HomeMy WebLinkAboutDRC-2021-016767 - 0901a06880f877ecOCT 2 6 2021
Energy Fuels Resources (USA) Inc. 225 Union Blvd. Suite 600
Lakewood, CO, US, 80228
303 974 2140
www.energyfuels.com ENERGY FUELS
Div 04- Waste Managen-,ent
and RadLation Control
October 22, 2021
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
DK-2 021- o I G7(07
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, 2021 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 24, 2021.
Pursuant to Part I.G.1.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 of review, 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 I.G.1 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 I.G.1 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, 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:
Letter to Mr. Doug Hansen
October 22, 2021
Page 2
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.
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 2021. A 30-day plan and schedule contemplated in Part I.G.1 c) of
the GWDP will be required 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.
Letter to Mr. Doug Hansen
October 22, 2021 Page 3
MW-11
• The chloride concentration exceeded its GWCL in all of the Q3 2021 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.
• Sulfate has exceeded the GWCL for both the Q3 2021 and August 2021 sampling events. This is
the first consecutive exceedance for sulfate in MW-11. Therefore, a plan and schedule for
assessment will be submitted under separate cover within 30 days of this Exceedance Notice.
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 2021 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.
• Nitrate + nitrite has exceeded its GWCL in the August and September 2021 monthly 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 the August and September 2021 monthly
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 2021 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 2021 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
Letter to Mr. Doug Hansen
October 22, 2021 Page 4
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 2021 sampling events. A plan and schedule
for assessment was submitted on August 25, 2021. The plan and time schedule was approved by
DWMRC on September 29, 2021. Therefore, an additional plan to address this consecutive
exceedance is not necessary and is not being submitted.
MW-31
• Nitrate + nitrite has exceeded its GWCL in all of the Q3 2021 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 2021 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 TDS concentration exceeded its GWCL in all of the Q3 2021 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 sulfate concentration exceeded its GWCL in all of the Q3 2021 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.
• Uranium concentrations exceeded the GWCL in all of the Q3 2021 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
Five new exceedances for the Q3 2021 quarterly well sampling program are listed below. These
exceedances will result in an accelerated sampling frequency from quarterly to monthly. The wells listed
below will only be sampled during the monthly events for those constituents that exceeded the GWCLs and
Letter to Mr. Doug Hansen
October 22, 2021
Page 5
will be sampled for all constituents listed in the GWDP during the quarterly events as that is the regularly
scheduled sampling for the quarterly wells.
• Manganese in MW-11 was slightly above the GWCL in the Q3 2021 sampling event.
• TDS in MW-11 was slightly above the GWCL in the Q3 2021 sampling event.
• TDS in MW-25 was slightly above the GWCL in the Q3 2021 sampling event.
• TDS in MW-26 was slightly above the GWCL in the Q3 2021 sampling event.
• TDS in MW-30 was slightly above the GWCL in the Q3 2021 sampling event.
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 2021 and Q3 2021).
MW-24
• Beryllium concentrations exceeded the GWCL in MW-24 in the Q2 2021 and Q3 2021 sampling
events. Beryllium exceedances 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. As a result
of DWMRC's acceptance of the study strategy, a plan and schedule to address this consecutive
exceedance 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.
• Cadmium concentrations exceeded the GWCL in MW-24 in the Q2 2021 and Q3 2021 sampling
events. Cadmium exceedances 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. As a result
of DWMRC's acceptance of the study strategy, a plan and schedule to address this consecutive
exceedance 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.
• Fluoride concentrations exceeded the GWCL in MW-24 in the Q2 2021 and Q3 2021 sampling
events. Fluoride exceedances 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. As a result
of DWMRC's acceptance of the study strategy, a plan and schedule to address this consecutive
exceedance 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.
• Nickel concentrations exceeded the GWCL in MW-24 in the Q2 2021 and Q3 2021 sampling
events. Nickel exceedances 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. As a result of
DWMRC's acceptance of the study strategy, a plan and schedule to address this consecutive
exceedance 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.
Letter to Mr. Doug Hansen
October 22, 2021
Page 6
• Thallium concentrations exceeded the GWCL in MW-24 in the Q2 2021 and Q3 2021 sampling
events. Thallium exceedances 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. As a result
of DWMRC' s acceptance of the study strategy, a plan and schedule to address this consecutive
exceedance 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.
• Sulfate concentrations exceeded the GWCL in MW-24 in the Q2 2021 and Q3 2021 sampling
events. A SAR was submitted to DWMRC on 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. As a result of DWMRC' s
acceptance of the study strategy, a plan and schedule to address this consecutive exceedance 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.
• Manganese concentrations exceeded the GWCL in MW-24 in the Q2 2021 and Q3 2021 sampling
events. A SAR was submitted to DWMRC on 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 çollocated well strategy by letter dated September 5, 2019. As a result of DWMRC' s
acceptance of the study strategy, a plan and schedule to address this consecutive exceedance 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.
• TDS concentrations exceeded the GWCL in MW-24 in the Q2 2021 and Q3 2021 sampling events.
A SAR was submitted to DWMRC on 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. As a result of DWMRC' s
acceptance of the study strategy, a plan and schedule to address this consecutive exceedance 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-27
• The nitrate+nitrite concentration exceeded its GWCL for both the Q2 2021 and Q3 2021 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-28
• Chloride has exceeded the GWCL for both the Q2 2021 and Q3 2021 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 2021 and Q3 2021 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
Letter to Mr. Doug Hansen
October 22, 2021
Page 7
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 2021 and Q3 2021 sampling events. A SAR
was submitted to DWIVIRC 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-29
• Uranium has exceeded the GWCL for both the Q2 2021 and Q3 2021 sampling events. A Plan and
Time Schedule was submitted on May 11, 2021 and accepted by DWMRC on June 9, 2021. A
SAR was submitted on September 7, 2021. Therefore, a plan to address this consecutive
exceedance is not necessary and is not being submitted.
2.2 Semi-annual Wells with New Exceedances Reported in Q3
There were no new single exceedance for the Q3 2021 semi-annual well sampling program.
Yours truly,
Al-;44
ENERGY FUELS RESOURCES (USA) INC.
Kathy Weinel
Quality Assurance Manager
cc: Scott Bakken, David Frydenlund, Logan Shumway, Terry Slade
Table 1 - GWCL Exceedances under the March 8, 2021 GWDP
Q1 2021 Results Q2 2021 Results Q3 2021 Results
Monitoring
% ell (Water
Class)
Constituent Exceeding (WCL
GWCL in
March 8 ,
2021
GWDP
Q1 2021
Sample Da e
Q1 202
Result
February
2021
Monthly
Sample Date
February
2021
Monthly
Result
March 2021
Monthly
Sample Date
March 202
Monthly
Result
Q2 2021
Sample Date
Q 2021 2
Result Monthly
Sample Date
Monthly
Result
Monthly
Sample Date
onthly
Result
Sample
Date
(:=
gust 2021
Monthly
Sample Date
August 2021
Monthly'
Result
Septeinher
2021
Monthly
Sample Da e
September
2021
Monthly
Result
Required Quarterly Sampling Wells Required Quarterly Sampling Weils Required Quarterly Sainpling Wells
MW-11
(Class II)
Chloride (mg/L) 39.16
1/12/2021
46.4
2/9/2021
46.4
3/8/2021
46.9
4/20/2021
47.7
5/10/2021
4 4
6/8/2021
52.
7/27/2021
4&3
8/10/2021
57.0
9/7/2021
.49.6
Manganese (ug/L) 217 185 254 221 237 NA NA 376 NA NA
Sulfate (mg/L) 1309 1140 1260 1270 1290 1280 1270 1470 1370 1240
TDS (mg/L) 2528 2010 2160 1950 • 2110 2190 1960 2680 NA NA
MW-25 (Class
III) TDS (mg/L) 2976 1/11/2021 2660 NS NA NS NA 4/14/2021 2720 NS NA NS NA 7/28/2021 3100 NS NA NS NA
MW-26
(Class III)
Nitrate + Nitrite (as N) (mg/L) 0.62
1/14/2021
0.619
2/10/2021
0.764
3/9/2021
0.617
4/21/2021
1.42
5/11/2021
1.06
6/8/2021
0.368
7/28/2021
0.352
8/10/2021
1.42
9/9/2021
0.710
Ch oroform (ug/L) 70 2200 1930 2 90 777 733 1590 723 996 5 6
Ch oride (mg/L) 58 57.4 71.3 63.9 57.5 69 6 54 9 54.0 61.4 59.3
TDS (mg/L) 284.19 3100 2700 3060 2790 NA NA 3390 NA NA
Carbon Tetrachloride S 26.1 NA NA <1 00 <1.00 <1.00 <1.00 <1.00 <1.00
Me hylene Chloride (ug/L) 5 7.65 3.43 1 27 <1 00 <1.00 1.90 <1.00 1.25 < .00
MW-30
(Class II)
Nitrate + Nitrite (as N) (mg/L) 2 5
1/11/2021
17.7
2/10/2021
14.3
3/9/2021
17.0
4/14/2021
17.7
5/11/2021
18 6
6/8/2021
17.0
7/29/2021
20.6
8/9/2021
16.5
9/8/2021
15.4
Chloride (mg/L) I 28 184 189 192 162 188 170 188 161 183
Selenium (ug/L) 53 6 55.6 55.3 56.3 55.7 58.3 54. 56.3 56.1 60.4
TDS (molL) 1918 1660 N, 1 NA 1580 NA NA 2010 NA NA
Uran um (ug/L) 9 2 9.86 11.6 10.2 10,3 10.7 9.84 9.60 9.38 9 74
MW-31
(Class III)
Nitrate + Nitrite (as N) (mg/L) 5
1/12/2021
17.1
2/9/2021
14.3
3/8/2021
17.4
4/13/2021
18.6
5/10/2021
18.9
6/7/2021
20.6
7/27/2021
18.7
8/9/2021
1" 7
9/7/2021
16.0
Sulfate (mg/L) 99 1070 1130 12 0 1170 1200 1170 1210 1130 1130
TDS (mg/L) 21 2 2460 2960 2400 2300 26 0 2400 3100 2600 2870
Uranium (ug/L) 15 19.7 22.7 20.2 20.1 21.7 20.8 20.0 19.3 20.2
Chloride (mg/L) l 43 354 380 388 377 384 374 391 365 56
Required Semiannual Sampling Wells Required Semiannual Sampling Wells R quired Semiannual Sampling Wells
MW-12
(Class III)
Uranium (ug/L) 23.5 1/14/2021 25.0 NS NA NS NA 4/20/2021 22.9 NS NA NS NA 7/21/2021 22.2 NS NA NS NA Selenium (ug/L) . 39 35.1 28.8 32.4
MW-24
(Class III)
.
Beryllium (ug/L) 2
1/14/2021
2.75
NS
NA
NS
NA
4/29/2021
2.78
NS
NA
NS
.
NA
7/29/2021
2.71
NS
NA
NS
NA
Cadmium (ug/L) 6.43 8 79 NA NA 8.08 NA NA 9,26 NA NA
Fluoride (mg/L) 0.47 0 916 NA NA 0.925 NA NA 1.4 NA NA
Nickel (mg/L) 50 70.4 NA NA 72.4 NA NA 76.7 NA NA
Manganese (ug/L) 7507 7460 NA NA 7540 NA NA 7890 NA NA
Thallium (ug/L) 2.0 2 74 NA NA 3.02 NA NA 2.91 NA NA
Gross Alpha (pCi/L) 7.5 2.94 NA NA 3.18 NA NA 1.92 NA NA
Sulfate (mg/L) 2903 2980 NA NA 2960 NA NA 3050 NA NA
TDS (mg/L) 4450 4260 NA NA 4460 NA NA 4940 NA NA
Field pH (S.U.) 5 01 - 8 5.08 NA NA 5 00 NA NA 5.85 NA NA
MW 27
(Class III) Nitrate + Nitrite (as N) (mg/L) 5.6 1/14/2021 5.16 NS NA NS NA 4/15/2021 6.57 NS NA NS NA 7/22/2021 6.32 NS NA NS NA
MW-28
(Class III)
Chloride (mg/L) 105
1/15/2021
128
NS
NA
NS
NA
4/15/2021
144
NS
NA ' -
NS
NA
7/23/2021
152
NS
NA
NS
NA
Selenium (ug/L) 11.1 4 0 NA NA 13.4 NA NA 18.5 NA NA
Nitrate + Nitrite (as N) (mg/L) 5 3.44 NA NA 4.09 NA NA 6.09 NA NA
• Uranium (ug/L) 4.9 10.3 NA NA 8.52 • NA NA 13.80 NA NA
MW-29
lass I) (C II , Uranium (ug/L) 1/15/2021 16.9 NS NA NS NA 4/14/2021 16.2 NS NA NS NA 7/22/2021 li8 NS NA NS NA
MW-32
( Class III) Chloride (mg/L) 9 1/14/2021 36.9 NS NA NS NA 4/13/2021 31.8 NS NA NS NA 7/28/2021 36.5 NS NA NS NA ,
Notes:
NS= Not Required and Not Sampled
NA= Not Applicable
Exceedances are shown in yellow
These GWCLs were reset with the issuance of the March 8, 2021 GWDP. The new GWas became effective on March 8, 2021 and the first
exceedance under the revised GWDP was noted in the March monthly data.