DRC-2024-004668

February 26, 2024
Sent VIA E-MAIL AND EXPRESS DELIVERY
Mr. Doug Hansen
Director
Division of Waste Management and Radiation Control
Utah Department of Environmental Quality
195 North 1950 West
Salt Lake City, UT 84114-4880
Energy Fuels Resources (USA) Inc.
225 Union Blvd. Suite 600
Lakewood, CO, US, 80228
303 974 2140
www .eneruvfuels.com
Re: Transmittal of Q4-23 Data Quality Report ("DQR") for the White Mesa Cell 2 Cover Test
Section Monitoring
Dear Mr. Hansen:
In accordance with the Stipulation and Consent Agreement ("SCA") dated February 23, 2017, between the
Division of Waste Management and Radiation Control ("DWMRC") and Energy Fuels Resource (USA) Inc.
("EFRI"), EFRI constructed a cover performance monitoring test section on Cell 2 in 2016 and initiated
performance monitoring. This letter transmits the data quality report for monitoring data collected during the
fourth quarter of 2023. Please note that this report is for quality assurance only and does not provide
interpretive information. Interpretive information is provided in annual reports.
For your convenience, two hard copies of the report and two CDs, each containing a word searchable electronic
copy of the files, will be mailed to DWMRC.
If you should have any questions regarding this transmittal please contact me at 303-389-4134.
Yours very truly,
ENERGY FUELS RESOURCES (USA) INC .
Kathy W einel
Director, Regulatory Compliance
CC: David Frydenlund
Garrin Palmer
Logan Shumway
Scott Bakken
Jordan App
DRC-2024-004668

Q4-23 DATA QUALITY REPORT FOR THE
PRIMARY TEST SECTION

WHITE MESA MILL – TAILINGS MANAGEMENT
CELL 2

ENERGY FUELS RESOURCES (USA) INC.

SAN JUAN COUNTY, UTAH

18 February 2024

1
1.0 INTRODUCTION

This Data Quality Report (DQR) was prepared to document data quality assurance for the
White Mesa Mill cover performance monitoring test section (Primary Test Section) for
fourth quarter 2023 (Q4-23). This report is documentary and not interpretative. The annual
report includes interpretation of the monitoring data.

The Primary Test Section was constructed in August – September 2016 over tailings
management Cell 2 at Energy Fuels Resources (USA) Inc.’s White Mesa Mill in San Juan
County, Utah. Hydrological monitoring was initiated on 29 September 2016. A large-scale
“ACAP” drainage lysimeter monitors the test section. The lysimeter is equipped to monitor
water balance components and meteorological data.

Fig. 1 shows a profile of the final cover being evaluated at White Mesa (minimum
thickness). Fig. 2 shows a cross-sectional schematic of the lysimeter. The test section is
instrumented with two nests of vertically stacked and co-located sensors to monitor soil
temperature and soil water content, as illustrated in Figs. 1 and 2. The nests are on the
centerline of the test section at the upper and lower third points. Probes in the lower nest
are odd numbered and probes in the upper nest are even numbered. The water content
probes were calibrated with on-site soils collected during construction. Temperature
compensation was incorporated into the calibrations.

Flows from runoff, lateral flow (interflow), and percolation collection points in the test
section are routed via pipe (Fig. 2) to collection basins in a subsurface vault downslope
from the test section. Flow into each basin is monitored by tipping buckets and a pressure
transducer. Flows reported by the tipping bucket are described in terms of “tips,” whereas
water elevations reported by the transducers are reported as “stage.” Flows are reported
in mm of water per unit area. The tipping buckets and pressure transducers were initially
calibrated in September 2016 and have been re-calibrated annually. The most recent
calibration was on 2 August 2023.

2.0 WATER BALANCE DATA

Data within this DQR were collected during Q4-23 from 28 September 2023 to 02 January
2024. These dates align with automated data downloads and do not correspond precisely
to the conventional start and end of Q4-23. Data for 3 January 2024 and onward will be
included in the Q1-24 report.

Table 1 summarizes the water balance quantities and Fig. 3 shows the water balance
graph for the test section. Fig. 4 shows cumulative percolation along with daily
precipitation measured at the test section. Figs. 5 to 32 show data from each sensor
collected during Q4-23. The quality assurance summary is on pp. 7-8.

Approximately 45 mm of precipitation was recorded in Q4-23, most of which was from a
series of storm events in late November and through December (Fig. 8). The uppermost
water content sensors responded to infiltration from these storms, with water contents
increasing in the upper 0.5 m of the cover (Fig. 14). None of the deeper sensors responded
to the precipitation events (Figs. 15-20), indicating no deeper penetration of water in Q4-
23. Approximately 0.06 mm of percolation was transmitted in Q4-23, with percolation
ceasing for the year in mid-November (Fig. 29). A trace of runoff (~0.02 mm) was recorded
in response to the aforementioned storms (Fig. 24). No lateral flow was recorded (Fig. 27).

2
3.0 CONCERNS

None at this time.

4.0 RESOLVED ISSUES

The apparent periodic loss of power to the vault that was reported in the previous year
has been resolved. The sensing device used to monitor power in the vault was defective
and replaced during the 2023 annual calibration and maintenance event on 02 August
2023. No apparent or actual power loss has been detected since the repair was made.

5.0 ACTION ITEMS

None at this time.

3

Fig. 1. Schematic of Cover Profile Evaluated at White Mesa.
0
0
0
0
0.5 ft Erosion Layer
3.5 ft Growth Medium
3.0 ft Compacted Cover
2.5 ft Interim Layer
0 = WCR or thermocouple

4

Fig. 2. Schematic of Lysimeter used for the White Mesa Primary Test Section.
rosion layer (0.5 ft)
____________________________ Growt h Medium (3 .5 ft) ____________________ _
Root Barrier
Sump
Percolation Pipe
Compacted
Subgrade
Compacted Cover (3.0 ft)
.................................. 1nterim .cover (2.S_ftJ.
60 mil LLDPE GM Geocomposite Drain Compac ted
Subgrade
60mil
LLDPE
GM

5

Table 1. Water balance quantities for the final cover test section at White Mesa from 09/29/16 to
01/02/24.
Calendar
Year
Water Balance Quantities (mm)
Precipitation Runoff Lateral
Flow ET D Storage Percolation
2016a 59.9 0.03 0.00 34.6 16.9 0.00
2017b 222.7 0.06 0.00 324.8 39.4 0.65
2018 163.4 0.09 0.00 124.6 37.9 0.90
2019 309.1 0.28 0.00 325.9 0.9 1.01
2020 130.4 0.04 0.00 175.6 -64.5 0.89
2021 223.4 0.19 0.00 242.4 -19.5 0.60
2022 179.8 0.11 0.01 168.9 25.0 0.28
2023 242.1 0.09 0.00 259.9 -26.8 0.45
2024 0.0 0.00 0.00 0.0 1.3 0.00
Notes: aPartial year. bDamage from vault flooding precluded measuring flows from 7
February 2017 – 25 March 2017.

6

Fig. 3 . Water balance quantities for the final cover test section at White Mesa from
09/29/16 to 01/02/24.
0
500
1000
1500
2000
0
1
2
3
4
5
9/20/16 12/7/17 2/24/19 5/13/20 7/31/21 10/18/22 1/5/24
Soil Water
Storage
ET
Surface
Runoff
Percolation
Lateral Flow
S
oil Water
St
orage
, C
um
ulativ
e
P
rec
ipit
ation
,
a
nd
Cum
ula
tive Ev
apotra
nspira
tio
n (mm)
Cumulat
ive
Runo
ff
, Late
ral Flo
w, a
nd Pe
rco
lat
ion

(m
m)
Precipitation
White Mesa, UT

7

DATA QUALITY REPORT SUMMARY: Q4-23
White Mesa Primary Test Section
09/28/23 through 01/02/24

Water Balance Summary
• Table 1 summarizes the water balance of the test section since inception.
• Fig. 3 presents the water balance graph for the test section since inception.
• Fig. 4 shows graphs of daily precipitation and cumulative percolation for the test section
since inception.

Meteorology
• The battery and solar panel are working properly (Fig. 5).
• All meteorological sensors are working properly (Figs. 6-13).
• The on-site precipitation data are generally consistent with the WRCC data, but are
greater than the NWS data recorded at the Blanding station (KBDG, 37.62° N,
109.47° W, Elev. 6001 ft) (Fig.8). The NWS Blanding station is missing precipitation
data on several dates during this period, which results in under reporting.
Independent precipitation measurements recorded by the Geonor gauge and the
tipping bucket are generally in agreement (Fig. 9).
• Solar radiation data are consistent with data recorded at the NWS Blanding station
(Fig. 13).

Test Section
• The WCR probes for measuring water content are functioning properly (Figs. 14-20).
Differences in water content of approximately 0.04 are reported by Probes 3 and 4 in
the growth medium layer at 914 mm bgs (Fig. 16). Differences in water content of
approximately 0.04 are reported by Probes 3 and 4 in the compacted layer at 2134
mm bgs (Fig. 19). Differences in water content of approximately 0.05 are reported by
Probes 1 and 2 in the interim layer at 2743 mm bgs (Fig. 20). These differences in
water content are real and reflect spatial variations in water content that remain from
the deep penetration of a wetting front in Q1-17.
• The thermocouples used to measure soil temperature are functioning properly (Fig. 21).
• Flows reported by the transducer and tippers for runoff are reasonably consistent
(Figs. 22-24).

8

• Flows reported by the transducer and tippers for lateral flow are reasonably consistent
(Figs. 25-27).
• Flows reported by the transducer and tippers for percolation are reasonably
consistent (Figs. 28-30).
• The vault stage has remained negative (Fig. 31). There is no water accumulating in
the vault.
• The voltage sensor that monitors the power supply in the vault is functioning properly
(Fig. 32).

9

Fig
.

4
.

Da
i
l
y

p
r
e
c
i
p
i
t
a
t
i
o
n

(
b
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)

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n
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c
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(
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)

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Wh
i
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e
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o
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09
/2
9/16
to

01
/
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/24
.

Fi
g
.

5.

Ba
t
t
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r
y

v
o
l
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r

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t
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i
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e

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a

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o
m

09
/
2
8/
23
to

01/02/24
.
0 10 20 30 40 50
0.
0
1.
0
2.
0
3.
0
4.
0
5.
0
9/
2
0
/
1
6
12
/
7
/
1
7
2/
2
4
/
1
9
5/
1
3
/
2
0
7/
3
1
/
2
1
10
/
1
8
/
2
2
1/
5
/
2
4
Da i ly P r ec ip it at io n (m m )
Cumulative Percolation (mm)
Wh
i
t
e

M
e
s
a
,

U
T
Pe
r
c
o
l
a
t
i
o
n
Pr
e
c
i
p
i
t
a
t
i
o
n
10 11 12 13 14
9/
2
5
/
2
3
10
/
1
2
/
2
3
10
/
2
9
/
2
3
11
/
1
5
/
2
3
12
/
2
/
2
3
12
/
1
9
/
2
3
1/
5
/
2
4
B atte ry (Vo lts)
t

10

Fig. 6. Daily precipitation at the final cover test section at White Mesa from 09/28/23
to 01/02/24.

Fig. 7. Frequency of Geonor precipitation gauge at White Mesa from 09/28/23 to
01/02/24. Frequency recorded by load cell is proportional to weight of liquid in
gauge and precipitation.
9/25/23 10/12/23 10/29/23 11/15/23 12/2/23 12/19/23 1/5/24
0
2
4
6
8
10
Daily Pr
e
cipi
tation (m
m)
9/25/23 10/12/23 10/29/23 11/15/23 12/2/23 12/19/23 1/5/240
1000
2000
3000
Frequency
of Geonor Prec
ipitation G
auge (Hz)

11

Fig. 8. Cumulative precipitation at the final cover test section at White Mesa (blue),
WRCC Kane Gulch-Blanding (green), and NWS Blanding station (red) from
09/28/23 to 01/02/24.

Fig. 9. Precipitation from tipper and Geonor precipitation gauge at the final cover test
section at White Mesa from 09/28/23 to 01/02/24.
9/25/23 10/12/23 10/29/23 11/15/23 12/2/23 12/19/23 1/5/24
0
20
40
60
80
100
Cumulative Precipitation (mm)
White Mesa
NWS Blanding
WRCC Kane Gulch-Blanding
0
5
10
15
20
25
0 5 10 15 20 25
White Mesa, UT
Tip
per P
rec
ip
itation (mm)
Geonor Precipitation (mm)

12

Fig. 10. Daily air temperature at the final cover test section at White Mesa from 09/28/23
to 01/02/24.

Fig. 11. Daily relative humidity at the final cover test section at White Mesa from
09/28/23 to 01/02/24.
9/25/23 10/12/23 10/29/23 11/15/23 12/2/23 12/19/23 1/5/24
Min Air Temp
Avg. Air Temp
Max Air Temp
-10
0
10
20
30
40
Dail
y A
ir Temperature (o
C)
9/25/23 10/12/23 10/29/23 11/15/23 12/2/23 12/19/23 1/5/24
Min RH
Avg. RH
Max RH
0
20
40
60
80
100
120
D
ail
y
R
e
la
ti
v
e H
um
id
ity
(
%
)

13

Fig. 12. Daily mean wind speed at the final cover test section at White Mesa from
09/28/23 to 01/02/24.

Fig. 13. Total daily solar radiation at the final cover test section at White Mesa (blue)
and NWS Blanding station (red) from 09/28/23 to 01/02/24.
0
2
4
6
8
10
9/25/23 10/12/23 10/29/23 11/15/23 12/2/23 12/19/23 1/5/24
D
ai
ly Mean Wi
nd Speed (m/s)
0
2000
4000
6000
8000
10000
9/25/23 10/15/23 11/4/23 11/25/23 12/15/23 1/5/24
S
olar Rad
iat
ion
(W-h
r/
m
2)
White
Mesa
Blanding

14

Fig. 14. Volumetric water content in the growth medium layer (457 mm bgs) of the final
cover test section at White Mesa from 09/28/23 to 01/02/24. Odd numbered
probe is downslope and even is upslope.

Fig. 15. Volumetric water content in the growth medium layer (685 mm bgs) of the final
cover test section at White Mesa from 09/28/23 to 01/02/24. Odd numbered
probe is downslope and even is upslope.
0.0
0.1
0.2
0.3
0.4
0.5
9/25/23 10/15/23 11/4/23 11/25/23 12/15/23 1/5/24
White Mesa, UT
(457-mm Depth Topsoil Layer)
Vo
lum
etric Wate
r C
onte
nt
Probe 13
Probe 14
0.0
0.1
0.2
0.3
0.4
0.5
9/25/23 10/15/23 11/4/23 11/25/23 12/15/23 1/5/24
White Mesa, UT
(685-mm Growth Medium Layer)
Volumetric Wate
r C
ontent
Probe 11
Probe 12
:::::::::::::::==:::::~==::::::::==~
,I

15

Fig.16. Volumetric water content in the growth medium layer (914 mm bgs) of the final
cover test section at White Mesa from 09/28/23 to 01/02/24. Odd numbered
probe is downslope and even is upslope.

Fig. 17. Volumetric water content in the compacted layer (1524 mm bgs) of the final
cover test section at White Mesa from 09/28/23 to 01/02/24. Odd numbered
probe is downslope and even is upslope.
0.0
0.1
0.2
0.3
0.4
0.5
9/25/23 10/15/23 11/4/23 11/25/23 12/15/23 1/5/24
White Mesa, UT
(914-mm Depth Growth Medium Layer)
Vo
lum
etric
Wate
r C
onte
nt
Probe 9
Probe 10
0.0
0.1
0.2
0.3
0.4
0.5
9/25/23 10/15/23 11/4/23 11/25/23 12/15/23 1/5/24
White Mesa, UT
(1524-mm Depth Compacted Layer)
Volu
met
ric
Wat
er Content
Probe 8
Probe 7
I
I I I I
--
--
r~~::::::::=!/~========::r============ -)'
--
' '

16

Fig. 18. Volumetric water content in the compacted layer (1829 mm bgs) of the final
cover test section at White Mesa from 09/28/23 to 01/02/24. Odd numbered
probe is downslope and even is upslope.

Fig. 19. Volumetric water content in the compacted layer (2134 mm bgs) of the final
cover test section at White Mesa from 09/28/23 to 01/02/24. Odd numbered
probe is downslope and even is upslope.
0.0
0.1
0.2
0.3
0.4
0.5
9/25/23 10/12/23 10/29/23 11/15/23 12/2/23 12/19/23 1/5/24
White Mesa, UT
(1829-mm Depth Compacted Layer)
Vol
umetric Water Content
Probe 6
Probe 5
0.0
0.1
0.2
0.3
0.4
0.5
9/25/23 10/12/23 10/29/23 11/15/23 12/2/23 12/19/23 1/5/24
White Mesa, UT
(2134-mm Depth Compacted Layer)
Volumetric Water Content
Probe 4
Probe 3
I

17

Fig. 20. Volumetric water content in the interim layer (2743 mm bgs) of the final cover
test section at White Mesa from 09/28/23 to 01/02/24. Odd numbered probe is
downslope and even is upslope.

Fig. 21. Soil temperature in the final cover test section at White Mesa from 09/28/23 to
01/02/24 (sensor depths in mm bgs in legend, D = downslope; U = upslope).
0.0
0.1
0.2
0.3
0.4
0.5
9/25/23 10/15/23 11/4/23 11/25/23 12/15/23 1/5/24
White Mesa, UT
(2743-mm Depth Interim Layer)
Volumetric Water C
onte
nt
Probe 2
Probe 1
0
10
20
30
40
9/25/23 10/12/23 10/29/23 11/15/23 12/2/23 12/19/23 1/5/24
White Mesa, UT 2743 mm D
2743 mm U
2134 mm D
2134 mm U
1829 mm D
1829 mm U
1524 mm D
1524 mm U
914 mm D
914 mm U
685 mm D
685 mm U
457 mm D
457 mm U
S
o
il Te
m
p
e
rat
u
e

(oC
)
2743 mm (D)
457 mm (U)

18

Fig. 22. Cumulative tips from tipper in the runoff basin for the final cover test section at
White Mesa from 09/28/23 to 01/02/24.

Fig. 23. Pressure transducer stage in the runoff basin for the final cover test section at
White Mesa from 09/28/23 to 01/02/24.
0
1
2
3
4
5
9/25/23 10/15/23 11/4/23 11/25/23 12/15/23 1/5/24
White Mesa, UT
Cumulative Tips for Runoff
Tipper (1 L)
0
100
200
300
400
500
9/25/23 10/12/23 10/29/23 11/15/23 12/2/23 12/19/23 1/5/24
White Mesa, UT
Run
off Basin
Stag
e fo
r Ru
no
ff (
mm
)
I I I I
... -
... ....--
... -
... -
. / I -
I I I I I
-
-
-

19

Fig. 24. Cumulative flow from pressure transducer stage and from the tipper in the runoff
basin for the final cover test section at White Mesa from 09/28/23 to 01/02/24.

Fig. 25. Cumulative tips from tipper in the lateral flow basin for the final cover test section
at White Mesa from 09/28/23 to 01/02/24.
0.0
0.1
0.2
0.3
0.4
0.5
9/25/23 10/12/23 10/29/23 11/15/23 12/2/23 12/19/23 1/5/24
White Mesa, UT
Cumulati
ve F
low in Runoff Basin (mm)
Tipper (1 L)Pressure Transducer
0
1
2
3
4
5
9/25/23 10/12/23 10/29/23 11/15/23 12/2/23 12/19/23 1/5/24
White Mesa, UT
C
u
mula
tive
Tips fo
r L
ater
al Flo
w
Tipper 1B (1 L)Tipper 1A (1 L)

20

Fig. 26. Pressure transducer stage in lateral flow basin for the final cover test section at
White Mesa from 09/28/23 to 01/02/24.

Fig. 27. Cumulative flow from pressure transducer stage and from tipper in lateral flow
basin for the final cover test section at White Mesa from 09/28/23 to 01/02/24.
0
100
200
300
400
500
9/25/23 10/12/23 10/29/23 11/15/23 12/2/23 12/19/23 1/5/24
White Mesa, UT
Pr
essu
re
Tra
n
sdu
ce
r Stage fo
r L
a
te
ral
F
lo
w
(m
m)

0.0
0.1
0.2
0.3
0.4
0.5
9/25/23 10/12/23 10/29/23 11/15/23 12/2/23 12/19/23 1/5/24
White Mesa, UT
C
umulative Flow in Lateral Flow B
asin (mm)
Tipper (1 L)Pressure Transducer

21

Fig. 28. Cumulative tips from the 70-mL tippers in the drainage basin for the final cover
test section at White Mesa from 09/28/23 to 01/02/24.

Fig. 29. Pressure transducer stage in drainage basin for the final cover test section at
White Mesa from 09/28/23 to 01/02/24.
0
50
100
150
200
9/25/23 10/12/23 10/29/23 11/15/23 12/2/23 12/19/23 1/5/24
C
u
m
u
la
ti
v
e Tip
s

f
o
r
D
rai
n
a
g
e

Tipper 1-L
Tipper 70 mL
0
100
200
300
400
500
9/25/23 10/12/23 10/29/23 11/15/23 12/2/23 12/19/23 1/5/24
White Mesa, UT
P
re
s
su
r
e Tra
n
sd
u
cer
Sta
g
e fo
r Dra
in
ag
e
(mm
) I I I I I
-
-
-
-I I I I I

22

Fig. 30. Cumulative flow from pressure transducer stage and from tippers in drainage
basin for the final cover test section at White Mesa from 09/28/23 to 01/02/24.

Fig. 31. Vault stage for the final cover test section at White Mesa from 09/28/23 to
01/02/24.
0.0
0.1
0.2
0.3
0.4
0.5
9/25/23 10/12/23 10/29/23 11/15/23 12/2/23 12/19/23 1/5/24
White Mesa, UT
C
u
mu
la
tive

Flo
w
in
D
r
ain
a
ge

Bas
in

(m
m)

Tipper (70 mL)
Pressure Transducer
Tipper (1 L)
-15.0
-10.0
-5.0
0.0
9/25/23 10/12/23 10/29/23 11/15/23 12/2/23 12/19/23 1/5/24
White Mesa, UT
Va
u
lt Sta
ge (
mm)

I

23

Fig. 32. Vault voltage in the basin for the final cover test section at White Mesa from
09/28/23 to 01/02/24.
0
100
200
300
400
500
9/25/23 10/15/23 11/4/23 11/25/23 12/15/23 1/5/24
White Mesa, UT
Vault Voltage
(volt)