DRC-2009-002123 - 0901a0688011a5fa

DENISOIS^i
MINES
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Denison Mines (USA) Corp.
1050 17th Street, Suite 950
Denver, CO 80265
USA
Tel: [phone]
Fax:[phone]
www.denisonmines.com
May 26, 2009
Mr. David A. Rupp P.E.
Geotechnical Services Section
Utah Department of Environmental Quality
Division of Radiation Control
168 North 1950 West
P.O. Box 144850
Salt Lake City, UT 84114-4850
Dear Mr. Rupp:
Re: December 11, 2008 DUSA Letter: Amendment Requests Relating to Freeboard Limit
Calculations for Tailings Cells; November 20, 2008 DRC Letter: Conditional Approval of
Interim Variance; October 9, 2008 DUSA Letter: Interim Variance Requested Relating to
Freeboard Limit Calculations; March 23, 2009 UDEQ Letter: Comments and Request for
Resolution and Modifications
Reference is made to your March 23, 2009 letter in which you made certain comments and a
request for resolution and modification relating to Denison Mines (USA) Corp's ("DUSA's")
December 11, 2008 request to amend the manner of calculating freeboard liniits for the tailings
cells at DUSA's White Mesa uranium mill (the "Mill"). DUSA received your letter on March
26, 2009.
The purpose of this letter is to provide the requested response. Each concern or recommendation
is shown in italics below, followed by DUSA's response.
/. Pertaining to runoff control from Cell 3, Section 3 of tiie December 11, 2008 DUSA letter states that,
"so long as enough freeboard is retained in Cell 4Afor tiie PMP volume for all of Cells 2, 3 and 4A,
there is no need to set a freeboard limit for Cell 3." The Ground Water Discharge Permit (the
permit) paragraph I.D.3(c) states that, "upon closure of any tailings cell, the Permittee shall ensure
that the maximum elevation of the tailings waste solids does not e.xceed the top of the FML liner."
Therefore, it appears under current regulations, tailings could be placed in Cell 3 up to the top of the
FML liner.
DUSA's intention as to the schedule for tailings placement and the final height of tailings to be
placed in Cell 3, as it pertains to runoff control, is unknown. It appears that there is a need to have a
tnethod to effectively manage nmoff from the tailings above, or north of, the southern dike of Cell 3, if
the tails are to be placed up to the top ofthe FML liner.
It appears DUSA may have assumed that any runofffrom the tailings surface 'in Cell 3 will freely
drain into Cell 4A. The basis for such an assumption is unclear. If Cell 3 is completely filled with
tailings to tlie top of the FML liner, without other drainage provisions, portions of the runoff could
overflow the Cell 3 soutliern dike, instead of witolly discharging through the spillway between Cells
3 and 4A.
The top of the flexible membrane liner ("FML") on the Cell 3 dike is 5608.5 feet above mean sea level
("amsl"). The top of the Cell 3 dike is 5610.0 feet amsl. The maximum elevation of the tailings solids
upon closure of Cell 3 is limited to the top of the FML, which islS inches below the top of the Cell 3
dike. The invert elevation of the spillway between Cell 3 and Cell 4A is at 5604.5, being four feet below
the top of the Cell 3 dike and two and one half feet below the top of the FML.
Cell 3 has been, and continues to be operated in such a manner that tailings solids are deposited around
the perimeter of the Cell on the west, north, and east sides of the Cell. Tailings solutions are allowed to
separate from the solids and pool in the south central area of the Cell. The pool area is always maintained
next to the spillway, to allow for solutions from the pool area to overflow into Cell 4A through the
spillway, if necessary.
Tailings solids are deposited in "beaches", or cones, and allowed to dewater. Once the tailings solids are
at, or near, the fmal allowable elevation, the surface area of the tailings is graded to fill in any low spots,
or re-contoured to ensure that no areas of the solids are above the elevation of the FML. Tailings solids
will continue to be deposited around the perimeter of the cell and the solution pool area will continue to
shrink. Tailings solids will continue to be deposited from the north side of the cell to the south, ensuring
that solids are not placed above the FML on the upstream side of the Cell 3 dike. The last area to be
filled with tailings solids will be the area immediately adjacent to the spillway from Cell 3 to Cell 4A
(which would be the location of any remaining pool area). Because the tailings solids can never exceed
the elevation of the FML, and because the FML is two and a half feet lower at the spillway area than at
any other area of the cell, the tailings solids will always slope towards the spillway, thereby maintaining
the spillway as a means for surface runoff from the tailings to be directed towards and into Cell 4A, even
when there is no remaining pool area in Cell 3.
The most recent aerial contouring of the Cell 3 area (February 29, 2008) confirms that the tailings solids
in the westem half of the Cell are 4 to 6 feet below the top of the Cell 3 dike and therefore 2V2 to 4'A feet
below the top of the FML.
As a result of the foregoing, the top of the FML, and the maximum elevation of tailings solids, will
always be 18 inches below the top of the Cell 3 dike, except in the spillway area. This eighteen inch
height difference will act as a berm, and as a result, precipitation runoff from the Cell 3 area will be
contained in the interior of Cell 3. If there is a pool area in Cell 3, precipitation runoff from the tailings
sand areas of the cell will either flow to the pool area or infiltrate into the tailings solids and ultimately
find its way to the pool area. Should the precipitation event exceed the available free board capacity of
Cell 3, the excess solution will flow from the pool area through the spillway into Cell 4A. If tailings
solids have been placed to the top of the FML in all areas of the cell and there is no pool area, the
eighteen inch height difference between the top of the dike and the top of the FML will contain the
precipitation in the tailings cell. The runoff will either infiltrate into the tailings solids in the cell or flow
DENISOh^i MINES
naturally to the lowest point ofthe surface ofthe cell, which would be at the spillway, and would flow via
the spillway into Cell 4A. Any infiltration into the tailings solids of Cell 3 could increase the solution
level in Cell 3. However, the solution level in Cell 3 could never exceed the FML, because it would
surface at and flow over the spillway into Cell 4A.
To the extent interim cover is placed on portions of Cell 3 while there is still a pool area, most if not all of
the precipitation will find its way to the pool area, and a small amount may infiltrate into the interim
cover. If there is no pool area, the spillway will nevertheless be maintained until the final reclamation
cover is in place. Most of the precipitation runoff from Cell 3, which would be clean water, un-impacted
by tailings, would naturally flow towards the spillway, being the lowest point in the cell, and via the
spillway into Cell 4A. Any runoff that did not find its way into the spillway would be un-impacted by
tailings and would be expected to be minimal and could be managed under existing Mill procedures.
The southern dike of Cell 3 may be vulnerable to erosive forces when Cell 3 is full of tailings, and
storm water nmoff ensues. Potentially dikes could breacli, depending on storm water runoff
magnitudes.
As discussed above, the top of the FML, and hence the maximum elevation of tailings solids, will always
be at least 18 inches below the top of the Cell 3 dike. As long as the tailings solids are at or below the
elevation ofthe FML liner, precipitation from the PMP event (10 inches) that does not infiltrate into the
tailings solids will either drain from the Cell 3 solids area and fiow to the solution pool area or, if there is
no pool area, to the spillway. Should the precipitation event exceed the available free board capacity of
Cell 3, the excess solution will flow from the pool area through the spillway into Cell 4A. The spillway
will be maintained until the placement of the final reclamation cover; therefore it will continue to act as a
low point on the cell to catch precipitation runoff after interim cover has been placed on the cell and
direct such runoff into Cell 4A.
b. Contaminated surface discharge from runoff, over tlie western side of the south dike of Cell 3,
would not be subsequently captured by another tailings cell, as an approved Cell 4B is not
currently constructed.
Because the tailings solids in Cell 3 cannot exceed the elevation of the FML, and the FML is eighteen
inches below the elevation of the top of the dike, it is not possible for contaminated surface discharge to
leave the confines of the tailings system. As described above, precipitation runoff from Cell 3 would
either flow to the existing pool and via the spillway into Cell 4A or via surface flow to the spillway and
via the spillway into Cell 4A. Any possible surface runoff would be off of the interim cover, and would
therefore not be contaminated by Mill tailings.
c. There are possible runoff drainage problems at the spillway. Will DUSA limit the maximum
tailings elevation to be no higher than the top of the fle.xible membrane liner (FML) beneath the
spillway between Cell 3 and 4A? Is there to be a controlled grading ofthe tailings or other plans
to convey runoff to the spillway? What effect will such plans have on runoff control?
MINES
Tailings solids will continue to be deposited around the perimeter of Cell 3 and the solution pool area will
continue to shrink. The last area to be filled with tailings solids will be the area immediately adjacent to
the spillway from Cell 3 to Cell 4A. This will be the final area filled with tailings solids prior to the
placement of the initial phase of the reclamation cover. The spillway from Cell 3 to Cell 4A is 4 feet
below the top of the Cell 3 dike and 2'/2 feet below the top of the FML. At no time will the tailings solids
exceed the elevation of the FML, including at the spillway. Run off from the Cell 3 area will therefore
pass through the spillway to Cell 4A and will not contact the unlined area ofthe Cell 3 dike.
d. A portion of the upper surface ofthe southern dike on Cell 3 is unlined. Transient contaminated
runoff over and on the south dike could infiltrate into the unlined soils of the dike and carry
contaminants to the ground water below. Please justify such discharge to ground water would be
de-minimus, or provide steps to maintain tailings wastewater to be over FML at all times.
See comments to l.b. above. It is not possible for contaminated runoff to leave the confines of Cell 3
except via the spillway to Cell 4A.
2. The DMT Plan
a. Depending on DUSA's plans, provisions for preventing runoff' overtopping the southem
Cell 3 dike may be appropriate to be mentioned in the proposed DMT Plan in paragraph
6.3.3.
For the reasons discussed in 1 above, tailings runoff will not overtop the southern Cell 3 dike.
Therefore, no mention of such runoff need be made in the proposed DMT Plan in paragraph
6.3.3.
b. In the proposed DMT Plan, paragraph 6.3.4(b) the last sentence is recomrnended to be
revised as follows: "The maximum elevation of the beach area will be determined by
monthly surveys performed by Mill personnel in accordance with the Mill's DMT Planj
which will be revised to include this requirement (sec Sections 6.1 below).
We agree with this recommendation.
c. Similar to Cell 3, some provisions for preventing runoff overtopping the Cell 4A dike may
be appropriate to be mentioned in the proposed DMT Plan in paragraph 6.4(e), as
follows:
"(e) When a Spillway is Added to Cell 4A that Allows Overflow Into a New Tailings
Cell"
"When a spillway is added between Cell 4A and a new tailings cell (Cell 4B), then, if the
an approved freeboard limit calculation method for the new cell is set to cover the entire
PMP event for Cell 2, 3, 4A and 4B, the freeboard limitfor Cell 4 A will be inapplicable,,
except for approved provisions to prevent storm water runofffrom overtopping dikes."
DENISO
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We agree with these recommended changes.
The O&M Plan:
e. On pages 7-9 in the proposed O&M Plan, the paragraph in Routine Maintenance and
Monitoring, under Solutions Elevation is recommended to be revised as follows:
"Measurements of solution elevation in Cell 4A are to be taken by survey on a weekly
basis, and measurements of the beach area in Cell 4A with the highest elevation are to be
taken by survey on a monthly basis, by the use of the procedures and equipment specified
in Section 3. Ithe latest approved edition ofthe DMT Plan. "
We agree with this recommended change.
/ On page 12 in the proposed O&M Plan, tmder Tailings Emergencies, the first sentence of
the third paragraph under Cell 4A Solution Freeboard Calculation is recommended to be
revised as follows:
"Condition 10.3 states that "The Freeboard limit for Cell I shall be 5615.4 feet above
mean sea level, and the freeboard limit for Cell 4A sluill be set annually in accordance
with the procedures set out in Section 6.3the latest edition of the Wliite Mesa Mill
Tailings Management System and Discharge Minimization Technology (DMT)
monitoring Plan, which is included as a Ssection Srl—of the Mill's Environmental
Protection ProgramManual."
We agree with this recommended change.
g. On page 13 of the same proposed O&M Plan as above, the first and second full
paragraphs, the last sentences of each, are recommended to be revised as follows:
Delete the words "Section 6.3. "
We agree that the words "Section 6.3 of can be deleted from the last sentences of each of those
paragraphs.
The Radioactive Materials License (changes proposed to existing Amendment 3):
h. We note the License Condition 10.3 rewording proposed by DUSA in the December 11,
2008 letter. Section 7. The verbiage below illustrates the proposed DUSA changes to the
existing License Condition 10.3 of License Amendment 3:
DENISO
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10.3 The Freeboard limitfor Cell 1 shall be 5615.4 feet above mean sea level, and net
annually in accordance with the procedures set out in Section 3.0 to Appendix E
of the previously approved NRC license application, including the January 10,
1990 Drainage Report. Tthe freeboard limitfor Cell S4A shall be setrccalculated
annually in accordance with the procedures set out in Section 6.3 of the White
Mesa Mill Tailings Management Svstem and Discharge Minimization Technology
(DMT) Monitoring Plan, which is included as Section 3.1 of the Mill's
Environmental Protection Manual.in the October 13,—1999 revision to the
Drainage Report. Said calculations shall be submitted as part of the annual
Technical Evaluation Report. Said report shall be submitted for Executive
Secretary approval no later than September 1, of each year.
DRC recommends some additional wording adjustments to the above. These are to keep
the license DMT Plan references current by removing numerical section references,
adding report basis language for the Annual Technical Evaluation Report (ATER) and
resetting the date for submitting the ATER report to November 15 each year, (to be
current with DUSA's proposed annual freeboard calculations to be reset annually each
November 1). These recommendations are shown in blue below:
(1) 10.3 The Freeboard limitfor Cell 1 shall be 5615.4 feet above mean sea level,
and the freeboard limit for Cell 4A shall be set annually in accordance with the
procedures set out in the latest approved editionSection 6.3 of the White Mesa
Mill Tailings Management System and Discharge Minimization Technology
(DMT) Monitoring Plan, which is included as a Ssection 3.1 of the Mill's
Environmental Protection Manual.. Said calculations shall be submitted as part
of the €iAnnual Technical Evaluation Report (ATER). Said report shall be
submitted for Executive Secretary approval no later than September INovember
15, of each year.
The latest approved DMT Monitoring Plan discusses the required contents of the
ATER report. The ATER report is to be prepared in accordance with latest
approved edition of the White Mesa Mill (WMM) Environmental Protection
Manual.
We agree with the recommended changes to DUSA's proposed revised Section 10.3 of the
License, with the exception that the word "the" should be added before the word "latest" in the
new second paragraph to that condition set out above.
Enclosed with this letter are revised versions of the BAT Plan and Oc&M Plan, marked to
indicate the wording changes discussed above.
DENISO
MINES
rfjMM
If you should have any questions or require additional information, please contact the
undersigned at 303-389-4130 or Harold Roberts at 303-389-4160.
Yours very truly.
DENISON MINES (1>SA) CORP.
By:
David C. Fry(|enlund
Vice President, Regulatory Affairs and Counsel
cc: Ron P. Hochstein
Harold R. Roberts
Steven D. Landau
David E. Turk
DENISO MINES
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White Mesa Mill - Standard Operating Procedures 455/089 Revision: Denison-?8
Book 11: Environmental Protection Manual, Section 3,1 Page 1 of 42
,^7r?«29i$
^ ''\;^HITE MESA MILL TAILINGS MANAGEMENT SYSTEM
^-^"^ 't\ AND
5) DISCHARGE MINIMIZATION TECHNOLOGY (DMT)
MONITORING PLAN
NTRODUCTION
This Tailings Management System and Discharge Minimization Technology Monitoring Plan (the
"Plan") for the White Mesa Mill (the "Mill") provides procedures for monitoring ofthe tailings cell
system as required under State of Utah Radioactive Materials License No. UT 1900479 (the
"Radioactive Materials License"), as well as procedures for operating and maintenance of monitoring
equipment and reporting procedures that are adequate to demonstrate DMT compliance under State
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 ofthe 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. The Plan requires daily, weekly, quarterly, monthly and annual inspections and evaluations and
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 by the inspector will be recorded on the Daily Inspection Data form (a copy of
which is attached in Appendix A). The Daily Inspection Data form contains an inspection checklist,
which includes a tailings cells map, and spaces to record observations, especially those of immediate
White Mesa Mill - Standard Operating Procedures -155/089 Revision: Denison-?8
Book 11: Environmental Protection Manual, Section 3.1 Page 2 of 42
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 concem 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, spray evaporation. 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.
Daily inspections ofthe tailings lines are required to be performed when the Mill
is operating. The lines to be inspected include the: tailings slurry lines from CCD
to the active tailings cell; SX raffinate lines that can discharge into Cell 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.
o
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 455/089 Revision: Denison-?8
Book 11: Environmental Protection Manual, Section 3.1 Page 3 of 42
j) Wind movement of tailings and dust minimization.
Wind movement of tailings will be evaluated for conditions which may require
initiation of preventative dust minimization measures for cells containing tailings
sand. During tailings inspection, general surface conditions will be evaluated for
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,
expressed as a percentage ofthe total cell area. The evaluations will be reviewed
on a weekly basis, or more frequently if warranted, and will be used to direct dust
minimization activities.
k) Observation of flow and operational status of the dust control/spray evaporation
system(s).
1) Observations of any abnormal variations in tailings pond elevations in Cells 1,3,
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 ofthe tailings
cells will be made when warranted by changes in the solution level of the
respective leak detection system.
The trigger for further action when evaluating the measurements in the Cell 1 and
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
above the lowest point on the bottom flexible membrane liner (elevation 5556.14
feet amsl). If any of these observations are made, the Mill Manager should be
notified immediately and the leak detection system pump started.
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Book 11: Environmental Protection Manual, Section 3,1 Page 4 of 42
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 Materials License, to
determine whether or not the flow rate into the leak detection system is in excess
of the License Conditions.
q) An estimate ofthe percentage ofthe tailings beach surface area and solution pool
area is made, including estimates of solutions, cover areas, and tailings sands for
Cells 3 and 4A.
Items (a), (m), (n), and (o) are to be done only when the Mill is operating. When the Mill is down,
these items cannot be performed.
2.2. Daily Operations Inspection
During Mill operation, the Shift Foreman, or other person with the training specified in Section 2.4
below, designated by the Radiafion Safety Officer, will perform an inspection ofthe tailings line and
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 notify the Radiation Safety Officer
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.
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Book 11: Environmental Protection Manual, Section 3.1 Page 5 of 42
2.5. 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 Radiafion Safety Officer, one of whom 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).
3. WEEKLY TAILINGS AND DMT INSPECTION AND WEEKLY AND MONTHLY
SURVEYS
3.1. Weekly Tailings Inspections
Weekly tailings inspections are to be conducted by the Radiation Safety Department and include the
following:
a) Leak Detection Systems
Each tailings cell's leak detection system shall be checked weekly to determine
whether it is wet or dry. If marked wet, the liquid levels need to be measured and
reported. In Cell 1 and Cell 3 the leak detection system is measured by use ofa
pipe that is removed from the system which will indicate the presence of
solutions in the LDS system. The Cell 4A 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 pressure transducer is calibrated
for fluid with a specific gravity of 1.0. 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
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Book 11: Environmental Protection Manual, Section 3.1 Page 6 of 42
If sufficient fluid is present in the leak detection system of any cell, the fluid shall
be pumped from the LDS, to the extent reasonably possible, and record the
volume of fluid recovered. Any fluid pumped from an LDA shall be returned to a
disposal cell.
If fluid is pumped from an LDS, the flow rate shall be calculated by dividing the
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 calculafion shall be documented as part of the weekly
inspection.
Upon the initial pumping of fluid from an LDS, a fluid sample shall be coUected
and analyzed in accordance with paragraph 11.3 C. ofthe Radioactive Materials
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) Cell 3 is an active tailings cell while Cell 2 is partially reclaimed with approximately
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 ofthe
slimes drain. As taken from actual measurements, the bottom ofthe 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;
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Book 11: Environmental Protection Manual, Section 3.1 Page 7 of 42
(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
minutes before being pumped again. Based on measurements taken in August 2006,
the water level in the Cell 2 slimes drain recharges to a depth of about 28.50 feet
before each pumping and is pumped to a depth of 38 feet after each pumping, in each
case measured below the water level measuring point on the slimes drain access pipe.
The average wastewater head in the Cell 2 slimes drain is therefore about 5 feet. The
depth to water of about 28.50 feet after recharge is below the phreafic 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 safisfactory and is as low as reasonably
achievable. Based on past experience, cycling the pump more than 15 minutes every
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
that the timer is 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 fixed or
replaced within 15 days;
(v) Depth to wastewater in the Cell 2 slimes drain access 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 (the notch at the north side of the access pipe), and made to the
nearest 0.01 foot. The results will be recorded as depth-in-pipe measurements on the
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
Monthly Inspection Data form, by measuring the depth to water below the water level
measuring point on the slimes drain access pipe;
(vii) No process liquids shall be allowed to be discharged into Cell 2;
(viii) If at any time the most recent average annual head in the Cell 2 slimes drain is
found to have increased above the average head for the previous calendar year, the
Licensee will comply with the requirements of Part l.G.3 ofthe GWDP, including the
requirement to provide notification to the Executive Secretary orally within 24 hours
followed by written notificafion;
(ix)Because Cell 3 and Cell 4A are currently active, no pumping from the Cell 3 or Cell
4A slimes drain is authorized. Prior to initiation of tailings dewatering operations for
Cell 3 or Cell 4A, a similar procedure will be developed for ensuring that average
White Mesa Mill - Standard Operating Procedures 455/089 Revision: Denison-?8
Book 11: Environmental Protection Manual, Section 3.1 Page 8 of 42
head elevations in the Cell 3 and Cell 4A slimes drains are kept as low as reasonably
achievable, and that the Cell 3 and Cell 4A slimes drains are inspected and the results
reported in accordance with the requirements of the permit."
c) Wind Mo vement of Tailings
An evaluation of wind movement of tailings or dusting and control measures
shall be taken if needed.
d) Tailings Wastewater Pool and Beach Area Elevation Monitoring
Solution elevation measurements in Cells 1 and 4A and Roberts Pond are to be taken by
survey on a weekly basis, and the beach area in Cell 4A with the maximum elevation is to
be taken by survey on a monthly 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 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 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 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 or beach 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 ofthe Cell 1/Roberts Pond
Reference Point. For Cell 4A, this is typically on the road on the Cell 3 dike
approximately 100 feet east ofthe Cell 4 A 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 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;
White Mesa Mill - Standard Operating Procedures
Book 11; Environmental Protection Manual, Section 3,1
455/089 Revision: Denison-?8
Page 9 of42
(vii) The Surveyor will focus the cross hairs ofthe 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;
(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 Cell 1, Cell 4A or Roberts
Pond, or the area of the beach in Cell 4A with the highest elevation, as the case
may be. These designated locafions, and the methods to be used by the Assistant
to consistently use the same locations are as follows:
A. Pond Surface Measurements
I. 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.
n. Cell
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
III. 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 Cell 1 and 4A pond surface are:
Roberts Pond
Cell 1
Cell 4A
Northing
323,041
322,196
320,300
Easting
2,579,697
2,579,277
2,579,360
These coordinate locafions may vary somewhat depending on solution
elevations in the Pond and Cells;
B. Cell 4A Beach Elevation
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Book 11: Environmental Protection Manual, Section 3,1 Page 10 of 42
The Assistant will place the Survey Rod at the point on the beach area of Cell 4A
that has the highest elevation. If it is not clear which area of the beach has the
highest elevation, then multiple points on the beach area will be surveyed until the
Surveyor is satisfied that the point on the Cell 4A beach area with the highest
elevation has been surveyed. If it is clear that all points on the Cell 4A beach area
are below 5,593 FMSL, then the Surveyor may rely on one survey point;
(ix)The Assistant will hold the Survey Rod vertically with one end of the Survey Rod
just touching the pond or beach 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 histrument on the scale on
the Survey Rod, and record the number (the "Surface Reading"), which represents
the number of feet the Survey Instrument is reading above the pond or beach
surface level.
The Surveyor will calculate the elevation of the pond or beach surface as FSML by adding
the Reference Point Reading for the Cell or Roberts Pond, as the case may be, to the
Reference Point Elevation for the Cell or Roberts Pond and subtracting the Surface Reading
for the Cell or Roberts Pond, and will record the number accurate to 0.01 feet.
e) Summary
hi addition, the weekly inspection should summarize all activities conceming the
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
On a weekly basis, solution elevations are taken on Robeits Pond, in accordance with the procedures
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 FML at the Pond
Surface Reading area for Roberts Pond, is approximately six inches above the lowest point on the
pond's FML. Ifthe pond solution elevation at the Pond Surface Reading area is at or below the FML
for that area, the pond will be recorded as being dry.
3.3. Weekly Feedstock Storage Area Inspections
Weekly feedstock storage area inspections will be performed by the Radiation Safety Department, to
confirm that:
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Book 11: Environmental Protection Manual, Section 3.1 Page 11 of 42
a) the bulk feedstock materials are stored and maintained within the defined area described in
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.
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
requirement or observed leaking alternate feedstock dmms or other containers will be brought to the
attention of Mill Management and recfified within 15 days.
4. MONTHLY TAILINGS INSPECTION
Monthly tailings inspections will be performed by the Radiation Safety Officer or his designee from
the Radiation Safety Department and recorded on the Monthly Inspection Data form, an example of
which is contained in Appendix A. Monthly inspections are to be performed no sooner than 14 days
since the last monthly tailings inspection and can be conducted concurrenfly 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 measured using an ultrasonic device by
either the radiation safety staff or other trained designees. The critical points of the
pipe include bends, slope changes, valves, and junctions, which are crifical to dike
stability. These locations to be monitored will be determined by the Radiation Safety
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,
undesirable vegetation, and obstmction of flow. Diversion berm 2 should be checked
for stability and signs of distress.
c) Sedimentation Pond
Activities around the Mill and facilities area sedimentation pond shall be summarized
for the month.
d) Overspray Dust Minimization
White Mesa Mill - Standard Operating Procedures 455/089 Revision: Denison-?8
Book 11: Environmental Protection Manual, Section 3.1 Page 12 of 42
The inspection shall include an evaluation of overspray minimization, if applicable.
This entails ensuring that the overspray system is functioning properly. In the event
that overspray is carried more than 50 feet from the cell, the overspray system should
be immediately shut-off.
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Book 11: Environmental Protection Manual, Section 3.1 Page 13 of 42
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 quarterly tailings inspecfion is performed by the Radiation Safety Officer 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 inspecfion was performed.
Each quarterly inspection shall include an Embankment Inspection, an Operations/Maintenance
Review, a Constmction Review and a Summary, as follows:
a) Embankment Inspection
The Embankment inspection involves a visual inspection ofthe 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 Constmcfion Review consists of reviewing any constmction changes or
modifications made to the tailings area on a quarterly basis.
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Book 11: Environmental Protection Manual, Section 3.1 Page 14 of 42
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 ofthe 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 stmctures. 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
Evaluation also includes a review and summary ofthe annual movement monitor survey (see Section
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
stmctures.
In the event tailings capacity evaluafions (as per SOP PBL-3) were performed for the receipt of
alternate feed material during the year, the capacity evaluation forms and associated calculafion
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 evaluafion.
Tailings inspection records will consist of daily, weekly, monthly, and quarterly tailings inspections.
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 ofthe tailings area will be taken. The training of individuals will be
reviewed as a part of the Annual Technical Evaluation.
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Book 11: Environmental Protection Manual, Section 3.1 Page 15 of 42
The registered engineer will obtain copies of selected tailings inspecfions, along with the monthly
and quarterly summaries of observations of concern and the corrective actions taken. These copies
will then be included in the Annual Technical Evaluafion Report.
The Annual Technical Evaluation Report must be submitted by September 1^' of every year to:
Direcfing Dam Safety Engineer
State of Utah, Natural Resources
1636 West North Temple, Suite 220
Sak 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
quarter of each year. The movement monitor survey consists of surveying monitors along dikes 3-S,
4A-W, and 4A-S to detect any possible setfiement 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
The freeboard limits set out in this Section are intended to capture the Local 6-hour Probable
Maximum Precipitation (PMP) event, which was determined in the January 10, 1990 Drainage
Report (the "Drainage Report") for the White Mesa site to be 10 inches.
The flood volume from the PMP event over the Cell 1 pond area plus the adjacent drainage areas,
was calculated in the Drainage Report to be 103 acre feet of water, with a wave run up factor of
0.90 feet.
The flood volume from the PMP event over the Cell 2 and Cell 3 pond areas, plus the adjacent
drainage areas was calculated in the Drainage Report to be 123.4 acre-feet of water.
The flood volume from the PMP event over the Cell 4A area was calculated in the Drainage
Report to be 36 acre-feet of water (40 acres, plus the adjacent drainage area of 3.25 acres, times
the PMP of 10 inches), with a wave mn up factor of 0.77 feet.
The total pool surface area in Cell I is 52.9 acres and in Cell 4A is 40 acres. The top of the
flexible membrane liner ("FML") for Cell 1 is 5,618.2 FMSL and for Cell 4A is 5,598.5 FMSL.
Based on the foregoing, the freeboard limits for the Mill's tailings cells will be set as follows:
White Mesa Mill - Standard Operating Procedures 455/089 Revision: Denison-?8
Book 11: Environmental Protection Manual, Section 3.1 Page 16 of 42
6.3.1. Cell
The freeboard limit for Cell 1 will be set at 5,615.4 FMSL. This will allow Cell 1 to capture all of
the PMP volume associated with Cell 1. The total volume requirement for Cell 1 is 103 acre feet
divided by 52.9 acres equals 1.95 feet, plus the wave mn up factor of 0.90 feet equals 2.85 feet. The
freeboard limit is then 5,618.2 FMSL minus 2.85 feet equals 5,615.4 FMSL. Under Radioactive
Materials License condition 10.3, this freeboard limit is set and is not recalculated annually.
6.3.2. Cell 2
The freeboard limit for Cell 2 is inapplicable, since Cell 2 is filled with solids. All of the PMP
volume associated with Cell 2 will be attributed to Cell 4A (and/or any future tailings cells).
6.3.3. Cell 3
The freeboard limit for Cell 3 is inapplicable, since Cell 3 is close to being filled with solids, and all
of the PMP flood volume associated with Cell 3 will be attributed to Cell 4A (and/or any future
tailings cells).
6.3.4. Cell 4A
The freeboard limit for Cell 4A will be set assuming that the total PMP volume for Cells 2,3 and 4A
of 159.4 acre feet will be accommodated in Cell 4A. The procedure for calculating the freeboard
limit for Cell 4A is as follows:
(a) When the Pool Surface Area is 40 Acres
When the pool surface area in Cell 4A is 40 acres (i.e., when there are no beaches), the freeboard
limit for Cell 4A will be 5,593.7 FMSL, which is 4.76 feet below the FML (being the quotient of
159.4 acre feet divided by 40 acres, which equals 3.99 feet, plus the wave mn up factor for Cell 4A
of 0.77 feet, rounded to the nearest one-tenth of a foot);
(b) Wlien the Maximum Elevation ofthe Beach Area is 5,593 FMSL or Less
When the maximum elevation ofthe beach area in Cell 4A is 5593 FMSL or less, then the freeboard
limit will be 5,593.7 FMSL, which is the same as in (a) above. This allows for the situation where
there may be beaches, but these beaches are at a lower elevation than the freeboard limit established
in (a) above, and there is therefore ample freeboard above the beaches to hold the maximum PMP
volume. The maximum elevation of the beach area will be determined by monthly surveys
performed by Mill personnel in accordance with the Mill's DMT Plan^,, which will bo rovisod to
include this requirement (see Secfion 6.1 below).
(c) When the Maximum Elevation ofthe Beach Area First Exceeds 5,593 FMSL
When the maximum elevation of the beach area in Cell 4A first exceeds 5,593 FMSL, then the
freeboard limit for the remainder ofthe ensuing year (period t=0) (until the next November 1) will be
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Book 11: Environmental Protection Manual, Section 3.1 Page 17 of 42
calculated when that elevation is first exceeded (the "Initial Calculation Date"), as follows:
i) The total number of dry tons of tailings that have historically been deposited into Cell
4A prior to the Initial Calculation Date ("To") will be determined;
ii) The expected number of dry tons to be deposited into Cell 4A for the remainder ofthe
ensuing year (up to the next November 1), based on production esfimates for that
period ("AQ*"), will be determined;
iii) AO* will be grossed up by a safety factor of 150% to allow for a potential
underestimation of the number of tons that will be deposited in the cell during the
remainder of the ensuing year. This grossed up number can be referred to as the
"modeled tonnage" for the period;
iv) The total design tailings solid storage capacity of Cell 4A will be accepted as
2,094,000 dry tons of tailings;
v) The available remaining space in Cell 4A for solids as at the Initial Calculation Date
will be calculated as 2,094,000 dry tons minus To;
vi) The reduction in the pool surface area for the remainder of the ensuing year will be
assumed to be directly proportional to the reducfion in the available space in Cell 4A
for solids. That is, the reduced pool surface area for period t=0 ("RPAo"), after the
reduction, will be calculated to be:
(1 - (Ao* X 1.5) / (2,094,000 - To)) x 40 acres = RPAo
vii) The required freeboard for Cell 4A for the remainder of the period t=0 can be
calculated in feet to be the wave run up factor for Cell 4A of 0.77 feet plus the
quotient of 159.4 acre feet divided by the RPAo. The freeboard limit for Cell 4A for
the remainder of period t=0 would then be the elevation of the FML for Cell 4A of
5598.5 FMSL less this required freeboard amount, rounded to the nearest one-tenth of
a foot; and
viii) The foregoing calculations will be performed at the Initial Calculation Date and the
resulting freeboard limit will persist until the next November 1.
An example ofthis calculafion is set out in Appendix F.
(d) Annual Freeboard Calculation When the Maximum Elevation ofthe Beach Area Exceeds
5,593 FMSL
On November 1 of each year (the "Annual Calculation Date"), the reduction in pool area for the
ensuing year (referred to as period t) will be calculated by:
i) First, calculating the Adjusted Reduced Pool Area for the previous period (ARPAi.i)
to reflect actual tonnages deposited in Cell 4A for the previous period (period t-l).
The RPAt-i used for the previous period was based on expected tonnages for period t-
1, grossed up by a safety factor. The ARPAn is merely the RPA that would have
been used for period t-l had the actual tonnages for year t-l been known at the outset
of period t-1 and had the RPA been calculated based on the actual tonnages for period
t-l. This allows the freeboard calculations to be corrected each year to take into
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Book 11: Environmental Protection Manual, Section 3,1 Page 18 of 42
account actual tonnages deposited in the cell as of the date of the calculation. The
ARPAt-i can be calculated using the following formula:
(1 - A,.i / (2,094,000 - Tn)) x ARPAt.2= ARPAn
Where:
• At-i is the actual number of dry tons of tailings solids deposited in Cell 4A
during period t-1;
• Tt-i is the actual number of dry tons of tailings solids historically deposited in
Cell 4A prior to the beginning of period t-1; and
• ARPAt.2 is the Adjusted Reduced Pool Area for period t-2. If period t-2
started at the Initial Calculation Date, then ARPA(-2 is 40 acres;
ii) Once the ARPAt-i for the previous period (period t-l) has been calculated, the RPA
for the subject period (period t) can be calculated as follows:
(1 - (At* X 1.5) / (2,094,000 - T)) x ARPAi., = RPA,
Where:
• At* is the expected number of dry tons of tailings to be deposited into Cell 4A
for the ensuing year (period t), based on production estimates for the year (as
can be seen from the foregoing formula, this expected number is grossed up
by a safety factor of 1.5);
• Tt is the actual number of dry tons of tailings solids historically deposited in
Cell 4A prior to the beginning of period t; and
• ARPAt-i is the Adjusted Reduced Pool Area for period t-l, which is the pool
surface area for the previous period (period t-l) that should have applied
during that period, had modeled tonnages (i.e., expected tonnages grossed up
by the 150% safety factor) equaled actual tonnages for the period;
iii) The required freeboard for period t can be calculated in feet to be the wave mn up
factor for Cell 4A of 0.77 feet plus the quotient of 159.4 acre feet divided by the
RPAt. The freeboard limit for Cell 4A for period t would then be the elevation ofthe
FML for Cell 4A of 5598.5 FMSL less this required freeboard amount, rounded to the
nearest one-tenth of a foot; and
iv) The foregoing calculations will be performed at the Annual Calculation Date for
period t and the resulting freeboard limit will persist until the next Annual Calculation
Date for period t-l-1.
An example of this calculation is set out in Appendix F.
(e) Wlien a Spillway is Added to Cell 4A that Allows Overflow Into a New Tailings Cell
When a spillway is added between Cell 4A and a new tailings cell (Cell 4B), then, iftfeean approved
freeboard limit calculation method for the new cell is set to cover the entire PMP event for Cells 2,
3,4A and 4B, the freeboard limit for Cell 4A will be inapplicable, except for approved provisions to
White Mesa Mill - Standard Operating Procedures 455/089 Revision: Denison-?8
Book 11: Environmental Protection Manual, Section 3.1 Page 19 of 42
prevent storm water mnoff from overtopping dikes.
6.3.5. 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
All daily, weekly, monthly, quarterly and annual inspecfions and evaluations should be performed as
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
In addition to the Dcdly Inspection Data, Weekly Tailings Inspection, Monthly Inspection Data 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 acfivities
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
taken during the month will be documented along with the observations where appropriate. All daily
and weekly tailings inspection forms will be attached to the report. A monthly inspection form will
also be attached. Quarterly inspection forms will accompany the report when applicable. The report
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 20 of 42
8.2. DMT Reports
Quarterly reports of DMT monitoring acfivifies of all required information required by Part 1.F.2 of
the GWDP relating to the inspections described in Section 3.1(b) (Slimes Drain Water Level
Monitoring), 3.1(d) (Tailings Wastewater Pool and Beach Area 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 Secretary on the schedule provided in Table 5 ofthe GWDP. An
annual summary and graph for each calendar year of the depth to wastewater in the Cell 2 slimes
drain must be included in the fourth quarter report. After the first year, and beginning in 2008,
quarterly reports 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 21 of 42
APPENDIX A
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White Mesa Mill - Standard Operating Procedures -155/089 Revision: Denison-?8
Book 11: Environmental Protection Manual, Section 3,1 Page 26 of 42
APPENDIX A (CONT)
DENISON MINES (USA) CORP.
WEEKLY TAILINGS INSPECTION
Date: Inspectors:
1. Pond and Beach Cell 1: (a) Pond Solution Elevation
elevations (msl,ft)
(b) FML Bottom Elevation 5597_
(c) Depth of Water above FML ((a)-(b))
2. Slimes Drain Liquid Levels Cell 2 Pump ftinctioning properly.
Cell 4A: (a)Pond Solution Elevation
(b)FML Bottom Elevation 5564_
(c)Depth of Water above FML ((a)-(b))
(d)Elevation of Beach Area
with Highest elevadon (monthly)
Roberts
Pond: (a)Pond Solution Elevation
(b)FML Bottom Elevation 5612.34_
(c)Depth of Water above FML ((a)-(b))
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 =
White Mesa Mill - Standard Operating Procedures
Book 11: Environmental Protection Manual, Section 3,
455/089 Revision: Denison-?8
Page 27 of 42
3. Leak Detection Systems
Observation:
Is LDS wet or dry?
If wet. Record
liquid level:
If sufficient fluid is
present, record
volume of fluid
pumped and flow
rate:
Was fluid sample
collected?
Cell 1
wet dry
Ft to
Liquid
Volume
Flow Rate
ves no
Cell 2
wet dry
Ft to
Liquid
Volume
Flow Rate
ves no
Cell 3
wet dry
Ft to
Liquid
Volume
Flow Rate
ves no
Cell 4A
wet dry
Ft to
Liquid *
Volume
Flow Rate
ves 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 fiexible 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.
White Mesa Mill - Standard Operating Procedures
Book 11: Environmental Protection Manual, Section 3.1
455/089 Revision: Denison-?8
Page 28 of 42
Inspector:
Date:
APPENDIX A (CONT.)
MONTHLY INSPECTION DATA
1. Slurry Pipeline:
Pipe Thickness:, _(To be measured only during periods when the Mill is operating)
2. Diversion Ditches and Diversion Berm:
Observation:
Diversion Ditches:
Sloughing
Erosion
Undesirable
Vegetation
Obstruction of Flow
Diversion Berm:
Stability Issues
Signs of Distress
Diversion Ditch I
_yes_
_yes_
_yes_
_yes_
_no
_no
.no
no
Diversion Ditch 2 Diversion Ditch 3 Diversion Berm 2
_yes_
_yes_
_yes_
_yes_
_no
_no
_no
no
_yes_
_yes_
_yes_
_yes_
_no
.no
_no
no
_yes_
_yes_
_no
no
Comments:
3. Summary of Activities Around Sedimentation Pond:
White Mesa Mill - Standard Operating Procedures
Book 11: Environmental Protection Manual, Section 3,
455/089 Revision: Denison-?8
Page 29 of 42
4, Overspray Dust Minimization:
Overspray system functioning properly: _yes_
Overspray carried more than 50 feet from the cell:
If "yes", was system immediately shut off?
Comments:
no
_yes_
_yes_
no
no
5. Remarks:
6. Settlement Monitors
Cell2Wl
Cell 2 W2
Cell 2 W3
Cell 2 W4
Cell 2W7-C
Cell 2 W7N
Cell 2 W6C
Cell 4A-Toe
Cell 3-2C:
Cell 2W3-S:
Cell2El-N:
Cell2EI-lS:
Cell2El-2S:
Cell 2 East:
Cell 2 W7S
Cell 2 W6S
Cell 2 W4S
Cell 3-2S:
Cell3-1N:_
Cell3-lC:_
Cell3-lS:_
Cell 3-2N: _
Cell 2W5-N
Cell 2 W6N
Cell 2 W4N:
Cell 2 W5C
7. Summary of Daily, Weekly and Quarteriy Inspections:
Monthly Slimes Drain Static Head Measurement for Cell 2 (Depth-in-Pipe Water Level
Reading):
White Mesa Mill - Standard Operating Procedures 455/089 Revision: Denison-78
Book 11: Environmental Protection Manual, Section 3.1 Page 30 of 42
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:
White Mesa Mill - Standard Operating Procedures -155/089 Revision: Denison-7^8
Book 11: Environmental Protection Manual, Section 3,1 Page 31 of 42
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:
White Mesa Mill - Standard Operating Procedures 455/089 Revision: Denison-?8
Book 11: Environmental Protection Manual, Section 3,1 Page 32 of 42
APPENDIX B
TAILINGS INSPECTOR TRAINING
This document provides the training necessary for qualifying management-designated individuals for
conducting daily tailings inspecfions. Training information is presented by the Radiation Safety
Officer or designee from the Environmental Department. Daily tailings inspections are conducted in
accordance with the White Mesa Mill Tailings Management System and Discharge Minimizafion
Technology (DMT) Monitoring Plan. The Radiation Safety Officer or designee from the Radiation
Safety Department is responsible for performing monthly and quarterly tailings inspecfions. 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:
The inspector is required to record whether all inspection items are normal (safisfactory, requiring no
action) or that conditions of potential concern exist (requiring action). A "check" mark indicates no
action required. If conditions of potential concern 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
taken and the concern is remedied. The dates of all corrective actions should be noted on the reports
as well.
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 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).
Inspections:
All areas of the tailings disposal system are routinely patrolled and visible observations are to be
noted on a daily tailings inspection form. Refer to Appendix A for an example of the daily tailings
inspection form. The inspection form consists of three pages and is summarized as follows:
I. Tailings Slurry Transport System:
The slurry pipeline is to be inspected for leaks, damage, and sharp bends. The pipeline joints
are to be monitored for leaks, and loose connections. The pipeline supports are to be
White Mesa Mill - Standard Operating Procedures -155/089 Revision: Denison-?8
Book 11: Environmental Protection Manual, Section 3.1 Page 33 of 42
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
areas of concern and should be noted. Beach areas that are observed as having cracks, severe
erosion or cavities are also items that require invesfigation and notation on daily forms.
Exposed liner or absence of cover from erosion are potential items of concern for ponds and
covered areas. These should also be noted on the daily inspection form.
Cells 1, 3 and 4A solufion levels are to be monitored closely for condifions nearing
maximum operafing 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
PVC liner needs to be monitored closely for exposed liner, especially after storm events. It is
important to cover exposed liner immediately as exposure to sunlight will cause degradation
ofthe PVC liner. Small areas of exposed liner should be covered by hand. Large sections of
exposed liner will require the use of heavy equipment
These conditions are considered serious and require immediate action. After these conditions
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 of concern
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.
In addition, the dikes, in particular dikes 3,4A-S and 4A-W, should be inspected closely for
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.
White Mesa Mill - Standard Operating Procedures 455/089 Revision: Denison-7^8
Book 11: Environmental Protection Manual, Section 3.1 Page 34 of 42
4. Flow Rates:
Presence of all flows in and out of the cells should be noted. Flow rates are to be estimated
in gallons per minute (GPM). Rates need to be determined for slurry lines, pond return, SX-
tails, and the spray system. During non-operafional 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):
A physical inspection of all slurry lines has to be made every 4 hours during operafion ofthe
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 by the 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:
All observations of concern during the inspection should be noted in this section. Corrective
action should follow each area of concern noted. All work orders issued, contacts, or
notificafions 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 are complete and
accurate.
8. Map of Tailings Cells:
The last section ofthe inspection involves drawing, as accurately as possible, the following
items where applicable.
1. Cover area
2. Beach/tailing sands area
White Mesa Mill - Standard Operating Procedures -155/089 Revision: Denison-?8
Book 11: Environmental Protection Manual, Section 3.1 Page 35 of 42
3. Solution as it exists
4. Pump lines
5. Acfivifies 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
meet the required MSHA regulations for the tailings area. Please pay particular notice to the
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 used to perform any work; an approved life jacket and goggles must
be worn at all times. There must also be an approved safety watch with a two-way hand-
held radio on shore. A portable eyewash must be present on site as well.
10. Preservation of Wildlife:
Every effort should be made to prevent wildlife and domesticated animals from entering the
tailings area. All wildlife observed should be reported on the Wildlife Report Worksheet
during each shift. Waterfowl seen near the tailings cells should be discouraged from landing,
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. The Radiation Safety Officer authorizes certificafion. Refer to the Certification
Form, Appendix C. This form should be signed and dated only after a thorough review ofthe
tailings information previously presented. The form will then be signed by the Radiation
Safety Officer and filed.
White Mesa Mill - Standard Operating Procedures 455/089 Revision: Denison-78
Book 11: Environmental Protection Manual, Section 3.1 Page 36 of 42
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
White Mesa Mill - Standard Operating Procedures 455/089 Revision: Denison-?8
Book 11: Environmental Protection Manual, Section 3.1 Page 37 of 42
APPENDIX D
FEEDSTOCK STORAGE AREA
White Mesa Mill - Standard Operating Procedures 455/089 Revision: Denison-?8
Book 11: Environmental Protection Manual, Section 3,1 Page 38 of 42
APPENDIX E
TABLES
White Mesa Mill - Standard Operating Procedures
Book 11: Environmental Protection Manual, Section 3.
455/089 Revision: Denisonn'S
Page 39 of 42
Table 1
Calculated Action leakage Rates
for Various head Conditions
Cell 4A White mesa Mill
Blanding, Utah
Head above Liner System (feet)
5
10
15
20
25
30
35
37
Calculated Acfion leakage Rate
( gallons / acre / day )
222.04
314.01
384.58
444.08
496.50
543.88
587.46
604.01
White Mesa Mill - Standard Operating Procedures
Book 11: Environmental Protection Manual, Section 3.
455/089 Revision: Denison-^8
Page 40 of 42
APPENDIX F
Example of Freeboard Calculations
For Cell 4A
Assumpfions and Factors:
o Total PMP volume to be stored in Cell 4A - 159.4 acre feet
o Wave runup factor for Cell 4A - 0.77 feet
o Total capacity of Cell 4A - 2,094,000 dry tons
o Elevation of FML of Cell 4A - 5,598.5 FMSL
o Maximum pool surface area of Cell 4A - 40 acres
o Total tailings solids deposited into Cell 4A at time beach area first exceeds 5,593
FMSL - 1,000,000 dry tons*
o Date beach area first exceeds 5,593, FMSL - March 1, 2009*
o Expected and actual production is as set forth in the following table:
Time Period
March 1, 2009
to November 1,
2009
November 1,
2009 to
November 1,
2010
November 1,
2010 to
November 1,
2011
Expected
Tailings Solids
Disposition into
Cell 4A
Determined at
the beginning of
the period (dry
tons)*
150,000
300,000
200,000
Expected
Tailings
Solids
Dispositio
n into Cell
4A at the
beginning
ofthe
period,
multiplied
by 150%
Safety
Factor
(dry tons)
225,000
450,000
300,000
Actual Tailings
Solids
Disposition into
Cell 4A
determined at
end of the
period (dry
tons)*
225,000
275,000
250,000
White Mesa Mill - Standard Operating Procedures 455/089 Revision: Denison-?8
Book 11: Environmental Protection Manual, Section 3,1 Page 41 of 42
*These expected and actual tailings and production numbers and dates are fictional and have
been assumed for illustrative purposes only.
Based on these assumptions and factors, the freeboard limits for Cell 4A would be calculated
as follows:
1. Prior to March 1.2009
Prior to March 1, 2009, the maximum elevation of the beach area in Cell 4 is less than or
equal to 5,593 FMSL, therefore the freeboard limit is set at 5,593.7 FMSL.
2. March 1. 2009 to November 1. 2009
The pool surface area would be reduced to the following amount
(1 - 225,000/ (2,094,000 - 1,000,000)) x 40 acres = 31.77 acres
Based on this reduced pool area, the amount of freeboard would be 159.4 acre feet divided by 31.77
acres equals 5.02 feet. When the wave run up factor for Cell 4A of 0.77 feet is added to this, the total
freeboard required is 5.79 feet. This means that the freeboard limit for Cell 4A would be reduced
from 5593.7 FMSL to 5592.7 FMSL (5598.5 FMSL minus 5.79 feet, rounded to the nearest one-
tenth of a foot). This calculation would be performed at March 1, 2009, and this freeboard limit
would persist until November 1, 2009.
3. November 1. 2009 to November 1. 2010
The pool surface area would be reduced to the following amount:
First, recalculate the pool surface area that should have applied during the previous period,
had modeled tonnages (i.e., expected tonnages grossed up by the 150% safety factor) equaled
actual tonnages for the period. Since the actual tonnage of 225,000 dry tons was the same as
the modeled tonnage of 225,000 dry tons, the recalculated pool surface area is the same as
the modeled pool surface area for the previous period, which is 31.77 acres.
Then, calculate the modeled pool surface area to be used for the period:
(1 -450,000/(2,094,000- 1,000,000-225,000)) x 31.77 acres = 15.32 acres
Based on this reduced pool area, the amount of freeboard would be 159.4 acre feet divided by
15.32 acres equals 10.40 feet. When the wave run up factor for Cell 4A of 0.77 feet is added
to this, the total freeboard required is 11.17 feet. This means that the freeboard limit for Cell
4A would be reduced from 5592.7 FMSL to 5587.3 FMSL (5598.5 FMSL minus 11.17 feet,
rounded to the nearest one-tenth of a foot). This calculation would be performed at
November 1, 2009, and this freeboard limit would persist unfil November 1, 2010.
White Mesa Mill - Standard Operating Procedures 455/089 Revision: Denison-78
Book 11: Environmental Protection Manual, Section 3.1 Page 42 of 42
4. November 1. 2010 to November 1. 2011
The pool surface area would be reduced to the following amount:
First, recalculate the pool surface area that should have applied during the previous period,
had modeled tonnages (i.e., expected tonnages grossed up by the 150% safety factor) equaled
actual tonnages for the period. Since modeled tonnages exceeded actual tonnages, the pool
area was reduced too much during the previous period, and must be adjusted. The
recalculated pool area for the previous period is:
(1 - 275,000 / (2,094,000 - 1,000,000 - 225,000) x 31.77 acres = 21.72 acres.
This recalculated pool surface area will be used as the starting point for the freeboard
calculation to be performed at November 1, 2010.
Then, calculate the modeled pool surface area to be used for the period:
(1 - 300,000/ (2,094,000 - 1,000,000 - 225,000 - 275,000)) x 21.72 acres:
10.75 acres
Based on this reduced pool area, the amount of freeboard would be 159.4 acre feet divided by
10.75 acres equals 14.83 feet. When the wave run up factor for Cell 4A of 0.77 feet is added
to this, the total freeboard required is 15.60 feet. This means that the freeboard limit for Cell
4A would be reduced from 5587.3 FMSL to 5582.9 FMSL (5598.5 FMSL minus 15.60 feet,
rounded to the nearest one-tenth of a foot). This calculation would be performed at
November 1, 2010, and this freeboard limit would persist unfil November 1, 2011.
45/985/09 Revision Denison 1.45
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^^27282^^
I.D.6, LE.8,andI.F.8oftheGWDP. /7^ 7 ^'-"A
Cell Design
(V Received
\'
Tailings Cell 4A consists of the following major elements: \*A Pa^atio" Cofi
a) Dikes - consisting of earthen embankments of compacted soil, construbl|U^^. -^V^
between 1989-1990, and composed of four dikes, each including a IS-fooT^
wide road at the top (minimum). On the north, east, and south margins these
dikes have slopes of 3H to IV. The west dike has a interior slope of 2H to
IV. 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 locafions, the primary FML will be in contact with the
slimes drain collection system (discussed below).
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Cell 4A BAT Monitoring, Operations and Maintenance Plan 09/08 Revision Denison 1.3
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 comer. 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 permeabiUty 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 pattem
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 hydrauUc connection to the perforated slimes drain collection
pipe. A series of confinuous 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 tum overiain 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 primaiy FML. In turn, the gravel is overlain
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Cell 4A BAT Monitoring. Operations and Maintenance Plan 09/08 Revision Denison 1.3
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 constmcted near the westem
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 stmcture will be constmcted at Cell 4A. All stormwater mnoff
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
the Cell will allow the solution pool to gradually rise around the slimes drain
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Cell 4A BAT Monitoring, Operations and Maintenance Plan 09/08 Revision Denison 1.3
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 fime 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 wiU 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
operafional 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 inifial 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 locafion 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 protecfive 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 mbber fired 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.
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Cell 4A BAT Monitoring, Operations and Maintenance Plan 09/08 Revision Denison 1.3
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 constmcted
and maintained to ensure that the flexible membrane liner is not damaged during
the initial filling of the cell or subsequent operafion and maintenance acfivities.
The condifion 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 constmction defects or operafional 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
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Cell 4A BAT Monitoring, Operations and Maintenance Plan 09/08 Revision Denison 1,3
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, 123/08 Revision: Denison-7 (the "DMT
Plan"), 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 inifiates pumping condifions 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.
Page 6
Cell 4A BAT Monitoring. Operations and Maintenance Plan 09/08 Revision Denison 1.3
Solution Elevation
Measurements of solution elevation in Cell 4A are to be taken by survey
on a weekly basis, and measurements of the beach area in Cell 4A with the
highest elevafion are to be taken by survey on a monthly basis, by the use
of the procedures and equipment specified in Section 3.Ithe latest
approved edition of the DMT Plan.
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 detecfion 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
feet. The pump has a 1.5 inch diameter discharge, and operates on 460
Page 7
Cell 4A BAT Monitoring, Operations and Maintenance Plan 09/08 Revision Denison 1.3
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 inspecfion 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 instaUed 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 ofthe 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 coUector 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, Tsummi 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
slimes drain access pipe, near the ground surface level. The pump
Pages
Cell 4A BAT Monitoring, Operations and Maintenance Plan 09/08 Revision Denison 1,3
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 CeU 4A slimes drain pump will be checked weekly to observe that it
is operafing and that the level probes are set properly, which is noted on
the Weekly Tailings Inspection Form. If at any fime 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;
(y) 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 untU 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 operafing 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
will notify Corporate Management. If dam failure occurs, nofify your supervisor and the
Mill Manager immediately. The Mill Manager will then notify Corporate Management,
Page 9
Cell 4A BAT Monitoring, Operations and Maintenance Plan 09/08 Revision Denison 1,3
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 and Cell 4A are regulated
by condifion 10.3 ofthe White Mesa Mill 1 le.(2) Materials License, in accordance with
procedures set out in the DMT Plan.
Condifion 10.3 states that "The Freeboard limit for Cell 1 shall be 5615.4 feet above
mean sea level, and the freeboard limit for Cell 4A shall be set annually in
accordance with the procedures set out in Section 6.3the latest edition of the White
Mesa Mill Tailings Management System and Discharge Minimization Technology
(DMT) Monitoring Plan, which is included as a.Ssection 3j4-of the Mill's
Environmental Protection ProgramManual. Said calculations shall be submitted as
part of the annual Technical Evaluation Report. Said report shall be submitted for
Executive Secretary approval no later than September I, of each year."
The freeboard limits set out in Section 6.3 of the DMT Plan are intended to capture the
Local 6-hour Probable Maximum Precipitation (PMP) event, which was determined in
the January 10, 1990 Drainage Report for the White Mesa site to be 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 operafions or conditions in Cells 2, 3 or 4A.
Cells 2 and 3 have no freeboard limit because those Cells are full or near full of tailings
solids and all precipitation falling on Cells 2 and 3 and the adjacent drainage area must be
contained in Cell 4A. The flood volume from the PMP event over the Cell 2 and Cell 3
pond areas, plus the adjacent drainage areas, which must be contained in Cell 4A, is
123.4 acre-feet of water.
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 159.4 acre-feet, including the 123.4 acre-feet of
water from Cells 2 and 3, that must be contained in Cell 4A. The procedure for
calculating the freeboard Umit for Cell 4A is set out in Section 6.3 of the DMT Plan.
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 Cells 1 and 4A, but
based on License condition 10.3 and the procedure set out in Section 6.3 of the DMT
Plan, the freeboard limits for Cells 1 and 4A will be at least three feet.
Figure 7, Hydraulic Profile Schematic, shows the relationship between the Cells, and the
relafive elevations ofthe solution pools and the spillway elevations.
Page 10
Cell 4A BAT Monitoring, Operations and Maintenance Plan 09/08 Revision Denison 1.3
The required freeboard for Cell 4A will be recalculated annually.
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Cell 4A BAT Monitoring, Operations and Maintenance Plan 09/08 Revision Denison 1.3
Attachments
1) Figure 1, Inifial Filling Plan, GeoSyntec Consultants
2) Figure 2, Initial Filling Plan, Details and Sections, GeoSyntec Consultants
3) Figure 3, Inifial Filling Plan, Solution and Slurry PipeUne Routes, GeoSyntec
Consultants
4) Figure 4, Interim FilUng Plan, GeoSyntec Consultants
5) Figure 5, Leak Detection System Sump, GeoSyntec Consultants
6) Figure 6, Leak Detecfion Sump Operating Elevafions
7) Figure 7, Hydraulic Profile Schematic
8) Table 1, Calculated Action leakage Rates for Various Head Conditions,
CeU 4A, White Mesa Mill, Blanding, Utah, GeoSyntec Consultants
9) White Mesa Mill Tailings Management System and Discharge Minimization
Technology (DMT) Monitoring Plan, 12/08 Revision: DUSA-7, or currenfiy
approved version of the DMT
Page 12