DRC-2014-003187 - 0901a06880438a51

Energy Fuels Resources (USA) Inc.
225 Union Blvd. Suite 600
Lakewood, CO, US, 80228
303 974 2140
F www.energvfuels.com
ENERGYFUELS DRC-2014-003187
Mr. Rusty Lundberg
Division of Radiation Control
May 1, 2014
Sent VIA E-MAIL AND OVERNIGHT DELIVERY
Utah Department of Environmental Quality ^^~n32X^
195 North 1950 West
P.O. Box 144850
Salt Lake City, UT 84114-4820
Re: Transmittal of Background Report for Monitoring Wells MW-35, MW-36, and MW-37
Groundwater Quality Discharge Permit UGW370004 White Mesa Uranium Mill
Dear Mr. Lundberg:
Enclosed are two copies of the White Mesa Uranium Mill Background Report for monitoring wells
MW-35, MW-36, and MW-37 as required by the Groundwater Quality Discharge Permit
UGW370004. Also enclosed are two CDs, each containing a word searchable electronic copy of the
report and the associated appendices.
As noted in the Background Report, these wells have been sampled quarterly since installation in 2010
and 2011. The GWDP required the completion of a Background Report after the collection of eight
quarters of data. Analysis of the background data, after eight quarters, indicated that additional data
were required to meet the statistical requirements of the flowsheet. Data collection continued until
sufficient data were available to complete the background analyses. As discussed with Division of
Radiation Control personnel by telephone on June 17, 2013, this Background Report was completed
after there were eight statistically valid data points for MW-35, MW-36 and MW-37.
If you should have any questions regarding this report please contact me.
Yours very truly,
ENERGY FUELS RESOURCES (USA) INC.
Kathy Weinel
Quality Assurance Manager
cc: David C. Frydenlund
Harold R. Roberts
David E. Turk
Dan Hillsten
BACKGROUND GROUNDWATER QUALITY
REPORT FOR MONITORING WELLS MW-35,
MW-36, AND MW-37
WHITE MESA URANIUM MILL
Blanding, Utah

Prepared for:
Energy Fuels Resources (USA) Inc.
225 Union Boulevard, Suite 600
Lakewood, CO 80228

Prepared by:
6000 Uptown Boulevard NE, Suite 220 Albuquerque, New Mexico 87110

May 1, 2014

Background Groundwater Quality Report for MW-35, MW-36, and MW-37 White Mesa Uranium Mill
Blanding, Utah ES-i May 1, 2014
EXECUTIVE SUMMARY
Monitoring well (“MW”) MW-35 was installed along the western edge of Cell 4B in 2010, while
MW-36 and MW-37 were installed on the western and southern edges of Cell 4B, respectively,
in 2011. Since completion of these wells, they have been monitored on a routine frequency. The
purpose of this Report is to evaluate the data from these wells, establish background groundwater
quality conditions, and determine groundwater compliance limits (“GWCLs”) for each
groundwater discharge permit constituent in each well.
Background at the White Mesa Uranium Mill (the “Mill”) site was recently thoroughly studied in
the previously submitted “Existing Wells Background Report” and “New Wells Background
Report” (INTERA, 2007; 2008), in the University of Utah Study (Hurst and Solomon, 2008), and
in several Source Assessment Reports (“SARs”) (INTERA, 2012-2014). All of these evaluations
concluded that groundwater at the Mill site has not been impacted by Mill operations. All of
these studies also acknowledged that there are natural influences at play at the site that have
given rise to increasing groundwater concentration trends and general variability of background
groundwater at the site.
Groundwater sampling data from these new wells were analyzed according to the Flow Sheet
that was approved by the State of Utah Division of Radiation Control (“DRC”). Analysis of data
from MW-35, MW-36, and MW-37 confirms the high variability of all constituents across the
site and the region described in previous reports. Indicator parameters chloride, fluoride, sulfate,
and uranium are not exhibiting statistically significant increasing trends, supporting the
conclusions stated in the other Background Reports and investigations performed at the site that
groundwater at the site has not been impacted by Mill operations.
Increasing trends in some constituents were identified during the background analysis. Based on
the DRC-approved Flow Sheet, the indicated action for trending constituents is “Consider
Modified Approach to GWCL.” The modified approach, presented herein, uses fundamental
methodology from the United States Environmental Protection Agency (“USEPA”) Unified
Guidance (USEPA, 2009), along with established elements of the current State of Utah Ground
Water Discharge Permit UGW370004, to determine GWCLs that take naturally occurring trends
into account while remaining protective of human health and the environment. This modified
approach has been applied to the trending constituents in MW-35, MW-36, and MW-37.
GWCLs for permit constituents that did not exhibit an increasing trend were determined
according to the Flow Sheet.

Background Groundwater Quality Report for MW-35, MW-36, and MW-37 White Mesa Uranium Mill
Blanding, Utah i May 1, 2014
TABLE OF CONTENTS
EXECUTIVE SUMMARY ..................................................................................................... ES-i
LIST OF FIGURES ...................................................................................................................... ii
LIST OF TABLES ........................................................................................................................ ii
LIST OF APPENDICES .............................................................................................................. ii
ABBREVIATIONS AND ACRONYMS .................................................................................... iii
1.0 INTRODUCTION............................................................................................................. 1
2.0 STATISTICAL ANALYSIS OF BACKGROUND GROUNDWATER QUALITY DATA ................................................................................................................................. 4
3.0 RESULTS OF ANALYSIS AND DETERMINATION OF GROUNDWATER COMPLIANCE LIMITS ................................................................................................. 6
3.1 Indicator Parameters ............................................................................................... 6
3.2 Trending Constituents ............................................................................................. 6 3.3 Groundwater Compliance Limits ............................................................................ 6
3.4 Modified Approach for Groundwater Compliance Limits for Trending
Constituents............................................................................................................. 7
3.4.1 Gross Alpha ............................................................................................... 8
3.4.2 Nitrate ........................................................................................................ 9 3.4.3 Total Dissolved Solids ............................................................................... 9
3.4.4 Selenium .................................................................................................. 10
3.4.5 Sulfate ...................................................................................................... 11
3.4.6 Thallium .................................................................................................. 11
3.5 Hydraulic Properties ............................................................................................. 11 3.6 Relationship to Tailings Cells ............................................................................... 11
4.0 CONCLUSIONS ............................................................................................................. 13
5.0 REFERENCES ................................................................................................................ 14

Background Groundwater Quality Report for MW-35, MW-36, and MW-37 White Mesa Uranium Mill
Blanding, Utah ii May 1, 2014
LIST OF FIGURES
Figure 1 Location of Groundwater Monitoring Wells MW-35, MW-36, and MW-37
Figure 2 Groundwater Data Preparation and Statistical Process Flow for Calculating Groundwater Compliance Limits
Figure 3 Addendum to Groundwater Data Preparation and Statistical Process Flow for
Calculating Groundwater Compliance Limits for Trending Constituents

LIST OF TABLES
Table 1 Monitoring Parameters and Groundwater Quality Standards Table 2 Laboratory Analytical Methods
Table 3 Comparison of Calculated and Measured TDS for Samples with Complete Major
Ion Analysis
Table 4 Charge Balance of Major Cations and Anions Table 5 Relative Percent Difference Between Primary and Duplicate Samples Table 6a Descriptive Summary Statistics for Constituents with Greater than 50 Percent Detects
Table 6b Descriptive Summary Statistics for Constituents with Less than 50 Percent Detects
Table 7 Geometric Mean and Standard Deviation of Normally or Lognormally Distributed
Data Table 8 Summary of Flow Sheet GWCL Calculations Based on UDEQ-Approved Flow Sheet Table 9 Summary of Trending Constituents and Modified GWCLs Based on the Flow Sheet
Table 10 Summary of Proposed Groundwater Compliance Limits
Table 11 Well Construction and Hydraulic Parameters
LIST OF APPENDICES
Appendix A Box Plots
Appendix B Histograms and the Shapiro-Wilk Test for Data Sets with 0%-50% Non-Detects
Appendix C Linear Regression Plots – Substituting Half the MDL for Non-Detected Values
(Regression Plots for Wells and Constituents with 15%-100% Non-Detects are
Considered Exploratory Statistics) Appendix D Probability Plots – Substituting Half the MDL for Non-Detected Values
Appendix E Censored and Detected Values Only Probability Plots and Mean Adjustments –
Normally and Lognormally Distributed Data Sets with 15%-50% Non-Detected
Values
Appendix F Mann-Kendall Trend Analysis for Data Sets not Normally or Lognormally Distributed and with 0%-90% Non-Detected Values
Appendix G Data That Have Been Removed or Modified Prior to Statistical Analyses
Appendix H Input and Output Files (Electronic Only)
Appendix I Increasing Trends Modified GWCL Approach

Background Groundwater Quality Report for MW-35, MW-36, and MW-37 White Mesa Uranium Mill
Blanding, Utah iii May 1, 2014
ABBREVIATIONS AND ACRONYMS
µg/L micrograms per liter
CFCs chlorofluorocarbons

Director Director of the Division of Radiation Control
DRC State of Utah Division of Radiation Control EFRI Energy Fuels Resources (USA) Inc.

GWCL groundwater compliance limit
GWDP State of Utah Ground Water Discharge Permit UGW370004 GWQS Groundwater Quality Standard
HGC Hydro Geo Chem, Inc.
HHV highest historical value
MCL maximum contaminant level mg/L milligrams per liter
Mill White Mesa Uranium Mill
MW monitoring well
pCi/L picocuries per liter
SAR Source Assessment Report
SD standard deviation
TDS Total Dissolved Solids
USEPA United States Environmental Protection Agency

Background Groundwater Quality Report for MW-35, MW-36, and MW-37 White Mesa Uranium Mill
Blanding, Utah 1 May 1, 2014
1.0 INTRODUCTION
Energy Fuels Resources (USA) Inc. (“EFRI”) operates the White Mesa Uranium Mill (the
“Mill”) located near Blanding, Utah (Figure 1), under State of Utah Ground Water Discharge
Permit UGW370004 (the “GWDP”).
Monitoring well (“MW”) MW-35 was installed along the western edge of Cell 4B in 2010, while
MW-36 and MW-37 were installed on the western and southern edges of Cell 4B, respectively,
in 2011. This Report on background groundwater quality for MW-35, MW-36, and MW-37 at
the Mill was prepared to meet the requirements stated in Part I.H.5 of the Mill’s GWDP issued
by the State of Utah Division of Radiation Control (“DRC”) on August 24, 2012:
5. Background Groundwater Quality Report for Well MW-35 and New
Monitoring Wells - within 30 calendar days of Executive Secretary approval of
the new monitoring well As-built Report, required by Part I.H.4, above, the
Permittee shall commence a quarterly groundwater sampling program that will comply with the following Permit requirements: a) Routine groundwater compliance monitoring requirements of Part I.E. 1.
b) Well monitoring procedure requirements of Part I.E.5.
c) After completion of eight consecutive quarters of groundwater sampling
and analysis of well MW-35 and the new wells required by Part I.H.4, the Permittee shall submit a Background Report for Executive Secretary approval, that will include:
1) Data preparation and statistical analysis of groundwater quality data,
including, but not limited to, evaluation of data characteristics and internal
data consistency, treatment of non-detectable values, and statistical methods used. These statistics shall be calculated using the Decision Tree/Flowchart used for the previous Background Reports that was
conditionally approved by the DRC on August 24, 2007.
2) Shallow aquifer average linear groundwater velocity calculated for the
new wells, based on well specific hydraulic conductivity, hydraulic gradient, and effective aquifer porosity. d) If after review of the report, and the Executive Secretary determines that
additional information is required, the Permittee shall provide all requested
information, resolve all issues identified, and re-submit the report for
Executive Secretary review and approval within a timeframe approved by the Executive Secretary. After approval of this report, the Executive Secretary will re-open this Permit and establish an appropriate monitoring frequency in
accordance with the criteria found in Part LE.l(b) or (c), and establish
Groundwater Compliance Limits in Table 2 for well MW-35 and the each of
the new wells.

Background Groundwater Quality Report for MW-35, MW-36, and MW-37 White Mesa Uranium Mill
Blanding, Utah 2 May 1, 2014
Upon review and approval of this Report by the DRC, the proposed groundwater compliance
limits (“GWCLs”) for MW-35, MW-36, and MW-37 will be added to the GWDP and subject to
the permit and Statement of Basis requirements.
This Background Report follows a similar format to the previously submitted Background
Reports:
• Revised Background Groundwater Quality Report: Existing Wells for Denison Mines
(USA) Corp.’s Mill Site, San Juan County, Utah, October 2007, prepared by INTERA,
Inc. (the “Existing Wells Background Report”).
• Revised Addendum: Evaluation of Available Pre-Operational and Regional Background
Data, Background Groundwater Quality Report: Existing Wells for Denison Mines
(USA) Corp.’s Mill Site, San Juan County, Utah, November 16, 2007, prepared by
INTERA, Inc. (the “Regional Background Report”).
• Revised Addendum: Background Groundwater Quality Report: New Wells for Denison
Mines (USA) Corp.’s Mill Site, San Juan County, Utah, April 30, 2008, prepared by
INTERA, Inc. (the “New Wells Background Report,” and together with the “Existing
Wells Background Report” and the “Regional Background Report,” the “Background
Reports”).
• Background Groundwater Quality Report for Wells MW-20 and MW-22 for Denison
Mines (USA) Corp.’s White Mesa Mill Site, San Juan County, Utah, June 1, 2010,
prepared by INTERA, Inc.
A description of the approach used for analysis is provided in Section 2.0, and the results of the
analysis are presented in Section 3.0. Conclusions and recommendations are reviewed in
Section 4.0, and references are included in Section 5.0.
The tables and appendices consist of the analyses performed for this assessment. The appendices
are organized in the following manner: Appendix A contains box and whisker plots for each
permit constituent and each well included in this Report. Appendix B contains histograms of the
log-transformed data along with results of the Shapiro-Wilk test for normality. Appendix C
contains the linear regression plots for each of the constituents in each well. The data plots for
constituents that were detected less than 50% of the time are included for visual aid and
completeness and are considered exploratory statistics only. Appendix D contains probability
plots for constituents that fall into the category requiring such analysis. Appendix E is the
censored and detected value only probability plots for normally or lognormally distributed
constituents with 15%-50% non-detected values. Appendix F contains the results from the
Mann-Kendall trend analysis for data sets that are not normally or lognormally distributed and

Background Groundwater Quality Report for MW-35, MW-36, and MW-37 White Mesa Uranium Mill
Blanding, Utah 3 May 1, 2014
have 0%-90% non-detected values. Appendix G is a table of data that have been removed prior
to statistical analysis. Appendix H is an electronic-only file that contains the input and output
files used for statistical analysis. Appendix I contains the supporting analysis for trending
constituents using the modified approach. The constituents that were identified as trending but
are not included in Appendix I did not require additional analysis because they did not have
extreme outliers due to a trend.

Background Groundwater Quality Report for MW-35, MW-36, and MW-37 White Mesa Uranium Mill
Blanding, Utah 4 May 1, 2014
2.0 STATISTICAL ANALYSIS OF BACKGROUND
GROUNDWATER QUALITY DATA
In evaluating the data from MW-35, MW-36, and MW-37, an approach similar to the one
described in the New Wells Background Report (INTERA, 2008) was used. See that document
for a detailed discussion of methods used for the quality assurance evaluation of new data and
data validation. The New Wells Background Report (INTERA, 2008) summarized methods used
in a flow sheet (the “Flow Sheet”) for the statistical analysis and the determination of the
GWCLs for each constituent in each well that is presented in Figure 1 of this report. See the
Existing Wells Background Report (INTERA 2007) for a summary of historical operations and a
discussion of the geology and hydrology of the site.
MW-35, MW-36, and MW-37 have been sampled on a routine basis for the GWDP constituents
listed in Table 1. Laboratory analytical methods for those parameters are presented in Table 2.
Groundwater monitoring results from MW-35, MW-36, and MW-37 were subject to a quality
assurance evaluation in accordance with the methods outlined in the Flow Sheet. Internal
consistency checks, including a comparison of measured and calculated TDS and charge balance
of major cations and anions, are presented in Tables 3 and 4, respectively. The relative percent
difference between primary and duplicate samples are presented in Table 5. The first analysis
performed using the database was the creation of box and whisker plots to identify and remove
any extreme outliers prior to statistical analysis (Appendix A). The complexity and
inconsistency of groundwater quality at the site has been documented in several rounds of
Background Reports and Source Assessment Reports (“SARs”). Although a minimum of eight
data points are required according to the Flow Sheet, this number is truly a minimum
requirement. The strength of the statistical analysis will increase with more data points, and
caution should be used when setting GWCLs for constituents with a limited data set (fewer than
20 samples, per United States Environmental Protection Agency [“USEPA”] Unified Guidance
[USEPA, 2009]). Descriptive statistics were calculated for all data sets and are presented in
Tables 6a and 6b. Table 7 presents the geometric mean and standard deviation of normally or
lognormally distributed data sets.
The process for calculating GWCLs was performed for each constituent that had at least
eight sample results, according to the Flow Sheet, with each step summarized in Table 8. The
percentage of non-detected values was calculated. Distribution was determined by log-
transforming all data with 0%-50% non-detected values and performing the Shapiro-Wilk test for
normality. The results of this test are presented on the histograms in Appendix B.
Linear regression and Mann-Kendall trend analyses were performed on each constituent in each
well, as appropriate. For constituents that were normally or lognormally distributed with 15% or

Background Groundwater Quality Report for MW-35, MW-36, and MW-37 White Mesa Uranium Mill
Blanding, Utah 5 May 1, 2014
fewer non-detects, linear regression analysis alone was performed (Appendix C). For
constituents that were normally or lognormally distributed with greater than 15% but less than or
equal to 50% non-detects, Mann-Kendall analysis as well as linear regression were performed.
For all other constituents, Mann-Kendall analysis was performed (Appendix F).
Data plots for all constituents are set out in Appendix C. Linear regression analysis is provided
as a visual aid in viewing the data and should be considered as “exploratory statistics” only in
cases where Mann-Kendall trend analysis is required. Rising or decreasing trends identified by
either linear regression (for normally or lognormally distributed constituents having 50% or
fewer non-detects) or Mann-Kendall analysis (for all non-parametric constituents and all
constituents with greater than 15% non-detects) that are statistically significant are identified in
red in Appendix C. All other trends are not statistically significant. See Sections 4.0, 5.0, and
6.0 of the Existing Wells Background Report (INTERA 2007) for a full discussion of the
statistical approaches used in this Report.

Background Groundwater Quality Report for MW-35, MW-36, and MW-37 White Mesa Uranium Mill
Blanding, Utah 6 May 1, 2014
3.0 RESULTS OF ANALYSIS AND DETERMINATION OF
GROUNDWATER COMPLIANCE LIMITS
MW-35, MW-36, and MW-37 have been determined to be Class III wells based on their total
dissolved solids (“TDS”) concentrations (all three of the wells have mean concentrations of TDS
that are greater than 3,000 milligrams per liter [“mg/L”]) according to the rules set forth in
UTAC R317-6-3.
3.1 Indicator Parameters
Chloride, fluoride, sulfate, and uranium have been identified as the best indicator parameters of
potential tailings cell seepage at the site as described in Section 9.0 of the Background Report
(INTERA, 2007). Review of the data plots for indicator parameters in each well demonstrate that
concentrations of indicator parameters in MW-35 are either not trending at all or are trending
downward. Indicator parameters in MW-36 are behaving similarly with decreasing trends in
concentrations for chloride, sulfate, and uranium, and a slight increasing trend in fluoride
concentrations. Chloride and uranium concentrations are decreasing in MW-37, while fluoride
and sulfate concentrations are increasing slightly. The presence of an increasing trend in fluoride
and sulfate without corresponding increasing trends in the other indicator parameters, chloride
and uranium, supports the findings of previous investigations at the Site, which conclude that
there has been no impact to groundwater from potential tailings cell seepage and that the
increases are naturally occurring.
3.2 Trending Constituents
Trending constituents were identified by one of two trend test methods, according to the Flow
Sheet. Linear regression analysis was performed for normally or lognormally distributed
constituent data sets (Appendix C), and the Mann-Kendall trend test was performed for the data
sets which are not normally or lognormally distributed (Appendix F). Statistically significantly
increasing trends include TDS in MW-35, gross alpha in MW-36, and selenium and thallium in
MW-37. Constituents that are exhibiting increasing trends that are not statistically significant
include gross alpha and selenium in MW-35, TDS and nitrate in MW-36, and sulfate in MW-37.
3.3 Groundwater Compliance Limits
GWCLs were determined based on the DRC-approved Flow Sheet (Figure 2) and in a similar
manner to the other Background Reports with the exception of additional steps that were taken to
address the naturally occurring increasing trends.

Background Groundwater Quality Report for MW-35, MW-36, and MW-37 White Mesa Uranium Mill
Blanding, Utah 7 May 1, 2014
GWCLs for constituents in MW-35, MW-36, and MW-37 that were not exhibiting any
increasing trends were determined by following the Flow Sheet, without any modifications.
Table 8 contains a summary of the results of the Flow Sheet along with the proposed GWCLs
based on that analysis.
3.4 Modified Approach for Groundwater Compliance Limits for Trending
Constituents
When the Flow Sheet was originally developed in 2007, potential problems with setting a
GWCL for constituents that are trending based on the mean + 2 standard deviations (“SD”)
approach or the non-parametric equivalent were identified. For this reason, the last box on the
Flow Sheet states “Consider Modified Approach to GWCL.”
EFRI and INTERA have been working to identify a compliance process that can be applied to
data sets that are exhibiting increasing trends; however, because of the complexity of the Site,
the complexity of permitting, and the lack of guidance on the subject, a single process is unlikely
to provide a solution for compliance for all of the trending constituents. As such, the “modified
approach” taken when calculating GWCLs on trending constituents in MW-35, MW-36, and
MW-37 was performed on a case-by-case basis using established elements of the current GWDP
as presented in Figure 3, which illustrates an addendum to the Flow Sheet.
With respect to trending constituents, the Flow Sheet has been completed in two ways:
(1) without taking trends into consideration, i.e., deferring to the next-to-last box on the Flow
Sheet in the event of a trend, and (2) considering a modified approach to setting GWCLs for
constituents that are trending, as the Flow Sheet suggests. GWCLs determined by both
approaches are summarized in Table 8.
The modified approach that was considered for trending constituents, as indicated in the DRC-
approved Flow Sheet, consists of further analysis of the constituent as presented in Figure 3.
Data sets of constituents exhibiting an increasing trend are reviewed for outliers that may have
been removed in the initial steps of the original Flow Sheet analysis. USEPA guidance states “In
groundwater data collection and testing, background conditions may not be static over time.
Caution should be observed in removing observations which may signal a change in natural
groundwater quality. Even when conditions have not changed, an apparently extreme
measurement may represent nothing more than a portion of the background distribution that has
yet to be observed. This is particularly true if the background data set contains fewer than
20 samples.” (USEPA, 2009). If review of outliers shows that an outlier that is part of an
increasing trend was removed, then the outlier is placed back into the data set and the original
Flow Sheet analysis is repeated, including calculating a new GWCL based on the revised data set
that contains outliers. If that GWCL is in danger of being exceeded, or if there were no outliers

Background Groundwater Quality Report for MW-35, MW-36, and MW-37 White Mesa Uranium Mill
Blanding, Utah 8 May 1, 2014
removed initially, a review of the fractional Groundwater Quality Standard (“GWQS”) for Class
III wells, along with primary and secondary USEPA maximum contaminant levels (“MCLs”),
was performed. If the risk-based fractional GWQS (or MCL) value was not in danger of being
exceeded in the near future, it was chosen as the proposed GWCL for the trending constituent.
When fractional GWQSs or MCLs were not available or were in danger of being exceeded in the
near future, the GWCL was determined using the mean + 4SD or the highest historical value
(“HHV”) + 2SD, based on the distribution of the data set. USEPA Unified Guidance states “A
two standard deviation increase over the background average might not be protective of human
health and/or the environment for some monitoring situations. For others, a four standard
deviation increase or more may be tolerable before any threat is posed.” In the case of the
trending constituents in MW-35, MW-36, and MW-37, all of the modified approach GWCLs are
not significantly higher than the conventionally determined GWCLs, and they remain less than
their respective GWQSs, which were established to be protective of human health and the
environment; therefore, the modified approach GWCLs are protective of human health and the
environment. The modified approach for trending constituents is summarized in Table 9. The
proposed GWCLs for all permit constituents are presented in Table 10, along with the rationale
for determining the GWCL.
3.4.1 Gross Alpha
Gross alpha concentrations in both MW-35 and MW-36 are within normal range of site-wide
gross alpha counts. As stated in Section 10.4 of the Background Report (INTERA, 2007), gross
alpha may not be a good indicator of potential milling impacts because of the large number of
radionuclides that decay by the spontaneous emission of alpha particles. Additionally, indicator
parameters in MW-35 and MW-36 are not exhibiting any increasing trends, with the exception of
fluoride in MW-36, which is showing a slight increase.
The data set for gross alpha in MW-35 contains a reported result that was identified as an
extreme outlier during the box and whisker plot analysis (Appendix A). The value in question is
9.51 picocuries per liter (“pCi/L”), collected in the first quarter of 2013. When this value is
removed from analysis, the data set is normally or lognormally distributed, and although the
linear regression plot shows an increasing trend, the trend is not of statistical significance. The
calculated GWCL, using the data that omitted the extreme outlier for gross alpha in MW-35, is
6.69 pCi/L, which is the mean + 2SD, and does not take into account a modified approach for
increasing trends. Historically, there have been five sample results that are greater than
6.0 pCi/L, and one that has exceeded 6.69 pCi/L; therefore, setting the GWCL at 6.69 pCi/L is
not appropriate for gross alpha in this well.

Background Groundwater Quality Report for MW-35, MW-36, and MW-37 White Mesa Uranium Mill
Blanding, Utah 9 May 1, 2014
A modified approach for calculation of the GWCL has been applied, where the extreme outlier
was retained for analysis, assuming that the elevated value is representative of data that are
trending upward. Modified approach was also performed with the outlier removed. The results of
the modified approach on both data sets are presented in Table 9. When retaining the outlier, the
data set is no longer normally or lognormally distributed, and the result of the Mann-Kendall
trend test is that the concentrations are significantly increasing. In calculating the GWCL for this
data set, the HHV is what would be considered if there was no evidence of an increasing trend.
According to the Flow Sheet, it is acceptable to consider a modified approach in the event of an
increasing trend. Therefore, the proposed GWCL for gross alpha in MW-35 is 12.21 pCi/L,
which is the HHV + 2SD. This value is less than the GWQS of 15 pCi/L, which is protective of
human health and the environment.
Gross alpha in MW-36 is exhibiting a statistically significant increasing trend. This data set does
not contain any extreme outliers. It is normally or lognormally distributed, and the mean +2SD
GWCL according to the Flow Sheet, and not taking into account a modified approach for the
increasing trend, would be 3.23 pCi/L. Historically there have been no results that have exceeded
that value; however, upon review of the linear regression plot (Appendix C), it is likely that a
value would exceed the 3.23 pCi/L GWCL in the near future. Therefore, a modified approach
has been used to determine a GWCL of 7.5 pCi/L for gross alpha in MW-36, which is the
fractional GWQS for Class III wells and is protective of human health and the environment.
3.4.2 Nitrate
Nitrate in MW-36 is exhibiting an increasing trend. The data set is not normally or lognormally
distributed, and the trend is not significant. Since a trend is observed, the modified approach has
been applied to this data set in determination of the GWCLs; however, in this case, both
approaches indicate that the fractional GWQS of 5mg/L should be used as the GWCL.
3.4.3 Total Dissolved Solids
TDS concentrations in MW-35 and MW-36 are exhibiting increasing trends. Both data sets are
within normal site-wide ranges for TDS. Indicator parameter analyses for both wells support
previous conclusions that there is no evidence of impact from potential tailings seepage.
TDS concentrations in MW-35 are exhibiting a statistically significant increasing trend
(Appendix C). The TDS data set in MW-35 contains an extreme outlier that was identified
during the box and whisker plots. The outlier is the lowest value in the data set, and was
collected during the first round of sampling, which suggests that the value (2,200 mg/L) is a
component of the increasing trend in concentrations. When the value was omitted from analysis,
the data set was lognormally or normally distributed and exhibited a statistically significant
trend. The mean + 2SD using this data set is 4,121 mg/L, just 49 mg/L lower than the last sample

Background Groundwater Quality Report for MW-35, MW-36, and MW-37 White Mesa Uranium Mill
Blanding, Utah 10 May 1, 2014
result of 4,170 mg/L. When retaining the outlier, the distribution of the data set changed,
suggesting that the GWCL would be the HHV if there was not an increasing trend. Results of the
modified approach for both data sets are summarized in Table 9. Since there is an increasing
trend, a modified approach for calculating the GWCL was used. The proposed GWCL for TDS
in MW-35 is 5,123mg/L, which is the HHV + 2SD.
MW-36 is showing increasing concentrations of TDS. TDS in MW-36 is lognormally or
normally distributed. According to the Flow Sheet, the calculated GWCL would be 4,618 mg/L,
which is the mean +2SD. Since there is an increasing trend, a GWCL calculated using the
modified approach is proposed: 4,860 mg/L, which is calculated using the mean + 4SD.
3.4.4 Selenium
Selenium concentrations in MW-35 and MW-37 are exhibiting increasing and statistically
significant increasing trends, respectively. Selenium in both wells is within the normal range of
concentrations for the site. Since indicator parameters chloride, fluoride, sulfate, and uranium in
MW-35 are not exhibiting increasing trends, the trend in selenium can be attributed to natural
background conditions. Indicator parameters chloride and uranium in MW-37 are exhibiting
decreasing trends, while fluoride and sulfate are increasing slightly. The presence of an
increasing trend in sulfate without an increasing trend in chloride, which is considered the best
indicator parameter, supports the conclusion that the increasing trend in selenium is due to
natural background conditions.
According to the Flow Sheet, the GWCL for selenium in MW-35, which contains 27% non-
detected values, would be the fractional GWQS of 25 micrograms per liter (“µg/L”) if there was
no evidence of an increasing trend. Since there is an increasing trend, and since the HHV is
approaching the fractional GWQS, 25 µg/L is not appropriate for selenium in this well and a
modified approach has been taken. The modified approach GWCL is 33.73 µg/L, which is the
HHV + 2SD, and is less than the GWQS of 50 µg/L, ensuring that this value is protective of
human health and the environment.
Selenium in MW-37 is normally or lognormally distributed, indicating the mean + 2SD GWCL
of 9.78 µg/L if no trend was present. Two sample results have already been reported above
9.0 µg/L. With the increasing trend, concentrations are guaranteed to exceed the 9.78 µg/L value
in the near future. The modified approach GWCL is 25 µg/L, which is the fractional GWQS and
is protective of human health and the environment.

Background Groundwater Quality Report for MW-35, MW-36, and MW-37 White Mesa Uranium Mill
Blanding, Utah 11 May 1, 2014
3.4.5 Sulfate
Sulfate in MW-37 is exhibiting an increasing trend. The data set used for analysis contains nine
data points, which is just above the minimum number of data records required by the Flow Sheet
for statistical analysis. Although the trend is not statistically significant, it is likely that future
sample results will continue to increase in concentration. The GWCL for sulfate in MW-37 if no
trend was present would be 2,927 mg/L, which is the mean + 2SD. The HHV concentration of
sulfate in this well is 2,750 mg/L, just under 200 mg/L less than the 2,927 mg/L value. Since
concentrations are likely to increase, the modified approach GWCL using the mean + 4SD is
3,311 mg/L, which is more appropriate for sulfate in MW-37.
3.4.6 Thallium
Thallium concentrations in MW-37 are exhibiting a statistically significant increasing trend.
Thallium has only been detected four out of the ten times it was sampled. The first several
sample results were not detected above the reporting limit, and the samples that were detected
above the reporting limit have been detected within normal range for the site. Caution should be
used when setting the GWCL based on only four detected values. The variability of the site and
the small size of this data set suggest that any detected values of thallium in this well could be
greater than the proposed GWCL. As more data become available, the GWCL should be
reviewed and re-assessed for accuracy. The proposed GWCL for thallium in MW-37 is 1 µg/L,
which is the fractional GWQS, according to the Flow Sheet.
3.5 Hydraulic Properties
The average linear groundwater velocity calculated for MW-35, MW-36, and MW-37, based on
the geometric mean of well-specific estimates of hydraulic conductivities, hydraulic gradient,
and effective aquifer porosity, is presented in Table 11 with supporting data presented in the
installation and hydraulic testing reports prepared by Hydro Geo Chem, Inc. (HGC 2010; 2011).
The calculated average linear groundwater velocities for MW-35, MW-36, and MW-37, are 8,
13, and 0.6 feet per year respectively. These average linear velocity estimates indicate that
groundwater is moving very slowly in this area. Further, there are indications that groundwater
is dissipating in this area based on dry wells MW-33 and MW-34.
3.6 Relationship to Tailings Cells
Based on the foregoing analysis, concentrations of constituents in groundwater samples from
MW-35, MW-36, and MW-37 have not been influenced by any potential seepage from the
tailings cells.
An analysis of data from sampling of MW-35, MW-36, and MW-37 confirms the high variability
of all constituents across the site and the region described in previous reports. There is no

Background Groundwater Quality Report for MW-35, MW-36, and MW-37 White Mesa Uranium Mill
Blanding, Utah 12 May 1, 2014
consistent spatial relationship between the primary indicator parameters and the location of the
tailings impoundments. It is therefore not possible to conclude that higher concentrations of
constituents or increasing trends in these wells necessarily imply contamination from site
activities. The variability in data for MW-35, MW-36, and MW-37 is consistent with and
reinforces our conclusions drawn from the other Background Reports and investigations
performed at the site.

Background Groundwater Quality Report for MW-35, MW-36, and MW-37 White Mesa Uranium Mill
Blanding, Utah 13 May 1, 2014
4.0 CONCLUSIONS
Background at the Mill site was recently thoroughly studied in the Background Reports, in the
University of Utah Study, and in several SARs. All of these investigations concluded that
groundwater at the site has not been impacted by Mill operations. A recent investigation into the
decreasing trends in pH at the site concluded that oxidation of pyrite at the site is contributing to
decreasing pH and, in turn, mobilizing metals (HGC, 2012). All of those studies also
acknowledged that there are natural influences at play at the site that have given rise to
increasing groundwater concentration trends and general variability of background groundwater
at the site.
Analysis of data from sampling of MW-35, MW-36, and MW-37 confirms the high variability of
all constituents across the site and the region described in previous reports. There is no consistent
spatial relationship between the primary indicator parameters and the location of the tailings
impoundments. It is therefore not possible to conclude that higher concentrations of constituents
or increasing trends in these wells necessarily imply contamination from site activities. The
variability in data for MW-35, MW-36, and MW-37 is consistent with and reinforces the
conclusions drawn from the other Background Reports and investigations performed at the site.
MW-36 and MW-37 have relatively small data sets due to their recent installation and limited
sampling history. Based on previous experience with GWCLs for wells included in the New
Wells Background Report (INTERA, 2008) and the documented variability in natural
background conditions at the site, it is likely that background conditions are not being truly
represented in MW-36 and MW-37 at this time, and EFRI anticipates revisions to these GWCLs,
if necessary, as more data become available.
Increasing trends in some constituents have been identified. Indicator parameters for all of the
wells support the conclusion that these trends are not due to impacts from potential tailings cell
seepage. Based on the DRC-approved Flow Sheet, the indicated action for trending constituents
is “Consider Modified Approach to GWCL.” The modified approach, which uses the
fundamental methodology included in the USEPA Unified Guidance along with established
elements of the current GWDP, has been applied to each of the trending constituents, resulting in
GWCLs that take naturally occurring trends into account while remaining protective of human
health and the environment.
A summary of proposed GWCLs based on the Flow Sheet or the modified approach is presented
in Table 10.

Background Groundwater Quality Report for MW-35, MW-36, and MW-37 White Mesa Uranium Mill
Blanding, Utah 14 May 1, 2014
5.0 REFERENCES
Energy Fuels Resources (USA) Inc. (EFRI), 2009-2012. White Mesa Uranium Mill Nitrate
Monitoring Reports.
Hurst, T.G., and Solomon, D.K., 2008. Summary of Work Completed, Data Results,
Interpretations and Recommendations for the July 2007 Sampling Event at the Denison
Mines, USA, White Mesa Uranium Mill Near Blanding Utah. Prepared by Department of
Geology and Geophysics, University of Utah. May 2008.
Hydro Geo Chem, Inc. (HGC), 2010. Installation and Hydraulic Testing of Perched Monitoring Wells MW-33, MW-34, and MW-35 at the White Mesa Uranium Mill near Blanding,
Utah. October 11.
––––––. 2011. Installation and Hydraulic Testing of Perched Monitoring Wells MW-36 and
MW-37 at the White Mesa Uranium Mill Near Blanding, Utah. June 28.
––––––. 2012. Site Hydrology and Estimation of Groundwater Travel Times in the Perched Zone, White Mesa Uranium Mill Site Near Blanding, Utah. Prepared for Denison Mines
(USA) Corp. by Hydro Geo Chem Inc., July 10, 2012.
INTERA Incorporated (INTERA), 2007. Revised Background Groundwater Quality Report:
Existing Wells for Denison Mines (USA) Corp.’s White Mesa Mill Site, San Juan County, Utah. October 2007 (“Existing Wells Background Report”).
––––––. 2008. Revised Addendum, Background Groundwater Quality Report: New Wells for
Denison Mines (USA) Corp’s White Mesa Mill Site, San Juan County, Utah. April 30,
2008 (“New Wells Background Report”).
______. 2012-2014. Source Assessment Reports.
United States Environmental Protection Agency (USEPA), 2009. Statistical Analysis of Groundwater Monitoring Data at RCRA Facilities, Unified Guidance. EPA 530/R-09-
007. Office of Resource Conservation and Recovery, Program Implementation and
Information Division. March.

FIGURES
Cell No. 1
Cell No. 2
Cell No. 3
Cell No. 4A
W i l d l i f e P o n d
W i l d l i f e P o n d

Mill Site
Cell No. 4B
MW-37
MW-36
MW-35
MW-34
MW-33
MW-32MW-31
MW-30
MW-29
MW-28
MW-27
MW-26
MW-25
MW-24
MW-23
MW-22
MW-21
MW-20
MW-19
MW-18
MW-17
MW-15 MW-14
MW-12
MW-11
MW-05
MW-04
MW-03
MW-02
MW-01
MW-03A
S : \ P r o j e c t s \ I U C - 0 0 1 - 0 1 - 0 0 1 D e n i s o n M i n e s \ G I S \ m a p d o c s \ 2 0 1 4 _ B a c k g r o u n d R p t \ F i g 0 1 _ L o c M a p _ M W 3 5 _ 3 6 _ 3 7 . m x d D a t e : 4 / 2 9 / 2 0 1 4
F i g u r e 1 L o c a t i o n o f G r o u n d w a t e r M o n i t o r i n g W e l l s M W - 3 5 , M W - 3 6 , a n d M W - 3 7 W h i t e M e s a M i l l S i t e , S a n J u a n C o u n t y , U t a h
1 , 0 0 0 0 1 , 0 0 0 5 0 0
F e e t
S o u r c e ( s ) : A e r i a l N A I P U t a h 2 0 1 1 ; W e l l s H G C , I n c . , M a y 2 0 0 8 r e p o r t .
L e g e n d
G r o u n d w a t e r M o n i t o r i n g W e l l s
U T A H U T A H
W h i t e M e s a U r a n i u m M i l l
S:\Projects\IUC-001-01-001 Denison Mines\2014\Background Report\Report\Figures\Fig02_Flowsheet_EDITED.pdf
Figure 2
Groundwater Data Preparation and
Statistical Process Flow for Calculating
Groundwater Compliance Limits
White Mesa Mill Site, San Juan County, Utah
Negative Value?
Zero Value?
Truncated Value?
Duplicate Value?
Units Consistant?
Non-detects Exceeding Criteria Specie d by URS Memo*
Analysis Internally Consistent?
(TDS and Charge Balance Check)
YesNo
No
Yes
No
No
No
Yes
Yes
No
Yes
Yes
Yes
Radionuclide?
Yes
Remove from DatasetDetection Limit and U-Flag Data Quali er NoNo
Review for Units
Remove from
Dataset
If chloride,
sulfate, or TDS, Remove from Dataset
Correct Value
Con rmed?
Remove from Dataset
Remove from Dataset
Determine Percentage Non-Detects in Remaining Data
Plot Data Sets as Box Plots to Identify
Extreme Values As Speci ed in Background Report.
Extreme Value?
No Remove from
Dataset
Yes
At Least 8 Data Points Remaining?
Defer Analysis Until Eight Data Points Avalible
0-15 Percent Non-Detects >15-50 Percent Non-Detects >90 Percent Non-Detects
No
Yes
No
Substitute One Half of
Detection Limit
Log Transform Data
Use Probability Plots to Determine if Cohen’s or
Aitchison’s Method
Calculate Descriptive Statistics
(Redo Tables In Background
Report)
Screen for Trends Using Least Squares Regression.
Calculate GWCL (Mean +2Sigma)
Calculate Descriptive Statistics
(Redo Tables In Background
Report)
Yes
No
Calculate GWCL (Mean
+2Sigma)
Calculate GWCL Using Greater of
Fraction Approach under UAC R317-6-4-4.5(B)(2) or 4.6(B)(2) or Poisson Prediction Limit
Yes
No
>50-90 Percent Non-Detects
Calculate Upper Prediction
Limit (Highest Historical Value)
Calculate GWCL Using Greater of Fraction Approach under UAC R317-6-4-4.5(B)(2) or 4.6(B)(2) or the Highest Historic Value
Estimate Mean and Standard Deviation
Screen for Trends Using Mann-Kendall Screen for Trends Using Mann-Kendall
Yes
Use Non-Parametric StatisticsNo
Screen for Trends Using Least
Squares Regression
Upward Trend?Upward Trend?
No No
Yes
Consider Modied Approch t o GWCL
Upward Trend?Upward Trend?
No No
Yes
Consider Modi ed Approch to GWCL
Log Transform Data
Log-Normal or Normal?Shapiro WilkProbability PlotsHistograms
Log-Normal or Normal?
Shapiro WilkProbability Plots
Histograms
*A non-detect considered “insensitive” will be the maximum reporting limit in a dataset and
will exceed other non-detects by, for example, an order of magnitude (e.g., <10 versus <1.0 µg/L).
In some cases, insensitive non-detects may also exceed detectable values in a dataset (e.g., <10 versus 3.5 µg/L).
Database of Wells and Analytes Listed in the Statement of Basis
S:\Projects\GE1-UNC_St_Anthony\Stage 2 Abatement Plan\GIS\MapDocuments\Stage2_Reporting\Section_2\Fig02-8_AltH-PC5.pdf
Figure 3
Addendum to Groundwater Data Preparation and
Statistical Process Flow for Calculating Groundwater
Compliance Limits for Trending Constituents
White Mesa Mill Site, San Juan County, Utah
D R A F T
YesYesWereoutliersremovedpriortoanalysis?
No
P lot raw data over time.
Are outliers part of a trend?
R eplace outliers and redo Flow S heet analysis.
Is calculated G W C L in danger of being exceeded?
Is G W QS F ractional approach or primary or secondary E PA MC L available for this con-
s tituent?C onfirm or revise well Class (II or III)based on R ules in the UTAC .
Is G W QS Fractional approach or primary or secondary E PA MC L
in danger of being exceeded?Yes
Set G W C L at G W QS Fractional Approach or Primary or S econdary E PA MC L S et GWCL Using R e-calculated Flow Sheet method including outliersSetGWCLasMean+4S igma or HHV +2S igmaa
No
No
Yes
No
Yes
C onsider Modified Approach to G W C L
Yes
F rom Original Flow S heet
Upward Trend?
a:Mean +2SD for normally or lognormally distributed data sets,highest historical value (HHV)+2SD for not normally or lognormally distributed data sets.US EPA Unified Guidance (2009)states (p 3-20)“A two standard deviation increase over the background aver-
age might not be protective of human health and/or the environment for some monitoring situations.For others,a four standard deviation increase or more may be tolerable before any threat is posed.”In the case of trends in M-35,MW-36,and MW-37,all of thesemodifiedGWCLsremainlessthantheGWCL,ensuring protection of human health and the environment.

TABLES

TABLE 1
Monitoring Parameters and Groundwater Quality Standards
Page 1 of 1
Table 1
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
Type Constituent GWQS Units
Nutrient Ammonia, N 25 mg/L
Nutrient Nitrate+Nitrite, N 10 mg/L
Metal Arsenic 50 µg/L
Metal Beryllium 4 µg/L
Metal Cadmium 5 µg/L
Metal Chromium 100 µg/L
Metal Cobalt 730 µg/L
Metal Copper 1,300 µg/L
Metal Iron 11,000 µg/L
Metal Lead 15 µg/L
Metal Manganese 800 µg/L
Metal Mercury 2 µg/L
Metal Molybdenum 40 µg/L
Metal Nickel 100 µg/L
Metal Selenium 50 µg/L
Metal Silver 100 µg/L
Metal Thallium 2 µg/L
Metal Tin 17,000 µg/L
Metal Uranium 30 µg/L
Metal Vanadium 60 µg/L
Metal Zinc 5,000 µg/L
Radiologic Gross Alpha 15 pCi/LVOCAcetone700µg/L
VOC Benzene 5 µg/L
VOC Methyl Ethyl 4,000 µg/L
VOC Carbon 5 µg/L
VOC Chloroform 70 µg/L
VOC Chloromethane 30 µg/L
VOC Dichloromethane 5 µg/L
VOC Naphthalene 100 µg/L
VOC Tetrahydrofuran 46 µg/L
VOC Toluene 1,000 µg/L
VOC Total Xylenes 10,000 µg/L
Other Chloride TBD mg/LOtherFluoride4mg/LOtherField pH 6.5 to 8.5 pHOtherSulfateTBDmg/LOtherTDSTBDmg/L
Notes:
mg/L = milligrams per liter
pCi/L = picocuries per liter
VOC = volatile organic compound
TBD = to be determined (defined as the value of the
arithmetic mean plus two standard deviations or equivalent)
µg/L = micrograms per liter
TDS = total dissolved solids
GWQS = Ground Water Quality Standard (R317-6-2 UT
Administrative Code)
TABLE 2
Laboratory Analytical Methods
Sample Analysis Method
Chloride A4500-Cl B, E, E300.0
Fluoride A4500-F C, E300.0
Gross Alpha minus Rn and U E900.1
Iron, Manganese, Molybdenum, Nickel, Chromium, Cobalt, Vanadium, Tin, Zinc E200.7
Mercury E245.1
All other Metals E200.8
Nitrogen, Ammonia as N A4500-NH3 G, E350.1, E353.2
Nitrogen, Nitrate + Nitrite as N E353.2
pH Field Parameter
Sulfate A4500-SO4 E, E300.0Total Dissolved Solids A2540 C
Volatile Organic Compounds SW8260B
Page 1 of 1
Table 2
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah 
TABLE 3
Comparison of Calculated and Measured TDS for Samples with Complete Major Ion Analysis
Well Date
HCO3 as
Alkalinity
(mg/L)
Calcium
(mg/L)
Chloride
(mg/L)
Potassium
(mg/L)
Magnesium
(mg/L)
Sodium
(mg/L)
Sulfate
(mg/L)
Measured
TDS
(mg/L)
Calculated
TDS
(mg/L)Ratio
MW‐35 12/1/2010 412 490 69 11.7 142 379 2310 3760 3814 98.59%
MW‐35 2/15/2011 266 289 41 7.7 86.6 227 1140 2200 2057 106.94%
MW‐35 6/7/2011 407 500 60 11.2 143 419 2310 3730 3850 96.88%
MW‐35 8/30/2011 394 524 59 11.6 155 416 2330 3720 3890 95.64%
MW‐35 10/3/2011 385 502 61 11 149 352 2400 3750 3860 97.15%
MW‐35 2/14/2012 398 532 59 11.5 159 414 2330 3840 3904 98.37%
MW‐35 5/2/2012 407 502 59 12.2 151 342 2240 3960 3713 106.65%
MW‐35 7/10/2012 400 504 64 10.3 150 366 2230 3860 3724 103.64%
MW‐35 11/13/2012 409 512 66.6 12.8 153 391 1600 3840 3144 122.13%
MW‐35 2/26/2013 406 502 65.3 12.4 163 410 2110 3760 3669 102.48%
MW‐35 5/13/2013 429 502 60 10.9 151 417 1880 3940 3450 114.19%
MW‐35 7/9/2013 422 496 64.3 11.4 146 358 1870 3960 3368 117.58%
MW‐35 11/19/2013 398 500 61 11.6 144 379 2210 4170 3703 112.60%
MW‐36 8/9/2011 340 445 54 9.8 136 716 2740 4320 4441 97.28%
MW‐36 10/3/2011 338 442 56 9.8 137 628 2860 4270 4471 95.51%
MW‐36 2/20/2012 350 453 73 10.5 140 724 2690 4360 4441 98.19%
MW‐36 5/8/2012 355 464 58 12.8 149 730 2700 4540 4469 101.59%
MW‐36 7/11/2012 353 433 60 8.8 134 635 2660 4420 4284 103.18%
MW‐36 11/14/2012 359 432 58.9 9.54 135 682 2100 4240 3776 112.28%
MW‐36 2/26/2013 353 426 58 11.4 144 738 2150 4220 3880 108.76%
MW‐36 5/14/2013 368 428 53.3 9.45 131 740 2430 4340 4160 104.32%
MW‐36 7/10/2013 368 430 59.8 9.88 131 631 2960 4530 4590 98.69%
MW‐36 11/20/2013 367 423 54.7 10.1 130 669 2480 4520 4134 109.34%
MW‐37 8/11/2011 291 457 55 13.9 129 556 2440 3820 3942 96.91%
MW‐37 10/19/2011 261 481 50 14.2 133 556 2620 3980 4115 96.71%
MW‐37 2/29/2012 297 482 36 15.2 132 554 2500 3900 4016 97.11%
MW‐37 5/29/2012 264 479 50 16.3 140 595 2460 4000 4004 99.89%
MW‐37 7/30/2012 265 486 51 15.1 133 575 2700 4090 4225 96.80%
MW‐37 12/5/2012 282 454 46.6 14.2 131 514 1010 3830 2452 156.22%
MW‐37 3/20/2013 256 487 44.5 14.7 139 546 2130 3770 3617 104.22%
MW‐37 6/3/2013 261 492 48.8 15.2 137 522 2570 3700 4046 91.45%
MW‐37 7/23/2013 257 467 43.2 14.4 123 478 2720 3890 4103 94.81%
MW‐37 12/18/2013 235 475 46.1 14.6 132 512 2750 3950 4165 94.83%
Notes:
HCO3= Bicarbonate
Ratio= Difference between measured and calculated values
Bold values are not internally consistent and/or were identified as extreme outliers and have been
removed from the dataset prior to statistical analysis.
mg/L = milligrams per liter
TDS= Total Dissolved Solids
Page 1 of 1
Table 3
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
TABLE 4
Charge Balance of Major Cations and Anions
Page 1 of 1
Table 4
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
Well Date
Calcium
(meq/L)
Sodium
(meq/L)
Magnesium
(meq/L)
Potassium
(meq/L)
Total
Cation
Charge
(meq/L)
HCO3
(meq/L)
Chloride
(meq/L)
SO4
(meq/L)
Total
Anion
Charge
(meq/L)
Percent
Difference
MW-35 12/1/2010 24.45 16.49 11.68 0.30 52.92 -6.75 -1.95 -48.09 -56.79 -7.32%
MW-35 2/15/2011 14.42 9.87 7.12 0.20 31.62 -4.36 -1.16 -23.74 -29.25 7.48%
MW-35 6/7/2011 24.95 18.23 11.76 0.29 55.23 -6.67 -1.69 -48.09 -56.46 -2.23%
MW-35 8/30/2011 26.15 18.09 12.75 0.30 57.29 -6.46 -1.66 -48.51 -56.63 1.15%
MW-35 10/3/2011 25.05 15.31 12.26 0.28 52.90 -6.31 -1.72 -49.97 -58.00 -9.64%
MW-35 2/14/2012 26.55 18.01 13.08 0.29 57.93 -6.52 -1.66 -48.51 -56.70 2.13%
MW-35 5/2/2012 25.05 14.88 12.42 0.31 52.66 -6.67 -1.66 -46.64 -54.97 -4.39%
MW-35 7/10/2012 25.15 15.92 12.34 0.26 53.67 -6.56 -1.81 -46.43 -54.79 -2.08%
MW-35 11/13/2012 25.55 17.01 12.59 0.33 55.47 -6.70 -1.88 -33.31 -41.89 24.48%
MW-35 2/26/2013 25.05 17.83 13.41 0.32 56.61 -6.66 -1.84 -43.93 -52.43 7.38%
MW-35 5/13/2013 25.05 18.14 12.42 0.28 55.89 -7.04 -1.69 -39.14 -47.87 14.35%
MW-35 7/9/2013 24.75 15.57 12.01 0.29 52.63 -6.92 -1.81 -38.93 -47.67 9.43%
MW-35 11/19/2013 24.95 16.49 11.85 0.30 53.58 -6.52 -1.72 -46.01 -54.25 -1.25%
MW-36 8/9/2011 22.21 31.14 11.19 0.25 64.79 -5.57 -1.52 -57.05 -64.14 1.00%
MW-36 10/3/2011 22.06 27.32 11.27 0.25 60.89 -5.54 -1.58 -59.55 -66.66 -9.48%
MW-36 2/20/2012 22.60 31.49 11.52 0.27 65.88 -5.74 -2.06 -56.01 -63.80 3.16%
MW-36 5/8/2012 23.15 31.75 12.26 0.33 67.49 -5.82 -1.64 -56.21 -63.67 5.67%
MW-36 7/11/2012 21.61 27.62 11.02 0.23 60.48 -5.78 -1.69 -55.38 -62.86 -3.94%
MW-36 11/14/2012 21.56 29.67 11.11 0.24 62.57 -5.88 -1.66 -43.72 -51.26 18.08%
MW-36 2/26/2013 21.26 32.10 11.85 0.29 65.50 -5.78 -1.64 -44.76 -52.18 20.34%
MW-36 5/14/2013 21.36 32.19 10.78 0.24 64.56 -6.04 -1.50 -50.59 -58.13 9.96%
MW-36 7/10/2013 21.46 27.45 10.78 0.25 59.93 -6.04 -1.69 -61.63 -69.35 -15.72%
MW-36 11/20/2013 21.11 29.10 10.70 0.26 61.16 -6.02 -1.54 -51.63 -59.20 3.21%
MW-37 8/11/2011 22.80 24.18 10.61 0.36 57.96 -4.77 -1.55 -50.80 -57.12 1.44%
MW-37 10/19/2011 24.00 24.18 10.94 0.36 59.49 -4.28 -1.41 -54.55 -60.24 -1.25%
MW-37 2/29/2012 24.05 24.10 10.86 0.39 59.40 -4.87 -1.02 -52.05 -57.93 2.47%
MW-37 5/29/2012 23.90 25.88 11.52 0.42 61.72 -4.33 -1.41 -51.22 -56.95 7.72%
MW-37 7/30/2012 24.25 25.01 10.94 0.39 60.59 -4.34 -1.44 -56.21 -62.00 -2.32%
MW-37 12/5/2012 22.65 22.36 10.78 0.36 56.15 -4.62 -1.31 -21.03 -26.96 51.99%
MW-37 3/20/2013 24.30 23.75 11.44 0.38 59.86 -4.20 -1.26 -44.35 -49.80 16.81%
MW-37 6/3/2013 24.55 22.71 11.27 0.39 58.92 -4.28 -1.38 -53.51 -59.16 -0.42%
MW-37 7/23/2013 23.30 20.79 10.12 0.37 54.58 -4.22 -1.22 -56.63 -62.07 -13.71%
MW-37 12/18/2013 23.70 22.27 10.86 0.37 57.21 -3.86 -1.30 -57.26 -62.42 -9.11%
Notes:
SO4 = Sulfate
HCO3= Bicarbonate
meq/L= milliequivalent per
TABLE 5
Relative Percent Difference Between Primary and Duplicate Samples
Well Chemical Sample Date Result Qualifier
Duplicate
Result
Duplicate
Qualifier Units
Relative
percent
difference
MW 35 Gross Alpha minus Rn and U 4/10/2012 4.1 4.3 pCi/L 4.65%
MW 35 Gross Alpha minus Rn and U 9/19/2012 5.4 6 pCi/L 10.00%MW 35 Gross Alpha minus Rn and U 10/23/2012 4.31 5.84 pCi/L 26.20%MW 35 Gross Alpha minus Rn and U 1/23/2013 6.62 7.79 pCi/L 15.02%
MW 35 Gross Alpha minus Rn and U 1/8/2014 4.12 5.45 pCi/L 24.40%
MW 35 Manganese 9/7/2011 270 275 µg/L 1.82%
MW 35 Manganese 4/10/2012 277 279 µg/L 0.72%
MW 35 Manganese 9/19/2012 283 273 µg/L 3.66%
MW 35 Manganese 10/23/2012 253 248 µg/L 2.02%
MW 35 Manganese 1/23/2013 247 246 µg/L 0.41%
MW 35 Manganese 1/8/2014 252 253 µg/L 0.40%
MW 35 Selenium 9/19/2012 8.2 9.7 µg/L 15.46%
MW 35 Selenium 10/23/2012 19 18.4 µg/L 3.26%
MW 35 Selenium 1/23/2013 11 10.2 µg/L 7.84%
MW 35 Selenium 1/8/2014 8.95 8.46 µg/L 5.79%MW 35 Thallium 4/10/2012 0.59 0.6 µg/L 1.67%
MW 35 Thallium 9/19/2012 0.54 0.5 U µg/L 8.00%
MW 35 Thallium 10/23/2012 0.517 0.68 µg/L 23.97%
MW 35 Thallium 1/23/2013 0.5 U 0.5 U µg/L 0.00%
MW 35 Thallium 1/8/2014 0.535 0.5 U µg/L 7.00%
MW 35 Uranium 9/7/2011 22.3 23 µg/L 3.04%
MW 35 Uranium 4/10/2012 22.4 22.9 µg/L 2.18%
MW 35 Uranium 9/19/2012 22.9 22.6 µg/L 1.33%
MW 35 Uranium 10/23/2012 22.4 23.7 µg/L 5.49%
MW 35 Uranium 1/23/2013 23.6 22.5 µg/L 4.89%
MW 35 Uranium 1/8/2014 20.8 21.4 µg/L 2.80%
MW 36 Arsenic 11/20/2013 5 U 5 U µg/L 0.00%MW 36 Arsenic 3/5/2014 5 U 5 U µg/L 0.00%MW 36 Beryllium 11/20/2013 0.5 U 0.5 U µg/L 0.00%
MW 36 Beryllium 3/5/2014 0.5 U 0.5 U µg/L 0.00%
MW 36 Cadmium 11/20/2013 0.5 U 0.5 U µg/L 0.00%
MW 36 Cadmium 3/5/2014 0.5 U 0.5 U µg/L 0.00%
MW 36 Carbon tetrachloride 11/20/2013 1 U 1 U µg/L 0.00%
MW 36 Carbon tetrachloride 3/5/2014 1 U 1 U µg/L 0.00%
MW 36 Chloride 11/20/2013 54.7 59 mg/L 7.29%
MW 36 Chloride 3/5/2014 57.7 57.6 mg/L 0.17%
MW 36 Chloroform 11/20/2013 1 U 1 U µg/L 0.00%
MW 36 Chloroform 3/5/2014 1 U 1 U µg/L 0.00%
MW 36 Chloromethane 11/20/2013 1 U 1 U µg/L 0.00%
MW 36 Chloromethane 3/5/2014 1 U 1 U µg/L 0.00%MW 36 Chromium 11/20/2013 25 U 25 U µg/L 0.00%
MW 36 Chromium 3/5/2014 25 U 25 U µg/L 0.00%
MW 36 Cobalt 11/20/2013 10 U 10 U µg/L 0.00%
MW 36 Cobalt 3/5/2014 10 U 10 U µg/L 0.00%
MW 36 Copper 11/20/2013 10.4 10 U µg/L 4.00%
MW 36 Copper 3/5/2014 10 U 10 U µg/L 0.00%
MW 36 Fluoride 11/20/2013 0.35 0.297 mg/L 17.85%
MW 36 Fluoride 3/5/2014 0.287 0.279 mg/L 2.87%
MW 36 Gross Alpha minus Rn and U 11/20/2013 1.42 1.94 pCi/L 26.80%
MW 36 Gross Alpha minus Rn and U 3/5/2014 1 U 1 U pCi/L 0.00%
MW 36 Iron 11/20/2013 30 U 30 U µg/L 0.00%
MW 36 Iron 3/5/2014 30 U 30 U µg/L 0.00%
Page 1 of 2
Table 5
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
TABLE 5
Relative Percent Difference Between Primary and Duplicate Samples
Well Chemical Sample Date Result Qualifier
Duplicate
Result
Duplicate
Qualifier Units
Relative
percent
difference
MW 36 Lead 11/20/2013 1 U 1 U µg/L 0.00%
MW 36 Lead 3/5/2014 1 U 1 U µg/L 0.00%MW 36 Manganese 11/20/2013 10 U 10 U µg/L 0.00%MW 36 Manganese 3/5/2014 10 U 10 U µg/L 0.00%
MW 36 Mercury 11/20/2013 0.5 U 0.5 U µg/L 0.00%
MW 36 Mercury 3/5/2014 0.5 U 0.5 U µg/L 0.00%
MW 36 Methyl ethyl ketone 11/20/2013 20 U 20 U µg/L 0.00%
MW 36 Methyl ethyl ketone 3/5/2014 20 U 20 U µg/L 0.00%
MW 36 Methylene chloride 11/20/2013 1 U 1 U µg/L 0.00%
MW 36 Methylene chloride 3/5/2014 1 U 1 U µg/L 0.00%
MW 36 Molybdenum 11/20/2013 10 U 10 U µg/L 0.00%
MW 36 Molybdenum 3/5/2014 10 U 10 U µg/L 0.00%
MW 36 Naphthalene 11/20/2013 1 U 1 U µg/L 0.00%
MW 36 Naphthalene 3/5/2014 1 U 1 U µg/L 0.00%
MW 36 Nickel 11/20/2013 20 U 20 U µg/L 0.00%MW 36 Nickel 3/5/2014 20 U 20 U µg/L 0.00%
MW 36 Nitrate + Nitrite as N 11/20/2013 0.208 0.209 mg/L 0.48%
MW 36 Nitrate + Nitrite as N 3/5/2014 0.149 0.135 mg/L 10.37%
MW 36 Nitrogen, Ammonia as N 11/20/2013 0.05 U 0.05 U mg/L 0.00%
MW 36 Nitrogen, Ammonia as N 3/5/2014 0.05 U 0.05 U mg/L 0.00%
MW 36 Selenium 11/20/2013 235 233 µg/L 0.86%
MW 36 Selenium 3/5/2014 244 241 µg/L 1.24%
MW 36 Silver 11/20/2013 10 U 10 U µg/L 0.00%
MW 36 Silver 3/5/2014 10 U 10 U µg/L 0.00%
MW 36 Sulfate 11/20/2013 2480 2550 mg/L 2.75%
MW 36 Sulfate 3/5/2014 2790 2640 mg/L 5.68%
MW 36 Tetrahydrofuran 11/20/2013 1 U 1 U µg/L 0.00%MW 36 Tetrahydrofuran 3/5/2014 1 U 1 U µg/L 0.00%MW 36 Thallium 11/20/2013 0.575 0.583 µg/L 1.37%
MW 36 Thallium 3/5/2014 0.843 0.849 µg/L 0.71%
MW 36 Tin 11/20/2013 100 U 100 U µg/L 0.00%
MW 36 Tin 3/5/2014 100 U 100 U µg/L 0.00%
MW 36 Toluene 11/20/2013 1 U 1 U µg/L 0.00%
MW 36 Toluene 3/5/2014 1 U 1 U µg/L 0.00%
MW 36 Total Dissolved Solids 11/20/2013 4520 4860 mg/L 7.00%
MW 36 Total Dissolved Solids 3/5/2014 4460 4630 mg/L 3.67%
MW 36 Uranium 11/20/2013 24.3 26.7 µg/L 8.99%
MW 36 Uranium 3/5/2014 24.8 23.1 µg/L 7.36%
MW 36 Vanadium 11/20/2013 15 U 15 U µg/L 0.00%
MW 36 Vanadium 3/5/2014 15 U 15 U µg/L 0.00%MW 36 Xylenes, Total 11/20/2013 1 U 1 U µg/L 0.00%
MW 36 Xylenes, Total 3/5/2014 1 U 1 U µg/L 0.00%
MW 36 Zinc 11/20/2013 10 U 10 U µg/L 0.00%
MW 36 Zinc 3/5/2014 10 U 10 U µg/L 0.00%
Notes:
µg/L = micrograms per liter
mg/L = milligrams per liter
pCi/L = picocuries per liter
Rn and U = Radon and uranium
U (as qualifier) = result not detected above the laboratory reporting limit
Page 2 of 2
Table 5
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
TABLE 6a
Descriptive Summary Statistics for Constituents with Greater than 50 Percent Detects
Type Well Constituent Units N % Non-
Detects
Mean* Geometric
Mean
Std.
Dev.**
Q25 Median Q75 Min.
Conc.
Max.
Conc.
Range Skewness
ALL MW-35 Ammonia mg/L 13 8%0.10 0.08 0.07 0.06 0.08 0.10 0.05 0.31 0.26 2.72
ER MW-35 Ammonia mg/L 12 8%0.08 0.07 0.03 0.05 0.08 0.09 0.03 0.15 0.13 0.89
ALL MW-35 Chloride mg/L 13 0%60.71 60.30 6.75 59.00 61.00 64.30 41.00 69.00 28.00 -2.15
ER MW-35 Chloride mg/L 12 0%62.35 62.27 3.38 59.50 61.00 64.80 59.00 69.00 10.00 0.75
ALL MW-36 Chloride mg/L 10 0%58.57 58.35 5.61 54.70 58.00 59.80 53.30 73.00 19.70 2.12
ALL MW-37 Chloride mg/L 10 0%47.12 46.84 5.20 44.50 47.70 50.00 36.00 55.00 19.00 -0.84
ALL MW-35 Field pH s.u 33 0%6.71 6.71 0.28 6.51 6.67 6.84 6.25 7.46 1.21 0.89
ALL MW-36 Field pH s.u 10 0%6.95 6.94 0.23 6.76 6.92 7.10 6.57 7.33 0.76 0.12
ALL MW-37 Field pH s.u 11 0%6.86 6.86 0.13 6.73 6.89 6.94 6.65 7.04 0.39 -0.45
ALL MW-35 Fluoride mg/L 13 0%0.37 0.37 0.02 0.35 0.37 0.39 0.32 0.41 0.09 -0.10
ALL MW-36 Fluoride mg/L 10 0%0.32 0.32 0.02 0.30 0.32 0.33 0.29 0.35 0.06 0.13
ALL MW-37 Fluoride mg/L 10 0%0.25 0.25 0.03 0.23 0.25 0.27 0.22 0.30 0.08 0.52
ALL MW-35 GrossAlpha pCi/L 31 0%4.77 4.60 1.35 4.10 4.50 5.39 2.60 9.51 6.91 1.42
ER MW-35 GrossAlpha pCi/L 30 0%4.61 4.49 1.04 4.10 4.50 5.10 2.60 6.62 4.02 0.19
ALL MW-36 GrossAlpha pCi/L 10 0%1.38 1.04 0.93 0.50 1.41 2.04 0.30 2.68 2.38 0.20
ALL MW-37 GrossAlpha pCi/L 10 20%1.77 1.49 1.10 1.00 1.20 2.70 0.60 3.89 3.29 0.88
ALL MW-35 Iron µg/L 13 0%180.94 168.83 74.57 137.00 182.00 207.00 73.20 388.00 314.80 1.74
ALL MW-35 Manganese µg/L 33 0%279.12 272.62 80.29 248.00 260.00 272.00 240.00 698.00 458.00 4.76
ER MW-35 Manganese µg/L 30 0%259.87 259.44 15.41 247.00 257.50 271.00 240.00 304.00 64.00 0.83
ALL MW-36 NitrateNitrite µg/L 10 0%0.20 0.20 0.02 0.18 0.19 0.20 0.18 0.26 0.08 2.13
ALL MW-37 NitrateNitrite µg/L 10 0%2.76 1.25 5.42 0.75 0.92 1.66 0.37 18.10 17.73 3.10
ER MW-37 NitrateNitrite µg/L 9 0%1.05 0.93 0.59 0.75 0.90 1.19 0.37 2.27 1.90 1.26
ALL MW-35 Selenium µg/L 26 27%11.39 10.05 5.57 5.00 10.90 15.90 5.00 22.60 17.60 0.43
ALL MW-36 Selenium µg/L 10 0%262.90 262.06 22.26 254.00 263.00 273.00 229.00 307.00 78.00 0.37
ALL MW-37 Selenium µg/L 10 20%6.80 6.65 1.49 5.20 6.75 7.45 5.00 9.07 4.07 0.33
ALL MW-35 Sulfate mg/L 13 0%2073.85 2036.83 364.77 1880.00 2230.00 2310.00 1140.00 2400.00 1260.00 -1.69
ALL MW-36 Sulfate mg/L 10 0%2577.00 2562.19 284.61 2430.00 2675.00 2740.00 2100.00 2960.00 860.00 -0.62
ALL MW-37 Sulfate mg/L 10 0%2390.00 2313.38 517.62 2440.00 2535.00 2700.00 1010.00 2750.00 1740.00 -2.52
ER MW-37 Sulfate mg/L 9 0%2543.33 2536.52 192.16 2460.00 2570.00 2700.00 2130.00 2750.00 620.00 -1.22
ALL MW-35 TDS mg/L 13 0%3730.00 3692.62 476.78 3750.00 3840.00 3940.00 2200.00 4170.00 1970.00 -3.14
ER MW-35 TDS mg/L 12 0%3857.50 3855.47 132.06 3755.00 3840.00 3950.00 3720.00 4170.00 450.00 1.21
ALL MW-36 TDS mg/L 10 0%4376.00 4374.50 121.12 4270.00 4350.00 4520.00 4220.00 4540.00 320.00 0.27
ALL MW-37 TDS mg/L 10 0%3893.00 3891.42 116.81 3820.00 3895.00 3980.00 3700.00 4090.00 390.00 0.00
ALL MW-35 Thallium µg/L 31 48%0.58 0.57 0.14 0.50 0.51 0.61 0.50 1.14 0.64 2.77
ER MW-35 Thallium µg/L 29 48%0.55 0.54 0.07 0.50 0.50 0.57 0.50 0.72 0.22 1.37
ALL MW-36 Thallium µg/L 10 0%0.87 0.85 0.24 0.73 0.82 0.98 0.58 1.43 0.86 1.44
ALL MW-35 Uranium µg/L 33 0%21.95 21.76 2.78 21.00 22.20 23.60 12.70 27.20 14.50 -1.19
ER MW-35 Uranium µg/L 32 0%22.24 22.13 2.26 21.15 22.25 23.80 16.10 27.20 11.10 -0.33
ALL MW-36 Uranium µg/L 10 0%23.45 23.41 1.48 22.00 23.65 24.00 21.40 26.50 5.10 0.56
Page 1 of 2
Table 6a
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
TABLE 6a
Descriptive Summary Statistics for Constituents with Greater than 50 Percent Detects
Type Well Constituent Units N % Non-
Detects
Mean* Geometric
Mean
Std.
Dev.**
Q25 Median Q75 Min.
Conc.
Max.
Conc.
Range Skewness
ALL MW-37 Uranium µg/L 10 0%13.16 12.97 2.46 11.40 12.35 15.50 10.30 18.10 7.80 0.99
ALL MW-37 Zinc µg/L 10 0%25.95 25.13 7.65 20.30 24.05 28.00 20.00 45.00 25.00 1.93
Notes:
% Non-Detects = the percent of non-detected values in a data set
*Mean = arithmetic mean (For constituents with greater than 15% and less than 50% non-detects, means are determined in a separate manner in Table 8.)
**Std. Dev. = standard deviation (For constituents with greater than 15% and less than 50% non-detects, the standard deviation is determined in a separate manner in Table 8.)
ER = extreme outliers were removed prior to analysis
Median = 50th percentile of the sample population
Q75 = 75th percentile of the sample population
Max. Conc. = maximum concentration
µg/L = micrograms per liter
mg/L = milligrams per liter
All = entire data set (The data set did not contain extremes.)
pCi/L = picocuries per liter
s.u.= standard units
TDS = total dissolved solids
Min. Conc. = minimum concentration
N = number of data points in a data set
Q25 = 25th percentile of the sample population
Skewness = measure of skewness of the data distribution (Indicates the degree of assymetry and direction of the skewness. Values greater than 2 indicate significant skew, with negative
values indicating left skew, and positive values indicating right skew.)
Page 2 of 2
Table 6a
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
TABLE 6b
Descriptive Summary Statistics for Constituents with Less than 50 Percent Detects
Type Well Constituent Units N % Non-
Detects
Mean* Geometric
Mean
Std.
Dev.**
Q25 Median Q75 Min.
Conc.
Max.
Conc.
Range Skewness
ALL MW-36 Ammonia mg/L 10 100%0.05 0.05 0.0000 0.05 0.05 0.05 0.05 0.05 0.000
ALL MW-37 Ammonia mg/L 10 100%0.05 0.05 0.0000 0.05 0.05 0.05 0.05 0.05 0.000
ALL MW-35 Arsenic µg/L 13 100%5.00 5.00 0.00 5.00 5.00 5.00 5.00 5.00 0.00
ALL MW-36 Arsenic µg/L 10 100%5.00 5.00 0.00 5.00 5.00 5.00 5.00 5.00 0.00
ALL MW-37 Arsenic µg/L 10 100%5.00 5.00 0.00 5.00 5.00 5.00 5.00 5.00 0.00
ALL MW-35 Beryllium µg/L 13 100%0.50 0.50 0.00 0.50 0.50 0.50 0.50 0.50 0.00
ALL MW-36 Beryllium µg/L 10 100%0.50 0.50 0.00 0.50 0.50 0.50 0.50 0.51 0.01 3.16
ER MW-36 Beryllium µg/L 9 100%0.50 0.50 0.00 0.50 0.50 0.50 0.50 0.50 0.00
ALL MW-37 Beryllium µg/L 10 100%0.50 0.50 0.00 0.50 0.50 0.50 0.50 0.50 0.00
ALL MW-35 Cadmium µg/L 13 100%0.50 0.50 0.00 0.50 0.50 0.50 0.50 0.50 0.00
ALL MW-36 Cadmium µg/L 10 100%0.50 0.50 0.00 0.50 0.50 0.50 0.50 0.51 0.01 3.16
ER MW-36 Cadmium µg/L 9 100%0.50 0.50 0.00 0.50 0.50 0.50 0.50 0.50 0.00
ALL MW-37 Cadmium µg/L 10 100%0.50 0.50 0.00 0.50 0.50 0.50 0.50 0.50 0.00
ALL MW-35 Chromium µg/L 13 100%25.00 25.00 0.00 25.00 25.00 25.00 25.00 25.00 0.00
ALL MW-36 Chromium µg/L 10 100%25.00 25.00 0.00 25.00 25.00 25.00 25.00 25.00 0.00
ALL MW-37 Chromium µg/L 10 100%25.00 25.00 0.00 25.00 25.00 25.00 25.00 25.00 0.00
ALL MW-35 Cobalt µg/L 13 100%10.62 10.46 2.22 10.00 10.00 10.00 10.00 18.00 8.00 3.61
ER MW-35 Cobalt µg/L 12 100%10.00 10.00 0.00 10.00 10.00 10.00 10.00 10.00 0.00
ALL MW-36 Cobalt µg/L 10 100%10.00 10.00 0.00 10.00 10.00 10.00 10.00 10.00 0.00
ALL MW-37 Cobalt µg/L 10 100%10.00 10.00 0.00 10.00 10.00 10.00 10.00 10.00 0.00
ALL MW-35 Copper µg/L 13 100%10.00 10.00 0.00 10.00 10.00 10.00 10.00 10.00 0.00
ALL MW-36 Copper µg/L 10 100%10.04 10.04 0.13 10.00 10.00 10.00 10.00 10.40 0.40 3.16
ER MW-36 Copper µg/L 9 100%10.00 10.00 0.00 10.00 10.00 10.00 10.00 10.00 0.00
ALL MW-37 Copper µg/L 10 100%10.00 10.00 0.00 10.00 10.00 10.00 10.00 10.00 0.00
ALL MW-36 Iron µg/L 10 100%30.00 30.00 0.00 30.00 30.00 30.00 30.00 30.00 0.00
ALL MW-37 Iron µg/L 10 100%34.36 32.82 13.79 30.00 30.00 30.00 30.00 73.60 43.60 3.16
ER MW-37 Iron µg/L 9 100%30.00 30.00 0.00 30.00 30.00 30.00 30.00 30.00 0.00
ALL MW-35 Lead µg/L 13 100%1.00 1.00 0.00 1.00 1.00 1.00 1.00 1.00 0.00
ALL MW-36 Lead µg/L 10 100%1.00 1.00 0.00 1.00 1.00 1.00 1.00 1.00 0.00
ALL MW-37 Lead µg/L 10 100%1.00 1.00 0.00 1.00 1.00 1.00 1.00 1.00 0.00
ALL MW-36 Manganese µg/L 10 100%10.00 10.00 0.00 10.00 10.00 10.00 10.00 10.00 0.00
ALL MW-37 Manganese µg/L 10 67%23.31 15.28 32.77 10.00 10.00 16.60 10.00 115.00 105.00 2.98
ER MW-37 Manganese µg/L 9 67%13.12 12.21 6.35 10.00 10.00 12.50 10.00 29.00 19.00 2.42
ALL MW-35 Mercury µg/L 13 100%0.50 0.50 0.00 0.50 0.50 0.50 0.50 0.50 0.00
ALL MW-36 Mercury µg/L 10 100%0.50 0.50 0.00 0.50 0.50 0.50 0.50 0.50 0.00
ALL MW-37 Mercury µg/L 10 100%0.50 0.50 0.00 0.50 0.50 0.50 0.50 0.50 0.00
ALL MW-35 Molybdenum µg/L 19 100%11.07 10.60 4.68 10.00 10.00 10.00 10.00 30.40 20.40 4.36
ER MW-35 Molybdenum µg/L 18 100%10.00 10.00 0.00 10.00 10.00 10.00 10.00 10.00 0.00
ALL MW-36 Molybdenum µg/L 10 100%10.00 10.00 0.00 10.00 10.00 10.00 10.00 10.00 0.00
ALL MW-37 Molybdenum µg/L 10 100%10.00 10.00 0.00 10.00 10.00 10.00 10.00 10.00 0.00
Page 1 of 3
Table 6b
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
TABLE 6b
Descriptive Summary Statistics for Constituents with Less than 50 Percent Detects
Type Well Constituent Units N % Non-
Detects
Mean* Geometric
Mean
Std.
Dev.**
Q25 Median Q75 Min.
Conc.
Max.
Conc.
Range Skewness
ALL MW-35 Nickel µg/L 13 100%20.69 20.63 1.80 20.00 20.00 20.00 20.00 26.00 6.00 2.68
ER MW-35 Nickel µg/L 11 100%20.00 20.00 0.00 20.00 20.00 20.00 20.00 20.00 0.00
ALL MW-36 Nickel µg/L 10 100%20.00 20.00 0.00 20.00 20.00 20.00 20.00 20.00 0.00
ALL MW-37 Nickel µg/L 10 100%20.00 20.00 0.00 20.00 20.00 20.00 20.00 20.00 0.00
ALL MW-35 NitrateNitrite mg/L 13 100%0.11 0.11 0.05 0.10 0.10 0.10 0.10 0.28 0.18 3.61
ER MW-35 NitrateNitrite mg/L 12 100%0.10 0.10 0.00 0.10 0.10 0.10 0.10 0.10 0.00
ALL MW-35 Silver µg/L 13 100%10.00 10.00 0.00 10.00 10.00 10.00 10.00 10.00 0.00
ALL MW-36 Silver µg/L 10 100%10.00 10.00 0.00 10.00 10.00 10.00 10.00 10.00 0.00
ALL MW-37 Silver µg/L 10 100%10.00 10.00 0.00 10.00 10.00 10.00 10.00 10.00 0.00
ALL MW-37 Thallium µg/L 10 60%0.57 0.56 0.10 0.50 0.50 0.63 0.50 0.79 0.29 1.37
ALL MW-35 Tin µg/L 13 100%100.00 100.00 0.00 100.00 100.00 100.00 100.00 100.00 0.00
ALL MW-36 Tin µg/L 11 100%100.00 100.00 0.00 100.00 100.00 100.00 100.00 100.00 0.00
ALL MW-37 Tin µg/L 11 100%100.00 100.00 0.00 100.00 100.00 100.00 100.00 100.00 0.00
ALL MW-35 Vanadium µg/L 13 100%15.00 15.00 0.00 15.00 15.00 15.00 15.00 15.00 0.00
ALL MW-36 Vanadium µg/L 10 100%15.00 15.00 0.00 15.00 15.00 15.00 15.00 15.00 0.00
ALL MW-37 Vanadium µg/L 10 100%15.00 15.00 0.00 15.00 15.00 15.00 15.00 15.00 0.00
ALL MW-35 Zinc µg/L 13 100%10.31 10.26 1.11 10.00 10.00 10.00 10.00 14.00 4.00 3.61
ER MW-35 Zinc µg/L 12 100%10.00 10.00 0.00 10.00 10.00 10.00 10.00 10.00 0.00
ALL MW-36 Zinc µg/L 10 100%13.90 12.37 8.62 10.00 10.00 10.00 10.00 35.00 25.00 2.16
ER MW-36 Zinc µg/L 8 100%10.00 10.00 0.00 10.00 10.00 10.00 10.00 10.00 0.00
ALL MW-35 Acetone µg/L 13 100%20.00 20.00 0.00 20.00 20.00 20.00 20.00 20.00 0.00
ALL MW-36 Acetone µg/L 11 100%20.00 20.00 0.00 20.00 20.00 20.00 20.00 20.00 0.00
ALL MW-37 Acetone µg/L 10 100%20.00 20.00 0.00 20.00 20.00 20.00 20.00 20.00 0.00
ALL MW-35 Benzene µg/L 13 100%1.00 1.00 0.00 1.00 1.00 1.00 1.00 1.00 0.00
ALL MW-36 Benzene µg/L 11 100%1.00 1.00 0.00 1.00 1.00 1.00 1.00 1.00 0.00
ALL MW-37 Benzene µg/L 10 100%1.00 1.00 0.00 1.00 1.00 1.00 1.00 1.00 0.00
ALL MW-35 Carbon tetrachloride µg/L 13 100%1.00 1.00 0.00 1.00 1.00 1.00 1.00 1.00 0.00
ALL MW-36 Carbon tetrachloride µg/L 11 100%1.00 1.00 0.00 1.00 1.00 1.00 1.00 1.00 0.00
ALL MW-37 Carbon tetrachloride µg/L 10 100%1.00 1.00 0.00 1.00 1.00 1.00 1.00 1.00 0.00
ALL MW-35 Chloroform µg/L 13 100%1.00 1.00 0.00 1.00 1.00 1.00 1.00 1.00 0.00
ALL MW-36 Chloroform µg/L 11 100%1.00 1.00 0.00 1.00 1.00 1.00 1.00 1.00 0.00
ALL MW-37 Chloroform µg/L 10 100%1.00 1.00 0.00 1.00 1.00 1.00 1.00 1.00 0.00
ALL MW-35 Chloromethane µg/L 13 100%1.00 1.00 0.00 1.00 1.00 1.00 1.00 1.00 0.00
ALL MW-36 Chloromethane µg/L 11 100%1.00 1.00 0.00 1.00 1.00 1.00 1.00 1.00 0.00
ALL MW-37 Chloromethane µg/L 10 100%1.00 1.00 0.00 1.00 1.00 1.00 1.00 1.00 0.00
ALL MW-35 Methyl ethyl ketone µg/L 13 100%20.00 20.00 0.00 20.00 20.00 20.00 20.00 20.00 0.00
ALL MW-36 Methyl ethyl ketone µg/L 11 100%20.00 20.00 0.00 20.00 20.00 20.00 20.00 20.00 0.00
ALL MW-37 Methyl ethyl ketone µg/L 10 100%20.00 20.00 0.00 20.00 20.00 20.00 20.00 20.00 0.00
ALL MW-35 Methylene chloride µg/L 13 100%1.00 1.00 0.00 1.00 1.00 1.00 1.00 1.00 0.00
ALL MW-36 Methylene chloride µg/L 11 100%1.00 1.00 0.00 1.00 1.00 1.00 1.00 1.00 0.00
Page 2 of 3
Table 6b
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
TABLE 6b
Descriptive Summary Statistics for Constituents with Less than 50 Percent Detects
Type Well Constituent Units N % Non-
Detects
Mean* Geometric
Mean
Std.
Dev.**
Q25 Median Q75 Min.
Conc.
Max.
Conc.
Range Skewness
ALL MW-37 Methylene chloride µg/L 10 100%1.00 1.00 0.00 1.00 1.00 1.00 1.00 1.00 0.00
ALL MW-35 Naphthalene µg/L 13 100%1.00 1.00 0.00 1.00 1.00 1.00 1.00 1.00 0.00
ALL MW-36 Naphthalene µg/L 11 100%1.00 1.00 0.00 1.00 1.00 1.00 1.00 1.00 0.00
ALL MW-37 Naphthalene µg/L 10 100%1.00 1.00 0.00 1.00 1.00 1.00 1.00 1.00 0.00
ALL MW-35 Tetrahydrofuran µg/L 15 66%1.00 1.00 0.00 1.00 1.00 1.00 1.00 1.00 0.00
ALL MW-36 Tetrahydrofuran µg/L 11 91%1.00 1.00 0.00 1.00 1.00 1.00 1.00 1.00 0.00
ALL MW-37 Tetrahydrofuran µg/L 10 91%1.00 1.00 0.00 1.00 1.00 1.00 1.00 1.00 0.00
ALL MW-35 Toluene µg/L 13 100%1.00 1.00 0.00 1.00 1.00 1.00 1.00 1.00 0.00
ALL MW-36 Toluene µg/L 11 100%1.00 1.00 0.00 1.00 1.00 1.00 1.00 1.00 0.00
ALL MW-37 Toluene µg/L 10 100%1.00 1.00 0.00 1.00 1.00 1.00 1.00 1.00 0.00
ALL MW-35 Xylenes, Total µg/L 13 100%1.00 1.00 0.00 1.00 1.00 1.00 1.00 1.00 0.00
ALL MW-36 Xylenes, Total µg/L 11 100%1.00 1.00 0.00 1.00 1.00 1.00 1.00 1.00 0.00
ALL MW-37 Xylenes, Total µg/L 10 90%1.00 1.00 0.00 1.00 1.00 1.00 1.00 1.00 0.00
Notes:
% Non-Detects = The percent of non-detected values in a data set
µg/L = Micrograms per liter
Max. Conc. = maximum concentration
Median = 50th percentile of the sample population
mg/L = milligrams per liter
Min. Conc. = minimum concentration
pCi/L = picocuries per liter
Q25 = 25th percentile of the sample population
Q75 = 75th percentile of the sample population
s.u.= standard units
TDS = total dissolved solids
Skewness = measure of skewness of the data distribution (Indicates the degree of assymetry and direction of the skewness. Values greater than 2 indicate significant skew, with negative
values indicating left skew, and positive values indicating right skew.)
N = number of samples
All = entire data set (The data set did not contain extremes.)
*Mean = Arithmetic mean; for constituents with greater than 15% and less than 50% non-detects, means used to calculate GWCLs are determined in a separate manner in Table 8.
**Std.Dev. = Standard deviation; for constituents with greater than 15% and less than 50% non-detects, the standard deviation is determined in a separate manner in Table 8.
ER = extreme outliers were removed prior to analysis
Page 3 of 3
Table 6b
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
TABLE 7
Geometric Mean and Standard Deviation of Normally or Log-Normally Distributed Data
Well Constituent GWQS N
% Non-
Detect
Geometric
Mean
Geometric
Standard
Deviation
MW-35 Ammonia (mg/L) 25 12 8% 0.07 1.57
MW-35 Chloride (mg/L) TBD 12 0% 62.27 1.05
MW-35 Field pH (s.u.) TBD 33 0% 821.32 1.32
MW-35 Fluoride (mg/L) 4 13 0% 0.37 1.07
MW-35 GrossAlpha (pCi/L) 15 30 0% 4.49 1.26
MW-35 Iron (µg/L) 11,000 13 0% 168.83 1.47
MW-35 Manganese (µg/L) 800 30 0% 259.44 1.06
MW-35 TDS (mg/L) TBD 12 0% 3,855.47 1.03
MW-35 Uranium (µg/L) 30 32 0% 22.13 1.11
MW-36 Field pH (s.u.)6.5 to 8.5 10 0% 1,038.99 1.26
MW-36 Fluoride (mg/L) 4 10 0% 0.32 1.06
MW-36 GrossAlpha (pCi/L) 15 10 0% 1.04 2.37
MW-36 Selenium (µg/L) 50 10 0% 262.06 1.09
MW-36 Sulfate (mg/L) TBD 10 0% 2,562.19 1.12
MW-36 TDS (mg/L) TBD 10 0% 4,374.50 1.03
MW-36 Thallium (µg/L) 2 10 0% 0.85 1.29
MW-36 Uranium (µg/L) 30 10 0% 23.41 1.06
MW-37 Chloride (mg/L) TBD 10 0% 46.84 1.12
MW-37 Field pH (s.u.)6.5 to 8.5 11 0% 953.37 1.13
MW-37 Fluoride (mg/L) 4 10 0% 0.25 1.11
MW-37 GrossAlpha (pCi/L) 15 10 20% 1.49 1.85
MW-37 NitrateNitrite (mg/L) 10 9 0% 0.93 1.71
MW-37 Selenium (µg/L) 50 10 20% 6.65 1.25
MW-37 Sulfate (mg/L) TBD 9 0% 2,536.52 1.08
MW-37 TDS (mg/L) TBD 10 0% 3,891.42 1.03
MW-37 Uranium (µg/L) 30 10 0% 12.97 1.19
MW-37 Zinc (µg/L) 5,000 10 0% 25.13 1.29
Notes:
s.u. = standard units
µg/L = micrograms per liter
pCi/L = pico Curies per liter
TBD = to be determined (defined as the value of the arithmetic mean plus two standard deviations or equivalent)
GWQS= Ground Water Quality Standard (R317-6-2 UT Administrative Code)
% Non-Detected = the percent of non-detected values in a data set
N = Number of data points
mg/L = milligrams per liter
Page 1 of 1
Table 7
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
TABLE 8
Summary of Flow Sheet GWCL Calculations Based on UDEQ-Approved Flow Sheet
r p r2 Sp Mean SD
MW-35 Ammonia 25 12 8% Yes -0.4142 0.1806 0.172 0.08 0.03 12.5 0.14 Mean + 2SD
MW-35 NitrateNitrite 10 12 100% Not Tested 0.94 5 5 Fractional
MW-35 Arsenic 50 13 100% Not Tested 9.58 25 25 Fractional
MW-35 Beryllium 4 13 100% Not Tested 2.09 2 2 Fractional
MW-35 Cadmium 5 13 100% Not Tested 2.09 2.5 2.5 FractionalMW-35 Chromium 100 13 100% Not Tested 34.99 50 50 Fractional
MW-35 Cobalt 730 12 100% Not Tested 16.39 365 365 Fractional
MW-35 Copper 1300 13 100% Not Tested 16.39 650 650 Fractional
MW-35 Iron 11000 13 0% Yes -0.5902 0.0337 0.348 Decreasing 180.94 74.57 5500 330.08 Mean + 2SDMW-35 Lead 15 13 100% Not Tested 3.16 7.5 7.5 Fractional
MW-35 Manganese 800 30 0% Yes -0.3735 0.0421 0.14 Decreasing 259.87 15.41 400 290.68 Mean + 2SD
MW-35 Mercury 2 13 100% Not Tested 2.09 1 1 Fractional
MW-35 Molybdenum 40 18 100% Not Tested 16.39 20 20 FractionalMW-35 Nickel 10 11 100% Not Tested 28.96 5 5 FractionalMW-35 Selenium 50 26 27% No 10 0.421 Increasing 11.39 5.57 22.600 25 25 Fractional 33.73 HHV+2SD due to increasing trend
MW-35 Silver 100 13 100% Not Tested 16.39 50 50 Fractional
MW-35 Thallium 2 29 48% No -92 0.0325 Decreasing 0.715 1 1 FractionalMW-35 Tin 17000 13 100% Not Tested 119.79 8500 8500 FractionalMW-35 Uranium 30 32 0% Yes -0.2468 0.1732 0.061 22.24 2.26 15 26.76 Mean + 2SD
MW-35 Vanadium 60 13 100% Not Tested 22.79 30 30 Fractional
MW-35 Zinc 5000 12 100% Not Tested 16.39 2500 2500 Fractional
MW-35 GrossAlpha 15 30 0% Yes 0.3404 0.0657 0.116 Increasing 4.61 1.04 7.5 6.69 Mean + 2SD 12.21 HHV+2SD due to increasing trend
MW-35 Acetone 700 13 100% Not Tested 28.49 350 350 Fractional
MW-35 Benzene 5 13 100% Not Tested 3.01 2.5 2.5 FractionalMW-35 Methyl ethyl ketone 4000 13 100% Not Tested 28.49 2000 2000 Fractional
MW-35 Carbon tetrachloride 5 13 100% Not Tested 3.00 2.5 2.5 Fractional
MW-35 Chloroform 70 13 100% Not Tested 3.00 35 35 Fractional
MW-35 Chloromethane 30 13 100% Not Tested 3.00 15 15 FractionalMW-35 Methylene chloride 5 13 100% Not Tested 3.00 2.5 2.5 Fractional
MW-35 Naphthalene 100 13 100% Not Tested 3.00 50 50 Fractional
MW-35 Tetrahydrofuran 46 15 66% Not Tested 3.00 23 23 Fractional
MW-35 Toluene 1000 13 100% Not Tested 3.00 500 500 FractionalMW-35 Xylenes, Total 10000 13 100% Not Tested 3.00 5000 5000 Fractional
MW-35 Chloride (mg/L)12 0% Yes -0.0142 0.965 2E-04 62.35 3.38 69.12 Mean + 2SD
MW-35 Fluoride (mg/L) 4 13 0% Yes -0.0971 0.7523 0.009 0.37 0.02 2 0.42 Mean + 2SDMW-35 Field pH (s.u.)33 0%Yes 0 0.6125 0.008 6.71 0.28 6.15 Mean - 2SDMW-35 Sulfate (mg/L)13 0% No -26 0.0629 2400 2400 HHV
MW-35 TDS (mg/L)12 0% Yes 0.7605 0.0041 0.578 Increasing Increasing 3857.50 132.06 4170 4121.61 Mean + 2SD 5123.55 HHV+2SD due to increasing trend
Radiologics (pCi/L)
HHV
Poisson
Prediction
Fractional
Approach
Aitchison Flowsheet
GWCL
Linear Regression Mann-Kendall Significant
Trend
ANY
TREND? Mean St. Dev.Well Constituent GWQS
Flowsheet GWCL
Rationale
Proposed
Modified Modified GWCL Rationale
Nutrients (mg/L)
Heavy Metals (µg/L)
N %ND
Normally or
Lognormally
Volatile Organic Compounds (µg/L)
Other
Page 1 of 3
Table 8
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
TABLE 8
Summary of Flow Sheet GWCL Calculations Based on UDEQ-Approved Flow Sheet
r p r2 Sp Mean SDHHV
Poisson
Prediction
Fractional
Approach
Aitchison Flowsheet
GWCL
Linear Regression Mann-Kendall Significant
Trend
ANY
TREND? Mean St. Dev.Well Constituent GWQS
Flowsheet GWCL
Rationale
Proposed
Modified Modified GWCL RationaleN %ND
Normally or
Lognormally
MW-36 Ammonia 25 10 100% Not Tested 0.72 12.5 12.5 Fractional
MW-36 NitrateNitrite 10 10 0% No 1 0.5 Increasing 0.259 5 5 Fractional
MW-36 Arsenic 50 10 100% Not Tested 9.58 25 25 Fractional
MW-36 Beryllium 4 9 100% Not Tested 2.09 2 2 Fractional
MW-36 Cadmium 5 9 100% Not Tested 2.09 2.5 2.5 FractionalMW-36 Chromium 100 10 100% Not Tested 34.99 50 50 Fractional
MW-36 Cobalt 730 10 100% Not Tested 16.39 365 365 Fractional
MW-36 Copper 1300 9 100% Not Tested 16.39 650 650 Fractional
MW-36 Iron 11000 10 100% Not Tested 40.93 5500 5500 FractionalMW-36 Lead 15 10 100% Not Tested 3.16 7.5 7.5 Fractional
MW-36 Manganese 800 10 100% Not Tested 16.39 400 400 Fractional
MW-36 Mercury 2 10 100% Not Tested 2.09 1 1 Fractional
MW-36 Molybdenum 40 10 100% Not Tested 16.39 20 20 FractionalMW-36 Nickel 100 10 100% Not Tested 28.96 50 50 FractionalMW-36 Selenium 50 10 0% Yes 0.006 0.987 0 262.90 22.26 25 307.42 Mean + 2SD
MW-36 Silver 100 10 100% Not Tested 16.39 50 50 Fractional
MW-36 Thallium 2 10 0% Yes -0.7423 0.0139 0.551 Decreasing 0.87 0.24 1 1.35 Mean + 2SDMW-36 Tin 17000 11 100% Not Tested 119.79 8500 8500 FractionalMW-36 Uranium 30 10 0% Yes -0.2886 0.4186 0.083 23.45 1.48 15 26.42 Mean + 2SD
MW-36 Vanadium 60 10 100% Not Tested 22.79 30 30 Fractional
MW-36 Zinc 5000 8 100% Not Tested 16.39 2500 2500 Fractional
MW-36 GrossAlpha 15 10 0% Yes 0.6975 0.0249 0.487 Increasing Increasing 1.38 0.93 7.5 3.23 Mean + 2SD 7.50 Fractional approach due to increasing trend
MW-36 Acetone 700 11 100% Not Tested 26.47 350 350 Fractional
MW-36 Benzene 5 11 100% Not Tested 2.85 2.5 2.5 FractionalMW-36 Methyl ethyl ketone 4000 11 100% Not Tested 26.47 2000 2000 Fractional
MW-36 Carbon tetrachloride 5 11 100% Not Tested 2.85 2.5 2.5 Fractional
MW-36 Chloroform 70 11 100% Not Tested 2.85 35 35 Fractional
MW-36 Chloromethane 30 11 100% Not Tested 2.85 15 15 FractionalMW-36 Methylene chloride 5 11 100% Not Tested 2.85 2.5 2.5 Fractional
MW-36 Naphthalene 100 11 100% Not Tested 2.85 50 50 Fractional
MW-36 Tetrahydrofuran 46 11 91% Not Tested 2.85 23 23 Fractional
MW-36 Toluene 1000 11 100% Not Tested 2.85 500 500 FractionalMW-36 Xylenes, Total 10000 11 100% Not Tested 2.85 5000 5000 Fractional
MW-36 Chloride (mg/L)10 0% No -2 0.464 73 73 HHV
MW-36 Fluoride (mg/L) 4 10 0% Yes 0.0527 0.8851 0.003 0.32 0.02 2 0.35 Mean + 2SDMW-36 Field pH (s.u.)10 0% Yes 0.0852 0.815 0.007 6.95 0.23 6.49 Mean - 2SDMW-36 Sulfate (mg/L)10 0% Yes -0.3763 0.2839 0.142 2577.00 284.61 3146.21 Mean + 2SD
MW-36 TDS (mg/L)10 0% Yes 0.3397 0.3368 0.115 Increasing 4376.00 121.12 4618.25 Mean + 2SD 4860.50 Mean + 4SD due to increasing trend
Nutrients (mg/L)
Heavy Metals (µg/L)
Radiologics (pCi/L)
Volatile Organic Compounds (µg/L)
Other
Page 2 of 3
Table 8
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
TABLE 8
Summary of Flow Sheet GWCL Calculations Based on UDEQ-Approved Flow Sheet
r p r2 Sp Mean SDHHV
Poisson
Prediction
Fractional
Approach
Aitchison Flowsheet
GWCL
Linear Regression Mann-Kendall Significant
Trend
ANY
TREND? Mean St. Dev.Well Constituent GWQS
Flowsheet GWCL
Rationale
Proposed
Modified Modified GWCL RationaleN %ND
Normally or
Lognormally
MW-37 Ammonia 25 10 100% Not Tested 0.72 12.5 12.5 Fractional
MW-37 NitrateNitrite 10 9 0% Yes -0.8625 0.0028 0.744 Decreasing 1.05 0.59 5 2.22 Mean + 2SD
MW-37 Arsenic 50 10 100% Not Tested 9.58 25 25 Fractional
MW-37 Beryllium 4 10 100% Not Tested 2.09 2 2 Fractional
MW-37 Cadmium 5 10 100% Not Tested 2.09 2.5 2.5 FractionalMW-37 Chromium 100 10 100% Not Tested 34.99 50 50 Fractional
MW-37 Cobalt 730 10 100% Not Tested 16.39 365 365 Fractional
MW-37 Copper 1300 10 100% Not Tested 16.39 650 650 Fractional
MW-37 Iron 11000 9 100% Not Tested 40.93 5500 5500 FractionalMW-37 Lead 15 10 100% Not Tested 3.16 7.5 7.5 Fractional
MW-37 Manganese 800 9 67% Not Tested -1 0.5 29 400 400 Fractional
MW-37 Mercury 2 10 100% Not Tested 2.09 1 1 Fractional
MW-37 Molybdenum 40 10 100% Not Tested 16.39 20 20 FractionalMW-37 Nickel 100 10 100% Not Tested 28.96 50 50 FractionalMW-37 Selenium 50 10 20% Yes 0.6903 0.0271 0.477 Increasing Increasing 6.80 1.49 25 5.8 3.2667 12.33 Aitchison Mean + 2SD 25.00 Fractional approach due to increasing trend
MW-37 Silver 100 10 100% Not Tested 16.39 50 50 Fractional
MW-37 Thallium 2 10 60% Not Tested 20 0.0267 Increasing Increasing 0.787 1 1 FractionalMW-37 Tin 17000 11 100% Not Tested 119.79 8500 8500 FractionalMW-37 Uranium 30 10 0% Yes -0.604 0.0644 0.365 13.16 2.46 15 18.08 Mean + 2SD
MW-37 Vanadium 60 10 100% Not Tested 22.79 30 30 Fractional
MW-37 Zinc 5000 10 0% Yes -0.1774 0.6239 0.032 25.95 7.65 2500 41.25 Mean + 2SD
MW-37 GrossAlpha 15 10 20% Yes 0.0383 0.9164 0.002 1.77 1.10 7.5 1.569 1.3147 4.20 Aitchison Mean + 2SD
MW-37 Acetone 700 10 100% Not Tested 24.43 350 350 Fractional
MW-37 Benzene 5 10 100% Not Tested 2.68 2.5 2.5 FractionalMW-37 Methyl ethyl ketone 4000 10 100% Not Tested 24.43 2000 2000 Fractional
MW-37 Carbon tetrachloride 5 10 100% Not Tested 2.68 2.5 2.5 Fractional
MW-37 Chloroform 70 10 100% Not Tested 2.68 35 35 Fractional
MW-37 Chloromethane 30 10 100% Not Tested 2.68 15 15 FractionalMW-37 Methylene chloride 5 10 100% Not Tested 2.68 2.5 2.5 Fractional
MW-37 Naphthalene 100 10 100% Not Tested 2.68 50 50 Fractional
MW-37 Tetrahydrofuran 46 10 91% Not Tested 2.68 23 23 Fractional
MW-37 Toluene 1000 10 100% Not Tested 2.68 500 500 FractionalMW-37 Xylenes, Total 10000 10 90% Not Tested 2.68 5000 5000 Fractional
MW-37 Chloride (mg/L)10 0% Yes -0.3117 0.3806 0.097 47.12 5.20 57.53 Mean + 2SD
MW-37 Fluoride (mg/L) 4 10 0% Yes 0.0328 0.9283 0.001 0.25 0.03 2 0.31 Mean + 2SDMW-37 Field pH (s.u.)11 0% Yes 0.5222 0.0994 0.273 6.86 0.13 6.61 Mean - 2SDMW-37 Sulfate (mg/L)9 0% Yes 0.2283 0.5547 0.052 Increasing 2543.33 192.16 2927.65 Mean + 2SD 3311.97 Mean + 4SD due to increasing trend
MW-37 TDS (mg/L)10 0% Yes -0.2495 0.487 0.062 3893.00 116.81 4126.63 Mean + 2SD
Notes:
%ND = the percent of non-detected values in a data set r = strength and direction of the linear relationship, where a negative value indicates decreasing trend.
µg/L = micrograms per liter r2 = The measure of how well the trendline fits the data where r2=1 represents a perfect fit.
GWCL = groundwater concentration lilmit
GWQS = Ground Water Quality Standard (R317-6-2 UT Administrative Code)
HHV = Highest historical value Std. Dev. = standard deviation
mg/L = milligrams per liter s.u. = standard units
N = number of data points in a data set
p = probability, where a value <0.05 is significant
pCi/L = picocuries per liter
S = Mann-Kendall statistic indicating how strong the trend is and which direction the data are trending (ie. A large positive S value indicates a strong increasing
trend, where a small negative value indicates a weaker decreasing trend)
Other
Nutrients (mg/L)
Heavy Metals (µg/L)
Radiologics (pCi/L)
Volatile Organic Compounds (µg/L)
Page 3 of 3
Table 8
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
TABLE 9
Summary of Trending Constituents and Modified GWCLs Based on the Flow Sheet
Page 1 of 1
Table 9
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
Outlier Removed MW-35 GrossAlpha 30 0%Yes No increasing 4.611 1.0382 6.62 15 7.5 6.69 Mean + 2SD 8.76 Mean + 4SD due to increasing trend
Outiler Retained MW-35 GrossAlpha 31 0%No Increasing Increasing 4.769 1.348 9.51 15 7.5 9.51 HHV 12.21 HHV+2SD due to increasing trend
Outlier Removed MW-35 TDS 12 0%Yes Increasing Increasing 3857.500 132.0554 4170 NA NA 4121.61 Mean + 2SD 4385.72 Mean + 4SD due to increasing trend
Outiler Retained MW-35 TDS 13 0%No No Increasing 3730.000 476.777 4170 NA NA 4683.55 Mean + 2SD 5123.55 HHV+2SD due to increasing trend
No outliers MW-36 GrossAlpha 10 0%Yes Increasing Increasing 1.376 0.9266 2.68 15 7.5 3.23 Mean + 2SD 7.50 Fractional approach due to increasing trend
No outliers MW-35 Selenium 26 27%No No increasing 11.385 5.5670 22.60 50 25 25 Fractional 33.73 HHV+2SD due to increasing trend
No outliers MW-37 Selenium 10 20%Yes Increasing increasing 6.800 1.4922 9.07 50 25 12.33 Aitchison Mean + 2SDe 25.00 Fractional approach due to increasing trend
No outliers MW-37 Sulfate 9 0%Yes No increasing 2543.333 192.1588 2750 NA NA 2927.65 Mean + 2SD 3311.97 Mean + 4SD due to increasing trend
No outliers MW-36 TDS 10 0%Yes No Increasing 4376.000 121.1244 4540 NA NA 4618.25 Mean + 2SD 4860.50 Mean + 4SD due to increasing trend
No outliers MW-37 Thallium 10 60%Not Tested Increasing Increasing 0.568 0.1023 0.79 2 1 1 Fractional 1f Fractional
No outliers MW-36 NitrateNitrite 10 0%No No Increasing 0.198 0.0238 0.26 NA 5 5 Fractional 5f Fractional
Notes:
a= Distribution determined by histograms and Shapiro-Wilk test, Appendix B
b= Significant trends determined by linear regression or Mann-Kendall, results in Appendices C and E and on Table 8
c= Visual trends identified on linear regression plots, Appendix C
d= GWCLs determined by Flowsheet, not taking trends into account
e= GWCLs determined by following the Addendum to the Flowsheet for constituents with increasing trends
f= modified approach results in the same GWCL as the 'Flowsheet' approach
%ND = The percent of non-detected values in a data set
GWCL = groundwater concentration limit
GWQS = Ground Water Quality Standard (R317-6-2 UT Administrative Code)
HHV = Highest historical value
N = number of samples
TDS = total dissolved solids
SD = standard deviation
SDOutliersWellParameterN%ND
Normally or
Lognormally
distributed?a
Significant
trend?b
Any
Trend?c Mean
Modified
GWCLe Modified GWCL RationaleHHVGWQS
Fractional
GWQS
(Class III)
Flowsheet
GWCLd Flowsheet GWCL
Rational
TABLE 10
Summary of Proposed Groundwater Compliance Limits
Page 1 of 3
Table 10
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
Well Constituent GWQS Proposed GWCL Rationale
MW-35 Ammonia 25 0.14 Mean + 2SD
MW-35 NitrateNitrite 10 5 Fractional
MW-35 Arsenic 50 25 Fractional
MW-35 Beryllium 4 2 Fractional
MW-35 Cadmium 5 2.5 Fractional
MW-35 Chromium 100 50 Fractional
MW-35 Cobalt 730 365 Fractional
MW-35 Copper 1300 650 Fractional
MW-35 Iron 11000 330.08 Mean + 2SD
MW-35 Lead 15 7.5 Fractional
MW-35 Manganese 800 290.68 Mean + 2SD
MW-35 Mercury 2 1 Fractional
MW-35 Molybdenum 40 20 Fractional
MW-35 Nickel 10 5 Fractional
MW-35 Selenium 50 33.73 HHV+2SD due to increasing trend
MW-35 Silver 100 50 Fractional
MW-35 Thallium 2 1 Fractional
MW-35 Tin 17000 8500 Fractional
MW-35 Uranium 30 26.76 Mean + 2SD
MW-35 Vanadium 60 30 Fractional
MW-35 Zinc 5000 2500 Fractional
MW-35 GrossAlpha 15 12.21 HHV+2SD due to increasing trend
MW-35 Acetone 700 350 Fractional
MW-35 Benzene 5 2.5 Fractional
MW-35 Methyl ethyl ketone 4000 2000 Fractional
MW-35 Carbon tetrachloride 5 2.5 Fractional
MW-35 Chloroform 70 35 Fractional
MW-35 Chloromethane 30 15 Fractional
MW-35 Methylene chloride 5 2.5 Fractional
MW-35 Naphthalene 100 50 Fractional
MW-35 Tetrahydrofuran 46 23 Fractional
MW-35 Toluene 1000 500 Fractional
MW-35 Xylenes, Total 10000 5000 Fractional
MW-35 Chloride (mg/L)TBD 69.12 Mean + 2SD
MW-35 Fluoride (mg/L)4 0.42 Mean + 2SD
MW-35 Field pH (s.u.)TBD 6.15 Mean - 2SD
MW-35 Sulfate (mg/L)TBD 2400 HHV
MW-35 TDS (mg/L)TBD 5123.55 HHV+2SD due to increasing trend
Nutrients (mg/L)
Heavy Metals (µg/L)
Radiologics (pCi/L)
Volatile Organic Compounds (µg/L)
Other
TABLE 10
Summary of Proposed Groundwater Compliance Limits
Page 2 of 3
Table 10
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
Well Constituent GWQS Proposed GWCL Rationale
MW-36 Ammonia 25 12.5 Fractional
MW-36 NitrateNitrite 10 5 Fractional
MW-36 Arsenic 50 25 Fractional
MW-36 Beryllium 4 2 Fractional
MW-36 Cadmium 5 2.5 Fractional
MW-36 Chromium 100 50 Fractional
MW-36 Cobalt 730 365 Fractional
MW-36 Copper 1300 650 Fractional
MW-36 Iron 11000 5500 Fractional
MW-36 Lead 15 7.5 Fractional
MW-36 Manganese 800 400 Fractional
MW-36 Mercury 2 1 Fractional
MW-36 Molybdenum 40 20 Fractional
MW-36 Nickel 100 50 Fractional
MW-36 Selenium 50 307.42 Mean + 2SD
MW-36 Silver 100 50 Fractional
MW-36 Thallium 2 1.35 Mean + 2SD
MW-36 Tin 17000 8500 Fractional
MW-36 Uranium 30 26.42 Mean + 2SD
MW-36 Vanadium 60 30 Fractional
MW-36 Zinc 5000 2500 Fractional
MW-36 GrossAlpha 15 7.50 Fractional approach due to increasing tr
MW-36 Acetone 700 350 Fractional
MW-36 Benzene 5 2.5 Fractional
MW-36 Methyl ethyl ketone 4000 2000 Fractional
MW-36 Carbon tetrachloride 5 2.5 Fractional
MW-36 Chloroform 70 35 Fractional
MW-36 Chloromethane 30 15 Fractional
MW-36 Methylene chloride 5 2.5 Fractional
MW-36 Naphthalene 100 50 Fractional
MW-36 Tetrahydrofuran 46 23 Fractional
MW-36 Toluene 1000 500 Fractional
MW-36 Xylenes, Total 10000 5000 Fractional
MW-36 Chloride (mg/L)TBD 73 HHV
MW-36 Fluoride (mg/L)4 0.35 Mean + 2SD
MW-36 Field pH (s.u.)TBD 6.49 Mean - 2SD
MW-36 Sulfate (mg/L)TBD 3146.21 Mean + 2SD
MW-36 TDS (mg/L)TBD 4860.50 Mean + 4SD due to increasing trend
Nutrients (mg/L)
Heavy Metals (µg/L)
Radiologics (pCi/L)
Other
Volatile Organic Compounds (µg/L)
TABLE 10
Summary of Proposed Groundwater Compliance Limits
Page 3 of 3
Table 10
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
Well Constituent GWQS Proposed GWCL Rationale
MW-37 Ammonia 25 12.5 Fractional
MW-37 NitrateNitrite 10 2.22 Mean + 2SD
MW-37 Arsenic 50 25 Fractional
MW-37 Beryllium 4 2 Fractional
MW-37 Cadmium 5 2.5 Fractional
MW-37 Chromium 100 50 Fractional
MW-37 Cobalt 730 365 Fractional
MW-37 Copper 1300 650 Fractional
MW-37 Iron 11000 5500 Fractional
MW-37 Lead 15 7.5 Fractional
MW-37 Manganese 800 400 Fractional
MW-37 Mercury 2 1 Fractional
MW-37 Molybdenum 40 20 Fractional
MW-37 Nickel 100 50 Fractional
MW-37 Selenium 50 25.00 Fractional approach due to increasing tr
MW-37 Silver 100 50 Fractional
MW-37 Thallium 2 1 Fractional
MW-37 Tin 17000 8500 Fractional
MW-37 Uranium 30 18.08 Mean + 2SD
MW-37 Vanadium 60 30 Fractional
MW-37 Zinc 5000 41.25 Mean + 2SD
MW-37 GrossAlpha 15 4.20 Aitchison Mean + 2SD
MW-37 Acetone 700 350 Fractional
MW-37 Benzene 5 2.5 Fractional
MW-37 Methyl ethyl ketone 4000 2000 Fractional
MW-37 Carbon tetrachloride 5 2.5 Fractional
MW-37 Chloroform 70 35 Fractional
MW-37 Chloromethane 30 15 Fractional
MW-37 Methylene chloride 5 2.5 Fractional
MW-37 Naphthalene 100 50 Fractional
MW-37 Tetrahydrofuran 46 23 Fractional
MW-37 Toluene 1000 500 Fractional
MW-37 Xylenes, Total 10000 5000 Fractional
MW-37 Chloride (mg/L)TBD 57.53 Mean + 2SD
MW-37 Fluoride (mg/L)4 0.31 Mean + 2SD
MW-37 Field pH (s.u.)TBD 6.61 Mean - 2SD
MW-37 Sulfate (mg/L)TBD 3311.97 Mean + 4SD due to increasing trend
MW-37 TDS (mg/L)TBD 4126.63 Mean + 2SD
Notes:
µg/L = micrograms per liter N = number of data points in a data set
GWCL = groundwater concentration lilmit p = probability, where a value <0.05 is significant
HHV = Highest historical value TBD = to be determined
mg/L = milligrams per liter
GWQS = Ground Water Quality Standard
(R317-6-2 UT Administrative Code)
pCi/L = picocuries per liter
SD = standard deviation
Volatile Organic Compounds (µg/L)
Other
Nutrients (mg/L)
Heavy Metals (µg/L)
Radiologics (pCi/L)
TABLE 11
Well Construction and Hydraulic Parameters
Page 1 of 1
Table 11
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
Well
Approximate
Depth to Top
of Screen
(feet)
Approximate
Depth of Base
of Screen
(feet)
Approximate
Depth to Base of
Bore Annular Seal
(feet)
Approximate
Depth to
Brushy Basin
(feet)
Depth to
Water1
(feet bls)
Approximate
Casing
Diameter
(inches)
Approximate
Bore
Diameter
(inches)
Effective
Screen
Length
(feet)
Filter
Pack
(yes/no)
Hydraulic
Conductivity K
(cm/s)Porosity
Hydraulic
gradient
(ft/ft)
Average
Linear
Groundwater
Velocity
(ft/yr)
MW-35 86.3 123.6 127.5 123 110.5 4 11 37.3 yes 3.48E-04 0.18 0.004 8
MW-36 79.9 119.9 120 115 109.6 4 11 40 yes 4.51E-04 0.18 0.005 13
MW-37 80.2 120.2 120.2 117 110.6 4 11 40 yes 1.28E-05 0.18 0.008 0.6
Data from HGC 2010, 2011
1Depth to water was at time of tests (2010, 2011)
bgs = below ground surface
cm/s = centimeters per second
ft/ft = foot per foot
Notes:

APPENDIX A
Box Plots
Appendix A: Box Plots
Page 1 of 19
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
MW-35 MW-36 MW-37
Ammonia
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0.16
0.18
0.20
0.22
0.24
0.26
0.28
0.30
0.32
0.34
Am
m
o
n
i
a

(
m
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
MW-35 MW-36 MW-37
Arsenic
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
Ar
s
e
n
i
c

(
u
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
Appendix A: Box Plots
Page 2 of 19
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
MW-35 MW-36 MW-37
Beryllium
0.498
0.500
0.502
0.504
0.506
0.508
0.510
0.512
Be
r
y
l
l
i
u
m

(
u
g
)
/
L
Median
25%-75%
1%-99%
Outliers
Extremes
MW-35 MW-36 MW-37
Cadmium
0.498
0.500
0.502
0.504
0.506
0.508
0.510
0.512
Ca
d
m
i
u
m

(
u
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
Appendix A: Box Plots
Page 3 of 19
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
MW-35 MW-36 MW-37
Chloride
30
35
40
45
50
55
60
65
70
75
Ch
l
o
r
i
d
e

(
m
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
MW-35 MW-36 MW-37
Chromium
23
24
25
26
27
Ch
r
o
m
i
u
m

(
u
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
Appendix A: Box Plots
Page 4 of 19
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
MW-35 MW-36 MW-37
Cobalt
9
10
11
12
13
14
15
16
17
18
19
Co
b
a
l
t

(
u
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
MW-35 MW-36 MW-37
Copper
9.95
10.00
10.05
10.10
10.15
10.20
10.25
10.30
10.35
10.40
10.45
Co
p
p
e
r

(
u
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
Appendix A: Box Plots
Page 5 of 19
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
MW-35 MW-36 MW-37
Fluoride
0.20
0.22
0.24
0.26
0.28
0.30
0.32
0.34
0.36
0.38
0.40
0.42
Fl
u
o
r
i
d
e

(
m
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
MW-35 MW-36 MW-37
GrossAlpha
-2
0
2
4
6
8
10
Gr
o
s
s
A
l
p
h
a

(
p
C
i
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
Appendix A: Box Plots
Page 6 of 19
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
MW-35 MW-36 MW-37
Iron
0
50
100
150
200
250
300
350
400
450
Ir
o
n

(
u
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
MW-35 MW-36 MW-37
Lead
-1
0
1
2
3
Le
a
d

(
u
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
Appendix A: Box Plots
Page 7 of 19
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
MW-35 MW-36 MW-37
Manganese
-100
0
100
200
300
400
500
600
700
800
Ma
n
g
a
n
e
s
e

(
u
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
MW-35 MW-36 MW-37
Mercury
-2
-1
0
1
2
3
Me
r
c
u
r
y

(
u
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
Appendix A: Box Plots
Page 8 of 19
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
MW-35 MW-36 MW-37
Molybdenum
8
10
12
14
16
18
20
22
24
26
28
30
32
Mo
l
y
b
d
e
n
u
m

(
u
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
MW-35 MW-36 MW-37
Nickel
19
20
21
22
23
24
25
26
27
Ni
c
k
e
l

(
u
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
Appendix A: Box Plots
Page 9 of 19
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
MW-35 MW-36 MW-37
NitrateNitrite
-2
0
2
4
6
8
10
12
14
16
18
20
Ni
t
r
a
t
e
N
i
t
r
i
t
e

(
m
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
MW-35 MW-36 MW-37
Location ID
Field pH
6.2
6.4
6.6
6.8
7.0
7.2
7.4
7.6
pH

(
s
.
u
.
)
Median
25%-75%
1%-99%
Outliers
Extremes
Appendix A: Box Plots
Page 10 of 19
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
MW-35 MW-36 MW-37
Silver
8
9
10
11
12
Sil
v
e
r

(
u
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
MW-35 MW-36 MW-37
Selenium
-50
0
50
100
150
200
250
300
350
Se
l
e
n
i
u
m

(
u
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
Appendix A: Box Plots
Page 11 of 19
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
MW-35 MW-36 MW-37
Sulfate
800
1000
1200
1400
1600
1800
2000
2200
2400
2600
2800
3000
3200
Su
l
f
a
t
e

(
m
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
MW-35 MW-36 MW-37
TDS
2000
2200
2400
2600
2800
3000
3200
3400
3600
3800
4000
4200
4400
4600
4800
TD
S

(
m
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
Appendix A: Box Plots
Page 12 of 19
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
MW-35 MW-36 MW-37
Thallium
0.4
0.6
0.8
1.0
1.2
1.4
1.6
Th
a
l
l
i
u
m

(
u
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
MW-35 MW-36 MW-37
Tin
98
99
100
101
102
Ti
n

(
u
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
Appendix A: Box Plots
Page 13 of 19
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
MW-35 MW-36 MW-37
Uranium
8
10
12
14
16
18
20
22
24
26
28
Ur
a
n
i
u
m

(
u
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
MW-35 MW-36 MW-37
Vanadium
13
14
15
16
17
Va
n
a
d
i
u
m

(
u
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
Appendix A: Box Plots
Page 14 of 19
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
MW-35 MW-36 MW-37
Zinc
5
10
15
20
25
30
35
40
45
50
Zi
n
c

(
u
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
MW-35 MW-36 MW-37
Acetone
18
19
20
21
22
Ac
e
t
o
n
e

(
u
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
Appendix A: Box Plots
Page 15 of 19
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
MW-35 MW-36 MW-37
Benzene
-1
0
1
2
3
Be
n
z
e
n
e

(
u
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
MW-35 MW-36 MW-37
Carbon tetrachloride
-1
0
1
2
3
Ca
r
b
o
n

t
e
t
r
a
c
h
l
o
r
i
d
e

(
u
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
Appendix A: Box Plots
Page 16 of 19
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
MW-35 MW-36 MW-37
Chloroform
-1
0
1
2
3
Ch
l
o
r
o
f
o
r
m

(
u
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
MW-35 MW-36 MW-37
Chloromethane
-1
0
1
2
3
Ch
l
o
r
o
m
e
t
h
a
n
e

(
u
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
Appendix A: Box Plots
Page 17 of 19
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
MW-35 MW-36 MW-37
Methyl ethyl ketone
18
19
20
21
22
Me
t
h
y
l

e
t
h
y
l

k
e
t
o
n
e

(
u
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
MW-35 MW-36 MW-37
Methylene chloride
-1
0
1
2
3
Me
t
h
y
l
e
n
e

c
h
l
o
r
i
d
e

(
u
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
Appendix A: Box Plots
Page 18 of 19
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
MW-35 MW-36 MW-37
Naphthalene
-1
0
1
2
3
Na
p
h
t
h
a
l
e
n
e

(
u
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
MW-35 MW-36 MW-37
Tetrahydrofuran
-1
0
1
2
3
Te
t
r
a
h
y
d
r
o
f
u
r
a
n

(
u
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
Appendix A: Box Plots
Page 19 of 19
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
MW-35 MW-36 MW-37
Toluene
-1
0
1
2
3
To
l
u
e
n
e

(
u
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
MW-35 MW-36 MW-37
Xylenes, Total
-1
0
1
2
3
Xy
l
e
n
e
s
,

T
o
t
a
l

(
u
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes

APPENDIX B
Histograms and the Shapiro-Wilk test for Data Sets with
0-50% Non-Detects
Appendix B: Histograms and the Shapiro-Wilk Test for Data Sets with 0%-50% Non-Detects
Ammonia as N
Ammonia in MW-35SW-W = 0.9538, p = 0.6929
-1.7 -1.6 -1.5 -1.4 -1.3 -1.2 -1.1 -1.0 -0.9 -0.8 -0.7
Log_Result
0
1
2
3
4
5
No

o
f

o
b
s
Page 1 of 14
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix B: Histograms and the Shapiro-Wilk Test for Data Sets with 0%-50% Non-Detects
Chloride
Chloride in MW-35 SW-W = 0.885, p = 0.1015
1.76 1.77 1.78 1.79 1.80 1.81 1.82 1.83 1.84 1.85
Log_Result
0
1
2
3
4
5
6
No

o
f

o
b
s
Chloride in MW-37 SW-W = 0.9176, p = 0.3377
1.52 1.54 1.56 1.58 1.60 1.62 1.64 1.66 1.68 1.70 1.72 1.74 1.76
Log_Result
0
1
2
3
4
No

o
f

o
b
s
Chloride in MW-36 SW-W = 0.8053, p = 0.0168
1.70 1.72 1.74 1.76 1.78 1.80 1.82 1.84 1.86 1.88
Log_Result
0
1
2
3
4
5
6
No

o
f

o
b
s
Page 2 of 14
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix B: Histograms and the Shapiro-Wilk Test for Data Sets with 0%-50% Non-Detects
Fluoride
Fluoride in MW-35 SW-W = 0.9599, p = 0.7519
-0.51 -0.50 -0.49 -0.48 -0.47 -0.46 -0.45 -0.44 -0.43 -0.42 -0.41 -0.40 -0.39 -0.38 -0.37
Log_Result
0
1
2
3
4
No

o
f

o
b
s
Fluoride in MW-36 SW-W = 0.9609, p = 0.7960
-0.55 -0.54 -0.53 -0.52 -0.51 -0.50 -0.49 -0.48 -0.47 -0.46 -0.45 -0.44
Log_Result
0
1
2
3
4
No

o
f

o
b
s
Fluoride in MW-37 SW-W = 0.9442, p = 0.6011
-0.68 -0.66 -0.64 -0.62 -0.60 -0.58 -0.56 -0.54 -0.52 -0.50
Log_Result
0
1
2
3
4
No

o
f

o
b
s
Page 3 of 14
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix B: Histograms and the Shapiro-Wilk Test for Data Sets with 0%-50% Non-Detects
Gross Alpha minus Rn and U
Gross Alpha in MW-35 SW-W = 0.9574, p = 0.2659
0.35 0.40 0.45 0.50 0.55 0.60 0.65 0.70 0.75 0.80 0.85 0.90
Log_Result
0
1
2
3
4
5
6
7
8
No

o
f

o
b
s
Gross Alpha in MW-36 SW-W = 0.8728, p = 0.1078
-0.7 -0.6 -0.5 -0.4 -0.3 -0.2 -0.1 0.0 0.1 0.2 0.3 0.4 0.5 0.6
Log_Result
0
1
2
3
No

o
f

o
b
s
Gross Alpha in MW-37 SW-W = 0.9254, p = 0.4041
-0.4 -0.3 -0.2 -0.1 0.0 0.1 0.2 0.3 0.4 0.5 0.6 0.7
Log_Result
0
1
2
3
4
No

o
f

o
b
s
Page 4 of 14
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix B: Histograms and the Shapiro-Wilk Test for Data Sets with 0%-50% Non-Detects
Iron
Iron in MW-35 SW-W = 0.9329, p = 0.3721
1.7 1.8 1.9 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7
Log_Result
0
1
2
3
4
5
6
No

o
f

o
b
s
Page 5 of 14
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix B: Histograms and the Shapiro-Wilk Test for Data Sets with 0%-50% Non-Detects
Manganese
Manganese in MW-35 SW-W = 0.9438, p = 0.1153
2.36 2.37 2.38 2.39 2.40 2.41 2.42 2.43 2.44 2.45 2.46 2.47 2.48 2.49 2.50
Log_Result
0
1
2
3
4
5
6
7
No

o
f

o
b
s
Page 6 of 14
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix B: Histograms and the Shapiro-Wilk Test for Data Sets with 0%-50% Non-Detects
Nitrate + Nitrite as N
Nitrate + Nitrite as N in MW-36 SW-W = 0.8001, p = 0.0146
-0.78 -0.76 -0.74 -0.72 -0.70 -0.68 -0.66 -0.64 -0.62 -0.60 -0.58 -0.56
Log_Result
0
1
2
3
4
No

o
f

o
b
s
Nitrate + Nitrite as N in MW-37 SW-W = 0.9812, p = 0.9700
-0.6 -0.5 -0.4 -0.3 -0.2 -0.1 0.0 0.1 0.2 0.3 0.4 0.5
Log_Result
0
1
2
3
No

o
f

o
b
s
Page 7 of 14
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix B: Histograms and the Shapiro-Wilk Test for Data Sets with 0%-50% Non-Detects
Field pH
Field pH in MW-35SW-W = 0.9461, p = 0.1021
6.16.26.36.46.56.66.76.86.97.07.17.27.37.47.57.6
pH Field Measurement
0
1
2
3
4
5
6
7
No

o
f

o
b
s
Field pH in MW-36SW-W = 0.9851, p = 0.9865
6.4 6.5 6.6 6.7 6.8 6.9 7.0 7.1 7.2 7.3 7.4 7.5
pH Field Measurement
0
1
2
3
No

o
f

o
b
s
Field pH in MW-37SW-W = 0.9275, p = 0.3865
6.60 6.65 6.70 6.75 6.80 6.85 6.90 6.95 7.00 7.05 7.10
pH Field Measurement
0
1
2
3
4
5
6
No

o
f

o
b
s
Page 8 of 14
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix B: Histograms and the Shapiro-Wilk Test for Data Sets with 0%-50% Non-Detects
Selenium
Selenium in MW-35 SW-W = 0.8978, p = 0.0140
0.6 0.7 0.8 0.9 1.0 1.1 1.2 1.3 1.4 1.5
Log_Result
0
1
2
3
4
5
6
7
8
No

o
f

o
b
s
Selenium in MW-36 SW-W = 0.9634, p = 0.8241
2.34 2.36 2.38 2.40 2.42 2.44 2.46 2.48 2.50
Log_Result
0
1
2
3
4
No

o
f

o
b
s
Selenium in MW-37 SW-W = 0.9059, p = 0.2538
0.65 0.70 0.75 0.80 0.85 0.90 0.95 1.00
Log_Result
0
1
2
3
4
No

o
f

o
b
s
Page 9 of 14
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix B: Histograms and the Shapiro-Wilk Test for Data Sets with 0%-50% Non-Detects
Sulfate
Sulfate in MW-35 SW-W = 0.7335, p = 0.0012
3.00 3.05 3.10 3.15 3.20 3.25 3.30 3.35 3.40 3.45
Log_Result
0
1
2
3
4
5
6
7
No

o
f

o
b
s
Sulfate in MW-36 SW-W = 0.9074, p = 0.2637
3.30 3.32 3.34 3.36 3.38 3.40 3.42 3.44 3.46 3.48 3.50
Log_Result
0
1
2
3
4
5
No

o
f

o
b
s
Sulfate in MW-37 SW-W = 0.875, p = 0.1392
3.31 3.32 3.33 3.34 3.35 3.36 3.37 3.38 3.39 3.40 3.41 3.42 3.43 3.44 3.45 3.46
Log_Result
0
1
2
3
4
No

o
f

o
b
s
Page 10 of 14
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix B: Histograms and the Shapiro-Wilk Test for Data Sets with 0%-50% Non-Detects
TDS
TDS in MW-35 SW-W = 0.8838, p = 0.0979
3.56 3.57 3.58 3.59 3.60 3.61 3.62 3.63
Log_Result
0
1
2
3
4
5
6
No

o
f

o
b
s
TDS in MW-36 SW-W = 0.9072, p = 0.2620
3.620 3.625 3.630 3.635 3.640 3.645 3.650 3.655 3.660 3.665
Log_Result
0
1
2
3
4
No

o
f

o
b
s
TDS in MW-37 SW-W = 0.9907, p = 0.9976
3.56 3.57 3.58 3.59 3.60 3.61 3.62
Log_Result
0
1
2
3
4
No

o
f

o
b
s
Page 11 of 14
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix B: Histograms and the Shapiro-Wilk Test for Data Sets with 0%-50% Non-Detects
Thallium
Thallium in MW-37 SW-W = 0.7484, p = 0.0034
-0.34 -0.32 -0.30 -0.28 -0.26 -0.24 -0.22 -0.20 -0.18 -0.16 -0.14 -0.12 -0.10 -0.08
Log_Result
0
1
2
3
4
5
6
7
No

o
f

o
b
s
Page 12 of 14
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix B: Histograms and the Shapiro-Wilk Test for Data Sets with 0%-50% Non-Detects
Uranium
Uranium in MW-35 SW-W = 0.9608, p = 0.2883
1.18 1.20 1.22 1.24 1.26 1.28 1.30 1.32 1.34 1.36 1.38 1.40 1.42 1.44 1.46
Log_Result
0
1
2
3
4
5
6
7
8
9
No

o
f

o
b
s
Uranium in MW-36 SW-W = 0.9288, p = 0.4366
1.32 1.33 1.34 1.35 1.36 1.37 1.38 1.39 1.40 1.41 1.42 1.43 1.44
Log_Result
0
1
2
3
No

o
f

o
b
s
Uranium in MW-37 SW-W = 0.9223, p = 0.3761
0.98 1.00 1.02 1.04 1.06 1.08 1.10 1.12 1.14 1.16 1.18 1.20 1.22 1.24 1.26 1.28 1.30
Log_Result
0
1
2
3
4
No

o
f

o
b
s
Page 13 of 14
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix B: Histograms and the Shapiro-Wilk Test for Data Sets with 0%-50% Non-Detects
Zinc
Zinc in MW-37 SW-W = 0.8463, p = 0.0525
1.25 1.30 1.35 1.40 1.45 1.50 1.55 1.60 1.65 1.70
Log_Result
0
1
2
3
4
5
6
No

o
f

o
b
s
Page 14 of 14
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah

APPENDIX C
Linear Regression Plots: Substituting Half the MDL for Non-detected
Values (Regression Plots for Wells and Constituents with 15%-100%
Non-detects are Considered Exploratory Statistics)
Appendix C: Linear Regression Plots – Substituting Half the MDL for Non-Detected Values
(Regression Plots for Wells and Constituents with 15%-100% Non-Detects are Considered Exploratory Statistics)
MW-35(8% Non-Detect) r = -0.4142, p = 0.1806; r2 = 0.1716
8/10/10 2/26/11 9/14/11 4/1/12 10/18/12 5/6/13 11/22/13 6/10/14
Date_Sampled
0.02
0.04
0.06
0.08
0.10
0.12
0.14
0.16
Am
m
o
n
i
a

(
m
g
/
L
)
Detected Values Non-Detected Values
MW-36(100% Non-Detect)
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
-2
-1
0
1
2
3
Am
m
o
n
i
a

(
m
g
/
L
)
Detected Values Non-Detected Values
MW-37(100% Non-Detect)
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
-2
-1
0
1
2
3
Am
m
o
n
i
a

(
m
g
/
L
)
Detected Values Non-Detected Values
Page 1 of 27
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix C: Linear Regression Plots – Substituting Half the MDL for Non-Detected Values
(Regression Plots for Wells and Constituents with 15%-100% Non-Detects are Considered Exploratory Statistics)
MW-35(100% Non-Detect)
8/10/10 2/26/11 9/14/11 4/1/12 10/18/12 5/6/13 11/22/13 6/10/14
Date_Sampled
3
4
5
6
7
Ar
s
e
n
i
c

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-36(100% Non-Detect)
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
3
4
5
6
7
Ars
e
n
i
c

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-37(100% Non-Detect)
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
3
4
5
6
7
Ar
s
e
n
i
c

(
u
g
/
L
)
Detected Values Non-Detected Values
Page 2 of 27
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix C: Linear Regression Plots – Substituting Half the MDL for Non-Detected Values
(Regression Plots for Wells and Constituents with 15%-100% Non-Detects are Considered Exploratory Statistics)
MW-35(100% Non-Detect)
8/10/10 2/26/11 9/14/11 4/1/12 10/18/12 5/6/13 11/22/13 6/10/14
Date_Sampled
-2
-1
0
1
2
3
Be
r
y
l
l
i
u
m

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-36(100% Non-Detect)
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
-2
-1
0
1
2
3
Be
r
y
l
l
i
u
m

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-37(100% Non-Detect)
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
-2
-1
0
1
2
3
Be
r
y
l
l
i
u
m

(
u
g
/
L
)
Detected Values Non-Detected Values
Page 3 of 27
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix C: Linear Regression Plots – Substituting Half the MDL for Non-Detected Values
(Regression Plots for Wells and Constituents with 15%-100% Non-Detects are Considered Exploratory Statistics)
MW-35(100% Non-Detect)
8/10/10 2/26/11 9/14/11 4/1/12 10/18/12 5/6/13 11/22/13 6/10/14
Date_Sampled
-2
-1
0
1
2
3
Ca
d
m
i
u
m

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-36(100% Non-Detect)
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
-2
-1
0
1
2
3
Ca
d
m
i
u
m

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-37(100% Non-Detect)
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
-2
-1
0
1
2
3
Ca
d
m
i
u
m

(
u
g
/
L
)
Detected Values Non-Detected Values
Page 4 of 27
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix C: Linear Regression Plots – Substituting Half the MDL for Non-Detected Values
(Regression Plots for Wells and Constituents with 15%-100% Non-Detects are Considered Exploratory Statistics)
MW-35(0% Non-Detect) r = -0.0142, p = 0.9650; r2= 0.0002
8/10/10 2/26/11 9/14/11 4/1/12 10/18/12 5/6/13 11/22/13 6/10/14
Date_Sampled
58
60
62
64
66
68
70
Ch
l
o
r
i
d
e

(
m
g
/
L
)
Detected Values Non-Detected Values
MW-36(0% Non-Detect)r = -0.2067, p = 0.5667; r2 = 0.0427
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
52
54
56
58
60
62
64
66
68
70
72
74
Ch
l
o
r
i
d
e

(
m
g
/
L
)
Detected Values Non-Detected Values
MW-37(0% Non-Detect) r = -0.3117, p = 0.3806; r2 = 0.0972
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
34
36
38
40
42
44
46
48
50
52
54
56
Ch
l
o
r
i
d
e

(
m
g
/
L
)
Detected Values Non-Detected Values
Page 5 of 27
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix C: Linear Regression Plots – Substituting Half the MDL for Non-Detected Values
(Regression Plots for Wells and Constituents with 15%-100% Non-Detects are Considered Exploratory Statistics)
MW-35(100% Non-Detect)
8/10/10 2/26/11 9/14/11 4/1/12 10/18/12 5/6/13 11/22/13 6/10/14
Date_Sampled
23
24
25
26
27
Ch
r
o
m
i
u
m

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-36(100% Non-Detect)
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
23
24
25
26
27
Ch
r
o
m
i
u
m

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-37(100% Non-Detect)
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
23
24
25
26
27
Ch
r
o
m
i
u
m

(
u
g
/
L
)
Detected Values Non-Detected Values
Page 6 of 27
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix C: Linear Regression Plots – Substituting Half the MDL for Non-Detected Values
(Regression Plots for Wells and Constituents with 15%-100% Non-Detects are Considered Exploratory Statistics)
MW-35(100% Non-Detect)
8/10/10 2/26/11 9/14/11 4/1/12 10/18/12 5/6/13 11/22/13 6/10/14
Date_Sampled
8
9
10
11
12
Co
b
a
l
t

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-36(100% Non-Detect)
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
8
9
10
11
12
Co
b
a
l
t

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-37(100% Non-Detect)
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
8
9
10
11
12
Co
b
a
l
t

(
u
g
/
L
)
Detected Values Non-Detected Values
Page 7 of 27
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix C: Linear Regression Plots – Substituting Half the MDL for Non-Detected Values
(Regression Plots for Wells and Constituents with 15%-100% Non-Detects are Considered Exploratory Statistics)
MW-35(100% Non-Detect)
8/10/10 2/26/11 9/14/11 4/1/12 10/18/12 5/6/13 11/22/13 6/10/14
Date_Sampled
8
9
10
11
12
Co
p
p
e
r

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-36(100% Non-Detect)
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13
Date_Sampled
8
9
10
11
12
Co
p
p
e
r

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-37(100% Non-Detect)
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
8
9
10
11
12
Co
p
p
e
r

(
u
g
/
L
)
Detected Values Non-Detected Values
Page 8 of 27
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix C: Linear Regression Plots – Substituting Half the MDL for Non-Detected Values
(Regression Plots for Wells and Constituents with 15%-100% Non-Detects are Considered Exploratory Statistics)
MW-35(0% Non Detect) r = -0.0971, p = 0.7523; r2 = 0.0094
8/10/10 2/26/11 9/14/11 4/1/12 10/18/12 5/6/13 11/22/13 6/10/14
Date_Sampled
0.30
0.32
0.34
0.36
0.38
0.40
0.42
Fl
u
o
r
i
d
e

(
m
g
/
L
)
Detected Values Non-Detected Values
MW-36(0% Non-Detect)r = 0.0527, p = 0.8851; r2 = 0.0028
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
0.28
0.29
0.30
0.31
0.32
0.33
0.34
0.35
0.36
Fl
u
o
r
i
d
e

(
m
g
/
L
)
Detected Values Non-Detected Values
MW-37(0% Non-Detect) r = 0.0328, p = 0.9283; r2 = 0.0011
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
0.21
0.22
0.23
0.24
0.25
0.26
0.27
0.28
0.29
0.30
0.31
Flu
o
r
i
d
e

(
m
g
/
L
)
Detected Values Non-Detected Values
Page 9 of 27
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix C: Linear Regression Plots – Substituting Half the MDL for Non-Detected Values
(Regression Plots for Wells and Constituents with 15%-100% Non-Detects are Considered Exploratory Statistics)
MW-35(0% Non-Detect) r = 0.3404, p = 0.0657; r2 = 0.1158
8/10/10 2/26/11 9/14/11 4/1/12 10/18/12 5/6/13 11/22/13 6/10/14
Date_Sampled
2.0
2.5
3.0
3.5
4.0
4.5
5.0
5.5
6.0
6.5
7.0
Gr
o
s
s

A
l
p
h
a

(
p
C
i
/
L
)
Detected Values Non-Detected Values
MW-36(0% Non-Detect)r = 0.6975, p = 0.0249; r2 = 0.4865
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.4
2.6
2.8
Gr
o
s
s

A
l
p
h
a

(
p
C
i
/
L
)
Detected Values Non-Detected Values
MW-37(%20 Non-Detect) r = 0.0383, p = 0.9164; r2 = 0.0015
9/14/11 4/1/12 10/18/12 5/6/13 11/22/13
Date_Sampled
0.0
0.5
1.0
1.5
2.0
2.5
3.0
3.5
4.0
4.5
Gr
o
s
s

A
l
p
h
a

(
p
C
i
/
L
)
Detected Values Non-Detected Values
Page 10 of 27
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix C: Linear Regression Plots – Substituting Half the MDL for Non-Detected Values
(Regression Plots for Wells and Constituents with 15%-100% Non-Detects are Considered Exploratory Statistics)
MW-35(0% Non-Detect) r = -0.5902, p = 0.0337; r2 = 0.3483
8/10/10 2/26/11 9/14/11 4/1/12 10/18/12 5/6/13 11/22/13 6/10/14
Date_Sampled
50
100
150
200
250
300
350
400
450
Ir
o
n

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-36(100% Non-Detect)
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
28
29
30
31
32
Ir
o
n

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-37(100% Non-Detect)
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13
Date_Sampled
28
29
30
31
32
Ir
o
n

(
u
g
/
L
)
Detected Values Non-Detected Values
Page 11 of 27
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix C: Linear Regression Plots – Substituting Half the MDL for Non-Detected Values
(Regression Plots for Wells and Constituents with 15%-100% Non-Detects are Considered Exploratory Statistics)
MW-35(100% Non-Detect)
8/10/10 2/26/11 9/14/11 4/1/12 10/18/12 5/6/13 11/22/13 6/10/14
Date_Sampled
-1
0
1
2
3
Le
a
d

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-36(100% Non-Detect)
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
-1
0
1
2
3
Le
a
d

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-37(100% Non-Detect)
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
-1
0
1
2
3
Le
a
d

(
u
g
/
L
)
Detected Values Non-Detected Values
Page 12 of 27
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix C: Linear Regression Plots – Substituting Half the MDL for Non-Detected Values
(Regression Plots for Wells and Constituents with 15%-100% Non-Detects are Considered Exploratory Statistics)
MW-35(0% Non-Detect) r = -0.3735, p = 0.0421; r2 = 0.1395
8/10/10 2/26/11 9/14/11 4/1/12 10/18/12 5/6/13 11/22/13 6/10/14
Date_Sampled
230
240
250
260
270
280
290
300
310
Ma
n
g
a
n
e
s
e

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-36(100% Non-Detect)
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
8
9
10
11
12
Ma
n
g
a
n
e
s
e

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-37(67% Non-Detect) r = -0.3776, p = 0.3164; r2 = 0.1426
9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
8
10
12
14
16
18
20
22
24
26
28
30
Ma
n
g
a
n
e
s
e

(
u
g
/
L
)
Detected Values Non-Detected Values
Page 13 of 27
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix C: Linear Regression Plots – Substituting Half the MDL for Non-Detected Values
(Regression Plots for Wells and Constituents with 15%-100% Non-Detects are Considered Exploratory Statistics)
MW-35(100% Non-Detect)
8/10/10 2/26/11 9/14/11 4/1/12 10/18/12 5/6/13 11/22/13 6/10/14
Date_Sampled
-2
-1
0
1
2
3
Me
r
c
u
r
y

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-36(100% Non-Detect)
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
-2
-1
0
1
2
3
Me
r
c
u
r
y

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-37(100% Non-Detect)
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
-2
-1
0
1
2
3
Me
r
c
u
r
y

(
u
g
/
L
)
Detected Values Non-Detected Values
Page 14 of 27
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix C: Linear Regression Plots – Substituting Half the MDL for Non-Detected Values
(Regression Plots for Wells and Constituents with 15%-100% Non-Detects are Considered Exploratory Statistics)
MW-35(100% Non-Detect)
8/10/10 2/26/11 9/14/11 4/1/12 10/18/12 5/6/13 11/22/13 6/10/14
Date_Sampled
8
9
10
11
12
Mo
l
y
b
d
e
n
u
m

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-36(100% Non-Detect)
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
8
9
10
11
12
Mo
l
y
b
d
e
n
u
m

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-37(100% Non-Detect)
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
8
9
10
11
12
Mo
l
y
b
d
e
n
u
m

(
u
g
/
L
)
Detected Values Non-Detected Values
Page 15 of 27
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix C: Linear Regression Plots – Substituting Half the MDL for Non-Detected Values
(Regression Plots for Wells and Constituents with 15%-100% Non-Detects are Considered Exploratory Statistics)
MW-35(100% Non-Detect)
8/10/10 2/26/11 9/14/11 4/1/12 10/18/12 5/6/13 11/22/13 6/10/14
Date_Sampled
18
19
20
21
22
Nic
k
e
l

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-36(100% Non-Detect)
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
18
19
20
21
22
Nic
k
e
l

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-37(100% Non-Detect)
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
18
19
20
21
22
Nic
k
e
l

(
u
g
/
L
)
Detected Values Non-Detected Values
Page 16 of 27
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix C: Linear Regression Plots – Substituting Half the MDL for Non-Detected Values
(Regression Plots for Wells and Constituents with 15%-100% Non-Detects are Considered Exploratory Statistics)
MW-35(100% Non-Detect)
8/10/10 2/26/11 9/14/11 4/1/12 10/18/12 5/6/13 11/22/13 6/10/14
Date_Sampled
-2
-1
0
1
2
3
Nit
r
a
t
e

+

N
i
t
r
i
t
e

a
s

N

(
m
g
/
L
)
Detected Values Non-Detected Values
MW-36(0% Non-Detect)r = 0.1932, p = 0.5928; r2 = 0.0373
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
0.17
0.18
0.19
0.20
0.21
0.22
0.23
0.24
0.25
0.26
0.27
Nit
r
a
t
e

+

N
i
t
r
i
t
e

a
s

N

(
m
g
/
L
)
Detected Values Non-Detected Values
MW-37(0% Non-Detect) r = -0.8625, p = 0.0028; r2 = 0.7439
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
0.2
0.4
0.6
0.8
1.0
1.2
1.4
1.6
1.8
2.0
2.2
2.4
Nit
r
a
t
e

+

N
i
t
r
i
t
e

a
s

N

(
m
g
/
L
)
Detected Values Non-Detected Values
Page 17 of 27
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix C: Linear Regression Plots – Substituting Half the MDL for Non-Detected Values
(Regression Plots for Wells and Constituents with 15%-100% Non-Detects are Considered Exploratory Statistics)
MW-35(0% Non-Detect) r = -0.0915, p = 0.6125; r2 = 0.0084
8/10/2010 2/26/2011 9/14/2011 4/1/2012 10/18/2012 5/6/2013 11/22/2013 6/10/2014
Date Measured
6.2
6.4
6.6
6.8
7.0
7.2
7.4
7.6
Fie
l
d

p
H

(
s
.
u
.
)
MW-36(0% Non-Detect)r = 0.0852, p = 0.8150; r2 = 0.0073
6/6/20119/14/201112/23/20114/1/20127/10/201210/18/20121/26/20135/6/20138/14/201311/22/20133/2/2014
Date Measured
6.5
6.6
6.7
6.8
6.9
7.0
7.1
7.2
7.3
7.4
Fie
l
d

p
H

(
s
.
u
.
)
MW-37(0% Non-Detect) r = 0.5222, p = 0.0994; r2 = 0.2727
6/6/20119/14/201112/23/20114/1/20127/10/201210/18/20121/26/20135/6/20138/14/201311/22/20133/2/2014
Date Measured
6.60
6.65
6.70
6.75
6.80
6.85
6.90
6.95
7.00
7.05
7.10
Fie
l
d

p
H

(
s
.
u
.
)

Page 18 of 27
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix C: Linear Regression Plots – Substituting Half the MDL for Non-Detected Values
(Regression Plots for Wells and Constituents with 15%-100% Non-Detects are Considered Exploratory Statistics)
MW-35(27% Non-Detect) r = 0.1494, p = 0.4664; r2 = 0.0223
8/10/10 2/26/11 9/14/11 4/1/12 10/18/12 5/6/13 11/22/13 6/10/14
Date_Sampled
4
6
8
10
12
14
16
18
20
22
24
Se
l
e
n
i
u
m

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-36(0% Non-Detect)r = 0.0060, p = 0.9870; r2 = 0.0000
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
220
230
240
250
260
270
280
290
300
310
320
Se
l
e
n
i
u
m

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-37(20% Non-Detect)
r = 0.6903, p = 0.0271; r2 = 0.4765
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
4.5
5.0
5.5
6.0
6.5
7.0
7.5
8.0
8.5
9.0
9.5
Se
l
e
n
i
u
m

(
u
g
/
L
)
Detected Values Non-Detected Values
Page 19 of 27
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix C: Linear Regression Plots – Substituting Half the MDL for Non-Detected Values
(Regression Plots for Wells and Constituents with 15%-100% Non-Detects are Considered Exploratory Statistics)
MW-35(100% Non-Detect)
8/10/10 2/26/11 9/14/11 4/1/12 10/18/12 5/6/13 11/22/13 6/10/14
Date_Sampled
8
9
10
11
12
Silv
e
r

(
u
g
/
L
)
Detected Values
Non-Detected Values
MW-36(100% Non-Detect)
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
8
9
10
11
12
Sil
v
e
r

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-37(100% Non-Detect)
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
8
9
10
11
12
Sil
v
e
r

(
u
g
/
L
)
Detected Values Non-Detected Values
Page 20 of 27
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix C: Linear Regression Plots – Substituting Half the MDL for Non-Detected Values
(Regression Plots for Wells and Constituents with 15%-100% Non-Detects are Considered Exploratory Statistics)
MW-35(0% Non-Detect) r = -0.0661, p = 0.8300; r2= 0.0044
8/10/10 2/26/11 9/14/11 4/1/12 10/18/12 5/6/13 11/22/13 6/10/14
Date_Sampled
1000
1200
1400
1600
1800
2000
2200
2400
2600
Su
l
f
a
t
e

(
m
g
/
L
)
Detected Values Non-Detected Values
MW-36(0% Non-Detect)r = -0.3763, p = 0.2839; r2 = 0.1416
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
2000
2100
2200
2300
2400
2500
2600
2700
2800
2900
3000
Su
l
f
a
t
e

(
m
g
/
L
)
Detected Values Non-Detected Values
MW-37(0% Non-Detect) r = 0.2283, p = 0.5547; r2 = 0.0521
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
2100
2200
2300
2400
2500
2600
2700
2800
Su
l
f
a
t
e

(
m
g
/
L
)
Detected Values Non-Detected Values
Page 21 of 27
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix C: Linear Regression Plots – Substituting Half the MDL for Non-Detected Values
(Regression Plots for Wells and Constituents with 15%-100% Non-Detects are Considered Exploratory Statistics)
MW-35(0% Non-Detect) r = 0.7605, p = 0.0041; r2 = 0.5783
8/10/10 2/26/11 9/14/11 4/1/12 10/18/12 5/6/13 11/22/13 6/10/14
Date_Sampled
3700
3800
3900
4000
4100
4200
TD
S

(
m
g
/
L
)
Detected Values Non-Detected Values
MW-36(0% Non-Detect)r = 0.3397, p = 0.3368; r2 = 0.1154
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
4200
4250
4300
4350
4400
4450
4500
4550
4600
TD
S

(
m
g
/
L
)
Detected Values Non-Detected Values
MW-37(0% Non-Detect) r = -0.2495, p = 0.4870; r2 = 0.0622
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
3650
3700
3750
3800
3850
3900
3950
4000
4050
4100
4150
TD
S

(
m
g
/
L
)
Detected Values Non-Detected Values
Page 22 of 27
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix C: Linear Regression Plots – Substituting Half the MDL for Non-Detected Values
(Regression Plots for Wells and Constituents with 15%-100% Non-Detects are Considered Exploratory Statistics)
MW-35(48% Non-Detect) r = -0.2302, p = 0.2296; r2 = 0.0530
8/10/10 2/26/11 9/14/11 4/1/12 10/18/12 5/6/13 11/22/13 6/10/14
Date_Sampled
0.48
0.50
0.52
0.54
0.56
0.58
0.60
0.62
0.64
0.66
0.68
0.70
0.72
0.74
Th
a
l
l
i
u
m

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-36(0% Non-Detect)r= -0.7423, p = 0.0139; r2 = 0.5510
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
0.5
0.6
0.7
0.8
0.9
1.0
1.1
1.2
1.3
1.4
1.5
Th
a
l
l
i
u
m

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-37(60% Non-Detect) r = 0.6900, p = 0.0272; r2 = 0.4761
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
0.45
0.50
0.55
0.60
0.65
0.70
0.75
0.80
Th
a
l
l
i
u
m

(
u
g
/
L
)
Detected Values Non-Detected Values
Page 23 of 27
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix C: Linear Regression Plots – Substituting Half the MDL for Non-Detected Values
(Regression Plots for Wells and Constituents with 15%-100% Non-Detects are Considered Exploratory Statistics)
MW-35(100% Non-Detect)
8/10/10 2/26/11 9/14/11 4/1/12 10/18/12 5/6/13 11/22/13 6/10/14
Date_Sampled
98
99
100
101
102
Tin

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-36(100% Non-Detect)
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
98
99
100
101
102
Tin

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-37(100% Non-Detect)
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
98
99
100
101
102
Tin

(
u
g
/
L
)
Detected Values Non-Detected Values
Page 24 of 27
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix C: Linear Regression Plots – Substituting Half the MDL for Non-Detected Values
(Regression Plots for Wells and Constituents with 15%-100% Non-Detects are Considered Exploratory Statistics)
MW-35(0% Non-Detect) r = -0.2468, p = 0.1732; r2 = 0.0609
8/10/10 2/26/11 9/14/11 4/1/12 10/18/12 5/6/13 11/22/13 6/10/14
Date_Sampled
14
16
18
20
22
24
26
28
Ura
n
i
u
m

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-36(0% Non-Detect);r = -0.2886, p = 0.4186; r2 = 0.0833
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
21
22
23
24
25
26
27
Ura
n
i
u
m

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-37(0% Non-Detect) r = -0.6040, p = 0.0644; r2 = 0.3648
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/149
10
11
12
13
14
15
16
17
18
19
Ur
a
n
i
u
m

(
u
g
/
L
)
Detected Values Non-Detected Values
Page 25 of 27
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix C: Linear Regression Plots – Substituting Half the MDL for Non-Detected Values
(Regression Plots for Wells and Constituents with 15%-100% Non-Detects are Considered Exploratory Statistics)
MW-35(100% Non-Detect)
8/10/10 2/26/11 9/14/11 4/1/12 10/18/12 5/6/13 11/22/13 6/10/14
Date_Sampled
13
14
15
16
17
Va
n
a
d
i
u
m

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-36(100% Non-Detect)
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
13
14
15
16
17
Va
n
a
d
i
u
m

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-37(100% Non-Detect)
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
13
14
15
16
17
Va
n
a
d
i
u
m

(
u
g
/
L
)
Report_Result ND_Result
Page 26 of 27
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix C: Linear Regression Plots – Substituting Half the MDL for Non-Detected Values
(Regression Plots for Wells and Constituents with 15%-100% Non-Detects are Considered Exploratory Statistics)
MW-35(100% Non-Detect)
8/10/10 2/26/11 9/14/11 4/1/12 10/18/12 5/6/13 11/22/13 6/10/14
Date_Sampled
8
9
10
11
12
Zi
n
c

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-36(100% Non-Detect)
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
8
9
10
11
12
Zi
n
c

(
u
g
/
L
)
Detected Values Non-Detected Values
MW-37(0% Non-Detect) r = -0.1774, p = 0.6239; r2 = 0.0315
6/6/11 9/14/11 12/23/11 4/1/12 7/10/12 10/18/12 1/26/13 5/6/13 8/14/13 11/22/13 3/2/14
Date_Sampled
18
20
22
24
26
28
30
32
34
36
38
40
42
44
46
Zi
n
c

(
u
g
/
L
)
Detected Values Non-Detected Values
Page 27 of 27
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah

APPENDIX D
Probability Plots: Substituting Half the MDL for Non-detected Values
Appendix D: Probability Plots – Substituting Half the MDL for Non-Detected Values
Page 1 of 14
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
Ammonia as N
0.02 0.04 0.06 0.08 0.10 0.12 0.14 0.16
Observed Value
Ammonia in MW-35(8% Non-Detect)
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
Appendix D: Probability Plots – Substituting Half the MDL for Non-Detected Values
Page 2 of 14
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
Chloride
58 60 62 64 66 68 70
Observed Value
Chloride in MW-35(0% Non-Detect)
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
52 54 56 58 60 62 64 66 68 70 72 74
Observed Value
Chloride in MW-36(0% Non-Detect)
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
34 36 38 40 42 44 46 48 50 52 54 56
Observed Value
Chloride in MW-37(0% Non-Detect)
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
Appendix D: Probability Plots – Substituting Half the MDL for Non-Detected Values
Page 3 of 14
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
Fluoride
0.30 0.32 0.34 0.36 0.38 0.40 0.42
Observed Value
Fluoride in MW-35(0% Non-Detect)
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
0.28 0.29 0.30 0.31 0.32 0.33 0.34 0.35 0.36
Observed Value
Fluoride in MW-36(0% Non-Detect)
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
0.21 0.22 0.23 0.24 0.25 0.26 0.27 0.28 0.29 0.30 0.31
Observed Value
Fluoride in MW-37(0% Non-Detect)
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
Appendix D: Probability Plots – Substituting Half the MDL for Non-Detected Values
Page 4 of 14
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
Gross Alpha minus Rn and U
2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0
Observed Value
Gross Alpha in MW-35(0% Non-Detect)
-2.5
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
2.0 2.5 3.0 3.5 4.0 4.5 5.0 5.5 6.0 6.5 7.0
Observed Value
Gross Alpha in MW-35(0% Non-Detect)
-2.5
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5
Observed Value
Gross Alpha in MW-37(0% Non-Detect)
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
Appendix D: Probability Plots – Substituting Half the MDL for Non-Detected Values
Page 5 of 14
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
Iron
50 100 150 200 250 300 350 400 450
Observed Value
Iron in MW-35(0% Non-Detect)
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
Appendix D: Probability Plots – Substituting Half the MDL for Non-Detected Values
Page 6 of 14
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
Manganese
230 240 250 260 270 280 290 300 310
Observed Value
Manganese in MW-35(0% Non-Detect)
-2.5
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
Appendix D: Probability Plots – Substituting Half the MDL for Non-Detected Values
Page 7 of 14
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
Nitrate + Nitrite as N
0.17 0.18 0.19 0.20 0.21 0.22 0.23 0.24 0.25 0.26 0.27
Observed Value
Nitrate + Nitrite as N in MW-36(0% Non-Detect)
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
0.2 0.4 0.6 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 2.4
Observed Value
Nitrate + Nitrite as N in MW-37(0% Non-Detect)
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
Appendix D: Probability Plots – Substituting Half the MDL for Non-Detected Values
Page 8 of 14
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
Field pH
6.2 6.4 6.6 6.8 7.0 7.2 7.4 7.6
Observed Value
Field pH in MW-35(0% Non-Detect)
-2.5
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
6.5 6.6 6.7 6.8 6.9 7.0 7.1 7.2 7.3 7.4
Observed Value
Field pH in MW-36(0% Non-Detect)
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
6.60 6.65 6.70 6.75 6.80 6.85 6.90 6.95 7.00 7.05 7.10
Observed Value
Field pH in MW-37(0% Non-Detect)
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
Appendix D: Probability Plots – Substituting Half the MDL for Non-Detected Values
Page 9 of 14
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
Selenium
4 6 8 10 12 14 16 18 20 22 24
Observed Value
Selenium in MW-35(27% Non-Detect)
-2.5
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
220 230 240 250 260 270 280 290 300 310 320
Observed Value
Selenium in MW-36(0% Non-Detect)
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
4.5 5.0 5.5 6.0 6.5 7.0 7.5 8.0 8.5 9.0 9.5
Observed Value
Selenium in MW-37(20% Non-Detect)
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
Appendix D: Probability Plots – Substituting Half the MDL for Non-Detected Values
Page 10 of 14
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
Sulfate
1000 1200 1400 1600 1800 2000 2200 2400 2600
Observed Value
Sulfate in MW-35(0% Non-Detect)
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
1000 1200 1400 1600 1800 2000 2200 2400 2600
Observed Value
Sulfate in MW-35(0% Non-Detect)
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
2100 2200 2300 2400 2500 2600 2700 2800
Observed Value
Sulfate in MW-37(0% Non-Detect)
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
Appendix D: Probability Plots – Substituting Half the MDL for Non-Detected Values
Page 11 of 14
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
TDS
3700 3800 3900 4000 4100 4200
Observed Value
TDS in MW-35(0% Non-Detect)
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
4200 4250 4300 4350 4400 4450 4500 4550 4600
Observed Value
TDS in MW-36 (0% Non-Detect)
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
3650 3700 3750 3800 3850 3900 3950 4000 4050 4100 4150
Observed Value
TDs in MW-37(0% Non-Detect)
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
Appendix D: Probability Plots – Substituting Half the MDL for Non-Detected Values
Page 12 of 14
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
Thallium
0.48 0.50 0.52 0.54 0.56 0.58 0.60 0.62 0.64 0.66 0.68 0.70 0.72 0.74
Observed Value
Thallium in MW-35(48% Non-Detect)
-2.5
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
0.48 0.50 0.52 0.54 0.56 0.58 0.60 0.62 0.64 0.66 0.68 0.70 0.72 0.74
Observed Value
Thallium in MW-35(48% Non-Detect)
-2.5
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
Appendix D: Probability Plots – Substituting Half the MDL for Non-Detected Values
Page 13 of 14
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
Uranium
14 16 18 20 22 24 26 28
Observed Value
Uranium in MW-35(0% Non-Detect)
-2.5
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
2.5
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
21 22 23 24 25 26 27
Observed Value
Uranium in MW-36(0% Non-Detect)
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
9 10 11 12 13 14 15 16 17 18 19
Observed Value
Uranium in MW-37(0% Non-Detect)
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
Appendix D: Probability Plots – Substituting Half the MDL for Non-Detected Values
Page 14 of 14
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
Zinc
18 20 22 24 26 28 30 32 34 36 38 40 42 44 46
Observed Value
Zinc in MW-37(0% Non-Detect)
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e

APPENDIX E
Censored and Detected Values Only Probability Plots and Adjusted
Means: Normally and Lognormally Distributed Data Sets with 15-50%
Non-Detected Values
Appendix E: Censored and Detected Values Only Probability Plots – Normally and
Lognormally Distributed Data Sets with 15%-50% Non-Detected Values
Page 1 of 2
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
Censored Probablility Plot
Gross alpha in MW-37 (20% Non-Detected Values)
SW-W = 0.8798, p = 0.1298
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5
Observed Value
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
Detected Values Only Probability Plot
Gross alpha in MW-37 (20% Non-Detected Values)
SW-W = 0.926, p = 0.4802
0.0 0.5 1.0 1.5 2.0 2.5 3.0 3.5 4.0 4.5
Observed Value
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
Appendix E: Censored and Detected Values Only Probability Plots – Normally and
Lognormally Distributed Data Sets with 15%-50% Non-Detected Values
Page 2 of 2
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
Censored Probability Plot
Selenium in MW-37 (20% Non-Detected Values)
SW-W = 0.8773, p = 0.1214
0 1 2 3 4 5 6 7 8 9 10
Observed Value
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
Censored Probability Plot
Selenium in MW-37 (20% Non-Detected Values)
SW-W = 0.8773, p = 0.1214
0 1 2 3 4 5 6 7 8 9 10
Observed Value
-2.0
-1.5
-1.0
-0.5
0.0
0.5
1.0
1.5
2.0
Ex
p
e
c
t
e
d

N
o
r
m
a
l

V
a
l
u
e
Basic Statistics
Parameter: GrossAlpha
Original Data (Not Transformed)
Aitchison's Adjustment
Total Measurements 10
Total Non-Detects 2 (20%)
Pooled Mean 1.569
Pooled Std Dev 1.31467
Compliance Meas.0
Compliance Mean 0
Compliance Std Dev 0
Background Meas.10
Background Mean 1.569
Background Std Dev 1.31467
Background Locations
There is 1 background location
Location Meas.Non-Detects % ND Total
MW-37 10 2 20 15.69
Location Mean Std Dev Std Err Rank Sum Rank Mean
MW-37 1.569 1.31467 0 55 5.5
Compliance Locations
There are 0 compliance location
Analysis of Variance StatisticsSS Wells 0
SS Total 17.5553
Kruskal-Wallis StatisticsNon-Detect Rank 1.5
Background Rank Sum 55
Background Rank Mean 5.5
Appendix E2
Background Groundwater Quality Report MW-35, MW-36, and MW-37White Mesa Uranium MillBlanding, Utah
APPENDIX E2: Mean Adjustments
Page 1 of 4
H Statistic 0
H Adjusted for Ties 0
Appendix E2
Background Groundwater Quality Report MW-35, MW-36, and MW-37
White Mesa Uranium MillBlanding, Utah
APPENDIX E2: Mean Adjustments
Page 2 of 4
Basic Statistics
Parameter: Selenium
Original Data (Not Transformed)
Aitchison's Adjustment
Total Measurements 10
Total Non-Detects 2 (20%)
Pooled Mean 5.8
Pooled Std Dev 3.26666
Compliance Meas.0
Compliance Mean 0
Compliance Std Dev 0
Background Meas.10
Background Mean 5.8
Background Std Dev 3.26666
Background Locations
There is 1 background location
Location Meas.Non-Detects % ND Total
MW-37 10 2 20 58
Location Mean Std Dev Std Err Rank Sum Rank Mean
MW-37 5.8 3.26666 0 55 5.5
Compliance Locations
There are 0 compliance location
Analysis of Variance StatisticsSS Wells 0
SS Total 146.039
Kruskal-Wallis StatisticsNon-Detect Rank 1.5
Background Rank Sum 55
Background Rank Mean 5.5
Appendix E2
Background Groundwater Quality Report MW-35, MW-36, and MW-37White Mesa Uranium MillBlanding, Utah
APPENDIX E2: Mean Adjustments
Page 3 of 4
H Statistic 0
H Adjusted for Ties 0
Appendix E2
Background Groundwater Quality Report MW-35, MW-36, and MW-37
White Mesa Uranium MillBlanding, Utah
APPENDIX E2: Mean Adjustments
Page 4 of 4

APPENDIX F
Mann-Kendall Trend Analysis for Data Sets not Normally or
Lognormally Distributed and with 0-90% Non-Detected Values
Appendix F: Mann-Kendall Trend Analysis for Data Sets not Normally or
Lognormally Distributed and with 0%-90% Non-Detected Values
Page 1 of 4
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
Approximate p-value 0.0629
Tabulated p-value 0.064
Standard Deviation of S 16.33
Standardized Value of S -1.531
SEM 101.2
Mann-Kendall Test
Test Value (S)-26
Geometric Mean 2037
Median 2230
Standard Deviation 364.8
Minimum 1140
Maximum 2400
Mean 2074
trend at the specified level of significance.
Report_Result-sulfate
General Statistics
Number of Values 13
Standardized Value of S 0.201
Approximate p-value 0.421
Insufficient evidence to identify a significant
Test Value (S)10
Critical Value (0.05)1.645
Standard Deviation of S 44.88
Standard Deviation 5.567
SEM 1.092
Mann-Kendall Test
Mean 11.39
Geometric Mean 10.05
Median 10.9
Number of Values 26
Minimum 5
Maximum 22.6
Level of Significance 0.05
Report_Result-selenium
General Statistics
From File MK35.wst
Full Precision OFF
Confidence Coefficient 0.95
Mann-Kendall Trend Test Analysis
User Selected Options
Date/Time of Computation 3/28/2014 9:56:35 PM
Appendix F: Mann-Kendall Trend Analysis for Data Sets not Normally or
Lognormally Distributed and with 0%-90% Non-Detected Values
Page 2 of 4
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
Statistically significant evidence of a decreasing
trend at the specified level of significance.
Standard Deviation of S 49.32
Standardized Value of S -1.845
Approximate p-value 0.0325
Mann-Kendall Test
Test Value (S)-92
Critical Value (0.05)-1.645
Median 0.5
Standard Deviation 0.0678
SEM 0.0126
Maximum 0.715
Mean 0.546
Geometric Mean 0.543
General Statistics
Number of Values 29
Minimum 0.5
Insufficient evidence to identify a significant
trend at the specified level of significance.
Report_Result-thallium
Appendix F: Mann-Kendall Trend Analysis for Data Sets not Normally or
Lognormally Distributed and with 0%-90% Non-Detected Values
Page 1 of 4
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
10
53.3
73
58.57
58.35
58
5.605
1.773
-2
0.431
11.14
-0.0898
0.464
10
0.178
0.259
0.198
0.197
0.195
0.0238
0.00752
1
0.5
11.09
0
0.5
Insufficient evidence to identify a significant
trend at the specified level of significance.
Mann-Kendall Test
Test Value (S)
Tabulated p-value
Standard Deviation of S
Standardized Value of S
Approximate p-value
Report_Result-nitratenitrite
General Statistics
Number of Values
Minimum
Maximum
Mean
Geometric Mean
Median
Standard Deviation
SEM
trend at the specified level of significance.
Standard Deviation
SEM
Mann-Kendall Test
Test Value (S)
Tabulated p-value
Standard Deviation of S
Standardized Value of S
Approximate p-value
Insufficient evidence to identify a significant
Median
Level of Significance 0.05
Report_Result-chloride
General Statistics
Number of Values
Minimum
Maximum
Mean
Geometric Mean
From File MK36.wst
Full Precision OFF
Confidence Coefficient 0.95
Mann-Kendall Trend Test Analysis
User Selected Options
Date/Time of Computation 3/28/2014 9:55:54 PM
Appendix F: Mann-Kendall Trend Analysis for Data Sets not Normally or
Lognormally Distributed and with 0%-90% Non-Detected Values
Page 1 of 4
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
9
10
29
13.12
12.21
10
6.355
2.118
-1
0.54
7.979
0
0.5
10
0.5
0.787
0.568
0.561
0.5
0.102
0.0323
20
0.036
9.832
1.932
0.0267
Statistically significant evidence of an increasing
trend at the specified level of significance.
Mann-Kendall Test
Test Value (S)
Tabulated p-value
Standard Deviation of S
Standardized Value of S
Approximate p-value
Report_Result-thallium
General Statistics
Number of Values
Minimum
Maximum
Mean
Geometric Mean
Median
Standard Deviation
SEM
trend at the specified level of significance.
Standard Deviation
SEM
Mann-Kendall Test
Test Value (S)
Tabulated p-value
Standard Deviation of S
Standardized Value of S
Approximate p-value
Insufficient evidence to identify a significant
Median
Level of Significance 0.05
Report_Result-manganese
General Statistics
Number of Values
Minimum
Maximum
Mean
Geometric Mean
From File MK37.wst
Full Precision OFF
Confidence Coefficient 0.95
Mann-Kendall Trend Test Analysis
User Selected Options
Date/Time of Computation 3/28/2014 9:55:01 PM

APPENDIX G
Data That Have Been Removed or
Modified Prior to Statistical Analyses
Appendix G: Data That Have Been Removed or Modified Prior to Statistical Analyses
Field_Sample_ID Location_ID Date_Sampled SDG Parameter_Name
Report_
Result
Report_U
nits
Lab_
Qualifier
Sample_
Type
Reason
Removed
MW-35R_02142011 MW-35 2/14/2011 C11020544 Ammonia 0.05 mg/L U BW Equip. Blank
MW-35R_06062011 MW-35 6/6/2011 C11060429 Ammonia 0.05 mg/L U BW Equip. Blank
MW-35R_02142011 MW-35 2/14/2011 C11020544 Arsenic 5 µg/L U BW Equip. Blank
MW-35R_06062011 MW-35 6/6/2011 C11060429 Arsenic 5 µg/L U BW Equip. Blank
MW-35R_02142011 MW-35 2/14/2011 C11020544 Beryllium 0.5 µg/L U BW Equip. Blank
MW-35R_06062011 MW-35 6/6/2011 C11060429 Beryllium 0.5 µg/L U BW Equip. Blank
MW-35R_02142011 MW-35 2/14/2011 C11020544 Cadmium 0.5 µg/L U BW Equip. Blank
MW-35R_06062011 MW-35 6/6/2011 C11060429 Cadmium 0.5 µg/L U BW Equip. Blank
MW-35R_02142011 MW-35 2/14/2011 C11020544 Chloride 1 mg/L U BW Equip. Blank
MW-35R_06062011 MW-35 6/6/2011 C11060429 Chloride 1 mg/L U BW Equip. Blank
MW-35R_02142011 MW-35 2/14/2011 C11020544 Chromium 25 µg/L U BW Equip. Blank
MW-35R_06062011 MW-35 6/6/2011 C11060429 Chromium 25 µg/L U BW Equip. Blank
MW-35R_02142011 MW-35 2/14/2011 C11020544 Cobalt 10 µg/L U BW Equip. Blank
MW-35R_06062011 MW-35 6/6/2011 C11060429 Cobalt 10 µg/L U BW Equip. Blank
MW-35R_02142011 MW-35 2/14/2011 C11020544 Copper 10 µg/L U BW Equip. Blank
MW-35R_06062011 MW-35 6/6/2011 C11060429 Copper 10 µg/L U BW Equip. Blank
MW-35R_02142011 MW-35 2/14/2011 C11020544 Fluoride 0.1 mg/L U BW Equip. Blank
MW-35R_06062011 MW-35 6/6/2011 C11060429 Fluoride 0.1 mg/L U BW Equip. Blank
MW-35R_02142011 MW-35 2/14/2011 C11020544 GrossAlpha 0.09 pCi/L U BW Equip. Blank
MW-35R_06062011 MW-35 6/6/2011 C11060429 GrossAlpha 0.02 pCi/L U BW Equip. Blank
MW-65_04102012 MW-35 4/10/2012 C12040736 GrossAlpha 4.3 pCi/L GW Field Dup
MW-65_09192012 MW-35 9/19/2012 C12090804 GrossAlpha 6 pCi/L GW Field Dup
MW-65_10232012 MW-35 10/23/2012 316260 GrossAlpha 5.84 pCi/L GW Field Dup
MW-65_01232013 MW-35 1/23/2013 319074 GrossAlpha 7.79 pCi/L GW Field Dup
MW-35R_02142011 MW-35 2/14/2011 C11020544 Iron 55 µg/L BW Equip. Blank
MW-35R_06062011 MW-35 6/6/2011 C11060429 Iron 30 µg/L U BW Equip. Blank
MW-35R_02142011 MW-35 2/14/2011 C11020544 Lead 1 µg/L U BW Equip. Blank
MW-35R_06062011 MW-35 6/6/2011 C11060429 Lead 1 µg/L U BW Equip. Blank
MW-35R_02142011 MW-35 2/14/2011 C11020544 Manganese 10 µg/L U BW Equip. Blank
MW-35R_06062011 MW-35 6/6/2011 C11060429 Manganese 10 µg/L U BW Equip. Blank
MW-65_09072011 MW-35 9/7/2011 C11090325 Manganese 275 µg/L GW Field Dup
MW-65_04102012 MW-35 4/10/2012 C12040736 Manganese 279 µg/L GW Field Dup
MW-65_09192012 MW-35 9/19/2012 C12090804 Manganese 273 µg/L GW Field Dup
MW-65_10232012 MW-35 10/23/2012 316260 Manganese 248 µg/L GW Field Dup
MW-65_01232013 MW-35 1/23/2013 319074 Manganese 246 µg/L GW Field Dup
Page 1 of 4
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix G: Data That Have Been Removed or Modified Prior to Statistical Analyses
Field_Sample_ID Location_ID Date_Sampled SDG Parameter_Name
Report_
Result
Report_U
nits
Lab_
Qualifier
Sample_
Type
Reason
Removed
MW-35R_02142011 MW-35 2/14/2011 C11020544 Mercury 0.5 µg/L U BW Equip. Blank
MW-35R_06062011 MW-35 6/6/2011 C11060429 Mercury 0.5 µg/L U BW Equip. Blank
MW-35R_02142011 MW-35 2/14/2011 C11020544 Molybdenum 10 µg/L U BW Equip. Blank
MW-35R_06062011 MW-35 6/6/2011 C11060429 Molybdenum 10 µg/L U BW Equip. Blank
MW-35R_02142011 MW-35 2/14/2011 C11020544 Nickel 20 µg/L U BW Equip. Blank
MW-35R_06062011 MW-35 6/6/2011 C11060429 Nickel 20 µg/L U BW Equip. Blank
MW-35R_02142011 MW-35 2/14/2011 C11020544 NitrateNitrite 0.1 mg/L BW Equip. Blank
MW-35R_06062011 MW-35 6/6/2011 C11060429 NitrateNitrite 0.1 mg/L U BW Equip. Blank
MW-35R_02142011 MW-35 2/14/2011 C11020544 Selenium 5 µg/L U BW Equip. Blank
MW-35R_06062011 MW-35 6/6/2011 C11060429 Selenium 5 µg/L U BW Equip. Blank
MW-65_09192012 MW-35 9/19/2012 C12090804 Selenium 9.7 µg/L GW Field Dup
MW-65_10232012 MW-35 10/23/2012 316260 Selenium 18.4 µg/L GW Field Dup
MW-65_01232013 MW-35 1/23/2013 319074 Selenium 10.2 µg/L GW Field Dup
MW-35R_02142011 MW-35 2/14/2011 C11020544 Silver 10 µg/L U BW Equip. Blank
MW-35R_06062011 MW-35 6/6/2011 C11060429 Silver 10 µg/L U BW Equip. Blank
MW-35R_02142011 MW-35 2/14/2011 C11020544 Sulfate 1 mg/L BW Equip. Blank
MW-35R_06062011 MW-35 6/6/2011 C11060429 Sulfate 1 mg/L U BW Equip. Blank
MW-35R_02142011 MW-35 2/14/2011 C11020544 TDS 10 mg/L U BW Equip. Blank
MW-35R_06062011 MW-35 6/6/2011 C11060429 TDS 10 mg/L U BW Equip. Blank
MW-35R_02142011 MW-35 2/14/2011 C11020544 Thallium 0.5 µg/L U BW Equip. Blank
MW-35R_06062011 MW-35 6/6/2011 C11060429 Thallium 0.5 µg/L U BW Equip. Blank
MW-65_04102012 MW-35 4/10/2012 C12040736 Thallium 0.6 µg/L GW Field Dup
MW-65_09192012 MW-35 9/19/2012 C12090804 Thallium 0.5 µg/L U GW Field Dup
MW-65_10232012 MW-35 10/23/2012 316260 Thallium 0.68 µg/L GW Field Dup
MW-65_01232013 MW-35 1/23/2013 319074 Thallium 0.5 µg/L U GW Field Dup
MW-35R_02142011 MW-35 2/14/2011 C11020544 Tin 100 µg/L U BW Equip. Blank
MW-35R_06062011 MW-35 6/6/2011 C11060429 Tin 100 µg/L U BW Equip. Blank
MW-35R_02142011 MW-35 2/14/2011 C11020544 Uranium 0.3 µg/L U BW Equip. Blank
MW-35R_06062011 MW-35 6/6/2011 C11060429 Uranium 0.3 µg/L U BW Equip. Blank
MW-65_09072011 MW-35 9/7/2011 C11090325 Uranium 23 µg/L GW Field Dup
MW-65_04102012 MW-35 4/10/2012 C12040736 Uranium 22.9 µg/L GW Field Dup
MW-65_09192012 MW-35 9/19/2012 C12090804 Uranium 22.6 µg/L GW Field Dup
MW-65_10232012 MW-35 10/23/2012 316260 Uranium 23.7 µg/L GW Field Dup
MW-65_01232013 MW-35 1/23/2013 319074 Uranium 22.5 µg/L GW Field Dup
MW-35R_02142011 MW-35 2/14/2011 C11020544 Vanadium 15 µg/L U BW Equip. Blank
Page 2 of 4
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix G: Data That Have Been Removed or Modified Prior to Statistical Analyses
Field_Sample_ID Location_ID Date_Sampled SDG Parameter_Name
Report_
Result
Report_U
nits
Lab_
Qualifier
Sample_
Type
Reason
Removed
MW-35R_06062011 MW-35 6/6/2011 C11060429 Vanadium 15 µg/L U BW Equip. Blank
MW-35R_02142011 MW-35 2/14/2011 C11020544 Zinc 10 µg/L U BW Equip. Blank
MW-35R_06062011 MW-35 6/6/2011 C11060429 Zinc 10 µg/L U BW Equip. Blank
MW-65_11202013 MW-36 11/20/2013 1311470 Ammonia 0.05 mg/L U GW Field Dup
MW-65_11202013 MW-36 11/20/2013 1311470 Arsenic 5 µg/L U GW Field Dup
MW-65_11202013 MW-36 11/20/2013 1311470 Beryllium 0.5 µg/L U GW Field Dup
MW-65_11202013 MW-36 11/20/2013 1311470 Cadmium 0.5 µg/L U GW Field Dup
MW-65_11202013 MW-36 11/20/2013 1311470 Chloride 59 mg/L GW Field Dup
MW-65_11202013 MW-36 11/20/2013 1311470 Chromium 25 µg/L U GW Field Dup
MW-65_11202013 MW-36 11/20/2013 1311470 Cobalt 10 µg/L U GW Field Dup
MW-65_11202013 MW-36 11/20/2013 1311470 Copper 10 µg/L U GW Field Dup
MW-65_11202013 MW-36 11/20/2013 1311470 Fluoride 0.297 mg/L GW Field Dup
MW-65_11202013 MW-36 11/20/2013 338188 GrossAlpha 1.94 pCi/L GW Field Dup
MW-65_11202013 MW-36 11/20/2013 1311470 Iron 30 µg/L U GW Field Dup
MW-65_11202013 MW-36 11/20/2013 1311470 Lead 1 µg/L U GW Field Dup
MW-65_11202013 MW-36 11/20/2013 1311470 Manganese 10 µg/L U GW Field Dup
MW-65_11202013 MW-36 11/20/2013 1311470 Mercury 0.5 µg/L U GW Field Dup
MW-65_11202013 MW-36 11/20/2013 1311470 Molybdenum 10 µg/L U GW Field Dup
MW-65_11202013 MW-36 11/20/2013 1311470 Nickel 20 µg/L U GW Field Dup
MW-65_11202013 MW-36 11/20/2013 1311470 NitrateNitrite 0.209 mg/L GW Field Dup
MW-65_11202013 MW-36 11/20/2013 1311470 Selenium 233 µg/L GW Field Dup
MW-65_11202013 MW-36 11/20/2013 1311470 Silver 10 µg/L U GW Field Dup
MW-65_11202013 MW-36 11/20/2013 1311470 Sulfate 2550 mg/L GW Field Dup
MW-65_11202013 MW-36 11/20/2013 1311470 TDS 4860 mg/L GW Field Dup
MW-65_11202013 MW-36 11/20/2013 1311470 Thallium 0.583 µg/L GW Field Dup
MW-65_11202013 MW-36 11/20/2013 1311470 Tin 100 µg/L U GW Field Dup
MW-65_11202013 MW-36 11/20/2013 1311470 Uranium 26.7 µg/L GW Field Dup
MW-65_11202013 MW-36 11/20/2013 1311470 Vanadium 15 µg/L U GW Field Dup
MW-65_11202013 MW-36 11/20/2013 1311470 Zinc 10 µg/L U GW Field Dup
MW-65_12142011 MW-35 12/14/2011 C11120540 GrossAlpha 3.9 pCi/L GW Field Dup
MW-65_12142011 MW-35 12/14/2011 C11120540 Manganese 250 µg/L GW Field Dup
MW-65_12142011 MW-35 12/14/2011 C11120540 Thallium 0.58 µg/L GW Field Dup
MW-65_12142011 MW-35 12/14/2011 C11120540 Uranium 25.6 µg/L GW Field Dup
MW 35_12012010 MW-35 12/1/2010 C10120105 Ammonia 0.31 mg/L GW Extreme Outlier
MW-36_02202012 MW-36 2/20/2012 C12020833 Beryllium 0.51 µg/L U GW Extreme Outlier
Page 3 of 4
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah
Appendix G: Data That Have Been Removed or Modified Prior to Statistical Analyses
Field_Sample_ID Location_ID Date_Sampled SDG Parameter_Name
Report_
Result
Report_U
nits
Lab_
Qualifier
Sample_
Type
Reason
Removed
MW-36_02202012 MW-36 2/20/2012 C12020833 Cadmium 0.51 µg/L U GW Extreme Outlier
MW-35_02152011 MW-35 2/15/2011 C11020544 Chloride 41 mg/L GW Extreme Outlier
MW 35_12012010 MW-35 12/1/2010 C10120105 Cobalt 18 µg/L GW Extreme Outlier
MW-36_11202013 MW-36 11/20/2013 1311470 Copper 10.4 µg/L GW Extreme Outlier
MW-35_03192013 MW-35 3/19/2013 322416 GrossAlpha 9.51 pCi/L GW Extreme Outlier
MW-37_12182013 MW-37 12/18/2013 1312464 Iron 73.6 µg/L GW Extreme Outlier
MW 35_12012010 MW-35 12/1/2010 C10120105 Manganese 698 µg/L GW Extreme Outlier
MW-35_06072011 MW-35 6/7/2011 C11060429 Manganese 369 µg/L GW Extreme Outlier
MW-35_07202011 MW-35 7/20/2011 C11070824 Manganese 348 µg/L GW Extreme Outlier
MW-37_08112011 MW-37 8/11/2011 C11080529 Manganese 115 µg/L GW Extreme Outlier
MW-35_11132012 MW-35 11/13/2012 315400 Molybdenum 30.4 µg/L GW Extreme Outlier
MW 35_12012010 MW-35 12/1/2010 C10120105 Nickel 26 µg/L GW Extreme Outlier
MW-35_10032011 MW-35 10/3/2011 C11100300 Nickel 23 µg/L GW Extreme Outlier
MW-35_02152011 MW-35 2/15/2011 C11020544 NitrateNitrite 0.28 mg/L GW Extreme Outlier
MW-37_06032013 MW-37 6/3/2013 1306068 NitrateNitrite 18.1 mg/L GW Extreme Outlier
MW-37_12052012 MW-37 12/5/2012 1212130 Sulfate 1010 mg/L GW Extreme Outlier
MW-35_02152011 MW-35 2/15/2011 C11020544 TDS 2200 mg/L GW Extreme Outlier
MW 35_12012010 MW-35 12/1/2010 C10120105 Thallium 1.14 µg/L GW Extreme Outlier
MW-35_06242013 MW-35 6/24/2013 1306566 Thallium 0.946 µg/L GW Extreme Outlier
MW-35_02152011 MW-35 2/15/2011 C11020544 Uranium 12.7 µg/L GW Extreme Outlier
MW 35_12012010 MW-35 12/1/2010 C10120105 Zinc 14 µg/L GW Extreme Outlier
MW-36_08092011 MW-36 8/9/2011 C11080529 Zinc 35 µg/L GW Extreme Outlier
MW-36_02202012 MW-36 2/20/2012 C12020833 Zinc 24 µg/L GW Extreme Outlier
Notes:
µg/L = micrograms per liter
mg/L = milligrams per liter
pCi/L = picocuries per liter
U = result not detected above the laboratory reporting limit
Bold records indicate extreme outliers that were returned to data sets for Modified Approach
Page 4 of 4
Background Groundwater Quality Report for MW‐35, MW‐36, and MW‐37
White Mesa Uranium Mill
Blanding, Utah

APPENDIX H
Input and Output Files (Electronic Only)

APPENDIX I
Increasing Trends Modified GWCL Approach
Appendix I: Increasing Trends Modified GWCL Approach
Page 1 of 4
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
MW-35
Box Plot for Gross Alpha minus Rn and U in MW-35
2
3
4
5
6
7
8
9
10
Gr
o
s
s

A
l
p
h
a

(
p
C
i
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
MW-35
Box Plot for TDS in MW-35
2000
2200
2400
2600
2800
3000
3200
3400
3600
3800
4000
4200
4400
TD
S

(
m
g
/
L
)
Median
25%-75%
1%-99%
Outliers
Extremes
Appendix I: Increasing Trends Modified GWCL Approach
Page 2 of 4
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
Gross Alpha in MW-35 (Outlier included)
r = 0.3352, p = 0.0653; r2 = 0.1123
8/10/2010 2/26/2011 9/14/2011 4/1/2012 10/18/2012 5/6/2013 11/22/2013 6/10/2014
2
3
4
5
6
7
8
9
10
Gr
o
s
s

A
l
p
h
a

(
p
C
i
/
L
)
TDS in MW-35 (Outlier Included)
r = 0.5562, p = 0.0484; r2 = 0.3094
8/10/2010 2/26/2011 9/14/2011 4/1/2012 10/18/2012 5/6/2013 11/22/2013 6/10/2014
2000
2200
2400
2600
2800
3000
3200
3400
3600
3800
4000
4200
4400
TD
S

(
m
g
/
L
)
Appendix I: Increasing Trends Modified GWCL Approach
Page 3 of 4
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
Gross Alpha in MW-35
(Outlier included)
SW-W = 0.8996, p = 0.0071
1 2 3 4 5 6 7 8 9 10 11
Report_Result
0
2
4
6
8
10
12
14
16
No

o
f

o
b
s
TDS in MW-35
(Outlier included)
SW-W = 0.5027, p = 0.00001
3.30 3.35 3.40 3.45 3.50 3.55 3.60 3.65
Log_result
0
2
4
6
8
10
12
No

o
f

o
b
s
Appendix I: Increasing Trends Modified GWCL Approach
Page 4 of 4
Background Groundwater Quality Report for MW-35, MW-36, and MW-37
White Mesa Uranium Mill
Blanding, Utah
Mann-Kendall Trend Test Analysis
4/8/2014 1:37:34 PM
WorkSheet.wst
OFF
0.95
0.05
31
2.6
9.51
4.769
4.604
4.5
1.348
0.242
126
1.645
58.79
2.126
0.0167
13
2200
4170
3730
3693
3840
476.8
132.2
27
0.064
16.3
1.595
0.0553
User Selected Options
Date/Time of Computation
From File
Full Precision
Confidence Coefficient
Median
Level of Significance
Result-grossalpha
General Statistics
Number of Values
Minimum
Maximum
Mean
Geometric Mean
trend at the specified level of significance.
Standard Deviation
SEM
Mann-Kendall Test
Test Value (S)
Critical Value (0.05)
Standard Deviation of S
Standardized Value of S
Approximate p-value
Statistically significant evidence of an increasing
Result-tds
General Statistics
Number of Values
Minimum
Maximum
Mean
Geometric Mean
Median
Standard Deviation
SEM
Insufficient evidence to identify a significant
trend at the specified level of significance.
Mann-Kendall Test
Test Value (S)
Tabulated p-value
Standard Deviation of S
Standardized Value of S
Approximate p-value