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Home My WebLink AboutDRC-2024-005392?:;De L _~/~~ERGYFUELS April 19, 2024 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 first quarter ("Ql ") groundwater monitoring during the period from January 1, to March 31, 2024 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 March 22, 2024. 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 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 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 April 19, 2024 Page2 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 Q 1 2024. A 3 0-day plan and schedule contemplated in Part I.G .1 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. Letter to Mr. Doug Hansen April 19, 2024 Page 3 MW-11 • The chloride concentration exceeded its GWCL in all of the QI 2024 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 QI 2024 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 QI 2021 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. • Manganese has exceeded the GWCL for both the February and March 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 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 . MW-25 • The chloride concentration exceeded its GWCL in December 2023 and QI 2024 sampling events. MW-26 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 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 QI 2024 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 Letter to Mr. Doug Hansen April 19, 2024 Page4 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 Ql 2024 and February 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. MW-30 • Nitrate + nitrite has exceeded its GWCL in all of the Ql 2024 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 QI 2024 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. • Selenium has exceeded the GWCL for all of the Ql 2024 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. • Uranium has exceeded the GWCL all of ~he Q 1 2024 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 Q 1 2024 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 Ql 2024 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. Letter to Mr. Doug Hansen April 19, 2024 Page 5 • The TDS concentration exceeded its GWCL in all of the QI 2024 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 QI 2024 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. • Uranium concentrations exceeded the GWCL in all of the Q 1 2024 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 Ql One new exceedance for the QI 2024 quarterly well sampling program is listed below. This exceedance will result in an accelerated sampling frequency from quarterly to monthly. The well listed below will only be sampled during the monthly events for those constituents that exceeded the GWCLs and 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. • Tetrahydrofuran in MW-26 was above the GWCL in the QI 2024 sampling event. Relative to accelerated reporting requirements, reporting of exceedances is required to be completed within 30 days of receipt of the last data package for a quarterly monitoring event. Similarly, accelerated monitoring is required to commence the month following the submission of the Exceedance Notice for a specified quarter for wells that are being accelerated from quarterly to monthly and the quarter following the submission of the Exceedance Notice for wells that are being accelerated from semiannually to 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 (Q4 2023 and QI 2024). MW-24 Beryllium, cadmium, fluoride, nickel, thallium, and field pH exceeded their GWCLs in MW-24 in the Q4 2023 and QI 2024 sampling events. Letter to Mr. Doug Hansen April 19, 2024 Page 6 The exceedances noted above are addressed in the SAR dated June 27, 2019. As a result of the SAR, EFRl 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 EFRl 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 decrease, suggesting that agitation alone, such as would occur during routine purging and sampling oflow permeability wells such as MW-24A, could result in metals mobilization. Based on the results of the MW-24A study EFRl 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. EFRl 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 ofDWMRC'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 Q4 2023 and Q 1 2024 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 Q4 2023 and Ql 2024 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 Q4 2023 and Ql 2024 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. Letter to Mr. Doug Hansen April 19, 2024 Page7 MW-32 • The chloride concentration exceeded its GWCL in Q4 2023 and Ql 2024 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. 2.2 Semi-annual Wells with New Exceedances Reported in Ql There are no new single exceedances for the Ql 2024 semi-annual well sampling program . Yours truly, i(~?Jr~ ENERGY FUELS RESOURCES (USA) INC. Kathy Weinel Director, Regulatory Compliance cc: Scott Bakken, David Frydenlund, Logan Shumway, Garrin Palmer, Jordan App, Tanner Holliday Monitoring WeU(Water Constituent Exceeding GWCL Class) Nitrate+ Nitrite (as N) (mg/L_) Chloride (mg/L) MW-11 Manganese (ug/L) (Class II) Sulfate (mg/L) Selenium (ug/L) MW-25 (Class Chloride (mg/L) III) Nitrate+ Nitrite (as N) (mg/L) MW-26 Chloroform (ug/L) (Class III) Tetrahydrofuran ( ug/L) Chloride (m"/1 ) Nitrate+ Nitrite (as N) (m<!ll) MW-30 Chloride (mg/L) (Class II) Selenium (ug/L) 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 III) 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 III) 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 rm MW-32 Chloride (mg/L) (Class III) MW-37 Field pH (S .U.) (Class III) Notes: NS= Not Required and Not Sampled NA= Not Applicable Exceedances are shown in yellow GWCLin QI 2021 March 8, 2021 Sample Date GWDP 2.5 39.16 237 1/12/21 1309 12.5 35 1/11/21 0.62 70 1/14/21 23 58.31 2.5 128 1/11/21 53.6 9.82 5 993 2132 1/12/21 15 143 109.58 NS 7.5 NS 46.8 NS 2 6.43 0.47 50 7507 2 .01 1/14/21 7.5 2903 4450 5.03 -8.5 5.6 1/14/21 0.85 105 11.1 5 1/15/21 3852 4.9 15 1/15/21 35.39 1/14/21 6.61 -8.5 NS QI 2021 Results February February March March 2021 2021 QI 2021 2021 2021 Result Monthly Monthly Monthly Monthly Sample Sample Date Result Date Result Required Quarterly Sampling Wells 1.21 NA NA 46.4 46.4 46.9 185 2/9/21 254 3/8/21 221 1140 1260 1270 <5 NA NA 34 NS NA NS NA 0.619 0.764 0.617 2200 2/10/21 1930 3/9/21 2190 <1 .0 NA NA 57.4 71.3 63.9 17.7 14.3 17.0 184 2/10/21 189 3/9/21 192 55.i S:5_$ 56.3 9.8& ll6 10.2 17.1 14.3 17.4 1070 1130 1210 2460 2/9/21 2960 3/8/21 2400 19.7 22.2 20.2 354 380 388 Required Semiannual Sampling Wells NA NS NA NS NA NA NS NA NS NA NA NS NA NS NA 2.75 NA NA 8.79 NA NA 0.916 NA NA 70.4 NA NA 7460 NA NA 2.74 NS NA NS NA 2.94 NA NA 2980 NA NA 4260 NA NA 5.08 NA NA 5,16 NS NA NS NA NA 128 NA NA 14.0 NA NA 3.44 NS NA NS NA NA NA NA 10.3 NA NA 16.9 NS NA NS NA 36.9 NS NA NS NA NA NS NA NS NA 2021 . th.e Table 3-GWCL Exceedances under the March 8, 2021 GWDP Q2 2021 Results May2021 June 2021 Q22021 May2021 June 2021 Q32021 Q2 2021 Monthly Monthly Sample Result Sample Monthly Sample Monthly Sample Date Result Result Date Date Date Required Quarterly Sampling WeUs 0.948 NA NA 47.7 46.4 52.1 04/20/21 237 5/10/21 NA 6/8/21 NA 7/27/21 1290 1280 1270 <5 NA NA 04/14/21 34.8 NS NA NS NA 7//8/21 1.42 1.06 0.368 04/21/21 777 5/11/21 733 6/8/21 1590 7/28/21 <1 .0 NA NA 57.5 69.6 54 .9 17.7 18.6 17.0 04/14/21 162 5/11/21 188 6/8/21 170 7/29/21 55.7 58.3 54.1 10.3 10.7 9.84 18.6 18.9 20.6 1170 1200 1170 04/13/21 2300 5/10/21 2610 6/7/21 2400 7/27/21 20.1 21.7 20.8 377 384 374 Required Semiannual Sampling Wells 4/27/21 740 NS NA NS NA NS 4/20/21 0.599 NS NA NS NA NS 4/26/21 32.6 NS NA NS NA NS 2.78 NA NA 8.08 NA NA 0.925 NA NA 72.4 NA NA 7540 NA NA 4/29/21 3.02 NS NA NS NA 7/29/21 3.18 NA NA 2960 NA NA 4460 NA NA 5.00 NA NA 6.57 4/15/21 NS NA NS NA 7/22/21 0.69 144 NA NA 13.4 NA NA 4/15/21 4 .09 NS NA NS NA 7/23/21 3740 NA NA 8.52 NA NA 4/14/21 16.2 NS NA NS NA 7/22/21 4/13/21 31.8 NS NA NS NA 7/28/21 5/12/21 7.00 NS NA NS NA NS Q3 2021 Results Q4 2021 Results August August September September 2021 Q42021 November November December December Q32021 2021 2021 2021 Q42021 2021 2021 2021 2021 Result Monthly Monthly Monthly Monthly Sample Result Monthly Monthly Monthly Monthly Sample Date Date Result Sample Date Result Sample Date Result Sample Date Result Reg_uired Quarterly Sampling Wells Required Quarterly Sampling WeUs 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 <5 NA NA 6_75 NA NA 34 .2 NS NA NS NA 10/21/21 33. l 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 10/21/21 540 568 1160 11/16/21 12/15/21 <1.0 NA NA <10 NA NA 54 .0 61.4 59.3 55.2 56 .9 75.9 20.6 16.5 15.4 14.3 18.0 18.6 188 8/9/21 161 9/8/21 183 10/19/21 182 182 184 11/17/21 12/14/21 56.3 56.1 60.4 54.6 53.6 58.8 9.60 9.38 9.74 9.76 9 .67 10.1 18.7 15.7 16.0 18.1 19.3 17.9 1210 1130 1130 1220 1180 1220 3100 8/9/21 2600 9/7/21 2870 10/19/21 2600 11/15/21 2610 12/13/21 2420 20.0 19.3 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 11/2/21 36.1 NS NA NS NA NA NS NA NS NA 11/17/21 706 NS NA NS NA Table 3 -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 May2022 June 2022 Q32022 2022 Q42022 Well (Water Constituent Exceeding GWCL March 8, 2021 Sample QI 2022 Monthly 2022 Monthly 2022 Sample Q22022 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 Req_uired 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_)6 51.1 57.2 67. 7 54.9 59.5 46.4 54.0 67.4 68.1 72.1 71.9 52.3 MW-II Manganese ( ug/L) 237 1/18/22 156 2/8/22 233 3/8/22 224 4/18/22 180 5/4/22 254 6/6/22 228 7/12/22 297 8/8/22 201 9/21/22 10/10/22 11/8/22 12/14/22 (Class II) 212 214 220 273 Sulfate (mg/L) 1309 1020 1240 1170 1240 1270 866 1390 1260 1300 1140 1140 1330 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 III) NA NS NA 4/12/22 334 NS NA NS NA 7/13/22 22 4 NS NA NS NA 10/10/22 35.8 NS NA NS NA Nitrate+ Nitrite (as N) (mg/L) 0,62 0 .601 0 .367 0 _600 0.8 1.1 0.60 1.63 1.56 0 .491 0.632 0.408 2.66 MW-26 Chloroform ( ug/L) 70 1/20/22 818 2/9/22 1580 3/8/22 1460 4/20/22 447 5/4/22 616 6/7/22 1250 7/14/22 <LO 8/9/22 1120 9/20/22 810 10/13/22 749 11/10/22 512 12/15/22 460 (Class III) Tetrahydrofuran (ug/L) 23 <1.0 NA NA <1.0 NA NA <10 NA NA <1.0 NA NA Chloride (mg/L) 58.31 77.1 58.6 64.1 56 .8 63.2 47.4 61.0 65.0 62.1 65.5 59.2 60.6 Nitrate+ Nitrite (as N) (mg/L) 2.5 14.5 13.6 16.6 17 15 11.0 17.6 13.5 16.5 17.9 15.9 16.1 MW-30 Chloride (mg/L) 128 1/17/22 181 2/9/22 184 3/7/22 196 4/20/22 173 5/4/22 195 6/7/22 126 7/13/22 108 8/9/22 185 9/20/22 182 10/13/22 196 I 1/9/22 156 12/13/22 195 (Class II) Selenium (ug/L) 53.6 56.7 57.7 62.0 64.9 69.4 65.7 61.1 64.3 70.0 65.1 75.6 70.8 Uranium (ug/L) 9.82 JO.I 10.3 9.9 96 10.1 9 .6 10.0 10.1 8.3 9 .8 10.1 13.0 Nitrate+ Nitrite (as N) (mg/L) 5 18.0 13.5 17.0 18.0 13.0 13.0 16.9 16.8 17.1 17.0 16.0 12.6 Sulfate (mg/L) 993 1210 1250 731 1180 1220 1110 1260 1230 1200 972 1380 1280 MW-31 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 (Class III) Uranium (ug/L) 15 21.7 22.1 22.5 22.0 22.9 21.5 22.6 22.7 18.8 23.3 24.5 26.2 Chloride (mg/L) 143 370 379 416 372 381 351 421 396 390 397 243 335 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 (Class III) NA NS NA 4/27/22 87.4 NS NA 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 II) NA NS NA 4/18/22 0 .5 NS NA NS NA NS NA NS NA NS NA 10/12/22 04 NS NA NS NA MW-17 Chloride (mg/L) 46.8 NS NA NS NA NS NA 4/18/22 31.5 NS NA NS NA NS NA NS NA NS NA 10/17/22 54.0 NS NA NS NA (Class III) Beryllium {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 8130 NA NA (Class III) Thallium (ug/L) 2.01 1/27/22 2.66 NS NA NS NA 4/27/22 3.1 NS NA NS NA 7/28/22 3.0 NS NA NS NA 11/2/22 3.5 NS NA NS NA Gross Alpha (pCi/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 III) 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 161 NA NA MW-28 Selenium (ug/L) 1.1.1 13.3 NA NA 19.8 NA NA 20.8 NA NA 23.7 NA NA 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 7115122 5.16 NS NA NS NA 10/12/22 5.69 NS NA NS NA (Class III) 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 JO.JO NA NA 12.4 NA NA 12.5 NA NA MW-29 Uranium (ug/L) 15 1/18/22 15.1 NS !Class ill) NA NS NA 4/14/22 15.7 NS NA NS NA 7/14/22 15.1 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 (Class III) NA NS NA 4/11/22 28 .6 NS NA NS NA 7/15/22 28 .2 NS NA NS NA 10/11/22 37.1 NS NA NS NA MW-37 Field pH (S .U .) 6.61-8.5 NS NA NS (Class III) NA NS NA 5/17/22 7.04 NS NA NS NA NS NA NS NA NS NA 11/1/22 6.60 NS NA NS NA Table 3-GWCL Exceedances under the March 8, 2021 GWDP QI 2023 Results Q2 2023 Results Q3 2023 Results Q4 2023 Results February February Manh March May2023 June 2023 August2023 September September December Monitoring GWCLin QI 2023 2023 2023 Q2 2023 May 2023 June 2023 Q32023 August2023 October 2023 October Q42023 December Well (Water Constituent Exceeding GWCL March 8, Sample QI 2023 Monthly 2023 Monthly 2023 Sample Q22023 Monthly Monthly Monthly Monthly Sample Q32023 Monthly Monthly 2023 2023 Monthly 2023 Sample Q4 2023i 2023 2023 Class) 2021GWDP Date Result Sample Monthly Sample Monthly Date Result Sample Result Sample Result Date Result Sample Result Monthly Monthly Sample Date Monthly Date Result Monthly Monthly Date Result Date Result Date Date Date Sample Date Result Result Sample Date Result I Reguired Quarterly Sam_pling Wells Required Quarterly Sampling Wells Required Quarterly Sampling Wells Re![uired Quarterly Sampling Wells Nitrate+ Nitrite (as N) (mg/L) 2.5 3.49 2.89 2.53 2.98 2.64 2.86 3.22 4.30 4.10 3.74 3.96 3.28 Chloride (mg/L) 39.16 70.7 71.4 66.3 70.6 66.0 69.0 77.1 87.2 80.3 77.3 80.2 75.0 MW-II Manganese (ug/L) 237 1/25/23 193 2/8/23 161 3/14/23 21 l 4/17/23 224 5/9/23 233 6/5/23 283 7/11 /23 8/2/23 9/5/23 !0/3/23 11 /1/23 12/13/23 (Class 11) 238 149 233 254 217 336 Sulfate (mg/L) 1309 1240 1!00 1430 1330 1230 1340 1370 l 190 1330 1290 1270 1550 Selenium (ug/L) 12.5 17.5 17.7 14.9 14.2 16.8 15.3 17.1 22.0 21 .1 20.9 20.I 19.5 MW-25 (Class Chloride (mg/L) 35 1/23/23 32.4 2/7/23 32 .2 3/15/23 32 .6 4/19/23 35.8 5/10/23 34 .9 6/6/23 35.2 7/11 /23 36.7 8/1 /23 33 7 9/6 /23 33 I !0/4/23 33 5 11 /7/23 35.7 12/1 4/23 36.7 III) Nitrate+ Nitrite (as N) (mg/L) 0 62 1.82 1.94 0.875 0.671 0.945 1.430 0.726 0 .383 1.530 0.327 1.87 0 ,319 MW-26 Chloroform (ug/L) 70 1/26/23 709 2/8/23 664 3/14/23 1060 4/27/23 650 5/10/23 512 6/6/23 426 7/13/23 2190 8/2/23 777 475 731 1230 425 (Class III) Tetrahydrofuran (ug/L) 23 <LO NA NA <LO NA NA <1.0 NA 9/6/23 NA 10/4/23 NA 11/2/23 <1.0 12/13 /23 NA Chloride (mg/L) 58 .31 5 l.5 52 .2 47 7 64.4 64.4 60.0 68.0 52 .5 55 5 45 .3 72.5 60.4 Nitrate+ Nitrite (as N) (mg/L) 2.5 18.J 15.9 17.3 15.9 15.3 16.J 16.6 17.4 17.1 16.9 16.7 17.4 MW-30 Chloride (me/I) 128 1/25/23 166 2/8/23 173 3/15/23 199 4/26/23 202 5/10/23 181 6/6/23 203 7/11/23 205 8/2/23 204 186 197 211 204 (Class II) Selenium (ug/L) 53 .6 72.1 9/5/23 10/4/23 11/1/23 12/14/23 68.8 70.6 65.1 70.9 71.4 70.7 70.8 73.0 73.2 70.l 79.5 Uranium (ug/L) 9 .82 10.8 9.6 9 .6 9.5 10.5 11.0 9 ,5 10.3 11.4 10.5 JO.I 10.5 Nitrate+ Nitrite (as N) (mg/L) 5 18.7 16.5 17.9 14.3 15.4 16.4 16.6 17.5 16.8 17.0 18.0 17.2 MW-31 Sulfate (mg/L) 993 1230 1190 951 1350 1270 1290 1290 1290 1220 1290 1350 1340 (Class III) TDS (mg/L) 2132 1/24/2 3 2740 2/7/23 2730 3/14/23 2520 4/24/23 2670 0 5/9/23 2570 6/5/23 2610 7/10/23 2780 8/1/23 2630 9/6/23 2940 10/3/23 2490 11/6/23 2580 l 2/13/23 2820 Uranium (ug/L) 15 25.4 23.3 23.7 24.0 25.2 26.7 23.4 25.8 27.1 25.3 26.2 26.6 Chloride (mg/L) 143 333 388 302 297 388 397 429 404 417 396 407 408 Required Semiannual Sampling Wells Required Semiannual Samp_ling Wells Required Semiannual SaJl!p_ling Wells Required Semiannual Sampling Wells MW-03A Selenium (ug/L) !09.58 NS NA NS NA NS NA 4/27/23 112.0 NS NA NS NA 7/12/23 171 NS NA NS NA NS NA 10/19/23 132 NS NA (Class III) MW-05 (Class Uranium (ug/L) 7 .5 NS NA NS NA NS NA 4/19/23 26.3 NS NA NS NA 7/13/23 5 .5 NS NA NS NA NS NA 10/19/23 2.5 NS NA 11) MW-17 Chloride (mg/L) 46.8 1/30/23 26.5 NS NA NS NA 4/25/23 27 .9 NS NA NS NA 7/13 /23 33 .1 NS NA NS NA NS NA 10/23 /23 33.4 NS NA (Class III) Beryllium (ug/L) 2 2.4 NA NA 2.6 NA NA 2.4 NA NA NA 2.3 NA Cadmium (ug/L) 6.43 9.2 NA NA 9.4 NA NA 9.4 NA NA NA 9.1 NA Fluoride (m g/L) 0.47 0.699 NA NA 0.597 NA NA 0.544 NA NA NA 0.502 NA Nickel (me/I ) 50 72.5 NA NA 72.7 NA NA 70.1 NA NA NA 77.0 NA MW-24 Manganese ( ug/L) 7507 7000 NA NA 7030 NA NA 7300 NA NA NA 6960 NA (Class III) Thallium (ug/L) 2.01 1/31 /23 2.9 NS NA NS NA 5/2/23 3.1 NS NA NS NA 7/12/23 2.8 NS NA NS NA NS NA 10/26/23 3.0 NS NA Gross Alpha (pCi/L) 7.5 2.27 NA NA 3.15 NA NA 3 .60 NA NA NA 11.4 NA Sulfate (mg/L) 2903 2720 NA NA 2720 NA NA 2810 NA NA NA 2690 NA TDS (mg/L) 4450 4220 NA NA 4020 NA NA 4180 NA NA NA 4200 NA Field pH (S .U) 5 .03 -8 5 4.76 NA NA 4.94 NA NA 4.96 NA NA NA 4.50 NA MW-2/ N itrate+ Nitrite (as NJ (mg/L) 5 ,6 5 25 5.32 5 .24 5 49 (Class III) 1/27/23 NS NA NS NA 4/18/23 NS NA NS NA 7/13/23 NS NA NS NA NS NA 11 /7/23 NS NA Fluoride (mg/L) 0.85 0 .685 0 .613 0 .5 61 0 .607 Chloride ( mg/L) 105 140 NA NA 155 NA NA 150 NA NA NA 141 NA MW-28 Selenium (ug/L) 11.1 <5.0 NA NA 22.8 NA NA 23.5 NA NA NA 16.6 NA (Class III) Nitrate+ Nitrite (as N) (m g/L) 5 1/27/23 4.57 NS NA NS NA 4/18/23 4 82 NS NA NS NA 7/13/23 5.41 NS NA NS NA NS NA I 0/1 8/23 4.47 NS NA TDS (mg/L) 3852 NA NA NA 3870 NA NA 3840 NA NA NA 3780 NA Uranium (ug/L) 49 15.5 NA NA 11.8 NA NA 11.2 NA NA NA 8.2 NA MW-29 Uranium (ug/L) 15 1/27/23 9 .7 NS NA NS NA 4/19/23 15.3 NS NA NS NA 7/12/23 14 .1 NS NA NS NA NS NA 10/18/23 15.1 NS NA (Class III\ MW-32 Chloride (mg/L) 35 .39 1/30/23 27.9 NS (Class III) NA NS NA 4/25/23 36.1 NS NA NS NA 7/10/23 38.4 NS NA NS NA NS NA 11 /6/23 36.8 NS NA MW-37 Field pH (S U ) 6 .61-8,5 2/9/23 6.55 NS (Cl ass ill) NA NS NA 5/11 /23 6.94 NS NA NS NA 7/17/23 7.02 NS NA NS NA NS NA 11/16/23 6.82 NS NA Table 3-GWCL Exceedances under the March 8, 2021 GWDP QI 2024 Results February February March March Monitoring GWCLin QI 2043 Q12024 2024 2024 2024 2024 Well(Water Constituent Exceeding GWCL March 8, Sample Result Monthly Monthly Monthly Monthly Class) 2021 GWDP Date Sample Result Sample Result Date Date Required Quarterly Sampling Wells Nitrate+ Nitrite (as N) (mg/L) 2.5 4.30 3.6 3.85 Chloride (mg!L) 39.16 81.7 78.3 69.8 MW-Ii Manganese (ug/L) 237 1/10/24 206 2/6/24 269 3/6/24 265 (Class II) Sulfate (mg/L) 1309 1210 1290 1270 Selenium (ug/L) 12 .5 19.4 16.8 17.9 MW-25 (Class Chloride (mg/L) 35 1/9/24 36.8 2/7/24 32 .9 3/5/24 34 .9 III) Nitrate+ Nitrite (as N) (mg/L) 0.62 1.43 0.830 0 560 MW-26 Chloroform ( ug/L) 70 1/11/24 912 2/7/24 410 3/6/24 833 (Class III) Tetrahydrofuran (ug/L) 23 77.7 NA NA Chloride (mg/L) 58.31 54.6 62.0 54 .5 Nitrate+ Nitrite (as N) (mg/L) 2.5 16.2 17.2 16.1 MW-30 Chloride (mJ!}L) 128 1/9/24 197 2/7/24 194 3/5/24 207 (Class II) Selenium (ug/L) 53 .6 73.2 66.7 67.5 Uranium (ug/L) 9.82 11.2 10.0 10.9 Nitrate+ Nitrite (as N) (mg/L) 5 17.1 18.1 16.7 MW-31 Sulfate (mg/L) 993 1260 1230 1330 TDS (m!!/1) 2132 1/10/24 2780 2/6/24 2890 3/6/24 2880 (Class III) Uranium (ug/L) 15 25.0 24.9 27.6 Chloride (mg/L) 143 397 377 411 Required Semiannual Samplin_g Wells MW-03A Selenium (ug/L) 109 .58 1/26/24 99.6 NS NA NS NA (Class III) MW-05 (Class Uranium (ug/L) 7.5 1/23/24 1.8 NS NA NS NA II) MW-17 Chloride (mg/L) 46 .8 1/17/24 33 .3 NS NA NS NA (Class III) Beryllium (ug/L) 2 2.2 NA NA Cadmium (ug/L) 6.43 9.3 NA NA Fluoride (mg/L) 0.47 0.555 NA NA Nickel (mg/L) 50 70.2 NA NA MW-24 Manganese (ug/L) 7507 7250 NA NA (Class III) Thallium (uEVL) 2.01 1/25/24 3.0 NS NA NS NA Gross Alpha (pCi/L) 7.5 3.73 NA NA Sulfate (me/L) 2903 2400 NA NA TDS (mg/L) 4450 4070 NA NA Field pH (S .U.) 5 .03 -8 5 4.79 NA NA MW-27 Nitrate+ Nitrite (as N) (mg/L) 5,6 5.45 (Class III) 1/24/24 NS NA NS NA Fluoride (mg/L) 0.85 0,529 Chloride (mg/L) 105 129 NA NA MW-28 Selenium (ug/L) 11.1 26.5 NA NA (Class III) Nitrate+ Nitrite (as N) (mg/L) 5 1/24/24 6.13 NS NA NS NA TDS (mg/L) 3852 3780 NA NA Uranium (uEVL) 49 13.3 NA NA MW-29 Uranium (ug/L) 15 1/23/24 16.4 NS NA NS NA (Classlll) MW-32 Chloride (mg/L) 35.39 1/26/24 38.5 NS NA NS NA (Class III) MW-37 Field pH (S .U.) 6.61 -8.5 1/30/24 6.93 NS NA NS NA (Class III)