DRC-2021-007041 - 0901a06880e9543d

0017,1717%.
State of Utah
SPENCER J. COX
Governor
DEIDRE HENDERSON
Lieutenant Governor
Department of
Environmental Quality
Kimberly D. Shelley
Executive Director
DIVISION OF WASTE MANAGEMENT
AND RADIATION CONTROL
Ty L. Howard
Director
DRC-Zoli -00 goLpf
MEMORANDUM
TO: File
THROUGH: Phil Goble, Manager pgc )/12(
FROM: Tom Rushing, P.G. 12 3 /31/2
DATE: March 31, 2021
SUBJECT: Review of the Energy Fuels Resources (USA) Inc. 4th Quarter 2020 Ground Water
Monitoring Report for the White Mesa Uranium Mill
Review Summary:
The Utah Division of Waste Management and Radiation Control ("DWMRC") has reviewed the
following documents submitted by Energy Fuels Resources (USA) Inc. ("EFR"):
1. EFR, February 17, 2021, Transmittal of 4th Quarter 2020 Groundwater Monitoring
Report Groundwater Quality Discharge Permit UGW370004 White Mesa Uranium
Mill (Received by DWMRC on February 19, 2021).
2. EFR, January 25, 2021, State of Utah Ground Water Discharge Permit No.
UGW370004 White Mesa Uranium Mill — Notice Pursuant to Part I.G.1(a).
The review was conducted to ensure compliance with all applicable parts of Utah Groundwater
Discharge Permit No. UGW370004 ("Permit") issued for the White Mesa Uranium Mill located in
Blanding, Utah (Mill).
1. Checklist of Significant Findings of the 4th Otr. 2020 Report and Related Actions at the
White Mesa Uranium Mill:
1. The 4th Quarter 2020 Report was received on February 19, 2021, which was before
the due date (Permit Part I.F.1 - due date of March 1).
2. DWMRC notes that samples were analyzed by American West Analytical
Laboratories ("AWAL") with the exception of Gross Alpha, which was analyzed
by GEL Laboratories LLC, Charleston, South Carolina. DWMRC verified that the
195 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
Pnnted on 100% recycled paper
EFR 4th Quarter 2020 Groundwater Monitoring Report
DWMRC Review Memo
Page 2
laboratories have current Utah certification. It was noted that GEL laboratories has
addressed issues noted on previous reports regarding the method used for gross
alpha radium and is now reporting that method 903.0 is used. This method is now
included in the facility QAP and GEL has current Utah certification to use that
method.
3. Laboratory QA/QC flags were documented in the review period analytical data
reports from the contract laboratories and an in-house QA/QC review was
conducted by EFR regarding all field and laboratory data. Per DWMRC review it
appears that all discrepancies were self-reported by EFR.
4. Two new compliance parameters went into accelerated monitoring frequency based
on sampling during the 3' Quarter 2020: MW-24 (Gross Alpha) and MW-29
(Uranium).
5. The 4th Quarter groundwater monitoring completes a full year of analysis for new
groundwater monitoring well MW-24A. Per data review the rand 4th Quarter
00C parameters, data for MW-24/MW-24A continue to show significant
increasing trends. It is recommended that accelerated monitoring continue at MW-
24/MW-24A. Per findings, the analytical results for MW-24A confirm that out-of-
compliance parameters in MW-24 were not due to problems with well
construction. It was additionally noted that based on current groundwater
monitoring data and trends it may be appropriate for EFR to consider additional
information and data points (e.g. new monitoring wells) to evaluate the observed
concentrations in MW-24 and MW-24A. It is noted that groundwater
concentrations of nearby and downgradient monitoring well MW-02 are not
currently indicating the same exceedances or trends and that the primary indicator
parameter for a tailings solution source, chloride, is not showing concentration
increase or trends at MW-24. However, additional data at point(s) downgradient
and near MW-24/MW-24A and additional source assessment is needed to better
evaluate the exceedances and potential source. This issue will be included in a
transmittal letter to EFR.
2. Accelerated Monitoring and POC Wells Exceeding GWCL's:
When a monitoring well has a pollutant that exceeds a Ground Water Compliance Limit (GWCL)
set forth in Table 2 of the Permit, it is in Probable Out-of-Compliance (POOC) status. According
to the Permit, EFR is then required to immediately initiate accelerated sampling of that pollutant
(see the Permit, Part I.G.1). When monitoring wells have parameters that have exceeded the
Ground Water Compliance Limit (GWCL) two or more consecutive times they are in Out-of-
Compliance (00C) status (see the Permit, Part I.G.2).
In the event a constituent is in 00C status, EFR is required to prepare and submit within 30
calendar days to the Director a plan and time schedule for assessment of the sources, extent and
potential dispersion of the contamination, and an evaluation of potential remedial action to restore
and maintain groundwater quality to ensure that Permit limits will not be exceeded at the
compliance monitoring point and that DMT or BAT will be re-established, in accordance with
Part I.G.4(c) of the Permit.
EFR 4th Quarter 2020 Groundwater Monitoring Report
DWMRC Review Memo
Page 3
Two new compliance parameters went into accelerated monitoring frequency (POOC) based on
sampling during the 4th Quarter 2020: MW-24 (Gross Alpha) and MW-29 (Uranium).
Current Accelerated Monitoring Status:
The table below (Table 1) lists monitoring wells with parameters currently in 00C or POOC
status and therefore required to be sampled under the accelerated monitoring requirements:
Table 1 - Wells Monitored Quarterly Accelerated to Monthly Monitorin
Well Class *Position Parameter Date of First
Exceedance of
GWCL
Date Accelerated
Monitoring First
Required
MW-11 Class II water D-3
Manganese
Chloride
Sulfate
Total Dissolved Solids
2nd Quarter 2018
3rd Quarter 2019
3rd Quarter 2019
3' Quarter 2020
September 2018
November 2019
November 2019
4th Quarter 2020
MW-25 Class III water C-3 Cadmium 1st Quarter 2020 May 2020
MW-26(a) Class III water C-2
Nitrate + Nitrite (as N)
Chloroform
Chloride
Total Dissolved Solids
February 2010
February 2010
February 2010
3" Quarter 2020
May 2010
May 2010
May 2010
4th Quarter 2020
MW-30 Class II water D-2
Nitrate + Nitrite (as N)
Chloride
Uranium
Selenium
February 2010
1st Quarter 2011
4th Quarter 2013
lst Quarter 2019
May 2010
May 2011
March 2014
May 2019
MW-31 Class III water D-2
Nitrate + Nitrite (as N)
Chloride
Total Dissolved Solids
Sulfate
Uranium
1st Quarter 2010
1st Quarter 2011
3rd Quarter 2019
3' Quarter 2019
2nd Quarter 2020
May 2010
May 2011
November 2019
November 2019
August 2020
D = Down-gradient; U = Up-gradient; C = Cross-gradient;
a = Monitoring well MW-26 is a pumping well for the
Wells Monitored Semi-annually Accelerated to Quarterly
1,2,3,4A, 4B =
Chloroform investigation
Monitorin&
Date of First
Exceedance of
GWCL
Cell #
Date Accelerated
Monitoring First
Required
Well Class *Position Parameter
MW-12 Class III water D-3 Uranium
Selenium
2nd Quarter 2017
2nd Quarter 2020
3rd Quarter 2017
3rd Quarter 2020
MW-24 Class III water D-1 Beryllium
Cadmium
Thallium
Field pH
Fluoride
Nickel
Manganese
4th Quarter 2017
2nd Quarter 2018
2nd Quarter 2018
2nd Quarter 2018
4th Quarter 2018
4th Quarter 2018
4th Quarter 2019
lst Quarter 2018
3" Quarter 2018
3rd Quarter 2018
3rd Quarter 2018
3rd Quarter 2019
3rd Quarter 2019
1st Quarter 2020
EFR 4th Quarter 2020 Groundwater Monitoring Report
DWMRC Review Memo
Page 4
Well Class *Position Parameter Date of First
Exceedance of
GWCL
Date Accelerated
Monitoring First
Required
Sulfate
Gross Alpha
1" Quarter 2020
4th Quarter 2020
3rd Quarter 2020
3rd Quarter 2021
MW-27 Class III water U-1 Nitrate + Nitrite (as N) 2"d Quarter 2010 3rd Quarter 2010
MW-28 Class III water D-1
Chloride
Cadmium
Uranium
Gross Alpha
Selenium
2nd Quarter 2010
2"d Quarter 2014
2"d Quarter 2014
4th Quarter 2018
2"d Quarter 2019
3rd Quarter 2010
2nd Quarter 2014
2nd Quarter 2014
3rd Quarter 2019
3rd Quarter 2019
MW-29 Class III water D-2 Uranium 4th Quarter 2020 3rd Quarter 2021
MW-32 Class III water C-2 Chloride 1st Quarter 2015 2nd Quarter 2014
* D = Down-gradient; U = Up-gradient; C = Cross-gradient; 1, 2, 3, 4A, 4B = Cell #
Table 1 above is a comprehensive list of all Groundwater Monitoring Wells in Accelerated Status
as of the 4th Quarter of 2020. EFR is required to notify the DWMRC on a quarterly basis
regarding wells and parameters which went into accelerated monitoring during the period [Part
I.G.1(a), Accelerated Monitoring Status Reports (AMSR)]. For the 4th Quarter 2020 monitoring,
the AMSR was dated January 25, 2021. Review of the AMSR is included in a separate section
below.
3. Monitoring Wells Purged for Two Casing Volumes Before Sample Collection:
As stated in Section 6.2.7 of the EFR Quality Assurance Plan (QAP), Rev. 7.6, EFR has a choice
regarding purge volumes as follows:
"1. Purging three well casing volumes with a single measurement of field parameters
2. Purging two casing volumes with stable field parameters (within 10% RPD)
3. Purging a well to dryness and stability of a limited list of field parameters after recovery"
Per DWMRC review of the Report, the following purge methods were used during the 4th Quarter
2020 (including accelerated samples). Purge methods and volumes are summarized in Tab G, on
Table G-1A and G-1B of the Report:
Quarter # Purged 2 Casing # Purged to Dryness # Purged 3 Casing Volumes
Volumes
4th Qtr. 2020 34 7 4 (continuous pumping)
When purging two casing volumes, the QAP directs EFR to first calculate the amount of time to
evacuate two casing volumes and then to pump for that length of time. Per DWMRC cross-check
of the field data sheets for each of the reports reviewed, it appears EFR correctly calculated the
well casing volumes and evacuated the required two volumes (when 2 casing volume method
selected) in monitoring wells prior to sample collection during the 4th Quarter 2020 monitoring
period. Volumes are calculated according to measured pump rates and can be verified by
calibration marks on the collection containers.
EFR 4th Quarter 2020 Groundwater Monitoring Report
DWMRC Review Memo
Page 5
During the 4th Quarter of 2020 monitoring period seven wells were pumped or bailed to dryness.
In cases where wells are evacuated to dryness the QAP Rev. 7.4 (Attachment 2-3) requires that:
"(vii) If the well is purged to dryness:
Record the number of gallons purged on the Field Data Worksheet.
The well should be sampled as soon as a sufficient volume of groundwater is available to fill
sample containers.
Upon arrival at the well after recovery or when sufficient water is available for sampling measure
depth to water and record on the Field Data Worksheet.
Take one set of measurements of field parameters for pH, specific conductance and temperature
only.
Collect the samples into the appropriate sample containers.
Take an additional set of measurements of field parameters for pH, specific conductance and
temperature after the samples have been collected.
If the field parameters of pH, specific conductance and temperature are within 10% RPD the
samples can be shipped for analysis.
If the field parameters of pH, specific conductance and temperature are not within 10% RPD,
dispose of the sample aliquots, and purge the well again as described above.
Repeat this process if necessary, for three complete purging events. If after the third purging the
event, the parameters of pH, specific conductance and temperature do not stabilize to within 10%
RPD, the well is considered sufficiently purged and collected samples can be submitted for
analysis."
DWMRC staff verified that in cases where the monitoring well was evacuated to dryness and
samples were collected, the number of gallons evacuated was recorded in compliance with the
QAP. Additionally, depth to water before sample collection was recorded on all applicable field
data worksheets which resolved past DWMRC comments.
4. Relative Percentage Difference Calculations and Radiological Comparisons for Blind
Duplicate Analysis:
DWMRC conducted a review of the blind duplicate samples collected during the 4th Quarter 2020.
Per the QAP, one blind duplicate must be collected with each sample batch. DWMRC confirmed
that one blind duplicate was collected for each batch (note that the quarterly TDS samples were
resampled during November for several monitoring wells, 11/18/2020) — 4 total during the
EFR 4th Quarter 2020 Groundwater Monitoring Report
DWMRC Review Memo
Page 6
quarterly event — two with the baseline samples (MW-35/MW-65/75 on 10/15/2020 and
11/18/2020 and MW-40/MW-70 on 10/22/2020), and two with the accelerated samples (MW-
30/MW-65 on 11/17/2020 and MW-25/MW-65 on 12/8/2020).
The duplicates are required to be within 20% Relative Percent Difference (RPD), unless "the
measured concentrations are less than 5 times the required detection limit (Standard Methods,
1998)."
Per the QAP, if any of the samples do not meet the comparison criteria (and are not qualified
according to the 5 times method detection limit criteria) then EFR is required to conform to the
procedures for corrective action listed as follows:
1. Notify the laboratory,
2. Request the laboratory review all analytical results for transcription and calculation errors,
and,
3. If the samples are still within holding time, the QA Manager may request the laboratory re-
analyze the affected samples.
Per DWMRC cross check of the blind duplicate samples collected and analyzed during the 4th
Quarter 2020 sampling event all but two sample results conform to the Permit requirements
(within 20% RPD). Ammonia and Fluoride in the October 15, 2020 duplicates were above the
20% RPD (39.4% and 24.56% respectively). In both of these cases the duplicate results were
within the acceptance limits of the current approved QAP, both results were not greater than 5
times the RL. No further action is required.
Radiological duplicate sample results met duplicate counting error requirements in the currently
approved QAP for the 4th Quarter 2020. No additional action is required.
5. Analytical Laboratories Used by EFR Certified by State of Utah to Perform Analysis
for all Analytes:
The analytical laboratories (GEL Laboratories LLC, Charleston, SC and American West
Analytical Laboratories, Salt Lake City, UT) were contracted by EFR to perform analysis on the
samples collected during the 4th Quarter 2020. Per DWMRC review of the National
Environmental Laboratory Accreditation Management System Website (cross check of laboratory
certification for specific parameters) it appears that the EFR contract laboratories were certified to
perform analysis for the specified parameters (Per the laboratory data sheets):
GEL Laboratories LLC Current Certification
Basic Details
Name GEL Laboratories, LLC
Type of Lab Not Specified
TNI Lab Code TNI00188
EPA Code SC00012
EFR 4th Quarter 2020 Groundwater Monitoring Report
DWMRC Review Memo
Page 7
State ID 8037697376
Website
Extended Details
Primary AB responsible
for lab demographics Utah Department of Health
GIS Location
Description
Comments
Effective Date n/a
Commercial Samples Yes
Active Yes
Location Address
Company
Contact Carey J. Bocklet
Address 1 2040 Savage Road
Address 2
City Charleston
State South Carolina
Zip 29407-
Country USA
Phone [phone]
Fax [phone]
Email [e-mail]
American West Analytical Laboratories Current Utah Certification
Basic Details
Name American West Analytical Laboratories
Type of Lab Not Specified
TNI Lab Code TNI01955
EPA Code UT00031
State ID 8012638686
Website www.awal-labs.com
Extended Details
Primary AB responsible
for lab demographics Utah Department of Health
GIS Location
Description
Comments
Effective Date n/a
Commercial Samples Yes
Active Yes
EFR 4th Quarter 2020 Groundwater Monitoring Report
DWMRC Review Memo
Page 8
Location Address
Company
Contact Kyle Gross
Address 1 3440 South 700 West
Address 2
City Salt Lake City
State Utah
Zip 84119-
Country USA
Phone [phone]
Fax [phone]
Email [e-mail]
6. Laboratory Report Turn Around Times:
Per DWMRC review of EFR Table 1 included in the 4th Qtr. 2020 Report, it was noted that
laboratory report turnaround times (from date of EFR sample submission to the contract
laboratory) for normal frequency monitoring was approximately 30 day for all samples (not
including re-submission/corrected reports). Per DWMRC review it was noted that EFR acted
quickly to identify any deficiencies in the reports and request corrected versions.
There is not a turnaround time requirement in the current QAP; therefore, current turnaround
times are judgment based. DWMRC has raised concern over excessive laboratory turn-around
times in the past and the Director may require a turn-around date be included in the facility QAP if
any future concerns regarding analysis turnaround times are noted. Based on DWMRC review the
turn-around times for the 4th Quarter 2020, data turn-around times and EFR data review timelines
appear to be reasonable/appropriate.
7. Sample Holding Times:
Per the Report Section 3.4.2 and Tables in Tab G of the Report, all method holding times and
reporting limits were met for each analyte submitted for laboratory analysis. DWMRC staff cross
checked all holding time requirements and verified that all samples/analytes appeared to be
analyzed within holding times during the 4th Qtr. 2020 reporting period.
8. Sample Preservation:
Per review of the 4th Quarter 2020 Report (Section 3.4.3, Tables Tab G, and Laboratory Check-in
Sheets) it appears that all samples required to be chilled (<6° C) met the temperature preservation
requirements. Per review of the laboratory check in sheets and laboratory QA/QC, no issues
related to sample preservation were noted.
9. Sample Trip Blank Evaluation:
EFR 4th Quarter 2020 Groundwater Monitoring Report
DWMRC Review Memo
Page 9
Per Section 3.4.6 of the Report and Tables in Tab G of the Report trip blanks and 2 samples (MW-
1 and MW-12) associated with THF showed detection of tetrahydrofuran, however, all other
samples associated with the blanks were non-detect for THF. Per the Report the Quality
Assurance Manager followed the Quality Assurance Plan and notified the laboratory to verify the
sample results and investigate causes of THF in the trip blanks. The laboratory verified the
sample results and the Quality Assurance Manager determined that the results are usable. It was
noted that the samples were out of hold time for re-analysis. The laboratory investigation of the
trip blanks is ongoing.
10. Laboratory QA/QC Flags — 4th Quarter 2020:
QA/QC issues and DWMRC findings for the 4th Quarter 2020 are summarized below:
Non-Conformance
Summary
Self-
Identified?
EFR Corrective Action
Summary
DWMRC Findings
Laboratory reporting
limits were raised for
various
samples/parameters.
Y EFR states that the raised
RL's are due to sample
dilution and qualifies the
data based on all sample
results being above the
raised RL.
The EFR QAP allows for
raised RL's if due to the
need for dilution.
DWMRC verified that in
all cases when the RL was
raised above the QAP
required RL the sample
result was higher in
concentration.
Radiological counting
error > 20%
Y Per the Permit, if the value
of the result is less than the
appropriate GWCL then
the counting error can be >
20% (Table G-8A).
The EFR QAP Part 9.1.4.b
allows that if the
applicable result is less
than the GWCL then the
counting variance can be
greater than 20%.
Matrix Spike % recovery
outside of range for
various wells/parameters.
Y Per AWAL Data Sheet:
Matrix spike recovery
indicates matrix
interference. The method
is in control as indicated
by the LCS. EFR included
the data qualifiers in the
footnotes of the Report
Tab G.
Per the QAP Part 8.1.2(a)
matrix spikes are required
but there are no
requirements which would
disqualify the laboratory
data. Data was reported
with a qualifier.
Laboratory Duplicate %
Recovery Comparison
Outside of Range for
various wells/parameters.
Y Same AWAL comments as
per the matrix spike %
recovery item above. EFR
included the data qualifiers
in the footnotes of the
Report Tab G.
Data was reported with a
qualifier.
EFR 4th Quarter 2020 Groundwater Monitoring Report
DWMRC Review Memo
Page 10
Note: DWMRC reviewed the holding time summary chart; no exceedances of holding times
were noted.
DWMRC reviewed the temperature check charts, all sample batches were received by the
laboratory <6° C.
11. Review of Time-Concentration Plots
The Permit Part I.F.1.g requires EFR to submit Time-Concentration Plots for each monitoring
well for primary indicators of cell leakage; chloride, fluoride, sulfate, and uranium. DWMRC
notes that per the discussions with EFR, it was agreed to that EFR need not plot trend lines on the
Time Concentration Plots and that all data is included on the plots (no data culled from the set).
Per DWMRC review of the 4th Qtr. 2020 Report, the reviewed plots appear to be in conformance
with the agreed upon changes.
12. Review of Depth to Groundwater Measurements and Water Table Contour Maps
Per DWMRC cross checks of groundwater elevation measurement calculations used for the 4th
Quarter 2020, approximately 5% of wells cross checked, comparing surface measured elevations
minus measured static levels with plotted elevations, no errors were noted.
The upper wildlife ponds at the White Mesa Mill were taken offline (pond recharge from
Recapture Reservoir discontinued) during the 4th Quarter 2011 in order to re-establish
groundwater contours. Hydrographs of the upper wildlife pond ground water piezometers (Water
Level Elevation vs. Time) are included below. It was also noted that the static water levels in
several monitoring wells close to the upper wildlife ponds showed significant decrease in water
levels since the ponds were taken offline. These declines can be attributed to natural dissipation
of the area ground water mound and/or ground water pumping activities related to corrective
action of nitrate and chloroform contamination plumes (development of cone of depressions
around pumping wells).
UC W Mrsa Mt11 I lydographs Ple,orneters til Nortt he Ponds
EFR 4th Quarter 2020 Groundwater Monitoring Report
DWMRC Review Memo
Page 11
!MC WNW Mesa Mill Hydrographs: Pom IP South Wikilde Ponds
Wa
le
,
Le
ve
l Ete
ya
lio
n t-
a
n.1)
5546
5545
5544 5.543
5542
5.541 • 5.540
5.539
5.538
5.531 5.536
5.535
5.514 5.533
5$32
5531 5.530
5529
5$28 5521
5.526
5525 5.524
5523
5,522 5521
5520
5,518
5.518 5,517
Nitrate and Chloroform Corrective Action Platt Pumping Wells:
Ground water elevations are being impacted by effects from ground water pumping for the nitrate
and chloroform contamination plume remediation. The following monitoring wells have been
converted to active pumping wells:
Nitrate Pumping Wells — TW4-22, TW4-24, TW4-25, TWN-2 (The nitrate pumping project was
initiated during January 2013).
Chloroform Pumping Wells — MW-4, MW-26, TW4-1, TW4-2, TW4-4, TW4-11, TW4-19, TW4-
20, TW4-21, TW4-22, TW4-24, TW4-25, TW4-37, TW4-39.
The pumping wells for both the nitrate and chloroform projects are set up with a delay device
wherein the wells purge for a set amount of time then shut off in order to let the well recharge.
All pumping wells include a flow meter which records the volume of water pumped from the well
in gallons. Quarterly nitrate and chloroform reports are prepared by EFR and include pump
volumes and delineation of pump capture zones based on kriged water contours.
DWMRC expects that ground water elevation contours will continue to adjust in response to the
pumping activities and discontinuance of recharge to the upper wildlife ponds.
13. EFR January 25, 2021 Notice Pursuant to the Permit Part I.G.1(a)
The EFR January 25, 2021 Notice Pursuant to the Permit Part I.G.1(a) ("Notice") discusses the
status of monitoring wells and parameters in probable out-of-compliance ("POOC") and out-of-
EFR 4th Quarter 2020 Groundwater Monitoring Report
DWMRC Review Memo
Page 12
compliance ("00C") status, as updated through the 4th Quarter 2020. DWMRC notes that the
Notice was submitted timely regarding currently agreed upon schedules, reporting of exceedances
within 30 days after the end of the monitoring quarter, and has been updated based on issuance of
the renewed modified GWDP (Issued effective March 19, 2019) in effect during the monitoring
period.
Per the Notice, two new wells/parameters went into POOC or 00C status during the 4th Quarter
2020: MW-24 (Gross Alpha) and MW-29 (Uranium). Based on DWMRC review of the Notice it
appears that all requirements of the Permit were met.
14. Conclusions and Recommendations
Based on DWMRC staff review of the above listed documents and review the following will be
included in a close-out and confirmatory action letter:
1. Close-out regarding DWMRC review of the EFR February 17, 2021, 4th Quarter 2020
Groundwater Monitoring Report.
2. Close-out regarding DWMRC review of the EFR January 25, 2021 Notice Pursuant to Part
I.G.1(a).
3. Review of the MW-24/MW-24A 3rd and 4th Quarter 2020 data and needs for continued
accelerated monitoring and additional investigation of the source of the 00C constituents
and trends.
15. References
l Energy Fuels Resources (USA) Inc., February 17, 2021, 4th Quarter2020 Groundwater
Monitoring Report, Groundwater Discharge Permit UGW370004, White Mesa Uranium Mill.
2 Energy Fuels Resources (USA) Inc., January 25, 2021, State of Utah Ground Water Discharge
Permit No. UGW370004 White Mesa Uranium Mill — Notice Pursuant to Part I.G.1(a).
3 Energy Fuels Resources (USA) Inc., May 14, 2019, White Mesa Uranium Mill Ground Water
Monitoring Quality Assurance Plan (QAP), Revision 7.5.
4. INTERA Incorporated, 2007, Revised Background Groundwater Quality Report: Existing Wells
for Dension Mines (USA) Corp.'s White Mesa Uranium Mill Site, San Juan County, Utah.
5 INTERA Incorporated, 2007, Background Groundwater Quality Report: New Wells for Denison
Mines (USA) Corp.'s White Mesa Uranium Mill Site, San Juan County, Utah.
6 Hurst, T.G., and Solomon, D.K., 2008. Summary of Work Completed, Data Results,
Interpretations and Recommendations for the July 2007 Sampling Event at the Denison
EFR 4th Quarter 2020 Groundwater Monitoring Report
DWMRC Review Memo
Page 13
Mines, USA, White Mesa Uranium Mill located near Blanding Utah. Prepared by University of
Utah Department of Geology and Geophysics.
7 Utah Department of Environmental Quality, March 19, 2019, Utah Ground Water Discharge
Permit No. UGW370004 issued for the Energy Fuels Resources (USA) Inc. White Mesa Uranium
Mill.