DRC-2023-076494 - 0901a068812bba68

November 15, 2023
Div of Waste Management
and Radiation Control
NOV 1 7 2023
Sent VIA E-MAIL AND EXPRESS DELIVERY
Doug Hansen
Director
Division of Waste Management and Radiation Control
State of Utah Department of Environmental Quality
195 North 1950 West
Salt Lake City, UT 84116
Energy Fuels Resources (USA) Inc.
225 Union Blvd. Suite 600
Lakewood, CO, US, 80228
303 974 2140
www .energyfuels.com
Re: Transmittal of Plan and Time Schedule under Utah Ground Water Discharge Permit
UGW370004 Part I.G.4 (c) White Mesa Mill (the "Mill")
Dear Mr. Hansen:
This letter transmits Energy Fuels Resources (USA) Inc. 's ("EFRl's") Plan and Time Schedule pursuant to
State of Utah Groundwater Discharge Permit UGW370004 (the "Pennit") Part I.G.4(c) for MW-03A for the
third quarter of 2023. Part I.G.2 of the Permit provides that out-of-compliance ("OOC") status exists when the
concentration of a pollutant in two consecutive samples from a compliance monitoring point exceeds a
groundwater compliance limit ("GWCL"). While consecutive exceedance have been noted in other wells at the
site, a plan and time schedule have not been required or appropriate in light of other actions currently being
undertaken by EFRI or in light of other reports submitted by EFRI.
This Plan covers selenium in MW-03A that was identified as being in violation of Part I.G.2 of the Penn it, in
the Thirdt Quarter 2023 Exceedance Notice, dated October 25, 2023.
Please contact me if you have any questions or require any further infonnation.
Yours very truly,
ENERGY FUELS RESOURCES (USA) INC.
-f{~)y~
Kathy Weinel
Director, Regulatory Compliance
cc: Jordan App
Scott Bakken
David Frydenlund
Garrin Palmer
Logan Shumway
Angie Persico (lntera)
Stewart Smith (HGC)
DRC-2023-076494
WHITE MESA MILL
State of Utah Ground Water Discharge Permit UGW370004
Plan and Time Schedule
Under Part I.G.4 (c)
For
Exceedance in MW-03A in the Third Quarter of2023
Energy Fuels Resources (USA) Inc.
225 Union Boulevard, Suite 600
Lakewood, CO 80228
November 15, 2023
1. INTRODUCTION
Energy Fuels Resources (USA) Inc. ("EFRI") operates the White Mesa Uranium Mill (the "Mill"),
located near Blanding Utah, under State of Utah Ground Water Discharge Permit UGW370004
(the "Permit").
This is the plan and time schedule (the "Plan") required under Part I.G.4(c) of the Permit relating
to violations of Part I.G.2 of the Permit for the MW-03A for the third quarter of 2023. Part I.G.2
of the Permit provides that out-of-compliance status exists when the concentration of a pollutant
in two consecutive samples from a compliance monitoring point exceeds a groundwater
compliance limit ("GWCL") in Table 2 of the Permit. Selenium concentrations in MW-03A
exceeded their respective GWCLs during the third quarter of2023 and are the subject of this Plan.
While consecutive exceedances of other constituents may have been noted in other wells, a P&TS
and SAR have not been required or appropriate in light of other actions currently being undertaken
by EFRI or in light of other reports submitted by EFRI, and as determined by Division of Waste
Management and Radiation Control ("DWMRC") Staff. Specifically, consecutive exceedances,
which occurred in previous reporting periods are discussed in previous SARs submitted to
DWMRC. A description of the other actions and reports which have affected the requirement to
submit a P&TS are as follows:
1. Nitrate + nitrite and chloride in monitoring wells at the site have been the subject of
ongoing investigations at the Mill. Based on the results of the previous investigations,
EFRI and the Director acknowledge that it has not been possible to date to determine the
source(s), cause(s), attribution, magnitudes of contribution, and proportion(s) of the local
nitrate + nitrite and chloride in groundwater. However, as the commingled nitrate and
chloride plumes ( collectively the nitrate/chloride plume) extended upgradient of the
tailings management system ("TMS"), it can be concluded that at least the northern portion
of the plume had an upgradient source. EFRI submitted a Corrective Action Plan ("CAP")
in February 2012 for nitrate+ nitrite and chloride in groundwater. The CAP was approved
on December 12, 2012 and the activities associated with the CAP are on-going. Based on
information provided by DWMRC in teleconferences on April 27, and May 2, 2011, due
to the ongoing activities and actions, the 30-day plan and schedule for assessment is not
required for nitrate + nitrite and chloride exceedances at this time.
2. A P&TS will not be prepared for monitoring wells with two successive exceedances, if
those successive exceedances were reported in a previous quarter and /or were included in
a previous SAR during the current permit period beginning March 8, 2021, because the
conclusions and actions delineated in those reports were accepted by DWMRC.
3. A chloroform plume commingles with the central portion of the nitrate/chloride plume.
Chloroform and associated daughter product methylene chloride are the subject of the
ongoing chloroform pumping program and are covered by State of Utah Notice of
Violation ("NOV") and Groundwater Corrective Action Order ("CAO") State of Utah
Department of Environmental Quality ("UDEQ") Docket No. UGW-20-01. As a result,
the 30-day plan and schedule for assessment of chloroform and its daughter product
exceedances is not required.
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Groundwater at the Mill site has been evaluated in multiple recent investigations and reports,
including the 2007 Revised Background Groundwater Quality Report and the 2008 New Wells
Background Report, an isotopic investigation performed by Hurst and Solomon in 2008, the 2012
Pyrite Report, and multiple SARs.
Based on a review of the Background Reports and other information and analyses the Director re-
opened the Permit and modified the GWCLs to be equal to the mean concentration plus two
standard deviations or the equivalent of background for each constituent on an intrawell basis. The
modified GWCLs became effective on January 20, 2010. A new GWDP was issued on January
19, 2018. The January 19, 2018 GWDP incorporated the revised GWCLs that resulted from
previous SARs. Revised GWDPs were issued on March 19, 2019 and March 8, 2021. The revised
GWDPs incorporated the revised GWCLs that resulted from previous SARs among other changes.
Part I.G.4 c) of the GWDP states, with respect to exceedances ofGWCLs, "that the Permittee shall
prepare and submit within 30 calendar days to the Executive Secretary a P&TS for assessment of
the sources, extent and potential dispersion of the contamination, and an evaluation of potential
remedial action to restore and maintain groundwater quality to insure that Permit limits will not be
exceeded at the compliance monitoring point and that DMT or BAT will be reestablished."
Pursuant to this requirement, EFRI has previously submitted P&TSs and SARs to address previous
dual exceedances ( as required in light of other actions currently being undertaken by EFRI and as
determined by DWMRC Staff and stated in teleconferences with EFRI on April 27 and May 2,
2011).
This Plan covers selenium in MW-03A, identified as being in violation of Part I.G.2 of the Permit,
in the Third Quarter 2023 Exceedance Notice, dated October 25, 2023.
2. CONSTITUENTS AND WELLS SUBJECT TO THIS PLAN
The following constituent is covered by this Plan:
Table 1
Constituent and Well Subject to this Plan
Constituent POCWell Current Results
GWCL Q2 Q3
2023 2023
Selenium (ug/L) MW-03A 109.58 112.0 171
It should be noted that the third quarter 2023 Exceedance Notice identifies a number of wells, with
consecutive exceedances of other constituents. None of those constituents are included in this
Plan, for the reasons stated in Section 1 above and in the Third Quarter Exceedance Notice.
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3. CATEGORIES FOR ANALYSIS
Previously EFRI has categorized wells and constituents in several categories as follows:
1. Constituents Potentially Impacted by Decreasing pH Trends Across the Site
2. Newly Installed Wells with Interim GWCLs
3. Constituents in Wells with Previously Identified Rising Trends
4. Pumping Wells
5. Other Constituents
Selenium can fall within the first category when downward pH trends are noted, and pH in MW-
03A does exhibit a decreasing trend during certain time periods; although the overall trend is nearly
flat. Selenium in MW-03A can also fall within the third category: constituents in wells with
previously identified rising trends, because a rising trend was noted for selenium in the 2012 SAR.
Due to the multiple categories that are applicable to selenium in MW-03A, for this SAR the fifth
category: Other Constituents will be used. Assessment of this constituent in MW-03A will follow
the process noted below.
3 .1. Other Constituents
Preliminary analysis of indicator parameters shows that chloride and sulfate concentrations are
stable and fluoride and uranium concentrations are decreasing. Stable to decreasing indicator
parameters demonstrates that MW-03A is un-impacted by the TMS. In addition, the 2008 Hurst
and Solomon isotopic study, noted that MW-03A was tritium-free, contained very small amounts
of chlorofluorocarbons ("CFCs"), and did not bear isotopic signatures similar to those of either the
tailings cells or the wildlife pond, which suggests that trace metal concentrations and trends in the
groundwater system near MW-03A result from natural, background influences.
4. PLAN
4 .1. General
This Plan is a plan and time schedule to assess the potential sources, extent and potential dispersion
of selenium, and to evaluate potential remedial action to restore and maintain groundwater quality
to ensure that Permit limits will not be exceeded at the compliance monitoring point and that, to
the extent applicable, discharge minimization technology and best available technology will be
reestablished.
The first step in the analysis will be an assessment of the potential sources to determine whether
the exceedance is due to background influences or Mill activities. If an exceedance is determined
to be the result of background influences then it will not be necessary to perform any further
evaluations on the extent and potential dispersion of any contamination or to perform an evaluation
of potential remedial actions. Monitoring will continue, and where appropriate revised GWCLs
will be proposed to reflect changes in background conditions at the site.
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However, if any exceedance is determined to be caused by Mill activities, then EFRI will proceed
to the next step and will consider the extent and potential dispersion of the contamination, and will
perform an evaluation of potential remedial actions to restore and maintain groundwater quality to
ensure that Permit limits will not be exceeded at the compliance monitoring point.
This two-step approach is necessary, because, as a result of variable background conditions at the
site, it cannot be assumed that consecutive exceedances of a constituent in a well represents
contamination that has been introduced to the groundwater. It is first necessary to establish
whether or not any exceedance results from background influences.
Based on the site-wide analyses provided in the Background Reports, SARs, Pyrite Report and
other recent information and investigations at the site, exceedances in MW-03A are likely due to
natural background influences that impact the geochemical conditions at MW-03A (including
changing water levels and enhanced oxygen transport to groundwater via the well casing). In
particular, stable to decreasing indicator parameters chloride, fluoride, sulfate and uranium
demonstrate that increasing selenium cannot result from potential TMS seepage. Therefore it is
unlikely that analysis will reveal the need for any further evaluation of the extent and potential
dispersion of any contamination or for an evaluation of potential remedial actions.
4.2. Approach for Analysis
The first step in the analysis will be an assessment of the potential sources for selenium in MW-
03A to determine whether the exceedances are due to background influences or Mill activities.
This assessment will include an analysis of selenium and field pH as well as the other indicator
parameters chloride, sulfate, fluoride and uranium to determine if the behavior of the water in
MW-03A has changed since the time of the Background Reports.
As discussed above, preliminary analysis of indicator parameters chloride, fluoride, sulfate and
uranium indicate that these parameters are stable to decreasing, demonstrating that MW-03A
cannot be impacted by potential TMS seepage. Therefore the selenium exceedance is attributable
to background influences, and it is anticipated that any further evaluations on the extent and
potential dispersion of the contamination, or an evaluation of potential remedial actions, will be
unnecessary. Monitoring will continue, and revised GWCLs are anticipated to be proposed to
reflect changes in background conditions at the site.
The revised GWCL process will include a statistical analysis of selenium data from MW-03A
using the methods described in the Existing Wells Background Report (INTERA, 2007a) and the
State of Utah Department of Environmental Quality approved Flowsheet ("the Flowsheet").
As mentioned in the SARs, the United States Environmental Protection Agency ("EPA") has
recognized the need to update compliance limits periodically to reflect changes to background
conditions.
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In 2009 guidance, EPA states:
"We recommend that other reviews of background also take place periodically.
These include the following situations:
• When periodically updating background, say every 1-2 years
• When performing a 5-10 year permit review
During these reviews, all observations designated as background should be evaluated
to ensure that they still adequately reflect current natural or baseline groundwater
conditions. In particular, the background samples should be investigated for apparent
trends or outliers. Statistical outliers may need to be removed, especially if an error
or discrepancy can be identified, so that subsequent compliance tests can be improved.
If trends are indicated, a change in the statistical method or approach may be
warranted."
and
"Site-wide changes in the underlying aquifer should be identifiable as similar trends
in both upgradient and compliance wells. In this case, it might be possible to remove
a common trend from both the background and compliance point wells and to perform
interwell testing on the trend residuals."
(EPA 530/R-09-007, March 2009, Statistical Analysis Of Groundwater Monitoring Data At RCRA
Facilities Unified Guidance, Environmental Protection Agency, Office Of Resource Conservation
And Recovery.)
4.3. Experts Reports to be Prepared
The results of the statistical analysis and, if appropriate, recalculation of the GWCL will be
compiled as a SAR that will be submitted to DWMRC within 90 days of the approval of this Plan.
The SAR will detail the results of all analyses to be performed and the conclusions to be drawn
from such analyses, including proposed revision to the existing GWCL. Specifically, the SAR
will follow the format of the originally submitted SAR (October 10, 2012) and will include
discussions, results and conclusions of the analyses and appendices containing the following:
A Statistical analysis of SAR Parameters
Comparison of calculated and measured TDS for samples with complete major ions
Charge balance calculations
Descriptive statistics
Box plots to identify extreme outliers
Histograms and Shapiro Wilk test for normality
Regression or Mann Kendall trend analysis
Evaluation of inflection points and data subsets
Proposed Revised GWCLs
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) .
A statistical analysis of Indicator Parameters
Descriptive Statistics
Box plots to identify extreme outliers
Histograms and Shapiro Wilk test for normality
Regression and/or Mann Kendall trend analysis
5. TIME SCHEDULE
The SAR will be submitted to the Director within 90 days after approval of this Plan. The SAR
contemplated by this submission, may be combined with any subsequent SARs resulting from
other Plans and Schedules for other out of compliance constituents, as necessary.
6. CONCLUSION
Given the varied background groundwater quality at the site it cannot be assumed that consecutive
exceedances of a constituent in a monitoring well means that contamination has been introduced
to groundwater in that well.
Preliminary analysis of MW-03A indicator parameters shows that chloride and sulfate
concentrations are stable and fluoride and uranium concentrations are decreasing. Stable to
decreasing indicator parameters demonstrate that MW-03A is un-impacted by the TMS.
In addition, the 2008 Hurst and Solomon isotopic study noted that MW-03A was tritium-free,
contained very small amounts of chlorofluorocarbons ("CFCs"), and did not bear isotopic
signatures similar to those of either the tailings cells or the wildlife pond, which suggests that trace
metal concentrations and trends in the groundwater system near MW-03A result from natural,
background influences. That the selenium exceedance in MW-03A is likely due to natural
background influences that impact the groundwater geochemistry near MW-03A (including
changing water levels and enhanced oxygen transport to groundwater via the well casing) is also
consistent with recent site-wide analyses in the Background Reports, SARs, and the Pyrite Report.
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