DRC-2023-067122 - 0901a06881227314

DRC-2023-067122 195 North 1950 West • Salt Lake City, UT
Mailing Address: P.O. Box 144880 • Salt Lake City, UT 84114-4880
Telephone [phone] • Fax [phone] • T.D.D. 711
www.deq.utah.gov
Printed on 100% recycled paper
State of Utah

SPENCER J. COX
Governor

DEIDRE HENDERSON
Lieutenant Governor
Department of
Environmental Quality

Kimberley D. Shelley
Executive Director

DIVISION OF WASTE MANAGEMENT
AND RADIATION CONTROL

Douglas J. Hansen
Director

June 29, 2023

Kathy Weinel, Quality Assurance Manager
Energy Fuels Resources (USA) Inc.
225 Union Blvd., Suite 600
Lakewood, CO 80228

RE: Energy Fuels Resources (USA) Inc. May 24, 2023, Transmittal of Plan and Time Schedule;
Utah Groundwater Discharge Permit No. UGW370004 (Permit)

Dear Ms. Weinel:

The Division of Waste Management and Radiation Control has reviewed the Energy Fuels Resources
(USA) Inc. (EFRI) May 24, 2023, Transmittal of Plan and Time Schedule under Utah Groundwater
Discharge Permit No. UGW370004 Part I.G.4(c) White Mesa Mill (EFRI Plan). The EFRI Plan
addresses dual exceedances of the Groundwater Compliance Limits (GWCL’s) for selenium in
monitoring well MW-11 and Field pH in MW-37. Both are in out-of-compliance status per the Permit
Part I.G.2. based on the EFRI 1st Quarter 2023 Exceedance Notice dated April 25, 2023, and are
therefore required to undergo corrective action per the Permit Part I.G.4.

The table below summarizes the preliminary findings in the EFRI Plan:

Monitoring
Well Parameters EFRI Noted Preliminary Findings and Source Assessment
MW-11 Selenium
• MW-11 is located downgradient of the nitrate/chloride
plume. Low concentrations of nitrate and recent increases
in chloride concentrations are consistent with downgradient
migration of the nitrate/chloride plume.
• The increasing chloride and low nitrate concentrations at
MW-11 also suggest that a natural attenuation process is
affecting nitrate but not chloride.
• The EFRI Plan hypothesizes that reduction of nitrate by
pyrite may be mobilizing naturally occurring selenium
while also degrading nitrate but not chloride.
Monitoring
Well Parameters EFRI Noted Preliminary Findings and Source Assessment
• The EFRI Plan discusses the source assessment study and
source assessment report (SAR). A statistical analysis will
be performed to determine whether the selenium
exceedances are due to background influences or Mill
activities.
• The Division notes that a submitted SAR must show
through evidence and evaluation that the Mill is not the
source of the exceedances and must conform to signatory
requirements of the Permit. Although an evaluation of
potential natural sources of the exceedances is
informational and provides a potential mechanism for the
observed concentrations, the SAR must show that the Mill
is not the potential source.
MW-37 Field pH
• EFRI preliminary analysis shows that concentrations of
indicator parameters chloride, fluoride, sulfate, and
uranium do not show significant increasing trends.
• The Plan hypothesizes that “exceedances” of field pH in
MW-37 are likely due to background influences and a
small and unrepresentative background data set used to
calculate the GWCLs at the time of the Background Report.
• The EFR Plan discusses the source assessment study and
source assessment report (SAR). A statistical analysis will
be performed to determine whether the selenium
exceedances are due to background influences or Mill
activities.

A SAR which will include the EFRI Plan discussed as well as a source investigation and statistical
analysis, will be submitted to the Division Director within 90 days after approval of the EFRI Plan.
The Division again notes that the conclusions of the SAR must definitively eliminate or support a Mill
source of the observed exceedances.

Based on review of the EFRI Plan it appears that the proposed activities are appropriate, and the EFRI
Plan is hereby approved with Division comments as noted above.

If you have any questions, please call Chris Leahy at 385-602-5505.

Sincerely,

Phil Goble, Uranium Mills and Radioactive Materials Manager
Division of Waste Management and Radiation Control

PRG/CL/wa

c: Grant Sunada, Executive Director/Health Officer, San Juan County Public Health Department
Ronnie Nieves, Environmental Health Director, San Juan County Public Health Department
Russell Seeley, District Engineer, UDEQ