DRC-2015-001665 - 0901a0688050d786

Energy Fuels Resources
(USA) Inc.
WHITE MESA MILL
Probabilistic Seismic Hazard
Analysis
March 2015
O MWH DRC-2015-001665
BUILDING A BETTER WOULD
3665 JFK Parkway
Suite 206
Fort Collins, CO USA

Probabilistic Seismic Hazard Analysis

Energy Fuels Resources (USA) Inc. MWH Americas, Inc.
i March 2015
TABLE OF CONTENTS
1.0 INTRODUCTION ............................................................................................................... 1 
1.1 Background and Purpose ...................................................................................... 1 
1.2 Approach ............................................................................................................... 1 
1.3 Design Criteria ....................................................................................................... 2 
2.0 GEOLOGIC SETTING ...................................................................................................... 3 
2.1 Regional Setting .................................................................................................... 3 
2.2 Site Geology .......................................................................................................... 3 
3.0 SEISMOTECTONIC SETTING AND HISTORICAL SEISMICITY .................................... 4 
3.1 Historical Seismicity .............................................................................................. 4 
3.2 Catalogs of Earthquake Data ................................................................................ 4 
3.2.1 Petersen Catalog ....................................................................................... 4 
3.2.2 ComCat...................................................................................................... 4 
3.2.3 Combined Catalog and Magnitude Bias Correction ................................... 5 
3.2.4 Earthquakes Attributed to Specific Faults .................................................. 5 
3.2.5 Artificially Induced Earthquakes ................................................................. 5 
3.3 Magnitude Conversion .......................................................................................... 5 
3.4 Developing Recurrence Parameters ..................................................................... 6 
3.4.1 Assessment of Catalog Completeness ...................................................... 6 
3.4.2 Estimation of the Recurrence Parameters ................................................. 7 
4.0 SEISMIC SOURCE CHARACTERIZATION ..................................................................... 8 
4.1 Faults ..................................................................................................................... 8 
4.1.1 Capable Faults........................................................................................... 8 
4.1.2 Fault Sources............................................................................................. 8 
4.2 Seismic Sources .................................................................................................... 9 
4.2.1 Colorado Plateau ..................................................................................... 10 
4.2.2 Intermountain Seismic Belt ...................................................................... 11 
4.3 Shear Wave Velocity ........................................................................................... 11 
4.3.1 Summary of Site-Specific Vp Values ........................................................ 11 
4.3.2 Development of Vp/Vs Ratio .................................................................... 12 
4.3.3 Estimation of Site-Specific Vs Values ...................................................... 14 
5.0 GROUND MOTION PREDICTION EQUATIONS ........................................................... 16 
6.0 PROBABILISTIC SEISMIC HAZARD ANALYSIS ......................................................... 17 
6.1 PSHA Code and Methodology............................................................................. 17 
6.2 PSHA Inputs ........................................................................................................ 17 
6.2.1 Areal Source Zones ................................................................................. 18 
6.2.2 Fault Sources........................................................................................... 18 
6.3 Probabilistic Seismic Hazard Analysis Results .................................................... 18 
7.0 RESULTS AND COMPARISON WITH PREVIOUS STUDIES ....................................... 20 
8.0 REFERENCES ................................................................................................................ 21 

Probabilistic Seismic Hazard Analysis
Energy Fuels Resources (USA) Inc. MWH Americas, Inc.
ii March 2015
LIST OF TABLES
Table 1. Time Periods for Complete Event Reporting ................................................................. 6 
Table 2. Colorado Plateau – Magnitude Bins and Cumulative N* Values ................................... 7 
Table 3. Intermountain Seismic Belt– Magnitude Bins and Cumulative N* Values ..................... 7 
Table 4. Minimum Criteria for Faults Considered in Seismic Investigation (NRC 10
CFR Appendix A to Part 100) ..................................................................................... 8 
Table 5. Envelope of Vp and Vs Values for the White Mesa Site ............................................... 15 
Table 6. GMPEs used in the PSHA ........................................................................................... 16 
Table 7. PSHA Input Parameters ............................................................................................... 17 
Table 8. PSHA Results .............................................................................................................. 18 

LIST OF FIGURES

Figure 1 Quaternary Faults Within the Study Area
Figure 2 Faults and Earthquake Events Included in PSHA
Figure 3 Catalog Completeness Plots
Figure 4 Areal Source Zones
Figure 5 Gutenberg-Richter Relationship, Colorado Plateau
Figure 6 Gutenberg-Richter Relationship, Intermountain Seismic Belt
Figure 7 Seismic Refraction Data and Boring Locations
Figure 8 Fault Traces as Modeled in the PSHA
Figure 9 Uniform Hazard Spectra Comparison of VS30
Figure 10 Peak Ground Acceleration Seismic Source Contribution
Figure 11 Deaggregation of PGA 10,000-Year Return Period

LIST OF ATTACHMENTS

Attachment 1 List of Earthquake Events within the White Mesa Study Area
Attachment 2 List of Faults and Fault Characteristics Included in the PSHA
Attachment 3 Summary of Individual Fault Parameters
Attachment 4 Dames & Moore Boring Logs (1978)

Probabilistic Seismic Hazard Analysis
Energy Fuels Resources (USA) Inc. MWH Americas, Inc.
1 March 2015
1.0 INTRODUCTION
This report presents results of a site-specific probabilistic seismic hazard analysis (PSHA) to
develop the seismic design criteria for reclamation of the White Mesa Mill (site). The site is
approximately 6 miles (10 km) south of Blanding, Utah at approximately 37.5° N latitude and
109.5° W longitude. Site facilities consist of a uranium processing mill and five lined
tailings/process solution storage cells located within an approximately 686-acre restricted area.

The probabilistic seismic hazard analysis is based on a seismotectonic model and source
characterization of the site and surrounding area. The study evaluated a 200-mile (322-km)
radius surrounding the site. For purposes of this report, this area is termed the “study area”
(Figure 1).

The seismotectonic model identified three general seismic sources in the study area: 1)
seismicity of the Intermountain Seismic Belt (ISB), 2) seismicity of the Colorado Plateau (CP),
and 3) crustal faults that meet the NRC minimum criteria discussed in Section 4.1.1. Each
source zone was characterized to establish input parameters for the seismic hazard analyses.
The PSHA was performed using HAZ43 (2014) software developed by Dr. Norman
Abrahamson. Operational and long-term design recommendations were developed based on
the results from this PSHA and previous seismic investigations at the site.

1.1 Background and Purpose
The Utah Division of Radiation Control (DRC) requested that Energy Fuels Resources (USA),
Inc. (EFRI) conduct a site-specific PSHA for reclamation of the site. This request was part of
DRC’s February 2013 review comments (DRC, 2013) on EFRI’s August 2012 responses to
DRC’s Round 1 interrogatories for the White Mesa Reclamation Plan Rev. 5.0 (EFRI, 2012).

The PSHA was performed to better understand the likelihood of the potential earthquake
sources, to correlate results with previous analyses conducted for the site, and to evaluate the
contribution of the seismic sources (e.g. deaggregation). This analysis assessed the site-
specific seismic hazard using Ground Motion Prediction Equations (GMPEs) to estimate
seismically induced ground motions at the site. Seismic hazard analyses were previously
conducted for the design of the Cell 4A and 4B facilities (MFG, 2006; Tetra Tech, 2010) and in
response to DRC review of EFRI responses to interrogatories on the Reclamation Plan (MWH,
2012). These analyses indicated that the seismic hazard at the site is dominated by background
events in the Colorado Plateau.

This report presents a description and results of analyses conducted to respond to the DRC’s
comment on ERFI’s interrogatory responses (DRC, 2013) requesting a site-specific seismic
hazard evaluation be performed to develop site-specific seismic design parameters. This report
also addresses comments later provided by URS (URS, 2015) in response to a previous version
of this report. This report has been prepared by MWH Americas, Inc. (MWH) at the request of
EFRI.

1.2 Approach
This evaluation used data on faults and earthquakes occurring within a 200-mile (322-km)
radius of the site to develop seismic source characterization for the PSHA. An earthquake
catalog was compiled and the historical seismicity and information on specific faults was used to
develop the seismic source models for the three seismic sources described above. The PSHA
Probabilistic Seismic Hazard Analysis
Energy Fuels Resources (USA) Inc. MWH Americas, Inc.
2 March 2015
considered all defined seismic sources with the goal of identifying the major contributor(s) to the
seismic hazard at the site. The hazard is defined according to GMPEs selected for the region.

1.3 Design Criteria
The design life for the reclaimed facility is required to be 1,000 years to the extent reasonably
achievable, and at least 200 years, per the US Environmental Protection Agency (EPA) (EPA 40
CFR 192) and the US Nuclear Regulatory Commission (NRC) (NRC 10 CFR Appendix A to Part
100 A) (NRC, 2013). An event with a 10,000-year return period has a 2 percent probability of
exceedance during a 200-year period and a less than 10 percent probability of exceedance in a
1,000-year period. Therefore, the peak ground acceleration (PGA) calculated using a 10,000-
year return period is conservative, but appropriate for the reclaimed (long-term) seismic design
criteria for the site.

The peak ground acceleration calculated in this PSHA will be used during reclamation design to
evaluate liquefaction potential and slope stability of the reclaimed tailings cells. These analyses
use either the PGA or a pseudostatic coefficient of 2/3 of the PGA (DOE, 1989).

Probabilistic Seismic Hazard Analysis
Energy Fuels Resources (USA) Inc. MWH Americas, Inc.
3 March 2015
2.0 GEOLOGIC SETTING
2.1 Regional Setting
The Reclamation Plan for White Mesa Mill (Denison, 2011), and previous seismic studies
(MWH, 2006; Tetra Tech, 2010) provide information on the regional geologic setting. Only
information relevant to the PSHA will be included here.

The site is located within the Colorado Plateau physiographic province in southeastern Utah.
The Colorado Plateau is a broad, roughly circular region of relative structural stability. The
contemporary seismicity of the Colorado Plateau was investigated by Wong and Humphrey
(1989), based on seismic monitoring. Their study characterized seismicity of the plateau as
small to moderate magnitude with a low to moderate rate of widely-distributed earthquakes with
hypocentral depths of 9 to 12 miles (15 to 20 km). The area is characterized by generally
northwest-striking normal faulting.

Regional geology approximately 50 to 100 miles (80 to 161 km) north to northeast of the site is
characterized by the Uncompahgre Uplift and salt tectonics of the Paradox Valley area. The
Uncompahgre Uplift is a northwest-trending, east-tilted fault block located in southwest
Colorado. For purposes of this PSHA, faults associated with the Uncompahgre Uplift are
considered seismogenic. Faults in the area of the Paradox Valley are generally related to salt
tectonics and are considered non-seismogenic.

The western extent of the study area is bounded by the eastern extent of the Intermountain
Seismic Belt (ISB). The ISB runs from northwestern Montana south into northern Arizona and is
one of the most extensive zones of seismicity within the continental United States (Wong et al.,
1997). Much of the ISB near the site is characterized by north-trending normal faults. The two
largest earthquakes recorded in the study area, moment magnitude (Mw) 6.0 and 6.5, occurred
within the ISB.

The southern and southeastern extent of the study area is a relatively stable area of the
Colorado Plateau with no Quaternary faults. One exception is the Northern Nacimiento fault,
located in northeastern New Mexico.

2.2 Site Geology
Information on site geology is provided in the Reclamation Plan for the White Mesa Mill
(Denison, 2011). This information is summarized below.

The site is located near the center of the White Mesa in southeastern Utah. The area is a north-
south trending mesa characterized by steep canyons formed by stream erosion. The site is
underlain by the Dakota Sandstone, predominately composed of cross-bedded, fine- to coarse-
grained, well-cemented sand (Denison, 2011). Site soils are predominantly derived from wind-
blown sediment. In the area of the tailings cells, soils were removed during construction, as
discussed in Section 4.3.1.

Probabilistic Seismic Hazard Analysis
Energy Fuels Resources (USA) Inc. MWH Americas, Inc.
4 March 2015
3.0 SEISMOTECTONIC SETTING AND HISTORICAL SEISMICITY
3.1 Historical Seismicity
The seismic hazard analysis for the site includes a review of historic earthquakes within the
study area. The historic earthquake record for the study area contains earthquakes from 1887
through the end of 2014 and provides a general overview of the seismicity of the study area.

Figure 2 shows seismicity [events with moment magnitude (Mw) greater than or equal to 3.0 (Mw
≥ 3.0)] within the study area. The earliest recorded event included in the final PSHA catalog
occurred in 1887. The PSHA catalog contains two events larger than or equal to moment
magnitude 6.0 (Mw ≥ 6.0) and 11 events with moment magnitudes greater than or equal to 5 and
less than 6 (6 > Mw ≥ 5). The remaining events are all less than Mw 5.0 (Mw < 5). All events
described in this report are given in moment magnitude unless specified otherwise.

The following paragraphs summarize development of the earthquake catalog used in the PSHA.

3.2 Catalogs of Earthquake Data
3.2.1 Petersen Catalog
Catalogs from the US Geological Survey (USGS) NSHMP for the Western United States (WUS)
and Central and Eastern United States (CEUS) (Petersen et al., 2014) were used to compile
information regarding historic earthquakes within 200 miles (322 km) of the site. Petersen et al.
(2014) compiled the catalogs for the WUS and CEUS by reviewing and combining other
available catalogs. Petersen et al. (2014) used their interpretation of catalog reliability to
eliminate duplicate records when earthquakes were listed in more than one catalog. Since
attenuation relations, completeness, and magnitude conversion rules all vary regionally,
Petersen et al. (2014) built two catalogs generally following the approach used by the CEUS-
SSCn (NRC et al., 2012): a catalog for WUS and a catalog for the CEUS. Petersen et al. (2014)
converted both catalogs to Mw from the original magnitude recorded.

Within the study area, the Petersen et al. (2014) database includes historical seismic events
from 1887 through 2012 for the WUS and events from 1910 through 2012 for the CEUS. Both
catalogs contain events with Mw ≥ 3.0. AutoCAD software was used to delineate a 200-mile
(322-km) radius around the site to identify only those events within the seismic study area.
Further steps taken to develop the final PSHA catalog are discussed below. The PSHA catalog
includes 328 events from the Petersen catalog.

3.2.2 ComCat
Earthquake information from the WUS and CEUS catalogs was supplemented by a search of
the Advanced National Seismic System (ANSS) Comprehensive Catalog (ComCat), also
maintained by the USGS. ComCat was used to obtain additional earthquake information from
January 1, 2013 through February 7, 2015. The catalog was accessed on February 8, 2015.
ComCat contains data from networks that contribute to the ANSS database as well as historical
data from the USGS National Earthquake Information Center’s (NEIC) Preliminary
Determination of Epicenters (PDE) catalog
(http://earthquake.usgs.gov/earthquakes/eqarchives/epic/). AutoCAD software was used to
delineate a 200-mile (322-km) radius around the site to identify only those events within the
seismic study area. The final catalog includes six ComCat events.

Probabilistic Seismic Hazard Analysis
Energy Fuels Resources (USA) Inc. MWH Americas, Inc.
5 March 2015
The ComCat was declustered for this PSHA using the Reasenberg (1985) algorithm to remove
dependent events (aftershocks and foreshocks). In order to use the independence assumption
of a Poisson model (typically assumed in PSHA analyses), events that can be associated with
other close-in-time and near-in-space events must be removed from the catalog. Reasenberg’s
algorithm identifies events that occur within time and distance windows, termed clusters. These
clusters are then replaced with the mainshock.

3.2.3 Combined Catalog and Magnitude Bias Correction
The ComCat and Petersen catalogs were combined to create a final declustered catalog for the
PSHA. The Petersen catalog reports magnitude as expected moment magnitude E[MW]
(Petersen et al., 2014). The conversion of various magnitudes to E[Mw] for events from the
ComCat was completed following the guidance presented in CEUS-SSCn (NRC et al., 2012).
This approach is identical to that used in development of the Petersen catalog.

The PSHA catalog includes expected magnitude E[MW], magnitude uncertainty, and a counting
factor termed N* (or nstar) for each event. The counting factor N* was used to compute
unbiased earthquake rates following guidance presented in CEUS-SSCn (NRC et al., 2012).
Earthquake recurrence parameters were computed using the maximum likelihood approach by
using the N* factor instead of the observed counts. This approach has been shown to work well
for catalogs with variable levels of catalog completeness as a function of magnitude (CEUS-
SSCn, NRC et al., 2012).

3.2.4 Earthquakes Attributed to Specific Faults
In order to prevent double-counting earthquakes in both the fault and areal source models,
earthquakes occurring within 3.1 miles (5 km) of faults were evaluated in detail. Within the study
area, 31 events were located within 3.1 miles (5 km) of Quaternary faults. In order to evaluate
the difference between the earthquake recurrence parameters, the recurrence was computed
with and without these events. The result was very little variation in the a and b parameters with
or without the 31 events. Additionally, the recurrence calculations for the catalog including the
31 events resulted in an exponential distribution with a better fit to the data. Therefore, given the
small variation in results, and the fact that the literature indicates most earthquakes within the
CP (Wong and Humphrey, 1989) and ISB (dePolo, 1994) are not related to surface ruptures, all
earthquake events in the areal source zones were included in the recurrence calculations.

3.2.5 Artificially Induced Earthquakes
Several areas of artificially induced seismic activity are located within the study area. These
include: 1) an area between Glenwood Springs and Paonia, Colorado (Swanson et al., 2008,
and CGS, undated), 2) the Book Cliffs-eastern Wasatch Plateau area near Price, Utah (Arabasz
et al., 2005), and 3) the Paradox Valley area (Ake et al., 2005). The areas listed above were
examined against the Petersen catalog and were confirmed as having been removed from the
Petersen catalog. Furthermore, no events in the ComCat fall within these areas of artificially
induced seismicity.

3.3 Magnitude Conversion
All events described here are reported in moment magnitude unless specified otherwise. The
events included in the Petersen catalog were all given in Mw; therefore, it was only necessary to
convert those events from the ComCat. This conversion was completed by following the
Probabilistic Seismic Hazard Analysis
Energy Fuels Resources (USA) Inc. MWH Americas, Inc.
6 March 2015
approach used to compile the Petersen catalog and guidance provided in CEUS-SSCn (NRC et
al., 2012).

The earthquake catalog used in the recurrence calculations for this PSHA includes the
combined Petersen et al. (2014) catalog and ComCat. The data was declustered and screened
to exclude artificially-induced earthquakes due to anthropogenic activity. The final catalog used
for the PSHA includes 334 earthquakes. These earthquakes are shown on Figure 2.

Earthquakes included in the final catalog for the computation of recurrence parameters
generally have small magnitudes, with over 90 percent of the earthquakes having a Mw < 5.0.
Figure 2 shows that earthquake activity within a 200-mile (322-km) radius of the site is diffuse,
with the exception of those in the ISB located on the western edge of the study area, and in
western Colorado (the northeast corner of the study area). A list of historical earthquakes is
included in Attachment 1.

3.4 Developing Recurrence Parameters
To estimate probabilistic ground motions for the site, recurrence parameters are required to
characterize seismic activity in the study area. Two areal source zones were delineated within
the study area, as discussed in Section 4.2.

3.4.1 Assessment of Catalog Completeness
In order to estimate a recurrence rate for earthquakes, an assessment of the completeness of
the earthquake catalog was necessary. One way to test completeness is to plot the rate of the
earthquakes (number of events greater than a specified magnitude divided by the time period)
as a function of time, starting at present time and moving back towards the beginning of the
catalog. If the rate of earthquakes is represented by a stationary Poisson process (the rate -m-
does not change with time) for the study area, which is the typical assumption, then the rate of
earthquakes should remain constant for the portions of the catalog that have complete
reporting.

The evaluation was performed using the Stepp (1972) method, which includes generating
completeness plots to visually inspect the rate of events over the years. Plots were developed
starting at a minimum magnitude of 3.0 and carried out for each 0.5 to 1.0 magnitude unit,
depending on the size of the magnitude bins. Based on this evaluation, the catalog is
considered complete for the date and magnitude ranges shown in Table 1. Figure 3 shows the
catalog completeness plots developed for this study.

The catalog is complete for those events greater than Mw 5.5 for approximately 130 years, this
corresponds to the 1880’s, when settlement became more widespread for southeastern Utah.
The first event in the catalog is a Mw 5.7 which occurred in 1887.

Table 1. Time Periods for Complete Event Reporting
Magnitude Range Period of Complete
Reporting
3≤M<3.5 1984 2014
3.5≤M<4.0 1964 2014
4.0≤M<4.5 1964 2014
4.5≤M<5.0 1959 2014
5.0≤M<5.5 1904 2014
M≥5.5 1884 2014
Probabilistic Seismic Hazard Analysis
Energy Fuels Resources (USA) Inc. MWH Americas, Inc.
7 March 2015

3.4.2 Estimation of the Recurrence Parameters
After the completeness intervals for each magnitude range were developed and dependent
events were removed, the recurrence parameters were computed. A common way to
characterize this frequency is by using the Gutenberg-Richter relationship, which is linear when
the magnitude is plotted against the frequency of events on a semi-logarithmic scale. The
magnitude-frequency relation expressed in its cumulative form is:

logܰሺܯሻ ൌܽെܾܯ

where M is the magnitude and N is the cumulative frequency of earthquakes greater than
magnitude M. The calculation of cumulative frequency of earthquakes (N) used the N* value (a
counting factor used to compute unbiased rates) instead of observed counts. Recurrence
relationships were then estimated using the maximum likelihood procedure developed by
Weichert (1980). The maximum likelihood line is characterized by the slope of the line, or b-
value, and the log N value at a magnitude of zero (a-value). For this study, a minimum
magnitude of 3.0 was used to develop the recurrence parameters. The inputs used to calculate
the recurrence parameters are summarized in Table 2 and Table 3. The recurrence parameters
(a- and b-values) were developed for each seismic source zone, as discussed in Section 4.2.

Table 2. Colorado Plateau – Magnitude Bins and Cumulative N* Values
Magnitude Bin Cumulative N* value Cumulative Observed
Counts
3≤M<3.5 78.59 69
3.5≤M<4.0 52.65 46
4.0≤M<4.5 18.25 16
4.5≤M<5.0 8.03 7
5.0≤M<5.5 4.82 4
5.5≤M<6.0 1.21 1

Table 3. Intermountain Seismic Belt– Magnitude Bins and Cumulative N* Values
Magnitude Bins Cumulative N* value Cumulative Observed
Counts
3≤M<3.5 136.51 133
3.5≤M<4.0 81.48 78
4.0≤M<4.5 32.56 31
4.5≤M<5.0 14.89 14
5.0≤M<5.5 7.98 7
5.5≤M<6.0 4.71 4
6.0≤M<6.5 2.41 2
6.5≤M≤7.0 1.21 1

Probabilistic Seismic Hazard Analysis
Energy Fuels Resources (USA) Inc. MWH Americas, Inc.
8 March 2015
4.0 SEISMIC SOURCE CHARACTERIZATION
The seismic source model includes crustal fault sources, seismicity of the ISB, and seismicity of
the Colorado Plateau (CP). These sources are described below.

4.1 Faults
4.1.1 Capable Faults
A “capable fault” is defined by the Nuclear Regulatory Commission (NRC) in 10 CFR Appendix
A to Part 100, Seismic and Geologic Siting Criteria for Nuclear Power Plants, as a fault that has
exhibited one or more of the following characteristics:

1. Movement at or near the ground surface at least once within the past 35,000 years or
movement of a recurring nature within the past 500,000 years.
2. Macro-seismicity (magnitude 3.5 or greater) instrumentally determined with records of
sufficient precision to demonstrate a direct relationship with the fault.
3. A structural relationship to a capable fault according to characteristics (1) or (2) above
such that movement on one could be reasonably expected to be accompanied by
movement on the other.

Capable faults must also meet the minimum criteria for fault length and distance from the site,
as defined by NRC 10 CFR Appendix A to Part 100, and included in Table 4. A fault that is
deemed capable by the criteria listed above, but does not meet the minimum criteria provided in
Table 4, does not need to be considered in the seismic hazard analysis.

The term “capable fault” may be abandoned by the NRC, but this is not yet reflected in the CFR,
so the term is used in this report.

Table 4. Minimum Criteria for Faults Considered in Seismic Investigation (NRC 10 CFR
Appendix A to Part 100)
Distance from Site
(mi)
Minimum Length of Fault to be
Considered
(mi)
0 to 20 1
20 to 50 5
50 to 100 10
100 to 150 20
150 to 200 40

All capable faults that meet the minimum criteria presented above were considered in the
PSHA.

4.1.2 Fault Sources
The existence and location of faults with Quaternary displacement were primarily identified
using the USGS Quaternary Fault and Fold database (USGS et al., 2013). All faults identified
with potential Quaternary-age offset that exist within a 200-mile (322-km) radius of the site are
shown in Figure 1. Those faults were further screened to those that meet the criteria listed in
Table 4 and shown in Figure 2.

Probabilistic Seismic Hazard Analysis
Energy Fuels Resources (USA) Inc. MWH Americas, Inc.
9 March 2015
All faults that meet the requirements outlined in Table 4 were considered in this seismic
investigation. This is a conservative approach, because although the NRC defines a “capable
fault” as one having “movement at or near the ground surface at least once within the past
35,000 years or movement of a recurring nature within the past 500,000 years,” including all
identifiable faults with Quaternary displacement would include fault movement over the past 1.8
million years. The 41 faults considered in the seismic hazard analysis are listed in
Attachment 2.

The USGS separates faults with Quaternary displacement into classes. These classes are
provided below, as described by USGS et al. (2013).

 For a Class A fault, geologic evidence demonstrates the existence of a Quaternary fault
of tectonic origin, whether the fault is exposed by mapping or inferred from liquefaction
or other deformational features.
 For a Class B fault, geologic evidence demonstrates the existence of Quaternary
deformation, but either 1) the fault might not extend deeply enough to be a potential
source of significant earthquakes, or 2) the currently available geologic evidence is too
strong to confidently assign the feature to Class C but not strong enough to assign it to
Class A.
 For a Class C fault, geologic evidence is insufficient to demonstrate 1) the existence of
tectonic faulting, or 2) Quaternary slip or deformation associated with the feature.
 For a Class D fault, geologic evidence demonstrates that the feature is not a tectonic
fault or feature; this category includes features such as joints, landslides, erosional or
fluvial scarps, or other landforms resembling fault scarps but of demonstrable non-
tectonic origin.

The faults with Quaternary displacement that meet the NRC minimum criteria and are included
in this analysis are either Class A or B.

Many of the faults in Colorado are attributed to the Uncompahgre Uplift. The Uncompahgre
Uplift faults are typically northwest-trending normal faults with minimal evidence to constrain the
slip rates. Faults located north of the site in the area of the Paradox Valley are associated with
salt tectonics and are therefore considered non-seismogenic. Faults in the western section of
the study area are assumed to be seismogenic. Tectonic features in this area include Basin
and Range extension, multiple small-scale mountains and plateaus, and the southern extent of
the Wasatch Plateau in central Utah.

Characteristics of individual faults that meet the criteria specified in Table 4, including
subsurface orientation, depth, slip rate, probability of activity, and age were obtained where
possible from USGS et al. (2013), Wong et al. (1989 and 1996), and Hecker (1993). A
comprehensive list of fault characteristics used in the PSHA is included in Attachment 2 and
Attachment 3. Published fault characteristics were used when available. When there were no
published sources for specific faults, a weighted range of values were used. The probability of
activity is the probability that a fault is seismogenic. For purposes of this analysis, non-
seismogenic faults were assigned a value of probability of activity of 0.5 or less and
seismogenic faults are assigned a probability activity of 1.0.

4.2 Seismic Sources
The hazard from background events unassociated with known faults was assessed by dividing
the area of the 200-mile (322-km) radius around the site into two areal source zones that were
Probabilistic Seismic Hazard Analysis
Energy Fuels Resources (USA) Inc. MWH Americas, Inc.
10 March 2015
assessed independently. The first zone is a portion of the Intermountain Seismic Belt (ISB),
discussed previously in Section 2.1. This area includes the western portion of the study area,
as shown in Figure 4. The second areal source zone is the Colorado Plateau (CP), and includes
the remaining portion of the study area, as shown in Figure 4. The CP is characterized by a
dispersed distribution of historic seismic events, and the ISB is characterized by a denser
distribution of seismic events.

Boundaries of the areal source zones were developed based on regional geology, tectonic
regime, and similar patterns of historical seismicity. As discussed in Section 2.1, the Colorado
Plateau physiographic province extends through eastern and southern Utah through northern
Arizona. The Basin and Range province extends through western Utah, Nevada, and southern
Arizona. Within the study area, the ISB runs adjacent to the Colorado Plateau and Basin and
Range boundary (Wong and Olig, 1998 and Sbar, 1984). The boundary presented in Figure 4,
is based on observed seismicity and the delineation provided by Sbar (1984). Catalog seismicity
within each source zone was used to estimate the Gutenberg-Richter a and b parameters.
Earthquake locations within each zone are assumed to be uniformly located within the space.
Parameters for defining seismicity within each source zone include the following: minimum and
maximum depth, activity rate (number of events per year > Mmin) and b-value estimated from
the historical seismicity catalog for that zone, probability of activity, and parameters for rupture
length estimation based on magnitude.

4.2.1 Colorado Plateau
The site is located within the CP, as shown on Figure 4. This zone exhibits relatively sparse
concentrations of earthquake events. Within a 200-mile (322-km) radius, 134 events were
included in the catalog between 1910 and February 2015 within the CP source zone. One event
was of Mw ≥ 5.5. The largest earthquake event within the CP source zone developed for this
project was a Mw 5.5 event that occurred on August 18, 1912 approximately 131 miles (188 km)
from the site. Based on the historical seismicity, the closest event was an Mw 3.7 event that
occurred on June 6, 2008 approximately 12 miles (19 km) from the site.

As discussed previously, the a- and b-values for the Gutenberg-Richter recurrence relationship
were estimated using the maximum likelihood method developed by Weichert (1980) and the
collected seismicity for the project-specific CP source zone. The estimated b-value for the CP is
0.88 and the calculated activity rate is 0.07 earthquake events per year greater than Mw 5.0. The
cumulative event rates with magnitude for the CP are shown in Figure 5, along with the 5
percent and 95 percent confidence intervals at each magnitude increment. Figure 5 only shows
the fit to the data and the development of the a and b parameters; the figure does not show a
representation of the truncated exponential recurrence relationship used in the PSHA. A
maximum magnitude of Mw 6.75 was used for the CP, based on Wong and Olig (1998). A
maximum magnitude of 6.0 to 6.5 is recommended in the study area and a standard error of ±
0.25 was added for an upper estimate of Mw of 6.75. The maximum magnitude value is also
equivalent to the Intermountain Seismic Belt’s maximum magnitude. The minimum and
maximum depth of events specified for the CP is 1.9 miles and 12 miles (3 km and 20 km),
respectively. The CP background source has a maximum magnitude of 6.75 and magnitudes
below 7.0 are not likely to rupture the surface, therefore the minimum depth was assigned to be
1.9 miles (3 km). 

Probabilistic Seismic Hazard Analysis
Energy Fuels Resources (USA) Inc. MWH Americas, Inc.
11 March 2015
4.2.2 Intermountain Seismic Belt
Within the study area, the ISB exhibited a denser distribution of historical earthquake events
than the CP. Within the ISB source zone, 200 events were included in the catalog between
1887 to February 2015. Four events were Mw 5.5 or greater. Of the events within the study area,
the largest earthquake event within the ISB was an Mw 6.5 that occurred on November 14, 1901
approximately 164 miles (264 km) from the site.

The estimated b-value for the ISB is 0.84 and the calculated activity rate is 0.15 earthquake
events per year greater than Mw 5.0. The cumulative event rates with magnitude for the ISB are
shown in Figure 6, along with the 5 percent and 95 percent confidence intervals at each
magnitude increment. Figure 6 only shows the fit to the data and the development of the a and b
parameters; the figure does not show a representation of the truncated exponential recurrence
relationship used in the PSHA. A maximum magnitude of Mw 6.75 was used for the ISB based
on the recommendation of dePolo (1994) of an Mmax 6¾. Mw 6.75 is a generally-accepted
maximum magnitude within the Basin and Range Province. The minimum and maximum depth
of events specified for the ISB is 1.9 miles and 12 miles (3 km and 20 km), respectively. The
ISB areal zone has a maximum magnitude of 6.75 and magnitudes below 7.0 are not likely to
rupture the surface, therefore the minimum depth was assigned to be 1.9 miles (3 km).

4.3 Shear Wave Velocity
The following paragraphs summarize the method used to calculate a site-specific shear wave
velocity for use in the PSHA. The time-averaged shear-wave velocity in the top 30 meters at
the site (Vs30) was calculated from measured seismic refraction data. The uncertainty in the Vs30
estimation was addressed in the PSHA by calculating a lower bound, best estimate, and upper
bound Vs30, as described below.

4.3.1 Summary of Site-Specific Vp Values
As discussed in Section 2.2, the site is underlain by the Dakota Sandstone, predominately
composed of cross-bedded, fine-to coarse-grained, well-cemented sand (Denison, 2011).
Borings were drilled across the site by Dames & Moore in 1977 to depths ranging from 6.5 to
132.4 feet (Dames & Moore, 1978). The boring locations are shown on Figure 7, and the boring
logs are provided in Attachment 4. The boring logs show sandstone underlying the site to
depths greater than 132 feet.

Site-specific compression wave velocity (Vp) data are available for the White Mesa site from
Nielsons Incorporated (1978). During site characterization for construction of the tailings cells,
Nielsons performed thirteen seismic refraction surveys at several locations across the site to
estimate the compressive wave velocity and depth to bedrock, and to evaluate the excavation
characteristics of the material underlying the proposed cells. Nielsons reported Vp values for
various soils and rock to a depth of 33 feet. Locations of the seismic refraction surveys and
measured Vp data are shown in Figure 7.

Seismic refraction survey results show unconsolidated and/or compact soil to depths ranging
from 4 to 18 feet, overlying Dakota Sandstone. This upper soil material was excavated during
grading and construction of the tailings cells, as documented in the design and construction
completion reports (D’Appolonia, 1979, 1981, 1982; Energy Fuels Nuclear, 1983; Geosyntec,
2006, 2007) and by personal communication with site personnel (Roberts, personal
communication, 2013). Sheet 7 and Sheet 8 of D’Appolonia (1979) are cross sections through
Probabilistic Seismic Hazard Analysis
Energy Fuels Resources (USA) Inc. MWH Americas, Inc.
12 March 2015
the tailings cells showing the planned excavation of the tailings cells below through the upper
soil material and into shallow bedrock.

The Nielsons report divides the Dakota Sandstone into four categories based upon compressive
wave velocity, as summarized below (with the reported range of measured Vp values):

 Soft Rippable Rock (Vp = 3,100 to 4,000 ft/s)
 Medium Soft Rippable Rock (Vp = 3,500 to 4,500 ft/s)
 Medium Hard Rippable Rock (Vp = 5,000 ft/s)
 Drill & Shoot Rock (Vp = 6,500 to 8,400 ft/s)

At all of the seismic survey locations, Vp increased with depth. At seven out of the thirteen
locations, “Drill & Shoot Rock” was encountered as the deepest material (Vp = 6,500 to 8,400
ft/s). The Vp value was less than 4,000 ft/s at the greatest depths profiled at only two of the
survey locations.

As shown on Figure 7, two of the seismic refraction surveys (S-12 and S-13) were conducted
more than 2,000 feet north of the existing mill and impoundment area and are not considered
relevant to the tailings impoundment reclamation design. The remaining eleven seismic
locations (S-1 through S-11) are relevant to the current study because they are within or near
the footprint of the existing tailings cells, or they are in areas of potential future tailings facility
expansion. For these eleven locations, the Vp values for the Dakota Sandstone ranged from
3,100 ft/s to 8,400 ft/s at the greatest depth profiled, with an average value of 6,009 ft/s and a
median value of 6,500 ft/s.

Based on these site-specific Vp values, a Vp of 6,500 ft/s was chosen as the best estimate of the
compression wave velocity for the upper 100 feet (30 meters) of material underlying the site.
This value is the median value of compressive wave velocities measured at a depth of 33 feet
(10 meters) (the greatest depth profiled at each relevant location) underlying or near the cells.
Compressive wave velocities at depths greater than 33 feet (10 meters) are expected to be
equal to or greater than the velocity at 33 feet (10 meters), since measured Vp increases with
depth at each survey location. Thus, the velocity measured at the bottom of the profile at a
depth of 33 feet (10 meters) is considered potentially conservative, but is the most
representative measurement of Vp for the entire upper 30 meters (100 feet) of material at the
site.

To account for uncertainty in the Vp data measured across the site, a lower bound and upper
bound Vp was estimated from the site data. Vp values of 4,400 ft/s to 7,400 ft/s envelope the
compression wave velocity for the site. This range of values encompasses all but three of the
Vp data measured at the site at the deepest depth profiled, and is approximately equivalent to
plus or minus one standard deviation from the average. The three values not included are the
two lowest values (3,100 ft/s and 4,000 ft/s) measured more than 300 ft from the tailings cells,
and the highest value measured at the site (8,400 ft/s).

4.3.2 Development of Vp/Vs Ratio
To estimate the shear wave velocity (Vs) from the compression wave velocity (Vp) measured at
the site, it is necessary to assume a Vp/Vs ratio. A Vp/Vs ratio can be calculated from a
Poisson’s ratio, or an appropriate Vp/Vs ratio can be found in the literature. Several published
references were reviewed to determine typical Poisson’s ratios for sandstone. We also
reviewed several references to determine the typical range of the Vp/Vs ratio and the typical
Probabilistic Seismic Hazard Analysis
Energy Fuels Resources (USA) Inc. MWH Americas, Inc.
13 March 2015
range of Vs for sandstone. These references were reviewed to select the most appropriate
Vp/Vs ratio, and verify that the computed values for VS30 fall within the expected range for the
material.

Poisson’s ratios from select references are summarized below:
 Goodman (1989) provides a table of Poisson’s ratios for various rock specimens, as
determined from laboratory unconfined compression testing. The following Poisson’s
ratio values are presented for three sandstone samples: 0.38 (Mississipian Berea
Sandstone from Ohio), 0.46 (Jurassic Navajo Sandstone from Arizona), and 0.11
(Pennsylvian Tensleep Sandstone from Wyoming).
 Burger (1992) presents a table of laboratory-measured elastic properties for common
rocks. A Poisson’s ratio of 0.06 is presented for a sandstone sample from Wyoming.
 Hatcher (1990) presents a table of Poisson’s ratios for various rock types. A value of
0.26 is presented for Mississippian sandstone from Berea, Ohio.
 Unpublished notes by Dr. David Boore of the USGS (Boore, 2007) were
reviewed. These notes present an evaluation of Poisson’s ratio calculated from Vp and
Vs data from over 300 boreholes in California which were logged using surface source,
downhole receiver method or P-S suspension logging. The notes indicate a range of
Poisson’s ratio from about 0.2 to 0.48 for the various materials, including unconsolidated
sediments, with the data centered around a Poisson’s ratio of about 0.3. Dr. Boore
concludes that the Poisson’s ratio is generally less than 0.4 for materials above the
water table.

Several studies were also reviewed to determine typical Vp/Vs ratios for sandstone, and to
determine the typical range of Vs values for sandstone:
 Castagna et al. (1985) present a variety of data related to the relationship between Vs
and Vp for clastic silicate rocks. For dry sandstones, the paper reports that both
laboratory data and modeling results indicate a nearly constant Vp/Vs ratio of 1.4 to 1.5.
The reported Vs values for dry sandstone range from approximately 500 to 3,500 m/s,
with most values in the range of approximately 1,500 to 3,500 m/s.
 Wu and Liner (2011) present a case study that compares shear wave and compression
wave velocities for the Dickman field in Ness County, Kansas. For sandstones, the
paper reports Vp/Vs ratios ranging from 1.6 to 2.0. The paper presents estimated Vs
values that range from approximately 1,000 to 2,300 m/s for depths less than 500 m.
 Lin and Heuze (1986) reviewed sonic borehole logs for boreholes drilled in Colorado and
Wyoming through shales and sandstones of the Mesaverde formation. The authors
computed in-situ Vp and Vs values from the sonic data, and a review of these results
indicates Vp/Vs ratios ranging from 1.5 to 1.8 for both shales and sandstones. The
associated Vs values (measured in-situ) range from approximately 1,800 to 2,800 m/s for
all depths evaluated in the study.
 Han et al. (1986) present Vp and Vs values measured on 75 laboratory samples of
sandstone. The samples had a variety of clay content values and were measured at
confining pressures ranging from 5 to 40 MPa. Nearly all of the computed Vp/Vs ratios
fall within the range of 1.5 to 2.0. The reported laboratory-measured Vs values range
from approximately 1,500 to 3,600 m/s.
Probabilistic Seismic Hazard Analysis
Energy Fuels Resources (USA) Inc. MWH Americas, Inc.
14 March 2015
 Willis and Clahan (2006) present mean Vs30 values for a variety of California geological
units. Vs was measured at 24 sites underlain by Tertiary bedrock, and the paper
presents a mean Vs30 value of 515 m/s for Tertiary sandstone. Vs was measured at
6 sites underlain by Cretaceous sandstone, and the paper presents a mean Vs30 of
566 m/s for this material.

The references regarding Poisson’s ratio indicate that the ratio for sandstone, in particular the
laboratory-measured ratio, can have a broad range, from as low as 0.06 to as high as 0.46. Of
particular interest is the range of values presented in Boore (2007) (about 0.2 to 0.48) because
this range of values was derived from in-situ downhole data.

The studies regarding the Vp/Vs ratio indicate that typical ratios for sandstones generally range
from about 1.4 to 2.0. The Vs values presented in the studies indicate Vs values ranging from
about 500 to 3,600 m/s, with most values greater than 1,000 m/s.

Based on this review, a Poisson’s ratio of 0.35 was selected to compute a best estimate Vp/Vs
ratio. The Poisson’s ratio of 0.35 falls within the range of laboratory-measured data presented
by Goodman (1989), Burger (1992) and Hatcher (1990), and is near the center of the in-situ
data presented by Boore (2007). Using a Poisson’s ratio of 0.35, a Vp/Vs ratio of 2.1 was
computed. This value is slightly higher than the range of values discussed above, and is
therefore considered potentially conservative.

To account for epistemic uncertainty in the Vp/Vs ratio, a range of values of 1.9 to 2.3 was
evaluated. This range of Vp/Vs ratios is representative of a Poisson’s ratio ranging from 0.31 to
0.38.

4.3.3 Estimation of Site-Specific Vs Values
Site-specific Vs30 values were computed from the upper bound, lower bound, and best estimate
Vp values using the Vp/Vs ratios described in Section 4.3.2. The results envelope the Vs30 data
as follows:

 A lower bound Vs30 calculated from the lower bound Vp of 4,400 ft/s (1,340 m/s) and a
Vp/Vs ratio of 2.3.
 A best estimate Vs30 calculated from the best estimate Vp of 6,500 ft/s (1,980 m/s) and a
Vp/Vs ratio 2.1.
 An upper bound Vs30 calculated from the upper bound Vp of 7,400 ft/s (2,255 m/s) and a
Vp/Vs ratio of 1.9.

The resulting Vs30 values range from 583 m/s to 1,187 m/s, as shown in Table 5. For purposes
of the PSHA, Vs30 values of 580 m/s, 940 m/s, and 1,190 m/s were evaluated in the PSHA to
envelope the PGA. These values were compared to the Vs values published in the references
discussed above. The values used in the analysis fall within the low end of the expected range
of values for sandstone (500 to 3,600 m/s).

Probabilistic Seismic Hazard Analysis
Energy Fuels Resources (USA) Inc. MWH Americas, Inc.
15 March 2015
Table 5. Envelope of Vp and Vs Values for the White Mesa Site
Measured
Vp
Computed
Vs
Vs Used in
Analysis
(ft/s) (m/s) (m/s) (m/s)
Lower Bound 4,400 1,340 583 580
Best Estimate 6,500 1,980 943 940
Upper Bound 7,400 2,255 1,187 1,190

Probabilistic Seismic Hazard Analysis
Energy Fuels Resources (USA) Inc. MWH Americas, Inc.
16 March 2015
5.0 GROUND MOTION PREDICTION EQUATIONS
GMPEs are applied to earthquakes to estimate the ground motion at the site. GMPEs are
mathematical expressions that define how seismic waves propagate from the source to the site.
Several factors combine to cause the decrease in amplitude or intensity as the wave travels to
the site, including refraction, reflection, diffraction, geometric spreading, and absorption.

GMPEs estimate the ground motion as a function of magnitude, distance, and site conditions
(e.g. soil, rock, or Vs30). The relationships are derived by fitting equations to data obtained by
strong-motion instruments for a specific region.

For the crustal faults, the following Next Generation of Attenuation (NGA) relationships were
used: Abrahamson, et al. (2014), Boore, et al. (2014), Campbell and Bozorgnia (2014), and
Chiou and Youngs (2014). Idriss (2014) was not used because the maximum applicable
distance is limited to 93 miles (150 km) and the areal source zones extend to a 200-mile (322-
km) radius.

Current NGA West 2 relationships were used as the GMPEs for the crustal faults and the areal
source zones. The GMPEs were equally weighted. It should be noted that the GMPEs
implemented in this study use the best available information, as these models have been shown
to be applicable worldwide. Table 6 lists the relationships and the associated weights. The
logarithmic mean of the four NGA relationships was used.

Table 6. GMPEs used in the PSHA
GMPE Weight 
Abrahamson, et al. (2014) 0.25 
Boore, et al. (2014) 0.25 
Campbell and Bozorgnia (2014) 0.25
Chiou and Youngs (2014) 0.25

Probabilistic Seismic Hazard Analysis
Energy Fuels Resources (USA) Inc. MWH Americas, Inc.
17 March 2015
6.0 PROBABILISTIC SEISMIC HAZARD ANALYSIS
The following sections describe the PSHA methodology, inputs for analysis, and results.

6.1 PSHA Code and Methodology
The methodology for PSHA was developed by Cornell (1968), and is used to provide a
framework in which uncertainties in size, location, and rate of recurrence of earthquakes can be
considered to provide a probabilistic understanding of seismic hazard.

A PSHA can be described as a procedure of four steps (Kramer 1996):

 Identification and characterization of earthquake sources, along with the assignment of a
probability distribution to each source zone
 Characterization of earthquake recurrence
 Estimation of ground motion produced at the site by earthquakes of any possible size
occurring at any possible point in each source zone
 Calculation of the probability that the ground motion parameter will be exceeded during a
particular time period given uncertainties in earthquake location, earthquake size and
ground motion parameters

Calculations for this report were performed using the computer code HAZ43, developed by Dr.
Norman Abrahamson. Earlier versions of this code were verified under the PEER PSHA Code
Verification Workshop (Thomas et al., 2010).

6.2 PSHA Inputs
A PSHA uses a combination of areal sources and fault sources. Exponential relationships were
developed to characterize the seismicity of the areal source zones. Historical seismicity was
used to characterize activity based on Gutenberg-Richter relationships within each of the
seismic zones that are shown in Figure 4. Areal sources are described in Section 4.2 and the
GMPEs considered are explained in Section 5.0.

Additional input parameters [depth to (1.0 km/s) (Z1.0) and depth to (2.5 km/s) (Z2.5)] were
estimated from the input Vs30 value. Each of these values are summarized in Table 7.

Table 7. PSHA Input Parameters
Input Parameter Value
VS30 ft/s (m/s) 1,903 ft/s
(580m/s)
3,083 ft/s
(940 m/s)
3,904 ft/s
(1,190 m/s)
Z1.0 (km) 0.152 km 0.012 km 0.0 km
Z2.5 (km) 0.827 km 0.476 km 0.363 km

Probabilistic Seismic Hazard Analysis
Energy Fuels Resources (USA) Inc. MWH Americas, Inc.
18 March 2015

6.2.1 Areal Source Zones
Characteristics of the two areal source zones (the CP and the ISB) included in this analysis are
described in Section 4.2. The earthquake recurrence for the areal source zones is based on the
rate of historical seismicity within each zone. The estimation of the recurrence parameters for
each source zone was presented in Section 4.2. Although recurrence parameters were
developed considering events with magnitudes as low as Mw 3.0, a minimum magnitude of Mw
5.0 was used in the probabilistic analysis, as events with magnitudes less than Mw 5.0 are
unlikely to generate a significant hazard at the site. The maximum magnitude assigned to the
areal source zones was Mw 6.75.

6.2.2 Fault Sources
Quaternary faults that meet the minimum criteria presented in Table 4 were included in the
analysis. The mapped fault lineation (USGS et al., 2013) was simplified in the analysis by
tracing the mapped lineation and redrawing the faults as they appear in Figure 8.

Fault recurrence were modeled as both characteristic and truncated exponential. Characteristic
events were assigned a probability of 0.7 and the exponential model was weighted 0.3. The
weighting was set to balance out the two different models. The truncated distribution predicts a
higher ratio of lower magnitudes to higher magnitudes than is observed on a single fault. In
contrast, the characteristic model, in its most simple application, predicts fewer earthquakes on
a fault than are generally observed. Additional information on the fault parameters, including
dip, slip rate, depth, type of fault, and probability of activity, is included in Attachment 2.

6.3 Probabilistic Seismic Hazard Analysis Results
Ground motions at the site are calculated for the average horizontal component of motion in
terms of PGA. In order to bracket the PGA and account for uncertainty in the site-specific Vs30,
the PGA was calculated for the range of Vs30values presented in Section 4.3.3. The results are
summarized below in Table 8 and shown on Figure 9.

Table 8. PSHA Results
Return Period Vs30
(ft/s)
Vs30
(m/s)
Mean PGA
(g)
10,000
1,903 580 0.19
3,084 940 0.15
3,904 1,190 0.14

The PSHA is used to calculate the annual frequency of exceeding a specified ground motion
level. The results of the PSHA are typically presented in terms of ground motion as a function
of annual exceedance probability. Figure 10 shows the total hazard curve plotted for the lower
bound Vs30 of 1,903 ft/s (580 m/s) which resulted in the highest mean PGA. At the 10,000-year
return period, the hazard is controlled by the background earthquake from the CP areal source
zone. The ISB and crustal faults have little effect on the total hazard due to the distance from
the site.

The hazard was deaggregated to evaluate the magnitude and distance contributions to the
lower bound Vs30 or highest mean PGA. The deaggregation of the hazard allows the probability
Probabilistic Seismic Hazard Analysis
Energy Fuels Resources (USA) Inc. MWH Americas, Inc.
19 March 2015
density to be calculated for selected distance and magnitude bins. The deaggregated hazard is
shown on Figure 11. The plots also include mean magnitude, mean distance, and mean epsilon
values. Figure 11 shows that the hazard is generally dominated by earthquakes greater than
Mw 5.0 located less than 19 miles (30 km) from the site.

Probabilistic Seismic Hazard Analysis
Energy Fuels Resources (USA) Inc. MWH Americas, Inc.
20 March 2015
7.0 RESULTS AND COMPARISON WITH PREVIOUS STUDIES
Based on the results of this PSHA, the mean PGA for reclaimed (long-term) conditions is
estimated to range from 0.14 g to 0.19 g. This PGA is associated with an average return period
of 10,000 years, or a probability of exceedance of 2 percent to 10 percent for a design life of
200 to 1,000 years, respectively. The Vs30 values used for the analysis ranged from 1,903 ft/s to
3,904 ft/s (580 m/s to 1,190 m/s). Selection of the PGA or a pseudostatic coefficient used for
reclamation design shall be performed during final design and be based on the results
presented in Table 8.

Results of this site-specific PSHA were compared to previous analyses conducted for the site
(MWH, 2012). Results of MWH, 2012 indicate a PGA of 0.15 g for a return period of 9,900
years, using an estimated Vs30 of 2,493 ft/s (760 m/s). The PGA for reclaimed conditions from
MWH (2012) is equal to the best estimate PGA value calculated in this PSHA.

Additionally, results of this site-specific PSHA were compared to USGS 2014 NSHMP gridded
hazard curves. The USGS 2014 NSHMP indicate a PGA of 0.10 g for a return period of 2,475
years, which compare well to this study’s result of 0.10 g at a VS30 of 3,904 ft/s (580 m/s) for the
same return period. For a return period of 10,000 years, using an estimated Vs30 of 2,493 ft/s
(760 m/s), the 2014 NSHMP PGA is about 0.23 g, which is approximately 0.04 g greater than
the highest PGA calculated in this PSHA. The USGS NSHMP methodology was developed for
return periods up to 2,475 years, meaning that estimating the 10,000-year return period from the
2014 NSHMP is outside the intended use of the data and likely explain the differences in the
PGA.

Probabilistic Seismic Hazard Analysis
Energy Fuels Resources (USA) Inc. MWH Americas, Inc.
21 March 2015
8.0 REFERENCES
Abrahamson, N.A., W.J. Silva, and R. Kamai (2014) Summary of the ASK14 Ground-Motion
Relation for Active Crustal Regions. Earthquake Spectra. Volume 30, Issue3. August.

Ake, J., K. Mahrer, D. O’Connell, and L. Block, 2005. Deep-injection and Closely Monitored
Induced Seismicity at Paradox Valley, Colorado: Bulletin of the Seismological Society of
America, v. 95, p. 664-683.

Arabasz, W.J., S.J. Nava, M.K. McCarter, K.L. Pankow, J.C. Pechmann, J. Ake, and A. McGarr,
2005. Coal-Mining Seismicity and Ground-Shaking Hazard: A Case Study in the Trail
Mountain Area, Emery County, Utah. Bulletin of the Seismological Society of America, v.
95, pp. 18-30.

Boore, P.M., J.P. Stewart, E. Seyhan, and G.M. Atkinson (2014). NGA-West 2 Equations for
Predicting PGA, PGV, and 5%-Damped PSA for Shallow Crustal Earthquakes.
Earthquake Spectra. Volume 30, Issue 3. August.

Boore, D. M., 2007. Dave Boore’s notes on Poisson’s ratio (the relation between Vp and
Vs. Unpublished notes available at www.daveboore.com. March 24.

Campbell, K. W., and Y. Bozorgnia, (2014). NGA-West2 Ground Motion Model for the Average
Horizontal Components of PGA, PGV, and 5%-Damped Linear Acceleration Response
Spectra. Earthquake Spectra. Volume 30, Issue 3. August

Castagna, J.P., M.L. Batzle and R.L. Eastwood. 1985. Relationships between compressional-
wave and shear-wave velocities in clastic silicate rocks. Geophysics, Vol. 50, No. 4, pp.
571-581.

Chiou, B. S., and R.R. Youngs, 2014. Update of the Chiou and Youngs NGA Model for the
Average Horizontal Component of Peak Ground Motion and Response Spectra.
Earthquake Spectra. Volume 30, Issue 3. August.

Colorado Geological Survey (CGS), Undated. Earthquakes Triggered by Humans in Colorado –
A Background Paper.

Cornell, C.A. 1968. Engineering seismic risk analysis, Bulletin of Seismological Society of
America, v.58 p. 1583-1606.

Dames & Moore, 1978. Environmental Report, White Mesa Uranium Project, San Juan County,
Utah, for Energy Fuels Nuclear, Inc. January 30.

D’Appolonia. 1979. Engineers Report, Tailings Management System, White Mesa Uranium
Project, Blanding, Utah. June.

D’Appolonia. 1981. Engineer’s Report, Second Phase Design – Cell 3, Tailings Management
System, White Mesa Uranium Project, Blanding, Utah. May.

Probabilistic Seismic Hazard Analysis
Energy Fuels Resources (USA) Inc. MWH Americas, Inc.
22 March 2015
D’Appolonia. 1982. Construction Report, Initial Phase – Tailings Management System, White
Mesa Uranium Project. Prepared for Energy Fuels Nuclear, Inc. February.

Denison Mines (USA) Corporation. (Denison) 2011. Reclamation Plan, White Mesa Mill,
Blanding Utah, Radioactive Materials License No. UT1900479, Rev. 5. September.

dePolo, C.M., 1994. The Maximum Background Earthquake for the Basin and Range Province,
Western North America. Bulletin of the Seismological Society of America, v. 84, no. 2, p.
446-472. April.

Energy Fuels Nuclear, Inc., 1983. Construction Report, Second Phase, Tailings Management
System. March.
Energy Fuels Resources (USA) Inc. (EFRI), 2012. Responses to Interrogatories – Round 1 for
Reclamation Plan, Revision 5.0, March 2012. August 15.
Geosyntec Consultants, 2006. Cell 42A Lining System Design Report for the White Mesa Mill,
Blanding, Utah. January.

Geosyntec Consultants, 2007. Cell 4B Design Report, White Mesa Mill, Blanding, Utah.
December.

Han, D-h, A. Nur and D. Morgan, 1986. Effects of porosity and clay content on wave velocities
in sandstones. Geophysics, Vol. 51, No. 11, pp. 2093-2107.

Hecker, S., 1993. Quaternary Tectonics of Utah with Emphasis on Earthquake-hazard
Characterization. Utah Geological Survey Bulletin 127.

Idriss I. M., 2014. An NGA Empirical Model for Estimating the Horizontal Spectral Values
Generated By Shallow Crustal Earthquakes. Earthquake Spectra. Volume 30, Issue 3.
August.

Kramer, S.L., 1996. Geotechnical Earthquake Engineering, Upper Saddle River, New Jersey,
Prentice Hall.

Lin, W. and F.E. Heuze, 1986. In-Situ Dynamic Elastic Moduli of Mesaverde Rocks and a
Comparison with Static and Dynamic Laboratory Moduli. Lawrence Livermore National
Laboratory (Unconventional Gas Program, Western Gas Sands Research). UCID-
20611.

MFG, Inc., 2006. White Mesa Uranium Facility, Cell 4 Seismic Study, Blanding, Utah.
November 27.

MWH, 2012. Memorandum: Site-Specific Probabilistic Seismic Hazard Analysis, White Mesa
Uranium Facility, Blanding, Utah. May 30.

Nielsons Incorporated, 1978. Seismograph Survey of Blanding Mill Site, San Juan County,
Utah. Prepared for Energy Fuels Nuclear, Inc.

Petersen, M.D., M.O. Moschetti, P.M. Powers, C.S. Mueller, K.M. Haller, A.D. Frankel, Y. Aeng,
S. Rezaeian, S.C. Harmsen, O.S. Boyd, N. Field, R. Chen, K.S. Rukstales, N. Luco, R.S.
Probabilistic Seismic Hazard Analysis
Energy Fuels Resources (USA) Inc. MWH Americas, Inc.
23 March 2015
Wheeler, R.A. Williams, and A.H. Olsen, 2014. Documentation for the 2014 Update of
the United States National Seismic Hazard Maps. United States Geological Survey
Open-File Report 2014-1091.

Reasenberg, P., 1985. Second-order moment of central California seismicity, 1969-82, J.
Geophys. Res., 90, 5479 - 5495.

Roberts, H., 2013. Personal communication from Harold Roberts, Energy Fuels (USA) Corp., to
Melanie Davis, MWH Americas, Inc. May 29.

Swanson, P., C. Stewart, and W. Koontz, 2008. Monitoring Coal Mine Seismicity with an
Automated Wireless Digital Strong-Motion Network. In: Proceedings of the 27th
International Conference on Ground Control in Mining, July 29 - July 31, 2008,
Morgantown, West Virginia, pg. 79-86.

Tetra Tech, Inc., 2008. Seismic Hazard Analysis for Shootaring Canyon Uranium Processing
Facility. April.

Thomas, P., I. Wong, and N. Abrahamson, 2010. Verification of Probabilistic Seismic Hazard
Analysis Computer Programs. May.

Sbar, M.L. 1982. Delineation and Interpretation of Seismotectonic Domains in Western North
America. Journal of Geophysical Research, v. 87, no. B5, p. 3919-3928. May.

Stepp, J.C., 1972. Analysis of the completeness of the earthquake hazard sample in the Puget
Sound area and its effects on statistical estimates of earthquake hazard, Proc. Intern.
Conf. Microzonation for Safer Construct. Res. Appl., Seattle, Washington 2, 897-909.

URS, 2015. Review Comments on White Mesa Mill, Probabilistic Seismic Hazard Analysis
Report. January.

U.S. Department of Energy (DOE), 1989. Technical Approach Document: Revision II, UMTRA-
DOE/AL 050425.0002, Uranium Mill Tailings Remedial Action Project. Washington, D.C.

U.S. Geological Survey (USGS). 2013. Arizona Geological Survey, Colorado Geological Survey,
Utah Geological Survey, New Mexico Bureau of Mines and Mineral Resources, 2006.
Quaternary fault and fold database for the United States, accessed May 7, 2013, from
USGS web site: http://earthquake.usgs.gov/hazards/qfaults.

U.S. Nuclear Regulatory Commission (NRC). 2013. 10 CFR Appendix A to Part 100 – Seismic
and Geologic Siting Criteria for Nuclear Power Plants. http://www.nrc.gov/reading-
rm/doc-collections/cfr/part100/part100-appa.html. Accessed March.

U.S. Nuclear Regulatory Commission (NRC), U.S. Department of Energy (DOE), and Electric
Power Research Institute (EPRI); (CEUS-SSCn). 2012. Technical Report: Central and
Eastern United States Seismic Source Characterization for Nuclear Facilities.

Utah Department of Environmental Quality, Division of Radiation Control (DRC). 2013. Review
of August 15, 2012 (and May 31, 2012) Energy Fuels Resources (USA), Inc. Responses
to Round 1 Interrogatories on Revision 5 Reclamation Plan Review, White Mesa Mill,
Blanding, Utah, report dated September, 2011. February 13.
Probabilistic Seismic Hazard Analysis
Energy Fuels Resources (USA) Inc. MWH Americas, Inc.
24 March 2015

Weichert, D. 1980. Estimation of the earthquake recurrence parameters for unequal observation
periods for different magnitudes. Bulletin of the Seismological Society of America 70:
1337-1346.

Wong, l.G., and J.R. Humphrey, 1989. Contemporary seismicity, faulting, and the state of stress
in the Colorado Plateau, Geological Society of America Bulletin 101: 1127-1146.

Wong, l.G., S.S. Olig, and J.D.J. Bott, 1996. Earthquake potential and seismic hazards in the
Paradox Basin, southeastern Utah, In A.C. Huffman, W.R. Lund, and L.H. Godwin, eds.,
Geology and Resources of the Paradox Basin, 1996 Special Symposium, Utah
Geological Association and Four Corners Geological Society Guidebook 25: 241-250.

Wong, I.G., S.S. Olig, B.W. Hassinger, and R.E. Blublaugh. 1997. Earthquake hazards in the
Intermountain US: Issues relevant to uranium mill tailings disposal. In Proceedings of
the Fourth International Conference of Tailings and Mine Waste ’97, Fort Collins,
Colorado, USA, January 13-17, p. 203-212.

Wong, I.G. and S.S. Olig. 1998. Seismic Hazards in the Basin and Range Province:
Perspectives from Probabilistic Analyses. In Western States Seismic Policy Council
Proceedings. p. 110-127.

Wu, Q. and C. Liner. 2011. Case study: Comparison on shear wave velocity estimation in
Dickman field, Ness County, Kansas. 2011 SEG San Antonio Annual Meeting.

Probabilistic Seismic Hazard Analysis

FIGURES
COLORADO SPRINGS
LAS VEGAS
U T A H
A R I Z O N A N E W
M E X I C O
C O L O R A D O
N

E

V

A

D

A
MOAB
R=200

M
I
L
E
S
LAKE POWELL
COLORADO RIVER
GRAND JUNCTION
CORTEZ
SALINA
DENVER
FLAGSTAFF
ALBUQUERQUE
PAONIA
GLENWOOD SPRINGS
20 MI
50 MI
100 MI
150 MI
Energy Resources (USA) Inc.Fuels
B
WHITE MESA MILL, UTAH
WHITE MESA PSHA
QUATERNARY FAULTS WITHIN STUDY AREA 1009740 - ALL FAULTS
NOTES:
LEGEND:
FIGURE 1
COLORADO SPRINGS
BIG GYPSUM
VALLEY
NEEDLES FAULT ZONE
SHAY GRABEN
FAULTS
BRIGHT ANGEL FAULT SYSTEM
LISBON
VALLEY
DOLORAS
CANNIBAL
RED ROCKS
MONITOR CREEK
RIDGEWAY FAULT
UNNAMED -
SAN MIGUEL
ROUBIDEAU CREEK
SALT AND CACHE VALLEY
WASATCH MONOCLINE
THOUSAND LAKE
AQUARIUS AND AWAPA
SEVIER/TOROWEAP-
SIEVER SECTION
EMINENCE
BRIGHT ANGEL FAULT ZONE
WEST KAIBAB
PRICE RIVER
NACIMIENTO- N. SECTION
SAND FLAT GRABEN
RYAN CREEK
UNNAMED- PINE MTN.
PARADOX
VALLEY
SINBAD
VALLEY
GRANITE
CREEK
UNNAMED - S. LOVE MESA
UNNAMED -
HANKS CREEK
UNNAMED-
RED CANYON
FISHER
VALLEY
UNNAMED-
PINTO MESA
TEN MILE GRABEN
MOAB FAULT AND
SPANISH VALLEY
BEAVER BASIN- INTRABASIN
BEAVER BASIN- EASTERN MARGIN
PAUNSAUGUNT
SEVIER/TOROWEAP-
NORTHERN SECTION
UNNAMED- ATKINSON
CENTRAL KAIBAB
GRAND JUNCTION
MOAB
CORTEZ
SALINA
DENVER
FLAGSTAFF
R=20
0

M
I
L
E
S
U T A H
A R I Z O N A N E W
M E X I C O
C O L O R A D O
N

E

V

A

D

A
ALBUQUERQUE
20 MI
50 MI
100 MI
150 MI
SOUTHERN
JOES VALLEY
WESTERN JOES VALLEY
PAONIA
GLENWOOD SPRINGS
Energy Resources (USA) Inc.Fuels
B
WHITE MESA MILL, UTAH
WHITE MESA PSHA
FAULTS AND EARTHQUAKE EVENTS
INCLUDED IN PSHA
FIGURE 2
1009740 - FAULTS & EQS
EARTHQUAKES:
LEGEND:
NOTES:
PROJECT
TITLE
DATE
FILENAME
MAR 2015
P:
\Ad
m
i
n
i
s
t
r
a
t
i
v
e
\MW
H

R
e
p
o
r
t
s
\Te
m
p
l
a
t
e

f
o
r

F
i
g
u
r
e
s

FIGURE 3
WHITE MESA PSHA
Figures_set 2.pptx
CATALOG COMPLETENESS PLOTS
0.01
0.1
1
10
1 10 100 1000
An
n
u
a
l

F
r
e
q
u
e
n
c
y

Time before 2014 (yrs)
3 ≤ M < 3.5
3.5 ≤ M < 4
4 ≤ M < 4.5
4.5 ≤ M < 5
5 ≤ M < 5.5
110 years
50 years
30 years
55 years
Magnitude Bins
COLORADO SPRINGS
BIG GYPSUM
VALLEY
NEEDLES FAULT ZONE
SHAY GRABEN
FAULTS
BRIGHT ANGEL FAULTS
LISBON
VALLEY
DOLORAS
CANNIBAL
RED ROCKS
MONITOR CREEK
RIDGEWAY FAULT
UNNAMED -
SAN MIGUEL
UNNAMED- SE MONTROSE
ROUBIDEAU CREEK
SALT AND CACHE VALLEY
WASATCH MONOCLINE
THOUSAND LAKE
AQUARIUS AND AWAPA
SEVIER/TOROWEAP-
SIEVER SECTION
EMINENCE
BRIGHT ANGEL FAULT ZONE
WEST KAIBAB
PRICE RIVER
NACIMIENTO- N. SECTION
SAND FLAT GRABEN
RYAN CREEK
UNNAMED- PINE MTN.
PARADOX
VALLEY
SINBAD
VALLEY
GRANITE
CREEK
UNNAMED - S. LOVE MESA
UNNAMED -
HANKS CREEK
UNNAMED-
RED CANYON
FISHER
VALLEY
UNNAMED-
PINTO MESA
TEN MILE GRABEN
MOAB FAULT AND
SPANISH VALLEY
BEAVER BASIN- INTRABASIN
BEAVER BASIN- EASTERN MARGIN
PAUNSAUGUNT
SEVIER/TOROWEAP-
NORTHERN SECTION
UNNAMED- ATKINSON
CENTRAL KAIBAB
LAS VEGAS
MOAB
SOUTHERN
JOES VALLEY
WESTERN JOES VALLEY
MOAB
GRAND JUNCTION
CORTEZ
SALINA
DENVER
FLAGSTAFF
R=20
0

M
I
L
E
S
U T A H
A R I Z O N A N E W
M E X I C O
C O L O R A D O
N

E

V

A

D

A
ALBUQUERQUE
PAONIA
IN
T
E
R
M
O
U
N
T
A
I
N

S
E
I
S
M
I
C

B
E
L
T
CO
L
O
R
A
D
O

P
L
A
T
E
A
U
GLENWOOD SPRINGS
20 MI
50 MI
100 MI
150 MI
LAKE POWELL
COLORADO RIVER
LAKE POWELL
Energy Resources (USA) Inc.Fuels
B
WHITE MESA MILL, UTAH
WHITE MESA PSHA
AREAL SOURCE ZONES FIGURE 4
1009740 - AREAL
EARTHQUAKES:
LEGEND:
NOTES:
PROJECT
TITLE
DATE
FILENAME
MAR 2015
P:\Ad
m
i
n
i
s
t
r
a
t
i
v
e
\MW
H

R
e
p
o
r
t
s
\Te
m
p
l
a
t
e

f
o
r

F
i
g
u
r
e
s

GUTENBERG-RICHTER RELATIONSHIP
COLORADO PLATEAU FIGURE 5
WHITE MESA PSHA
0.0001
0.001
0.01
0.1
1
10
100
1000
3 4 5 6 7 8 9
Cu
m
u
l
a
t
i
v
e

R
a
t
e
/
Y
e
a
r

Magnitude
logN=3.3-0.88M
Activity Rate (M>=5)=0.07
Figures_set 2.pptx
PROJECT
TITLE
DATE
FILENAME
MAR 2015
P:\Ad
m
i
n
i
s
t
r
a
t
i
v
e
\MW
H

R
e
p
o
r
t
s
\Te
m
p
l
a
t
e

f
o
r

F
i
g
u
r
e
s

GUTENBERG-RICHTER RELATIONSHIP
INTERMOUNTAIN SEISMIC BELT FIGURE 6
WHITE MESA PSHA
0.0001
0.001
0.01
0.1
1
10
100
1000
3 4 5 6 7 8 9
Cu
m
u
l
a
t
i
v
e

R
a
t
e
/
Y
e
a
r

Magnitude
logN=3.4-0.84M
Activity Rate (M>=5)=0.15
Figures_set 2.pptx
S-13
S-12
S-1
S-2
S-4
S-3
S-8
S-7
S-9S-10S-11
S-6
US 0-6 1,750
MSR 6-33 3,700
US 0-5 1,500
CS 5-17 2,450
DS 17-33 7,000
US 0-5 1,300
MSR 5-13 4,200
DS 13-33 6,800
US 0-3 1,250
CS 3-18 2,200
DS 18-33 6,500
US 0-3 900
CS 3-15 1,700
DS 15-33 6,500
US 0-5 800
MSR 5-13 3,500
DS 13-33 8,400
US 0-3 1,300
CS 3-9 2,000
SR 9-33 3,100
US 0-7 1,400
MSR 7-33 4,500
US 0-4 900
SR 4-33 4,000
US 0-6 900
DS 6-33 7,000
US 0-6 1,400
MSR 6-33 4,400
US 0-11 1,500
DS 11-33 7,400
US 0-6 1,300
MHR 6-33 5,000CELL 1
CELL 2
CELL 3
CELL 4A
CELL 4B
MILL SITE
S-5
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
23
24
26
27
28
22
29
Energy Resources (USA) Inc.Fuels
B
WHITE MESA MILL, UTAH
WHITE MESA PSHA
LEGEND:
x
x
x
KEY FOR SEISMIC REFRACTION DATA:
US 0-3 900
MSR 3-15 1,700
DS 15-33 6,500
S-12
SEISMIC REFRACTION DATA AND
BORING LOCATIONS
FIGURE 7
1009740 - SEISMIC
29
COLORADO SPRINGS
GRAND JUNCTION
CORTEZ
SALINA
DENVER
FLAGSTAFF
R=20
0

M
I
L
E
S
U T A H
A R I Z O N A N E W
M E X I C O
C O L O R A D O
N

E

V

A

D

A
ALBUQUERQUE
BIG GYPSUM
VALLEY
NEEDLES FAULT ZONE
SHAY GRABEN
FAULTS
LISBON
VALLEY
DOLORAS
CANNIBAL
RED ROCKS
MONITOR CREEK
UNNAMED -
SAN MIGUEL
ROUBIDEAU CREEK
WASATCH MONOCLINE
THOUSAND LAKE
AQUARIUS AND AWAPA
SEVIER/TOROWEAP-
SIEVER SECTION
EMINENCE
BRIGHT ANGEL FAULT ZONE
WEST KAIBAB
PRICE RIVER
NACIMIENTO- N. SECTION
SAND FLAT GRABEN
UNNAMED- PINE MTN.
SINBAD
VALLEY
UNNAMED - S. LOVE MESA
UNNAMED -
HANKS CREEK
UNNAMED-
RED CANYON
FISHER
VALLEY
UNNAMED-
PINTO MESA
TEN MILE GRABEN
MOAB FAULT AND
SPANISH VALLEY
BEAVER BASIN- INTRABASIN
PAUNSAUGUNT
SEVIER/TOROWEAP-
NORTHERN SECTION
UNNAMED- ATKINSON
CENTRAL KAIBAB
LAS VEGAS
MOAB
BIG GYPSUM
VALLEY
NEEDLES FAULT ZONE
SHAY GRABEN
FAULTS
BRIGHT ANGEL FAULT SYSTEM
LISBON
VALLEY
DOLORAS
CANNIBAL
RED ROCKS
MONITOR CREEK
RIDGEWAY
FAULT
UNNAMED -
SAN MIGUEL
ROUBIDEAU CREEK
SALT AND CACHE VALLEY
WASATCH MONOCLINE
THOUSAND LAKE
AQUARIUS AND AWAPA
SEVIER/TOROWEAP-
SIEVER SECTION
EMINENCE
BRIGHT ANGEL FAULT ZONE
WEST KAIBAB
PRICE RIVER
NACIMIENTO- N. SECTION
SAND FLAT GRABEN
UNCOMPAHGRE
UNNAMED- PINE MTN.
PARADOX
VALLEY
SINBAD
VALLEY
UNNAMED - S. LOVE MESA
UNNAMED -
HANKS CREEK
UNNAMED-
RED CANYON
FISHER
VALLEY
UNNAMED-
PINTO MESA
TEN MILE GRABEN
MOAB FAULT AND
SPANISH VALLEY
BEAVER BASIN- INTRABASIN
PAUNSAUGUNT
SEVIER/TOROWEAP-
NORTHERN SECTION
UNNAMED- ATKINSON
CENTRAL KAIBAB
WESTERN JOES VALLEY
SOUTHERN
JOES VALLEY
BEAVER BASIN-
EASTERN MARGIN
PAONIA
GLENWOOD SPRINGS
20 MI
50 MI
100 MI
150 MI
Energy Resources (USA) Inc.Fuels
B
WHITE MESA MILL, UTAH
WHITE MESA PSHA
FAULT TRACES AS MODELED IN THE PSHA FIGURE 8
1009740 - FAULTS ONLY
LEGEND:
NOTES:
PROJECT
UNIFORM HAZARD SPECTRA
COMPARISON OF Vs30
TITLE
DATE
FILENAME
FIGURE 9
WHITE MESA PSHA
MAR 2015
CLIENT LOGO
Figures_set 1.pptx
0.0
0.1
0.2
0.3
0.4
0.5
0.01 0.1 1
Sp
e
c
t
r
a
l

A
c
c
e
l
e
r
a
t
i
o
n

(
g
)

Period (s)
10000 Year Return Period Vs30=580 m/s
10000 Year Return Period Vs30=940 m/s
10000 Year Return Period Vs30=1190 m/s
PROJECT
TITLE
DATE
FILENAME
MAR 2015
P:
\Ad
m
i
n
i
s
t
r
a
t
i
v
e
\MW
H

R
e
p
o
r
t
s
\Te
m
p
l
a
t
e

f
o
r

F
i
g
u
r
e
s

PEAK GROUND ACCELERATION
SEISMIC SOURCE CONTRIBUTION FIGURE 10
WHITE MESA PSHA
Note: Information shown for lower-bound Vs30 [Vs30 = 1,903 ft/s (580 m/s)]
Figures_set 2.pptx
10
100
1,000
10,000
100,0001.E-05
1.E-04
1.E-03
1.E-02
1.E-01
0 0.2 0.4 0.6 0.8 1
Re
t
u
r
n

P
e
r
i
o
d

(
y
e
a
r
s
)

An
n
u
a
l

P
r
o
b
a
b
i
l
i
t
y

o
f

E
x
c
e
e
d
a
n
c
e

Peak Ground Acceleration (g)
Intermountain Seismic Belt
Colorado Plateau
Crustal Faults
Total
PROJECT
DEAGGREGATION OF PGA
10,000-YEAR RETURN PERIOD
(Vs30=580m/s)
TITLE
DATE
FILENAME
FIGURE 11
WHITE MESA PSHA
MAR 2015
CLIENT LOGO
Figures_set 1.pptx
5.
0
0

-

5
.
5
0
5.
5
0

-

6
.
0
0
6.
0
0

-

6
.
5
0
6.
5
0

-

7
.
0
0
7.
0
0

-

8
.
5
0
0.00E+00
2.00E-02
4.00E-02
6.00E-02
8.00E-02
1.00E-01
1.20E-01
1.40E-01
1.60E-01
%
C
o
n
t
r
i
b
u
t
i
o
n

Distance (km)
5.00 - 5.50
5.50 - 6.00
6.00 - 6.50
6.50 - 7.00
7.00 - 8.50
M-D Bins
10,000-yr Return Period, PGA
Mean Magnitude: 5.78
Mean Distance: 27 km
Mean Epsilon: 0.9

Probabilistic Seismic Hazard Analysis

ATTACHMENT 1

LIST OF EARTHQUAKE EVENTS WITHIN THE WHITE MESA STUDY AREA
Attachment 1

List of Earthquake Events Within the White Mesa Study Area
Notes:
1) Two areal source zones are present within the study area, the Colorado Plateau (CP) and Intermountain Seismic Belt (ISB).
2) Originating Network is the seismic network that first recorded the event.
3) Earthquakes included in the PSHA are limited to those of Mw ≥3.0 within a 200-mile radius of the Site.

Page 1 of 14

Expected
Moment
Magnitude
(E[Mw])
Location Hypocentral
Depth (km)
Date
Mwsig N* Areal Source
Zone1
Originating
Network2 Catalog Latitude Longitude Year Month Day
3.0 39.8 -110.5 0.0 1965 2 26 0.25 1.180 CP SRA CEUS
3.0 39.0 -110.3 7.0 1965 10 22 0.2 1.112 CP SRA CEUS
3.0 37.6 -110.2 7.0 1968 2 23 0.2 1.112 CP SRA CEUS
3.0 36.4 -112.3 6.0 1970 11 24 0.222 1.087 ISB PDE WUS
3.0 36.8 -111.8 5.0 1971 12 15 0.222 1.087 CP PDE WUS
3.0 37.6 -110.5 3.0 1983 12 15 0.2 1.112 CP SRA CEUS
3.0 39.0 -106.5 5.0 1987 7 20 0.25 1.180 CP PDE CEUS
3.0 37.9 -111.2 15.0 1988 8 8 0.2 1.112 CP PDE CEUS
3.0 38.6 -107.9 5.0 1992 5 15 0.25 1.180 CP PDE CEUS
3.0 38.2 -107.7 5.0 1994 1 17 0.25 1.180 CP PDE CEUS
3.0 38.1 -112.2 1.0 2000 5 26 0.111 1.021 ISB COM WUS
3.0 39.2 -106.7 5.0 2002 10 13 0.25 1.180 CP PDE CEUS
3.0 37.6 -111.1 6.0 2005 4 8 0.25 1.180 CP PDE CEUS
3.0 39.0 -107.4 1.0 2005 6 23 0.25 1.180 CP PDE CEUS
3.0 39.0 -107.5 1.0 2006 8 13 0.25 1.180 CP PDE CEUS
3.0 38.9 -107.6 1.0 2006 8 27 0.25 1.180 CP PDE CEUS
3.0 38.8 -107.5 1.0 2007 5 26 0.25 1.180 CP PDE CEUS
3.0 38.3 -110.6 1.0 2009 2 19 0.25 1.180 CP PDE CEUS
3.0 39.8 -107.4 5.0 2010 3 30 0.25 1.180 CP PDE CEUS
3.0 37.6 -112.7 7.0 1964 1 1 0.222 1.087 ISB SRA WUS
3.0 38.8 -112.2 7.0 1964 8 24 0.222 1.087 ISB SRA WUS
3.0 39.2 -111.5 7.0 1964 9 6 0.222 1.087 ISB SRA WUS
3.0 39.0 -112.2 7.0 1964 11 29 0.222 1.087 ISB SRA WUS
3.1 38.9 -110.9 7.0 1964 7 7 0.25 1.180 CP SRA CEUS
Attachment 1

List of Earthquake Events Within the White Mesa Study Area (continued)

Notes: 1) Two areal source zones are present within the study area, the Colorado Plateau (CP) and Intermountain Seismic Belt (ISB).
2) Originating Network is the seismic network that first recorded the event.
3) Earthquakes included in the PSHA are limited to those of Mw ≥3.0 within a 200-mile radius of the Site.

Page 2 of 14
Expected
Moment
Magnitude
(E[Mw])
Location Hypocentral
Depth (km)
Date
Mwsig N* Areal Source
Zone1
Originating
Network2 Catalog Latitude Longitude Year Month Day
3.1 39.3 -110.4 5.0 1967 2 15 0.24 1.165 CP SRA CEUS
3.1 38.4 -112.2 7.0 1976 8 13 0.111 1.021 ISB SRA WUS
3.1 39.6 -109.4 0.0 1982 2 25 0.25 1.180 CP SRA CEUS
3.1 39.7 -107.6 5.0 1982 11 22 0.25 1.180 CP PDE CEUS
3.1 39.0 -106.9 5.0 1986 4 11 0.25 1.180 CP PDE CEUS
3.1 37.5 -106.7 5.0 1988 1 15 0.111 1.021 CP COM WUS
3.1 39.2 -112.0 2.0 1988 7 11 0.111 1.021 ISB COM WUS
3.1 36.0 -112.3 5.0 1988 9 8 0.111 1.021 ISB COM WUS
3.1 38.2 -112.5 1.0 1989 2 3 0.111 1.021 ISB COM WUS
3.1 37.0 -112.9 5.0 1989 3 12 0.111 1.021 ISB COM WUS
3.1 39.2 -110.9 5.0 1989 3 21 0.25 1.180 ISB PDE CEUS
3.1 39.5 -111.5 10.0 1990 2 5 0.111 1.021 ISB COM WUS
3.1 38.2 -112.5 1.0 1990 3 28 0.111 1.021 ISB COM WUS
3.1 39.1 -110.9 11.0 1990 12 3 0.2 1.112 ISB PDE CEUS
3.1 38.0 -112.5 4.0 1992 9 24 0.111 1.021 ISB COM WUS
3.1 38.1 -112.6 5.0 1993 10 5 0.111 1.021 ISB COM WUS
3.1 39.5 -108.6 5.0 1994 3 8 0.25 1.180 CP PDE CEUS
3.1 37.8 -113.0 5.0 1994 11 19 0.111 1.021 ISB COM WUS
3.1 38.0 -112.8 1.0 1995 11 3 0.111 1.021 ISB COM WUS
3.1 38.2 -112.7 0.0 1995 12 3 0.111 1.021 ISB COM WUS
3.1 39.0 -112.0 2.0 1995 12 31 0.111 1.021 ISB COM WUS
3.1 37.8 -111.9 10.0 1997 10 20 0.111 1.021 ISB COM WUS
3.1 38.0 -112.4 2.0 1998 5 22 0.111 1.021 ISB COM WUS
3.1 37.1 -112.3 10.0 1999 2 23 0.111 1.021 ISB COM WUS
3.1 37.8 -112.5 2.0 1999 4 25 0.111 1.021 ISB COM WUS
Attachment 1

List of Earthquake Events Within the White Mesa Study Area (continued)

Notes: 1) Two areal source zones are present within the study area, the Colorado Plateau (CP) and Intermountain Seismic Belt (ISB).
2) Originating Network is the seismic network that first recorded the event.
3) Earthquakes included in the PSHA are limited to those of Mw ≥3.0 within a 200-mile radius of the Site.

Page 3 of 14
Expected
Moment
Magnitude
(E[Mw])
Location Hypocentral
Depth (km)
Date
Mwsig N* Areal Source
Zone1
Originating
Network2 Catalog Latitude Longitude Year Month Day
3.1 38.6 -112.2 1.0 1999 9 5 0.111 1.021 ISB COM WUS
3.1 38.7 -112.5 1.0 2000 3 24 0.111 1.021 ISB COM WUS
3.1 39.3 -107.3 5.0 2000 12 5 0.25 1.180 CP PDE CEUS
3.1 39.5 -108.7 5.0 2002 3 19 0.25 1.180 CP PDE CEUS
3.1 39.2 -106.8 5.0 2003 1 1 0.25 1.180 CP PDE CEUS
3.1 37.0 -111.8 10.0 2003 11 7 0.111 1.021 CP COM WUS
3.1 38.5 -112.5 2.0 2003 11 29 0.111 1.021 ISB COM WUS
3.1 38.3 -110.6 4.0 2003 12 29 0.25 1.180 CP PDE CEUS
3.1 39.5 -111.5 3.0 2005 11 15 0.111 1.021 ISB COM WUS
3.1 38.3 -112.3 4.0 2005 12 11 0.111 1.021 ISB COM WUS
3.1 38.3 -112.6 0.0 2007 2 8 0.111 1.021 ISB COM WUS
3.1 37.5 -112.5 1.0 2007 7 4 0.111 1.021 ISB COM WUS
3.1 37.7 -110.4 0.0 2009 4 14 0.25 1.180 CP PDE CEUS
3.1 39.8 -107.2 5.0 2009 5 1 0.25 1.180 CP PDE CEUS
3.1 39.0 -109.4 1.0 2010 5 31 0.25 1.180 CP PDE CEUS
3.1 36.3 -112.2 3.0 2011 7 8 0.111 1.021 ISB COM WUS
3.1 36.8 -113.0 1.0 2011 12 13 0.111 1.021 ISB COM WUS
3.1 39.4 -111.9 13.0 2012 11 4 0.111 1.021 ISB COM WUS
3.1 36.8 -111.9 6.4 2013 1 7 0.111 1.021 CP PDE COMCAT
3.1 38.2 -112.6 0.0 1990 5 6 0.111 1.021 ISB COM WUS
3.2 39.0 -110.9 7.0 1964 8 5 0.25 1.180 CP SRA CEUS
3.2 39.3 -107.3 5.0 1978 5 29 0.25 1.180 CP PDE CEUS
3.2 36.8 -110.4 1.0 1981 5 29 0.2 1.112 CP SRA CEUS
3.2 36.8 -110.3 0.0 1981 7 14 0.2 1.112 CP SRA CEUS
3.2 38.2 -111.3 9.0 1982 4 17 0.25 1.180 CP SRA CEUS
Attachment 1

List of Earthquake Events Within the White Mesa Study Area (continued)

Notes: 1) Two areal source zones are present within the study area, the Colorado Plateau (CP) and Intermountain Seismic Belt (ISB).
2) Originating Network is the seismic network that first recorded the event.
3) Earthquakes included in the PSHA are limited to those of Mw ≥3.0 within a 200-mile radius of the Site.

Page 4 of 14
Expected
Moment
Magnitude
(E[Mw])
Location Hypocentral
Depth (km)
Date
Mwsig N* Areal Source
Zone1
Originating
Network2 Catalog Latitude Longitude Year Month Day
3.2 35.2 -109.0 5.0 1982 11 3 0.25 1.180 CP PDE CEUS
3.2 40.4 -109.5 21.0 1985 10 7 0.2 1.112 CP SRA CEUS
3.2 37.4 -110.3 1.0 1986 11 7 0.2 1.112 CP SRA CEUS
3.2 38.1 -107.8 5.0 1989 11 19 0.25 1.180 CP PDE CEUS
3.2 39.0 -110.8 11.0 1990 6 25 0.2 1.112 CP PDE CEUS
3.2 37.2 -110.4 1.0 1991 6 25 0.2 1.112 CP PDE CEUS
3.2 37.4 -110.5 3.0 2002 9 26 0.25 1.180 CP PDE CEUS
3.2 37.7 -110.5 7.0 2009 3 31 0.25 1.180 CP PDE CEUS
3.2 38.0 -111.1 0.0 2012 6 22 0.25 1.180 CP PDE CEUS
3.2 37.8 -113.0 5.0 1974 4 29 0.111 1.021 ISB COM WUS
3.2 39.1 -111.4 5.0 1975 10 6 0.111 1.021 ISB COM WUS
3.2 39.3 -111.7 7.0 1979 10 6 0.111 1.021 ISB COM WUS
3.2 37.5 -113.0 7.0 1980 12 21 0.111 1.021 ISB COM WUS
3.2 36.8 -113.0 5.0 1989 2 4 0.111 1.021 ISB COM WUS
3.2 37.3 -113.0 4.0 1991 3 26 0.111 1.021 ISB COM WUS
3.2 39.4 -112.0 5.0 1995 3 31 0.111 1.021 ISB COM WUS
3.2 37.9 -113.2 5.0 1996 12 28 0.111 1.021 ISB COM WUS
3.2 38.4 -113.0 5.0 1999 1 14 0.111 1.021 ISB COM WUS
3.2 38.7 -112.5 1.0 1999 1 26 0.111 1.021 ISB COM WUS
3.2 39.6 -111.7 6.0 2000 8 3 0.111 1.021 ISB COM WUS
3.2 37.3 -112.7 8.0 2002 1 8 0.111 1.021 ISB COM WUS
3.2 38.8 -111.5 6.0 2002 11 8 0.111 1.021 ISB COM WUS
3.2 37.9 -111.8 0.0 2005 8 20 0.111 1.021 ISB COM WUS
3.2 38.3 -112.2 1.0 2005 11 21 0.111 1.021 ISB COM WUS
3.2 37.4 -113.2 4.0 2009 3 23 0.111 1.021 ISB COM WUS
Attachment 1

List of Earthquake Events Within the White Mesa Study Area (continued)

Notes: 1) Two areal source zones are present within the study area, the Colorado Plateau (CP) and Intermountain Seismic Belt (ISB).
2) Originating Network is the seismic network that first recorded the event.
3) Earthquakes included in the PSHA are limited to those of Mw ≥3.0 within a 200-mile radius of the Site.

Page 5 of 14
Expected
Moment
Magnitude
(E[Mw])
Location Hypocentral
Depth (km)
Date
Mwsig N* Areal Source
Zone1
Originating
Network2 Catalog Latitude Longitude Year Month Day
3.2 36.4 -106.6 5.0 2010 12 18 0.111 1.021 CP COM WUS
3.2 39.2 -111.9 10.0 2011 1 20 0.111 1.021 ISB COM WUS
3.2 39.3 -111.5 33.0 1965 7 5 0.222 1.087 ISB PDE WUS
3.2 38.7 -111.5 1.0 1990 10 23 0.111 1.021 ISB COM WUS
3.2 37.8 -113.0 3.0 1991 3 22 0.111 1.021 ISB COM WUS
3.2 37.6 -112.2 2.0 1999 1 30 0.111 1.021 ISB COM WUS
3.2 38.2 -112.6 7.0 1964 1 17 0.222 1.087 ISB SRA WUS
3.2 39.2 -110.9 7.0 1962 9 7 0.25 1.180 ISB SRA CEUS
3.2 37.5 -110.5 7.0 1981 9 10 0.25 1.180 CP PDE CEUS
3.2 39.3 -107.2 5.0 1984 4 22 0.25 1.180 CP PDE CEUS
3.2 38.5 -108.9 7.0 1989 5 13 0.2 1.112 CP PDE CEUS
3.2 39.2 -106.7 5.0 1993 7 8 0.25 1.180 CP PDE CEUS
3.2 40.0 -107.7 5.0 2005 10 27 0.25 1.180 CP PDE CEUS
3.2 39.1 -107.4 1.0 2008 5 9 0.25 1.180 CP PDE CEUS
3.3 38.5 -112.6 5.0 1975 9 10 0.111 1.021 ISB COM WUS
3.3 38.7 -112.5 4.0 1978 12 9 0.111 1.021 ISB COM WUS
3.3 38.1 -112.8 1.0 1981 8 8 0.111 1.021 ISB SRA WUS
3.3 36.1 -112.0 5.0 1983 8 31 0.111 1.021 CP COM WUS
3.3 38.6 -112.6 1.0 1986 10 5 0.111 1.021 ISB COM WUS
3.3 38.8 -111.8 1.0 1992 4 7 0.111 1.021 ISB COM WUS
3.3 39.6 -112.1 5.0 1993 3 15 0.111 1.021 ISB COM WUS
3.3 38.4 -112.2 5.0 1994 6 3 0.111 1.021 ISB COM WUS
3.3 39.5 -111.5 5.0 1994 11 23 0.111 1.021 ISB COM WUS
3.3 39.9 -111.6 10.0 1995 7 6 0.111 1.021 ISB COM WUS
3.3 36.2 -112.5 5.0 1998 11 8 0.111 1.021 ISB COM WUS
Attachment 1

List of Earthquake Events Within the White Mesa Study Area (continued)

Notes: 1) Two areal source zones are present within the study area, the Colorado Plateau (CP) and Intermountain Seismic Belt (ISB).
2) Originating Network is the seismic network that first recorded the event.
3) Earthquakes included in the PSHA are limited to those of Mw ≥3.0 within a 200-mile radius of the Site.

Page 6 of 14
Expected
Moment
Magnitude
(E[Mw])
Location Hypocentral
Depth (km)
Date
Mwsig N* Areal Source
Zone1
Originating
Network2 Catalog Latitude Longitude Year Month Day
3.3 38.6 -112.2 0.0 1999 8 4 0.111 1.021 ISB COM WUS
3.3 38.7 -112.3 0.0 2003 2 11 0.111 1.021 ISB COM WUS
3.3 37.0 -111.8 7.0 2003 7 8 0.111 1.021 CP COM WUS
3.3 39.7 -111.9 1.0 2004 3 18 0.111 1.021 ISB COM WUS
3.3 37.8 -113.1 6.0 2004 12 18 0.111 1.021 ISB COM WUS
3.3 37.5 -112.3 0.0 2008 8 28 0.111 1.021 ISB COM WUS
3.3 36.9 -112.9 2.0 1988 12 29 0.111 1.021 ISB COM WUS
3.3 38.2 -112.6 3.0 1989 8 9 0.111 1.021 ISB COM WUS
3.3 36.6 -112.3 10.0 1991 4 26 0.111 1.021 ISB COM WUS
3.3 37.1 -112.1 10.0 1993 5 27 0.111 1.021 ISB COM WUS
3.3 36.4 -110.4 5.0 1973 2 9 0.25 1.180 CP PDE CEUS
3.3 38.3 -110.6 7.0 1983 5 3 0.25 1.180 CP PDE CEUS
3.3 39.3 -107.2 5.0 1984 5 14 0.25 1.180 CP PDE CEUS
3.3 37.4 -110.6 5.0 1986 5 14 0.25 1.180 CP PDE CEUS
3.3 36.0 -111.2 5.0 2007 7 4 0.25 1.180 CP PDE CEUS
3.3 38.8 -107.2 1.0 2007 11 5 0.25 1.180 CP PDE CEUS
3.3 39.2 -110.5 15.0 2011 11 12 0.25 1.180 CP PDE CEUS
3.3 39.7 -112.0 3.9 2014 12 29 0.24 1.103 ISB PDE COMCAT
3.4 40.2 -108.9 2.0 1979 3 19 0.25 1.180 CP PDE CEUS
3.4 37.8 -110.7 7.0 1983 1 27 0.2 1.112 CP SRA CEUS
3.4 38.4 -107.4 5.0 1983 8 14 0.111 1.021 CP COM WUS
3.4 35.2 -109.1 5.0 1985 4 14 0.25 1.180 CP PDE CEUS
3.4 38.6 -112.7 1.0 1987 9 2 0.111 1.021 ISB COM WUS
3.4 36.4 -110.4 5.0 1988 7 15 0.25 1.180 CP PDE CEUS
3.4 37.5 -106.6 5.0 1991 5 10 0.111 1.021 CP COM WUS
Attachment 1

List of Earthquake Events Within the White Mesa Study Area (continued)

Notes: 1) Two areal source zones are present within the study area, the Colorado Plateau (CP) and Intermountain Seismic Belt (ISB).
2) Originating Network is the seismic network that first recorded the event.
3) Earthquakes included in the PSHA are limited to those of Mw ≥3.0 within a 200-mile radius of the Site.

Page 7 of 14
Expected
Moment
Magnitude
(E[Mw])
Location Hypocentral
Depth (km)
Date
Mwsig N* Areal Source
Zone1
Originating
Network2 Catalog Latitude Longitude Year Month Day
3.4 38.3 -112.4 3.0 1993 6 11 0.111 1.021 ISB COM WUS
3.4 37.6 -113.0 5.0 1997 11 30 0.111 1.021 ISB COM WUS
3.4 38.0 -112.5 5.0 1998 4 5 0.111 1.021 ISB COM WUS
3.4 38.9 -112.0 4.0 2000 3 8 0.111 1.021 ISB COM WUS
3.4 38.2 -112.6 0.0 2002 8 12 0.111 1.021 ISB COM WUS
3.4 38.2 -108.0 5.0 2006 11 21 0.25 1.180 CP PDE CEUS
3.4 37.0 -110.8 3.0 2009 7 13 0.25 1.180 CP PDE CEUS
3.4 37.0 -112.1 1.0 2011 6 23 0.111 1.021 ISB COM WUS
3.4 38.7 -112.2 33.0 1965 3 16 0.222 1.087 ISB PDE WUS
3.4 39.4 -112.0 5.0 1971 4 22 0.222 1.087 ISB PDE WUS
3.4 39.0 -111.9 1.0 1991 2 21 0.111 1.021 ISB COM WUS
3.4 37.8 -112.4 1.0 1999 3 9 0.111 1.021 ISB COM WUS
3.4 36.6 -106.5 12.0 2009 9 14 0.1 1.017 CP SLU WUS
3.5 39.4 -110.4 7.0 1962 12 11 0.25 1.180 CP SRA CEUS
3.5 40.0 -108.3 5.0 1994 11 3 0.25 1.180 CP PDE CEUS
3.5 36.0 -111.1 5.0 1998 10 18 0.25 1.180 CP PDE CEUS
3.5 39.5 -107.0 5.0 2012 8 21 0.25 1.180 CP PDE CEUS
3.5 39.0 -110.4 7.0 1966 1 14 0.24 1.165 CP SRA CEUS
3.5 37.8 -110.2 7.0 1967 2 1 0.24 1.165 CP SRA CEUS
3.5 39.2 -110.5 7.0 1968 6 2 0.24 1.165 CP SRA CEUS
3.5 39.3 -107.4 33.0 1968 6 23 0.24 1.165 CP SRA CEUS
3.5 40.2 -109.6 7.0 1971 7 10 0.24 1.165 CP SRA CEUS
3.5 37.7 -113.1 0.0 1979 1 12 0.111 1.021 ISB COM WUS
3.5 38.7 -111.8 5.0 1987 6 26 0.111 1.021 ISB COM WUS
3.5 37.0 -112.9 10.0 1988 1 2 0.111 1.021 ISB COM WUS
Attachment 1

List of Earthquake Events Within the White Mesa Study Area (continued)

Notes: 1) Two areal source zones are present within the study area, the Colorado Plateau (CP) and Intermountain Seismic Belt (ISB).
2) Originating Network is the seismic network that first recorded the event.
3) Earthquakes included in the PSHA are limited to those of Mw ≥3.0 within a 200-mile radius of the Site.

Page 8 of 14
Expected
Moment
Magnitude
(E[Mw])
Location Hypocentral
Depth (km)
Date
Mwsig N* Areal Source
Zone1
Originating
Network2 Catalog Latitude Longitude Year Month Day
3.5 38.1 -112.7 5.0 1993 6 16 0.111 1.021 ISB COM WUS
3.5 36.0 -112.3 5.0 1993 6 21 0.111 1.021 ISB COM WUS
3.5 39.0 -111.9 5.0 1993 10 21 0.111 1.021 ISB COM WUS
3.5 38.7 -112.1 1.0 1999 4 19 0.111 1.021 ISB COM WUS
3.5 38.9 -112.0 6.0 1999 7 18 0.111 1.021 ISB COM WUS
3.5 38.7 -112.5 1.0 2001 5 9 0.111 1.021 ISB COM WUS
3.5 38.2 -112.7 1.0 2002 1 20 0.111 1.021 ISB COM WUS
3.5 36.9 -112.6 20.0 2005 3 15 0.111 1.021 ISB COM WUS
3.5 38.6 -112.7 1.0 2005 7 20 0.111 1.021 ISB COM WUS
3.5 36.4 -112.6 5.0 2008 6 4 0.111 1.021 ISB COM WUS
3.5 36.5 -112.6 5.2 2013 7 7 0.1 1.017 ISB PDE COMCAT
3.5 39.9 -111.3 33.0 1965 3 9 0.222 1.087 ISB PDE WUS
3.5 36.0 -112.2 33.0 1965 6 7 0.222 1.087 ISB SRA WUS
3.5 38.8 -111.6 1.0 1999 1 8 0.111 1.021 ISB COM WUS
3.5 38.7 -112.1 7.0 1969 4 10 0.222 1.087 ISB SRA WUS
3.5 35.4 -109.1 5.0 1976 4 19 0.25 1.180 CP SRA CEUS
3.5 37.9 -110.9 7.0 1979 10 23 0.25 1.180 CP SRA CEUS
3.5 38.9 -107.1 5.0 1986 9 3 0.25 1.180 CP PDE CEUS
3.5 40.1 -109.5 3.0 1990 4 7 0.25 1.180 CP PDE CEUS
3.5 37.7 -111.4 9.0 1991 1 26 0.25 1.180 CP PDE CEUS
3.6 37.5 -112.8 7.0 1972 11 16 0.111 1.021 ISB SRA WUS
3.6 37.4 -112.5 7.0 1982 2 12 0.111 1.021 ISB COM WUS
3.6 38.6 -112.6 7.0 1983 12 9 0.111 1.021 ISB COM WUS
3.6 36.0 -112.2 5.0 1993 2 4 0.111 1.021 ISB COM WUS
3.6 38.8 -112.1 2.0 1993 7 20 0.111 1.021 ISB COM WUS
Attachment 1

List of Earthquake Events Within the White Mesa Study Area (continued)

Notes: 1) Two areal source zones are present within the study area, the Colorado Plateau (CP) and Intermountain Seismic Belt (ISB).
2) Originating Network is the seismic network that first recorded the event.
3) Earthquakes included in the PSHA are limited to those of Mw ≥3.0 within a 200-mile radius of the Site.

Page 9 of 14
Expected
Moment
Magnitude
(E[Mw])
Location Hypocentral
Depth (km)
Date
Mwsig N* Areal Source
Zone1
Originating
Network2 Catalog Latitude Longitude Year Month Day
3.6 38.2 -112.7 5.0 1994 11 17 0.111 1.021 ISB COM WUS
3.6 38.2 -112.9 5.0 1995 7 21 0.111 1.021 ISB COM WUS
3.6 38.6 -112.5 1.0 2001 11 19 0.111 1.021 ISB COM WUS
3.6 37.5 -112.5 7.0 2005 6 24 0.111 1.021 ISB COM WUS
3.6 38.2 -112.2 0.0 2008 2 1 0.111 1.021 ISB COM WUS
3.6 37.6 -112.3 7.0 1991 12 21 0.111 1.021 ISB COM WUS
3.6 37.9 -112.1 15.0 2011 9 28 0.1 1.017 ISB SLU WUS
3.6 36.5 -106.4 15.0 2008 6 4 0.1 1.017 CP SLU WUS
3.6 37.9 -112.5 9.0 2012 2 12 0.1 1.017 ISB SLU WUS
3.7 39.4 -110.3 7.0 1964 11 4 0.24 1.165 CP SRA CEUS
3.7 39.5 -110.3 2.0 1967 10 25 0.24 1.165 CP SRA CEUS
3.7 37.9 -108.3 33.0 1970 2 3 0.24 1.165 CP SRA CEUS
3.7 39.3 -107.3 5.0 1977 9 24 0.24 1.165 CP PDE CEUS
3.7 39.4 -111.9 10.0 1984 8 16 0.111 1.021 ISB COM WUS
3.7 38.7 -112.2 11.0 1989 7 23 0.111 1.021 ISB COM WUS
3.7 36.7 -112.4 5.0 1989 9 19 0.111 1.021 ISB COM WUS
3.7 39.5 -111.5 5.0 1994 9 10 0.111 1.021 ISB COM WUS
3.7 35.5 -112.0 5.0 1997 3 31 0.111 1.021 CP COM WUS
3.7 38.0 -112.6 5.0 1997 8 13 0.111 1.021 ISB COM WUS
3.7 38.8 -112.1 1.0 2005 7 29 0.111 1.021 ISB COM WUS
3.7 40.3 -109.2 5.0 2000 11 11 0.25 1.180 CP PDE CEUS
3.7 37.4 -109.5 9.0 2008 6 6 0.25 1.180 CP PDE CEUS
3.7 38.0 -111.1 16.0 2010 4 14 0.1 1.027 CP SLU CEUS
3.7 39.2 -111.4 5.0 1970 10 25 0.222 1.087 ISB PDE WUS
3.7 35.3 -111.6 5.0 1972 4 20 0.111 1.021 CP PDE WUS
Attachment 1

List of Earthquake Events Within the White Mesa Study Area (continued)

Notes: 1) Two areal source zones are present within the study area, the Colorado Plateau (CP) and Intermountain Seismic Belt (ISB).
2) Originating Network is the seismic network that first recorded the event.
3) Earthquakes included in the PSHA are limited to those of Mw ≥3.0 within a 200-mile radius of the Site.

Page 10 of 14
Expected
Moment
Magnitude
(E[Mw])
Location Hypocentral
Depth (km)
Date
Mwsig N* Areal Source
Zone1
Originating
Network2 Catalog Latitude Longitude Year Month Day
3.7 36.0 -112.4 5.0 1992 3 14 0.111 1.021 ISB COM WUS
3.7 36.0 -112.2 5.0 1995 4 17 0.111 1.021 ISB COM WUS
3.7 36.3 -112.1 33.0 1967 7 20 0.222 1.087 CP SRA WUS
3.7 37.8 -113.1 0.2 2013 2 8 0.1 1.017 ISB PDE COMCAT
3.7 39.4 -111.6 15.0 2007 11 5 0.1 1.017 ISB SLU WUS
3.8 37.9 -111.0 7.0 1979 4 30 0.25 1.180 CP PDE CEUS
3.8 37.4 -110.6 5.0 1986 8 22 0.25 1.180 CP PDE CEUS
3.8 39.2 -110.9 0.0 2006 1 27 0.25 1.180 ISB PDE CEUS
3.8 39.4 -110.4 7.0 1966 7 30 0.24 1.165 CP SRA CEUS
3.8 37.7 -107.9 33.0 1967 1 16 0.24 1.165 CP SRA CEUS
3.8 37.7 -113.2 3.0 1992 6 29 0.111 1.021 ISB COM WUS
3.8 39.6 -111.9 1.0 2003 12 27 0.111 1.021 ISB COM WUS
3.8 39.6 -107.4 9.0 2006 2 10 0.1 1.027 CP SLU CEUS
3.8 38.3 -112.7 33.0 1963 11 13 0.222 1.087 ISB PDE WUS
3.8 37.6 -113.0 9.0 2010 1 4 0.1 1.017 ISB SLU WUS
3.8 36.4 -112.6 33.0 1967 8 7 0.222 1.087 ISB SRA WUS
3.9 38.3 -107.6 33.0 1966 9 4 0.24 1.165 CP SRA CEUS
3.9 39.7 -111.4 0.0 1987 10 19 0.111 1.021 ISB COM WUS
3.9 40.2 -108.9 5.0 1995 3 20 0.24 1.165 CP PDE CEUS
3.9 38.1 -112.4 5.0 1995 4 27 0.111 1.021 ISB COM WUS
3.9 34.9 -110.5 5.0 1998 1 6 0.111 1.021 CP COM WUS
3.9 38.4 -113.0 5.0 1998 4 10 0.111 1.021 ISB COM WUS
3.9 38.8 -112.0 2.0 1999 10 11 0.111 1.021 ISB COM WUS
3.9 39.6 -111.9 33.0 1964 3 2 0.222 1.087 ISB PDE WUS
3.9 39.4 -112.0 15.0 1964 8 12 0.222 1.087 ISB PDE WUS
Attachment 1

List of Earthquake Events Within the White Mesa Study Area (continued)

Notes: 1) Two areal source zones are present within the study area, the Colorado Plateau (CP) and Intermountain Seismic Belt (ISB).
2) Originating Network is the seismic network that first recorded the event.
3) Earthquakes included in the PSHA are limited to those of Mw ≥3.0 within a 200-mile radius of the Site.

Page 11 of 14
Expected
Moment
Magnitude
(E[Mw])
Location Hypocentral
Depth (km)
Date
Mwsig N* Areal Source
Zone1
Originating
Network2 Catalog Latitude Longitude Year Month Day
3.9 37.8 -112.3 33.0 1968 3 20 0.222 1.087 ISB PDE WUS
3.9 38.5 -112.3 7.0 1968 9 20 0.222 1.087 ISB SRA WUS
3.9 34.8 -108.7 33.0 1969 8 23 0.222 1.087 CP PDE WUS
3.9 38.7 -112.6 5.0 1971 6 23 0.222 1.087 ISB PDE WUS
3.9 38.1 -112.3 5.0 1994 9 6 0.111 1.021 ISB COM WUS
3.9 38.9 -108.7 5.0 1971 11 12 0.25 1.180 CP SRA CEUS
3.9 39.7 -107.4 5.0 2001 8 9 0.25 1.180 CP PDE CEUS
3.9 38.3 -109.0 1.2 2013 1 24 0.1 1.027 CP PDE COMCAT
4.0 38.8 -111.6 4.0 1999 12 22 0.1 1.017 ISB SLU WUS
4.0 39.4 -110.3 7.0 1965 3 26 0.24 1.165 CP SRA CEUS
4.0 39.5 -107.3 33.0 1971 1 7 0.24 1.165 CP SRA CEUS
4.0 36.0 -112.3 5.0 1989 3 5 0.111 1.021 ISB COM WUS
4.0 39.1 -110.9 0.0 1996 1 6 0.24 1.165 ISB PDE CEUS
4.0 38.1 -112.7 6.0 1999 10 22 0.1 1.017 ISB SLU WUS
4.0 39.4 -111.4 8.8 2014 6 29 0.1 1.017 ISB PDE COMCAT
4.0 38.0 -112.1 33.0 1968 9 24 0.222 1.087 ISB PDE WUS
4.0 39.0 -111.9 31.0 1969 5 23 0.222 1.087 ISB PDE WUS
4.0 38.0 -112.7 3.0 1991 4 20 0.111 1.021 ISB COM WUS
4.0 36.0 -112.2 5.0 1992 7 5 0.111 1.021 ISB COM WUS
4.0 38.0 -112.5 2.0 1998 6 18 0.111 1.021 ISB COM WUS
4.1 39.0 -107.5 33.0 1967 1 12 0.24 1.165 CP SRA CEUS
4.1 39.3 -108.6 5.0 1975 1 30 0.24 1.165 CP PDE CEUS
4.1 38.2 -108.0 10.0 1994 9 13 0.24 1.165 CP PDE CEUS
4.1 37.8 -112.1 17.0 2012 4 12 0.1 1.017 ISB SLU WUS
4.1 38.0 -112.9 7.0 1965 1 18 0.222 1.087 ISB SRA WUS
Attachment 1

List of Earthquake Events Within the White Mesa Study Area (continued)

Notes: 1) Two areal source zones are present within the study area, the Colorado Plateau (CP) and Intermountain Seismic Belt (ISB).
2) Originating Network is the seismic network that first recorded the event.
3) Earthquakes included in the PSHA are limited to those of Mw ≥3.0 within a 200-mile radius of the Site.

Page 12 of 14
Expected
Moment
Magnitude
(E[Mw])
Location Hypocentral
Depth (km)
Date
Mwsig N* Areal Source
Zone1
Originating
Network2 Catalog Latitude Longitude Year Month Day
4.1 39.3 -112.1 33.0 1968 1 16 0.222 1.087 ISB PDE WUS
4.1 38.7 -112.2 33.0 1969 6 18 0.222 1.087 ISB PDE WUS
4.1 36.2 -111.6 33.0 1967 9 4 0.222 1.087 CP SRA WUS
4.1 39.6 -111.9 2.0 2003 4 17 0.1 1.017 ISB SLU WUS
4.2 38.7 -111.6 2.0 2001 7 19 0.1 1.017 ISB SLU WUS
4.2 38.1 -111.2 7.0 1963 9 30 0.24 1.165 CP SRA CEUS
4.2 39.4 -110.4 7.0 1965 1 14 0.24 1.165 CP SRA CEUS
4.2 38.3 -107.8 33.0 1967 4 4 0.24 1.165 CP SRA CEUS
4.2 37.9 -112.6 33.0 1963 6 19 0.222 1.087 ISB PDE WUS
4.2 39.9 -111.4 33.0 1963 7 10 0.222 1.087 ISB PDE WUS
4.2 38.8 -112.3 33.0 1967 7 22 0.222 1.087 ISB PDE WUS
4.2 37.8 -113.1 5.0 1971 11 10 0.222 1.087 ISB PDE WUS
4.2 39.1 -111.5 10.0 1973 7 16 0.111 1.021 ISB COM WUS
4.2 38.7 -112.6 10.0 2001 2 23 0.1 1.017 ISB SLU WUS
4.3 39.4 -110.3 7.0 1963 4 24 0.24 1.165 CP SRA CEUS
4.3 39.0 -106.5 5.0 1966 12 19 0.24 1.165 CP SRA CEUS
4.3 35.9 -108.3 22.0 1977 3 5 0.24 1.165 CP PDE CEUS
4.3 37.9 -112.1 18.0 1966 5 20 0.222 1.087 ISB PDE WUS
4.3 36.9 -107.0 33.0 1967 1 6 0.222 1.087 CP PDE WUS
4.3 38.3 -112.3 17.0 1974 11 4 0.111 1.021 ISB COM WUS
4.3 37.0 -112.9 21.0 1962 2 15 0.222 1.087 ISB SRA WUS
4.4 39.2 -111.4 33.0 1966 4 23 0.222 1.087 ISB PDE WUS
4.4 35.8 -111.6 34.0 1966 10 3 0.222 1.087 CP PDE WUS
4.4 37.9 -111.6 10.0 1970 4 18 0.222 1.087 CP PDE WUS
4.4 38.6 -112.1 5.0 1972 1 3 0.111 1.021 ISB PDE WUS
Attachment 1

List of Earthquake Events Within the White Mesa Study Area (continued)

Notes: 1) Two areal source zones are present within the study area, the Colorado Plateau (CP) and Intermountain Seismic Belt (ISB).
2) Originating Network is the seismic network that first recorded the event.
3) Earthquakes included in the PSHA are limited to those of Mw ≥3.0 within a 200-mile radius of the Site.

Page 13 of 14
Expected
Moment
Magnitude
(E[Mw])
Location Hypocentral
Depth (km)
Date
Mwsig N* Areal Source
Zone1
Originating
Network2 Catalog Latitude Longitude Year Month Day
4.4 35.3 -107.7 18.0 1973 12 24 0.111 1.021 CP COM WUS
4.4 38.8 -111.6 0.0 1992 6 24 0.111 1.021 ISB COM WUS
4.4 36.9 -112.4 26.0 1962 2 15 0.222 1.087 ISB USH WUS
4.4 38.0 -112.1 33.0 1962 6 5 0.222 1.087 ISB USH WUS
4.5 38.2 -112.5 16.0 1998 1 2 0.1 1.017 ISB SLU WUS
4.6 38.6 -112.2 5.0 1972 6 2 0.111 1.021 ISB PDE WUS
4.6 38.2 -107.6 25.0 1962 2 5 0.222 1.087 CP USH WUS
4.7 35.8 -108.3 25.0 1976 1 5 0.24 1.165 CP PDE CEUS
4.7 38.7 -112.0 9.0 1982 5 24 0.111 1.021 ISB COM WUS
4.7 39.2 -112.0 1.0 1986 3 24 0.111 1.021 ISB COM WUS
4.8 38.3 -112.3 5.0 2011 1 3 0.1 1.017 ISB CMT WUS
4.8 37.0 -107.0 0.0 1966 1 23 0.111 1.030 CP SHM WUS
4.8 38.1 -112.4 3.0 1970 5 23 0.222 1.087 ISB PDE WUS
4.9 39.6 -111.9 33.0 1963 7 7 0.222 1.087 ISB PDE WUS
4.9 38.2 -113.1 29.0 1966 10 21 0.222 1.087 ISB PDE WUS
4.9 37.8 -112.8 0.0 1933 1 20 0.222 1.087 ISB PCH WUS
4.9 37.7 -113.1 0.0 1942 8 30 0.222 1.087 ISB PCH WUS
4.9 38.8 -112.0 0.0 1945 11 18 0.222 1.087 ISB PCH WUS
4.9 38.0 -112.5 0.0 1959 2 27 0.222 1.087 ISB PCH WUS
4.9 35.5 -111.5 0.0 1959 10 13 0.222 1.087 CP USH WUS
4.9 39.3 -111.7 0.0 1961 4 16 0.222 1.087 ISB PCH WUS
4.9 37.0 -107.0 3.0 1966 1 23 0.15 1.055 CP SHM CEUS
5.0 38.4 -113.0 0.0 1908 4 15 0.333 1.207 ISB PCH WUS
5.0 38.7 -112.2 0.0 1910 1 10 0.333 1.207 ISB PCH WUS
5.0 36.0 -111.1 0.0 1910 9 24 0.3 1.269 CP SHM CEUS
Attachment 1

List of Earthquake Events Within the White Mesa Study Area (continued)

Notes: 1) Two areal source zones are present within the study area, the Colorado Plateau (CP) and Intermountain Seismic Belt (ISB).
2) Originating Network is the seismic network that first recorded the event.
3) Earthquakes included in the PSHA are limited to those of Mw ≥3.0 within a 200-mile radius of the Site.

Page 14 of 14
Expected
Moment
Magnitude
(E[Mw])
Location Hypocentral
Depth (km)
Date
Mwsig N* Areal Source
Zone1
Originating
Network2 Catalog Latitude Longitude Year Month Day
5.2 38.3 -107.6 49.0 1960 10 11 0.24 1.165 CP USH CEUS
5.2 39.1 -110.9 9.0 1988 8 14 0.24 1.165 ISB PDE CEUS
5.2 38.5 -112.1 18.0 1967 10 4 0.222 1.087 ISB PDE WUS
5.3 35.6 -112.1 10.0 1993 4 29 0.1 1.017 CP CMT WUS
5.3 38.8 -111.6 24.0 1989 1 30 0.1 1.017 ISB CMT WUS
5.5 36.5 -111.5 0.0 1912 8 18 0.333 1.207 CP PCH WUS
5.5 36.8 -112.4 0.0 1959 7 21 0.222 1.087 ISB USH WUS
5.7 37.0 -112.5 0.0 1887 12 5 0.333 1.207 ISB PCH WUS
6.0 38.7 -112.2 0.0 1921 10 1 0.333 1.207 ISB PCH WUS
6.5 38.8 -112.1 0.0 1901 11 14 0.333 1.207 ISB PCH WUS

Probabilistic Seismic Hazard Analysis

ATTACHMENT 2

LIST OF FAULTS AND FAULT CHARACTERISTICS INCLUDED IN THE PSHA
Attachment 2

List of Faults and Fault Characteristics Included in the PSHA

Page 1 of 4

USGS
Fault ID
Number1
Name1 Weight
of Dip
Dip
Angle
(°)
Weight
of Slip
Rate
Slip
Rate
(mm/yr)
Dip Direction Approximate
Strike1
Bottom2
(km bls)
Modeled
Length3
(km)
Sense of
Movement1
Probability
of Activity
2505 Aquarius and
Awapa
0.2 45
1 0.2 W N19°E 15 55.5 Normal 1.0 0.6 60
0.2 75
2492a Beaver Basin, E
Margin
0.2 45 0.2 0.2
W N12°E 10 37.7 Normal 1.0 0.6 60 0.6 0.04
0.2 75 0.2 0.05
2492b Beaver Basin,
Intrabasin
0.2 45 0.2 0.2
W N12°E 10 40.4 Normal 1.0 0.6 60 0.6 0.04
0.2 75 0.2 0.05
2288 Big Gypsum
Valley
0.2 45
1 0.04 NE N54°W 15 32.9 Normal 0.1 0.6 60
0.2 75
2514 Bright Angel
Fault System
0.2 45
1 0.2 Dispersed - W N6°W 15 90.0 Normal 0.1 0.6 90
0.2 135
991 Bright Angel
Fault Zone
0.33 45 0.33 0.08
NW N36°E 15 66.9 Normal 1.0 0.34 66 0.34 0.1
0.33 87 0.33 0.18
2337 Cannibal fault
0.2 45
1 0.2 W N20°W 15 50.6 Normal 1.0 0.6 60
0.2 75
993 Central Kaibab
0.2 71 0.33 0.08
W, SW, NW N2°E 15 90.2 Normal 1.0 0.6 86 0.34 0.1
0.2 90 0.33 0.18
2289 Doloras
0.2 45
1 0.04 SW N67°W 15 9.9 Normal 0.1 0.6 60
0.2 75
992 Eminence fault
zone
0.165 45 0.33 0.08
NW; SE4 N34°E 15 36.9 Normal 1.0 0.17 66 0.34 0.1
0.165 87 0.33 0.18
2478 Fisher Valley
faults
0.2 45
1 0.006 NE N21°W 15 19.2 Normal 0.1 0.6 60
0.2 75
2456 Joes Valley
Southern
0.2 45
1 0.231 W N4°E 15 47.2 Normal 1.0 0.6 60
0.2 75

Attachment 2

List of Faults and Fault Characteristics Included in the PSHA (continued)
Page 2 of 4
USGS
Fault ID
Number1
Name1 Weight
of Dip
Dip
Angle
(°)
Weight
of Slip
Rate
Slip
Rate
(mm/yr)
Dip Direction Approximate
Strike1
Bottom2
(km bls)
Modeled
Length3
(km)
Sense of
Movement1
Probability
of Activity
2453 Joes Valley West
0.2 40
1 0.231 W N0°E 15 83.8 Normal 1.0 0.6 50
0.2 60
2511 Lisbon Valley
0.1 45
1 0.04 NE; SW4 N47°W 15 37.4 Normal 0.1 0.3 60
0.1 75
2476 Moab Fault and
Spanish Valley
0.2 50
1 0.015 NE N52°W 15 72.4 Normal 0.1 0.6 65
0.2 80
2268 Monitor Creek
fault
0.2 45
1 0.2 S N86°W 15 31.0 Normal 1.0 0.6 60
0.2 75
2002 Nacimiento Fault
0.2 40
1 0.228 E N3°E 15 81.8 Normal 1.0 0.6 50
0.2 60
2286 Paradox Valley
Graben
0.2 45
1 0.04 NE N46°W 15 56.2 Normal 0.1 0.6 60
0.2 75
2504 Paunsaugunt
0.2 45
1 0.2 W N6°E 15 45.3 Normal 1.0 0.6 60
0.2 75
2457 Price River area
faults
0.1 60
1 0.2 N; S4 N81°W 15 54.2 Normal 0.1 0.3 75
0.1 90
2291 Red Rocks fault
0.33 75
1 0.2 NE N59°W 15 38.5 Normal 1.0 0.34 80
0.33 90
2276 Ridgway fault
0.2 60 0.2 0.005
S N87°E 15 23.9 Oblique-
Slip 0.5 0.6 75 0.6 0.02
0.2 90 0.2 0.06
2270 Roubideau Creek
fault
0.2 45
1 0.2 NE N74°W 15 20.5 Normal/
Reverse 1.0 0.6 60
0.2 75
2474 Salt and Cache
Valleys
0.1 45
1 0.006 NE; SW4 N61°W 15 56.7 Normal 0.1 0.3 60
0.1 75

Attachment 2

List of Faults and Fault Characteristics Included in the PSHA (continued)
Page 3 of 4
USGS
Fault ID
Number1
Name1 Weight
of Dip
Dip
Angle
(°)
Weight
of Slip
Rate
Slip
Rate
(mm/yr)
Dip Direction Approximate
Strike1
Bottom2
(km bls)
Modeled
Length3
(km)
Sense of
Movement1
Probability
of Activity
2475 Sand Flat
Graben
0.1 45
1 0.2 N; S4 N78°W 15 21.9 Normal 1.0 0.3 60
0.1 75
997b Sevier/Toroweap,
N Toroweap
0.2 40
1 0.123 W N17°E 15 84.2 Normal 1.0 0.6 50
0.2 60
997a Sevier/Toroweap,
Sevier section
0.2 40
1 0.441 W N18°E 15 90.6 Normal 1.0 0.6 50
0.2 60
2513 Shay Graben
Faults
0.1 45
1 0.01 N; S4 N66°E 15 40.3 Normal 0.2 0.3 60
0.1 75
2285 Sinbad Valley
Graben
0.1 45
1 0.2 NE; SW4 N50°W 15 30.4 Normal 0.1 0.3 60
0.1 75
2473 Ten Mile Graben
0.1 45
1 0.008 N; S4 N72°W 15 33.3 Normal 0.1 0.3 60
0.1 75
2506 Thousand Lake
0.2 45
1 0.2 W N10°E 15 49.9 Normal 1.0 0.6 60
0.2 75
---- Uncompahgre
0.2 45
1 0.1 NE N63°W 15 41.5 Normal 1.0 0.6 60
0.2 75
2281 Unnamed at
Hanks Creek
0.2 60
1 0.2 SW, W N47°W 15 20.9 Normal 1.0 0.6 75
0.2 90
2279 Unnamed at Red
Canyon
0.2 60
1 0.2 S N69°W 15 24.4 Normal 1.0 0.6 75
0.2 90
2284 Unnamed at San
Miguel
0.1 45
1 0.2 SW; NE4 N53°W 15 33.0 Normal 0.1 0.3 60
0.1 75
2269 Unnamed E of
Atkinson
0.2 60
1 0.2 SW, S N63°W 15 43.8 Normal 1.0 0.6 75
0.2 90

Attachment 2

List of Faults and Fault Characteristics Included in the PSHA (continued)
Page 4 of 4
USGS
Fault ID
Number1
Name1 Weight
of Dip
Dip
Angle
(°)
Weight
of Slip
Rate
Slip
Rate
(mm/yr)
Dip Direction Approximate
Strike1
Bottom2
(km bls)
Modeled
Length3
(km)
Sense of
Movement1
Probability
of Activity
2267 Unnamed near
Pine Mtn.
0.2 66
1 0.2 NE N52°W 15 32.3 Normal 1.0 0.6 81
0.2 90
2277 Unnamed of
Pinto Mesa
0.2 60
1 0.2 SW N43°W 15 20.7 Normal 1.0 0.6 75
0.2 90
2271 Unnamed S of
Love Mesa
0.2 60
1 0.2 N N80°W 15 18.0 Normal 0.1 0.6 75
0.2 90
2450 Wasatch
Monocline
0.2 45
1 0.2 E N13°E 15 109.8 Normal/
Monocline 0.5 0.6 60
0.2 75
994 West Kaibab
0.2 71 0.33 0.08 Near Vertical -
E N4°W 15 74.0 Normal 1.0 0.6 86 0.34 0.1
0.2 90 0.33 0.18

Notes:
(1) U.S. Geological Survey, Arizona Geological Survey, Colorado Geological Survey, Utah Geological Survey, New Mexico Bureau of Mines and Mineral
Resources, 2006, Quaternary fault and fold database for the United States, accessed May 7, 2013, from USGS web site:
http://earthquake.usgs.gov/hazards/qfaults
(2) bls = below land surface
(3) Modeled length taken from Figure 9.
(4) Fault modeled in both dip directions listed. A total of six dips are modeled.
(5) Additional information on dip angle, dip direction, slip rate and probability of activity provided in Attachment 3.
(6) All faults extend to ground surface.
(7) Dip values and slip rates reported to an accuracy of a hundredth (0.01) or greater are typically taken from literature. Additional information is provided in
Attachment 3.

Probabilistic Seismic Hazard Analysis

ATTACHMENT 3

SUMMARY OF INDIVIDUAL FAULT PARAMETERS

Attachment 3

Page 1 of 10

Summary of Individual Fault Parameters
White Mesa Probabilistic Seismic Hazard Analysis
Created September, 2013

*Note: The fault summaries are organized in the following fashion:
 Name of fault
o Type of fault
o Age of fault
o Probability of activity
o Slip rate and weighting factor
o Dip and weighting factor
o Depth
o Other relevant information

 Aquarius and Awapa
o Diffuse area of normal faulting (USGS et al., 2012)
o Quaternary (<1.6 Ma) (USGS et al., 2012)
o Faulting assumed to have a probability of activity of 1 (seismogenic).
o Slip rate recorded as <0.2 mm/year by USGS (USGS et al., 2012). The fault will be
modeled as 0.2 mm/year to reflect the maximum possible slip rate.
o Dip angle uncertain, therefore modeled as 45°, 60°, and 75° to the west with weighting
factors of 0.2, 0.6, and 0.2, respectively.
o No recorded fault depth found, typical depth of 15 km assumed.
 Beaver Basin, E Margin
o Complex zone of generally north-trending normal faulting (USGS et al., 2012)
o Early Holocene (Hecker, 1993)
o Faulting assumed to have a probability of activity of 1 (seismogenic).
o Per Hecker (1993) slip rates calculated for >500 ka = 0.2 mm/year, 250-500 ka = 0.05
mm/year, and <250 ka = 0.04 mm/year. The slip rate is modeled as 0.2, 0.04, and 0.05
mm/year with weighting factors of 0.2, 0.6, and 0.2, respectively. The slip rate of 0.04
mm/year is given the highest weight because it is the most recent measurement.
(Hecker, 1993)
o Dip angle uncertain, therefore modeled as 45°, 60°, and 75° to the west with weighting
factors of 0.2, 0.6, and 0.2, respectively.
o Depth is modeled as 10 km (USGS et al., 2012)
 Beaver Basin, Intrabasin
o Complex zone of generally north-trending normal faulting (USGS et al., 2012)
o Late Pleistocene to Holocene (Hecker, 1993)
o Faulting assumed to have a probability of activity of 1 (seismogenic).
o No known measurements of slip, due to close proximity (0 miles) slip values are taken
from Beaver Basin, E. Margin, above. The slip rate is modeled as 0.2, 0.04, and 0.05
mm/year with weighting factors of 0.2, 0.6, and 0.2, respectively. The slip rate of 0.04
mm/year is given the highest weight because it is the most recent measurement.
(Hecker, 1993)
o Dip angle uncertain, modeled as 45°, 60°, and 75° to the west with weighting factors of
0.2, 0.6, and 0.2, respectively.
o Depth is not recorded, assumed same as E. Margin faults, modeled as 10 km (USGS et
al., 2012).
 Big Gypsum Valley
o Normal faulting on the crest of a salt-cored anticline (USGS et al., 2012)
o Quaternary (<1.6 Ma) (USGS et al., 2012)
o Probability of activity modeled as 0.1 due to strong evidence of salt tectonics in formation
of the fault (Wong, et al., 1996).
o Slip rate of 0.04 mm/year suggested by Wong et al (1996). Slip modeled as 0.04
mm/year.
o Dip angle uncertain, therefore modeled as 45°, 60°, and 75° to the northeast with
weighting factors of 0.2, 0.6, and 0.2, respectively.
o No recorded fault depth found, typical depth of 15 km assumed.
Attachment 3

Page 2 of 10

 Bright Angel Fault System
o Diffuse area of bedrock faults, normal sense of movement (USGS et al., 2012)
o Jurassic, Quaternary (?)
o Northeast trending faults in the area tend to not be active (Wong and Humphrey, 1989), a
probability of activity of 0.1 was assigned.
o Slip rate recorded as <0.2 mm/year by USGS (USGS et al., 2012). The fault will be
modeled as 0.2 mm/year to reflect the maximum possible slip rate.
o Dip direction and angle are unknown, modeled as 45°, 90°, and 135° to the west with
weighting factors of 0.2, 0.6, and 0.2, respectively.
o No recorded fault depth found, typical depth of 15 km assumed.
 Bright Angel Fault Zone
o Normal (USGS et al., 2012)
o Quaternary (<1.6 Ma) (USGS et al., 2012)
o Faulting assumed to have a probability of activity of 1 (seismogenic).
o Slip rate recorded as <0.2 mm/year by USGS (USGS et al., 2012). Model slip rate based
on Hurricane and Toroweap faults, due to relatively close proximity (located 55 and 45
miles west, respectively), well constrained slip rate, and considered the most active faults
in the region (Fenton, et al., 2001). Slip rate modeled as 0.08, 0.10, and 0.18 mm/year
weighted 0.33, 0.34, and 0.33, respectively. The range reflects the lower value
presented, 0.08 mm/year, the average slip rate value, 0.10 mmm/year, and the highest
documented value, 0.18 mm/year, presented in Fenton, et al. (2001). The change in
weighting factors is to reflect higher variability and uncertainty in the analysis.
o Dip angle recorded by USGS (USGS et al., 2012) range from 45° to 87°. Dip modeled as
45°, 66°, and 87° to the northwest with weighting factors of 0.33, 0.34, and 0.33 to reflect
variability and uncertainty.
o No recorded fault depth found, typical depth of 15 km assumed.
 Cannibal fault
o Normal fault located in area characterized by extensive Tertiary volcanism (USGS et al.,
2012)
o Late Quaternary (<130 ka) (USGS et al., 2012)
o Faulting assumed to have a probability of activity of 1 (seismogenic).
o Slip rate recorded as <0.2 mm/year by USGS (USGS et al., 2012). The fault will be
modeled as 0.2 mm/year to reflect the maximum possible slip rate.
o Dip angle uncertain, therefore modeled as 45°, 60°, and 75° to the west with weighting
factors of 0.2, 0.6, and 0.2, respectively.
o No recorded fault depth found, typical depth of 15 km assumed.
 Central Kaibab
o Normal faults, predominantly west-facing graben escarpments.
o Paleozoic
o Faulting assumed to have a probability of activity of 1 (seismogenic).
o Slip rate recorded as <0.2 mm/year by USGS (USGS et al., 2012). Model slip rate based
on Hurricane and Toroweap faults, located 62 and 53 miles west, respectively, based on
the well constrained slip rate and considered the most active faults in the region (Fenton,
et al., 2001). Slip rate modeled as 0.08, 0.10, and 0.18 mm/year weighted 0.33, 0.34, and
0.33, respectively. The range reflects the lower value presented, 0.08 mm/year, the
average slip rate value, 0.10 mmm/year, and the highest documented value, 0.18
mm/year, presented in Fenton, et al. (2001). The change in weighting factors is to reflect
higher variability and uncertainty in the analysis.
o Dip is assumed to be similar to West Kaibab fault, measured at 86°. Dip is modeled as
71°, 86°, and 90° with weighting factors of 0.2, 0.6, and 0.2, respectively. Dip is to the
west, variations in the strike cause variations from southwest to northwest.
o No recorded fault depth found, typical depth of 15 km assumed.
 Dolores
o Normal faults on the crest of the Dolores anticline, a salt-cored structured (USGS et al.,
2012).
o Quaternary (<1.6 Ma) (USGS et al., 2012)
Attachment 3

Page 3 of 10

o Faulting assumed to have a probability of 0.1 due to the relation to salt dissolution.
o Slip is based on the adjacent Lisbon Valley fault, estimated by Wong, et al. (1996). Slip
modeled as 0.04 mm/year.
o Dip angle uncertain, therefore modeled as 45°, 60°, and 75° to the southwest with
weighting factors of 0.2, 0.6, and 0.2, respectively.
o No recorded fault depth found, typical depth of 15 km assumed.
 Eminence fault zone
o Normal faulting (USGS et al., 2012)
o Quaternary (<1.6 Ma) (USGS et al., 2012)
o Faulting assumed to have a probability of activity of 1 (seismogenic).
o Slip rate recorded as <0.2 mm/year by USGS (USGS et al., 2012). Model slip rate based
on Hurricane and Toroweap faults, located 75 and 67 miles west, respectively, based on
the well constrained slip rate and considered the most active faults in the region (Fenton,
et al., 2001). Slip rate modeled as 0.08, 0.10, and 0.18 mm/year weighted 0.33, 0.34, and
0.33, respectively. The range reflects the lower value presented, 0.08 mm/year, the
average slip rate value, 0.10 mmm/year, and the highest documented value, 0.18
mm/year, presented in Fenton, et al. (2001). The change in weighting factors is to reflect
higher variability and uncertainty in the analysis.
o Dip direction is recorded as both NW and SE due to general uncertainty in the area and
evidence of a narrow graben along the base of the fault. Dip angle is based on the Bright
Angel fault zone due to the Eminence fault zone being part of the regional system. Dip
modeled as 45°, 66°, and 87° with weighting factors of 0.165, 0.17, and 0.165,
respectively for both the NW and SE dip directions. Weighting factors selected to reflect
variability and uncertainty in the fault zone.
o No recorded fault depth found, typical depth of 15 km assumed.
 Fisher Valley faults
o Normal faulting on the crest of a long anticlinal structure that includes Salt and Cache
Valleys in Utah (Hecker, 1993)
o Quaternary (<1.6 Ma) (USGS et al., 2012)
o Probability of activity modeled as 0.1 due to strong evidence of salt tectonics in formation
of the fault (Wong, et al., 1996).
o Slip rate of 0.006 mm/year suggested by Wong et al (1996). Slip modeled as 0.006
mm/year.
o Dip angle uncertain, therefore modeled as 45°, 60°, and 75° to the northeast with
weighting factors of 0.2, 0.6, and 0.2, respectively.
o No recorded fault depth found, typical depth of 15 km assumed.
 Granite Creek Fault Zone
o Modeled as part of the Uncompahgre fault, based on Wong, et al. (1996). Not included
as a separate fault in this study.
 Joes Valley Southern
o Normal faults that split the Wasatch Plateau (USGS et al., 2012)
o Middle to Late Quaternary (>750 ka) (USGS et al., 2012)
o Faulting assumed to have a probability of activity of 1 (seismogenic).
o Slip rate recorded as 0.231 mm/year by the NSHM 2014 update (Bird, 2013).
o Dip angle uncertain, therefore modeled as 45°, 60°, and 75° to the west with weighting
factors of 0.2, 0.6, and 0.2, respectively.
o No recorded fault depth found, typical depth of 15 km assumed.
 Joes Valley West
o Normal faults that split the Wasatch Plateau (USGS et al., 2012)
o Latest Quaternary (>15 ka) (USGS et al., 2012)
o Faulting assumed to have a probability of activity of 1 (USGS, 2010) (seismogenic).
o Slip rate recorded as 0.231 mm/year by the NSHM 2014 update (Bird, 2013).
o Dip is taken from the USGS National Seismic Hazards database. Dip will be modeled as
40°, 50°, and 60° to the west weighted 0.2, 0.6, and 0.2, respectively (USGS, 2010).
o Depth is recorded as 15 km (USGS, 2010).
 Lisbon Valley
Attachment 3

Page 4 of 10

o Normal faulting on suspected salt anticline feature (USGS et al., 2012)
o Quaternary (<1.6 Ma) (USGS et al., 2012)
o Probability of activity modeled as 0.1 due to strong evidence of salt tectonics in formation
of the fault (Wong, et al., 1996).
o Slip rate of 0.04 mm/year suggested by Wong et al. (1996). Slip modeled 0.04 mm/year.
o Dip direction is recorded as both NE and SW due to the anticlinal features. Dip angle is
uncertain, therefore modeled as 45°, 60°, and 75° with weighting factors of 0.1, 0.3, and
0.1, respectively for both the NE and SW dip directions.
o No recorded fault depth found, typical depth of 15 km assumed.
 Moab Fault and Spanish Valley
o Normal faulting, probably from salt tectonics (Hecker, 1993)
o Quaternary (<1.6 Ma) (USGS et al., 2012)
o Probability of activity modeled as 0.1 due to strong evidence of salt tectonics in formation
of the fault (Wong, et al., 1996).
o Slip rate of 0.015 mm/year suggested by Wong et al. (1996). Slip modeled as 0.015
mm/year.
o Dip is recorded as 60-68°, modeled as 50°, 65°, and 80° to the northeast with weighting
factors of 0.2, 0.6, and 0.2, respectively.
o No recorded fault depth found, typical depth of 15 km assumed.
 Monitor Creek fault
o Normal fault, marked by a south-facing scarp on the Cretaceous Dakota Sandstone
(USGS et al., 2012).
o Quaternary (<1.6 Ma) (USGS et al., 2012)
o Faulting assumed to have a probability of activity of 1 (seismogenic).
o Slip rate recorded as <0.2 mm/year by USGS (USGS et al., 2012). The fault will be
modeled as 0.2 mm/year to reflect the maximum possible slip rate.
o Dip angle uncertain, therefore modeled as 45°, 60°, and 75° to the south with weighting
factors of 0.2, 0.6, and 0.2, respectively.
o No recorded fault depth found, typical depth of 15 km assumed.
 Nacimiento Fault
o High-angle, west-vergent reverse fault predecessor with current normal sense of
movement (USGS et al., 2012).
o Quaternary (<1.6 Ma) (USGS et al., 2012)
o Faulting has a probability of activity of 1 (USGS, 2010) (seismogenic).
o Slip rate recorded as 0.228 mm/year by the NSHM 2014 update (Bird, 2013). The fault
will be modeled as 0.228 mm/year.
o Dip is recorded as 40°, 50°, and 60° to the east and weighted 0.2, 0.6, and 0.2,
respectively (USGS, 2010).
o Depth is recorded as 15 km (USGS, 2010)
 Paradox Valley Graben
o Normal fault on the crest of a salt-cored anticline (USGS et al., 2012).
o Quaternary (<1.6 Ma) (USGS et al., 2012)
o Probability of activity modeled as 0.1 due to strong evidence of salt tectonics in formation
of the fault (Wong, et al., 1996).
o Slip rate of 0.04 mm/year suggested by Wong et al. (1996). Slip modeled as 0.04
mm/year.
o Dip angle uncertain, therefore modeled as 45°, 60°, and 75° to the northeast with
weighting factors of 0.2, 0.6, and 0.2, respectively.
o No recorded fault depth found, typical depth of 15 km assumed.
 Paunsaugunt
o Normal faults, generally north-trending fault along the eastern side of Grass Valley west
of the Aquarius Plateau, near the southeastern edge of the Basin and Range (USGS et
al., 2012).
o Quaternary (<1.6 Ma) (USGS et al., 2012)
o Faulting assumed to have a probability of activity of 1 (seismogenic).
Attachment 3

Page 5 of 10

o Slip rate recorded as <0.2 mm/year by USGS (USGS et al., 2012). The fault will be
modeled as 0.2 mm/year to reflect the maximum possible slip rate.
o Dip angle uncertain, therefore modeled as 45°, 60°, and 75° to the west with weighting
factors of 0.2, 0.6, and 0.2, respectively.
o No recorded fault depth found, typical depth of 15 km assumed.
 Price River area faults
o Normal faults that are steeply to vertically dipping, formed in relation to salt tectonics
(Hecker, 1993)
o Quaternary (<1.6 Ma) (USGS et al., 2012)
o Probability of activity modeled as 0.1 due to strong evidence of salt tectonics in formation
of the fault (Hecker, 1993).
o Slip rate recorded as <0.2 mm/year by USGS (USGS et al., 2012). The fault will be
modeled as 0.2 mm/year to reflect the maximum possible slip rate.
o Dip direction is recorded as both N and S due to the underlying collapsed anticline. Dip
angle is uncertain, characterized by Hecker (1993) to dip steep to vertical, therefore
modeled as 60°, 75°, and 90° with weighting factors of 0.1, 0.3, and 0.1, respectively for
both the N and S dip directions.
o No recorded fault depth found, typical depth of 15 km assumed.
 Red Rocks fault
o Normal fault that originated as an oblique reverse or tear fault, renewed in late Cenozoic
with normal sense (USGS et al., 2012)
o Quaternary (<1.6 Ma) (USGS et al., 2012)
o Faulting assumed to have a probability of activity of 1 (seismogenic).
o Slip rate recorded as <0.2 mm/year by USGS (USGS et al., 2012). The fault will be
modeled as 0.2 mm/year to reflect the maximum possible slip rate.
o Dip recorded as 75-90° by USGS (2012). Dip modeled as 75°, 80°, and 90° to the
northeast with weighting factors of 0.33, 0.34, and 0.33, respectively.
o No recorded fault depth found, typical depth of 15 km assumed.
 Ridgway fault
o Fault lies on the southwest margin of the Uncompahgre Uplift (USGS et al., 2012), fault is
listed as normal and having oblique slip movement (Ake, et al., 2002)
o Quaternary (<1.6 Ma) (USGS et al., 2012)
o Faulting assumed to have a probability of activity of 0.5 (Ake, et al., 2002).
o Slip is recorded as 0.005-0.06 mm/year with a median of 0.02 mm/year. Slip is modeled
as 0.005, 0.02, and 0.06 mm/year with weighting factors of 0.2, 0.6, and 0.2, respectively
(Ake, et al., 2002).
o Dip is steep according to Ake, et al., (2002), modeled as 60°, 75°, and 90° to the south
with weighting factors of 0.2, 0.6, and 0.2, respectively.
o No recorded fault depth found, typical depth of 15 km assumed.
 Roubideau Creek fault
o Normal fault on the east flank of the Uncompahgre Uplift, could have possible reverse
movement in the Quaternary (USGS et al., 2012), model as normal and reverse.
o Latest Quaternary (<15 ka) (USGS et al., 2012).
o Faulting assumed to have a probability of activity of 1 (seismogenic).
o Slip rate recorded as <0.2 mm/year by USGS (USGS et al., 2012). The fault will be
modeled as 0.2 mm/year to reflect the maximum possible slip rate.
o Dip angle uncertain, therefore modeled as 45°, 60°, and 75° to the northeast with
weighting factors of 0.2, 0.6, and 0.2, respectively.
o No recorded fault depth found, typical depth of 15 km assumed.
 Ryan Creek Fault Zone
o Modeled as part of the Uncompahgre fault, based on Wong et al., 1996. Not included as
a separate fault in this study.
 Salt and Cache Valleys
o Zone of folding, faulting, and warping related to dissolution and collapse of the Salt Valley
anticline in eastern Utah (USGS et al., 2012). Classified as normal.
o Quaternary (<1.6 Ma) (USGS et al., 2012)
Attachment 3

Page 6 of 10

o Probability of activity modeled as 0.1 due to strong evidence of salt tectonics in formation
of the fault (Wong, et al., 1996).
o Slip rate of 0.006 mm/year suggested by Wong et al. (1996). Slip modeled as 0.006
mm/year.
o Dip direction is recorded as both NE and SW due to the anticlinal features (Hecker,
1993). Dip angle is uncertain, therefore modeled as 45°, 60°, and 75° with weighting
factors of 0.1, 0.3, and 0.1, respectively for both the NE and SW dip directions.
o No recorded fault depth found, typical depth of 15 km assumed.
 Sand Flat Graben
o Normal faults on the southwestern margin of the Uncompahgre uplift (USGS et al., 2012)
o Quaternary (<1.6 Ma) (USGS et al., 2012)
o Faulting assumed to have a probability of activity of 1 (seismogenic).
o Slip rate recorded as <0.2 mm/year by USGS (USGS et al., 2012). The fault will be
modeled as 0.2 mm/year to reflect the maximum possible slip rate.
o Dip direction is recorded as both N and S due to the graben-bounding faulting. Dip angle
is uncertain, therefore modeled as 45°, 60°, and 75° with weighting factors of 0.1, 0.3,
and 0.1, respectively for both the N and S dip directions.
o No recorded fault depth found, typical depth of 15 km assumed.
 Sevier/Toroweap N Toroweap
o Normal fault along the western margin of the Colorado Plateau (USGS et al., 2012)
o Late Quaternary (<130 ka) (USGS et al., 2012)
o Faulting assumed to have a probability of activity of 1 (USGS, 2010) (seismogenic).
o Slip rate recorded as 0.123 mm/year by the NSHM 2014 update (Bird, 2013).
o Dip is taken from the USGS National Seismic Hazards database. Dip will be modeled as
40°, 50°, and 60° to the west weighted 0.2, 0.6, and 0.2, respectively (USGS, 2010).
o Depth is recorded as 15 km (USGS, 2010).
o Sevier/Toroweap Northern (N) Toroweap is labeled as the southern section in the
National Seismic Hazard Map Database and as N Toroweap in the USGS Faults and
Folds Database. This fault will remain the N Toroweap for the purposes of this report.
 Sevier/Toroweap Sevier section
o Normal fault along the western margin of the Colorado Plateau (USGS et al., 2012)
o Late Quaternary (<130 ka) (USGS et al., 2012)
o Faulting assumed to have a probability of activity of 1 (USGS, 2010) (seismogenic).
o Slip rate recorded as 0.441 mm/year by the NSHM 2014 update (Bird, 2013).
o Dip is taken from the USGS National Seismic Hazards database. Dip will be modeled as
40°, 50°, and 60° to the west weighted 0.2, 0.6, and 0.2, respectively (USGS, 2010).
o Depth is recorded as 15 km (USGS, 2010).
o Sevier/Toroweap Sevier section is labeled as the northern section in the National Seismic
Hazard Map Database and as the Sevier section in the USGS Faults and Folds
Database. This fault will remain the Sevier section for the purposes of this report.
 Shay Graben Faults
o Northeast-trending graben-bound normal faults along the northern side of Shay Mountain
in the Paradox Basin of eastern Utah (USGS et al., 2012).
o Quaternary (<1.6 Ma) (USGS et al., 2012)
o Probability of activity modeled as 0.2 due to strong evidence of salt tectonics in formation
of the fault (Wong, et al., 1996).
o Slip rate of 0.01 mm/year suggested by Wong et al. (1996). Slip modeled as 0.01
mm/year.
o Dip direction is recorded as both N and S due to graben-bounding faulting. Dip angel is
uncertain, therefore modeled as 45°, 60°, and 75° with weighting factors of 0.1, 0.3, and
0.1, respectively for both the N and S dip directions.
o No recorded fault depth found, typical depth of 15 km assumed.
 Sinbad Valley Graben
o Graben formed along the collapsed crest of a slat-cored anticline in response to salt
dissolution (USGS et al., 2012). Classified as normal.
o Quaternary (<1.6 Ma) (USGS et al., 2012)
Attachment 3

Page 7 of 10

o Probability of activity modeled as 0.1 due to strong evidence of salt tectonics in formation
of the fault.
o Slip rate recorded as <0.2 mm/year by USGS (USGS et al., 2012). The fault will be
modeled as 0.2 mm/year to reflect the maximum possible slip rate.
o Dip direction is recorded as both NE and SW due to the graben-bounding faulting. Dip
angle is uncertain, therefore modeled as 45°, 60°, and 75° with weighting factors of 0.1,
0.3, and 0.1, respectively for both the NE and SW dip directions.
o No recorded fault depth found, typical depth of 15 km assumed.
 Ten Mile Graben
o Normal faulting, strongly related to salt tectonics (USGS et al., 2012).
o Quaternary (<1.6 Ma) (USGS et al., 2012)
o Probability of activity modeled as 0.1 due to strong evidence of salt tectonics in formation
of the fault (Wong, et al., 1996).
o Slip rate of 0.008 mm/year suggested by Wong et al. (1996). Slip modeled as 0.008
mm/year.
o Dip direction is recorded as both N and S due to the graben-bounding faulting. Dip angle
is uncertain, therefore modeled as 45°, 60°, and 75° with weighting factors of 0.1, 0.3,
and 0.1, respectively for both the N and S dip directions.
o No recorded fault depth found, typical depth of 15 km assumed.
 Thousand Lake
o Long, generally north-trending, sinuous range-front fault along the west side of Thousand
Lake. Normal movement (USGS et al., 2012)
o Middle to Late Quaternary (>750 ka) (USGS et al., 2012)
o Faulting assumed to have a probability of activity of 1 (seismogenic).
o Slip rate recorded as <0.2 mm/year by USGS (USGS et al., 2012). The fault will be
modeled as 0.2 mm/year to reflect the maximum possible slip rate.
o Dip angle uncertain, therefore modeled as 45°, 60°, and 75° to the west with weighting
factors of 0.2, 0.6, and 0.2, respectively.
o No recorded fault depth found, typical depth of 15 km assumed.
 Uncompahgre
o Combination of both Granite Creek and Ryan Creek fault zones (Wong et al., 1996)
o Both Granite and Ryan Creek fault zones classified as normal faults, Uncompahgre will
therefore be modeled with normal movement.
o Quaternary (<1.6 Ma) (USGS et al., 2012)
o Faulting assumed to have a probability of activity of 1 (Wong et al., 1996) (seismogenic).
o Slip rate of 0.1 mm/year suggested by Wong et al. (1996). Slip modeled 0.1 mm/year.
o Dip angle uncertain, therefore modeled as 45°, 60°, and 75° to the northeast with
weighting factors of 0.2, 0.6, and 0.2, respectively.
o No recorded fault depth found, typical depth of 15 km assumed
 Unnamed at Hanks Creek
o Normal faults on the southwest margin of the Uncompahgre Uplift (USGS et al., 2012)
o Quaternary (<1.6 Ma) (USGS et al., 2012)
o Faulting assumed to have a probability of activity of 1 (seismogenic).
o Slip rate recorded as <0.2 mm/year by USGS (USGS et al., 2012). The fault will be
modeled as 0.2 mm/year to reflect the maximum possible slip rate.
o Dip is recorded as high angle by the USGS (2012). Dip is modeled as 60°, 75°, and 90°
with weighting factors of 0.2, 0.6, and 0.2, respectively. Due to strike variations, the dip is
modeled to the southwest or south, depending on the geometry of the fault.
o No recorded fault depth found, typical depth of 15 km assumed.
 Unnamed at Red Canyon
o Normal faults on the southwest margin of the Uncompahgre Uplift (USGS et al., 2012)
o Quaternary (<1.6 Ma) (USGS et al., 2012)
o Faulting assumed to have a probability of activity of 1 (seismogenic).
o Slip rate recorded as <0.2 mm/year by USGS (USGS et al., 2012). The fault will be
modeled as 0.2 mm/year to reflect the maximum possible slip rate.
Attachment 3

Page 8 of 10

o Dip is recorded as high angle by the USGS (2012). Dip is modeled as 60°, 75°, and 90°
to the south with weighting factors of 0.2, 0.6, and 0.2, respectively.
o No recorded fault depth found, typical depth of 15 km assumed.
 Unnamed at San Miguel
o Normal faults on the southeast end of the Uncompahgre Uplift, considered to be salt-
related (USGS et al., 2012).
o Quaternary (<1.6 Ma) (USGS et al., 2012)
o Faulting assumed to have a probability of activity of 0.1 due to salt tectonics.
o Slip rate recorded as <0.2 mm/year by USGS (USGS et al., 2012). The fault will be
modeled as 0.2 mm/year to reflect the maximum possible slip rate.
o Dip direction is recorded as both SW and NE due to the salt tectonic related uncertainty
in the area. Dip angle is uncertain, modeled as 45°, 60°, and 75° with weighting factors
of 0.1, 0.3, and 0.1, respectively for both the SW and NE dip directions.
o No recorded fault depth found, typical depth of 15 km assumed
 Unnamed E of Atkinson
o Normal faulting on the southeast flank of the Uncompahgre Uplift (USGS et al., 2012)
o Quaternary (<1.6 Ma) (USGS et al., 2012)
o Faulting assumed to have a probability of activity of 1 (seismogenic).
o Slip rate recorded as <0.2 mm/year by USGS (USGS et al., 2012). The fault will be
modeled as 0.2 mm/year to reflect the maximum possible slip rate.
o Dip is recorded as high angle by the USGS (2012). Dip is modeled as 60°, 75°, and 90°
with weighting factors of 0.2, 0.6, and 0.2, respectively. Due to strike variations, the dip is
modeled to the southwest or south, depending geometry of the fault.
o No recorded fault depth found, typical depth of 15 km assumed.
 Unnamed near Pine Mtn.
o Normal faults on the southwest flank of the Uncompahgre Uplift (USGS et al., 2012)
o Quaternary (<1.6 Ma) (USGS et al., 2012)
o Faulting assumed to have a probability of activity of 1 (seismogenic).
o Slip rate recorded as <0.2 mm/year by USGS (USGS et al., 2012). The fault will be
modeled as 0.2 mm/year to reflect the maximum possible slip rate.
o USGS (2012) records dip as 81°. Dip modeled as 66°, 81°, and 90° to the northeast with
weighting factors of 0.2, 0.6, and 0.2, respectively.
o No recorded fault depth found, typical depth of 15 km assumed.
 Unnamed of Pinto Mesa
o Normal fault on the southwest flank of the Uncompahgre Uplift (USGS et al., 2012)
o Quaternary (<1.6 Ma) (USGS et al., 2012)
o Faulting assumed to have a probability of activity of 1 (seismogenic).
o Slip rate recorded as <0.2 mm/year by USGS (USGS et al., 2012). The fault will be
modeled as 0.2 mm/year to reflect the maximum possible slip rate.
o Dip is recorded as high angle by the USGS (2012). Dip is modeled as 60°, 75°, and 90°
to the southwest with weighting factors of 0.2, 0.6, and 0.2, respectively.
o No recorded fault depth found, typical depth of 15 km assumed.
 Unnamed S of Love Mesa
o Normal faulting on the south end of the Uncompahgre Uplift, attributed to salt tectonics
(USGS et al., 2012).
o Quaternary (<1.6 Ma) (USGS et al., 2012)
o Faulting assumed to have a probability of activity of 0.1 due to salt tectonics.
o Slip rate recorded as <0.2 mm/year by USGS (USGS et al., 2012). The fault will be
modeled as 0.2 mm/year to reflect the maximum possible slip rate.
o Dip is recorded as high angle by the USGS (2012). Dip is modeled as 60°, 75°, and 90°
to the north with weighting factors of 0.2, 0.6, and 0.2, respectively.
o No recorded fault depth found, typical depth of 15 km assumed.
 Wasatch Monocline
o Monocline within the transition between the Colorado Plateaus and Basin and Range
physiographic provinces (USGS et al., 2012), modeled as normal based on the assumed
underlying normal fault.
Attachment 3

Page 9 of 10

o Quaternary (<1.6 Ma) (USGS et al., 2012)
o Due to possibility of salt tectonics in the formation of the fault (Hecker, 1993), a
probability of activity of 0.5 is assumed.
o Slip rate recorded as <0.2 mm/year by USGS (USGS et al., 2012). The fault will be
modeled as 0.2 mm/year to reflect the maximum possible slip rate.
o Dip angle uncertain, therefore modeled as 45°, 60°, and 75° to the east with weighting
factors of 0.2, 0.6, and 0.2, respectively.
o No recorded fault depth found, typical depth of 15 km assumed.
 West Kaibab
o Large normal faults along the western flank of the Kaibab Plateau.
o Quaternary (<1.6 Ma) (USGS et al., 2012)
o Faulting assumed to have a probability of activity of 1 (seismogenic).
o Slip rate recorded as <0.2 mm/year by USGS (USGS et al., 2012). Model slip rate based
on Hurricane and Toroweap faults, located 48 and 40 miles west, respectively, based on
the well constrained slip rate and considered the most active faults in the region (Fenton,
et al., 2001). Slip rate modeled as 0.08, 0.10, and 0.18 mm/year weighted 0.33, 0.34, and
0.33, respectively. The range reflects the lower value presented, 0.08 mm/year, the
average slip rate value, 0.10 mmm/year, and the highest documented value, 0.18
mm/year, presented in Fenton, et al. (2001). The change in weighting factors is to reflect
higher variability and uncertainty in the analysis.
o USGS (2012) records the dip as 86°. Dip is modeled as 71°, 86°, and 90° with weighting
factors of 0.2, 0.6, and 0.2, respectively. Dip is recorded too close to vertical to have an
accurate dip direction, modeled as east dipping.
o No recorded fault depth found, typical depth of 15 km assumed.

References:

Ake, J., D. Ostenaa, K. Mahrer, C. Sneddon, and L. Block, 2002. Seismotectonic Evaluation and
Probabilistic Seismic Hazard Analysis for Ridgway Dam, Dallas Creek Project, Colorado. Rep.
Denver, Colorado: Seismotectonics and Geophysics Group Technical Service Center Bureau of
Reclamation. Print

Bird, P., 2013. “Estimation of fault slip rates in the conterminous western United States with statistical and
kinematic finite-element programs.” Documentation for the 2014 Update of the United States
National Seismic Hazard Maps, Appendix C (2013).

Fenton, C.R., Webb, R.H., Pearthree, P.A., Cerling, T.E., Poreda, R.J., 2001. "Displacement rates on the
Toroweap and Hurricane faults: Implications for Quaternary downcutting in the Grand Canyon,
Arizona." Geology 29.11 (2001): 1035-1038.

Hecker, S., 1993. Quaternary Tectonics of Utah with Emphasis on Earthquake-hazard Characterization.
Salt Lake City, UT: Utah Geological Survey, 1993. Print.

U.S. Geological Survey (USGS), Arizona Geological Survey, Colorado Geological Survey, Utah
Geological Survey, New Mexico Bureau of Mines and Mineral Resources, 2006, Quaternary fault
and fold database for the United States, accessed May 7, 2013, from USGS web site:
http://earthquake.usgs.gov/hazards/qfaults

U.S. Geological Survey (USGS), 2010. "2008 United States National Seismic Hazard Maps." 2008
United States National Seismic Hazard Maps. USGS, January. Web.
<http://earthquake.usgs.gov/hazards/products/conterminous/2008/>.

Wong, I.G., S.S. Logi, and J.D. Bott, 1996. Earthquake potential and seismic hazards in the Paradox
Basin, southeastern Utah. In C. Huffman (ed.) 1996 Symposium and Field Conference on the
Geology and Resources of the Paradox Basin (in press).
Attachment 3

Page 10 of 10

Wong, I.G., and J.R. Humphrey, 1989, Contemporary seismicity, faulting, and the state of stress in the
Colorado Plateau: Geological Society of America Bulletin, v. 101, p. 1127-1146.

Probabilistic Seismic Hazard Analysis

ATTACHMENT 4

DAMES & MOORE BORING LOGS (1978)
r--
'\_' APPENDIX A
FIELD EXPLORATION
GEOLOGIC RECONNAISSANCE
During the site selection phase of the investigation, a brief
geologic reconnaissance visit was conducted at each of tbe feasible,
alternate tailings disposal areas. These areas are shown on Plate 2 in
the text of this report. During this geologic reconnaissance, general
geologic, topographic, and environmental considerations for each of the
four sites were studied. This information was used to help select the
most suitable tailing retention site.
A more detailed geologic reconnaissance was carried out at the site
after the proposed location of the tailing retention facility had been
selected. The purpose of this reconnaissance, which was conducted by an
experienced engineering geologist, was to identify the general geologic
conditions at the site, including the relationships of the geologic
units, the locations of springs, and the general occurrences of potential
borrow sources for the pond construction.
SUBSURFACE INVESTIGATION
Subsurface conditions at the site area were investigated by dril-
ling, sampling, and logging a total of 28 borings which ranged in depth
from 6.5 feet to 132.4 feet. Of these borings, 23 were augered to
bedrock to enable soil sampling and the estimation of the thickness of
the soil cover. The remaining 5 borings were drilled through bedrock to
below the water table, with continuous in situ permeability testing where
possible and selective coring in bedrock. Standpipes were installed in
each of the cored holes to enable monitoring of the water table level.
Four shallow borings and one deep hole were drilled within the porposed
mill site. Ten shallow borings and one deep hole were drilled in the
immediate vicinity of the proposed tailing retention facility. The
remaining holes were located around the perimeters of and within the
North and South alternative sit~s. The locations of all borings are
shown on Plate 2, Plot Plan, in the text of this report.
The field exploration program was conducted and supervised by an
experienced Dames and Moore soils engineer. The borings were advanced
using a truck mounted CME 55 rotary drilling rig using 4 inch diameter,
continuous-flight augers in soil and a tricone bit in the bedrock.
Relatively undisturbed soil samples were obtained using a Dames &
Moore soil sampler Type U, as shown on Plate A-1. Disturbed soil samples
were recovered from the Standard Penetration Test sampler. Selective
diamond coring in the bedrock was achieved using a 5 foot long NX double
tube core barrel with a split inner tube.
The soils encountered in the borings were classified by visual and
textural examination in the field, and a complete log for each boring was
maintained. Field classifications were supplemented and verified by
inspection and testing in the Dames & Moore laboratory. A graphical
representation of the soils encountered in the borings is presented on
Plates A-3 through A-11, Log of Borings. Along with written descriptions
of the soils, data on in situ moisture content and density, type of
sample obtained, blow counts, and ground water levels are presented on
the logs. The terminology used to describe the soils encountered in the
borings is shown on Plate A-2, Unified Soil Classification System and
Graphic Log Symbols.
A geotechnical log was maintained for all rock core recovered
during drilling. The following items were logged:
1) Rock type and description of rock material
2) Core run and percent recovery
3) Descripton of rock defects, such as bedding plane breaks and
joints
4) Rock quality designation (RQD: the RQD is a modified core
recovery percentage in which only the pieces of sound core over
4 inches long are counted as recovery)
5) Degree of alteration or weathering
6) Relative strength of the rock
The core log for each cored hole is presented as the continuation of
the soil log for the same hole. Information on bedrock between the cored
section was developed from drill response and interpolation from avail-
able core.
Single packer field permeability tests were performed on the
bedrock to provide in situ permeability data. Permeability was measured
over the full length of the bedrock where field conditions permitted.
Results of the permeability tests are presented on the boring logs.
* * *
The following plates are attached and complete this Appendix:
Plate A-1 Soil Sampler Type U
Plate A-2 Unified Soil Classification System and
Graphic Log Symbols
Plate A-3 through A-11 Log of Borings
NOTE:
WATER OUTLETS
NOTCHES FOR
ENGAGING FISHING TOOL
HEAO
•HEAD EXTENSION" CAN
BE INTRODUCED BETWEEN "HEAD" AND "SPLIT BARREL"
SPLIT BARREL --
(TO FACILITATE REMOVAL
OF CORE SAMPLE)
l
.. l :~
SOIL SAMPLER TYPE U
FOR SOILS DIFFICULT TO RETAIN IN SAMPLER
CHECK VALVES
VALVE CAGE
CORE-RETAINER RINGS
(2·1/2" 0.0. BY 1" LONG)
CORE-RETAINING tiA-----DEVICE
RETAINER RING
RETAINER PLATES
(INTERCHANGEABLE WITH
OTHER TYPES)
ALTERNATE ATTACHMENTS
SPLIT BARREL
LOCKING--..V,-~
RING
SPLIT FERRULE
THIN.WALL ED
SAMPLING TUBE
(INTERCHANGEABLE
LENGTHS)
·CORE-RETAINING DEVICE
DAM•SBMOOR•
PLATE A-I
MAJOR DIVISIONS GRAPH LETTER TYPICAL DESCRIPTIONS SYMBOL SYMBOL
COARSE
GRAINED
SOILS
GRAVEL
ANO
GRAVELLY
SOILS
CLEAN GRAVELS
!LITTLE OR NO
FINES!
MORE THAN
OF COARSE F:~;:• GRAVELS WITH FINES
WELL -GRADED GRAVELS, GRAVEL·
SANO MIXTURES, LITTLE OR
NO FINES GW
POORLY-GRADED GRAVELS, GRAVEL-
SANO MllCTURES, LITTLE OR GP
NO F1NES
SILTY GRAVELS, GR'AVEL-SAND-GM SILT MIXTURES
TION ll!!!.!il.2 APPRECIABLE AMOUNT tl'lo~ ......... ...a-!f------+---------------1
MORE TiiAN &O %
Of MATERIAL IS
.i....A.Ril..B. THAN NO.
~90 SI EVE SIZE
FI NE
GRAINED
SOILS
MORE THAN '50 %,
OF MATERIAL 1$
~THAN NO.
200 SIEVE SIZE
ON NO. 4 SIEVE
SAND
AND
SA NOY
SOILS
OF FINES)
CLEAN SAND
(LITTLE OR NO
FINES
MORE THAN 00 % SANDS WITH FINES
Of COARSE f'RAC· (APPR[CIAl!ILE AMOUNT
TION ~ OF FINES)
NO. 4 SIEVE
SILTS
AND
CLAYS
SILTS
ANO
CLAYS
LIOUID LIMIT
JJ.ll THAN ~0
LIQUID LIMIT
lift~ THAN 50
HIGHLY ORGANIC SOILS
GC
SW
SP
SM
SC
ML
CL
OL
MH
CH
OH
PT
CLAYEY GRAVELS, GRAVEL SANO·
CLAY MIXTURES
WELL -GRADED SANOS, GRAVELLY
SANOS, LITTLE OR NO FINES
POORLY -GRADED SANOS, GRAVELLY
SANOS, LITTLE OR NO FINES
SIL!Y SANOS, SANO-SILT MIXTURES
CLAYEY SANOS, SANO-CLAY MIXTURES
INORGA~IC Sil. TS AND VERY flfrilE
SANDS, ROCK FLOUR, SILTY OR
CLAYEY FINE SANDS OR CLAYEY
SIL TS WITH SLIGHT PLASTICITY
INORGANIC CLAYS or LOW TO MEDIUM
PLASTICITY, GAAVELLY CLAYS,
SANDY CLAYS, SILTY CLAYS, LEAN
CLAYS
ORGANIC SIL TS ANO ORGANIC
SILTY cr..AYS or LOW PLASTICITY
INORGANIC SILTS, MICACEOUS OR
DIATOMACEOUS fl NE SAND OR
SIL TY SOILS
INORGANIC CLAYS OF HIGH
PLASTICITY, FAT CLAYS
ORGANIC CLAYS OF MEDIUM TO HIGH
PLASTICTY, ORGANIC SILTS
PEAT, HUMUS, SWAMP SOILS
WITH HIGH ORGANIC CONTENTS
NOTE: DUAL SYMBOLS ARE USED TO INDICATE BORDERLINE SOIL CLASSIFICATIONS.
~---­-----
SOIL CLASSIFICATION CHART
sos SANDSTONE ~~~--'<1
;::~_-..:-~ SLN SILTSTONE
CLS CLAYSTONE CGL CONGLOMERATE
GRAPHIC LOG SYMBOLS FOR ROCK
UNIFIED SOIL CLASSIFICATION SYSTEM
AND GRAPHIC LOG SYMBOLS
DAM•8BMOOA•
PLATE A-2
::;"~
... w w IL
:!!:
:c ... D.. w Q
6.0%-118
10
15
BORING NO.
EL. 5629.0 FT.
75
20
SM ML RED-BROWN FINE SAND AND SILT,
MEDIUM DENSE
GRADING CALCAREOUS WITH Cl\L-
CITE STRINGERS
LIGHT BROWN, SILTY CLAY, HAW.~
(WEATHERED CLAYS1'0NE)
MEDIUM BROWN, VERY FINE-GRAINED
SANDSTONE; INTERLAYERED WELL-
CEMENTED AND THIN, POORLY-
CEMENTED BANDS
HOLE COMPLETED 9/10/77
NO GROUND WATER ENCOUNTERED
BORING NO. 2
EL. 5634.3 FT.
50/
• 5'i"
SM/ ML RED-BROWN FIHE SAND AND SILT,
MEDIUM DENSE
GRADING CALCAREOUS WITH CAL-
CITE STRINGERS
... 5. 7%-110
90/
l" w w IL
:!!: CL GREEN-BROWN SILTY CLAY (WEATHERED
CLAYSTONE), HARD I= ff; 15----•-0_0--1-
c
... w w IL
:!!:
:c ... D.. w Q
25------
GREENISH-BROWN, FINE-GRAINED SAND-
STONE; INTERLAYERED WELL CEt-·ENTED
AND POORLY-CEMENTED BANDS
HOLE COMPLETED 9/10/77
NO GROUND WATER ENCOUNTERED
BORING NO. 4
EL. 5623.2 FT.
SM/ RED-BROWN FINE SAND AND SIL'J', ML MEDIUM DENSE
GRADING CALCAREOUS WITH CAI..-
crrE STRINGERS
5.1%-107 70
sos GREEN PINE-GRAINED SANDSTONE; IN-
TEHLAYERED WELL CEMENTED AND ~ POORLY-CEMENTED BANDS
15 HOLE COMPLETED 9/10/77
NO GROUND WATER ENCOUNTERED
LOG OF
i-w w IL
:!!:
:c ... Q.. w Q
... w w IL
:!!:
:c ... D.. w Q
BORING NO. 5
EL. 5632.9 FT.
SM/ .ML RED-BROWN FINE SAND AND SILT,
MEDIUM. DENSE
GRADING CALCAREOUS WITH CAL-
CITE STRINGERS
6.2%-97 53
10 16
15
sos GREEN TO BROWN, FINE-GRAINED SlrnD-
STONE; LAYERED UEDIUM TO WELL CE-
MENTED WITH LITTLE POORLY CEMENTED
20------HOLE COMPLETED 9/10/77
NO GROUND WATER ENCOUNTERED
BORING NO. 6
EL. 5633.5 FT.
: SM/ RED-BROWN FINE SAND AND SILT, ML MEDIUM DENSE
GRADES CALCAREOUS WITH CAL-
ISi 39 CITE STRINGERS AND OCCASION
ZONES OF MASSIVE CALCITE CE-
AL
MENTATION
901
5. 6%-108 • 10"
LIGHT BROWN TO GREEN CLAY
15
• 82 (WEATHERED CLAYSTONE) , HARD v.%:; CL
'"""'''"'~ OFF-WHITE SANDSTONE, VERY WELL
CEMENT Bil
20 HOLE COMPLETED 9/18/77
NO GROUND WATER ENCOUNTERED
KEY
A-8 • INDICATES DEPTH AT WHICH UNDISTURBED SAMPLE WAS EX-
TRACTED USING DAMES & MOORE SAMPLER
r~
T
IF l
0 c
!SJ c
A
B
D
E
F
NA
NOTE:
INDICATES DEPTH AT WHICH DISTURBED SAMPLE WAS EXTRACTED
USING DAMES & MOORE SAMPLER
INDICATES SAMPLE ATTEMPT WITH NO RECOVERY
INDICATES DEPTH AT WHICH DISTURBED SAMPLE WAS ·EXTRACTED
USING STANDARD PENETRATION TEST SAMPLER
FIELD MOISTURE EXPRESSED AS A PERCENTAGE OF THE DRY
WEIGHT OF SOIL
DRY DENSITY EXPRESSED IN LBS/CU FT
BLOWS/FT OF PENETRATION USING A 140-LB HAMMER
DROPPING 30 INCHES
INDICATES NC CORE RUN
PERCENT OF CORE RECOVERY
RQD*
INDICATES PACKER TEST SECTION
PERMEABILITY MEASURED BY SINGLE PACKER TEST IN FT/YR
NOT APPLICABLE (USED FOR RQD IN CLAYS OR MECHANICALLY
FRACTURED ZONES)
ELEVATIONS PROVIDED BY ENERGY FUELS NUCLEAR, INC.
* ROCK QUALITY DESIGNATION --PERCENTAGE OF CORE RECOVERED IN
LENGTHS GREATER THAN 4 INCHES
BORINGS
DAMES e MOORE
PLATE A-3
<·j
···1
.... w w IL
;!;
:c .... 0.. w Q
·."·:
BORING NO. 3
EL. 5634.4 FT.
7.6%-100
7.0%-108 • 35
rSJ 13 lo-----ittm
25
T
30
I 568
I
T
35
2.8
40
I
+
45
5.8
so
-1..
55
16.2
60
I
T
65
I I s. 3
70
-1..
75
3. 2
80
.SM/ ML RED-BROWN, FINE SAND AND SILT,
LOOSE
GRADING CALCAREOUS WITH MINOR
CALCITE STRINGERS
BROWN SILTY CLAY (WEATHERED CLAY-
STONE) , HARD
DARK GRAY, FHJ:C: GRAINED, SIL'l'Y
SANDSTONE WITH YELLOW BANDS; MOSTLY
WELL CEMENTED ilUT WITH SOME THIN,
SOFT, CLAYEY BANDS
LIGHT GRAY, MEDIUM GRAINED, WELL
CEMENTED SANDSTONE WITH ORANGE
LIMONITE s·rAINED BANDS
LIGHT TO MEDIUM GREEN-BROWN,
MEDIUM TO COARSE-GRAINED SAND-
STONE
WELL CEMENTED
GROUND WATER LEVEL 56. 8 FT
11/4/77
CONGLOMERATE IN LIGH'l' GRAY, FINE
SAND MATRIX FROM 62. 4 TO 63 FT
GRADES THROUGH WHITE SILTSTONE
TO A GREEN CLAYSTONE
YELLOW, MEDIUM-GRAINED SANDSTONE
DRILLING INDICATES GENERALLY
WELL-CEMENTED SANDSTONE WITH
MINOR CONGLOMERATE BANDS
MATCH LINE
LOG OF
100
4.9 I
105
I
T
I
110
.... w w IL
;!; 115
:c .... 0.. w Q
120
145------
BORINGS
MATCH LINE
LIGHT GRAY, FINE-GRAINED SAND-
STONE, POORLY CEMENTED IN PARTS
LIGHT BROWN TO PALE GRAY, FINE TO
MEDIUM-GRAINED SANDS'l'ONE
INTERLAYERED E.ANDS OF SANDY, GREEN
CLAYSTONE AND PALE BROWN SANDSTONE
DRILLING IhDICA'IES UNFRACTURED,
WELL CEMEN'IED SP..NDSTONE
HOLE COMPLETED 9/14/77
DAMES e MOORE
PLATE A-4
.... w w IL = :c .... IL w c
.... w w IL = :c .... IL w c
.... w w IL = :c .... IL -,:"i w c
BORING NO. 7
3. 9%-103
10
15
EL. 5656.9 FT.
90/
• 11"
SM ML
OS
RED-BR01VN FINE SAND AND SILT,
MEDIUl1 DENSE
GRADING CALCAREOUS WITH CALCITE
STRINGERS AND OCCASIONAL ZONES
OF MASSIVE CALCITE CEMENTATION
PALE BROWN, FINE GRAINED, WEATHERED
SANDS1'0NE, GRADING HARDER
DARK BROWN TO DARK GRAY, FINE TO
MEDIUf.'~ GRAINED, WEATHERED SANDSTO~VE,
GRADES HARDER AND TAN COLORED
INTERBEDDED HARD AND VERY HARD,
LIGHT GRAY SA"•mSTONE
20------HOLE COMPLETED 9/18/77
NO GROUND WATER ENCOUNTERED
BORING NO. 10
EL. 5690.9 FT.
SM/ ML RED-BROWN
DENSE
FINE SAND AND SIL'!',
6. 7%-106 • ~~(. GRADING CALCAREOUS WITH CAL-
CITE STRINGERS
~ 84/
10 8"
15
GRADING VERY CALCAREOUS AND
VERY DENSE
YELLOW TO GREEN, FHlE TO MEDIUM
GRAINED, WEATHERED SANDSTONE
GRADING HARD, GREEN, MEDIUM TO
COAP.SE-GRAINED SANDSTONE
HOLE COMPLETED 9/19/77
20------NO GROUND WATER ENCOUNTERED
10
BORING NO. 13
EL. 5602.4 FT.
RED-BROWN FINE SAND AND SILT,
MEDIUM DENSE
PALE GREEN, MEDIUM-GRAINED SANDSTONE
BECOMES VERY WELL-CEMENTED
HOLE COMPLETED 9/18/77
NO GROUND WATER ENCOUNTERED
LOG OF
.... w w IL = :c .... IL w c
.... w w IL =
:c .... IL w c
.... w w IL =
10
15
20
BORING NO. 8
EL. 5668.4 FT.
54/
1816"
37
50/ _-_::-_-0 2J," --_-
SM/ ML RED-BROWN FINE SAND AND SILT,
DENSE
GRADING CALCAREOUS WITH CAL-
CITE STRINGERS
GRADING TO MASSIVE CALCITE
CEMENTATION
GREEN, MEDIUM TO COARSE GRAINED,
WEATHERED SANDSTONE
DARK GRAY, SILTY CLAYSTONE,
WEA'l'HERED WITH YELLOW-ORANGE IRON
STAINING, GEi~ERALLY VERY DRY
GRADES TO VERY HARD
DARK GRAY, MEDIUM-GRAINED SANDSTONE,
RELATIVELY UNCBMENTED
OFF-WHITE, MEDIUM-GRAINED SANDSTONE,
~VELL CEMENTED
HOLE COMPLETED 9/19/77
NO GROUND WATER ENCOUNTERED
30------
BORING NO. II
EL. 5677.8 FT.
50/
1814'>"
SM/
.ML RED-BROWN FINE SAHD AND SILT
GRADING CALCAREOUS WITH CAL-
CITE STRINGERS AND SOME ZONES
OF MASSIVE CALCITE CEMENTATION
:c 50/ t ~4'>"
LIGHT BROWN, FINE GRAINED,
WEATHERED SAiilDSTONE
~ !Q------L
GRADING WELL CEMENTED
HOLE COMPLETED 9/18/77
NO GROUND WATER ENCOUNTERED
is------
BORING NO. 14
EL. 5597 .5 FT.
SM/ ML RED-BROWN FINE SAND AND SILT,
MEDIUM DENSE
3. 2%-105 • 42
GRADING CALCAREOUS WITH CAL-
CITE STRINGERS
10
15------
LIGHT GRAY TO OFF-WHITE, MEDIUM
TO COARSE-GRAINED SANDSTONE, VERY
WELL CEMENTED
COLOR GRADES TO YELLOW-TAN
HOLE COMPLETED 9/18/77
NO GROUND WATER ENCOUNTERED
BORINGS
DAMES e MOORE
PLATE A-5
10
15
20
25
30
35
Iii 40 w IL
3
:c ~ 4S c
50
55
60
65
70
75
80
BORING NO. 9
EL. 5679.3 FT.
M/ ML
82/ ~~-•~9"_'+'~-~:~:~_-~C-L-S~
RED-BROWN FINE SAND AND SILT
MOTTLED OFF-WHI'l'E A1'1D GREEN,
WEATHERED SILTY CLAYSTONE
OFF-WHITE TO GREEN, CLAYEY,
WEATHERED SANDSTONE
GRADES HARDER TO GREEN SANDSTONE
GREEN, FINE TO MEDIUM-GRAINED,
WEATHERED, CLAYEY SANDSTONE
Mf:DIUM GRAY I CI.AVEY SII.'T'S'l'ONP.
BLACK, HIGHLY WEATHLRED, SOFT,
LAMINA'l'ED CLAYSTONE WITH ORANGE
LlMONTTE-STAINED LAYERS
MEDIUM BROWN, FINE TO MEDIUM-GRAINED
SANDSTONE; VARIES FROM MODERATELY
CEMENTED TO VERY POORLY-CEMENTED
MEDit:M-GRAiNED SANDSTONE, MODERATELY
CEUENTED, WITH IRON STAINING ALONG
HORIZONTAL FRACTURE
BANDED, LIGHT TO MEDIUM GREEN SILT-
STONE, CLAYEY AND SOFT IN PART
DARK GRAY TO BLACK, r·lEDIUM GRAINEUr
WELL CEMENTED, CARBONACEOUS SANDSTONE
WITH SOME SOFT, BLACK, CLAYEY BANDS
OCCASIONAL THIN, CARBONACEOUS
BANDS CQNT:::NUE
VERY WELL CEMENTED, LIGHT GRAY TO OFF-
WHITE, MEDIUM-GRAINED SANDSTONE
POORLY-CEMENTED PEBBLE CONGLOMERATE
IN BROWN, SANDY MATRIX, SOME UNCENENTED
SANDY BANDS
MODERATELY-CEMENTED TO POORLY-CEMEN'l'ED
SANDSTONE
GRADES WELL CEMENTED
MATCH LINE
1.1
100
.... w w
"-105
3
:c I .... I ... w c 100 110
89
115
120
0.3
125
I 130 I
J..
135
LOG OF BORINGS
MATCH LINE
GRAY-BROWN, MEDIUN GRAINED, MODER-
ATELY TO POORLY-CEMENTED SANDSTONE,
HIGHLY FRACTURED BY DISKING PERPEN-
DICULAR TO CORE AXIS
GROUND WATER LEVEL 99.8 FT, 11/4/77
PALE GREEN, MEDIUM GRAINED, HARD,
SILICIFIEil SANDSTONE.
PALE GREEN, SANDY CLAYSTONE FROM
10 7. 7 TO 108. 2 FT
DARK GREEN, MEDIUM GRAINED, CLAYEY
SANDSTONE, MODERATELY HARD WITH MINOR
INCLUSIONS OF DARK BROWN, ANGULAR
GRAVEL-SIZED CHERT
HOLE COMPLETED 9/27/77
DAllllES B llllOOAE
PLATE A-6
1-w w IL
BORING NO. 1.2
EL. 5648.1 FT.
S4/
181 6"
88/
6.2%-104. 4"
lS
20
2S
30
I
I
I
-t
J_
I
S.l
79.2
SM/
:ML RED-BROWN
DENSE
FINE SAND AND SILT,
GRADING CALCAREOUS WITH THIN
LAYERS OF VERY CALCAREOUS
MATERIAL
GREEN AND YELLOW, FINI:: TO MEDIUM
GRAINED, tV'LATHERED SANDSTONE
GREEN, FINE GRAINED, CLAYEY,
WEATHERED SANDSTONE WITH YELLOW
AND RED IRON STAINING
BECOMES LESb CLAYEY; MOST
CIRCULATION LOS'!
VERY LIGHT BROWN TO GRAY, MEDIUM-
GRAINED SANUSTONE WITH SOME ORANGE
STAINING; MODERATELY TO WELL
CEMENTED AT TOP, BECOMES POOiH .. Y-
CEMENTED AT 35 FT
GENERALLY MODERATELY-CEMENTED
SANDSTONE
~40 ~-----<"
I= ... w c WELL-CEMENTED SANDSTONE
4S
0.9 MODERATELY-CEME.N'l'ED SANDSTONE
so WELL CEMENTED
tzz¢:::::tCLS~ · ~=~;;;~-CLS :rsos GREEN, SANf)Y CLAYSTONE WITH
SS -'----+=__..,======~ SOME RED IRON STAINING, SOF'l'
+
1. 4
SOS~ GREEN, FINE GRAINED, MODER-
ATELY-CEMENTED SANDSTONE
INTERLAYERED SANDSTONE AND SANDY
CLAYS'l'Oi:~l:;
WELL-CEMENTED SANDSTONE, APPAR-
ENTLY WITH OCCASIONAL FRACTURELJ
ZONES
LIGHT BROWN, MEDIUM-GRAINED SAND-
STONE, MODERATELY CEMENTED, GRADING
WELL CEMENTED
LOG OF
100
J_
I-~105
IL
1!::
:c I-... ~110
llS
120
12S
130
13S
GROUND WATER LEVEL 81.3 FT, 11/4/77
CIRCULATION LOST, STILL APPEARS
WELL CEMENTED
BECOMES LESS CEMENTED
SOME CIRCULATION nEGAINED BUT
STILL LARGE WATER LOSSES
WELL-CEtfili.'lTED SANDSTONE
POORLY-CEMENTED SANDSTONE
POORLY-CE~IBNTED SANDSTONE
WELL-CEMLNTED SANDSTONE
POORLY-CEMENTED, POSSIBLY CONGLO!!-
ERATE OR FRACTURED SANDSTONE
MODERATELY-CEME.NTED SANDSTONE
POORLY-CEMENTED SANDSTONE
WELL-CEMENTED SANDSTONE
HOLE COMPLETED 9/29/77
BORING NO. 15
EL. 5600.7 FT.
I-. w w IL
1!::
I= ... ~ 10
• 63
ISi 81
lS------
BORINGS
SM/ ML
CLS
RED-BROWN FINE SAND AND SILT,
MEDIUM DENSE
GRADING CALCAREOUS WITH CALCITE
STRINGERS
GREEN, WEl\THERED CLAYSTONE
GREEN, FINE TO MEDIUM-GRAINED
SANDSTONE
GRADES WELL CEMENTED
HOLE COMPLETED 9/17/77
NO GROUND WATER ENCOUNTERED
DAMES B MOORE
PLATE A-7
1-w w IL
BORING NO. 16
6.3%-104
EL. 5597.5 FT •.
SM :.··· :ML RED-BRONN FINE SAND AND SILT / MEDIUM DENSE
GRADING CALCAREOUS WITH CAL-
CITE STRINGERS
GRA.DES DENSE
~ 10 ---'-"-=-'JI
:c J.W ............. -
1-IL w c
... w w IL
PALE GREEN TO WHITE, FINE TO
COARSE-GRAINED SANDSTONE, ALTER-
NATING WELL-CEMENTED AND POORLY-
CE~IENTED BANDS
BECOMES C0i'1TINUOUSLY WELL-
CE~1ENTED
20------HOLE COMPLETED 9/10/77
.llO GROUND WATER ENCOUNTERED
10
BORING NO. 18
EL. 5608.5 FT.
.SM/
:Ml. RED-BROWN FINE SAND AND SILT,
MEDIUM DENSE
GRADING CALCAREOUS WITH CAL-
CITE STRINGERS
OFF-WH !TE, POORLY CEMENTED,
WEATHERED SANDSTONE WITH LAYERS
OF WEATHERED CLAYSTONE
GREEN SANDSTONE
;!: 15 _____ _J: GREEN, WEATHERED CLAYSTONE WITH
OAANGt: IHON STAINING :c Ii: w c
... w w IL
;!:
:c ... IL w c
50/ =-=-=-r;;J 4" ---
25 ------I:
50/ ==-=-=-
00" ------30 ------HOLE COMPLETED 9/17/77
NO GROUND WATER ENCOUNTERED
BORING NO. 20
10
EL. 5570.4 FT.
· · SM/ ML RED-BROWN FINE SAND AND SILT,
LOOSE TO MEDIUM DENS:>:
LIGHT BROWN, FINE TO MEDIUM-
GRAINED SANDSTONE, GRADING WELL-
CEMENTED
HOLE COMPLETED 9/17/77
NO GROUND WATER ENCOUNTERED
LOG OF
BORING NO. 17
EL. 5582.0 FT.
... 5.5%-105. 76 w w IL
;!:
:c Ii: w 10 _____ _,,,,
c
15------
SM/ ML RED-BROW::-J FINE SAND AND SILT
GRADING CALCAREOUS WITH CAL-
CITE STRINGERS AND INCLUSIONS
SOS GREEN, FINE TO MEDIUM-GRAINED
SANDSTONE, INIITALLY WEATHERED,
GRADING WELL CEMENTED
LAYERED POORLY-CEMENTED AND
WELL-CEMENTED, POSSIBLY SOME CI:.AY-
STONE LAYERS
LAYERED WELL-CEMENTED AND VERY
WELL-CEMENTED
HOLE COMPLETED 9/17/77
NO GROUND WATER E~COUNTERED
BORING NO. 21
EL. 5584.5 FT.
1-w w IL
;!:
:c Ii: w 10-----~" c
15------
RED-BROWN FINE SAND AND SILT,
LOOSE TO MEDIUM DENSE
GREEN CLAY WITH SOME GYPSUM
CRYSTALS,(WEATHERED CLAYSTONE}
STIFF TO VERY STIFF
GREEN, FINE GRAINED, WEATHERED
SANDSTONE
BECOMES WELL-CEMENTED
HOLE COMPLETED 9/17/77
NO GROUND WATER ENCOUNTERED
BORING NO. 22
EL. 5585.3 FT.
73/
12. 5%-llB.10'!'
60/ .: ..
r;;J 6" ... w 101-----~ w IL
;!:
i= IL ~ 15
50/
1814"
55/
r;;J 6"
25------
BORINGS
SM/ ML
CL
RED-BROWN FINE SAND AND SILT
GRADING CALCAREOUS WITH CAL-
CITE STRINGERS
GRADES CLAYIER
LIGHT BROWN TO OFF-WHITE, SILTY
CLAY
GREEN, Flt~L GRAii·mD, 'i4EATHi:::RED
SANDSTONE WITH HIGH CLAY CONTENT,
POORLY-CEMENTED
BECOMES WELL-CEMENTED
HOLE COMPLETED 9/17/77
NO GROUND WATER ENCOUNTERED
DAMES £. MOORE
PLATE A-8
'
.... w w IL
z
BORING NO. 19
EL. 5600.3 FT.
93/.
12.4.%-92 • 11"
10
15
25
30
35
-'-I
7.0
10
95/
!SJ 9"
•'SM/ :·:··.ML
.,.
RED-BROWN FINE SAND AND SILT,
MEDIUM DENSE
GRADING CALCAREOUS WTIH
CALCITE STRINGERS
GRADES VERY CALCAREOUS AND
VERY DENSE
BECOMES VERY LOOSE, POSSIBLY
WITH VOI.JS
BECOMES DENSE
GREEN, FINE TO MEDIUM-GRAINED
SANDSTONE, >VEATHE.RED, WITH SOME
ORANGE AND YELLOW IRON STAINING
GRAY-GREEN, FINE TO MEDIUM GRAINED,
WEATHERED, CLAYEY SANDSTONE WI'l'H
ORANGE AND YELLOW IRON STAINI~G
BECOMES LESS WEATHERED WITH LESS
CLAY, PREDOMINANTLY GRAY WITH
ORANGE IRON STAINING, MODERATELY
CEMENTED, MEDIUM GRAINED
BROWN-YELLOW, COARSE-GRAINED SANDSTONE
FINE GRAVEL CONGLOMERATE WITH CONSID-
ERABLE COARSE-GRAINED SAND AND CAL-
CAREOUS MATRIX
-40
:c .... IL w c
943
45
BROWN TO YELLOW, COARSE-GRAINED SAND-
STONE WITH CONSIDERABLE NEAR HORI-
ZONTAL FRACTURING AND SOME ORANGE
IRON STAINING, MODERATELY CEMENTED
WATER RETURN COMPLETELY LOST
LIGHT GRAY, MEDIUM TO COARSE-GRAINED
SANDSTONE; HIGHLY FRACTURED ALONG
HORIZONTAL BEDDING, CONSIDERABLE
LIMONITE STAINING ALONG BEDDING FRACTURES; MODERATELY CEMENTED TO
UNCEMENTED, CORE LOSSES ASSUMED
DUE TO WASHING AWAY OF UNCEMENTED
ZONES
LIMITED WATER RETURN
BECOMES VERY UNCEMBNTED, WATER
RETURN LOST
HOLE LOST AT 72 FT; HOLE 19A
DRILLED 15 FT SOUTH OF HOLE 19;
NO WATER RETURN OBTAINED; NO
SAMPLING POSSIBLE; HOLE LOGGED
FROM DRILLING PROGRESS
VERY WELL-CEMENTED SANDSTONE ( 72 FT)
MODERATELY-CEMENTED SANDSTONE (73 FT)
LOG OF
.... w w IL
~105-------1
~ IL w c
130------
BORINGS
MODERATELY WELL-CEMENTED CONGLOMERATE
OR FRACTURED SANDSTONE, GRADING BETTER
CEMENTED
GRADING LESS CEMENTED
VERY POORLY-CEMENTED SANDSTONE
MODERATELY-CEMENTED CLAYSTONE
POORLY-CEMENTED SANDSTONE WITH
MINOR HARD LENSBS
MODERATELY-CEMENTED SANDSTONE
GRADES LESS CEMENTED
APPEARS CLAYEY
MODERATELY-CEMENTED SANDSTONE
GROUND WATER LEVEL llO FT, ll/ 4/77
POORLY-CEMENTED SANDSTONE WITH
OCCASIONAL BANDS OF GRAVEL OR
CONGLOMERATE
VERY WELL-CEMENTED SANDSTONE
VERY POORLY-CEMENTED SANDSTONE
VERY WELL-CEMENTED SANDSTONE
BECOMES LESS CEMENTED AND CLAYEY
HOLE COMPLETED 9/25/77
DAMES e MOORE
PLATE A-9
..
I-w w IL
:!:
:c I-IL w c
I-w w IL
:!:
:c I-IL w c
~ w c
10
15
BORING NO. 23
EL. 5555.9 FT.
RED-BROWL'l FINE SAND AND SILT 1 LOOSE TO MEDIUM DENSE
GRADING CALCAREOUS WITH CAL-
CITE STRINGERS
GRADES MEDIUM-GRAINED
MOTTLED COLORS FROM RED TO
W6ITE AND YELLOW
YELLOW TO LIGHT BROWN, MEDIUM TO
COARSE-GRAINED SAND (WEATHERED
SANDSTONE) ___ __1l2..::_j=:i:ztl:;:;:;;fCL GREEN TO WHITE MOTTLED CLAY SDS (WEATHERED CLAYSTONE)
OFF-WHITE TO YELLOW BROWN, MEDIUM
TO COARSE-GRAINED, POORLY CEMENTED
SANDSTONE, GRADES WELL CEMENTED
HOLE COMPLE1'ED 9/10/77
NO GROUND WATER ENCOUNTERED
20------
10
15
BORING NO. 24
EL. 5573.4 FT
SM/ ML
!81~~/ ~-..... ,,.,,., -----"--I
50/
rs!%"
RED-BROWN FINE SAND AND SILT,
LOOSE TO MEDIUM DENSE
GRADING CALCAREOUS WITH CALCITE
STRINGERS
OFF-WHITE, FINE GRAINED, WEATHERED SANDSTONE, GRADES WELL-CEMENTED
OFF-WHITE, FINE TO MEDIUM GRAINED,
MODERATELY WELL-CEMENTED SANDSTONE
LIGHT BROWN, FINE TO MEDIUM GRAINED,
WELL-CEMEi.~TED SANDSTONE
HOLE COMPLETED 9/17/77
NO GROUND WATER ENCOUNTERED
BORING NO. 26
EL. 5578.3 FT.
RED-BROWN FINE SAND AND SILT,
LOOSE TO MEDIUM DENSE
GRADING CALCAREOUS WITH CALCITE SD S STRINGERS
OFF-WHITE, FINE TO MEDIUM-GRAINED
SANDSTONE, WEATHERED, GRADING WELL-
CEMENTED
10 ------
VERY WELL CEMENTED
HOLE COMPLETED 9/17/77
NO GROUND WATER ENCOUNTERED
LOG OF
I-w w IL
:!:
:c I-IL w c
10
I-w w IL
:!:
:c I-IL w c
10
BORING NO. 27
EL. 5555.0 FT •
. ·<.·SM/ . "ML
18J50/JW!,1,ij;b~ ~~~~2_"~" SDS
RED-BRO°i'JN FINE SAND AND SILT,
LOOSE TO MEDIUM DENSE
GRADING C.\LCAREOUS WITH CALCITE
STRINGERS
GREENISH, FL.JE TO MEDIUM-GRAINED
SANDSTONE, VERY WELL-CEMENTED
HOLE COMPLETED 9/17/77
NO GROUND WATER ENCOUNTERED
BORING NO. 29
EL. 5655.0 FT. !APPROX.)
SM ML RED-BROWN FINE SAND AND SILT,
LOOSE
GRADES MEDIUM DENSE
GRADING CALCAREOUS
WHITE TO SLIGHTLY TAN SANDSTONE
BECOMES WELL-CEMENTED
HOLE COMPLETED 9/30/77
NO GROUND WATER ENCOUNTERED
BORINGS
DAIWES e IWOOAE
PLATE A-10
t-w w u.
BORING NO. 28
EL. 5547.6 FT.
76/
10 --~-"-'-......_llltl
15 15 ---~---ll'fl
ISJ ~~(, 20----"-"'-IJ
T
.SM/ ML RED-BROWN FINE SAND AND SILT'
MEDIUM DENSE
GRADING Cl1LCAREOUS Wl'l'H
CALCITE STRINGERS
GRADES LIGHT BROWN AND VERY DENSE
BECOMES LOOSE
BECOMES VERY DENSE
ORANGE TO YELLOW, MEDIUM TO FINE
GRAINED, SILTY SAND (WEATHERED
SANDSTONE)
LIGHT GREENISH-GRAY, FINE TO
MEDIUM-GRAINED SANDSTONE WI'l'H
SOME GRAVEL TO PEBBLE-SIZED IN-
CLLSIONS; SOi1E MINOR LIMONITE
STAINING; FRACTURE.$ HORIZONTAL
LIGHT GREEN, FINE-GRAINED SAI\'D-
STONE WITtl LAYE.RS OF GREEN CLAY-
STONE UP TO 4 INCHES THICK
:a: 40~----1-="-""
:c t-Q. w 0
75------<
T
I
MEDIUM TO LIGHT BROWN, MEDIUM TO
COARSE GRAINED, WE.LL-CEMENTED SAND-
STONE, IRON STAINING EVIDENT AT
CONTACT WITH OVERLYING FINI::R-
GRAINED SANDSTONE
CIRCULATION LOST
LIGHT GRAY, MEDIUM TO COARSE-
GRAINED SANDSTONE WITH SECTIO~S OF
VERY POORLY-CEMENTED SANDSTONE
INTERLAYERED, POORLY-CEMENTED AND
WELL-CEMENTED SANDSTOi>J"E AND CON-
GLOMERATE
CASING INSTALLED TO 74 FT
GROUND WATER LEVEL 75. 7 FT, ll/ 4/77
MATCH LINE
LOG OF
80
85
90
t-
I
14. 3
I
I
J.
I 0.3
I
:!Jl05 ~-----I"
u.
:!!!: j_
I
I
I
0.2
135------
BORINGS
MATCH LINE
GRAVEL AND PEBBLE CONGLOMERATE WITH
SANDY MATRIX IN PLACES UNCEMENTED
LIGHT GRAY TO OFF-WHITE, FINE TO
MEDIUM-GRAINED SANDSTONE, WELL
CEMENTED
GENERALLY LIGHT GRAY SANDSTONE WITH
OCCASIONAL 3ANDS OF BROWN, CLAYIER
SANDSTONE
GRADES DARKER GRAY
LIGHT GRAY, WELL-CEMENTED SANDSTONE
LIGHT GRAY, MEDIUM GRAINED, WELL-
CEMENTED SANDSTONE; FRACTURES
GENERALLY NEAR HORIZONTAL
HOLE COMPLETED 9/21/77
DAMES e MOORE
PLATE A-11