radium-226: 8.37
Uranium-238: 5 47
Anojyhgal - \Z lfl frgftl
Arsenic: 2 9
Lead: 7 7
Molybdenum: 9
Mercury: 0.012
Radium-226: 3 06
Uranlum-238: 4 45
Analytical Results (0 - 6 in bos)
Arsenic: 3 3
Load: 10
Molybdenum; 10
MdfCUfy: 0 011
Rndium-226: 2
Uranium-238: 2 07
Analytical Results (0- 6 in boat
Arsenic: 230
Lead: 150
Molybdenum: 2006
Mercury: 13
Radium-226: 945
Uranium -238: 328
Arsenic: 3 2
Lead: 7 5
Molybdenum: 10
Mercury: 0.012
Radium-226: 2 47
Uranlum-238: 4 67
Analytical Results (6 • 12 in btisl
Arwnic; 3.1
Lead: 8 7
Molybdenum: 9 7
Mercury: 0 01
Radium-226: 1.89
Uranlum-238: 1 77
Analytica|^Re»ulJj, 6 n
Lead: 32
Molybdenum- 160
Mercury: 0 1
Radium-226: 57 1
Uranium-238: 21.9
iAnalylical Results (Q - 6 m bgsl
Arsenic: 95
Lead: 77
Molybdenum: 960
Mercury: 8. 7
Radium-226: 747
Mrninium-239; 266
mi iiitnw i ul i ¦
Aiseriic;3S
Lead: 9 5
Molybdenum: It
Mercury: 0,012
Radium-226: 1,64
Uranium-238: 1 28
Analytical (P • 6 «n bqs)
Arsenic: 10
Lead: 26-
Molybdenum; 140
Mercury: 0.037
Radium 226: 27.2
Uranium-238: 8.16
Analytical ResuBls 10' - 6 in bg»)
' Arsenic: 72
Lead1: 66
Molybdenum: 910
Mercury: 0 88
Radium-226: 411
Uranium<238: 164
Analytical Resutts to • 6 in bg». 4.87-SS-6 Ottp\
Anwrtlc; 54
Lead: 52
Molybdenum: 650
Mercury: 0.8
Radium-226: 382
Uranium-238: 187
Analytical Results (12 - 18 in bgs»
Arsenic; 3 3
Lead: 6 3
Molybdenum: 10
Mercury: 0 011
Radium-226: 1 07
Uranium-238: 1 43
Analytical Result* (0 • § in bas
Arsenic: 3,2
Lead:18
Molybdenum: 10
Mercury: 0 028
Radium-226: 2 87
Uranium-238: 3 07
Analytical Results (0 - 6 in bfl*)
Arsenic: 3
Lead: 9.7
Molybdenum: 9 4
Mercury: 0.014
Rjidium-226: i 38
Uramum-23&: 2 43
Analytical Results- <0 - 6 in bqs. 4jS7-SS-f? Otm)
Arsenic - '
Lead: 18
Molybdenum: 9 6
Mercury: 0.O32
Radium-226: 3.19
Uranlum-238: 2 04
Analytical Results 10 - 6 In bqs)
Arsenic: 3 3
Lead: 7
Molybdenum: 11
Mercury: 0 012
Radium-226: 1 18
Uranium-238: 2 21
Analyticpl Results -f6 -12 in b get
Aryornr
Lead: 5 1
Molybdenum: 10
Mercury: 0 01
Radium-?26 : 0 957
Urenium*23A: 1 16
Arsenic: 3 2
Lead: 4- 7
Molybdenum: 10
Mercury: 0 011
Radium-226: 18
Uranium-238: 1.41
From Weston, 2014
Project No. 110704 Note: Metal Concentration in mg/kg March 2021
Radionuclide Concentration in pCi/g Rev 1.2
Engineering Analytics, Inc. FIGURE 1-2
AUM 457 PCOC SOILS CONCENTRATIONS
BABBITT RANCHES
m
-------
Fig 3-8 • Soil Analytical Results
(Arsenic, Lead, Molybdenum, Mercury,
Radium-226 and Uranium-238)
AUM 458
s Navajo Nation • Arizona
Lead: 13
Molybdenum: 18
Mercury: 0,015
Radium-226: 9 84
Uramum-238. 8.3$
- 12 m l?a»i
Leed: 6.0
Molybdenum: 10
Mercury: O.Qtl
Radium-226: 6.01
Uranium-238: 4 38
AnalyticalI Results (0 -6 in bqsl
Arsenic: 31
Lend: 16
Molybdenum: 180
Mcrcurv: 0 093
Radium-226: 51 6
Uranium-238: 18,7
Analytical. Result? [12 -18 m bci>)
Arsenic: 4 5
Lead: 12
Molybdenum: 99
Mercury: 0 -081
Radium-226: 22 a
Uranium-238: 11.3
Arsenic: '-J
Lead: 9 1
Molybdtnum; 130
Mercury: 0.043
Radium-226: 28 7
Uranium-238: 16 2
AnnlvlKmi Kasuu* 10 • tin litis)
Areonic: 31
Lead: 18
Molybdenum: 440
Mercury: 0 36
Radium-2261 39 1
Uranium-23$: 34 4
Analytical Results (Q - 6 in bqsl
Arsenic: 12
Lead:17
Molybdenum; 48
Mercury : 0 028
Radium-226: 11 1
Uranium-238: 7 04
Analytical Results t6 - 12
ArWfliC: 12
Lead: 13
Molybdenum: 87
Mercury: 0.074
Radium-226: 18 7
Uranium-238: 11 1
Arsenic: 9 4
Lead: 13
Molybdenum- 87
Mercury: 0.086
Radium-226: 16 7
Uranium-238 : 7 73
Analytical 18 lf> b06*
Lead: 14 "
Molybdenum: 110
M«rcury: 0.14
Radium-226: 21.5
Urantum-238: 16 6
Arsenic: 140
Lead: 68
Molybdenum: 490
Mercury; 0,35
Radium-226: 93 4
Uranium-238: 76 3
Annw leal R»»uH» 10 ¦ 6 in no si
Arsenic: 3 1
Lead: 6,2
Molybdenum: 99
Mercury: 0 011
Radium-226:: 0 748
Uremum-23S: 0 198
Analytical Results 10 ~ 6 in bas. 45S-SS-61
Arsenic: 160
Lead: 110
Molybdenum: &4Q
Mercury: 0 33
Radium-226: 83.5
Uranium-238: 72 9
NOTE; Soi wmpie results featured r.
nsel I scaled approiximacely 600 fi tai
from the eastern boundary ofAUM 458
Analytical Rasults (0 - 6 in bq»>
Arsenic: 3.2
Lead: 5 9
Molybdenum: 10
Mercury: 0.011
Radium-226: 0.537
Uranium-238: 0 564
Analytical Results (0_¦ 6 in bqs.>
Arsenic: 2.7
Lead: 7.5
Molybdenum: 8 6
Mercury: 0 01
Radium-226: 1.39
Uranium-238: 2.05
Analytic^.n
Leed: 6 fi
MoiytKtenum: 5 6
Mircury- 0 01
RlKllum-22«: 5,735
Uranium.?38: 0 345
Anaiyi'tff'» P?- H
Lead: i"«
"sawi?*
fttdlum.2}«; 0 766
Uraruum.2S8: 0.3 59
Anply^al
Molybdenum: 10
Mercury: 0.011
Radium-226: 1 13
Uranium-238: O 995
Analytical Results (12 -18 in bus)
Arsenic: 3,3
Lead: 6.6
Molybdenum: 10
Mercury: 0 011
Radium-226: 1.06
Uramum<238: 0 736
Sample Locations
Sample Exceedances
2xSD
Waste Pite
~ W3s!b Area
~ Site Bo-undary
From Weston, 2014
Project No. 110704 Note: Metal Concentration in mg/kg March 2021
Radionuclide Concentration in pCi/g Rev 1.2
Engineering Analytics, Inc. FIGURE 1-3
AUM 458 PCOC SOILS CONCENTRATIONS
BABBITT RANCHES
m
-------
Arsonic: 99
Lead: 13
Molybdenum; 130
Mercury: 0.082
Radium-226: 24 1
Ureniurn-238: 19.7
Areenic: 9 2
Lead: 5.7
Molybdenum. 42
Mercury: 0.044
Radium-226: 10 6
Uranium-238: 5 56
Analytical Results (0 - 6 in b-ge)
Arsenic: 16
Lead: 16
Molybdenum: 21
Mercury: 0 062
Radium-226: 16 5
Uranium-238: 10.9
Arsenic 3 3
Lead:12
Molybdenum: 10
Mercury: D.0H
Radiu»n-22&: 5.36
Uranium-238: 4 3
Fig 3-9 • Soil Analytical Results
(Arsenic, Lead, Molybdenum, Mercury,
Radium-226 and Uranium-238)
AUM 459
Navajo Nation ~ Arizona
s Sample Locations
Sample Exceedances
2xSD
0 3xBG
KWaste Pile
~1 Waste Area
Site Boundary
Section 9
Section 16
l>Ml 12 ,n
Lead: IS
Molybdenum: 260
Mercury: 0 16
Radium-226: 30 3
Urankum.238: 43 5
• 19 in ban
Lead: 20
Uranium: 240
Mercury: 0.51
Radium-226: 37 1
Uranium-238- 44
*U':* • r
Lead: 4?
Molybdenum: 240
Mercurv: 1 8
Mercury: 1 8
R8dlunw26: 201
Uranium-238: 192
Anj lyt>tl\l tf.- 5 in Hj|;|
n Arwsnic: f-a
Load: 7 2
Molybdenum: 42
Mercury: 0 053
Radium-226: 18 8
Uranium-238: 10.3
Analytical Result* (0 - 6 in bft|)
Arsonic: 9.7
Lead: 4 7
Molybdenum: 46
Mercury: 0 022
Radium-226: 9 23
Uranium-238: 4,36
Analytical ^e>»ij|» 16 • 12 tn bas»
Lead: 5 6
Molybdenum: 32
Mercury: O 029
Radium-226: 10.1
Uranium-238: 5.8
Arsenic: _
Lead; 6
Molybdenum: 36
Mercury: 0.033 '
Radium-226: 976
Uranium-238: 6.57
Analytical Rcsujts (0; 8 in bo&>
Arsenic: 0 4
Lead: 6.9
Molybdenum: 80
Mercury . 0,061
Radium-226: 18 4
Uranium-238: 8.05
Analytical Result* 10 - 'n6b^s- ^9-SS-6 Oup)
Lead: 7 2
Molybdenum: 42
Mercury: 0 053
Rodiuni-226: 18 8
Uranium-238: 10.3
Lead: 33
Molybdenum; 180
Mercury: 0.25
Radium-226: 11.8
Uranium-238: 24 4
Project No. 110704 Note: Metal Concentration in mg/kg March 2021
Radionuclide Concentration in pCi/g Rev 1.2
m
Engineering Analytics, Inc. FIGURE 1-4
AUM 459 PCOC SOILS CONCENTRATIONS
BABBITT RANCHES
6 m tw»t
Lead: 9 8^
Molybdenum: 10
Mercury : 0.02
Radium-226: 1 82
Ur/iniiim.238: 0.934
From Weston, 2014
-------
Project No. 110704
m
Engineering Analytics, Inc.
March 2021
Rev 1.2
FIGURE 2-1
SITE LOCATION AND PROPOSED AREA OF
POTENTIAL EFFECT FOR PHASE III WORK
BABBITT RANCHES
-------
March 2021
Rev 1.2
FIGURE 2-2
WESTON GAMMA SURVEY DATA, AUM 457
BABBITT RANCHES
Project No. 110704
Engineering Analytics, Inc.
Sample Locations
jcjmjj Waste Pile
~ Waste Area
Wetlands [2013 EPA Evaluation)
—Drainage Direction
Gamma Radiation Measurements
• < 2 x Background
2 to 3 x Background
3 to 5 x Background
• 5 to 10 x Background
• 10 to 20 x Background
• > 20 x Background
0;
From Weston, 2014
Figure 3-2
Site Characterization
AUM 457
Navajo Nation * Arizona
-------
Sample Locations
e'Sri Was,e pile
~ Waste Area
I Wetlands (2013 EPA Evaluation)
Drainage Direction
Gamma Radiation Measurements
• < 2 x Background
2 to 3 x Background
3 to 5 x Background
• 5 to 10 x Background
• 10 to 20 x Background
• > 20 x Background
Figure 3-3
Site Characterization
AUM 458
Navajo Nation * Arizona
March 2021
Rev 1.2
FIGURE 2-3
WESTON GAMMA SURVEY DATA, AUM 458
BABBITT RANCHES
Eznvironmpntcal Ebervicpsj, Inc.
Project No. 110704
Engineering Analytics, Inc.
From Weston, 2014
-------
From Weston, 2014
V * W jr.
VI ntftfjr
Figure 3-4
Site Characterization
AUM 459
Navajo Nation • Arizona
Project No. 110704
Engineering Analytics, Inc.
Eznvironmpntcal Ebervlce^, Inc.
March 2021
Rev 1.2
FIGURE 2-4
WESTON GAMMA SURVEY DATA, AUM 459
BABBITT RANCHES
3 Sample Locations
Waste Pile
~ Waste Area
Wetlands (2013 EPA Evaluation)
Drainage Direction
Gamma Radiation Measurements
• < 2 x Background
2to3x Background
3 to 5 x Background
• 5 to 10 x Background
• 10 to 20 x Background
• > 20 x Background
-------
EXPLANATION
EPAAUM Boundary
Area of Potential Effect
Geologic Units
Qae Alluvial/Eolian Deposit
Qaf Artificial Fill
Qay Alluvial Fan Deposit
Qd Dune Sand
Qf Floodplain Deposit
Qgy Terrace Deposit
Qps Ponded Sediments
Qs Stream Channel Deposits
Qv Valley Fill
TRcp Petrified Forest Member
TRcs Shinarump Member
0 500 1,000
2,000
3 Feet
Project No. 110704
March 2021
Rev 1.2
FIGURE 2-5
SITE GEOLOGY (BILLINGSLEY ET AL., 2007)
BABBITT RANCHES
-------
T:\1107Q4 Babbitt Ranch\RSE Report\AUM Features.dwg SAVED: 3/17/21 PRINTED: 3/17/21
AUM 457 and Overall Site Legend
Section Line
—— Little Colorado River (1969 USGS Centerline)
~ EPA AUM Boundary
EPA Identified Drainage Area Boundary
EPA Identified Drainage Network
Surface Water General Flow Direction
~ EPA Identified "Wetland 3"
~ EPA Identified Road Buffer (50-ft)
EPA Identified Road Centerline
i Area of Potential Effect
~ Other Mine Related Disturbance
Upgrader Foundation
• 2019 Little Colorado River (NHD)
0 290 580
1160
i Feet
1740
NOTE: FOR INFORMATIONAL PURPOSES ONLY.
NOT FOR FIELD IMPLEMENTATION.
Project No. 110704
Engineering Analytics, Inc.
fcnviranme>n1"c3l Service's, Inc.
March 2021
Rev 1.2
FIGURE 2-6
PHYSICAL CONCEPTUAL SITE MODEL
FOR THE AREA OF POTENTIAL EFFECT
BABBITT RANCHES
-------
T:\11Q704 Babbitt Ranch\RSE Report\AUM Features.dwg SAVED: 3/17/21 PRINTED: 3/17/21
! Northern
I Concrete
Upgrader Foundation
Waste Rock Piles
Drainage
from Upgrader]
Upgrader Area|
Waste Rock Piles!
[Bedrock Ridge]
LEGEND:
Section Line
——— Little Colorado River (1969 USGS Centerline)
~ EPAAUM Boundary
EPA Identified Drainage Area Boundary
- ° - EPA Identified Drainage Network
~ EPA Identified "Wetland 3"
~ EPA Identified Road Buffer (50-ft)
EPA Identified Road Centerline
_j Area of Potential Effect
Other Mine Related Disturbance
PQ* Upgrader Foundation
Surface Water General Flow Direction
— 2019 Little Colorado River (NHD)
i Feet NOTE: FOR INFORMATIONAL PURPOSES ONLY.
100 200 400 600 NOT FOR FIELD IMPLEMENTATION.
Project No. 110704
m
Engineering Analytics, Inc.
E:nvironm6an1"c3l Eaerviczps., Inc.
March 2021
Rev 1.2
FIGURE 2-7
PHYSICAL CONCEPTUAL SITE MODEL FOR AUM 457
BABBITT RANCHES
-------
T:\1107Q4 Babbitt Ranch\RSE Report\AUM Features.dwg SAVED: 3/17/21 PRINTED: 3/17/21
Drainage Within!
IaUM 458 |
Drainage Outsidel
of AUM 458
^Drainage Outsidel
of AUM 458
Exploratory Boring Locations
Drainage from Ridge I
MSouth of AUM 458 j
iDrainage South
of AUM 458
'AUNU459
'Drainage NWj
!of AUM 459 |
[Drainage from'
I AUM 459 I
Gamma Scan Results
• 0 - 0.5*IL
>0.5-IL-TIL
>V\L-2"\L
• >2*IL - 3"IL
• >3*IL
LEGEND:
Section Line
~ EPA AUM Boundary
EPA Identified Drainage Area Boundary
- - - • ERA Identified Drainage Network
Surface Water General Flow Direction
~ EPA Identified Road Buffer (50-ft)
EPA Identified Road Centerline
J Area of Potential Effects
~ Other Mine Related Disturbance
1 — 2019 Little Colorado River (NHD)
0 110
Project No. 110/04
Engineering Analytics, Inc.
fcnviranme>n1"c3l Service's, Inc.
March 2021
Rev 1.2
FIGURE 2-8
PHYSICAL CONCEPTUAL SITE MODEL FOR AUMS 458 AND 459
BABBITT RANCHES
-------
LEGEND
EPA BRA Location
Babbitt BSA Locations
~ Other Mine Related Disturbance
Other Mine Related Disturbance - Road Scanning
! Area of Potential Effect
Section Lines
EPAAUM Boundary
EPA Identified Drainage Area Boundary
EPA Identified Drainage Network
¦ ¦ ¦ 2019 Little Colorado River (NHD)
EPA Identified "Wetland 3"
EPA Identified Road Buffer (50-ft)
EPA Idenfied Road Centerline
0 0.175 0.35
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION.
0.7
5 Miles
Project No. 110704
March 2021
Rev 1.2
FIGURE 3-1
LOCATIONS OF BSAs AND OTHER MINE RELATED DISTURBANCE
BABBITT RANCHES
-------
LEGEND
Babbitt BSA Locations
S Area of Potential Effect
Gamma Count Rate
• 0.5 x Mean or Less
0.5 x Mean - 0.75 x Mean
0.75 x Mean - Mean
Mean - 1.25 x Mean
• 1.25 x Mean - 1.5 x Mean
NOTE: The mean gamma count for
Alluvial BSA#1 is 45,668 cpm.
0 15 30
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION.
60
Feet
Project No. 110704
m
Engineering Analytics, Inc.
CAG
March 2021
Rev 1.2
FIGURE 4-1
GAMMA SCAN RESULTS FOR ALLUVIAL BSA #1
BABBITT RANCHES
-------
LEGEND
Babbitt BSA Locations
S Area of Potential Effect
J
Gamma Count Rate
• 0.5 x Mean or Less
0.5 x Mean - 0.75 x Mean
0.75 x Mean - Mean
Mean - 1.25 x Mean
• 1.25 x Mean - 1.5 x Mean
NOTE: The mean gamma count for
Alluvial BSA #2 is 44,771 cpm.
0 12.5 25
50
Feet
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION.
Project No. 110704
m
Engineering Analytics, Inc.
CAG
March 2021
Rev 1.2
FIGURE 4-2
GAMMA SCAN RESULTS FOR ALLUVIAL BSA #2
BABBITT RANCHES
-------
LEGEND
Babbitt BSA Locations
S Area of Potential Effect
J
Gamma Count Rate
• 0.5 x Mean or Less
0.5 x Mean - 0.75 x Mean
0.75 x Mean - Mean
Mean - 1.25 x Mean
• 1.25 x Mean - 1.5 x Mean
NOTE: The mean gamma count for
Drainage BSA#2 is 39,586 cpm.
0 12.5 25
50
Feet
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION.
Project No. 110704
m
Engineering Analytics, Inc.
CAG
March 2021
Rev 1.2
FIGURE 4-3
GAMMA SCAN RESULTS FOR DRAINAGE BSA #2
BABBITT RANCHES
-------
LEGEND
Babbitt BSA Locations
S Area of Potential Effect
Section Lines
Gamma Count Rate
• 0.5 x Mean or Less
0.5 x Mean - 0.75 x Mean
0.75 x Mean - Mean
Mean - 1.25 x Mean
• 1.25 x Mean - 1.5 x Mean
NOTE: The mean gamma count for
Terrace BSA#1 is 40,191 cpm.
0
15 30
60
Feet
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION.
Project No. 110704
m
Engineering Analytics, Inc.
CAG
March 2021
Rev 1.2
FIGURE 4-4
GAMMA SCAN RESULTS FOR TERRACE BSA #1
BABBITT RANCHES
-------
LEGEND
EPA BRA Location
S Area of Potential Effect
Gamma Count Rate
• 0.5 x Mean or Less
0.5 x Mean - 0.75 x Mean
0.75 x Mean - Mean
Mean - 1.25 x Mean
• 1.25 x Mean - 1.5 x Mean
NOTE: The mean gamma count for
EPA Qter BRA is 38,676 cpm.
0
15 30
60
Feet
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION.
Project No. 110704
m
Engineering Analytics, Inc.
CAG
March 2021
Rev 1.2
FIGURE 4-5
GAMMA SCAN RESULTS FOR EPA QTer BRA
BABBITT RANCHES
-------
LEGEND
Babbitt BSA Locations
S Area of Potential Effect
Gamma Count Rate
• 0.5 x Mean or Less
0.5 x Mean - 0.75 x Mean
0.75 x Mean - Mean
Mean - 1.25 x Mean
• 1.25 x Mean - 1.5 x Mean
NOTE: The mean gamma count for
LCR BSA is 23,190 cpm
0 15 30
60
Feet
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION.
Project No. 110704
m
Engineering Analytics, Inc.
CAG
March 2021
Rev 1.2
FIGURE 4-6
GAMMA SCAN RESULTS FOR LITTLE COLORADO RIVER BSA
BABBITT RANCHES
-------
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION.
LEGEND
m Babbitt BSA Locations
Gamma Count Rate
• 0.5 x Mean or Less
0.5 x Mean - 0.75 x Mean
0.75 x Mean - Mean
Mean - 1.25 x Mean
• 1.25 x Mean - 1.5 x Mean
NOTE: The mean gamma count for
Terrace BSA #2 is 41,106 cpm.
0 12.5 25
50
Feet
Project No. 110704
m
Engineering Analytics, Inc.
CAG
March 2021
Rev 1.2
FIGURE 4-7
GAMMA SCAN RESULTS FOR TERRACE BSA #2
BABBITT RANCHES
-------
Little Colorado River BSA
Figure 4-11
Figure 4-12
Drainage BSA #2
Terrace BSA #1
EPA "Qter BRA"
Alluvial BSA #2
Project No. 110704
March 2021
Rev 1.2
LEGEND
EPA BRA Location
Babbitt BSA Locations
Area of Potential Effect
Section Lines
EPAAUM Boundary
— " ¦ ¦ 2019 Little Colorado River (NHD)
Gamma Scan Results
• 0 - 0.5*IL
>0.5*IL - 1*IL
>1*IL-2*IL
• >2*IL - 3*IL
• >31L
NOTES:
1) IL Values are provided on Table 5-22,
2) The IL Application Areas are shown on Figure 5-14.
0 0.125 0,25 0.5
Miies
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION.
Terrace BSA #2
Alluvial BSA #1
Figure 4-9
|~~A Engineering Analytics, Inc. _
UT~~ €AG
FIGURE 4-8
RESULTS OF MOBILE GAMMA SCAN SURVEY
BABBITT RANCHES
-------
LEGEND
EPA BRA Location
~
Babbitt BSA Locations
1 j
1
Area of Potential Effect
~
Section Lines
~
EPAAUM Boundary
— ¦ ¦ ¦ 2019 Little Colorado River (NHD)
Gamma Scan Results
• 0 - 0.5*IL
>0.5*IL - 1*IL
>1*IL-2*IL
• >2*IL - 3*IL
• >31L
NOTES:
1) IL Values are provided on Table 5-22.
2) The IL Application Areas are shown on Figure 5-14.
0 0.0375 0.075
0.15
3 Miles
AUM 457
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION
Project No. 110704
|~~A Engineering Analytics, Inc. —
u\— €RG
March 2021
Rev 1.2
FIGURE 4-9
RESULTS OF MOBILE GAMMA SCAN SURVEY NE QUADRANT
BABBITT RANCHES
-------
LEGEND
EPA BRA Location
Babbitt BSA Locations
Area of Potential Effect
Section Lines
EPAAUM Boundary
Gamma Scan Results
• 0 - 0.5*IL
>0.5*IL - 1*IL
>1*IL- 2"IL
• >2*IL - 3*IL
• >31L
NOTES:
1) IL Values are provided on Table 5-22.
2) The IL Application Areas are shown on Figure 5-14.
0 0.0375 0.075
0.15
Miies
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION.
Project No. 110704
|~~A Engineering Analytics, Inc. —
u\— €RG
March 2021
Rev 1.2
FIGURE 4-10
RESULTS OF MOBILE GAMMA SCAN SURVEY NW QUADRANT
BABBITT RANCHES
-------
Wr
46 r
t \:-u* -if/
\ \
v .
>•/ \
/ \
\
%
\
. r • ,wu.f Ji
W\'. • ¦ m:
0| r
-'•'A '
I % a r*flw ^ *. •
i >«
\
/ 1 »
/
J
.V'- •¦•<'¦ >
.i&M
RjggM
Ji* s.- .vial
V, 1
W-.VVV'' :'
T >*Ax?
¦. ' ^ .
v *'' . \<" "iT®
, ' -> *'
vy, ¦ •" '
I * ' f
-
*f, : ^
>'
SN-i
rtv
IT
« W
mi
-'*>¦
_£ i
,X1
.
. ' / . 1
> V<-
' \ B
Z\ S< A J
\
'feVfc; ?:
' '. * *'•*# v\. ¦
kkM • •
Vk V* '• ¦• % ' r< " *
v * • »
V V »-:; A r v
Little Colorado River BSA
ci*. * a
ft
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION.
LEGEND
EPA BRA Location
~
Babbitt BSA Locations
Area of Potential Effect
~
Section Lines
~
EPAAUM Boundary
¦ ¦ ¦ 2019 Little Colorado River (NHD)
Gamma Scan Results
• 0 - 0.5*IL
>0.5*IL - 1*IL
>1*IL - 2*IL
>2*IL - 3*IL
• >3*IL
NOTES:
1) IL Values are provided on Table 5-22.
2) The IL Application Areas are shown on Figure 5-14.
0 0.035 0.07
0.14
3 Miles
Project No. 110704
Engineering Analytics, Inc.
m
€RG
March 2021
Rev 1.2
FIGURE 4-11
RESULTS OF MOBILE GAMMA SCAN SURVEY SE QUADRANT
BABBITT RANCHES
-------
/• •'
n
EPA "Qter BRA'
J
\ <
K
/
F i'lip'i,
HHLlii
¦If
HI
¦it
C!
•\1 1
v\ 5V*a
«, v
jV
m
\\
l
I
-v
#-
r >
Sf
.. .
•""SfiSSs
•'•-.J- gggs£aWfl
4sl
. 1 s
n^.
' •
/
- Ja /' -•
/ . ./¦ —
*. j
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION.
LEGEND
EPA BRA Location
~
Babbitt BSA Locations
Area of Potential Effect
—
Section Lines
~
EPAAUM Boundary
— ¦ ¦ ¦ 2019 Little Colorado River (NHD)
Gamma Scan Results
• 0 - 0.5*IL
>Q.5*IL - 1*IL
>1*IL - 2*IL
>2*IL - 3*IL
• >3*1 L
NOTES:
1) IL Values are provided on Table 5-22.
2) The IL Application Areas are shown on Figure 5-14.
0 0.035 0.07
0.14
3 Miles
Project No. 110704
Engineering Analytics, Inc.
m
€RG
March 2021
Rev 1.2
FIGURE 4-12
RESULTS OF MOBILE GAMMA SCAN SURVEY SW QUADRANT
BABBITT RANCHES
-------
LEGEND
Phase III Test Pit Actual Locations With Max Gamma Results
EPAAUM Boundary
Area of Potential Effect
Section Lines
Other Mine Related Disturbance (6)
EPA Identified Drainage Area Boundary
EPA Identified Road Buffer (50-ft)
EPA Identified Road Centerline
Total Gamma (cpm)
• 14034-53184
53185- 125687
125688-242715
242716-442102
• 442103-717439
• 717440 - 999960
• 999961-1293180
• 1293181-1922580
NOTES:
1) IL Values are provided on Table 5-22.
Pooled BSA
95% Gamma UTL
(cpm)
H (cpm)
Alluvial BSA =1 and # 2, Tenace BSA #1
and#2: EPA "Qter BRA"
48,212
51,824
Drainage BSA #2
43,564
47,176
Little Colorado River BSA
26,053
29,665
2) The IL Application Areas are shown on Figure 5-14.
3) Test Pit Gamma Readings are the maximum gross
reading encountered in the test pit (December 2018).
4) Test Pit Gamma Scans were completed using a
2-inch x 2-inch Nal detector.
5) Gamma Scan Results were completed using a
3-inch x 3-inch Nal detector.
6) Other Mine Related Disturbance as defined in the
Phase II Work Plan (approved September 6, 2017).
Project No. 110704
|~~A Engineering Analytics, Inc. —
u\— €RG
March 2021
Rev 1.2
FIGURE 4-13
ADDITIONAL SCANNING, AUM 457 (CPM), NE QUADRANT
BABBITT RANCHES
-------
\
I %
TP-18 (8574 cpm)
O TP-19 (18507 cpm)
AUM 458
0
37.5 75
150
5 Feet
LEGEND
O Phase III Test Pit Actual Locations With Max Gamma Results
EPA AUM Boundary
j Area of Potential Effect
Section Lines
Total Gamma (cpm)
14034-53184
53185-125687
125688-242715
242716-442102
442103-717439
717440-999960
999961 -1293150
1293151 -1922580
NOTES:
1) IL Values are provided on Table 5-22.
Pooled BSA
95% Gamma UTL
(cpm)
IL (epm)
Alluvial BSA #1 and # 2, Terrace BSA #1
and £2, EPA "Qter BRA"
48,212
51,824
Drainage BSA #2
43,564
47,176
Little Colorado liver BSA
26:053
29,665
2) The IL Application Areas are shown on Figure 5-14
3) Test Pit Gamma Readings are the maximum gross
reading encountered in the test pit (December 2018).
4) Test Pit Gamma Scans were completed using a
2-inch x 2-inch Nal detector.
5) Gamma Scan Results were completed using a
3-inch x 3-inch Nal detector.
Project No. 110704
Engineering Analytics, Inc.
m
€RG
March 2021
Rev 1.2
FIGURE 4-14
ADDITIONAL SCANNING AREA, AUM 458 (CPM), SE QUADRANT
BABBITT RANCHES
-------
Figure 4-17
Figure 4-16
AUM 457
AUM 458
Figure 4-19
Figure 4-18
AUM 459
Project No. 110704
March 2021
Rev 1.2
LEGEND
¦ ¦ - 2019 Little Colorado River (NHD)
EPA AUM Boundary
EPA BRA Location
Babbitt BSA Locations
Area of Potential Effect
Section Lines
Other Mine Related Disturbance
EPA Identified Drainage Area Boundary
EPA Identified Drainage Network
EPA Identified Road Buffer (50-ft)
EPA Identified Road Centerline
Total Gamma (cpm)
14034 - 531 84
53185 - 125687
125688 - 242715
242716-442102
442103-717439
717440 - 999960
NOTES:
1) IL Values are provided on Table 5-22.
Pooled BSA
95% Gamma UTL
(cpm)
IL (cpm)
Alluvial BSA #1 and # 2. Terrace BSA #1
and #2, EPA "Qter BRA:'
48.212
51.824
Drainage BSA #2
43.564
47.176
Little Colorado River BSA
26.053
29.665
2) The IL Application Areas are shown on Figure 5-14.
3) Test Pit Gamma Readings are the maximum gross
reading encountered in the test pit (December 2018).
4) Test Pit Gamma Scans were completed using a
2-inch x 2-inch Nal detector.
5) Gamma Scan Results were completed using a
3-inch x 3-inch Nal detector.
|~~A Engineering Analytics, Inc. _
UT~~ €AG
FIGURE 4-15
RESULTS OF MOBILE GAMMA SCAN SURVEY (CPM)
BABBITT RANCHES
-------
M
r
X
V
V '
X
vfclL
XK
X
w > vl
X
V
V
X
X
X
V
v
X
X
X
X
X
X
X
X
X
X
X
N
X
X
X
X
A.
X
X
X
X
X
X
X
X
X
X
0
250
500
Project No. 110704
Engineering Analytics, Inc.
m
€RG
i .1
LEGEND
Babbitt BSA Locations
1 Area of Potential Effect
Section Lines
EPA Identified Road Buffer (50-ft)
EPA Identified Road Centerline
Total Gamma (cpm)
• 14034- 531 84
53185 - 125637
125638 - 242715
242716 -442102
442103-717439
• 71 7440 - 999960
NOTES:
1) IL Values are provided on Table 5-22.
Pooled BSA
95% Gamma UTL
(cpm)
IL (epm)
Alluvial BSA #1 and # 2, Terrace BSA #1
and £2, EPA "Qter BRA"
48,212
51,824
Drainage BSA #2
43,564
47,176
Little Colorado liver BSA
26:053
29:665
2) The IL Application Areas are shown on Figure 5-14
3) Test Pit Gamma Readings are the maximum gross
reading encountered in the test pit (December 2018).
4) Test Pit Gamma Scans were completed using a
2-inch x 2-inch Nal detector.
5) Gamma Scan Results were completed using a
3-inch x 3-inch Nal detector.
March 2021
Rev 1.2
FIGURE 4-16
RESULTS OF MOBILE GAMMA SCAN SURVEY (CPM), NW QUADRANT
BABBITT RANCHES
-------
Project No. 110704
March 2021
Rev 1.2
LEGEND
EPA Identified Road Centerline
EPA Identified Drainage Network
EPA Identified Drainage Area Boundary
EPA Identified Road Buffer (50-ft)
Other Mine Related Disturbance (6)
! Area of Potential Effect
Section Lines
EPA AUM Boundary
2019 Little Colorado River (NHD)
Total Gamma (cpm)
14034-53184
53135 - 125637
125633 -242715
242716-442102
442103-717439
717440-999960
NOTES:
1) IL Values are provided on Table 5-22.
Pooled BSA
95% Gamma UTL
(cpm)
IL (cpm)
Alluvial BSA #1 and # 2, Terrace BSA #1
and £2. EPA"QterBRA"
48.212
51.824
Drainage BSA #2
43,564
47=176
Little Colorado River BSA
26.053
29.665
2) The IL Application Areas are shown on Figure 5-14.
3) Test Pit Gamma Readings are the maximum gross
reading encountered in the test pit (December 2018).
4) Test Pit Gamma Scans were completed using a
2-inch x 2-inch Nal detector.
5) Gamma Scan Results were completed using a
3-inch x 3-inch Nal detector.
6) Other Mine Related Disturbance as defined in the
Phase II Work Plan (approved September 6, 2017).
AUM 457
m
Engineering Analytics, Inc.
CAG
FIGURE 4-17
RESULTS OF MOBILE GAMMA SCAN SURVEY (CPM), NE QUADRANT
BABBITT RANCHES
-------
'
1 ¦ Mm**-
2 ,f
Ai .. . £22
I-
rf /. • f
I 1
^ « iil^
¦| J jn- • s»-|. 4* * si Iffip w»m-
' • #.
• H
¦
i -if
/ ,;
'fllflnpli!
- -jr*-
I
<•
V
4 #.
—^UK/V <
Jt '.
*-> ',
AUM458
L
!¦* ¦
Jt f
X
gfrjk.
i
i \
I \
'HIV »" /1* • .' « • >,
» ®ISrl([,| ,jT
fc\
#:7'v
rwi
1$
* ' *. " *v'
V X
\ / \
» . 8f
( ' u
I
»X
'¦> K
i"
*
I. JR
.
WfrW ¦
^¦mfL
- <
'Wafyf? w / ¦ r >..¦ .
• ' - ; ¦'- -» ( to / t <.,} ' f
/ 7^ / it I ' '' I /
jAUM4S^\y , yt ^ ' '
~>\v \
*V\ j '•.~ * Wf *
*' V \
a * V*!*- r •>, • .-V'
rjl ' •:¦» v VfcXV
J%:.y
k \
\ \
E# \
\ \
*j1 m*
4Jl v * v ~ ¦*
250
500
LEGEND
EPA Identified Road Centerline
EPA Identified Drainage Network
EPA Identified Drainage Area Boundary
EPA Identified Road Buffer (50-ft)
Other Mine Related Disturbance (6)
Babbitt BSA Locations
j Area of Potential Effect
Section Lines
EPA AUM Boundary
• ' ¦ 2019 Little Colorado River (NHD)
Total Gamma (cpm)
• 14034- 53184
53185 - 125687
125688 - 242715
242716-442102
442103-717433
• 717440 - 999960
NOTES:
1) IL Values are provided on Table 5-22.
Pooled BSA
95% Gamma UTL
(cpm)
IL (cpm)
Alluvial BSA #1 and # 2, Terrace BSA #1
and£2: EPA "Qter BRA"
48;212
5L824
Drainage BSA #2
43,564
47=176
Little Colorado River BSA
26,053
29:665
2) The IL Application Areas are shown on Figure 5-14
3) Test Pit Gamma Readings are the maximum gross
reading encountered in the test pit (December 2018).
4) Test Pit Gamma Scans were completed using a
2-inch x 2-inch Nal detector.
5) Gamma Scan Results were completed using a
3-inch x 3-inch Nal detector.
6) Other Mine Related Disturbance as defined in the
Phase II Work Plan (approved September 6, 2017).
Project No. 110704
Engineering Analytics, Inc.
m
€RG
March 2021
Rev 1.2
FIGURE 4-18
RESULTS OF MOBILE GAMMA SCAN SURVEY (CPM), SE QUADRANT
BABBITT RANCHES
-------
J-
\
V
0
250 500
1,000
5 Feet
LEGEND
EPA AUM Boundary
EPA BRA Location
Babbitt BSA Locations
¦ Area of Potential Effect
Section Lines
Other Mine Related Disturbance (6)
~ EPA Identified Drainage Area Boundary
EPA Identified Drainage Network
EPA Identified Road Buffer (50-ft)
EPA Identified Road Centerline
Total Gamma (cpm)
14034-53184
53185- 1256.37
125688 - 242715
242716-442102
MS103 - ?f 7433
717440 - 999960
NOTES:
1) IL Values are provided on Table 5-22.
Pooled BSA
95% Gamma UTL
(cpm)
H (cpm)
Alluvial BSA #1 and # 2: Terrace BSA #1
and#2: EPA "Qter BRA"
48.212
51,824
Drainage BSA #2
43,564
47,176
Little Colorado River BSA
26:053
29:665
2) The IL Application Areas are shown on Figure 5-14
3) Test Pit Gamma Readings are the maximum gross
reading encountered in the test pit (December 2018).
4) Test Pit Gamma Scans were completed using a
2-inch x 2-inch Nal detector.
5) Gamma Scan Results were completed using a
3-inch x 3-inch Nal detector.
6) Other Mine Related Disturbance as defined in the
Phase II Work Plan (approved September 6, 2017).
Project No. 110704
€RG
March 2021
Rev 1.2
FIGURE 4-19
RESULTS OF MOBILE GAMMA SCAN SURVEY (CPM), SW QUADRANT
BABBITT RANCHES
-------
T:\110704 Babbitt Ranch\RSE Repgrt.\Bovpl.ots.dW9 SAVED: 3/1 7/21 PRINTED: 3/1 7/21
3000-
6000-
>
-V—1
E
O
o
CO
CT
CB
GO
JZ
CL
O
o
03
T—
-------
T:\11S204 BSilsitt Ranch \BS£ MfM\BMpHs.(M| BWED: 3/1 7/21 PRINTED: 3/1 7/21
Project No. 110704
SC
Survey Group
NOTES:
• IN A TUKEY-STYLE BOXPLOT, BOXES REPRESENT THE 25TH-75™ PERCENTILES OF DATA AND DARK LINES THE MEDIAN.
POTENTIAL OUTLIERS ARE IDENTIFIED AS DOTS, WHILE WHISKERS SHOW THE RANGE OF THE REMAINDER OF THE DATA.
. ERG CLASSIFIED THE LOCATIONS TO BE SURVEYED INTO 13 GROUPS: BOTTOM WALL (BW), CEMENT BOX (CB),
HIGHEST SLAB (HS), LOWER BLOCK (LB), LOWER SLAB (LS), REAR SLAB (RS), SMALL CORRIDOR (SC), SMALL WALL (SW),
TOP NORTHERN SLAB (TNS), TOP SLAB (TS), UPPER WALL (UW), UPPER WEST BLOCK (UWB), AND WEST WALL (WW).
March 2021
Rev 1.2
m
Engineering Analytics, Inc.
CftG
FIGURE 4-21
BOXPLOT SHOWING BETA SURFACE ACTIVITY BY SURVEY GROUP
BABBITT RANCHES
-------
Figure 4-28
AUM 457
( [TPJ12 (2408 cpm,
TF -8 (1453jD;cpm)
Figures 4-23 and 4-24
]\i ' , ¦ ,
TP-20 (13303 cpm)
AUM 458
TP-19 (18507 cpm)
.TP-2,1,(5307 cpm)
Figure 4-27
Figures 4-25 and 4-26
AUM 459
March 2021
Rev 1.2
LEGEND
Phase III Test Pit Actual Locations With Max Gamma Results
EPA AUM Boundary
EPA BRA Location
Babbitt BSA Locations
Area of Potential Effect
Section Lines
Other Mine Related Disturbance (6)
EPA Identified Drainage Area Boundary
EPA Identified Drainage Network
EPA Identified Road Buffer (50-ft)
EPA Identified Road Centerline
• • ¦ 2019 Little Colorado River (NHD)
Gamma Scan Results Relative to Investigation Level (IL) (5)
• 0 - 0.5*IL
>0.5*IL-1*IL
>1*IL-2*IL
• >2*IL - 3*IL
• >3*IL
NOTES:
1) IL Values are provided on Table 5-22.
Pooled BSA
95% Gamma UTL
(cpm)
IL (cpm)
Alluvial BSA #1 and # 2: Terrace BSA ?1
and #2, EPA "Qter BRA"
48,212
51.824
Drainage BSA #2
43:564
47J76
Little Colorado River BSA
26:053
29,665
2) The IL Application Areas are shown on Figure 5-14.
3) Test Pit Gamma Readings are the maximum gross
reading encountered in the test pit (December 2018).
4) Test Pit Gamma Scans were completed using a
2-inch x 2-inch Nal detector.
5) Gamma Scan Results were completed using a
3-inch x 3-inch Nal detector.
6) Other Mine Related Disturbance as defined in the
Phase II Work Plan (approved September 6, 2017).
Project No. 110704
3L *
|~~A Engineering Analytics, Inc. _
UT~~ €AG
FIGURE 4-22
TEST PIT LOCATIONS AND MAXIMUM GAMMA READINGS
BABBITT RANCHES
-------
(7070 fcpm)
J TP-6/(6114 cpm)
L ^TP-9 (16635 cpm)
TP-1 (31992 fcpm)
AUM 457
Source: Esri, Maxar, Geo Eye. Earthstap@eographlps,|^^ESi®^M^RslilSDA, USGS, AerqGRID''IGW;-tand
the GIS User Community ;|.v T \ \
March 2021
Rev 1.2
LEGEND
O Phase III Test Pit Actual Locations With Max Gamma Results
EPA Identified Road Ceriterline
EPA Identified Drainage Network
EPA identified Drainage Area Boundary
EPA Identified Road Buffer (50-ft)
Other Mine Related Disturbance (6)
Area of Potential Effect
Section Lines
EPA AUM Boundary
2019 Little Colorado River (NHD)
Gamma Scan Results Relative to Investigation Level (IL) (5)
• 0-0.51L
>0.5 "IL 11L
>11L-2*IL
>21L - 3*IL
• >31L
NOTES:
1) IL Values are provided on Table 5-22.
Pooled BSA
95% Gamma UTL
(cpm)
IL (cpm)
Alluvial BSA #1 and # 2: Terrace BSA #1
and #2. EPA"QterBRA"
48,212
51,824
Drainage BSA #2
43,564
47=176
Little Colorado River BSA
26:053
29:665
2) The IL Application Areas are shown on Figure 5-14.
3) Test Pit Gamma Readings are the maximum gross
reading encountered in the test pit (December 2018).
4) Test Pit Gamma Scans were completed using a
2-inch x 2-inch Nal detector.
5) Gamma Scan Results were completed using a
3-inch x 3-inch Nal detector.
6) Other Mine Related Disturbance as defined in the
Phase II Work Plan (approved September 6, 2017).
Project No. 110704
|~~A Engineering Analytics, Inc. _
UT~~ €AG
FIGURE 4-23
TEST PIT LOCATIONS WITH RESULTS OF GAMMA SCAN SURVEY (COMPARED TO IL), NE QUADRANT
BABBITT RANCHES
-------
Berm
k'v
W—TWiWi
Concrete Slab
Upgrader Foundation
Drainage from Upgrader
Waste Rock Piles
Dozer Push Area
Project No. 110704
March 2021
Rev 1.2
LEGEND
0 Phase !!! Test Pits
Area of Potential Effect
Section Lines
EPAAUM Boundary
EPA Identified Drainage Area Boundary
EPA Identified Drainage Network
EPA Identified "Wetland 3"
EPA Identified Road Buffer (50-ft)
EPA Identified Road Centerline
Other Mine Related Disturbance (1)
2019 Little Colorado River (NHD)
NOTES:
1) Other Mine Related Disturbance as defined in the
Phase II Work Plan (approved September 6, 2017).
2) High Resolution photo from Maser (2016)
3) For informational purposes only - not for field
implementation.
Concrete Slab
m
Engineering Analytics, Inc.
FIGURE 4-24
TEST PIT LOCATIONS IN AREA OF AUM 457
BABBITT RANCHES
-------
I J
LEGEND
O Phase III Test Pit Actual Locations With Max Gamma Results
EPA Identified Road Ceriterline
EPA Identified Drainage Network
EPA identified Drainage Area Boundary
EPA Identified Road Buffer (50-ft)
Other Mine Related Disturbance (6)
Babbitt BSA Locations
1 Area of Potential Effect
Section Lines
EPAAUM Boundary
• • • 2019 Little Colorado River (NHD)
Gamma Scan Results Relative to Investigation Level (IL) (5)
• 0 0.51L
>0.5*IL - 11L
>11L - 2SIL
>21L -3*IL
• >31L
NOTES:
1) IL Values are provided on Table 5-22.
Pooled BSA
95% Gamma UTL
(cpm)
IL (cpm)
Alluvial BSA #1 and # 2, Terrace BSA #1
and£2: EPA "Qter BRA"
48;212
51,824
Drainage BSA #2
43,564
47=176
Little Colorado River BSA
26.053
29:665
2) The IL Application Areas are shown on Figure 5-14
3) Test Pit Gamma Readings are the maximum gross
reading encountered in the test pit (December 2018).
4) Test Pit Gamma Scans were completed using a
2-inch x 2-inch Nal detector.
5) Gamma Scan Results were completed using a
3-inch x 3-inch Nal detector.
6) Other Mine Related Disturbance as defined in the
Phase II Work Plan (approved September 6, 2017).
Project No. 110704
Engineering Analytics, Inc.
m
€RG
March 2021
Rev 1.2
FIGURE 4-25
TEST PIT LOCATIONS WITH RESULTS OF GAMMA SCAN SURVEY (COMPARED TO IL), SE QUADRANT
BABBITT RANCHES
-------
I , ti
,
TP-15
M • . iS.
LTPJ6 * ¦ • >
'
* %
Dozer Push
TP-17
TP-20
TP-19
TP-21
Exploratory Boring Locations
Dozer Push
iTP-23
Pit Area
March 2021
Rev 1.2
¦
Road Cut
Road Cut
Project No. 110704
LEGEND
0 Phase III Test Pits
Area of Potential Effect
Section Lines
EPAAUM Boundary
EPA Identified Drainage Area Boundary
EPA Identified Drainage Network
EPA Identified Road Buffer (50-ft)
EPA Identified Road Centerline
Other Mine Related Disturbance (1)
2019 Little Colorado River (NHD)
Notes:
1) Other Mine Related Disturbance as defined in the
Phase I! Work Plan (approved September 6, 2017).
2) High Resolution photo from Maser (2016)
3) For informational purposes only - not for field
implementation.
Dozer Push
m
Engineering Analytics, Inc.
FIGURE 4-26
TEST PIT LOCATIONS IN AREA OF AUMS 458 AND 459
BABBITT RANCHES
-------
/ JV
S
O
>¦
\
*
X
TP-18 (8574 cpm)
TP-22 (5529 cpm
\
\
—L
\ /. „
\TP-19 (18507 cpm)
0
250 500
1,000
3 Feet
LEGEND
O Phase III Test Pit Actual Locations With Max Gamma Results
EPAAUM Boundary
EPA BRA Location
Babbitt BSA Locations
; Area of Potential Effect
L.—.j
Section Lines
Other Mine Related Disturbance (6)
EPA Identified Drainage Area Boundary
EPA Identified Drainage Network
EPA Identified Road Buffer (50-ft)
EPA Identified Road Centerline
Gamma Scan Results Relative to Investigation Level (IL) (5)
• 0-0.51L
>0.5 *IL 11L
>11L Z'lL
>21L 3*IL
• >31L
NOTES:
1) IL Values are provided on Table 5-22.
Pooled BSA
95% Gamma UTL
(cpm)
IL (epm)
Alluvial BSA #1 and # 2, Terrace BSA #1
and?2s EPA "Qter BRA"
48,212
51,824
Drainage BSA #2
43,564
47,176
Little Colorado liver BSA
26:053
29:665
2) The IL Application Areas are shown on Figure 5-14
3) Test Pit Gamma Readings are the maximum gross
reading encountered in the test pit (December 2018).
4) Test Pit Gamma Scans were completed using a
2-inch x 2-inch Nal detector.
5) Gamma Scan Results were completed using a
3-inch x 3-inch Nal detector.
6) Other Mine Related Disturbance as defined in the
Phase II Work Plan (approved September 6, 2017).
Project No. 110704
Engineering Analytics, Inc.
m
€RG
March 2021
Rev 1.2
FIGURE 4-27
TEST PIT LOCATIONS WITH RESULTS OF GAMMA SCAN SURVEY (COMPARED TO IL), SW QUADRANT
BABBITT RANCHES
-------
X
X
X.
TP-1 S1
X\
v
X
X
X
X,
X
X
TP-1 S3
V ^
x
\
X
X
X
X
xv
X
X
X
X
X
X.
TP-1 S4
X.
X
x
X
TP-13
x
....
O
0
250 500
1,000
3 Feet
LEGEND
O Phase III Test Pit Actual Locations With Max Gamma Results
Babbitt BSA Locations
¦ Area of Potential Effect
Section Lines
EPA Identified Road Buffer (50-ft)
EPA Identified Road Centerline
Gamma Scan Results Relative to Investigation Level (IL) (5)
• (I 11.51L
>0.5 IL 11L
>11L-2*IL
>21L 3*11.
• >311.
NOTES:
1) IL Values are provided on Table 5-22.
Pooled BSA
95% Gamma UTL
(cpm)
IL (epm)
Alluvial BSA #1 and # 2, Terrace BSA #1
and £2, EPA "Qter BRA"
48,212
51,824
Drainage BSA #2
43,564
47,176
Little Colorado liver BSA
26:053
29,665
2) The IL Application Areas are shown on Figure 5-14
3) Test Pit Gamma Readings are the maximum gross
reading encountered in the test pit (December 2018).
4) Test Pit Gamma Scans were completed using a
2-inch x 2-inch Nal detector.
5) Gamma Scan Results were completed using a
3-inch x 3-inch Nal detector.
6) Other Mine Related Disturbance as defined in the
Phase II Work Plan (approved September 6, 2017).
Project No. 110704
Engineering Analytics, Inc.
m
€RG
March 2021
Rev 1.2
FIGURE 4-28
TEST PIT LOCATIONS WITH RESULTS OF GAMMA SCAN SURVEY (COMPARED TO IL), NW QUADRANT
BABBITT RANCHES
-------
T:\11D704 Babbitt Ranch\R5E Report\Boxplots.dwg SAVED: 3/17/21 PRINTED: 3/17/21
RADIUM-226 DATA BY BSA
4-
5Z
o
ro 'S
3
-------
T210
Terrace BSA #2
Radium 226:
2.14 pCi/g
T207
T208
T209
Radium 226:
2.27 pCi/g
Radium 226:
2.20 pCi/g
Radium 226:
2.38 pCi/g
T204
Radium 226:
2.13 pCi/g
T205
Radium 226:
2.31 pCi/g
T206
Radium 226:
2.05 pCi/g
O
T201
T202
T203
Radium 226:
2.23 pCi/g
ZT^'t
Radium 226:
2.54 pCi/g
4
Radium 226:
3.72 pCi/g
LEGEND
O Soil Sample Location
~
Babbitt BSA Locations
0 12.5 25
50
Feet
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION.
Project No. 110704
|~~A Engineering Analytics, Inc. —
u\— €RG
March 2021
Rev 1.2
FIGURE 4-30
TERRACE BSA #2 RADIUM-226 CONCENTRATIONS
BABBITT RANCHES
-------
Alluvial BSA #1
Radium 226
4.91 pCi/g
Radium 226
2.96 pCi/g
Radium 226
2.41 pCi/g
Radium 226
3.59 pCi/g
Radium 226
2.16 pCi/g
Radium 226
2.44 pCi/g
Radium 226
3.01 pCi/g
Radium 226
1.79 pCi/g
Radium 226
2.76 pCi/g
Radium 226
1.97 pCi/g
Radium 226
1.57 pCi/g
Radium 226
2.0 pCi/g
Radium 226
4.16 pCi/g
Radium 226
3.5 pCi/g
Radium 226
2.08 pCi/g
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION
Project No. 110704
LEGEND
O Soil Sample Location
Babbitt BSA Locations
! Area of Potential Effect
0 15 30
60
Feet
March 2021
Rev 1.2
|~~A Engineering Analytics, Inc. _
UT~~ €AG
FIGURE 4-31
ALLUVIAL BSA #1 RADIUM-226 CONCENTRATIONS
BABBITT RANCHES
-------
Alluvial BSA #2
207
Radium 226:
2.27 pCi/g
Radium 226:
3.2 pCi/g
Radium 226:
3.16 pCi/g
Radium 226:
2.9 pCi/g
LEGEND
O Soil Sample Location
Babbitt BSA Locations
! Area of Potential Effect
L J
0 12.5 25
50
Feet
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION.
Project No. 110704
|~~A Engineering Analytics, Inc. —
u\— €RG
March 2021
Rev 1.2
FIGURE 4-32
ALLUVIAL BSA #2 RADIUM-226 CONCENTRATIONS
BABBITT RANCHES
-------
EPA "Qter BRA'
QT07
Radium 226:
2.06 pCi/g
QT08
F1
Radium 226:
1.9 pCi/g
QTOS
Radium 226:
2.98 pCi/g
QT10
Radium 226:
2.15 pCi/g
QT04
QT05
QT06
Radium 226:
1.78 pCi/g
Radium 226:
2.15 pCi/g
Radium 226:
1.84 pCi/g
QT01
QT02
Radium 226:
1.82 pCi/g
Radium 226:
1.52 pCi/g
QT03
O
Radium 226:
1.7 pCi/g
LEGEND
O Soil Sample Location
EPA BRA Location
! Area of Potential Effect
P"-"1
0 15 30
60
Feet
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION.
Project No. 110704
|~~A Engineering Analytics, Inc. —
u\— €RG
March 2021
Rev 1.2
FIGURE 4-33
EPA QTer BRA RADIUM-226 CONCENTRATIONS
BABBITT RANCHES
-------
Drainage BSA #2
D204
D205
Radium 226:
1.04 pCi/g
Radium 226:
1.12 pCi/g
O
Wl
D206
Radium 226:
1.17 pCi/g
U
Wt
D201
D202
D203
Radium 226:
1.11 pCi/g
Radium 226:
1.34 pCi/g
Radium 226:
1.71 pCi/g
LEGEND
O Soil Sample Location
Babbitt BSA Locations
! Area of Potential Effect
L" .
.. — ..J
0
15
30
60
Feet
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION.
Project No. 110704
|~~A Engineering Analytics, Inc. —
u\— €RG
March 2021
Rev 1.2
FIGURE 4-34
DRAINAGE BSA #2 RADIUM-226 CONCENTRATIONS
BABBITT RANCHES
-------
Project No. 110704
m
Engineering Analytics, Inc.
Terrace BSA #1
T106
Radium 226:
2.47 pCi/g
Radium 226:
2.37 pCi/g
Radium 226:
1.85 pCi/g
Radium 226:
1.33 pCi/g
T103
Radium 226:
1.87 pCi/g
Radium 226:
2.64 pCi/g
O
Pi
TT.04
Radium 226:
2.02 pCi/g
T101
Radium 226:
1.85 pCi/g
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION.
CAG
i
LEGEND
O Soil Sample Location
Babbitt BSA Locations
! Area of Potential Effect
Section Lines
0
15 30
60
Feet
March 2021
Rev 1.2
FIGURE 4-35
TERRACE BSA #1 RADIUM-226 CONCENTRATIONS
BABBITT RANCHES
-------
Little Colorado River BSA
LCR09
HTi
Radium 226:
0.8 pCi/g
Radium 226:
0.76 pCi/g
LCR05
L.CR06
LCR07
p
~
Radium 226:
Radium 226:
Radium 226:
0.96 pCi/g
0.75 pCi/g
0.88 pCi/g
LCR02
LCR.03
LCR04
1
.^1
Radium 226:
Radium 226:
Radium 226:
¦
1.09 pCi/g
V
0.6 pCi/g
0.86 pCi/g
A
> * v
LCR01
Radium 226:
0.83 pCi/g
LEGEND
O Soil Sample Location
Babbitt BSA Locations
! Area of Potential Effect
0 15 30
60
Feet
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION.
Project No. 110704
Engineering Analytics, Inc.
m
€RG
March 2021
Rev 1.2
FIGURE 4-36
LITTLE COLORADO RIVER BSA RADIUM-226 CONCENTRATIONS
BABBITT RANCHES
-------
T:\110704 Babbitt Ranch\RSE Repgrt.\Bovpl.ots.dW9 SAVED: 3/1 7/21 PRINTED: 3/1 7/21
ARSENIC DATA BY BSA
5-
i—
c 0)3
8 E
c
o
O
2-
Alluvial #1
Alluvial #2
Drainage #2 Little Colorado River
Background Study Area
Qter BRA
Terrace #1
Terrace #2
NOTE:
IN A TUKEY-STYLE BOXPLOT, BOXES REPRESENT THE 25th-75th PERCENTILES OF DATA AND DARK LINES THE MEDIAN.
POTENTIAL OUTLIERS ARE IDENTIFIED AS DOTS. WHILE WHISKERS SHOW THE RANGE OF THE REMAINDER OF THE DATA.
Project No. 110704
|~~A Engineering Analytics, Inc. jflfe
tAi" ~~ €RG
March 2021
Rev 1.2
FIGURE 4-37
BOXPLOT SHOWING SOIL CONCENTRATIONS OF
ARSENIC BY BACKGROUND STUDY AREA
BABBITT RANCHES
-------
T:\110704 Babbitt Rgneh^BSE Repgrt\Bovplots..di»g ¦SAVED: 3/17/21 PRINTED: 3/17/21
MERCURY DATA BY BSA
0.020
0.015
c
o _
c: o>
p
£ 3 0.010
o
o
0.005
Alluvial #1
Alluvial #2
Drainage #2 Little Colorado River
Background Study Area
Qter BRA
Terrace #1
Terrace #2
NOTE:
IN A TUKEY-STYLE BOXPLOT, BOXES REPRESENT THE 25th-75th PERCENTILES OF DATA AND DARK LINES THE MEDIAN.
POTENTIAL OUTLIERS ARE IDENTIFIED AS DOTS. WHILE WHISKERS SHOW THE RANGE OF THE REMAINDER OF THE DATA.
Project No. 110704
|~~A Engineering Analytics, Inc. ^g|
tAi" — €RG
March 2021
Rev 1.2
FIGURE 4-38
BOXPLOT SHOWING SOIL CONCENTRATIONS OF
MERCURY BY BACKGROUND STUDY AREA
BABBITT RANCHES
-------
T:\110704 Babbitt Ranch\RSE Repgrt.\Bovpl.ots.dW9 SAVED: 3/1 7/21 PRINTED: 3/1 7/21
MOLYBDENUM DATA BY BSA
0.6-
0.5
ro co
<1)
O .
a
o
O
6)0.4-
0.3 -
0.2-
Alluvial #1
Alluvia] #2
Drainage #2 Little Colorado River
Background Study Area
Qter BRA
Terrace #1
Terrace #2
NOTE:
IN A TUKEY-STYLE BOXPLOT, BOXES REPRESENT THE 25th-75th PERCENTILES OF DATA AND DARK LINES THE MEDIAN.
POTENTIAL OUTLIERS ARE IDENTIFIED AS DOTS. WHILE WHISKERS SHOW THE RANGE OF THE REMAINDER OF THE DATA.
Project No. 110704
|~~A Engineering Analytics, Inc. jflfe
tAi" — €RG
March 2021
Rev 1.2
FIGURE 4-39
BOXPLOT SHOWING SOIL CONCENTRATIONS OF
MOLYBDENUM BY BACKGROUND STUDY AREA
BABBITT RANCHES
-------
T:\110704 Babbitt Ranch\RSE Repgrt.\Bovpl.ots.dW9 SAVED: 3/1 7/21 PRINTED: 3/1 7/21
SELENIUM DATA BY BSA
1.5-
o
to
r en
® f=
o C
s=
o
O
1.0
0.5"
Alluvial #1
Alluvial #2
Drainage #2 Little Colorado River
Background Study Area
Qter BRA
Terrace #1
Terrace #2
NOTE:
IN A TUKEY-STYLE BOXPLOT, BOXES REPRESENT THE 25th-75th PERCENTILES OF DATA AND DARK LINES THE MEDIAN.
POTENTIAL OUTLIERS ARE IDENTIFIED AS DOTS. WHILE WHISKERS SHOW THE RANGE OF THE REMAINDER OF THE DATA.
Project No. 110704
|~~A Engineering Analytics, Inc. jflfe
tAi" — €RG
March 2021
Rev 1.2
FIGURE 4-40
BOXPLOT SHOWING SOIL CONCENTRATIONS OF
SELENIUM BY BACKGROUND STUDY AREA
BABBITT RANCHES
-------
T:\11S204 BSilsitt Ranch \BS£ MfM\BMpHs.(M| BWED: 3/1 7/21 PRINTED: 3/1 7/21
Alluvial #1
Alluvial #2
Drainage #2
Little Colorado River
Background Study Area
Qter BRA
Terrace #1
Terrace #2
NOTE:
IN A TUKEY-STYLE BOXPLOT, BOXES REPRESENT THE 25th-75th PERCENTILES OF DATA AND DARK LINES THE MEDIAN.
POTENTIAL OUTLIERS ARE IDENTIFIED AS DOTS. WHILE WHISKERS SHOW THE RANGE OF THE REMAINDER OF THE DATA.
Project No. 110704
|~~A Engineering Analytics, Inc. ^g|
tAi" — €RG
March 2021
Rev 1.2
FIGURE 4-41
BOXPLOT SHOWING SOIL CONCENTRATIONS OF
URANIUM BY BACKGROUND STUDY AREA
BABBITT RANCHES
-------
T:\11S204 BSilsitt Ranch \BS£ MfM\BMpHs.(M| BWED: 3/1 7/21 PRINTED: 3/1 7/21
Alluvial #1
Alluvial #2
Drainage #2
Little Colorado River
Background Study Area
Qter BRA
Terrace #*1
Terrace #2
NOTE:
IN A TUKEY-STYLE BOXPLOT, BOXES REPRESENT THE 25th-75th PERCENTILES OF DATA AND DARK LINES THE MEDIAN.
POTENTIAL OUTLIERS ARE IDENTIFIED AS DOTS. WHILE WHISKERS SHOW THE RANGE OF THE REMAINDER OF THE DATA.
Project No. 110704
|~~A Engineering Analytics, Inc. ^g|
tAi" — €RG
March 2021
Rev 1.2
FIGURE 4-42
BOXPLOT SHOWING SOIL CONCENTRATIONS OF
VANADIUM BY BACKGROUND STUDY AREA
BABBITT RANCHES
-------
T210
Arsenic: 2.8 mg/kg
Mercury: 0.01 mg/kg
Molybdenum: 0.34 mg/kg
Selenium: 0.24 mg/kg
Uranium: 3.7 mg/kg
Vanadium: 41 mg/kg
Terrace BSA #2
T207
O
Arsenic: 2.5 mg/kg
Mercury: 0.011 mg/kg
Molybdenum: 0.1S mg/kg
Selenium: 0.23 mg/kg
Uranium: 3.1 mg/kg
Vanadium: 39 mg/kg
T208
Arsenic: 4.9 mg/kg
Mercury: 0.009 mg/kg
Molybdenum: 0.34 mg/kg
Selenium: 0.47 mg/kg
Uranium: 5.4 mg/kg
Vanadium: 42 mg/kg
T209
O
Arsenic: 2.4 mg/kg
Mercury: 0.01 mg/kg
Molybdenum: 0.34 mg/kg
Selenium: 0.25 mg/kg
Uranium: 3.9 mg/kg
Vanadium: 32 mg/kg
T204
T205
T206
Arsenic: 3.0 mg/kg
Mercury: 0.008 mg/kg
Molybdenum: 0.38 mg/kg
Selenium: 0.25 mg/kg
Uranium: 4.1 mg/kg
Vanadium: 43 mg/kg
Arsenic: 2.8 mg/kg
Mercury: 0.008 mg/kg
Molybdenum: 0.36 mg/kg
Selenium: 0.25 mg/kg
Uranium: 4.7 mg/kg
Vanadium: 38 mg/kg
Arsenic: 1.8 mg/kg
Mercury: 0.006 mg/kg
Molybdenum: 0.53 mg/kg
Selenium: 0.25 mg/kg
Uranium: 4.1 mg/kg
Vanadium: 22 mg/kg
T201
O
Arsenic: 2.9 mg/kg
Mercury: 0.011 mg/kg
Molybdenum: 0.26 mg/kg
Selenium: 0.24 mg/kg
Uranium: 3.4 mg/kg
Vanadium: 45 mg/kg
T202
O
—
Arsenic: 3.1 mg/kg
Mercury: 0.011 mg/kg
Molybdenum: 0.4 mg/kg
Selenium: 0.23 mg/kg
Uranium: 3.4 mg/kg
Vanadium: 46 mg/kg
T203
O
Arsenic: 2.6 mg/kg
Mercury: 0.01 mg/kg
Molybdenum: 0.52 mg/kg
Selenium: 0.24 mg/kg
Uranium: 4.1 mg/kg
Vanadium: 39 mg/kg
LEGEND
O Soil Sample Location
~
Babbitt BSA Locations
0 12.5 25
50
Feet
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION.
Project No. 110704
|~~A Engineering Analytics, Inc. —
\n~~ €RG
March 2021
Rev 1.2
FIGURE 4-43
TERRACE BSA #2 METALS CONCENTRATIONS
BABBITT RANCHES
-------
N
V
\
X
X
Arsenic: 4.7 mg/kg
Mercury: 0.008 mg/kg
Molybdenum: 0.28 mg/kg
Selenium: 0.29 mg/kg
Uranium: 13 mg/kg
Vanadium: 57 mg/kg
A112
Arsenic: 2.8 mg/kg
Mercury: 0.009 mg/kg
Molybdenum: 0.19 mg/kg
Selenium: 0.29 mg/kg
Uranium: 3.9 mg/kg
Vanadium: 93 mg/kg
A11
Arsenic: 2.6 mg/kg
Mercury: 0.006 mg/kg
Molybdenum: 0.65 mg/kg
Selenium: 0.4 mg/kg
Uranium: 4.6 mg/kg
Vanadium: 67 mg/kg
Arsenic: 2.9 mg/kg
Mercury: 0.005 mg/kg
Molybdenum: 0.3 mg/kg
Selenium: 0.28 mg/kg
Uranium: 2.7 mg/kg
Vanadium: 80 mg/kg
Arsenic: 2.5 mg/kg
Mercury: 0.007 mg/kg
Molybdenum: 0.18 mg/kg
Selenium: 0.39 mg/kg
Uranium: 2.4 mg/kg
Vanadium: 68 mg/kg
Arsenic: 2.7 mg/kg
Mercury: 0.017 mg/kg
Molybdenum: 0.22 mg/kg
Selenium: 0.24 mg/kg
Uranium: 3.0 mg/kg
Vanadium:85 mg/kg
A105
X
WI
X
X
Arsenic: 2.5 mg/kg
Mercury: 0.006 mg/kg
Molybdenum: 0.5 mg/kg
Selenium: 0,63 mg/kg
Uranium: 2.3 mg/kg
Vanadium: 65 mg/kg
A106
/V
A107
A108
Arsenic: 2.3 mg/kg
Mercury: 0.008 mg/kg
Molybdenum: 0.51 mg/kg
Selenium: 0.24 mg/kg
Uranium: 2.7 mg/kg
Vanadium: 65 mg/kg
_A102
K_
X
Arsenic: 2.6 mg/kg
Mercury: 0.008 mg/kg
Molybdenum: 0.63 mg/kg
Selenium: 0.29 mg/kg
Uranium: 2.6 mg/kg
Vanadium: 73 mg/kg
_/\-
3s
103
Arsenic: 2.3 mg/kg
Mercury: 0.006 mg/kg
Molybdenum: 0.42 mg/kg
Selenium: 0.24 mg/kg
Uranium: 2.5 mg/kg
Vanadium: 59 mg/kg
Arsenic: 2.6 mg/kg
Mercury: 0.011 mg/kg
Molybdenum: 0.62 mg/kg
Selenium: 0.24 mg/kg
Uranium: 3.1 mg/kg
Vanadium: 82 mg/kg
Arsenic: 2.2 mg/kg
Mercury: 0.008 mg/kg
Molybdenum: 0.61 mg/kg
Selenium: 0.24 mg/kg
Uranium: 4.0 mg/kg
Vanadium: 64 mg/kg
Arsenic: 2.1 mg/kg
Mercury: 0.015 mg/kg
Molybdenum: 0.28 mg/kg
Selenium: 0.24 mg/kg
Uranium: 3.0 mg/kg
Vanadium: 57 mg/kg
X
V
A104
?\ /
Arsenic: 2.8 mg/kg
Mercury: 0.006 mg/kg
Molybdenum: 0.48 mg/kg
Selenium: 0.23 mg/kg
Uranium: 6.4 mg/kg
Vanadium: 55 mg/kg
A101
Arsenic: 2.1 mg/kg
Mercury: 0.008 mg/kg
Molybdenum: 0.25 mg/kg
Selenium: 0.24 mg/kg
Uranium: 2.6 mg/kg
Vanadium: 49 mg/kg
v
X
LEGEND
O Soil Sample Location
Babbitt BSA Locations
! Area of Potential Effect
L" .
.....J
0
15 30
60
Feet
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION.
Project No. 110704
|~~A Engineering Analytics, Inc. —
\n~~ €RG
March 2021
Rev 1.2
FIGURE 4-44
ALLUVIAL BSA #1 METALS CONCENTRATIONS
BABBITT RANCHES
-------
Arsenic: 2.9 mg/kg
Mercury: 0.004 mg/kg
Molybdenum: 0.19 mg/kg
Selenium: 0.24 mg/kg
Uranium: 2.2 mg/kg
Vanadium: 62 mg/kg
Arsenic: 3.2 mg/kg
Mercury: 0.006 mg/kg
Molybdenum: 0.18 mg/kg
Selenium: 0.45 mg/kg
Uranium: 1.9 mg/kg
Vanadium: 64 mg/kg
Arsenic: 3.2 mg/kg
Mercury: 0.005 mg/kg
Molybdenum: 0.34 mg/kg
Selenium: 0.88 mg/kg
Uranium: 2.5 mg/kg
Vanadium: 73 mg/kg
Arsenic: 3.6 mg/kg
Mercury: 0.007 mg/kg
Molybdenum: 0.45 mg/kg
Selenium: 0.24 mg/kg
Uranium: 3.0 mg/kg
Vanadium: 82 mg/kg
A208
A209
A210
A211
Arsenic: 3.7 mg/kg
Mercury: 0.006 mg/kg
Molybdenum: 0.22 mg/kg
Selenium: 0.55 mg/kg
Uranium: 2.4 mg/kg
Vanadium: 73 mg/kg
Arsenic: 3.4 mg/kg
Mercury: 0.008 mg/kg
Molybdenum: 0.19 mg/kg
Selenium: 0.24 mg/kg
Uranium: 2.3 mg/kg
Vanadium: 70 mg/kg
Arsenic: 3.3 mg/kg
Mercury: 0.004 mg/kg
Molybdenum: 0.18 mg/kg
Selenium: 0.44 mg/kg
Uranium: 2.0 mg/kg
Vanadium: 67 mg/kg
Arsenic: 3.3 mg/kg
Mercury: 0.006 mg/kg
Molybdenum: 0.19 mg/kg
Selenium: 0.3 mg/kg
Uranium: 2.5 mg/kg
Vanadium: 65 mg/kg
A204
A205
A206
Arsenic: 3.7 mg/kg
Mercury: 0.008 mg/kg
Molybdenum: 0.59 mg/kg
Selenium: 0.28 mg/kg
Uranium: 3.1 mg/kg
Vanadium: 90 mg/kg
Arsenic: 3.7 mg/kg
Mercury: 0.01 mg/kg
Molybdenum: 0.31 mg/kg
Selenium: 0.24 mg/kg
Uranium: 2.8 mg/kg
Vanadium: 70 mg/kg
Arsenic: 2.8 mg/kg
Mercury: 0.007 mg/kg
Molybdenum: 0.29 mg/kg
Selenium: 0.49 mg/kg
Uranium: 2.6 mg/kg
Vanadium: 58 mg/kg
Arsenic: 3.4 mg/kg
Mercury: 0.009 mg/kg
Molybdenum: 0.37 mg/kg
Selenium: 1.1 mg/kg
Uranium: 2.9 mg/kg
Vanadium: 71 mg/kg
A201
Arsenic: 3.5 mg/kg
Mercury: 0.007 mg/kg
Molybdenum: 0.49 mg/kg
Selenium: 1.9 mg/kg
Uranium: 3.9 mg/kg
Vanadium: 77 mg/kg
Arsenic: 3.7 mg/kg
Mercury: 0.007 mg/kg
Molybdenum: 0.24 mg/kg
Selenium: 0.23 mg/kg
Uranium: 3.1 mg/kg
Vanadium: 87 mg/kg
Arsenic: 3.0 mg/kg
Mercury: 0.006 mg/kg
Molybdenum: 0.18 mg/kg
Selenium: 0.59 mg/kg
Uranium: 3.2 mg/kg
Vanadium: 59 mg/kg
LEGEND
O Soil Sample Location
Babbitt BSA Locations
! Area of Potential Effect
L J
0 12.5 25
50
Feel
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION.
Project No. 110704
|~~A Engineering Analytics, Inc. —
u\— €RG
March 2021
Rev 1.2
FIGURE 4-45
ALLUVIAL BSA #2 METALS CONCENTRATIONS
BABBITT RANCHES
-------
EPA "Qter BRA"
QT07
O
Arsenic: 3.6 mg/kg
Mercury: 0.016 mg/kg
Molybdenum: 0.32 mg/kg
Selenium: 0.48 mg/kg
Uranium: 1.8 mg/kg
Vanadium: 63 mg/kg
QT08
O
Arsenic: 4.4 mg/kg
Mercury: 0.019 mg/kg
Molybdenum: 0.34 mg/kg
Selenium: 0.46 mg/kg
Uranium: 2.2 mg/kg
Vanadium: 64 mg/kg
QTOS
Arsenic: 4.7 mg/kg
Mercury: 0.017 mg/kg
Molybdenum: 0.19 mg/kg
Selenium: 0.25 mg/kg
Uranium: 3.5 mg/kg
Vanadium: 70 mg/kg
QT10
O
Arsenic: 3.0 mg/kg
Mercury: 0.018 mg/kg
Molybdenum: 0.18 mg/kg
Selenium: 0.23 mg/kg
Uranium: 1.9 mg/kg
Vanadium: 60 mg/kg
Arsenic: 3.3 mg/kg
Mercury: 0.013 mg/kg
Molybdenum: 0.19 mg/kg
Selenium: 0.24 mg/kg
Uranium: 2.0 mg/kg
Vanadium: 72 mg/kg
QT04
QT05
QT06
Arsenic: 4.1 mg/kg
Mercury: 0.011 mg/kg
Molybdenum: 0.19 mg/kg
Selenium: 0.27 mg/kg
Uranium: 2.3 mg/kg
Vanadium: 70 mg/kg
Arsenic: 4.5 mg/kg
Mercury: 0.016 mg/kg
Molybdenum: 0.19 mg/kg
Selenium: 0.24 mg/kg
Uranium: 2.4 mg/kg
Vanadium: 72 mg/kg
Arsenic: 4.6 mg/kg
Mercury: 0.018 mg/kg
Molybdenum: 0.18 mg/kg
Selenium: 0.51 mg/kg
Uranium: 2.1 mg/kg
Vanadium: 76 mg/kg
QT01
.QT02
Arsenic: 5.0 mg/kg
Mercury: 0.016 mg/kg
Molybdenum: 0.19 mg/kg
Selenium: 0.24 mg/kg
Uranium: 2.7 mg/kg
Vanadium: 88 mg/kg
Arsenic: 3.3 mg/kg
Mercury: 0.014 mg/kg
Molybdenum: 0.19 mg/kg
Selenium: 0.5 mg/kg
Uranium: 2.0 mg/kg
Vanadium: 61 mg/kg
LEGEND
O Soil Sample Location
EPA BRA Location
! Area of Potential Effect
P"-"1
0 15 30
60
Feet
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION.
Project No. 110704
|~~A Engineering Analytics, Inc. —
u\— €RG
March 2021
Rev 1.2
FIGURE 4-46
EPA QTer BRA METALS CONCENTRATIONS
BABBITT RANCHES
-------
Drainage BSA #2
D204
D205
D206
Arsenic: 3.1 mg/kg
Mercury: 0,005 mg/kg
Molybdenum: 0.17 mg/kg
Selenium: 0.22 mg/kg
Uranium: 1.2 mg/kg
Vanadium: 33 mg/kg
Arsenic: 3.0 mg/kg
Mercury: 0.004 mg/kg
Molybdenum: 0.22 mg/kg
Selenium: 0.23 mg/kg
Uranium: 0.93 mg/kg
Vanadium: 35 mg/kg
Arsenic: 3.4 mg/kg
Mercury: 0.009 mg/kg
Molybdenum: 0.36 mg/kg
Selenium: 0.24 mg/kg
Uranium: 1.4 mg/kg
Vanadium: 32 mg/kg
D201
D202
D203
Arsenic: 2.9 mg/kg
Mercury: 0.005 mg/kg
Molybdenum: 0.18 mg/kg
Selenium: 0.68 mg/kg
Uranium: 1.2 mg/kg
Vanadium: 35 mg/kg
r
4-
Arsenic: 3.3 mg/kg
Mercury: 0.006 mg/kg
Molybdenum: 0.18 mg/kg
Selenium: 0.34 mg/kg
Uranium: 1.4 mg/kg
Vanadium: 35 mg/kg
Arsenic: 3.5 mg/kg
Mercury: 0.009 mg/kg
Molybdenum: 0.18 mg/kg
Selenium: 0.51 mg/kg
Uranium: 1.5 mg/kg
Vanadium: 31 mg/kg
\
LEGEND
O Soil Sample Location
Babbitt BSA Locations
! Area of Potential Effect
L" .
.....J
0
15
30
60
Feet
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION.
Project No. 110704
|~~A Engineering Analytics, Inc. —
\n~~ €RG
March 2021
Rev 1.2
FIGURE 4-47
DRAINAGE BSA #2 METALS CONCENTRATIONS
BABBITT RANCHES
-------
Arsenic: 1.1 mg/kg
Mercury: 0.011 mg/kg
Molybdenum: 0.19 mg/kg
Selenium: 0.37 mg/kg
Uranium: 1.2 mg/kg
Vanadium: 16 mg/kg
Arsenic: 2.4 mg/kg
Mercury: 0.014 mg/kg
Molybdenum: 0.19 mg/kg
Selenium: 0.24 mg/kg
Uranium: 1.4 mg/kg
Vanadium: 20 mg/kg
T105
Arsenic: 2.0 mg/kg
Mercury: 0.02 mg/kg
Molybdenum: 0.3 mg/kg
Selenium: 0.44 mg/kg
Uranium: 1.4 mg/kg
Vanadium: 21 mg/kg
T106
T107
Arsenic: 1.0 mg/kg
Mercury: 0.012 mg/kg
Molybdenum: 0.17 mg/kg
Selenium: 0.53 mg/kg
Uranium: 1.4 mg/kg
Vanadium: 13 mg/kg
Arsenic: 3.1 mg/kg
Mercury: 0.011 mg/kg
Molybdenum: 0.28 mg/kg
Selenium: 0.69 mg/kg
Uranium: 2.3 mg/kg
Vanadium: 28 mg/kg
T1Q2
T103
TT.04
Arsenic: 1.1 mg/kg
Mercury: 0.007 mg/kg
Molybdenum: 0.3 mg/kg
Selenium: 0.23 mg/kg
Uranium: 1.6 mg/kg
Vanadium: 35 mg/kg
7
Arsenic: 1.9 mg/kg
Mercury: 0.011 mg/kg
Molybdenum: 0.19 mg/kg
Selenium: 0.24 mg/kg
Uranium: 2.0 mg/kg
Vanadium: 21 mg/kg
Arsenic: 3.4 mg/kg
Mercury: 0.005 mg/kg
Molybdenum: 0.18 mg/kg
Selenium: 0.23 mg/kg
Uranium: 2.0 mg/kg
Vanadium: 32 mg/kg
T101
Arsenic: 2.7 mg/kg
Mercury: 0.01 mg/kg
Molybdenum: 0.2 mg/kg
Selenium: 0.24 mg/kg
Uranium: 1.7 mg/kg
Vanadium: 21 mg/kg
Arsenic: 2.2 mg/kg
Mercury: 0.011 mg/kg
Molybdenum: 0.54 mg/kg
Selenium: 0.23 mg/kg
Uranium: 1.8 mg/kg
Vanadium: 41 mg/kg
i
LEGEND
O Soil Sample Location
Babbitt BSA Locations
! Area of Potential Effect
Section Lines
0
15 30
60
Feet
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION.
Project No. 110704
€RG
March 2021
Rev 1.2
FIGURE 4-48
TERRACE BSA #1 METALS CONCENTRATIONS
BABBITT RANCHES
-------
Arsenic: 1.5 mg/kg
Mercury: 0.004 mg/kg
Molybdenum: 0.18 mg/kg
Selenium: 0.23 mg/kg
Uranium:0.47 mg/kg
Vanadium: 12 mg/kg
Arsenic: 2.4 mg/kg
Mercury: 0.003 mg/kg
Molybdenum: 0.19 mg/kg
Selenium: 0.25 mg/kg
Uranium:0.64 mg/kg
Vanadium: 14 mg/kg
Arsenic: 1.7 mg/kg
Mercury: 0.004 mg/kg
Molybdenum: 0.25 mg/kg
Selenium: 0.24 mg/kg
Uranium:0.50 mg/kg
Vanadium: 11 mg/kg
LCR06
i
Arsenic: 1.7 mg/kg
Mercury: 0.001 mg/kg
Molybdenum: 0.19 mg/kg
Selenium: 0.24 mg/kg
Uranium:0.66 mg/kg
Vanadium: 11 mg/kg
LCR07
O
\
Arsenic: 1.8 mg/kg
Mercury: 0.004 mg/kg
Molybdenum: 0.2 mg/kg
Selenium: 0.26 mg/kg
Uranium:0.72 mg/kg
Vanadium: 13 mg/kg
LCR.03
Arsenic: 1.6 mg/kg
Mercury: 0.002 mg/kg
Molybdenum: 0.18 mg/kg
Selenium: 0.23 mg/kg
Uranium:0.52 mg/kg
Vanadium: 11 mg/kg
LCR01
Arsenic: 1.9 mg/kg
Mercury: 0.003 mg/kg
Molybdenum: 0.22 mg/kg
Selenium: 0.28 mg/kg
Uranium:0.66 mg/kg
Vanadium: 13 mg/kg
Arsenic: 2.2 mg/kg
Mercury: 0.005 mg/kg
Molybdenum: 0.21 mg/kg
Selenium: 0.27 mg/kg
Uranium:0.69 mg/kg
Vanadium: 13 mg/kg
LEGEND
O Soil Sample Location
Babbitt BSA Locations
! Area of Potential Effect
0 15 30
60
Feet
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION.
Project No. 110704
|~~A Engineering Analytics, Inc. —
u\— €RG
March 2021
Rev 1.2
FIGURE 4-49
LITTLE COLORADO RIVER BSA METALS CONCENTRATIONS
BABBITT RANCHES
-------
3.5-
0.0075-
3.0-
0.0050-
0.0025-
0.0000-
As
Hg
g 0.4-
5 ra
0.2-
1.3-
2 §
|» 1.2-
1.1-
0.9-
Se
Project No. 110704
Engineering Analytics, Inc.
€RG
1.7"
1.5-
1.3'
1-
Mo
1.1-
Ra-226
NOTE:
IN A TUKEY-STYLE BOXPLOT, BOXES REPRESENT
THE 25th -75th PERCENTILES OF DATA AND DARK
LINE THE MEDIAN, POTENTIAL OUTLIERS ARE
IDENTIFIED AS DOTS, WHILE WHISKERS SHOW THE
RANGE OF THE REMAINDER OF THE DATA.
March 2021
Rev 1.2
FIGURE 4-50
BOXPLOT SHOWING SOIL ACTIVITY AND CONCENTRATIONS FOR DRAINAGE BSA #2
BABBITT RANCHES
-------
T: \110704- Babbitt Ranch'-.RSE Report/Bo:-plots.dwg SAVED: 5/1 7/21 PRINTED: 3/1 7/21
Gamma Count Rate (cpm)
Project No. 110704
March 2021
Rev 1.2
Engineering Analytics, Inc.
€I!G
FIGURE 5-1
CORRELATION BETWEEN HORIZONTAL GAMMA SURVEY CORRELATION
DATA AND SOIL RADIUM ACTIVITY CONCENTRATION
BABBITT RANCHES
-------
T: \110704- Babbitt Ranch'-.RSE Report/Bo:-plots.dwg SAVED: 5/1 7/21 PRINTED: 3/1 7/21
17.5
15 -
.O)
O
^Q.
C
o
"-i—*
2
"c
o
o
c
o
O
E
3
TD
CO
CL
O
LT)
O)
L_
CD
a.
Q.
12.5
10 -
7.5
2.5
UPPER 95% Ra = 0.8386701 + 0.0001111*GAMMA
20,000
I
40,000
I
60,000
80,000 100,000
Gamma Count Rate (cpm)
i
120,000
I
140,000
160,000
Project No. 110704
Engineering Analytics, Inc.
€I!G
March 2021
Rev 1.2
FIGURE 5-2
CORRELATION BETWEEN THE UPPER 95% CONFIDENCE
INTERVAL OF THE MEAN HORIZONTAL GAMMA SURVEY
RESPONSE AND SOIL RADIUM ACTIVITY CONCENTRATION
BABBITT RANCHES
-------
T:\110704 Babbitt Ranch \RSE Report\Boi plots.dwg SAVED: 3/1 7/21 PRINTED: 3/1 7/21
Project No. 110704
March 2021
Rev 1.2
Engineering Analytics, Inc.
€HG
FIGURE 5-3
CORRELATION BETWEEN HIGH-PRESSURIZED ION CHAMBER
EXPOSURE RATE AND MEAN VERTICAL GAMMA SURVEY RESPONSE
BABBITT RANCHES
-------
T:\110704 Babbitt Ranch \RSE Report\Boi plots.dwg SAVED: 3/1 7/21 PRINTED: 3/1 7/21
Project No. 110704
March 2021
Rev 1.2
Engineering Analytics, Inc.
€HG
FIGURE 5-4
CORRELATION BETWEEN SOIL RADIUM-226 ACTIVITY CONCENTRATION
AND HIGH-PRESSURIZED ION CHAMBER EXPOSURE RATE
BABBITT RANCHES
-------
Terrace BSA #2
Alluvial BSA #1
Alluvial BSA #2
EPA "Qter BRA'
AUM 458
Drainage BSA #2
r '
Little Colorado River BSA
Terrace BSA #1
¦
• vi.l v
I p
¦=i
L"
j
LEGEND
EPA BRA Location
Babbitt BSA Locations
S Area of Potential Effect
Section Lines
EPA AUM Boundary
Exposure Rate (uR/hr)
• <4.5
4.5 - 9.9
9.9-16.9
• >16.9
NOTES:
1. For display purposes only.
2. Exposure rate calculated from walkover gamma
data using the mean regression result.
3. Exposure [uR/hr] = 4.5400457+0.0002339*Gamma
0 0.125 0.25 0.5
Miies
March 2021
Rev 1.2
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION.
Project No. 110704
|~~A Engineering Analytics, Inc. _
UT~~ €AG
FIGURE 5-5
EXPOSURE RATE FOR THE ENTIRE APE
BABBITT RANCHES
-------
T: \110704- Babbitt Ranch/RSE Report/Correlation Figs.dwg SAVED: 3/1 7/21 PRINTED: 3/1 7/21
Adj. r2: 0.21, p = 0.002
D)
0
Q.
CD
CM
CM
I
E
3
TD
03
01
c
o
-I—'
-§—«
c
0
O
c
o
O
90-
70-
50-
30-
10-
-10-
-30-
1
_|
1
"1
\-
h'
•—1
T
*
_L
l-S-
H
—1
i—I—i
—r~
—±
1
EH
H
5,000
10,000
NOTE:
1) ERROR BARS REPRESENT THE 95% CONFIDENCE LEVEL UNCERTAINTY FOR
RADIONUCLIDES AND ± 20% FOR METALS. THE GREY BANDED REGION
REPRESENTS THE 95% PREDICTION INTERVAL OF THE REGRESSION MODEL.
15,000 20,000 25,000 30,000
Concentration of Arsenic (ug/kg)
35,000
40,000
45,000
Project No. 110704
|~~A Engineering Analytics, Inc.
^ €RG
March 2021
Rev 1.2
FIGURE 5-6
CORRELATION BETWEEN RADIUM-226 AND ARSENIC
BABBITT RANCHES
-------
T: \110704- Babbitt Ranch/RSE Report/Correlation Figs.dwg SAVED: 3/1 7/21 PRINTED: 3/1 7/21
Adj. r2: 0.71, p < 0.001
15
Mean Predicted Concentration of Ra-226 (pCi/g)
30 45 60 75 90 105
120
135
150
140 -
120 -
^ 100
o
Q.
CD
CM
CM
I
03
a:
c
o
80-
60-
03 40 -
CD
O
c
o
O
20-
0-
-20-
h
H
Hh
L
"
.
s
$
*
fji:
NOTE:
1) ERROR BARS REPRESENT THE 95% CONFIDENCE LEVEL UNCERTAINTY FOR
RADIONUCLIDES AND ± 20% FOR METALS. THE GREY BANDED REGION
REPRESENTS THE 95% PREDICTION INTERVAL OF THE REGRESSION MODEL.
2) A 2-INCH BY 2-INCH Nal DETECTOR WAS USED TO COLLECT GAMMA DATA.
3000 6000 9000 12000 15000 18000 21000
Net Shielded Gamma Count Rate (cpm)
24000
27000
30000
Project No. 110704
m
Engineering Analytics, Inc.
€RG
March 2021
Rev 1.2
FIGURE 5-7
CORRELATION BETWEEN RADIUM-226 AND GAMMA COUNT RATE
BABBITT RANCHES
-------
T: \110704- Babbitt Ranch/RSE Report/Correlation Figs.dwg SAVED: 3/1 7/21 PRINTED: 3/1 7/21
Adj. r2
: 0.40, p < 0.001
90-
80-
70-
d5
Q 60-
Q.
CD
cm 50 -
C\l
E
.2 40-
T3
CO
a:
ZZ 30-
o
~ 20-
CD
§ 10-
o
c
o
O o-
-10-
-20-
1
i
1—*—1
¥ , ,
—m •
—;—1 !¦- '—^ 1
—i
-30-
0.00 0.03 0.06 0.09 0.12 0.15 0.18 0.21 0.24
Concentration of Mercury (mg/kg)
1) ERROR BARS REPRESENT THE 95% CONFIDENCE LEVEL UNCERTAINTY FOR
RADIONUCLIDES AND ± 20% FOR METALS. THE GREY BANDED REGION
REPRESENTS THE 95% PREDICTION INTERVAL OF THE REGRESSION MODEL.
0.27 0.30 0.33
Project No. 110704
|~~A Engineering Analytics, Inc.
^ €RG
March 2021
Rev 1.2
FIGURE 5-8
CORRELATION BETWEEN RADIUM-226 AND MERCURY
BABBITT RANCHES
-------
T: \110704- Babbitt Ranch/RSE Report/Correlation Figs.dwg SAVED: 3/1 7/21 PRINTED: 3/1 7/21
Adj. r: 0.52, p < 0.001
en
O
Q.
CD
CM
CM
3
T3
03
an
c
o
-t—'
-i—'
c
CD
O
c
o
O
110-
100-
90
80
70
60
50
40
30
20
10
0
-10
-20
I
-20
30
80
NOTE:
1) ERROR BARS REPRESENT THE 95% CONFIDENCE LEVEL UNCERTAINTY FOR
RADIONUCLIDES AND ± 20% FOR METALS. THE GREY BANDED REGION
REPRESENTS THE 95% PREDICTION INTERVAL OF THE REGRESSION MODEL.
130 180 230 280
Concentration of Molybdenum (mg/kg)
330
380
Project No. 110704
|~~A Engineering Analytics, Inc.
^ €RG
March 2021
Rev 1.2
FIGURE 5-9
CORRELATION BETWEEN RADIUM-226 AND MOLYBDENUM
BABBITT RANCHES
-------
T: \110704- Babbitt Ranch/RSE Report/Correlation Figs.dwg SAVED: 3/1 7/21 PRINTED: 3/1 7/21
Adj. r: 0.02, p = 0.27
en
O
Q.
CD
CM
CM
3
T3
03
an
c
o
-t—'
-i—'
c
CD
O
c
o
O
85-
65-
45-
25-
5-
-15-
-35-
0.00 0.08 0.16 0.24 0.32 0.40 0.48 0.56
Concentration of Selenium (mg/kg)
0.64
0.72
0.80
NOTE:
1) ERROR BARS REPRESENT THE 95% CONFIDENCE LEVEL UNCERTAINTY FOR
RADIONUCLIDES AND ± 20% FOR METALS. THE GREY BANDED REGION
REPRESENTS THE 95% PREDICTION INTERVAL OF THE REGRESSION MODEL
Project No. 110704
Engineering Analytics, Inc.
^ €RG
March 2021
Rev 1.2
FIGURE 5-10
CORRELATION BETWEEN RADIUM-226 AND SELENIUM
BABBITT RANCHES
-------
T: \110704- Babbitt Ranch/RSE Report/Correlation Figs.dwg SAVED: 3/1 7/21 PRINTED: 3/1 7/21
Adj. r2: 0.68, p < 0.001
100,000
120,000
20,000
40,000
60,000
80,000
1) ERROR BARS REPRESENT THE 95% CONFIDENCE LEVEL UNCERTAINTY FOR COnCentratlOfl Of UraniUm (lig/kg)
RADIONUCLIDES AND ± 20% FOR METALS. THE GREY BANDED REGION
REPRESENTS THE 95% PREDICTION INTERVAL OF THE REGRESSION MODEL.
Project No. 110704
Engineering Analytics, Inc.
^ €RG
March 2021
Rev 1.2
FIGURE 5-11
CORRELATION BETWEEN RADIUM-226 AND URANIUM
BABBITT RANCHES
-------
T: \110704- Babbitt Ranch/RSE Report/Correlation Figs.dwg SAVED: 3/1 7/21 PRINTED: 3/1 7/21
Adj. r: 0.03, p = 0.14
O)
O
CL
CO
CM
CM
I
£
3
13
aj
a:
c
o
aj
a>
o
c
o
a
80-
60
40-
20-
o-
-20-
-40-
^ 1*1
0.0 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0
Concentration of Vanadium (mg/kg)
45.0
50.0
55.0
NOTE:
1) ERROR BARS REPRESENT THE 95% CONFIDENCE LEVEL UNCERTAINTY FOR
RADIONUCLIDES AND ± 20% FOR METALS. THE GREY BANDED REGION
REPRESENTS THE 95% PREDICTION INTERVAL OF THE REGRESSION MODEL
Project No. 110704
Engineering Analytics, Inc.
^ €RG
March 2021
Rev 1.2
FIGURE 5-12
CORRELATION BETWEEN RADIUM-226 AND VANADIUM
BABBITT RANCHES
-------
T: \110704- Babbitt Ranch/RSE Report/Correlation Figs.dwg SAVED: 3/1 7/21 PRINTED: 3/1 7/21
Adj. r2: 0.90, p < 0.001
Mean Predicted Concentration of Ra-226 (pCi/g)
0 10 20 30 40 50 60
80-
70-
-10-
2000 4500 7000 9500 12000 14500 17000
note: Net Shielded Gamma Count Rate (cpm)
1) ERROR BARS REPRESENT THE 95% CONFIDENCE LEVEL UNCERTAINTY FOR
RADIONUCLIDES AND ± 20% FOR METALS. THE GREY BANDED REGION
REPRESENTS THE 95% PREDICTION INTERVAL OF THE REGRESSION MODEL.
2) A 2-INCH BY 2-INCH Nal DETECTOR WAS USED TO COLLECT GAMMA DATA.
Project No. 110704
Engineering Analytics, Inc.
^ €RG
March 2021
Rev 1.2
FIGURE 5-13
CORRELATION BETWEEN RADIUM-226 AND
GAMMA COUNT RATE WITH OUTLIERS REMOVED
BABBITT RANCHES
-------
Little Colorado River BSA
Terrace BSA #2
LEGEND
EPA BRA Location
Babbitt BSA Locations
Area of Potential Effect
~ EPAAUM Boundary
LCR Criteria
Drainage Pooled Criteria
Alluvial Pooled Criteria
Section Lines
0 600 1,200 2,400
Feet
Project No. 110704
March 2021
Rev 1.2
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION.
Alluvial BSA #1
A uv a BSA #2
EPA Qter BRA
Drainage BSA #2
a /\
^
Terrace BSA #2
|~~A Engineering Analytics, Inc. _
UT~~ €AG
FIGURE 5-14
LOCATION OF BSA APPLICATION AREAS
BABBITT RANCHES
-------
LEGEND
Category
• NORM
• TENORM
EPA BRA Location
Babbitt BSA Locations
Area of Potential Effect
Section Lines
Other Mine Related Disturbance
EPA Identified Drainage Area Boundary
I J
EPA Identified Drainage Network
EPA Identified Road Buffer (50-ft)
EPA Idenfied Road Centerline
2019 Little Colorado River (NHD)
0 700 1,400
2,800
3 Feet
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION.
Project No. 110704
m
Engineering Analytics, Inc.
CAG
March 2021
Rev 1.2
FIGURE 5-15
MAP OF TENORM V NORM
BABBITT RANCHES
-------
LEGEND
Category
• NORM
• TENORM
EPAAUM
EPA BRA Location
Babbitt BSA Locations
Area of Potential Effect
Section Lines
Other Mine Related Disturbance
EPA Identified Drainage Area
EPA Identified Drainage Network
EPA Identified Road Buffer (50 ft
EPA Idenfied Road Centerline
I
0 200 400
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION.
800
3 Feel
Project No. 110704
m
Engineering Analytics, Inc.
CAG
March 2021
Rev 1.2
FIGURE 5-16
MAP OF TENORM V NORM FOR NW QUADRANT
BABBITT RANCHES
-------
. >.>
LEGEND
EPAAUM Boundary
EPA BRA Location
Babbitt BSA Locations
Area of Potential Effect
Section Lines
Other Mine Related Disturbance
EPA Identified Drainage Area Boundary
EPA Identified Drainage Network
EPA Identified Road Buffer (50-ft)
EPAIdenfied Road Centerline
=—• > ¦ » 2019 Little Colorado River (NHD)
Category
• NORM
• TENORM
0 180 360
720
3 Feet
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION.
Project No. 110704
m
Engineering Analytics, Inc.
CAG
March 2021
Rev 1.2
FIGURE 5-17
MAP OF TENORM V NORM FOR NE QUADRANT
BABBITT RANCHES
-------
LEGEND
Category
• NORM
• TENORM
EPAAUM Boundary
EPA BRA Location
Babbitt BSA Locations
Area of Potential Effect
Section Lines
Other Mine Related Disturbance
EPA Identified Drainage Area Boundary
EPA Identified Drainage Network
EPA Identified Road Buffer (50-ft)
EPAIdenfied Road Centerline
0 180 360
720
3 Feet
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION.
Project No. 110704
m
Engineering Analytics, Inc.
CAG
March 2021
Rev 1.2
FIGURE 5-18
MAP OF TENORM V NORM FOR SW QUADRANT
BABBITT RANCHES
-------
,£Vi
pje.fa'
LEGEND
Category
• NORM
TENORM
EPAAUM Boundary
EPA BRA Location
Babbitt BSA Locations
Area of Potential Effect
Section Lines
Other Mine Related Disturbance
EPA Identified Drainage Area Boundary
EPA Identified Drainage Network
2019 Little Colorado River (NHD)
EPA Identified Road Buffer (50-ft)
EPAIdenfied Road Centerline
0 180 360
720
3 Feet
NOTE: FOR INFORMATIONAL PURPOSES ONLY. NOT FOR FIELD IMPLEMENTATION.
Project No. 110704
m
Engineering Analytics, Inc.
CAG
March 2021
Rev 1.2
FIGURE 5-19
MAP OF TENORM V NORM FOR SE QUADRANT
BABBITT RANCHES
-------
AUM 457.
i
P-4 (7486 cpm)
TP-6"(6114 cqmM
T©!f(16635 cpm)
TP-1 (31992;cpm)
EPA Wetlands 3
TP-14 (3016 cpm)
ylp-20 (13303 cpm:
AUM 458
AUM 459
EPA Wetlands 4
EPA Wetlands 2
LEGEND
O Phase III Test Pit Actual Locations With Max Gamma Results
— ¦ ¦ - 2019 Little Colorado River (NHD)
Area of Potential Effect
EPA Identified Wetlands
EPA AUM Boundary
J J EPA Identified Drainage Area Boundary
Gamma Results Legend
Gamma Scan Results (CPM)
• 21,028 - 23,588
23,589 - 35,383
35,384-47,176
47,177-70,764
• 70,765 - 94,352
• 94,353- 141,528
• 141,529-646,741
Surface Water General Flow Direction
NOTES:
1) Gamma Data Obtained from ERG.
2) The Drainage Pooled Criteria shown on Figure 5-14
were used as the boundary for showing the drainage
gamma results.
3) The legend shows the minimum (21,028) and
maximum (646,741) readings obtained for the
drainage areas.
4) IL Values are provided on Table 5-22.
Pooled BSA
95% Gamma UTL
(cpm)
IL (cpm)
Alluvial BSA #1 and # 2: Terrace BSA #1
and #2. EPA"QterBRA"
48,212
51,824
Drainage BSA #2
43,564
47=176
Little Colorado River BSA
26:053
29.665
5) The IL Application Areas are shown on Figure 5-14.
6) Test Pit Gamma Readings are the maximum gross
reading encountered in the test pit (December 2018).
7) Test Pit Gamma Scans were completed using a
2-inch x 2-inch Nal detector.
8) Gamma Scan Results were completed using a
3-inch x 3-inch Nal detector.
0 400 800
March 2021
Rev 1.2
FIGURE 5-20
GAMMA CONCENTRATIONS IN DRAINAGE AREAS
BABBITT RANCHES
Project No. 110704
m
Engineering Analytics, Inc.
-------
WTO
Mil
LEGEND:
100-YR FLOODPLAIN
APPROX. EXTENT OF
PIT BOUNDARY
EXISTING CONTOURS
(LiDAR, MASER, 2016)
AUM BOUNDARY
VALLEY CHANNEL
EXISTING ROAD
APPROXIMATE
SCALE IN FEET
NORTH,
- APPROX. EXTENT
R OF PIT BOUNDARY
AUM BOUNDARY ,sv
\S».w \
~r yzy \*;Y »Hlf f
" t»fcbi l «TwM\ 8Hmf
: t%i M\iWi v
' .¦ ?\ -t a ?
UM 457
Vvv>-
i3> >• '*
/^ilHnis. i
100-YR
FLOODPLAIN
BOUNDARY-
i^Ts '1 I
T:\110704.Bafabitt Raneh\Lidar Data 457,dwq SAVED: 3/1 7/21 PRINTED: 3/17/21
Project No. 110704
m
Engineering Analytics, Inc.
100-YEAR FLOODPLAIN BOUNDARY
EXPORTED FROM FEMA MAPPING
ON 8/27/2019.
March 2021
Rev 1.2
FIGURE 9-1
AUM 457 LiDAR DATA (MASER, 2016)
BABBITT RANCHES
-------
T:\110704 Babbitt Ranch\bidar Data 457.dwg SAVED: 3/17/21 PRINTED: 3/1 7/21
LEGEND:
ITP-3
TEST PIT LOCATION
VNORTH/
PROPOSED COVER
CONTOURS
EXISTING CONTOURS
(LiDAR, MASER, 2016)
AUM BOUNDARY
APPROXIMATE
SCALE IN FEET
Project No. 110704
Pit Volume: 1340 CuYd
3' Cover Above Pit: 3130 Cu Yd
Total Volume: 4470 Cu Yd
Engineering Analytics, Inc.
March 2021
Rev 1.2
FIGURE 9-2
AUM 457 CONCEPTUAL REPOSITORY DESIGN
CHANNEL COVER SURFACE
BABBITT RANCHES
-------
T:\110704 Babbitt Ranch \l_idar Data 457.dwg SAVED: 3/1 7/21 PBIHTED: 5/17/21
Project No. 110704
Engineering Analytics, Inc.
Pit Volume: 1560 CuYd
3' Cover Above Pit: 3070 Cu Yd
Total Volume: 4630 Cu Yd
March 2021
Rev 1.2
FIGURE 9-3
AUM 457 CONCEPTUAL REPOSITORY DESIGN
MOUND COVER SURFACE
BABBITT RANCHES
-------
T:\110704. Babbitt Rgneh\Lidar Data 458. dug SAVED: 3/1 7/21 PRINTED: 5/17/21
LEGEND:
100-YEAR FLOODPLAIN BOUNDARY
EXPORTED FROM FEMA MAPPING
ON 8/27/2019.
APPROXIMATE
SCALE IN FEET
100-YR FLOODPLAIN
.NORTK
APPROX. EXTENT OF
PIT BOUNDARY
EXISTING CONTOURS
(LiDAR, MASER, 2016)
AUM BOUNDARY
AUM BOUNDARY
APPROX. EXTENT
OF PIT BOUNDARY
v ^ ilm
/0/mwW /t
Ss ,, v < > lufe /Jr. i(L
X&W • . ' rr o >
SV:, ' ° "0-cX> o ^ . . 1 L
i-j100-YR FLOODPLAIN BOUNDARYj-'O %
" ~oT"J € ,-N
Project No. 110704 March 2021
Rev 1.2
l—A Engineering Analytics, Inc.
tAf
FIGURE 9-4
AUM 458 LiDAR DATA (MASER, 2016)
BABBITT RANCHES
-------
T:\110704 Babbitt Ranch \l_idar Data 458.dwg SAVED: 3/1 7/21 PBIHTED: 5/17/21
TEST PIT LOCATION
PROPOSED COVER
CONTOURS
EXISTING CONTOURS
(LiDAR, MASER, 2016)
AUM BOUNDARY
APPROXIMATE
SCALE IN FEET
NORTH,
< //^J
( ihf '
j am j * ,
/ \M\\ /
> mw r,n
AUM BOUNDARY^
Project No. 110704
Pit Volume: 740 Cu Yd
3' Cover Above Pit: 2030 Cu Yd
Total Volume: 2770 Cu Yd
m
Engineering Analytics, Inc.
March 2021
Rev 1.2
FIGURE 9-5
AUM 458 CONCEPTUAL REPOSITORY DESIGN
CHANNEL COVER SURFACE
BABBITT RANCHES
-------
T:\110704 Babbitt Ranch \l_idar Data 458.dwg SAVED: 3/1 7/21 PBIHTED: 5/17/21
TEST PIT LOCATION
PROPOSED COVER
CONTOURS
EXISTING CONTOURS
(LiDAR, MASER, 2016)
AUM BOUNDARY
APPROXIMATE
SCALE IN FEET
NORTH,
< //^J
( ihf '
j am j * ,
/ \M\\ /
> mw r,n
AUM BOUNDARY^
Project No. 110704
Pit Volume: 800 Cu Yd
3' Cover Above Pit: 2020 Cu Yd
Total Volume: 2820 Cu Yd
m
Engineering Analytics, Inc.
March 2021
Rev 1.2
FIGURE 9-6
AUM 458 CONCEPTUAL REPOSITORY DESIGN
MOUND COVER SURFACE
BABBITT RANCHES
-------
T:\110704 Babbitt Ranch\l_idar Data 458 -2.dwg SAVED: 3/1 7/21 PRINTED: 3/17/21
PROPOSED COVER
CONTOURS
EXISTING CONTOURS
(LiDAR, MASER, 2016)
AUM BOUNDARY
APPROXIMATE
SCALE IN FEET
NORTH,
/ ///¦>>?/!, I
< //^J
( ihf '
j am j * ,
/ \M\\ /
> mw r,n
AUM BOUNDARY^
Project No. 110704 Waste Volume: 5670 Cu Yd March 2021
3' Cover Above Waste: 3700 Cu Yd Rev 1 2
Total Volume: 9370 Cu Yd FIGURE 9-7
Engineering Analytics, Inc. AUM 458 CONCEPTUAL REPOSITORY DESIGN
RAISED MOUND COVER SURFACE
BABBITT RANCHES
-------
AUM 457
Alluvial BSA #1
AUM 458
Little Colorado River BSA
AUM 459
Figure 9-14
Terrace BSA #1
EPA "Qter BRA"
LEGEND
O Phase III Test Pits
• Alluvial TENORM Gamma Result above IL
Drainage TENORM Gamma Result above IL
EPA Identified Drainage Network
• ' ¦ 2019 Little Colorado River (NHD)
EPA Identified Road Centerline
~ EPA Identified Drainage Area Boundary
EPA Identified Road Buffer (50-ft)
Other Mine Related Disturbance (1)
EPA BRA Location
Babbitt BSA Locations
i Area of Potential Effect
Section Lines
EPAAUM Boundary
NOTES:
1) Other Mine Related Disturbance as defined in the
Phase II Work Plan (approved September 6, 2017).
2) The IL Application Areas are shown on Figure 5-14,
3) IL Values are as follows:
TABLE A: HORIZONTAL CORRELATION
Background
IL
gamma -
Pool
pCi/g
PCi/g
mean cpm
Drainage
1.71
2.95
48419
Alluvial
3.72
4.96
67169
LCR
1.26
2.5
44221
TABLE B: VERTICAL CORRELATION
Background
IL
NET gamma -
Pool
PCi/g
PCi/g
mean cpm
Drainage
1.71
2.95
1828
Alluvial
3.72
4.96
2307
LCR
1.26
2.5
1721
4) Total Removal Volume for IL in the four quadrants is
31,500 cubic yards.
2,500
Feet
0 625 1,250
Project No. 110704
March 2021
Rev 1.2
Terrace BSA #2
Drainage BSA #2
m
Engineering Analytics, Inc.
CAG
FIGURE 9-8
RESULTS OF MOBILE GAMMA SCAN SURVEY ABOVE IL WITH TEST PIT LOCATIONS
BABBITT RANCHES
-------
X
\
v
V
;v
x
V
X
V
X
V
X
X
X
X
X
X
X.
V
v
X
X
X
x
TP-l
(ALLUVIAL)
Net
Exceeds IL
Depth
Gamma
(2295)
0-0.5'
6,122
YES
0.5'-1.0'
12,658
YES
1.0'-1.5'
16,230
YES
1.5'-2.0'
30,360
YES
2.0' 2.5"
6,764
YES
2.5'-3.0'
3,185
YES
3.0'-3.5'
N/A
N/A
X
X
X
X
X
X.
X
X
X
Alluvial BSA #1
X
X
X
X
X
X
o
X
X
c?
X /
s, /
\ /
v/
X
y
LEGEND
O
i i
Phase III Test Pits
Alluvial TENORM Gamma Result above IL
Depth of TENORM above IL Contours
Babbitt BSA Locations
Area of Potential Effect
EPA Identified Road Buffer (50-ft)
EPA Identified Road Centerline
NOTES:
1) The iL Application Areas are shown on Figure 5-14.
2) IL Values are as follows:
TABLE A: HORIZONTAL CORRELATION
Background
IL
gamma -
Pool
pCi/g
PCi/g
mean cpm
Drainage
1.71
2.95
48419
Alluvial
3.72
4.96
67169
LCR
1.26
2.5
44221
TABLE B: VERTICAL CORRELATION
Background
IL
NET gamma -
Pool
PCi/g
PCi/g
mean cpm
Drainage
1.71
2.95
1828
Alluvial
3.72
4.96
2307
LCR
1.26
2.5
1721
3) Total volume of TENORM above IL in this
Quadrant: 4087 Cu. Yd.
4) Not all 1" contours are shown.
Alluvial BSA #2
'/ TT
0 150 300
600
m Feet
Project No. 110704
m
Engineering Analytics, Inc.
CAG
March 2021
Rev 1.2
FIGURE 9-9
RESULTS OF MOBILE GAMMA SCAN SURVEY ABOVE IL WITH TEST PIT LOCATIONS
NW QUADRANT
BABBITT RANCHES
-------
(DRAINAGE)
(DRAINAGE)
Net
Gamma
Exceeds IL
(1814)
Net
Gamma
(ALLUVIAL)
Net
Gamma
(DRAINAGE)
Net
Gamma
(DRAINAGE)
Exceeds IL
(1814)
(ALLUVIAL)
Exceeds IL
(2295)
Net
Gamma
Mounds
July 2020
(ALLUVIAL)
Net
Gamma
(DRAINAGE)
Exceeds IL
(1814)
(DRAINAGE)
Exceeds IL
(1814)
Net
Gamma
(DRAINAGE)
Net
Gamma
(ALLUVIAL)
Exceeds IL
(2295)
Net
Gamma
k
\
V
Project No. 110704
m
Engineering Analytics, Inc.
€HG
LEGEND
O Phase III Test Pits
EPA Identified Drainage Network
• • ¦ 2019 Little Colorado River (NHD)
Depth of TENORM above IL Contours
• Alluvial TENORM Gamma Result above IL
Drainage TENORM Gamma Result above IL
EPA Identified Road Centerline
EPA Identified Drainage Area Boundary
EPA Identified Road Buffer (50-ft)
Other Mine Related Disturbance (1)
! Area of Potential Effect
Section Lines
EPAAUM Boundary
NOTES:
1) Other Mine Related Disturbance as defined in the
Phase II Work Plan (approved Septembers, 2017).
2) The IL Application Areas are shown on Figure 5-14,
3) ILValues are as follows:
TABLE A: HORIZONTAL CORRELATION
Background
IL
gamma -
Pool
pCi/g
PCi/g
mean cpm
Drainage
1.71
2.95
48419
Alluvial
3.72
4.96
67169
LCR
1.26
2.5
44221
TABLE B: VERTICAL CORRELATION
Background
IL
NET gamma -
Pool
PCi/g
PCi/g
mean cpm
Drainage
1.71
2.95
1828
Alluvial
3.72
4.96
2307
LCR
1.26
2.5
1721
4) Volume estimates for this quadrant are shown
on Figure 9-11.
5) Not all 1" contours are shown.
0 150 300
600
3 Feel
March 2021
Rev 1.2
FIGURE 9-10
RESULTS OF MOBILE GAMMA SCAN SURVEY ABOVE IL WITH TEST PIT LOCATIONS
NE QUADRANT
BABBITT RANCHES
-------
Project No. 110704
Engineering Analytics, Inc.
m
€RG
LEGEND
O Phase III Test Pits
• Alluvial TENORM Gamma Result above IL
Drainage TENORM Gamma Result above IL
Existing Contours (Maser, 2016)
Depth of TENORM above IL Contours
EPAAUM Boundary
S Area of Potential Effect
Section Lines
Other Mine Related Disturbance (1)
EPA Identified Drainage Area Boundary
EPA Identified Drainage Network
EPA Identified Road Buffer (50-ft)
EPA Identified Road Centerline
NOTES:
1) Other Mine Related Disturbance as defined in the
Phase II Work Plan (approved September 6, 2017).
2) The IL Application Areas are shown on Figure 5-14.
3) ILValues are as follows:
TABLE A: HORIZONTAL CORRELATION
Background
IL
gamma -
Pool
pCi/g
PCi/g
mean cpm
Drainage
1.71
2.95
48419
Alluvial
3.72
4.96
67169
LCR
1.26
2.5
44221
TABLE B: VERTICAL CORRELATION
Background
IL
NET gamma -
Pool
PCi/g
PCi/g
mean cpm
Drainage
1.71
2.95
1828
Alluvial
3.72
4.96
2307
LCR
1.26
2.5
1721
4) Total volume of TENORM above IL in this
Quadrant: 10,209 Cu. Yd.
5) Not all 1" contours are shown.
0 75 150
300
3 Feel
March 2021
Rev 1.2
FIGURE 9-11
VOLUME ESTIMATE ABOVE IL ATAUM 457
BABBITT RANCHES
-------
Project No. 110704
Engineering Analytics, Inc.
\
V
TP-19
(ALLUVIAL)
Net
Exceeds IL
Depth
Gamma
(2295)
0-0.5'
16,340
YES
0.5'-0.75'
15,141
YES
m.
TP-18
(ALLUVIAL)
Net
Exceeds IL
Depth
Gamma
(2295)
J
V;
0-0.5'
5,446
YES
0.5'-1.0'
6,393
YES
l.O'-l.S"
4,510
YES
1.5'-2.0'
5,298
YES
* '
2.0'-2.5'
2,711
YES
7/
2.5-3.3'
3,214
YES
¦ i
3.3'-4.0'
3,433
YES
' 4
4.0'-5.0'
3,353
YES
9'11
AUM 458
n
TP-20
(ALLUVIAL)
Net
Exceeds IL
Depth
Gamma
(2295)
0-0.5'
3,136
YES
0.5'-1.0'
11,159
YES
1.0'-1.5'
8,550
YES
1.5'-2.0'
8,698
YES
TP-22
(DRAINAGE)
TP-21
(ALLUVIAL)
Net
Exceeds IL
I U\\
Net
Exceeds IL
Depth
Gamma
(1814)
I J) (
Depth
Gamma
(2295)
0-0.5'
2,397
YES
it
0-0.5'
2,465
YES
0.5'-1.0'
3,173
YES
I 1
II
0.5'-1.0'
3,037
YES
l.O'-l.S'
3,261
YES
1.0'-1.17'
2,591
YES
1.5'-2.0'
N/A
N/A
\\s
7
LEGEND
Phase III Test Pits
Alluvial TENORM Gamma Result above IL
Drainage TENORM Gamma Result above IL
Depth of TENORM above IL Contours
EPA AUM Boundary
S Area of Potential Effect
Section Lines
Other Mine Related Disturbance (1)
EPA Identified Drainage Area Boundary
EPA Identified Drainage Network
EPA Identified Road Buffer (50-ft)
EPA Identified Road Centerline
NOTES:
1) Other Mine Related Disturbance as defined in the
Phase II Work Plan (approved September 6, 2017).
2) The IL Application Areas are shown on Figure 5-14.
TABLE A: HORIZONTAL CORRELATION
Background
IL
gamma -
Pool
pCi/g
PCi/g
mean cpm
Drainage
1.71
2.95
48419
Alluvial
3.72
4.96
67169
LCR
1.26
2.5
44221
TABLE B: VERTICAL CORRELATION
Background
IL
NET gamma -
Pool
PCi/g
PCi/g
mean cpm
Drainage
1.71
2.95
1828
Alluvial
3.72
4.96
2307
LCR
1.26
2.5
1721
4) Volume estimates for this quadrant are shown
on Figure 9-13.
5) Not all 1" contours are shown.
600
m Feet
0 150 300
m
€RG
March 2021
Rev 1.2
FIGURE 9-12
RESULTS OF MOBILE GAMMA SCAN SURVEY ABOVE IL WITH TEST PIT LOCATIONS
SW QUADRANT
BABBITT RANCHES
-------
PIT CROSS-SECTION
r
/-EXCA
V ROCK
VATED AND EXPOSED
FACE REMAIN
NATIVE
RQCK
\r
/^~ T
I
ATIVE
OCK
p-
SEDIMENT 0.75" THICK
+00 0+20 0+
40 0+60 0+80 1+00 1+20 1+40 1+60 1+
80 2+
00 2+20 2+
Project No. 110704
Engineering Analytics, Inc.
m
€RG
LEGEND
O Phase III Test Pits
• Alluvial TENORM Gamma Result above IL
Drainage TENORM Gamma Result above IL
Existing Contours (Maser, 2016)
Depth of TENORM above IL Contours
Cross Section A-A'
EPAAUM Boundary
! Area of Potential Effect
Section Lines
Other Mine Related Disturbance (1)
~ EPA Identified Drainage Area Boundary
EPA Identified Drainage Network
EPA Identified Road Buffer (50-ft)
EPA Identified Road Centerline
NOTES:
1) Other Mine Related Disturbance as defined in the
Phase II Work Plan (approved September 6, 2017).
2) The IL Application Areas are shown on Figure 5-14.
3) IL Values are as follows:
TABLE A: HORIZONTAL CORRELATION
Background
IL
gamma -
Pool
pCi/g
PCi/g
mean cpm
Drainage
1.71
2.95
48419
Alluvial
3.72
4.96
67169
LCR
1.26
2.5
44221
TABLE B: VERTICAL CORRELATION
Background
IL
NET gamma -
Pool
PCi/g
PCi/g
mean cpm
Drainage
1.71
2.95
1828
Alluvial
3.72
4.96
2307
LCR
1.26
2.5
1721
4) Total volume of TENORM above IL in this
Quadrant: 7818 Cu. Yd.
5) Not all 1" contours are shown.
0 75 150
300
3 Feel
March 2021
Rev 1.2
FIGURE 9-13
VOLUME ESTIMATE ABOVE IL AT AUM 458
BABBITT RANCHES
-------
TP-15
(ALLUVIAL)
Net
Exceeds IL
Depth
Gamma
(2295)
0-0.5'
3,128
YES
0.5-1.0'
2,381
YES
1.0'-1.25
N/A
N/A
TP-23
(DRAINAGE)
Net
Exceeds IL
Depth
Gamma
(1814)
0-0.5'
4,480
YES
0.5'-1.0'
5,048
YES
1.0'-1.5'
3,385
YES
1.5' 2.0'
3,025
YES
2.0'-2.5'
2,982
YES
2.5'-3.0'
2,888
YES
TP-16
(DRAINAGE)
Net
Exceeds IL
Depth
Gamma
(1814)
0-0.5'
1,164
NO
0.5'-1.0'
896
NO
1.0'-1.5'
783
1.5'-2.0'
956
NO
i \ I* ' B
•f. Ai \
I \ \
{ / \
3p / \ ;
• f \
i
> «u
-!ij
' M - f-*fc
JjilMl
4jk1 h.
./ ¦ fir'
TP-17
(ALLUVIAL)
Net
Exceeds IL
Depth
Gamma
(2295)
0-0.5'
3,090
YES
0.5'-1.0'
2,299
YES
l.O'-l. 5'
1,861
NO
1.5'-2.0'
1,906
NO
2.0'-2.5'
1,362
NO
2.5'-3.0'
1,420
NO
3.0'-3.5'
1,831
NO
3.5'-4.0'
1,960
NO
4.0'-4.5'
2,628
YES
r
Project No. 110704
Engineering Analytics, Inc.
Litt e Colorado River
BSA
m
LEGEND
O Phase III Test Pits
- Depth of TENORM above IL Contours
• Alluvial TENORM Gamma Result above IL
Drainage TENORM Gamma Result above IL
EPA Identified Road Centerline
EPA Identified Drainage Network
• • • 2019 Little Colorado River (NHD)
EPA Identified Drainage Area Boundary
EPA Identified Road Buffer (50-ft)
Other Mine Related Disturbance (1)
Babbitt BSA Locations
i Area of Potential Effect
Section Lines
EPAAUM Boundary
NOTES:
1) Other Mine Related Disturbance as defined in the
Phase II Work Plan (approved September 6, 2017).
2) The IL Application Areas are shown on Figure 5-14.
3) IL Values are as follows:
TABLE A: HORIZONTAL CORRELATION
Background
IL
gamma -
Pool
pCi/g
PCi/g
mean cpm
Drainage
1.71
2.95
48419
Alluvial
3.72
4.96
67169
LCR
1.26
2.5
44221
TABLE B: VERTICAL CORRELATION
Background
IL
NET gamma -
Pool
PCi/g
PCi/g
mean cpm
Drainage
1.71
2.95
1828
Alluvial
3.72
4.96
2307
LCR
1.26
2.5
1721
4) Total volume of TENORM above IL in this
Quadrant: 9436 Cu. Yd.
5) Not all 1" contours are shown.
0 150 300
m
March 2021
Rev 1.2
FIGURE 9-14
RESULTS OF MOBILE GAMMA SCAN SURVEY ABOVE IL WITH TEST PIT LOCATIONS
SE QUADRANT
BABBITT RANCHES
-------
LEGEND
Tenorm Results Above 160 pCi/g
O Phase III Test Pits
EPA Identified Road Centerline
~ EPA Identified Drainage Area Boundary
EPA Identified Drainage Network
— " - 2019 Little Colorado River (NHD)
EPA Identified Road Buffer (50-ft)
Other Mine Related Disturbance (1)
EPA BRA Location
Babbitt BSA Locations
j Area of Potential Effect
Section Lines
EPA AUM Boundary
NOTES:
1) Other Mine Related Disturbance as Defined in the
Phase II Work Plan (approved September 6, 2017).
2) Total Removal Volume for 160 pCi/g in the
4 quadrants is estimated to be 942 cubic yards.
0 625 1,250
2,500
H Feet
Project No. 110704
m
Engineering Analytics, Inc.
CAG
March 2021
Rev 1.2
FIGURE 9-15
RISK BASED RESULTS OF MOBILE GAMMA SCAN SURVEY ABOVE 160 pCi/g AND TEST PIT LOCATIONS
BABBITT RANCHES
-------
LEGEND
TENORM Results Above 160 pCi/g
O Phase III Test Pits
Babbitt BSA Locations
, ,
| Area of Potential Effect
EPA Identified Drainage Area Boundary
EPA Identified Road Buffer (50-ft)
EPA Identified Road Centeriine
Notes:
1) Other Mine Related Disturbance as defined in the
Phase II Work Plan (approved September 6, 2017).
2) No risk based removal volume in this quadrant.
0 125 250
500
5 Feet
Project No. 110704
m
Engineering Analytics, Inc.
CAG
March 2021
Rev 1.2
FIGURE 9-16
RISK BASED RESULTS OF MOBILE GAMMA SCAN SURVEY ABOVE 160 pCi/g
NW QUADRANT
BABBITT RANCHES
-------
i i1
r * -
K n /'* • *£
¦f 1 fkvicpk ffl\ . v
v\ t \ t$£3U>X- \ •
i v
»•> :»
LEGEND
TENORM Results Above 160 pCi/g
O Phase III Test Pits
Risk Based Action Level Contours
EPA Identified Road Centerline
~ EPA Identified Drainage Area Boundary
EPA Identified Drainage Network
— ¦ ¦ - 2019 Little Colorado River (NHD)
EPA Identified Road Buffer (50-ft)
Other Mine Related Disturbance (1)
Area of Potential Effect
Section Lines
EPAAUM Boundary
Notes:
1) Other Mine Related Disturbance as defined in the
Phase II Work Plan (approved September 6, 2017).
2) Total Removal Volume for this quadrant is shown
on Figure 9-18.
3) Some 1" contours may not be shown.
0 125 250
500
3 Feet
Project No. 110704
m
Engineering Analytics, Inc.
CAG
March 2021
Rev 1.2
FIGURE 9-17
RISK BASED RESULTS OF MOBILE GAMMA SCAN SURVEY ABOVE 160 pCi/g
NE QUADRANT
BABBITT RANCHES
-------
LEGEND
TENORM Results Above 160 pCi/g
O Phase III Test Pits
« Risk Based Action Level Contours
Existing Contours (Maser, 2016)
EPAAUM Boundary
Area of Potential Effect
Section Lines
Other Mine Related Disturbance (1)
EPA Identified Drainage Area Boundary
EPA Identified Drainage Network
EPA Identified Road Buffer (50-ft)
EPA Identified Road Centerline
L „ j
NOTES:
1) Other Mine Related Disturbance as defined in the
Phase II Work Plan (approved September 6, 2017).
2) Total Removal Volume of TENORM above 160 pCi/g
in this Quadrant is estimated to be 940 Cu. Yd.
3) Some 1" contours may not be shown.
0 75 150
300
3 Feel
Project No. 110704
m
Engineering Analytics, Inc.
CAG
March 2021
Rev 1.2
FIGURE 9-18
VOLUME ESTIMATE ABOVE 160 pCi/g ATAUM 457
BABBITT RANCHES
-------
LEGEND
TENORM Results Above 160 pCi/g
O Phase II! Test Pits
' Risk Based Action Level Contours
EPAAUM Boundary
j Area of Potential Effect
Section Lines
Other Mine Related Disturbance (1)
EPA Identified Drainage Area Boundary
EPA Identified Drainage Network
EPA Identified Road Buffer (50-ft)
EPA Identified Road Centerline
NOTES:
1) Other Mine Related Disturbance as defined in the
Phase II Work Plan (approved Septembers, 2017).
2) Total Removal Volume for this quadrant is shown
on Figure 9-20.
3) Some 1" contours may not be shown.
0 125 250
500
3 Feet
Project No. 110704
m
Engineering Analytics, Inc.
CAG
March 2021
Rev 1.2
FIGURE 9-19
RISK BASED RESULTS OF MOBILE GAMMA SCAN SURVEY ABOVE 160 pCi/g
SW QUADRANT
BABBITT RANCHES
-------
Project No. 110704
March 2021
Rev 1.2
LEGEND
TENORM Results Above 160 pCi/g
O Phase III Test Pits
¦ Risk Based Action Level Contours
< Existing Contours (Maser, 2016)
Cross Section A-A'
EPAAUM Boundary
Area of Potential Effect
Section Lines
Other Mine Related Disturbance (1)
EPA Identified Drainage Area Boundary
EPA Identified Drainage Network
EPA Identified Road Buffer (50-ft)
EPA Identified Road Centerline
NOTES:
1) Other Mine Related Disturbance as defined in the
Phase II Work Plan (approved September 6, 2017).
2) Total Removal Volume of TENORM above 160 pCi/g
in this Quadrant is estimated to be 2 Cu. Yd.
3) Some 1" contours may not be shown.
0 75 150
k4 "
« '*¦ att'
PIT CROSS-SECTION
|~~A Engineering Analytics, Inc. _
UT~~ €AG
FIGURE 9-20
VOLUME ESTIMATE ABOVE 160 pCi/g ATAUM 458
BABBITT RANCHES
-------
r\——»
V -
, MHHFfv jj* Ht
~ j f:,—>
inv - v* V. - i ^ vt •*
I \
/'' \>- ."¦ ,.;l|-'i
\ r
r . . \ IMiB
W \
i> | \
LEGEND
TENORM Results Above 160 pCi/g
O Phase III Test Pits
• Risk Based Level Contours
EPA Identified Road Centerline
EPA Identified Drainage Area Boundary
EPA Identified Drainage Network
2019 Little Colorado River (NHD)
EPA Identified Road Buffer (50-ft)
Other Mine Related Disturbance 1)
Babbitt BSA Locations
Area of Potential Effect
!„ i
Section Lines
EPAAUM Boundary
NOTES:
1) Other Mine Related Disturbance as Defined in the
Phase II Work Plan appeared (September 6, 2017)
2) No risk based removal volume in this quadrant.
0 125 250
500
5 Feet
Project No. 110704
m
Engineering Analytics, Inc.
CAG
RISK BASED RESULTS OF
March 2021
Rev 1.2
FIGURE 9-21
MOBILE GAMMA SCAN SURVEY ABOVE 160 pCi/g
SE QUADRANT
BABBITT RANCHES
-------
LEGEND
O Phase II! Test Pits
TENORM Results above 12 pCi/g
EPA Identified Road Centerlirie
EPA Identified Drainage Network
— ¦ • - 2019 Little Colorado River (NHD)
EPA Identified Drainage Area Boundary
EPA Identified Road Buffer (50-ft)
Other Mine Related Disturbance (1)
EPA BRA Location
Babbitt BSA Locations
¦ Area of Potential Effect
Section Lines
EPA AUM Boundary
NOTES:
1) Other Mine Related Disturbance as Defined in the
Phase II Work Plan (approved September 6, 2017).
2) Total Volume removal estimate per area is on
figures 9-23 through 9-26.
3) Total Removal Volume for 12 pCi/g in the 4 quadrants
is estimated to be 10,036 cubic yards.
0 625 1,250
2,500
H Feet
Project No. 110704
m
Engineering Analytics, Inc.
CAG
March 2021
Rev 1.2
FIGURE 9-22
RISK BASED RESULTS OF MOBILE GAMMA SCAN SURVEY AND VOLUME ESTIMATE ABOVE 12 pCi/g AND TEST PIT LOCATIONS
BABBITT RANCHES
-------
LEGEND
• TENORM Results Above 12 pCi/g
O Phase ill Test Pits
' Risk Based Action Level Contours 12 pCi/g
EPA Identified Road Centerline
EPA Identified Drainage Area Boundary
EPA Identified Road Buffer (50-ft)
Babbitt BSA Locations
J Area of Potential Effect
Notes:
1) Other Mine Related Disturbance as defined in the
Phase II Work Plan (approved Septembers, 2017).
2) Total Removal Volume in this quadrant is estimated
to be 1,166 cubic yards.
3) All removal contours in this quadrant are 3 feet deep.
0 125 250
500
5 Feet
Project No. 110704
m
Engineering Analytics, Inc.
CAG
March 2021
Rev 1.2
FIGURE 9-23
RISK BASED RESULTS OF MOBILE GAMMA SCAN SURVEY AND VOLUME ESTIMATE ABOVE 12 pCi/g
NW QUADRANT
BABBITT RANCHES
-------
LEGEND
Risk Based Action Level Contour 12 pCi/g
O Phase III Test Pits
• TENORM Results Above 12 pCi/g
EPA Identified Road Centerline
EPA identified Drainage Network
— ¦ ¦ - 2019 Little Colorado River (NHD)
~ EPA Identified Drainage Area Boundary
EPA Identified Road Buffer (50-ft)
Other Mine Related Disturbance (1)
Area of Potential Effect
Section Lines
EPAAIJM Boundary
Notes:
1) Other Mine Related Disturbance as defined in the
Phase II Work Plan (approved Septembers, 2017).
2) Total Removal Volume for this quadrant is estimated
to be 2,688 cubic yards.
3) Some 1" contours may not be shown.
0 125 250
500
3 Feet
Project No. 110704
m
Engineering Analytics, Inc.
CAG
March 2021
Rev 1.2
FIGURE 9-24
RISK BASED RESULTS OF MOBILE GAMMA SCAN SURVEY AND VOLUME ESTIMATE ABOVE 12 pCi/g
NE QUADRANT
BABBITT RANCHES
-------
~r
v
\
\
\
"H
K/k
"A'
\ •
>1 » ^7Ht
i| • (
% •.
i
1-
' -V* .
LEGEND
9 TENORM Results Above 12 pCi/g
O Phase III Test Pits
1 Risk Based Action Level Contours 12 pCi/g
EPA Identified Drainage Network
EPA Identified Road Centerline
~ EPA Identified Drainage Area Boundary
EPA Identified Road Buffer (50-ft)
Other Mine Related Disturbance (1)
| Area of Potential Effect
Section Lines
EPAAUM Boundary
NOTES:
1) Other Mine Related Disturbance as defined in the
Phase II Work Plan (approved September 6, 2017).
2) Total Removal Volume for this quadrant is estimated
to be 5,535 cubic yards.
3) Some 1" contours may not be shown.
0 125 250
500
5 Feet
Project No. 110704
m
Engineering Analytics, Inc.
CAG
March 2021
Rev 1.2
FIGURE 9-25
RISK BASED RESULTS OF MOBILE GAMMA SCAN SURVEY AND VOLUME ESTIMATE ABOVE 12 pCi/g
SW QUADRANT
BABBITT RANCHES
-------
a 5
' mi \
u s \
¦ « V * -
, t/- ., v^\^v
iMal^ \ ¦
< • I Mi
\V
'/ \ A *
LEGEND
Risk Based Level Countours 12 pCi/g
• TENORM Results Above 12 pCi/g
O Phase III Test Pits
EPA Identified Road Centerline
EPA Identified Drainage Network
— ¦ ¦ ¦ 2019 Little Colorado River (NHD)
~ EPA Identified Drainage Area Boundary
EPA Identified Road Buffer (50-ft)
Other Mine Related Disturbance 1)
Babbitt BSA Locations
Area of Potential Effect
Section Lines
EPAAUM Boundary
NOTES:
1) Other Mine Related Disturbance as Defined in the
Phase II Work Plan appeared (September 6, 2017)
2) Total Removal Volume for this quadrant is estimated
to be 647 cubic yards.
0 125 250
500
5 Feet
Project No. 110704
m
Engineering Analytics, Inc.
CAG
March 2021
Rev 1.2
FIGURE 9-26
RISK BASED RESULTS OF MOBILE GAMMA SCAN SURVEY AND VOLUME ESTIMATE ABOVE 12 pCi/g
SE QUADRANT
BABBITT RANCHES
-------
LEGEND
TENORM Results above 12 pCi/g
Tenorm Results Above 160 pCi/g
O Phase III Test Pits
EPA Identified Road Centerline
— ¦ • - 2019 Little Colorado River (NHD)
EPA Identified Drainage Network
EPA Identified Drainage Area Boundary
EPA Identified Road Buffer (50-ft)
Other Mine Related Disturbance (1)
EPA BRA Location
Babbitt BSA Locations
¦ Area of Potential Effect
Section Lines
EPA AUM Boundary
NOTES:
1) Other Mine Related Disturbance as Defined in the
Phase II Work Plan (approved September 6, 2017).
2) Total Removal Volumes are shown in the table below.
AUM
Removal Volume
Difference
>12 pCi/g
>160 pCi/g
NE
2,688
940
1,748
SE
647
0
647
SW
5,535
2
5,533
NW
1,166
0
1,166
Total
10,036
942
9,094
0 625 1,250
2,500
H Feet
Project No. 110704
Engineering Analytics, Inc.
m
€RG
March 2021
Rev 1.2
FIGURE 9-27
RISK BASED RESULTS OF MOBILE GAMMA SCAN SURVEYS COMPARING ABOVE 12 pCi/g AND ABOVE 160 pCi/g AND TEST PIT LOCATIONS
BABBITT RANCHES
-------
/A
/ \
/ 9
TP-1
o o
%
X /
/
V /
y
/ : If
I h
¦ .* /
! I • V\ V *
i-' J i'.V '' .
#• "A fS*k!/i's
iff rjjj -j
! Si: \ L J
m
LEGEND
Tenorm Results Above 160 pCi/g
TENORM Results Above 12 pCi/g
O Phase III Test Pits
EPA Identified Road Centerline
— ¦ ¦ - 2019 Little Colorado River (NHD)
EPA Identified Drainage Network
EPA Identified Drainage Area Boundary
EPA Identified Road Buffer (50-ft)
Other Mine Related Disturbance (1)
j Area of Potential Effect
Section Lines
EPAAUM Boundary
NOTES:
1) Other Mine Related Disturbance as Defined in the
Phase II Work Plan (approved September 6, 2017),
2) Total Removal Volumes are shown in the table on
Figure 9-27.
0 175 350
700
3 Feel
Project No. 110704
m
Engineering Analytics, Inc.
CAG
March 2021
Rev 1.2
FIGURE 9-28
RISK BASED RESULTS OF MOBILE GAMMA SCAN SURVEYS COMPARING ABOVE 12 pCi/g AND ABOVE 160 pCi/g AND TEST PIT LOCATIONS
NE QUADRANT
BABBITT RANCHES
-------
\ \
v \
r ¦«,.!N \
LEGEND
Tenorm Results Above 160 pCi/g
TENORM Results Above 12 pCi/g
O Phase III Test Pits
EPA Identified Road Centerline
— ¦ ¦ - 2019 Little Colorado River (NHD)
EPA Identified Drainage Network
EPA Identified Drainage Area Boundary
EPA Identified Road Buffer (50-ft)
Other Mine Related Disturbance (1)
j Area of Potential Effect
Section Lines
EPAAUM Boundary
NOTES:
1) Other Mine Related Disturbance as Defined in the
Phase II Work Plan (approved September 6, 2017),
2) Total Removal Volumes are shown in the table on
Figure 9-27.
0 175 350
700
3 Feel
Project No. 110704
m
Engineering Analytics, Inc.
CAG
March 2021
Rev 1.2
FIGURE 9-29
RISK BASED RESULTS OF MOBILE GAMMA SCAN SURVEYS COMPARING ABOVE 12 pCi/g AND ABOVE 160 pCi/g AND TEST PIT LOCATIONS
SE QUADRANT
BABBITT RANCHES
------- |