DRC-2010-005243 - 0901a068801c6d8b

State of Utah
GARY R. HERBERT
Governor
GREG BELL
Lieutenant Governor
Department of
Environmentai Quality
Amanda Smith
Executive Diiector
DIVISION OF RADIATION CONTROL
Rusty Lundberg
Director DRC-2010-00524 5
September 27, 2010
Certified Mail
(Retum Receipt Requested)
Ms. Jo Ann Tischler
Director, Compliance and Permitting
Denison Mines (USA) Corporation (DUSA)
1050 17* Street, Suite 950
Denver, CO 80265
Dear Ms. Tischler:
SUBJECT: July 15, 2010 DUSA Response Letter; June 3, 2010 DRC Letter on Engineering Inspection
Module 75E Request for Information: Inspection Closeout
We received the subject DUSA letter dated July 15,2010 in response to the DRC Request for Information
Letter dated June 3, 2010. Our findings on this DUSA response follows below, using the same numbering
format as that letter.
1. Ore Storage Pad Buffer Zone. As requested, DUSA supplied a photograph of their recent work
which removed material along the northem border of the ore storage pad area. Ore-like appearing
materials were noted earlier, to be in contact with the fence. The DUSA photograph shows that
this materia] was removed as requested.
2, Per review of the DUSA response to DRC Comment 2, DRC has the following comments and
recommendations:
a. DRC agrees that although the DUSA SWBMPP (June 2008) requires grading and
diversion ditches to deliver all direct precipitation runoff to the tailings management
system (Part 2.0 SCOPE), a spill from pregnant liquor tanks or accumulations from steam
condensate do require additional consideration. Using secondary containment at the site of
such tanks, and inspection of tanks and secondary containment areas is appropriate.
b. Mill Sile Reagent Storage, For your information, in the Statement of Basis for the permit
dated December 1, 2004, pages 26-27, in a section regarding Mill Site Reagent Storage,
DRC documented its negotiations with lUC and an agreement regarding reagent tanks. An
excerpt from that statement is included with this letter. It part it states that,
". . . At new facilities, the performance goal for secondary containment should
include prevention of spills from contacting the ground surface. During
195 Nonh 1950 West • Salt Lake City, UT
Mailing Address: P.O. Box 144850 'Salt Lake City, UT 84114-4850
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Printed on 100% recycled paper
Ms. Jo Ann Tischler
Page 2
discussion with lUC, the company responded that this was impractical in that
the existing reagent storage facilities had been in existence for decades.
Further, lUC contended that: 1) secondary containment had been designed
and constructed at each of the existing reagent storage facilities, albeit it
earthen lined, 2) any soils affected by spills could be easily excavated and
disposed in the tailings cells should a spill occur, 3) after removal ofthe soils
affected by major spills, new construction could be completed to replace and
restore the secondary containment; which at that time could meet the new
performance criteria for prevention of ground contact, and 4) any required
improvements for chemical reagent storage should focus on changes to
operational and/or spill response measures, and not on re-design or reconstruction
of these facilities. Because the lUC facility is a pre-existing
operation under the Ground Water Quality Protection Regulations, DRC staff
agreed . . . However, should any of the existing reagent storage facilities be
re-built, provisions were added to the Permit to require the higher standard at
re-construction, that being secondary containment that would prevent contact
of any spill with the ground surface."
c. An engineering drawing titled VPL Area Containment was provided in the subject DUSA
response. The drawing shows two existing above ground tanks, i.e. a vanadium pregnant
liquor (VPL) tank and an equivalent size cooling water tank, process lines, and a new five-
sided symmetrically designed concrete containment pad with a 6" high curbed perimeter
and two sumps of 25 gallons containment volume each, to contain steam condensate from
each tank. The concrete pad has the following characteristics shown on the drawing:
1) . It has dimensions of 15'-2" on the eastem side and 28' on the westem
side. The concrete pad has a 6" dividing curb, not bisecting the pad, but
beginning at 10'-5" from the far northem side of the pad. The sumps
mentioned above are located on each side ofthe dividing curb.
2) . It does not enclose or surround either the VPL Tank or cooling water tank.
3) . It is enclosed with a perimeter curbing that is 6-inches high above the slab.
The construction of this VPL Area Containment pad could serve to separate condensate
process water from direct precipitation. DRC agrees that discharges of process water via
surface ditches was not the intent of the SWBMPP, thus, the minimization of commingled
water (process and storm water fiows) is considered an improvement.
De-minimus Designation. You have inquired about the need for a permit approval for the
VPL Area Containment Pad. After consideration of its engineering design we have
determined that no Ground Water Discharge Permit is necessary for this project as
"facilities and modifications thereto which the Executive Secretary determines after a
review of the application wil] have a de-minimis actual or potential effect on ground water
quality" (R317-6-6.2.A.25). This decision is based on the fact that the steam condensate to
be contained in the proposed concrete containment sumps in the VPL Area Containment
wiJ] have:
• A low daily accumulated volume,
• Low potential for any condensate to be contaminated, and
• Will be contained in 25 gallon sumps,
• Will be inspected weekly or more often if necessary, and
• Accumulated fluids will be removed to prevent discharge of the sumps, and
Ms. Jo Ann Tischler
Page 3
• Fluids removed from the sumps will be conveyed to the condensate drainage system,
which flows to Cell 1 via piping.
Therefore no further review of the concrete containment area is necessary prior to DUSA
construction of the same, and DUSA is free to proceed at its discretion. DRC will inspect
the constructed containment areas and collection sumps to assure the above criteria are met
during an upcoming annual storm water inspection scheduled for this fall at the mill.
d. During the May, 2010 inspection, DRC was concerned that some of the water in the VPL
containment area was due to storm water run-on from upland areas. Please insure that all
upland drainage of storm water is diverted around the containment and is channeled to the
tailings management system as required by the SWBMPP (Part 2.0). The DRC will
inspect for this diversion at its next storm water inspection.
e. DRC appreciates the additional planned weekly inspection activities for VPL area, which
includes weekly inspections of the VPL area sumps and low laying areas (proposed to be
included on the Ore Storage Sample Plant Inspection Form). However, it would be
preferable to DRC that DUSA document reagent and process tank SWBMPP activities
with the storm water program inspection forms. DRC therefore suggests that these
SWBMPP related observations not be recorded on the DMT forms, but to the storm water
weekly inspection form. DRC also recommends that visual inspections of the VPL tanks
to check for leaks, cracks, corrosion points, paint peeling, bulges, dents, etc. be included
on the weekly storm water checklist. In a telephone conversation with Mr. Rupp of DRC
on September 8, 2010, you stated that DUSA is willing to make these adjustments.
These updates will be reviewed during the upcoming 2010 DRC storm water inspection.
The above items address all the open issues of the subject inspection. Therefore, the 2010 DMT/BAT
Inspection Module 75E is hereby closed-out. Please contact Mr. Tom Rushing of DRC, if you have any
questions on the above.
UTAH WATER QUALITY BOARD
Rusty Lundberg, Co-Executive Secretary
DAR:TR:dr
Cc: Thomas Rushing, DRC
Dean Henderson, DRC
Harold Roberts, DUSA
Enclosure
F:\DUSA\ lnspections\DMT&BATi2010 inspection Closeout Ltr 9-27-lO.doc
File: Documentum
Statement of Basis DRAFT December 1, 2004
this requirement. Also, lUC will be required to install three (3) additional
monitoring wells between Cell 2 and 3 to allow discrete monitoring of
Cell 2 (MW-29, MW-30, and MW-3]).
E. Operational Changes and Improved Operations Monitoring - changes to disposal
cell operation that can increase efforts to minimize potential seepage losses, and
thereby improve protection of local groundwater quality are also important.
Related requirements for monitoring are also added to confirm that these changes
are in place and are actively being used by lUC. Examples of some of these
changes include:
1) Maximum Waste and Wastewater Pool Elevations - imposed in Part I.D.3 for
all the tailings cells and Roberts Pond to require that lUC continue to ensure
that impounded wastes and wastewaters are held and maintained over a
flexible membrane liner (FML).
2) Slimes Drain Maximum Allowable Head - required for Tailings Cells 2 and 3
in Part I.D.3(b) to ensure that lUC provides constant pumping efforts to
minimize the accumulation of leachates over the FML, and thereby minimize
potential FML leakage to the foundation and groundwater. This requirernent
was immediately imposed in the Permit for Cell 2, because lUC is already
actively dewatering that cell. Imposition at Cell 3 was delayed by the
Executive Secretary in response to lUC arguments that premature slimes drain
pumping poses a risk that the layer will plug with sulfate salts during tailings
cell operation, and not be available for slimes de-watering when lUC is ready ^
to advance a cover over the tailings cell. Such untimely loss of the slimes ;j
drain layer would greatly complicate and delay cover construction, and in tum \^
increase the overall potential for leachates to be released from the fmal waste ^
embankment. Details as to an appropriate average wastewater head in the \^
slimes drain layer at both Cells 2 and 3 are to be proposed by lUC and
approved by the Executive Secretary in development of a DMT Monitoring
Plan required by Part I.H. 13 of the Permit.
3) Feedstock Storage - in order to constrain and minimize potential generation of
contaminated stormwater or leachates the Permit requires lUC to continue it
existing practice of [see Part I.D.3(d)]: 1) limiting open air storage of
feedstock materials to the historical storage area found along the eastem
margin of the mill site (as defined by the survey coordinates found in Permit
Table 5), and 2) maintaining water-tight containerized storage of feedstock
material found anywhere else at the JUC facility.
4) Mill Site Reagent Storage - is of potential concem for groimdwater quality in
the event that reagent storage tank leaks or spills could release contaminants
to site soils or groundwater. In an effort to prevent this possible problem, and
provide proper spill prevention and control, Part I.D.3(e) requires lUC to
demonstrate that it has adequate provisions for spill response, cleanup, and
reporting for reagent storage facilities, and to include these in the Stormwater
Best Management Practices Plan. Content of this plan is stipulated in Part
I.D.8, and submittal arid approval of the plan required under Part I.H. 17.
•s At new facilities^ the performance goal for secondary contai^^ ^
include prevention of spills fi'om contacting the ground surface. During
26 ' ' ' " •' ;
Statement of Basis DRAFT December 1,2004
discussion with lUC, the company responded that this was impractical in that
the existing reagent storage facilities had been in existence for decades.
Further, lUC contended that: I) secondary containment had been designed
and constructed at each of the existing reagent storage facilities, albeit it
earthen lined, 2) any soils affected by spills could be easily excavated and
disposed in the tailings cells should a spill occur, 3) after removal ofthe soils
affected by major spills, new construction could be completed to replace and
restore the secondary containment; which at that time could meet the new
performance criteria for prevention of ground contact, and 4) any required
improvements for chemical reagent storage should focus on changes to
operational and/or spill response measures, and not on re-design or re-
constmction of these facilities. Because the lUC facility is a pre-existing
operation under the Ground Water Quality Protection Regulations, DRC staff
agreed with these arguments, and wrote the requirements of Part I.D.3(e)
accordingly. However, should any of the existing reagent storage facilities be
re-built, provisions were added to the Permit to require the higher standard at
re-constmction, that being secondary containment that would prevent contact
of any spill with the ground surface.
F. Evaluafion of Tailings Cell Cover Svstem Design -cover system design and
constraction needs to be evaluated in order to ensure that infiltration into the
tailings waste is minimized and groundwater quality protected during the post-
closure period. To this end. Part I.H.I 1 of the Permit requires lUC to submit an
Infiltrafion and Contaminant Transport Modeling report for Executive Secretary
review and approval. After review of this report, the Executive Secretary will
determine if any changes are need in the proposed cover system. Minimum cover
system performance criteria are stipulated in Part I.D.6 of the Permit.
10. Exisfing Tailings Cell Design / Constmcfion Findings -during review of the existing
• tailings cell design and constraction the Executive Secretary found that constraction
documentation for Tailings Cell 1 is limited to one (1) as-built report dated Febmary,
• 1982 by D'Appolonia Consulting Engineers (p. 3-1). In this report the as-built
information is limited to only a topographic map of the Cell 1 floor prior to FML
installafion (ibid., Fig. 12). Authors of the report state that they were involved in
constmction of Cell 2, and that Tailings Cell 1 constraction was done by the previous
White Mesa owner. Energy Fuels Nuclear (EFN). No other Cell 1 as-built informafion is
available, nor is there any documentafion of any Cell 1 constraction quality assurance /
quality control. DRC field inspecfions have confirmed the existence of an earthen dike at
the south margin of Cell 1 and a FML liner inside this cell. Without any other
information, the Executive Secretary has assumed that the Cell 1 constraction largely
followed the cell's original design found in a June, 1979 D'Appolonia Engineers Report.
From lUC plan maps the Executive Secretary estimated the Cell 1 footprint area to be
about 57 acres.
As for Tailings Cells 2 and 3, as-built reports were found and reviewed by DRC staff;
fmdings from which are found in a June 27, 2000 DRC Memorandum. These reviews
resulted in a summary descripfion of the liner technology for these two (2) disposal cells,
as outlined in Part I.D. 1(b) and (c) of the Permit. From lUC plan maps the Executive
Secretary esfimated the footprint area to be about 68 and 55 acres for Cells 2 and 3,
respegtively.
• 27 . •