DRC-2021-019768 - 0901a06880fa915d

NERGY FUELS
November 16, 2021
Sent VIA E-MAIL AND EXPRESS DELIVERY
Doug HAnsen
Director
Waste Management and Radiation Control
State of Utah Department of Environmental Quality
195 North 1950 West
Salt Lake City, UT 84116
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 ("EFRI' s") Plan and Time Schedule pursuant to
State of Utah Groundwater Discharge Permit UGW370004 (the "Permit") Part I.G.4(c) for MW-11 for the third
quarter of 2021. Part I.G.2 of the Permit provides that out-of-compliance ("00C") 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 manganese and sulfate in MW-11 that was identified as being in violation of Part I.G.2 of the
Permit, in the Third Quarter 2021 Exceedance Notice, dated October 22, 2021.
Please contact me if you have any questions or require any further information.
Yours very truly,
ENERGY FUELS RESOURCES (USA) INC.
Kartei
Kathy Weinel
Quality Assurance Manager
cc: Scott Bakken
David Frydenlund
Garrin Palmer
Logan Shumway
Terry Slade
Angie Persico (Intera) Stewart Smith (HGC)
Energy Fuels Resources (USA) Inc.
225 Union Blvd. Suite 600
Lakewood, CO, US, 80228
303 974 2140
DRC-202.1-019766 www.energyfuels.com
WHITE MESA MILL
State of Utah Ground Water Discharge Permit UGW370004
Plan and Time Schedule
Under Part I.G.4 (c)
For
Exceedances in MW-11 in the Third Quarter of 2021
Energy Fuels Resources (USA) Inc.
225 Union Boulevard, Suite 600
Lakewood, CO 80228
November 16, 2021
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-11 for the third quarter of 2021. 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. Sulfate concentrations in MW-11
exceeded their respective GWCLs during the third quarter of 2021 and are the subject of this
Plan. In addition, this Plan and the associated Source Assessment Report ("SAR") will address
manganese in MW-11. Manganese is included herein and in the associated SAR because the fourth
quarter 2021 result exceeded the GWCL in two consecutive sampling events due to statistically
significant trends, as noted in these previous studies. While consecutive exceedances of other
constituents have been noted in MW-11, 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. Bawd 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
1
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.
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 of GWCLs, "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 sulfate in MW-11, identified as being in violation of Part I.G.2 of the Permit, in
the Third Quarter 2021 Exceedance Notice, dated October 22, 2021. As previously stated,
manganese is being included in this Plan and the associated SAR due to a consecutive
exceedance reported in the fourth quarter 2021 data.
2. CONSTITUENTS AND WELLS SUBJECT TO THIS PLAN
The following constituents are covered by this Plan:
Table 1
Constituent and Well Subject to this Plan
Constituent POC Well Current
GWCL
Results
Q3 2021
Q4
2021
Sulfate (mg/L) MW-11 1309 1470,
1370
1360
Manganese (ug/L) MW-11 237 376 286
2
It should be noted that the third quarter 2021 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.
This Plan and the subsequent SAR are being submitted to DWMRC by EFRI to address
exceedances in MW-11 for sulfate and for manganese which were noted as having statistically
significant trends noted in previous studies.
Chloride concentrations in MW-11 are associated with the Nitrate/Chloride plume, and are
currently covered by the December 12, 2012 Stipulation and Consent Order.
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
Sulfate and manganese in MW-11 fall within the third category: Constituents in Wells with
Previously Identified Rising Trends. Assessment of these constituents in MW-11 will follow the
process noted below with additional considerations to address the previously identified rising
trends. It is important to note that manganese also falls into the first category: Constituents
Potentially Impacted by Decreasing pH Trends Across the Site.
3.1. Constituents in Wells with Previously Identified Rising Trends
Sulfate and manganese concentrations in MW-11 were exhibiting increasing statistically
significant trends at the time of the Background Report. These trends were also present at the
time of the 2008 Hurst and Solomon isotopic investigation which concluded that no impacts to
ground water from the TMS were occurring, thereby indicating that the source of these trends
was not the TMS. Manganese was addressed in a previous SAR but has exceeded the most recent
recalculated GWCL specified in the March 8, 2021 GWDP due to statistically significant trends,
as noted in these previous studies.
The observed manganese trend in MW-11 is attributable to increased pyrite oxidation and the
resulting decrease in pH, which causes dissolution of carbonate cement in the Burro Canyon
Formation, thereby mobilizing manganese substituted for calcium in the carbonate cement.
Increasing sulfate concentrations result from pyrite oxidation associated with increases in water
levels in MW-11. The water levels in MW-11 rose 15 feet between 1990 and 2012. Water levels
currently have a slightly increasing to stable trend at MW-11 (following a strongly increasing
trend prior to 2012). The rate of water level increase is substantially lower since 2012. Trends at
MW-11 are generally consistent with the behavior at other wells on the site in response to
3
changes in wildlife pond recharge. However, changes at MW-11 were likely facilitated by the
generally higher conductivity in the vicinity of MW-11.
The location of MW-11 is important when determining potential sources of contamination. MW-
11 is directly downgradient of the nitrate/chloride plume. Nitrate concentrations at MW-5
(adjacent to MW-11) and MW-11 have historically been low (non-detect to approximately 1
mg/L). These low nitrate concentrations are consistent with the relative stability of the
downgradient margin of the nitrate plume. However, since 2019, low but detectable nitrate at
MW-11 (up to a maximum of approximately 1 mg/L), and post-2019 increases in chloride, are
consistent with the ongoing (but slow) downgradient migration of the nitrate/chloride plume. The
increasing chloride and low nitrate concentrations at MW-11 suggest that a natural attenuation
process that is affecting nitrate but not chloride is occurring upgradient of MW-11. A process
that would degrade nitrate but leave chloride unaffected is reduction of nitrate by pyrite. This
process in the perched zone is discussed in HGC, December 7 2012; Investigation of Pyrite in
the Perched Zone, White Mesa Uranium Mill Site, Blanding, Utah. A more detailed discussion is
presented in HGC, December 11, 2017; Nitrate Corrective Action Comprehensive Monitoring
Evaluation (CACME) Report, White Mesa Uranium Mill Near Blanding, Utah. It is important to
note, however, that while the absence of a rising trend in chloride concentration would indicate
that there has been no impact from the TMS, a rising trend in chloride concentrations as well as
in other indicator parameters could also be due to natural influences (see Section 12.0 of
INTERA, 2007a).
Concentrations of indicator parameters fluoride and uranium display overall decreasing and
relatively stable trends, respectively. Decreasing fluoride indicates that MW-11 is un-impacted
by the TMS; and, although a recent increase in uranium has occurred, similar increases in 1988-
1989; 1995-1996; and 2000-2001 were followed by decreases, contributing to the overall
absence of a trend. In addition, as discussed above, although sulfate is trending upward, an
increasing trend was present at the time of the 2008 Hurst and Solomon isotopic study, which
concluded that no impacts to ground water from the TMS were occurring, thereby indicating that
the source of the sulfate trend was not the TMS.
4. PLAN
4.1. General
This Plan is a plan and time schedule 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 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.
Given the recent site-wide analyses in the Background Reports, SARs, and Pyrite Report and
other recent information relating to the Chloroform and Nitrate/Chloride investigations at the
site, EFRI believes that exceedances in MW-11 are likely due to background influences
4
(including changing water levels in some wells and other factors), disruption of the aquifer by
pumping, and/or the geochemical influences of the existing chloroform and nitrate/chloride
plumes. The head of the nitrate/chloride plume extends more than 1 .000 feet upgradient of the
TMS.
Therefore, the first step in the analysis will be to perform an assessment of the potential sources
for each exceedance to determine whether the exceedance is due to background influences or
Mill activities. If an exceedance is determined to be due to background influences then it will
not be necessary to perform any further evaluations on the extent and potential dispersion of the
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.
However, if any of the exceedances are 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, in light of the varied background conditions at the
site, it can't 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 the exceedances represent background influences.
4.2. Constituents With Pre-Existing Rising Trends
It was well known at the time of setting the current GWCLs that certain constituents had rising
trends. On page 3 of the Existing Well Background Report, INTERA concluded:
"There are numerous cases of both increasing and decreasing trends in
constituents in upgradient, far downgradient, and Mill site wells, which provide
evidence that there are natural forces at work that are impacting groundwater
quality across the entire site.
In almost all cases where there are increasing trends in constituents in wells at the
site, there are increasing trends in those constituents in upgradent wells.
Furthermore, and more importantly, in no case is there any evidence in the wells
in question of increasing trends in chloride, which is considered the most mobile
and best indicator of potential tailings cell leakage at the site. We consider the
combination of these factors to be conclusive evidence that all increasing trends at
the site are caused by natural forces and not by Mill activities".
The Groundwater Data Preparation and Statistical Process Flow for Calculating Groundwater
Protection Standards, White Mesa Mill Site, San Juan County, Utah, (the "Flowsheet") which
was approved by the Director, states in the final decision box, for circumstances where the data
5
indicate an increasing trend to consider a modified approach to GWCLs. If necessary, a modified
approach may be submitted as part of the SAR.
The revised GWCL process will include a statistical analysis of manganese and sulfate data from
MW-11 using the methods described in the approved Flowsheet.
As mentioned in previous SARs, the United States Environmental Protection Agency ("EPA")
has recognized the need to update compliance limits periodically to reflect changes to
background conditions.
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:
6
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
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.
The location of MW-11 is important when determining potential sources of contamination. MW-
11 is directly downgradient of the nitrate/chloride plume. Nitrate concentrations at MW-5
(adjacent to MW-11) and MW-11 have historically been low (non-detect to approximately 1
mg/L). Low nitrate concentrations at MW-11 are consistent with the relative stability of the
downgradient margin of the nitrate plume. However, since 2019, low but detectable nitrate at
MW-11 (up to a maximum of approximately 1 mg/L), and post-2019 increases in chloride, are
consistent with the ongoing (but slow) downgradient migration of the nitrate/chloride plume.
The relative stability of the downgradient (southern) margin of the nitrate component of the
nitrate/chloride plume implies a degradation mechanism that affects nitrate but not chloride; the
most likely mechanism is degradation (reduction) of nitrate by naturally-occurring pyrite in the
formations hosting perched groundwater at the site.
Concentrations of indicator parameters fluoride and uranium display overall decreasing and
relatively stable trends, respectively. Decreasing fluoride indicates that MW-11 is un-impacted
by the TMS; and, although recent increases in uranium have occurred, similar increases in 1988-
1989; 1995-1996; and 2000-2001 were followed by decreases, contributing to the overall
7
absence of a trend. In addition, although sulfate is trending upward, an increasing trend was
present at the time of the 2008 Hurst and Solomon isotopic study, which concluded that no
impacts to ground water from the TMS were occurring, thereby indicating that the source of the
trend was not the TMS.
8