DRC-2024-005024

Department of
Environmental Quality
State of Utah
Kimberly D. Shelley
Executive Director
SPENCER J. COX
Governor
DIVISION OF WASTE MANAGEMENT
AND RADIATION CONTROL
DEIDRE HENDERSON
lieutenant Governor
Douglas J. Hansen
Director
TO:
FROM:
DATE:
SUBJECT:
MEMORANDUM
Phil Goble FE & 0<J/4oL'-j
0)r I /:Jo /-v> 21Dean Henderson
January 30, 2024
Review of the November 15, 2023 3rd Quarter 2023 Nitrate Monitoring Report (DRC-
2023-076788) for the Nitrate Contamination Investigation, Energy Fuels Resources
(USA) Inc. ("EFRI") White Mesa Uranium Mill, near Blanding, Utah
The Utah Division of Waste Management and Radiation Control ("Division") has reviewed the EFRI
November 15, 2023, 3rd Quarter, 2023 White Mesa Uranium Mill Nitrate Monitoring Report ("Report")
for the Nitrate Contamination Investigation.
For the review of this Report the following regulatory enforcement documents were used:
•Energy Fuels Resources (USA) Inc., White Mesa Uranium Mill, Groundwater Discharge Permit
No. UGW370004, signed March 19, 2019 ("Permit").•Corrective Action Plan for Nitrate White Mesa Uranium Mill near Blanding, Utah, May 7, 2012,
("CAP") approved December 12, 2012.•The EFR Quality Assurance Plan ("QAP") February 15, 2022 (Revision. 7.7)
REVIEW
The CAP requires the 3rd quarter Nitrate Monitoring Report for the Nitrate Contamination Investigation
to be submitted to Division on or before December 1, of each year. The Report was received by the
Division on November 21, 2023 (date of Report November 15, 2023) which meets the CAP
requirement.
Monitor Wells Sampled and Parameters Analyzed
The following monitor wells were sampled and analyzed for inorganic chloride and nitrate+ nitrite (as
N), and field data work sheets were filled out for each well as required in the CAP:
DRC-20 I 95 North 1950 West• Salt Lake City, UT
Mailing Address P.O. Box 144880 • Salt Lake City, UT 84114-4880
Telephone [phone] • Fax [phone] • T.D.D. [phone]
www.deq.11tail.gov
Printed on I 00% recycled paper
DRC-2024-005024
Page 2
TWN-1, TWN-2, TWN-3, TWN-4, TWN-7, TWN-18, TNW-20, TWN-21, TW4-22 (pumping well),
TW4-24 (pumping well), and TW4-25 (pumping well), and Piezometer 1, Piezometer 2, and
Piezometer 3A.
Groundwater Head Monitoring
For the 3rd Quarter, 2023 depth to groundwater was measured in the following wells and/or piezometers
as required in Part I.E.3 of the Permit:
•The quarterly groundwater compliance monitoring wells.
•Existing monitoring well MW-4 and all of the temporary chloroform investigation
wells.
•Piezometers P-1, P-2, P-3A, P-4 and P-5.
•MW-20, MW-22 and MW-34
•Nitrate monitoring wells.
•The DR piezometers which were installed during the Southwest Hydrologic
Investigation.
In addition to the above, depth to water measurements are routinely observed in conjunction with
sampling events for all wells sampled during quarterly and accelerated efforts, regardless of the
sampling purpose. All well levels used for groundwater contour mapping were measured and recorded
within 5 calendar days of each other.
The monitoring wells were purged using the three approved QAP well purging strategies and meet QAP
requirements for each strategy:
1.Purging two casing volumes with stable field parameters for specific conductivity,
turbidity, pH, redox potential, and water temperature (within 10% RPD):
Wells: TWN-1, TWN-4, and TWN-18.
2.Purging a well to dryness and stability of field parameters for pH, specific conductivity, and
water temperature only after recovery:
Wells: TWN-3, TWN-7, TWN-20, and TWN-21
3.Continuously Pumped Wells that are considered sufficiently evacuated to immediately
collect a sample:
Wells: TWN-2, TW4-22, TW4-24, and TW4-25.
Detection Limits
All sample sets were measured and reported to the required QAP reporting limits.
Page 3
Sample Duplicates
One duplicate sample was collected at TWN-18 and identified as TWN-65. The duplicate sample
analytical results for this sample/duplicate pair QA/QC were within the 20% acceptance limits as
required in the QAP (see Table 2 below).
Holding Times
The method holding times for each parameter for samples collected at each monitor well were received
and analyzed within the required holding times in the QAP.
Receipt Temperature
All samples were received within the required QAP temperature limit of 6° C.
Analytical Methods
Chloride and nitrate+ nitrite (as N) were analyzed for methods consistent with the requirements of the
QAP.
Estimation of Pumped Nitrate Mass Removal
An estimated 49 lbs. of nitrate were removed from the chloroform pumping wells (MW-4, MW-26,
TW4-1, TW4-2, TW4-4, TW4-11, TW4-19, TW4-37, TW4-39 and TW4-41) and the nitrate pumping
wells (TWN-2, TW4-22, TW4-24, and TW4-25). Of the 49 lbs. removed, approximately 27 lbs. (or
55%) were removed by the nitrate pumping wells (see Table 3 below).
Reporting
The Report included the following information as required in the CAP:
a)Introduction
b)Sampling and Monitoring Plan:
i.Description of monitor wells sampled;
ii.Description of sampling methodology, equipment and decontamination
procedures;
iii.Identification of all quality assurance samples, e.g. equipment blanks
duplicate samples, etc.
c)Data Interpretation:1. Interpretation of groundwater levels, gradients, and flow directions. The interpretation will
include a discussion on: 1) current site groundwater contour map, 2) hydrographs to show
groundwater elevation in each monitor well over time, 3) depth to groundwater measured and
groundwater elevation from each monitor well summarized in data table that includes historic
groundwater level data for each well, 4) calculations documenting quarterly nitrate mass
removed by pumping;11.Interpretation of all analytical results for each well including a discussion on: 1) a current
nitrate isoconcentration map, 2) graphs showing nitrate concentration trends in each well
through time and, analytical results for each well summarized in data table that includes
historic analytical results for each well; and
Page4
iii.An electronic copy of all laboratory results for groundwater quality monitoring conducted
during the quarter will be provided to the Executive Secretary.
d)Conclusions and Recommendations
e)Copies of EFR field reports, laboratory reports, and chain of custody forms.
Evaluation of the Nitrate Contaminate Plume and Its Associated Contaminants
The groundwater monitoring data appeared to show that the nitrate contaminate plume ("Plume") is
bound by up gradient, cross gradient, and down gradient wells that have nitrate concentrations below the
Utah 10 mg/L GWQS.
Conclusions on Compliance with the CAP, QAP
Per the Division review it appears that the 3rd Quarter, 2023 Nitrate Monitoring Report for the Nitrate
Contamination Investigation, Energy Fuels Resources (USA) Inc. complies with the CAP and QAP.
Therefore, a letter will be drafted notifying EFRI of the review and closing out of this Report.
Table 1 of 16 Historic Nitrate, Nitrate+ Nitrite and Cloride Concentrations in Monitor Wells Up to the 3rd Quarter 2023
Nitrate Contamination Investigation
TWN-1
Sampling Event
lstQtr 3/17/2010 2ndQtr 5/26/2010 3rdQtr 9/27/2010 4thQtr 12/7/2010 lstQtr 1/26/2011 2ndQtr 4/20/2011 3rd Qtr 7/26/2011 4th Qtr 10/17/2011 lstQtr 1/9/2012 2nd Qtr 4/18/2012 3rd Qtr I 7/24/2012 4th Qtr ___ 10/17/2012 lstQtr 2/18/2013 2ndQtr 4/23/2013 3rd Qtr 8/27/2013 4th Qtr 10/16/2013
lrwN-65 duplicat ofTWN-1
ORC split ofTWN-1
DRC duplicate ofTWN-1 1st Qtr I 1/14/2014 2nd Qtr 5/6/2014 3rd Qtr 8/5/2014
t,'WN-65 duplicate ofTWN-1 4th Qtr I 10/8/2014 lstQtr I 2/18/2015
lrwN-65 dup of TWN·l 2ndQtr 5/13/2015 3rdQtr 8/25/2015 4th Qtr 10/13/2015 lstQtr 2/23/2016 2nd Qtr 5/17/2016 3rdQtr 7/20/2016 4th Qtr 10/6/2016 lstQtr 2/15/2017
trWN-65 duplicate ofTWN-1 2ndQtr I 6/1/2017
tfwN--65 duplicate ofTWN-1 3rdQtr I 7/19/2017
trwN-65 duplicate ofTWN-1 4th Qtr I 10/4/2017
h'wN-65 duplicate ofTWN-1 lstQtr 1/18/2018 2ndQtr 5/8/2018 3rdQtr 8/8/2018 4th Qtr 11/20/2018 1st Qtr 2/20/2019 2nd Qtr 5/29/2019 3rdQtr 8/14/2019 4th Qtr 10/16/2019
OWMRC split ofTWN-1 lstQtr 1/29/2020 2nd Qtr 5/20/2020 3rdQtr 7/15/2020 4th Qtr 11/12/2020
lstQtr 2/17/2021 2nd Qtr 5/25/2021 3rdQtr 8/18/2021 14th Qtr 11/23/2021 lstQtr 2/15/2022 2nd Qtr 5/24/2022 3rd Qtr 8/17/2022 4th Qtr 10/25/2022 1st Qtr 2/21/2023 2ndQtr 6/8/2023 3rd Qtr 7/19/2023
Parameter
GWQS
Nitrate, Nitrate + Nitrite (10 mg/L) 0.50 0.6 0.6 0.6 0.5 0.5 0.5 0.5 0.6 0.6 1-------------0.6 0.43 '"""-----------0.68 0.84 1.24 1.61 1.48 1.6 0.22 1.47 1.63 1.7 1.4 1.46 1.37 1.41 0.65 0.624 1.35 1.51 1.73 1.76 1.98 2.06 1.98 1.89
1.88 2.07 1.89 1.95 1.99 1.86 1.89 1.97 1.98 2.1 1.93 2.15 2.35 2.1 2.24 2.24 2.36 1.89 2.53 3.18 2.47 1.91 3.01 2.1 2.94 2.75 1.96 2.6 2.46
White Mesa Uranium Mill
TWN-2 (Pumpingwellstartingin
Januarv2013)
Sampling Event
Chloride (mg/I) NoGWQS 17 1st Qtr 3/24/2010 20 2nd Qtr 6/2/2010 19 3rd Qtr 9/29/2010 14 4th Qtr 12/9/2010 17 1st Qtr 2/1/2011 19 2nd Qtr 4/28/2011 14 3rd Qtr 7/28/2011 10 4th Qtr 10/20/2011 15 1st Qtr 1/12/2012 17 2nd Qtr 4/20/2012 -------17 17.5 -------17.6 17.4 24.1 26.8 27.1 30 30 29.2 31.1
-----------3rd Qtr J 7/31/2012 4th Qtr 7/17/2012 ----------lstQtr 2/19/2013 2ndQtr 4/24/2013 3rd Qtr 8/27/2013 4th Qtr 7/16/2013
ORC split ofTWN-2
1st Qtr 1/13/2014 2nd Qtr 5/7/2014 28 3rd Qtr 8/6/2014 28 27.6 4thQtr 10/8/2014
27.8 lstQtr 2/18/2015 29.0 29.2 2nd Qtr 5/12/2015 33.2 3rdQtr 8/25/2015 27.7 4th Qtr 10/14/2015 30.3 lstQtr 2/23/2016 32.1 2nd Qtr 5/17/2016 29.6 3rdQtr 7/20/2016 33 4th Qtr 10/11/2016 31.2 lstQtr 2/15/2017 31.5 32.7 2nd Qtr I 6/1/20171 31.5 31.2 3rdQtr I 7/19/20171 31.4 30.8 4th Qtr I 10/4/20171 32.0 30.4 lstQtr 1/19/2018 28.4 2nd Qtr 5/9/2018 34.2 3rdQtr 8/8/2018 28.9 4thQtr· 11/20/2018 31.4 lstQtr 2/20/2019 32.6 2nd Qtr 5/29/2019 30.3 3rdQtr 8/14/2019 32.0 4th Qtr 10/16/2019 31.0 OWMRC split ofTWN-2 33.8 lstQtr 1/29/2020 33.0 2nd Qtr 5/20/2020 30.8 3rdQtr 7/15/2020 29.2 4th Qtr 11/12/2020 34.1 lstQtr 2/18/2021 34.7 2nd Qtr 5/25/2021 35.7 3rdQtr 8/18/2021 37.4 4thQtr 11/23/2021 35.6 lstQtr 2/15/2022 33.7 2nd Qtr 5/24/2022 36.7 3rdQtr 8/17/2022 30.1 4th Qtr 10/25/2022 30.8 1st Qtr 2/21/2023 36.1 2ndQtr 6/8/2023 35.3 3rd Qtr 7/19/2023
Shaded = Nitrate, Nitrate+ Nitrite concentrations greater than the Ground Water Quality Standard of 10 mg/I
DRC = Utah Division or Radiation Control.
DWMRC = Utah Division of Waste Management and Radiation Control
Nitrate Pumpmg System Started m January 2013
, As of March 2012 both north and south wlld hfe ponds no longer receiving water _
Parameter
GWQS
Nitrate, Nitrate + Nitrite (10 mg/L)
•m•M•- -••
62 69 69 48 43 40 33 33 31 48
Chloride (mg/I) NoGWQS
85 97 104 93 93 85 74 76 86 103 ------------�-------54 93 22 1 79 --------------------57.3 80.5 57.7 82.1 80.0 75.9 111 70.4 200 75
42.6 72.4 44.7 84.9 42 80
71 81 48.6 87.8
52.8 83.6 49.7 87.8 45 74.9 86.3 73.9 45.4 74.5 35.3 68.8 32.6 69.8 27.4 65.8
25.ol 61.5
23 91 64.2
31.91 60.5
19.6 57.1 19.8 62.3 18.6 61.5 19.6 56 19.0 50.7 45.1 102 23.2 50.7 18.2 53 16.0 52 16.5 66.1 16.1 59.E 17.2 55.6 12 53.' 15.4 6U 13.8 61.5 15.3 58.9 12.7 62.3 15.3 59.5 14.0 60.2 13.9 61.8 14.0 48.9 11.2 44.9 13.6 49.7 14 56.2
TWN-3
Table 2 of 16 Historic Nitrate, Nitrate+ Nitrite and Cloride Concentrations in Monitor Wells Up to the 3rd Quarter 2023
Nitrate Contamination Investigation White Mesa Uranium Mill
Parameter TWN-4 Parameter
Sampling Event GWQS Sampling Event GWQS
Nitrate, Nitrate + Nitrite Chloride (mg/I) 110 mg/L) NoGWQS lstQtr 3/25/2010 25.3 111 2ndQtr 6/3/2010 26 118 3rdQtr 7/16/2010 27 106 4th Qtr 12/10/2010 24 117 lstQtr 2/1/2011 24 138 2ndQtr 4/28/2011 26 128 3rd Qtr 7/29/2011 25 134 4thQtr 10/20/2011 25 129 lstQtr 1/12/2012 25 143 2ndQtr _jQ��� 24 152 -------------------3rdQtr 7/31/2012 27 158 12.1 149
lstQtr 3/16/2010 2ndQtr 5/27/2010 3rd Qtr 9/27/2010 4th Qtr 12/8/2010 lstQtr 1/25/2011 2ndQtr 4/20/2011 3rd Qtr 7/26/2011 4th Qtr 10/18/2011 lstQtr 1/9/2012 2nd Qtr 4/18/2012 ---------
TWN-65 duplicate ofTWN-4 3rd Qtr I 7/25/2012
TWN-65 duplicate of TWN-4
Nitrate, Nitrate + Nitrite (10 mg/L) 0.9 1.0 0.9 1.0 0.9 0.9 1.1 0.9 0.9 1.1 ------------1.1 1.4 1.5 1.45
Chloride (mg/I) NoGWQS 22 22 19 21 21 21 35 20 20 ______ 2j 24 25 26 26.4 4th Qtr ___ 10/17/2012 �------------------4th Qtr -�-7/15/201� --------------------1st Qtr 2/19/2013 22.2 157 2ndQtr 4/24/2013 27.2 158 3rdQtr 8/28/2013 20.9 171 4th Qtr 10/17/2013 23.5 163 lstQtr 1/15/2014 19.6 160 2ndQtr 5/7/2014 23.6 168 3rd Qtr 8/6/2014 19.5 174 4thQtr 10/9/2014 19.1 153 lstQtr 2/19/2015 19.4 164 2ndQtr 5/14/2015 17.2 141 3rd Qtr 8/26/2015 16.2 156 4th Qtr 10/14/2015 16.3 129 lstQtr 2/24/2016 16.8 128 2ndQtr 5/18/2016 135 116 3rd Qtr 7/20/2016 16.8 110 4th Qtr 10/7/2016 15.8 113 lstQtr 2/16/2017 17.4 113 2ndQtr 6/2/2017 15.9 108 3rd Qtr 7/20/2017 15.9 106 4th Qtr 10/4/2017 15.6 111 1st Qtr 1/19/2018 14.4 107 2ndQtr 5/9/2018 16.4 115 3rd Qtr 8/9/2018 19.4 149 4th Qtr 11/21/20181 20.11 123 1st Qtr 2/21/2019 20.7 140 2nd Qtr 5/30/2019 18.7 137 3rdQtr 8/15/2019 19.8 133 4th Qtr 10/17/2019 19.6 126
OWMRC split of TWN-3 17.0 130
1st Qtr I 1/30/2020; I 19.�I 156 2ndQtr 5/21/2020 24 136
3rdQtr I 7/15/20201 22.21 130
4th Qtr 11/13/2020 18 137 lstQtr 2/18/2021 23 .8 145 2nd Qtr 5/27/2021 25 156 3rdQtr 8/19/2021 24.3 146 4th Qtr 11/24/2021 17.4 147
lstQtr 2/16/2022 25.3 140 2ndQtr 5/25/2022 24 157 3rd Qtr 8/18/2022 28.2 163 4th Qtr 10/26/2022 26 156 lstQtr 2/22/2023 28 109.0 2ndQtr 6/9/2023 26.4 158 3rd Qtr I 7/20/20231 26.1I 160
1st Qtr 2/18/2013
TWN-65 duplicate ofTWN-4 2nd Qtr I 4/23/2013 3rdQtr 8/27/2013
TWN-65 duplicate ofTWN-4 4th Qtr I 7/16/2013
TWN-65 duplicate of TWN-4 lstQtr I 1/14/2014
TWN-65 duplicate of TWN-4 2ndQtr 15/6/2014
TWN-65 duplicate ofTWN-4 3rd Qtr 8/5/2014 4th Qtr 10/8/2014 1st Qtr 2/18/2015 2ndQtr 5/13/2015 3rd Qtr 8/25/2015
TWN-65 duplicate ofTWN-4 4th Qtr I 10/13/2015
TWN-65 duplicate ofTWN-4 1st Qtr 2/23/2016 2ndQtr 5/17/2016 3rd Qtr 7/20/2016 4th Qtr 10/6/2016 1st Qtr 2/15/2017 2ndQtr 6/1/2017 3rd Qtr 7/19/2017 4th Qtr 10/4/2017 lstQtr 1/18/2018 2nd Qtr 5/9/2018 3rdQtr 8/8/2018
TWN-65 duplicate ofTWN-4 4thQtr I 1112012018
TWN-65 duplicate ofTWN-4 lstQtr 2/20/2019 2nd Qtr 5/29/2019 3rdQtr 8/14/2019 4th Qtr 10/16/2019
TWN-65 duplicate ofTWN-4
OWMRC split of TWN-4
TW4-40 OWMRC duplicate ofTWN·
4 lstQtr I 1/29/2020 2nd Qtr 5/20/2020
TWN-65 duplicate of TWN-4 3rdQtr I 7/15/2020
TWN·65 duplicate ofTWN-4 4thQtr 11/12/2020 lstQtr 2/17/2021 2nd Qtr 5/25/2021 3rdQtr 8/18/2021 4thQtr 11/23/2021
TWN-65 duplicate ofTWN-4 lstQtr 2/16/2021 2nd Qtr 5/25/2022 3rdQtr 8/18/2022 4th Qtr 10/25/2022 lstQtr 2/21/2023 2nd Qtr 6/8/2023
TWN-65 duplicate of TWN-4 3rd Qtr I 7/19/20231
Shaded = Nitrate, Nitrate+ N1tnte concentrations greater than the Ground Water Quahty Standard of 10 mg/I
Nitrate Pumping System Started in January 2013
,As of March 2012 both north and south wild life ponds no longer receIvIng water_
1.5 25.3 1.5 25.9 1.63 24.4 1.6 27.2 1.57 29.0 1.69 29.4 0.22 32 1.41 28.4 1.33 26.4 1.55 29.6 1.54 26.6 2.0 28 1.44 30.7 1.48 31.5 0.733 31.9 0.974 35.2 1.160 35.2 1.58 28.4 1.45 25.6 -----------2.02 30.7 2.97 31.7 3.14 28.0 ---3.09 31.3 2.63 31.2 2.4 28.6 2.35 28.0 2.27 27.4 2.63 31.2 1.9 27.7 1.54 28 1.51 27.6 1.48 22.7 1.51 23.2 1.53 25.3 1.5 26.� 1.81 23.7 2.15 25.4 2.15 24.7 1.9 26.0 1.9 26.0 1.89 27.2 1.75 25.1 1.71 25.4 1.75 23.1 1.73 23.1 1.18 22.E 1.64 24.2 1.70 23.2 1.28 23.7 1.18 23.2 1.02 23.2 1.5 22.7 1.20 20.9 1.39 21.6 1.31 21.2 0.904 12.2 1.21 15.9 1.1311 18.8 1.08 17.E
Table 3of16
Historic Nitrate, Nitrate+ Nitrite and Cloride Concentrations In Monitor Wells Up to the 3rd Quarter 2023
Nitrate Contamination Investigation
White Mesa Uranium Mill
TWN-5
Sampling Event
Parameter
GWQS
TWN-6
Sampling Event
Parameter
GWQS
Nitrate, Nitrate+ Nitrite Chloride (mg/I)
(10 mg/L) No GWQ S
1st Qtr 3/16/2 4 3 1st Qtr
2nd Qt r 5 /26/2 44 2nd Qtr
lf-4'-'th"--"Qtccr __ ----===c.c.+--------'-"+-----'45'-14th Qt r
��. . .. 44W®
�® 44�®
4th Qtr 10 �--<----------<-----4_,5 4t h Qt r
2nd Qtr 4 39 2nd Qtr
4th Qt r 43.5 4th Qtr
1st Qtr 1st Qtr 2013
1�2_n_d _Q�tr _____ 2_01_3�N_A _____________ __.2nd (lt r 20B TWN-5 abandoned on July 31, 2013 3rd Qt r 2013
4th Qtr 2013
1st (ltr2014
2nd Qt r 2014
3rd Qtr 2014
3r d Qt r 2015
4th Qtr 2015
2n.d (ltr 2016
3r d Qtr 2016
4th Qtr 2016
1st Qtr2017
2nd Qtr 2017.
3rd . Qtr 201.7
4t h Qt r 2017
1st Q tr2018
1st Qt r 2019
2nd Qt r 2019
3rd Q tr 201.9
4th Qt r 2019
1st (ltr2020
2n.d Qtr 2020
3r d Qtr 2020.
4th Qtr 2020
1st Qtr 2021
2.nd Qt r 2021
3rd Qtr 2021
4th Qtr 2021
1st Qtr2022
2nd Qtr 2022
3rd Qt r 2022
4th Qt r 2022
1st Qtr 2023
2nd Qtr 2023
:i,d Qt, 2023
Nitrate, Nitrate + Nitrite
(10 mg/L)
Chloride (mg/I)
NoGWQS
3/23/2010 19
6/1/2010 22
7/13/2010 1.4 73
12/7/2010f----------"'-c+----.c.21CJI 1/26/2011 18
4/20/2011 22
7/27/2011 17
10/18/2011 ._. ________ ._. ____ 2_,1, 1/10/2012 20
4 /18/2012 22
7/25 /2012 22
7/15 /2012
NA
NA
NA
Table 4 of 16 Historic Nitrate, Nitrate+ Nitrite and Cloride Concentrations in Monitor Wells Up to the 3rd Quarter 2023
Nitrate Contamination Investigation
TWN-7
Sampling Event
1st Qtr 3/17/2010 2nd Qtr 5/28/2010 3rd Qtr 7/14/2010
4th Qtr 12/10/2010 1st Qtr 1/27/2011
2ndQtr 4/21/2011 3rd Qtr 7/29/2011 4th Qtr 10/19/2011
lstQtr 1/11/2012 2nd Qtr 4/20/2012 3rd Qtr I 7/26/2012 4th Qtr ___ 10/16/2012
lstQtr 2/19/2013 2nd Qtr 4/24/2013
Parameter
GWQS
Nitrate, Nitrate + Nitrite (10 mg/L) 0.8 1.2
1.8 1 1.3
1.7 0.7
2.2 2.3
1.2 0.9
0.64 0.59 1.16
White Mesa Uranium Mill
TWN-8
Sampling Event
Chloride (mg/I)
NoGWQS 6 lstQtr 3/16/2010 6 2nd Qtr 5/26/2010 7 3rdQtr 7/12/2010 4 4th Qtr 12/7/2010 6 1st Qtr 1/25/2011 6 2nd Qtr 4/19/2011 5 3rd Qtr 7/26/2011 6 4th Qtr 10/17/2011 5 1st Qtr 1/9/2012 6 2nd Qtr 4/18/2012
6 3rd Qtr 5.67 4th Qtr 10/15/2012
5.68 1st Qtr 2013
5.88 2ndQtr 2013
Parameter
GWQS
Nitrate, Nitrate + Nitrite (10 mg/L) <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1
NA
NA 3rd Qtr 8/28/2013 0.835 6.96 TWN-8 abandoned on July 31, 2013 4th Qtr 10/16/2013 0.986 5.7
lstQtr 1/15/2014 0.882 5.75 2nd Qtr 5/7/2014 0.564 5.26
3rdQtr 8/6/2014 0.9 6
4th Qtr 10/9/2014 0.968 5.93
lstQtr 2/19/2015 1.04 5.58 2nd Qtr 5/14/2015 0.779 6.18 3rdQtr 8/6/2015 0.348 6.12 4th Qtr 10/14/2015 0.672 5.84
lstQtr 2/24/2016 0.24 6.06
2nd Qtr 5/18/2016 0.732 6.26
3rdQtr 7/21/2016 0.81 5.97
4th Qtr 10/7/2016 0.698 6.17
lstQtr 2/16/2017 1.63 14.0 2nd Qtr 6/2/2017 3.74 29.7
3rd Qtr 7/20/2017 2.7 29.0
4th Qtr 10/5/2017 3.58 41.4 1st Qtr 1/19/2018 5.82 69.4 2ndQtr 5/9/2018 10.2 94.7 3rd Qtr 8/9/2018 10.6 105 4th Qtr 11/21/2018 11.5 104 lstQtr 2/21/2019 12.9 107 2ndQtr 5/30/2019 13.5 122 3rd Qtr 8/15/2019 12.9 120 4th Qtr 10/17/2019 14.5 119
DWMRC split of TWN-7 12.0 120 1st Qtr 1/30/2020 14.2 128
2ndQtr 5/21/2020 14.6 126 3rd Qtr 7/16/2020 15.2 116 4th Qtr 11/13/2020 11.8 121
lstQtr 2/18/2021 16.0 129 2ndQtr 5/27/2021 16.4 129
3rdQtr 8/19/2021 15.l 121 4th Qtr 11/24/2021 7.66 130
lstQtr 2/17/2022 16.9 120 2nd Qtr 5/25/2022 16.0 127 3rd Qtr 8/18/2022 14.6 128
4th Qtr 10/26/2022 15.7 129 1st Qtr 2/22/2023 14.S 150 2ndQtr 6/9/2023 14.0 122 3rd Qtr 7/20/2023 13.7 124.
Shaded= Nitrate, Nitrate+ Nitrite concentrations greater than the Ground Water Quality Standard of 10 mg/I
NA= Per the CAP and SCO, not sampled
Nitrate Pumping System Started in January 2013
,As of March 2012 both north and south wild life ponds no longer receiving water_
Chloride (mg/I)
NoGWQS 11
11 11 9 13 10
18 10 11 15
11 11.l
Table 5 of 16
Historic Nitrate, Nitrate + Nitrite and Cloride Concentrations in Monitor Wells Up to the 3rd Quarter 2023
Nitrate Contamination Investigation
White Mesa Uranium Mill
TWN-9 Parameter TWN-10 Parameter
Sampling Event GWQS Sampling Event GWQS
Nitrate, Nitrate + Nitrite Chloride (mg/I) Nitrate, Nitrate + Nitrite
(10 mg/L) NoGWQS (10 mg/L)
lstQtr 3/23/2010 7.6 183 lstQtr 3/23/2010 1.5
2nd Qtr 6/1/2010 7.7 175 2nd Qtr 6/2/2010 1.0
3rdQtr 7/15/2010 10.7 210 3rd Qtr 7/14/2010 0.2
4th Qtr 12/9/2010 8.0 172 4th Qtr 12/8/2010 1.3
lstQtr 2/1/2011 9.5 217 lstQtr 1/26/2011 0.3
2nd Qtr 4/28/2011 10.0 192 2nd Qtr 4/21/2011 1.2
3rdQtr 7/29/2011 11.0 208 3rd Qtr 7/27/2011 0.1
4th Qtr 10/20/2011 10.9 134 4th Qtr 10/18/2011 0.2
lstQtr 1/12/2012 12.2 202 1st Qtr 1/10/2012 0.8
0.7
2ndQtr 4/20/2012 10.6 209 2ndQtr 4/19/2012 0.9
3rd Qtr 7/31/2012 12.3 215 3rdQtr 7/25/2012 0.6
4th Qtr 10/17/2012 12.5 194 4th Qtr 7/16/2012 0.12
lstQtr 2013 1st Qtr 2013
2nd Qtr 2013 2nd Qtr 2013
TWN-9 abandoned on July 31, 2013 TWN-10 abandoned on July 31, 2013
TWN-11
Sampling Event
lstQtr
2ndQtr
3rd Qtr
4th Qtr
1st Qtr
2ndQtr
3rd Qtr
4th Qtr
1st Qtr 2013
2nd Qtr 2013
3/17/2010
6/1/2010
9/27/2010
12/8/2010
1/27/2011
4/26/2011
7/27/2011
10/17/2011
1/10/2012
4/19/2012
7/25/2012
10/16/2012
Parameter
GWQS
Nitrate, Nitrate + Nitrite
(10 mg/L)
1.4
1.3
1.4
1.4
1.4
1.4
0.1
1.6
1.6
1.6
1.6
1.8
1.84
TWN-12
Sampling Event
Chloride (mg/I)
NoGWQS
73 1st Qtr
72 2nd Qtr
76 3rd Qtr
72 4th Qtr
84 lstQtr
76 2nd Qtr
76 3rd Qtr
76 4th Qtr
69 lstQtr
70
71 2nd Qtr
77 3rd Qtr
76.4 4th Qtr
1st Qtr 2013
2nd Qtr 2013
3/17/2010
5/26/2010
7/12/2010
12/7/2010
1/26/2011
4/26/2011
7/26/2011
10/17/2011
1/10/2012
4/18/2012
7/25/2012
7/16/2012
Parameter
GWQS
Nitrate, Nitrate + Nitrite
(10 mg/L)
0.7
0.8
0.7
0.7
4.2
1.0
0.6
1.2
0.9
1.2
1.4
1.41
TWN-11 abandoned on July 31, 2013 TWN-12 abandoned on July 31, 2013
Shaded= Nitrate, Nitrate+ Nitrite concentrations greater than the Ground Water Quality Standard of 10 mg/I
NA= Per the CAP and sea, not sampled
Shaded= Nitrate, Nitrate+ Nitrite concentrations greater than the Ground Water Quality Standard of 10 mg/I
Chloride (mg/I)
NoGWQS
54
30
21
2!
28
33
44
28
33
30.8
Chloride (mg/I)
NoGWQS
113
106
112
103
87
109
102
87
104
106
102
101
Table6of16
Historic Nitrate, Nitrate+ Nitrite and Clorlde Concentrations in Monitor Wells Up to the 3rd Quarter 2023
Nitrate Contamination Investigation
TWN-13
Sampling Event
Parameter
GWQS
Nitrate, Nitrate + Nitrite
(10 mg/L)
lstQtr
2ndQtr
3rdqtr
4thQtr
lstQtr
2ndQtr
3r.d Qtr
4thQtr
lstQtr
2ndQtr
3.rdQtr
4th Qtr
lstQtr
2ndQtr
3/17/2010 <O
.. 5/26/2010
10
4
7
NA= Per the CAP and SCO, not sampled
White Mesa Uranium Mill
Chloride (mg/I)
NoGWQS
TWN-14
Sampling Event
3r.d.Qtr
4thQtr
lstQtr .
2nd Qtr
.3r.dQtr
4th Qtr
lstQtr
2ndQtr
3r.dQtr
4thQtr
.lstQtr
2n.d Qtr
3r.dQtr
4thQtr
lstQtr
2ndQtr
3rdQtr
4th Qtr
lstQtr
2ndQtr
3rdQtr
4thQtr
lstQtr
2nd Qtr
3rdQtr
4thQtr
lstQtr
2ndO,tr
3rdQtr
4thQtr
1s.tQtr
2nd Qtr
3rdQtr
4thQtr
lstQtr
2ndQtr
3r.dQtr
4thQtr
lstQtr
2nd Qtr
3rd Cl.tr
Parameter
GWQS
Nitrate, Nitrate+ Nitrite Chloride (mg/I)
2014 NA
2015 NA
2015 NA
2015 NA
2015 NA
2016 NA
(10 mg/L) No GWQS
24
30
26
28
24
30
25
27
26
27
27
3.8 27
2016 ._N�A.,__ _______ �
2016 1-'N.:cA.:__ _______ �
2016 NA
2017 NA
2017 NA
2017 NA
2018 NA
Table7 of 16 Historic Nitrate, Nitrate + Nitrite and Cloride Concentrations in Monitor Wells Up to the 3rd Quarter 2023 Nitrate Contamination Investigation
TWN-15 Sampling Event
3/18/2010 lstQtr ...... . . 5/28/2010 2ndQtr 3rdQtr . . 1 7/13/20104thQtr 12/9/2010 lstQtr. 1/27/2011 2ndQtr 4/27/2011 3rdQtr 7/28/2011 4thQtr •• 10/19/2011 lstQtr 1/11/2012 I· 4/20/20li 2ndQtr
TW4-70 duplicate ofTWN-15 3r.dQtr I 7/26/2012 4th Qtr 10/17/ioiz
TW4-70 duplicate ofTWN-15 lstQtr 2013 2ndQtr 2013
Parameter GWQS Nitrate, Nitrate + Nitrite (10 mg/L) 0.7 ·-------·---------·-••••-•M••••• 1.0 ·-·-----· 1.0 1.21.4 1.6 1.6
1.3 1.5 1.61.7 2.1 1.79 2.0 NA NA TWN-15 abandoned on July 31, 2013
NA= Per the CAP and SCO, not sampled
White Mesa Uranium Mill
TWN-16 Parameter Sampling Event GWQS Chloride (mg/I) Nitrate, Nitrate + Nitrite NoGWQS (10 mg/L) 43 1st Qtr ... 3/17/2010 , ... 1.2 ... -----· 39 2ndQtr 5/27/2010, .... 1.3 ••-•'••rn••• ••••••M•o -----36 3rd Qtr 9/27/2010 2.6 38 4th Qtr 12/9/2010 2 43 lst.Qtr 1/27/2011 4.6 49 2n.dQtr 4/27/2011 1.6 47 3rd Qtr 7/27/2011 2.4 38 4th Qtr 10/18/2011 2.6 .38 lstQtr , .. 1/.10/2012 2.8 46 2nd (ltr 4/19/2012 2.0 46 50 3rd Qtr 7/25/2012 2.4 47 4th Qtr 7/16/2012 2.50 44.4
•••••• .lstQtr 2013 NA 2nd Qtr 2013 NA .3rdQtr 2013 NA 4thQtr 2013 NA 1st Qtr 2014 NA 2ndQtr 2014 NA 3rdQtr 2014 NA 4thQtr 2014 NA lstQtr 2015 NA 2ndQtr 2015 NA 3rd Qtr 2015 NA 4thQtr 2015 NA lstQtr 2016 NA 2nd Qtr .... 2016 JI!� 3r.dQtr ... 2016 NA 4th Qtr 2016 NA lstQtr .2017 NA 2.nd Qtr 2017 NA }r.d (ltr 2017 NA 4thQtr 2017 NA lstQtr 2018 NA 2ndQtr 2018 NA 3rdQtr 2018 NA 4th Qtr 2018 NA lstQtr 2019 NA 2ndQtr 2019 NA 3rdQtr 2019 NA ... 4th Qtr 2019 NA 1s.tQtr ........ 2020 NA 2.nd. (ltr 2020 NA 3rdQtr ........ 2020 NA 4thQtr 2020 NA lstQtr 2021 NA 2nd Qt,· io2i NA 3rdQtr 2021 NA 4thQtr 2021 NA lstQtr 2022 NA 2nd (ltr 2022 NA 3r.dQtr 2022 NA 4thQtr 2022 NA lstQtr 2023 NA 2nd Qtr 2023 NA 3rdQtr 2023 NA
Chloride (mg/I) NoGWQS 35 .. ••M•mrn• 35 ---·----------------35 30 34 39 31 34 3350
33 32.1
·�
Table 8 of 16 Historic Nitrate, Nitrate + Nitrite and Cloride Concentrations in Monitor Wells Up to the 3rd Quarter 2023
Nitrate Contamination Investigation
TWN-17
Sampling Event
lstQtr 3/24/2010 2nd Qtr 6/3/2010 3rdQtr 7/15/2010 4th Qtr 12/10/2010 lstQtr 2/1/2011 2nd Qtr 4/28/2011 3rdQtr 7/29/2011 4thQtr 10/20/2011 lstQtr 1/12/2012 2nd Qtr 4/20/2012 3rd Qtr I 7/27/2012 4th Qtr ___ 10/17/2012 lstQtr 2013 2nd Qtr 2013 3rdQtr 2013
Parameter
GWQS
Nitrate, Nitrate + Nitrite (10 mg/L) 10.4 11 8.9
8 8.6 9 8.5 8.1 8.7 9.1 9.5 9.65
NA
NA
NA TWN-17 abandoned on July 31, 2013
NA= Per the CAP and SCO, not sampled
White Mesa Uranium Mill
TWN-18
Sampling Event
Chloride (mg/I) NoGWQS 78 lstQtr 3/17/2010 87 2nd Qtr 6/1/2010 66 3rd Qtr 9/27/2010 65 4th Qtr 12/9/2010 90 lstQtr 1/27/2011 81 2nd Qtr 4/26/2011 74 3rd Qtr 7/28/2011 71 4th Qtr 10/18/2011 79 lstQtr 1/10/2012 80 2nd Qtr 4/19/2012 3rd Qtr � 7/26/2012 85
84.8 4th Qtr 7/16/2012 1st Qtr 2/18/2013 2nd Qtr 4/23/2013
TW4-65 dup of TWN-18 3rdQtr 8/27/2013 4th Qtr 10/16/2013
ORCsplitsample lstQtr 2/14/2014 2nd Qtr 5/6/2014 3rdQtr 8/5/2014 4thQtr 10/8/2014
TW4-65 dup ofTWN-18 lstQtr I 2/18/2015 2nd Qtr 5/13/2015
TW4-65 dup of TWN-18 3rdQtr I 8/25/2015 4th Qtr 10/13/2015
TW4-65 dup of TWN-18 lstQtr 2ndQtr __ 3rdgt_r:____ 4th Qtr lstQtr 2nd Qtr 3rdQtr 4thQtr lstQtr 2nd Qtr 3rdQtr 4th Qtr 1st Qtr
2/23/2016 ___2_17/2016 7/21/2016 10/6/2016 2/15/2017 6/1/2017 7/19/2017 10/4/2017 1/18/2018 5/8/2018 8/8/2018 11/21/2018 2/20/2019
TWN-65 dup ofTWN-18 2ndQtr 5/29/2019
TWN-65 dup of TWN-18 3rd Qtr 8/14/2019
TWN-65 dup ofTWN-18 4th Qtr 10116/2019
OWMRC duplicate ofTWN-18 1st Qtr 1/29/2020
TWN-65 dup ofTWN-18 2ndQtr I 5/20/2020 3rd Qtr 7/15/2020 4th Qtr 11/12/2020
TWN-65 dup ofTWN-18 1st Qtr 2/17/2021
TWN-65 dup ofTWN-18 2ndQtr 5/25/2021
TWN-65 dup ofTWN-18 3rd Qtr 8/17/2021
TWN-65 dup ofTWN-18 4th Qtr I 11/23/2021 lstQtr 2/15/2022
TWN-65 dup of TWN-18 2nd Qtr 5/24/2022
TWN-65 dup ofTWN-18 3rdQtr 8/17/2022
TWN-65 dup ofTWN-18 4th Qtr 10/25/2022 1st Qtr 2/21/2023
TWN-65 dup ofTWN-18 2ndQtr I 6/8/2023 3rd Qtr 7/19/2023
TWN-65 dup of TWN-18
Shaded = Nitrate, Nitrate+ N1tnte concentrations greater than the Ground Water Quality Standard of 10 mg/I
DRC = Utah Division of Radiation Control
Nitrate Pumping System Started in January 2013
,As of March 2012 both north and south wild life ponds no longer receiving water __ _
Parameter
GWQS
Nitrate, Nitrate+ Nitrite (10 mg/L) 1.6 1.8 1.8 1.6 1.4 1.8 1.8 1.9 1.9 2.1 2.3 1.95 2.27 2.32 2.46 2.04 2.15 0.29 2.33 2.18 1.8 1.47 1.47 1 1.35 <0.10 0.35 0.668 0.645 0.648 0.497 <0.100 0.501 0.47 0.392 0.419 0.256 0.332 0.283 0.348 0.16 0.155 0.174 0.129 0.152 0.181 0.184 0.162 0.13 0.224 0.249 0.223 0.232 0.208 0.171 0.228 0.227 0.22 0.247 0.199 0.208 0.245 0.199 <0.1 0.34 0.3 0.328 0.349 0.212 0.253 0.184 0.267 <0.1 0.129
Chloride (mg/I) NoGWQS 42 63 64 59 61 67 65 60 64 64 67 67.5 68.7 64.3 66.1 70.4 67.3 74 68.4 76.5 70 74.8 72.3 73.3 76.6 76.9 81.3 69 68.6 67.6 69.9 52.7 67.4 62.1 63.9 59.0 56.6 53.1 57.8 59.7 48.1 46.4 49.9 50.0 53.3 46.9 47.3 47.1 43.0 51.9 50.6 47.4 44.0 42.3 41.9 46.2 46.1 44.9 44.1 42.9 44.1 46.5 40.9 40.5 40.7 39.6 40.8 40.7 35.6 33.2 32.5 36.1 38.1 35.5
TWN-19
Sampling Event
ls.tQtr
2n.d Qtr
3rdQtr
4thQtr
lstQtr
2ndQtr
3rdCltr
4thQtr
1st Qtr
2ndQtr
3rdQtr
4thQtr
lstQtr
2n.dQtr
3r.d.Qtr
4thQtr
1st Qtr
2n.d Clt., ...
3r.d .Cltr 4thQtr
lstqtr
2ndQtr
3rdqtr
4thQtr
1st Qtr
2n.d Qtr.
3rdQtr .
4thQtr
lstQtr
2ndQtr
3rd.Qt,
4thQtr
1st Qtr
2nd Qtr.
3r.dQtr
4thQtr
lst.Qtr
2n.d Cltr
3rdQtr
4thQtr
lstQtr .
2ndQtr
3rdQtr
4th Qtr
lstQtr
2nd qtr
3r.d qtr
4th Qtr
lstQtr
2nd qtr
3r.dQtr
4thQtr
lstQtr
2nd Qtr
3rd Qir
TWN-20
Sampling Event
Table9of16
Historic Nitrate, Nitrate+ Nitrite and Cloride Concentrations in Monitor Wells Up to the 3rd Quarter 2023
Nitrate Contamination Investigation
Parameter
GWQS
Nitrate, Nitrate + Nitrite
(10 mg/L)
Parameter
GWQS
White Mesa Uranium Mill
Chloride (mg/I)
NoGWQS
Upper Wildlife Pond
Sampling Event
Parameter
GWQS
Nitrate, Nitrate + Nitrite
(10 mg/L)
8/2010 <0.1
Chloride (mg/I)
NoGWQS
TWN-21
Sampling Event
50 2nd Qtr
Pond no longer ln service
Parameter
GWQS
Nitrate, Nitrate + Nitrite
(10 mg/L)
1.01
NA= Per the CAP and SCO, not sampled
Chloride (mg/I)
NoGWQS
Table 10 of 16 Historic Nitrate, Nitrate+ Nitrite and Cloride Concentrations in Monitor Wells Up to the 3rd Quarter 2023
2ndQtr 6/2/2010 3rd Qtr 7/19/2010 4thQtr 12/10/2010 lstQtr 1/31/2011 2nd Qtr 4/25/2011 3rdQtr 7/25/2011 4thQtr 10/19/2011 lstQtr 1/11/2012 lstQtr 1/10/2012 2nd Qtr 4/20/2012 3rd Qtr I 7/27/2012 4th Qtr ___ 10/17/2012 lstQtr 2/19/2013 2nd Qtr 4/24/2013 3rdQtr 8/28/2013 4th Qtr 10/16/2013
□RC split of Piez-1 lstQtr 1/13/2014 2nd Qtr 5/7/2014 3rdQtr 8/6/2014 4th Qtr 10/8/2014 lstQtr 2/18/2015 2nd Qtr 5/12/2015 3rdQtr 8/26/2015 4thQtr 10/14/2015 lstQtr 2/23/2016 2nd Qtr 5/12/2016 3rdQtr 7/19/2016 4th Qtr 10/11/2016 lstQtr 2/15/2017 2nd Qtr 6/1/2017 3rdQtr 7/20/2017 4th Qtr 10/4/2017 lstQtr 1/17/2018 2nd Qtr 5/9/2018 3rdQtr 8/8/2018 4th Qtr 11/21/2018 lstQtr 2/19/2019 2nd Qtr 5/30/2019 3rd Qtr 8/14/2019 4th Qtr 10/16/2019
OWMRC_duplicate of P-1 lstQtr 1/30/2020 2nd Qtr 5/20/2020 3rdQtr 7/15/2020 4thQtr 11/13/2020 lstQtr 2/18/2021 2ndQtr 5/27/2021 3rd Qtr 8/19/2021 4thQtr 11/23/2021 lstQtr 2/16/2022 2ndQtr 5/24/2022 3rdQtr 8/17/2022 4thQtr 10/25/2022 lstQtr 2/21/2023 2nd Qtr 6/8/2023 3rdQtr 7/19/2023
Parameter
(10 mg/L) 7.2 6.8 6.5 7 6.8 7 6.6 7.1 7.0 6.6 7.2 7.66 8.11 8.88 7.83 6.68 1.3 6.79 7.57 5.1 5.75 6.41 5.95 4.96 6.17 8.31 6.33 6.78 6.42 6.75 6.6 6.8 6.21 6.35 6.56 6.66 6.7 6.72 6.75 6.81 7.21 6.4 7.12 6.95 7.36 7.51 7.34 7.89 7.6 4.69 7.4 5.9 6.37 6.36 5.34 5.9 5.65
DRC = Utah Division of Radiation Control
Nitrate Pumping System Started m January 2013
White Mesa Uranium Mill
NoGWQS 52 2nd Qtr 6/2/2010 52 3rd Qtr 7/19/2010 60 4th Qtr 12/10/2010 60 1st Qtr 1/31/2011 58 2nd Qtr 4/25/2011 53 3rd Qtr 7/25/2011 55 4th Qtr 10/19/2011 78 lstQtr 1/11/2012 114 lstQtr 1/31/2012 58 2nd Qtr 4/20/2012 56 3rd Qtr 7/27/2012 55 4th Qtr 7/17/2012 56.7 lstQtr 2/19/2013 53.3 2nd Qtr 4/24/2013 55.1 3rdQtr 8/28/2013 54.1 4thQtr 10/16/2013
56.2 lstQtr 1/13/2014 52.1 2nd Qtr 5/7/2014 55 3rd Qtr 8/6/2014 57.6 4thQtr 10/8/2014 55.9 lstQtr 2/18/2015 57.5 2nd Qtr 5/12/2015 64.2 3rdQtr 8/6/2015 54.4 4th Qtr 10/14/2015 56.5 lstQtr 2/23/2016 59.1 2nd Qtr 5/12/� 53.9 3r� 7/19/20� 58.1 4th Qtr 10/11/2016 54.5 lstQtr 2/15/2017 54.7 2ndQtr 6/1/2017 58 3rd Qtr 7/20/2017 54.4 4th Qtr 10/4/2017 55.3 1st Qtr 1/17/2018 58 2nd Qtr 5/9/2018 63.5 3rdQtr 8/8/2018 55.5 4th Qtr 11/20/2018 56.8 1st Qtr 2/19/2019 59.4 2ndQtr 5/30/2019 61.1 3rd Qtr 8/14/2019 59.3 4th Qtr 10/16/2019
68.9 1st Qtr 1/30/2020 67.7 2nd Qtr 5/20/2020 63.6 3rd Qtr 7/15/2020 63.9 4th Qtr 11/13/2020 57.5 1st Qtr 2/18/2021 69.9 2ndQtr 5/27/2021 70 3rd Qtr 8/19/2021 65.5 4th Qtr 11/23/2021 68.8 lstQtr 2/16/2022 70.3 2ndQtr 5/24/2022 72 3rd Qtr 8/17/2022 73.6 4thQtr 10/25/2022 50.8 lstQtr 2/21/2023 65.l 2nd Qtr 6/8/2023 70.7 3rdQtr 7/19/2023
. As of March 2012 both north and south wild hfe ponds no longer rece,vmg water __ _
Parameter
(10 mg/L) 0.6 0.6 0.2 0.3 0.3 0.1 0.1 0.1 0.1 0.2 0.2 0.19 0.22 0.172 0.198 0.36 0.27 0.169 0.736 0.8 0.755 0.749 0.646 0.7 0.692 ----------0.615 0.665 0.669 0.732 0.696 0.345 0.555 0.684 0.716 0.776 0.818 0.648 0.599 0.702 0.606 0.573 0.36 0.740 0.679 0.793 0.544 0.401 <0.l 0.11 <0.l 0.330 0.48 0.71 0.703 0.607 0.68 0.74
NoGWQS
8 8 6 9 8 9
8 9 1 8 9 9.5 9.67 10.3 9.66 9.22 11 11.4 11.4 12 12.2 12.5 13.1 15.5 13.3 13.4 14 12.4 13.4 12.4 13.2 13.4 12.7 13.0 14.0 15.1 12.3 12.9 12.6 13.2 12.6 21 14.2 14.4 12.7 12.9 15.7 13.9 14.6 14.8 14.0 12.6 14.7 13.4 9.8 12.8 14.6
Table 11 of 16 Historic Nitrate, Nitrate+ Nitrite and Cloride Concentrations in Monitor Wells Up to the 3rd Quarter 2023
Nitrate Contamination Investigation
ro•vm�«• 3
Sampling Event
lstQtr 2nd Qtr 3rdQtr 4th_Qtr __ lstQtr 2nd Qtr 3rdQtr 4thQtr lstQtr
3/24/2010 6/2/2010 7/19/2010 12/9/2010 1/31/2011 4/25/2011 7/25/2011 10/19/2011 1/11/2012 2nd Qtr 4/20/2012 3rd Qtr I 7/27/2012 4th Qtr ___ 10/17/2012 lstQtr 2/24/2013 2nd Qtr 4/24/2013 3rd Qtr 8/28/2013 4th Qtr 10/16/2013
lstQtr 1/13/2014 12nd Qtr 5/7/2014 l3rdQtr 8/6/2014 14th Qtr 10/8/2014 lstQtr 2/18/2015 12nd Qtr 5/12/2015 l3rdQtr 8/26/2015
Parameter
GWQS
Nitrate, Nitrate + Nitrite (10 mg/L) 1.7 1.6 1.8 1.8 1.8 1.7 1.8 1.7 1.8 1.7 1.8 2.75 1.85 1.83 1.81 1.8 0.33 1.7 1.79 1.7 1.74 1.82 1.75 1.87
White Mesa Uranium Mill
Pizometer 3A Parameter
Sampling Event GWQS
Chloride (mg/I) Nitrate, Nitrate + Nitrite NoGWQS (10 mg/L) 116 36 35 25 40 35 61 12 20 53 21 20.1 21 21.2 22.4 23.5 27 26 23.9 26 28.3 27.3 30.2 54.8
Chloride (mg/I) NoGWQS
14th Qtr 10/14/2015 2.24 39.5 New piezometer P-3A to replace piezometer P-3 drilled and installed in lstQtr 2/23/2016 1.82 27.3 Pizometer-3 abandonded May 2016 (1)2nd Qtr 3rdQtr 4th Qtr lstQtr 2nd Qtr 3rdQtr 4th Qtr ______ lstQtr 2nd Qtr 3rdQtr 4th Qtr lstQtr 2nd Qtr 3rdQtr 4th Qtr
S/12/2016 7/19/2016 10/11/2016 2/15/2017 6/1/2017 7/20/2017 ---10/4/2017 2/17/2018 5/9/2018 8/8/2018 11/20/2018 2/17/2019 5/30/2019 8/14/2019 10/16/2019
DWMRC duplicate of P-3a lstQtr 1/30/2020 2nd Qtr 5/20/2020 3rdQtr 7/15/2020 4th Qtr 11/13/2020 lstQtr 2/18/2021 2nd Qtr S/27/2021 3rdQtr 8/19/2021 4th Qtr 11/23/2021 lstQtr 2/16/2022 2nd Qtr 5/24/2022 3rd Qtr 8/17/2022 4th Qtr 10/25/2022 1st Qtr 2/21/2023 2ndQtr 6/8/2023 3rd Qtr 7/19/2023
1. New piezometer PIEZ-3A to replace PIEZ-3 drilled and mstalled in May 2016. First monitoring event.
Shaded = Nitrate, Nitrate+ Nitrite concentrations greater than the Ground Water Quality Standard of 10 mg/I
DRC = Utah Division of Radiation Control
Nitrate Pumping System Started m January 2013
, As of March 2012 both north and south wild life ponds no longer rece1vmg water. __ _
May 2016. 8.33 109
8.83 93.8 8.44 100 10.0 111 10.1 124 9.31 105 9.65 107 8.61 94.3 9.98 100 12.1 122 11.8 105 11.8 102 11.8 104 10.7 96.2 8.97 83.0 6.4 98.0 10.5 99.5 12.4 88.3 12.8 82.7 13 72.8 11.1 85.9 14.4 85.6 11.2 81.5 9.11 84.6 12.1 91.7 8.8 114.0 10.6 109 11.5 81.5 11.9 60.8 11.9 82.6 12.8 77.3
Table 12 of 16 Historic Nitrate, Nitrate+ Nitrite and Cloride Concentrations in Monitor Wells Up to the 3rd Quarter 2023
Nitrate Contamination Investigation
TW4-19(Pumping well starting in
Apri12003)
Sampling Event
lstQtr 3/16/2005 2nd Qtr 5/25/2005 3rdQtr 8/31/2005 4th Qtr 12/7/2005 lstQtr 3/9/2006 2nd Qtr 6/14/2006 3rdQtr 7/20/2006 4th Qtr 11/8/2006 lstQtr 2/28/2007 2nd Qtr 6/27/2007 3rdQtr 8/15/2007 4th Qtr 10/10/2007 lstQtr 3/28/2008 2nd Qtr 6/25/2008 3rdQtr 9/10/2008 4th Qtr 10/15/2008 lstQtr 3/4/2009 2nd Qtr 6/23/2009 3rdQtr 9/14/2009 4th Qtr 12/22/2009 lstQtr 2/17/2010 2nd Qtr 6/14/2010 3rdQtr 8/16/2010 4th Qtr 10/15/2010 lstQtr 2/17/2011 2nd Qtr 6/7/2011 3rdQtr 8/17/2011 4th Qtr 11/17/2011 1st Qtr ___ 1/23/2012 2nd Qtr 3rd Qtr 4th Qtr lstQtr 2nd Qtr 3rd Qtr 4th Qtr 1st Qtr 2ndQtr 3rd Qtr 4th Qtr 1st Qtr 2ndQtr 3rd Qtr 4th Qtr _____ 1st Qtr 2ndQtr 3rd Qtr 4th Qtr lstQtr 2nd Qtr 3rd Qtr 4th Qtr lstQtr 2nd Qtr 3rdQtr 14th Qtr lstQtr 2nd Qtr 3rd Qtr 14th Qtr 1st Qtr 2nd Qtr
6/6/2012 9/4/2012 10/3/2012 2/13/2013 6/5/2013 9/3/2013 10/29/2013 1/27/2014 5/19/2014 8/11/2014 10/21/2014 3/9/2015 6/8/2015 8/31/2015 10/19/2015 3/9/2016 5/26/2016 7/25/2016 10/13/2016 3/8/2017 6/13/2017 7/26/2017 10/11/2017 3/12/2018 6/8/2018 8/30/2018 11/28/2018 3/8/2019 6/5/2019 9/4/2019 12/10/2019 2/19/2020 5/27/2020
Parameter
GWQS
Nitrate, Nitrate + Nitrite (10 mg/L) 5.3 5.7 4.6 <0.1 4 5.2 4.3 4.6 4
White Mesa Uranium Mill
TW4-20 {Pumping well stating in
August 2005)
Sampling Event
Chloride (mg/I) NoGWQS NA
NA NA 2nd Qtr J 5/25/2005 3rd Qtr 8/31/2005 81 4th Qtr 12/7/2005 86 1st Qtr 3/9/2006 116 2nd Qtr 6/14/2006 123 3rdQtr 7/20/2006 134 4th Qtr 11/8/2006 133 lstQtr 2/28/2007
not sampled 2nd Qtr 6/27/2007 4.1 129 3rd Qtr 8/15/2007 4 132 4th Qtr 10/10/2007 2.2 131 lstQtr 3/28/2008 2.8 128 2nd Qtr 6/25/2008 35.2 113 3rd Qtr 9/10/2008 47.8 124 4th Qtr 10/15/2008 3.2 127 lstQtr 3/4/2009 2.4 132 2nd Qtr 6/23/2009 <0.1 43 3rd Qtr 9/14/2009 26.7 124 4th Qtr 12/22/2009 2 144 lstQtr 2/17/2010 4.4 132 2nd Qtr 6/14/2010 5.9 142 3rdQtr 8/16/2010 2.7 146 4thQtr 10/15/2010 17.0 135 lstQtr 2/17/2011 12.0 148 2nd Qtr 6/7/2011 3.0 148 3rdQtr 8/17/2011 5.0 148 4thQtr 11/17/2011 0.6 138 lstQtr 1/23/2012 --6/6/2012 2.4 149 2nd Qtr 2.5 149 3rdQtr 9/4/2012 4.1 150 4thQtr 10/3/2012 8.0 164 lstQtr 2/13/2013 3.0 148 2nd Qtr 6/5/2013 17.6 179 3rdQtr 9/3/2013 4.7 134 4th Qtr 10/29/2013 1.6 134 lstQtr 1/27/2014 1.3 152 2nd Qtr 5/19/2014 1.6 140 3rd Qtr 8/11/2014 4.7 130 4th Qtr 10/21/2014 8.56 238 1st Qtr 3/9/2015 0.916 180 2nd Qtr 6/8/2015 11.6 326 3rd Qtr 8/31/2015 10.6 252 4th Qtr 10/19/201?_ ------------------15.70 276 1st Qtr 3/9/2016 1.27 204 2ndQtr 5/26/2016 10.5 214 3rd Qtr 7/25/2016 10.0 200 4th Qtr 10/13/2016 11.1 461 lstQtr 3/8/2017 0.243 135 2ndQtr 6/13/2017 1.120 218 3rd Qtr 7/26/2017 0.377 139 4th Qtr 10/11/2017 8.6 193 lstQtr 3/12/2018 0.494 138 2nd Qtr 6/8/2018 2.55 166 3rd Qtr 8/30/2018 0.233 140 4th Qtr 11/28/2018 6.6 197 lstQtr 3/8/2019 6.580 160 2nd Qtr 6/5/2019 0.33 153 3rdQtr 9/4/2019 0.535 147 4th Qtr 12/10/2019 10.1 205 lstQtr 2/19/2020 1.140 147 2nd Qtr 5/27/2020
Parameter
GWQS
Nitrate, Nitrate + Nitrite (10 mg/L)
10.10 2.90 1.80 3.80 9.40 2.90 3.50 4.20 2.30 2.10 5.60 0.90 8.00 4.44 5.51 5.10 2.90 3.30 5.30 2.00 5.60 5.30 4.60 4.40 4.80 6.50 4.20 7.90 11.00 10.80 11.00 9.07 9.80 8.65 9.64 7.56 5.95 4.30 7.67 9.80 5.76 9.3 6.23 10.30 11.2 11.3 11.4 12.0 9.76 10.8 8.91 9.5 10.40 8.14 9.72 6.7 9.59 10.2 9.75 9.81 7.23 3rd Qtr 9/4/2020 11.6 188 TW 4-20 Abandonded October 2020 14th Qtr 12/10/2020 1.1 104 1st Qtr 2/23/2021 6.6 167 2ndQtr 6/9/2021 4.04 115 3rd Qtr 8/24/2021 6.68 172 4th Qtr 12/1/2021 11.l 184 lstQtr 3/9/2022 1.7 119 2ndQtr 6/8/2022 1.4 128 3rdQtr 8/30/2022 4.76 178 4th Qtr 11/30/2022 3.6 129 lstQtr 3/7/2023 1.8 122 2nd Qtr 6/13/2023 6.7 167 3rd Qtr 8/9/2023 1.57 122
Shaded= Nitrate, Nitrate+ N1tnte concentrations greater than the Ground Water Quality Standard of 10 mg/I
, As of March 2012 both north and south wild life ponds no longer receiving water. __ •
, (2)Pumping well stating in August 2005
Chloride (mg/I) NoGWQS
NA NA 131 120 235 134 124 124 112 117 170 132 191 156 168 164 164 153 187 179 200 196 203 220 177 207 186 207 262 289 302 252 250 260 272 254 269 299 292 290 296 365 293 293 318 307 301 290 281 292 293 289 258 282 295 272 279 286 307 310 301
Table 13 of 16 Historic Nitrate, Nitrate+ Nitrite and Cloride Concentrations in Monitor Wells Up to the 3rd Quarter 2023
Nitrate Contamination Investigation White Mesa Uranium Mill
TW4-21 (Pumping well s1arting in Parameter TW4-22 (Pumping well staling in Parameter June2015) August 2005) Sampling Event GWQS Sampling Event GWQS
Nitrate, Nitrate + Nitrite Chloride (mg/I) Nitrate, Nitrate + Nitrite (10 mg/LI NoGWQS (10 mg/L) Chloride (mg/I) NoGWQS lstQtr 3/16/2005 was not sampled 1st Qtr 3/16/2005 was not sampled 2ndQtr 5/25/2005 14.6 NA 2ndQtr 5/25/2005 18.2 3rd Qtr 8/31/2005 10.1 NA 3rd Qtr 8/31/2005 15.7 ;4thQtr 12/7/2005 9.6 353 4th Qtr 12/7/2005 15.1 1st Qtr 3/9/2006 8.5 347 1st Qtr 3/9/2006 15.3 '2nd Qtr 6/14/2006 10.2 318 2ndQtr 6/14/2006 14.3 3rd Qtr 7/20/2006 8.9 357 3rdQtr 7/20/2006 14.5 4th Qtr 11/8/2006 8.7 296 4th Qtr 11/8/2006 15.9 lstQtr 2/28/2007 8.7 306 lstQtr 2/28/2007 20.9 2nd Qtr 6/27/2007 8.6 327 2nd Qtr 6/27/2007 19.3 3rdQtr 8/15/2007 8.6 300 3rdQtr 8/15/2007 19.3 4th Qtr 10/10/2007 8.3 288 4th Qtr 10/10/2007 18.8 lstQtr 3/28/2008 14.3 331 lstQtr 3/28/2008 39.1 2nd Qtr 6/25/2008 8.8 271 2nd Qtr 6/25/2008 41.9 3rdQtr 9/10/2008 7.57 244 3rdQtr 9/10/2008 38.7 4th Qtr 10/15/2008 8.0 284 4th Qtr 10/15/2008 36.3 lstQtr 3/11/2009 8.3 279 lstQtr 3/11/2009 20.7 2nd Qtr 6/23/2009 8.1 291 2nd Qtr 6/23/2009 20.6 3rdQtr 9/14/2009 9.2 281 3rdQtr 9/14/2009 40.3 4th Qtr 12/22/2009 8.4 256 4thQtr 12/29/2009 17.8 ------------------------------lstQtr 2/25/2010 8.4 228 lstQtr 3/3/2010 36.8 2nd Qtr 6/14/2010 12.0 266 2ndQtr 6/14/2010 19.0 3rdQtr 8/13/2010 14.0 278 3rd Qtr 8/24/2010 15.0 �!!'..CJ,�r 10/15/2010 7.0 210 4th Qtr 10/15/2010 16.0 lstQtr 2/22/2011 9.0 303 1st Qtr 2/22/2011 18.0 2ndQtr 6/28/2011 12.0 290 2ndQtr 6/1/2011 17.0 3rd Qtr 8/17/2011 14.0 287 3rd Qtr 8/17/2011 15.0 4th Qtr 11/16/2011 13.0 287 4th Qtr 11/16/2011 19.0 . . ... , ...... (i)lst Qtr 17i§/26i2 !2).!:'!..�-1/19/2012 -5jiji'iciii2ndQtr 3rd Qtr 9/13/2012 4th Qtr 10/4/2012 1st Qtr 2/13/2013 2nd Qtr 6/18/2013 3rd Qtr 9/13/2013 4th Qtr 11/13/2013 lstQtr 2/5/2014 2nd Qtr 5/22/2014 3rdQtr 8/27/2014 4th Qtr 10/29/2014 lstQtr 3/12/2015 l2)2nd Qtr 6/8/2015 -----------3rdQtr 4th Qtr _____ lstQtr 2nd Qtr 3rdQtr 4th Qtr lstQtr 2nd Qtr 3rdQtr 4th Qtr
8/31/2015 10/19/2015 3/9/2016 5/23/2016 7/25/2016 10/12/2016 3/8/2017 6/13/2017 7/26/2017 10/11/2017
OWMRC split TW4-21 lstQtr 3/12/2018 2nd Qtr 6/8/2018 3rdQtr 8/22/2018 4th Qtr 10/22/2018 lstQtr 3/8/2019 2ndQtr 6/5/2019 3rdQtr 9/4/2019 4th Qtr 12/10/2019
lstQtr 2/19/2020 2nd Qtr 5/27/2020 3rdQtr 9/4/2020 4th Qtr 10/28/2020 lstQtr 2/23/2021 2ndQtr 6/9/2021 3rdQtr 8/24/2021 4th Qtr 12/1/2021 lstQtr 3/9/2022 2nd Qtr 6/8/2022 3rdQtr 8/30/2022 4th Qtr 11/30/2022 1st Qtr 3/7/2023 2nd Qtr 6/13/2023 3rd Qtr 8/9/2023
NA= not analyzed
15.0 ------------11.0 13.0 14.0 11.8 13.8 10.3 9.0 11.4 11.5 7.1 10.0 10.9 13.1 �-----------14.7 14.3 ------------------------------14.6 13.1 16.5 13.5 17.7 9.53 18.20 16.90 11.0 15.8 14.1 0.236 15.2 9.0 17.5 14.7 5.73 8.9 15.4 12.6 16.30 15.2 21.5 12.9 17.2 2.2 8.9 14.3 2.1 10.9 17.3 6.13
228 -------285 142 270 221 243 207 206 200 243 230 252 255 494 -------499 413 --------------452 425 457 --439 452 309 447 378 310 447 387 182 378 180 456 478 339 446 353 382 411 454 461 375 227 110 331 425 158 335 397 161
---------2nd Qtr J 6/13/2012 3rd Qtr 9/12/2012 4th Qtr 10/4/2012 ---------(3)1st Qtr 2/11/2013 2nd Qtr 6/5/2013 3rdQtr 9/3/2013 4thQtr 10/29/2013 lstQtr 1/27/2014 2nd Qtr 5/19/2014 3rdQtr 8/11/2014 4th Qtr 10/29/2014 lstQtr 3/9/2015 2nd Qtr 6/8/2015 3rdQtr 8/31/2015 4th Qtr ______ _ 10/19/2015 lstQtr 3/9/2016 2nd Qtr 5/23/2016 3rdQtr 7/25/2016 4th Qtr 10/12/2016 lstQtr 3/8/2017 2nd Qtr 6/13/2017 3rdQtr 7/26/2017 4thQtr 10/11/2017
DWMRC split of TW4-22 lstQtr 3/12/2018 2ndQtr 6/8/2018 3rd Qtr 8/22/2018 4th Qtr 11/28/2018 lstQtr 3/8/2019 2ndQtr 6/5/2019 3rd Qtr 9/4/2019 4th Qtr 12/10/2019 lstQtr 2/19/2020 2ndQtr 5/27/2020 3rd Qtr 9/4/2020 4th Qtr 10/28/2020 1st Qtr 2/23/2021 2ndQtr 6/9/2021 3rdQtr 8/24/2021 4th Qtr 12/1/2021 lstQtr 3/9/2022 2nd Qtr 6/8/2022 3rdQtr 8/30/2022 4thQtr 11/30/2022 lstQtr 3/7/2023 2nd Qtr 6/13/2023 3rdQtr 8/9/2023
(1) As of March 2012 both north and south wild life ponds no longer rece1v1ng water (2) Chloroform pumping well started 6/9115.
(3) Chloroform pumping well started 1126/13
Shaded = Nitrate, Nitrate+ Nitrite concentrations greater than the Ground Water Quality Standard of 10 mg/I
DWMRC = Utah Division of Waste Management and Radiation Control
14.0 ------------12.8 7.0 14.0 ------------58.0 50.2 29.7 45.2 54.6 47.2 41.5 54.9 69.2 47.1 64.7 56.1 ---------------31.1 58.4 61.3 61.5 69.8 70.8 66.1 80.1 79.0 62.3 72.5 55.4 75.7 71.9 83.9 72.5 59.9 57.7 60.5 64.8 64.9 69.6 89.3 35.l 68.8 40.4 45.0 69.9 62.0 49.1 49.8 58.8
NA NA 253 236 221 221 236 347 273 259 23! 511 271 524 539 177 177 391 175 427 134 130 134 114 138 120 174 36 -------35 121 130 -------130 586 487 501 598 614 540 596 675 390 557 567 ---------583 598 � 588 566 572 391 600 610 607 580 613 567 528 662 588 608 606 578 514 523 618 408 410 586 442 564 637 601 562 596 617
Table 14 of 16
Historic Nitrate, Nitrate + Nitrite and Cloride Concentrations in Monitor Wells Up to the 3rd Quarter 2023
Nitrate Contamination Investigation
White Mesa Uranium Mill
January2013)
Sampling Event
2nd Qtr 6/27/2007
3rd Qtr 8/15/2007
4th Qtr 10/10/2007
lstQtr 3/28/2008
2ndQtr 6/25/2008
3rd Qtr 9/10/2008
4th Qtr 10/15/2008
lstQtr 3/4/2009
2nd Qtr 6/23/2009
3rd Qtr 9/14/2009
4th Qtr 12/16/2009
1st Qtr 2/25/2010
2ndQtr 6/14/2010
3rd Qtr 8/24/2010
4th Qtr 10/15/2010
lstQtr 2/17/2011
2ndQtr 5/26/2011
3rd Qtr 8/17/2011
4th Qtr 11/16/2011
1st Qtr _ _ _ 1/16/2012
2ndQtr 6/6/2012
3rd Qtr 8/30/2012
4th Qtr 10/3/2012
lstQtr
2ndQtr 6/5/2013
3rdQtr 8/30/2013
4th Qtr 10/29/2013
lstQtr 1/27/2014
2nd Qtr 5/19/2014
3rdQtr 8/11/2014
4th Qtr 10/21/2014
lstQtr 3/9/2015
2nd Qtr 6/8/2015
3rdQtr 8/31/2015
4th Qtr 10/19/2015
lstQtr 3/9/2016
2nd Qtr 5/23/2016
3rdQtr 7/25/2016
4th Qtr 10/12/2016
1st Qtr 3/8/2017
2nd Qtr 6/13/2017
3rdQtr 7/26/2017
4th Qtr 10/11/2017
OWMRC split ofTW4-24
lstQtr 3/16/2018
2nd Qtr 6/14/2018
3rdQtr 8/22/2018
4thQtr 11/28/2018
lstQtr 3/8/2019
2ndQtr 6/5/2019
3rdQtr 9/4/2019
4th Qtr 12/10/2019
lstQtr 2/19/2020
2nd Qtr 5/27/2020
3rdQtr 9/4/2020
4th Qtr 10/28/2020
lstQtr 2/23/2021
2nd Qtr 6/9/2021
3rdQtr 8/24/2021
4th Qtr 12/1/2021
lstQtr 3/9/2022
2ndQtr 6/8/2022
3rd Qtr 8/30/2022
4th Qtr 11/30/2022
lstQtr 3/7/2023
2ndQtr 6/13/2023
3rd Qtr 8/9/2023
Parameter
GWQS
Nitrate, Nitrate + Nitrite
(10 mg/LI
26.1
29
24.7
24.4
45.3
38.4
44.8
30.S
30.4
30.7
28.3
33.1
30
31
31
31
35
34
35
37
37
37
38
35.9
23.7
33
35
31.6
35.0
31.5
35.7
34.6
31.8
25.3
29.6
29.1
24.2
34.4
31.9
41.3
39.9
40.0
31.7
32.0
44.9
33.6
33.8
38.4
39.3
33.2
36.4
33.8
37.1
41.7
39.1
35.90
41.9
48.0
26.7
43.60
36.2
35.0
32.0
27.6
36.2
35.9
26.2
Chloride (mg/I)
NoGWQS
770
791
692
740
834
1,180
1,130
1,010
759
618
1,080
896
639
587
522
1,100
1,110
967
608
373
355
489
405
916
998
1,030
809
1,020
1,150
1,050
944
1,290
788
909
989
771
1,180
1,010
1,090
1,080
1,230
895
1,100
1,320
792
996
1,100
1,040
1,020
1,130
1,090
1,010
1060
1100
1050
1,170
938
1010
1140
890
944
868
972
932
866
928
As of March 2012 both north and south wild hfe ponds no longer receIvIng water
Chloroform pumping well started January 2013.
TW4-25
January JOU)
Sampling Event
2ndQtr 6/27/2007
3rd Qtr 8/15/2007
4th Qtr 10/10/2007
lstQtr 3/28/2008
2ndQtr 6/25/2008
3rd Qtr 9/10/2008
4th Qtr 10/15/2008
lstQtr 3/4/2009
2ndQtr 6/23/2009
3rdQtr 9/14/2009
4th Qtr 12/14/2009_
lstQtr 2/23/2010
2nd Qtr 6/14/2010
3rdQtr 8/10/2010
4th Qtr 10/15/2010
1st Qtr 2/16/2011
2nd Qtr 5/25/2011
3rdQtr 8/16/2011
4th Qtr 11/15/2011
lstQtr 1/16/2012
2ndQtr 5/31/2012
3rdQtr 9/4/2012
4thQtr 10/3/2012
lstQtr 27ii]2013
(2)2nd Qtr 6/5/2013
3rdQtr 9/4/2013
4thQtr 10/31/2013
lstQtr 1/27/2014
2nd Qtr 5/19/2014
3rdQtr 8/11/2014
4th Qtr 10/21/2014
lstQtr 3/9/2015
2nd Qtr 6/8/2015
3rdQtr 8/31/2015
4th Qtr 10/19/2015
DWMRC split of TW4-25
lstQtr 3/9/2016
2ndQtr 5/23/2016
3rdQtr 7/25/2016
4thQtr 10/12/2016
lstQtr 3/8/2017
2nd Qtr 6/13/2017
3rd Qtr 7/26/2017
4th Qtr 10/11/2017
lstQtr 3/12/2018
2nd Qtr 6/14/2018
3rdQtr 8/22/2018
4th Qtr 11/28/2018
lstQtr 3/8/2019
2nd Qtr 6/5/2019
3rdQtr 9/4/2019
4th Qtr 12/10/2019
lstQtr 2/19/2020
2nd Qtr 5/27/2020
3rdQtr 9/4/2020
4th Qtr 10/28/2020
lstQtr 2/23/2021
2nd Qtr 6/9/2021
3rdQtr 8/24/2021
4th Qtr 12/1/2021
lstQtr 3/9/2022
2nd Qtr 6/8/2022
3rdQtr 8/30/2022
4th Qtr 11/30/2022
1st Qtr 3/7/2023
2ndQtr 6/13/2023
3rd Qtr 8/9/2023
Shaded = Nitrate, Nitrate+ Nitrite concentrations greater than the Ground Water Quality Standard of 10 mg/I
DWMRC = Utah Division of Waste Management and Radiation Control
Parameter
GWQS
Nitrate, Nitrate + Nitrite
(10 mg/L)
17.1
29
17
18.7
22.1
18.8
21.3
15.3
15.3
3.3
14.2
14.4
16
14
15
15
16
16
16
16
16
17
17
9.04
5.24
5.69
6.1
2.16
1.21
1.6
1.03
14.4
1.14
1.63
1.78
1.50
0.837
0.959
1.78
1.24
17.0
0.976
1.23
1.29
2.23
1.14
0.810
0.634
0.639
0.821
0.548
0.841
0.607
0.851
0.994
1.6
3.43
1.57
0.793
0.978
1.8
0.88
1.51
1.47
1.96
1.03
0.79
Chloride (mg/I)
NoGWQS
395
382
358
374
344
333
366
332
328
328
371
296
306
250
312
315
321
276
294
304
287
334
338
190
136
119
88.6
85.7
51.1
67
58.1
310
58.3
69.2
93.7
94
62.7
75.S
74.1
59.8
285
69.8
70.1
68.0
70.S
60.3
69.1
59.70
65.0
59.0
58.1
73.10
86.0
76.8
67.3
61.3
100.0
55.1
69.3
93.7
70.3
72.8
82.5
67.2
96.7
73
79.9
Table 15 of 16
Historic Nitrate, Nitrate+ Nitrite and Cloride Concentrations in Monitor Wells Up to the 3rd Quarter 2023
Nitrate Contamination Investigation
White Mesa Uranium Mill
TW4-37(Pumping well starting 1n Parameter June2015)
Sampling Event GWQS
Nitrate, Nitrate + Nitrite Chloride (mg/I)
(10 mg/LI NoGWQS
2ndQtr 6/8/2015 35.2 345
3rd Qtr 8/31/2015 32.4 374
4th Qtr 10/19/2015 34.6 399 --------------------------lstQtr 3/9/2016 28.4 332
2ndQtr I 5/23/2016 27.9 389
3rd Qtr 7/25/2016 33.4 294
4th Qtr 10/12/2016 26.1 304
lstQtr 3/8/2017 32.3 305
2ndQtr 6/15/2017 31.2 281
3rdQtr 7/26/2017 30.5 277
4th Qtr 10/11/2017 30.6 255
lstQtr 3/12/2018 30.0 263
2nd Qtr 6/8/2018 28.6 275
3rdQtr 8/22/2018 25.3 387
4thQtr 11/28/2018 27.3 264
lstQtr 3/8/2018 30.1 209
2nd Qtr 6/5/2019 31.2 250
3rdQtr 9/4/2019 25.8 228
4th Qtr 12/10/2019 25.5 220
lstQtr 2/19/2020 28.3 236
2nd Qtr 5/27/2020 28.3 321
3rdQtr 9/4/2020 29.5 273
4thQtr 10/28/2020 28.7 254
lstQtr 2/23/2021 26.9 242
2nd Qtr 6/9/2021 26.6 176
3rdQtr 8/24/2021 25.8 220
4thQtr 12/1/2021 31.3 410
lstQtr 3/9/2022 29.8 414
2ndQtr 6/8/2022 28.0 276
3rdQtr 8/30/2022 26.6 243
4thQtr 11/30/2022 30.9 578
lstQtr 3/7/2023 19.1 209
2ndQtr 6/13/2023 35.9 329
3rdQtr 8/9/2023 25.1 252
Shaded = Nitrate, Nitrate+ N1tnte concentrations greater than the Ground Water Quahty Standard of 10 mg/I
MW-30
Table 16 of 16
Historic Nitrate, Nitrate+ Nitrite and Cloride Concentrations in Monitor Wells Up to the 3rd Quarter 2023
Nitrate Contamination Investigation
White Mesa Uranium Mill
Parameter MW-31 Parameter
Sampling Event GWQS Sampling Event GWQS
Nitrate, Nitrate + Nitrite Chloride (mg/I) Nitrate, Nitrate + Nitrite
(10 mg/LI NoGWQS (10 mg/LI
2ndQtr 6/22/2005 12.4 125 2ndQtr 6/22/2005 24.2
3rd Qtr 9/22/2005 12.8 125 3rd Qtr 9/22/2005 22.4
4th Qtr 12/14/2005 13.6 128 4th Qtr 12/14/2005 23.8
lstQtr 3/22/2006 13.8 125 lstQtr 3/22/2006 24.1
2ndQtr 6/21/2006 14.5 124 2ndQtr 6/21/2006 25.3
3rd Qtr 9/13/2006 14.1 118 3rd Qtr 9/13/2006 24.6
4th Qtr 10/25/2006 14.6 124 4th Qtr 10/25/2006 25.1
lstQtr 3/15/2007 14.4 125 lstQtr 3/15/2007 23.2
Chloride (mg/I)
NoGWQS
139
136
135
133
138
131
127
132
2nd Qtr 2007 not sampled 2nd Qtr 2007 not sampled
3rd Qtr 8/22/2007 14.6 126 3rd Qtr 8/22/2007 23.3 136
4th Qtr 10/24/2007 14.9 122 4th Qtr 10/24/2007 24.6 122
lstQtr 3/19/2008 14.8 118 lstQtr 3/19/2008 25 124
2nd Qtr 6/3/2008 18.7 125 2nd Qtr 6/3/2008 29.3 128
3rd Qtr 8/4/2008 17.3 121 3rdQtr 8/4/2008 28.7 124
4th Qtr 11/5/2008 15.6 162 4th Qtr 11/5/2008 29.9 119
lstQtr 2/3/2009 15.3 113 lstQtr 2/3/2009 23.4 115
2nd Qtr 5/13/2009 15.1 122 2nd Qtr 5/13/2009 22.4 124
3rdQtr 8/24/2009 20.9 118 3rdQtr 8/24/2009 15.4 122
4th Qtr 10/14/2009 15.0 129 4th Qtr 10/14/2009 22.6 138
lstQtr 2/9/2010 16.1 127 lstQtr 2/9/2010 21.7 128
2nd Qtr 4/27/2010 15.8 97 2nd Qtr 5/21/2010 23 128
3rd Qtr 9/14/2010 15.0 111 3rd Qtr 9/13/2010 21 139
4th Qtr 12/14/2010 16.0 126 4th Qtr 11/9/2010 20 138
lstQtr 2/1/2011 16.0 134 lstQtr 2/1/2011 21 145
2nd Qtr 6/20/2011 16.0 124 2nd Qtr 6/20/2011 22 145
3rd Qtr 9/7/2011 17.0 127 3rd Qtr 9/7/2011 21 148
4th Qtr 12/12/2011 16.0 124 4th Qtr 12/12/2011 21 148
lstQtr 3/14/2012 18.0 128 lstQtr 3/13/2012 22 152
2nd Qtr 6/18/2012 15 131 2nd Qtr 6/18/2012 21.6 138
3rd Qtr 9/19/2012 16 130 3rdQtr 9/18/2012 21 172
4th Qtr 12/26/2012 17.2 122 4th Qtr 12/18/2012 22.2 170
lstQtr 2/26/2013 21.4 129 lstQtr 2/19/2013 19.3 174
2nd Qtr 5/15/2013 18.8 119 2nd Qtr 5/13/2013 23.8 169
3rdQtr 7/10/2013 17.6 130 3rdQtr 7/9/2013 21.7 182
4th Qtr 11/20/2013 19.5 124 4th Qtr 11/18/2013 23.9 174
lstQtr 2/25/2014 18.4 135 lstQtr 2/17/2014 20.6 197
2nd Qtr 6/3/2014 19.5 128 2nd Qtr 6/3/2014 23.1 173
3rdQtr 9/9/2014 16.8 139 3rdQtr 9/3/2014 18.9 210
4th Qtr 11/10/2014 16.2 154 4th Qtr 11/4/2014 20.9 204
lstQtr 2/4/2015 14.9 136 lstQtr 2/2/2015 18.7 211
2nd Qtr 4/8/2015 17 142 2nd Qtr 4/7/2015 19 211
3rdQtr 8/11/2015 17.9 165 3rd Qtr 8/10/2015 19.9 264
4th Qtr 11/11/2015 16.3 140 4th Qtr 11/9/2015 18.4 215
lstQtr 2/10/2016 20 145 lstQtr 2/10/2016 18.8 246
2nd Qtr 5/4/2016 17.3 139 2nd Qtr 5/3/2016 18.6 243
3rd Qtr 8/18/2016 18 150 3rd Qtr 8/16/2016 19.7 272
4th Qtr 11/3/2016 18 143 4th Qtr 11/1/2016 19.8 267
lstQtr 2/2/2017 17.4 150 1st Qtr 2/7/2017 21.l 266
2nd Qtr 4/5/2017 18.3 146 2nd Qtr 5/1/2017 18.3 263
3rd Qtr 8/14/2017 19.2 173 3rd Qtr 8/14/2017 19.5 310
4th Qtr 11/1/2017 17.4 156 4th Qtr 11/1/2017 19 292
1st Qtr 2/22/2018 17.6 158 1st Qtr 2/20/2018 18.8 292
2ndQtr 4/12/2018 17.3 145 2ndQtr 4/17/2018 19 308
3rd Qtr 9/11/2018 18 183 3rd Qtr 9/10/2018 20.1 333
�!� _ _!?.tr 10/22/2018 17.2 140 4th Qtr 10/24/2018 18.3 286 ----------------------
1st Qtr 2/13/2019 18.2 167 lstQtr 2/12/2019 18.6 296
2ndQtr 4/10/2019 18.5 138 2ndQtr 4/10/2019 19.7 294
3rd Qtr 7/16/2019 19.3 181 3rd Qtr 7/16/2019 19.8 374
4th Qtr 10/8/2019 18.2 170 4th Qtr 10/9/2019 19.8 318
lstQtr 1/15/2020 16.4 182 lstQtr 1/15/2020 17.5 381
2nd Qtr 4/6/2020 18.1 195 2nd Qtr 4/6/2020 18.8 376
3rd Qtr 7/6/2020 18.4 185 3rd Qtr 7/7/2020 19.2 370
4thQtr 12/8/2020 12 166 4th Qtr 12/7/2020 18.8 311
lstQtr 3/8/2021 17 192 lstQtr 3/9/2021 17.4 388
2nd Qtr 4/14/2021 17.7 162 2nd Qtr 4/13/2021 18.6 377
3rdQtr 7/29/2021 20.6 188 3rdQtr 7/27/2021 18.7 391
4th Qtr 10/19/2021 14.3 182 4th Qtr 10/19/2021 18.1 371
1st Qtr 1/17/2022 14.5 181 1st Qtr 1/19/2022 18.0 370
2nd Qtr 4/20/2022 17.0 173 2ndQtr 4/11/2022 18.0 372
3rd Qtr 7/12/2022 17.6 108 3rd Qtr 7/12/2022 16.9 421
4th Qtr 10/13/2022 17.9 195 4th Qtr 10/11/2022 17 397
1st Qtr 1/25/2023 18.l 166 1st Qtr 1/24/2023 18.7 333
2ndQtr 4/26/2023 15.9 202 2ndQtr 4/24/2023 14.3 297
3rd Qtr 7/11/2023 16.6 205 3rd Qtr 7/10/2023 16.6 429
Shaded= Nitrate, Nitrate+ Nitrite concentrations greater than the Ground Water Quality Standard of 10 mg/I
Table 2
Summary of QA/QC Duplicate Sample
3rd Quarter 2023
Parameter GWQS Duplicate of TWN-18
TWN-18 TWN-65
Nitrate + Nitrite ( as�
Chloride
10 mg/L
none
<0.1
38.1
NC= Not Analyzed
0.129
35.5
RPO
NC
7.1
Data Discriptions
MW4 MW-26 TW4-1 TW4-2
Nitrate (mg/L) 3.90 0.324 3.83 3.23
Nitrate <�i�i ....... I······ 3.90E-03 3.24E-04 3.83E-03 3.23E-03 .... Nitriite (lbs/�) 8.62E-06 7.16E-07 8.46E-06 7.14E-06 .... f\litrate (lbs/giil) 3.26E-05 2.71E-06 3.20E-05 2.70E-05 .... }'ota.I gaUon�pumped 95944.3 26841.5, 8419.4 11513.8 ...... lbs of nitrate removed 3.13 0.07 0.27 0.31
Gallons of nitrate removed ..... ....... 0.25 0.01 0.02 0.03
Total lbs nitrate removed from all pumping wells
Total lbs nitrate removed from nitrate p umping wells
Tabel 3
DWMRC Nitrate Mass Removal Calculations
Energy Fuels Resorses Inc. White Mesa Mill, Bland, Utah
3rd Quarter 2023
Chloroform Pumping Wells
TW4-4 TW4-11 TW4-19 TW4-21 TW4-37
6.08 6.05 1.57 6.13 25.1 I 6.08E-03 6.05E-03 1.57E-03 6.13E-03 2.51E-02 I·· ..... 1.34E-05 1.34E-05 3.47E-06 1.35E-05 5.55E-05
5.08E-05 5.06E-05 1.31E-05 5.13E-05 2.10E-04
TW4-39
5.01
5.01E-03
1.11E-05
4.19E-05 I··· ...... .... ... 8580.2 1277.7 104098.2 89276.6 46548.5 34299.4 ..... I···· ........ 0.44 0.06 1.37 4.58 9.77 1.44 , . ...... ... 0.04 0.01 0.11 0.37 0.80 0.12
49.53
26.91
Nitrate Pumpina Wells
TW4-40 TW4-41 TWN-2 TW4-22 ntV4-24 TW4-25
1.88 5.59 14.0 58,�,. 26.2 0.79 ........... 1.88E-03 5.59E-03 1.40E-02 I 5.88E-02 . .... 2.62E-02 7.90E-04
4.15E-06 1.24E-05 3.09E-05 1.30E-04 5.79E-05 1.75E-06 ..... 1.57E-05 4.67E-05 1.17E-04 4.92E-04 2.19E-04 6.61E-06
43550.1 ....... 10780.6 ... 17,74�.7 23422.7 57213.1 117564.3 , .. 0.7 0.50 2.08 11.52 12.54 0.78 ' ' 0.06 0.04 0.17 0.94 1.02 0.06