DRC-2011-006587 - 0901a06880242808

Denison Mines (USA) Corp.
1050 17th Street, Suite 950
Denver, CO 80265
USA
Tel: [phone]
Fax: [phone]
www.denisonmines.com
June 13, 2011
VIA PDF AND FEDERAL EXPRESS
Mr. Rusty Lundberg
Co-Executive Secretary
Utah Water Quality Board
State of Utah Department of Environmental Quality
195 North 1950 West
P.O. Box 144810
Salt Lake City, UT 84114-4810
Dear Mr. Lundberg:
ird Re: DUSA I^^Quarter 2010 (dated May 19, 2010), 2"'' Quarter 2010 (dated August 26, 2010) and 3'
Quarter 2010 (dated November 22, 2010) Groundwater Monitoring Reports - Notice of Violation and
Compliance Order, Docket No. UGW11-02
This letter is in response to the foregoing Notice of Violation (the "Notice") dated May 9, 2011, which
Denison Mines (USA) Corp. ("DUSA") received on May 12, 2011. The Notice lists five violations (the
"Violations") of the White Mesa Mill's (the "Mill's") Ground Water Quality Discharge Permit No.
UGW370004 (the "Permit"), based on a review of the Mill's Groundwater Monitoring Reports for the I^V
2"^ and 3'''Quarters of 2010.
Pursuant to Utah Code Annotated 19-5-111 (1953 as amended), this letter describes:
a) the root cause of the noncompliance;
b) steps that have been or will be taken to correct the violation;
c) date when compliance was or will be regained; and
d) steps taken or to be taken to prevent reoccurrence of the noncompliance.
DUSA responds as follows:
1. Part I.E. 1 (a) of the Permit and Section 6.2.7(d)(v) of the DUSA QAP for failing to achieve
stable turbidity conditions before collecting groundwater samples in 4 wells during the 2nd
Quarter, 2010 monitoring event.
a) Root Cause of the Noncompliance
The four wells referred to in Table 2 and in Violation 1 were MW-17, MW-20, MW-25 and MW-29.
DUSA believes that the violation, with respect to MW-20, is in error and should be rescinded. MW-20 was
purged to dryness prior to achieving 2 casing volumes. Four sets of field measurements were collected
during purging. Violation 1 charges that MW-20 had not achieved stable turbidity measurements, based
on the Mill's Groundwater Monitoring Quality Assurance Plan ("QAP") requirement for percent difference
within 10%.
Section 6.2.7(d)(v) of the QAP states:
"If the well is purged to dryness or is purged such that full recovery exceeds two hours, the well should be
sampled as soon as a sufficient volume of groundwater is available to fill sample containers."
Per Section 6.2.7(d)(vii) of the QAP,
"If the well cannot yield two casing volumes,
A) Evacuate the well to dryness and record the number of gallons evacuated on the field data
worksheet; and
B) Prior to sampling measure and record depth to groundwater on the field data worksheet following
the procedures set out in paragraph 6.1.3, above."
in neither section does the QAP require that stabilized parameters must be achieved in the case when a
well is purged to dryness. In DUSA's previous experience with DRC regarding wells purged to dryness,
stable parameters have not been required. Purging the well to dryness, and sampling upon recovery is
itself a demonstration that representative formation water is being sampled.
In addition, the two values for MW-20 which DRC claimed did not meet stable turbidity based on the
requirement to be within the 10 percent difference, were turbidity values of 0 NTU and 0.3 NTU,
respectively. At any set of values which are both below 1 NTU, when measured to one decimal place, it
is mathematically impossible to achieve either a percent difference or a relative percent difference less
than 10 percent. (The 1992 TEGD does not require sensitivity below one decimal place, or 0.1 NTU, and
requires only that values stabilize to approximately 10 percent). Further, the percent difference is a
meaningless value when one of the compared values is zero. In that case, there is no second value,
other than 0, that would not lead to an infinite value for percent difference or relative percent difference.
The current QAP standard is impossible to implement on clean water. In the situation cites in the NOV,
the groundwater sample was too clear (turbidity too low) to meet the requirement that percent difference
be within 10 percent. That is, the only way to meet the QAP requirement would be to continue to monitor
until a cloudier, more turbid (non-zero) value is achieved that could be compared favorably with another
non-zero value. DUSA is in the process of preparing a request to modify the QAP to address these
issues.
It should be noted that both of the turbidity measurements from MW-20 had turbidity low enough to meet
the US EPA Drinking Water Standard of 1 NTU for untreated and 0.5 NTU for filtered water; Since the
goal of pre-sampling stabilization is to avoid cloudy, turbid samples as a demonstration that clear
formation water has been sampled, this goal obviously was met.
The root cause of the violation with respect to MW-17, MW-25 and MW-29 is as follows. At the time of
sampling, the turbidity sensor on the field Hydrolab multi-meter was not functioning properly.
Simultaneously the Mill sampling personnel were under the mistaken understanding that a variance had
been issued by DRC such that purging was complete after the removal of two casing volumes, regardless
of stability of parameters. As a result, the field personnel purged to two casing volumes when they were
unable to collect dependable turbidity readings.
DUSA realizes that Notices of Violation have been issued in the past for non-compliance with Section
6.2.7(d)(v) of the QAP, and that DUSA has instructed its field personnel in the past on the proper
interpretation of that Section of the QAP. However, DUSA had already initiated discussions with the
Executive Secretary including a phone call on April 5, 2010 in which it argued that it was not practicable
to obtain stable turbidity conditions in the Mill's monitoring wells, and proposed that the QAP be modified
to permit low flow sampling instead. These discussions resulted in a formal letter request of April 2, 2010,
and proposed revision to the QAP dated June 4, 2010. This request led to subsequent correspondence
between DRC staff and DUSA and the implementation of a well re-development program at the Mill,
which is currently under way. Mill field sampling personnel were under the understanding that, in light of
these submissions by DUSA and the steps that were being taken to address the problems that were
being encountered with turbidity at the Mill, that DRC had waived strict compliance with the stable
turbidity requirements of the QAP pending resolution of the issues.
b) Steps That Have Been Taken to Correct the Violation
The following steps have been taken to correct the violation:
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Mill sampling personnel have been re-instructed that Section 6.2.7(d)(v) ofthe QAP requires that for wells
that are not purged to dryness, purging is completed after two casing volumes have been removed AND
field parameters have stabilized to within lOpercent over at least two consecutive measurements.
Further, Mill sampling personnel have been reminded that existing provisions of the QAP must be
followed unless and until a formal written variance or modification has been approved by the Executive
Secretary.
c) Date When Compliance Was or Will be Regained
Compliance was regained in the first quarter of 2011 when all wells that were not purged to dryness were
purged to two casing volumes and achieved stable parameters. Compliance was technically achieved in
the fourth quarter of 2010 when all wells that were not purged to dryness were purged to two casing
volumes and achieved stable parameters (except one well for which the turbidity values were so low that
it is mathematically impossible to generate a percent difference less than 10 percent).
d) Steps Taken to Prevent Reoccurrence of the Noncompliance
See item (b) above.
2. Part I.E.I (a) of the Permit and Section 6.2.7(d)(v) of the DUSA QAP for failing to achieve stable
turbidity conditions before collecting groundwater samples in 1 well during the June, 2010
accelerated monitoring event.
a) Root Cause of the Noncompliance
DUSA submits that Violation No. 2 is in error and should be rescinded. MW-26 is a continuously pumping
well. The stable turbidity requirements of Section 6.2.7(d)(v) of the QAP do not apply to pumping wells.
Per the QAP Chloroform Addendum:
"Wells MW-26 and MW-32 may be monitored under either the chloroform program or the
groundwater program." Additionally the Addendum states "In the case of chloroform pumping
wells only 1 set of field parameters is required to be measured prior to sampling."
The Draft Chloroform Operations and Maintenance ("O&M") Plan includes no requirement to purge any
specific volume of well water and no requirement to measure and stabilize parameters before sampling.
The goal of pre-sampling stabilization activities is to ensure that representative samples of formation
water are collected. The multiple sets of parameters were collected inadvertently and were not required.
Nothing in the chloroform addendum requires that if multiple measurements are collected, that
stabilization of measurements is required to demonstrate that steady state has been achieved, or
formation water has been collected.
In any event, even though the stable turbidity requirements of Section 6.2.7(d)(v) of the QAP do not apply
to MW-26, as a matter of practice at least two casing volumes are typically purged immediately prior to
each sampling of that well. The pump on MW-26 runs on a 15 minute on and 45 minute off cycle. Mill
personnel sample pumping wells in one of the following two ways. If the well pump is on at the time of
sampling, a sample is collected from the 5 gallon-per-minute pump discharge. If the pump is off, the
sampler turns the pump on, and allows it to run 10 to 15 minutes at 5 gallons per minute. After 10 to 15
minutes, a sample is collected from the pump discharge. That is, a sample is collected after a minimum
of 50 gallons. Since MW-26 is a 4 inch well, and has a casing volume of 23.72 gallons (based on a well
depth of 121.33 feet and typical depth to water of 85.01 feet), at least two casing volumes are purged.
However, because the well is continuously pumped there is no risk that the water being sampled at any
time is not representative of formation water, regardless of how many casing volumes may have been
purged immediately prior to each sampling.
b) Steps That Have Been Taken to Correct the Violation
The following steps have been taken to correct the violation:
DUSA believes we are already in compliance with the requirements of the QAP Chloroform Addendum
and the Draft Chloroform O&M Plan.
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c) Date When Compliance Was or Will be Regained
DUSA believes we are already in compliance with the requirements of the QAP Chloroform Addendum
and the Draft chloroform O&M Plan.
d) Steps Taken to Prevent Reoccurrence of the Noncompliance
DUSA believes we are already in compliance with the requirements of the QAP Chloroform Addendum
and the Draft chloroform O&M Plan.
3. Part I.E.I (a) of the Permit and Section 6.2.7(d)(v) of the DUSA QAP for failing to achieve stable
turbidity conditions before collecting groundwater samples in 3 wells during the July, 2010
accelerated monitoring event.
a) Root Cause of the Noncompliance
The three wells referred to in Table 2 and in Violation 3 were MW-14, MW-26, and MW-31.
DUSA submits that with respect to MW-26, Violation No. 3 is in error and should be rescinded for the
same reasons described in item 2 above. That is, the stable turbidity requirements of Section 6.2.7(d)(v)
of the QAP do not apply to pumping wells, such as MW-26. The extra sets of field parameters were
collected inadvertently and are of no relevance. Per the QAP Chloroform Addendum:
"Wells MW-26 and MW-32 may be monitored under either the chloroform program or the
groundwater program." Additionally the Addendum states "In the case of chloroform pumping
wells only 1 set of field parameters is required to be measured prior to sampling."
The Draft Chloroform Operations and Maintenance ("O&M") Plan includes no requirement to purge any
specific volume of well water and no requirement to measure and stabilize parameters before sampling.
The goal of pre-sampling stabilization activities is to ensure that representative samples of formation
water are collected. The multiple sets of parameters were collected inadvertently and were not required.
Nothing in the chloroform addendum requires that if multiple measurements are collected, that
stabilization of measurements is required to demonstrate that steady state has been achieved, or
formation water has been collected.
The pump on MW26 runs on a 15 minute on and 45 minute off cycle. Mill personnel sample pumping
wells in one of the following two ways. If the well pump is on at the time of sampling, a sample is
collected from the 5 gallon-per-minute pump discharge. If the pump is off, the sampler turns the pump
on, and allows it to run 10 to 15 minutes at 5 gallons per minute. After 10 to 15 minutes, a sample is
collected from the pump discharge. That is, a sample is collected after a minimum of 50 gallons. Since
MW26 is a 4 inch well, and has a casing volume of 23.72 gallons (based on a well depth of 121.33 feet
and typical depth to water of 85.01 feet), at least two casing volumes are purged. That is, formation water
is being purged. (However, as mentioned above, the Chloroform O&M Plan has no requirement to purge
any specific volume of well water before sampling.)
With respect to MW-14 and MW-31, the root cause of the violation is the same as the root cause of the
violations relating to MW-17, MW-25 and MW-29 descnbed in item 1 above.
b) Steps That Have Been Taken to Correct the Violation
Mill sampling personnel have been re-instructed that the Section 6.2.7(d)(v) of the QAP requires that for
wells that are not purged to dryness, purging is completed after two casing volumes have been removed
AND field parameters have stabilized to within 10 percent over at least two consecutive measurements.
c) Date When Compliance Was or Will be Regained
Compliance was regained in the first quarter of 2011 when all wells that were not purged to dryness were
purged to two casing volumes and achieved stable parameters. Compliance was technically achieved in
the fourth quarter of 2010 when all wells that were not purged to dryness were purged to two casing
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volumes and achieved stable parameters (except one well for which the turbidity values were so low that
it is mathematically impossible to generate a percent difference less than 10 percent).
d) Steps Taken to Prevent Reoccurrence of the Noncompliance
See item (b) above.
4. Utah Water Quality Act (UC 19-5~107) and Parts I.C.10 ofthe Permit for failing to protect the
waters of the state in that 6 contaminants have exceeded their respective GWCL in Table 2 of the
Permit for two consecutive sampling events.
a) Root Cause of the Noncompliance
DUSA submits that the violations cited for the following constituents and wells are in error and should be
rescinded:
• successive exceedances in thallium in MW-18 in January and March 2010; and
• successive exceedances in TDS in MW-27 in Ql and Q2, 2010.
In each of these cases one or both of the samples used in determining two sequential exceedances was
a non-required sample collected in error in Ql 2010. The samples in question were taken as accelerated
samples based on the old Groundwater Compliance Limits ("GWCLs") and not the current GWCLs that
were set in January 2010. Hence, they were not required to be accelerated under the new GWCLs and
were therefore taken in error. Agreement on handling of results from non-required accelerated samples
collected in Ql 2010 has already been established in correspondence between DRC and DUSA dated
February 16 and February 17, 2011. Per the February 16, 2011 email from David Frydenlund, approved
by Philip Goble on February 17, 2011:
"Accelerated monitoring for subsequent quarters will depend on the application of Part
I.G.1 of the permit to results from groundwater samples required to be taken in the first
quarter of 2010 and from any subsequent sample results. The notice requirements of
Part I.G. 1 .a) of the Permit will apply to any exceedances observed in groundwater
samples required to be taken in the first quarter of 2010 and from any subsequent
sample results [emptiasis added].
The analytical results for any accelerated monitoring that may have taken place in
January 2010 will be kept on file atthe Mill but will not be included in the 1st quarter 2010
Groundwater Monitoring Report for the Mill."
Mr. Goble concurred with the determination in this portion of the February 16, 2011 email from David
Frydenlund, in his response on February 17, 2011, stating that
"We agree with everything in your e-mail except the last paragraph"
and adding that:
"If DUSA collected accelerated groundwater samples in January before the
revised Permit was modified (January 20, 2010) you need to include these results with
the 1st Quarter, 2010 GW Report (due March 1, 2010), in orderto comply with Part II.F of
the Permit."
DUSA believes it was understood at the time that no samples inadvertently taken in Ql 2010 would be
used to determine compliance with Part I.G.1 of the Permit, regardless of whether or not they were taken
before or after January 20, 2010. DUSA advised DRC in February 2010 that the fact that the new
GWCLs created a "clean slate" and that no constituents were in accelerated status as of January 20,
2010 was not fully implemented by Mill field sampling personnel until sometime after that date, and that,
as a result, some non-required samples were taken after January 20, 2010.
DUSA also submits that Violation 4, with respect to selenium in MW-30 is in error and should be
rescinded. There were not two successive exceedances of the GWCL for selenium in MW-30 in Ql, Q2
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or Q3 2010. The data cited in Table 2 for MW-30 indicates selenium exceedances in Q2 2010 and
August 2010. However, there was an intervening monitoring period, July 2010, in which selenium in MW-
30 was 33.5 ug/L compared to a GWCL of 35 ug/L, that is, it was not an exceedance.
With respect to the remaining constituents and wells, namely:
Cadmium MW24
Manganese MWll
Selenium MWI 2
Thallium MWI 8, MW24
Uranium MW26
TDS MW27
DUSA will submit a Work Plan and Schedule (the "Plan") by June 13, 2011, for Executive Secretary
approval, to evaluate the root cause and response action (if necessary) for the consecutive exceedances
of GWCLs for those constituents in those wells. The Plan will also address any additional consecutive
exceedances identified in Q4 2010 and Ql 2011.
The Plan will set out a plan and time schedule for assessment of the sources, extent and potential
dispersion of the contamination, and an evaluation of potential remedial action to restore and maintain
groundwater quality to ensure that Permit limits will not be in exceedance at the compliance monitoring
point, as required under Part I.G.4 of the Permit and Section E.4 of the Notice.
DUSA is in the process of determining the root cause through the development and implementation of the
Plan, once approved.
b) Steps That Have Been Taken to Correct the Violation
Accelerated monitoring of the constituents in the wells identified above is continuing, as required by Part
I.G.4(b) of the Permit. DUSA will submit the Plan on or before June 13, 2011, and will implement the
Plan once approved by the Executive Secretary.
c) Date When Compliance Was or Will be Regained
Compliance will be regained in the manner and in accordance with the schedule set out in the Plan, as
approved by the Executive Secretary.
d) Steps Taken to Prevent Reoccurrence of the Noncompliance
See paragraph (b) above.
5. Part I.G.4(c) of the Permit for failing to provide a plan and schedule for assessment of the
sources, extent and potential dispersion of the contamination, and an evaluation of potential
remedial action to restore and maintain groundwater quality to insure that Permit limits will not be
exceeded at the compliance monitoring point and that DMT or BAT will be reestablished.
a) Root Cause of the Noncompliance
DUSA mistakenly believed that it would have a chance to consult with the Executive Secretary in any
circumstance when the concentration of a constituent in two consecutive samples from a compliance
monitoring well exceeds a GWCL, before implementation of the requirements of Part I.G.4 of the Permit.
DUSA assumed that identification of the successive exceedances would result in an opportunity for joint
evaluation with the Executive Secretary for the following reasons:
(i) five of the constituents identified as being OOC (manganese in MW-11, selenium in MW-
3, and selenium in MW-12, thallium in MW-18, uranium in Mw-26) have already been
identified in DUSA's groundwater background reports of June and October 2007 (the
"Background Reports") as constituents with rising trends in jntra-well background
concentrations, for which eventual exceedance of the GWCLs is not unexpected. It was
further acknowledged that the rising trends were due to natural background influences
and were not caused by Mill operations. The decision flow diagram in the Background
Groundwater Reports contemplated that special consideration would be given to such
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constituents when setting GWCLs in the Permit. However, a solution to this problem was
not identified at the time the GWCLs were set in the Permit in January 2010, and the
GWCLs were therefore set as if the rising trends did not exist. DUSA expected that,
because the GWCLs set in the Permit did not recognize these rising trends it would have
a chance to discuss the circumstances with the Executive Secretary at the time any of
these constituents exceeded their GWCLs, especially in light of paragraphs (iii) and (iv)
below;
(ii) one of the constituents (uranium in MW-26) is in a pumping well, which was identified in
the September, 2009 Statement of Basis as follows: "It should be noted that, because
MW-26 is a pumping well for chloroform removal, concentrations of all constituents in that
well are subject to potential variation overtime as a result of the pumping activity. This
will be taken into consideration by the Executive Secretary on determining compliance for
this well." Again, the GWCLs that were set did not properly take into account the nature
of this well. DUSA expected that it would have a chance to discuss the circumstances
with the Executive Secretary at the time of an exceedance of any constituent in this well,
especially in light of paragraphs (iii) and (iv) below;
(iii) the questions of rising trends and the influences of pumping were analyzed in detail in the
Background Reports. It is not clear what new or additional analysis could be performed
in a plan and schedule to be submitted under Part I.G.4, in light of this previous analysis.
DUSA therefore assumed that some dialogue would take place before it would be
required to submit a new plan and schedule under Part I.G.4 to redo an analysis that had
just recently been extensively analyzed in the Background Reports; and
(iv) from the initial date of issuance of the Permit up until the date of the Notice, there had
been numerous multiple consecutive exceedances of GWCLs, for which the Executive
Secretary did not enforce the requirements of Part I.G.4 of the Permit. Those GWCLs
were set in 2005 as a fraction of the Ground Water Quality Standards for drinking water
or the equivalent and were not tied to background. We understood this to mean that by
setting GWCLs the Executive Secretary had the ability to enforce against the Permit
holder, but that the Executive Secretary would exercise discretion in enforcing in
circumstances where the GWCLs may not appropriately reflect background. It was this
understanding that led DUSA to believe that any consecutive exceedances of GWCLs
after January 20, 2010, especially in the circumstances described above where the
GWCLs do not take into account rising trends in background or the influences of
pumping, DUSA would have a chance to consult with the Executive Secretary on the
proper course to follow (which could involve changing the GWCLs) prior to initiation of the
provisions of Part I.G.4 of the Permit.
b) Steps That Have Been Taken to Correct the Violation
The Plan will be submitted to the Executive Secretary on or before June 13, 2011. See item 4(b) above.
c) Date When Compliance Was or Will be Regained
Compliance will be regained on June 13, 2011 upon submission of the Plan.
d) Steps Taken to Prevent Reoccurrence of the Noncompliance
DUSA now understands that the provisions of Part I.G.4 apply to all situations when the concentration of
a constituent in two consecutive samples from a compliance monitoring point exceeds a GWCL in Table 2
of the Permit, and will act accordingly.
If you have any questions or require any further information, please contact the undersigned.
Yours very truly.
DUSA MINES (USA) CORP.
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cc:
David C. Frydetilu"d RonF.Hochstem
Uoren Morton
HaroW R. Roberts
David E.Turi^
Katherine weinel