DRC-2010-007672 - 0901a0688025cd75

State of Utah
GARY R. HERBERT
Governor
GREG BELL
Lieutenant Governor
Department of
Environmental Quality
Amanda Smith
Executive Director
DIVISION OF RADIATION CONTROL
Rusty Lundberg
Director
MEMORANDUM
TO: File
Denison Mines (USA) Corp.
Blanding, Utah
FROM: David Rupp^^^^^-;^
Geotechnical Services Section
DATE: Monday, November 8, 2010
SUBJECT: DUSA White Mesa Mill
Site Visit and Cell 4B Construction
On November 3, 2010 I visited the subject site and took photographs. A copy of the photos is
attached to this MEMO on a compact disk. These photos and captions augment this MEMO, and
are self-explanatory. The main focus of this inspection was the construction of tailings cell 4B,
and the photos are dominated by pictures of Cell 4B.
1. Cell 4A Freeboard> The current freeboard for Cell 4B is approved as 5593.74 famsl. This is
4.76 feet below the FML. A spillway is now being constructed between Cells 4A and 4B.
The upper elevation of the spillway is 5596.3 famsl or 2.46 feet above ofthe current freeboard
limit. However, the water level in Cell 4A is currently about 10 vertical feet below the
spillway. According to the proposed DMT Plan version 10.1, which is near approval, once
Cell 4B is approved to receive mill discharge, the freeboard limit for Cell 4A becomes zero.
Cell 4B is not yet completed. The lining contractor expects to be done with all lining by
November 13, 2010 and completely done with all other aspects of the project by November
25, 2010, which is Thanksgiving Day. It is hard to gage how realistic this projection is. I
plan to retum to the site on November 22, 2010 to check progress. If Cell 4B will not be
completed this calendar year, a new freeboardjimit for Cell 4A will need to be established.
2. Cell 4B Sandbags. I discussed the placement of slimes drain sandbags concurrently with
Messrs. Dave Turk and Steve Snyder of DUSA, and Michael Beaman of AEGL, the lining
contractor. No photo was taken. It appears the bags have generally now been piggy-backed
onto each other, like half-fallen dominoes. I pointed out that this placement method has
created numerous void openings to the slimes drains. The specifications show the bags to be
butted on long edge, and to have a 3-inch depth. DUSA's letter of October 8, 2010 states that
195 North 1950 West • Salt Lake City, UT
Mailing Address: P.O. Box 144850 • Salt Lake City, UT 84114-4850
Telephone [phone] • Fax [phone] • T.D.D. [phone]
www.deq.utah.gov
Printed on lOO'^* recycled paper
Page 2
the sandbags will be replaced as well as new bags placed in accordance with these
specifications. I did not see any significant effort with respect to sandbag replacement or
initial placement work.
I replaced a pair of sandbags in the manner of the specifications. We noted that such
replacement could be accomplished fairly rapidly. AEGL plans to begin reorienting the bags
after completion of the liner placement. In a later discussion with Mr. Bartlett of DUSA, he
expressed concem that if there is delay, frozen sandbags may be impossible to place correctly.
3. Completion of Cell 4B. Completion of the cell this calendar year, as discussed above, depends
on the weather. As shown in the photos, there was some weather related damage to the liner
leak detection system (LDS) sumps from bulging was created by water entering the system.
Apparently, there was no pump installed to remove the water. Recently there was runoff from
a l-inch storm, of long duration entering the LDS.
We discussed that winter shutdown provisions may be needed. DUSA and AEGL are
determined to finish the work this autumn. They are watching the local weather forecasts, and
feel it is possible at this location. For this week the local forecast is rain likely tonight, with
20% chance of rain this aftemoon, Tuesday moming and Wednesday night. Rest of the time
this week forecast is partly cloudy.
3. Surety. I took several photos of some buildings and an area for consideration in the surety
estimate. The truck shop south of main entry road, across from the administration building is
currently used for barrel painting now. A "Spmng Structure" brand building is used for ore
sample storage. To its north is the electrical and maintenance storage building. The Main
shop building has 2 overhead doors on the east side and 3 on the west. This shop is used for
both vehicle as well as repair of all other types of equipment. A small CMU shed is located
east of the main shop. There are significant deposits of junked tanks and other materials east
of the tailings cell area in a boneyard.
4. Placement of Cell 4B Excavated Soils on Cell 3. Dave Turk of DUSA and I discussed that the
original drawings called for 4 feet of excavated soils from Cell 4B to be placed on the east side
of tailings Cell 3. Mr. Turk noted that this was not done. However, some excavated soils
were placed on the west side of Cell 3.

195 North 1950 West • Salt Lake City, UT
Mailing Address: P.O. Box 144850 • Salt Lake City, UT 84114-4850
Telephone [phone] • Fax [phone] • T.D.D. [phone]
www.deq.utah.gov
Printed on 100% recycled paper
State of Utah

GARY R. HERBERT
Governor

GREG BELL
Lieutenant Governor
Department of
Environmental Quality

Amanda Smith
Executive Director

DIVISION OF RADIATION CONTROL
Rusty Lundberg
Director

M E M O R A N D U M

TO: File
Denison Mines (USA) Corp.
Blanding, Utah

FROM: David Rupp
Geotechnical Services Section

DATE: Monday, November 8, 2010

SUBJECT: DUSA White Mesa Mill
Site Visit and Cell 4B Construction

On November 3, 2010 I visited the subject site and took photographs. A copy of the photos is
attached to this MEMO on a compact disk. These photos and captions augment this MEMO, and
are self-explanatory. The main focus of this inspection was the construction of tailings cell 4B,
and the photos are dominated by pictures of Cell 4B.

1. Cell 4A Freeboard. The current freeboard for Cell 4B is approved as 5593.74 famsl. This is
4.76 feet below the FML. A spillway is now being constructed between Cells 4A and 4B.
The upper elevation of the spillway is 5596.3 famsl or 2.46 feet above of the current freeboard
limit. However, the water level in Cell 4A is currently about 10 vertical feet below the
spillway. According to the proposed DMT Plan version 10.1, which is near approval, once
Cell 4B is approved to receive mill discharge, the freeboard limit for Cell 4A becomes zero.

Cell 4B is not yet completed. The lining contractor expects to be done with all lining by
November 13, 2010 and completely done with all other aspects of the project by November
25, 2010, which is Thanksgiving Day. It is hard to gage how realistic this projection is. I
plan to return to the site on November 22, 2010 to check progress. If Cell 4B will not be
completed this calendar year, a new freeboard limit for Cell 4A will need to be established.

2. Cell 4B Sandbags. I discussed the placement of slimes drain sandbags concurrently with
Messrs. Dave Turk and Steve Snyder of DUSA, and Michael Beaman of AEGL, the lining
contractor. No photo was taken. It appears the bags have generally now been piggy-backed
onto each other, like half-fallen dominoes. I pointed out that this placement method has
created numerous void openings to the slimes drains. The specifications show the bags to be
butted on long edge, and to have a 3-inch depth. DUSA’s letter of October 8, 2010 states that
Page 2
the sandbags will be replaced as well as new bags placed in accordance with these
specifications. I did not see any significant effort with respect to sandbag replacement or
initial placement work.

I replaced a pair of sandbags in the manner of the specifications. We noted that such
replacement could be accomplished fairly rapidly. AEGL plans to begin reorienting the bags
after completion of the liner placement. In a later discussion with Mr. Bartlett of DUSA, he
expressed concern that if there is delay, frozen sandbags may be impossible to place correctly.

3. Completion of Cell 4B. Completion of the cell this calendar year, as discussed above, depends
on the weather. As shown in the photos, there was some weather related damage to the liner
leak detection system (LDS) sumps from bulging was created by water entering the system.
Apparently, there was no pump installed to remove the water. Recently there was runoff from
a 1-inch storm, of long duration entering the LDS.

We discussed that winter shutdown provisions may be needed. DUSA and AEGL are
determined to finish the work this autumn. They are watching the local weather forecasts, and
feel it is possible at this location. For this week the local forecast is rain likely tonight, with
20% chance of rain this afternoon, Tuesday morning and Wednesday night. Rest of the time
this week forecast is partly cloudy.

3. Surety. I took several photos of some buildings and an area for consideration in the surety
estimate. The truck shop south of main entry road, across from the administration building is
currently used for barrel painting now. A “Sprung Structure” brand building is used for ore
sample storage. To its north is the electrical and maintenance storage building. The Main
shop building has 2 overhead doors on the east side and 3 on the west. This shop is used for
both vehicle as well as repair of all other types of equipment. A small CMU shed is located
east of the main shop. There are significant deposits of junked tanks and other materials east
of the tailings cell area in a boneyard.

4. Placement of Cell 4B Excavated Soils on Cell 3. Dave Turk of DUSA and I discussed that the
original drawings called for 4 feet of excavated soils from Cell 4B to be placed on the east side
of tailings Cell 3. Mr. Turk noted that this was not done. However, some excavated soils
were placed on the west side of Cell 3.

DUSA Pictures 11-3-2010. Photos mainly feature the Construction of Cell 4B. Note the
black geonet material being placed in the bottom and on some dikes of the cell. Weather
damage repair was occurring in near corner.

1C4B: Looking NW. Subject as above, repairs in SE corner.

Looking NW, same as above. Note sandbags installed over strip drains.

Same perspective as above. Anchor trench at top of dike in foreground.

Cell 4B side of new spillway. The splash-pad is the black FML.

Concrete pour imminent on the new spillway between C4A & C4B.

East side of the spillway mentioned above. Approx. 25’ down slope to
the wastewater surface of Cell 4A from future spillway surface. That would
have a vertical equivalent to about 10-feet on the 2:1 slope. Freeboard ok.

C4B: Black geofabric topping the upper liner in corner above the 18-inch dia.
LDS and slimes ports.

Central herringbone of LDS system, looking west. Note piping
in foreground, which continues to spine of the LDS, closeby.

Spine of herringbone LDS at left with black geofabric trench top at left.
The spine was removed to form thoroughfare for wheeled vehicles to transport materials.
The sump area was damaged by run-on, and had to be reconstructed.

Looking north, near west side of C4B. LDS herringbone spine in foreground.
Geonet still needs to be placed westward, to the NW corner, both sides.
A spectating geonet crew is observed in S.W. corner of cell 4B.

Geonet on this west and northern dike needs to be covered by primary upper liner.

Sample storage sprung structure. This is immediately south of the electrical storage bldg.

View of the buildings mentioned above, looking NNW.
New reagent storage building, with new heavy precipitation curtains.

New boneyard area east of the tailings cells. This will need to be disposed of, and
perhaps included in surety next time.

Crew is pouring concrete for spillway between C4A to Cell 4B. Looking westward:
As seen on the Cell 4A side.