DRC-2011-007451_13 - 0901a0688027e870

Reclamation Plan

White Mesa Mill

Blanding, Utah

Radioactive Materials License No. UT1900479

Revision 5.0

September 2011

Prepared by:
Denison Mines (USA) Corp.
1050 17th Street, Suite 950
Denver, CO 80265
[phone]
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TABLE OF CONTENTS
Page
INTRODUCTION...................................................................................................................... I-1 
Summary of Plan ...................................................................................................................... I-1 
Plan Organization ..................................................................................................................... I-2 
1 SITE CHARACTERISTICS............................................................................................. 1-1 
1.1 Climate and Meteorology .............................................................................................. 1-5 
1.1.1 Regional ................................................................................................................. 1-5 
1.1.2 Storms (FES Section 2.1.4, updated) ..................................................................... 1-9 
1.1.3 On Site ................................................................................................................... 1-9 
1.2 Topography ................................................................................................................. 1-12 
1.3 Archeological Resources ............................................................................................. 1-12 
1.3.1 Archeological Sites .............................................................................................. 1-12 
1.3.2 Current Status of Excavation ............................................................................... 1-15 
1.4 Surface Water .............................................................................................................. 1-17 
1.4.1 Surface Water Description (FES Section 2.6.1.1) ............................................... 1-17 
1.4.2 Surface Water Quality as of the Date of the FES (FES Section 2.6.1.2) ............. 1-21 
1.4.3 Surface Water Background Quality ..................................................................... 1-25 
1.5 Groundwater ................................................................................................................ 1-30 
1.5.1 Groundwater Characteristics ................................................................................ 1-30 
1.5.2 Seep and Spring Occurrence and Hydrogeology ................................................. 1-41 
1.5.3 Groundwater Quality ........................................................................................... 1-46 
1.5.4 Background Groundwater Quality in the Perched Aquifer .................................. 1-51 
1.5.5 Quality of Ground Water at the Compliance Monitoring Point .......................... 1-57 
1.5.6 Springs and Seeps ................................................................................................ 1-57 
1.5.7 Groundwater Appropriations Within a Five Mile Radius.................................... 1-61 
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1.6 Geology ....................................................................................................................... 1-90 
1.6.1 Regional Geology ................................................................................................ 1-91 
1.6.2 Blanding Site Geology ....................................................................................... 1-104 
1.6.3 Seismic Risk Assessment ................................................................................... 1-122 
1.7 Biota (1978 ER Section 2.9) ..................................................................................... 1-123 
1.7.1 Terrestrial (1978 ER Section 2.9.1) ................................................................... 1-123 
1.7.2 Aquatic Biota (1978 ER Section 2.9.2) ............................................................. 1-132 
1.7.3 Background Radiation (2007 ER, Section 3.13.1) ............................................. 1-133 
1.7.4 Mill Site Background (1978 ER Section 2.10) .................................................. 1-136 
1.7.5 Current Monitoring Data.................................................................................... 1-137 
2 EXISTING FACILITY ..................................................................................................... 2-1 
2.1 Facility Construction History ........................................................................................ 2-1 
2.1.1 Mill and Tailings Management Facility ................................................................. 2-1 
2.2 Facility Operations ........................................................................................................ 2-2 
2.2.1 Operating Periods................................................................................................... 2-2 
2.2.2 Mill Circuit............................................................................................................. 2-3 
2.2.3 Tailings Management Facilities ............................................................................. 2-5 
2.3 Monitoring Programs .................................................................................................... 2-8 
2.3.1 Monitoring and Reporting Under the Mill’s GWDP ............................................. 2-8 
2.3.2 Monitoring and Inspections Required Under the License ................................... 2-12 
3 TAILINGS RECLAMATION PLAN .............................................................................. 3-1 
3.1 Location and Property Description ............................................................................... 3-1 
3.2 Facilities to be Reclaimed ............................................................................................. 3-3 
3.2.1 Summary of Facilities to be Reclaimed ................................................................. 3-3 
3.2.2 Tailings and Evaporative Cells .............................................................................. 3-4 
3.3 Design Criteria .............................................................................................................. 3-9 
3.3.1 Regulatory Criteria................................................................................................. 3-9 
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3.3.2 Radon Flux Attenuation ....................................................................................... 3-11 
3.3.3 Infiltration Analysis ............................................................................................. 3-12 
3.3.4 Freeze/Thaw Evaluation ...................................................................................... 3-13 
3.3.5 Soil Cover Erosion Protection ............................................................................. 3-14 
3.3.6 Slope Stability Analysis ....................................................................................... 3-15 
3.3.7 Tailings Dewatering ............................................................................................. 3-15 
3.3.8 Liquefaction ......................................................................................................... 3-17 
3.3.9 Settlement ............................................................................................................ 3-18 
3.3.10 Soil Cover-Animal Intrusion................................................................................ 3-19 
3.3.11 Soil Cover Vegetation .......................................................................................... 3-20 
3.3.12 Cover Material/Cover Material Volumes ............................................................ 3-20 
4 MILL DECOMMISSIONING PLAN .............................................................................. 4-1 
REFERENCES .......................................................................................................................... R-1 

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LIST OF TABLES
Table Description Page
Table I-1 Revisions to Attachments and Appendices in Reclamation Plan ......................... I-1 
Table 1.1-1 Period of Record General Climate Summary – Precipitation .............................. 1-7 
Table 1.1-2 Period of Record General Climate Summary - Temperature ............................... 1-8 
Table 1.3-1 Distribution of Recorded Sites According to Temporal Position ...................... 1-14 
Table 1.4-1 Drainage Areas of Project Vicinity and Region ................................................ 1-20 
Table 1.4-2 Summary of FES and Subsequent Sampling Results For Cottonwood
Wash and Westwater Creek ............................................................................... 1-26 
Table 1.5-1 Surveyed Locations and Elevations of Seeps and Springs and the Frog
Pond (December, 2009) ..................................................................................... 1-41 
Table 1.5-2 Water Quality of the Navajo Sandstone Aquifer in the Mill Vicinity ............... 1-48 
Table 1.5-3 Results of Quarterly Sampling Ruin Spring (2003-2004) ................................. 1-58 
Table 1.5-4 Seeps and Springs Sampling .............................................................................. 1-60 
Table 1.5-5 Wells Located Within a 5-Mile Radius of the White Mesa Uranium Mill
(Denison, 2009a) ................................................................................................ 1-62 
Table 1.6-1 Generalized Stratigraphic Section of Subsurface Rocks Based on Oil-Well
Logs (Table 2.6-1 UMETCO)............................................................................ 1-94 
Table 1.6-2 Generalized Stratigraphic Section of Exposed Rocks in the Project
Vicinity (Table 2.6-2 UMETCO) ...................................................................... 1-95 
Table 1.6-3 Modified Mercalli Scale .................................................................................. 1-113 
Table 1.7-1 Community Types and Expanse Within the Project site Boundary ................. 1-125 
Table 1.7-2 Ground Cover For Each Community Within the Project Site Boundary ......... 1-125 
Table 1.7-3 Birds Observed in the Vicinity of the White Mesa Project ............................. 1-128 
Table 1.7-4 Endangered, Threatened and Candidate Species in the Mill Area ................... 1-131 
Table 1.7-5 Species Managed Under Conservation Agreements/Strategies at the Mill
Area .................................................................................................................. 1-132 
Table 2.3-1 Groundwater Monitoring Constituents Listed in Table 2 of the GWDP ........... 2-11 
Table 2.3-2 Operational Phase Surface Water Monitoring Program .................................... 2-20 
Table 3.3-1 Average Radon Flux From Tailings Cells 2004-2010 ....................................... 3-12 
Table 3.3-2 Results of Slope Stability Analyses ................................................................... 3-15 
Table 3.3-3 Estimate of Future Settlement in Tailings Cells ................................................ 3-19 
Table 3.3-4 Reclamation Cover Material Quantity Summary .............................................. 3-21 

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LIST OF FIGURES
Figure Description Page
Figure 1-1 White Mesa Mill Regional Location Map .......................................................... 1-2 
Figure 1-2 White Mesa Mill Location Map ......................................................................... 1-3 
Figure 1.1-1 Wind Rose - 2010 ............................................................................................. 1-11 
Figure 1.4-1 Drainage Map of the Vicinity of the White Mesa Mill. Adapted from:
Dames & Moore (1978b), Plate 2.6-5 .............................................................. 1-18 
Figure 1.4-2 Streamflow Summary in the Blanding, Utah Vicinity (Adapted from
Dames & Moore (1978b), Plate 2.6-6, updated) .............................................. 1-22 
Figure 1.4-3 Surface Water Quality Sampling Stations in the White Mesa Mill
Vicinity Prior to Mill Operations (Adapted from Dames & Moore
(1978b), Plate 2.6-10) ....................................................................................... 1-23 
Figure 1.5-1 Generalized Stratigraphy of White Mesa Mill (Adapted from the 2007
ER, Figure 3.7-1) .............................................................................................. 1-32 
Figure 1.5-2 Approximate Elevation of Top of Brushy Basin (Adapted from HGC,
2010, Figure 3) ................................................................................................. 1-34 
Figure 1.5-3 2nd Kriged Perched Water Levels 2nd Quarter, 2010 (Adapted from
HGC, 2010, Figure 4) ....................................................................................... 1-37 
Figure 1.5-4 Depth to Perched Water 2nd Quarter, 2010 (Adapted from HGC, 2010,
Figure 6) ........................................................................................................... 1-39 
Figure 1.5-5 Perched Zone Saturated Thickness 2nd Quarter, 2010 (Adapted from
HGC, 2010, Figure 5) ....................................................................................... 1-40 
Figure 1.5-6 Seeps and Springs on USGS Topographic Base, White Mesa (Adapted
from HGC, 2010, Figure 7) .............................................................................. 1-42 
Figure 1.5-7 Geologic Map on USGS Topographic Base (HGC, 2010 Figure 8) ............... 1-44 
Figure 1.5-8 Groundwater (Well or Spring) Sampling Stations in the White Mesa
Vicinity (Adapted from the 2007 ER, Figure 3.7-8) ........................................ 1-50 
Figure 1.5-9 Ground Water Appropriation Applications Within a 5-Mile Radius ............... 1-89 
Figure 1.6-1 Colorado Plateau Geology Map (Adapted from the 2007 ER, Figure 3.4-
1) ....................................................................................................................... 1-92 
Figure 1.6-2 White Mesa Millsite Geology of Surrounding Area ...................................... 1-105 
Figure 1.6-3 Seismicity Within 320km of the White Mesa Mill ........................................ 1-112 
Figure 1.6-4 Seismicity Within 200km of the White Mesa Mill ........................................ 1-115 
Figure 1.6-5 Seismicity of the Western United States 1950 to 1976 .................................. 1-117 
Figure 1.6-6 Colorado Lineament ....................................................................................... 1-120 
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Figure1.7-1 Vegetation Community Types on the White Mesa Mill Site ......................... 1-126 
Figure 2.3-1 Site Plan and Perched Well Locations White Mesa Site (Adapted from
HydroGeochem, Figure A-1) ........................................................................... 2-10 
Figure 2.3-2 High Volume Air Monitoring Stations (Adapted from the 2007 ER,
Figure 3.3-2) ..................................................................................................... 2-14 
Figure 3.1-1 White Mesa Mill Regional Map Showing Land Position .................................. 3-2 

LIST OF DRAWINGS
REC-0 Title Sheet and Project Location Map
REC-1 Plan View of Reclamation Features
REC-2 Mill Site and Ore Pad Final Grading Plan
REC-3 Sedimentation Basin Detail
TRC-1 Interim Fill Grading Plan
TRC-2 Compacted Cover Grading Plan
TRC-3 Final Cover Surface Layout
TRC-4 Reclamation Cover Erosion Protection
TRC-5 Cover Over Cell 4A & 4B Cross Sections
TRC-6 Cover Over Cell 3 Cross Sections
TRC-7 Cover Over Cell 2 Cross Sections
TRC-8 Reclamation Cover Details

LIST OF ATTACHMENTS
Attachment Description
A Plans and Technical Specifications for Reclamation of White Mesa Mill Facility,
Blanding, Utah.
B Construction Quality Assurance/Quality Control Plan for Reclamation of White
Mesa Mill Facility, Blanding, Utah.
C Cost Estimates for Reclamation of White Mesa Facility in Blanding, Utah.
D Radiation Protection Manual for Reclamation
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LIST OF APPENDICES
Appendix Description
A Semi-Annual Effluent Report (January through June, 2011) for the Mill
B Hydrogeology of the Perched Groundwater Zone and Associated Seeps and
Springs Near the White Mesa Uranium Mill Site, Blanding, Utah, November 12,
2010, prepared by Hydro Geo Chem, Inc. (the “2010 HGC Report”)
C The Mill’s Stormwater Best Management Practices Plan, Revision 1.3, June 12,
2008, Emergency Response Plan, Revision 2.1, August 18, 2009, and Spill
Prevention, Control, and Countermeasures Plan, 2011.
D Updated Tailings Cover Design Report, White Mesa Mill, September 2011.
MWH Americas, Inc.
E National Emission Standards for Hazardous Air Pollutants Radon Flux
Measurement Program, White Mesa Mill Site, 2010, Tellco Environmental
F Semi-Annual Monitoring Report January 1 – June 30, 2011, White Mesa Mill
Meteorological Station, August 19, 2011, McVehil-Monnett Associates, Inc.
G Preliminary Mill Decommissioning Plan, White Mesa Mill, September 2011,
MWH Americas, Inc.

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INTRODUCTION

This Reclamation Plan (the “Plan”) has been prepared by Denison Mines (USA) Corp.
(“Denison”)1 for Denison’s White Mesa Uranium Mill (the “Mill”), located approximately six
miles south of Blanding, Utah. This Plan presents Denison’s plans and estimated costs for the
reclamation of tailings Cells 1, 2, 3, 4A, and 4B at the Mill site, and for decommissioning of the
Mill and Mill site.2

Summary of Plan
The uranium and vanadium processing areas of the Mill, including all equipment, structures and
support facilities will be decommissioned and disposed of in tailings or buried at the Mill site as
appropriate. All equipment (including tankage and piping, agitation, process control
instrumentation and switchgears, and contaminated structures) will be cut up, removed, and
buried in tailings prior to final cover placement. Concrete structures and foundations will be
demolished and removed for disposal in tailings or covered in place with soil as appropriate.

The sequence of demolition will proceed so as to allow the maximum use of support areas of the
facility, such as the office and shop areas. Any uncontaminated or decontaminated equipment to
be considered for salvage will be released in accordance with United States Nuclear Regulatory
Commission (“NRC”) guidance and in compliance with the conditions of the Denison’s State of
Utah Radioactive Materials License No. UT1900479 (the “License”). As with the equipment for
disposal, any contaminated soils from the Mill and surrounding areas and any ore or feed
materials on the Mill site will be disposed of in the tailings cells in accordance with Attachment
A, Plans and Technical Specifications.

1 Prior to December 16, 2006, Denison was named “International Uranium (USA) Corporation.” 2 Cell 1 was previously referred to as Cell 1-I. It is now referred to as Cell 1.
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The estimated reclamation costs for surety are set out in Attachment C. Attachment C will be
reviewed and updated on a yearly basis.

Plan Organization
General site characteristics pertinent to this Plan are contained in Section 1.0. Descriptions of
the facility construction, operations and monitoring are given in Section 2.0. The current
environmental monitoring program is described in Section 2.3. Seismic risk is assessed in
Section 1.6.3.

The reclamation plan itself, including descriptions of facilities to be reclaimed and design
criteria, is presented in Section 3.0. Attachments A through D comprise the Plans and Technical
Specifications, Construction Quality Assurance/Quality Control (QA/QC) Plan, Cost Estimates,
and Radiation Protection Manual for Reclamation.

Supporting documents, which have been reproduced as appendices for ease of review, include:

 Semi-Annual Effluent Report (January through June, 2011), for the Mill (Appendix A);
 Hydrogeology of the Perched Groundwater Zone and Associated Seeps and Springs Near
the White Mesa Uranium Mill Site, Blanding, Utah, November 12, 2010, prepared by
Hydro Geo Chem, Inc. (the “2010 HGC Report”) (Appendix B);
 The Mill’s Stormwater Best Management Practices Plan, Revision 1.3, June 12, 2008,
Emergency Response Plan, Revision 2.1, August 18, 2009, and Spill Prevention, Control,
and Countermeasures Plan, 2011. (Appendix C);
 Updated Tailings Cover Design Report, September 2011. MWH Americas, Inc.
(Appendix D);
 National Emission Standards for Hazardous Air Pollutants Radon Flux Measurement
Program, White Mesa Mill Site, 2010, Tellco Environmental (Appendix E); and
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 Semi-Annual Monitoring Report January 1 – June 30, 2010, White Mesa Mill
Meteorological Station, August 19, 2011, McVehil-Monnett Associates, Inc. (Appendix
F).
 Mill Decommissioning Plan, September, 2011. MWH Americas, Inc. (Appendix G)

As required by Part I.H.11 of the Mill’s State of Utah Ground Water Discharge Permit No.
UGW370004 (the “GWDP”), Denison has completed an infiltration and contaminant transport
model of the final tailings cover system to demonstrate the long-term ability of the cover to
protect nearby groundwater quality (MWH, 2010). The updated cover design is included in the
Updated Tailings Cover Design Report (MWH, 2011b) included as Appendix D to this
Reclamation Plan, and includes a monolithic evapotranspiration (ET) cover for the tailings cells.
The revised cover design and basis will be used for this version of the Plan.

Revisions to this Reclamation Plan include information related to the updated tailings cover
design and the construction of tailings Cell 4B, as well as results of data collection and
monitoring since Version 4.0 of this Plan (Denison, 2009). Revisions to the attachments and
appendices of the Reclamation Plan are listed in a tabular format in Table I-1.

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Table I-1
Revisions to Attachments and Appendices in Reclamation Plan
Attachments/
Appendices Reclamation Plan v. 4.0 (2009) Reclamation Plan v. 5.0 (2011)
Attachment A Plans and Specifications for Reclamation of White
Mesa Mill Facility, Blanding, Utah
Updated - Plans and Technical Specifications for
Reclamation of White Mesa Mill Facility, Blanding,
Utah
Attachment B Quality Plan for Construction Activities, White Mesa
Project, Blanding, Utah
Updated - Construction Quality Assurance/Quality
Control Plan for Reclamation of White Mesa Mill
Facility, Blanding, Utah
Attachment C Cost Estimates for Reclamation of White Mesa
Facility in Blanding, Utah
Updated - Cost Estimates for Reclamation of White
Mesa Facility in Blanding, Utah
Attachment D Reclamation Material Characteristics Deleted – pertinent information now included in
Updated Tailings Cover Design Report (Appendix D);
New Attachment D - Radiation Protection Manual for
Reclamation
Attachment E Evaluation of Potential Settlement Due to Earthquake-
Induced Liquefaction and Probabilistic Seismic Risk
Assessment
Deleted – updated analyses and latest seismic hazard
analysis included in Updated Tailings Cover Design
Report (Appendix D)
Attachment F Radon Emanation Calculations (Revised) Deleted – updated analyses included in Updated
Tailings Cover Design Report (Appendix D)
Attachment G Channel and Toe Apron Design Calculations of White
Mesa Facilities in Blanding, Utah.
Deleted – updated analyses included in Updated
Tailings Cover Design Report (Appendix D)
Attachment H Rock Test Results - Blanding Area Gravel Pits Deleted – test results included in Updated Tailings
Cover Design Report (Appendix D)
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Table I-1
Revisions to Attachments and Appendices in Reclamation Plan (continued)
Attachments/
Appendices Reclamation Plan v. 4.0 (2009) Reclamation Plan v. 5.0 (2011)
Appendix A Semi-Annual Effluent Reports (January through
June, 2008), (June through December, 2008) and
(January through June, 2009), for the Mill
Updated - Semi-Annual Effluent Report (January through
June, 2011), for the Mill
Appendix B Site Hydrogeology and Estimation of Groundwater
Travel Times In The Perched Zone White Mesa
Uranium Mill Site Near Blanding, Utah, August 27,
2009, prepared by Hydro Geo Chem, Inc. (the “2009
HGC Report”)
Updated - Hydrogeology of the Perched Groundwater
Zone and Associated Seeps and Springs Near the White
Mesa Uranium Mill Site, Blanding, Utah, November 12,
2010, prepared by Hydro Geo Chem, Inc. (the “2010 HGC
Report”)
Appendix C The Mill’s Stormwater Best Management Practices
Plan, Revision 1.3: June 12, 2008
Updated - The Mill’s Stormwater Best Management
Practices Plan, Revision 1.3, June 12, 2008, Emergency
Response Plan, Revision 2.1, August 18, 2009, and Spill
Prevention, Control, and Countermeasures Plan, 2011.
Appendix D Tailings Cover Design, White Mesa Mill, October
1996. Titan Environmental Corporation
Updated - Updated Tailings Cover Design Report, White
Mesa Mill, September 2011. MWH Americas, Inc.
Appendix E National Emission Standards for Hazardous Air
Pollutants Radon Flux Measurement Program,
White Mesa Mill Site, 2008, Tellco Environmental
Updated - National Emission Standards for Hazardous
Air Pollutants Radon Flux Measurement Program, White
Mesa Mill Site, 2010, Tellco Environmental
Appendix F Semi-Annual Monitoring Report July 1 -- December
31, 2008 and Annual Monitoring Summary for 2008,
White Mesa Mill Meteorological Station, January 20,
2009, McVehil-Monnett Associates, Inc.
Updated - Semi-Annual Monitoring Report January 1 -
June 30, 2010, White Mesa Mill Meteorological Station,
August 19, 2011, McVehil-Monnett Associates, Inc.
Appendix G N/A New appendix - Preliminary Mill Decommissioning Plan,
White Mesa Mill, September 2011, MWH Americas, Inc.

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1 SITE CHARACTERISTICS

Denison operates the Mill, which is located approximately six miles south of Blanding, Utah (see
Figures 1-1 and 1-2). The Mill was initially licensed by the NRC in May 1980 under NRC
Source Material License No. SUA-1358. Upon the State of Utah becoming an Agreement State
for uranium mills in August 2004, the Mill’s NRC license was replaced with the Mill’s current
State of Utah License and the Mill’s GWDP.

The License was up for timely renewal on March 31, 2007 in accordance with Utah
Administrative Code (“UAC”) R313-22-36.3 In accordance with R313-22-36, Denison
submitted an application to the Executive Secretary on February 27, 2007 for renewal of the
License under R313-22-37 (the “2007 License Renewal Application”). Similarly, the GWDP is
up for timely renewal on March 8, 2010, in accordance with UAC”) R317-6-6.7. On September
2, 2009, Denison filed an application (the “2009 GWDP Renewal Application”) to the Executive
Secretary for renewal of the GWDP for another 5 years under R313-6-6.7.

The Mill is also subject to State of Utah Air Quality Approval Order DAQE-AN1205005-06 (the
“Air Approval Order”) which was re-issued on July 20, 2006 and is not up for renewal at this
time.

3 The License was originally issued by the NRC as a source material license under 10 CFR Part 40 on March 31, 1980. It was
renewed by NRC in 1987 and again in 1997. After the State of Utah became an Agreement State for uranium mills in August
2004, the License was re-issued by the Executive Secretary as a State of Utah Radioactive Materials License on February 16,
2005, but the remaining term of the License did not change.
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Revision 3.0 of this Plan was submitted to and approved by NRC in 2000. A copy of Revision
3.0 of this Plan was also submitted to the Executive Secretary as part of the 2007 License
Renewal Application. Revision 4.0 of this Plan was submitted to the Executive Secretary in
November 2009. Denison has prepared this Revision 5.0 of the Plan, which updates the Plan to
incorporate changes since 2009 and to address interrogatories from the Executive Secretary
(DRC, 2010 and 2011).

This Section 1.0 of the Plan incorporates by reference, updates or supplements, information
previously submitted in previous environmental analyses performed at the Mill, as described
below.

A Final Environmental Statement Related to Operation of White Mesa Uranium Project, Energy
Fuels Nuclear, Inc., May, 1979, Docket No. 40-8681 (the “FES”) was prepared by NRC for the
original License application in May 1979, which is incorporated by reference into, updated or
supplemented by this Section 1.0. The basis for the FES was the Environmental Report, White
Mesa Uranium Project San Juan County, Utah, dated January 1978, prepared by Dames &
Moore (the “1978 ER”). In addition, the following environmental evaluations and other reports
have also been performed for the Mill and are incorporated by reference into, updated or
supplemented by this Section 1.0:

 the Environmental Assessment (“EA”) that was prepared for this Plan in February 2000
by NRC (the “2000 EA”);
 the EA that was prepared in August, 2002 by NRC (the “2002 EA”) in connection with a
License amendment issued by NRC authorizing receipt and processing at the Mill of
certain alternate feed materials from the Maywood Formerly Utilized Sites Remedial
Action Program site in Maywood, New Jersey;
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 the Statement of Basis that was prepared in December 2004 by the State of Utah
Department of Environmental Quality (“UDEQ”) Division of Radiation Control (“DRC”)
in connection with the issuance of the GWDP (the “GWDP Statement of Basis”);
 the Environmental Report in Support of the License Renewal Application, State of Utah
Radioactive Materials License No. UT1900479, February 28, 2007 (the “2007 ER”);
 the Revised Background Groundwater Quality Report: Existing Wells For Denison
Mines (USA) Corp.’s White Mesa Mill Site, San Juan County, Utah, October 2007,
prepared by INTERA, Inc. (the “Existing Well Background Report”);
 the Revised Addendum: -- Evaluation of Available Pre-Operational and Regional
Background Data, Background Groundwater Quality Report: Existing Wells For
Denison Mines (USA) Corp.’s White Mesa Mill Site, San Juan County, Utah, November
16, 2007, prepared by INTERA, Inc. (the “Regional Background Report”); and
 the Revised Addendum: -- Background Groundwater Quality Report: New Wells For
Denison Mines (USA) Corp.’s White Mesa Mill Site, San Juan County, Utah, April 30,
2008, prepared by INTERA, Inc. (the “New Well Background Report”, and together with
the Existing Well Background Report and the Regional Background Report, the
“Background Reports”).

1.1 Climate and Meteorology

1.1.1 Regional

The climate of southeastern Utah is classified as dry to arid continental. Although varying
somewhat with elevation and terrain, the climate in the vicinity of the Mill can be considered as
semi-arid with normal annual precipitation of about 13.32 inches. See Table 1.1-1. Most
precipitation is in the form of rain with snowfall accounting for about 29 percent of the annual
total precipitation. There are two separate rainfall seasons in the region, the first in late summer
and early autumn (August to October) and the second during the winter months (December to
Page 1-6
Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

March). The mean annual relative humidity is about 44 percent and is normally highest in
January and lowest in July. The average annual Class A pan evaporation rate is 68 inches
(National Oceanic and Atmospheric Administration and U.S. Department of Commerce, 1977),
with the largest evaporation rate typically occurring in July. This evaporation rate is not
appropriate for determining water balance requirements for the tailings management system and
must be reduced by the Class A pan coefficient to determine the latter evaporation rate. Values
of pan coefficients range from 60 to 81 percent. Denison assumes for water balance calculations
an average value of 70 percent to obtain an annual lake evaporation rate for the Mill area of 47.6
inches. Given the annual average precipitation rate of 13.32 inches, the net evaporation rate is
34.28 inches per year.

The weather in the Blanding area is typified by warm summers and cold winters. The National
Weather Service Station in Blanding, Utah is located about 6.25 miles north of the Mill. Data
from the station is considered representative of the local weather conditions (1978 ER, Section
2.7.2). The mean annual temperature in Blanding was 50.3°F, based on the current Period of
Record Summary (1904 - 2006). January is usually the coldest month and July is usually the
warmest month. See Table 1.1-2.
Page 1-7
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Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

Table 1.1-1
Period of Record General Climate Summary – Precipitation
Station:(420738) BLANDING
From Year=1904 To Year=2006
Precipitation Total Snowfall
Mean High Year Low Year 1 Day Max.
>=
0.01 in.
>=
0.10 in.
>=
0.50 in.
>=
1.00 in. Mean High Year
in. in. - in. - in.
dd/yyyy
or
yyyymmdd
# Days # Days # Days # Days in. in. -
January 1.39 5.31 1993 0.00 1972 1.49 15/1978 6 4 1 0 10.8 46.9 1979
February 1.21 3.87 1913 0.00 1906 1.50 03/1908 6 3 1 0 7.3 39.7 1913
March 1.05 3.72 1906 0.00 1932 1.13 01/1970 6 3 1 0 4.4 17.9 1970
April 0.87 4.35 1926 0.00 1908 1.33 04/1987 5 2 0 0 1.9 15.2 1957
May 0.71 2.62 1926 0.00 1910 1.26 25/1994 4 2 0 0 0.2 4.0 1978
June 0.45 2.84 1948 0.00 1906 1.40 28/1938 3 1 0 0 0.0 0.0 1905
July 1.15 3.55 1914 0.00 1920 1.74 21/1985 6 3 1 0 0.0 2.5 1906
August 1.38 4.95 1968 0.03 1985 4.48 01/1968 7 4 1 0 0.0 0.0 1905
September 1.28 4.80 1927 0.00 1912 1.85 29/1905 5 3 1 0 0.0 3.5 1905
October 1.45 7.01 1916 0.00 1915 2.00 19/1908 5 3 1 0 0.3 6.0 1984
November 1.05 4.17 1905 0.00 1929 2.79 27/1919 4 3 1 0 3.3 19.0 1931
December 1.33 6.84 1909 0.00 1917 3.50 23/1909 5 3 1 0 9.8 55.0 1909
Annual 13.32 24.42 1909 4.93 1956 4.48 19680801 62 36 7 1 38.2 121.0 1909
Winter 3.93 11.95 1909 0.29 1964 3.50 19091223 17 10 2 0 27.9 100.2 1979
Spring 2.63 7.77 1926 0.10 1972 1.33 19870404 15 8 1 0 6.5 28.7 1970
Summer 2.98 6.90 1987 0.12 1960 4.48 19680801 16 8 2 0 0.0 2.5 1906
Fall 3.78 8.70 1972 0.50 1917 2.79 19191127 14 9 2 1 3.7 19.5 1908
Table updated on Jul 28, 2006
For monthly and annual means, thresholds, and sums:
Months with 5 or more missing days are not considered
Years with 1 or more missing months are not considered
Seasons are climatological not calendar seasons
Winter = Dec., Jan., and Feb. Spring = Mar., Apr., and May
Summer = Jun., Jul., and Aug. Fall = Sep., Oct., and Nov.
Page 1-8
Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

Table 1.1-2
Period of Record General Climate Summary - Temperature
Station:(420738) BLANDING
From Year=1904 To Year=2006

Monthly
Averages Daily Extremes Monthly Extremes Max. Temp. Min. Temp.
Max. Min. Mean High Date Low Date
Highest
Mean Year Lowest
Mean Year >=
90 F
<=
32 F
<=
32 F
<=
0 F
F F F F
dd/yyyy
or
yyyymmdd
F
dd/yyyy
or
yyyymmdd
F - F - #
Days
#
Days
#
Days
#
Days
January 39.1 17.2 28.2 63 31/2003 -20 12/1963 40.2 2003 12.6 1937 0.0 6.2 30.3 1.8
February 44.9 22.3 33.6 71 28/1906 -23 08/1933 44.2 1995 18.8 1933 0.0 2.0 26.1 0.7
March 52.7 27.8 40.3 86 31/1906 -3 28/1975 51.0 2004 33.0 1948 0.0 0.3 23.4 0.0
April 62.2 34.3 48.2 88 19/1905 10 24/1913 56.9 1992 39.4 1928 0.0 0.0 12.4 0.0
May 72.3 42.1 57.2 98 31/2002 15 16/1910 65.0 2000 50.1 1917 0.4 0.0 2.7 0.0
June 83.3 50.7 67.0 110 22/1905 28 03/1908 75.3 2002 61.2 1907 6.3 0.0 0.2 0.0
July 88.7 57.9 73.3 109 19/1905 36 15/1934 81.1 2003 66.3 1916 15.1 0.0 0.0 0.0
August 86.2 56.2 71.2 106 18/1905 38 23/1968 77.2 1926 65.6 1968 9.0 0.0 0.0 0.0
September 78.2 48.3 63.3 100 01/1905 20 26/1908 70.2 2001 56.6 1922 1.3 0.0 0.3 0.0
October 66.0 38.0 52.0 99 08/1905 10 30/1971 59.6 2003 44.6 1969 0.1 0.0 6.6 0.0
November 51.4 26.7 39.1 74 04/1905 -7 25/1931 47.3 1999 32.4 1952 0.0 0.4 23.6 0.1
December 41.2 19.2 30.2 65 03/1929 -13 23/1990 39.4 1980 19.4 1931 0.0 4.5 30.0 0.9
Annual 63.8 36.7 50.3 110 19050622 -23 19330208 55.1 2003 47.2 1932 32.2 13.5 155.6 3.4
Winter 41.7 19.5 30.7 71 19060228 -23 19330208 37.5 1907 19.3 1933 0.0 12.7 86.4 3.3
Spring 62.4 34.7 48.6 98 20020531 -3 19750328 54.8 2004 43.6 1909 0.4 0.3 38.5 0.0
Summer 86.0 54.9 70.5 110 19050622 28 19080603 76.4 2002 67.4 1941 30.4 0.0 0.2 0.0
Fall 65.2 37.7 51.4 100 19050901 -7 19311125 58.3 1926 47.8 1912 1.4 0.4 30.5 0.1
Table updated on Jul 28, 2006
For monthly and annual means, thresholds, and sums:
Months with 5 or more missing days are not considered
Years with 1 or more missing months are not considered
Seasons are climatological not calendar seasons
Winter = Dec., Jan., and Feb. Spring = Mar., Apr., and May
Summer = Jun., Jul., and Aug. Fall = Sep., Oct., and Nov.
Page 1-9
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Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

Winds are usually light to moderate in the area during all seasons, although occasional stronger
winds may occur in the late winter and spring. The predominant winds are from the north
through north-east (approximately 30 percent of the time) and from the south through south-west
(about 25 percent of the time). Winds are generally less than 15 mph, with wind speeds faster
than 25 mph occurring less than one percent of the time (1978 ER, Section 2.7.2). As an element
of the pre-construction baseline study and ongoing monitoring programs, the Mill operates an
onsite meteorological station, described in greater detail below. Further details about weather
and climate conditions are provided in the 1978 ER (Section 2.7) and in the FES (Section 2.1).

1.1.2 Storms (FES Section 2.1.4, updated)

Thunderstorms are frequent during the summer and early fall when moist air moves into the area
from the Gulf of Mexico. Related precipitation is usually light, but a heavy local storm can
produce over an inch of rain in one day. The maximum 24-hour precipitation reported to have
fallen during period 1904-2006 at Blanding was 4.48 inches (11.36 cm). Hailstorms are
uncommon in this area. Although winter storms may occasionally deposit comparable amounts
of moisture, maximum short-term precipitation is usually associated with summer thunderstorms.

Tornadoes have been observed in the general region, but they occur infrequently. Strong winds
can occur in the area along with thunderstorm activity in the spring and summer. The Mill area
is susceptible to occasional dust storms, which vary greatly in intensity, duration, and time of
occurrence. The basic conditions for blowing dust in the region are created by wide areas of
exposed dry topsoil and strong, turbulent winds. Dust storms usually occur following frontal
passages during the warmer months and are occasionally associated with thunderstorm activities.

1.1.3 On Site

On-site meteorological monitoring at the Mill was initiated in early 1977 and continues today.
The original purpose of the meteorological monitoring program was to document the regional
Page 1-10
Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

atmospheric baseline and to provide data to assist in assessing potential air quality and
radiological impacts arising from operation of the Mill.

After the Mill construction was completed, the monitoring programs were modified to facilitate
the assessment of Mill operations. The current meteorological monitoring program includes data
collection for wind speed, wind direction, atmospheric stability according to the standard
Pasquill scheme (via measurements of deviations in wind direction, referred to as sigma-theta),
and precipitation as either rain or snow. The recorded on-site meteorological conditions are
reported to Denison on a semi-annual basis and are described in semi-annual reports prepared for
Denison and maintained at the Mill. Figure 1.1-1 shows the windrose for the Mill site for the
period of January – December 2010, the most recent full year of compiled meteorological data.

WIIIO AI)!;E PlOT.
White Mesa Mill
Meteorological Station
' \
' I
' '
OISI'I.AV.
Wind Spetd
DirKtion (blowing from)
--,-------~NofriH ------
----.. ·-... --...
' ' I
---
""'., I ,' .. .... I ....
---I SOIJTH ---..... --.. --·-----.,. ....
DATA P£11101>-
' ' ' " '
' ' WINO SPEED
(mls)
D >•11.o
• &.4·11,0
• 5.4· 8.4
• 3.3· 5.4 u 1..8· 3.3
• 0.4·1.8
calms: 0.03%
2010 D~nlson Mines (USA) Corporation
Jan 1 ·Dec 31
00:00 • 23:00
0.03%
AVG. WINO SIUO.
3.43 mls
MOoi!L!lt'
McVehii-Monnett
Associates
8714 hrs.
111412011
PROJKT NO.:
2397-10
~w=~~~=r~v--.--u~-~e~~~~-~---~~~~~-----------------L----------------~----------------~
Denison Mines (USA) Corp II»ENISOJ)~~
MINES
REVISIONS
07-11 GM
White Mesa Mill
Counly: San Juan I ::Ollll8: ur
L.ooallon:
WIND ROSE -2010
(McVehii-Monnett Associates)
FIGURE 1.1-1
I Dlllo: , , -23-011 I Drall8d By. DLS
Page 1-12
Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

1.2 Topography

The following text is reproduced from Section 2.3 of the FES.

The site is located on a "peninsula" platform tilted slightly to the south-southeast and surrounded
on almost all sides by deep canyons, washes, or river valleys. Only a narrow neck of land
connects this platform with high country to the north, forming the foothills of the Abajo
Mountains. Even along this neck, relatively deep stream courses intercept overland flow from
the higher country. Consequently, this platform (White Mesa) is well protected from runoff
flooding, except for that caused by incidental rainfall directly on the mesa itself. The land on the
mesa immediately surrounding the Mill site is relatively flat.

1.3 Archeological Resources

The following discussion of archeological sites is adapted from Section 2.5.2.3 of the FES.

1.3.1 Archeological Sites

Archeological surveys of portions of the entire Mill site were conducted between the fall of 1977
and the spring of 1979. The total area surveyed contained parts of Section 21, 22, 27, 28, 32, and
33 of T37S, R22E, and encompassed 2,000 acres (809 ha), of which 200 acres (81 ha) are
administered by the U. S. Bureau of Land Management (“BLM”) and 320 acres (130 ha) are
owned by the State of Utah. The remaining acreage is privately owned. During the surveys, 121
sites were recorded and all were determined to have an affiliation with the San Juan Anasazi who
occupied this area of Utah from 0 A.D. to 1300 A.D. All but 22 of the sites were within the Mill
site boundaries.

Page 1-13
Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

Table 1.3-1, adapted from FES Table 2.18, summarizes the recorded sites according to their
probable temporal positions. The dates of occupation are the best estimates available, based on
professional experience and expertise in the interpretation of archeological evidence. Available
evidence suggests that settlement on White Mesa reached a peak in perhaps 800 A.D.
Occupation remained at approximately that level until sometime near the end of Pueblo II or in
the Pueblo II/Pueblo III transition period. After this period, the population density declined
sharply, and it may be assumed that the White Mesa area was, for the most part, abandoned by
about 1250 A.D.

Archeological test excavations were conducted by the Antiquities Section, Division of State
History, in the spring of 1978, on 20 sites located in the area later to be occupied by tailings cells
2, 3 and 4 (now comprised of Cell 4A and proposed Cell 4B). Of these sites, 12 were deemed by
the State Archeologist to have significant National Register potential and four to have possible
significance. The primary determinant of significance in this study was the presence of
structures, though storage features and pottery artifacts were also common.

In the fall of 1978, a surface survey was conducted on much of the previously unsurveyed
portions of the proposed Mill site. Approximately 45 archeological sites were located during this
survey, some of which are believed to be of equal or greater significance than the more
significant sites from the earlier study. Determination of the actual significance of all untested
sites would require additional field investigation.

Page 1-14
Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

Table 1.3-1
Distribution of Recorded Sites According to Temporal Position

Temporal position

Approximate dates (A.D.)a

Number of sites

Basket Maker III

575-750

2

Basket Maker III/Pueblo I

575-850

27

Pueblo I

750-850

12

Pueblo I/Pueblo II

850-950

13

Pueblo II

950-1100

14

Pueblo II/Pueblo III

1100-1150

12

Pueblo III

1150-1250

8

Pueblo II+

B

5

Multicomponent

C

3

Unidentified

D

14

a Includes transitional periods.

b Although collections at these locations were lacking in diagnostic material, available
evidence indicates that the site would have been used or occupied no earlier than 900 A.D. and
possibly later.

c Ceramic collections from each of these sites indicate an occupation extending from
Pueblo I through Pueblo II and into Pueblo III.

d These sites did not produce evidence strong enough to justify any identification.

Source: Adapted from Dames & Moore (1978b) (1978 ER), Table 2.3-2, FES, Page 2-20, Table
2.18, and from supplementary reports on project archeology.
Page 1-15
Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

Pursuant to 10 CFR Part 63.3, the NRC submitted on March 28, 1979, a request to the Keeper of
the National Register for a determination of eligibility for the area which had been surveyed and
tested. The area contained 112 archeological sites and six historical sites. The determination by
the Keeper of the National Register on April 6, 1979, was that the White Mesa Archeological
District is eligible for inclusion in the National Register.

1.3.2 Current Status of Excavation

Archeological investigations for the entire Mill site and for Cells 1 through Cell 4 (now
comprised of Cell 4A and Cell 4B) were completed with the issuance of four separate reports
covering 30 sites, excluding re-investigations. (Lindsay 1978, Nielson 1979, Casjens et al 1980,
and Agenbroad et al 1981).

The sites reported as excavated are as follows:

6380

6394

6437

6381

6395

6684
6384

6396

6685
6385

6397

6686
6386

6403

6697
6387

6404

6698

6388

6420

6699
6391

6429

6754
6392

6435

6757
6393

6436

7754

Page 1-16
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Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

Sites for which excavation has not been required are:

6379

6441

7658

7690
6382

6443

7659

7691
6405

6444

7660

7693
The sites remaining to be excavated or investigated for significance are:

6408

6445

7657

7687
6421

6739

7661

7689
6427

6740

7665

7696
6430

7653

7668

7700
6432

7655

7675

7752
6439

7656

7684

7876
The following site was excavated in 2009 in connection with the construction of the new
decontamination pad at the Mill:

42Sa27732

The following sites were excavated in the summer of 2010 in connection with the construction of
Cell 4B and the final report is in preparation:

42Sa6391

42Sa6392

42Sa6393

42Sa6397

42Sa6431

42Sa6757

42Sa8014

42Sa28128

42Sa28129

42Sa28130

42Sa28131

42Sa28132

42Sa28133

42Sa28134

Page 1-17
Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

1.4 Surface Water

The following description of undisturbed surface water conditions is adapted from Section 2.6.1
of the FES and Section 3.7.1 of the 2007 ER updated to include current data.

The Mill was designed and constructed to prevent runon or runoff of storm water by a) diverting
runoff from precipitation on the Mill site to the tailings cells; and b) diverting runoff from
surrounding areas away from the Mill site. In addition to these designed control features, the
facility has developed a Stormwater Best Management Practices Plan, Revision 1.3: June 12,
2008 which includes a description of the site drainage features and the best management
practices employed to assure appropriate control and routing of stormwater. A copy of the Mill’s
Stormwater Best Management Practices Plan is included as Appendix C to this Plan.

1.4.1 Surface Water Description (FES Section 2.6.1.1)

The Mill site is located on White Mesa, a gently sloping (1 percent SSW) plateau that is
physically defined by the adjacent drainages which have cut deeply into regional sandstone
formations. There is a small drainage area of approximately 62 acres (25 ha) above the site that
could yield surface runoff to the site. Runoff from the Mill area is conducted by the general
surface topography to either Westwater Creek, Corral Creek, or to the south into an unnamed
branch of Cottonwood Wash. Local porous soil conditions, topography and low acreage annual
rainfall of 13.32 inches cause these streams to be intermittently active, responding to spring
snowmelt and local rainstorms (particularly thunderstorms). Surface runoff from approximately
384 acres (155 ha) of the Mill site drains westward and is collected by Westwater Creek, and
runoff from another 384 acres (155 ha) drains east into Corral Creek. The remaining southern
and southwestern portions of the site drain indirectly into Cottonwood Wash (Dames & Moore,
1978b, p. 2-143). The site and vicinity drainages carry water only on an intermittent basis. The
major drainages in the project vicinity are depicted in Figure 1.4-1 and their drainages tabulated
USGS GAUGE NO. 09376900
USGS GAUGE NO. 09378630
USGS GAUGE NO. 09378700
Project
Denison Mines (USA) Corp.
WHITE MESA MILL
UT
Figure 1.4-1
Drainage Map of the Vicinity
of the White Mesa Mill
Page 1-19
Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

in Table 1.4-1. Total runoff from the site area (total yield per watershed area) is estimated to be
less than 0.5 inch (1.3cm) annually (Dames & Moore, 1978b, p. 2-143).

There are no perennial surface waters on or in the vicinity of the Mill site. This is due to the
gentle slope of the mesa on which the site is located, the low average annual rainfall of 13.32
inches (33.8 cm) per year at Blanding, local soil characteristics and the porous nature of local
stream channels. Prior to construction, three small ephemeral catch basins were present on the
site to the northwest and northeast of the Mill site.

Corral Creek is an intermittent tributary to Recapture Creek. The drainage area of that portion of
Corral Creek above and including drainage from the eastern portion of the site is about 5 square
miles (13 km2). Westwater Creek is also an intermittent tributary of Cottonwood Wash. The
Westwater Creek drainage basin covers nearly 27 square miles (70 km2) at its confluence with
Cottonwood Wash 1.5 miles (2.5 km) west of the Mill site. Both Recapture Creek and
Cottonwood Wash are similarly intermittently active, although they carry water more often and
for longer periods of time due to their larger watershed areas. They both drain to the south and
are tributaries of the San Juan River. The confluences of Recapture Creek and Cottonwood
Wash with the San Juan River are approximately 18 miles (29 km) south of the Mill site. The
San Juan River, a major tributary for the upper Colorado River, has a drainage of 23,000 square
miles (60,000 km2) measured at the USGS gauge to the west of Bluff, Utah (Dames & Moore,
1978b, p. 2-130).

Page 1-20
Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

Table 1.4-1
Drainage Areas of Project Vicinity and Region

Basin description

Drainage area

km2
sq. miles

Corral Creek at confluence
with Recapture Creek

15.0

5.8

Westwater Creek at confluence
with Cottonwood Wash

68.8

26.6

Cottonwood Wash at USGS
gage west of project site

<531

<205

Cottonwood Wash at confluence
with San Juan River

<860

<332

Recapture Creek at USGS gage

9.8

3.8

Recapture Creek at confluence
with San Juan River

<518

<200

San Juan River at USGS gage
downstream at Bluff, Utah

<60,000

<23,000

Source: Adapted from Dames & Moore (1978b), Table 2.6-3

Page 1-21
Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

Storm runoff in these streams is characterized by a rapid rise in the flow rates, followed by rapid
recession primarily due to the small storage capacity of the surface soils in the area. For
example, on August 1, 1968, a flow of 20,500 cfs (581 m3/sec) was recorded in Cottonwood
Wash near Blanding. The average flow for that day, however, was only 4,340 cfs (123 m3/sec).
By August 4, the flow had returned to 16 cfs (0.5 m3/sec) (Dames & Moore, 1978b, p. 2-135).
Monthly streamflow summaries updated from Figure 2.4 of the FES are presented in Figure 1.4-
2 for Cottonwood Wash, Recapture Creek and Spring Creek. Flow data are not available for the
two smaller water courses closest to the Mill site, Corral Creek and Westwater Creek, because
these streams carry water infrequently and only in response to local heavy rainfall and snowmelt,
which occurs primarily in the months of April, August, and October. Flow typically ceases in
Corral and Westwater Creeks within 6 to 48 hours after precipitation or snowmelt ends.

1.4.2 Surface Water Quality as of the Date of the FES (FES Section 2.6.1.2)

Sampling of surface water quality in the Mill vicinity began in July 1977 and continued through
March 1978. Baseline data describe and evaluate existing conditions at the Mill site and vicinity.
Sampling of the temporary on-site surface waters (two catch basins) was attempted but without
success because of the lack of naturally occurring water in these basins. Sampling of ephemeral
surface waters in the vicinity was possible only during major precipitation events, as these
streams are normally dry at other times. See FES Section 2.6.1.2

The locations of the surface water sample sites used prior to Mill operations are presented in
Figure 1.4-3. The water quality values obtained for these sample sites are given in Dames &
Moore (1978b) Table 2.6-7, and FES Table 2.22. Water quality samples were collected during
the spring at several intermittently active streams that drain the Mill area. These streams include
Westwater Creek (S1R, S9) Corral Creek below the small irrigation pond (S3R), the junction of

tii w u. w a: ~
~ ...J u.
~ :I: f-z 0 ~ w ~ w ~
tii w u. w a: ~
~ ...J .., u. i ~ .., :I:
~ f-z 0 ~ ~ w
N ~ * ~ w ~
I i'ii
~ ~
I!! ~ ... Iii 1[ ~ ~ c ~ E .. al ~ ! :il ~ ~ ~
400
350
300
250
200
150
100
50
400
AVERAGE ANNUAL FLOW=950 AF-(1966-2001)
DRAINAGE AREA=3. T7 SQ. MI.
AVERAGE ANNUAL YIELD=252.1 AFISQ. MI.
-
-YIELD-AF/SQ. Ml
MIN. AVG.
2.7 252
(1990)
-
_,---,_ J
JAN FEB MAR APR MAY JUN JUl AlJO SEP OCT NOV DEC
MONTH
RECAPTURE CREEK NEAR BLANDING
USGS GAUGE 09378630
AVERAGE ANNUAL FLOW=T757 AF-(1966-1971)
DRAINAGE AREA=4.95 SQ. MI.
AVERAGE ANNUAL YIELD=153AFISQ. MI.
-
MAX.
881
(1983)
YIELD-AFISQ. Ml
1600
tii 1400
~ ~ 1200
AVERAGE ANNUAL FLOW=6547 AF-(1965-1986)
DRAINAGE AREA=205 SQ. MI.
AVERAGE ANNUAL YIELD=32 AFISQ. MI.
-~1000 g r-YIELD-AF/SQ. Ml
MIN. AVG . u. 800 ~
i!: 600 t5
-
~ r-
w 400 ~ w 200 r--~
JAN FEB liAR APR MAY JUN JUL AU<J SEP OCT NOV DEC
MONTH
COTTONWOOD WASH NEAR BLANDING
USGS GAUGE 09378700
NOTES
1. FOR THE LOCATION OF WATER COURSES
SUMMARIZED, SEE FIGURE 3.7-1
4.9 32
(1976)
2. SOURCE OF DATA. WATER RESOURCES DATA RECORDS.
MAX.
88
(1983)
350
300
250
200
MIN. AVG. MAX . COMPILED AND PUBLISHED BY USGS.
150
100 -
46.9
(1971)
50
o ~~~~~~~~=~~~J
JAN FEB MAR APR MAY JUN JUl AlJO SEP OCT NOV DEC
MONTH
SPRING CREEK ABOVE DIVERSIONS,
USGS GAUGE 09376900
153 262
(1966)
Denison Mines (USA) Corp. OENIISOJ)~J
MINES
Project:
County:
0111&: Nov,2009
WHITE MESA MILL
SanJuan I :>tala: Utah
FIGURE 1.4-2
Streamflow Summary
Blanding, UT Vicinity
1 Design: 1 Draltsd Bit: DLS
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White Mesa Mill Reclamation Plan

Corral Creek and Recapture Creek (S4R), and Cottonwood Creek (S8R). Samples were also
taken from a surface pond southeast of the Mill (S5R). No samples were taken at S2R on Corral
Creek or at the small wash (S6R) located south of the site.

Natural surface water quality in the vicinity of the Mill is generally poor. Waters in Westwater
Creek (S1R and S9) were characterized by high total dissolved solids (TDS; mean of 674
mg/liter) and sulfate levels (mean 117 mg of SO4 per liter). The waters were typically hard (total
hardness measured as CaCO3; mean 223 mg/liter) and had an average pH of 8.25. Estimated
water velocities for Westwater Creek averaged 0.3 fps (0.08 m/sec) at the time of sampling.

Samples from Cottonwood Creek (S8R) at the time of the FES were generally similar in quality
to Westwater Creek water samples, although the TDS and sulfate levels were lower (TDS
averaged 264 mg/liter; SO4 averaged 40 mg/liter) during heavy spring flow conditions [80 fps
(24 m/sec) water velocity].

The concentrations of TDS increased downstream in Corral Creek, averaging 3,180 mg/liter at
S3R and 6,660 mg/liter (one sample) at S4R. Total hardness averaged in excess of 2,000
mg/liter, and pH values were slightly alkaline. Estimated water velocities in Corral Creek were
typically less than 0.1 fps (0.03 m/sec) during sampling.

The spring sample collected at the surface pond south of the Mill site (S5R) indicated a TDS
concentration of less than 300 mg/liter. The water was slightly alkaline with moderate dissolved
sulfate levels averaging 42 mg/liter.

During heavy runoff, the concentration of total suspended solids in these streams increased
sharply to values in excess of 1,500 mg/liter (FES, Table 2.22). High concentrations of certain
trace elements were measured in some sampling areas. Levels of mercury (total) were reported
as high as 0.002 mg/liter (S3R, 7/25/77; S8R, 7/25/77). Total iron measured in the pond (S5R,
11/10/77) was 9.4 mg/liter. The FES concluded (Section 2.6.1.2 of the FES) that these values
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Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

appear to reflect groundwater quality in the vicinity and are probably due to evaporative
concentration and not due to human perturbation of the environment. Corral Creek was also
sampled at the time of the FES, but it has not been included in subsequent operational
monitoring at the Mill. See Table 2.22 of the FES for sampling results for Corral Creek.

1.4.3 Surface Water Background Quality

Surface water samples are collected for Cottonwood Wash and Westwater Creek as part of the
Mill’s operational monitoring program. Samples were also taken prior to Mill construction and
summarized in the FES as well as at various times and for various parameters since then. A
comparison of the FES results and subsequent sampling results during Mill operation is set out in
Table 1.4-2. Surface water values over time for both Cottonwood Wash and Westwater Creek
are included in the Semi-Annual Effluent Reports.

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Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

Table 1.4-2
Summary of FES and Subsequent Sampling Results For Cottonwood Wash and Westwater Creek
Parameter
FES
Cottonwood Wash
(7/25/77-3/28/78)*

Cottonwood Wash
(9/16/81-6/20/09)

Cottonwood
Wash
2010

Cottonwood
Wash
2011
FES
Westwater Creek
(11/10/77-3/23/78)*

Westwater
Creek
(2/22/82-
6/20/09)

Westwater
Creek
2010

Westwater
Creek
2011

Field Specific Conductivity
(µmhos/cm) 240-550 -
16123
16253
16003

- 320-620 -
17073
17823
16503

-
Field pH 6.6 to 8.1 - 6.423
6.673
- 7.6-8.3 - 7.033
6.983
-
Dissolved Oxygen - - - - - - - -
Temperature (ºC) 6.0 to 35 -
16.173
15.853
15.053
-
3-14 -
17.993
17.213
10.13
-
Estimated Flow m/hr 0.4 to 80 - - - 0.28 to 39.9 - - -
pH 7.5 to 8.21 - 7.473 - 8.2 to 8.35 - 7.383 -

TDS (@180ºC) 253 to 944 10 to 803* 9003 mg/L 9785 mg/L 496 to 969 93-1370* 12703 mg/L 8536 mg/L
Redox Potential 210 to 260 - 5013
4923
- 186 to 220 4013
3423
- -
Alkalinity (as CaCO3) 134 to 195 76 to 257* - - 147 to 229 230* - -
Hardness, total (as CaCO3) 148 to 195 - - - 117 to 289 - - -
Carbonate (as CO3) 0.0 ND ND3 65 mg/L 0.0 to 2.3 ND ND3 ND5
Bicarbonate (as HCO3) - 316 mg/L 3403 mg/L 3165 mg/L - 465 mg/L 3715 mg/L
Aluminum, dissolved 0.16 to 3.0 - - - 0.1 to 4.0 - - -
Ammonia (as N) <0.1 to 0.16 ND ND3 ND5 <0.1 to 0.75 ND 0.503 mg/L 0.065 mg/L
Arsenic, total 0.02 to 0.041 - - - 0.007 to 0.037 - - -
Arsenic, Dissolved - ND ND3 ND5 - ND ND3 12.35 ug/L
Barium, total 0.2 to 1.2 - - - <0.2 to 0.81 - - -
Beryllium, dissolved - ND ND3 ND5 - ND ND3 0.915 ug/L
Boron, total <0.1 to 0.2 - - - <0.1 to 0.1 - - -
Cadmium, total <0.002 to 0.01 - - - <0.002 to 0.006 - - -
Cadmium, dissolved - ND ND3 ND5 - ND ND3 0.95 ug/L
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White Mesa Mill Reclamation Plan

Table 1.4-2
Summary of FES and Subsequent Sampling Results For Cottonwood Wash and Westwater Creek (continued)
Parameter
FES
Cottonwood Wash
(7/25/77-3/28/78)*

Cottonwood Wash
(9/16/81-6/20/09)

Cottonwood
Wash
2010

Cottonwood
Wash
2011
FES
Westwater Creek
(11/10/77-3/23/78)*

Westwater
Creek
(2/22/82-
6/20/09)

Westwater
Creek
2010

Westwater
Creek
2011

Calcium, dissolved 54 to 178 90.3 mg/L 92.23 mg/L 94.26 mg/L 76 to 172 191 mg/L 1793 mg/L 2475 mg/L
Calcium - 37 to 71* - - - 94.5* - -
Chlorine - - - - - 41* - -
Chloride 6 to 24 5 to 33.3* 1123 mg/L 1345 mg/L 17 to 125 76* 403 mg/L 215 mg/L
Sodium - 18 to 104* - - - 160.5* - -
Sodium, dissolved 21 to 66 205 mg/L 2143 mg/L 2275 mg/L 31 to 60 196 mg/L 1603 mg/L 1125 mg/L
Silver, dissolved 0.002 to <0.005 ND ND3 ND5 <0.005 to 0.006 ND ND3 ND5
Sulfate, dissolved (as SO4) 39.7 to 564 57 to 245* 3893 mg/L 3895 mg/L 85 to 163 408* 6073 mg/L 3545 mg/L
Vanadium, dissolved <0.005 to <0.018 ND ND3 ND5 <0.001 to 0.008 ND ND3 ND5
Manganese, dissolved 0.02 to 0.84 ND ND3 ND5 0.03 to 0.60 37 ug/L 873 ug/L 2685 ug/L
Chromium, total <0.01 to 0.14 - - - <0.01 to 0.60 - - -
Chromium, dissolved - ND ND3 ND5 - ND ND3 ND5
Copper, total 0.005 to 0.09 - -- <0.005 to 0.05 - - -
Copper, dissolved - ND ND3 ND5 - ND ND3 165 ug/L
Cobalt, dissolved - ND ND3 ND5 - ND ND3 ND5
Fluoride, dissolved 0.2 to 0.36 0.4 mg/L 0.383 mg/L 0.385 mg/L 0.2 to 0.4 0.7 mg/L 0.603 mg/L 0.545 mg/L
Iron, total 5.9 to 150 - - - 0.28 to 44 - - -
Iron, dissolved 0.11 to 1.9 ND ND3 ND5 0.17 to 2.5 89 ug/L 563 ug/L 45405 ug/L
Lead, total 0.05 to 0.14 - -- <0.05 to 0.1 - - -
Lead, dissolved - ND ND3 ND5 - ND ND3 41.45 ug/L
Magnesium - 10.5 to 38.1* - - - 23.5* - -
Magnesium, dissolved 17 to 28 25 mg/L 24.83 mg/L 25.25 mg/L 13 to 26 - 44.73 mg/L 34.75 mg/L
Mercury, total 0.00006 to 0.002 - - - <0.00003 to <0.0005 - - -
Mercury, dissolved - ND ND3 ND5 - ND ND3 ND5
Molybdenum, dissolved 0.002 to 0.10 ND ND3 ND5 0.002 to 0.006 ND 293 ug/L ND5
Nitrate (as N) 0.12 to 1.77 0.1 mg/L ND3 ND5 <0.05 to 0.05 0.8 mg/L ND3 ND5
Nickel, dissolved - ND ND3 ND5 - - ND3 ND5
Phosphorus, total (as P) 0.05 to 3.2 - - - 0.05 to 0.88 - - -

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Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

Table 1.4-2
Summary of FES and Subsequent Sampling Results For Cottonwood Wash and Westwater Creek (continued)
Parameter
FES
Cottonwood Wash
(7/25/77-3/28/78)*

Cottonwood Wash
(9/16/81-6/20/09)

Cottonwood
Wash
2010

Cottonwood
Wash
2011
FES
Westwater Creek
(11/10/77-3/23/78)*

Westwater
Creek
(2/22/82-
6/20/09)

Westwater
Creek
2010

Westwater
Creek
2011

Potassium, dissolved 1.2 to 6.9 1.77 to 4 mg/L 5.773 mg/L 5.95 mg/L 2.0 to 3.2 4.05* 6.573 mg/L 3.95 mg/L
Selenium, dissolved <0.005 to 0.08 ND ND3 ND5 <0.005 to 0.003 ND ND3 ND5
Silica, dissolved (as SiO2) 8 to 18 - - - 7 to 11 - - -
Strontium, total 0.34 to 0.64 - - - 0.44 to 0.76 - - -
Thallium, dissolved - ND ND3 ND5 - ND ND3 ND5
Tin, dissolved - - ND3 ND5 - ND ND3 ND5
Uranium, total 0.004 to 0.27 - - - 0.006 to 0.004 - - -
Uranium, dissolved 0.004 to 0.015 8.42 ug/L 8.243 ug/L 8.685 ug/L 0.002 to 0.015 15.1 ug/L 46.63 ug/L 6.645 ug/L
Zinc, dissolved 0.008 to 0.06 ND ND3 ND5 0.04 to 0.12 ND 223 ug/L 285 ug/L
Total Organic Carbon 7 to 12 - - - 6 to 16 - - -
Chemical Oxygen Demand 61 to 163 - - - 23 to 66 - - -
Oil and Grease 2 - - - 1 - - -
Total Suspended Solids 146 to 2,025 0 to 24,300* 4944 mg/L 7.06 mg/L 12 to 1940 <4 to 1,190* 134 mg/L -
Total Dissolve Solids - 188 to 1,130* 331-6245 mg/L 425-4637 mg/L - 1370 mg/L 11404 mg/L -

Gross Alpha - <1.0E-9 to 9.0E-7* - 1E-10 to 4.5E-9 <1.0E-9* - -
Gross Alpha minus Rn & U - - 0.54 pCi/L 0.26 pCi/L - - 0.34 pCi/L 0.55 pCi/L
Gross Beta - - - - 0 to 8E-9 - - -
Uranium, dissolved 1.02E-9 to 2.79E-9 2.23E-9 to 6.02E-6* 0.00604 mg/L 10.26 ug/L 1.03E-9 to 1.35E-9 8.8E-7* 0.00574 mg/L -
Uranium, total2 21.83E-7 - - - 6.09E-7 - - -
Uranium, suspended - <2.0E-10 to 2.0E-7* 0.00144 mg/L ND6 0 to 1E-9 6.09E-7* 0.00054 mg/L -
Th-230, dissolved - <2.0E-10 to 4.14E-6* 0.054 pCi/L 0.076 pCi/L - <2.0E-10* ND4 pCi/L -
Th-230, suspended - <2.0E-10 to <9.0E-7* 0.74 pCi/L 0.26 pCi/L 2E-10 3.0E-10* 0.24 pCi/L -
Ra-226, dissolved - <2.0E-10 to 2.0E-9* 0.094 pCi/L 0.066 pCi/L - 2.0E-10* 0.184 pCi/L -
Ra-226, suspended - <2.0E-10 to <2.0E-7* 1.34 pCi/L ND6 7E-10 to 1.1E-9 <2.0E-10* 4.34 pCi/L -
Pb-210 - - - - 0 to 1E-10 - - -

Acetone - ND ND3 ND5 - ND ND3 ND5
Benzene - ND ND3 ND5 - ND ND3 ND5
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Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

Table 1.4-2
Summary of FES and Subsequent Sampling Results For Cottonwood Wash and Westwater Creek (continued)
Parameter
FES
Cottonwood Wash
(7/25/77-3/28/78)*

Cottonwood Wash
(9/16/81-6/20/09)

Cottonwood
Wash
2010

Cottonwood
Wash
2011
FES
Westwater Creek
(11/10/77-3/23/78)*

Westwater
Creek
(2/22/82-
6/20/09)

Westwater
Creek
2010

Westwater
Creek
2011

Carbon Tetrachloride - ND ND3 ND5 - ND ND3 ND5
Chloroform - ND ND3 ND5 - ND ND3 ND5
Chloromethane - ND ND3 ND5 - ND ND3 ND5
Methyl ethyl ketone - ND ND3 ND5 - ND ND3 ND5
Methylene chloride - ND ND3 ND5 - ND ND3 ND5
Napthalene - ND ND3 ND5 - ND ND3 ND5
Toluene - ND ND3 ND5 - ND ND3 ND5
Xylenes, total - ND ND3 ND5 - ND ND3 ND5
Source: FES Table 2.22 and Mill Sample Data
*Data are from historic sampling events. All other data were collected during the 2009 annual Seeps and Springs and Semi-Annual Effluent sampling events. 2 Calculated by Denison for activity comparison using the Specific Activity for U-nat (6.77E-7 Ci U-nat/g U-nat) 3 Data are from the 2010 Seeps and Springs sampling event. 4 Data are from 2010 SAER sampling events. 5 Data are from 2011 Seeps and Springs sampling event. 6 Data are from 2011 SAER quarterly sampling events.
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Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

1.5 Groundwater

1.5.1 Groundwater Characteristics

This Section is excerpted from the Report entitled: Hydrogeology of the Perched Groundwater
Zone and Associated Seeps and Springs Near the White Mesa Uranium Mill Site, November 12,
2010, prepared by Hydro Geo Chem, Inc. (“HGC”) (the “2010 HGC Report”) (HGC, 2010b), a
copy of which is included as Appendix B. The HGC 2010 report supplements the “HGC 2009”
report summarized in Revision 4.0 of the Reclamation Plan, and provides additional information
in response to Part I.H, Section 10 of the GWDP. Specifically, the additional information
contained in the HGC 2010 report includes information on seeps and springs in the vicinity of
the Mill, the relationship of the seeps and springs with the perched water system, and estimated
travel times for shallow groundwater to travel from the tailings cells to the nearest discharge
points, all of which address items requested by Part I.H, Section 10 of the GWDP.

1.5.1.1 Geologic Setting

The Mill is located within the Blanding Basin of the Colorado Plateau physiographic province.
Typical of large portions of the Colorado Plateau province, the rocks underlying the site are
relatively undeformed. The average elevation of the site is approximately 5,600 ft (1,707 m)
above mean sea level (amsl).

The site is underlain by unconsolidated alluvium and indurated sedimentary rocks consisting
primarily of sandstone and shale. The indurated rocks are relatively flat lying with dips
generally less than 3 degrees. The alluvial materials consist mostly of aeolian silts and fine-
grained aeolian sands with a thickness varying from a few feet to as much as 25 to 30 ft (7.6 to
9.1 m) across the site. The alluvium is underlain by the Dakota Sandstone and Burro Canyon
Formation, which are sandstones having a total thickness ranging from approximately 100 to 140
ft (31 to 43 m). Beneath the Burro Canyon Formation lies the Morrison Formation, consisting,
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Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

in descending order, of the Brushy Basin Member, the Westwater Canyon Member, the
Recapture Member, and the Salt Wash Member. The Brushy Basin and Recapture Members of
the Morrison Formation, classified as shales, are very fine grained and have a very low
permeability. The Westwater Canyon and Salt Wash Members also have a low average vertical
permeability due to the presence of interbedded shales. See Figure 1.5-1 for a generalized
stratigraphic column for the region.

Beneath the Morrison Formation lies the Summerville Formation, an argillaceous sandstone with
interbedded shales, and the Entrada Sandstone. Beneath the Entrada lies the Navajo Sandstone.
The Navajo and Entrada Sandstones constitute the primary aquifer in the area of the site. The
Entrada and Navajo Sandstones are separated from the Burro Canyon Formation by
approximately 1,000 to 1,100 ft (305 to 335 m) of materials having a low average vertical
permeability. Groundwater within this system is under artesian pressure in the vicinity of the
site, and is used only as a secondary source of water at the site.

1.5.1.2 Hydrogeologic Setting

The site is located within a region that has a dry to arid continental climate, with average annual
precipitation of less than 13.3 in. and an annual lake evaporation rate of approximately 47.6
inches. Recharge to aquifers occurs primarily along the mountain fronts (for example, the
Henry, Abajo, and La Sal Mountains), and along the flanks of folds such as Comb Ridge
Monocline.

Although the water quality and productivity of the Navajo/Entrada aquifer are generally good,
the depth of the aquifer (approximately 1,200 ft below land surface (bls)) makes access difficult.
The Navajo/Entrada aquifer is capable of yielding significant quantities of water to wells
(hundreds of gallons per minute (gpm)). Water in wells completed across these units at the site
rises approximately 800 ft above the base of the overlying Summerville Formation.

I -8
i
~
"' I!! :::>
~ !!
(/)
(/) w z
~
0
I ~
w ~ ~
X
0
0::::
0....
0....
<(
0 m
2
0
0
rr)
2
0 <0
2
0
""'" N 2
0 I[')
rr)
2
0 0 ......
2
0 0 N
2
COVERED BY UNCONSOUDATED All..UVIUM,
COLLUVIUt.A AND TALUS
- - - - - - - - - - - - - --sAND AND SILT, REDDISH BROWN VERY EOLIAN SAND FINE-GRAINED = = = = = = =!MANCOS SHA[E!:::: = ~HALE, UGHT GRAY, SOFT
DAKOTA SANDSTONE
BURRO CANYON FORMATION
BRUSHY BASIN MEMBER
SALT WASH MEMBER
SUMMERVILLE FORMATION
ENTRADA SANDSTONE
NAVAJO SANDSTON E
Project
SANDSTONE, OUARlZ, UGHT YELLOW BROWN,
POORLY SORTED, IRON CONCREATIONS.
WELL INDURATED
SANDSTONE, QUARTZ, UGHT GRAY TO LIGHT
BROWN, CROSS-BEDDED, CONGLOMERAllC,
POORLY SORTED INTERBEDDED WITH
GRAY-GREEN SHALE
SHALE, GRAY. GRAY-GREEN, AND PURPLE.
SILTY IN PART WITH SOME SANDSTONE
LENSES
SANDSTONE, ARKOSIC. YELLOW TO GREENISH
GRAY, FINE TO COARSE GRAINED, INTERBEDDED
WITH GREENISH-GRAY TO REDDISH-BROWN
SHALE
SANDSTONE, QUARTZ, YELLOWISH-TO
REDDISH BROWN, FINE-TO COARSE-
GRAINED INTERBEDDED WITH REDDISH-
GRAY SHALE
SANDSTONE, RED-BROWN, THIN-BEDDED, WITH
RIPPLE MARKS. ARGILLACEOUS WITH SHALE
INTERBEDS
SANDSTONE, QUARlZ WHITE TO GRAYISH
BROWN, IAASSIVE, CROSS-BEDDED, FINE-
TO MEDIUM-GRAINED
SANDSTONE, QUARTZ, UGHT YELLOWISH-
BROWN TO UGHT-GRAY AND WHITE, MASSIVE,
CROSS-BEDDED, FRIABLE, FINE-TO
MEDIUM-GRAINED
Denison Mines (USA) Corp.
WHITE MESA MILL
· UT
Figure 1.5-1
Generalized Stratigraphy of
White Mesa Mill
~ ~ Taken from Stratigraphic Section near Water Well #J
Page 1-33
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Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

1.5.1.3 Perched Zone Hydrogeology

Perched groundwater beneath the site occurs primarily within the Burro Canyon Formation.
Perched groundwater at the site has a generally low quality due to high total dissolved solids
(“TDS”) in the range of 1,100 to over 7,900 milligrams per liter (mg/L) and is used primarily for
stock watering and irrigation in the areas upgradient (north) of the site. The saturated thickness
of the perched water zone generally increases to the north of the site, increasing the yield of the
perched zone to wells installed north of the site. Perched water is supported within the Burro
Canyon Formation by the underlying, fine grained Brushy Basin Member. Figure 1.5-2 is a
contour map showing the approximate elevation of the contact of the Burro Canyon Formation
with the Brushy Basin Member, which essentially forms the base of the perched water zone at
the site. Wells and piezometers shown in Figure 1.5-2 consist of surveyed perched zone
monitoring wells and piezometers that include temporary perched zone monitoring wells (TW-4-
series wells, including MW-4, TW4-4, TW4-19, TW4-20, and MW-26) associated with an area
of elevated perched zone chloroform concentrations located east and northeast (cross gradient to
upgradient) of the tailings cells (HGC, 2007). Contact elevations are based on monitoring well
drilling and geophysical logs and surveyed land surface elevations. As indicated, the contact
generally dips to the south/southwest beneath the site.

The permeability of the Dakota Sandstone and Burro Canyon Formation at the site is generally
low. No significant joints or fractures within the Dakota Sandstone or Burro Canyon Formation
have been documented in any wells or borings installed across the site (Knight Piésold, 1998).
Any fractures observed in cores collected from site borings are typically cemented, showing no
open space.

1.5-2
EXPLANATION
8 Perched Monitoring Well
Ruin Spring
J. Seep or Spring
HYDRO
GEO
CHEM,INC. APPROVED
SJS
APPROXIMATE ELEVATION OF TOP
OF BRUSHY BASIN (FEET AMSL)
(generated by kriging data from on-site wells)
DATE REFERENCE H:/718000/cell4bjuly201 0/
springQ2/phbbQ2.srf
FIGURE
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Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

Based on samples collected during installation of wells MW-16 (no longer used) and MW-17
(the locations of the various monitoring wells are indicated on Figure 1.5-2), located
immediately downgradient of the tailings cells at the site, porosities of the Dakota Sandstone
range from 13.4 percent to 26 percent, averaging 20 percent, and water saturations range from
3.7 percent to 27.2 percent, averaging 13.5 percent. The average volumetric water content is
approximately 3 percent. The hydraulic conductivity of the Dakota Sandstone based on packer
tests in borings installed at the site ranges from 2.71E-06 centimeters per second (cm/s) to 9.12E-
04 cm/s, with a geometric average of 3.89E-05 cm/s.

The average porosity of the Burro Canyon Formation is similar to that of the Dakota Sandstone.
Based on samples collected from the Burro Canyon Formation at MW-16 (no longer used),
located immediately downgradient of tailings Cell 3, porosity ranges from 2 percent to 29.1
percent, averaging 18.3 percent, and water saturations of unsaturated materials range from 0.6
percent to 77.2 percent, averaging 23.4 percent. Titan reported (Titan, 1994a) that the hydraulic
conductivity of the Burro Canyon Formation ranges from 1.9E-07 to 1.6E-03 cm/s, with a
geometric mean of 1.1E-05 cm/s, based on the results of 12 pump/recovery tests performed in
monitoring wells and 30 packer tests performed in borings prior to 1994.

Subsequent hydraulic testing of perched zone wells has yielded a range of 2E-07 to 0.01 cm/s
(HGC, 2010b). In general, the highest permeabilities and well yields are immediately northeast
and east (upgradient to cross gradient) of the tailings cells. A relatively continuous, higher
permeability zone has been inferred to exist in this portion of the site. Analysis of drawdown
data collected from this zone during long-term pumping of MWH-4, MW-26 (TW4-15), and
TW4-19 yielded estimates of hydraulic conductivity ranging from 4E-05 to 1E-03 cm/s. The
decrease in perched zone permeability to the south to southwest of this area indicates that this
higher permeability zone “pinches out” to the south and southwest.

Permeabilities downgradient of the tailings cells are generally low. Hydraulic tests at wells
located at the downgradient edge of the cells, and south and southeast of the cells yielded
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Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

geometric average hydraulic conductivities of 2.3E-05 and 4.3E-05 cm/s depending on the
testing and analytical methods. The low permeabilities and shallow hydraulic gradients
downgradient of the tailings cells result in average perched groundwater pore velocity estimates
that are among the lowest on site (approximately 1.7 ft/yr to 3.2 ft/yr based on calculations
presented in HGC, 2009a).

Because of the generally low permeability of the perched zone beneath the site, well yields are
typically low (less than 0.5 gpm), although yields of as much as 4 gpm are possible in wells
intercepting larger saturated thickness and higher permeability zones on the east side of the site.
Sufficient productivity can generally be obtained only in areas where the saturated thickness is
greater, which is the primary reason that the perched zone has been used on a limited basis as a
water supply to the north (upgradient) of the site, but has not been used downgradient of the site.

1.5.1.4 Perched Groundwater Flow

Perched groundwater flow at the site is generally to the south/southwest. Figure 1.5-3 displays
the local perched groundwater elevation contours at the Mill, as measured in the second quarter
of 2010. A local depression of the perched water table occurs near wells MW-4, TW4-4, TW4-
19, TW4-10, and MW-26. These wells are pumped to reduce chloroform mass in the perched
zone east and northeast of the tailings cells. As shown in Figure 1.5-3, the perched groundwater
gradient changes from generally southwesterly in the western portion of the site to generally
southerly in the eastern portion of the site. Perched zone hydraulic gradients currently range
from a maximum of approximately 0.08 ft/ft east of tailings Cell 2 (near pumping well TW4-4)
to approximately 0.01 ft/ft downgradient of the tailings cells.
1.5-3
EXPLANATION
Perched Monitoring Well
Ruin t pring Seep or Spring
..,... Estimated Dry Area (Kriged
Brushy Basin Surface >
Kriged Perched Water Surface)
NOTES: MW-4, TW4-4, TW4-15 (MW-26), TW4-19 and TW4-20 are pumping wells;
Water levels for MW-33, MW-34, MW-35 (installed August 201 0),
are from the 3rd Quarter, 201 0
HYDRO
GEO
CHEM, INC.
2nd QUARTER, 2010 PERCHED WATER
ELEVATION CONTOURS (FEET AMSL)
(generated by kriging data from on-site wells)
APPROVED DATE
SJS
REFERENCE H:/718000/cell4bjuly201 0/
springQ2/phwiQ2.srf
AGURE
Page 1-38
Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

1.5.1.5 Perched Zone Hydrogeology Beneath and Downgradient of The Tailings Cells

Perched water, as of the 2nd Quarter, 2010, ranged from depths of approximately 16 feet in the
northeastern portion of the site (adjacent to the wildlife ponds) to approximately 117 feet at the
southwest margin of Cell 3 (Figure 1.5-4). The saturated thickness of the perched zone as of the
2nd Quarter, 2010 ranged from approximately 93 ft in the northeast portion of the site to less
than 6 ft in the southwest portion of the site (Figure 1.5-5). The relatively large saturated
thicknesses in the northeastern portion of the site are likely related to seepage from the wildlife
ponds located northeast and east of the tailings cells.

Perched zone hydraulic gradients currently range from a maximum of approximately 0.05 feet
per foot (ft/ft) east of Cell 2 to approximately 0.01 ft/ft downgradient of Cell 3, between Cell 3
and MW-20. The average hydraulic gradient between the downgradient edge of tailings Cell 3
and Ruin Spring was approximated by HGC to be approximately 0.012 ft/ft. HGC also
estimated a hypothetical worst case average perched zone hydraulic gradient, assuming the
perched water elevation to be coincident with the base of tailings Cell 3, to be approximately
0.019 ft/ft (HGC, 2009a).

HGC also estimated the average permeability of the perched zone downgradient of tailings Cell
3, based on pump/recovery test and slug test data obtained from perched zone wells located
along the downgradient edge of and south of Cell 3, to be between 2.3E-05 cm/s and 4.3E-05
cm/s (HGC, 2009a).

1.5-4
EXPLANATION
1 0 Depth to Perched Water (feet)
Ruin Spring 6 Seep or Spring
_, \
Cell #1 ·
~---~
NOTE: Depths to water for MW-34 and MW-35 (installed August 201 0), are from the 3rd Quarter, 2010
HYDRO
GEO
CHEM,INC.
2nd QUARTER, 2010 DEPTHS TO PERCHED WATER
WHITE MESA SITE
APPROVED DATE
SJS
REFERENCE H:/718000/cell4bjuly2010/
springQ2/phdtwQ2.srf
FIGURE
1.5-5
12
EXPLANATION
Perched Zone Saturated
Thickness (feet)
Ruin Spring
~ Seep or Spring
59
I 59
44 23
70 ·54 31
42
79 '\: 83 93
. -~ \
Cell #1 ·
i -.-...__ .
NOTE: Saturated thicknesses for MW-34 and MW-35 (installed August 201 0), are from the 3rd Quarter, 2010
HYDRO
GEO
CHEM,INC. APPROVED
SJS
2nd QUARTER, 2010 PERCHED ZONE
SATURATED THICKNESS
WHITE MESA SITE
DATE REFERENCE H:/718000/cell4bjuly201 01
springQ2/phsatQ2.srf
FIGURE
Page 1-41
Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

1.5.2 Seep and Spring Occurrence and Hydrogeology

In response to Part I.H, Section 10 of the GWDP, the HGC 2010 report discusses the
hydrogeology of the seeps and springs at the margins of Mill, and the relationship of these seeps
and springs to the hydrogeology of the site. The following paragraphs are excerpted from HGC
(2010b).

All seeps and springs examined have associated cottonwood trees that suggest a relatively
consistent source of water. Seeps and springs occurring at the margins of White Mesa are
typically associated with sandstones of the Burro Canyon Formation, except Cottonwood Seep,
associated with the lower portion of the Brushy Basin Member of the Morrison Formation.
Figure 1.5-6 shows the December 2009 surveyed locations of seeps and springs and the Frog
Pond. As shown on Figure 1.5-6, all springs and seeps are located within drainages, and except
for Cottonwood Seep, are located at the mesa margins. Table 1.5-1 provides surveyed locations
and elevations of the seeps and springs and the Frog Pond. The December, 2009 seep and spring
survey data shown in Table 1.5-1 will be used in all future reporting where seep and spring
locations and elevations are relevant.

Table 1.5-1
Surveyed Locations and Elevations of Seeps and Springs and the Frog Pond
(December, 2009)
Location Latitude (N) Longitude (W) Elevation
FROG POND 37°33'03.5358" 109°29'04.9552" 5589.56
CORRAL CANYON 37°33'07.1392" 109°29'12.3907" 5623.97
ENTRANCE 37°32'01.6487" 109°29'33.7005" 5559.71
CORRAL SPRINGS 37°29'37.9192" 109°29'35.8201" 5383.35
RUIN SPRING 37°30'06.0448" 109°31'23.4300" 5380.03
COTTONWOOD 37°31'21.7002" 109°32'14.7923" 5234.33
WEST WATER 37°31'58.5020" 109°31'25.7345" 5468.23
Re-Surveyed July 2010
RUIN SPRING 37°30'06.0456" 109°31'23.4181" 5380.01
COTTONWOOD 37°31'21.6987" 109°32'14.7927" 5234.27
WEST WATER 37°31'58.5013" 109°31'25.7357" 5468.32







CORRAL CANYON
5624
CORRAL SPRINGS
5383
COTTONWOOD
5234
ENTRANCE SPRING
5560
FROG POND
5590
RUIN SPRING
5380
WESTWATER
5468
Approved Date Author Date File Name Figure
+<'52
*(2
&+(0,1&
SEEPS AND SPRINGS
ON USGS TOPOGRAPHIC BASE
WHITE MESA
7180002G09/17/10SJS 707/16/10DRS
0.5 0 0.5 10.25
Mile
Cell No. 1
Cell No. 3
Cell No. 2
Cell No. 4A
-K:\718000\GIS\7180002G.mxd: Friday, September 17, 2010 1:02:59 PM
Cell No. 4B
WESTWATER
5468
Seep or Spring
Elevation (feet) above mean sea level 1.5-6
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Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

Figure 1.5-3 shows second quarter 2010 perched water level contours and the locations of seeps
and springs on an aerial photographic base. These contours are based on water levels measured
in the perched groundwater monitoring wells shown in the figure, and do not include elevations
of the seeps. Based on Figure 1.5-3, Corral Canyon Seep is located upgradient of the tailings
cells, and Entrance Spring and Corral Springs are located cross gradient of the tailings cells.
Both Entrance Spring and Corral Springs are separated from the tailings cells by a groundwater
divide. Ruin Spring is located downgradient of the tailings cells, and Westwater Seep appears to
be cross gradient of the tailings cells. Cottonwood Seep is neither cross gradient nor
downgradient of the tailings cells because it is interpreted to receive water from a source other
than the perched groundwater system hosted by the Burro Canyon Formation.

The relationship between seeps and springs and the geology of White Mesa are shown in Figure
1.5-7. The geology in Figure 1.5-7 is based on Kirby (2008) and Hintze, et al. (2000), and has
been modified locally by field reconnaissance. The Burro Canyon Formation and the Dakota
Sandstone are undifferentiated on the geologic map. As shown on Figure 1.5-7, all seeps and
springs except Cottonwood Seep are associated with outcrops of the Burro Canyon Formation
(and/or Dakota Sandstone). Some are also associated with mixed eolian and alluvial deposits
stratigraphically above the Burro Canyon Formation and/or Dakota Sandstone. Ruin Spring and
Westwater Seep are located at the contact between the Burro Canyon Formation and underlying
Brushy Basin Member. Westwater Seep (where typically sampled) occurs within alluvium at the
Burro Canyon Formation/Brushy Basin Member contact whereas Ruin Spring occurs at the
contact but above the alluvium in the associated drainage. Corral Canyon Seep, Entrance Spring,
and Corral Springs occur within alluvium near the contact of the alluvium with the Burro
Canyon Formation, but at an elevation above the contact between the Burro Canyon Formation
and Brushy Basin Member. In contrast, Cottonwood Seep is mapped within the Brushy Basin
Member, approximately 1,500 feet west of the contact of the Burro Canyon Formation and
Brushy Basin Member, and stratigraphically approximately 200 feet below the contact. The
0.5 0 0.5 10.25
Mile







Cell No. 1
Cell No. 2
Cell No. 3
Cell No. 4A
4K4OEE
4OEE
4OEE
4OEE
.GEF
.GEF
.GEF
.GEF
.GEF
.GEF
.GEF
-PEE
-PEE
-PEE
-PEE
-PEE
-PEE
-PEE
4HD
4HD
4HD
4HD
4D
4D
4D
4D
4D
.GEF
.GEF
-PEE
4D
.GEF
Cell No. 4B
CORRAL CANYON
CORRAL SPRINGS
COTTONWOOD
ENTRANCE SPRING
FROG POND
RUIN SPRING
WESTWATER
Approved Date Author Date File Name Figure
+<'52
*(2
&+(0,1&
GEOLOGIC MAP
ON USGS TOPOGRAPHIC BASE
WHITE MESA
7180005G09/09/10SJS 07/27/10DRS-K:\718000\GIS\7180005G.mxd: Tuesday, September 14, 2010 12:53:25 PM
8
Contact - dashed where uncertain
EXPLANATION
Tailings cell
Artificial cut and fill
Stream alluvium
Slumps and landslides, Brushy Basin
Mixed eolian and alluvial deposits
Dakota Sandstone and Burro Canyon Formation (undifferentiated)
Brushy Basin Member of the Morrison Formation
4HD
-PEE
.GEF
4OEE
4K
4D
1.5-7
Page 1-45
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Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

Burro Canyon Formation does not exist at Cottonwood Seep because it has been eroded.
Cottonwood Seep is interpreted to receive water from a source stratigraphically below the Burro
Canyon Formation and from a hydrogeologic system other than the perched water system at the
site. Westwater Seep, Corral Canyon Seep, Entrance Spring, and Corral Canyon Seep may
receive water from both alluvial and bedrock (perched water) sources. Corral Springs, located
immediately downgradient of a stock pond, may receive water primarily from alluvium
recharged from the stock pond.

Springs occurring within alluvium deposited within drainages cutting the Burro Canyon
Formation may or may not receive a contribution from perched water. Except for Ruin Spring
(and “2nd Seep” immediately to the north of Cottonwood Seep), each spring and seep occurs in
alluvial materials within a drainage that will supply surface water during wet periods and help to
recharge any alluvial materials within the drainage as well as bedrock near the drainage. Any
alluvial materials within the drainage or marginal bedrock that are recharged during precipitation
events will likely, at least temporarily, yield water to the seeps.

The results of the HGC (2010b) investigation show that only Ruin Spring and Westwater Seep
originate at the contact between Burro Canyon Formation and underlying Brushy Basin Member,
that Ruin Spring receives its flow predominantly from perched water, and that Westwater Seep
likely receives a significant portion of its flow from perched water. Coral Canyon Seep,
Entrance Spring, and Corral Springs occur within alluvium in drainages cutting Burrow Canyon
Formation at elevations above the contact between the Burro Canyon Formation and the Brushy
Basin Member. The data presented by HGC (2010b) imply that Westwater Seep is the closest
discharge point west of the tailings cells and Ruin Spring is the closest discharge point south-
southwest of the tailings cells. HGC (2010b) provides additional discussion regarding the
relationship between the perched groundwater system and surrounding seeps, in order to satisfy
requests of the GWDP, however the assumption that the seep or spring elevation is
representative of the perched water elevation is likely to be correct only in cases where the
feature receives most or all of its flow from the perched water, and where the supply is relatively
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Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

continuous (for example, Ruin Spring). The uncertainty that results from including seeps and
springs in the contouring of perched water levels must be considered when interpreting data
presented in HGC (2010b). Although there are uncertainties associated with incorporation of
seep and spring elevations into maps depicting perched water elevations or maps depicting the
Burro Canyon Formation/Brushy Basin Member contact elevations, future perched water
elevation maps will incorporate seep and spring elevations, and future contact elevation maps
will incorporate Westwater Seep and Ruin Spring elevations.

Using the same methodology presented in HGC (2009a), perched water pore velocities and travel
times between the tailings cells and Ruin Spring and between the tailings cells and Westwater
Seep were calculated using second Quarter, 2010 water levels. As discussed in more detail in
HGC (2010b), the calculated travel times between the southeastern corner of Cell 4B to Ruin
Spring ranges from approximately 3,225 to 5,850 years. The calculated travel time between the
southwest corner of Cell 1 to Westwater Seep ranges from approximately 2,330 to 2,890 years.

1.5.3 Groundwater Quality

1.5.3.1 Entrada/Navajo Aquifer

The Entrada and Navajo Sandstones are prolific aquifers beneath and in the vicinity of the site.
Water wells at the site are screened in both of these units, and therefore, for the purposes of this
discussion, they will be treated as a single aquifer. Water in the Entrada/Navajo Aquifer is under
artesian pressure, rising 800 to 900 ft above the top of the Entrada’s contact with the overlying
Summervillle Formation; static water levels are 390 to 500 ft below ground surface.

Within the region, this aquifer is capable of yielding domestic quality water at rates of 150 to 225
gpm, and for that reason, it serves as a secondary source of water for the Mill. Additionally, two
domestic water supply wells drawing from the Entrada/Navajo Aquifer are located 4.5 miles
Page 1-47
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Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

southeast of the Mill site on the Ute Mountain Ute Reservation. Although the water quality and
productivity of the Navajo/Entrada aquifer are generally good, the depth of the aquifer (>1,000 ft
bls) makes access difficult.

Table 1.5-2 is a tabulation of groundwater quality of the Navajo Sandstone aquifer as reported in
the FES and subsequent sampling. TDS ranges from 216 to 1,110 mg/liter in three samples
taken over a period from January 27, 1977, to May 4, 1977. High iron concentrations are found
in the Navajo Sandstone. Because the Navajo Sandstone aquifer is isolated from the perched
groundwater zone by approximately 1,000 to 1,100 ft of materials having a low average vertical
permeability, sampling of the Navajo Sandstone is not required under the Mill’s previous NRC
Point of Compliance monitoring program or under the GWDP. However, samples were taken at
two other deep aquifer wells (#2 and #5) on site (See Figure 1.5-8 for the locations of these
wells), on June 1, 1999 and June 8, 1999, respectively, and the results are included in Table 1.5-
2.

Page 1-48
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Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

Table 1.5-2
Water Quality of the Navajo Sandstone Aquifer in the Mill Vicinity
Parameter
FES, Test Well
(G2R)
(1/27/77 - 3/23/781)
Well #2
6/01/991
Well #5
6/08/991
Field Specific Conductivity
(umhos/cm) 310 to 400
Field pH 6.9 to 7.6
Temperature (ºC) 11 to 22
Estimated Flow m/hr (gpm) 109(20)
pH 7.9 to 8.16
Determination, mg/liter
TDS (@180ºC) 216 to 1110
Redox Potential 211 to 220
Alkalinity (as CaCOS3) 180 to 224
Hardness, total (as CaCO3) 177 to 208
Bicarbonate 226 214
Carbonate (as CO3) 0.0 <1.0 <1.0
Aluminum 0.003 0.058
Aluminum, dissolved <0.1
Ammonia (as N) 0.0 to 0.16 <0.05 <0.05
Antimony <0.001 <0.001
Arsenic, total .007 to 0.014 0.018 <0.001
Barium, total 0.0 to 0.15 0.119 0.005
Beryllium <0.001 <0.001
Boron, total <0.1 to 0.11
Cadmium, total <0.005 to 0.0 <0.001 0.018
Calcium 50.6 39.8
Calcium, dissolved 51 to 112
Chloride 0.0 to 50 <1.0 2.3
Sodium 7.3 9.8
Sodium, dissolved 5.3 to 23
Silver <0.001 <0.001
Silver, dissolved <0.002 to 0.0
Sulfate 28.8 23.6
Sulfate, dissolved (as SO4) 17 to 83
Vanadium 0.003 0.003
Vanadium, dissolved <.002 to 0.16
Manganese 0.011 0.032
Manganese, dissolved 0.03 to 0.020
Chromium, total 0.02 to 0.0 0.005 0.005
Copper, total 0.005 to 0.0 0.002 0.086
Fluoride 0.18 0.18
Fluoride, dissolved 0.1 to 0.22
1 Zero values (0.0) are below detection limits.

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White Mesa Mill Reclamation Plan

Table 1.5-2
Water Quality of the Navajo Sandstone Aquifer in the Mill Vicinity (continued)
Parameter
FES, Test Well
(G2R)
(1/27/77 - 3/23/781)
Well #2
6/01/991
Well #5
6/08/991
Iron, total 0.35 to 2.1 0.43 0.20
Iron, dissolved 0.30 to 2.3
Lead, total 0.02 - 0.0 <0.001 0.018
Magnesium 20.4 21.3
Magnesium, dissolved 15 to 21
Mercury, total <.00002 to 0.0 <0.001 <0.001
Molybdenum 0.001 <0.001
Molybdenum, dissolved 0.004 to 0.010
Nickel <0.001 0.004
Nitrate + Nitrate as N <0.10 <0.10
Nitrate (as N) <.05 to 0.12
Phosphorus, total (as P) <0.01 to 0.03
Potassium 3.1 3.3
Potassium, dissolved 2.4 to 3.2
Selenium <0.001 <0.001
Selenium, dissolved <.005 to 0.0
Silica, dissolved (as SiO2) 5.8 to 12
Strontium, total (as U) 0.5 to 0.67
Thallium <0.001 <0.001
Uranium, total (as U) <.002 to 0.16 0.0007 0.0042
Uranium, dissolved (as U) <.002 to 0.031
Zinc 0.010 0.126
Zinc, dissolved 0.007 to 0.39
Total Organic Carbon 1.1 to 16
Chemical Oxygen Demand <1 to 66
Oil and Grease 1
Total Suspended Solids 6 to 1940 <1.0 10.4
Turbidity 5.56 19.1
Determination (pCi/liter)
Gross Alpha <1.0
Gross Alpha + precision 1.6+1.3 to 10.2+2.6
Gross Beta <2.0
Gross Beta + precision 8+8 to 73+19
Radium 226 + precision 0.3+0.2
Radium 228 <1.0
Ra–226 + precision 0.1+.3 to 0.6+0.4
Th–230 + precision 0.1+0.4 to 0.7+2.7
Pb–210 + precision 0.0+4.0 to 1.0+2.0
Po–210 + precision 0.0+0.3 to 0.0+0.8
Source: Adapted from FES Table 2.25 with additional Mill sampling data
1 Zero values (0.0) are below detection limits.

1: ~ E D u • ~ ~ i ~ ~ 1
18 16
19 23
~A~~ .. • I
j·'[ ~' !.~ ~ j ~. ·. ) r, •. 21 26 .,.J ·~. 30 I : -: ... r._ 28 ~·,· :\.
• • J
'.•~ ~ . . ,~ ~ .
·, •• ~ ,.,.-' •' /MILL ,~~~·}· ~:· I
• • .J
I
)
\ \
,.. / • I CELL NO. 1 lL SITEn ~ G2R \ ... ~--i J ~ ;; J •
.A,G4R
PROPERTY BOUNDARY
RESERVATION BOUNDARY
CANYON RIM
GROUNDWATER (WELL OR SPRING)
SAMPLING LOCATION
5+ WATERSUPPLYWELL
N
1,500' 0 1,500' 3,000'
•
~
i
i
·'
Denison Mines (USA) Corp OENISOJ)~~
MINES
REVISIONS Project: White Mesa Mill
Date By County: san Juan I :O'Iate: UT
09-11 GM Location:
1-----+----t GROUNDWATER (WELL OR SPRING) SAMPLING
STATIONS IN THE WHITE MESA VICINITY
!i iL-----------------------------------------------------~u~m~~~FL-_.~-~~·b~m~--T~~-=~~~~g~2-~._~T-0~---~-=o-.S-Ied-d_. FIGURE 1.5-8
SCALE: 1" = 3,000'
Page 1-51
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Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

1.5.3.2 Perched Groundwater Zone

Perched groundwater in the Dakota/Burro Canyon Formation is used on a limited basis to the
north (upgradient) of the site because it is more easily accessible. The quality of the Burro
Canyon perched water beneath and downgradient from the site is poor and extremely variable.
The concentrations of TDS measured in water sampled from upgradient and downgradient wells
range between approximately 600 and 5,300 mg/1. Sulfate concentrations measured in three
upgradient wells varied between 670 and 1,740 mg/l (Titan, 1994a). The perched groundwater
therefore is used primarily for stock watering and irrigation. The saturated thickness of the
perched water zone generally increases to the north of the site. See Section 1.5.3 below for a
more detailed discussion of background ground water quality in the perched aquifer.

1.5.4 Background Groundwater Quality in the Perched Aquifer

A significant amount of historic groundwater quality data had been collected by Denison and
previous operators of the Mill for many wells at the facility.

At the time of original issuance of the GWDP, the Executive Secretary had not yet completed an
evaluation of the historic data, particularly with regard to data quality, and quality assurance
issues. The Executive Secretary also noted several groundwater quality issues that needed to be
resolved prior to a determination of background groundwater quality at the site, such as a number
of constituents that exceeded their respective Groundwater Quality Standard (“GWQS”) and
long term trends in uranium in downgradient wells MW-14, MW-15 and MW-17, and a spatial
high of uranium in those three downgradient wells.

As a result of the foregoing, the Executive Secretary required that an Existing Well Background
Report be prepared to address and resolve these issues. Prior to the approval of the Existing
Well Background Report, Ground Water Compliance Levels (“GWCLs”) were set in Table 2 of
the GWDP as 0.25 and 0.5 time the GWQS for Class II and III groundwater respectively.
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Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

Denison submitted the Existing Well Background Report to the Executive Secretary. The
Executive Secretary reviewed the Background Reports and GWCLs that reflect background
groundwater quality have been set for all monitoring wells except newly installed MW-35, MW-
36, and MW-37. In the case of MW-35, MW-36 and MW-37, background data are being
collected for the establishment of GWCLs that reflect background groundwater quality. The
Background Reports were prepared by INTERA, Inc. (“INTERA”).

As required by the GWDP, the Existing Well Background Report addressed all available historic
data, which included pre-operational and operational data, for the compliance monitoring wells
under the GWDP that were in existence at the date of issuance of the GWDP. The Regional
Background Report focuses on all pre-operational site data and all available regional data to
develop the best available set of background data that could not conceivably have been
influenced by Mill operations. The New Well Background Report, which is required by Part
I.H.4 of the GWDP, analyzes the data collected from the new wells (MW-3A, MW-23, MW-24,
MW-25, MW-27, MW-28, MW-29, MW-30 and MW-31), which were installed in 2005, to
determine background concentrations for constituents listed in the GWDP for each new well.

The purpose of the Existing Well Background Report and the New Well Background Report was
to satisfy several objectives: first, in the case of the Existing Well Background Report, to
perform a quality assurance evaluation and data validation of the existing and historical on-site
groundwater quality data in accordance with the requirements of Part I.H.3 of the GWDP, and to
develop a database consisting of historical groundwater monitoring data for “existing” wells and
constituents.

Second, in the case of the New Well Background Report, to compile a database consisting of
monitoring results for new wells, which were collected subsequent to issuance of the GWDP, in
accordance with the Mill’s Groundwater Quality Assurance Plan (“QAP”) data quality
objectives.

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Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

Third, to perform a statistical, temporal and spatial evaluation of the existing well and new well
data bases to determine if there have been any impacts to groundwater from Mill activities.
Since the Mill is an existing facility that has been in operation since 1980, such an analysis of
historic groundwater monitoring data was required in order to ensure that the monitoring results
to be used to determine background groundwater quality at the site and GWCLs have not been
impacted by Mill activities.

Finally, in the event the analysis demonstrates that groundwater has not been impacted by Mill
activities, to develop a GWCL for each constituent in each well.

The Regional Background Report was prepared as a supplement to the Existing Well
Background Report to provide further support to the conclusion that Mill activities have not
impacted groundwater.

In evaluating the historic data for the existing wells, INTERA used the following approach:

 If historic data for a constituent in a well do not demonstrate a statistically significant
upward trend, then the proposed GWCL for that constituent is accepted as representative
of background, regardless of whether or not the proposed GWCL exceeds the GWQS for
that constituent. This is because the monitoring results for the constituent can be
considered to have been consistently representative since commencement of Mill
activities or installation of the well; and

 If historic data for a constituent in a monitoring well represent a statistically significant
upward trend or downward trend in the case of pH, then the data is further evaluated to
determine whether the trend is the result of natural causes or Mill activities. If it is
concluded that the trend results from natural causes, then the GWCL proposed in the
Existing Well Background Report will be appropriate.
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After applying the foregoing approach, INTERA concluded that, other than some detected
chloroform and related organic contamination at the Mill site, which is the subject of a separate
investigation and remedial action, and that is the result of pre-Mill activities, there have been no
impacts to groundwater from Mill activities.

In reaching this conclusion, INTERA noted that, even though there are a number of increasing
trends in various constituents at the site, none of the trends are caused by Mill activities, for the
following reasons:

 Chloride is unquestionably the best indicator parameter, and there are no significant
trends in chloride in any of the wells;

 There are no noteworthy correlations between chloride and uranium in wells with
increasing trends in uranium, other than in upgradient wells MW-19 and MW-18, which
INTERA concluded are not related to any potential tailings seepage. INTERA noted that
it is inconceivable to have an increasing trend in any other parameter caused by seepage
from the Mill tailings without a corresponding increase in chloride;

 There are significant increasing trends upgradient in MW-1, MW-18 or MW-19 in
uranium, sulfate, TDS, iron, selenium, thallium, ammonia and fluoride and far
downgradient in MW-3 in uranium and selenium, sulfate, TDS and pH (decreasing
trend). INTERA concluded that this provides very strong evidence that natural forces at
the site are causing increasing trends in these constituents (decreasing in pH) in other
wells and supports the conclusion that natural forces are also causing increasing trends in
other constituents as well; and

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White Mesa Mill Reclamation Plan

 On a review of the spatial distribution of constituents, it is quite apparent that the
constituents of concern are dispersed across the site and not located in any systematic
manner that would suggest a tailings plume.

INTERA concluded that, after extensive analysis of the data, and given the conclusion that there
have been no impacts to groundwater from Mill activities, the proposed GWCLs set out in Table
16 of the Existing Well Background Report are appropriate, and are indicative of background
ground water quality. INTERA did advise, however, that proposed GWCLs for all the trending
constituents should be re-evaluated upon GWDP renewal to determine if they are still
appropriate at the time of renewal.

In evaluating the new well data, INTERA used the same approach in the New Well Background
Report that was used in the Existing Background Report for existing well data. In addition,
INTERA compared the groundwater monitoring results for the new wells to the results for the
existing wells analyzed in the Existing Well Background Report and to the pre-operational and
regional results analyzed in the Regional Background Report. This was particularly important
for the new wells because there is no historic data for any constituents in those wells that goes
back to commencement of Mill operations. A long-term trend in a constituent may not be
evident from the available data for the new wells. By comparing the means for the constituents
in the new wells to the results for the existing wells and regional background data, INTERA was
able to determine if the concentrations of any constituents in the new wells are consistent with
background at the site.

INTERA concluded that after applying the foregoing approach, there have been no impacts to
groundwater in the new monitoring wells from Mill activities. INTERA concluded that the
groundwater monitoring results for the new wells are consistent with the results for the existing
wells analyzed in the Existing Well Background Report and for the pre-operational and regional
wells, seeps and springs analyzed in the Regional Background Report. INTERA noted that there
Page 1-56
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Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

were some detections of chloroform and related organic contamination and degradation products
and nitrate and nitrite in the new wells, which are the subject of a separate investigation, but that
such contamination was the result of pre-Mill activities.

As a result, given its conclusion that there have been no impacts to groundwater from Mill
activities, INTERA concluded that the proposed GWCLs for new wells set out in Table 10 of the
New Well Background Report are appropriate, and are indicative of background ground water
quality. Again, INTERA noted that GWCLs for trending constituents should be re-evaluated
upon GWDP renewal to determine if they are still appropriate at the time of renewal.

During the course of discussions with Denison staff, and further DRC review, DRC decided to
supplement the analysis provided in the Background Reports by commissioning the University of
Utah to perform a geochemical and isotopic groundwater study at the Mill. This resulted in the
University of Utah completing a study entitled Summary of work completed, data results,
interpretations and recommendations for the July 2007 Sampling Event at the Denison Mines,
USA, White Mesa Uranium Mill Near Blanding Utah, May 2008, prepared by T. Grant Hurst and
D. Kip Solomon, Department of Geophysics, University of Utah (the “University of Utah
Study”). The purpose of the University of Utah Study was to verify if the increasing and
elevated trace metal concentrations (such as uranium) found in the monitoring wells at the Mill
were due to potential leakage from the on-site tailings cells. To investigate this potential
problem, the study examined groundwater flow, chemical composition, noble gas and isotopic
composition, and age of the on-site groundwater. Similar evaluations were also made on
samples of the tailings wastewater and nearby surface water stored in the northern wildlife ponds
at the facility. Fieldwork for the University of Utah Study was conducted July 17 - 26 of 2007.
The conclusions in the University of Utah Study supported Denison’s conclusions in the
Background Reports.

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Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

1.5.5 Quality of Ground Water at the Compliance Monitoring Point

All of the analytical results from groundwater sampling are reported quarterly in Groundwater
Monitoring Reports, which are filed with the Executive Secretary pursuant to Part I.F.1 of the
GWDP.

1.5.6 Springs and Seeps

As discussed in Section 1.5.1.4, perched groundwater at the Mill site discharges in springs and
seeps along Westwater Creek Canyon and Cottonwood Canyon to the west-southwest of the site,
and along Corral Canyon to the east of the site, where the Burro Canyon Formation outcrops.
Water samples have been collected and analyzed from springs and seeps in the Mill vicinity as
part of the baseline field investigations reported in the 1978 ER (See Table 2.6-6 in the 1978
ER).

During the period 2003-2004, Denison implemented a sampling program for seeps and springs in
the vicinity of the Mill which had been sampled in 1978, prior to the Mill’s construction. Four
locations were designated for sampling (shown on Figure 1.5-8). These are Ruin Spring (G3R),
Cottonwood Seep (G4R), west of Westwater Creek (G5R) and Corral Canyon (G1R). During
the 2-year study period only two of the four locations were able to be sampled, Ruin Spring and
Cottonwood Canyon. The other two locations, Corral Creek and the location west of Westwater
Creek were not flowing (seeping) and samples could not be collected. With regard to the
Cottonwood seep, while water was present, the volume was not sufficient to complete all
determinations, and only organic analyses were conducted. The results of the organic analysis
did not detect any detectable organics.

Samples at Ruin Spring were analyzed for major ions, physical properties, metals, radionuclides,
volatile and semi-volatile organic compounds, herbicides and pesticides, and synthetic organic
compounds. With the exception of one chloromethane detection, all organic determinations were
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Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

at less than detectable concentrations. The detection of chloromethane is not uncommon in
groundwater and can be due to natural sources. In fact, chloromethane has been observed by
Denison at detectable concentrations in field blank samples during routine groundwater sampling
events.

The results of the 2003/2004 sampling for the other parameters tested are shown in Table 1.5-3.
The results of the sampling did not indicate the presence of Mill derived groundwater
constituents and are representative of background conditions.

Table 1.5-3
Results of Quarterly Sampling Ruin Spring (2003-2004)
Parameter Ruin Spring
Q1-03 Q2-03 Q3-03 Q4-3 Q1-04 Q2-04 Q3-04 Q4-04
Major Ions (mg/L)
Alkalinity - - 196 198 193 191 195 183
Carbon Dioxide - - ND ND ND ND 12 ND
Carbonate - - ND ND ND ND ND ND
Bicarbonate - - 239 241 235 232 238 223
Hydroxide - ND ND ND ND ND ND
Calcium 153 156 149 158 158 162 176 186
Chloride 28.1 21.5 27.4 28.0 29.3 28.5 26 25
Fluoride - - ND 0.5 0.5 0.6 0.6 0.6
Magnesium 34.8 34.2 31.7 34.2 35.8 35.1 37.1 38.6
Nitrogen, Ammonia As N ND ND ND ND ND 0.06 ND 0.06
Nitrogen, Nitrate+Nitrite as N 1.6 1.5 1.4 1.4 1.73 1.85 1.34 1.7
Phosphorous 0.10 ND - ND ND ND ND ND
Potassium 2.6 3.3 3.3 3.9 3.4 3.6 4.0 3.7
Sodium 110 105 103 113 104 110 113 116
Sulfate 503 501 495 506 539 468 544 613
Physical Properties
Conductivity (umhos/cm) - - 1440 1410 1390 1440 1320 1570
pH - - 7.91 7.98 - - -
TDS (mg/L) - - 1040 1000 1050 1110 1050 1070
TSS (mg/L) - - 13.5 ND ND ND ND ND
Turbidity (NTU) - - 0.16 0.13 ND 0.12 - -
Metals-Dissolved (mg/L)
Aluminum ND ND 0.40 ND ND ND ND ND
Antimony ND ND ND ND ND ND ND ND
Arsenic 0.001 ND ND 0.001 ND ND ND ND
Barium ND ND ND ND ND ND ND ND
Beryllium ND ND ND ND ND ND ND ND
Cadmium ND ND ND ND ND ND ND ND
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White Mesa Mill Reclamation Plan

Table 1.5-3
Results of Quarterly Sampling Ruin Spring (2003-2004) (continued)
Parameter Ruin Spring
Q1-03 Q2-03 Q3-03 Q4-3 Q1-04 Q2-04 Q3-04 Q4-04
Major Ions (mg/L)
Chromium ND ND ND ND ND ND ND ND
Copper ND ND 0.082 ND ND ND ND ND
Iron ND ND ND ND ND ND ND ND
Lead ND ND ND ND ND ND ND ND
Manganese ND ND ND ND ND ND ND ND
Mercury ND ND ND ND ND ND ND ND
Molybdenum ND ND ND ND ND ND ND ND
Nickel ND ND ND ND ND ND ND ND
Selenium 0.013 0.012 0.012 0.012 0.012 0.012 0.012 0.012
Silver ND ND ND ND ND ND ND ND
Thallium ND ND ND ND ND ND ND ND
Uranium 0.009 0.011 0.010 0.010 0.011 0.011 0.009 0.010
Vanadium ND ND ND ND ND ND ND ND
Zinc 0.014 ND ND ND ND ND ND ND
Radionuclides (pCi/L)
Gross Alpha Minus Rn & U - - - - ND ND 1.4 ND
Lead 210 42 ND ND ND ND ND ND ND
Radium 226 0.3 ND 0.3 ND ND ND 1.3 ND
Thorium 230 0.3 0.2 0.5 ND ND ND 0.4 ND
Thorium 232 - - ND ND ND ND ND -
Thorium 228 - - ND ND ND ND - -
Source: Table 3.7-9 of 2007 ER.

During 2009, the Mill implemented an annual sampling program for seeps and springs. The
seeps and springs sampling program is included in the Sampling Plan for Seeps and Springs in
the Vicinity of the White Mesa Uranium Mill Revision: 0, March 17, 2009 (and as submitted to
UDEQ for approval, Draft Sampling Plan for Seeps and Springs, Revision 1, June 10, 2011).
The annual sampling program for seeps and springs requires sampling once per year at the four
seeps and springs described above, plus a fifth seep, Corrals Seep, to the extent water flow is
sufficient for sampling. Samples were collected in July 2009, August and November 2010, and
May and July 2011 Under the Plan only springs and seeps that had sufficient water flow for
sampling. The results of the annual sampling are shown in Table 1.5-4.

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Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

Table 1.5-4
Seeps and Springs Sampling
Constituent Ruin Spring Ruin Spring Duplicate Cottonwood Spring Entrance Spring Westwater Seep
Major Ions (mg/L) 09 10 11 09 10 11 09 10 11 09 10 11 09 10 11
Carbonate ND <1 1 ND <1 2 ND <1 6 ND <1 7 <1 <1 <1
Bicarbonate 233 254 239 232 254 236 316 340 316 282 332 299 465 450 371
Calcium 151 136 148 149 137 147 90.3 92.2 94.2 90.8 96.5 96.6 191 179 247
Chloride 28 23 44 27 23 27 124 112 134 60 63 64 41 40 21
Fluoride 0.5 0.53 0.5 0.5 0.51 0.49 0.4 0.38 0.38 0.7 0.73 0.58 0.7 0.6 0.54
Magnesium 32.3 29.7 31.1 31.6 30.4 30.9 25.0 24.8 25.2 26.6 28.9 28.4 45.9 44.7 34.7
Nitrogen, Ammonia As N 0.09 <0.05 <0.05 ND <0.05 <0.05 ND <0.05 <0.05 0.28 <0.05 0.32 <0.05 0.5 0.06
Nitrogen, Nitrate+Nitrite as N 1.4 1.7 1.6 1.4 1.7 1.7 0.1 <0.1 <0.1 1.4 1 0.5 0.8 <0.1 <0.1
Potassium 3.3 3.07 3.3 3.2 3.08 3.3 5.7 5.77 5.9 2.4 2.74 2.9 1.19 6.57 3.9
Sodium 104 93.4 111 103 97.4 108 205 214 227 61.4 62.7 68.6 196 160 112
Sulfate 528 447 484 520 444 483 383 389 389 178 179 171 646 607 354
Physical Properties
pH 7.85 7.51 8.14 7.7 7.55 8.10 7.73 7.47 8.04 7.85 7.56 8.17 8.01 7.38 7.20
TDS (mg/L) 1010 903 905 996 950 911 1010 900 978 605 661 582 1370 1270 853
Metals-Dissolved (ug/L)
Arsenic ND <5 <5 ND <5.0 <5.0 ND <5 <5 ND <5 <5 <5 <5 12.3
Beryllium ND < 0.5 < 0.5 ND <0.05 <0.05 ND <0.5 <0.5 ND <0.5 <0.5 <0.5 <0.5 0.91
Cadmium ND <0.5 <0.5 ND <0.05 <0.05 ND <0.5 <0.5 ND <0.5 <0.5 <0.5 <0.5 0.90
Chromium ND <25 <25 ND <25 <25 ND <25 <25 ND <25 <25 <25 <25 <25
Cobalt ND <10 <10 ND <10 <10 ND <10 <10 ND <10 <10 <10 <10 <10
Copper ND <10 <10 ND <10 <10 ND <10 <10 ND <10 <10 <10 <10 16
Iron ND <30 <30 ND 36 36 ND <30 <30 ND <30 55 89 56 4540
Lead ND <1.0 <1.0 ND <1.0 <1.0 ND <1.0 <1.0 ND <1.0 <1.0 <1.0 <1.0 41.4
Manganese ND <10 <10 ND <10 <10 ND <10 <10 ND 11 84 37 87 268
Mercury ND <0.5 <0.5 ND <0.05 <0.05 ND <0.5 <0.5 ND <0.5 <0.5 <0.5 <0.5 <0.5
Molybdenum 17 17 17 17 17 17 ND <10 <10 ND <10 <10 29 29 <10
Nickel ND <20 <20 ND <20 <20 ND <20 <20 ND <20 <20 <20 <20 29
Selenium 12.2 10 10.2 12.3 9.5 9.7 ND <5.0 <5.0 ND 9.2 5.5 <5.0 <5.0 <5.0
Silver ND <10 <10 ND <10 <10 ND <10 <10 ND <10 <10 <10 <10 <10
Thallium ND <0.5 <0.5 ND <0.5 <0.5 ND <0.5 <0.5 ND <0.5 <0.5 <0.5 <0.5 <0.5
Tin ND <100 <100 ND <100 <100 ND <100 <100 ND <100 <100 <100 <100 <100
Uranium 9.11 8.47 8.63 9.00 8.52 8.28 8.42 8.24 8.68 ND 17.8 15.3 15.1 46.6 6.64
Vanadium ND <15 <15 ND <15 <15 ND <15 <15 ND <15 <15 <15 <15 34
Zinc ND <10 <10 ND <10 <10 ND <10 <10 ND <10 <10 <10 <10 28
Radionuclides (pCi/L)
Gross Alpha Minus Rn & U <0.2 <0.2 <-0.05 -0.02 <0.3 <-0.1 0.3 <0.2 <-0.1 0.9 <0.5 1.6 < -0.1 <0.3 0.5
Volatile Organic Compounds (ug/l)
Acetone ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND
Benzene ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND
Carbon tetrachloride ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND
Chloroform ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND
Chloromethane ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND
MEK ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND
Methylene Chloride ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND
Naphthalene ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND
Tetrahydrofuran ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND
Toluene ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND
Xylenes ND ND ND ND ND ND ND ND ND ND ND ND ND ND ND
Page 1-61
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Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

1.5.7 Groundwater Appropriations Within a Five Mile Radius

Two hundred sixty one groundwater appropriation applications, within a five-mile radius of the
Mill site, are on file with the Utah State Engineer's office. A summary of the applications is
presented in Table 1.5-5 and shown on Figure 1.5-9. The majority of the applications are by
private individuals and for wells drawing small, intermittent quantities of water, less than eight
gpm, from the Burro Canyon formation. For the most part, these wells are located upgradient
(north) of the Mill site. Domestic water, stock watering, and irrigation are listed as primary uses
of the majority of the wells. It is important to note that no wells completed in the perched
groundwater of the Burro Canyon formation exist directly downgradient of the site within the
five-mile radius. Two water wells, which available data indicate are completed in the
Entrada/Navajo sandstone (Clow, 1997), exist approximately 4.5 miles southeast of the site on
the Ute Mountain Ute Reservation. These wells supply domestic water for the Ute Mountain Ute
White Mesa Community, situated on the mesa along Highway 191 (see Figure 1.5-9). Data
supplied by the Tribal Environmental Programs Office indicate that both wells are completed in
the Entrada/Navajo sandstone, which is approximately 1,200 feet below the ground surface.
Insufficient data are available to define the groundwater flow direction in the Entrada/Navajo
sandstone in the vicinity of the Mill.

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Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan
Table 1.5-4
Water Rights
IN!!er l Diversion I 'i:!1 llstatusl Priority B~I ACFTII Owner Name I Type/Location
Jo9-1006 llunderground II llu ll1977111oi[!Dio.5 oollo.ooo llooROTHY PERKINS I
D
S30 W20 E4 02 37S
DDDDDD
NORTH RESERVOIR 22ESL ROAD (37-1)
109-1008 llunderground II JIT ll19771noi[!Dio.5ool !o.ooo IJARDEN NIELSON I
D
S460 Ell? W4 01 DDDDDDIP.O.BOX#378 I 37S 22E SL
109-1009 ~~Underground IDD~DB8 BARM. K.RANCHES ~ 19771110 I 0.500 0.000 INCORPORATED
D N1200 E990 W4 14 37S 22E SL DDDDDC]P.O.BOX576 I
109-1 009 II Underground I DD~DB8 BARM.K.RANCHES ~ 19771110 I 0.500 0.000 INCORPORATED
D
0 W990 N4 14 37S DDDDDDIP.O.BOX576 I 22ESL
109-1009 ~~Underground IDDil9771110IDio.soollo.ooo I BAR M. K. RANCHES INCORPORATED
D
N990 W990 S4 11 DDDDDDIP.O.BOX576 37S 22E SL
109-101 IIUnderground II:~ IDI1945070211Drs llo.oo411o.ooo II lLo M. BROWN
D
N1275 E2708 SW 01 DDDDDDIBLANDINGUT84535 37S 22E SL
109-1013 IIUnderground II liP II 19771207 IIQ[~]o.msllo.ooo IILEwrs A. BLACK
D N2510E75 S4 34 36S 22E SL DDDDDDIP.O.BOX#403 j
109-1016 !!underground IDDI1978010311Drs llo.soollo.ooo ~~~~~J!i; I
D
N559 0 S4 34 36S DDDDDD ~~6~~RTH 100WEST 22ESL
Jo9-1017 llunderground r1 liP II197801osi[Q[Jio.msJio.ooo IIJoHN BRAKE I D N150 E137 S4 34 36S 22ESL DDDDDDIP.O.BOX#173 I
109-1018 llunderground IDDI1978010411ms llo.o1sllo.ooo ~~~~~~E. I
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White Mesa Mill Reclamation PlanD S2620 W840 NE 36 36S 22E SL DDDDDDIP.O.BOX#ZJ! I lo9-1023 !lunderground II liT II19780126IInis IILooollo.ooo llcALVIN BLACK I D SlO W4000 NE 16 DDDDDDIP.O.BOX#885 I 37S 22E SL
lo9-1023 llunderground II liT jj19780126IIDIS IILooollo.ooo llcALVIN BLACK I D S600 W1320 NE 16 DDDDDDIP.O.BOX#885 I 37S 22E SL
109-103 llunderground II:~ IDI1945ono1Dio.oo311o.ooo ~~~= M. I
D Sl394 E2295 NW 02 DDDDDDIBLANDINGUT845351 37S 22E SL
109-1031 IIUnderground 11:~ IDI1983042siEJio.13611o.ooo 1 COLLEGE OF EASTERN UTAH
D 0 ElOOO SW 23 38S DDDDDDI451 EAST400NORTHI 21ESL
jo9-1032 IIUnderground II liT II19780309jjois 11o.o1s11o.ooo IIBLANDING CITY I D S840 W875 NE 15 DDDDDDIBLANDINGUT845111 37S 22ESL
109-1033 llunderground II:~ IDI1978030911ois llo.Oisllo.ooo I BARRY LEE AND LOREE A. WOOLLEY
D N1050 W1195 SE 10 DDDDDD191 BUTTERNUT 37S 22E SL DRIVE NORTH
109-1042 llunderground II:~ IDI1978ososiEJio.Ois111.450 IIAROE o. BROWN I D N1580 Wl090 SE 01 DDDDDDIBLANDINGUT845111 37S 22E SL
jo9-1043 llunderground II liT II19780505I~I0.015jjo.OOO jjARVID K. BLACK I D S1000 E300 NW 01
DDDDDDisox 339 I 37S 22E SL
109-1044 Jlunderground II liP II19780429I~Io.o1sllo.ooo JIPETE M. BLACK I D S150 E1840 W4 36 36S 22E SL DDDDDDIBOXJS6 I
109-1045 llunderground II:~ IDI197S05041frs llomsllo.ooo IIKENNETH BROWN I
D N1580 W1040 SE 01 DDDDDDIP.O.BOX#637 I 37S 22E SL
109-1047 llunderground II:~ IDI197som llms llomsl§~]v AN Q. JONES I
I IIN105 W1110 E4 02 II II II IDOl 11881 EAST BROWNS I
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Denison Mines (USA) Corp.
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I II37S 22E SL II II II IDOl IICANYON ROAD I
109-1048 llunderground II:~ IC 11197so5u llms llo.ot5 11o.ooo llooRIS GUYMON I
D
N105 WlllO E4 02 DDDDDDIP.O.BOX#117 I 37S 22E SL
109-1057 llunderground I~D~EJB8EUGENE& info P 19780623 DIS 0.015 0.000 DORTHEA GUYMON
D
SlOO W1400 NE 02 DDDDDDisoxu 7 I 37S 22E SL
109-1058 1 Underground DDI19780623I[IIo.toollo.ooo 1 g~;~~
D
N400 W400 E4 02 DDDDDD IBOXll? I 37S 22ESL
109-1059 1 1:~ IDI19780623IIms llo.10ollo.ooo I
EUGENE& Underground DOROTHEA GUYMON
D S100W1400NE02 37S 22E SL DDDDDDisox 117
109-1063 ~~Underground IDDI197808o211Do llo.m511o.ooo ~~~~N~TRUCTION
D
N900 W660 SE 34 DDDDDDIP.O.BOX415 36S 22ESL
lo9-1 071 IIUnderground II liT II 197808241Dio.o15llo.ooo !IJAMES J. HARRIS
D
S600 W1280 E4 36 DDDDDD isox 392 36S 22E SL
109-1090 ~~Underground 11:~ IDI197905211EJio.01511o.ooo 1 GUY DENTON AND PEGGY DENTON
D
N1090 W20 S4 02
DDDDDD
632 EAST BROWNS 37S 22E SL CANYON ROAD
~~Underground II:~ IDI1946041511ois llo.10ollo.ooo IIHENRY M. LYMAN
D
N1305 W1023 E4 03 DDDDDDIBLANDINGUT 84511 37S 22E SL
Jo9-11 00 II underground II IIA IJ197909o4IIQ[Jio.msllo.ooo IJLoYD ROPER
D
N1430 E275 S4 34 DDDDDDIP.O.BOX469 36S 22E SL
109-1110 llunderground I~D~EJBBRICHARDW.& ~nfo P 19830304 DI 0.015 0.000 ARLEEN HURST
I IIN1170 W1000 SE Ol ll II II IDOl IJP.O. BOX 1090 I
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Denison Mines (USA) Corp.
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I II37S 22E SL II II II IDOl I I
I 109-1124 IJunderground II liP JI19860818J~]o.ms llo.ooo IIIoHN BRAKE
D N310 E280 S4 34 36S 22E SL DDDDDDI1300S. 300W. (60-9)
lo9-1128 IJ underground II JIP JI19800310JIDIS Jlo.OlsJIO.OOO IJJAMES A. LAWS
D S1610E560N402 37S 22ESL DDDDDDIP.O.BOX 1210
109-1144 ~~Underground IDDI19800630IIois llo.o1sllo.ooo I LEER. & MARYLYNN SMITH
D
Nl272 E149 S4 34 DDDDDDIP.O.BOX 1169 I 36S 22E SL
109-1145 llunderground IDDI1980063ollois llo.m511o.ooo ~~~~~~NN SMITH I
D
Nl272 E149 S4 34 DDDDDDIP.O.BOX1l 69 I 36S 22E SL
109-1146 llunderground IDDI1980063ollois llo.msllo.ooo I ~~~~NN SMITH
D
N1272 E149 S4 34 DDDDDDIP.O. BOX 1169 36S 22E SL
109-1147 llunderground IDDI1980063ollois llo.msllo.ooo ~~~~~NN SMITH
D
N1272 E149 S4 34 DDDDDD IP.O.BOX 1169 36S 22E SL
109:..1153 ~~Underground IDDI198008251EJio.m511o.ooo ~~~~~i; v. & REVA
D DDDDDD PARLEY ANDREVA N1350 E1150 SW 34 REDDFAMILY 36S 22E SL LNINGTRUST (1981)
r-1156 1 1:~ IDI19800909IIms llo.oi5IIo.ooo I
ALB. CLARKE AND Underground SHIRLEYW. CLARKE
D N2580 W921 S401 DDDDDD 1555 BROWN'S 37S 22E SL CANYON ROAD
109-1157 llunderground IDDI198009121EJio.7ooll511.54~~~~ WlllTE MESA I
D N1200 E280 sw 21 DDDDDD 1050 17TH STREET. 37S 22E SL SUITE 950
109-1157 llunderground IDDI 198009121EJio.7oollm.54011~~ WlllTE MESA I
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D
N200 W200 SE 28
DDDDDD
1050 17TH STREET,
37S 22E SL SUITE950
109-1157 llunderground IDDI 198009121[Jio.7ool ls11.54oll~~ WHITE MESA I
D
N1200 W200 SE 33 DDDDDD1050 17TH STREET, 37S 22E SL SUITE 950
109-1157 ~~Underground IDDI198009121EJio.7ooll511.54oll~~ WHITE MESA I
D
N1200 0 SE 21 37S
DDDDDD
1050 17TH STREET,
22ESL SUITE950
0 1underground IDDI194609o31Dio.oo511o.ooo ~~~~~TMILTON I
D
S150 W925 E4 35
DDDDDD
747 NORTH 300 36S 22E SL WEST (34-2)
jo9-1167 llunderground II liP II19801209I!ois 11o.o121 1o.ooo IILYNDA HARRELSoN!
D
S1430 W270 N4 02 DDDDDDI~:~~TH100 I 37S 22E SL
109-1173 1 Underground 0[11!9swzo21D io.ooo iiJ.ooo ~~~:1~ION INCORPORATED
D
S 1550 W1300 NE 32 DDDDDDictoK&AIHELTON I 38S 22E SL
109-1176 llunderground IDDI198009121EJio.6oo llo.ooo ~~~~~'IIITE MESA I
D N1400 W3000 SE 28 DDDDDD 1050 17TH STREET, 37S 22E SL SUITE 950
109-1176 llunderground II:~ ID I198009121 EJio.6oollo.ooo ~~~~~ITE MESA I
D N1300W2400SE28 DDDDDD 1050 17TH STREET,
37S 22E SL SUITE950
109-1176 ~~Underground II:~ ID I198009121EJio.6oollo.ooo ~~~~~HITE MESA I
D
N2100 W2200 SE 28
DDDDDD
1050 17TH STREET,
37S 22E SL SUITE950
109-1176 ~~Underground IDDI198009121EJio.6oollo.ooo ~~~~~ITE MESA I
D
N1290 W170 SE 33 DDDDDD 1050 17TH STREET, 37S 22E SL SUITE 950
109-1176 llunderground IDDI198009121EJio.6oollo.ooo ~~~~~ITE MESA I
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Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan
D N1000 E650 sw 22
DDDDDD
1050 17TH STREET, 37S 22E SL SUITE950
109-1198 !!underground IDDI1981040611ms llo.orsilo.ooo ~~~~~ALMER I
D
S585 E1460 W4 01
DDDDDD
12 EAST 5TH SOUTH 37S 22E SL 107-5
109-1199 ll underground II liT III98104031Dio.o52llo.ooo IIIVANR. WATKINS I D S2722E310NW01 37S 22E SL DDDDDDIP.O.BOX372 I 109-1201 ll underground II liP III9810416IIDIS 11o.01s11o.ooo II KAREN c. KNIGHT I
D
N100 E1920 W4 36 DDDDDDI2164BLUFFROAD I 36S 22ESL
109-1221 lfnderground IDEJBElBEJ
DENNIS F. AND EDITH G. ANDERSON
D
N760 E1532 W4 02 DDDDDDI1307 SO MAIN I 37S 22ESL
jo9-1225 llunderground II liT III98107o8llois 11o.10o11o.ooo IIDENNIS E. GUYMON I
D N105W1110E402 37S 22E SL DDDDDDIBOX 657 I
109-1227 ''Underground II:~ J[J1198108101DI0.015 IIo.ooo 1
DENNIS F. AND EDITH G. ANDERSON
D
N760 E1532 W4 02
DDDDDD
1307 SOUTH MAIN 37S 22ESL (79-9)
109-123 !!underground II:~ IDI194708221Dio.01511o.ooo IIGEORGEF. LYMAN I
D
N500 E200 SW 15 DDDDDDIBLANDINGUT 84511 1 37S 22E SL
!09-1230 llunderground II liT II I981092II inis llo.oisllo.ooo IIRICHARD ARTHUR I
D
N750 E2390 W4 02 DDDDDDI~;~UTHlOO I 37S 22E SL
jo9-1233 llunderground II liP III9811007 IIDIS llo.ooo[l3.266 IIKIRK BLACK I
D N306 E51 W4 01 DDDDDD1727SOUfH 37S 22E SL ~~y~~3~3
109-1236 I Underground 1:~ [JJ1981110211DIS Jr.01+.000 1
JAMESR. AND CHRISTINA J. BRANDT
I i!S910 E2020 W4 01 II II II IDOl 1!139 SOUTH 100 I
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Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan
I II37S 22E SL II II II IDOl IIWEST (68-2) I
[o9-1238 llunderground [[:~ [[]19811223[EJ[o.DIS[[o.OOO [[ALYCE M. RENTZ I D N1300 ESO S4 01 37S 22E SL DDDDDDBROWNCANYON ROAD 103-8
109-1248 llunderground II liP JI198202o9JEJio.o1sJio.ooo IIREED HURST I
D
S1470 E125 N4 02 DDDDDDI354S.300W.#56 I 37S 22E SL
109-1262 [[underground [[:~~ IDI198208111EJ[o.o1sl[o.ooo [[oERALD B. HEINER I
D
N132 E2244 W4 02 DDDDDDIP.O.BOX 1127 I 37S 22E SL
109-1287 [[underground [[:~ [0[198302o7[[nis [[o.o1s[[o.ooo IIAL viN H. KAER I
D
N476 E2256 W4 02 DDDDDDIP.O. BOX 1133 I 37S 22E SL
109-1290 ~~Underground [00[19830323[EJ[o.o1s[[o.ooo [[~ru:E~E=Es I
D
S932 W363 N4 03 DDDDDDI~u':ST 1600
I 37S 22ESL
[o9-1346 iiunderground [00[198403os[0[o.o1s[[o.ooo [[~=!;vAL. I
D S1321 W1980E415 DDDDDD578 SOUTH 200 37S 22E SL WEST 61-1
[o9-138 [[underground IDDI195005251Dio.Olsiio.ooo II~~.~~ I
D S1326 W1205 E402 DDDDDDI"66 SOUTH 100 37S 22E SL EAST I
109-13% I Underground DDBEJBEJ WINTERSHALL OIL &GAS CORPORATION
D
S2722 E10 NW 01
DDDDDD
1020 15TH STREET, 37S 22E SL SUITE 122E
109-14021 DDBtJBEJ C/0 PERMITCO
Underground WINTERSHALL OIL &GAS CORPORATION
D S2722 EIO NW OJ DDDDDD
1020 15TH STREET, 37S 22ESL SUITE22E
[o9-141 [[underground 1[:~ [0[!9S009Js[0[o.DJs[[o.ooo ~~~~~ M. I
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Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan
D N1287 W448 SE 10
DDDDDDIBLANDINGUT84511 1 37S 22E SL
109-1457 1 DDBEJBEJ WINTERSHALL OIL
Underground &GAS
CORPORATION C/0
PERMIT CO
D S2722 E10 NW 12
DDDDDD
1020 15TH STREET
37S 22E SL SUITE22E
109-1468 ~~Underground IDDI1986041411ois llo.01sllo.ooo ~~~~~I~~. KIRK
D S570 E1458 W4 01 DDDDDDBROWNCANYON 37S 22E SL ROAD (103-9)
109-1477 ~~Underground II:~ IDI199311081EJio.01sllo.ooo IIJOANN WATKINS I D N750 W2180 SE 01 DDDDDDEASTBROWN 37S 22E SL i:NYON ROAD 103-
109-1535 1 D DBEJBEJQUNTANA Underground T 19871013 0 0.000 3.000 PETROLEUM
CORPORATION
D DDDDDD ATTN: LISA GREEN,
S2722 E10 SW 01 AGENT FOR
37S 22E SL QUINTANA
PETROLEUM
109-1548 ~~Underground IDDI198712021EJio oool ls ooo I YATES PETROLEUM . . CORPORATION
D N2558 E10 SW 01 DDDDDDI~~.PERMITS WEST I 37S 22E SL
109-1664 llunderground IDDI1989091311ois llo.01sllo.ooo ~~~T~~gHAM I D N340 W305 SE 34 DDDDDD1244SOUTH100 36S 22E SL EAST (80-1)
109-1673 llunderground I I::~ ID I199405241EJio.01sllo.ooo ~~~~~~LYDE I D S3000 E200 NW 01
DDDDDD
1000BROWNS
37S 22E SL CANYON 103-14
109-1686 I Underground
DDBEJBEJ
GENERAL
ATLANTIC
RESOURCES INC.
D S2722 E10 NW 01 DDDDDDC/OPERMITSWEST 37S 22E SL INC. ATTN: BRIAN
Page 1-70
Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan
I I I II II IDOl IJ wooD I
109-1709 [[underground ID D8DBBGORDONREDD P 19900504 I 0.000 1.120 MANAGEMENT INC.
D N2505 E1629 S4 34 36S 22E SL DDDDDDI~i:~iHMAIN I
[o9-1734 [[underground [00[199010IO[EJ[o.ooo[[2.ooo [ ~~~:~~NERGY
D S2722E10NW01 37S 22E SL DDDDDDI~~.PERMITSWEST I
Jo9-1785 llunderground II II A JI 19911031 JJ ors llo.woiJo.ooo IIBERTHA SNYDER I
D
S200 E800 W4 01
DDDDDD
409 EAST 1000 37S 22E SL NORTH
109-1794 [[underground [[:~ [0[19920313[EJ[o.wo[[o.ooo [[JAMES D. REDD
D N1115 E2320 sw 02 37S 22E SL DDDDDDI~::AFEHEIGHTS
[o9-180 1 [[underground IDDI199207141EJio.ooo[[9.000 II~~L~2·
D
S2722 ElO NW 01 DDDDDO[c;oBILLYHAss 37S 22E SL
109-1822 llunderground I I:~ IDI199303151E}·oo+.730 l=i~::ND
D
S250 W250 NE 03 DDDDDDI1307 SOUTH MAIN I 37S 22E SL
109-1843 [[underground [[:~ [0[19940323[[DIS [[o.ooo[[Ls6o [[JEROLD PERKINS I D S201 E1530 NW 03 DDD DDD 1092 EAST BROWNS 37S 22E SL CANYON ROAD (103-18)
109-1844 [[underground [[:~ [0[19940331[EJ[o.ooo[[3.760 ~~~~~oN KIRK I
D N2125 E846 SW02 DDDDDD292 WEST CENTER 37S 22E SL STREET BOX 67-7
[o9-1845 [[underground [00[19940331[[~_]o.ooo[[3.760 [[=;oN KmK I
D N1115 E1220 sw 02 DDDDDD 292 WEST CENTER 37S 22E SL STREET BOX 67-7
109-1848 [[underground ~~~~~ 1[][1994041li[Jio.ooollo.750 I[M. DALE SLADE I
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Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan
D N35 E40 SW 04 37S
DDDD DD
332 WEST400
23ESL SOUTH (64-5)
109-1862 llunderground IDDI19950ttsi[~Jio.soollo.ooo ~~~g~[;;;5' I
D N200 W2250 E4 36 DDDDDD 36 EAST 500 SOUTH 36S 22E SL (77-15)
109-1875 llunderground IDDI1995041711nis llo.oooii4.730 ~~~~~~~;ANDRA I
D N2105 W235 SE 34 DDDDDD686 NORTH 36S 22E SL DAYBREAK DRIVE
lo9-1878 Jlunderground II liP jj1995oso5jiC)Io.oooj iL68o II BRUCE J. LYMAN I
D S92 W2566 E4 33
DDDDDD
SHIRT AIL JUNCTION
36S 23E SL (105-7)
109-1880 llunderground II:~ IDI1995062oiiDis llo.oooii4.730 I MITCHELL H. &
JANA L. BAILEY
D S945 E1095 NW 15
DDDDDD
SHIRT AIL CORNER
37S 22E SL 105-14
109-1886 ~~Underground II:~ IDI1995080711nis llo.oooll l.730 ~~~~~N ~oWN I
D N868 W1260 SE01 DDDDDDBROWN'S CANYON 37S 22E SL ROAD (103-16)
109-1912 ~~Underground II:~ IDI199605211EJio.oooii4.730 IITHOMAS A. MAY I D N500 W545 S4 02 DDDDDD2202SOUTHClliCO 37S 22E SL CEDROS ROAD (104-8)
lo9-193 II underground II liP II19560316IICJio.msllo.ooo IIALMA u. JONES I
D S50 W1420 E4 33 DDDDDDIBLANDINGUT84511 1 37S 22E SL
109-1934 ~~Underground 11:~ IDI1996083olloiS llo.oooll1.882 1 RONALD F. &
MERLE MCDONALD
D N1816 W651 S4 01
DDDDDD
1500 BROWN'S
37S 22E SL CANYON ROAD
(103-2)
109-194 7 IIUnderground ~~~ ~~~~1996112611ms lf·oo~EJITHoMAs A. MAY I
D N174 W901 S4 02 DDDDDD2202SOUTHClliCO 37S 22E SL ;)EDROS ROAD (104-
lo9-1953 llunderground II liT IJ1997043ollnis llo.ooolj4.730 IIJERRY HOLLIDAY I
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Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan
D ~~~9{2:~tNEOZ DDDDDCIIP.O. BOX 502 I
jo9-1955 llunderground II:~ IDI199705271EJio.oooll4.730 ~~~~~ARY I
D ~i~;;:s~59 SE01 DDDDDCII~:roRTH5oo I
109-1959 1 Und~ground DDI199707291Dio.ooo j[4.73o [5E~
D N2339 E191 sw 35 DDDDDD859 SOUTH lOOEAST 36S 22E SL (82-9)
~=========:I 109-1964 Jlunderground IJ:~ JDJzo030512JJois JJo.oooJJo.990 JJsEN J. BLACK J
D N516 E625 W4 02 DDDDDD83 WEST 300 SOUTH 37S 22E SL 75-5 109-1968 JJunderground JJ:~ JD J1997091511ms llo.oooiJ4.730 l:=:=~=~=~i=&=P=E=G=G=Y==:I
D ~~~~8:~sE01 DDDDDDJPoBOXll45 J
~~ ~~o~Qh:J~uTEMOUNTAIN c=:___j Underground ~ P ~E_j~~ UTE TRIBE
D ~i~~;:;~7 s423 DDDDDDITOWAOCC081334 I
Jo9-1972 IJunderground JDDJ19971023 JJois JJo.oooJJ4.730 ~~~~~MARTHA J
D ~i~;;:;t5 E4 21 D D DDDCIJP.O. BOX?29 I
~~ ~~o~in:lW~PAULREDD&LISA ~Underground~ P ~~~E._j MACDONALD
D NllO W2339 W4 34 DDDDDD466 WEST 800 36S 22E SL SOUTH 60-15
Jo9-1982 JJunderground JDDJ 19980320JJoiS JJo.ooojJ4.730 ~~~~~B. I
D ~ii;~;'f{60 sEo1 DDDDDDJm souTH?OOEAsTJ
~~ ~~o~EJWh::!DoNc. &REBECCA ~Underground ~P ~DI ~~P.LARSON
D S251 E933 W4 35 DDDDDD301 E. EAGLE VIEW 36S 22E SL LN. 95-19 ~=====~I ~]underground I=::JD~EJBBI~~=~D I
Page 1-73
Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan
I I I II II IDOl IIFELSTEAD I
D
N1847 W893 SE 01
DDDDDD
1863 NORTH
37S 22E SL CANYON VIEW DRIVE (103-22)
[o9-1991 [[underground [[:~~ [0[199807o2[[ois [[o.ooo[[4.730 [ ARDEN C. & BILLIE SUE NIELSON
O ~ii~~:;~os SE II DDDDDD[sox 864 I
[o9-2001 [[underground [[:~ [0[19981002[[ois [[o.ooo[[1.480 [[ANNA M. RAFFERTY [
D S860 E315 NW 22 DDDDDDIP.O.BOX553 I 37S 22E SL
109-2006 llunderground II liT II19990112IIors llo.oooi i4.730 IIMARTHA LYMAN I D S660 W700 NE 21 DDDDDD[P.O.BOX96 I 37S 22E SL
[o9-2010 [[underground [[:~ [0 [19990315[EJ[o.ooo[EJ STEVEN C. AND SHAUNA E. BLACK
D N2430 E2540 SW 36
DDDDDD
1606 EAST HARRIS 36S 22E SL LANE (102-9)
109-2012 1 DDII99904021BE+·194 1
JULIE MAY KNITTEL Underground AND CAROL ANN BLISS
D S76 W1085 E4 02
DDDDDD
2250 NORTH 1200 37S 22E SL EAST
[o9-2021 [[underground [[:~ [0[19990810[[ois [[o.ooo[~[sHELLYBLAKE I D S275 E561 W4 35
DDDDDD
853 SOUTH 200 EAST 36S 22E SL (95-23)
109-2033 1 DDI20000412I Ims llo.oooll4.730 1
RANDALL& Underground MARILYN PEMBERTON
D
N1652 E30 SW 36
DDDDDD
1727 SOUTH
36S 22ESL AROUND THE WORLD 103-23
[o9-2035 [[underground [[:~ [0[2ooooso4[EJ[o.ooo[[4.73o [[ALAN SHUMWAY I
D
N1151 E577 SW 35
DDDDDD
1201 SOUTH 200 36S 22E SL EAST (95-22)
[o9-2040 [[underground [[:~ [0[zoooons[[ms [[o.ooo[[4.730 [[~=AY I
I I N112 W270 E4 35 I II II IDOl 11755 SOUTH MAIN I
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Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan
I II36S 22E SL II II II IDOl II STREET I
109-2065 !!underground IDDI2001122111ms llo.oooll4.73o I JAMES G. AND STACY MONTELLA
D SlOO W650 E4 02
DDDDDD
978 EAST BROWN CANYON ROAD 37S 22E SL (103-19)
109-2068 !!underground II:~~ IDI2oo7o5o211nis llo.oooii2.904 IIBRUCE E. sTEVENS I D S80W710NE02 37S 22E SL DDDDDD1314SOUTI11100 EAST 102-16
109-2069 1 [:~ /[]200709121Fis [[o.ooo/8
JOE(JR)AND Underground SHIRLEY A. GRISHAM
D
S1110 W277 E4 02
DDDDDD
2044SOUTH PERKINS LANE 103-37S 22E SL 20
[09-2070 I Underground [:~ IDI200204091Elooo[[1.45o [
RICHARD I. AND MARIEANN WATKINS
DS162W4489E401
DDDDDD
1302BROWN CANYON ROAD 103-37S 22E SL 24
109-2074 IIUnderground II liT ll2o0205211Dio.oooii4.730 IIBRUCE J. LYMAN I D N1020 W1220 SE 15
DDDDDD
SHIRT AIL JUNCTION 37S 22E SL 105-7
r9-2075 [[underground IDDBEJBEJ
USA CORPORATION INTERNATIONAL URANIUM
D S769 W1812 NE 33 37S 22E SL DDDDDDIP.O.BOX809 I
109-2075 I Underground DDI200206031/ox 1/o.ooo/[16.140 I
USA CORPORATION INTERNATIONAL URANIUM
D S1039 W1600NE33 DDDDDDIPO BOX 809 37S 22E SL .. I
109-2075 1 DDI200206o3 [[ox 1/o.ooo/116.140 I
USA CORPORATION Underground INTERNATIONAL URANIUM
D
S1156 W1591 NE 33 DDDDDDIP.O.BOX809 I 37S 22E SL
lo9-2075 llunderground II liT II200206o3 llox llo.oooji16.140 llusA coRPORATION I
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Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan
D l IDDDDDD INTERNATIONAL URANIUM
D S1023 W1576 NE 33 DDDDDCIIP.O.BOXS09 I 37S 22ESL
109-2075 1 Underground DDBEJBEJUSACORPORATION T 20020603 OX 0.000 16.140 ~~i0~IONAL
D S903 W1563 NE 33 DDDDDDIP.O.BOX809 I 37S 22E SL
r9-2075 1 DD~06031EJBI ~6.140 1
USA CORPORATION Underground INTERNATIONAL URANIUM D S1434 W1537 NE 33 37S 22E SL DDDDDDIP.O.BOX809 I
109-2087 ~~Underground II:~~ ID I2002081sllois llo.oooll3.o10 IIBEN J. BLACK I
D N516 E631 W4 02 DDDDDD 303 EAST BROWNS 37S 22E SL CANYON RD.
109-2094 ~~Underground IDDI2o0209241EJio.ooollo.838 ~~~~~~gN I
D N125 W907 E4 34 DDDDDD 788 SOUTH MAIN 36S 22E SL STREET 78-11
109-2097 ll underground IDCII2o0210041EJio.oooll4.73o ~~~:=F. I
D S581 E53 W4 01 37S D DDDDD 63 NORTH 100 WEST 22ESL (17-2)
109-2100 I Underground D DI20021118IIox llo.oooll32.280 1
INTERNATIONAL URANIUM USA CORPORATION D N36 W2249 SE 28 37S 22ESL DDDD DDIP.O.BOX809 I
109-2100 1 DDBEJBE~rTERNATIONAL Underground T 20021118 OX 0.000 32.280 URANIUM USA CORPORATION
D N139W2146SE28 DDDDDDIPO BOX809 37S 22E SL .. I ~~ IDDBEJBE~rNTERNATIONAL Underground T 20021118 OX 0.000 32.280 ~~~ri~~
D N138 W1890SE28 DDDDDDIPO BOX809 37S 22E SL . ' I
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Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan
109-2100 I Underground DDI20021118IIox llo.oooll32.280 I =i:J~s~AL
CORPORATION
D:=~=1i=~=~=1=s6L=96=S=E=2=8==:DDDDDC~J.o. Box 809
r9-2100 !underground DDI20021118IIox !Jo.oooll32.280 l~:~~s~AL
CORPORATION
D~~~=sw=2=~~=1=;L=NE=3=3 ==:DDDDDDIP.o. Box 809
109-2100 jjundfiground IDDI20021118l!ox jjo.oooii32.280 I =E~1AL
D~~7=1~=82=~=1=~r=8=NE=3=3~DDDDDDIP.O. BOX 809 Cll I~Dr::JDDEJ USABUREAUOF EJ Underground~ P ~ S u 0.000 ~GEMENT
D N3279 E3641 SW29 DDDDDD2370 SOUTH2300
38S 23E SL WEST ~=====~I 109-2125 llunderground II:~ IDI200307151EJio.oooll4.730 IISAN JUAN COUNTY I
D ~~~~~3SE34 DDDDDL]~.O.BOX9 I
r9-2139 llunderground IDDI200401261frs lf.oooll4.730 ~~~~LL H. I
D
N95 E1830 SW 10 000.0 0 0 105-14 SHIRTAIL
37S 22E SL CORNER ~=====~I 109-2140 lfnderground II:~ IDI2004021711ms llo.oooll4.730 IITONY F. GUYMON I
D
N2565 E2680 sw 02 DDDDDDBROWN CANYON
37S 22E SL ROAD 104-7
109-2152 llunderground ID D I2004111511ms llo.oooll4.73o l=vRLA~ING
0 ~~~~~;~NW36 0000001~~STHARRIS 1 ~, IDDr=::l~c:l~LEER. &DENIECE t==_j Underground A ~~~~A. MEYERS
D
N1095 W725 E4 21 DDDD DD 1051 WEST 4350
37S 22E SL SOUTH 105-10
1;=lo9=-2=17=o==;llunderground llwell liP ll20060103 l!Q[Jio.oool!4.730 IIDANIELAND
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Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan
Dl IEJDDDDDI~~~R I
D
S 1285 E573 NW 06
DDDDDD
1551 S. BOOTS & 37S 23E SL SPURS LANE
109-2182 ~~Underground IDD~EJB~GLENN &GLORIA A 20060814 DIS 0.000 4.730 PATTERSON
D N1390 E90 S4 02 37S 22E SL DDDDDDIP.OBOX972 I !09-2185 !!underground II jjT 1!2o060908jfQD!o.oooj!4.730 !!MARTHA A. LYMAN I
D SlOO W990 NE 21 37S 22E SL DDDDDDI90WEST 100SOUTH I
109-2187 1 1:~ IDI2006092ollms llo.oooii4.730 I
RANDALL& Underground MARlLYN PEMBERTON
D
N784 E278 W4 01
DDDDDD
72 SOUTH 100 WEST 37S 22E SL 70-1
109-226 ~~Underground II:~ IDI195souoiEJio.o1511o.ooo ~~~¢~sHA OF I
D
S1639 E1689 N4 03 DDDDDDIBOX#7l4 I 37S 22E SL
109-2263 llunderground [JDI2oo701241fJS lf.oo+730 ~~~~sSANDRA I D N2010 W235 SE 34 DDDDDD
686NORTH 36S 22E SL DAYBREAK
109-2267 llunderground II:~ IDI200703231EJio.ooollo.4so I JEFF&SHERI MONTELLA
D
S516 E2 E4 02 37S DDDDDDIP.O.BOX285 I 22ESL
109-2270 ~~Underground I~DBEJBEJCRAIGB.AND info A 20070530 DIS 0.000 2.562 JOANNE T BARLOW
D
N2383 E1328 SW 35 DDDDDDIP.O.BOX625 I 36S 22E SL
109-2276 1 1:~ IDI2007082911DIS 1~·00~12.478 I
GLENNT.AND Underground GLORIAJ. PATTERSON
D N348 Wl021 E4 01 37S 22ESL DDDDDD~~OKOPELLI I
109-2286 !!underground IDDI2o07!21811ms llo.oooii4.730 ~~~~~~~
D
N834 E1230 S4 16 DDDDDDI~~~·SHIRTTAIL I 37S 22E SL
Page 1-78
Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan
lo9-2290 llunderground II !lA 1!200802211!DIS llo.oool!4.730 I!LOIS SHUMWAY I
D
S284 W423 NE 03 DDDDDDIPOBOX447 I 37S 22E SL
109-2296 llunderground IDDI2oososo511ois llo.oooii4.730 ~~~YNDELL & ELIZA I
D S1255 W814 E4 02 37S 22ESL DDDDDDIP.O.BOX555 I
109-2297 llunderground ID D8EJB EJNELLADEEAND A 20080516 D1S 0.000 4.728 JACK L. STREET
D S100W650E402
DDDDDD
1004 EAST BROWNS
37S 22ESL CANYON ROAD
109-2306 llunderground II:~ 1012oos10o61 EJio.ooollo.534 II~Jrf ALICIA I
D S400 E738 W4 36 36S 22E SL DDDDDDI1312 HARRJSLANE I
lo9-2309 llunderground II IIA !120081103!1DIS l!o.oooji4.470 I!KEVIN BLACK
D
S955 E192 NW 01 D DDDDDI41 FAST 300 SOUTH 37S 22E SL
109-2311 llunderground IDDI2008111ollois llo.oooi i4.730 ~~~~f: TERRI
D S50 W990 NE 21 37S 22E SL DDDDDDIPOBOX106
109-2312 llunderground IDDI2oos123ollms llo.oooii4.730 I ~~~ NELLADEE
D
S72 W662 E4 02 37S
D DDDDD
1004 EAST BROWNS
22ESL CANYONRD
109-2316 ~~Underground IDDI2009020911nis llo.oooll4.59o ~~~~~~ P. I
D
S1095 W725 NE 21
DDDDDD
4238 SOUTH 1000
37S 22E SL WEST
109-255 1 DDB DBEJ USA BUREAU OF
Underground LAND
MANAGEMENT
D
S688 E128 W4 14
DDDDD D
2370 SOUTH 2300
38S 21E SL WEST
109-275 I Underground DDBDElEl UTAH SCHOOL AND
INSTITUTIONAL
TRUST LANDS
ADMIN.
'D S943 W546 N4 32
D D D DDD
675 EAST 500
38S 23E SL SOUTH, 5TH FLOOR
Page 1-79
Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan
109-348 !!underground IDDII96405131 D io.ou llo.ooo I KELLY G. & TERRIJ.
LAWS
D N2265 W900 S4 33 36S 23E SL DDDDDDI295W.400N. I
jo9-365 llunderground II liP llt964IOI31Dio.ots 1Jo.ooo IIEUGENE GUYMON I
D
N747 W932 E4 02 DDDDDDIP.O.BOX117 I 37S 22ESL
lo9-385 II underground II liT ll t96507Is!Dio.sooJio.ooo IIHARRIS SHUMWAY I
D
S1320 E395 NW 33
DDDDDDIBOXI 72 I 37S 22E SL
lo9-423 !I underground II JIP Jjt9350522IInis 11o.o22J1s.sso IIFRED s. LYMAN I
D
N340 W750 S4 10 DDDDDDIBLANDINGUT84511 1 37S 22E SL
lo9-466 Jlunderground II liP llt96803os1Dio.o07J jo.ooo jjLORENzo HAWKINS I
D S152 W76 NE 32 37S 22E SL DDDDDDIP.O.BOX182 I
109-473 I Underground DDBEJBEJ USA UTAH LAUNCH
COMPLEX WHITE
SANDS MISSLE
RANGE D 8608 W327 NE 27 DDDDDD C/OA.MURAY
37S 22E SL MAUGHN, SITE
DIRECTOR
109-474 !!underground IDDII96903031Dio.Oisllo.ooo ~~~~~~R I o ~~~o~2:;~oON4 35 DDDDDDIBOX232 I
109-496 1 DDBDBEJ MONTICELLO
Underground DISTRICT USA BUREAU OF LAND
MANAGEMENT
D NI098 El642 sw II DDDDDDIP 0 BOX 1327 38S 21E SL .. I
109-504 . DDBDBEJ USA BUREAU OF
Underground LAND
MANAGEMENT
D
S3219 E3255 NW 08
DDDDDD
2370 SOUTH 2300
37S 22ESL WEST
lo9-5IO Jlunderground II liT llt97I03IsiDI2.oool!o.ooo JlwiLLIAM B. REDD I
D
N200 E2750 SW 03
DDDDDDisoxs31 I 37S 21E SL
Page 1-80
Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan
lo9-510 l!underground II liT llt97103tsiDI2.ooo!lo.ooo llwiLLIAM B. REDD I
D
NO E3000 SW 03
D DDDDDisox 53' I 37S 21E SL
lo9-528 !I Underground II liP llt972031Sj!DIS Jlo.ots jlo.OOO jiJ. PARLEY LAWS I
D N3110 W1790 SE02 DDDDDDIPO BOX#315 37S 22E SL .. I
109-541 1 DDBDBEJ
BLANDING Underground VACATIONS
INCORPORATED
o ~~~5~2~~f NW
15 oooooo1PO BOX 66 1
lo9-544 !!underground II liT ll t97209221Dio.ot5jlo.ooo !!ROBERT E. HOSLER I
o ~:~~::i3 SE03 ooooooiPOBOX421 I
109-546 IIUnderground IDDI,97210121EIIo.D3ollo.ooo 1 ri:: ~.AND
D
S3273 E1687 N4 03 DDDDDDIP.O. BOX#263 37S 22E SL
lo9-573 l!underground II liP ll t9730927jlois llo.os4l!o.ooo IIERWIN OLIVER
D
N1610 E1260 SW 35 ooooo cJr.O.BOX#2BS 36S 22E SL
lo9-581 I! underground II liP llt97405o21Dio.3oo!lo.ooo l!nELORES HURST
D S70 W900E4 35 36S DDDDDD516 WEST 100 22E SL SOUTH (50-5)
lo9-581 IIUnderground II liP llt97405021Dio.3oojlo.ooo llnELORES HURST I
D S750 W430 E4 35
DDDDDD
516 WEST 100
36S 22ESL SOUTH (50-5)
jo9-581 I! underground II liP ll t97405o21Dio.3ool lo.ooo lloELOREs HURST I
D S20 W325 E4 35 36S
DDDDDD
516WEST 100
22E SL SOUTH (50-5)
109-582 IJunderground IDDI197405o21Dio.750IIo.ooo ~~~~TMILTON I
D S75W1185E435 DDDDDD747NORTH300 36S 22ESL WEST (34-2)
F-582 IJunderground IDDit97405021[}.75ollo.ooo II=~~~VAN I
D S60 W860 E4 35 36S
DDDDD D
747 NORTH 300
22ESL WEST (34-2)
jo9-584 I!Underground jjwell jjP jj1974o5o3 jEJjo.otsl!o.ooo !!LEONARD R. HOWE I
Page 1-81
Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan
I I jinfo II II IDOl I
D S619 W135 N4 03 DDDDDDIP.O.BOX#1025 I 37S 22E SL
lo9-597 llunderground II liP II19740829ID1o.Ol sjjo.ooo llnoROTHY PERKINS I D S590 W810 E4 21
DDDDDD
NORTH RESERVOIR 37S 22E SL ROAD (37-1)
jo9-606 liUnderground II jjT jj19741127jjnrs jjo.10ollo.ooo liJEss M. GROVER I
D N2040 W350 S4 01 DDDDDDIP.O.BOX#564 I 37S 22E SL
[o9-61 8 [[underground [[:~ [0[19750421[[ors [[o.o10[[o.ooo [[~~~~~ENE I
D $1140 W220 N4 03
DDDDDD
444 WEST 1600 37S 22E SL SOUTH (79-2)
lo9-619 llunderground II liT [I1975061 9[jors [lo.ols[lo.ooo IIBOYD LAWS I D S2400 W210 N4 22 DDDDDDIP.O.BOX#317 I 37S 22E SL
109-631 I!Underground II liP ll1975112ojjors llo.IOol!o.ooo [!EuGENE GUYMON I
D N747 W932 E4 02 DDDDDDIP.O.BOX#117 I 37S 22E SL
!09-631 !!Underground II liP l[1975112ollors llo.IOol[o.ooo !!EUGENE GUYMON I
D N400 W350 E4 02 oooooor.O.BOX#l17 I 37S 22E SL
!09-631 [!Underground II [[P [[1975112oi[DIS jjO.lOOjjO.OOO [[EUGENE GUYMON I D N275 W150 E4 02 DDDDDDIP.O.BOX#117 I 37S 22E SL
[o9-634 [[underground [[:~ [0[19751 129[0[o.o1s[[o.ooo [ LORRAINE ROSE
AND VERL J. ROSE
D S1326 W1205 E4 02
DDDDDD
1166 SOUTH 100
37S 22ESL EAST
[o9-637 [[underground [[:~• [0[19760103[EJ[o.2oo[[o.ooo [[~~';;iYDE I D S2722 ElO NW 01 37S 22E SL DDDDDDEASTBROWN i:NYON ROAD 103-
[09-663 [[Underground II liT II19760623[j ors 11o.o1s11o.ooo IIGRANT L. BAYLES I D N1155 E870 sw 22 37S 22ESL DDDDDC}·o.sox#275 I
[o9-666 [[underground [00[I976to21[EJ[uxJO[[o.ooo [[:~~E~~ I
Page 1-82
Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan
D N3200 W2600 SE 23
DDDDDD
1325 SOUTH 800 37S 21E SL EAST
109-666 !!underground IDDI197610211EJI1.00011o.ooo ii~~;E~~s I D N3000 W1300 SE 23
DDDDDD
1325 SOUTH 800
37S 21E SL EAST
109-666 !!underground IDDI197610211EJILoooiio.ooo ~~~~;~~s I D N2100 W200 SE 23
DDDDDD
1325 SOUTH 800 37S 21E SL EAST
109-666 !!underground IDDI197610211EJI1.00011o.ooo ii~~;E~~s I D N2100 E1200 sw 24
DDDDDD
1325 SOUTH 800 37S 21E SL EAST
109-672 !!underground II:~ IDI197612101EJio.m511o.ooo ~~~:~~~FUELS I
D
N640 W1650 SE 28 DDDDDD 1200 17TH STREET,
37S 22E SL ONE TABOR
CENTER SUITE 2500
109-689 !!underground II:~ IDI 1977030711Mosiil.uoii8o3.60oii~~ WHITE MESA I D N1400 W3000 SE 28
DDDDDD
1050 17TH STREET 37S 22E SL SUITE950
109-689 !!underground II:~~ IDI1977030711Mosii1.110118o3.60oii~~ WHITE MESA I D N1300 W2400 SE 28 DDDDDD 1050 17TH STREET 37S 22E SL SUITE 950
109-689 !!underground II:~~ IDI1977030711Mosiil.110118o3.60oii~:~GY FUELS I
D N2100W2200SE28 DDDDDD 1200 17TH STREET,
37S 22E SL ONE TABOR
CENTER SUITE 2500
109-689 !!underground IDDI1977030711Mosii1.1101 18o3.6ooii~~ WHITE MESA I D NlOOO E650 SW 22
DDDDDD
1050 17TH STREET 37S 22E SL SUITE 950
109-713 iiunderground II:~ IDI197704o7iiois ilo.m51io.ooo llnEAN w. GUYMON I D S360 W350 NE 03 DDDDDC~J.o.aox#J94 I 37S 22E SL
lo9-740 llunderground llwell liP II19770419ID!o.o1sllo.ooo jjwiNSTON AND I
Page 1-83
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Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan
Dl IEJDDDDD
KATHRYN J. HURST
BAYLISS
D N320 W1240 E4 27 38S 22E SL DDDDDCII~ORTHIOO I
lo9-743 II Underground II liT ll 19851016l[Q[Jjo.015IIo.ooo llo. FROST BLACK I
D
N150 E50 SW 36
DDDDDD
208 SOUTH 200
36S 22E SL WEST (65-5)
109-771 llunderground IDDil97704271Df.Q151lo.ooo 1 ELIZABETH ANN
HURST PHILLIPS
D
N670 E950 S4 34 DDDDDDIP.O. BOX#389 I 36S 22E SL
lo9-778 II underground II liT II 19770504I~Io.OI5IIo.ooo IIREx D. ANDERSON I
D S310E1240W415 37S 22E SL DDDDDDIP.O.BOX569 I
109-792 ~~Underground II:~ IDI197705o911Drs llo.Ols llo.ooo ~~~~~LYDE I
D S80 E220 W4 0137S DDDDDD 1000 EAST BROWNS
22ESL CANYON ROAD 103-
14
109-805 ~~Underground IDDI1977051ollors llo.015 11o.ooo I BAR M. K. RANCHES
INCORPORATED
D ~iii~i~~ow403 DDDDDDIBOXS?6 I
f 9-806 llunderground IDDI1977051ollors llo.015 11o.ooo I BAR M. K. RANCHES
INCORPORATED
D
N1200 E990 W414
DDDDDDIBOXS76 I 37S 22E SL
109-808 llunderground IDDI1977051011Drs llo.Oisllo.ooo I BAR M. K. RANCHES
INCORPORATED
D
N990 W990 S4 11
DDDDDDisox 576 I 37S 22E SL
lo9-826 llunderground II llu III9770523 IIDrs llo.5oollo.ooo llcLISBEE LYMAN I
D N665 W1015 S410 DDDDDD435 SOUTH200 37S 22E SL WEST 63-2
lo9-826 IIUnderground II llu II19770523IInrs Jlo.5oo llo.ooo !lcLISBEE LYMAN I
D
N70 W790 S4 10 37S
DDDDDD
435 SOUTH 200
22ESL WEST63-2
lo9-826 !lunderground II llu IJ19770523IjDIS Jlo.5oollo.OOO l!cLISBEE LYMAN I
D
N340 W750 S4 10
DDDDDD
435 SOUTH 200
37S 22E SL WEST63-2
Page 1-84
Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan
jo9-826 jjunderground II llu Jj19770523JjDIS IJo.500jjO.OOO j!CLISBEE LYMAN I
D N315W450S410
DDDDDD
435 SOUTH 200
37S 22E SL WEST 63-2
jo9-831 II Underground II liT lj 19800516jjDIS ljo.o1sljo.ooo !IJ. KEITH ROGERS I
D
N2306 E217 SW 35
DDDDDD
3488 FOOTHILL
36S 22E SL DRIVE
jo9-832 II underground II liT II19800516!1DIS jjo.015IIo.ooo Ill KEITH ROGERS I
D
N1728 E215 SW 35 DDDDDDI~~~OOTHILL I 36S 22E SL
jo9-833 jjunderground II jjP II19800516JD !o.015IIo.ooo Ill KEITH ROGERS I
D N1265 W250 SE 34 36S 22E SL DDDDDD3488NORTH FOOTHILL DRIVE
jo9-834 i!Underground II liT II19800516IIDIS jjo.01s11o.ooo jjJ. KEITH ROGERS I
D
N2208 E2252 S4 34 DDDDDDI~~~OOTHILL I 36S 22E SL
109-843 !!underground IDDI199003osiEJio.Oisiio.ooo I STAN AND SANDRA
PERKINS
D N2220 E1930 S4 34
DDDDDD
864NORTH
36S 22E SL DAYBREAK DRIVE
109-860 !!underground 11:~ IDI197706201EJio.015ilo.ooo II=L~~u
D S830E1740W401 37S 22E SL DDDDDDIP.O.BOX#SZZ
jo9-871 jjUnderground II liP II197706o61Dio.015IIo.ooo ljJEss M. GROVER
D
N270 E520 W4 36 DDDDDDIBLANDINGUT 84511 36S 22E SL
109-872 !!underground II:~ IDI197706o61Dio.Olsiio.ooo IIJEss M. GROVER
D S420 E2080 W4 01 37S 22E SL DDDDDDIBLAND1NGUT845111
109-875 !!underground II:~ IDI1977063oiEJio.015112.512 !lARoE G. BROWN I
D
N1570 W1230 SE 01
DDDDDDIBOX 213 I 37S 22E SL
109-876 IIUnderground JJ:~ IDI197706301EJ015111.400 1
PETERD.AND
GEORGIAR.
KARAMESINES
D
N1150 W1900 SE 01
DDDDDD
1527 LINCOLN
37S 22E SL STREET APT. #4
jo9-879 !I Underground II liP II197707o61Dio.o15jjo.ooo I JAMES DEWEY AND
Page 1-85
Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan
D l IDDDDDD
SHIRLEY LOU B. BRADFORD
D
N570 W700 SE 36 DDDDDDI149 SOUTH800EAST I 36S 22E SL
109-885 ~~Underground IDDI197707111Dio.01511o.ooo ll~i~¥~:D I D N1280 W1050 SE 36 36S 22E SL DDDDDDIBOX 855 I
109-888 ~~Underground II:~ IDI19770711 EJio.otsllo.ooo IIPREDE. HALLIDAY I
o ~~~~~s:iNWll DDDDDC]soX335 I lo9-895 llunderground II liT ll19800925~~~0.015l!O.OOO IJNELDON E. HOLT I CJ ~j~~~~~ON421 DDDDDDIBOX394 I
109-896 llunderground II:~ IDI197707131Dio.oo711o.ooo II NELDON E. HOLT
D
NlOO E680 SW 15 DDDDDDinox 394 37S 22E SL
lo9-906 !!underground II liT II19770719Jiois llo.o15Jio.ooo IIREED E. BAYLES
D N1520 E650 S4 35 36S 22E SL DDDDDDIP.O.BOX#203
jo9-914 I!Underground II liP II 19770726Jf![Jio.01sllo.ooo IIEUGENE GUYMON
D
N275 W150 E4 02 DDDDDDIP.O.BOX#l1 7 I 37S 22E SL
lo9-915 IIUnderground II llu 1]19770726lf![]lo.wol]o.ooo IIEUGENE GUYMON I
D
N300 WlOO E4 02 DDDDDDIP.O.BOX#117 I 37S 22E SL
109-925 ll underground ~~~~ IDI1977072811DIS llo.Olsllo.ooo IIDOROTHY PERKINS I
o ~~~ ic5 E4 0237S DDDDDDI205 EAST700 SOUTH I
109-93 ll underground IDDI194409291Dio.01311o.ooo 1 BARRY LEE AND LOREE A. WOOLLEY
D
N644 W855 SE 10
DDDDDD
191 BUTTERNUT 37S 22E SL DRIVE NORTH
lo9-949 I!Underground II jjT IJ19770816IIDIS l!o.o1sj!o.ooo !!BERTHA SNYDER I
D
S200 E800 W4 01 DDDDDC::IIP.O.BOX 1318 I 37S 22ESL
lo9-954 I!Underground II liP II197709o7Jjois jjo.OlsJio.ooo jjPHYLLIS B. JONES I
Page 1-86
Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan
D
N500 W1280 SE 36 DDDDDDIP.O.BOX#472 I 36S 22E SL
Jo9-955 IIUnderground II IJP II 197709o7101o.m5!1o.ooo llo. FROST BLACK I D S175E50W43636S 22ESL DDDDDDIP.O.BOX#71 I
109-958 ~~Underground IDDI197709151EJio.015I Io.ooo 1 RICHARD& NORMAN NIELSON
D
S2640 W400 NE 14 DDDDDDIP.O.BOX#245 I 37S 22E SL
r-959 1 0[1119840329IIom llomsljo.ooo I
NORMAN AND
Underground RICHARD C. NIELSON
D N1700W1100SE 11 37S 22ESL DDDDDD ~:7~~RTH lOOWEST
109-960 llunderground IDDI198806221EJio.o15 11o.ooo I NORMAN AND RICHARD NIELSON
D
S585 E40 W4 01 37S
DDDDDD
63 NORTH 100 WEST 22ESL (17-2)
109-977 llunderground IDDI1977100511DIS llo.o1sllo.ooo ~~~~~~~ I D N559 0 S4 34 36S DDDDDD
60 NORTH 100 WEST 22ESL (16-5)
109-983 1 DDBEJBB PETER D. AND
Underground GEORGIAR. KARAMESINES
D N1270 W1980 SE 01
DDDDDD
1527 LINCOLN 37S 22E SL STREET APT. #4
109-984 ~~Underground II:~ IDI1977101311DIO llo.o1sllo.ooo ~~~~~tLA I D S545 W505 E4 03 DDDDDD P.O. BOX#643,
37S 22E SL HIGHWAY 163 NORTH
109-988 llunderground IDDI198111171EJio.o1511o.ooo ~~~~~o~D
D N700 W270 SE 36 36S 22E SL DDDDDDIP.O.BOX#l357
jo9-989 I! underground II liT jj1977103111Do llo.o1s1Jo.ooo jjREXD. ANDERSON
o ~;;;:i~~W415 oooooor.O.BOX569
f9-990 lfnderground II:~ IDI1977110IIEJfms111.2so ~~UGENE GUYMON I
Page 1-87
Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan
D N400 W350 E4 02 37S 22E SL DDDDDDIP.O. BOX#117 I
lo9-993 !I underground II jjP jj19771027IIQ[Jio.015jjo.OOO jjBERNAL BRADFORD j
D N1260 W200 SE 36 DDDDDDIP.O.BOX#594 I 36S 22E SL
109-994 1 DDB DBEJUTAHSCHOOLAND Underground P 19771108 S 0 015 0 000 INSTITUTIONAL . . TRUST LANDS
ADMIN.
D S660 W660 NE 32
DDDDDD
675EAST 500
38S 22E SL SOUTH, 5TH FLOOR
la12177 ~~Underground IDDI1982022311ois llo.01511o.ooo ll~i¢~ALMER I
D S551 E1540 W4 01
DDDDDD
12 EAST 5TH SOUTH
37S 22E SL 107-5
la13054 llunderground IDDI198312051EJio.o1511o.ooo I NORMAN AND
RICHARD NIELSON
D ~~~5s~o W4 0137S DDDDDDir.o. 8 ox#245 I
la20266 llunderground II liT ll 197703t5IKJI2.ooollo.ooo IIBLANDING CITY I o ~~~2~i~~45
NE
35 DDDDDDI50 WEST 100 SOUTH I
la20266 !Iunder ground II liT ll 197703t5IKJI2.ooollo.ooo IIBLANDING CITY
D S2440 W870 NE 35 DDDDDDI5o WEST 100 souTH 36S 22E SL
la21545 ~~Underground 11:~ IDI199709151EJio.oooll4.730 ll~~~~y
D N3055 W1059 SE 01 DDDDDDI~~ORTH500 37S 22E SL
la24139 ~~Underground II:~ IDI2oooo2o1llois llo.oooii1.480 IlANNA M. RAFFERTY
D S860 E315 NW 22 DDDDDDIP.O.BOX553 37S 22E SL
Ja35842 !IUnderground II llu Jlzoo90819IKJI2.oool lo.ooo II BLANDING CITY I D N938 E135 W4 01 DDDDDDI5o WEST 100 souTH I 37S 22E SL
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D S145 El33 N4 12 DDDDDDisoffilST IOOSOUTH I 37S 22E SL
Ja35896 I!Underground II llu JI200909osllois llo.oooJI4.730 IIMITCHELL H. & I
Page 1-88
Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan
I I I II II IDOl !liANA L. BAILEY I D N256 W943 SE !6
37S 22E SL DDDDDDI~~~·SHIRTTAIL I
jt89-09-0l i!Underground II liT II19890118I~Io.oool!s.ooo IIIV AN R. WATKINS I
D S2722 ElO NW 01 DDDDDDFoxg38 I 37S 22ESL
jt89-09-02 11Underground II liT II 19890S04I~Io.ooolls.ooo IIIv AN R. WATKINS I D S2722 ElO NW 01 DDDDDDisox 938 I 37S 22ESL
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Denison Mines (USA) Corp llENIIOJ)~~
MINU
FEIIISIONS fP'Cfad: White Mesa Mill
DIIIB By Coully: San Juan I :.11118: ur
09-11 GM --ux:atron:
1----1---1 GROUNDWATER APPROPRIATIONS WITHIN A
5-MILE RADIUS OF THE WHITE MESA MILL
FIGURE 1.5-9 i
i ._--------------------------------------------------------------------~L_ __ l_~~::·~u:nb:~:•:m--~I~~!Mw1Jm~1~o~JI:0~::~:·J~~S~I~~d~
Page 1-90
Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

The well yield from wells completed in the Burro Canyon formation within the White Mesa site
is generally lower than that obtained from wells in this formation upgradient of the site. For the
most part, the documented pumping rates from on-site wells completed in the Burro Canyon
formation are less than 0.7 cfs. Even at this low rate, the on-site wells completed in the Burro
Canyon formation are typically pumped dry within a couple of hours.

This low productivity suggests that the Mill is located over a peripheral fringe of perched water;
with saturated thickness in the perched zone discontinuous and generally decreasing beneath the
site, and with conductivity of the formation being very low. These observations have been
verified by studies performed for the U.S. Department of Energy's disposal site at Slick Rock,
which noted that the Dakota Sandstone, Burro Canyon formation, and upper claystone of the
Brushy Basin Member are not considered aquifers due to the low permeability, discontinuous
nature, and limited thickness of these units (U.S. DOE, 1993).

1.6 Geology

The following text is copied, with minor revisions, from the 1978 ER (Dames and Moore,
1978b). The text has been duplicated herein for ease of reference and to provide background
information concerning the site geology. 1978 ER Subsections used in the following text are
shown in parentheses immediately following the subsection titles.

The site is near the western margin of the Blanding Basin in southeastern Utah and within the
Monticello uranium-mining district. Thousands of feet of multi-colored marine and non-marine
sedimentary rocks have been uplifted and warped, and subsequent erosion has carved a
spectacular landscape for which the region is famous. Another unique feature of the region is the
wide-spread presence of unusually large accumulations of uranium-bearing minerals.

Page 1-91
Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

1.6.1 Regional Geology

The following descriptions of regional physiography; rock units; and structure and tectonics are
reproduced from the 1978 ER for ease of reference and as a review of regional geology.

1.6.1.1 Physiography (1978 ER Section 2.4.1.1)

The Mill site lies within the Canyon Lands section of the Colorado Plateau physiographic
province. To the north, this section is distinctly bounded by the Book Cliffs and Grand Mesa of
the Uinta Basin; western margins are defined by the tectonically controlled High Plateaus
section, and the southern boundary is arbitrarily defined along the San Juan River. The eastern
boundary is less distinct where the elevated surface of the Canyon Lands section merges with the
Southern Rocky Mountain province.

Canyon Lands has undergone epeirogenic uplift and subsequent major erosion has produced the
region's characteristic angular topography reflected by high plateaus, mesas, buttes, structural
benches, and deep canyons incised into flat-laying sedimentary rocks of pre-Tertiary age.
Elevations range from approximately 3,000 feet (914 meters) in the bottom of the deeper
canyons along the southwestern margins of the section to more than 11,000 feet (3,353 meters)
in the topographically anomalous laccolithic Henry, Abajo and La Sal Mountains to the
northeast. Except for the deeper canyons and isolated mountain peaks, an average elevation in
excess of 500 feet (1,524 meters) persists over most of the Canyon Lands section.

On a more localized regional basis, the Mill site is located near the western edge of the Blanding
Basin, sometimes referred to as the Great Sage Plain (Eardly, 1958), lying east of the north-south
trending Monument Uplift, south of the Abajo Mountains and adjacent to the northwesterly-
trending Paradox Fold and Fault Belt (Figure 1.6-1). Topographically, the Abajo Mountains are
the most prominent feature in the region, rising more than 4,000 feet (1,219 meters) above the
broad, gently rolling surface of the Great Sage Plain.
LEGEND ___ ...,..,.
--r\
-I -
BOUNDARY OF TECTONIC DIVISION
MONOCLINE SHOWING TRACE OF AXIS
AND DIRECTION OF DIP
ANTICLINE SHOWING TRACE OF AXIS
AND DIRECTION OF PLUNGE
SYNCLINE SHOWING TRACE OF AXIS
AND DIRECTION OF PLUNGE
/ ' (LA SAL)
\MlNS.
-.....!
Figure 1 .6-1
Colorado Plateau Geologic Map
Page 1-93
Revision 5.0
Denison Mines (USA) Corp.
White Mesa Mill Reclamation Plan

The Great Sage Plain is a structural slope, capped by the resistant Burro Canyon formation and
the Dakota Sandstone, almost horizontal in an east-west direction but descends to the south with
a regional slope of about 2,000 feet (610 meters) over a distance of nearly 50 miles (80
kilometers). Though not as deeply or intricately dissected as other parts of the Canyon Lands,
the plain is cut by numerous narrow and vertical-walled south-trending valleys 100 to more than
500 feet (30 to 152+ meters) deep. Water from the intermittent streams that drain the plain flow
southward to the San Juan River, eventually joining the Colorado River and exiting the Canyon
Lands section through the Grand Canyon.

1.6.1.2 Rock Units (1978 ER Section 2.4.1.1)

The sedimentary rocks exposed in southeastern Utah have an aggregate thickness of about 6,000
to 7,000 feet (1,829 to 2,134 meters) and range in age from Pennsylvanian to Late Cretaceous.
Older unexposed rocks are known mainly from oil well drilling in the Blanding Basin and
Monument Uplift. These wells have encountered correlative Cambrian to Permian rock units of
markedly differing thicknesses but averaging over 5,000 feet (1,524 meters) in total thickness
(Witkind, 1964). Most of the wells drilled in the region have bottomed in the Pennsylvanian
Paradox Member of the Hermosa formation. A generalized stratigraphic section of rock units
ranging in age from Cambrian through Jurassic and Triassic (?), as determined from oil-well
logs, is shown in Table 1.6-1. Descriptions of the younger rocks, Jurassic through Cretaceous,
are based on field mapping by various investigators and are shown in Table 1.6-2.

Paleozoic rocks of Cambrian, Devonian and Mississippian ages are not exposed in the
southeastern Utah region. Most of the geologic knowledge regarding these rocks was learned
from the deeper oil wells drilled in the region, and from exposures in the Grand Canyon to the

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Table 1.6-1
Generalized Stratigraphic Section of Subsurface Rocks Based on Oil-Well Logs (Table 2.6-
1 UMETCO)

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Table 1.6-2
Generalized Stratigraphic Section of Exposed Rocks in the Project Vicinity (Table 2.6-2
UMETCO)

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southwest and in the Uinta and Wasatch Mountains to the north. A few patches of Devonian
rocks are exposed in the San Juan Mountains in southwestern Colorado. These Paleozoic rocks
are the result of periodic transgressions and regressions of epicontinental seas and their
lithologies reflect a variety of depositional environments.

In general, the coarse-grained feldspathic rocks overlying the Precambrian basement rocks grade
upward into shales, limestones and dolomites that dominate the upper part of the Cambrian.
Devonian and Mississippian dolomites, limestones and interbedded shales unconformably
overlay the Cambrian strata. The complete absence of Ordovician and Silurian rocks in the
Grand Canyon, Uinta Mountains, southwest Utah region and adjacent portions of Colorado, New
Mexico and Arizona indicate that the region was probably epeirogenically positive during these
times.

The oldest stratigraphic unit that crops out in the region is the Hermos formation of Middle and
Late Pennsylvanian age. Only the uppermost strata of this formation are exposed, the best
exposure being in the canyon of the San Juan River at the "Goosenecks" where the river
traverses the crest of the Monument uplift. Other exposures are in the breached centers of the
Lisbon Valley, Moab and Castle Valley anticlines. The Paradox Member of the Hermosa
formation is sandwiched between a relatively thin lower unnamed member consisting of dark-
gray shale siltstone, dolomite, anhydrite, and limestone, and an upper unnamed member of
similar lithology but having a much greater thickness. Composition of the Paradox Member is
dominantly a thick sequence of interbedded slate (halite), anhydrite, gypsum, and black shale.
Surface exposures of the Paradox in the Moab and Castle Valley anticlines are limited to
contorted residues of gypsum and black shale.

Conformably overlying the Hermosa is the Pennsylvanian and Permian (?) Rico formation,
composed of interbedded reddish-brown arkosic sandstone and gray marine limestone. The Rico
represents a transition zone between the predominantly marine Hermosa and the overlying
continental Cutler formation of Permian age.
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Two members of the Cutler probably underlying the region south of Blanding are, in ascending
order, the Cedar Mesa Sandstone and the Organ Rock Tongue. The Cedar Mesa is a white to
pale reddish-brown, massive, cross-bedded, fine-to medium-grained eolian sandstone. An
irregular fluvial sequence of reddish-brown fine-grained sandstones, shaly siltstones and sandy
shales comprise the Organ Rock Tongue.

The Moenkopi formation, of Middle (?) and Lower Triassic age, unconformably overlies the
Cutler strata. It is composed of thin, evenly-bedded, reddish to chocolate-brown, ripple-marked,
cross-laminated siltstone and sandy shales with irregular beds of massive medium-grained
sandstone.

A thick sequence of complex continental sediments known as the Chinle formation
unconformably overlies the Moenkopi. For the purpose of making lithology correlations in oil
wells this formation is divided into three units: The basal Shinarump Member, the Moss Back
Member and an upper undivided thick sequence of variegated reddish-brown, reddish- to
greenish-gray, yellowish-brown to light-brown bentonitic claystones, mudstones, sandy siltstone,
fine-grained sandstone, and limestones. The basal Shinarump is dominantly a yellowish-grey,
fine- to coarse-grained sandstone, conglomeratic sandstone and conglomerate characteristically
filling ancient stream channel scours eroded into the Moenkopi surface. Numerous uranium
deposits have been located in this member in the White Canyon mining district to the west of
Comb Ridge. The Moss Back is typically composed of yellowish- to greenish-grey, fine- to
medium-grained sandstone, conglomeratic sandstone and conglomerate. It commonly comprises
the basal unit of the Chinle where the Shinarump was not deposited, and in a like manner, fills
ancient stream channels scoured into the underlying unit.

In the Blanding Basin the Glen Canyon Group consists of three formations which are, in
ascending order, the Wingate Sandstone, the Kayenta and the Navajo Sandstone. All are
conformable and their contacts are gradational. Commonly cropping out in sheer cliffs, the Late
Triassic Wingate Sandstone is typically composed of buff to reddish-brown, massive, cross-
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bedded, well-sorted, fine-grained quartzose sandstone of eolian origin. Late Triassic (?) Kayenta
is fluvial in origin and consists of reddish-brown, irregularly to cross-bedded sandstone, shaly
sandstone and, locally, thin beds of limestone and conglomerate. Light yellowish-brown to light-
gray and white, massive, cross-bedded, friable, fine- to medium-grained quartzose sandstone
typifies the predominantly eolian Jurassic and Triassic (?) Navajo Sandstone.

Four formations of the Middle to Late Jurassic San Rafael Group unconformably overly the
Navajo Sandstone. These strata are composed of alternating marine and non-marine sandstones,
shales and mudstones. In ascending order, the formations are the Carmel formation, Entrada
Sandstone, Summerville formation, and Bluff Sandstone. The Carmel usually crops out as a
bench between the Navajo and Entrada Sandstones. Typically reddish-brown muddy sandstone
and sandy mudstone, the Carmel locally contains thin beds of brown to gray limestone and
reddish- to greenish-gray shale. Predominantly eolian in origin, the Entrada is a massive cross-
bedded fine- to medium-grained sandstone ranging in color from reddish-brown to grayish-white
that crops out in cliffs or hummocky slopes. The Summerville is composed of regular thin-
bedded, ripple-marked, reddish-brown muddy sandstone and sandy shale of marine origin and
forms steep to gentle slopes above the Entrada. Cliff-forming Bluff Sandstone is present only in
the southern part of the Monticello district thinning northward and pinching out near Blanding.
It is a white to grayish-brown, massive, cross-bedded eolian sandstone.

In the southeastern Utah region the Late Jurassic Morrison formation has been divided in
ascending order into the Salt Wash, Recapture, Westwater Canyon, and Brushy Basin Members.
In general, these strata are dominantly fluvial in origin but do contain lacustrine sediments. Both
the Salt Wash and Recapture consist of alternating mudstone and sandstone; the Westwater
Canyon is chiefly sandstone with some sandy mudstone and claystone lenses, and the
heterogenous Brushy Basin consists of variegated bentonitic mudstone and siltstone containing
scattered thin limestone, sandstone, and conglomerate lenses. As strata of the Morrison
formation are the oldest rocks exposed in the Mill area vicinity and are one of the two principal
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uranium-bearing formations in southeast Utah, the Morrison, as well as younger rocks, are
described in more detail in Section 1.6.2.2.

The Early Cretaceous Burro Canyon formation rests unconformably (?) on the underlying
Brushy Basin Member of the Morrison formation. Most of the Burro Canyon consists of light-
colored, massive, cross-bedded fluvial conglomerate, conglomerate sandstone and sandstone.
Most of the conglomerates are near the base. Thin, even-bedded, light-green mudstones are
included in the formation and light-grey thin-bedded limestones are sometimes locally
interbedded with the mudstones near the top of the formation.

Overlying the Burro Canyon is the Dakota Sandstone of Upper Cretaceous age. Typical Dakota
is dominantly yellowish-brown to light-gray, thick-bedded, quartzitic sandstone and
conglomeratic sandstone with subordinate thin lenticular beds of mudstone, gray carbonaceous
shale and, locally, thin seams of impure coal. The contact with the underlying Burro Canyon is
unconformable whereas the contact with the overlying Mancos Shale is gradational from the
light-colored sandstones to dark-grey to black shaly siltstone and shale.

Upper Cretaceous Mancos Shale is exposed in the region surrounding the project vicinity but not
within it. Where exposed and weathered, the shale is light-gray or yellowish-gray, but is dark, to
olive-gray where fresh. Bedding is thin and well developed; much of it is laminated.

Quaternary alluvium within the project vicinity is of three types: alluvial silt, sand and gravels
deposited in the stream channels; colluvium deposits of slope wash, talus, rock rubble and large
displaced blocks on slopes below cliff faces and outcrops of resistant rock; and alluvial and
windblown deposits of silt and sand, partially reworked by water, on benches and broad upland
surfaces.

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1.6.1.3 Structure and Tectonics (1978 ER Section 2.4.1.3)

According to Shoemaker (1954 and 1956), structural features within the Canyon Lands of
southeastern Utah may be classified into three main categories on the basis of origin or
mechanism of the stress that created the structure. These three categories are: (1) structures
related to large-scale regional uplifting or downwarping (epeirogenic deformation) directly
related to movements in the basement complex (Monument Uplift and the Blanding Basin); (2)
structures resulting from the plastic deformation of thick sequences of evaporite deposits, salt
plugs and salt anticlines, where the structural expression at the surface is not reflected in the
basement complex (Paradox Fold and Fault Belt); and (3) structures that are formed in direct
response to stresses induced by magmatic intrusion including local laccolithic domes, dikes and
stocks (Abajo Mountains).

Each of the basins and uplifts within the Mill area region is an asymmetric fold usually separated
by a steeply dipping sinuous monocline. Dips of the sedimentary beds in the basins and uplifts
rarely exceed a few degrees except along the monocline (Shoemaker, 1956) where, in some
instances, the beds are nearly vertical. Along the Comb Ridge monocline, the boundary between
the Monument Uplift and the Blanding Basin, approximately eight miles (12.9 kilometers) west
of the Mill area, dips in the Upper Triassic Wingate sandstone and in the Chinle formation are
more than 40 degrees to the east.

Structures in the crystalline basement complex in the central Colorado Plateau are relatively
unknown but where monoclines can be followed in Precambrian rocks they pass into steeply
dipping faults. It is probable that the large monoclines in the Canyon Lands section are related to
flexure of the layered sedimentary rocks under tangential compression over nearly vertical
normal or high-angle reverse faults in the more rigid Precambrian basement rocks (Kelley, 1955;
Shoemaker, 1956; Johnson and Thordarson, 1966).

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The Monument Uplift is a north-trending, elongated, upwarped structure approximately 90 miles
(145 kilometers) long and nearly 35 miles (56 kilometers) wide. Structural relief is about 3,000
feet (914 meters) (Kelley, 1955). Its broad crest is slightly convex to the east where the Comb
Ridge monocline defines the eastern boundary. The uniform and gently descending western
flank of the uplift crosses the White Canyon slope and merges into the Henry Basin (Figure 1.6-
1).

East of the Monument Uplift, the relatively equidimensional Blanding Basin merges almost
imperceptibly with the Paradox Fold and Fault Belt to the north, the Four Corners Platform to the
southeast and the Defiance Uplift to the south. The basin is a shallow feature with
approximately 700 feet (213 meters) of structural relief as estimated on top of the Upper Triassic
Chinle formation by Kelley (1955), and is roughly 40 to 50 miles (64 to 80 kilometers) across.
Gentle folds within the basin trend westerly to northwesterly in contrast to the distinct northerly
orientation of the Monument Uplift.

Situated to the north of the Monument Uplift and Blanding Basin is the most unique structural
feature of the Canyon Lands section, the Paradox Fold and Fault Belt. This tectonic unit is
dominated by northwest trending anticlinal folds and associated normal faults covering an area
about 150 miles (241 kilometers) long and 65 miles (104 kilometers) wide. These anticlinal
structures are associated with salt flowage from the Pennsylvanian Paradox Member of the
Hermosa formation and some show piercement of the overlying younger sedimentary beds by
plug-like salt intrusions (Johnson and Thordarson, 1966). Prominent valleys have been eroded
along the crests of the anticlines where salt piercements have occurred or collapses of the central
parts have resulted in intricate systems of step-faults and grabens along the anticlinal crests and
flanks.

The Abajo Mountains are located approximately 20 miles (32 kilometers) north of the Mill area
on the more-or-less arbitrary border of the Blanding Basin and the Paradox Fold and Fault Belt
(Figure 1.6-1). These mountains are laccolithic domes that have been intruded into and through
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the sedimentary rocks by several stocks (Witkind, 1964). At least 31 laccoliths have been
identified. The youngest sedimentary rocks that have been intruded are those of Mancos Shale
of Late Cretaceous age. Based on this and other vague and inconclusive evidence, Witkind
(1964), has assigned the age of these intrusions to the Late Cretaceous or early Eocene.

Nearly all known faults in the region of the Mill area are high-angle normal faults with
displacements on the order of 300 feet (91 meters) or less (Johnson and Thordarson, 1966). The
largest known faults within a 40-mile (64 kilometer) radius around Blanding are associated with
the Shay graben on the north side of the Abajo Mountains and the Verdure graben on the south
side. Respectively, these faults trend northeasterly and easterly and can be traced for
approximate distances ranging from 21 to 34 miles (34 to 55 kilometers) according to Witkind
(1964). Maximum displacements reported by Witkind on any of the faults are 320 feet (98
meters). Because of the extensions of Shay and Verdure fault systems beyond the Abajo
Mountains and other geologic evidence, the age of these faults is Late Cretaceous or post-
Cretaceous and antedate the laccolithic intrusions (Witkind, 1964).

A prominent group of faults is associated with the salt anticlines in the Paradox Fold and Fault
Belt. These faults trend northwesterly parallel to the anticlines and are related to the salt
emplacement. Quite likely, these faults are relief features due to salt intrusion or salt removal by
solution (Thompson, 1967). Two faults in this region, the Lisbon Valley fault associated with
the Lisbon Valley salt anticline and the Moab fault at the southeast end of the Moab anticline
have maximum vertical displacements of at least 5,000 feet (1,524 meters) and 2,000 feet (609
meters), respectively, and are probably associated with breaks in the Precambrian basement
crystalline complex. It is possible that zones of weakness in the basement rocks represented by
faults of this magnitude may be responsible for the beginning of salt flowage in the salt
anticlines, and subsequent solution and removal of the salt by groundwater caused collapse
within the salt anticlines resulting in the formation of grabens and local complex block faults
(Johnson and Thordarson, 1966).

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The longest faults in the Colorado Plateau are located some 155 to 210 miles (249 to 338
kilometers) west of the Mill area along the western margin of the High Plateau section. These
faults have a north to northeast echelon trend, are nearly vertical and downthrown on the west in
most places. Major faults included in this group are the Hurrican, Toroweap-Sevier,
Paunsaugunt, and Paradise faults. The longest fault, the Toroweap-Sevier, can be traced for
about 240 miles (386 kilometers) and may have as much as 3,000 feet (914 meters) of
displacement (Kelley, 1955).

From the later part of the Precambrian until the middle Paleozoic the Colorado Plateau was a
relatively stable tectonic unit undergoing gentle epeirogenic uplifting and downwarping during
which seas transgressed and regressed, depositing and then partially removing layers of
sedimentary materials. This period of stability was interrupted by northeast-southwest tangential
compression that began sometime during late Mississippian or early Pennsylvanian and
continued intermittently into the Triassic. Buckling along the northeast margins of the shelf
produced northwest-trending uplifts, the most prominent of which are the Uncompahgre and San
Juan Uplifts, sometimes referred to as the Ancestral Rocky Mountains. Clearly, these positive
features are the earliest marked tectonic controls that may have guided many of the later
Laramide structures (Kelley, 1955).

Subsidence of the area southwest of the Uncompahgre Uplift throughout most of the
Pennsylvanian led to the filling of the newly formed basin with an extremely thick sequence of
evaporites and associated interbeds which comprise the Paradox Member of the Hermosa
formation (Kelley, 1956). Following Paradox deposition, continental and marine sediments
buried the evaporite sequence as epeirogenic movements shifted shallow seas across the region
during the Jurassic, Triassic and much of the Cretaceous. The area underlain by the Paradox
Member in eastern Utah and western Colorado is commonly referred to as the Paradox Basin
(Figure 1.6-1). Renewed compression during the Permian initiated the salt anticlines and
piercements, and salt flowage continued through the Triassic.

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The Laramide orogeny, lasting from Late Cretaceous through Eocene time, consisted of deep-
seated compressional and local vertical stresses. The orogeny is responsible for a north-south to
northwest trend in the tectonic fabric of the region and created most of the principal basins and
uplifts in the eastern-half of the Colorado Plateau (Grose, 1972; Kelley, 1955).

Post-Laramide epeirogenic deformation has occurred throughout the Tertiary; Eocene strata are
flexed sharply in the Grand Hogback monocline, fine-grained Pliocene deposits are tilted on the
flanks of the Defiance Uplift, and Pleistocene deposits in Fisher Valley contain three angular
unconformaties (Shoemaker, 1956).

1.6.2 Blanding Site Geology

The following descriptions of physiography and topography; rock units; structure; relationship of
earthquakes to tectonic structure; and potential earthquake hazards to the Mill area are
reproduced from the 1978 ER for ease of reference and as a review of the Mill site geology. (See
Figure 1.6-2)

1.6.2.1 Physiography and Topography (1978 ER Section 2.4.2.1)

The Mill site is located near the center of White Mesa, one of the many finger-like north-south
trending mesas that make up the Great Sage Plain. The nearly flat upland surface of White Mesa
is underlain by resistant sandstone caprock which forms steep prominent cliffs separating the
upland from deeply entrenched intermittent stream courses on the east, south and west.

Surface elevations across the Mill site range from about 5,550 to 5,650 feet (1,692 to 1,722
meters) and the gently rolling surface slopes to the south at a rate of approximately 60 feet per
mile (18 meters per 1.6 kilometer).

~ ... ~
&l ~ ~ c .Q
! ~ "' ~
REFERENCES: GEOLOGY, IN PART. AFTER HAYNES ET AL. • 1982. BASE MAP PREPARED FROM PORTIONS
. OF THE BLANDING. BRUSHY BASIN WASH. BLUFF. AND MONTEZUMA CREEK U.S.G.S. .
15·MINUTE TOPOGRAPHIC QUADRANGLES.
EXPl..ANATION
Qae
. Km~
Kdb
Jmb
Jmw·
Jmr
-----
LOESS
MANCOS SHALE
DAKOTA AND BURRO" CANYON
FORMATIONS (UNDIFFERENTIATED)
MORRISON FORMATION:
BRUSHY BASIN MEMBER
WESTWATER CANY.ON ~EMBER.
RECAPTURE MEMBER
CONTACT. DASHED WHERE APPROXIMATE .
N .
~'t•~ u,.,etG.c. IC!ea
1000 o :sooo eooo
liawwt;ea ;;4 I
SCALE IN FEET
Denison Mines (USA) Corp. OENISOJ)~J
MINES
roject: WHITE MESA MILL
County: SanJuan tate: Utah
FIGURE 1.6-2
WHITE MESA MILLSITE
GEOLOGY OF SURROUNDING AREA
~--------~~--------~===---------~ DOle: Nov. 2009 Design: ilr8fted By: RAH
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Maximum relief between the mesa's surface and Cottonwood Canyon on the west is about 750
feet (229 meters) where Westwater Creek joins Cottonwood Wash. These two streams and their
tributaries drain the west and south sides of White Mesa. Drainage on the east is provided by
Recapture Creek and its tributaries. Both Cottonwood Wash and Recapture Creeks are normally
intermittent streams and flow south to the San Juan River. However, Cottonwood Wash has
been known to flow perennially in the project vicinity during wet years.

1.6.2.2 Rock Units (1978 ER Section 2.4.2.2)

Only rocks of Jurassic and Cretaceous ages are exposed in the vicinity of the Mill site. These
include, in ascending order, the Upper Jurassic Salt Wash, Recapture, Westwater Canyon, and
Brushy Basin Members of the Morrison formation; the Lower Cretaceous Burro Canyon
formation; and the Upper Cretaceous Dakota Sandstone. The Upper Cretaceous Mancos Shale is
exposed as isolated remnants along the rim of Recapture Creek valley several miles southeast of
the Mill site and on the eastern flanks of the Abajo Mountains some 20 miles (32 kilometers)
north but is not exposed at the Mill site. However, patches of Mancos Shale may be present
within the Mill site boundaries as isolated buried remnants that are obscured by a mantle of
alluvial windblown silt and sand.

The Morrison formation is of particular economic importance in southeast Utah since several
hundred uranium deposits have been discovered in the basal Salt Wash Member (Stokes, 1967).

In most of eastern Utah, the Salt Wash Member underlies the Brushy Basin. However, just south
of Blanding in the project vicinity the Recapture Member replaces an upper portion of the Salt
Wash and the Westwater Canyon Member replaces a lower part of the Brushy Basin. A southern
limit of Salt Wash deposition and a northern limit of Westwater Canyon deposition has been
recognized by Haynes et al. (1972) in Westwater Canyon approximately three to six miles (4.8 to
9.7 kilometers), respectively, northwest of the Mill site. However, good exposures of Salt Wash
are found throughout the Montezuma Canyon area 13 miles (21 kilometers) to the east.
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The Salt Wash Member is composed dominantly of fluvial fine-grained to conglomeratic
sandstones, and interbedded mudstones. Sandstone intervals are usually yellowish-brown to pale
reddish-brown while the mudstones are greenish- and reddish-gray. Carbonaceous materials
("trash") vary from sparse to abundant. Cliff-forming massive sandstone and conglomeratic
sandstone in discontinuous beds make up to 50 percent or more of the member. According to
Craig et al. (1955), the Salt Wash was deposited by a system of braided streams flowing
generally east and northeast. Most of the uranium-vanadium deposits are located in the basal
sandstones and conglomeratic sandstones that fill stream-cut scour channels in the underlying
Bluff Sandstone, or where the Bluff Sandstone has been removed by pre-Morrison erosion, in
similar channels cut in the Summerville formation. Mapped thicknesses of this member range
from zero to approximately 350 feet (0-107 meters) in southeast Utah. Because the Salt Wash
pinches out in a southerly direction in Recapture Creek three miles (4.8 kilometers) northwest of
the Mill site and does not reappear until exposed in Montezuma Canyon, it is not known for
certain that the Salt Wash actually underlies the site.

The Recapture Member is typically composed of interbedded reddish-gray, white, and light-
brown fine- to medium-grained sandstone and reddish-gray, silty and sandy claystone. Bedding
is gently to sharply lenticular. Just north of the Mill site, the Recapture intertongues with and
grades into the Salt Wash and the contact between the two cannot be easily recognized. A few
spotty occurrences of uriniferous mineralization are found in sandstone lenses in the southern
part of the Monticello district and larger deposits are known in a conglomeratic sandstone facies
some 75 to 100 miles (121 to 161 kilometers) southeast of the Monticello district. Since
significant ore deposits have not been found in extensive outcrops in more favorable areas, the
Recapture is believed not to contain potential resources in the Mill site (Johnson and Thordarson,
1966).

Just north of the Mill site, the Westwater Canyon Member intertongues with and grades into the
lower part of the overlying Brushy Basin Member. Exposures of the Westwater Canyon in
Cottonwood Wash are typically composed of interbedded yellowish- and greenish-gray to
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pinkish-gray, lenticular, fine- to coarse-grained arkosic sandstone and minor amounts of
greenish-gray to reddish-brown sandy shale and mudstone. Like the Salt Wash, the Westwater
Canyon Member is fluvial in origin, having been deposited by streams flowing north and
northwest, coalescing with streams from the southwest depositing the upper part of the Salt
Wash and the lower part of the Brushy Basin (Huff and Lesure, 1965). Several small and
scattered uranium deposits in the Westwater Canyon are located in the extreme southern end of
the Monticello district. Both the Recapture Member and the Westwater Canyon contain only
traces of carbonaceous materials, are believed to be less favorable host rocks for uranium
deposition (Johnson and Thordarson, 1966) and have very little potential for producing uranium
reserves.

The lower part of the Brushy Basin is replaced by the Westwater Canyon Member in the
Blanding area but the upper part of the Brushy Basin overlies this member. Composition of the
Brushy Basin is dominantly variegated bentonitic mudstone and siltstone. Bedding is thin and
regular and usually distinguished by color variations of gray, pale-green, reddish-brown, pale
purple, and maroon. Scattered lenticular thin beds of distinctive green and red chert-pebble
conglomeratic sandstone are found near the base of the member, some of which contain
uranium-vanadium mineralization in the southernmost part of the Monticello district (Haynes et
al., 1972). Thin discontinuous beds of limestone and beds of grayish-red to greenish-black
siltstone of local extent suggest that much of the Brushy Basin is probably lacustrine in origin.

For the most part, the Great Sage Plain owes its existence to the erosion of resistant sandstones
and conglomerates of the Lower Cretaceous Burro Canyon formation. This formation
unconformably(?) overlies the Brushy Basin and the contact is concealed over most of the Mill
area by talus blocks and slope wash. Massive, light-gray to light yellowish-brown sandstone,
conglomeratic sandstone and conglomerate comprise more than two-thirds of the formation's
thickness. The conglomerate and sandstone are interbedded and usually grade from one to the
other. However, most of the conglomerate is near the base. These rocks are massive cross-
bedded units formed by a series of interbedded lenses, each lens representing a scour filled with
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stream-deposited sediments. In places the formation contains greenish-gray lenticular beds of
mudstone and claystone. Most of the Burro Canyon is exposed in the vertical cliffs separating
the relatively flat surface of White Mesa from the canyons to the west and east. In some places
the resistant basal sandstone beds of the overlying Dakota Sandstone are exposed at the top of
the cliffs, but entire cliffs of Burro Canyon are most common. Where the sandstones of the
Dakota rest on sandstones and conglomerates of the Burro Canyon, the contact between the two
is very difficult to identify and most investigators map the two formations as a single unit (Figure
1.6-2). At best, the contact can be defined as the top of a silicified zone in the upper part of the
Burro Canyon that appears to be remnants of an ancient soil that formed during a long period of
weathering prior to Dakota deposition (Huff and Lesure, 1965).

The Upper Cretaceous Dakota Sandstone disconformably overlies the Burro Canyon formation.
Locally, the disconformity is marked by shallow depressions in the top of the Burro Canyon
filled with Dakota sediments containing angular to sub-rounded rock fragments probably derived
from Burro Canyon strata (Witkind, 1964) but the contact is concealed at the Mill site. The
Dakota is composed predominantly of pale yellowish-brown to light gray, massive, intricately
cross-bedded, fine- to coarse-grained quartzose sandstone locally well-cemented with silica and
calcite; elsewhere it is weakly cemented and friable. Scattered throughout the sandstone are
lenses of conglomerate, dark-gray carbonaceous mudstones and shale and, in some instances,
impure coal. In general, the lower part of the Dakota is more conglomeratic and contains more
cross-bedded sandstone than the upper part which in normally more thinly bedded and marine-
like in appearance. The basal sandstones and conglomerates are fluvial in origin, whereas the
carbonaceous mudstones and shales were probably deposited in back water areas behind beach
ridges in front of the advancing Late Cretaceous sea (Huff and Lesure, 1965). The upper
sandstones probably represent littoral marine deposits since they grade upward into the dark-gray
siltstones and marine shales of the Mancos Shale.

The Mancos shale is not exposed in the project vicinity. The nearest exposures are small isolated
remnants resting conformably on Dakota Sandstone along the western rim above Recapture
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Creek 4.3 to 5.5 miles (6.9 to 8.9 kilometers) southeast of the Mill site. Additional exposures are
found on the eastern and southern flanks of the Abajo Mountains approximately 16 to 20 miles
(26 to 32 kilometers) to the north. It is possible that thin patches of Mancos may be buried at the
Mill site but are obscured by the mantle of alluvial windblown silt and sand covering the upland
surface. The Upper Cretaceous Mancos shale is of marine origin and consists of dark- to olive-
gray shale with minor amounts of gray, fine-grained, thin-bedded to blocky limestone and
siltstone in the lower part of the formation. Bedding in the Mancos is thin and well developed,
and much of the shale is laminated. Where fresh, the shale is brittle and fissile and weathers to
chips that are light- to yellowish-gray. Topographic features formed by the Mancos are usually
subdued and commonly displayed by low rounded hills and gentle slopes.

A layer of Quaternary to Recent reddish-brown eolian silt and fine sand is spread over the
surface of the Mill site. Most of the loess consists of subangular to rounded frosted quartz grains
that are coated with iron oxide. Basically, the loess is massive and homogeneous, ranges in
thickness from a dust coating on the rocks that form the rim cliffs to more than 20 feet (6
meters), and is partially cemented with calcium carbonate (caliche) in light-colored mottled and
veined accumulations which probably represent ancient immature soil horizons.

1.6.2.3 Structure (1978 ER Section 2.4.2.3)

The geologic structure at the Mill site is comparatively simple. Strata of the underlying
Mesozoic sedimentary rocks are nearly horizontal; only slight undulations along the caprock
rims of the upland are perceptible and faulting is absent. In much of the area surrounding the
Mill site the dips are less than one degree. The prevailing regional dip is about one degree to the
south. The low dips and simple structure are in sharp contrast to the pronounced structural
features of the Comb Ridge Monocline to the west and the Abajo Mountains to the north.

The Mill area is within a relatively tectonically stable portion of the Colorado Plateau noted for
its scarcity of historical seismic events. The epicenters of historical earthquakes from 1853
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through 1986 within a 200-mile (320 km) radius of the site are shown in Figure 1.6-3. More than
1,146 events have occurred in the area, of which at least 45 were damaging; that is, having an
intensity of VI or greater on the Modified Mercalli Scale. A description of the Modified
Mercalli Scale is given in Table 1.6-3. All intensities mentioned herein refer to this table. Table
1.6-3 also shows a generalized relationship between Mercalli intensities and other parameters to
which this review will refer. Since these relationships are frequently site specific, the table
values should be used only for approximation and understanding. Conversely, the border
between the Colorado Plateau and the Basin and Range Province and Middle Rocky Mountain

11~ t10W 108W
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~ NATIONAL GEOPHYSICAL DATA CENTER I NOAA BOULDER, CO 80303
Denison Mines (USA) Corp. OENIISOJ)~~
MINES
Project: WHITE MESA MILL
County: San Juan lata: Utah
Dill&: Nov. 2009
FIGURE 1.6-3
SEISMICITY WITHIN 320 KM
OF THE WHITE MESA MILL
Design: Draltsd Bit: RAH
Page 1-113
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Table 1.6-3
Modified Mercalli Scale
Modified Mercalli Scale, 1956 Versiona
Intensity Effects v. † cm/s g ‡

M

I.

Not felt. Marginal and long-period effects of large earthquakes (for details see text).

3

II.

Felt by persons at rest on upper floors, or favorably placed.

III.

Felt indoors. Hanging objects swing. Vibration like passing of light trucks. Duration
estimated. May not be recognized as an earthquake.

0.0035-0.007

4

IV.

Hanging objects swing. Vibration like passing of heavy trucks or sensation of a jolt like a
heavy ball striking the walls. Standing motor cars rock. Windows, dishes, doors rattle.
Glasses clink. Crockery clashes. In the upper range of IV wooden walls and frame creak.

0.007-0.015

V.

Felt outdoors: direction estimated. Sleepers wakened. Liquids disturbed. Some spilled.
Small unstable objects displaced or upset. Doors swing close, open. Shutters, pictures move.
Pendulum clocks stop, start, change rate.

1-3

0.015-0.035

5

VI.

Felt by all. Many frightened and run outdoors. Persons walk unsteadily. Windows, dishes,
glassware broken. Knickknacks, books, etc. off shelves. Pictures off walls. Furniture moved
or overturned. Weak plaster and masonry D cracked. Small bells ring (church, school). Trees,
bushes shaken (visibly, or heard to rustle - CFR).

3-7

0.035-0.07

6

VII.

Difficult to stand. Noticed by drivers of motor cars. Hanging objects quiver. Furniture broken.
Damage to masonry D including cracks. Weak chimneys broken at roof line. Fall of plaster,
loose bricks, stones, tiles, cornices (also unbraced parapets and architectural ornaments - CFR).
Some cracks in masonry C. Waves on ponds: water turbid with mud. Small slides and caving
in along sand or gravel banks. Large bells ring. Concrete irrigation ditches damaged.

7-20

0.07-0.15

VIII.

Steering of motor cars affected. Damage to masonry C; partial collapse. Some damage to
masonry B; none is masonry A. Fall of stucco and some masonry walls. Twisting, fall of
chimneys, factory stacks, monuments, towers, elevated tanks. Frame houses moved on
foundations if not bolted down; loose panel walls thrown out. Decayed piling broken off.
Branches broken from trees. Changes in flow or temperature of springs and wells. Cracks in
wet ground and on steep slopes.

20-80

0.15-0.35

7

IX.

General panic. Masonry D destroyed, masonry C heavily damaged. Sometimes with complete
collapse, masonry B seriously damaged. (General damage to foundations - CFR). Frame
structures, if not bolted, shifted off foundations. Frames rocked. Serious damage to reservoirs.
Underground pipes broken. Conspicuous cracks in ground. In alluviated areas sand and mud
ejected, earthquake fountains, sand craters.

.80-200

0.35-0.7

8

X.

Most masonry and frame structures destroyed with their foundations. Some well-built wooden
structures and bridges destroyed. Serious damage to dams, dikes, embankments. Large
landslides. Water thrown on banks of canals, rivers, lakes, etc. Sand and mud shifted
horizontally on beaches and flat land. Rails bent slightly.

200-500

0.7-1.2

XI.

Rails bent greatly. Underground pipelines completely out of service.

>1.2

XII.

Damage nearly total. Large rock masses displaced. Lines of sight and level distorted. Objects
thrown into the air.

From Fig. 11.14
Note: Masonry A, B, C, D. To avoid ambiguity of language, the quality of masonry, brick or otherwise, is specified by the following
lettering (which has no connection with the conventional Class A, B, C construction).
· Masonry A : Good workmanship, mortar, and design reinforced, especially laterally, and bound together by using steel,
concrete, etc.; designed to resist lateral forces.
· Masonry B : Good workmanship and mortar; reinforced, but not designed to resist lateral forces.
· Masonry C : Ordinary workmanship and mortar; no extreme weaknesses such as non-ded-ia corners, but masonry is neither reinforced
nor designed against horizontal forces.
· Masonry D : Week materials such as adobe, poor mortar, low standards of workmanship, week horizontally. aFrom Richter (1958). 1Adapted with permission of W. H. Freeman and Company by Hunt (1984).
†Average peak ground velocity, cm/s.
‡Average peak acceleration (away from source).
§Magnitude correlation.
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Province some 155 to 240 miles (249 to 386 km) west and northwest, respectively, from the site
is one of the most active seismic belts in the western United States.

Only 63 non-duplicative epicenters have been recorded within a 120 mile (200 km) radius of the
Mill area (Figure 1.6-4). Of these, 50 had an intensity IV or less (or unrecorded) and two were
recorded as intensity VI. The nearest event occurred in the Glen Canyon National Recreation
Area approximately 38 miles (63 km) west-northwest of the Mill area. The next closest event
occurred approximately 53 miles (88 km) to the northeast. Just east of Durango, Colorado,
approximately 99 miles (159 km) due east of the Mill area, an event having local intensity of V
was recorded on August 29, 1941 (Hadsell, 1968). It is very doubtful that these events would
have been felt in the vicinity of Blanding.

Three of the most damaging earthquakes associated with the seismic belt along the Colorado
Plateau's western border have occurred in the Elsinore-Richfield are about 168 miles (270 km)
northwest of the Mill site. All were of intensity VIII. On November 13, 1901, a strong shock
caused extensive damage from Richfield to Parowan. Many brick structures were damaged;
rockslides were reported near Beaver. Earthquakes with the ejection of sand and water were
reported, and some creeks increased their flow. Aftershocks continued for several weeks (von
Hake, 1977). Following several weeks of small foreshocks, a strong earthquake caused major
damage in the Monroe-Elsinore-Richfield area on September 29, 1921. Scores of chimneys were
thrown down, plaster fell from ceilings, and a section of a new two-story brick wall collapsed at
Elsinore's schoolhouse. Two days later, on October 1, 1921, another strong tremor caused
additional damage to the area's structures. Large rockfalls occurred along both sides of the
Sevier Valley and hot springs were discolored by iron oxides (von Hake, 1977). It is probable
that these shocks may have been perceptible at the Mill site but they certainly would not have
caused any damage.

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I-IV • v •
VD a
IX a
NATIONAL GEOPHYSICAL DATA CENTER I NOAA BOULDER, CO 80303
Denison Mines (USA) Corp. OENIISONI)JJ
MINES
Project: WHITE MESA MILL
County: SanJuan 1 ::.1ate: Utah
FIGURE 1.6-4
SEISMICITY WITHIN 200 KM
OF THE WHITE MESA MILL
Dallo: Nov. 2009 I Design: 1 o,.,tted By: RAH
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Seven events of intensity VII have been reported within 320 kilometers (km) around Blanding,
Utah, which is the area shown in Figure 1.6-3. Of these, only two are considered to have any
significance with respect to the Mill site. On August 18, 1912, an intensity VII shock damaged
houses in northern Arizona and was felt in Gallup, New Mexico, and southern Utah. Rock slides
occurred near the epicenter in the San Francisco Mountains and a 50-mile (80 km) earth crack
was reported north of the San Francisco Range (Cater, 1970). Nearly every building in Dulce,
New Mexico, was damaged to some degree when shook by a strong earthquake on January 22,
1966. Rockfalls and landslides occurred 10 to 15 miles (16 to 24 km) west of Dulce along
Highway 17 where cracks in the pavement were reported (Hermann et al., 1980). Both of these
events may have been felt at the Mill site but, again, would certainly not have caused any
damage. Figure 1.6-4 shows the occurrence of seismic events within 200 km of Blanding.

1.6.2.4 Relationship of Earthquakes to Tectonic Structures

The majority of recorded earthquakes in Utah have occurred along an active belt of seismicity
that extends from the Gulf of California, through western Arizona, central Utah, and northward
into western British Columbia. The seismic belt is possibly a branch of the active rift system
associated with the landward extension of the East Pacific Rise (Cook and Smith, 1967). This
belt is the Intermountain Seismic Belt shown in Figure 1.6-5 (Smith, 1978).

~ I
• 2GG ~OOkm
~-. f. i
.. . .
: . .. --. . . . . . .
• • • ... 9 • .. -·-•:
"·
I i .
-l-···-.. r
Modified from Smith. 1978
SHOWS RELATIONSHIP OF THE COLORADO
PLATEAU PROVINCE TO MARCANAL BELTS
Denison Mines (USA) Corp. OENIISOJ)~~
MINES
Project: WHITE MESA MILL
County: San Juan lata: Utah
FIGURE 1.6-5
SEISMICITY OF THE WESTERN UNITED STATES
1950TO 1976
~ A¥ter Um•tG.o. l'l'ee ~ ~0~--.---------=~~lg-n•---------..D~~~~~~.-~--------~ >L-----------------------------------------------~~--~N~~·~rooo~--~----------~--_.._ ______ __.
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It is significant to note that the seismic belt forms the boundary zone between the Basin and
Range - Great Basin Provinces and the Colorado Plateau - Middle Rocky Mountain Provinces.
This block-faulted zone is about 47 to 62 miles (75 to 100 km) wide and forms a tectonic
transition zone between the relatively simple structures of the Colorado Plateau and the complex
fault-controlled structures of the Basin and Range Province (Cook and Smith, 1967).

Another zone of seismic activity is in the vicinity of Dulce, New Mexico, near the Colorado
border. This zone, which coincides with an extensive series of tertiary intrusives, may also be
related to the northern end of the Rio Grande Rift. This rift is a series of fault-controlled
structural depressions extending southward from southern Colorado through central New Mexico
and into Mexico. The rift is shown on Figure 1.6-5 trending north-south to the east of the Mill
area.

Most of the events south of the Utah border of intensity V and greater are located within 50 miles
(80 km) of post-Oligocene extrusives. This relationship is not surprising because it has been
observed in many other parts of the world (Hadsell, 1968).

In Colorado, the Rio Grande Rift zone is one of three siesmotectonic provinces that may
contribute energy to the study area. Prominent physiographic expression of the rift includes the
San Luis Valley in southern Colorado. The valley is a half-graben structure with major faulting
on the eastern flank. Extensional tectonics is dominant in the area and very large earthquakes
with recurrence intervals of several thousand years have been projected (Kirkham and Rodgers,
1981). Mountainous areas to the west of the Rio Grande rift province include the San Juan
Mountains. These mountains are a complex domicil uplift with extensive Oligocene and
Miocene volcanic cover. Many faults are associated with the collapse of the calderas and
apparently have not moved since. Faults of Neogene age exist in the eastern San Juan Mountains
that may be related to the extension of the Rio Grande rift. Numerous small earthquakes have
been felt or recorded in the western mountainous province despite an absence of major Neogene
tectonic faults (Kirkham and Rodgers, 1981).
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The third seismotectonic province in Colorado, that of the Colorado Plateau, extends into the
surrounding states to the west and south. In Colorado, the major tectonic element that has been
recurrently active in the Quaternary is the Uncompahgre uplift. Both flanks are faulted and
earthquakes have been felt in the area. The faults associated with the Salt Anticlines are
collapsed features produced by evaporite solution and flowage (Cater, 1970). Their non-tectonic
origin and the plastic deformation of the salt reduce their potential for generating even moderate-
sized earthquakes (Kirkham and Rodgers, 1981).

Case and Joesting (1972) have called attention to the fact that regional seismicity of the Colorado
Plateau includes a component added by basement faulting. They inferred a basement fault
trending northeast along the axis of the Colorado River through Canyonlands. This basement
faulting may be part of the much larger structure that Hite (1975) examined and Warner (1978)
named the Colorado lineament (Figure 1.6-6). This 1,300-mile (2,100 km) long lineament that
extends from northern Arizona to Minnesota is suggested to be a Precambrian wrench-fault
system formed some 2.0 to 1.7 billion years before present. While it has been suggested that the
Colorado lineament is a source zone for larger earthquakes (m = 4 to 6) in the west-central
United States, the observed spatial relationship between epicenters and the trace of the lineament
does not prove a casual relation (Brill and Nuttli, 1983). In terms of contemporary seismicity,
the lineament does not act as a uniform earthquake generator. Only specific portions of the
proposed structure can presently be considered seismic source zones and each segment exhibits
seismicity of distinctive activity and character (Wong, 1981). This is a reflection of the different
orientations and magnitudes of the stress fields along the lineament. The interior of the Colorado
Plateau forms a tectonic stress province, as defined by Zoback and Zoback (1980), that is
characterized by generally east-west tectonic compression. Only where extensional stresses from
the Basin and Range province of the Rio Grande rift extend into the Colorado Plateau would the
Colorado lineament in the local area be suspected of having the capability of generating a large
magnitude earthquake (Wong, 1984). At the present time, the well-defined surface expression of
regional extension is far to the west and far to the east of the Mill area.

SOURCE: WARNER. 1978
Denison Mines (USA) Corp. OENIISOJ)~~
MINES
Project: WHITE MESA MILL
County: San Juan lata: Utah
Dill&: Nov. 2009
FIGURE 1.6-6
COLORADO LINEAMENT
Design: Draltsd 8)1: RAH
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Work by Wong (1984) has helped define the seismicity of the whole Colorado Plateau. He
called attention to the low level (less than ML = 3.6) but high number (30) of earthquakes in the
Capitol Reef Area from 1978 to 1980 that were associated with the Waterpocket fold and the
Cainville monocline, two other major tectonic features of the Colorado Plateau. Only five
earthquakes in the sequence were of ML greater than three, and fault plane solutions suggest the
swarm was produced by normal faulting along northwest-trending Precambrian basement
structures (Wong, 1984). The significance of the Capitol Reef seismicity is its relatively isolated
occurrence within the Colorado Plateau and its location at a geometric barrier in the regional
stress field (Aki, 1979). Stress concentration that produces earthquakes at bends or junctures of
basement faults as indicated by this swarm may be expected to occur at other locations in the
Colorado Plateau Province. No inference that earthquakes such as those at Capitol Reef are
precursors for larger subsequent events is implied.

1.6.2.5 Potential Earthquake Hazards to Mill Area

The Mill site is located in a region known for its scarcity of recorded seismic events. Although
the seismic history for this region is barely 135 years old, the epicentral pattern, or fabric, is
basically set and appreciable changes are not expected to occur. Most of the larger seismic
events in the Colorado Plateau have occurred along its margins rather than in the interior central
region. Based on the region's seismic history, the probability of a major damaging earthquake
occurring at or near the Mill site is very remote. Studies by Algermissen and Perkins (1976)
indicate that southeastern Utah, including the site, is in an area where there is a 90 percent
probability that a horizontal acceleration of four percent gravity (0.04g) would not be exceeded
within 50 years. In 2002, the USGS updated the National Seismic Hazard Maps (NSHM), which
show peak ground and spectral accelerations at 2 percent and 10 percent probability of
exceedance in 50 years. From these maps, it is determined that there is a 98 percent probability
that a horizontal acceleration of 0.09g would not be exceeded within 50 years (Tetra Tech,
2006). Furthermore, an updated seismic hazard analysis performed by Tetra Tech (2010) for the
site determined that there is a 98 percent probability that a horizontal acceleration of 0.15g would
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not be exceeded within a 200-year design life of the tailings cells. The Tetra Tech (2010) report
is included in Appendix D.

1.6.3 Seismic Risk Assessment

Static and pseudostatic analyses were performed to establish the stability of the side slopes of the
tailings cells. These analyses, together with analyses of radon flux attenuation, infiltration,
freeze/thaw effects, biointrusion, settlement, liquefaction, dewatering, and erosion protection, are
summarized below, and are detailed in Appendix D.

The side slopes are designed at an angle of 5H:1V. Because the side slope along the southern
section of Cell 4A is the longest and the ground elevation drops rapidly at its base, this slope was
determined to be critical and is thus the focus of the stability analyses.

Slope stability analyses were performed for both static and pseudostatic loading conditions, as
discussed further in Section 3.3. These data and results are included in Appendix E of the
Updated Tailings Cover Design Report (MWH, 2011b), attached to the Reclamation Plan as
Appendix D.

1.6.3.1 Static Analysis

For the static analysis, a Factor of Safety ("FOS") of 1.5 or more was used to indicate an
acceptable level of stability. The calculated FOS is 4.30, which indicates that the slope should
be stable under static conditions. Results of the computer model simulations are included in
Appendix E of the Updated Tailings Cover Design Report, included as Appendix D to this
report.

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1.6.3.2 Pseudostatic Analysis (Seismicity)

The slope stability analysis described above was repeated under pseudostatic conditions in order
to estimate a FOS for the slope when a seismic coefficient of of 0.10g is applied. This seismic
coefficient corresponds to a peak ground acceleration of 0.15g at the site (Tetra Tech, 2010), a
more conservative value than was used in previous analyses by Titan (1996). The slope
geometry and material properties used in the pseudostaticanalysis are identical to those used in
the static stability analysis. A FOS of 1.1 or more was used to indicate an acceptable level of
stability under pseudostatic conditions. The calculated FOS is 2.82, which indicates that the
slope should be stable under dynamic conditions. Details of the analysis and the simulation
results are included in Appendix E of the Updated Tailings Cover Design Report, attached to the
Reclamation Plan as Appendix D.

1.7 Biota (1978 ER Section 2.9)

1.7.1 Terrestrial (1978 ER Section 2.9.1)

1.7.1.1 Flora (1978 ER Section 2.9.1.1)

The natural vegetation presently occurring within a 25-mile (40-km) radius of the site is very
similar to that of the potential, being characterized by pinyon-juniper woodland intergrading with
big sagebrush (Artemisia tridentata) communities. The pinyon-juniper community is dominated
by Utah juniper (Juniperus osteosperma) with occurrences of pinyon pine (Pinus edulis) as a
codominant or subdominant tree species. The understory of this community, which is usually
quite open, is composed of grasses, forbs, and shrubs that are also found in the big sagebrush
communities. Common associates include galleta grass (Hilaria jamesii), green ephedra
(Ephedra viridis), and broom snakewood (Gutierrezia sarothrae). The big sagebrush
communities occur in deep, well-drained soils on flat terrain, whereas the pinyon-juniper
woodland is usually found on shallow rocky soil of exposed canyon ridges and slopes.
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Seven community types are present on the Mill site (Table 1.7-1 and Figure 1.7-1). Except for
the small portions of pinyon-juniper woodland and the big sagebrush community types, the
majority of the plant communities within the site boundary have been disturbed by past grazing
and/or treatments designed to improve the site for rangeland. These past treatments include
chaining, plowing, and reseeding with crested wheatgrass (Agropyron desertorum). Controlled
big sagebrush communities are those lands containing big sagebrush that have been chained to
stimulate grass production. In addition, these areas have been seeded with crested wheatgrass.
Both grassland communities I and II are the result of chaining and/or plowing and seeding with
crested wheatgrass. The reseeded grassland II community is in an earlier stage of recovery from
disturbance than the reseeded grassland I community. The relative frequency, relative cover,
relative density, and importance values of species sampled in each community are presented in
Dames and Moore (1978b), Table 2.8-2. The percentage of vegetative cover in 1977 was lowest
on the reseeded grassland II community (10.7 percent) and highest on the big sagebrush
community (33 percent) (Table 1.7-2).

Based upon dry weight composition, most communities on the site were in poor range condition
in 1977 (Dames & Moore (1978b), Tables 2.8-3 and 2.8-4). Pinyon-juniper, big sagebrush, and
controlled big sagebrush communities were in fair condition. However, precipitation for 1977 at
the Mill site was classed as drought conditions (Dames & Moore (1978b), Section 2.8.2.1). Until
July, no production was evident on the site.

Based on the work completed by Dames & Moore in the 1978 ER, no designated or proposed
endangered plant species occur on or near the Mill site (Dames & Moore (1978b), Section
2.8.2.1). Of the 65 proposed endangered species in Utah at that time, six have documented
distributions on San Juan County. A careful review of the habitat requirements and known
distributions of these species by Dames & Moore in the 1978 ER indicated that, because of the
disturbed environment, these species would probably not occur on the Mill site. The Navago
Sedge has been added to the list as a threatened species since the 1978 ER.
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Table 1.7-1
Community Types and Expanse Within the Project site
Boundary

Expanse

Community Type

Ha

Acres

Pinyon-juniper Woodland

5

13

Big Sagebrush

113

278

Reseeded Grassland I

177

438

Reseeded Grassland II

121

299

Tamarisk-salix

3

7

Controlled Big Sagebrush

230

569

Disturbed

17

41

Table 1.7-2
Ground Cover For Each Community Within the Project Site Boundary

Percentage of Each Type of Cover

Community Type

Vegetative Cover

Litter

Bare Ground

Pinyon-juniper Woodlanda

25.9

15.6

55.6

Big Sagebrush

33.3

16.9

49.9

Reseeded Grassland I

15.2

24.2

61.0

Reseeded Grassland II

10.7

9.5

79.7

Tamarisk-salix

12.0

20.1

67.9

Controlled Big Sagebrush

17.3

15.3

67.4

Disturbed

13.2

7.0

80.0
aRock covered 4.4% of the ground.

I I
D
D
D
D
D
D
I
Pinyon-Juniper
Reseeded Grassland I
Reseeded Grassland II
Big Sagebrush
Controlled Big Sagebrush
Disturbed
• • I
1,000' 0
h .I
N
1,000' 2,000'
21
\
I
Denison Mines (USA) Corp I)ENISOJ)~~
MINES
REVISIONS Project: White Mesa Mill
Date By County: San Juan 1State: UT
1 Hl9 DLS Location:
07-11 GM
VEGETATION COMMUNilY TYPES
ON THE WHITE MESA MILL SITE
FIGURE 1.7-1 SCALE: 1" = 2,000' ~L_ ______________________________________ _J~~_J~Au~th~~-------T~D-ate~:M=·~~19~99~~~-Dra-fte_d_By,-~--~
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In completing the 2002 EA, NRC staff contacted wildlife biologists from the BLM and the Utah
Wildlife Service to gather local information on the occurrences of additional species surrounding
the Mill. In the 2002 EA, NRC staff concluded that the Navajo Sedge has not been observed in
the area surrounding Blanding, and is typically found in areas of moisture (2002 EA at 4).

1.7.1.2 Fauna (1978 ER Section 2.9.1.2)

Wildlife data have been collected through four seasons at several locations on the site. The
presence of a species was based on direct observations, trappings and signs such as the
occurrence of scat, tracks, or burrows. A total of 174 vertebrate species potentially occur within
the vicinity of the mill (Dames & Moore (1978b), Appendix D, previously submitted), 78 of
which were confirmed (Dames & Moore (1978b), Section 2.8.2.2).

Although seven species of amphibians are thought to occur in the area, the scarcity of surface
water limits the use of the site by amphibians. The tiger salamander (Ambystoma tigrinum) was
the only species observed. It appeared in the pinyon-juniper woodland west of the Mill site
(Dames & Moore (1978b), Section 2.8.2.2).

Eleven species of lizards and five snakes potentially occur in the area. Three species of lizards
were observed: the sagebrush lizard (Sceloparas graciosus), western whiptail (Cnemidophorus
tigris), and the short-horned lizard (Phrynosoma douglassi) (Dames & Moore (1978b), Section
2.8.2.2). The sagebrush and western whiptail lizard were found in sagebrush habitat, and the
short-horned lizard was observed in the grassland. No snakes were observed during the field
work.

Fifty-six species of birds were observed in the vicinity of the Mill site (Table 1.7-3). The
abundance of each species was estimated by using modified Emlen transects and roadside bird
counts in various habitats and seasons. Only four species were observed during the February
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Table 1.7-3
Birds Observed in the Vicinity of the White Mesa Project

Species

Relative Abundance and Statusa

Species

Relative Abundance and Statusa

Mallard

CP

Pinyon Jay

CP

Pintail

CP

Bushtit

CP

Turkey Vulture

US

Bewick's Wren

CP

Red-tailed Hawk

CP

Mockingbird

US

Golden Eagle

CP

Mountain Bluebird

CS

Marsh Hawk

CP

Black-tailed Gnatcatcher

H

Merlin

UW

Ruby-crowned Kinglet

CP

American Kestrel

CP

Loggerhead Shrike

CS

Sage Grouse

UP

Starling

CP

Scaled Quail

Not Listed

Yellow-rumped Warbler

CS

American Coot

CS

Western Meadowlark

CP

Killdeer

CP

Red-winged Blackbird

CP

Spotted Sandpiper

CS

Brewer's Blackbird

CP

Mourning Dove

CS

Brown-headed Cowbird

CS

Common Nighthawk

CS

Blue Grosbeak

CS

White-throated Swift

CS

House Finch

CP

Yellow-bellied Sapsucker

CP

American Goldfinch

CP

Western Kingbird

CS

Green-tailed Towhee

CS

Ash-throated Flycatcher

CS

Rufous-sided Towhee

CP

Say's Phoebe

CS

Lark Sparrow

CS

Horned Lark

CP

Black-throated Sparrow

CS

Violet-green Swallow

CS

Sage Sparrow

UC

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Barn Swallow CS Dark-eyed Junco CW

Cliff Swallow

CS

Chipping Sparrow

CS
Table 1.7-3
Birds Observed in the Vicinity of the White Mesa Project (continued)

Species

Relative Abundance and Statusa

Species

Relative Abundance and Statusa

Scrub Jay

CP

Brewer's Sparrow

CS

Black-billed Magpie

CP

White-crowned Sparrow

CS

Common Raven

CP

Song Sparrow

CP

Common Crow

CW

Vesper Sparrow

CS

aW. H. Behle and M. L. Perry, Utah Birds, Utah Museum of Natural History, University of Utah, Salt Lake City, 1975.

Relative Abundance Status
C = Common P = Permanent
U = Uncommon S = Summer Resident
H = Hypothetical W = Winter Visitant
Source: Dames & Moore (1978b), Table 2.8-5

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sampling. The most abundant species was the horned lark (Eremophila aepestis) followed by the
common raven (Corvus corax), which were both concentrated in the grassland. Avian counts
increased drastically in May. Based on extrapolation of the Emlen transect data, the avian
density on grassland of the Mill site during spring was about 123 per 100 acres (305 per square
kilometer). Of these individuals, 94 percent were horned larks and western meadowlarks
(Sturnella neglecta). This density and species composition are typical of rangeland habitats. In
late June the species diversity declined somewhat in grassland but peaked in all other habitats.
By October the overall diversity decreased but again remained the highest in grassland.

Raptors are prominent in the western United States. Five species were observed in the vicinity
of the site (Table 1.7-3). Although no nests of these species were located, all (except the golden
eagle, Aquila chrysaetos) have suitable nesting habitat in the vicinity of the site. The nest of a
prairie falcon (Falco mexicanus) was found about 3/4 mile (1.2 km) east of the site. Although no
sightings were made of this species, members tend to return to the same nests for several years if
undisturbed (Dames & Moore (1978b), Section 2.8.2.2).

Of several mammals that occupy the site, mule deer (Odocoileus hemionus) is the largest species.
The deer inhabit the project vicinity and adjacent canyons during winter to feed on the sagebrush
and have been observed migrating through the site to Murphy Point (Dames & Moore (1978b),
Section 2.8.2.2). Winter deer use of the project vicinity, as measured by browse utilization, is
among the heaviest in southeastern Utah [25 days of use per acre (61 days of use per hectare) in
the pinyon-juniper-sagebrush habitats in the vicinity of the Mill site]. In addition, this area is
heavily used as a migration route by deer traveling to Murphy Point to winter. Daily movement
during winter periods by deer inhabiting the area has also been observed between Westwater
Creek and Murphy Point. The present size of the local deer herd is not known.

Other mammals present at the site include the coyote (Canis latrans), red fox (Vulpes vulpes),
gray fox (Urocyon cineroargenteus), striped skunk (Mephitis mephitis), badger (taxidea taxus),
longtail weasel (Mustela frenata), and bobcat (Lynx rufus). Nine species of rodents were trapped
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or observed on the site, the deer mouse (Peromyscus maniculatus) having the greatest
distribution and abundance. Although desert cottontails (Sylvilagus auduboni) were uncommon
in 1977, black-tailed jackrabbits (Lepus californicus) were seen during all seasons.

In the 2002 EA, NRC staff noted that, in the vicinity of the site, the U.S. Fish and Wildlife
Service had provided the list set out in Table 3.12-1, of the endangered, threatened, and
candidate species that may occur in the area around the site.

Table 1.7-4
Endangered, Threatened and Candidate Species in the Mill Area
Common Name Scientific Name Status
Navajo Sedge Carex specuicola Threatened
Bonytail Chub Gila elegans Endangered
Colorado Pikeminnow Ptychocheilus Lucius Endangered
Humpback Chub Gila cypha Endangered
Razorback Sucker Xyrauchen texanus Endangered
Bald Eagle Haliaeetus leucocephalus Threatened
California Condor Gymnogyps californianus Endangered
Gunnison Sage Grouse Centrocercus minimus Candidate
Mexican Spotted Owl Strix occidentalis lucida Threatened
Southwestern Willow Flycatcher Empidonax traillii extimus Endangered
Western Yellow-billed Cuckoo Coccyzus americanus occidentalis Candidate
Black-footed Ferret Mustela nigripes Endangered
Source: 2002 EA

The 2002 EA also noted that, in addition, the species listed on Table 3.12-2 may occur within the
Mill area that are managed under Conservation Agreements/Strategies.

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Table 1.7-5
Species Managed Under Conservation Agreements/Strategies at the Mill Area
Common Name Scientific Name
Colorado River Cutthroat Trout Oncorhynchus clarki pleuriticus
Gunnison Sage Grouse Centrocercus minimus
Source: 2002 EA

For the 2002 EA, NRC staff contacted wildlife biologists from the BLM and the Utah Wildlife
Service to gather local information on the occurrences of these additional species surrounding
the Mill. NRC staff made the following conclusions (2002 EA p. 4):

While the ranges of the bald eagle, peregrine falcon, and willow flycatcher
encompass the project area, their likelihood of utilizing the site is extremely low.
The black-footed ferret has not been seen in Utah since 1952, and is not expected
to occur any longer in the area. The California Condor has only rarely been
spotted in the area of Moab, Utah, (70 miles north) and around Lake Powell
(approximately 50 miles south). The Mexican Spotted Owl is only found in the
mountains in Utah, and is not expected to be on the Mesa. The Southwestern
Willow Flycatcher, Western Yellow-billed Cuckoo, and Gunnison Sage Grouse
are also not expected to be found in the immediate area around the Mill site.

1.7.2 Aquatic Biota (1978 ER Section 2.9.2)

Aquatic habitat at the Mill site ranges temporally from extremely limited to nonexistent due to
the aridity, topography and soil characteristics of the region and consequent dearth of perennial
surface water. Two small stock watering ponds, are located on the Mill site a few hundred yards
from the ore pad area (See Figure 1.5-3 above). One additional small “wildlife pond”, east of
Cell 4A, was completed in 1994 to serve as a diversionary feature for migrating waterfowl (see
Figure 1.5-3 above). Although more properly considered features of the terrestrial environment,
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they essentially represent the total aquatic habitat on the Mill site. These ponds probably harbor
algae, insects, other invertebrate forms, and amphibians.

They also provide a water source for small mammals and birds. Similar ephemeral catch and
seepage basins are typical and numerous to the northeast of the Mill site and south of Blanding.

Aquatic habitat in the project vicinity is similarly limited. The three adjacent streams (Corral
Creek, Westwater Creek, and an unnamed arm of Cottonwood Wash) are only intermittently
active, carrying water primarily in the spring during increased rainfall and snowmelt runoff, in
the autumn, and briefly during localized but intense electrical storms. Intermittent water flow
most typically occurs in April, August, and October in those streams. Again, due to the
temporary nature of these steams, their contribution to the aquatic habitat of the region is
probably limited to providing a water source for wildlife and a temporary habitat for insect and
amphibian species.

In the 2002 EA, NRC staff concluded that (p. 4) no populations of fish are present on the project
site, nor are any known to exist in the immediate area of the site. Four species of fish designated
as endangered or threatened (the Bonytail Chub, Colorado Pikeminnow, Humpback Chub and
Razorback Sucker) occur in the San Juan River 18 miles south of the site, which Dames &
Moore noted in the 1978 ER (Section 2.8.2) is the closest habitat suitable for these species. NRC
staff further concluded that there are no discharges of Mill effluents to surface waters, and
therefore, no impacts are expected for the San Juan River due to operations of the Mill.

1.7.3 Background Radiation (2007 ER, Section 3.13.1)

All living things are continuously exposed to ionizing radiation from a variety of sources
including cosmic and cosmogenic radiation from space and external radiation from terrestrial
radionuclides such as uranium, thorium and potassium-40 that occur in the earth’s crust, in
building materials, in the air we breathe, the food we eat, the water we drink and in our bodies.
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Some exposures, such as that from potassium-40, are controlled by our body’s metabolism and
are relatively constant throughout the world, but exposures from sources such as uranium and
thorium in soils and especially from radon in homes can vary greatly, by more than a factor of
ten, depending on location.

In order to provide a context for exposures potentially attributable to radioactive emissions from
processing ores and alternate feed materials at the Mill, this section provides some general
background information on exposures to natural background radiation worldwide, in the United
States and in the Colorado Plateau region where the Mill is located.

1.7.3.1 The World

In general terms, the worldwide breakdown of natural background radiation sources can be
summarized as follows (UNSCEAR, 2000):

Cosmic and Cosmogenic 39 mrem/yr
Terrestrial 48 mrem/yr
Inhaled (Radon) 126 mrem/yr
Ingested 29 mrem /yr
Total (Average) 242 mrem/yr (116 mrem/yr excluding radon)

According to the United Nations Scientific Committee on the Effects of Atomic Radiation
(“UNSCEAR”), the actual doses can vary considerably from the nominal values listed above,
and around the world vary from this value by more than a factor of 10. For example, the dose
from cosmic and cosmogenic radiation varies with altitude. The higher the altitude, the less is
the protection offered by the earth’s atmosphere. The dose from external gamma radiation can
vary greatly depending on the levels of uranium and thorium series radionuclides in the local
soil. One example is the elevated gamma fields seen on natural sands containing heavy minerals
as for example in regions around the Indian Ocean, in Brazil, and New Jersey. The high
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variability in indoor radon concentrations is a major source of the variation in natural
background dose. The variability in the dose from radon arises from many factors, including:
variability in soil radium concentrations from place to place; variation both over time and
location in housing stock, heating and ventilating systems; and variations in individual habits.
The worldwide average ambient (i.e. outdoor) radon concentration is about 10 Bq/m3
(UNSCEAR, 2000) and the world average concentration of U-238 and Th-232 in soils is about
0.7 pCi/g (25 Bq/kg) (NRC, 1994).

The definition of “background radiation” in 10 CFR 20.1003 specifically includes global fallout
as it exists in the environment from the testing of nuclear explosive devices or from past nuclear
accidents such as Chernobyl that contribute to background radiation and are not under the control
of the licensee. The calculation of background radiation in this Section 3.13.1 is conservative
because it does not include such fallout in background radiation for the Mill site.

1.7.3.2 United States

In the United States, nominal average levels of natural background radiation are as follows
(National Council of Radiation Protection and Measurements (“NCRP”), 1987):

Cosmic and Cosmogenic 28 mrem/yr
Terrestrial 28 mrem/yr
Inhaled (Radon) 200 mrem/yr
Ingested 40 mrem /yr
Total (Average) 296 mrem/yr (96 mrem/yr excluding radon)

As shown above, in the United States, the average annual dose from natural background
radiation is about 296 mrem/yr (including radon). The actual annual dose from natural
background varies by region within the United States. For example, the average dose from
external terrestrial radiation for a person living on the Colorado Plateau is in the order of 63
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mrem/yr, which is considerably higher than the average dose from terrestrial radiation for a
person living in Florida, where the average annual dose from external terrestrial radiation is only
about 16 mrem/yr. (NRC, 1994; NCRP, 1987). No comparison made. In the United States,
outdoor radon levels vary widely from about 0.1 pCi/l in New York City to about 1.2 pCi/L in
Colorado Springs (NCRP, 1987), generally consistent with nominal worldwide values noted in
the previous section.

1.7.4 Mill Site Background (1978 ER Section 2.10)

Radiation exposure in the natural environment is due to cosmic and terrestrial radiation and to
the inhalation of radon and its daughters. Measurements of the background environmental
radioactivity were made at the Mill site using thermoluinescent dosimeters (“TLDs”). The
results indicate an average total body dose of 142 millirems per year, of which 68 millirems is
attributable to cosmic radiation and 74 millirems to terrestrial sources. The cosmogenic radiation
dose is estimated to be about 1 millirem per year. Terrestrial radiation originates from the
radionuclides potassium-40, rubidium-87, and daughter isotopes from the decay of uranium-238,
thorium-232, and, to a lesser extent, uranium-235. The dose from ingested radionuclides is
estimated at 18 millirems per year to the total body. The dose to the total body from all sources
of environmental radioactivity is estimated to be about 161 millirems per year.

The concentration of radon in the area is estimated to be in the range of 500 to 1,000 pCi/m3,
based on the concentration of radium-226 in the local soil. Exposure to this concentration on a
continuous basis would result in a dose of up to 625 millirems per year to the bronchial
epithelium. As ventilation decreases, the dose increases; for example, in unventilated enclosures,
the comparable dose might reach 1,200 millirems per year.

The medical total body dose for Utah is about 75 millirems per year per person. The total dose
in the area of the mill from natural background and medical exposure is estimated to be 236
millirems per year.
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1.7.5 Current Monitoring Data

The most recent data for gamma, vegetation, air and stack sampling, groundwater, surface water,
meteorological monitoring, and soil sampling discussed in the following sections are found in the
Semi-Annual Effluent Report for January through June 2011, included as Appendix A. See
Section 2.3.2.1 below for a more detailed discussion of the environmental monitoring programs
at the Mill.

1.7.5.1 Environmental Radon

Until 10 CFR 20 standards were reduced to 0.1 pCi/l, environmental radon concentrations were
determined by using Track Etch detectors. There was one detector at each of five environmental
monitoring stations with a duplicate at BHV-2, the nearest residence. See the Semi-Annual
Effluent reports, for maps showing these locations. After 1995, with concurrence of the NRC,
environmental radon concentrations are no longer measured at these locations due to the lack of
sensitivity of available monitoring methods to meet the new 10 CFR 20 standard of 0.1 pCi/l.

1.7.5.2 Environmental Gamma

Gamma radiation levels are determined by optically stimulated luminescence dosimeters
(“OSLs”). The OLDs are placed at the five environmental stations located around the perimeter
boundary of the mill site discussed above. The badges are exchanged quarterly. The data are
presented in Appendix A.

1.7.5.3 Vegetation Samples

Vegetation samples are collected at three locations around the Mill periphery. The sampling
locations are northeast, northwest, and southwest of the Mill facility. Vegetation samples are
collected three times per year. Vegetation results are included in Appendix A. No trends are
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apparent, as the Ra-226 and Pb-210 concentrations at each sampling location have remained
consistent.

1.7.5.4 Environmental Air Monitoring and Stack Sampling

Air monitoring at the Mill is conducted at five high volume (40 standard cubic feet per minute)
stations located around the periphery of the Mill. These locations are shown in Appendix A and
on Figure 2.3-1. BHV-1 is located at the northern Mill boundary at the meteorological station
site. BHV-2 is further north at the nearest residence. BHV-4 is south of Cell 3, BHV-5 is just
south of the ore storage pad and BHV-6 is located on a vector between the Mill site and the
White Mesa Ute Community. The Semi-Annual Effluent reports contain air monitoring data.
The results of the quarterly stack samples are also presented in Appendix A.

Pursuant to NRC License Amendment No. 41 for the Mill’s Source Material License No. SUA-
1358, air particulate radionuclide monitoring at BHV-3 was discontinued at the end of the third
quarter of 1995. Appendix A tables show the radionuclide concentrations at each location. No
apparent trends are evident.

1.7.5.5 Surface Water

The results of surface water monitoring are presented in the Semi-Annual Effluent Reports.
Cottonwood Creek is sampled Semi-annually and Westwater Creek is sampled on an annual
basis. No trends are apparent.

1.7.5.6 Meteorological Monitoring

The Semi-Annual Air Quality and Meteorology Monitoring Report for January 1, 2011 through
June 30, 2011 was provided by McVehil-Monnett and is included as Appendix F.

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2 EXISTING FACILITY

The following sections describe the construction history of the Mill; the Mill and Mill tailings
management facilities; Mill operations including the Mill circuit and tailings management; and
both operational and environmental monitoring.

2.1 Facility Construction History

The Mill is a uranium/vanadium mill that was developed in the late 1970s by Energy Fuels
Nuclear, Inc. (“EFN”) as an outlet for the many small mines that are located in the Colorado
Plateau and for the possibility of Milling Arizona Strip ores. At the time of its construction, it
was anticipated that high uranium prices would stimulate ore production. However, prices
started to decline about the same time as Mill operations commenced.

As uranium prices fell, producers in the region were affected and mine output declined. After
about two and one-half years, the Mill ceased ore processing operations altogether, began
solution recycle, and entered a total shutdown phase. In 1984, a majority ownership interest was
acquired by Union Carbide Corporation's (“UCC”) Metals Division which later became Umetco
Minerals Corporation (“Umetco”), a wholly-owned subsidiary of UCC. This partnership
continued until May 26, 1994 when EFN reassumed complete ownership. In May 1997, Denison
(then named International Uranium (USA) Corporation) and its affiliates purchased the assets of
EFN and is the current owner of the facility.

2.1.1 Mill and Tailings Management Facility

The Source Materials License Application for the Mill was submitted to the NRC on February 8,
1978. Between that date and the date the first ore was fed to the Mill grizzly on May 6, 1980,
several actions were taken including: increasing Mill design capacity, permit issuance from the
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United States Environmental Protection Agency (“EPA”) and the State of Utah, archeological
clearance for the Mill and tailings areas, and an NRC pre-operational inspection on May 5, 1980.

Construction on the tailings area began on August 1, 1978 with the movement of earth from the
area of Cell 2. Cell 2 was completed on May 4, 1980, Cell 1 on June 29, 1981, and Cell 3 on
September 2, 1982. In January of 1990 an additional cell, designated Cell 4A, was completed
and initially used solely for solution storage and evaporation. Cell 4A was only used for a short
period of time and then taken out of service because of concerns about the synthetic lining
system. In 2007, Cell 4A was retrofitted with a new State of Utah approved lining system and
was authorized to begin accepting process solutions in September, 2008. Cell 4A was put back
into service in October of 2008. Cell 4B was constructed in 2010 and authorized to begin
accepting process solutions in February 2011.

2.2 Facility Operations

In the following subsections, an overview of Mill operations and operating periods are followed
by descriptions of the operations of the Mill circuit and tailings management facilities.

2.2.1 Operating Periods

The Mill was operated by EFN from the initial start-up date of May 6, 1980 until the cessation of
operations in 1983. Umetco, as per agreement between the parties, became the operator of
record on January 1, 1984. The Mill was shut down during all of 1984. The Mill operated at
least part of each year from 1985 through 1990. Mill operations again ceased during the years of
1991 through 1994. EFN reacquired sole ownership on May 26, 1994, and the Mill operated
again during 1995 and 1996. After acquisition of the Mill by Denison and its affiliates several
local mines were restarted and the Mill processed conventional ore during 1999 and early 2000.
With the resurgence in uranium and vanadium prices in 2003, Denison reopened several area
mines and again began processing uranium and vanadium ores in April of 2008. Mill operations
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were suspended in May of 2009, and resumed in March of 2010. Typical employment figures
for the Mill are 110 during uranium-only operations and 140 during uranium/vanadium
operations.

Commencing in the early 1990s through today, the Mill has processed alternate feed materials
from time to time when the Mill has not been processing conventional ores. Alternate feed
materials are uranium-bearing materials other than conventionally mined uranium ores. The Mill
installed an alternate feed circuit in 2009 that will allow the Mill to process certain alternate feed
materials simultaneously with conventional ores.

2.2.2 Mill Circuit

While originally designed for a capacity of 1,500 dry tons per day (dtpd.), the Mill capacity was
boosted to the present rated design of 1980 dtpd prior to commissioning.

The Mill uses an atmospheric hot acid leach followed by counter current decantation (CCD).
This in turn is followed by a clarification stage which precedes the solvent extraction (SX)
circuit. Kerosene containing iso-decanol and tertiary amines extracts the uranium and vanadium
from the aqueous solution in the SX circuit. Salt and soda ash are then used to strip the uranium
and vanadium from the organic phase.

After extraction of the uranium values from the aqueous solution in SX, uranium is precipitated
with anhydrous ammonia, dissolved, and re-precipitated to improve product quality. The
resulting precipitate is then washed and dewatered using centrifuges to produce a final product
called "yellowcake." The yellowcake is dried in a multiple hearth dryer and packaged in drums
weighing approximately 800 to 1,000 lbs. for shipping to converters.

After the uranium values are stripped from the pregnant solution in SX, the vanadium values are
transferred to tertiary amines contained in kerosene and concentrated into an intermediate
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product called vanadium product liquor (VPL). An intermediate product, ammonium
metavanadate (AMV), is precipitated from the VPL using ammonium sulfate in batch
precipitators. The AMV is then filtered on a belt filter and, if necessary, dried. Normally, the
AMV cake is fed to fusion furnaces where it is converted to the Mill's primary vanadium
product, V2O5 tech flake, commonly called "black flake."

The same basic process steps used for the recovery of uranium from conventional ores are used
for the recovery of uranium from alternate feed materials, with some variations depending on the
particular alternate feed material.

The Mill processed 1,511,544 tons of conventional ore and other materials from May 6, 1980 to
February 4, 1983. During the second operational period from October 1, 1985 through
December 7, 1987, 1,023,393 tons of conventional ore were processed. During the third
operational period from July 1988 through November 1990, 1,015,032 tons of conventional ore
were processed. During the fourth operational period from August 1995 through January 1996,
203,317 tons of conventional ore were processed. In the fifth operational period, from May 1996
through September 1996, the Mill processed 3,868 tons of calcium fluoride alternate feed
material. From 1997 to early 1999, the Mill processed 58,403 tons from several additional
alternate feed stocks.

With rising uranium prices in the late 1990s, company mines were reopened in 1997, and 87,250
tons of conventional ore were processed in 1999 and early 2000. In 2002 and 2003, the Mill
processed 266,690 tons of alternate feed material from government cleanup projects. An
additional 40,866 tons of alternate feed materials were processed in 2007. An additional 1,401
tons of alternate feed materials were processed in 2008 through July of 2011. From April 2008
through July 2011 the Mill processed an additional 722,843 tons of conventional ore.

Inception to date material processed through July, 2011 totals 4,934,607 tons. This total is for all
processing periods and feeds combined.
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2.2.3 Tailings Management Facilities

Tailings produced by the Mill from conventional ores typically contain 30 percent moisture by
weight, have an in-place dry density of 86.3 pounds per cubic foot (calculated from Cell 2
volume and tons placed), have a size distribution with a significant -200 to -325 mesh size
fraction, and have a high acid and flocculent content. Tailings from alternate feed materials that
are similar physically to conventional ores, which comprise most of the tons of alternate feed
materials processed to date at the Mill, are similar to the tailings for conventional ores. Tailings
from some of the higher grade, lower volume alternate feed materials may vary somewhat from
the tailings from conventional ores, primarily in moisture and density content.

The tailings facilities at the Mill currently consist of four cells as follows:

 Cell 1, constructed with a 30-Millimeter (ml) PVC earthen-covered liner, is used for the
evaporation of process solution (Cell 1 was previously referred to as Cell 1-I, but is now
referred to as Cell 1);
 Cell 2, constructed with a 30-Millimeter (ml) PVC earthen-covered liner, is used for the
storage of barren tailings sands. This Cell is full and has been partially reclaimed;
 Cell 3, constructed with a 30-Millimeter (ml) PVC earthen-covered liner, is used for the
storage of barren tailings sands and solutions. This cell is partially filled and has been
partially reclaimed; and
 Cell 4A, constructed with a geosynthetic clay liner, a 60 Millimeter (mil) HDPE liner, a
300 mil HDPE geonet drainage layer, a second 60 mil HDPE liner, and a slimes drain
network over the entire cell bottom. This cell was placed into service in October of 2008.
 Cell 4B, constructed with a geosynthetic clay liner, a 60 Millimeter (mil) HDPE liner, a
300 mil HDPE geonet drainage layer, a second 60 mil HDPE liner, and a slimes drain
network over the entire cell bottom. This cell was placed into service in February of
2011.
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Total estimated design capacity of Cells 2, 3, 4A, and 4B is approximately eight million (mm)
tons. Figures 1.5-4 and 1.5-5 show the locations of the tailings cells.

2.2.3.1 Tailings Management

Constructed in shallow valleys or swale areas, the lined tailings facilities provide storage below
the existing grade and reduce potential exposure. Because the cells are separate and distinct,
individual tailings cells may be reclaimed as they are filled to capacity. This phased reclamation
approach minimizes the amount of tailings exposed at any given time and reduces potential
exposure to a minimum.

Slurry disposal has taken place in Cells 2, 3 and 4A. Tailings placement in Cell 2 and Cell 3 was
accomplished by means of the final grade method, described below.

The final grade method used in Cell 2 and Cell 3 calls for the slurry to be discharged until the
tailings surface comes up to near final grade. The discharge points are set up in the east end of
the cell, and the final grade surface is advanced to the slimes pool area. Coarse tailings sand
from the discharge points is graded into low areas to reach the final disposal elevation. When the
slimes pool is reached, the discharge points are then moved to the west end of the cell and
worked back to the middle. An advantage to using the final grade method is that maximum
beach stability is achieved by (1) allowing water to drain from the sands to the maximum extent,
and (2) allowing coarse sand deposition to help provide stable beaches. Another advantage is
that radon release and dust prevention measures (through the placement of the initial layer of the
final cover) are applied as expeditiously as possible.

Slurry disposal in Cell 4A is from several pre-determined discharge points located around the
north and east sides of the cell. Slurry discharge is only allowed on skid pads, or protective
HDPE sheets, to prevent damage to the synthetic lining system. Once tailings solids have reach
the maximum elevation around the perimeter of the cell, discharge points can be moved toward
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the interior of the cell. Slurry disposal in Cell 4B will be conducted in the same manner as Cell
4A. Cell 4B is currently only accepting process solutions.

2.2.3.2 Liquid Management

As a zero-discharge facility, the Mill must evaporate all of the liquids utilized during processing.
This evaporation currently takes place in four (4) areas:

 Cell 1, which is used for solutions only;
 Cell 3, in which tailings and solutions exist;
 Cell 4A, in which tailings and solutions exist; and
 Cell 4B, presently used for solutions only.

The original engineering design indicated a net water gain into the cells would occur during Mill
operations. As anticipated, this has been proven to be the case. In addition to natural
evaporation, spray systems have been used at various times to enhance evaporative rates and for
dust control. To minimize the net water gain, solutions are recycled back for use in the Mill
circuit from the active tailings cells to the maximum extent possible. Solutions from Cells 1, 3,
4A, and 4B are brought back to the CCD circuit where metallurgical benefit can be realized.
Recycle to other parts of the Mill circuit are not feasible due to the acidic condition of the
solution.

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2.3 Monitoring Programs

2.3.1 Monitoring and Reporting Under the Mill’s GWDP

2.3.1.1 Groundwater Monitoring

a) Plugged and Excluded Wells

Wells MW-6, MW-7, and MW-8 were plugged because they were in the area of Cell 3, as was
MW-13, in the Cell 4A area. Wells MW-9 and MW-10 are dry and have been excluded from the
monitoring program. MW-16 is dry and has been plugged as part of the tailings Cell 4B
construction.

b) Groundwater Monitoring at the Mill Prior to Issuance of the GWDP

At the time of renewal of the License by NRC in March, 1997 and up until issuance of the
GWDP in March 2005, the Mill implemented a groundwater detection monitoring program to
ensure compliance to 10 CFR Part 40, Appendix A, in accordance with the provisions of the
License. The detection monitoring program was in accordance with the report entitled, Points of
Compliance, White Mesa Uranium Mill, prepared by Titan Environmental Corporation,
submitted by letter to the NRC dated October 5, 1994 (Titan, 1994b). Under that program, the
Mill sampled monitoring wells MW-5, MW-11, MW-12, MW-14, MW-15 and MW-17, on a
quarterly basis. Samples were analyzed for chloride, potassium, nickel and uranium, and the
results of such sampling were included in the Mill’s Semi-Annual Effluent Monitoring Reports
that were filed with the NRC up until August 2004 and with the DRC subsequent thereto.

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Between 1979 and 1997, the Mill monitored up to 20 constituents in up to 13 wells. That
program was changed to the Points of Compliance Program in 1997 because NRC had concluded
that:

 The Mill and tailings system had produced no impacts to the perched zone or deep
aquifer; and
 The most dependable indicators of water quality and potential cell failure were
considered to be chloride, nickel, potassium and natural uranium.

c) Issuance of the GWDP

On March 8, 2005, the Executive Secretary issued the GWDP, which includes a groundwater
monitoring program that supersedes and replaces the groundwater monitoring requirements set
out in the License. Groundwater monitoring under the GWDP commenced in March 2005, the
results of which are included in the Mill’s Quarterly Groundwater Monitoring Reports that are
filed with the Executive Secretary.

d) Current Ground Water Monitoring Program at the Mill Under the GWDP

The current groundwater monitoring program at the Mill under the GWDP consists of
monitoring at 25 point of compliance monitoring wells: MW-1, MW-2, MW-3, MW-3A, MW-
5, MW-11, MW-12, MW-14, MW-15, MW-17, MW-18, MW-19, MW-23, MW-24, MW-25,
MW-26, MW-27, MW-28, MW-29, MW-30, MW-31, MW-32 MW-35, MW-36, and MW-37.
The locations of these wells are indicated on Figure 2.3-1.

HYDRO
GEO
CHEM, INC.APPROVED DATE REFERENCE FIGURE
CELL NO. 2
CELL NO. 4A
3332
MW-21

3000
BOUNDARY
PROPERTY
SCALE IN FEET
0
CELL NO. 1
MILL SITE
CELL NO. 4B
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-32
MW-33
MW-34
MW-35
PIEZ-1
PIEZ-2
PIEZ-3
PIEZ-4
PIEZ-5
MW-26
TW4-1
TW4-2
TW4-3
TW4-4
TW4-5
TW4-6
TW4-9
TW4-11
TW4-12
TW4-13
TW4-14
TW4-16
TW4-18
TW4-20
TW4-21
TW4-26
MW-04TW4-7 TW4-8
TW4-10
TW4-22
TW4-19
TW4-23
TW4-24
TW4-25
TWN-1
TWN-2
TWN-3
TWN-4
TWN-5
TWN-6
TWN-7
TWN-8
TWN-9
TWN-10
TWN-11 TWN-12
TWN-13
TWN-14
TWN-15
TWN-16
TWN-17
TWN-18
TWN-19
MW-36
MW-37
MW-20
PIEZ-1
perched monitoring well
perched piezometer
temporary perched monitoring well
SITE PLAN
AND PERCHED WELL LOCATIONS
WHITE MESA SITE
H:/718000/aug11/welloc11.srf
TW4-19
EXPLANATION
wildlife pond
SJS
temporary perched nitrate
monitoring well
TWN-1
MW-34 perched monitoring well installed
August/September, 2010
perched monitoring well
installed April, 2011
MW-36
A-1
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Part I.E.1.(c) of the GWDP requires that each point of compliance well must be sampled for the
constituents listed in Table 2.3-1.

Table 2.3-1
Groundwater Monitoring Constituents Listed in Table 2 of the GWDP

Nutrients:
Ammonia (as N) Nitrate & Nitrite (as N)

Heavy Metals:
Arsenic
Beryllium
Cadmium
Chromium
Cobalt
Copper
Iron
Lead
Manganese
Mercury
Molybdenum
Nickel
Selenium
Silver
Thallium
Tin
Uranium
Vanadium
Zinc

Radiologics:
Gross Alpha

Volatile Organic Compounds:
Acetone
Benzene
2-Butanone (MEK)
Carbon Tetrachloride
Chloroform
Chloromethane
Dichloromethane
Naphthalene
Tetrahydrofuran
Toluene
Xylenes (total)

Others:
Field pH (S.U.)
Fluoride
Chloride
Sulfate
TDS

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Further, Part I.E.1.(d) of the GWDP, requires that, in addition to pH, the following field
parameters must also be monitored:

 Depth to groundwater
 Temperature
 Specific conductance

and that, in addition to chloride and sulfate, the following general organics must also be
monitored:

 Carbonate, bicarbonate, sodium, potassium, magnesium, calcium, and total anions and
cations.

Sample frequency depends on the speed of ground water flow in the vicinity of each well. Parts
I.E.1(b) and (c) of the GWDP provide that quarterly monitoring is required for all wells where
local groundwater average linear velocity has been found by the Executive Secretary to be equal
to or greater than 10 feet/year, and semi-annual monitoring is required where the local
groundwater average linear velocity has been found by the Executive Secretary to be less than 10
feet/year.

Based on these criteria, MW-11, MW-14, MW-25, MW-26, MW-30, MW-31, MW-35, MW-36
and MW-37 are monitored quarterly to collect background water quality data for the
establishment of GWCLs. Semi-annual monitoring is required at MW-1, MW-2, MW-3, MW-
3A, MW-5, MW-12, MW-15, MW-17, MW-18, MW-19, MW-23, MW-24, MW-27, MW-28,
MW-29 and MW-32.

In addition MW-20 and MW-22, which have been classified as general monitoring wells are
sampled semi-annually.
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2.3.1.2 Deep Aquifer

The culinary well (one of the supply wells) is completed in the Navajo aquifer, at a depth of
approximately 1,800 feet below the ground surface. Due to the fact that the deep confined
aquifer at the site is hydraulically isolated from the shallow perched aquifer (see the discussion
in Sections 1.5.1.1 and 1.5.1.2) no monitoring of the deep aquifer is required under the GWDP.

2.3.1.3 Seeps and Springs

Pursuant to Part I.E.6 of the GWDP, Denison has a Sampling Plan for Seeps and Springs in the
Vicinity of the White Mesa Uranium Mill, Revision: 0, March 17, 2009 (the “SSSP”) (and as
modified on June 10, 2011, Revision 1 – submitted to UDEQ for review) that requires the Mill to
perform groundwater sampling and analysis of all seeps and springs found downgradient or
lateral gradient from the tailings cells.

Under the SSSP, seeps and springs sampling is conducted on an annual basis between May 1 and
July 15 of each year, to the extent sufficient water is available for sampling, at five identified
seeps and springs near the Mill. The sampling locations were selected to correspond with those
seeps and springs sampled for the initial Mill site characterization performed in the 1978 ER,
plus additional sites located by Denison, the BLM and Ute Mountain Ute Indian Tribe
representatives.

Samples are analyzed for all groundwater monitoring parameters found in Table 2.3-1 above.
The laboratory procedures utilized to conduct the analyses of the sampled parameters are those
utilized for groundwater sampling. In addition to these laboratory parameters, the pH,
temperature and conductivity of each sample will be measured and recorded in the field.
Laboratories selected by Denison to perform analyses of seeps and springs samples will be
required to be certified by the State of Utah in accordance with UAC R317-6-6.12.A.

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The seeps and springs sampling events will be subject to the Mill’s QAP, unless otherwise
specifically modified by the SSSP to meet the specific needs of this type of sampling.

2.3.1.4 Discharge Minimization Technology and Best Available Technology Standards and
Monitoring

a) General

Part I.D. of the GWDP sets out a number of Discharge Minimization Technology (“DMT”) and
Best Available Technology (“BAT”) standards that must be followed. Part I.E. of the GWDP
sets out the Ground Water Compliance and Technology Performance Monitoring requirements,
to ensure that the DMT and BAT standards are met. These provisions of the GWDP, along with
the White Mesa Mill Tailings Management System and Discharge Minimization (DMT)
Monitoring Plan, 1/11 Revision: Denison-11.1 (the “DMT Plan”) (Section 3.1 of Denison,
2011b), the Cell 4A and 4B BAT Monitoring, Operations and Maintenance Plan and other plans
and programs developed pursuant to such Parts of the GWDP, set out the methods and
procedures for inspections of the facility operations and for detecting failure of the system.

In addition to the programs discussed above, the following additional DMT and BAT
performance standards and associated monitoring are required under Parts I.D and I.E. of the
GWDP.

b) Tailings Cell Operation

Part I.D.2 of the GWDP provides that authorized operation and maximum disposal capacity in
each of the existing tailings cells. Cells 1 and 4B shall not exceed the levels authorized by the
License and that under no circumstances shall the freeboard be less than three feet, as measured
from the top of the flexible membrane liner (“FML”). Part I.E.7(a) of the GWDP requires that
the wastewater pool elevations in Cells 1, 3, 4A and 4B must be monitored weekly to ensure
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compliance with the maximum wastewater elevation criteria mandated by Condition 10.3 of the
License, and in the case of Cell 4A to provided head information used in determining the
allowable leakage rate through the FML

Part I.D.2 further provides that any modifications by Denison to any approved engineering
design parameter at these existing tailings cells requires prior Executive Secretary approval,
modification of the GWDP and issuance of a construction permit.

c) Slimes Drain Monitoring

Part I.D.3(b)(1) of the GWDP requires that Denison must at all times maintain the average
wastewater head in the slimes drain access pipe to be as low as reasonably achievable (ALARA)
in each tailings disposal cell, in accordance with the approved DMT Plan. Compliance will be
achieved when the average annual wastewater recovery elevation in the slimes drain access pipe,
determined pursuant to the currently approved DMT Plan meets the conditions in Equation 1
specified in Part I.D.3(b)(1) of the GWDP.

Part I.E.7(b) of the GWDP requires that Denison must monitor and record quarterly the depth to
wastewater in the slimes drain access pipes as described in the currently approved DMT Plan at
Cell 2, and upon commencement of de-watering activities, at Cell 3, in order to ensure
compliance with Part I.D.3(b)(1) of the GWDP.

d) Maximum Tailings Waste Solids Elevation

Part I.D.3(c) of the GWDP requires that upon closure of any tailings cell, Denison must ensure
that the maximum elevation of the tailings waste solids does not exceed the top of the FML.

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e) Wastewater Elevation in Roberts Pond

Part I.D.3(e) of the GWDP requires that Roberts Pond be operated so as to provide a minimum
2-foot freeboard at all times, and that under no circumstances will the water level in the pond
exceed an elevation of 5,624 feet above mean sea level. Part I.D.3(e) also provides that in the
event the wastewater elevation exceeds this maximum level, Denison must remove the excess
wastewater and place it into containment in Cell 1 within 72 hours of discovery.

Part I.E.7(c) of the GWDP requires that the wastewater level in Roberts Pond must be monitored
and recorded weekly, in accordance with the currently approved DMT Plan, to determine
compliance with the DMT operations standard in Part I.D.3(e) of the GWDP;

f) Inspection of Feedstock Storage Area

Part I.D.3(f) of the GWDP requires that open-air or bulk storage of all feedstock materials at the
Mill facility awaiting Mill processing must be limited to the eastern portion of the Mill site (the
“ore pad”) described by the coordinates set out in that Part of the GWDP, and that storage of
feedstock materials at the facility outside of this defined area, must meet the requirements of Part
I.D.11 of the GWDP. Part I.D.11 requires that Denison must store and manage feedstock
materials outside the defined ore storage pad in accordance with the following minimum
performance requirements:

(i) Feedstock materials will be stored at all times in water-tight containers, and
(ii) Aisle ways will be provided at all times to allow visual inspection of each and
every feedstock container, or
(iii) Each and every feedstock container will be placed inside a water-tight overpack
prior to storage, or
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(iv) Feedstock containers shall be stored on a hardened surface to prevent spillage
onto subsurface soils, and that conforms with the following minimum physical
requirements:
A. A storage area composed of a hardened engineered surface of asphalt or
concrete, and
B. A storage area designed, constructed, and operated in accordance with
engineering plans and specifications approved in advance by the
Executive Secretary. All such engineering plans or specifications
submitted shall demonstrate compliance with Part I.D.4 of the GWDP, and
C. A storage area that provides containment berms to control stormwater run-
on and run-off, and
D. Stormwater drainage works approved in advance by the Executive
Secretary, or
(v) Other storage facilities and means approved in advance by the Executive
Secretary.

Part I.E.7(d) of the GWDP requires that Denison conduct weekly inspections of all feedstock
storage areas to:

(i) Confirm that the bulk feedstock materials are maintained within the approved
feedstock storage area specified by Part I.D.3(f) of the GWDP; and
(ii) Verify that all alternate feedstock materials located outside the approved
feedstock storage area are stored in accordance with the requirements found in
Part I.D.11 of the GWDP.

Part I.E.7(e) further provides that Denison must conduct weekly inspections to verify that each
feed material container complies with the requirements of Part I.D.11 of the GWDP.

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The Mill’s Standard Operating Procedure under the License for inspection of the Mill’s ore pad
is contained in Section 3.3 of the DMT Plan.

g) Monitor and Maintain Inventory of Chemicals

Part I.D.3(g) of the GWDP requires that for all chemical reagents stored at existing storage
facilities and held for use in the milling process, Denison must provide secondary containment to
capture and contain all volumes of reagent(s) that might be released at any individual storage
area. Response to spills, cleanup thereof, and required reporting must comply with the
provisions of the Mill’s Emergency Response Plan (a copy of which is included as Appendix C),
as stipulated by Part I.D.10 of the GWDP. Part I.D.3(g) further provides that for any new
construction of reagent storage facilities, such secondary containment and control must prevent
any contact of the spilled or otherwise released reagent or product with the ground surface.

Part I.E.9 of the GWDP requires that Denison must monitor and maintain a current inventory of
all chemicals used at the facility at rates equal to or greater than 100 kg/yr. This inventory must
be maintained on-site, and must include:

(iii) Identification of chemicals used in the milling process and the on-site laboratory;
and
(iv) Determination of volume and mass of each raw chemical currently held in storage
at the facility.

2.3.1.5 BAT Performance Standards for Cell 4A

a) BAT Operations and Maintenance Plan

Part I.D.6 and I.D.13 of the GWDP provides that Denison must operate and maintain Cell 4A
and Cell 4B respectively so as to prevent release of wastewater to groundwater and the
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environment in accordance with the Mill’s Cell 4A BAT Monitoring, Operations and
Maintenance Plan, pursuant to Part I.H.19 of the GWDP. The Mill’s Cell 4A and 4B BAT
Monitoring, Operations and Maintenance Plan, 01/11 Revision: Denison 2.2 includes the
following performance standards:

(i) The fluid head in the leak detection system shall not exceed 1 foot above the
lowest point in the lower membrane liner;
(ii) The leak detection system maximum allowable daily leak rate shall not exceed
24,160 gallons/day for Cell 4A and 26, 145 gallons/day for Cell 4B;
(iii) After Denison initiates pumping conditions in the slimes drain layer in Cell 4A or
Cell 4B, Denison will provide continuous declining fluid heads in the slimes drain
layer, in a manner equivalent to the requirements found in Part I.D.3(b) for Cells
2 and 3; and
(iv) Under no circumstances shall the freeboard be less than 3-feet in Cell 4B, as
measured from the top of the FML.

b) Implementation of Monitoring Requirements Under the BAT Operations and
Maintenance Plan

The Cell 4A and 4B BAT Monitoring, Operations and Maintenance Plan also requires Denison
to perform the following monitoring and recordkeeping requirements:

(i) Weekly Leak Detection System (LDS) Monitoring - including:

A. Denison must 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 pumping
or monitoring equipment not repaired and made fully operational within
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24-hours of discovery shall constitute failure of BAT and a violation of the
GWDP;

B. Denison must measure the fluid head above the lowest point on the
secondary FML by the use of procedures and equipment approved by the
Executive Secretary. Under no circumstance shall fluid head in the leak
detection system sump exceed a 1-foot level above the lowest point in the
lower FML, not including the sump;

C. Denison must measure the volume of all fluids pumped from the leak
detection system. Under no circumstances shall the average daily leak
detection system flow volume exceed 24,160 gallons/day for Cell 4A or
26, 145 for Cell 4B; and

D. Denison must operate and maintain wastewater levels to provide a 3-foot
Minimum of vertical freeboard in tailings Cell 4B. Such measurement
must be made to the nearest 0.1 foot.

(ii) Slimes Drain Recovery Head Monitoring

Immediately after the Mill initiates pumping conditions in the Cell 4A or Cell 4B slimes drain
system, quarterly recovery head tests and fluid level measurements will be made in accordance
with the requirements of Parts I.D.3(b) and I.E.7(b) of the GWDP and any plan approved by the
Executive Secretary.

2.3.1.6 Stormwater Management and Spill Control Requirements

Part I.D.10 of the GWDP requires that Denison will manage all contact and non-contact
stormwater and control contaminant spills at the facility in accordance with the Mill’s
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stormwater best management practices plan. The Mill’s Stormwater Best Management Practices
Plan, Revision 1.3: June 12, 2008 (a copy of which is included as Appendix C) includes the
following provisions:

a) Protect groundwater quality or other waters of the state by design, construction, and/or
active operational measures that meet the requirements of the Ground Water Quality
Protection Regulations found in UAC R317-6-6.3(G) and R317-6-6.4(C);
b) Prevent, control and contain spills of stored reagents or other chemicals at the Mill site;
c) Cleanup spills of stored reagents or other chemicals at the Mill site immediately upon
discovery; and
d) Report reagent spills or other releases at the Mill site to the Executive Secretary in
accordance with UAC 19-5-114.

2.3.1.7 Tailings and Slimes Drain Sampling

Part I.E.10 of the GWDP requires that, on an annual basis, Denison must collect wastewater
quality samples from each wastewater source at each tailings cell at the facility, including
surface impounded wastewaters, and slimes drain wastewaters, pursuant to the Mill’s Tailings
and Slimes Drain Sampling Program, Revision 0, November 20, 2008 (the “WQSP”). All such
sampling must be conducted in August of each calendar year.

The purpose of the WQSP is to characterize the source term quality of all tailings cell
wastewaters, including impounded wastewaters or process waters in the tailings cells, and
wastewater or leachates collected by internal slimes drains. The WQSP requires:

 Collection of samples from the pond area of each active cell and the slimes drain of each
cell that has commenced de-watering activities;
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 Samples of tailings and slimes drain material will be analyzed at an offsite contract
laboratory and subjected to the analytical parameters included in Table 2 of the GWDP
(see Table 2.3-1 above) and general inorganics listed in Part I.E.1(d)(2)(ii) of the GWDP,
as well as semi-volatile organic compounds;
 A detailed description of all sampling methods and sample preservation techniques to be
employed;
 The procedures utilized to conduct these analyses will be standard analytical methods
utilized for groundwater sampling and as shown in Section 8.2 of the Mill’s QAP;
 The contracted laboratory will be certified by the State of Utah in accordance with UAC
R317-6-6.12A; and
 30-day advance notice of each annual sampling event must be given, to allow the
Executive Secretary to collect split samples of all tailings cell wastewater sources.

The tailings and slimes drain sampling events are subject to the Mill’s QAP, unless otherwise
specifically modified by the WQSP to meet the specific needs of this type of sampling.

2.3.2 Monitoring and Inspections Required Under the License

2.3.2.1 Environmental Monitoring

The environmental monitoring program is designed to assess the effect of Mill process and
disposal operations on the unrestricted environment. Delineation of specific equipment and
procedures is presented in the Mill’s Environmental Protection Manual, included as Appendix A
to the 2007 License Renewal Application.

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c) Ambient Air Monitoring

(i) Ambient Particulate

Airborne radionuclide particulate sampling is performed at five locations, termed BHV-1, BHV-
2, BHV-4, BHV-5 and BHV-6. With the approval of the NRC and effective November, 1995,
BHV-3 was removed from the active air particulate monitoring program. At that time, the Mill
proposed (and NRC determined) that a sufficient air monitoring data base had been compiled at
station BHV-3 to establish a representative airborne particulate radionuclide background for the
Mill. BHV-6 was installed by the Mill at the request of the White Mesa Ute Community. This
station began operation in July of 1999 and provides airborne particulate information in the
southerly direction between the Mill and the White Mesa Ute Community. Figure 2.3-2 shows
the locations of these air particulate monitoring stations.

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18
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FIGURE 2.3-2
A1A1>or: HRR Jllflll>: Feb 2007 J Draftad By: BM
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The present sampling system consists of high volume particulate samplers utilizing mass flow
controllers to maintain an air flow rate of approximately 32 standard cubic feet per minute.
Samplers are operated continuously with a goal for on-stream operating period at ninety percent.
Filter rotation is weekly with quarterly site compositing for particulate radionuclide analysis.
Analysis is done for U-natural, Th-230, Ra-226, and Pb-210.

See Section 3.13.1.7(a) of the 2007 ER for a summary of historic monitoring results for airborne
particulate.

(ii) Ambient Radon

With the approval of the NRC, Radon-222 monitoring at the BHV stations was discontinued in
1995, due to the unreliability of monitoring equipment available at that time to detect the new 10
CFR standard of 0.1 pCi/l. From that time until the present, the Mill demonstrated compliance
with the requirements of R313-15-301 by calculation authorized by the NRC in September 1995
and as contemplated by R313-15-302 (2) (a).

This calculation was performed by use of the MILDOS code for estimating environmental
radiation doses for uranium recovery operations (Strenge and Bender 1981) in 1991 in support of
the Mill’s 1997 license renewal and more recently in 2007 in support of the 2007 License
Renewal Application, by use of the updated MILDOS AREA code (Yuan et al., 1998). The
analysis under both the MILDOS and MILDOS AREA codes assumed the Mill to be processing
high grade Arizona Strip ores at full capacity, and calculated the concentrations of radioactive
dust and radon at individual receptor locations around the Mill. Specifically, the modeling under
these codes assumed the following conditions:

 730,000 tons of ore per year
 Average grade of 0.53 percent U3O8
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 Yellowcake production of 4,380 tons of U3O8 per year (8.8 million pounds U3O8 per
year).

Based on these conditions, the MILDOS and MILDOS AREA codes calculated the combined
total effective dose equivalent from both air particulate and radon at the current nearest residence
(approximately 1.2 miles north of the Mill), i.e., the individual member of the public likely to
receive the highest dose from Mill operations, as well as at all other receptor locations, to be
below the ALARA goal of 10 mrem/yr for air particulate alone as set out in R313-15-101(4).
Mill operations are constantly monitored to ensure that operating conditions do not exceed the
conditions assumed in the above calculations. If conditions are within those assumed above,
radon has been calculated to be within regulatory limits. If conditions exceed those assumed
above, then further evaluation will be performed in order to ensure that doses to the public
continue to be within regulatory limits. Mill operations to date have never exceeded the License
conditions assumed above.

In order to determine if detection equipment has improved since 1995, the Mill has, commencing
with the first quarter of 2007, re-instituted direct measurements of radon at the five air particulate
monitoring locations currently utilized for air particulate sampling. The reliability of this data is
currently under review by Denison.

d) External Radiation

TLD badges, as supplied by Landauer, Inc., or equivalent, are utilized at BHV-1, BHV-2, BHV-
3, BHV-4, BHV-5 and BHV-6 to determine ambient external gamma exposures (see Figure 2.3-
1). System quality assurances are determined by placing a duplicate monitor at one site
continuously. Exchanges of TLD badges are on a quarterly basis. Badges consist of a minimum
of five TLD chips. Measurements obtained from location BHV-3 have been designated as
background due to BHV-3’s remoteness from the Mill site (BHV-3 is located approximately 3.5
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miles west of the Mill site). For further procedural information see Section 4.3 of the Mill’s
Environmental Protection Manual, included as Appendix A to the 2007 License Renewal
Application. See Section 3.13.1.7(c) of the 2007 ER for a summary of historic monitoring
results for external radiation.

e) Soil and Vegetation

(i) Soil Monitoring

Soil samples from the top one centimeter of surface soils are collected annually at each of BHV-
1, BHV-2, BHV-3, BHV-4 and BHV-5 (see Figure 2.3-1). A minimum of two kilograms of soil
is collected per site and analyzed for U-natural and Ra-226. For further procedural information
see Section 4.1 of the Mill’s Environmental Protection Manual included as Appendix A to the
2007 License Renewal Application. See Section 3.13.1.7.1 of the 2007 ER for a summary of the
historic results for soil monitoring. The 2007 ER concludes that the results of sampling are low,
less than the unrestricted release limits.

(ii) Vegetation Monitoring

Forage vegetation samples are collected three times per year from animal grazing locations to the
northeast (near BHV-l (the meteorological station)), northwest (to the immediate west of the site)
and southwest (by BHV-4) of the Mill site. Samples are obtained during the grazing season, in
the late fall, early spring, and in late spring. A minimum of three kilograms of vegetation are
submitted from each site for analysis of Ra-226 and Pb-210. For further procedure information
see Section 4.2 of the Mill’s Environmental Protection Manual included as Appendix A to the
2007 License Renewal Application. See Section 3.13.7(d) of the 2007 ER for a summary of the
historic results for vegetation monitoring. The 2007 ER concludes that the most recent results
indicate no increase in uptake of Ra-226 and Pb-210 in vegetation.

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d) Meteorological

Meteorological monitoring is done at a site near BHV-1. The sensor and recording equipment
are capable of monitoring wind velocity and direction, from which the stability classification is
calculated. Data integration duration is one-hour with hourly recording of mean speed, mean
wind direction, and mean wind stability (as degrees sigma theta).

The data from the meteorological station is retrieved monthly by down loading onto a Campbell
Scientific data module, or the equivalent. The data module is sent to an independent
meteorological contractor where the module is downloaded to a computer record, and the data is
correlated and presented in a Semi-Annual Meteorological Report.

Monitoring for precipitation consists of a daily log of precipitation using a standard NOAA rain
gauge, or the equivalent, installed near the administrative office, consistent with NOAA
specifications.

Windrose data is summarized in a format compatible with MILDOS and UDAD specifications
for 40 CFR 190 compliance. For further procedural information see Section 1.3 of the Mill’s
Environmental Protection Manual included as Appendix A to the 2007 License Renewal
Application. A windrose for the site is set out in Figure 1.1-1.

e) Point Emissions

Stack emission monitoring from yellowcake facilities follows EPA Method 5 procedures and
occurs on a quarterly basis, during operation of the facility. Particulate sampling is analyzed for
Unat on a quarterly basis and for Th-230, Ra-226, and Pb-210 on a semi-annual basis. Demister
and ore stack emission monitoring follows EPA Method 5 procedure on a semi-annual basis,
during operation of the facility. Particulate samples are analyzed for Unat, Th-230, Ra-226, and
Pb-2l0. Monitored data includes scrubber system operation levels, process feed levels,
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particulate emission concentrations, isokinetic conditions, and radionuclide emission
concentrations. For further procedure information see Section 1.4 of the Mill’s Environmental
Protection Manual included as Appendix A to the 2007 License Renewal Application. Historic
stack emission data are summarized in Section 3.13.1.7(e) of the 2007 ER.

f) Surface Water Monitoring

Surface water monitoring is conducted at two locations adjacent to the Mill facility known as
Westwater Canyon and Cottonwood Creek. Samples are obtained annually from Westwater and
quarterly from Cottonwood using grab sampling. For Westwater Creek, samples will be of
sediments if a water sample is not available. Field monitored parameters and laboratory
monitored parameters are listed in Table 2.3-2. For further procedural information see Section
2.1 of the Mill’s Environmental Protection Manual included as Appendix A to the 2007 License
Renewal Application. See Section 3.7.4 of the 2007 ER for a summary of the historic results for
surface water monitoring.

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Table 2.3-2
Operational Phase Surface Water Monitoring Program

Monitoring Sites
Westwater Creek and Cottonwood Creek

Field Requirements
1. temperature C;
2. Specific Conductivity umhos at 25 C;
3. pH at 25 C;
4. Sample date;
5. Sample ID Code;

Vendor Laboratory Requirements

Semiannual* Quarterly

One gallon Unfiltered and Raw One gallon Unfiltered and Raw
One gallon Unfiltered, Raw and preserved to
pH <2 with HNO3
One gallon Unfiltered, Raw and Preserved to
pH <2 with HNO3

Total Dissolved Solids Total Dissolved Solids
Total Suspended Solids Total Suspended Solids
Gross Alpha
Suspended Unat
Dissolved Unat
Suspended Ra-226
Dissolved Ra-226
Suspended Th-230
Dissolved Th-230
*Semiannual sample must be taken a minimum of four months apart.
**Annual Westwater Creek sample is analyzed for semi-annual parameters.
Radionuclides and LLDs reported in µCi/ml

2.3.2.2 Additional Monitoring and Inspections Required Under the License

Under the License daily, weekly, and monthly inspection reporting and monitoring are required
by NRC Regulatory Guide 8.31, Information Relevant to Ensuring that Occupational Radiation
Exposures at Uranium Recovery Facilities will be As Low As is Reasonable Achievable,
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Revision 1, May 2002 (“Reg Guide 8.31”), by Section 2.3 of the Mill’s ALARA Program and by
the DMT Plan, over and above the inspections described above that are required under the
GWDP. A copy of the Mill’s ALARA Program is included as Appendix I to the 2007 License
Renewal Application.

a) Daily Inspections

Three types of daily inspections are performed at the Mill under the License:

(i) Radiation Staff Inspections

Paragraph 2.3.1 of Reg. Guide 8.31 provides that the Mill’s Radiation Safety Officer (“RSO”) or
designated health physics technician should conduct a daily walk-through (visual) inspection of
all work and storage areas of the Mill to ensure proper implementation of good radiation safety
procedures, including good housekeeping that would minimize unnecessary contamination.
These inspections are required by Section 2.3.1 of the Mill’s ALARA Program, and are
documented and on file in the Mill’s Radiation Protection Office.

(ii) Operating Foreman Inspections

30 CFR Section 56.18002 of the Mine Safety and Health Administration regulations requires that
a competent person designated by the operator must examine each working place at least once
each shift for conditions which may adversely affect safety or health. These daily inspections are
documented and on file in the Mill’s Radiation Protection Office.

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(iii) Daily Tailings Inspection

Paragraph 2.2 of the DMT Plan requires that during Mill operation, the Shift Foreman, or other
person with the training specified in paragraph 2.4 of the DMT Plan, designated by the RSO, will
perform an inspection of the tailings line and tailings area at least once per shift, paying close
attention for potential leaks and to the discharges from the pipelines. Observations by the
Inspector are recorded on the appropriate line on the Mill’s Daily Inspection Data form.

b) Weekly Inspections

Three types of weekly inspections are performed at the Mill under the License:

(i) Weekly Inspection of the Mill Forms

Paragraph 2.3.1 of Reg. Guide 8.31 provides that the RSO and the Mill foreman should, and
Section 2.3.2 of the Mill’s ALARA Program provides that the RSO and Mill foreman, or their
respective designees, shall conduct a weekly inspection of all Mill areas to observe general
radiation control practices and review required changes in procedures and equipment. Particular
attention is to be focused on areas where potential exposures to personnel might exist and in
areas of operation or locations where contamination is evident.

(ii) Weekly Ore Storage Pad Inspection Forms

Paragraph 3.3 of the DMT Plan requires that weekly feedstock storage area inspections will be
performed by the Radiation Safety Department, to confirm that the bulk feedstock materials are
stored and maintained within the defined area of the ore pad and that all alternate feed materials
located outside the defined ore pad area are maintained within water tight containers. The results
of these inspections are recorded on the Mill’s Ore Storage/Sample Plant Weekly Inspection
Report.
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(iii) Weekly Tailings and DMT Inspection

Paragraphs 3.1 and 3.2 of the DMT Plan require that weekly inspections of the tailings area and
DMT requirements be performed by the radiation safety department.

c) Monthly Reports

Two types of monthly reports are prepared by Mill staff:

(i) Monthly Radiation Safety Reports

At least monthly, the RSO reviews the results of daily and weekly inspections, including a
review of all monitoring and exposure data for the month and provides to the Mill Manager a
monthly report containing a written summary of the month’s significant worker protection
activities (Section 2.3.4 of the Mill’s ALARA Program).

(ii) Monthly Tailings Inspection Reports

Paragraph 4 of the DMT Plan requires that a Monthly Inspection Data form be completed for the
monthly tailings inspection. This inspection is typically performed in the fourth week of each
month and is in lieu of the weekly tailings inspection for that week.

Mill staff also prepares a monthly summary of all daily, weekly, monthly and quarterly tailings
inspections.

d) Quarterly Tailings Inspections

Paragraph 5 of the DMT Plan requires that the RSO or his designee perform a quarterly tailings
inspection.
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e) Annual Evaluations

The following annual evaluations are performed under the License, as set out in Section 6 of the
DMT Plan.

(i) Annual Technical Evaluation

An annual technical evaluation of the tailings management system must be performed by a
registered professional engineer (PE), who has experience and training in the area of
geotechnical aspects of retention structures. The technical evaluation includes an on-site
inspection of the tailings management system and a thorough review of all tailings records for
the past year. The Technical Evaluation also includes a review and summary of the annual
movement monitor survey (see paragraph (ii) below).

All tailings cells and corresponding dikes are inspected for signs of erosion, subsidence,
shrinkage, and seepage. The drainage ditches are inspected to evaluate surface water control
structures.

In the event tailings capacity evaluations were performed for the receipt of alternate feed
material during the year, the capacity evaluation forms and associated calculation sheets will be
reviewed to ensure that the maximum tailings capacity estimate is accurate. The amount of
tailings added to the system since the last evaluation will also be calculated to determine the
estimated capacity at the time of the evaluation.

As discussed above, tailings inspection records consist of daily, weekly, monthly, and quarterly
tailings inspections. These inspection records are evaluated to determine if any freeboard limits
are being approached. Records will also be reviewed to summarize observations of potential
concern. The evaluation also involves discussion with the Environmental and/or Radiation
Technician and the RSO regarding activities around the tailings area for the past year. During
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the annual inspection, photographs of the tailings area are taken. The training of individuals is
also reviewed as a part of the Annual Technical Evaluation.

The registered engineer obtains copies of selected tailings inspections, along with the monthly
and quarterly summaries of observations of concern and the corrective actions taken. These
copies are then included in the Annual Technical Evaluation Report.

The Annual Technical Evaluation Report must be submitted by November 15th of every year to
the Executive Secretary and to the Directing Dam Safety Engineer, State of Utah, Natural
Resources.

(ii) Annual Movement Monitor Survey

A movement monitor survey is conducted by a licensed surveyor semi-annually for the first three
(3) years, and annually thereafter during the second quarter of each year. The movement
monitor survey consists of surveying monitors along dikes 4A-W, 4A-S and 4B-S to detect any
possible settlement or movement of the dikes. The data generated from this survey is reviewed
and incorporated into the Annual Technical Evaluation Report of the tailings management
system.

(iii) Annual Leak Detection Fluid Samples

In the event solution has been detected in a leak detection system in Cells 1, 2 or 3, a sample will
be collected on an annual basis. This sample will be analyzed according to the conditions set
forth in License Condition 11.3.C. The results of the analysis will be reviewed to determine the
origin of the solution.

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3 TAILINGS RECLAMATION PLAN

This section provides an overview of the Mill location and property; details the facilities to be
reclaimed; and describes the design criteria applied in this Plan. Reclamation plans and technical
specifications are presented in Attachment A. Attachment B presents the quality assurance and
quality control plan for construction activities. Attachment C presents cost estimates for
reclamation. Attachment D presents the Radiation Protection Manual for Reclamation.

3.1 Location and Property Description

The Mill is located approximately six miles south of Blanding, Utah on US Highway 191 on a
parcel of land encompassing all or part of Sections 21, 22, 27, 28, 29, 32, and 33 of T37S, R22E,
and Sections 4, 5, 6, 8, 9, and 16 of T38S, R22E, Salt Lake Base and Meridian described as
follows (Figure 3.1-1):

The south half of the south half of Section 21; the southeast quarter of the
southeast quarter of Section 22; the northwest quarter of the northwest quarter and
lots 1 and 4 of Section 27 all that part of the southwest quarter of the northwest
quarter and the northwest quarter southwest quarter of Section 27 lying west of
Utah State Highway 163; the northeast quarter of the northwest quarter, the south
half of the northwest quarter, the northeast quarter and the south half of Section
28; the southeast quarter of the southeast quarter of Section 29; the east half of
Section 32 and all of Section 33, Township 37 South, Range 22 East, Salt Lake
Base and Meridian. Lots 1 through 4, inclusive, the south half of the north half,
the southwest quarter, the west half of the southeast quarter, the west half of the
east half of the southeast quarter and the west half of the east half of the east half
of the southeast quarter of Section 4; Lots 1 through 4, inclusive, the south half of
the north half and the south half of Section 5 (all); Lots 1 and 2, the south half of
32 JJ •
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the northeast quarter and the south half of Section 6 (E1/2); the northeast quarter
of Section 8; all of Section 9 and all of Section 16, Township 38 South, Range 22
East, Salt Lake Base and Meridian. Additional land is controlled by 46 Mill site
claims. Total land holdings are approximately 5,415 acres.

3.2 Facilities to be Reclaimed

See the Drawings (Attachment A) for a general layout of the Mill yard and related facilities and
the restricted area boundary.

3.2.1 Summary of Facilities to be Reclaimed

The facilities to be reclaimed include the following:

 Cell 1 (evaporation). Cell 1 was previously referred to as Cell 1-I. It is now referred to
Cell 1;
 Cells 2, 3, 4A, and 4B (tailings);
 Mill buildings and equipment;
 On-site contaminated areas; and
 Off-site contaminated areas (i.e., potential areas affected by windblown tailings).

The reclamation of the above facilities will include the following:

 Placement of contaminated soils, crystals, and synthetic liner material and any
contaminated underlying soils from Cell 1 into the last active tailings cell;
 Placement of a compacted clay liner on a portion of the Cell 1 impoundment area to be
used for disposal of contaminated materials and debris from the Mill site;
 Decommissioning (the Cell 1 Tailings Area);
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 Placement of materials and debris from Mill decommissioning into the last active tailings
cell or Cell 1 Tailings Area cells;
 Placement of an engineered multi-layer cover over the entire area of Cells 2, 3, 4A, 4B,
and the Cell 1 Tailings Area;
 Construction of runoff control and diversion channels as necessary;
 Reclamation of Mill and ancillary areas; and
 Reclamation of borrow sources.

3.2.2 Tailings and Evaporative Cells

The following subsections describe the cover design and reclamation procedures for Cells 1, 2, 3,
4A, and 4B. Complete engineering details and text are presented in the Updated Tailings Cover
Design Report (MWH, 2011b) included as Appendix D to this Reclamation Plan.

3.2.2.1 Soil Cover Design

An ET cover was proposed by Denison for the White Mesa Mill disposal cells in the Infiltration
and Contaminant Transport Modeling (ICTM) reports (MWH 2007 and 2010) submitted to the
DRC to fulfill the White Mesa Mill’s Ground Water Discharge Permit No. UGW370004. A
conceptual design of the ET cover, to be placed over the uranium tailings and Mill
decommissioning materials in the Cell 1, Cell 2, Cell 3, Cell 4A and Cell 4B tailings area, was
provided in these reports. Denison stated their intent to submit an ET cover design as part of
their license renewal in a meeting with DRC on October 5, 2010 after review of the DRC
Reclamation Plan, Version 4.0 Interrogatories – Round 1 (DRC, 2010). The proposed
conceptual ET cover design was provided to DRC on October 7, 2010 and was essentially the
same as presented in the 2010 Infiltration and Contaminant Transport Model report (MWH,
2010). The ET cover proposed and evaluated as described in this report consists of the following
materials outlined below by individual layers and thicknesses from top to bottom:
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 0.5 ft (15 cm) Erosion Protection Layer (gravel-admixture)
 3.5 ft (107 cm) Water Storage/Biointrusion/Frost Protection/Radon Attenuation Layer
(random fill composed of loam to sandy clay)
 2.5 ft (75 cm) Radon Attenuation Layer (highly compacted random fill composed of loam
to sandy clay)
 2.5 ft (75 cm) Radon Attenuation and Grading Layer (random fill composed of loam to
sandy clay)

The 0.5-foot thick erosion protection layer is planned to be rock mulch consisting of topsoil
mixed with 25 percent gravel. The uppermost 3.5 feet of random fill will be placed at 85 percent
of standard Proctor compaction in order to optimize water storage and rooting characteristics for
plant growth. The middle layer (2.5 feet) of random fill will be compacted to 95 percent of
standard Proctor. The lower layer of random fill consists of 2.5 feet of random fill that is
assumed to be dumped and minimally compacted by construction equipment to approximately 80
percent standard Proctor. In Cell 2 and parts of Cell 3, the lower layer of random fill is already
placed and is approximately 3 feet thick. The upper 6 inches of this fill will be compacted to 95
percent of standard Proctor compaction and will thus comprise the bottom portion of the Radon
Attenuation Layer.

The majority of the cover will be constructed from materials available from within the site
boundaries. As a part of the soil cover, erosion protection will be placed as the top layer of the
cover to stabilize slopes and provide long-term erosion resistance (see Appendix D for
characterization of cover materials). The erosion protection materials will be obtained from off-
site sources.

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Uranium tailings soil cover design requirements for regulatory compliance include:

 Attenuate radon flux to an acceptable level (20 picoCuries-per meter squared-per second
[pCi/m2/sec]) (NRC, 1989) and 40 CFR 61.250-61.256;
 Minimize infiltration into the reclaimed tailings cells;
 Maintain a design life of up to 1,000 years to the extent reasonably achievable, and in any
case for at least 200 years; and
 Provide long-term slope stability and geomorphic durability to withstand erosional forces
of wind, the probable maximum flood event, and a horizontal ground acceleration of 0.1g
due to seismic events.

Several models/analyses were utilized in simulating the soil cover effectiveness: radon flux
attenuation, hydrologic evaluation of infiltration, freeze/thaw effects, soil cover erosion
protection, static and pseudostatic slope stability analyses, biointrusion, tailings dewatering,
liquefaction, and settlement. These analyses and results are discussed in detail in Sections 3.3.2
through 3.3.10, and calculations are also shown in the Updated Tailings Cover Design Report
(Appendix D).

The final grading plans are presented in the Drawings (Attachment A). As indicated in the
Drawings, the drainage on the top surface of the ET cover at Cells 1, 2, and 3 is planned at a 0.5
percent slope, with portions of Cell 2 top surface at a one percent slope and portions of Cells 4A
and 4B top surfaces at 0.8 percent slope. The side slopes, as well as transitional areas between
cells, will be graded to five horizontal to one vertical (5H:1V).

3.2.2.2 Cell 1

Cell 1, used during Mill operations solely for evaporation of process liquids, is the northernmost
existing cell and is located immediately west of the Mill. It is also the highest cell in elevation,
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as the natural topography slopes to the south. The drainage area above and including the cell is
216 acres. This includes drainage from the Mill site.

Cell 1 will be evaporated to dryness. The synthetic liner and raffinate crystals will then be
removed and placed in the tailings cells. Any contaminated soils below the liner will be
removed and also placed in the tailings cells. Based on current regulatory criteria, the current
plan calls for excavation of the residual radioactive materials to be designed to ensure that the
concentration of radium-226 in land averaged over any area of 100 square meters does not
exceed the background level by more than:

 5 pCi/g, averaged over the first 15 cm of soil below the surface, and
 15 pCi/g, averaged over a 15 cm thick layer of soil more than 15 cm below the surface.

A portion of Cell 1 (i.e., the Cell 1 Tailings Area), adjacent to and running parallel to the
downstream cell dike, may be used for permanent disposal of contaminated materials and debris
from the Mill site decommissioning and windblown cleanup. The actual area of the Cell 1
Tailings Area needed for storage of additional material will depend on the status of Cells 3, 4A,
and 4B at the time of final Mill decommissioning. A portion of the Mill area decommissioning
material may be placed in Cells 3, 4A or 4B if space is available, but for purposes of the
reclamation design the entire quantity of contaminated materials from the Mill site
decommissioning is assumed to be placed in the Cell 1 Tailings Area, which will subsequently
be covered with the ET cover. This results in approximately 10 acres of the Cell 1 area
constituting the Cell 1 Tailings Area and being utilized for permanent tailings storage. The
remaining area of Cell 1 will then be breached and converted to a sedimentation basin. All
runoff from the Cell 1 Tailings Area, the Mill area and the area immediately north of Cell 1 will
be routed into the sedimentation basin and will discharge onto the natural ground via the channel
located at the southwest corner of the basin. The channel is designed to accommodate the PMF
flood. Hydraulic and erosional analyses are provided in Appendix D. The channel will be a
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bedrock channel with a 0.1 percent channel slope, 150-foot bottom width, and 3 horizontal: 1
vertical sideslopes.

3.2.2.3 Cell 2

Cell 2 will be filled with tailings and covered with the ET cover to a minimum cover thickness of
nine feet. The final cover will drain to the south at a 0.5 percent gradient.

The cover will be as described in Section 3.2.2.1 above and will consist of a 2.5 feet of loam to
sandy clay, followed by 2.5 feet of highly compacted loam to sandy clay, overlain by 3.5 feet of
loam to sandy clay. 0.5 feet of rock mulch will be utilized as armor against erosion at the surface
of the cover. External side slopes or internal transition slopes will be graded to a 5:1 slope will
have 12 inches of angular riprap at the cover surface for erosion protection. A rock apron with a
thickness of 2 feet will be constructed at the transition areas of the toes of the side slopes of Cell
2.

3.2.2.4 Cell 3

Cell 3 will be filled with tailings, debris and contaminated soils and covered with the same ET
cover system and erosion protection as Cell 2.

3.2.2.5 Cell 4A

Cell 4A will be filled with tailings, debris and contaminated soils and will be covered with the
same ET cover system as Cell 2 and Cell 3. A rock apron with a thickness of 3.75 feet will be
constructed at the south and east side slopes of Cell 4A.

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3.2.2.6 Cell 4B

Cell 4B will be filled with tailings, debris, and contaminated soils and covered with the same ET
cover system as Cells 2, 3, and 4A.

3.3 Design Criteria

As required by Part I.H.11 of the GWDP, Denison has completed an infiltration and contaminant
transport model of the final tailings cover system to demonstrate the long-term ability of the ET
cover to protect nearby groundwater quality. The ET cover design and basis presented in
Appendix D (MWH, 2011b) will be used for this version of the Plan.

The design criteria summaries in this section are adapted from the Updated Tailings Cover
Design Report (MWH, 2011b). A copy of the Tailings Cover Design Report is included as
Appendix D. It contains all of the calculations used in design and summarized in this section.

3.3.1 Regulatory Criteria

Information contained in 10 CFR Part 20, 10 CFR Part 40 and Appendix A to 10 CFR Part 40
(which are incorporated by reference into UAC R313-24-4), and 40 CFR Part 192 were used as
criteria in final designs under this Plan. In addition, the following documents also provided
guidance:

 EPA, 1994, The Hydrologic Evaluation of Landfill Performance (HELP) Model, Version
3, EPA/600/R-94/168b, September
 NRC, 1989, Regulatory Guide 3.64 (Task WM-503-4) Calculation of Radon Flux
Attenuation by Earthen Uranium Mill Tailings Covers, March
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 NRC, 1984. Radon Attenuation Handbook for Uranium Mill Tailings Cover Design,
NUREG/CR-3533
 NRC, 1990, Final Staff Technical Position, Design of Erosion Protection Covers for
Stabilization of Uranium Mill Tailings Sites, August
 NUREG/CR-4620, Nelson, J. D., Abt, S. R., et al., 1986, Methodologies for Evaluating
Long-Term Stabilization Designs of Uranium Mill Tailings Impoundments, June
 Johnson, T.L., 2002. Design of Erosion Protection for Long-Term Stabilization. U.S.
Nuclear Regulatory Commission (NRC), NUREG-1623. September
 U. S. Department of Energy, 1988, Effect of Freezing and Thawing on UMTRA Covers,
Albuquerque, New Mexico, October
 NUREG 1620, 2003, Standard Review Plan for the Review of a Reclamation Plan for
Mill Tailings Sites Under Title II of the Uranium Mill Tailings Radiation Control Act of
1978; and
 U.S. Department of Energy, 1989. Technical Approach Document, Revision II, UMTRA-
DOE/AL 050425.0002, Uranium Mill Tailings Remedial Action Project, Albuquerque,
New Mexico

As mentioned above, the requirements set out in Part I.D.8 of the GWDP require that the cover
system for each tailings cell will be designed and constructed to meet the following minimum
performance requirements for a period of not less than 200 years:

 Minimize the infiltration of precipitation or other surface water into the tailings,
including, but not limited to the radon barrier;
 Prevent the accumulation of leachate head within the tailings waste layer that could rise
above or over-top the maximum FML elevation internal to any disposal cell, i.e. create a
“bathtub” effect; and
 Ensure that groundwater quality at the compliance monitoring wells does not exceed the
GWQSs or GWCLs specified in Part I.C.1 and Table 2 of the GWDP.
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3.3.2 Radon Flux Attenuation

Analyses of radon attenuation through the monolithic ET cover have been performed, and
incorporate the new cover design, changes to the final grading plan, and results of additional
geotechnical testing of material properties. The thickness of the ET cover necessary to limit
radon emanation from the disposal areas was analyzed using the NRC RADON model (NRC,
1989). The model was used to calculate the cover thickness required to achieve the State of
Utah’s long-term radon emanation standard for uranium mill tailings (Utah Administrative Code,
Rule 313-24), 20 picocuries per square meter per second (pCi/m2-s). The analyses were
conducted following the guidance presented in NRC publications NUREG/CR-3533 (NRC,
1984) and Regulatory Guide 3.64 (NRC, 1989).

The input parameters used in the model are based on engineering experience with similar
projects, recent laboratory testing results for samples of random fill (included in Appendix A.2),
and available data from previous work by others. Results of the RADON analyses show that the
proposed cover system reduces the rate of radon-222 emanation to less than 20 pCi/m2-s,
averaged over the entire area of the tailings impoundments. A complete description of the radon
attenuation analyses conducted for the ET cover system is included in Appendix D.

3.3.2.1 Empirical Data

Radon gas flux measurements have been made at the Mill tailings piles over Cells 2 and 3.
Currently Cell 2 is fully covered and Cell 3 is partially covered with three to four feet of random
fill. During the period 2004 through 2007, Cell 2 was only partially covered with such random
fill. Radon flux measurements, averaged over the covered areas, were as follows (Denison 2004-
2010):

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Table 3.3-1
Average Radon Flux From Tailings Cells 2004-2010
(pCi/m2/sec)
2004 2005 2006 2007 2008 2009 2010
Cell 2 13.9 7.1 7.9 13.5 3.9 3.9 3.9
Cell 3 10.8 6.2 10.0 8.9 3.1 3.1 3.1

Empirical data suggest that the random fill cover, alone, is currently providing an effective
barrier to radon flux. Thus, the proposed tailings cover configuration, which is thicker and
contains a highly compacted radon attenuation layer is expected to attenuate the radon flux to a
level below that predicted by the RADON model. The field radon flux measurements confirm
the conservatism of the cover design. This conservatism is useful, however, to guarantee
compliance with applicable regulations under long term climatic conditions over the required
design life of 200 to 1,000 years.

3.3.3 Infiltration Analysis

Infiltration modeling for the monolithic ET cover was completed by MWH and summarized in
the Infiltration and Contaminant Transport Modeling Report (MWH, 2010). These analyses
included the soil properties for materials proposed for use in the monolithic ET cover. The
evaluation of infiltration of precipitation through the cover system was evaluated with the
computer program HYDRUS-1D (Simunek et al., 2009). The modeling used historic values of
daily precipitation and evapotranspiration over a 57-year climate period, as well as assumptions
that were either conservative or based on anticipated conditions. Given the flat nature of the
cover (less than 1 percent slope), no runon- or runoff-based processes were assumed to occur.
As a result, precipitation applied to the cover surface was removed through evaporation or
transpiration, retained in the soil profile as storage, or transmitted downward as infiltration.

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The model-predicted water flux rate varies during the 57-year period from a minimum rate of
0.17 millimeters per year (mm/yr) to a maximum rate of 1.1 mm/yr, with an average long-term
flux rate through the cover system of 0.45 mm/yr. This average long-term water flux rate
corresponds to approximately 0.1 percent of the average annual amount of precipitation recorded
at the Blanding, Utah weather station.

The model-predicted water flux rate through the monolithic ET cover indicates that the available
storage capacity of the cover should be sufficient to significantly reduce infiltration, and the ET
cover should function properly as designed. A complete description of the infiltration analyses
conducted for the monolithic ET cover is provided in MWH (2010), and is included as a portion
of Appendix D to this Reclamation Plan.

3.3.4 Freeze/Thaw Evaluation

A freeze/thaw analysis was performed for the monolithic ET cover system, utilizing geotechnical
properties of materials specified for use in construction of the cover. The calculation of frost
penetration at the site was performed with the computer program ModBerg (CRREL), which
uses a built-in weather database, as well as user-defined soil parameters.

In summary, the freeze/thaw calculations show the total depth of frost penetration in the area of
the Mill site to be 27.1 inches (2.26 ft). This frost depth could potentially be exceeded in a given
year during the long-term design life of the cover, but the characteristics of the cover materials
are such that detrimental effects to the cover because of freezing and thawing are not expected.
Furthermore, because the cover has a total thickness of 9 feet, the impacts of freeze and thaw
will not have significant impacts to the overall integrity of the cover. A complete description of
the freeze/thaw analyses conducted for the proposed cover system is presented in the Updated
Tailings Cover Design Report (MWH, 2011b), attached as Appendix D to this Reclamation Plan.

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3.3.5 Soil Cover Erosion Protection

The erosional stability of the reclaimed tailings cells was evaluated in terms of long-term water
erosion under extreme storm conditions. An updated evaluation of erosional stability of the new
ET cover surface and reclaimed embankment slopes has been performed. The updated analyses
also include an evaluation of sheet erosion of the top slope of the cells, a rock apron at the toe of
the embankment slopes, and the need for filter material between riprap and the underlying soil.
The analyses have been conducted in general accordance with NRC guidelines (NRC, 1990;
Johnson, 2002). A detailed description of the analyses performed is presented in Appendix D.

The components of erosion protection for the reclaimed tailings cells consist of the following:
 The cover on the top surface of Cells 1, 2, and 3, with slopes of 0.5 percent, should be
constructed as a vegetated slope, with 6 inches of topsoil vegetated with a grass mixture.
 The portions of Cell 2 with a top surface of 1 percent slope, and the portions of Cells 4A
and 4B with 0.8 percent slope, should be constructed with 6 inches of topsoil mixed with
25 percent (by weight) gravel (maximum diameter of 1-inch).
 External side slopes or internal transition slopes graded to 5:1 (horizontal: vertical)
should be constructed with 12 inches of angular riprap with a median rock size of 7.4
inches.
 A rock apron is recommended for the south side slopes of the reclaimed surfaces of Cells
4A and 4B and the east side of Cell 4A. The rock apron should be constructed with 3.75
feet of angular riprap with a median rock size of 15 inches.
 A rock apron is recommended for the transition areas of the toes of the north and west
side slope and the east side slope of Cells 2 and 3. The rock apron should be constructed
with 2 feet of angular riprap with a median rock size of 7.4 inches.
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 A filter is recommended between the soil and rock protection, due to the size of riprap
required for the embankment slopes and the fine-grained nature of the underlying topsoil.

3.3.6 Slope Stability Analysis

Slope stability analyses have been performed for the new monolithic ET cover system, and
include updated geotechnical properties and seismic information, and an updated critical cross
section. The slope stability analyses were performed for both static (long-term) and pseudo-
static loading conditions, to meet NRC (2003) criteria. The analyses were performed using limit
equilibrium methods with the computer program SLOPE/W (Geo-Slope, 2007).

A complete description of the input parameters and assumptions used in the analyses are
included in Appendix D. The results of the stability analyses are provided in Table 3.3-2 below.
The minimum factors of safety required in design and presented in Table 3.3-2 meet the criteria
of NRC (2003). As shown in Table 3.3-2, the calculated factors of safety for both the long-term
static condition and the pseudo-static condition exceed the required values.

Table 3.3-2
Results of Slope Stability Analyses
Loading Condition Required Factor of
Safety
Calculated Factor of
Safety
Static Long-Term 1.5 4.30
Pseudo-static 1.1 2.82

3.3.7 Tailings Dewatering

An evaluation of the effects of dewatering in tailings Cells 2, 3, 4A and 4B was conducted to
estimate the time required to dewater the tailings, as well as to calculate the residual saturated
thickness of tailings after dewatering operations cease. Dewatering analyses for Cells 2 and 3
were conducted by MWH and are presented in Appendix J of MWH (2010). Dewatering
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analyses for Cells 4A and 4B were conducted by Geosyntec (2007a, 2007b). The pertinent
excerpts from MWH (2010), Geosyntec (2007a, 2007b), and DRC (2008) are included in
Appendix D.

3.3.7.1 Tailings Cells 2 and 3

Dewatering of Cells 2 and 3 will be performed via the drain network consisting of perforated
PVC pipe located across the base of the cells. The pipes drain to an extraction sump on the
southern side of each cell. Tailings water gravity drains to the sump and is then pumped to Cell
1 for evaporation. The design for the drains is the same for both cells, and each drain system
covers an approximate area of 400-feet by 600-feet in each cell. The drain pipes are covered by
an envelope of sand over the drains, in contrast to a continuous layer of sand across the bottom
of the tailing cells.

The analyses of dewatering of Cells 2 and 3 were performed with the computer code
MODFLOW (McDonald and Harbaugh, 1988; Harbaugh et al., 2000) with the Department of
Defense Groundwater Modeling System (GMS) pre- and post-processor. The slimes drains were
simulated with the Drain package in MODFLOW, and values of hydraulic conductivity were
based on measured values reported for uranium mill tailings at a similar facility (MWH, 2010).

The MODFLOW dewatering model completed for Cells 2 and 3 predicted that the tailings would
draindown nonlinearly through time reaching an average saturated thickness of 3.5 feet (1.07 m)
after 10 years of dewatering (MWH, 2010). The model also predicted that dewatering rates
would decline to approximately 2 gallons per minute (gpm) after 10 years of pumping. A
complete description of the dewatering modeling conducted for tailings Cells 2 and 3 is provided
in Appendix J of MWH (2010), and is attached as a portion of Appendix D of this Reclamation
Plan.

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3.3.7.2 Tailings Cells 4A and 4B

The drain network design in Cells 4A and 4B is the same for each cell, and is different from that
constructed in Cells 2 and 3. The drain network in Cells 4A and 4B consists of a series of 12-
inch wide HDPE strip drains wrapped in geotextile, and covered by sand bags. The drain
spacing is 50 feet across the entirety of both cells. The HDPE drains are connected to a
perforated 4-inch diameter PVC pipe bedded in drain aggregate and wrapped in geotextile. The
PVC pipe gravity drains the tailings water to the sump for extraction.

A tailings cell dewatering model was not constructed for Cells 4A and 4B because analytical
solutions presented by Geosyntec Consultants (2007a, 2007b) were deemed adequate given the
uniform distribution of the drain system in those cells. Material properties for tailings in Cells
4A and 4B were estimated based on results of laboratory tests. Results of the analyses indicated
the areas of Cells 4A and 4B with the maximum thickness of tailings will be drained within
approximately 5.5 years (Geosyntec Consultants, 2007a; 2007b). Cells 4A and 4B are estimated
to be dewatered significantly faster than Cells 2 and 3 due to the more extensive drain network.

3.3.8 Liquefaction

Liquefaction analyses were performed to evaluate the risk of earthquake-induced liquefaction of
the tailings. The analyses performed for the monolithic ET cover are an update to modeling
presented in the previous Reclamation Plan, Revision 4.0 (Denison, 2009a). These analyses
have been updated to incorporate the proposed monolithic ET cover system and a more recent
reference for liquefaction analyses (Youd et al., 2001). Material properties used in the analyses
were obtained from results of laboratory tests on tailings samples, or were estimated where site-
specific data was not available. Site-specific seismic hazard information from Tetra Tech (2010)
was used in the analysis and includes a peak ground acceleration of 0.15g for an approximate
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10,000 year return period, with the mean seismic source being a magnitude (Mw) 5.81 event
occurring 51.5 km from the site.

Based on the results of the liquefaction analysis, including assumed geotechnical material
properties and site-specific estimations of ground acceleration, the tailings are not susceptible to
earthquake-induced liquefaction. Computed factors of safety for an approximate 10,000 year
return period range from 1.3 to 1.9. A detailed discussion of the liquefaction analyses performed
is included in Appendix D.

3.3.9 Settlement

Settlement analyses were performed to evaluate the amount of tailings settlement expected to
occur due to placement of the interim cover, dewatering, and subsequent construction of the final
cover. Settlement of the tailings was modeled by applying loads corresponding to these loading
conditions. Historic monitoring data from monitoring points in Cells 2 and 3 were used to
estimate settlement parameters for calculation of future settlement. Material properties used in
the analyses were obtained from laboratory test results or estimated based on historic monitoring
data.

Settlement due to dewatering and placement of the interim cover is estimated to be
approximately 2 inches in Cell 2, and approximately 10 inches in Cells 3, 4A and 4B. After
placement of the interim cover, settlement monuments will be installed within Cells 3, 4A, and
4B. Monuments will be monitored on a regular basis in order to verify that most (90 percent) of
the settlement due to dewatering and interim cover placement has occurred prior to construction
of the final cover. The time required to reach 90 percent of total anticipated settlement ranges
from approximately 2.5 to 4 years. Additional settlement due to placement of the final cover is
estimated to be approximately 5 to 6 inches. The results of the analyses are summarized in Table
3.3-3. A detailed discussion of the settlement analyses performed for the ET cover is provided in
Appendix D.
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Table 3.3-3
Estimate of Future Settlement in Tailings Cells
Description Cell 2 Cell 3 Cells 4A/4B
Total Settlement due to Interim Cover
Placement and Dewatering 0.14 ft 0.83 ft 0.87 ft
Total Settlement due to Final Cover
Placement 0.42 ft 0.38 ft 0.38 ft
Time to Reach 90% Consolidation 2.6 yrs 3.8 yrs 4.1 yrs
Note: Values presented in table are based on average consolidation parameters (Cc and cv)

3.3.10 Soil Cover-Animal Intrusion

Based on a review of the wildlife survey data from the 1978 Environmental Report produced for
the White Mesa site (Dames & Moore, 1978b), and a thorough literature review of burrowing
depths and biointrusion studies, the maximum depth of on-site burrowing would be
approximately one meter or slightly over three feet. Wildlife survey data for the site identify
burrowing mammals as deer mice, kangaroo rats, chipmunks, desert cottontails, blacktailed
jackrabbits, and prairie dogs. Other burrowing mammals, such as pocket gophers and badgers
have not been observed in the area of the White Mesa site (Dames & Moore, 1978b). Of the list
of burrowing mammals that may occur on the site, the prairie dog is the species capable of
burrowing to the greatest depth. Studies by Shuman and Whicker (1986) and Cline et al. (1982)
conducted in southeast Wyoming, Grand Junction, Colorado and Hanford, Washington,
document maximum burrowing depths of prairie dogs between 60 and 100 cm. Based on this
empirical data and the potential species that may use the site as habitat, any burrowing activity
that may occur would be limited to about one meter below ground surface. In addition, prairie
dog habitat is characterized by low plant cover and vegetation that is short in vertical stature
(Holechek et al. 1998). The potential for prairie dogs colonizing the tailing cells is very low
because plant cover and stature will not match their habitat preferences. A complete discussion
of the evaluation of Biointrusion through the ET cover is presented in Appendix D.

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3.3.11 Soil Cover Vegetation

The plant species proposed for the cover system consist of native perennial grasses and forbs.
The use of these species in reclamation of the tailing cells should provide a permanent or
sustainable plant cover because of the highly adapted nature of these species to existing site
conditions, their tolerance to environmental stresses such as drought, fire, and herbivory, and
their ability to effectively reproduce over time. These species can coexist and fully utilize plant
resources to keep invasive weeds and deep rooted woody species from colonizing the site. Once
established, the proposed seed mixture should produce a grass-forb community of highly adapted
and productive species that can effectively compete with undesirable species, including shrubs
and trees native to the area.

The proposed ET cover does not contain a biobarrier (e.g. cobble layer) to minimize potential
intrusion by plant roots or burrowing animals. The proposed cover system is designed to
minimize both plant root and burrowing animal intrusion through the use of thick layers of soil
cover in combination with a highly compacted layer placed at a depth that is below the expected
rooting and burrowing depths among species that may inhabit the site. Root growth into the
highly compacted radon attenuation layer that begins at a depth of 122 cm will be restricted
because of the high density of this material (compaction to 95 percent Standard Proctor). In
addition, both root density and the size of roots decrease at a rapid rate with rooting depth,
further decreasing the potential for root growth into the compacted radon attenuation layer of the
cover system. Appendix D provides a complete discussion of cover vegetation.

3.3.12 Cover Material/Cover Material Volumes

The volume of materials required for construction of the interim cover, final cover, and erosion
protection are provided in Table 3.3-4. The quantities of materials available for construction of
the cover are also provided in Table 3.3-4. A summary of the volumes of borrow stockpiles is
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provided in Appendix D. Sufficient quantities are available from on-site sources for the topsoil
and random fill materials. The bedding and gravel materials would be obtained from off-site
commercial sources. Three commercial sources have been identified as potential sources for the
bedding and gravel materials, and these sources are described in further detail in Appendix D.
Sufficient quantities of material are available from the off-site sources identified. Samples from
each source were tested for durability in general accordance with guidelines for long-term
performance outlined by the US Nuclear Regulatory Commission (NRC). These guidelines are
for rock to be used for erosion protection material on exposed surfaces and utilize a rock scoring
value (Johnson, 2002). Results of the durability testing are provided in Appendix D and were
previously presented as Attachment H of the previous Reclamation Plan, Revision 4.0 (Denison,
2009a).
Table 3.3-4
Reclamation Cover Material Quantity Summary
Material
Quantity
Required for
Reclamation
(cy)
Quantity Available (Identified
Sources) (cy)
Topsoil (for Erosion Protection Layer) 226,000 284,100 (on-site stockpiles)
Gravel (1-inch minus for Erosion
Protection Layer) 25,000 Sufficient quantity available
(off-site commercial source)
Random Fill (total for water storage
and radon attenuation cover layers) 3,398,000 3,522,000 (on-site stockpiles)
Riprap (D50 = 7.4 and 15 inch for side
slopes and rock aprons) 54,000 Sufficient quantity available
(off-site commercial source)
Riprap Bedding/Filter Layer 21,0001
Sufficient quantity available
(off-site commercial source)
Note:
1. Based on 6-inch thick medium sand bedding/filter layer beneath riprap.
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4 MILL DECOMMISSIONING PLAN

The preliminary plans for decommissioning of the Mill are presented in MWH (2011a), and
included as Appendix G to this Reclamation Plan. This information has been updated since the
previous Reclamation Plan, Revision 4.0 (Denison, 2009a). The Decommissioning Plan attached
as Appendix G includes a description of the following activities to be performed during the
decommissioning process:

 development and implementation of health and safety procedures;
 execution of pre-decommissioning activities;
 demolition of above-ground and under-ground facilities, and placement of these materials
in disposal Cell 1 or the last active tailings cell;
 excavation of contaminated subsoils from the process area and placement in disposal Cell
1 or the last active tailings cell;
 clean-up of windblown contamination and placement in disposal Cell 1 or the last active
tailings cell; and
 regrading and revegetation.

The Plan further describes the requirements prior to demolition and the procedures to be used
for specific locations within the process area, as well as requirements for personnel training,
environmental monitoring, and management of water and contaminants. The work should be
conducted under the Denison Radiation Protection Manual, as directed by the site Radiation
Safety Officer.

The Denison Radiation Protection Manual for Reclamation is included as Attachment D to this
Reclamation Plan.
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REFERENCES

Agenbroad, L. D. et. al., 1981. 1980 Excavations in White Mesa, San Juan County, Utah.
Aki, K., 1979. Characterization of Barriers on an Earthquake Fault, Journal of Geophysical
Research, v. 84, pp. 6140-6148.
Algermissen, S. T. and Perkins, D. M., 1976. A Probabilistic Estimate of Maximum
Acceleration on Rock in the Contiguous United States, U. S. Geological Survey Open-
File Report, No. 76-416.
Behle, W. H. and M. L. Perry, 1975. Utah Birds, Utah Museum of Natural History, University
of Utah, Salt Lake City.
Brill, K. G. and Nuttli, O. W., 1983. Seismicity of the Colorado Lineament, Geology, v. 11, pp.
20-24.
Case, J. E. and Joesting, H. R., 1972. Regional Geophysical Investigations in the Central
Plateau, U. S. Geological Survey Professional Paper 736.
Casjens, L. A. et. al., 1980. Archeological Excavations on White Mesa, San Juan County, Utah,
1979; Volumes I through IV; June, 1980.
Cater, F. W., 1970. Geology of the Salt Anticline Region in Southwestern Colorado, U. S.
Geological Survey, Professional Paper 637.
Cline, J. F., F. G. Burton, d. A. Cataldo, W. E. Shiens, and K. A. Gano. 1982. Long-term
biobarriers to plant and animal intrusions of uranium mill tailings. Rep. PNL-4340. Pacific
Northwest Lab. Richland, WA.
Cook, K. L. and Smith, R. B., 1967. Seismicity in Utah, 1850 Through June 1965, Bull. Seism.
Soc. Am., v. 57, pp. 689-718.
Craig, L. C., Holmes, C.N., Cadigan, R.A., Freeman, V.L., Mullens, T.E., and Weir, G.W., 1955.
Stratigraphy of the Morrison and Related Formations, Colorado Plateau Region, a
Preliminary Report, U. S. Geological Survey Bulletin 1009-E, pp. 125-168.
Dames and Moore, 1978a. Site Selection and Design Study - Tailing Retention and Mill
Facilities, White Mesa Uranium Project, January 17, 1978.

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Dames and Moore, 1978b. Environmental Report, White Mesa Uranium Project, San Juan
County, Utah, January 20, 1978, revised May 15, 1978.
Denison Mines (USA) Corp. Semi-Annual Effluent Reports (January through June, 2008), (June
through December, 2008) and (January through June, 2009), for the White Mesa Mill.
Denison Mines (USA) Corp, February 28, 2007. White Mesa Uranium Mill License Renewal
Application State of Utah Radioactive Materials License No. UT1900479.
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