DRC-2009-008043 - 0901a06880140a1f

State of Utah
JON M.HUNTSMAN,JR.
Governor
GARY HERBERT
Lieutenant Governor
September 17,2008
Department of
Environmental Quality
Richard W.Sprott
Executive Director
DIVISION OFRADIATION CONTROL
Dane L.Finerfrock
Director
Mr.Ron Hochstein,President
Denison Mines (USA)Corp.(DUSA)
1050 17th Street,Ste.950
Denver,CO 80225
Dear Mr.Hochstein:
SUBJECT:September 16,2008 DUSA Email Conveying Proposed Revisions to the Ce1l4A BAT
Monitoring,Operations and Maintenance Plan (O&M Plan);September 16,2008 DRC
Email with Comments on the O&M Plan;September 12,2008 DUSA Email conveying
Proposed Revisions to the White Mesa Mill Tailings Management System;and Discharge
Minimization Technology (DMT)Monitoring Plan (DMT Plan)and the O&M Plan;
O&M and DMT Plan Approval,and Authorization to Operate Tailings Ce1l4A
We have received and reviewed the subject submittals.The September 16,2008 DUSA submittal
conveyed the "09/08 Revision Denison 1.3"of the O&M Plan for Ce1l4A without figure attachments.The
September 12,2008 DUSA submittal conveyed "09/08 Revision:Denison-6"ofthe DMT Plan and an
earlier "09/08 Revision Denison 1.2"version ofthe O&M Plan with all attachments.We have compared
these submittals to our comment email dated September 16,2008,and to our previous comment letter
dated September 10,2008.Therefore,we hereby approve these versions ofthe Cell 4A O&M Plan and
the DMT Plan with the September 12,2008 attachments,copies ofthese documents are attached herewith.
The items in our letter ofJuly 29,2008 regarding major items needing resolution prior to beginning the
operation ofthe cell now appear to be completed,therefore we hereby authorize DUSA to operate
reconstructed Cell 4A.
UTAH RADlAnON CONTROL BOARD
~~
Executive Secretary
DLF:LBM:DAR:dr
Attachments
cc:Mr.Harold Roberts,Executive V.P.,DUSA
F:\DUSA\Ce1l4A\Op Approval\Monitoring.O&M Plan\Plan Approvals &Auth10 Operate 09-08
168 North 1950 West·Salt Lake City.UT
Mailing Address:P.O.Box 144850·Salt Lake City.UT 84114-4850
Telephone [phone]·Fax [phone]·T.D.D.[phone]
www.deq.utah./iov
Printed on 100%recycled paper
09/08 Revision Denison 1.3
Page 1
Cell 4A BAT Monitoring, Operations and Maintenance Plan.
Introduction
Construction of Cell 4A was authorized by the Utah Department of Environmental
Quality, Division of Radiation Control (“DRC) on June 25, 2007. The construction
authorization provided that Cell 4A shall not be in operation until after a BAT
Monitoring, Operations and Maintenance Plan is submitted for Executive Secretary
review and approval.The Plan shall include requirements in Part F.3 of the Groundwater
Discharge Permit No. UGW370004 (“GWDP”) and full fill the requirements of Parts
I.D.6, I.E.8, and I.F.8 of the GWDP.
Cell Design
Tailings Cell 4A consists of the following major elements:
a)Dikes –consisting of earthen embankments of compacted soil, constructed
between 1989-1990, and composed of four dikes, each including a 15-foot
wide road at the top (minimum). On the north,east,and south margins these
dikes have slopes of 3H to 1V. The west dike has a interior slope of 2H to
1V. Width of these dikes varies; each has a minimum crest width of at least
15 feet to support an access road. Base width also varies from 89-feet on the
east dike (with no exterior embankment), to 211-feet at the west dike.
b)Foundation –including subgrade soils over bedrock materials. Foundation
preparation included excavation and removal of contaminated soils,
compaction of imported soils to a maximum dry density of 90%. Floor of
Cell 4A has an average slope of 1% that grades from the northeast to the
southwest corners.
c)Tailings Capacity –the floor and inside slopes of Cell 4A encompass about 40
acres and have a maximum capacity of about 1.6 million cubic yards of
tailings material storage (as measured below the required 3-foot freeboard).
d)Liner and Leak Detection Systems –including the following layers, in
descending order:
1)Primary Flexible Membrane Liner (FML)–consisting of impermeable 60
mil high density polyethylene (HDPE) membrane that extends across both
the entire cell floor and the inside side-slopes, and is anchored in a trench
at the top of the dikes on all four sides. The primary FML will be in direct
physical contact with the tailings material over most of the Cell 4A floor
area. In other locations, the primary FML will be in contact with the
slimes drain collection system (discussed below).
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2)Leak Detection System –includes a permeable HDPE geonet fabric that
extends across the entire area under the primary FML in Cell 4A, and
drains to a leak detection sump in the southwest corner. Access to the leak
detection sump is via an 18-inch inside diameter (ID)PVC pipe placed
down the inside slope, located between the primary and secondary FML
liners. At its base this pipe will be surrounded with a gravel filter set in
the leak detection sump, having dimensions of 10 feet by 10 feet by 2 feet
deep. In turn, the gravel filter layer will be enclosed in an envelope of
geotextile fabric. The purpose of both the gravel and geotextile fabric is to
serve as a filter.
3)Secondary FML –consisting of an impermeable 60-mil HDPE membrane
found immediately below the leak detection geonet. Said FML also
extends across the entire Cell 4A floor, up the inside side-slopes and is
also anchored in a trench at the top of all four dikes.
4)Geosynthetic Clay Liner –consisting of a manufactured geosynthetic clay
liner (GCL) composed of 0.2-inch of low permeability bentonite clay
centered and stitched between two layers of geotextile. Prior to disposal
of any wastewater in Cell 4A, the Permittee shall demonstrate that the
GCL has achieved a moisture content of at least 50% by weight.This
item is a revised requirement per DRC letter to DUSA dated September
28, 2007
e)Slimes Drain Collection System –including a two-part system of strip drains
and perforated collection pipes both installed immediately above the primary
FML, as follows:
1)Horizontal Strip Drain System –is installed in a herringbone pattern
across the floor of Cell 4A that drain to a “backbone” of perforated
collection pipes. These strip drains are made of a prefabricated two-part
geo-composite drain material (solid polymer drainage strip) core
surrounded by an envelope of non-woven geotextile filter fabric. The strip
drains are placed immediately over the primary FML on 50-foot centers,
where they conduct fluids downgradient in a southwesterly direction to a
physical and hydraulic connection to the perforated slimes drain collection
pipe. A series of continuous sand bags, filled with filter sand cover the
strip drains. The sand bags are composed of a woven polyester fabric
filled with well graded filter sand to protect the drainage system from
plugging.
2)Horizontal Slimes Drain Collection Pipe System –includes a “backbone”
piping system of 4-inch ID Schedule 40 perforated PVC slimes drain
collection (SDC) pipe found at the downgradient end of the strip drain
lines. This pipe is in turn overlain by a berm of gravel that runs the entire
diagonal length of the cell, surrounded by a geotextile fabric cushion in
immediate contact with the primary FML. In turn, the gravel is overlain
Cell 4A BAT Monitoring, Operations and Maintenance Plan 09/08 Revision Denison 1.3
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by a layer of non-woven geotextile to serve as an additional filter material.
This perforated collection pipe serves as the “backbone” to the slimes
drain system and runs from the far northeast corner downhill to the far
southwest corner of Cell 4A where it joins the slimes drain access pipe.
3)Slimes Drain Access Pipe –consisting of an 18-inch ID Schedule 40 PVC
pipe placed down the inside slope of Cell 4A at the southwest corner,
above the primary FML. Said pipe then merges with another horizontal
pipe of equivalent diameter and material, where it is enveloped by gravel
and woven geotextile that serves as a cushion to protect the primary FML.
A reducer connects the horizontal 18-inch pipe with the 4-inch SDC pipe.
At some future time, a pump will be set in this 18-inch pipe and used to
remove tailings wastewaters for purposes of de-watering the tailings cell.
f)Dike Splash Pads –A minimum of eight (8) 10-foot wide splash pads are
installed on the interior dike slopes to protect the primary FML from abrasion
and scouring by tailings slurry. These pads will consist of an extra layer of 60
mil HDPE membrane that will be placed down the inside slope of Cell 4A,
from the top of the dike and down the inside slope.The pads on the north side
of the Cell will extend to a point 5-feet beyond the toe of the slope to protect
the liner bottom during initial startup of the Cell.The exact location of the
splash pads is detailed on the As-Built Plans and Specifications.
g)Emergency Spillway –a concrete lined spillway constructed near the western
corner of the north dike to allow emergency runoff from Cell 3 into Cell 4A.
This spillway will be limited to a 6-inch reinforced concrete slab set directly
over the primary FML in a 4-foot deep trapezoidal channel. No other spillway
or overflow structure will be constructed at Cell 4A. All stormwater runoff
and tailings wastewaters not retained in Cells 2 and 3, will be managed and
contained in Cell 4A, including the Probable Maximum Precipitation and
flood event.
Cell Operation
Solution Discharge
Cell 4A will initially be used for storage and evaporation of process solutions
from the Mill operations. These process solutions will be from the
uranium/vanadium solvent extraction circuit, or transferred from Cell 1
evaporation pond or the free water surface from Cell 3. The solution will be
pumped to Cell 4A through 6 inch or 8 inch diameter HDPE pipelines.The initial
solution discharge will be in the southwest corner of the Cell. The discharge pipe
will be routed down the Splash Pad provided in the corner of the Cell to protect
the pipeline running from the solution reclaim barge. The solution will be
discharged in the bottom of the Cell, away from any sand bags or other
installation on the top of the FML. Building the solution pool from the low end of
Cell 4A BAT Monitoring, Operations and Maintenance Plan 09/08 Revision Denison 1.3
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the Cell will allow the solution pool to gradually rise around the slimes drain
strips, eliminating any damage to the strip drains or the sand bag cover due to
solution flowing past the drainage strips.The solution will eventually be
discharged along the dike between Cell 3 and Cell 4A, utilizing the Splash Pads
described above. The subsequent discharge of process solutions will be near the
floor of the pond, through a discharge header designed to discharge through
multiple points, thereby reducing the potential to damage the Splash Pads or the
Slimes Drain system.At no time will the solution be discharged into less than 2
feet of solution.As the cell begin to fill with solution the discharge point will be
pull back up the Splash Pad and allowed to continue discharging at or near the
solution level.
Initial Solids Discharge
Once Cell 4A is needed for storage for tailings solids the slurry discharge from
No. 8 CCD thickener will be pumped to the cell through 6 inch or 8 inch diameter
HDPE pipelines. The pipelines will be routed along the dike between Cell 3 and
Cell 4A, with discharge valves and drop pipes extending down the Splash Pads to
the solution level.One or all of the discharge points can be used depending on
operational considerations. Solids will settle into a cone, or mound, of material
under the solution level, with the courser fraction settling out closer to the
discharge point.The initial discharge locations are shown on Figure 1.Figure 2
illustrates the general location of the solution and slurry discharge pipelines and
control valve locations. The valves are 6” or 8” stainless steel knife-gate valves.
The initial discharge of slurry will be at or near the toe of the Cell slope and then
gradually moved up the slope, continuing to discharge at or near the water
surface. This is illustrated in Section A-A on Figure 2.Because of the depth of
Cell 4A,each of the discharge points will be utilized for an extended period of
time before the cone of material is above the maximum level of the solution. The
discharge location will then moved further to the interior of the cell allowing for
additional volume of solids to be placed under the solution level. The solution
level in the cell will vary depending on the operating schedule of the Mill and the
seasonal evaporation rates.The tailings slurry will not be allowed to discharge
directly on to the Splash Pads, in order to further protect the FML. The tailings
slurry will discharge directly in to the solution contained in the Cell, onto an
additional protective sheet, or on to previously deposited tailings sand.
Equipment Access
Access will be restricted to the interior portion of the cell due to the potential to
damage the flexible membrane liner. Only rubber tired all terrain vehicles or foot
traffic will be allowed on the flexible membrane liner. Personnel are also
cautioned on the potential damage to the flexible membrane liner through the use
and handling of hand tools and maintenance materials.
Cell 4A BAT Monitoring, Operations and Maintenance Plan 09/08 Revision Denison 1.3
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Reclaim Water System
A pump barge and solution recovery system will be installed in the southwest
corner of the cell to pump solution from the cell for water balance purposes or for
re-use in the Mill process.Figure 3 illustrates the routing of the solution return
pipeline and the location of the pump barge. The pump barge will be constructed
and maintained to ensure that the flexible membrane liner is not damaged during
the initial filling of the cell or subsequent operation and maintenance activities.
The condition of the pump barge and access walkway will be noted during the
weekly Cell inspections.
Interim Solids Discharge
Figure 4 illustrates the progression of the slurry discharge points around the east
side of Cell 4A.Once the tailings solids have been deposited along the north and
east sides of the Cell, the discharges points will subsequently be moved to the
sand beaches, which will eliminate any potential for damage to the liner system.
Liner Maintenance and QA/QC
Any construction defects or operational damage discovered during observation of
the flexible membrane liner will be repaired, tested and documented according to
the procedures detailed in the approved Revised construction Quality
Assurance Plan for the Construction of the Cell 4A Lining System, May
2007, by GeoSyntec Consultants.
BAT Performance Standards for Tailings Cell 4A
DUSA will operate and maintain Tailings Cell 4A so as to prevent release of wastewater
to groundwater and the environment in accordance with this BAT Monitoring Operations
and Maintenance Plan, pursuant to Part I.H.19 of the GWDP.These performance
standards shall include:
1)Leak Detection System Pumping and Monitoring Equipment –the
leak detection system pumping and monitoring equipment, includes a
submersible pump, pump controller,water level indicator (head
monitoring), and flow meter with volume totalizer. The pump controller
is set to maintain the maximum level in the leak detection system at no
more than 1 foot above the lowest level of the secondary flexible
menbrane.A second leak detection pump with pressure transducer, flow
meter, and manufacturer recommended spare parts for the pump controller
and water level data collector is maintained in the Mill warehouse to
ensure that the pump and controller can be replaced and operational within
24 hours of detection of a failure of the pumping system. The root cause
Cell 4A BAT Monitoring, Operations and Maintenance Plan 09/08 Revision Denison 1.3
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of the equipment failure will be documented in a report to Mill
management with recommendations for prevention of a re-occurrence.
2)Maximum Allowable Head –the Permittee shall measure the fluid head
above the lowest point on the secondary flexible membrane by the use of
procedures and equipment specified in the White Mesa Mill Tailings
Management System and Discharge Minimization Technology
(DMT) monitoring Plan, 3/07 Revision: Denison-3,or the currently
approved DMT Plan. Under no circumstance shall fluid head in the leak
detection system sump exceed a 1-foot level above the lowest point in
the lower flexible membrane liner.
3)Maximum Allowable Daily LDS Flow Rates -the Permittee shall
measure the volume of all fluids pumped from the LDS on a weekly
basis, and use that information to calculate an average volume pumped
per day. Under no circumstances shall the daily LDS flow volume
exceed 24,160 gallons/day.The maximum daily LDS flow volume will
be compared against the measured cell solution levels detailed on the
attached Table 1 to determine the maximum daily allowable LDS flow
volume for varying head conditions in the cell..
4)3-foot Minimum Vertical Freeboard Criteria –the Permittee shall
operate and maintain wastewater levels to provide a 3-foot Minimum of
vertical freeboard in Tailings Cell 4A. Said measurements shall be
made to the nearest 0.1 foot.
5)Slimes Drain Recovery Head Monitoring –immediately after the
Permittee initiates pumping conditions in the Tailings Cell 4A slimes
drain system, monthly recovery head tests and fluid level measurements
will be made in accordance with a plan approved by the DRC Executive
Secretary.The slimes drain system will pumping and monitoring
equipment, includes a submersible pump, pump controller,water level
indicator (head monitoring), and flow meter with volume totalizer.
Routine Maintenance and Monitoring
Trained personnel inspect the White Mesa tailings system on a once per day basis.Any
abnormal occurrences or changes in the system will be immediately reported to Mill
management and maintenance personnel. The inspectors are trained to look for events
involving the routine placement of tailings material as well as events that could affect the
integrity of the tailings cell dikes or lining systems.The daily inspection reports are
summarized on a monthly basis and reviewed and signed by the Mill Manager.
Solution Elevation
Cell 4A BAT Monitoring, Operations and Maintenance Plan 09/08 Revision Denison 1.3
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Measurements in Cell 4A are to be taken by survey on a weekly basis as follows:
(i)The survey will be performed by the Mill’s Radiation Safety Officer or
designee (the “Surveyor”) with the assistance of another Mill worker (the
“Assistant”);
(ii)The survey will be performed using a survey instrument (the “Survey
Instrument”) accurate to 0.01 feet, such as a Sokkai No. B21, or
equivalent, together with a survey rod (the “Survey Rod”) having a visible
scale in 0.01 foot increments;
(iii)The reference Points (the “Reference Points”) for Cells 4A are known
points established by Registered Land Surveyor. For Cell 4A, the
Reference Point is a piece of metal rebar located on the dike between Cell
3 and Cell 4A. The elevation at the top of this piece of rebar (the
Reference Point Elevation for Cell 4A is at 5,607.83 feet above mean sea
level (“amsl”);
(iv)The Surveyor will set up the Survey Instrument in a location where both
the applicable Reference Point and pond surface are visible. For Cell 4A,
this is typically on the road between Cell 3 and Cell4A, approximately 100
feet east of the Cell 4A Reference Point;
(v)Once in location, the Surveyor will ensure that the Survey Instrument is
level by centering the bubble in the level gauge on the Survey Instrument;
(vi)The Assistant will place the Survey Rod vertically on the Cell 4A
Reference Point. The Assistant will ensure that the Survey Rod is vertical
by gently rocking the rod back and forth until the Surveyor has established
a level reading;
(vii)The Surveyor will focus the cross hairs of the Survey Instrument on the
scale on the Survey Rod, and record the number (the “Reference Point
Reading”), which represents the number of feet the Survey Instrument is
reading above the Reference Point;
The Assistant will then move to a designated location where the Survey
Rod can be placed on the surface of the main solution pond in Cell 4A.
The designated location for Cell 4A is in the northeast corner of the Cell
where the side slope allows for safe access to the solution surface.
The approximate coordinate locations for the measuring points for Cell 4A
is 2,579,360 east, and 320,300 north.These coordinate locations may vary
somewhat depending on solution elevations in the Cell.
The Assistant will hold the Survey Rod vertically with one end of the
Survey Rod just touching the pond surface. The Assistant will ensure that
the Survey Rod is vertical by gently rocking the rod back and forth until
the Surveyor has established a level reading;
(viii)The Surveyor will focus the cross hairs of the Survey Instrument on the
scale on the Survey Rod, and record the number (the “Pond Surface
Cell 4A BAT Monitoring, Operations and Maintenance Plan 09/08 Revision Denison 1.3
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Reading”), which represents the number of feet the Survey Instrument is
reading above the pond surface level.
The Surveyor will calculate the elevation of the pond surface in feet amsl
by adding the Reference Point Reading for the Cell and subtracting the
Pond Surface Reading for the Cell, and will record the number accurate to
0.01 feet.
Leak Detection System
The Leak detection system is monitored on a continuous basis by use of a
pressure transducer that feeds water level information to an electronic data
collector. The water levels are measured every hour and the information
is stored for later retrieval. The water levels are measured to the nearest
0.10 inch. The data collector is currently programmed to store 7 days of
water level information. The number of days of stored data can be
increased beyond 7 days if needed.The water level data is downloaded to
a laptop computer on a weekly basis and incorporated into the Mill’s
environmental monitoring data base, and into the files for weekly
inspection reports of the tailings cell leak detection systems.Within 24
hours after collection of the weekly water level data, the information will
be evaluated to ensure that:1)the water level in the leak detection sump
did not exceed the allowable level (5556.14 feet amsl), and 2) the average
daily flow rate from the LDS did not exceed the maximum daily allowable
flow rate at any time during the reporting period.For Cell 4A, under no
circumstance shall fluid head in the leak detection system sump exceed a
1-foot level above the lowest point in the lower flexible membrane liner.
To determine the Maximum Allowable Daily LDS Flow Rates in the Cell
4A leak detection system,the total volume of all fluids pumped from the
LDS on a weekly basis shall be recovered from the data collector, and that
information will be used to calculate an average volume pumped per day.
Under no circumstances shall the daily LDS flow volume exceed 24,160
gallons/day.The maximum daily LDS flow volume will be compared
against the measured cell solution levels detailed on the attached Table 1,
to determine the maximum daily allowable LDS flow volume for varying
head conditions in Cell 4A.Any abnormal or out of compliance water
levels must be immediately reported to Mill management.The data
collector is also equipped with an audible alarm that sounds if the water
level in the leak detection sump exceeds the allowable level (5556.14 feet
amsl). The current water level is displayed at all times on the data
collector and available for recording on the daily inspection form.The
leak detection system is also equipped with a leak detection pump,EPS
Model #25S05-3 stainless steel, or equal. The pump is capable of
pumping in excess of 25 gallons per minute at a total dynamic head of 50
Cell 4A BAT Monitoring, Operations and Maintenance Plan 09/08 Revision Denison 1.3
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feet.The pump has a 1.5 inch diameter discharge, and operates on 460
volt 3 phase power.The pump is equipped with a pressure sensing
transducer to start the pump once the level of solution in the leak detection
sump is approximately 2.25 feet (elevation 5555.89)above the lowest
level of the leak detection sump (9 inches above the lowest point on the
lower flexible membrane liner, to ensure the allowable 1.0 foot (5556.14
feet amsl)above the lowest point on the lower flexible membrane liner is
not exceeded).The attached Figure 6, Leak Detection Sump Operating
Elevations, illustrates the relationship between the sump elevation, the
lowest point on the lower flexible membrane liner and the pump-on
solution elevation for the leak detection pump.The pump also has manual
start and stop controls.The pump will operate until the solution is drawn
down to the lowest level possible, expected to be approximately 4 inches
above the lowest level of the sump (approximate elevation 5554.0).The
pump discharge is equipped with a 1.5 inch flow meter,EPS Paddle
Wheel Flowsensor,or equal,that reads the pump discharge in gallons per
minute, and records total gallons pumped. The flow rate and total gallons
is recorded by the Inspector on the weekly inspection form.The leak
detection pump is installed in the horizontal section of the 18 inch,
horizontal, perforated section of the PVC collection pipe. The distance
from the top flange face, at the collection pipe invert,to the centerline of
the 22.5 degree elbow is 133.4 feet, and the vertical height is
approximately 45 feet.The pump is installed at least 2 feet beyond the
centerline of the elbow.The bottom of the pump will be installed in the
leak detection sump at least 135.4 feet or more from the top of the flange
invert.A pressure transducer installed with the pump continuously
measures the solution head and is programmed to start and stop the pump
within the ranges specified above.The attached Figure 5 illustrates the
general configuration of the pump installation.
A second leak detection pump with pressure transducer,flow meter, and
manufacturer recommended spare parts for the pump controller and water
level data collector will be maintained in the Mill warehouse to ensure that
the pump and controller can be replaced and operational within 24 hours
of detection of a failure of the pumping system. The root cause of the
equipment failure will be documented in a report to Mill management with
recommendations for prevention of a re-occurrence.
Slimes Drain System
(i)A pump,Tsurumi Model # KTZ23.7-62 stainless steel, or equal,will be
placed inside of the slimes drain access riser pipe and a near as possible to
the bottom of the slimes drain sump.The bottom of the slimes drain sump
is 38 feet below a water level measuring point at the centerline of the
Cell 4A BAT Monitoring, Operations and Maintenance Plan 09/08 Revision Denison 1.3
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slimes drain access pipe, near the ground surface level.The pump
discharge will be equipped with a 2 inch flow meter, E/H Model #33, or
equal, that reads the pump discharge in gallons per minute, and records
total gallons pumped. The flow rate and total gallons will be recorded by
the Inspector on the weekly inspection form.
(ii)The slimes drain pump will be on adjustable probes that allows the pump
to be set to start and stop on intervals determined by Mill management.
(iii)The Cell 4A slimes drain pump will be checked weekly to observe that it
is operating and that the level probes are set properly, which is noted on
the Weekly Tailings Inspection Form. If at any time the pump is observed
to be not working properly, it will be repaired or replaced within 15 days;
(iv)Depth to wastewater in the Cell 4A slimes drain access riser pipe shall be
monitored and recorded weekly to determine maximum and minimum
fluid head before and after a pumping cycle, respectively. All head
measurements must be made from the same measuring point,to the
nearest 0.01 foot. The results will be recorded as depth-in-pipe
measurements on the Weekly Tailings Inspection Form;
(v)On a monthly basis, the slimes drain pump will be turned off and the
wastewater in the slimes drain access pipe will be allowed to stabilize for
at least 90 hours. Once the water level has stabilized (based on no change
in water level for three (3) successive readings taken no less than one (1)
hour apart) the water level of the wastewater will be measured and
recorded as a depth-in-pipe measurement on the Monthly Inspection Data
form, by measuring the depth to water below the water level measuring
point on the slimes drain access pipe;
The slimes drain pump will not be operated until Mill management has
determined that no additional process solutions will be discharged to Cell 4A, and
the Cell has been partially covered with the first phase of the reclamation cap.
The long term effectiveness and performance of the slimes drain dewatering will
be evaluated on the same basis as the currently operating slimes drain system for
Cell 2.
Tailings Emergencies
Inspectors will notify the Radiation Safety Officer and/or Mill management immediately
if, during their inspection, they discover that an abnormal condition exists or an event has
occurred that could cause a tailings emergency. Until relieved by the Environmental or
Radiation Technician or Radiation Safety Officer, inspectors will have the authority to
direct resources during tailings emergencies.
Any major catastrophic events or conditions pertaining to the tailings area should be
reported immediately to the Mill Manager or the Radiation Safety Officer, one of whom
Cell 4A BAT Monitoring, Operations and Maintenance Plan 09/08 Revision Denison 1.3
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will notify Corporate Management. If dam failure occurs, notify your supervisor and the
Mill Manager immediately. The Mill Manager will then notify Corporate Management,
MSHA (303-231-5465), and the State of Utah, Division of Dam Safety (801-538-7200).
Cell 4A Solution Freeboard Calculation
The maximum tailings cell pond wastewater levels in Cells 1-I, Cell 2,Cell 3 and Cell 4A
are regulated by condition 10.3 of the White Mesa Mill 11e.(2) Materials License.
Condition 10.3 states that “Freeboard limits for Cells 1-1, and 3, shall be set
periodically in accordance with the procedures set out in Section 3.0 to Appendix E
of the previously approved NRC license application, including the October 13, 1999
revisions made to the January 10, 1990 Drainage Report. The freeboard limit for
Cell 3 shall be recalculated annually in accordance with the procedures set in the
October 13, 1999 revision to the Drainage Report.” The 1990 Drainage Report uses
the Local 6-hour Probable Maximum Precipitation (PMP) event for calculating the
freeboard requirements for each of the tailings cells. The PMP for the White Mesa site is
10 inches.
Based on the PMP storm event, the freeboard requirement for Cell 1 is a maximum
operating water level of 5615.4 feet above mean sea level (amsl). The Cell 1 freeboard
limit is not affected by operations or conditions in Cells 2,3 or 4A.
Cell 2 has no freeboard limit because the Cell is 99% full of tailings solids and all
precipitation falling on Cell 2 and the adjacent drainage area must be contained in Cell 3.
The flood volume from the PMP event over the Cell 2 and Cell 3 pond areas, plus the
adjacent drainage areas, is 123.4 acre-feet of water. According to the freeboard
calculation procedures, this volume currently must be contained in the existing 24-acre
pool area in Cell 3. This results in a maximum operating water level in Cell 3 of 5601.6
feet amsl.
The Cell 4A design includes a concrete spillway between Cell 3 and Cell 4A with the
invert elevation 4 feet below the top of the Cell 3 dike, at an elevation of 5604.5 feet
amsl. Once Cell 4A is placed in operation, the cell would be available for emergency
overflows from Cell 3, but as long as the freeboard limit in Cell 3 is maintained at 5601.6
it is extremely unlikely that Cell 4A would see any overflow water from Cell 3 unless the
full PMP event were to occur. Should Cell 3 receive the full PMP volume of 123.4 acre
feet of water, approximately 62 acre feet of that volume would flow through the spillway
into Cell 4A.
The flood volume from the PMP event over the Cell 4A area is 36 acre-feet of water (40
acres, plus the adjacent drainage area of 3.25 acres, times the PMP of 10 inches). This
would result in a total flood volume of 98 acre-feet,including the 62 acre-feet of solution
from Cell 3. The freeboard depth required for Cell 4A from the PMP event would be
2.44 feet, plus a wave run-up depth of 0.77 feet (from the 1990 Drainage Report), for a
Cell 4A BAT Monitoring, Operations and Maintenance Plan 09/08 Revision Denison 1.3
Page 12
total freeboard requirement of 3.2 feet. This calculation is illustrated on Attachment 4.
The Groundwater Quality Discharge Permit, No. UGW370004, for the White Mesa Mill
requires that the minimum freeboard be no less than 3.0 feet for any of the existing Cell
construction, but based on the above calculation the freeboard would be set 3.2 feet
below the top of liner.The freeboard for Cell 4A would therefore be 5595.3 amsl (top of
liner 5598.5 –3.2 feet).Figure 7, Hydraulic Profile Schematic, shows the relationship
between the Cells, and the relative elevations of the solution pools and the spillway
elevations.
If Cell 4A were required to store the entire PMP event for Cell 2, Cell 3 and Cell 4A, the
required storage volume would be approximately 160 acre-feet of solution. This would
increase the necessary freeboard to 4.77 feet.
The required freeboard for Cell 4A will be recalculated annually along with the re-
calculation of the Cell 3 freeboard requirement.A calculation of the current freeboard
calculation for both Cells is attached to this Plan.
Cell 4A BAT Monitoring, Operations and Maintenance Plan 09/08 Revision Denison 1.3
Page 13
Attachments
1)Figure 1, Initial Filling Plan, GeoSyntec Consultants
2)Figure 2,Initial Filling Plan,Details and Sections,GeoSyntec Consultants
3)Figure 3,Initial Filling Plan,Solution and Slurry Pipeline Routes, GeoSyntec
Consultants
4)Figure 4, Interim Filling Plan, GeoSyntec Consultants
5)Figure 5, Leak Detection System Sump, GeoSyntec Consultants
6)Figure 6, Leak Detection Sump Operating Elevations
7)Figure 7,Hydraulic Profile Schematic
8)Cell 3 and Cell 4A Freeboard Calculation
9)Table 1, Calculated Action leakage Rates for Various Head Conditions,
Cell 4A, White Mesa Mill, Blanding, Utah, GeoSyntec Consultants
10)White Mesa Mill Tailings Management System and Discharge Minimization
Technology (DMT) Monitoring Plan, 3/07 Revision: DUSA-2, 32 pages, or
currently approved version of the DMT
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FIGURE
SCALE IN FEET
INITIAL FILLING PLAN
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consultants PROJECTNO.SC0349
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FIGURE
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consultants PROJECTNO.5C0349 4
-~_.~~GEOSYNTlHETlC CLAY LINER
"'"~60 MIL HOPE GEOMEMBRANE (SMOOTlH)
CUSHION GEOTEXnlE
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LEAK DETECTlON SYSTlEM SUMP
CELL 4A WHITlE MESA MILLS
BLANDING.UTAH
~Geosyntec DATE JULY 2008
fJ..cons111!~1nrs PROJECT NO SC0349
FIGURE
Pump-on level
5555.89 feet amsl
Leak Detection Sump
Elevation -5553.64 feet amsl
Maximum Solution Elevation -5556.14 feet amsi
Lowest Level on Secondary Liner -5555.14 feet amsl
Project
Denison Mines (USA)Corp.
White Mesa Mill
REVISIONS
Date By
county:Son Juan County rState:UT
Location:White Meso Mill
Figure 6
Leak Detection Sump
Operating Levels
Scale:N/A
Author:HRR
I Date:09/2008 Ifigure 6.dwg1DraftedBy:8M
Not to Scale
PMP
Volume,
36 ac-ft.
plus 61.6
ac-ft from
Cell 2 and
Cell 3.
Ce1l4A
Freeboard Limit
5595.3 msl
PMP Volume,123.4 ac-ft.
61.6 ac-ft overflows to
Ce1l4A
Cell 3
Freeboard Limit
5601.9 msl
..
Cell 2 Spillway -E]ev.56]].0
Cell 2
Closed
Figure 7
Hydraulic Profile Schematic
Cell 3 Cell 4A Freeboard Calculation
Radioactive Materials License UT1900479,License Condition 10.3
Annual Recalculation
Annual Calculation Variables -Cell 3
PS
MDT
Cell 3 Pool Surface,from most recent survey
or aerial photograph (acres)(August 24,2003)
Estimated Maximum dry tons of Tailings
to be generated during next 12 months
(October1,2006 -September 30,2007 )
24.0
70,000
Definitions,Constant Factors and Calculations -Cell 3
PMP
ARF
WRU
DC
SWE
PMP Flood Volume Requirement (acre-feet)
Area Reduction Factor from January 10,1990
Drainage Report (dry tons peracre)
Wave Run Upfactor,from January 10,1990
Drainage Report (feet)
Top of Liner (Dike Crest),Cell 3 (feet above mean sea level)
Spillway Invert Elevation (feet above mean sea level)
123.4
39,146
0.78
5608.5
5604.5
MMP Maximum Mill Production (dry tons)1.5 x MDT 1.5 x 70,000
RPA Reduced Pool Area (acres)PS -(MMP I ARF)24.0 - (105,000 I 39,146
PMPFL PMP Freeboard Level (feet)PMP/RPA 123.4 I 21.3
TRF Total Required Freeboard (feet)PMPFL +WRU 5.8 +0.78
FL(3)Freeboard Limit (feet above mean sea level)DC -TRF 5608.5 6.6
AS(3)Available Storage Cell 3 (acre-feet)PMP -«SWE -FL(3))x PS)123.4 -(5604.5 5601.9 ) x
OFV(3)Overflow Volumeto Cell 4A (acre-feet)PMP -AS(3)123.4 61.8
Maximum Freeboard Limit from GWDP is 5605.5 feet msl
Maximum Freeboard Limit from runoff calculation is 5603.0 feet msl
Ifthe calculated FL is greater than 5603.0 feet msl,thenthe FL is 5603.0 msl
105,000 dry tons
21.3 acres
5.8 feet
6.6 feet
5601.9 feet msl
24.0 61.8 acre-feet
61.6
Cell 3 Cell 4A Freeboard Calculation
Radioactive Materials License UT1900479,License Condition 10.3
Annual Recalculation
Annual Calculation Variables -Cell 4A
PS(4)Cell 4A Pool Surface,from most recent survey
or aerial photograph (acres)
MDT(4)Estimated Maximumdrytons ofTailings
to be deposited in Cell 4Aduring next 12 months
(July 1,2008 -June 30,2009 )
ATS(4)Area of Tailings Solids above elevation 5593 (acres)
Definitions,Constant Factors and Calculations -Cell 4A
PMP(4)PMP Flood Volume Requirement (acre-feet)
ARF Area Reduction Factorfrom January 10,1990
Drainage Report (dry tons peracre)
WRU(4)Wave Run Up factor,from January 10,1990
Drainage Report (feet)
DC(4)Top of Liner (Dike Crest),Cell 4A (feet above mean sea level)
RPA(4)Reduced Pool Area (acres)
40.0
70,000
0.0
36.0
39,146
0.77
5598.5
PS(4)-ATS(4)40.0 -40.0 acres
PMPFL(4)PMP Freeboard Level (feet)PMP(4)+OFV(3)/RPA(4)36.0 +61.6 40.0 2.44 feet
TRF Total Required Freeboard (feet)PMPFL(4)+WRU(4)2.44 +0.77 3.2 feet
FL(4)Freeboard Limit (feetabove meansea level)DC(4)-TRF(4)5598.5 3.2 5595.3 feet msl
Maximum Freeboard Limit from GWDP is5595.5 feet msl
Maximum Freeboard Limit from runoff calculation is 5595.3 feet msl
If the calculated FL(4)is greater than 5595.5 feet msl,thenthe FL(4)is 5595.3 msl
Table 1
Calculated Action Leakage Rates
for Various Head Conditions
Cell 4A White Mesa Mill
Blanding,Utah
Head Above Liner Calculated Action Leakage
Svstem (feet)Rate (aallons/acre/dav)
5 222.04
10 314.01
15 384.58
20 444.08
25 496.50
30 543.88
35 587.46
37 604.01
GeoSyntec Consultants
White Mesa Mill –Standard Operating Procedures 9/08 Revision: Denison-6
Book 11: Environmental Protection Manual, Section 3.1 Page 1 of 36
WHITE MESA MILL TAILINGS MANAGEMENT SYSTEM
AND
DISCHARGE MINIMIZATION TECHNOLOGY (DMT)
MONITORING PLAN
1.INTRODUCTION
This Tailings Management System and Discharge Minimization TechnologyMonitoring Plan (the
“Plan”) for the White Mesa Mill (the “Mill”) provides procedures for monitoring of the tailings cell
system as required under State of Utah Radioactive Materials License No. UT1900479 (the
“Radioactive Materials License”), as well as procedures for operating and maintenance of monitoring
equipment andreportingprocedures thatare adequatetodemonstrateDMTcomplianceunderState
of Utah Ground Water Discharge Permit No. 370004 for the Mill (the “GWDP”).
This Plan is designed as a systematic program for constant surveillance and documentation of the
integrity of the tailings impoundment system including dike stability, liner integrity, and transport
systems, as well as monitoring of water levels in Roberts Pond and feedstock storage areas at the
Mill. ThePlanrequiresdaily,weekly,quarterly,monthlyandannualinspectionsandevaluationsand
monthly reporting to Mill management.
2.DAILY TAILINGS INSPECTIONS
The following daily tailings inspections shall be performed:
2.1.Daily Comprehensive Tailings Inspection
On a daily basis, including weekends, all areas connected with the four tailings cells will be
inspected. Observations will be made of the current condition of each cell, noting any corrective
action that needs to be taken.
The Environmental or Radiation Technician is responsible for performing the daily tailings
inspections, except on weekends when the Shift Foreman will perform the weekend tailings
inspections. The Radiation Safety Officer may designate other individuals with training, as
described in Section 2.4 below, to perform the daily tailings inspection.
Observations made bythe inspector will be recorded on the Daily Inspection Data form (a copyof
whichisattachedinAppendixA).The DailyInspectionData formcontainsaninspectionchecklist,
White Mesa Mill –Standard Operating Procedures 9/08 Revision: Denison-6
Book 11: Environmental Protection Manual, Section 3.1 Page 2 of 36
whichincludesatailings cellsmap,andspacestorecordobservations,especiallythoseofimmediate
concern and those requiring corrective action. The inspector will place a check by all inspection
items that appear to be operating properly. Those items where conditions of potential concern are
observed should be marked with an "X". A note should accompany the "X" specifying what the
concern is and what corrective measures will resolve the problem. This observation of concern
should be noted on the form until the problem has been remedied. The date that corrective action
was taken should be noted as well.
Areas to be inspected include the following: Cell 1, 2, 3, and 4A, Dikes 1, 2, 3, 4A-S, and 4A-W,
wind movement of tailings, effectiveness of dust minimization methods, sprayevaporation, Cell 2
spillway,Cell 3 spillway,Cell 3 and 4A liquid pools and associated liquid return equipment, cell
leak detection systems, and the wildlife ponds.
Operational features of the tailings area are checked for conditions of potential concern. The
following items require visual inspection during the daily tailings inspection:
a)Tailings slurry and SX raffinate transport systems from the Mill to the active
disposal cell(s), and pool return pipeline and pumps.
DailyinspectionsofthetailingslinesarerequiredtobeperformedwhentheMill
isoperating. Thelinestobeinspectedincludethe:tailingsslurrylinesfromCCD
to the active tailings cell; SX raffinate lines that candischargeintoCell 1,Cell 3
or Cell 4A; the pond return line from the tailings area to the Mill; and, lines
transporting pond solutions from one cell to another.
b)Cell 1.
c)Cell 2.
d)Cell 3.
e)Cell 4A.
f)Dike structures including dikes 1, 2, 3, 4A-S, and 4A-W.
g)The Cell 2 spillway,Cell 3 spillway,Cell 3 and Cell 4A liquid pools and
associated liquid return equipment.
h)Presence of wildlife and/or domesticated animals in the tailings area, including
waterfowl and burrowing animal habitations.
i)Spray evaporation pumps and lines.
White Mesa Mill –Standard Operating Procedures 9/08 Revision: Denison-6
Book 11: Environmental Protection Manual, Section 3.1 Page 3 of 36
j)Wind movement of tailings and dust minimization.
Wind movement of tailings will be evaluated for conditions which may require
initiationofpreventativedustminimizationmeasuresforcellscontainingtailings
sand. Duringtailingsinspection,generalsurfaceconditionswillbeevaluatedfor
the following: 1) areas of tailings subject to blowing and/or wind movement, 2)
liquid pool size, 3) areas not subject to blowing and/or wind movement,
expressedasapercentageofthetotalcellarea. Theevaluationswillbereviewed
onaweeklybasis,ormorefrequentlyifwarranted,andwillbeusedtodirectdust
minimization activities.
k)Observation of flow and operational status of the dust control/sprayevaporation
system(s).
l)Observationsofanyabnormalvariationsintailingspondelevationsin Cells1,3,
and 4A.
m)Locations of slurry and SX discharge within the active cells. Slurry and SX
discharge points need to be indicated on the tailings cells map included in the
Daily Inspection Data form.
n)An estimate of flow for active tailings slurry and SX line(s).
o)An estimate of flow in the solution return line(s).
p)Daily measurements in the leak detection system (LDS) sumps of the tailings
cells will be made when warranted by changes in the solution level of the
respective leak detection system.
Thetriggerforfurtheractionwhenevaluatingthemeasurementsinthe Cell1and
Cell 3 leak detection systems is a gain of more than 12 inches in 24 hours.The
solution level in Cell 4A leak detection is not allowed to be more than 1.0 foot
abovethelowestpointonthebottomflexiblemembraneliner(elevation5556.14
feet amsl).If any of these observation are made, the Mill Manager should be
notified immediately and the leak detection system pump started.
White Mesa Mill –Standard Operating Procedures 9/08 Revision: Denison-6
Book 11: Environmental Protection Manual, Section 3.1 Page 4 of 36
Whenever the leak detection system pump is operating and the flow meter
totalizer is recording, a notation of the date and the time will be recorded on the
Daily Inspection Data form. This data will be used in accordance with License
Condition 11.3.B through 11.3.E of the Mill’s Radioactive MaterialsLicense,to
determinewhetherornot theflowrateintotheleakdetectionsystemisinexcess
of the License Conditions.
q)Anestimateofthepercentageofthetailingsbeachsurfaceareaandsolutionpool
areais made,includingestimatesofsolutions,coverareas,andtailingssandsfor
Cells 3 and 4A.
Items (a), (m), (n), and (o) are to be done onlywhen the Mill is operating. When the Mill is down,
these items cannot be performed.
2.2.Daily Operations Inspection
DuringMill operation,theShift Foreman,orotherperson withthetrainingspecifiedinSection2.4
below,designatedbytheRadiationSafetyOfficer,willperformaninspectionofthetailingslineand
tailings area at least once per shift, paying close attention for potential leaks and to the discharges
from the pipelines. Observations by the Inspector will be recorded on the appropriate line on the
Operating Foreman’s Daily Inspection form.
2.3.Daily Operations Patrol
In addition to the inspections described in Sections 2.1 and 2.2 above,a Mill employee will patrol
the tailings area at least twice per shift during Mill operations to ensure that there are no obvious
safety or operational issues, such as leaking pipes or unusual wildlife activity or incidences.
No record of these patrols need be made, but the inspectors will notifythe Radiation SafetyOfficer
and/or Mill management in the event that during their inspection they discover that an abnormal
condition or tailings emergency has occurred.
2.4.Training
All individuals performing inspections described in Sections 2.1 and 2.2 above must have Tailings
Management System training as set out in the Tailings Inspection Training procedure, which is
attached as Appendix B. This training will include a training pack explaining the procedure for
performing the inspection and addressing inspection items to be observed. In addition, each
individual, after reviewing the training pack, will sign a certification form, indicating that training
has been received relative to his/her duties as an inspector.
White Mesa Mill –Standard Operating Procedures 9/08 Revision: Denison-6
Book 11: Environmental Protection Manual, Section 3.1 Page 5 of 36
2.5.Tailings Emergencies
Inspectors will notifythe Radiation SafetyOfficer and/or Mill management immediatelyif, during
theirinspection,theydiscoverthat anabnormal conditionexists oranevent has occurredthat could
cause a tailings emergency. Until relieved by the Environmental or Radiation Technician or
Radiation Safety Officer, inspectors will have the authority to direct resources during tailings
emergencies.
Any major catastrophic events or conditions pertaining to the tailings area should be reported
immediatelytotheMillManagerortheRadiationSafetyOfficer,oneofwhomwillnotifyCorporate
Management. Ifdamfailureoccurs,notifyyoursupervisorandtheMillManagerimmediately. The
Mill Manager will then notify Corporate Management, MSHA (303-231-5465), and the State of
Utah, Division of Dam Safety (801-538-7200).
3.WEEKLY TAILINGS AND DMT INSPECTION
3.1.Weekly Tailings Inspections
WeeklytailingsinspectionsaretobeconductedbytheRadiationSafetyDepartmentandinclude the
following:
a)Leak Detection Systems
Each tailings cell's leak detection system shall be checked weekly to determine
whetheritiswetordry. Ifmarkedwet,theliquidlevelsneedtobemeasuredand
reported. In Cell 1 and Cell 3 the leak detection system is measured byuse of a
pipe that is removed from the system which will indicate the presence of
solutions intheLDS system.The Cell4A leakdetectionsystemismonitoredon
a continuous basis by use of a pressure transducer that feeds water level
informationtoanelectronicdatacollector.Thepressuretransduceriscalibrated
forfluidwithaspecificgravityof1.0.Thewaterlevelsaremeasuredevery hour
andtheinformationisstoredforlaterretrieval. Thewaterlevelsaremeasuredto
thenearest 0.10inch. Thedatacollectoriscurrentlyprogrammedtostore7days
of water level information. The number of days of stored data can be increased
beyond 7 days if needed. The water level data is downloaded to a laptop
computer on a weekly basis and incorporated into the Mill’s environmental
monitoring data base, and into the files for weekly inspection reports of the
tailings cell leak detection systems
White Mesa Mill –Standard Operating Procedures 9/08 Revision: Denison-6
Book 11: Environmental Protection Manual, Section 3.1 Page 6 of 36
Ifsufficientfluidispresentintheleakdetectionsystemofanycell,thefluidshall
be pumped from the LDS, to the extent reasonably possible, and record the
volumeoffluidrecovered. AnyfluidpumpedfromanLDAshallbereturnedtoa
disposal cell.
If fluid is pumped from an LDS, the flow rate shall be calculated bydividingthe
recorded volume of fluid recovered by the elapsed time since fluid was last
pumped or increases in the LDS fluid levels were recorded, whichever is the
more recent. This calculation shall be documented as part of the weekly
inspection.
Upon the initial pumpingof fluid from anLDS,afluidsampleshall becollected
and analyzed in accordance with paragraph 11.3 C. oftheRadioactiveMaterials
License.
For Cell 4A, under no circumstance shall fluid head in the leak detection
system sump exceed a 1-foot level above the lowest point in the lower flexible
membrane liner.To determine the Maximum Allowable Daily LDS Flow
Rates in the Cell 4A leak detection system,the total volume of all fluids
pumped from the LDS on a weekly basis shall be recovered from the data
collector, and that information will be used to calculate an average volume
pumped per day. Under no circumstances shall the daily LDS flow volume
exceed 24,160 gallons/day.The maximum daily LDS flow volume will be
compared against the measured cell solution levels detailed on Table 1 in
Appendix E, to determine the maximum daily allowable LDS flow volume for
varying head conditions in Cell 4A.
b)Slimes Drain Water Level Monitoring
(i)Cell3isanactivetailingscellwhileCell2ispartiallyreclaimedwithapproximately
90% of the surface covered by platform fill. Each cell has a slimes drain system
which aids in dewatering the slimes and sands placed in the cell;
(ii)Cell 2 has a pump placed inside of the slimes drain access pipe at the bottom of the
slimes drain. As taken from actual measurements, the bottom of the slimes drain is
38 feet below a water level measuring point at the centerline of the slimes drain
access pipe, at the ground surface level. This means that the bottom of the slimes
drain pool and the location of the pump are one foot above the lowest point of the
FML in Cell 2, which, based on construction reports, is at a depth of 39 feet below
the water level measuring point on the slimes drain access pipe for Cell 2;
White Mesa Mill –Standard Operating Procedures 9/08 Revision: Denison-6
Book 11: Environmental Protection Manual, Section 3.1 Page 7 of 36
(iii)The slimes drain pump in Cell 2 is on a timed system, under which it pumps for 15
minutes each hour, thereby allowing the slimes wastewater to recharge for 45
minutesbeforebeingpumpedagain. BasedonmeasurementstakeninAugust2006,
the water level in the Cell 2 slimes drain recharges to a depth of about 28.50 feet
beforeeachpumpingandispumpedtoadepthof38feetaftereachpumping,ineach
casemeasuredbelowthewaterlevelmeasuringpointontheslimesdrainaccesspipe.
TheaveragewastewaterheadintheCell2slimesdrainisthereforeabout5feet. The
depth to water of about 28.50 feet after recharge is below the phreatic surface of
tailings Cell 2, which is at a depth of about 20 feet below the water level measuring
point on the slimes drain access pipe. As a result, there is a continuous flow of
wastewater from Cell 2 into the slimes drain collection system. Mill management
considers that the average allowable wastewater head in the Cell 2 slimes drain
resulting from pumping at these intervals is satisfactoryand is as low as reasonably
achievable. Basedonpastexperience,cyclingthepumpmorethan15minutesevery
hour can result in more replacement costs for pumps and more resulting system
downtime;
(iv)The Cell 2 slimes drain pump is checked weekly to observe that it is operating and
thatthetimerissetproperly,whichisnotedontheWeeklyTailingsInspectionForm.
If at any time the pump is observed to be not working properly, it will be fixed or
replaced within 15 days;
(v)Depth to wastewater in the Cell 2 slimes drain access pipe shall be monitored and
recorded weeklyto determine maximum and minimum fluid headbeforeandaftera
pumping cycle, respectively.All head measurements must be made from the same
measuring point (the notch at the north side of the access pipe), and made to the
nearest0.01foot.Theresultswillberecordedasdepth-in-pipemeasurementsonthe
Weekly Tailings Inspection Form;
(vi)On a monthly basis, the slimes drain pump will be turned off and the wastewater in
the slimes drain access pipe will be allowed to stabilize for at least 90 hours. Once
the water level has stabilized (based on no change in water level for three (3)
successive readings taken no less than one (1) hour apart) the water level of the
wastewater will be measured and recorded as a depth-in-pipe measurement on the
MonthlyInspectionDataform,bymeasuringthedepthtowaterbelowthewaterlevel
measuring point on the slimes drain access pipe;
(vii)No process liquids shall be allowed to be discharged into Cell 2;
(viii)IfatanytimethemostrecentaverageannualheadintheCell2slimesdrainis
found to have increased above the average head for the previous calendar year, the
LicenseewillcomplywiththerequirementsofPartI.G.3oftheGWDP,includingthe
requirementto provide notificationtotheExecutiveSecretaryorallywithin24hours
followed by written notification;
(ix)Because Cell 3 and Cell 4A are currentlyactive, no pumpingfrom the Cell 3 or Cell
4A slimesdrainisauthorized. Priortoinitiationof tailingsdewateringoperationsfor
Cell 3 or Cell 4A, a similar procedure will be developed for ensuring that average
White Mesa Mill –Standard Operating Procedures 9/08 Revision: Denison-6
Book 11: Environmental Protection Manual, Section 3.1 Page 8 of 36
headelevations intheCell 3 andCell 4A slimes drains arekept as lowasreasonably
achievable,andthattheCell3 andCell4A slimesdrains are inspectedandtheresults
reported in accordance with the requirements of the permit.”
c)Wind Movement of Tailings
An evaluation of wind movement of tailings or dusting and control measures
shall be taken if needed.
d)Tailings Wastewater Pool Elevation Monitoring
Solution elevation measurements in Cells 1, 3 and 4A and Roberts Pond are to be taken by
survey on a weekly basis as follows:
(i)The survey will be performed by the Mill’s Radiation Safety Officer or designee
(the “Surveyor”) with the assistance of another Mill worker (the “Assistant”);
(ii)The survey will be performed using a survey instrument (the “Survey Instrument”)
accurate to 0.01 feet, such as a Sokkai No. B21, or equivalent, together with a
survey rod (the “Survey Rod”) having a visible scale in 0.01 foot increments;
(iii)The reference Points (the “Reference Points”) for Cells 1, 3 and 4A,and Roberts
Pond are known points established by professional survey. For Cell 1 and Roberts
Pond, the Reference Point is a wooden stake with a metal disk on it located on the
southeast corner of Cell 1. The elevation of the metal disk (the “Reference Point
Elevation”) for Cell 1 and Roberts Pond is at 5,623.14 feet above mean sea level
(“FMSL”). For Cell 3 and cell 4A, the Reference Point is a piece of metal rebar
located on the south dike of Cell 3. The elevation at the top of this piece of rebar
(the Reference Point Elevation for Cell 3 and cell 4A) is at 5,607.83 FMSL;
(iv)The Surveyor will set up the Survey Instrument in a location where both the
applicable Reference Point and pond surface are visible. For Cell 1 and Roberts
Pond, this is typically on the road on the Cell 1 south dike between Cell 1 and
Roberts Pond, approximately 100 feet east of the Cell 1/Roberts Pond Reference
Point. For Cell 3 and Cell 4A, this is typically on the road on the Cell 3 dike
approximately 100 feet east of the Cell 3 Reference Point;
(v)Once in location, the Surveyor will ensure that the Survey Instrument is level by
centering the bubble in the level gauge on the Survey Instrument;
(vi)The Assistant will place the Survey Rod vertically on the Reference Point (on the
metal disk on the Cell 1/Roberts Pond Reference Point and on the top of the rebar
on the Cell 3 and cell 4A Reference Point. The Assistant will ensure that the
Survey Rod is vertical by gently rocking the rod back and forth until the Surveyor
has established a level reading;
(vii)The Surveyor will focus the cross hairs of the Survey Instrument on the scale on
the Survey Rod, and record the number (the “Reference Point Reading”), which
White Mesa Mill –Standard Operating Procedures 9/08 Revision: Denison-6
Book 11: Environmental Protection Manual, Section 3.1 Page 9 of 36
represents the number of feet the Survey Instrument is reading above the
Reference Point;
(viii)The Assistant will then move to a designated location where the Survey Rod can
be placed on the surface of the main solution pond in the Cell or Roberts Pond, as
the case may be. These designated locations, and the methods to be used by the
Assistant to consistently use the same locations are as follows:
A.Cell 3
A stake has been place in the central area of the south dike of Cell 3. The
Assistant will walk perpendicular to the dike from the stake to the nearest point
on the liquid surface of Cell 3 and place the Survey Rod at that location;
B. Cell 4A
The Assistant will walk down the slope in the northeast corner of Cell 4A and
place the Survey Rod at the liquid level.
C.Cell 1
A mark has been painted on the north side of the ramp going to the pump
platform in Cell 1. The Assistant will place the Survey Rod against that mark
and hold the rod vertically, with one end just touching the liquid surface; and
D Roberts Pond
A mark has been painted on the railing of the pump stand in Roberts Pond. The
Assistant will place the Survey Rod against that mark and hold the rod
vertically, with one end just touching the liquid surface.
Based on the foregoing methods, the approximate coordinate locations for the
measuring points for Roberts Pond and the Cells are:
Northing Easting
Roberts Pond 323,041 2,579,697
Cell 1 322,196 2,579,277
Cell 3 320,508 2,577,760
Cell 4A 320,300 2,579,360
These coordinate locations may vary somewhat depending on solution elevations
in the Pond and Cells;
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Book 11: Environmental Protection Manual, Section 3.1 Page 10 of 36
(ix)The Assistant will hold the Survey Rod vertically with one end of the Survey Rod
just touching the pond surface. The Assistant will ensure that the Survey Rod is
vertical by gently rocking the rod back and forth until the Surveyor has established
a level reading;
(x)The Surveyor will focus the cross hairs of the Survey Instrument on the scale on
the Survey Rod, and record the number (the “Pond Surface Reading”), which
represents the number of feet the Survey Instrument is reading above the pond
surface level.
The Surveyor will calculate the elevation of the pond surface as FSML by adding the
Reference Point Readingfor the Cell orRoberts Pond,as thecasemay be,totheReference
Point Elevation for the Cell or Roberts Pond and subtractingthe Pond Surface Readingfor
the Cell or Roberts Pond, and will record the number accurate to 0.01 feet.
e)Summary
Inaddition,theweeklyinspectionshouldsummarizeallactivitiesconcerningthe
tailings area for that particular week.
Results of the weekly tailings inspection are recorded on the Weekly Tailings and DMT Inspection
form. An example of the Weekly Tailings and DMT Inspection form is provided in Appendix A.
3.2.Weekly Inspection of Solution Levels in Roberts Pond
Onaweeklybasis,solutionelevationsaretakenonRobertsPond,inaccordancewiththeprocedures
set out in Section 3.1 d) above. The Weekly solution level in Roberts Pond is recorded on the
Weekly Tailings and DMT Inspection form.Based on historical observations, the FMLat the Pond
Surface Reading area for Roberts Pond, is approximately six inches above the lowest point on the
pond’s FML.IfthepondsolutionelevationatthePondSurfaceReading areaisatorbelowtheFML
for that area, the pond will be recorded as being dry.
3.3.Weekly Feedstock Storage Area Inspections
WeeklyfeedstockstorageareainspectionswillbeperformedbytheRadiationSafetyDepartment, to
confirm that:
a)the bulk feedstock materials are stored and maintainedwithinthedefinedareadescribedin
the GWDP, as indicated on the map attached hereto as Appendix D; and
b)all alternate feedstock located outside the defined Feedstock Area are maintained within
water tight containers.
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Book 11: Environmental Protection Manual, Section 3.1 Page 11 of 36
The results of this inspection will be recorded on the Ore Storage/Sample Plant Weekly Inspection
Report, a copy of which is contained in Appendix A. Any variance in stored materials from this
requirementorobservedleakingalternatefeedstockdrumsorothercontainerswillbebroughttothe
attention of Mill Management and rectified within 15 days.
4.MONTHLY TAILINGS INSPECTION
MonthlytailingsinspectionswillbeperformedbytheRadiationSafetyOfficerorhisdesigneefrom
theRadiationSafetyDepartmentandrecordedonthe MonthlyInspectionData form,anexampleof
whichiscontainedinAppendixA. Monthlyinspectionsaretobeperformednosoonerthan14days
since the last monthly tailings inspection and can be conducted concurrently with the quarterly
tailings inspection when applicable. The following items are to be inspected:
a)Tailings Slurry Pipeline
When the Mill is operating, the slurry pipeline will be inspected at key locations to
determine pipe wear. Pipe thickness will be measuredusinganultrasonicdeviceby
either the radiation safetystaff or other trained designees. The critical points of the
pipe include bends, slope changes, valves, and junctions, which are critical to dike
stability. TheselocationstobemonitoredwillbedeterminedbytheRadiationSafety
Officer or his designee from the Radiation Safety Department during the Mill run.
b)Diversion Ditches
Diversion ditches 1, 2 and 3 shall be monitored monthly for sloughing, erosion,
undesirablevegetation,andobstructionofflow. Diversionberm2shouldbechecked
for stability and signs of distress.
c)Sedimentation Pond
ActivitiesaroundtheMillandfacilitiesareasedimentationpondshallbesummarized
for the month.
d)Overspray Dust Minimization
The inspection shall include an evaluation of oversprayminimization, if applicable.
This entails ensuringthat the overspraysystem is functioningproperly. In the event
thatoversprayiscarriedmorethan50feetfromthecell,theoverspraysystemshould
be immediately shut-off.
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Book 11: Environmental Protection Manual, Section 3.1 Page 12 of 36
e)Remarks
A section is included on the Monthly Inspection Data form for remarks in which
recommendations can be made or observations of concern can be documented.
f)Summary of Daily, Weekly and Quarterly Inspections
The monthly inspection will also summarize the daily, weekly and, if applicable,
quarterly tailings inspections for the specific month.
In addition, settlement monitors are typically surveyed monthly and the results reported on the
Monthly Inspection Data form.
5.QUARTERLY TAILINGS INSPECTION
The quarterlytailings inspection is performed bythe Radiation SafetyOfficer or his designee from
the Radiation Safety Department, having the training specified in Section 2.4 above, once per
calendar quarter. A quarterly inspection should be performed no sooner than 45 days since the
previous quarterly inspection was performed.
Each quarterly inspection shall include an Embankment Inspection, an Operations/Maintenance
Review, a Construction Review and a Summary, as follows:
a)Embankment Inspection
The Embankment inspection involves a visual inspection of the crest, slope and toe
of each dike for movement, seepage, severe erosion, subsidence, shrinkage cracks,
and exposed liner.
b)Operations/Maintenance Review
The Operations/Maintenance Review consists of reviewing Operations and
Maintenance activities pertaining to the tailings area on a quarterly basis.
c)Construction Review
The Construction Review consists of reviewing any construction changes or
modifications made to the tailings area on a quarterly basis.
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d)Summary
The summary will include all major activities or observations noted around the
tailings area on a quarterly basis.
If any of these conditions are noted, the conditions and corrective measures taken should be
documented in the Quarterly Inspection Data form. An example of the Quarterly Inspection Data
form is provided in Appendix A.
6.ANNUAL EVALUATIONS
The following annual evaluations shall be performed:
6.1.Annual Technical Evaluation
An annual technical evaluation of the tailings management system is performed by a registered
professional engineer (PE), who has experience and training in the area of geotechnical aspects of
retention structures. The technical evaluation includes an on-site inspection of the tailings
management system and a thorough review of all tailings records for the past year. The Technical
Evaluationalsoincludesareviewandsummaryoftheannualmovementmonitorsurvey(seeSection
5.2 below).
All tailings cells and corresponding dikes will be inspected for signs of erosion, subsidence,
shrinkage, and seepage. The drainage ditches will be inspected to evaluate surface water control
structures.
In the event tailings capacity evaluations (as per SOP PBL-3) were performed for the receipt of
alternate feed material during the year, the capacity evaluation forms and associated calculation
sheets will be reviewed to ensure that the maximum tailings capacity estimate is accurate. The
amount of tailings added to the system since the last evaluation will also be calculated to determine
the estimated capacity at the time of the evaluation.
Tailingsinspectionrecordswillconsistofdaily,weekly,monthly,andquarterlytailingsinspections.
These inspection records will be evaluated to determine if any freeboard limits are being
approached. Records will also be reviewed to summarize observations of potential concern. The
evaluation also involves discussion with the Environmental and/or Radiation Technician and the
Radiation Safety Officer regarding activities around the tailings area for the past year. During the
annual inspection,photographs ofthetailingsareawillbetaken. Thetrainingofindividualswillbe
reviewed as a part of the Annual Technical Evaluation.
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Book 11: Environmental Protection Manual, Section 3.1 Page 14 of 36
The registered engineer will obtain copies of selected tailings inspections, along with the monthly
and quarterlysummaries of observations of concern and the corrective actions taken. These copies
will then be included in the Annual Technical Evaluation Report.
The Annual Technical Evaluation Report must be submitted by September 1st of every year to:
Directing Dam Safety Engineer
State of Utah, Natural Resources
1636 West North Temple, Suite 220
Salt Lake City, Utah 84116-3156
6.2.Movement Monitors
A movement monitor survey is to be conducted by a licensed surveyor annually during the second
quarterofeachyear. Themovementmonitorsurveyconsistsofsurveyingmonitorsalongdikes3-S,
4A-W, and 4A-S to detect any possible settlement or movement of the dikes. The data generated
from this survey is reviewed and incorporated into the Annual Technical Evaluation Report of the
tailings management system.
6.3.Freeboard Limits
a)Tailings Cells 1 and 4A
The freeboard limits are as per January 10, 1990 Drainage Report for Cells 1
and 4A and are stated below:
(i)A liquid maximum elevation of 5,615.4 feet mean sea level in Cell 1.
(ii)A liquid maximum elevation of 5,596.4 feet mean sea level in Cell 4A.
b)Tailings Cell 3
The freeboard limit for Cell 3 is determined annually using the following
procedure:
(i)From a survey of Cell 3, the pool surface will be determined.
(ii)An estimate of the maximum tons of dry tailings to be generated during
the next 12 months will be made. This estimate is multiplied by 1.5, a
factor of safety, to yield the Maximum Mill Production.
(iii)TheMaximumMillProductionisdividedbythenumberoftonsrequired
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Book 11: Environmental Protection Manual, Section 3.1 Page 15 of 36
to reduce the pool size by one acre and then subtracted from the pool
surface (determined in Step i), yielding the Reduced Pool Area.
(iv)The PMP Flood Volume Requirement, as per the January 10, 1990
Drainage Report, is 123.4 acre feet. The PMP Flood Volume
Requirement is dividedbytheReducedPool AreatodeterminethePMP
Freeboard Level.
(v)The Wave Run Up of 0.78 feet (as specified in the January 10, 1990
Drainage Report)is added to the PMP Freeboard Level todeterminethe
Total Required Freeboard.
The calculation of the Total Required Freeboard for Cell 3 will be calculated
annually and the calculation sheet filed in the Mill Central File.
c)Tailings Cell 4A
The freeboard limit for Cell 4A is determined annually using the following
procedure:
The Cell 4A design includes a concrete spillway between Cell 3 and Cell 4A,
with the invert elevation 4 feet below the top of the Cell 3 dike, at an elevation
of 5604.5 feet amsl.Should Cell 3 receive the full PMP volume of 123.4 acre
feet of water, approximately 62 acre feet of that volume would flow through
the spillway into Cell 4A.
The flood volume from the PMP event over the Cell 4A area is 36 acre-feet of
water (40 acres, plus the adjacent drainage area of 3.25 acres, times the PMP of
10 inches). This would result in a total flood volume of 98 acre-feet, including
the 62 acre-feet of solution from Cell 3. The freeboard depth required for Cell
4A fromthePMPeventwouldbe 2.44 feet,plusawaverun-updepthof0.77feet
(from the 1990 Drainage Report), for a total freeboard requirement of 3.2 feet.
This calculation is illustrated on Attachment 4. The Groundwater Quality
Discharge Permit, No. UGW370004, for the White Mesa Mill requires that the
minimum freeboard be no less than 3.0 feet for any of the existing Cell
construction, but based on the above calculation the freeboard would be set 3.2
feet belowthetopofliner.ThefreeboardforCell 4Awouldthereforebe5595.3
amsl (top of liner 5598.5 –3.2 feet).
The calculation of the Total Required Freeboard for Cell 4A will be calculated
annually and the calculation sheet filed in the Mill Central File.
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Book 11: Environmental Protection Manual, Section 3.1 Page 16 of 36
d)Roberts Pond
The freeboard limit for Roberts Pond is a liquid maximum elevation of 5,624.0
feet above mean sea level, as specified in the GWDP.
6.4.Annual Leak Detection Fluid Samples
In the event solution has been detected in a leak detection system, a sample will be collected on an
annual basis. This sample will be analyzed according to the conditions set forth in License
Condition 11.3.C. The results of the analysis will be reviewed to determine the origin of the
solution.
7.OTHER INSPECTIONS
Alldaily,weekly,monthly,quarterlyandannualinspectionsandevaluations shouldbeperformedas
specified in Sections 2, 3, 4, 5 and 6 above. However, additional inspections should be conducted
after any significant storm or significant natural or man-made event occurs.
8.REPORTING REQUIREMENTS
Inadditiontothe DailyInspectionData,WeeklyTailings Inspection,MonthlyInspectionData and
Quarterly Inspection Data forms included as Appendix A and described in Sections 2, 3, 4 and 5
respectively, and the Operating Foreman’s Daily Inspection and Weekly Mill Inspection forms
described in Sections 2 and 3, respectively, the following additional reports shall also be prepared:
8.1.Monthly Tailings Reports
Monthly tailings reports are prepared every month and summarize the previous month's activities
around the tailings area. If not prepared by the Radiation Safety Officer, the report shall be
submitted to the Radiation Safety Officer for review. The Mill Manager will review the report as
well before the report is filed in the Mill Central File. The report will contain a summary of
observations of concern noted on the daily and weekly tailings inspections. Corrective measures
takenduringthemonthwillbedocumentedalongwiththeobservationswhereappropriate. Alldaily
and weeklytailings inspection forms will beattachedto thereport. Amonthlyinspectionform will
alsobeattached. Quarterlyinspectionformswillaccompanythereportwhenapplicable. Thereport
will be signed and dated by the preparer in addition to the Radiation Safety Officer and the Mill
Manager.
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Book 11: Environmental Protection Manual, Section 3.1 Page 17 of 36
8.2.DMT Reports
Quarterlyreports ofDMTmonitoringactivitiesofallrequiredinformationrequiredbyPart1.F.2of
the GWDP relating to the inspections described in Section 3.1(b) (Slimes Drain Water Level
Monitoring), 3.1(d) (Tailings Wastewater Pool Elevation Monitoring), 3.2 (Weekly Inspection of
Solution Levels in Roberts Pond) and 3.3 (Weekly Feedstock Storage Area Inspections) will be
provided to the Executive Secretaryon the schedule provided in Table 5 of the GWDP.An annual
summaryandgraphforeachcalendaryearofthedepthtowastewaterintheCell2slimesdrainmust
beincludedinthefourthquarterreport. Afterthefirstyear,andbeginningin2008,quarterlyreports
shall include both the current year monthly values and a graphic comparison to the previous year.
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Book 11: Environmental Protection Manual, Section 3.1 Page 18 of 36
APPENDIX A
FORMS
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APPENDIX A (CONT.)
DAILY INSPECTION DATA
Inspector:________________
Date;___________________
Accompanied by:_________
Time:___________________
Any Item not “OK” must be documented. A check mark = OK, X = Action Required
I. TAILINGS SLURRY TRANSPORT SYSTEM
Inspection Items Conditions of Potential Concern Cell 1 Cell 2 Cell 3 Cell 4A
Slurry Pipeline Leaks, Damage, Blockage, Sharp Bends
Pipeline Joints Leaks, Loose Connections
Pipeline Supports Damage, Loss of Support
Valves Leaks, Blocked, Closed
Point(s) of Discharge Improper Location or Orientation
II. OPERATIONAL SYSTEMS
Inspection Items Conditions of Potential Concern Cell 1 Cell 2 Cell 3 Cell 4A
Water Level Greater Than Operating Level, Large Change
Since Previous Inspection
Beach Cracks, Severe Erosion, Subsidence
Liner and Cover Erosion of cover, Exposure of Liner
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Book 11: Environmental Protection Manual, Section 3.1 Page 20 of 36
III. DIKES AND EMBANKMENTS
Inspection Items Conditions of Potential Concern Dike
1-I
Dike 1-
1A
Dike 2 Dike 3 Dike 4A-
S
Dike 4A-
W
Slopes Sloughs or Sliding Cracks, Bulges, Subsidence,
Severe Erosion, Moist Areas, Areas of Seepage
Outbreak
Crest Cracks, Subsidence, Severe Erosion
IV. FLOW RATES
Slurry Line(s)Pond Return S-X Tails Spray System
GPM
V. PHYSICAL INSPECTION OF SLURRY LINES(S)
Walked to Discharge Point ____________Yes _____________No
Observed Entire Discharge Line ____________Yes _____________No
VI. DUST CONTROL
Cell 2 Cell 3 Cell 4A
Dusting
Wind Movement of Tailings
Precipitation: ______________________ inches liquid
General Meteorological conditions:__________________________
________________________________________________________
________________________________________________________
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Book 11: Environmental Protection Manual, Section 3.1 Page 21 of 36
VII. DAILY LEAK DETECTION CHECK
Cell 1 Cell 2 Cell 3 Cell 4A
Leak Detection System
Checked
_________Checked
______Wet______Dry
Initial level__________
Final level___________
Gal. pumped_________
_________Checked
______Wet______Dry
Initial level__________
Final level___________
Gal. pumped_________
_________Checked
______Wet______Dry
Initial level__________
Final level___________
Gal. pumped_________
_________Checked
______Wet______Dry
Initial level__________
Final level___________
Gal. pumped_________
VIII OBSERVATIONS OF POTENTIAL CONCERN Action Required
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[MAP OF TAILINGS AREA]
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APPENDIX A (CONT)
DENISON MINES (USA) CORP.
WEEKLY TAILINGS INSPECTION
Date:_________________Inspectors: ______________________________
1.Pond elevations (msl,ft)Cell 1:(a)Pond Solution Elevation ________________
(b)FML Bottom Elevation ______5597______
(c)Depth of Water above FML ((a)-(b))_______________
Cell 3:(a)Pond Solution Elevation ________________
(b)FML Bottom Elevation ______5570______
(c)Depth of Water above FML ((a)-(b))_______________
Cell 4A: (a)Pond Solution Elevation _______________
(b)FML Bottom Elevation ______5564_____
(c)Depth of Water above FML ((a)-(b)) ______________
Roberts
Pond:(a)Pond Solution Elevation _______________
(b)FML Bottom Elevation ______5612.34___
(c)Depth of Water above FML ((a)-(b)) _______________
2.Slimes Drain Liquid Levels Cell 2 Pump functioning properly ________
Pump Timer set at 15min on 45 min off ________
________________Depth to Liquid pre-pump
________________Depth to Liquid Post-pump
(all measurements are depth-in-pipe)
Pre-pump head is 38’-Depth to Liquid Pre-pump =
_______
Post-pump head is 38’ –Depth to Liquid Post-
pump = ______
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Book 11: Environmental Protection Manual, Section 3.1 Page 24 of 36
3.Leak Detection Systems
Observation:
Cell 1 Cell 2 Cell 3 Cell 4A
Is LDS wet or dry?_____wet____dry _____wet____dry _____wet____dry _____wet____dry
If wet, Record
liquid level:
_______Ft to
Liquid
_______Ft to
Liquid
_______Ft to
Liquid
_______Ft to
Liquid *
If sufficient fluid is
present, record
volume of fluid
pumped and flow
rate:
Volume _______
Flow Rate______
Volume _______
Flow Rate______
Volume _______
Flow Rate______
Volume _______
Flow Rate______
Was fluid sample
collected?
____yes____no ____yes____no ____yes____no ____yes____no
4.Tailings Area Inspection (Note dispersal of blowing tailings):
__________________________________________________________________________________
______________________________________________________________________
5.Control Methods Implemented:__________________________________________________
____________________________________________________________________________________
________________________________________________________________________
6.Remarks:__________________________________________________________________________
_____________________________________________________________________
7.Contaminated Waste Dump:____________________________________________________
* Does Level exceed 12 inches above the lowest point on the bottom flexible membrane liner (elevation
5556.14 amsl)? _____ no _____ yes
If Cell 4A leak detection system level exceeds 12 inches above the lowest point on the bottom flexible
membrane liner (elevation 5556.14 amsl), notify supervisor or Mill manager immediately.
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Book 11: Environmental Protection Manual, Section 3.1 Page 25 of 36
APPENDIX A (CONT.)
MONTHLY INSPECTION DATA
Inspector: ____________________________
Date: ________________________________
1.Slurry Pipeline: __________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
Pipe Thickness:____________(To be measured only during periods when the Mill is operating)
2.Diversion Ditches and Diversion Berm:
Observation:
Diversion Ditch 1 Diversion Ditch 2 Diversion Ditch 3 Diversion Berm 2
Diversion Ditches:
Sloughing _____yes_____no _____yes_____no _____yes_____no
Erosion _____yes_____no _____yes_____no _____yes_____no
Undesirable
Vegetation
_____yes_____no _____yes_____no _____yes_____no
Obstruction of Flow _____yes_____no _____yes_____no _____yes_____no
Diversion Berm:
Stability Issues _____yes_____no
Signs of Distress _____yes_____no
Comments:__________________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
3.Summary of Activities Around Sedimentation Pond: ____________________________________
____________________________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
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Book 11: Environmental Protection Manual, Section 3.1 Page 26 of 36
4.Overspray Dust Minimization:
Overspray system functioning properly: _______yes_______no
Overspray carried more than 50 feet from the cell: _____yes______no
If “yes”, was system immediately shut off? _____yes_____no
Comments:__________________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
5.Remarks: ________________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
6.Settlement Monitors
Cell 2 W1: ____________Cell 2W3-S: ____________Cell 3-1N: _____________
Cell 2 W2: ____________Cell 2E1-N: ____________Cell 3-1C: _____________
Cell 2 W3: ____________Cell 2E1-1S: ____________Cell 3-1S: _____________
Cell 2 W4: ____________Cell 2E1-2S: ____________Cell 3-2N: _____________
Cell 2W7-C: ____________Cell 2 East: ____________Cell 2W5-N: ___________
Cell 2 W7N: ____________Cell 2 W7S: ____________Cell 2 W6N: ___________
Cell 2 W6C: ____________Cell 2 W6S: ____________Cell 2 W4N: ___________
Cell 4A-Toe: ___________Cell 2 W4S: ____________Cell 2 W5C: ___________
Cell 3-2C: _____________Cell 3-2S: _____________
7.Summary of Daily, Weekly and Quarterly Inspections: __________________________________
____________________________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
8.Monthly Slimes Drain Static Head Measurement for Cell 2 (Depth-in-Pipe Water Level
Reading):__________________
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APPENDIX A (CONT.)
WHITE MESA MILL
TAILINGS MANAGEMENT SYSTEM
QUARTERLY INSPECTION DATA
Inspector: ____________________________
Date: ________________________________
1.Embankment Inspection: ______________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
________________________________________________
2.Operations/Maintenance Review: _______________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
________________________________________________
3.Construction Activites: ____________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
________________________________________________
4.Summary: ___________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
________________________________________________
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APPENDIX A (CONT.)
ORE STORAGE/SAMPLE PLANT WEEKLY INSPECTION REPORT
Week of _________ through _________ Date of Inspection:_________________
Inspector:_________________________
Weather conditions for the week:
____________________________________________________________________________________
____________________________________________________________________________________
________________________________________________
Blowing dust conditions for the week:
____________________________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
____________________________________
Corrective actions needed or taken for the week:
____________________________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
____________________________________
Are all bulk feedstock materials stored in the area indicated on the attached diagram:
yes:_______ no:________
comments:____________________________________________________________________________
___________________________________________________________
Are all alternate feedstock materials located outside the area indicated on the attached diagram maintained
within water-tight containers:
yes:_______ no:_______
comments (e.g., conditions of containers):______________________________________
____________________________________________________________________________________
____________________________________________________________
Conditions of storage areas for materials:
____________________________________________________________________________________
____________________________________________________________________________________
____________________________________________________________________________________
____________________________________
Other comments:
____________________________________________________________________________________
____________________________________________________________________________________
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APPENDIX B
TAILINGS INSPECTOR TRAINING
This documentprovidesthetrainingnecessaryforqualifyingmanagement-designatedindividualsfor
conducting daily tailings inspections. Training information is presented by the Radiation Safety
OfficerordesigneefromtheEnvironmentalDepartment. Dailytailingsinspectionsareconductedin
accordance with the White Mesa Mill Tailings Management System and Discharge Minimization
Technology(DMT) MonitoringPlan. TheRadiationSafetyOfficerordesigneefrom theRadiation
SafetyDepartmentisresponsibleforperformingmonthlyandquarterlytailingsinspections. Tailings
inspection forms will be included in the monthly tailings inspection reports, which summarize the
conditions, activities, and areas of concern regarding the tailings areas.
Notifications:
Theinspectorisrequiredtorecordwhetherallinspectionitemsarenormal(satisfactory,requiringno
action) or that conditions of potential concern exist (requiring action). A “check” mark indicates no
actionrequired. Ifconditionsofpotentialconcern exist the inspector should mark an “X” in the area
the condition pertains to, note the condition, and specify the corrective action to be taken. If an
observable concern is made, it should be noted on the tailings report until the corrective action is
takenandtheconcernisremedied. Thedatesofallcorrectiveactionsshouldbenotedonthereports
as well.
Any major catastrophic events or conditions pertaining to the tailings area should be reported
immediatelytotheMillManagerortheRadiationSafetyOfficer,oneofwhomwillnotifyCorporate
Management. Ifdamfailureoccurs,notifyyoursupervisorandtheMillManagerimmediately. The
Mill Manager will then notify Corporate Management, MSHA (303-231-5465), and the State of
Utah, Division of Dam Safety (801-538-7200).
Inspections:
All areas of the tailings disposal system are routinely patrolled and visible observations are to be
noted on a dailytailings inspection form. Refer to Appendix A for an example of the dailytailings
inspection form. The inspection form consists of three pages and is summarized as follows:
1.Tailings Slurry Transport System:
Theslurrypipelineistobeinspectedforleaks,damage,andsharpbends. Thepipelinejoints
are to be monitored for leaks, and loose connections. The pipeline supports are to be
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Book 11: Environmental Protection Manual, Section 3.1 Page 30 of 36
inspected for damage and loss of support. Valves are also to be inspected particularly for
leaks, blocked valves, and closed valves. Points of discharge need to be inspected for
improper location and orientation.
2.Operational Systems:
Operating systems including water levels, beach liners, and covered areas are items to be
inspected and noted on the daily inspection forms. Sudden changes in water levels
previously observed or water levels exceeding the operating level of a pond are potential
areasofconcernandshouldbenoted. Beachareasthatareobservedashavingcracks,severe
erosion or cavities are also items that require investigation and notation on daily forms.
Exposedlinerorabsenceofcoverfrom erosionarepotential items ofconcernforpondsand
covered areas. These should also be noted on the daily inspection form.
Cells 1, 3 and 4A solution levels are to be monitored closely for conditions nearing
maximum operating level and for large changes in the water level since the last inspection.
All pumping activities affecting the water level will be documented. In Cells 1 and 3, the
PVClinerneedstobemonitoredcloselyforexposedliner,especiallyafterstormevents. Itis
importanttocoverexposedlinerimmediatelyasexposuretosunlightwillcausedegradation
ofthePVCliner. Smallareasofexposedlinershouldbecoveredbyhand. Largesectionsof
exposed liner will require the use of heavy equipment
Theseconditionsareconsideredseriousandrequireimmediateaction. Aftertheseconditions
have been noted to the Radiation Safety Officer, a work order will be written by the
Radiation Safety Officer and turned into the Maintenance Department. All such repairs
should be noted in the report and should contain the start and finish date of the repairs.
3.Dikes and Embankments:
Inspection items include the slopes and the crests of each dike. For slopes, areas ofconcern
are sloughs or sliding cracks, bulges, subsidence, severe erosion, moist areas, and areas of
seepage outbreak. For crests, areas of concern are cracks, subsidence, and severe erosion.
When any of these conditions are noted, an “X” mark should be placed in the section marked
for that dike.
Inaddition,thedikes, inparticulardikes 3,4A-S and4A-W,shouldbeinspectedcloselyfor
mice holes and more importantly for prairie dog holes, as the prairie dogs are likely to
burrow in deep, possibly to the liner. If any of these conditions exist, the inspection report
should be marked accordingly.
4.Flow Rates:
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Book 11: Environmental Protection Manual, Section 3.1 Page 31 of 36
Presence of all flows in and out of the cells should be noted. Flow rates are to be estimated
ingallons perminute(GPM). Ratesneedtobedeterminedforslurrylines,pondreturn,SX-
tails, and the spraysystem. During non-operational modes, the flow rate column should be
marked as “0”. The same holds true when the spray system is not utilized.
5.Physical Inspection of Slurry Line(s):
Aphysical inspectionofall slurrylines has tobemadeevery4hoursduringoperationofthe
mill. If possible, the inspection should include observation of the entire discharge line and
discharge spill point into the cell. If “fill to elevation” flags are in place, the tailings and
build-up is to be monitored and controlled so as to not cover the flags.
6.Dust Control:
Dusting and wind movement of tailings should be noted for Cells 2, 3, and 4A. Other
observations to be noted include a brief description of present weather conditions, and a
record of any precipitation received. Any dusting or wind movement of tailings should be
documented. In addition, an estimate should be made for wind speed at the time of the
observed dusting or wind movement of tailings.
The Radiation Safety Department measures precipitation on a daily basis. Daily
measurements should be made as near to 8:00 a.m. as possible every day. Weekend
measurements will be taken bythe Shifter as close to 8:00 a.m. as possible. All snow or ice
should be melted before a reading is taken.
7.Observations of Potential Concern:
Allobservationsofconcernduringtheinspectionshouldbenotedinthissection. Corrective
action should follow each area of concern noted. All work orders issued, contacts, or
notifications made should be noted in this section as well. It is important to document all
these items in order to assure that the tailings management system records arecompleteand
accurate.
8.Map of Tailings Cells:
The last section of the inspection involves drawing, as accuratelyas possible, the following
items where applicable.
1.Cover area
2.Beach/tailing sands area
3.Solution as it exists
4.Pump lines
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Book 11: Environmental Protection Manual, Section 3.1 Page 32 of 36
5.Activities around tailings cell (i.e. hauling trash to the dump, liner repairs, etc.)
6.Slurry discharge when operating
7.Over spray system when operating
9.Safety Rules:
All safety rules applicable to the mill are applicable when in the tailings area. These rules
meettherequiredMSHAregulationsforthetailingsarea. Pleasepayparticularnoticetothe
following rules:
1.The posted speed limit for the tailings area is 15 mph and should not be exceeded.
2.No food or drink is permitted in the area.
3.All personnel entering the tailings area must have access to a two-way radio.
4.Horseplay is not permitted at any time.
5.Only those specifically authorized may operate motor vehicles in the restricted area.
6.When road conditions are muddy or slick, a four-wheel drive vehicle is required in the
area.
7.Any work performed in which there is a danger of falling or slipping in the cell will
require the use of a safety belt or harness with attended life line and an approved life
jacket. A portable eyewash must be present on site as well.
8.Anytime the boat is usedtoperform anywork; anapprovedlifejacket andgoggles must
bewornatalltimes. Theremustalsobeanapprovedsafetywatchwithatwo-wayhand-
held radio on shore. A portable eyewash must be present on site as well.
10.Preservation of Wildlife:
Everyeffort shouldbemadetoprevent wildlifeanddomesticatedanimalsfromenteringthe
tailings area. All wildlife observed should be reported on the Wildlife Report Worksheet
duringeachshift. Waterfowlseennearthetailingscellsshouldbediscouragedfromlanding
by the use of noisemakers.
11.Certification:
Following the review of this document and on-site instruction on the tailings system
inspection program, designated individuals will be certified to perform daily tailings
inspections. TheRadiationSafetyOfficerauthorizescertification. RefertotheCertification
Form,AppendixC.Thisformshouldbesignedanddatedonlyafterathoroughreviewofthe
tailings information previously presented. The form will then be signed by the Radiation
Safety Officer and filed.
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Book 11: Environmental Protection Manual, Section 3.1 Page 33 of 36
APPENDIX C
CERTIFICATION FORM
Date: __________________________
Name: _________________________
I have read the document titled “Tailings Management System, White Mesa Mill Tailings
Inspector Training” and have received on-site instruction at the tailings system. This instruction
included documentation of daily tailings inspections, analysis of potential problems (dike
failures, unusual flows), notification procedures and safety.
____________________________________
Signature
I certify that the above-named person is qualified to perform the daily inspection of the tailings
system at the White Mesa Mill.
____________________________________
Radiation Safety Personnel/ Tailings System
Supervisor
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Book 11: Environmental Protection Manual, Section 3.1 Page 34 of 36
APPENDIX D
FEEDSTOCK STORAGE AREA
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APPENDIX E
TABLES
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Table 1
Calculated Action leakage Rates
for Various head Conditions
Cell 4A White mesa Mill
Blanding, Utah
Head above Liner System (feet)Calculated Action leakage Rate
( gallons / acre / day )
5 222.04
10 314.01
15 384.58
20 444.08
25 496.50
30 543.88
35 587.46
37 604.01
OA 1U t{sPECTI ON REPORT
TAILINGS SLURRY DISCHARGE LOCATION
DATE:_~__-~-­
INSPECTOR:
HIll
AREA
CELL 2
O2I2MJ7 eM
REVISIONS County:tale:UT
Denison Mines (USA)Corp.
Feedstock Storage Area Map
0.1e Il LOC8lion:
Project WHITE MESA MILL