DRC-2018-002928 - 0901a068807d80b5

Department of
Environmental Quality
Alan Matheson
Executive Director
GARY R. HERBERT
Governor
SPENCER J COX
Lieutenant Governor
DIVISION OF WASTE MANAGEMENT
AND RADIATION CONTROL
Scott T. Anderson
Director
D 2,0 r3-00Z926
MEMORANDUM
TO: Project File C-2018-33 z-Aitt° c6 THROUGH: Phil Goble, Section Manager
FROM: Russell J. Topham, PE
DATE: February 28, 2018
SUBJECT: Engineering Module 75A, Review of the 4th Quarter 2017 (October-December, 2017)
DMT Performance Standards Monitoring Report and Cell 4A and Cell 4B BAT
Performance Standards Monitoring Report (Report). Groundwater Discharge Permit
(GWDP) UGW370004 — Energy Fuels Resources, Inc. (EFR) White Mesa Mill,
Blanding, Utah
This is a summary of Utah Division of Waste Management and Radiation Control (DWMRC) staff
review of the EFR DMT Performance Monitoring Report and Cell 4A and Cell 4B BAT Performance
Standards Monitoring Report dated February 12, 2018, for the 4th Quarter 2017 (October-December,
2017) monitoring period (Report). DWMRC received the Report on February 14, 2018 in both hard
copy and CD formats. Discussions in this document reference the White Mesa Mill Discharge
Minimization Technology (DMT) Monitoring Plan, Revision 12.4 (DMT Plan), dated December, 2016.
After review of this report, DWMRC staff findings and recommendations are as follows:
Summary of Findings
1. Weekly monitoring of Cell 1 solution pool elevations occurred as required, and the solution
pool elevation remained below the specified limit.
2. Weekly monitoring of Cell 4A solution pool elevations occurred as required to calculate
acceptable leakage rates, and the leakage rate thus determined remained below the specified
limit
3. Weekly monitoring of Cell 4B solution pool elevations occurred as required, and the solution
pool elevation remained below the specified limit.
DRC-20 195 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
Printed on 100% recycled paper
Review Memorandum, Project C-2018-33
February 22, 2018
Page 2
4. Data provided in Attachment C to the Report supports a conclusion that EFR has generally met
the requirement to keep water levels in the Cell 2 slimes drain as low as reasonably achievable.
However, the data also supports a hypothesis that the method of demonstrating successful
efforts to maintain fluid levels as low as possible that applied during this Thonitoring period may
be inadequate to reflect the realities encountered in the field. With the recently-completed
license renewal, the method of demonstrating that the fluid is being extracted as rapidly as
practicable has changed, but the monitoring period covered by this report predates
implementation of the new method.
5. Monitoring of the feedstock storage area occurred as required. The data support a conclusion
that no feedstock existed outside the designated feedstock storage areas.
6. EFR met the requirements for inspection of the liner systems. No damage was detected during
the reporting period.
7. EFR has met the requirements for inspecting the New Decontamination Pad, finding no
indication of leakage from secondary containment or other indicators of substandard
performance.
8. EFR has met the requirements for inspection of the used oil and fuel storage tanks and
associated concrete pads. Np leaks were observed, and cracks that had developed in the pads
over the past year were sealed.
9. EFR has met the requirements for inspecting the Old Decontamination Pad, finding no
indications of substandard conditions.
10. EFR has met the monitoring requirements for Cell 4A and 4B BAT performance and corrected
all mechanical failures the same day as detected.
11. The leak detection systems in Cells 1, 2, and 3 appear to have operated properly, and no fluids
were detected therein during the 4th Quarter 2017.
12. EFR has met the requirements for inspection and crack/joint repair of the Ammonium Sulfate
Pad.
Summary of Recommendations
1. The DWMRC should issue a closeout letter for the review of this report.
1.0 Tailings Wastewater Pool Elevation Monitoring
Requirements
Part I.E.7(a) of the GWDP requires EFR to monitor and record weekly the elevation of the wastewater
pool in Tailings Cells 1 and 3 to ensure compliance with Condition 10.3 of the License.
Review Memorandum, Project C-2018-33
February 22, 2018
Page 3
Part I.D.3(e) of the GWDP requires EFR to operate Roberts Pond to provide a minimum two feet of
freeboard at all times. Roberts Pond has been taken out of service, and the liner discarded in the Cell 3
disposal area set aside for plant-generated waste. The soils bounding the liner were surveyed for
contamination, and all contamination detected was remediated. The pond has been backfilled. The
requirement to monitor freeboard was removed during the just-completed renewal of the GWDP.
Reference to this requirement will not appear in future
Part 3.1(d) of the DMT/BAT Plan requires EFR to measure the solution pool elevation in Cells 4A and
4B weekly, and the tailings beach maximum elevation and area within Cells 4A and 4B monthly.
Results
Cell 1
Attachment A to the Report contains weekly pool elevations for Cell 1 indicating compliance with the
prescribed freeboard requirements.
Cell 3
Tailings have nearly completely filled Cell 3. Recognizing this, letters from the Director dated January
27, 2011 and March 14, 2011 formally eliminated the need for solution pool elevation measurement in
Cell 3. The January 27, 2011 letter and a letter from the Director dated March 15, 2011 concluded a
process ending the need for freeboard-related solution pool elevation monitoring in Cell 3. However,
Part 3.1(a) of the DMT/BAT Plan requires monitoring solution pool elevations in Cells 4A and 4B to
facilitate determination of compliance with FML leakage rate limitations.
As noted, no requirement for weekly solution pool elevation measurement at Cell 3 existed during the
monitoring period. Attachment A to the report reflects no measurements for the reported quarter.
Cell 4A
Attachment A to the Report contains weekly solution pool elevations for Cell 4A in support of
calculating acceptable leak rates for the liner system
Cell 4B
Attachment A to the Report includes solution pool elevation readings for Cell 48 indicating compliance
with the prescribed freeboard requirements.
Findings: The data presented in the report demonstrate EFR compliance with the solution pool
operational requirements of the DMT/BAT plan in force during the quarter.
2.0 Slimes Drain Water Level Monitoring
Requirements
Part I.F.2 of the GWDP requires EFR to include in the Report, all DMT performance standards
monitoring detailed in Parts I.D.3 and I.E.7 of the GWDP.
Review Memorandum, Project C-2018-33
February 22, 2018
Page 4
Part I.D.3(b)(1) of the GWDP requires EFR to maintain the fluid level in the slimes drain of Cells 2 and
3 as low as reasonably achievable at all times, and to demonstrate that performance through adherence
to the current DMT Monitoring Plan.
Part I.E.7(b) of the GWDP requires monthly monitoring and recording of the depth to wastewater in the
slimes drain access pipe as described in Part I.D.3 of the GWDP and the current DMT Monitoring Plan.
Part 3.1(b)(v) of the DMT Monitoring Plan requires EFR to monitor and record weekly the depth to
wastewater in the Cell 2 slimes drain access pipe to determine maximum and minimum head before and
after a pumping cycle, respectively.
Results
Section 4.1 of the Report asserts that the above discussed monitoring requirements only pertain to Cell 2
for the reporting period, as dewatering operations have not commenced in Cell 3. I concur with this
assessment.
Most of this section repeats, with appropriate edits, material presented in earlier review memoranda for
the past two years. The material is repeated because a technical violation condition is emerging that I do
not believe the Division should use as a point of enforcement. Physical processes beyond the control of
the licensee and installation of additional cover material deserve consideration. Furthermore, in the
license and permit renewal just completed, the method of determining that the licensee is doing all
within reason to remove fluid from the tailings mass has been modified to avoid the situation discussed
below.
Weekly water level monitoring of the Cell 2 slimes drain is not required as part of the DMT plan, but is
required under Part I.D.3(b)(1) of the GWDP. EFR retains records of Cell 2 slimes drain monitoring at
the mill.
Attachment C to the Report contains data from the quarterly recovery head measurements (discussed in
the next paragraph). The recovery head monitoring data provides indirect evidence that EFR has
maintained the fluid level in the Cell 2 slimes drain as low as reasonably achievable, as required in
GWDP, Part I.D.3(b)(1). From the graph of slimes drain recovery head data in Attachment D, it is
apparent that the downward trend that occurred between May of 2011 and April of 2014 has not
continued, as the performance measurement method assumed it would. All measurements since the 2nd
Quarter of 2014 are above this measurement. It appears that the readings beginning with the 2nd Quarter
of 2014 are roughly equivalent to each other, only varying by "noise," or imperfection, in the
measurement technique. Furthermore, the trend reversed abruptly during the 2nd Quarter of 2017. The
abrupt rise in the recovery head measurement is attributable to recent cover construction activity and
will be discussed toward the end of this section. The trend has again reversed, and is now declining.
In reviews of previous Reports, I stated that more information is required to understand whether
hydraulic equilibrium has been reached with approximately 7.5 feet of hydraulic head (approximately
22.5 feet from the surface of the temporary cover on the cell) at the pumping point (Report, Appendix
D). Table 2-1 on p. 7 of the Tailings Data Analysis Report (TDAR, April, 2015) presents a water table
at a depth of between 0.2 feet and 12.3 feet of the surface of the temporary cover. Likewise, Table 4-1
indicates the depth to top of saturated tailings varying from 3.92 feet to 11.58 feet below the temporary
cover surface, with the greater depths occurring closer to the slimes drain alignment (TDAR, p. 17).
Review Memorandum, Project C-2018-33
February 22, 2018
Page 5
These data indicate a substantial volume of fluid yet to be removed from the cell. Recent installation of
additional cover material has surcharged the tailings, resulting in increased the yield from the slimes
drain as well as increased fluid level within the tailings mass.
The TDAR postulates the presence of gypsum in the interstices within the tailings mass (p. 11). This
condition would reduce hydraulic conductivity within the tailings. The temporary cover is composed of
random fill, which on visual inspection appears to be a sandy gravel or gravelly sand with cobbles and
boulders. Sieve analysis reveals a fines fraction (material finer than the #200 sieve) of between 10% and
30%, with Atterberg Limits testing suggesting the presence of clay in the fines. However, the temporary
cover was placed without densification, which would offset to some degree the ability of any clay
present to resist percolation of water. The porosity of this cover would allow surface water to penetrate
into the tailings below. While the region in which the mill is sited has experienced drought conditions,
significant storms have occurred. Those may have recharged the cell, offsetting the withdrawal through
the slimes drain. 2015 saw wet conditions through the spring and early summer with normal-to-wet
conditions prevailing through the end of the year. Likewise, 2016 and 2017 saw spring and summer
storms.
Given the above hypotheses and the data presented in Attachment D to the report, I question whether the
current practice of withdrawing slimes will prove effective in rapidly reducing the fluid level in the cell.
Installation of additional platform fill and primary radon barrier has resulted in buildup of excess pore
pressure in the tailings mass which, in turn, has pushed the phreatic surface upward and delivered more
fluid to the drain for removal. The withdrawal rate has increased by approximately 2,000 gallons per
month.
The licensee has placed piezometers at the settlement monitoring points and will include the fluid levels
measured in the piezometers in future quarterly reports. I have received weekly reports of fluid level
measurements in the piezometers which showed a progressive rise in the phreatic surface as crews
placed and compacted the first two layers of the final cover system, followed by a fall in the phreatic
surface. I attribute the fall in the fluid surface to dissipation of the excess pore pressure created by
surcharging of the tailings mass and accelerated withdrawals of the slimes from the drain. The drop in
fluid surface from the peak is not yet significant, but the accelerated withdrawal rate from the slimes
drain has persisted.
The phreatic surface shows a dip along the alignment of the slimes drain. Having a network of
piezometers will provide a means of assessing the slimes content of the tailings mass and of estimating
the length of time that may be required to evacuate the slimes.
The placement of additional platform fill and primary Radon barrier has changed the conditions being
monitored. With that in mind, during the recent renewal of the GWDP, the monitoring criteria were
changed to measure quantity pumped over time and fluid head over the pump to demonstrate that
pumping is occurring as rapidly as developing fluid head allows. The newly completed surface of the
primary radon barrier is a smooth, compacted surface that should shed most of the precipitation that falls
on the cell. This should reduce concern for fluid recharge.
The change in criteria for demonstrating slimes removal did not occur until after this monitoring period.
Therefore, the requirement to demonstrate a reduction in the fluid head by plotting the 3-year running
average was in effect. The licensee is in violation of this condition because the 3-year trend has shown a
rise in the last two quarters; however, as discussed above, the placement of additional fill on the cell has
Review Memorandum, Project C-2018-33
February 22, 2018
Page 6
changed the hydraulic conditions, and the violation condition is attributable to that work. The new
material is the primary radon barrier, and its installation is beneficial. I see no reasonable rationale for
enforcing the requirement for slimes removal applicable during this monitoring period given these
conditions.
Finding.. Data provided in Attachment C to the Report supports a conclusion that EFR has generally
met the requirement to keep water levels in the Cell 2 slimes drain as low as reasonably achievable,
notwithstanding a technical violation attributable to the inability of the demonstration method to
account for current conditions in the field.
Recommendation: The DWMRC and EFR should continue to monitor the licensee's efforts to remove
slimes from the tailings mass. The new method for determining compliance will take effect for reporting
periods beginning January, 2018. No enforcement of the current provision should occur provided the
licensee continues to remove available fluid from the slimes drain.
3.0 Feedstock Storage Monitoring
This section addresses both bulk conventional feedstock (ore) and alternate feed stored onsite. Ore is
stored on the ore pad.
Requirement
Part I.D.11 of the GWDP anticipates and governs storage of alternate feed outside the confines of the
ore pad.
Results
Weekly inspection revealed no evidence of ore beyond the boundaries of the ore pad. Storage practices
for alternate feeds appear compliant with GWDP requirements.
The current report highlighted no example of significant standing water volume persisting on the ore pad
after storms.
Finding.. Monitoring of the feedstock storage area occurred as required. The data support a conclusion
that no feedstock existed outside the designated feedstock storage areas. Standing water problems were
addressed during the quarter.
Recommendation.. Efforts to address the storm water issue should be monitored over several inspections
and report review cycles to see that changes made by the licensee are effective and lasting. Inasmuch as
this is not a failure in monitoring, but in operations, this follow through activity should not prevent
closing out the review of the Report.
4.0 Tailings Cells and Pond Liner System Repairs
Requirement
Parts I.E.7(f) and I.G.3 specifies how the licensee must address leaks discovered in the pond liner
system. Part I.F.2 specifies reporting requirements for such liner breaches.
Review Memorandum, Project C-2018-33
February 22, 2018
Page 7
Results
Inspection of all cells occurred weekly during the period covered in the report. The report indicated no
cases of liner damage in the tailings cells discovered or repaired during the quarter.
Finding: EFR met the requirements for inspection and repair of the liners.
5.0 Decontamination Pads
Requirement
Weekly inspection of the New Decontamination Pad for leakage occurred as required under Part I.F.12
of the GWDP.
Results
The monitoring portals were dry during all inspections, indicating no leakage from primary containment.
Cracks were repaired during the Report period.
Finding.. EFR has met the routine and annual requirements for inspecting both the Old and New
Decontamination Pads, finding no indication of leakage from secondary containment.
6.0 Used Oil and Fuel Storage Tanks
Requirement
The Spill prevention, Control and Countermeasures Plan and the DMT Plan require annual inspection of
the used oil and fuel storage tanks. The associated concrete is to be inspected and sealed in the same
manner as the decontamination pads.
Results
Plant personnel inspected the tanks and pads during the 2'd quarter of 2017, noted no leakage from the
tanks, and applied sealant to joints and cracks in the pads and containment walls as required. The
requirement is annual, so no inspection was required during the quarter.
Finding: EFR has met the routine requirements for inspecting the used oil and fuel tanks and associated
secondary containment features, and has sealed joints and cracks therein.
7.0 Ammonium Sulfate Pad
Requirement
Phase I of the Nitrate Corrective Action Plan required installation of a concrete pad to prevent water
penetrating to nitrate-containing soils in the area of the ammonium sulfate crystal tank. This pad was
installed and inspected by DWMRC during the Report quarter. The DWMRC approved the construction
by letter on June 26, 2015. Inspections and filling of cracks are required quarterly for eight consecutive
Review Memorandum, Project C-2018-33
February 22, 2018
Page 8
quarters following approval, and annually thereafter. Annual inspection has now commenced and will
be done during the second quarter of 2018.
Results
Plant personnel inspected the pad and applied sealant to joints and cracks as required.
Finding: EFR has met the routine requirements for inspecting the Ammonium Sulfate Pad, and has
sealed joints and cracks therein.
8.0 Cells 4A and 4B BAT Performance Standards Monitoring
Requirement
Requirements for measuring BAT performance for Cells 4A and 4B include verifying that leak detection
system equipment operates appropriately, verifying that fluid head in the leak detection system sumps
does not exceed 1 foot above the lowest point in the secondary (lower) flexible membrane liner, and
recording the volume of fluid pumped from the leak detection systems for the two cells. EFR must also
record the fluid head in Cell 4B for compliance purposes, and in Cell 4A for computation of acceptable
leakage rate in Cell 4A.
The data provided in the report and its attachments provide evidence of compliance with the Cells 4A
and 4B BAT performance monitoring standards in place during the monitoring period.
Results
Cell 4A and 4B
No failures were noted in the Cell 4A or Cell 4B leak detection systems during the Report period.
Finding: EFR has met the monitoring requirements for Cell 4A and 4B BAT performance. No
mechanical failures were noted during the quarter.
9.0 Cells 1, 2 and 3 Leak Detection System Monitoring
Requirement
Leak detection system monitoring requirements for Cells 1, 2 and 3 appear in the Radioactive Materials
License rather than the GWDP. For consistency, the DWMRC requested that this monitoring be
included as part of the quarterly report and EFR has consented to do so.
Results
The report and its attachments contain weekly monitoring data for the operational status of the leak
detection system equipment, fluid levels detected in the leak detection systems, and volumes of fluid
pumped. From the data, EFR represents that no failures of the monitoring equipment occurred that were
not corrected within 24 hours. Leak detection systems for the three cells measured dry; therefore, no
fluids were pumped from them.
Review Memorandum, Project C-2018-33
February 22, 2018
Page 9
Finding.. The leak detection systems in Cells 1, 2 and 3 appear to have operated properly, and no fluids
were detected therein during reporting period.