DRC-2023-072002 - 0901a068812739a3

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 f R, b 1;: /4o z)
Dean Henderson M 1 / 1 / -,__,,z:._ �September 1, 2023
Review of the May 4, 2023 1st Quarter 2023 Nitrate Monitoring Report (DRC-2023-004226) 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 May 4, 2023, 1st Quarter, 2023 White Mesa Uranium Mill Nitrate Monitoring Report ("Report") for theNitrate 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 1st quarter Nitrate Monitoring Report for the Nitrate Contamination Investigationto be submitted to Division on or before June 1, of each year. The Report was received by the Division
on May 11, 2023 (date of Report May 4, 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.utah.gov Printed on I 00% recycled paper
DRC-2023-072002
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 1st 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 investigationwells.•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 HydrologicInvestigation.
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, andwater temperature only after recovery:
Wells: TWN-3, TWN-7, TWN-20, and TWN-21
3.Continuously Pumped Wells that are considered sufficiently evacuated to immediatelycollect 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 except for nitrate (see Table 2 below). Nitrate concentrations in TWN-18 and TWN-65 were 0.253 mg/Land 0.184 mg/L respectively and have a calculated relative percent difference (RPD) of 31.6%. Because these nitrate concentrations are well below the nitrate GWQS of 10 mg/L and just above the laboratory detection limit for nitrate of 0.1 mg/L exceeding the 20% acceptance limit is not a concern at this time and the data is considered acceptable.
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 57 lbs. of nitrate were removed from the chloroform pumping wells (MW-4, MW-26, TW4-l, 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 57 lbs. removed, approximately 35 lbs. were removed by the nitrate pumping wells (see Table 3below).
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 decontaminationprocedures;iii.Identification of all quality assurance samples, e.g. equipment blanksduplicate samples, etc.
c)Data Interpretation:
1.Interpretation of groundwater levels, gradients, and flow directions. The interpretation willinclude a discussion on: 1) current site groundwater contour map, 2) hydrographs to showgroundwater elevation in each monitor well over time, 3) depth to groundwater measured andgroundwater elevation from each monitor well summarized in data table that includes historicgroundwater level data for each well, 4) calculations documenting quarterly nitrate massremoved by pumping;
Page 4 11.Interpretation of all analytical results for each well including a discussion on: 1) a currentnitrate isoconcentration map, 2) graphs showing nitrate concentration trends in each wellthrough time and, analytical results for each well summarized in data table that includeshistoric analytical results for each well; andiii.An electronic copy of all laboratory results for groundwater quality monitoring conductedduring 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.
Based on water level data, groundwater contour, and capture zone maps in the it appears that up-gradient of pumping wells TW4-19, TW4-22, TW4-24, TW4-37, and TW4-39 the nitrate plume appears to being captured.
Conclusions on Compliance with the CAP, QAP
Per the Division review it appears that the 1st 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 1st Quarter 2023 Nitrate Contamination Investigation White Mesa Uranium Mill
TWN-1 Parameter TWN-2 (Pumpinawellsurtinarn
Sampling Event GWQS Nitrate, Nitrate + Nitrite (10 mg/L)
lstQtr 3/17/2010 0.50 2nd Qtr 5/26/2010 0.6 3rd Qtr 9/27/2010 0.6 4th Qtr 12/7/2010 0.6 1st Qtr 1/26/2011 0.5 2nd Qtr 4/20/2011 0.5 3rd Qtr 7/26/2011 0.5 4th Qtr 10/17/2011 0.5 lstQtr 1/9/2012 0.6 2nd Qtr 4/18/2012 0.6 37io.tr-------------------
4thQtr -----7/24/201� 0.6 10/17/2012 ----------0.43
lstQtr 2/18/2013 0.68 2nd Qtr 4/23/2013 0.84 3rd Qtr 8/27/2013 1.24 4th Qtr 10/16/2013 1.61
TWN-65 duplicat ofTWN-1 1.48
ORC split ofTWN-1 1.6
ORC duplicate ofTWN-1 0.22 lstQtr I 1/14/2014 1.47 2nd Qtr 5/6/2014 1.63 3rd Qtr 8/5/2014 1.7
TWN-65 duplicate of TWN-1 1.4 4th Qtr I 10/8/2014 1.46 1st Qtr I 2/18/2015 1.37
TWN-65 dup of TWN-1 1.41 2nd Qtr 5/13/2015 0.65 3rd Qtr 8/25/2015 0.624
4thQtr 10/13/2015 1.35 lstQtr 2/23/2016 1.51 2nd Qtr 5/17/2016 1.73 3rd Qtr 7/20/2016 1.76 4th Qtr 10/6/2016 1.98
lstQtr 2/15/2017 2.06
TWN-65 duplicate ofTWN-1 1.98 2nd Qtr I 6/1/2017 1.89
TWN-65 duplicate ofTWN-1 1.88 3rd Qtr I 7/19/2017 2.07
TWN-65 duplicate ofTWN-1 1.89 4th Qtr I 10/4/2017 1.95
TWN-65 duplicate of TWN-1 1.99 lstQtr 1/18/2018 1.86 2nd Qtr 5/8/2018 1.89 3rd Qtr 8/8/2018 1.97
4thQtr 11/20/2018 1.98 lstQtr 2/20/2019 2.1 2nd Qtr 5/29/2019 1.93 3rd Qtr 8/14/2019 2.15 4thQtr 10/16/2019 2.35
OWMRC split ofTWN-1 2.1 lstQtr 1/29/2020 2.24 2nd Qtr 5/20/2020 2.24 3rd Qtr 7/15/2020 2.36 4thQtr 11/12/2020 1.89 lstQtr 2/17/2021 2.53 2nd Qtr 5/25/2021 3.18 3rd Qtr 8/18/2021 2.47 4th Qtr 11/23/2021 1.91
lstQtr 2/15/2022 3.01 2nd Qtr 5/24/2022 2.1 3rd Qtr 8/17/2022 2.94 4th Qtr 10/25/2022 2.75 lstQtr 2/21/2023 1.96
JiinUilry2013)
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 lstQtr 2/1/2011 19 2nd Qtr 4/28/2011 14 3rd Qtr 7/28/2011 10 4th Qtr 10/20/2011 15 lstQtr 1/12/2012 17 2nd Qtr 4/20/2012 �-------------'ii31/2012 17 3rd Qtr 17.5 4�9,1!:__ 7/17/2012 --------ii19/2013 17.6 lstQtr 17.4 2nd Qtr 4/24/2013
24.1 3rd Qtr 8/27/2013 26.8 4th Qtr 7/16/2013 27.1 DRC split ofTWN-2 30 30 29.2 lstQtr 1/13/2014 31.l 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 3rd Qtr 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 3rd Qtr 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 3rd Qtr 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 3rd Qtr 8/8/2018 28.9 4th Qtr 11/20/2018 31.4 lstQtr 2/20/2019 32.6 2nd Qtr 5/29/2019 30.3 3rd Qtr 8/14/2019 32.0 4th Qtr 10/16/2019 31.0 DWMRC split of TWN-2 33.8 lstQtr 1/29/2020 33.0 2nd Qtr 5/20/2020
30.8 3rd Qtr 7/15/2020 29.2 4th Qtr 11/12/2020
34.l lstQtr 2/18/2021 34.7 2nd Qtr 5/25/2021 35.7 3rd Qtr 8/18/2021 37.4 4th Qtr 11/23/2021 35.6 lstQtr 2/15/2022 33.7 2nd Qtr 5/24/2022 36.7 3rd Qtr 8/17/2022 30.1 4th Qtr 10/25/2022 30.8 lstQtr 2/21/2023
Shaded= Nitrate, Nitrate+ Nitrite concentrations greater than the Ground Water Quality Standard of 10 mg/I
DRC = Utah Division or Radiation Control.
OWMRC = Utah Division of Waste Management and Radiation Control
Nitrate Pumping System Started in January 2013
As of March 2012 both north and south wild hfe ponds no longer rece1v1ng water,
Parameter
GWQS Nitrate, Nitrate + Nitrite Chloride (mg/I) (10 mg/L) NoGWQS 62 85 69 97 69 104 48 93 43 93 40 85 33 74 33 76 31 SE 48 103 ------------�------__________ 2:.�L _____ ;: 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 25.0 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 59.6 17.2 55.6
12 53.5 15.4 61.8 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
Table 2 of 16 Historic Nitrate, Nitrate + Nitrite and Cloride Concentrations in Monitor Wells Up to the 1st Quarter 2023 Nitrate Contamination Investigation
IWN-3 Parameter
Sampling Event GWQS
Nitrate, Nitrate + Nitrite (10 mg/L) lstQtr 3/25/2010 25.3 2nd Qtr 6/3/2010 26 3rd Qtr 7/16/2010 27 4th Qtr 12/10/2010 24 lstQtr 2/1/2011 24 2nd Qtr 4/28/2011 26 3rd Qtr 7/29/2011 25 4th Qtr 10/20/2011 25 lstQtr 1/12/2012 25 2nd Qtr _ 4/20/2012 -----------24-----3rd Qtr 7/31/2012 27 4thQtr _12/l! !3':Yl 12.1 -----------------lstQtr 2/19/2013 22.2 2nd Qtr 4/24/2013 27.2 13rd Qtr 8/28/2013 20.9 l4thQtr 10/17/2013 23.5 lstQtr 1/15/2014 19.6 12nd Qtr 5/7/2014 23.6 3rd Qtr 8/6/2014 19.5 4th Qtr 10/9/2014 19.l lstQtr 2/19/2015 19.4 2nd Qtr 5/14/2015 17.2 3rd Qtr 8/26/2015 16.2 4th Qtr 10/14/2015 16.3 -----------------------------------lstQtr 2/24/2016 16.8 2nd Qtr 5/18/2016 13.5 3rd Qtr 7/20/2016 16.8 4th Qtr 10/7/2016 15.8 lstQtr 2/16/2017 17.4 2nd Qtr 6/2/2017 15.9 3rd Qtr 7/20/2017 15.9 4th Qtr 101y2011 15.6 lstQtr 1/19/2018 14.4 2nd Qtr 5/9/2018 16.4 3rd Qtr 8/9/2018 19.4 4th Qtr 1112112018 I 20 11 lstQtr 2/21/2019 20.7 2nd Qtr 5/30/2019 18.7 3rd Qtr 8/15/2019 19.8 4thQtr 10/17/2019 19.6
OWMRC split ofTWN-3 17.0
lstQtr I 1/30/202�1 19�1 2nd Qtr 5/21/2020 24 3rd Qtr I 7/15/20201 22.21 4th Qtr 11/13/2020 18 lstQtr 2/18/2021 23.8 2nd Qtr 5/27/2021 25 3rd Qtr 8/19/2021 24.3 4th Qtr 11/24/2021 17.4 1st Qtr 2/16/2022 25.3 2nd Qtr 5/25/2022 24 3rd Qtr 8/18/2022 28.2 4thQtr 10/26/2022 26 lstQtr 2/22/2023 28
White Mesa Uranium Mill
Chloride (mg/I) NoGWQS 111 118 106 117 138 128 134 129 143 152 -------158 149 -------157 158 171 163 160 168 174 153 164 141 156 129 ---------------------128 116 110 113 113 108 106 111 107 115 149 123 140 137 133 126 130
156 136 130 137 145 156 146 147 140 157 163 156 109.0
TWN-4 Sampling Event
lstQtr 3/16/2010 2nd Qtr 5/27/2010 3rd Qtr 9/27/2010 4th Qtr 12/8/2010 lstQtr 1/25/2011 2nd Qtr 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 oflWN-4 !th Qtr _ 1 _ 7/15/2012 1st Qtr 2/18/2013
TWN-65 duplicate ofTWN-4 2nd Qtr I 4/23/2013 3rd Qtr 8/27/2013
TWN-65 duplicate ofTWN-4 4thQtr I 7/16/2013
TWN-65 duplicate ofTWN-4 lstQtr I 1/14/2014
TWN-65 duplicate oflWN-4 2nd Qtr I 5t612014
TWN-6S duplicate of TWN-4 3rd Qtr 8/5/2014 4th Qtr 10/8/2014 lstQtr 2/18/2015 2nd Qtr 5/13/2015 3rd Qtr 8/25/2015
TWN-65 duplicate of TWN-4 4thQtr I 10/13/2015
TWN-65 duplicate of TWN-4 lstQtr 2/23/2016 2nd Qtr 5/17/2016 3rd Qtr 7/20/2016 4thQtr 10/6/2016 lstQtr 2/15/2017 2nd Qtr 6/1/2017 3rd Qtr 7/19/2017 4thQtr 10/4/2017 lstQtr 1/18/2018 2nd Qtr 5/9/2018 3rd Qtr 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 3rd Qtr 8/14/2019 4th Qtr 10/16/2019
TWN-65 duplicate ofTWN-4
OWMRC split ofTWN-4
TW4-40 OWMRC duplicate of TWN-
4 lstQtr I 1/29/2020 2nd Qtr 5/20/2020
TWN-65 duplicate of TWN-4 3rd Qtr I 7/15/2020
TWN-65 duplicate ofTWN-4 4thQtr 11/12/2020 lstQtr 2/17/2021 2nd Qtr 5/25/2021 3rd Qtr 8/18/2021 4thQtr 11/23/2021
TWN-65 duplicate ofTWN-4 lstQtr 2/16/2021 2nd Qtr 5/25/2022 3rd Qtr 8/18/2022 4thQtr 10/25/2022 lstQtr 2/21/2023
Shaded= Nitrate, Nitrate+ Nitrite concentrations greater than the Ground Water Quality Standard of 10 mg/I
Nitrate Pumping System Started in January 2013
As of March 2012 both north and south wild hfe ponds no longer rece1v1ng water.
Parameter
GWQS
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 ------------1.5 1.5 1.63 1.6 1.57 1.69 0.22 1.41 1.33 1.55 1.54 2.0 1.44 1.48 0.733 0.974 1.160 1.58 1.45 -----2.02 2.97 3.14 3.09 2.63 2.4 2.35 2.27 2.63 1.9 1.54 1.51 1.48 1.51 1.53 1.5 1.81 2.15 2.15 1.9 1.9 1.89 1.75 1.71 1.75 1.73 1.18 1.64 1.70 1.28 1.18 1.02 1.5 1.20 1.39 1.31 0.904
Chloride (mg/I) NoGWQS 22 22 19 21 21 21 35 20 20 24 --------24 25 26 26.4 --------25.3 25.9 24.4 27.2 29.0 29.4 32 28.4 26.4 29.6 26.6 28 30.7 31.5 31.9 35.2 35.2 28.4 25.6 30.7 31.7 28.0 31.3 31.2 28.6 28.0 27.4 31.2 27.7 28 27.6 22.7 23.2 25.3 26.5 23.7 25.4 24.7 26.0 26.0 27.2 25.1 25.4 23.1 23.1 22.8 24.2 23.2 23.7 23.2 23.2 22.7 20.9 21.6 21.2 12.2
Table3 of 16 Historic Nitrate, Nitrate+ Nitrite and Cloride Concentrations in Monitor Wells Up to the 1st Quarter 2023 Nitrate Contamination Investigation
TWN-5 Sampling Event Parameter GWQS
White Mesa Uranium MIii
TWN-6 Sampling Event Parameter GWQS Nitrate, Nitrate + Nitrite (10 mg/L) Chloride (mg/I) Nitrate, Nitrate+ Nitrite Chloride (mg/I) No GWQS (10 mg/L) No GWQS 1st Qtr . 0.3 .. 43 1st Qtr 3/23/2010 19 2nd Qtr 5/26/2010 0.3 .... 4'I 2nd Qtr 6/1/2010 · 1.4 22 3rd Qtr . ·· · · 1jii/£0.3 ... 4.3 3rd Qtr 7/13/2010 1.4 73
4th Qtr =-;--------o_._3t-____ 4_5-14th Qtr 12/7/20101---------=+-----"-21CJ1 1st Qtr 0.4 47. 1st Qtr 1/26/2011 18 2.n.d. qtr . 0.3 .. 44 2nd Qtr 4/20/2011 . 22 3rd qtr 7/26/2011 0.3 ... 4:4 3rd Qtr 7/27/2011 17
4th Qtr 45 4th Qtr 10/18/2011,_ ________ _,__ _____ 2__.1, ��. ..��® ��u 20 2nd qtr ... .39 2nd Qtr 4/18/2012 3rdqtr .. 7/24/2012 0.3 .. 4.8 3rd Qtr 7/25/2012
,e4_th_Q�tr __ · ·_1�0/_i�S/�2_0_12..,·· ,_<_o:_1_· ·-------�----4_3_.5-+-4t_h_Q_t _r -��7/15/2012 1st qtr 2013 NA ......... 1st qtr 2013 NA
1�2_nc.c.d_Q�tr ____ -'2'-'0_13�N_A ____ ...,.... ________ ---1?ndCltr?013 .. TWN-5 aband oned on July 31, 2013 3r.d .Qtr .2.013. 4th Qtr 2013
NA= Per the CAP and SCO, not sampled
1st qt.r. 2014 ... 2nd Qtr 2014 3rd Qtr 2014
4th Qtr 2014 1st Qtr 2015 2nd Qtr 2015 3rd Qtr 2015 4th Qtr 2015 }stqtr2016 2.n.d Qtr201!; ?'d Qtr .2.0.16 .. 4th Qtr 2016 1st Cltr .2.0.17 .. 2ndO,tr.2017 .. . 3.rd ctt.r.20.11 .. . 4th Qtr 2017 1st Qtr 2018
3rd(),tr2018
lst Qtr 2019 2nd Qtr 2019 ... 3r.d. qtr 2019. 4th Qtr 2019 1st Qtr 2020 .. . 2.n d (),tr 20.20.
NA
NA NA
NA
NA
3r.d Qtr 2.0.20.. NA
4th Qtr 2020 NA 1st Qtr 2021 •........................ ,.NA 2nd. Qtr .2021... NA 3r� Qtr20?1 NA 4th Qtr 2021 1st Cltr 2022 . 2.n.d Cl.tr 202.2 ... 3rd qtr 20.2.2 .. . 4th Qtr 2022 1st Qtr 2023
Table 4 of 16 Historic Nitrate, Nitrate + Nitrite and Cloride Concentrations in Monitor Wells Up to the 1st Quarter 2023 Nitrate Contamination Investigation
TWN-7 Parameter
Sampling Event GWQS
lstQtr 2nd Qtr 3rd Qtr 4th Qtr lstQtr 2nd Qtr 3rd Qtr 4th Qtr lstQtr 2nd Qtr 37roTr--4thQtr -----lstQtr 2nd Qtr
Nitrate, Nitrate + Nitrite (10 mg/L) 3/17/2010 0.8 5/28/2010 1.2 7/14/2010 1.8 12/10/2010 1 1/27/2011 1.3 4/21/2011 1.7 7/29/2011 0.7 10/19/2011 2.2 1/11/2012 2.3 4/20/2012 1.2 7 /26/20121 0.9 10/16/2012 ----------0.64 2/19/2013 0.59 4/24/2013 1.16
White Mesa Uranium Mill
TWN-8 Sampling Event Chloride (mg/I) NoGWQS 6 1st Qtr 3/16/2010 6 2nd Qtr 5/26/2010 7 3rd Qtr 7/12/2010 4 4th Qtr 12/7/2010 6 lstQtr 1/25/2011 6 2nd Qtr 4/19/2011 5 3rd Qtr 7/26/2011 6 4th Qtr 10/17/2011 5 lstQtr 1/9/2012 6 2nd Qtr 4/18/2012 -------.,_ _____ -7i24/2012 6 3rd Qtr 5.67 4thQtr 1,�1�12,01,2 -------�-----5.68 lstQtr 2013 5.88 2nd Qtr I 2013
Parameter GWQS
Nitrate, Nitrate +Nitrite Chloride (mg/I) (10 mg/L) NoGWQS <0.1 11 <0.1 11 <0.1 11 <0.1 9 <0.1 13 <0.1 10 <0.1 18 <0.1 10 <0.1 11 <0.1 15 ------------�-------<0.1 11 <0.1 11.1 ------------�------NA NA 3rd Qtr 8/28/2013 0.835 6.96 TWN-8 abandoned on July 31, 2013 4thQtr 10/16/2013 0.986 5.7 lstQtr 1/15/2014 0.882 5.75 2nd Qtr 5/7/2014 0.564 5.26 3rd Qtr 8/6/2014 0.9 6 4thQtr 10/9/2014 0.968 5.93 lstQtr 2/19/2015 1.04 5.58 2nd Qtr 5/14/2015 0.779 6.18 3rd Qtr 8/6/2015 0.348 6.12 4thQtr 10/_�Y2015 0.672 5.84 -----------------lstQtr 2/24/2016 0.24 6.06 2nd Qtr 5/18/2016 0.732 6.26 3rd Qtr 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 lstQtr 1/19/2018 5.82 69.4 2nd Qtr 5/9/2018 10.2 94.7 3rd Qtr 8/9/2018 10.6 105 4thQtr 11/21/2018 11.5 104 lstQtr 2/21/2019 12.9 107 2nd Qtr 5/30/2019 13.5 122 3rdQtr 8/15/2019 12.9 120 4thQtr 10/17/2019 14.5 119
DWMRC split ofTWN-7 12.0 120 lstQtr 1/30/2020 14.2 128 2nd Qtr 5/21/2020 14.6 126 3rd Qtr 7/16/2020 15.2 116 4thQtr 11/13/2020 11.8 121 lstQtr 2/18/2021 16.0 129 2nd Qtr 5/27/2021 16.4 129 3rdQtr 8/19/2021 15.1 121 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 lstQtr 2/22/2023 14.5 150
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 rece1v1ng water,
Table 5 of 16 Historic Nitrate, Nitrate + Nitrite and Cloride Concentrations in Monitor Wells Up to the 1st 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
3rd Qtr 7/15/2010 10.7 210 3rd Qtr 7/14/2010 0.2 4th Qtr 12/9/2010 8.0 172 4thQtr 12/8/2010 1.3
lstQtr 2/1/2011 9.5 217 1st Qtr 1/26/2011 0.3 2nd Qtr 4/28/2011 10.0 192 2nd Qtr 4/21/2011 1.2
3rd Qtr 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 lstQtr 1/10/2012 0.8
TW4-65 dup of TWN-10 0.7
2nd Qtr 4/20/2012 10.6 209 2nd Qtr 4/19/2012 0.9
3rd Qtr 7/31/2012 12.3 215 3rd Qtr 7/25/2012 0.6 4th Qtr 10/17/2012 12.5 194 4th Qtr 7/16/2012 0.12
lstQtr 2013 NA lstQtr 2013 NA
2nd Qtr 2013 NA 2nd Qtr 2013 NA TWN-9 abandoned on July 31 2013 TWN-10 abandoned on July 31, 2013
TWN-11 Parameter TWN-12 Parameter
Sampling Event GWQS Sampling Event GWQS
Nitrate, Nitrate+ Nitrite Chloride (mg/I) Nitrate, Nitrate + Nitrite
(10 mg/L) NoGWQS (10 mg/L)
lstQtr 3/17/2010 1.4 73 lstQtr 3/17/2010 0.7
2nd Qtr I 6/1/2010 1.3 72 2nd Qtr 5/26/2010 0.8
3rd Qtr 9/27/2010 1.4 76 3rd Qtr 7/12/2010 0.7
4thQtr 12/8/2010 1.4 72 4th Qtr 12/7/2010 0.7
lstQtr 1/27/2011 1.4 84 1st Qtr 1/26/2011 4.2
2nd Qtr I 4/26/2011 1.4 76 2nd Qtr 4/26/2011 1.0
3rd Qtr 7/27/2011 0.1 76 3rd Qtr 7/26/2011 0.6
4th Qtr 10/17/2011 1.6 76 4th Qtr 10/17/2011 1.2
lstQtr 1/10/2012 1.6 69 lstQtr 1/10/2012 0.9
ate of lWN-11 1.6 70
2nd Qtr I 4/19/2012 1.6 71 2nd Qtr 4/18/2012 1.2
3rd Qtr 7/25/2012 1.8 77 3rd Qtr 7/25/2012 1.4
4th Qtr 10/16/2012 1.84 76.4 4th Qtr 7/16/2012 1.41
1st Qtr 2013 NA 1st Qtr 2013 NA
2nd Qtr 2013 NA 2nd Qtr 2013 NA 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 SCO, 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 28
40 28
28
�-� 44
28
33 30.8
Chloride (mg/I) NoGWQS
113 106
112 103
87
109 102
87 104
106
10,
10
Table 6 of 16 Historic Nitrate, Nitrate+ Nitrite and Cloride Concentrations in Monitor Wells Up to the 1st Quarter 2023 Nitrate Contamination Investigation
TWN-13 Sampling Event Parameter GWQS Nitrate, Nitrate + Nitrite (10 mg/L)
White Mesa Uranium Mill
Chloride (mg/I) NoGWQS
TWN-14 Sampling Event
1st Qtr 3/17/2010 <0.1 .. 4.7 1st qtr 3/24/2010
2nd qtr .. . s/i.r,}ioio . . . . .0.1 . 4.9 .. 2.n.d Cl.tr .· ...... _ .•....
.• 6/2/20io_ .· .
3rd Qtr 9/27/ioio 0.2 53 �rd Qtr 7/15/2010 4t h Qtr i2Jihoio . 0.4 57 4th Qt r 12Jicihoio lst. qtr .. .. 1/25/2011 1.6 ....... 10.3 .. 1s.t .. Cltr .. 1/28/2011 2nd qt, . ,ijii;jiiiii <0.1 .......... 4.� ?n�Cltr ... 4Ji11ioi1
Parameter GWQS Nitrate, Nitrate + Nitrite (10 mg/L) 2.9 2.9 3.5
4.2 3.7 3.5 3.5
Chloride (mg/I) NoGWQS 24 30 26 28 24 30 25 3.9 3rd Qtr ........ 7/2Ghoii .. .. .. .. .. . 0.1 . 4.9 3rd Qt r . . 7/29/2011 _
1�4'-'th"--"Q"-tr_-+-.;:l"'0/'-'1�7/cc2c..c0.c.ilc.i
. _<o.cc:.c.i_·· -------l------4-"'8+'-4t'-h --'Q"'t '-r --+-1=0/19/"'2'-'0.c.ll=+---------"-"+--lst Qtr 1/9/2012 <0.1 ....... 46 1st Qtr 1/11/2012 27
2nd..Cl,tr 4/is/ioii �o.i 53 2nd Cl.tr . . j/20/zo12 .
3rd(ltr j/i4/2012 0.1 ........... 4.8. 3rd Qtr 7/27/2012
TW4-70 duplicate ofTWN-14
3.5 26 3.4 27 3.7 27 3.8 27
4th Qtr ........... io/ishiii2 <O.i 4.03 27.4 4i311-i:ii<ii:r .. 1Ji11ccicc.occcii _______ --',-'-'-L----.C.CC-'jf 1st (ltr 1 • 2013 NA 2nd Qtr 2013 NA TWN-13 abandoned on July 31, 2013
NA = Per the CAP and SCO, not sampled
1st qtr. 2.n.d qtr 3rdQtr 4th Qtr lstQtr .. .2nd_ Clt r ... 3r�(ltr .... 4t h Qtr l�t qtr .. .2.n.d Cl.tr .. 3r� qt, 4th Qtr lstQtr .. 2nd Qtr 3rd Cl�r .. 4th Qt r lstqtr 2.n.d qtr 3rd (ltr 4th Qtr .�s.t .. Cltr .. 2nd(ltr .. �r.dQtr 4th Qtr 1st qt, 2.n.d qtr 3r.d(ltr
4th Qt r lstQtr ... 2nd Cltr 3rd(lt r 4th Qtr
1st qtr . . 2n.d qtr .3.r.d. qtr 4th Qtr 1st Qtr 2nd Cltr
.3rd.Clt., .. 4th Qtr 1st Qtr
2013 NA 2013 NA 2013 NA 2013 NA 2014 NA 2014 NA
2014 NA 2014 NA 2015 NA 2015 NA 2015 NA I···· 2015 NA 2016 NA 2016 NA 2016 NA
2016 NA 2017 NA 2017 NA 2017 NA 2017 NA 2018 NA 2018 NA 2018 NA .... 2018 NA 2019 NA 2019 NA 2019 NA 2019 NA 2020 NA
2020 NA 2020 NA 2020 NA 2021 NA 2021 NA
2021 NA 2021 NA
2022 NA 2022 NA 2022 NA 2022 NA 2023 NA
Table7 of 16 Historic Nitrate, Nitrate + Nitrite and Cloride Concentrations In Monitor Wells Up to the 1st Quarter 2023 Nitrate Contamination Investigation White Mesa Uranium Mill
TWN-15 Sampling Event Parameter GWQS TWN-16 Sampling Event
Nitrate, Nitrate + Nitrite (10 mg/L) Chloride (mg/I) NoGWQS
1st Qtr 3/18/2010 0.7 . _________ 1st (ltr 2nd Qtr · 5/28/2_0_1--+------------········ ___ 39_,2nd qtr
3rd _Cltr.. 7/13/201 .. _36_ 3rd Qtr 4th Qtr 12/.�c::12:::0=i:.i.
--------==+------=-38=+'4t.:.hc.:Q:,:t:...r --1--= lst(ltr 1/27/201 ...... _4_3_ lstQtr 2nd (ltr . ·· · · 4_9 ?ndqtr 3rd qtr ...... _··. 7/28/2011 . 4th Qtr 1st Qtr
2nd Qtr 4/20/2012 1.6 .......... �/� .... .
TW4-70 duplicate ofTWN-15
TW4-70 duplicate oflWN-15 1st qtr 2013 NA
1.7
2.1 1.79
2.0
46
......... 50 _3r_d (),tr .. 47 4th Qtr 44.4 ......... 1st (ltr
IF2-'n.:.d.cQ"'tr _ _,_ ___ 2-'-0-'-13'-'-"N-'A _____________ -f2nd(),tr .. TWN-15 abandoned on July 31, 2013 _3r_�qtr __ 4th Qtr
lstQtr __ 2ndqtr ___ ....
_3_r_d_ Cltr . 4th Qtr 1st Qtr 2_n_d qtr __ 3rd (ltr ... 4th Qtr lstQtr __
2013 NA 2013 NA
2014 NA 2014 NA 2014 NA 2014 NA 2015 NA 2015 NA 2015 NA
2015 NA 2016 NA
2016 NA
Parameter GWQS
2.50
Chloride (mg/I) NoGWQS
35 _ .................. ... __ 35 35 30 34 39 31 34 33
32.1
NA = Per the CAP and SCO, not sampled
3rd Qtr
4th Qtr 1st (ltr _2_n_d _Cltr_ .. 3rd(),tr ___ . 4th Qtr lstQtr 2nd Cltr
_3_rd_Cltr __ 4th Qtr 1st Qtr. _2nd (),tr. 3rdQtr. 4th Qtr lstQtr __
2nd (),tr 3rd Qtr . 4th Qtr 1st Qtr inc1 citr
_3r_d(),tr ..... 4th Qtr 1st Qtr 2nd Cltr .... 3r_d_(ltr.
4th Qtr 1st Qtr
2018 NA
2019 NA 2019 NA
2021 NA
2022 NA
Table 8of 16 Historic Nitrate, Nitrate + Nitrite and Cloride Concentrations in Monitor Wells Up to the 1st Quarter 2023 Nitrate Contamination Investigation White Mesa Uranium Mill TWN-17 Parameter TWN-18 Parameter Sampling Event GWQS
lstQtr 2nd Qtr 3rd Qtr 4th Qtr lstQtr 2nd Qtr 3rd Qtr 4th Qtr lstQtr 2nd Qtr 37rQTr--4th Qtr lstQtr 2nd Qtr
3rd Qtr
Nitrate, Nitrate + Nitrite (10 mg/L) 3/24/2010 10.4 6/3/2010 11 7/15/2010 12/10/2010 2/1/2011 4/28/2011 9 7/29/2011 10/20/2011 1/12/2012 8.7 4/20/2012 9.1 7/27/20121 9.5 10/17/2012 ----------9.65 2013 2013
2013 TWN-17 abandoned on July 31, 2013
NA= Per the CAP and SCO, not sampled
Sampling Event Chloride (mg/I) NoGWQS 78 1st Qtr 3/17/2010 87 2nd Qtr 6/1/2010 66 3rd Qtr 9/27/2010 65 4th Qtr 12/9/2010 90 1st Qtr 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 -ii26/2012 85 3rd Qtr 4thQtr 7/16/2012 -iiis12013 lstQtr 2nd Qtr 4/23/2013
TW4-6S dup ofTWN-18 3rd Qtr 8/27/2013 4th Qtr 10/16/2013
ORC split sample lstQtr 2/14/2014 2nd Qtr 5/6/2014 3rd Qtr 8/5/2014 4thQtr 10/8/2014
TW4-65 dup ofTWN-18 lstQtr 2/18/2015 2nd Qtr 5/13/2015
TW4-6S dup ofTWN-18 3rd Qtr 8/25/2015 4thQtr 10/13/2015
TW4-65 dup ofTWN-18 lstQtr 2/23/2016 2nd Qtr 5/17/2016 3rd Qtr 7/21/2016 4th Qtr 10/6/2016 lstQtr 2/15/2017 2nd Qtr 6/1/2017 3rd Qtr 7/19/2017 4th Qtr 10/4/2017 lstQtr 1/18/2018 2nd Qtr 5/8/2018 3rd Qtr 8/8/2018 4thQtr 11/21/2018 lstQtr 2/20/2019
TWN-65 dup of TWN-18 2nd Qtr 5/29/2019
TWN-65 dup ofTWN-18 3rd Qtr 8/14/2019
TWN-65 dup ofTWN-18 4thQtr 1011612019
OWMRC duplicate ofTWN-18 lstQtr 1/29/2020
TWN-65 dup of TWN-18 2nd Qtr I 5/20/2020 3rd Qtr 7/15/2020 4th Qtr 11/12/2020
TWN-65 dup of TWN-18 lstQtr I 2/17/2021
TWN-65 dup ofTWN-18 2nd Qtr 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 I 2/15/2022
TWN-65 dup ofTWN-18 2nd Qtr 5/24/2022
TWN-65 dup ofTWN-18 3rd Qtr 8/17/2022
TWN-65 dup ofTWN-18 4th Qtr I 10/25/2022 lstQtr I 2/21/2023
TWN-65 dup ofTWN-18
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 in January 2013 ______ • As of March 2012 both north and south wild life ponds no longer receiving water. __ .
GWQS Nitrate, Nitrate + Nitrite Chloride (mg/I) (10 mg/L) NoGWQS 1.6 42 1.8 63 64 1.6 59 1.4 61 1.8 67 65 1.9 6( 1.9 64 2.1 64 2.3 67 1.95 2.27 68.7 2.32 64.3 2.46 66.1 2.04 70.4 2.15 67.3 0.29 74 2.33 68.4 2.18 76.S 1.8 70 1.47 1.47 72.3 1 73.3 1.35 76.6 <0.10 76.9 0.35 0.668 69 0.645 68.6 0.648 67.6 0.497 69.9 <0.100 52.7 0.501 67.4 0.47 62.1 0.392 63.� 0.419 59.( 0.256 56.E 0.332 53.1 0.283 57.8 0.348 59.7 0.16 0.155 46.4 0.174 0.129 so.a 0.152 53.3 0.181 46.9 0.184 47.3 0.162 47.1 0.13 43.0 0.224 51.9 0.249 50.6 0.223 47.4 0.232 44.0 0.208 42.3 0.171 41.9 0.228 46.2 0.227 46.1 0.22 44.1 0.247 0.199 42.9 0.208 44.1 0.245 46.5 0.199 40.9 <0.1 40.5 0.34 40.7 0.3 39.1 0.328 40.1 0.349 40.i 0.212 35.6 0.253 33.2 32.5
Table9of 16 Historic Nitrate, Nitrate+ Nitrite and Cloride Concentrations in Monitor Wells Up to the 1st Quarter 2023 Nitrate Contamination Investigation White Mesa Uranium Mill
TWN-19 Sampling Event Parameter GWQS Upper Wildlife Pond Sampling Event Parameter GWQS Nitrate, Nitrate + Nitrite (10 mg/L) Chloride (mg/I) NoGWQS Nitrate, Nitrate + Nitrite (10 mg/L) 1st utr . 3/23/2010 .. 118 1st Qtr 3/18/2010 <0.1 2nd Cltr . i,ji;ioio . 6.2 .............. .11.3 .. 2.n_d .Cl.t.r. .. . . . i,/iJi.oio <0.l . �rdQtr 9/27iioio 7.2 113 �rdQtr jjiiiiioio <0.1 4th Qtr i.i.jij1.,,,i..,..01,..,o+·--------7-·o-t-____ 1 _07-t-4t_h_Qcctr_-+·...ci�2jio120io <O:i 1st qtr 2/1/2011 7.0 1/31/2011 2nd qtr . .. . .. . 4/2.Biioii . .. . 6.9 .. .. .. ,ijisiioi:i <cij 3r.d Qtr. .
. ... '7/is/ioii . . .. 1iisii.oii <O.i ...
Chloride (mg/I) NoGWQS <1.0 <1.0 <1.0
lt-4_th_Q�t _r_+·_1_o�Ji_s�h_o_i..,i1---------'--+-----'-'-'-t---'-"-c.._--l-1=iiji!ii20ii <ci.11st Qtr 1/10/2012 t----'----'---'1"-/3c..c1"-/2"-'0cclcc.2 L----------''-=-'------=111 2nd_Cltr .. . . . 'i./i.ij)ioii 6.8 Pond no longer in service 3.rd .. cttr.... . 7/2.Giioii. .7.5 4th Qtr i.o/iG/2012 7.7 1st qtr 2013 NA 2.n.d Cl.tr 2013 NA 3r.d qtr .. 2013 NA 4th Qtr 2013 NA 1st Qtr 2014 NA 2nd Cltr 2014 NA 3rdQtr 2014 NA 4th Qtr 2014 NA 1st Qtr .. 2015 NA 2..n.d. Cl.tr..... 2015 NA 3rd qtr 2015 NA 4th Qtr 2015 NA 1st Qt.,.... 2016 NA 2nd Cltr .. . 2016 NA 3rdQtr .. 2016 NA 4th Qtr lst qtr .... 2nd Cl.tr 3rdqtr
4th Qtr 1st Qtr 2nd Cltr ... 3rd_Cltr. 4th Qtr 1st Qtr 2n_d. qtr . 3r.d Qtr . 4th Qtr 1st Qtr. 2nd Cltr 3rd qtr. 4th Qtr
3rd qtr 4thQtr 1st Qtr 2.nd cttr ... 3r�_Qtr ..
4th Qtr 1st Qtr
2016 NA 2017 NA 2017 NA 2017 NA 2017 NA 2018 NA 2018 NA 2018 NA
2019 NA 2019 NA 2020 NA 2020 NA 2020 NA 2020 NA 2021 NA 2021 NA 2021 NA 2021 NA 2022 NA 2022 NA 2022 NA 2022 NA 2023 NA
TWN-20 Sampling Event Parameter GWQS Nitrate, Nitrate + Nitrite (10 mg/L)
117 118
Chloride (mg/I) NoGWQS
TWN-21 Sampling Event Parameter . GWQS Nitrate, Nitrate + Nitrite (10 mg/L) Chloride (mg/I) NoGWQS . n� qtr . 6/3/2021 ....... 5.o 2nd cttr . . 6/3/2021 1.03 41.9 r�Cltr . gjiijjioii 35.3 3rd Qtr 8/19/2021 1.16 40.5 th Qtr ii/23}202i 33:6 4th O.tr iiJij.�ji _ci_21__.··· _______ o_.6_9_6+-____ 4 _2.-u6 v-1-st-Q�t�,-.. -;-�2/71�6/°'2-=o.,..22:+----------,--,+----.-.--:. 3,...,.1-.,.2,t . .,..!s-.t.-=q�.t,-.. _-+-... �2./.16/2022 1.1 40.4 2nd Qtr S/is/ici'i.2 ...... 29J ?n� qtr 5/25/2022 1.1 39.8 �rdQtr. s/isho22· .}2.4 }r�qtr ..... s/ish.022 42.7 4th Qtr .......... io/'i.6/2022 32.0 4th Qtr . iohi;/2022 42.3 v-1,-st,...Q='t-,--t---='2;"'2-='2;"2-=o,,.,23:+--------=-=-=+----2c.:3-=_2+--1s-=t-=Q�t,--;--='2;22·�;2-o-2 -3,__ ________ +-____ 2_7 __ 5""'
NA= Per the CAP and SCO, not sampled
Table 10 of 16 Historic Nitrate, Nitrate + Nitrite and Cloride Concentrations in Monitor Wells Up to the 1st Quarter 2023 Nitrate Contamination Investigation
Pizometer 1 Parameter Sampling Event GWQS
2nd Qtr
3rd Qtr 4th Qtr lstQtr 2nd Qtr 3rd Qtr 4th Qtr lstQtr lstQtr 2nd Qtr
Nitrate, Nitrate + Nitrite (10 mg/L) 6/2/2010 7.2 7/19/2010 6.8
12/10/2010 6.5 1/31/2011 7
4/2S/2011 6.87/25/2011 7
10/19/2011 6.6 1/11/2012 7.1
1/10/2012 7.0 4/20/2012 6.6 -----------------------7/27/201� 7.23rd Qtr 4th Qtr -----lstQtr 2nd Qtr
3rd Qtr4th Qtr
DRC split of Plez-1 lstQtr 2nd Qtr 3rd Qtr 4th Qtr
lstQtr 2nd Qtr 3rd Qtr 4thQtr _____ lstQtr
2nd Qtr 3rd Qtr 4thQtr lstQtr 2nd Qtr 3rd Qtr 4thQtr
lstQtr 2nd Qtr 3rd Qtr 4th Qtr lstQtr 2nd Qtr 3rd Qtr 4th Qtr
10/17/2012 ----------7.662/19/2013 8.114/24/2013 8.88 8/28/2013 7.83
10/16/2013 6.68
1.3
1/13/2014 6.79 5/7/2014 7.57 8/6/2014 5.1 10/8/2014 5.75 2/18/2015 6.41
5/12/2015 5.95 8/26/201S 4.96
10/14/2015 6.17 -----------------------------------2/23/2016 8.31 5/12/2016 6.33
7/19/2016 6.78 10/11/2016 6.42
2/15/2017 6.75 6/1/2017 6.6
7/20/2017 6.810/4/2017 6.21
1/17/2018 6.35
5/9/2018 6.568/8/2018 6.66
11/21/2018 6.72/19/2019 6.72
5/30/2019 6.7S 8/14/2019 6.81
10/16/2019 7.21
OWMRC duplicate of P·l 6.4lstQtr 1/30/2020 7.12
2nd Qtr 5/20/2020 6.953rd Qtr 7/15/2020 7.36
4th Qtr 11/13/2020 7.51
1st Qtr 2/18/2021 7.34
2nd Qtr S/27/2021 7.89
3rd Qtr 8/19/2021 7.6
4th Qtr 11/23/2021 4.69
lstQtr 2/16/2022 7.4 2nd Qtr 5/24/2022 5.9
3rd Qtr 8/17/2022 6.37
4thQtr 10/25/2022 6.36 lstQtr 2/21/2023 5.34
DRC = Utah D1v1S1on of Rad1at1on Control
Nitrate Pumping System Started in January 2013 ______ •
White Mesa Uranium Mill
Pizometer 2 Sampling Event
Chloride (mg/I) NoGWQS S2 2nd Qtr 52 3rd Qtr 60 4th Qtr 60 1st Qtr 58 2nd Qtr S3 3rd Qtr 55 4th Qtr 78 1st Qtr 114 lstQtr S8 2nd Qtr -------�----S6 3rd Qtr 55 4th Qtr -------�----56.7 lstQtr 53.3 2nd Qtr 55.1 3rd Qtr S4.1 4th Qtr
60 DRC split of Piez-2 56.2 lstQtr
52.1 2ndQtr 55 3rd Qtr S7.6 5S.9 57.S 64.2S4.4 ---------------------S6.5S9.1 53.9 S8.1 S4.S
54.7
4th QtrlstQtr 2nd Qtr 3rd Qtr 4th Qtr _ lstQtr 2nd Qtr 3rd Qtr 4th Qtr lstQtr
2nd Qtr 58 3rd Qtr
54.4 4th Qtr SS.3 lstQtr S8 2nd Qtr 63.5 3rd Qtr 5S.S 4th Qtr
S6.8 lstQtr59.4 2nd Qtr 61.1 3rd Qtr 59.3 4th Qtr
6/2/2010 7/19/2010 12/10/2010 1/31/2011 4/25/20117/25/2011 10/19/20111/11/2012 1/31/2012 4/20/2012 -
Ji21/2012 7/17/2012 -
ii19/20134/24/2013 8/28/2013 10/16/2013
1/13/2014 5/7/2014 8/6/2014 10/8/2014 2/18/2015 5/12/2015 8/6/2015 10/14/201� 2/23/2016 5/12/2016 7/19/2016 10/11/2016 2/1S/2017 6/1/2017 7/20/2017 10/4/2017 1/17/2018 5/9/2018 8/8/2018 11/20/2018 2/19/2019 5/30/2019 8/14/2019 10/16/2019
60 DWMRC duplicate of P-2 68.9 lstQtr 1/30/2020 67.7 2nd Qtr 5/20/202063.6 3rd Qtr 7/15/2020 63.9 4th Qtr 11/13/2020 57.5 lstQtr 2/18/2021 69.9 2nd Qtr 5/27/202170 3rd Qtr 8/19/2021
65.5 4thQtr 11/23/2021 68.8 lstQtr 2/16/2022
70.3 2nd Qtr S/24/2022 72 3rd Qtr 8/17/2022 73.6 4th Qtr 10/25/2022 50.8 lstQtr 2/21/2023
As of March 2012 both north and south wild life ponds no longer receiving water ___ ,
Parameter
GWQS
Nitrate, Nitrate + Nitrite (10 mg/L) 0.6 0.6 0.2 0.3 0.3
0.10.1 0.10.1 0.2------------0.2 0.19 ------------0.22 0.172
0.198 0.36 0.270.169 0.736
0.8 0.755
0.7490.646 0.70.692 0.615 0.665 0.6690.732
0.6960.345
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
<0.1 0.11 <0.1 0.330 0.48 0.71 0.7030.607
Chloride (mg/I) NoGWQS
8 8 6
9 8
9
8 9 1 8 --------99.5 ----------9.67 10.3 9.66 9.22 11 11.4 11.4
12 12.2 12.5 13.1 15.5
13.3 ---------------------13.414 12.413.4
12.413.2
13.4 12.7 13.0 14.0 15.1
12.3 12.912.6 13.2 12.6
2114.2
14.4 12.7 12.9
1S.7 13.9
14.E 14.8 14.0 12.6 14.7 13.4 9.8
Table 11 of 16 Historic Nitrate, Nitrate+ Nitrite and Cloride Concentrations in Monitor Wells Up to the 1st Quarter 2023 Nitrate Contamination Investigation White Mesa Uranium Mill
Parameter Pizometer 3A Parameter
Sampling Event GWQS Sampling Event GWQS
Nitrate, Nitrate+ Nitrite Chloride (mg/I) Nitrate, Nitrate + Nitrite (10 mg/L) NoGWQS (10 mg/LI
lstQtr 3/24/2010 1.7 116
2nd Qtr 6/2/2010 1.6 36
3rd Qtr 7/19/2010 1.8 35
4th Qtr 12/9/2010 1.8 25 lstQtr 1/31/2011 40
2nd Qtr 4/25/2011 1.7 35 3rd Qtr 7/25/2011 1.8 61
4th Qtr 10/19/2011 1.7 12
lstQtr 1/11/2012 1.8 20 2nd Qtr 4/20/2012 1.7 53
-7/27/2012 3rd Qtr 1.8 21 4th Qtr 10/17/2012 2.75 20.1
lstQtr 2/24/2013 1.85 21 2nd Qtr 4/24/2013 1.83 21.2
3rd Qtr 8/28/2013 1.81 22.4
UhQtr 10/16/2013 1.8 23.5
)RC split sample 0.33 27
lstQtr 1/13/2014 1.7 26
2nd Qtr 5/7/2014 1.79 23.9
3rd Qtr 8/6/2014 1.7 26
14th Qtr 10/8/2014 1.74 28.3
lstQtr 21iii12015 1.82 27.3 2nd Qtr 5/12/2015 1.75 30.2
3rd Qtr 8/26/2015 1.87 54.8
Chloride (mg/I) NoGWQS
�Jh Qtr 10/14/2015 2.24 39.5 New piezometer P-3A to replace piezometer P-3 drilled and installed in
2/i.3/2016 lstQtr 1.82 27.3
Pizometer-3 abandonded May 2016 (1)2nd Qtr 3rd Qtr 4th Qtr
lstQtr 2nd Qtr 3rd Qtr 4th Qtr ______ lstQtr 2nd Qtr 3rd Qtr 4th Qtr lstQtr 2nd Qtr 3rd Qtr 4th Qtr
5/12/2016 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
OWMRC duplicate of P-3a lstQtr 1/30/2020 2nd Qtr 5/20/2020 3rd Qtr 7/15/2020 4thQtr 11/13/2020 lstQtr 2/18/2021 2nd Qtr 5/27/2021
3rd Qtr 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 lstQtr 2/21/2023
1. New piezometer PIEZ-3A to replace PIEZ-3 drilled and installed 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 in January 2013 ______ • As of March 2012 both north and south wild life ponds no longer receiving 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 91.7 114.0
10.6 109 11.5 81.5 11.9 60.8
Table 12 of 16 Historic Nitrate, Nitrate + Nitrite and Cloride Concentrations in Monitor Wells Up to the 1st Quarter 2023 Nitrate Contamination Investigation White Mesa Uranium Mill
TW4-19(Pumpin& wellstartin& In Parameter TW4-20 (Pumpin& well statin& in Parameter April2003)
Sampling Event
lstQtr 3/16/2005 2nd Qtr 5/25/2005 3rd Qtr 8/31/2005 4th Qtr 12/7/2005 lstQtr 3/9/2006 2nd Qtr 6/14/2006 3rd Qtr 7/20/2006
4th Qtr 11/8/2006 lstQtr 2/28/2007 2nd Qtr 6/27/2007 3rd Qtr 8/15/2007
4th Qtr 10/10/2007 lstQtr 3/28/2008 2nd Qtr 6/25/2008 3rd Qtr 9/10/2008
4thQtr 10/15/2008
lstQtr 3/4/2009 2nd Qtr 6/23/2009 3rd Qtr 9/14/2009 4th Qtr 12/22/2009 lstQtr 2/17/2010 2nd Qtr 6/14/2010 3rd Qtr 8/16/2010 4th Qtr 10/15/2010
lstQtr 2/17/2011
2nd Qtr 6/7/2011 3rd Qtr 8/17/2011 4th Qtr 11/17/2011 lstQtr _ 1f!.3L29...1!. -----2nd Qtr 6/6/2012 3rd Qtr 9/4/2012
4thQtr 10/3/2012
lstQtr 2/13/2013 2nd Qtr 6/5/2013 3rd Qtr 9/3/2013 4thQtr 10/29/2013
lstQtr 1/27/2014 2nd Qtr 5/19/2014 3rd Qtr 8/11/2014
4th Qtr 10/21/2014
lstQtr 3/9/2015 2nd Qtr 6/8/2015 3rd Qtr 8/31/2015 �th Qtr 10/19/2015 3/9/zoiG lstQtr 2nd Qtr 5/26/2016 3rd Qtr 7/25/2016
4thQtr 10/13/2016
lstQtr 3/8/2017 2nd Qtr 6/13/2017 3rd Qtr 7/26/2017
4thQtr 10/11/2017
lstQtr 3/12/2018 2nd Qtr 6/8/2018 3rd Qtr 8/30/2018 4thQtr 11/28/2018
lstQtr 3/8/2019 2nd Qtr 6/5/2019 3rd Qtr 9/4/2019
4th Qtr 12/10/2019 lstQtr 2/19/2020 2nd Qtr 5/27/2020
Auaust2005)
GWQS Sampling Event Nitrate, Nitrate + Nitrite Chloride (mg/I) (10 mg/L) NoGWQ5
5.3 NA 5.7 NA 2nd Qtr 5/25/2005 4.6 NA 3rd Qtr _ !!l3.!f1_0,£5 1------<0.1 81 4th Qtr 12/7/2005
4 86 1st Qtr 3/9/2006 5.2 116 2nd Qtr 6/14/2006 4.3 123 3rd Qtr 7/20/2006
4.6 134 4th Qtr 11/8/2006
4 133 lstQtr 2/28/2007 not sampled 2nd Qtr 6/27/2007
4.1
4 2.2
2.8 35.2 47.8 3.2
2.4 <0.1 26.7 2 4.4 5.9 2.7 17.0 12.0 3.0 5.0 0.6 ------------2.4 2.5
4.1
8.0 3.0 17.6 4.7
1.6
1.3
1.6
4.7
8.56 0.916 11.6 10.6 -----------------------------------15.70 1.27 10.5 10.0 11.1 0.243 1.120 0.377
8.6
0.494 2.55 0.233 6.6 6.580 0.33 0.535 10.1 1.140
129 3rd Qtr 132 4th Qtr 131 lstQtr
128 2nd Qtr 113 3rd Qtr
124 4th Qtr 127 lstQtr
132 2nd Qtr 43 3rd Qtr 124
144 132 142
146 135
148 148
148 138 -------149
149 150
164 148 179 134
134 152 140 130 238
180 326 252 ---------------------276 204 214 200
461 135
218
139 193
138 166
140 197 160 153 147 205 147
4th Qtr
lstQtr 2nd Qtr
3rd Qtr 4th Qtr
lstQtr 2nd Qtr 3rd Qtr 4th Qtr lstQtr ._ ____2nd Qtr 3rd Qtr 4th Qtr
lstQtr 2nd Qtr 3rd Qtr 4th Qtr
lstQtr 2nd Qtr 3rd Qtr
4th Qtr lstQtr 2nd Qtr 3rd Qtr 4th Qtr ______
lstQtr 2nd Qtr 3rd Qtr
4th Qtr
lstQtr 2nd Qtr 3rd Qtr 4th Qtr 1st Qtr 2nd Qtr 3rd Qtr 4thQtr
lstQtr 2nd Qtr 3rd Qtr 4thQtr
lstQtr 2nd Qtr
8/15/2007 10/10/2007
3/28/2008 6/25/2008 9/10/2008 10/15/2008 3/4/2009 6/23/2009 9/14/2009 12/22/2009 2/17/2010
6/14/2010
8/16/2010 10/15/2010 2/17/2011 6/7/2011 8/17/2011 11/17/2011 1/23/2012 -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
GWQS Nitrate, Nitrate + Nitrite Chloride (mg/I) (10 mg/L) NoGWQ5
---------
1
����: ----1.80 131
3.80 120 9.40 235 2.90 134 3.50 124 4.20 124 2.30 112 2.10 117 5.60 170 0.90 132
8.00 191
4.44 156 5.51 168
5.10 164 2.90 164 3.30 153 5.30 187 2.00 179
5.60 200
5.30 196 4.60 203
4.40 220
4.80 177 6.50 207 4.20 186 7.90 207 ------------1---------11.00 262 10.80 289 11.00 302 9.07 252
9.80 250 8.65 260 9.64 272 7.56 254 5.95 269
4.30 299 7.67 292
9.80 290 5.76 296 9.3 365 6.23 293 ---------------------10.30 293 11.2 318 11.3 307 11.4 301 12.0 290 9.76 281 10.8 292 8.91 293 9.5 289 10.40 258
8.14 282 9.72 295 6.7 272 9.59 279 10.2 286 9.75 307
9.81 310 7.23 301
3rd Qtr 9/4/2020 11.6 188 TW4-20 Abandonded October 2020
4thQtr 12/10/2020 1.1 104
lstQtr 2/23/2021 6.6 167 2nd Qtr 6/9/2021 4.04 115
3rd Qtr 8/24/2021 6.68 172 4thQtr 12/1/2021 11.1 184
lstQtr 3/9/2022 1.7 119 2nd Qtr 6/8/2022 1.4 128
3rd Qtr 8/30/2022 4.76 178
4th Qtr 11/30/2022 3.6 129
lstQtr 3/7/2023 1.8 122
Shaded = Nitrate, Nitrate+ Nitrite 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
Table 13 of 16
Historic Nitrate, Nitrate + Nitrite and Cloride Concentrations in Monitor Wells Up to the 1st Quarter 2023
Nitrate Contamination Investigation
White Mesa Uranium Mill
TW4-21 (Pumpina well st.1rtin1 in
June2015)
Sampling Event
lstQtr 2nd Qtr 3rd Qtr 4thQtr lstQtr 2nd Qtr 3rd Qtr 4th Qtr lstQtr 2nd Qtr 3rd Qtr 4th Qtr lstQtr 2nd Qtr 3rd Qtr 4th Qtr 1st Qtr 2nd Qtr 3rd Qtr 4th Qtr _____ lstQtr 2nd Qtr 3rd Qtr 4thQtr _____ lstQtr 2nd Qtr 3rdQtr 4th Qtr (l)lst Qtr -----2nd Qtr 3rd Qtr 4thQtr
lstQtr 2nd Qtr 3rd Qtr 4thQtr lstQtr 2nd Qtr 3rd Qtr 4thQtr lstQtr (2)2nd Qtr -----3rd Qtr 4th Qtr _____ lstQtr 2nd Qtr 3rd Qtr 4th Qtr lstQtr 2nd Qtr 3rd Qtr 4thQtr
3/16/2005 5/25/2005 8/31/2005 12/.?./2005
3/9/2006 6/14/2006 7/20/2006 11/8/2006 2/28/2007 6/27/2007 8/15/2007 10/10/2007 3/28/2008 6/25/2008 9/10/2008 10/15/2008 3/11/2009 6/23/2009 9/14/2009 12/22/2009
2/25/2010 6/14/2010 8/13/2010 10/15/2010 2/22/20i"i 6/28/2011 8/17/2011
11/16/2011
_2/}Jf39,_1� 6/13/2012 9/13/2012 10/4/2012
2/13/2013 6/18/2013 9/13/2013 11/13/2013 2/5/2014 5/22/2014 8/27/2014 10/29/2014 3/12/2015 6/8/2015 ------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
DWMRC split 1W4-21 lstQtr 3/12/2018 2nd Qtr 6/8/2018 3rd Qtr 8/22/2018 4th Qtr 10/22/2018 lstQtr 3/8/2019 2nd Qtr 6/5/2019
3rd Qtr 9/4/2019 4th Qtr 12/10/2019
lstQtr 2/19/2020
2nd Qtr 5/27/2020 3rd Qtr 9/4/2020
4th Qtr 10/28/2020 lstQtr 2/23/2021 2nd Qtr 6/9/2021 3rd Qtr 8/24/2021 4th Qtr 12/1/2021
lstQtr 3/9/2022 2nd Qtr 6/8/2022 3rd Qtr 8/30/2022 4th Qtr 11/30/2022 lstQtr 3/7/2023
NA = not analyzed
Parameter
GWQS Nitrate, Nitrate + Nitrite Chloride (mg/I) (10 mg/L) NoGWQS was not sampled 14.6 NA 10.1 NA 9.6 353 8.5 347 10.2 318 8.9 357 8.7 296 8.7 306 8.6 327 8.6 300 8.3 288 14.3 331
8.8 271 7.57 244
8.0 284 8.3 279 8.1 291
9.2 281 8.4 256 ------------------------8.4 228 12.0 266 14.0 278 7.0 210 ------------------------9.0 303 12.0 290 14.0 287 13.0 287 15.0 228 -------------------11.0 285
13.0 142 14.0 270
11.8 221 13.8 243 10.3 207 9.0 206 11.4 200 11.5 243 7.1 230
10.0 252 10.9 255 13.1 494 ------------�-------14.7 499 14.3 413 -----------------------------------------------14.6 452 13.1 425
16.5 457 13.5 439 17.7 452 9.53 309 18.20 447 16.90 378 11.0 310
15.8 447 14.1 387 0.236 182 15.2 378 9.0 180
17.5 456 14.7 478 5.73 339 8.9 446 15.4 353
12.6 382 16.30 411 15.2 454 21.5 461 12.9 375
17.2 227 2.2 110 8.9 331 14.3 425 2.1 158 10.9 335
TW4-22 (Pumpin1 well statin1 in
Au1ust2005)
Sampling Event
lstQtr 3/16/2005 2nd Qtr 5/25/2005 3rd Qtr 8/31/2005 4th Qtr 12/7/2005 lstQtr 3/9/2006 2nd Qtr 6/14/2006 3rd Qtr 7/20/2006 4th Qtr 11/8/2006 lstQtr 2/28/2007
2nd Qtr 6/27/2007 3rd Qtr 8/15/2007 4thQtr 10/10/2007 lstQtr 3/28/2008 2nd Qtr 6/25/2008 3rd Qtr 9/10/2008 4th Qtr 10/15/2008 lstQtr 3/11/2009 2nd Qtr 6/23/2009 3rd Qtr 9/14/2009 4th Qtr 12/29/2009 lstQtr 3/3/2010 2nd Qtr 6/14/2010 3rd Qtr 8/24/2010 4th Qtr 10/15/2010 lstQtr 2/22/2011
2nd Qtr 6/1/2011 3rd Qtr 8/17/2011 4th Qtr 11/16/2011 '(i)lstQtr 1/19/2012 ------Giii12012 2nd Qtr 3rd Qtr 9/12/2012 4th Qtr 10/4/2012 (3)1�Qt� -iiii,iicii3 2nd Qtr 6/5/2013 3rd Qtr 9/3/2013 4thQtr 10/29/2013 lstQtr 1/27/2014
2nd Qtr 5/19/2014 3rd Qtr 8/11/2014 4thQtr 10/29/2014 lstQtr 3/9/2015 2nd Qtr 6/8/2015
3rd Qtr 8/31/2015 4thQtr 10/19/2015
lstQtr 3/9/2016 2nd Qtr 5/23/2016 3rd Qtr 7/25/2016 4th Qtr 10/12/2016 lstQtr 3/8/2017 2nd Qtr 6/13/2017 3rd Qtr 7/26/2017 4th Qtr 10/11/2017
DWMRC split ofTW4-22 lstQtr 3/12/2018 2nd Qtr 6/8/2018 3rd Qtr 8/22/2018
4th Qtr 11/28/2018 lstQtr 3/8/2019 2nd Qtr 6/5/2019 3rd Qtr 9/4/2019 4th Qtr 12/10/2019
lstQtr 2/19/2020 2nd Qtr 5/27/2020 3rd Qtr 9/4/2020 4th Qtr 10/28/2020 lstQtr 2/23/2021 2nd Qtr 6/9/2021 3rd Qtr 8/24/2021 4th Qtr 12/1/2021 1st Qtr 3/9/2022 2nd Qtr 6/8/2022
3rd Qtr 8/30/2022 4th Qtr 11/30/2022 lstQtr 3/7/2023
(1) As of March 2012 both north and south wild hfe ponds no longer rece1vmg water
(2) Chloroform pumping well started 619115. (3) Chloroform pumping well started 1126113.
Shaded = Nitrate, Nitrate+ Nitrite concentrations greater than the Ground Water Quality Standard of 10 mg/I
OWMRC = Utah Division of Waste Management and Radiation Control
Parameter
GWQS Nitrate, Nitrate + Nitrite Chloride (mg/I) (10 mg/L) NoGWQS was not sampled 18.2 NA 15.7 NA 15.l 253 15.3 236 14.3 221 14.5 221 15.9 236 20.9 347 19.3 273 19.3 259 18.8 238 39.1 519 41.9 271 38.7 524 36.3 539 20.7 177
20.6 177 40.3 391 17.8 175 36.8 427 19.0 134 15.0 130
16.0 134 18.0 114 17.0 138 15.0 12( 19.0 17, 14.0 36 ------------._ _______ 12.8 35 7.0 121 14.0 130 ------------,_ _____ iiii 58.0
50.2 586 29.7 487 45.2 501 54.6 598 47.2 614 41.5 540 54.9 596 69.2 675 47.1 390 64.7 557
56.1 567 ------------------------------------31.1 583
58.4 598 61.3 619 61.5 588 69.8 566
70.8 572 66.l 391 80.l 600 79.0 610 62.3 607 72.5 580 55.4 613 75.7 567 71.9 528 83.9 662 72.5 588 59.9 608 57.7 606
60.5 578 64.8 514 64.9 523 69.6 618 89.3 408
35.1 410 68.8 586 40.4 442
45.0 564 69.9 637
62.0 601 49.1 562
Table 14 of 16 Historic Nitrate, Nitrate + Nitrite and Cloride Concentrations in Monitor Wells Up to the 1st Quarter 2023 Nitrate Contamination Investigation White Mesa Uranium Mill
TW4-24(Pumpin1 well m1rtin1 in Parameter TW4-25 (Pumpin& weU statin1 in Parameter January2013)
Sampling Event GWQS Nitrate, Nitrate + Nitrite Chloride (mg/I) (10 mg/L) NoGWQS 2nd Qtr 6/27/2007 26.1 770 3rd Qtr 8/15/2007 29 791 4th Qtr 10/10/2007 24.7 692 lstQtr 3/28/2008 24.4 740 2nd Qtr 6/25/2008 45.3 834 3rd Qtr 9/10/2008 38.4 1,180 4th Qtr 10/15/2008 44.8 1,130 lstQtr 3/4/2009 30.5 1,010 2nd Qtr 6/23/2009 30.4 759 3rd Qtr 9/14/2009 30.7 618 4th Qtr 12/16/2009 28.3 1,080 lstQtr 2/25/2010 33.1 896 2nd Qtr 6/14/2010 30 639 3rd Qtr 8/24/2010 31 587 4th Qtr 10/15/2010 31 522 lstQtr 2/17/2011 31 1,100 2nd Qtr 5/26/2011 35 1,110 3rd Qtr 8/17/2011 34 967 4th Qtr 11/16/2011 35 608 lstQtr _ 1f :..6L29..1!;_ 37 373 2nd Qtr 6/6/2012 37 355 3rd Qtr 8/30/2012 37 489 4th Qtr 10/3/2012 38 405 lstQtr _ 3/;_1!_2': • 35.9 2nd Qtr 6/5/2013 23.7 916 3rd Qtr 8/30/2013 33 998 4th Qtr 10/29/2013 35 1,030 lstQtr 1/27/2014 31.6 809 2nd Qtr 5/19/2014 35.0 1,020 3rd Qtr 8/11/2014 31.5 1,150 4th Qtr 10/21/2014 35.7 1,050 lstQtr 3/9/2015 34.6 944 2nd Qtr 6/8/2015 31.8 1,290 3rd Qtr 8/31/2015 25.3 788 4th Qtr 10/19/2015 29.6 909
lstQtr 3/9/2016 29 .. 1 989 2nd Qtr 5/23/2016 24.2 771 3rd Qtr 7/25/2016 34.4 1,180
4th Qtr 10/12/2016 31.9 1,010 lstQtr 3/8/2017 41.3 1,090
2nd Qtr 6/13/2017 39.9 1,080 3rd Qtr 7/26/2017 40.0 1,230 4th Qtr 10/11/2017 31.7 895
DWMRC split ofTW4-24 32.0 1,100 lstQtr 3/16/2018 44.9 1,320 2nd Qtr 6/14/2018 33.6 792 3rd Qtr 8/22/2018 33.8 996 4th Qtr 11/28/2018 38.4 1,100 lstQtr 3/8/2019 39.3 1,040
2nd Qtr 6/5/2019 33.2 1,020 3rd Qtr 9/4/2019 36.4 1,130 4th Qtr 12/10/2019 33.8 1,090 lstQtr 2/19/2020 37.1 1,010 2nd Qtr 5/27/2020 41.7 1060
3rd Qtr 9/4/2020 39.l 1100 4thQtr 10/28/2020 35.90 1050 lstQtr 2/23/2021 41.9 1,170 2nd Qtr 6/9/2021 48.0 938 3rd Qtr 8/24/2021 26.7 1010
4thQtr 12/1/2021 43.60 1140 lstQtr 3/9/2022 36.2 890 2nd Qtr 6/8/2022 35.0 944 3rd Qtr 8/30/2022 32.0 868 4thQtr 11/30/2022 27.6 972 lstQtr 3/7/2023 36.2 932 As of March 2012 both north and south wild hfe ponds no longer rece1v1ng water Chloroform pumping well started January 2013
Jilnuary2013)
Sampling Event
2nd Qtr 6/27/2007 3rd Qtr 8/15/2007 4thQtr 10/10/2007 lstQtr 3/28/2008 2nd Qtr 6/25/2008 3rd Qtr 9/10/2008 4thQtr 10/15/2008 lstQtr 3/4/2009 2nd Qtr 6/23/2009 3rd Qtr 9/14/2009 4thQtr 12/14/2009 lstQtr 2/23/2010 2nd Qtr 6/14/2010 3rd Qtr 8/10/2010 4th Qtr 10/15/2010 lstQtr 2/16/2011 2nd Qtr 5/25/2011 3rd Qtr 8/16/2011 4th Qtr 11/15/2011 lstQtr 2nd Qtr 5/31/2012 3rd Qtr 9/4/2012 4th Qtr 10/3/2012 lstQtr 2/11/2013
(2)2nd Qtr 6/5/2013 3rd Qtr 9/4/2013 4th Qtr 10/31/2013 lstQtr 1/27/2014 2nd Qtr 5/19/2014 3rd Qtr 8/11/2014 4th Qtr 10/21/2014 lstQtr 3/9/2015 2nd Qtr 6/8/2015 3rd Qtr 8/31/2015 4th Qtr 10/19/2015
DWMRC split of1W4-25 lstQtr 3/9/2016 2nd Qtr 5/23/2016 3rd Qtr 7/25/2016 4thQtr 10/12/2016 lstQtr 3/8/2017 2nd Qtr 6/13/2017 3rd Qtr 7/26/2017 4thQtr 10/11/2017
lstQtr 3/12/2018 2nd Qtr 6/14/2018 3rd Qtr 8/22/2018 4th Qtr 11/28/2018 lstQtr 3/8/2019 2nd Qtr 6/5/2019 3rd Qtr 9/4/2019 4th Qtr 12/10/2019 lstQtr 2/19/2020 2nd Qtr 5/27/2020 3rd Qtr 9/4/2020 4thQtr 10/28/2020 lstQtr 2/23/2021 2nd Qtr 6/9/2021 3rd Qtr 8/24/2021 4thQtr 12/1/2021 lstQtr 3/9/2022 2nd Qtr 6/8/2022 3rd Qtr 8/30/2022 4th Qtr 11/30/2022 lstQtr 3/7/2023
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
GWQS Nitrate, Nitrate + Nitrite Chloride (mg/I) (10 mg/L) NoGWQS 17.1 395 29 382 17 358 18.7 374 22.1 344 18.8 333 21.3 366 15.3 332 15.3 328 3.3 328 14.2 371 14.4 296 16 306 14 250 15 312 15 315 16 321 16 276 16 294 16 304 16 287 17 334 17 338 9.04 190 5.24 136 5.69 119 6.1 88.6 2.16 85.7 1.21 51.1 1.6 67 1.03 58.1 14.4 310 1.14 58.3 1.63 69.2 1.78 93.7 1.50 94 0.837 62.7 0.959 75.5 1.78 74.1 1.24 59.8 17.0 285 0.976 69.8 1.23 70.1 1.29 68.0
2.23 70.5 1.14 60.3 0.810 69.1 0.634 59.70 0.639 65.0 0.821 59.0 0.548 58.1 0.841 73.10 0.607 86.0 0.851 76.8 0.994 67.3 1.6 61.3 3.43 100.0 1.57 55.1 0.793 69.3 0.978 93.7 1.8 70.3 0.88 72.8 1.51 82.5 1.47 67.2 1.96 96.7
Table 15 of 16
Historic Nitrate, Nitrate+ Nitrite and Cloride Concentrations in Monitor Wells Up to the 1st Quarter 2023
Nitrate Contamination Investigation
TW4-37!Pumpin& well stirtin1 In
June2015)
Sampling Event
2nd Qtr .l 6/8/2015
:;� �:; _____ __ 1���!����!
stQtr 3/9/2016 2nd Qtr I 5/23/2016
3rd Qtr 7/25/2016
4th Qtr 10/12/2016
lstQtr 3/8/2017
2nd Qtr 6/15/2017 3rd Qtr 7/26/2017
lthQtr 10/11/2017 stQtr 3/12/2018
nd Qtr 6/8/2018 rd Qtr 8/22/2018
4th Qtr 11/28/2018
lstQtr 3/8/2018
2nd Qtr 6/5/2019
3rd Qtr 9/4/2019 14th Qtr 12/10/2019
lstQtr 2/19/2020
'nd Qtr 5/27/2020
3rd Qtr 9/4/2020 4th Qtr 10/28/2020
lstQtr 2/23/2021
2nd Qtr 6/9/2021 3rd Qtr 8/24/2021
4th Qtr 12/1/2021 lstQtr 3/9/2022
2nd Qtr 6/8/2022
3rd Qtr 8/30/2022
4th Qtr 11/30/2022
lstQtr 3/7/2023
White Mesa Uranium Mill
Parameter
GWQS
Nitrate, Nitrate + Nitrite Chloride {mg/I)
(10 mg/L) NoGWQS
35.2 345
32.4 374
34.6 399 --------------------------------------------------------28.4 332
27.9 389 33.4 294
26.1 304
32.3 305 31.2 281
30.5 277 30.6 255
30.0 263
28.6 275
25.3 387
27.3 264
30.1 209
31.2 250
25.8 228
25.5 220 28.3 23E
28.3 321
29.5 273
28.7 254
26.9 242 26.6 176
25.8 220 31.3 410
29.8 414
28.0 276
26.6 243
30.9 57! 19.1 20'
Shaded= Nitrate, Nitrate+ N1tnte concentrat1ons greater than the Ground Water Quality Standard of 10 mg/l
MW-30
Table 16 of 16
Historic Nitrate, Nitrate+ Nitrite and Cloride Concentrations in Monitor Wells Up to the 1st 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/L) NoGWQS (10 mg/L)
2nd Qtr 6/22/2005 12.4 125 2nd Qtr 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
2nd Qtr 6/21/2006 14.5 124 2nd Qtr 6/21/2006 25.3
3rd Qtr 9/13/2006 14.1 118 3rd Qtr 9/13/2006 24.6
4thQtr 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
4th Qtr 10/24/2007 14.9
lstQtr 3/19/2008 14.8
2nd Qtr 6/3/2008 18.7
3rd Qtr 8/4/2008 17.3
4th Qtr 11/5/2008 15.6
lstQtr 2/3/2009 15.3
2nd Qtr 5/13/2009 15.1
3rd Qtr 8/24/2009 20.9
4thQtr 10/14/2009 15.0
lstQtr 2/9/2010 16.1
2nd Qtr 4/27/2010 15.8
3rd Qtr 9/14/2010 15.0
4th Qtr 12/14/2010 16.0
lstQtr 2/1/2011 16.0
2nd Qtr 6/20/2011 16.0
3rd Qtr 9/7/2011 17.0
4th Qtr 12/12/2011 16.0
lstQtr 3/14/2012 18.0
2nd Qtr 6/18/2012 15
3rd Qtr 9/19/2012 16
4thQtr 12/26/2012 17.2
lstQtr 2/26/2013 21.4
2nd Qtr 5/15/2013 18.8
3rd Qtr 7/10/2013 17.6
4th Qtr 11/20/2013 19.5
lstQtr 2/25/2014 18.4
2nd Qtr 6/3/2014 19.5
3rd Qtr 9/9/2014 16.8
4th Qtr 11/10/2014 16.2
lstQtr 2/4/2015 14.9
2nd Qtr 4/8/2015 17
3rd Qtr 8/11/2015 17.9
4th Qtr 11/11/2015 16.3
lstQtr 2/10/2016 20
2nd Qtr 5/4/2016 17.3
3rd Qtr 8/18/2016 18
4th Qtr 11/3/2016 18
lstQtr 2/2/2017 17.4
2nd Qtr 4/5/2017 18.3
3rd Qtr 8/14/2017 19.2
4thQtr 11fy2011 17.4
lstQtr 2/22/2018 17.6
2nd Qtr 4/12/2018 17.3
3rd Qtr 9/11/2018 18
4th Qtr 10/22/20!!! 17.2
lstQtr 2/13/2019 18.2
2nd Qtr 4/10/2019 18.5
3rd Qtr 7/16/2019 19.3
4th Qtr 10/8/2019 18.2
lstQtr 1/15/2020 16.4
2nd Qtr 4/6/2020 18.1
3rd Qtr 7/6/2020 18.4
4th Qtr 12/8/2020 12
lstQtr 3/8/2021 17
2nd Qtr 4/14/2021 17.7
3rd Qtr 7/29/2021 20.6
4th Qtr 10/19/2021 14.3
lstQtr 1/17/2022 14.5
2nd Qtr 4/20/2022 17.0
3rd Qtr 7/12/2022 17.6
4th Qtr 10/13/2022 17.9
lstQtr 1/25/2023 18.1
126 3rd Qtr
122 4th Qtr
118 lstQtr
125 2nd Qtr 121 3rd Qtr
162 4thQtr 113 lstQtr
122 2nd Qtr 118 3rd Qtr
129 4th Qtr
127 lstQtr
97 2nd Qtr
111
126
134 124
127
124 128
131 130
122
129
119
130 124
135 128
139
154
136
142 165
140 145
139
150 143
150 146
173 156
158
145 183
140 167
138
181 170
182 195
185
166 192
162 188
182
181
173
108 195 166
3rd Qtr
4th Qtr
lstQtr 2nd Qtr
3rd Qtr
4thQtr lstQtr
2nd Qtr 3rd Qtr
4th Qtr
lstQtr
2nd Qtr
3rd Qtr 4thQtr
lstQtr
2nd Qtr
3rd Qtr
4th Qtr
lstQtr
2nd Qtr 3rd Qtr
4th Qtr
lstQtr
2nd Qtr
3rd Qtr 4th Qtr
lstQtr 2nd Qtr
3rd Qtr 4th Qtr
lstQtr
2nd Qtr 3rd Qtr
4th Qtr ______ lstQtr
2nd Qtr
3rd Qtr 4th Qtr
lstQtr 2nd Qtr
3rd Qtr
4th Qtr lstQtr
2nd Qtr 3rd Qtr
4th Qtr
lstQtr 2nd Qtr
3rd Qtr 4th Qtr lstQtr
8/22/2007
10/24/2007 3/19/2008
6/3/2008 8/4/2008
11/5/2008 2/3/2009
5/13/2009 8/24/2009
10/14/2009
2/9/2010
5/21/2010
9/13/2010 11/9/2010
2/1/2011 6/20/2011
9/7/2011
12/12/2011 3/13/2012
6/18/2012
9/18/2012
12/18/2012
2/19/2013 5/13/2013
7/9/2013
11/18/2013
2/17/2014
6/3/2014
9/3/2014
11/4/2014
2/2/2015
4/7/2015 8/10/2015
11/9/2015 2/10/2016
5/3/2016
8/16/2016 11/1/2016
2/7/2017 5/1/2017
8/14/2017
11/1/2017 2/20/2018
4/17/2018 9/10/2018
10/24/2018 2/12/2019
4/10/2019
7/16/2019 10/9/2019
1/15/2020
4/6/2020 7/7/2020
12/7/2020 3/9/2021
4/13/2021
7/27/2021
10/19/2021
1/19/2022 4/11/2022
7/12/2022
10/11/2022 1/24/2023
Shaded= Nitrate, Nitrate+ Nitrite concentrations greater than the Ground Water Quahty Standard of 10 mg/I
23.3 136
24.6 122 25 124
29.3 128 28.7 124
29.9 119 23.4 115
22.4 124
15.4 122 22.6 138
21.7 128 23 128
21 139 20 138
21 145
22 145
21 148
21 148 22 152
21.6 138
21 172 22.2 170
19.3 174
23.8 169
21.7 182
23.9 174 20.6 197
23.1 173 18.9 210
20.9 204 18.7 211
19 211
19.9 264
18.4 215
18.8 246
18.6 243
19.7 272
19.8 267
21.1 266
18.3 263 19.5 310
19 292
18.8 292
19 308
20.1 333
18.3 286
18.6 296
19.7 294
19.8 374
19.8 318 17.5 381
18.8 376
19.2 370
18.8 311
17.4 388 18.6 377
18.7 391
18.1 371
18.0 370
18.0 372
16.9 421
17 397
18.7 333
Table 2
Summary of QA/QC Duplicate Sample
1st Quarter 2023
Parameter GWQS Duplicate of TWN-20
TWN-18 TWN-65 RPO
Nitrate + Nitrite (as N) 10 mg/L 0.253 0.184 31
Chloride none 33.2 32.5 2
High lighted exceeding PRO (Relitve % difference) of 20%
NA= Not Analyzed
.6
.1
Data Discriptions
,1>1itr1a1te.(111.g/�J .... I\
Nitrate (lbs/L) N�rate (H>sigal)
f�t�I gali��� pu111ped lbs of nitrate removed
MW4 MW-26 4.44 0.694 4.44E-03 6.94E-04 9.81E-06 1.53E-06 3.71E-05 5.80E-06 90044.0 27474.7 3.34 0.16 Ga1ioris ofri�raieremoveci 1 0.211 0.01
Total lbs nitrate removed from all pumping wells
TW4-1 1.71 1.71E-03 3.78E-06 1.43E-05 7985.1 0.11 0.01
Total lbs nitrate removed from nitrate�umping wells
Tabel 3 DWMRC Nitrate Mass Removal Calculations Energy Fuels Resorses Inc. White Mesa Mill, Bland, Utah 1st Quarter 2023
Chloroform Pumping Wells
TW4-2 I TW4-4 I TW4-11 I TW4-19 I TW4-21 I TW4-37 I TW4-39 2.03 7.12 5.68 1.750 10.90 19.1 1.37 2.03E-03 .. 7.12E:oa .. . 5.68E-03 1.75E-03 ... 1 :osE:02 ... 1.91 E-02 . 1.37E-03 4.49E:os 1.57E-05 1.25E-05 ......... 3.87E:os 2.41 E-05 4.22E-05 . 3.03E-cis' ......... .. ... . ... 1.70E-05 5.95E-05 4.75E-05 1.46E-05 9.12E-05 1.60E-04 1.15E-05 10215.4 8236.o .......... 1.3.26.4 ...... 132291_8· 83943.5 j4$36.9 ···· · 3s�$i@l 0.17 0.49 0.06 1.94 7.65 7.11 0.41 ............ .. .. .. . ..... 0.01 0.04 0.01 0.16 0.62 0.58 0.03
57
35
Nitrate Pumping Wells __ JI
TW4-40 I TW4-41 I TWN-2 I TW4-22 I TW4-24 I TW4-25 JI �:��ii�� :::�i�� H�i�� ··••••·· ntf ii .. !:��r�� n�ii!II1.07E-05 3.SoE:os . 9.37E-05 4.11 E-04 3.03E-04 1.64E:o! 45os2.1 11511.2 57,�21,s 21183.o 15:,i24.5 8!2§!l,8 0.5 0.42 1.62 8.94 22.83 1.43 0.04 0.03 0.13 0.73 1.86 .... 0:12