DRC-2016-010003 - 0901a06880668c8c

rENERGYFUELS
Energy Fuels Resources (USA) Inc.
225 Union Blvd. Suite 600
Lakewood, CO, US, 80228
303 974 2140
www.energvfuels.com
September 9, 2016
VIA PDF AND OVERNIGHT DELIVERY
Scott Anderson,
Director of Waste Management and Radiation Control
State of Utah Department of Environmental Quality
195 North 1950 West
P.O. Box 144880
Salt Lake City, UT 84114-4880
Div of Waste Management
and Radiation Control
D RC - 2-011,-01 OOo3
Re: State of Utah Stipulation and Consent Order (“SCO”) Docket Number UGW-20-01
White Mesa Uranium Mill - Energy Fuels Resources (USA) Inc. (“EFRI”) Plan and Time
Schedule Pursuant to Part II.H.2 of the Groundwater Corrective Action Plan (“GCAP”)
included as Attachment 1 to the SCO
Dear Mr. Anderson:
Part II.H.l) of the GCAP states that “At any time EFR[I] submits a quarterly report that demonstrates an
exceedance (second quarter of chloroform exceedance), EFR[I] will provide a written exceedance notice
to the Director (“Exceedance Notice”) for all wells that have demonstrated such an exceedance.” EFRI
provided notice to the Director that the concentrations of chloroform in TW4-09 exceeded the respective
GCAL of 70 ug/L for two or more consecutive quarters by letter dated August 18, 2016.
Part II.H.2) of the GCAP requires that “Within 60 days after the time of submittal of a quarterly report
that demonstrates an exceedance as defined in Part II.G, EFR[I] will provide a plan and schedule for
remedial actions to address and resolve the excursion, for Director approval.”
This is the plan and schedule required under Part II.H.2) of the GCAP for TW4-09 for the second quarter
of 2016.
If you should have any questions regarding this submittal please contact me at [phone].
Yours truly,
ENERGY FUELS RESOURCES (USA) INC.
Kathy Weinel
Quality Assurance Manager
cc:David Frydenlund, Harold R. Roberts, David Turk, Logan Shumway, Scott Bakken
WHITE MESA MILL
State of Utah
Stipulation and Consent Order Docket No. UGW-20-01
Plan and Time Schedule
Under Part II.H.2
For
Exceedances in TW4-09 in the Second Quarter of 2016
Energy Fuels Resources (USA) Inc.
225 Union Boulevard, Suite 600
Lakewood, CO 80228
September 9, 2016
1. INTRODUCTION
Energy Fuels Resources (USA) Inc. (“EFRI”) operates the White Mesa Uranium Mill (the
“Mill”), located near Blanding Utah. EFRI performed second quarter 2016 chloroform
monitoring during the period from April 1, to June 30, 2016 under the September 14, 2015
Groundwater Corrective Action Plan (“GCAP”), included as Attachment 1 to the executed
Stipulation and Consent Order (“SCO”).
Part II.H.l) of the GCAP states that “At any time EFR[I] submits a quarterly report that
demonstrates an exceedance (second quarter of chloroform exceedance), EFR[I] will provide a
written exceedance notice to the Director (“Exceedance Notice”) for all wells that have
demonstrated such an exceedance.” EFRI provided notice to the Director that the concentrations
of chloroform in TW4-09 exceeded the respective GCAL of 70 ug/L for two or more consecutive
quarters by letter dated August 18, 2016.
Part II.H.2) of the GCAP requires that “Within 60 days after the time of submittal of a quarterly
report that demonstrates an exceedance as defined in Part II.G, EFR[I] will provide a plan and
schedule for remedial actions to address and resolve the excursion, for Director approval.”
This is the plan and schedule required under Part II.H.2) of the GCAP for TW4-09 for the second
quarter of 2016.
2. WELLS SUBJECT TO THIS PLAN
The following well is covered by this Plan:
Table 1
Chloroform Results in TW4-09
Constituent Monitoring
Event
GCAL
(ug/L)
Results
(ug/L)
Chloroform Q1 2016
Q2 2016
70.0 74.3
76.2
3. BACKGROUND
The chloroform plume is currently entirely within the Mill property boundary and is bounded on
all sides by wells having chloroform concentrations that are either non-detect or less than 70
pg/L. Data collected to date indicate there are sufficient chloroform monitoring and pumping
wells to effectively define, control, and monitor the plume. The plume is bounded to the north by
TW4-25; to the west and southwest by MW-31, MW-32, TW4-23, TW4-24, and TW4-26; to the
east by TW4-3, TW4-5, TW4-12, TW4-13, TW4-14, TW4-18, TW4-27, TW4-30, and TW4-36;
to the south by TW4-34; and to the southeast by TW4-35 (Figure 1).
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TW4-9 is located south of the northern wildlife ponds on the eastern margin of the chloroform
plume. Perched groundwater hydraulic gradients and flow directions in this portion of the site
have been impacted by past wildlife pond recharge.
The cessation of water delivery to the northern wildlife ponds, which are generally upgradient of
the chloroform plume at the site, resulted in changing conditions that were expected to impact
constituent concentrations and migration rates within the plume. Specifically, past recharge from
the ponds helped limit many constituent concentrations within the plume by dilution while the
associated groundwater mounding increased hydraulic gradients and contributed to plume
migration. Since use of the northern ponds was discontinued in March, 2012, increases in
constituent concentrations in many wells (including marginal and generally cross- to upgradient
wells such as TW4-9), and decreases in hydraulic gradients within the plume, are attributable to
reduced recharge and the decay of the associated groundwater mound. EFRI and its consultants
anticipated these changes and discussed these and other potential effects during discussions with
DWMRC in March 2012 and May 2013.
The impacts associated with cessation of water delivery to the northern ponds were expected to
propagate downgradient (south and southwest) over time. Wells close to the ponds were
generally expected to be impacted sooner than wells farther downgradient of the ponds.
Therefore, constituent concentrations were generally expected to increase in downgradient wells
close to the ponds before increases were detected in wells farther downgradient of the ponds.
Although such increases were anticipated to result from reduced dilution, the magnitude and
timing of the increases were anticipated to be and have been difficult to predict due to the
complex permeability distribution at the site and factors such as pumping and the rate of decay of
the groundwater mound.
Chloroform concentration increases that are attributable to reduced recharge (and dilution) from
the northern wildlife ponds at wells marginal to the plume have resulted in cross-gradient
expansion of the plume. Plume expansion to the east in the vicinity of TW4-9 is attributable
primarily to reduced dilution. Generally cross-gradient expansion to the west (for example near
nitrate pumping well TW4-24) is attributable to both reduced dilution and more westerly flow
induced by nitrate pumping. Although generally cross-gradient expansion of the plume has
occurred due to reduced dilution and nitrate pumping, chloroform pumping as of the second
quarter of 2016 (4.8 gpm) exceeds calculated ‘background’ flow through the plume (3.4 gpm)
and is therefore considered adequate. In addition, because of continued reductions in saturated
thicknesses and hydraulic gradients resulting from reduced wildlife pond recharge, ‘background’
flow through the plume is expected to continue to diminish, thereby reducing the pumping
needed to control the plume.
4. PLAN AND TIME SCHEDULE
This is a plan and schedule for actions to address and resolve the excursion noted in Table 1
above as required by the GCAP. Part II.H.2).i) of the GCAP states that the plan and schedule
may include, but is not limited to the installation of one or more pumping wells in the vicinity of
the well found in exceedance and installation of one or more replacement wells for the
compliance well in exceedance. EFRI plans to address the exceedance through the installation of
2
two wells (TW4-38 and TW4-39). Figure 1 shows 1) the proposed location of new compliance
monitoring well TW4-38; and 2) the area considered favorable for the installation of proposed
new chloroform pumping well TW4-39.
TW4-9 is located in an area where the groundwater flow direction transitions from sub­
perpendicular to sub-parallel to the chloroform plume boundary. Groundwater flow immediately
north of TW4-9 is generally across the plume boundary, while flow immediately south of TW4-9
is generally parallel with the plume boundary. TW4-38 is proposed to be installed east of TW4-9
(between the eastern plume boundary and TW4-12) as a new cross-gradient compliance well that
will allow early detection of any future plume expansion to the east. Although the GCAP
requires that a new downgradient well be installed, it would not be appropriate in this case
because TW4-9 is located within the upgradient portion of the plume, numerous wells within the
plume (including TW4-10 and TW4-11) are already positioned downgradient of TW4-9, and
plume expansion near TW4-9 appears to be mainly cross-gradient.
Pumping well TW4-39 is proposed to be installed to the west-northwest of TW4-9 within the
northern portion of the plume. This portion of the plume has relatively high chloroform
concentrations and saturated thicknesses and therefore a large residual mass. An analysis of
drawdowns resulting from the initiation of pumping at TW4-19 in 2003 indicates that this area is
also likely to have high productivity. Because of the heterogeneous nature of the perched zone,
however, small-diameter pilot holes are proposed to be installed within the area shown in Figure
1, and the most productive reamed and completed as pumping well TW4-39. Pumping within
this portion of the plume is expected to substantially increase chloroform mass removal rates and
reduce or halt further plume expansion to the east.
4.1. Experts Reports to be Prepared
As required by Part II.H.4) EFRI will submit an as-built report within 60 days of well installation
for the newly installed wells proposed in this plan and time schedule.
Assessment of the plume, hydraulic capture and effectiveness of the remediation strategy will be
discussed in the quarterly chloroform reports submitted as required by the GCAP.
4.2. Time Schedule
The installation of the proposed wells and the completion of the as-built reports will be
completed in accordance with the required timeframes specified in the approved and executed
GCAP. The proposed wells will be installed and operational within 90 days of director approval
of this plan and time schedule and the as-built report will be completed within 60 days of well
completion.
5. CONCLUSION
The chloroform plume is currently entirely within the Mill property boundary and is bounded on
all sides by wells having chloroform concentrations that are either non-detect or less than 70
pg/L. Data collected to date indicate there are sufficient chloroform monitoring and pumping
3
wells to effectively define, control, and monitor the plume. Chloroform pumping as of the
second quarter of 2016 (4.8 gpm) exceeds calculated ‘background’ flow through the plume (3.4
gpm) and is therefore considered adequate. In addition, because of continued reductions in
saturated thicknesses and hydraulic gradients resulting from reduced wildlife pond recharge,
‘background’ flow through the plume is expected to continue to diminish, thereby reducing the
pumping needed to control the plume.
As previously stated, the increase in concentration at TW4-9 and the generally cross-gradient
plume expansion to the east near TW4-9 is attributable to the reduced recharge (and dilution)
from the northern wildlife ponds. Although pumping is considered adequate at the present time,
in an effort to further increase the effectiveness of the chloroform pumping system and address
the requirements of the GCAP, EFRI is proposing to install an additional pumping well (TW4-
39) to the west-northwest of TW4-09 and a compliance monitoring well (TW4-38) to the east of
TW4-09.
Additional pumping in the northern portion of the plume to the west-northwest of TW4-9 is
expected to result in a substantial increase in chloroform mass removal rates due to the relatively
high concentrations and saturated thicknesses (and therefore mass) in this portion of the plume.
Furthermore, as discussed above, small-diameter pilot holes are proposed to be drilled in the area
shown in Figure 1, and the most productive reamed and completed as new pumping well TW4-
39. Pumping in this area will not only enhance mass removal rates but is expected to reduce or
halt further plume expansion to the east.
The proposed monitoring well (TW4-38) to the east of TW4-9 (between the eastern plume
boundary and TW4-12) will function as a cross-gradient compliance well positioned for early
detection of any future expansion to the east. Although the GCAP requires that a new
downgradient well be installed, it would not be appropriate in this case because TW4-9 is located
within the upgradient portion of the plume, numerous wells within the plume (including TW4-10
and TW4-11) are already positioned downgradient of TW4-9, and plume expansion near TW4-9
appears to be mainly cross-gradient.
4
FIGURE
L. ’ ‘j
& i
wildlife pond
■
wildlife pond
% ' 5-
PIEZ-3A
«
MW-25
TW4-7
o
PIEZ-2
e
area considered favorable for installation of
proposed new pumping well TW4-39
Q2 2016 chloroform plume boundary
May, 2016 replacement of perched
piezometer Piez-03
perched monitoring well
temporary perched monitoring well
perched piezometer
wildlife pond
NOTES: MW-4, MW-26, TW4-1, TW4-2, TW4-4, TW4-11, TW4-19, TW4-20, TW4-21 and TW4-37 are chloroform pumping wells;
TW4-22, TW4-24, TW4-25, and TWN-2 are nitrate pumping wells; TW4-11 water level is below the base of the Burro Canyon Formation
HYDRO
GEO
CHEM, INC.
PLAN MAP SHOWING PROPOSED LOCATIONS OF NEW
MONITORING WELL, AREA FAVORABLE FOR NEW PUMPING
WELL, 2nd QUARTER, 2016 KRIGED WATER LEVEL
CONTOURS, AND CHLOROFORM PLUME BOUNDARY
APPROVED DATE REFERENCE FIGURE
H:/718000/tw9/propwel_0816.srf 1