DRC-2023-074830 - 0901a068812a688f

October 25 , 2023
Div of Waste Managoment
and Radiation Control
OCT 2 7 2023
VIA PDF AND OVERNIGHT 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: State of Utah Ground Water Discharge Permit No. UGW370004
White Mesa Uranium Mill-Notice Pursuant to Part I.G.1 (a)
Dear Mr. Hansen:
The White Mesa Mill (the "Mill") performed third quarter ("Q3") groundwater monitoring during
the period from July 1, to September 30, 2023 under the March 8, 2021 version of the Mill's
Groundwater Discharge Permit (the "GWDP"). All analytical data needed for comparison to the
GWCLs were received during the period ending September 25 , 2023 .
Pursuant to Part LG. I.a) of the GWDP, please take notice that the concentrations of specific
constituents in the monitoring wells highlighted in yellow and bold italics in the columns for this
quarter in the attached Table 1 exceeded their respective GWCLs. For ease ofreview, Table 1 has
been formatted to simplify the tracking of any continued exceedances from one monitoring period
to the next by charting ongoing monitoring of the same well in the same row, and by highlighting
exceedances (in color and bold italics).
As a result of the issuance of a revised GWDP on March 8, 2021 , which sets revised GWCLs,
requirements to perform accelerated monitoring for certain constituents under Part LG.I of the
previous GWDP ceased effective on March 8, 2021 , and the effect of the issuance of the revised
GWDP was to create a "clean slate" for certain constituents going forward.
Part LG. I c) of the GWDP states "that the Permittee shall prepare and submit within 30 calendar
days to the Director a plan and a 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 DMT or BAT will be reestablished." The summary below relating to
exceedances includes, for each exceedance, a brief discussion of whether such a plan and schedule
is or is not required or appropriate at this time in light of other actions currently being undertaken
by Energy Fuels Resources (USA) Inc. ("EFRI") or in light of other reports submitted by EFRI,
DRC-2023-074830
Letter to Mr. Doug Hansen
October 25, 2023
Page2
and as determined by Division of Waste Management and Radiation Control ("DWMRC") Staff.
A description of the other actions and reports which have affected the requirement to submit a plan
and time schedule 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 acknowledged 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. 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 Plan and Time Schedule 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 Source Assessment Report ("SAR") during the current permit
period beginning March 8, 2021. Inclusion in a previous SAR means that the GWCLs
were modified based on conclusions and actions delineated in the previous SAR which
were accepted by DWMRC.
3. Chloroform and 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 methylene chloride exceedances is not required.
It is important to note that under the GWDP, GWCLs have been determined on a well-by-well
basis to reflect background groundwater quality, as defined by the mean plus second standard
deviation concentration, or the equivalent. Accordingly, the GWDP requires that constituent
concentrations in each monitoring well shall not exceed the GWCLs set out in Table 2 of the
GWDP. It should be noted that, because the GWCLs have been set at the mean plus second
standard deviation, or the equivalent, un-impacted groundwater would normally be expected to
exceed the GWCLs approximately 2.5% of the time. Therefore, exceedances are expected in
approximately 2.5% of all sample results, and do not necessarily represent impacts to groundwater
from Mill operations. In fact, more frequent sampling of a given analyte will increase the number
of exceedances due to statistical variation and not due to Mill activity. Additionally, given the
slow velocity of groundwater movement, accelerated sampling at a monthly frequency can result
in resampling of essentially the same water and can lead to repeat exceedances for accelerated
constituents not due to Mill activities, but due to repeat sampling of the same water.
Letter to Mr. Doug Hansen
October 25, 2023
Page 3
1.0 Exceedances in Required Quarterly Sampling Wells
1.1 Quarterly Wells with Two Successive Exceedances
As indicated in the attached Table 1, the analytes discussed below exceeded their respective
GWCLs for two successive sampling periods in Q3 2023. A 30-day plan and schedule
contemplated in Part LG. I c) of the GWDP will not be required for quarterly wells as noted below.
One-time exceedances and non-successive exceedances are noted on Table 1, but not listed below.
Consecutive exceedances which occurred in previous reporting periods are discussed in previously
submitted SARs.
MW-11
• The chloride concentration exceeded its GWCL in all of the Q3 2023 sampling events. As
mentioned above, a CAP has been submitted and approved to address nitrate+nitrite
contamination which is expected to address chloride in groundwater. The actions specified
in the CAP are currently being implemented; therefore, a plan to address this consecutive
exceedance is not necessary and is not being submitted.
• The nitrate concentration exceeded its GWCL in in all of the Q3 2023 sampling events. As
mentioned above, a CAP has been submitted and approved to address nitrate+nitrite
contamination which is expected to address chloride in groundwater. The actions specified
in the CAP are currently being implemented; therefore, a plan to address this consecutive
exceedance is not necessary and is not being submitted.
• The selenium concentration exceeded its GWCL in all of the Q3 2023 sampling events. A
plan and schedule for assessment was submitted to DWMRC on May 24, 2023. The plan
and schedule was approved by DWMRC by letter dated June 29, 2023 and a SAR was
submitted September 27, 2023. An additional plan to address this consecutive exceedance
is not necessary and is not being submitted.
• Sulfate has exceeded the GWCL for both the September 2023 and Q3 2023 sampling
events. A SAR was submitted on March 7, 2022. As a result of the SAR, the GWCLs
have been recalculated and accepted by DWMRC. The recalculated GWCLs will become
effective upon their publication in the next revision of the GWDP. As a result of
DWMRC's acceptance of the recalculated GWCLs, a plan and schedule to address this
consecutive exceedance is not necessary and will not be submitted. Until such time as the
new GWCLs become effective, the exceedances will continue to be noted and reported.
• Manganese has exceeded the GWCL for both the June 2023 and Q3 2023 sampling events.
A SAR was submitted on March 7, 2022. As a result of the SAR, the GWCLs have been
recalculated and accepted by DWMRC. The recalculated GWCLs will become effective
upon their publication in the next revision of the GWDP. As a result of DWMRC's
acceptance of the recalculated GWCLs, a plan and schedule to address this consecutive
exceedance is not necessary and will not be submitted. Until such time as the new GWCLs
become effective, the exceedances will continue to be noted and reported.
Letter to Mr. Doug Hansen
October 25, 2023
Page4
MW-25
• The chloride concentration exceeded its GWCL in June 2023 and Q3 2023 sampling
events. As mentioned above, a CAP has been submitted and approved to address
nitrate+nitrite contamination which is expected to address chloride in groundwater. The
actions specified in the CAP are currently being implemented; therefore, a plan to address
this consecutive exceedance is not necessary and is not being submitted.
MW-26
MW-26 Note: As stated in the September 2009 Statement of Basis (page 23) in support of the
January 20, 2010 revisions to the GWDP, "[i]t should be noted that, because MW-26 is a pumping
well for chloroform removal, concentrations of all constituents in that well are subject to potential
variation over time as a result of the pumping activity. This will be taken into account by the
Executive Secretary in determining compliance for this well." Based on information provided by
DWMRC in teleconferences on April 27, and May 2, 2011, due to the current pumping status as
part of the chloroform investigation program, the 30-day plan and schedule for assessment is not
required at this time for exceedances of chloroform and methylene chloride in MW-26.
• Chloroform has exceeded its GWCL in all of the Q3 2023 sampling events. MW-26 is
used as a pumping well for the ongoing chloroform capture program and is expected to
yield increased concentrations of chloroform. Because this well is used in the chloroform
capture program which is the subject of separate investigations and actions, a plan and time
schedule to address the consecutive exceedances is not necessary and is not being
submitted.
• The nitrate concentration exceeded its GWCL in the June 2023 and Q3 2023 sampling
events. As mentioned above, a CAP has been submitted and approved to address
nitrate+nitrite contamination which is expected to address chloride in groundwater. The
actions specified in the CAP are currently being implemented; therefore, a plan to address
this consecutive exceedance is not necessary and is not being submitted.
• The chloride concentration exceeded its GWCL in June 2023 and Q3 2023 sampling
events. As mentioned above, a CAP has been submitted and approved to address
nitrate+nitrite contamination which is expected to address chloride in groundwater. The
actions specified in the CAP are currently being implemented; therefore, a plan to address
this consecutive exceedance is not necessary and is not being submitted.
MW-30
• Nitrate + nitrite has exceeded its GWCL in all of the Q3 2023 sampling events. As
mentioned above, a CAP has been submitted and approved and the specified actions are
currently being implemented; therefore, a plan to address this consecutive exceedance is
not necessary and is not being submitted.
• The chloride concentration exceeded its GWCL in all of the Q3 2023 sampling events. As
mentioned above, a CAP has been submitted and approved to address nitrate+nitrite
Letter to Mr. Doug Hansen
October 25, 2023
Page 5
contamination which is expected to address chloride in groundwater. The actions specified
in the CAP are currently being implemented; therefore, a plan to address this consecutive
exceedance is not necessary and is not being submitted.
• Selenium has exceeded the GWCL for all of the Q3 2023 sampling events. A SAR was
submitted on January 28, 2022. As a result of the SAR, the GWCLs have been recalculated
and accepted by DWMRC. The recalculated GWCLs will become effective upon their
publication in the next revision of the GWDP. As a result ofDWMRC's acceptance of the
recalculated GWCLs, a plan and schedule to address this consecutive exceedance is not
necessary and will not be submitted. Until such time as the new GWCLs become effective,
the exceedances will continue to be noted and reported.
• Uranium has exceeded the GWCL in the August and September 2023 sampling events. A
SAR was submitted on January 28, 2022. As a result of the SAR, the GWCLs have been
recalculated and accepted by DWMRC. The recalculated GWCLs will become effective
upon their publication in the next revision of the GWDP. As a result of DWMRC's
acceptance of the recalculated GWCLs, a plan and schedule to address this consecutive
exceedance is not necessary and will not be submitted. Until such time as the new GWCLs
become effective, the exceedances will continue to be noted and reported.
MW-31
• Nitrate + nitrite has exceeded its GWCL in all of the Q3 2023 sampling events. As
mentioned above, a CAP has been submitted and approved and the specified actions are
currently being implemented; therefore, a plan to address this consecutive exceedance is
not necessary and is not being submitted.
• The sulfate concentration exceeded its GWCL in all of the Q3 2023 sampling events. A
SAR was submitted to DWMRC on June 24, 2020. As a result of the SAR, the GWCLs
have been recalculated and accepted by DWMRC. The recalculated GWCLs will become
effective upon their publication in the next revision of the GWDP. As a result of
DWMRC's acceptance of the recalculated GWCLs, a plan and schedule to address this
consecutive exceedance is not necessary and will not be submitted. Until such time as the
new GWCLs become effective, the exceedances will continue to be noted and reported.
• The TDS concentration exceeded its GWCL in all of the Q3 2023 sampling events. A SAR
was submitted to DWMRC on June 24, 2020. As a result of the SAR, the GWCLs have
been recalculated and accepted by DWMRC. The recalculated GWCLs will become
effective upon their publication in the next revision of the GWDP. As a result of
DWMRC's acceptance of the recalculated GWCLs, a plan and schedule to address this
consecutive exceedance is not necessary and will not be submitted. Until such time as the
new GWCLs become effective, the exceedances will continue to be noted and reported.
• The chloride concentration exceeded its GWCL in all of the Q3 2023 sampling events. As
mentioned above, a CAP has been submitted and approved to address nitrate+nitrite
contamination which is expected to address chloride in groundwater. The actions specified
Letter to Mr. Doug Hansen
October 25, 2023
Page 6
in the CAP are currently being implemented; therefore, a plan to address this consecutive
exceedance is not necessary and is not being submitted.
• Uranium concentrations exceeded the GWCL in all of the Q3 2023 sampling events. A
SAR was submitted to DWMRC on April 29, 2021. As a result of the SAR, the GWCLs
have been recalculated and accepted by DWMRC. The recalculated GWCLs will become
effective upon their publication in the next revision of the GWDP. As a result of
DWMRC's acceptance of the recalculated GWCLs, a plan and schedule to address this
consecutive exceedance is not necessary and will not be submitted. Until such time as the
new GWCLs become effective, the exceedances will continue to be noted and reported.
1.2 Quarterly Wells with New Exceedances Reported in Q3
There are no new exceedances for the Q3 2023 quarterly well sampling program.
2.0 Exceedances in Semiannual Sampling Wells Accelerated to Quarterly
2.1 Semi-annual Wells with Two Successive Exceedances
As indicated in the attached Table 1, the analytes discussed below exceeded their respective
GWCLs for two successive sampling periods (Q2 2023 and Q3 2023).
MW-03A
• The selenium concentration exceeded its GWCL in the Q2 and Q3 2023 sampling events.
This is the first consecutive exceedance for selenium in MW-03A. Therefore, a plan and
schedule for assessment will be submitted under separate cover within 30 days of this
Exceedance Notice.
MW-24
Beryllium, cadmium, fluoride, nickel, thallium, and field pH exceeded their GWCLs in MW-24 in
the Q2 2023 and Q3 2023 sampling events.
The exceedances noted above are addressed in the SAR dated June 27, 2019. As a result of the
SAR, EFRI installed a collocated well to study potential installation issues associated with MW-
24. DWMRC approved the collocated well strategy by letter dated September 5, 2019. In response
to the previously identified exceedances and increasing trends, in 2020 EFRI voluntarily
completed a study of MW-24A (collocated with MW-24) to determine what geochemical and
hydrogeological influences are present which may be impacting monitoring data collected at these
two wells and potentially other wells across the Mill site. The MW-24A study and report included
several additional field data collection and analytical activities based on the conclusions of other
Mill reports.
The results of the analytical and test data collected during the MW-24A study demonstrated that
natural processes unrelated to disposal of materials in the Tailings Management System can
account for the behavior of all trace metals of concern, as well as fluoride, in groundwater at MW-
24 and MW-24A. Bottle-roll test results indicated that naturally-occurring trace metals can be
mobilized at concentrations similar to or greater than in groundwater even without a large pH
Letter to Mr. Doug Hansen
October 25, 2023
Page 7
decrease, suggesting that agitation alone, such as would occur during routine purging and sampling
of low permeability wells such as MW-24A, could result in metals mobilization.
Based on the results of the MW-24A study EFRI has voluntarily agreed to implement a MW-24A
Phase 2 study to determine what geochemical and hydrogeological influences are present that may
be affecting monitoring data collected at other wells across the Mill site. EFRI coordinated the
Phase 2 study efforts with DWMRC. DWMRC approved the Phase 2 study plan by letter dated
June 16, 2022. The Phase 2 study will build on the results of the previous study and will
supplement the data using eight other Mill site locations.
As a result of DWMRC's acceptance of the study strategy, a plan and schedule to address these
consecutive exceedances is not necessary and will not be submitted. Until such time as the study
is complete, the exceedances will continue to be noted and reported.
MW-28
• Chloride has exceeded the GWCL for both the Q2 2023 and Q3 2023 sampling events and
during previous quarters. As mentioned above, a CAP has been submitted and approved
and the specified actions are currently being implemented; therefore, a plan to address this
consecutive exceedance is not necessary and is not being submitted.
• Uranium has exceeded the GWCL for both the Q2 2023 and Q3 2023 sampling events. A
SAR was submitted to DWMRC on October 19, 2020. As a result of the SAR, the GWCLs
have been recalculated and accepted by DWMRC. The recalculated GWCLs will become
effective upon their publication in the next revision of the GWDP. As a result of
DWMRC's acceptance of the recalculated GWCLs, a plan and schedule to address this
consecutive exceedance is not necessary and will not be submitted. Until such time as the
new GWCLs become effective, the exceedances will continue to be noted and reported.
• Selenium has exceeded the GWCL for both the Q2 2023 and Q3 2023 sampling events. A
SAR was submitted to DWMRC on October 19, 2020. As a result of the SAR, the GWCLs
have been recalculated and accepted by DWMRC. The recalculated GWCLs will become
effective upon their publication in the next revision of the GWDP. As a result of
DWMRC's acceptance of the recalculated GWCLs, a plan and schedule to address this
consecutive exceedance is not necessary and will not be submitted. Until such time as the
new GWCLs become effective, the exceedances will continue to be noted and reported.
MW-32
• The chloride concentration exceeded its GWCL in Q2 2023 and Q3 2023 sampling events.
As mentioned above, a CAP has been submitted and approved to address chloride in
groundwater. The actions specified in the CAP are currently being implemented;
therefore, a plan to address this consecutive exceedance is not necessary and is not being
submitted.
Letter to Mr. Doug Hansen
October 25, 2023
Page 8
2.2 Semi-annual Wells with New Exceedances Reported in Q3
There are no new single exceedances for the Q3 2023 semi-annual well sampling program.
Yours truly,
r(~){r;.uJ
ENERGY FUELS RESOURCES (USA) INC.
Kathy Weinel
Director, Regulatory Compliance
cc: Scott Bakken, David Frydenlund, Logan Shumway, Garrin Palmer, Jordan App, Tanner Holliday
Monitoring
Well (Water Constituent Exceeding GWCL
Class)
Nitrate+ Nitrite (as N) (mg/L)
Chloride (mg/L)
MW-II Manganese (ug/L)
(Class Il) Sulfate (mg/L)
TDS (mg/L)
Selenium (ug/L)
MW-25 (Class Chloride (mg/L) [JJ)
MW-26 Nitrate+ Nitrite (as N) (mg/L)
(Class III) Chloroform (ug/L)
Chl oride (mg/L)
Nitrate+ Nitrite (as N) (mg/L)
MW-30 Chloride (mg/L)
(Class 11) Selenium (ug/L)
Field pH (SU)
Uranium (ug/L)
Nitrate+ Nitrite (as N) (mg/L)
MW-31 Sulfate (mg/L)
(Class III) TDS (mg/L)
Uranium (ug/L)
Chloride (mg/L)
MW-03A Selenium (ug/L) (Class Ill)
MW-05 (Class Uranium (ug/L) II)
MW-17 Chloride (mg/L) (Class III)
Beryllium (ug/L)
Cadmium (ug/L)
Fluoride (mg/L)
Nickel (mg/L)
MW-24 Manganese ( ug/L)
(Class lll) Thallium (ug/L)
Gross Alpha (pCi/L)
Sulfate (mg/L)
TDS (mg/L)
Field pH (S.U)
MW-27 Nitrate+ Nitrite (as N) (mg/L)
(Class III)
Fluoride (mg/L)
Chloride (mg/L)
MW-28 Selenium (ug/L)
(Class III) Nitrate + Nitrite (as N) (mg/L)
TDS (mg/L)
Uranium (ug/L)
MW-29 Uranium (ug/L) (Class III)
MW-32 Chloride (mg/L) (Class III)
MW-37 Field pH (S.U.) (Class [II)
Notes:
NS= Not Required and Not Sampled
NA= Not Applicable
Exceedances are shown in yellow
I
GWCLin
March 8,
2021
GWDP
2.5
39.16
237
1309
2528
12.5
35
0.62
70
58.31
2.5
128
53.6
6.47 -8.5
9.82
5
993
2132
15
143
109.58
7.5
46.8
2
6.43
0.47
50
7507
2.0 1
7.5
2903
4450
5.03 -8.5
5.6
0.85
105
111
5
3852
4.9
15
35.39
6.61 -8.5
Ql 2021 Results
February February March
Ql 2021 Qt 2021 2021 2021 2021
Sample Monthly Monthly
Date Result Sample Monthly Sample
Date Result Date
Required Quarterly Sampling Wells
1.21 NA
46.4 46.4
1/12/21 185 2/9/21 254 3/8/21
1140 1260
2010 2 160
<5 NA
1/11/21 34 NS NA NS
0.6 19 0.764
1/14/21 2200 2/10/21 1930 3/9/21
57.4 71.3
17.7 14.3
184 189
1/1 1/21 55.6 2/10/21 55.3 3/9/21
7.49 7.25
9.86 11.6
17. I 14.3
1070 1130
1/12/21 2460 2/9/21 2960 3/8/21
/9. 7 22.2
354 380
Required Semiannual Sampling Wells
NS NA NS NA NS
NS NA NS NA NS
NS NA NS NA NS
2.75 NA
8.79 NA
0.916 NA
70.4 NA
7460 NA
1/14/21 2. 74 NS NA NS
2.94 NA
2980 NA
4260 NA
5.08 NA
5. 16
1/1 4/21 NS NA NS
NA
128 NA
14.0 NA
1/15/21 3.44 NS NA NS
NA NA
10.3 NA
1/15/21 16.9 NS NA NS
1/14/21 36.9 NS NA NS
NS NA NS NA NS
Table I -GWCL Exceedances under the March 8, 2021 GWDP
Q2 2021 Results
March May 2021 June 2021
2021 Q2 2021 Q2 2021 Monthly May 2021 Monthly June 2021 Q3 2021
Sample Monthly Monthly Sample Monthly Date Result Sample Result Sample Result Date Result Date Date
Required Quarterly Sampling Wells
NA 0.948 NA NA
46.9 47.7 46.4 52.l
221 04/20/21 237 5/10/21 NA 6/8/21 NA 7/27/21
1270 1290 1280 1270
1950 2110 2190 1960
NA <5 NA NA
NA 04/14/21 34.8 NS NA NS NA 7//8/21
0.617 1.42 1.06 0.368
2190 04/21 /21 777 5/11/21 733 6/8/21 1590 7/28/21
63.9 57.5 69.6 54.9
17.0 17.7 18.6 17.0
192 162 188 170
56.3 04/14/21 55.7 5/11/21 58.3 6/8/21 54.l 7/29/21
7.14 7.20 720 7.36
10.2 /0.3 10. 7 9.84
17.4 /8.6 18.9 20.6
1210 1170 1200 1170
2400 04/13/21 2300 5/10/21 2610 6/7/21 2400 7/27/21
20.2 20.1 21. 7 20.8
388 377 384 374
Required Semiannual Sampling Wells
NA 4/27/21 74.0 NS NA NS NA NS
NA 4/20/21 0.599 NS NA NS NA NS
NA 4/26/21 32.6 NS NA NS NA NS
NA 2.78 NA NA
NA 8.08 NA NA
NA 0.925 NA NA
NA 72.4 NA NA
NA 7540 NA NA
NA 4/29/21 3.02 NS NA NS NA 7/29/21
NA 3.18 NA NA
NA 2960 NA NA
NA 4460 NA NA
NA 5.00 NA NA
6.57
NA 4/15/21 NS NA NS NA 7/22/2 I
0.69
NA 144 NA NA
NA 13.4 NA NA
NA 4/15/21 4.09 NS NA NS NA 7/23/2 I
NA 3740 NA NA
NA 8.52 NA NA
NA 4/14/21 16.2 NS NA NS NA 7/22/21
NA 4/13/2 I 31.8 NS NA NS NA 7/28/21
NA 5/12/21 7.00 NS NA NS NA NS
[These GWCLs were reset with the issuance of the March 8, 2021 GWDP. The new GWCLs became effective on March 8, 2021 and the first exceedance under the revised GWDP was noted in the March monthly data.
Q3 2021 Results Q4 2021 Results
August August September September November November December December
Q3 2021 2021 2021 2021 2021 Q4 2021 Q4 2021 2021 2021 2021 2021 Monthly Sample Result Sample Monthly Monthly Monthly Date Result Monthly Monthly Monthly Monthly
Date Result Sample Date Result Sample Date Result Sample Date Result
Required Quarterly Sampling Wells Required Quarterly Sampling Wells
0.924 NA NA 1.5 NA NA
48.3 57.0 49.6 52.8 53.6 53.9
376 8/10/21 NA 9/7/21 NA 10/20/21 286 11/16/21 261 12/13/21 300
1470 1370 1240 1360 1300 1350
2680 NA NA 2200 2230 2140
<5 NA NA 6.75 NA NA
34.2 NS NA NS NA 10/21/21 33.1 NS NA NS NA
0.352 1.42 0.710 0.928 1.18 1. 76
723 8/10/21 996 9/9/21 516 10/21/21 540 11/16/21 568 12/15/21 1160
54.0 61.4 59.3 55.2 56.9 75.9
20.6 16.5 15.4 14.3 18.0 18.6
/88 161 183 182 182 184
56.3 8/9/21 56.1 9/8/21 60.4 10/19/21 54.6 11/17/21 53.6 12/14/21 58.8
6.98 6.84 6.70 6.77 7. 18 7.04
9.60 9.38 9.74 9.76 9.67 10.1
18. 7 15.7 16.0 /8. l 19.3 17.9
1210 1130 1130 /220 1180 1220
3100 8/9/21 2600 9/7/21 2870 I 0/19/21 2600 11/15/21 2610 12/13/21 2420
20.0 /9.3 20.2 20.9 21.5 21.8
391 365 356 371 366 376
Required Semiannual Sampling Wells Required Semiannual Sampling Wells
NA NS NA NS NA 11/10/21 75.5 NS NA NS NA
NA NS NA NS NA 10/26/21 0.446 NS NA NS NA
NA NS NA NS NA 11/8/21 33.4 NS NA NS NA
2.71 NA NA 2.66 NA NA
9.26 NA NA 9.30 NA NA
1.4 NA NA 0.988 NA NA
76. 7 NA NA 76. 7 NA NA
7890 NA NA 7430 NA NA
2.91 NS NA NS NA 11/10/21 3.14 NS NA NS NA
1.92 NA NA 1.56 NA NA
3050 NA NA 3220 NA NA
4940 NA NA 4730 NA NA
5.85 NA NA 5.23 NA NA
6.32 3.88
NS NA NS NA 10/26/21 NS NA NS NA
NA 0.65
152 NA NA 147 NA NA
18.5 NA NA . 11.2 NA NA
6.09 NS NA NS NA 10/26/21 1.89 NS NA NS NA
NA NA NA 3570 NA NA
13.80 NA NA 6.03 NA NA
15.8 NS NA NS NA 10/27/21 14.9 NS NA NS NA
36.5 NS NA NS NA 11/2/2 I 36. l NS NA NS NA
NA NS NA NS NA 11/17/21 7.06 NS NA NS NA
Table 1-GWCL Exceedances under the March 8, 2021 GWDP
QI 2022 Results Q2 2022 Results Q3 2022 Results Q4 2022 Results
February February March 2022 March May 2022 June 2022 August August September September November November December December Monitoring GWCLin QI 2022 2022 Q2 2022 May 2022 June 2022 Q3 2022 2022 Q4 2022
Well (Water Constituent Exceeding GWCL March 8, 2021 Sample QI 2022 Monthly 2022 Monthly 2022 Sample Q2 2022 Monthly Monthly Monthly Monthly Sample Q3 2022 Monthly 2022 2022 2022 Sample Q4 2022 2022 2022 2022 2022
Class) GWDP Date Result Sample Monthly Sample Monthly Date Result Sample Result Sample Result Date Result Sample Monthly Monthly Monthly Date Result Monthly Monthly Monthly Monthly
Date Result Date Result Date Date Date Result Sample Date Result Sample Date Result Sample Date Result
Required Quarterly Sampling Wells Required Quarterly Sampling Wells Required Quarterly Sampling Wells Required Quarterly Sampling Wells
Nitrate+ Nitrite (as N) (mg/L) 2.5 2.55 NA NA 2.2 1.6 1.9 2.12 2.45 2.65 2.90 2.74 1.30
Chloride (mg/L) 39.16 51./ 57.2 67.7 54.9 59.5 46.4 54.0 67.4 68.I 72.I 71.9 52.3
MW-11 Manganese (ug/L) 237 1/18/22 156 2/8/22 233 3/8/22 224 180 254 228 297 201 212 2 14 220 273
(Class 11) 4/18/22 5/4/22 6/6/22 7/12/22 8/8/22 9/2 1/22 I 0/10/22 11/8/22 12/14/22 Sulfate (mg/L) 1309 1020 1240 1170 1240 1270 866 1390 1260 1300 1140 1140 1330
TDS (mg/L) 2528 2050 1900 2080 2060 2290 2360 2520 3230 2280 2570 2270 2370
Selenium (ug/L) 12.5 9.29 NA NA 10.8 NA NA 9.3 NA NA 15.5 NA NA
MW-25 (Class Chloride (mg/L) 35 1/7/22 34.1 NS NA NS NA 4/12/22 33.4 NS NA NS NA 7/13/22 22.4 NS NA NS NA 10/10/22 35.8 NS NA NS NA lIJ)
MW-26 Nitrate + Nitrite (as N) (mg/L) 0.62 0.601 0.367 0.600 0.8 I.I 0.60 /.63 1.56 0.491 0.632 0.408 2.66
(Class Ill) Chloroform (ug/L) 70 1/20/22 818 2/9/22 1580 3/8/22 1460 4/20/22 447 5/4/22 6/6 6/7/22 1250 7/14/22 <1.0 8/9/22 1120 9/20/22 810 I 0/13/22 749 11/10/22 512 12/15/22 460
Chloride ( mg/L) 58.31 77.I 58.6 64./ 56.8 63.2 47.4 61.0 65.0 62. I 65.5 59.2 60.6
Nitrate+ Nitrite (as N) (mg/L) 2.5 14.5 13.6 /6.6 17 15 J/.0 17.6 13.5 16.5 17.9 15.9 16./
MW-30 Chloride (mg/L) 128 181 184 196 173 195 126 108 185 182 /96 156 195
(Class II) Selenium (ug/L) 53.6 1/17/22 56.7 2/9/22 57. 7 3/7/22 62.0 4/20/22 64.9 5/4/22 69.4 6/7/22 65.7 7/13/22 61. I 8/9/22 64.3 9/20/22 70.0 I 0/13/22 65./ I l/9/22 75.6 12/13/22 70.8
Field pH (S U) 6.47 -8.5 7.62 720 7.12 6.92 7.24 7.32 7.33 7.33 6.81 6.84 6.37 6.59
Uranium (ug/L) 9.82 IO. I /0.3 9.9 9.6 IO. I 9.6 10.0 JO.I 8.3 9.8 IO. I 13.0
Nitrate + Nitrite (as N) (mg/L) 5 18.0 /3.5 17.0 18.0 13.0 13.0 16.9 /6.8 17.1 17.0 16.0 12.6
MW-31 Sulfate (mg/L) 993 1210 1250 731 1180 1220 1110 1260 1230 /200 972 1380 1280
(Class III) TDS (mg/L) 2132 1/19/22 2620 2/8/22 2680 3/7/22 2530 4/11/22 4300 5/3/22 2660 6/6/22 2690 7/12/22 2700 8/8/22 2700 9/20/22 2830 10/11/22 2720 11/8/22 2670 12/13/22 2700
Uranium (ug/L) 15 21. 7 22./ 22.5 22.0 22.9 21.5 22.6 22.7 18.8 23.3 24.5 26.2
Chloride (mg/L) 143 370 379 416 372 38/ 351 421 396 390 397 243 335
Required Semiannual Sampling Wells Required Semiannual Sampling Wells Required Semiannual Sampling Wells Required Semiannual Sampling Wells
MW-03A Selenium (ug/L) 109.58 NS NA NS NA NS NA 4/27/22 87.4 NS NA (Class III) NS NA NS NA NS NA NS NA 10/19/22 97.5 NS NA NS NA
MW-05 (Class Uranium (ug/L) 7.5 NS NA NS NA NS NA 4/18/22 0.5 NS NA NS NA NS NA NS NA NS NA 10/12/22 0.4 NS NA NS NA II)
MW-17 Chloride (mg/L) 46.8 NS NA NS NA NS NA 4/18/22 31.5 NS NA (Class III) NS NA NS NA NS NA NS NA I 0/17/22 54.0 NS NA NS NA
Beryll ium (ug/L) 2 2. 71 NA NA 2.5 NA NA 2.7 NA NA 3.3 NA NA
Cadmium (ug/L) 6.43 8.46 NA NA 9.20 NA NA 8.6 NA NA 10.9 NA NA
Fluoride (mg/L) 0.47 I NA NA 0.8 NA NA 0.760 NA NA 1.53 NA NA
Nickel (mg/L) 50 80.9 NA NA 74.3 NA NA 69.9 NA NA 86.9 NA NA
MW-24 Manganese (ug/L) 7507 7630 NA NA 7070 NA NA 7/20/22 7540 NA NA 8/30 NA NA
(Class Ill) Thallium (ug/L) 2.01 1/27/22 2.66 NS NA NS NA 4/27/22 3./ NS NA NS NA 7/28/22 3.0 NS NA NS NA 11 /2/22 3.5 NS NA NS NA
Gross Aloha (oCi/L) 7.5 2.26 NA NA 2.28 NA NA 2.55 NA NA 2.70 NA NA
Sulfate (mg/L) 2903 3060 NA NA 3120 NA NA 2800 NA NA 2680 NA NA
TDS (mg/L) 4450 4140 NA NA 3350 NA NA 4200 NA NA 4440 NA NA
Field pH (S.U.) 5.03 -8.5 5.31 NA NA 4.81 NA NA 4.89 NA NA 4.39 NA NA 4.80
MW-27 Nitrate + Nitrite (as N) (mg/L) 5.6 6.25 6.30 5.18 5.26 (Class Ill) 1/18/22 NS NA NS NA 4/12/22 NS NA NS NA 7/15/22 NS NA NS NA 10/19/22 NS NA NS NA
Fluoride (mg/L) 0.85 NA 0.90 0.530 0.722
Chloride (mg/L) 105 140 NA NA 130 NA NA 159 NA NA /61 NA NA
MW-28 Selenium (ug/L) 11.1 13.3 NA NA 19.8 NA NA 20.8 NA NA 23.7 NA NA
(Class III) Nitrate+ Nitrite (as N) (mg/L) 5 1/20/22 4 03 NS NA NS NA 4/19/22 5.1 NS NA NS NA 7/15/22 5.16 NS NA NS NA 10/12/22 5.69 NS NA NS NA
TDS (mg/L) 3852 NA NA NA 3320 NA NA NA NA NA 3550 NA NA
Uranium (ug/L) 4.9 8.50 NA NA IO. IO NA NA 12.4 NA NA 12.5 NA NA
MW-29 Uranium (ug/L) 15 1/18/22 15. I NS (Class III) NA NS NA 4/14/22 15. 7 NS NA NS NA 7/14/22 15. I NS NA NS NA 10/12/22 15.2 NS NA NS NA
MW-32 Chloride ( mg/L) 35.39 1/19/22 35.0 NS NA NS NA 4/11/22 28.6 NS NA (Class Ill) NS NA 7/15/22 28.2 NS NA NS NA 10/1 1/22 37.I NS NA NS NA
MW-37 Field pH (S.U.) 6.61 -8.5 NS NA NS NA NS NA 5/17/22 7 04 NS NA (Class [II) NS NA NS NA NS NA NS NA 11/1/22 6.60 NS NA NS NA
. .
Table I -GWCL Exceedances under the March 8, 2021 GWDP
QI 2023 Results
February February March 2023 Monitoring GWCLin QI 2023 2023
Well (Water Constituent Exceeding GWCL March 8, 2021 Sample QI 2023 Monthly 2023 Monthly
Class) GWDP Date Result Sample Monthly Sample
Date Result Date
Required Quarterly Sampling Wells
Nitrate+ Nitrite (as N) (mg/L) 2.5 3.49 2.89
Chloride (mg/L) 39.16 70. 7 71.4
MW-II Manganese ( ug/L) 237 193 161
(Class II) 1/25/23 2/8/23 3/14/23 Sulfate (mg/L) 1309 1240 1100
TDS (mg/L) 2528 2390 2120
Selenium (ug/L) 12.5 17.5 17. 7
MW-25 (Class Chloride (mg/L) 35 1/23/23 32.4 2/7/23 32.2 3/15/23 Ill)
MW-26 Nitrate + Nitrite (as N) (mg/L) 0.62 1.82 /.94
(Class Ill) Chloroform (ug/L) 70 1/26/23 709 2/8/23 664 3/14/23
Chloride ( mg/L) 58.31 51.5 52.2
Nitrate + Nitrite (as N) (mg/L) 2.5 18./ 15.9
MW-30 Chloride (mg/L) 128 166 173
(Class II) Selenium (ug/L) 53.6 1/25/23 68.8 2/8/23 70.6 3/1 5/23
Field pH (S.U.) 6.47 -8.5 7.01 6.77
Uranium (ug/L) 9.82 10.8 9.6
Nitrate + Nitrite (as N) (mg/L) 5 18. 7 16.5
MW-31 Sulfate (mg/L) 993 1230 I 190
(Class Ill) TDS (mg/L) 2132 1/24/23 2740 217/23 2730 3/14/23
Uranium (ug/L) 15 25.4 23.3
Chloride (mg/L) 143 333 388
Required Semiannual Sampling Wells
MW-03A Selenium (ug/L) 109.58 NS NA NS NA NS (Class 111)
MW-05 (Class Uranium (ug/L) 7.5 NS NA NS NA NS II)
MW-17 Chloride (mg/L) 46.8 1/30/23 26.5 NS NA NS (Class III)
Beryllium (ug/L) 2 2.4 NA
Cadmium (ug/L) 6.43 9.2 NA
Fluoride (mg/L) 0.47 0.699 NA
Nickel (mg/L) 50 72.5 NA
MW-24 Manganese (ug/L) 7507 7000 NA
(Class Ill) Thallium (ug/L) 2.01 1/31 /23 2.9 NS NA NS
Gross Alpha (pCi/L) 7.5 2.27 NA
Sulfate (mg/L) 2903 2720 NA
TDS (mg/L) 4450 4220 NA
Field pH (SU) 5.03 -8.5 4.76 NA
MW-27 Nitrate + Nitrite (as N) (mg/L) 5.6 5.25
(Class Ill) 1/27/23 NS NA NS
Fluoride (mg/L) 0.85 0.685
Chloride ( mg/L) 105 /40 NA
MW-28 Selenium (ug/L) I LI <5.0 NA
(Class lll) Nitrate + Nitrite (as N) (mg/L) 5 1/27/23 4.57 NS NA NS
TDS (mg/L) 3852 NA NA
Uranium (ug/L) 4.9 15.5 NA
MW-29 Uranium (ug/L) 15 1/27/23 9.7 NS NA NS (Class Ill)
MW-32 Chloride (mg/L) 35.39 1/30/23 27.9 NS NA NS (Class III)
MW-37 Field pH (S U) 6.61-8.5 2/9/23 6.55 NS NA NS (Class Ill)
Pursuant to the DWM RC letter of August 22, 2023, these constituents will no longer be monitored ori ari acc:eleratedscfiedule. These
constituents will be dropped from this report after this quarter.
Q2 2023 Results
March May 2023 June 2023 Q2 2023 May 2023 2023 Sample Q2 2023 Monthly Monthly Monthly
Monthly Date Result Sample Result Sample
Result Date Date
Required Quarterly Sampling Wells
2.53 2.98 2.64
66.3 70.6 66.0
211 4/17/23 224 5/9/23 233 6/5/23 1430 1330 1230
2300 2450 2320
14.9 14.2 16.8
32.6 4/19/23 35.8 5/10/23 34.9 6/6/23
0.875 0.671 0.945
1060 4/27/23 650 5/10/23 512 6/6/23
47.7 64.4 64.4
17.3 15.9 15.3
199 202 181
72.I 4/26/23 65.l 5/10/23 70.9 616123
7.15 6.94 6.96
9.6 9.5 10.5
17.9 14.3 15.4
951 1350 12 70
2520 4/24/23 2670 519/23 2570 6/5/23
23.7 24.0 25.2
302 297 388
Required Semiannual Sampling Wells
NA 4/27/23 112.0 NS NA NS
NA 4/1 9/23 26.3 NS NA NS
NA 4/25/23 27.9 NS NA NS
NA 2.6 NA
NA 9.4 NA
NA 0.597 NA
NA 72. 7 NA
NA 7030 NA
NA 5/2/23 3./ NS NA NS
NA 3.15 NA
NA 2720 NA
NA 4020 NA
NA 4.94 NA
5.32
NA 4/1 8/23 NS NA NS
0.613
NA 155 NA
NA 22.8 NA
NA 4/18/23 4.82 NS NA NS
NA 3870 NA
NA 11.8 NA
NA 4/19/23 15.3 NS NA NS
NA 4/25/23 36.1 NS NA NS
NA 5/11/23 6.94 NS NA NS
Q3 2023 Results
August 2023 September September June 2023 Q3 2023 August2023
Monthly Sample Q3 2023 Monthly Monthly 2023 2023
Result Date Result Sample Result Monthly Monthly
Date Sample Date Result
Required Quarterly Sampling Wells
2.86 3.22 4.30 4.10
69.0 77./ 87.2 80.3
283 7/11/23 238 8/2/23 149 9/5/23 233
1340 1370 1190 1330
2160 2350 2080 NA
15.3 17.1 22.0 21./
35.2 7/11/23 36.7 8/1/23 33 .7 9/6/23 33.1
1.430 0.726 0.383 1.530
426 7/13/23 2190 8/2/23 777 9/6/23 475
60.0 68.0 52.5 55 .5
16.I 16.6 17.4 17.1
203 205 204 186
71.4 7/11/23 70. 7 8/2/23 70.8 9/5/23 73.0
7.13 6.89 7.16 6.93
11.0 9.5 10.3 11.4
16.4 16.6 17.5 16.8
1290 1290 1290 1220
2610 7/10/23 2780 8/1/23 2630 9/6/23 2940
26.7 23.4 25.8 27.1
397 429 404 417
Required Semiannual Sampling Wells
NA 7/12/23 171 NS NA NS NA
NA 7/13/23 5.5 NS NA NS NA
NA 7/13/23 33.1 NS NA NS NA
NA 2.4 NA NA
NA 9.4 NA NA
NA 0.544 NA NA
NA 70.1 NA NA
NA 7300 NA NA
NA 7/12/23 2.8 NS NA NS NA
NA 360 NA NA
NA 2810 NA NA
NA 4180 NA NA
NA 4.96 NA NA
5.24
NA 7/13/23 NS NA NS NA
0.561
NA 150 NA NA
NA 23.5 NA NA
NA 7/13/23 5.41 NS NA NS NA
NA 3840 NA NA
NA 11.2 NA NA
NA 7/12/23 14.1 NS NA NS NA
NA 7/10/23 38.4 NS NA NS NA
NA 7/17/23 7 02 NS NA NS NA