DRC-2009-006294 - 0901a0688014bd7a

^ILC- .^m-'00io9''H
DENISO
MINES
November 16,2009
Mi Denison Mines (USA) Corp.
1050 17th Street, Suite 950
Denver, CO 80265
USA
Tel: [phone]
Fax:[phone]
www.denlfionmlne5.com
VIA FEDERAL EXPRESS
Mr. Loren Morion
State of Utah Depanment of Enviroimiental Quality
168 North 1950 West
SaU Lake Cily. UT 84114-4850
Dear Mr. Morton;
Re: Transmittal of Hydraulic Testmg Information for Well at MW-24 at the White Mesa Mill
Enclosed is the letter report providing infonnation obtained from Hydraulic Testing at well MW-24 at
the Wliite Mesa Mill.
Yours very truly.
DENISON MINES (USA) CORP.
Steven D. Landau
Manager of Environmental Affairs
H:\718000\hydtst09\mw24\MW24report.doc

November 3, 2009

Mr. David Frydenlund, Esq.
Denison Mines (USA) Corporation
1050 17th Street, Suite 950
Denver, Colorado 80265

Dear Mr. Frydenlund,

This letter discusses hydraulic testing of MW-24 at the White Mesa Uranium Mill site (the
site) during the week of October 19, 2009, which was performed in conjunction with the hydraulic
testing of the recently installed TWN-series wells. The location of MW-24 is shown in Figure 1.

Test Procedures

Hydraulic testing procedures were substantially the same as those used previously at the site,
as reported in Hydro Geo Chem (HGC), 20051. Tests consisted of slug tests using submersible
pressure transducers and data loggers to continuously record water level data before and during each
test. Automatically logged data were obtained at 5-second intervals. Water levels were also measured
by hand before and during each test using an electric water level meter. The hand-collected data
served as an alternate set of data that could be independently evaluated and used to verify the
automatically logged data.

Results

Test data were reduced and analyzed using the Bouwer-Rice and KGS slug test solutions
available in AQTESOLV in substantially the same fashion as reported in HGC, 2005. Table 1
summarizes the results. Details of the analysis including the fits to the measured data are provided in
Appendix A.

1 Hydro Geo Chem, Inc. 2005. Perched Monitoring Well Installation and Testing at the White Mesa Uranium Mill,
April through June 2005.

ATTACHMENTS

TABLES

1 MW-24 Slug Test Results
2 Estimated Perched Zone Pore Velocity

FIGURE

1 Kriged 2nd Quarter, 2009 Water Levels. White Mesa Site

APPENDIX

A Detailed Data Analysis

TABLES
TABLE 1
MW-24 Slug Test Results
Bouwer-Rice Bouwer-Rice
Test Saturated
Thickness
K
(cm/s)
Ss
(1/ft)
K
(cm/s)
K
(cm/s)
Ss
(1/ft)
K
(cm/s)
MW-24 3.4 4.16E-05 5.20E-03 3.15E-05 3.03E-05 0.0152 3.03E-05
Notes:
Bouwer-Rice = Unconfined Bouwer-Rice solution method in Aqtesolv™
cm/s = Centimeters per second
ft = Feet
K = hydraulic conductivity
KGS = Unconfined KGS solution method in Aqtesolv™
Ss= specific storage
Automatically Logged Data Hand Collected Data
KGS KGS
H:\718000\hydtst09\mw24\MW24Tables.xls: Table 1 11/3/2009
TABLE 2
Estimated Perched Zone Pore Velocity at MW-24
Pathline Head Change Hydraulic Gradient Pore Velocity
(cm/s) (ft/yr) (ft) (ft)ft/ft ft/yr
MW-24 3.66E-05 3.74E+01 1635 20 1.22E-02 2.54
Notes:
a Average of KGS and Bouwer-Rice estimates.
Assumes effective porosity of 0.18
cm/s = Centimeters per second
ft/ft = Feet per foot
ft/yr = Feet per year
Well Hydraulic Conductivitya
H:\718000\hydtst09\mw24\MW24Tables.xls: Table 2 11/3/2009

FIGURE
HYDRO
GEO
CHEM, INC.APPROVED DATE REFERENCE FIGURE
3332
3000
SCALE IN FEET
0
5581
5503
5471
5502
5520
5501
5494
5493
5498
5586
5604
5460
5450
5497
5507
5537
5576
5543
5512
5537
5547 5557
5556
5587
5550
5585
5537
5583
5578
5564
5586
5571
5523
5545
5558
5548
55845548
5534
5580
5573
5593
5613
5602
5541
5539
MW-01
MW-02
MW-03
MW-05
MW-11
MW-12
MW-14
MW-15
MW-17
MW-18
MW-19
MW-20
MW-22
MW-23
MW-24
MW-25
MW-27
MW-28
MW-29
MW-30
MW-31

MW-26

MW-32
TW4-19

PIEZ-1
PIEZ-2
PIEZ-3
PIEZ-4
PIEZ-5
5551
5553 5553MW-04
5541
5567
5587
TW4-23
TW4-24
TW4-25
TW4-20
MW-20
PIEZ-1
5460
5593
perched monitoring well showing
elevation in feet amsl
temporary perched monitoring well installed
April, 2005 showing elevation in feet amsl
perched piezometer showing
elevation in feet amsl
5556
MW-31
5547
temporary perched monitoring well
showing elevation in feet amsl
5573
perched monitoring well installed April, 2005
showing elevation in feet amsl
KRIGED 2nd QUARTER, 2009 WATER LEVELS
SHOWING ASSUMED PATHLINE NEAR MW-24
WHITE MESA SITE
H:/718000/
hydtst09/mw24/wl0609p.srf
EXPLANATION
temporary perched monitoring well installed
May, 2007 showing approximate elevation
in feet amsl
5541
NOTES: Locations and elevations for TW4-23, TW4-24, and TW4-25 are approximate
SJS
pathline near MW-24
111/3/09

APPENDIX A

DETAILED DATA ANALYSIS

0.01 0.1 1. 10. 100. 1000.
0.
0.2
0.4
0.6
0.8
1.
Time (min)
Di
s
p
l
a
c
e
m
e
n
t

(
f
t
)
WELL TEST ANALYSIS
Data Set: H:\718000\hydtst09\mw24\mw24.aqt
Date: 11/03/09 Time: 10:39:55
PROJECT INFORMATION
Company: HGC
Client: Denison
Test Well: MW-24
AQUIFER DATA
Saturated Thickness: 3.4 ft
WELL DATA (mw24)
Initial Displacement: 0.5 ft Static Water Column Height: 3.4 ft
Total Well Penetration Depth: 3.4 ft Screen Length: 3.4 ft
Casing Radius: 0.167 ft Well Radius: 0.28 ft
SOLUTION
Aquifer Model: Unconfined Solution Method: KGS Model
Kr = 4.155E-5 cm/sec Ss = 0.005202 ft-1
Kz/Kr = 0.1
0. 40. 80. 120. 160. 200.
0.01
0.1
1.
Time (min)
Di
s
p
l
a
c
e
m
e
n
t

(
f
t
)
WELL TEST ANALYSIS
Data Set: H:\718000\hydtst09\mw24\mw24br.aqt
Date: 11/03/09 Time: 10:40:50
PROJECT INFORMATION
Company: HGC
Client: Denison
Test Well: MW-24
AQUIFER DATA
Saturated Thickness: 3.4 ft Anisotropy Ratio (Kz/Kr): 0.1
WELL DATA (mw24)
Initial Displacement: 0.5 ft Static Water Column Height: 3.4 ft
Total Well Penetration Depth: 3.4 ft Screen Length: 3.4 ft
Casing Radius: 0.167 ft Well Radius: 0.28 ft
SOLUTION
Aquifer Model: Unconfined Solution Method: Bouwer-Rice
K = 3.152E-5 cm/sec y0 = 0.3944 ft
0.1 1. 10. 100. 1000.
0.
0.2
0.4
0.6
0.8
1.
Time (min)
Di
s
p
l
a
c
e
m
e
n
t

(
f
t
)
WELL TEST ANALYSIS
Data Set: H:\718000\hydtst09\mw24\mw24h.aqt
Date: 11/03/09 Time: 10:41:06
PROJECT INFORMATION
Company: HGC
Client: Denison
Test Well: MW-24
AQUIFER DATA
Saturated Thickness: 3.4 ft
WELL DATA (mw24)
Initial Displacement: 0.5 ft Static Water Column Height: 3.4 ft
Total Well Penetration Depth: 3.4 ft Screen Length: 3.4 ft
Casing Radius: 0.167 ft Well Radius: 0.28 ft
SOLUTION
Aquifer Model: Unconfined Solution Method: KGS Model
Kr = 3.031E-5 cm/sec Ss = 0.01523 ft-1
Kz/Kr = 0.1
0. 40. 80. 120. 160. 200.
0.1
1.
Time (min)
Di
s
p
l
a
c
e
m
e
n
t

(
f
t
)
WELL TEST ANALYSIS
Data Set: H:\718000\hydtst09\mw24\mw24hbr.aqt
Date: 11/03/09 Time: 10:41:22
PROJECT INFORMATION
Company: HGC
Client: Denison
Test Well: MW-24
AQUIFER DATA
Saturated Thickness: 3.4 ft Anisotropy Ratio (Kz/Kr): 0.1
WELL DATA (mw24)
Initial Displacement: 0.5 ft Static Water Column Height: 3.4 ft
Total Well Penetration Depth: 3.4 ft Screen Length: 3.4 ft
Casing Radius: 0.167 ft Well Radius: 0.28 ft
SOLUTION
Aquifer Model: Unconfined Solution Method: Bouwer-Rice
K = 3.031E-5 cm/sec y0 = 0.3944 ft