DRC-2010-006304 - 0901a068801e7a30

A
State of Utah
GARY R. HERBERT
Govemor
GREG BELL
Lieulenanl Governor
Department of
Environmental Quality
Amanda Smith
E.xecutive Direcior
DIVISION OF RADIATION CONTROL
Rusty Lundberg
Direclor
DRC-2010-006304
December 9, 2010
Certified Mail
(Retum Receipt Requested)
Mr. Harold R. Roberts
Vice President, US Operations
Denison Mines (USA) Corp (DUSA)
1050 17"^ Street, Suite 950
Denver, CO 80265
Dear Mr. Roberts:
SUBJECT: November 30, 2010 DRC Cell 4B Construction Inspection, Denison Mines (USA)
Corporation (DUSA) White Mesa Mill Facility; November 24, 2010 DRC Letter,
Regarding Cell 4B Construction; Construction Deficiencies Noted from Photographs
On November 30, 2010 Messrs. Ryan Johnson and Phil Goble of the DRC visited the subject construction
site and took numerous photographs of the project. While on the construction site they spoke with Steve
Snyder, Ryan Palmer, and David Turk of DUSA, and Mike Carlson with GeoSyntec Consultants.
The items discussed in the DRC letter of November 24, 2010 are not yet completed. This letter is a
supplement the DRC November 24, 2010 letter.
From the photos taken, it appears adjustments are needed to the slimes drain header, to the sand bags
covering it, and to sand bags covering the slimes drain "herring-bones." A captioned copy of some
example photos taken during this inspection is attached to this letter. These are provided as examples of
locations with the problems at hand, and are not inclusive of all locations with the problems observed.
1. The Slimes Drain Windrow Header.
a. Improper Exterior Geotextile. See Photo No. 1. This photo shows a portion of the slimes
drain header. Cushion or non-woven geotextile is shown as the exterior cover ofthe
slimes drain header. Conversely, woven geotextile is the required exterior fabric for the
slimes drain header, per drawing sheet 6 of 8, Section B-7.
b. Inadequate Lateral Ballast on Slimes Drain Header. See Photo No. 5 in the attached
photos. The side flaps of the geotextile materials are not sand bag ballasted adequately,
because the sand bags are not placed over the entire flap width, as required by drawing
sheet 6 of 8, Section B-7. Note the contrast in the windrow header ballasting with this and
with Photo 1. Photo 1 shows the geotextile laying flat on the upper FML. Please fix these
situations as illustrated in Photo 5, by adjusting sand bag placement and /or adding
additional sand bag ballasting as needed.
195 North 1950 West • Salt Lake City. UT
Mailing Address; P.O. Box 144850 • Salt Uke City. UT 84114-4850
Telephone [phone] • Fax [phone] • T.D.D. [phone]
www.deq.utah.gov
Printed on 100% recycled paper
Mr, Harold R. Roberts
Page 2
2. Slimes Drain Sandbags in Cell 4B.
- a. Using Larger Bags lo Seal-off the Voids Created from the Piggy-bacliing of Smaller Bags.
See Photos 3,4, and 6. Mr. Carlson of GeoSyntec proposed to Mr. Goble of DRC, that the
larger bags could be used to seal off voids, created from use of the piggy-backing method
used during installation of the smaller bags.
This proposal conflicts with the approved plans and specifications and DUSA's letter of
October 8, 2010 regarding the correction of sand bag placement errors, committing that,
"All sandbags will be in full compliance with the thickness and strip composite coverage
requirements outlined in the approved plans and specifications upon completion ofthe
liner installation."
If DUSA wishes to pursue DRC acceptance of this method, DUSA must submit a
demonstration, for approval, that this method would be effective. Mr. Goble discussed this
issue with Mr. Snyder on November 30, 2010.
b. Piggy-backing of Larger Bags. Photo No. 6 shows a longitudinal view of a strip-drain,
which shows piggy-backing of larger bags onto smaller bags clearly. Also see Photo Nos. .
3 and 4. Notwithstanding the issues discussed above, these photos show that many ofthe
larger bags placed are actually being piggy-backed onto the existing smaller piggy-backed
bags, preserving the void pathways to the slimes drains.
In a previous DRC letter, dated November 24, 2010, it was mentioned that each individual line of
strip-drain and sandbag cover will be reviewed, corrected as needed, and separately documented by
GeoSyntec. Further, that an individual record for each strip-drain will be 'made by GeoSyntec in
the as-built report, or as an addendum thereto. This element will be critical to obtain final DRC
approval of the strip-draih/sand bag system.
These deficiencies noted above must be corrected prior to DRC authorization for use of Cell 4B. Please
provide written documentation, with dated photographs, certified by a Utah-licensed Professional
Engineer, that demonstrates completion of the needed corrections to the items describe above. Ifyou have
any questions, please contact me.
Sincerely,
David A. Rupp, P.E.
Geotechnical Services
DR:PG:LBM:dr
Attachment: Photographs
Cc: Mr. Greg Corcoran, GeoSyntec Consultants
F.Cell 4B\Coiistr\DeficienciesFrPhotos 12- 20J0.doc
Photos Taken by DRC Staff at DUSA White Mesa Mill Cell 4B, November 30, 2010 Photos by P. Goble.

Photo 1. View to the NW corner of Cell 4B. This photo shows cushion geotextile on exterior of slimes drain header.
Woven geotextile is the exterior fabric requirement for the slimes drain header,
per drawing sheet 6 of 8; Section B-7. [Photo P1010028].
Photo 2. View to the SE corner of Cell 4B. Note woven geotextile cover over slimes drain header, in contrast to the above photo. [Photo P1010029].

Photo 3. West side of Cell 4B. Some of the larger bags, in this case, have been placed on only one side the
slimes drain. Note: Some bags have been “piggy backed” onto the smaller bags. [Photo P1010041].

Photo 4. West side of Cell 4B. Possible “piggy-backed” larger bags are shown here. Note bags are
Not always on both sides of the slimes drain. This method was proposed in the field for masking voids created by the smaller bags being “piggy-backed” as well. This photo is provided as an example, that this piggy-back type of
placement is quite common in the other photos and observations made on 11-30-2010. [Photo P1010039].

Photo 5. View to the SE corner of Cell 4B. Flaps of the geotextile materials on right side
are not sand bag ballasted adequately, per drawing sheet 6 of 8; Section B-7. Note flaps on right are uplifted. The drawing shows ballast over entire flap width.
Flaps of the geotextile materials on left side also appear to not conform to drawing sheet 6 of 8; Section B-7. Bags also appear to be too sparse to be adequately ballasted. [Photo P1010064].

Photo 6. View looking north. Location: East-Central portion of Cell 4B. Note piggy-backed larger bags. This
type of placement is shown on many other photos taken 11-30-010. [Photo P1010070].

F:\Cell 4B\Constr\11-30-2010\Captioned Photos