DRC-2011-007041 - 0901a0688024ed78

JUL 20U
llivisiOTi of
* • Denison Mines (USA) uorp."
1050 17th Street, Suite 950
Denver, CO 80265
USA
Tel:
Fax
303 628-7798
303 389-4125
www.denisonmines.com
July 6, 2011
VIA E-MAIL AND OVERNIGHT DELIVERY
Rusty Lundberg, Co-Executive Secretary
Utah Water Quality Board
Utah Department of Environmental Quality
195 North 1950 West
P.O. Box 144810
Salt Lake City, UT 84114-4810
Re: state of Utah Ground Water Discharge Permit No. UGW370004 White Mesa Uranium Mill -
Notice Pursuant to Part I.G.3 of the Permit and UAC R317-6-6.16(C)
Dear Mr. Lundberg:
Please take notice pursuant to Part I.G.3 of the White Mesa Mill's (the "Mill's") State of Utah Groundwater
Discharge Permit No. UGW370004 (the "Permit") and Utah Administrative Code ("UAC") R313-6-6.16(C) that
Denison Mines (USA) Corp. ("Denison"), as operator of the Mill and holder of the Permit, failed to meet the
Best Available Technology ("BAT") standards in Part I.E.8.a.l of the Permit, by not providing continuous
operation of the Cell 4A leak detection system ("LDS") data recording equipment, as described in more detail
below.
This failure was discovered on Monday, June 27, 2011. Initial notice of this failure to maintain BAT was given
by telephone to Mr. David Rupp of the Utah Department of Environmental Quality at 3:30pm on Wednesday
June 28, 2011 at 801-536-4023 (within 24 hours of the discovery).
1. Facts and Background Information
a) The Cell 4A LDS instrumentation was installed in August 2008.
b) Section I.E.S.a.l of the Permit requires that "the Permittee shall provide continuous operation of the
leak detection system pumping and monitoring equipment, including, but not limited to, the
submersible pump, pump controller, head monitoring, and flow meter equipment approved by the
Executive Secretary. Failure of any LDS pumping or monitoring equipment not repaired or made fully
operational within 24-hours of discovery shall constitute a failure of BAT, and a violation of this
permit."
c) The Mill identified on June 27, 2011, at the time of the weekly tailings inspection, that the electronic
LDS log was not operating, and determined from review of the data log that it had not operated since
June 3, 2011.
N:\Notices\Cell 4A LDS notice 07.06.11\07.06.11 Notice to RLundberg Cell 4A LDS data.doc
Letter to Mr. Rusty Lundberg
Julys, 2011
Page 2
d) At the time of discovery, Mill environmental personnel immediately reboo,ted the data computer, reset
the system, and data logging resumed.
e) The data logging system computer and data storage flash drive have the capacity to store
approximately six weeks of data.
f) Mill environmental technicians manually record the same data daily during daily tailings inspections.
That is all data relative for BAT compliance was manually recorded even during the periods of
electronic data outage.
g) Environmental technicians have historically encountered periods when data could not be
downloaded from the Cell 4A LDS storage device. Environmental technicians were under the
mistaken impression that the system required time for data uploads from the level sensor to the data
computer, during which downloads were not feasible.
h) During the period from June 3 to June 27, encompassing three weekly attempts at the LDS data
download, environmental technicians assumed at each unsuccessful attempt that the system was
uploading, and that data was being stored for collection during a subsequent week. Further
inspection on June 27 identified that the system was not uploading, but had stopped recording.
i) Following the initial discovery of the system malfunction. Mill environmental personnel monitored the
system more closely in order to diagnose the cause of the shutdown. The data logger continued to
have the same problems with electronic shutdowns that required rebooting and resetting as follows:
Date system Days of Date of Days of
rebooted operation before malfunction missing data
malfunction before next
identified
June 27 2 June 29 2
July 1 4 July 5 1
2. Actions Taken
Upon identification of the initial malfunction, Denison took the following actions:
a) Mill environmental personnel notified Denison Corporate environmental staff;
b) The data computer was rebooted and the logger reset; and
c) Environmental technicians observed the system more frequently to confirm whether the correction
had rectified the malfunction, that is, whether the system would run continuously.
When the more frequent monitoring identified the recurring malfunction, Denison took the following actions:
a) Mill environmental personnel notified Denison Corporate environmental staff;
b) Mill environmental technicians contacted the manufacturer's technical team for assistance in
diagnosing the cause of the malfunction;
DENISO
MINES
Letter to Mr. Rusty Lundberg
July 6, 2011
Page 3
c) Mill environmental personnel developed a stepwise approach for isolating the cause of repeqted
system failure, as described in Section 4, below.
3. Root Cause
The root cause analysis is as follows:
a) Environmental technicians have historically encountered periods when data could not be downloaded
from the Cell 4A LDS storage device. Environmental technicians were under the mistaken
impression that the system required time for data uploads from the level sensor to the data computer,
during which downloads were not feasible. Environmental technicians were also aware that the
storage system could maintain up to six weeks of data, and assumed that because data was being
stored for multiple weeks, it was sufficient to return the following week for the data that could not be
downloaded.
b) During the period from June 3 to June 27, encompassing three weekly attempts at the LDS data
download, environmental technicians assumed at each unsuccessful attempt that the system was
uploading, and that data was being stored for collection during a subsequent week. Further
inspection on June 27 identified that the system was not uploading, but had stopped recording.
c) Environmental technicians were also aware that daily manual recording of the same data as collected
by the electronic logger is used for reporting, and mistakenly assumed that the electronic data was
redundant and not required.
4. Actions That Will be Taken to Prevent a Reoccurrence of this Incident
The following actions will be taken to prevent a re-occurrence of this incident:
a) Mill environmental technicians are in the process of procuring, installing, and testing one or more
alternate, more durable, data storage flash drive devices, consistent with the manufacturer's technical
team recommendation. Installation and testing will be complete by July 31, 2011.
b) Mill environmental technicians will attempt to download, install and test an upgraded version of the
data management software, consistent with the manufacturer's technical team recommendation.
Installation and testing will be complete by July 31, 2011.
c) Mill environmental personnel will monitor the newly installed data device and software daily for one
month after installation, through August 31, 2011, to confirm whether either or both of these were the
cause of the repeated outages.
d) If the modifications have not corrected the recurring outages by August 31, 2011, Denison will
evaluate further steps, potentially including repair or replacement of the storage computer. Denison
will develop and discuss a schedule for further steps with DRC at that time.
5. Affirmative Defense
Denison believes that the affirmative defense in Part I.G.3.C) of the Permit should be applicable to this
incident, for the following reasons:
DENISOI
MINES
Letter to Mr. Rusty Lundberg
Julys, 2011
Page 4
a) Notification
By virtue of the initial oral notification given to UDEQ at 3:30 PM on Tuesday, June 28, 2011 (within 24 hours
of the discovery) and this written notice, Denison has submitted notification according to UAC R317-6-6.13.
b) Failure was not Intentional or Caused by the Permittee's Negligence
The failure of the LDS instrumentation to record level data was not caused by Denison's negligence, either in
action or in failure to act. As discussed above. Mill personnel made weekly attempts to download the level
data, as well as daily visits to hand record and preserve data. The equipment malfunctioned between
monitoring events. Mill personnel have made efforts, in progress, to diagnose and correct the system.
c) The Permittee has Taken Adequate Measures to Meet Permit Conditions
Mill personnel have made multiple efforts to diagnose and correct the system, and proposed corrections to the
system are in progress. During the period in question, all of the relevant data was recorded manually to ensure
compliance with the applicable requirements in the Permit. The solution level within the LDS and the flow rate
were within the prescribed limits.
d) Denison has taken adequate measures to meet Permit conditions in a timely manner.
The provisions of the Permit were implemented immediately. UDEQ was notified within 24 hours of discovery
of the solution measurement information. In each case when the data recording system malfunctioned, it was
reset immediately upon discovery by Mill environmental personnel.
e) The Provisions of UCA 19-5-107 Have Not Been Violated
The provisions of Utah Code 19-5-107 have not been violated. There has been no discharge of a pollutant
into waters of the state. Denison has not caused pollution which constitutes a menace to public health and
welfare, or is harmful to wildlife, fish or aquatic life, or impairs domestic, agricultural, industrial, recreational, or
other beneficial uses of water, nor has Denison placed or caused to be placed any waste in a location where
there is probable cause to believe it will cause pollution.
There was no discharge of solutions from the Mill's tailings impoundments.
Please contact the undersigned if you have any questions or require any further information.
Yours very truly,
DENISON MINES (USA) CORP.
Jo Ann Tischler
Director, Compliance and Permitting
DENISOi
MINES
Letter to Mr. Rusty Lundberg
Julys, 2011
Page 5
cc: David C. Frydenlund
Harold R. Roberts
David E. Turk
Ryan Palmer
Katherine Weinel
Central files
DENISON
MINES