DRC-2009-002082 - 0901a0688011922f

t>tC'9w^{'00'7^'^X
>» Steve Landau <[e-mail]> 5/19/2009 5:07 PM >>>
Dear Mr. Finerfrock,
Please find attached a written notice In accordance with Part I.G.3,(a) of the GWDP for the White Mesa Mill. The notice pertains to
a repair of the liner In Cell 1 on the dyke, and above the pond solution level. This Is a follow-up to the oral notification given the
UDEQ Emergency Reporting Staff on May 15, 2009.
Should you have any questions regarding this notice, please contact me.
Yours truly,
Steven D. Landau
Manager, Environmental Affairs
Steve Landau
Manager, Environmentel Affairs
t: [phone] | f: [phone]
1050 17th Street, Suite 950, Denver, CO 80265
DENISON MINES (USA) CORP
www.denisonmines.com { httD,7/www.denisonmlnes,com/,)
This e-mail is intended for exclusive use the person(s) mentioned as the recipient(s). This message and any attached files with it
are confidential and may contain privileged or proprietary information. If you are not the intended reclplent(s) please delete this
message and notify the sender. You may not use, distribute print or copy this message if you are not the Intended recipient(s).
D i : D«ni«on Mines (USA) Corp.
& I 105017tft StTMt, Suite 9S0
m 01 D«nv«r, CO 80263
•mM "»A
AMINES Tal: 303 628-7798
Fax: [phone]S
www.danltonininas.com
May 19,2009 Mr. Dane Finerfrock, Executive Secretary
Utah Radiation Control Board
Utah Department ofEnvironmental Quality
168 North 1950 West
P.O. Box 144810
Salt Lake City, UT 84114-4810
Dear Mr. Finerfi"ock:
Re: White Mesa Mill Cell No. 1 Liner Repair
GWDP UGW37004- Part I.G.3.(a) Notification
In accordance with the provisions of Denison's procedure. Liner Maintenance Provisions-Cells
1,2,3 and Roberts Pond dated October 6, 2008, and Part I.G.3.(a) ofthe Ground Water Discharge
Permit, the following information is provided as a written follow-up to our oral notification that
was given to UDEQ's Emergency Reporting staff on May 15, 2009.
On May 14, 2009 at approximately 4:00 PM the Mill initiated work to repair a plugged tailings
line on the dyke near the Northeeist corner of Cell 1. The tailings pipe connection flange was
disassembled to allow flushing ofthe line, which unfortunately released a significant outflow of
tailings solufion and sand that eroded the soil cover over the liner exposing a part ofthe liner.
The exposed liner was observed to be damaged which appears to have been caused by the force
ofthe outflow, which also eroded some ofthe underlying soils. This occurred at the lip edge of
the dyke near the anchor trench well above the solution level. Because of the saturated soil in
the area ofthe damage, it will be several days before we can assess the extent ofthe damage and
make the required repairs.
Repair work will involve the installation ofa PVC repair patch over the damaged PVC liner,
above the solufion level in the pond. Subsequent to the repair installafion, the glued seams will
need to be tested by means of a vacuum box in order to assure that all seams are intact and that
no leakage will occur. Once that test is completed, the area will be recovered with earthen
material in order to preclude damage ofthe PVC from sunlight. In accordance with Denison's
procedure, Liner Maintenance Provisions-Cells 1,2,3 and Roberts Pond dated October 6, 2008,
Denison will issue a repair report once the work is completed, including the information
specified in the procedure.
Ifyou should require additional infoimation about this matter please contact me.
Yours very tmly.
DENISON MINES (USA) CORP.
STEVEN D. LANDAU
MANAGER, ENVIRONMENTAL AFFAIRS
DENISON J?
MINES