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HomeMy WebLinkAboutDRC-2020-017132 - 0901a06880d56f4dOctober 20, 2020 ENERGY FUELS Div of Wa5te Management and Radiation Control OCT 2 0 2020 Energy Fuels Resources (USA) Inc. 225 Union Blvd. Suite 600 Lakewood, CO, US, 80228 303 974 2140 DRC-2.0ZO- 017132_ www.energyfuels.com VIA PDF AND OVERNIGHT DELIVERY Ty L. Howard Director Division of Waste Management and Radiation Control State of Utah Department of Environmental Quality 195 North 1950 West P.O. Box 144880 Salt Lake City, UT 84114-4880 Re: State of Utah Ground Water Discharge Permit No. UGW370004 White Mesa Uranium Mill — Notice Pursuant to Part I.G.1 (a) Dear Mr. Howard: The White Mesa Mill (the "Mill") performed third quarter ("Q3") groundwater monitoring during the period from July 1, to September 30, 2020 under the March 19, 2019 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 21, 2020. 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 19, 2019, 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 19, 2019, 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. ("EFRr') 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. Ty L. Howard October 20, 2020 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 19, 2019. 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 2020. 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. Ty L. Howard October 20, 2020 Page 3 MW-11 • Manganese concentrations exceeded the GWCL in MW-11 in all of the Q3 sampling events. This consecutive exceedance is addressed in the SAR, dated June 27, 2019. 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 2020 and 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-25 • Cadmium concentrations exceeded the GWCL in MW-25 in the August and September monthly sampling events. This consecutive exceedance is addressed in the SAR, dated September 23, 2019. 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-26 • Nitrate + nitrite has exceeded its GWCL in the June and Q3 2020 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. • Chloroform has exceeded its GWCL in all of the Q3 2020 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 chloride concentration exceeded its GWCL in June and Q3 2020 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 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 Letter to Mr. Ty L. Howard October 20, 2020 Page 4 plan and schedule for assessment is not required at this time for exceedances of chloroform and methylene chloride in MW-26. MW-30 • Nitrate + nitrite has exceeded its GWCL in all of the Q3 2020 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 2020 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 Q3 2020 sampling events. This consecutive exceedance is addressed in the SAR, dated January 15, 2019. 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 concentrations exceeded the GWCL in all of the Q3 2020 sampling events. This consecutive exceedance is addressed in the SAR, dated January 15, 2019. 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 2020 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 2020 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 2020 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 Letter to Mr. Ty L. Howard October 20, 2020 Page 5 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 2020 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 2020 sampling events. This is the first consecutive exceedance for uranium in MW-31 under the March 19, 2019 GWDP. Therefore, a plan and schedule for assessment will be submitted under separate cover within 30 days of this Exceedance Notice. 1.2 Quarterly Wells with New Exceedances Reported in Q3 Two new exceedances for the Q3 2020 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 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 • TDS in MW-11 was slightly above the GWCL in the Q3 2020 sampling event. • TDS MW-26 was slightly above the GWCL in the Q3 2020 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 quarterly. 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 2020 and Q3 2020). MW-12 • Uranium concentrations exceeded the GWCL in the Q2 and Q3 2020 sampling events. This is the first consecutive exceedance for uranium in MW-12 under the March 19, 2019 GWDP. Therefore, a plan and schedule for assessment will be submitted under separate cover within 30 days of this Exceedance Notice. • Selenium concentrations exceeded the GWCL in the Q2 and Q3 2020 sampling events. This is the first consecutive exceedance for selenium in MW-12 under the March 19, 2019 GWDP. Therefore, a plan and schedule for assessment will be submitted under separate cover within 30 days of this Exceedance Notice. Letter to Mr. Ty L. Howard October 20, 2020 Page 6 MW-24 • Beryllium concentrations exceeded the GWCL in MW-24 in the Q2 2020 and Q3 2020 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 2020 and Q3 2020 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 2020 and Q3 2020 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 2020 and Q3 2020 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. • Manganese concentrations exceeded the GWCL in MW-24 in the Q2 2020 and Q3 2020 sampling events. As a result of the June 27, 2019 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. • Thallium concentrations exceeded the GWCL in MW-24 in the Q2 2020 and Q3 2020 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. Letter to Mr. Ty L. Howard October 20, 2020 Page 7 MW-27 • The nitrate+nitrite concentration exceeded its GWCL for both the Q2 2020 and Q3 2020 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 2020 sampling event and the Q3 2020 sampling event 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 2020 sampling event and the Q3 2020 sampling event. A Plan and Time Schedule that addresses exceedances of uranium and selenium in MW-28 was submitted to DWMRC on May 21, 2020. The Plan and Time Schedule was approved by DWMRC by letter dated June 22, 2020; therefore, an additional 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 No new single exceedances were reported for the Q3 2020 semi-annual well sampling program. Yours trul , Y-i( ,e.al ENERGY FUELS RESOURCES (USA) INC. Kathy Weinel Quality Assurance Manager cc: Scott Bakken, David Frydenlund, Logan Shumway, Terry Slade - GWCL Exceedances for Seconduarter 2020 under the March 19 2019 GWDP Q2 2019 Results Q3 2019 Results Q4 2019 Results Monitoring Well (Water Class) Constituent Exceeding GWCL GWCL in March 19, 2019 GWDP Q2 2019 Sample Date Q2 2019 Result May 2019 Monthly Sample Date May 2019 Monthly Result June 2019 Monthly Sample Date June 2019 Monthly Result Q3 2019 Sample Date Q3 2019 Result August 2019 Monthly Sample Date August 2019 Monthly Result Sept. 2019 Monthly Sample Date Sept. 2019 Monthly Result Q4 2019 Sample Date Q4 2019 Result November 2019 Monthly Sample Date Noveniber 2019 Monthly Result December 2019 Monthly Sample Date December 2019 Monthly Result Required Quarterly Sampling Wells MW-11 (Class II) Chloride (mg/L) 39.16 4/24/2019 34 5/7/2019 NA 6/3/2019 , NA 7/16/2019 48.4 8/5/2019 NA 9/24/2019 NA 10/15/2019 30.8 11/12/2019 39.1 12/3/2019 35.4 1100 1140 1290 NA NA 1410 NA NA 1160 Sulfate (mg/L) 1309 NA NA 2100 NA NA 1890 NA NA 1890 TDS (mg/L) 2528 167 206 185 174 202 199 210 210 181 Manganese (ug/L) 164.67 MW-14 (Class III) Fluoride (mg/L) 0.22 4/23/2019 <0.100 NS NA NS NA 7/15/2019 0.248 NS NA NS NA 10/9/2019 <0.100 11/13/2019 0.127 12/3/2019 0.120 2120 2110 2180 NA NA 2450 NA NA 1780 Sulfate (mg/L) 2330 MW-25 (Class III) Cadmium (ug/L) 1.5 4/10/2019 1.30 5/8/2019 1.41 6/4/2019 1.47 - 7/15/2019 1.23 8/6/2019 1.37 9/23/2019 1.38 10/9/2019 1.45 11/13/2019 1.36 12/4/2019 1.45 MW-26 (Class III) Nitrate + Nitrite (as N) (mg/L) 0.62 4/24/2019 3.00 5/7/2019 0.986 _ 6/4/2019 3.16 7/16/2019 2.06 8/6/2019 3.10 9/24/2019 1.59 10/9/2019 2.35 11/13/2019 2.90 12/4/2019 2.32 1110 1280 1710 1540 1090 3110 778 1140 4140 Chloroform (ug/L) 70 57.7 62.3 73.8 62.1 83.5 75.2 72.6 73.0 82.0 Chloride (mg/L) 58.31 NA NA 2920 NA NA 3100 NA NA 2820 TDS (mg/L) 3284.19 2.64 1.73 2.95 , 3.35 1.12 10.7 <1.00 1.69 4.16 Methylene Chloride (ug/L) 5 MW-30 (Class II) Nitrate + Nitrite (as N) (mg/L) 2.5 4/9/2019 18.5 5/7/2019 _ 17.9 6/3/2019 15.8 7/16/2019 19.3 8/6/2019 15.8 9/24/2019 17.9 10/8/2019 18.2 11/13/2019 17.2 12/4/2019 17.8 185 180 170 176 190 181 165 175 138 Chloride (mg/L) 128 56.4 47.8 56.8 49.1 50.9 48.4 49.9 47.1 53.6 Selenium (ug/L) 47.2 8.99 9.29 8.69 8.12 9.39 9.03 8.88 8.15 8.62 Uranium (ug/L) 8.32 MW-31 (Class III) N trate + Nitrite (as N) (mg/L) 5 4/10/2019 19.7 5/7/2019 18.9 6/3/2019 19.7 7/15/2019 19.8 8/5/2019 17.0 9/23/2019 19.5 10/9/2019 19.8 11/12/2019 18.8 12/3/2019 18.3 1020 990 1010 NA NA 1150 NA NA 917 Sulfate (mg/L) 993 2030 2650 2280 NA NA 2580 NA NA 2080 TDS (mg/L) 2132 NA NA 14.4 NA NA 14.3 NA NA 14 Uranium (ug/L) 15 343 338 318 365 372 374 325 346 294 Chloride (mg/L) 143 MW-36 (Class H1) Sulfate (mg/L) 3146.21 4/18/2019 2470 5/21/2019 NA 6/3/2019 NA 7/16/2019 3170 8/6/2019 NA 9/23/2019 NA 10/8/2019 2850 11/13/2019 2590 12/3/2019 2710 ' Required Semi-Annual Sampling Wells ' MW-12 (Class III) um ( Urani ug/L) 23 5 4/25/2019 23.2 NS NA NS NA 7/11/2019 23.1 NS NA NS NA 21.6 NS NA 10/23/2019 30.3 NS NA NA 33.9 Selenium (ug/L) 39 MW-24 (Class III) Beryllium (u /L) 2 5/2/2019 2.83 NS NA NS NA 7/18/2019 2.94 NS NA NS NA 3.25 NA NA l 9.31 NA NA NA NA 8.37 NA NA 8.24 Cadmium (ug/L) 6.43 0.667 NA NA NA 0.996 NA NA 0.839 Fluoride (mg/L) 0.47 75.4 NA NA NA 70.6 NA NA 63.9 Nickel (mg/L) 50 11/6/2019 7700 NS NS NA NA NA NA NA NA 7020 Man (ug/L) ganese 7507 2.88 NA NA NA 2.61 NA NA 2.73 Thallium (ug/L) 2.01 2630 NA NA NA NA NA NA 2790 Sulfate (mg/L) 2903 5.19 NA NA NA NA 5.03 NA NA 4.53 Field pH (S.U.) 5.03 - 8.5 MW-27 (Class HI) Nitrate + Nitrite (as N) (mg/L) 5.6 4/23/2019 6.33 NS NA NS NA 7/12/2019 8/15/2019 6.50 NS NA NS NA 10/22/2019 6.27 NS NA NS NA MW-28 (Class III) Chloride 105 4/24/2019 165 NS NA NS NA 7/12/2019 8/16/2019 133 NS NA NS NA 149 NA NA 16.5 NA NA NA NA 10.6 NA NA 12.4 SelenMm (ug/L) 11.1 10/22/2019 5.14 NS NA NS NA NA NA NA NA NA 3.7 Nitrate + Nitrite (as N) (mg/L) 5 <1.00 NA NA NA NA 1.20 NA NA 1.94 Gross Alpha (pCi/L) 2.42 12.4 NA NA NA NA 7.83 NA NA 9.60 Uranium (ug/L) 4.9 MW-32 (Class IH) Chloride (mg/L) 35.39 4/9/2019 34.5 NS NA NS NA 8/15/2019 35.7 NS NA NS NA 10/8/2019 35.3 NS NA NS NA MW-35 (Class 11) Nitrogen, Ammonia as N 0.14 4/18/2019 0.0634 NS NA NS NA 7/11/2019 0.0935 NS NA NS NA 10/8/2019 <0.0500 NS NA NS NA Notes: NS= Not Required and Not Sampled NA= Not Applicable Exceedances are shown in yellow Table 1 - GWCL Exceedances for Second Quarter 2020 under the March 19, 2019 GWDP Q1 2020 Results I Q2 2020 Results Q3 2020 Results Monitoring Well (Water Class) Constituent Exceeding GWC GWC1, in March 19, 2019 GWDP Q1 2020 Sample Date Q1 2020 Result February 2020 Monthly Sample Date February 2020 Monthly Result March 2020 Monthly Sample Date March 2020 Monthly Result Q2 2020 Sample Date Q2 2020 Result May 2020 lonthly Sample Date May 2020 Monthly Result June 2020 Monthly Sample Date June 2020 Monthly Result Q3 2020 Sample Da e Q3 2020 Result August 2020 Monthly Sample Date August 2021) Monthly Result September 2020 Monthly Sample Date September 2020 Monthly Result Requ red Quarterly Sampling Wells MW-11 (Class II) Ch oride (mg/L) 39 16 1/15/2020 1/28/2020 38.9 2/4/2020 42.1 3/10/2020 41.0 4/8/2020 38.3 5/5/2020 39 0 6/2/2020 40.1 7/7/2020 42.1 8/11/2020 43.9 9/2/2020 40.6 Sulfate (mg/L) 1309 1180 1260 1120 1180 1180 1310 1260 1220 1170 TDS (mg/L) 2528 1920 NA NA 1920 NA NA 2590 NA NA Manganese (ug/L) 164 67 169 227 183 189 206 211 178 276 230 MW-14 (Class III) Fluoride (mg/L) 0.22 1/15/2020 0.128 2/4/2020 0.145 3/10/2020 <0.100 4/6/2020 <0.100 5/5/2020 <0.100 6/2/2020 <0.100 7/6/2020 <0.100 NS NA NS NA Sulfate (mg/L) 2330 2250 2190 2150 2290 2150 2260 2000 NA NA MW-25 (Class 111) Cadmium (ug/L) 1 5 1/15/2020 1.35 2/5/2020 1.52 3/11/2020 1.41 4/7/2020 1.46 5/6/2020 1.52 6/3/2020 1.46 7/7/2020 1.39 8/10/2020 1.54 9/2/2020 1.61 MW-26 (Class III) Nitrate + Nitrite (as N) (mg/L) 0 62 1/15/2020 0.873 2/4/2020 0.978 3/10/2020 1.60 4/8/2020 0.747 5/6/2020 1.16 6/3/2020 3.44 7/9/2020 1.360 8/11/2020 0.407 9/2/2020 0.62 Chloroform (ug/L) 70 1260 1640 1720 1420 1200 1530 4030 1940 1070 Chloride (mg/L) 58 3 78.8 66.9 76.9 62.8 73.8 63.7 67.6 57.5 59.8 TDS (mg/L) 3284 9 3010 NA NA 2600 NA NA 3880 NA NA Methylene Chloride (ug/L) 5 2.79 2.76 4.44 1.94 1.48 2.35 6.59 2.67 <1.00 MW-30 (Class II) Nitrate + Nitrite (as N) (mg/L) 2 5 1/15/2020 16.4 2/5/2020 17.8 3/11/2020 19.0 4/6/2020 18.1 5/6/2020 18.6 6/3/2020 18.3 7/6/2020 18.4 8/11/2020 21.1 9/1/2020 18.3 Chloride (mg/L) 128 182 187 182 195 177 180 185 183 166 Selenium (ug/L) 47 "? 49.7 49.9 48.1 54.4 51.5 50.5 51.8 56.0 55.3 Uranium (ug/L) 8.32 8.88 9.06 9.50 9.24 8.94 9.28 9.76 10.6 9.90 MW-31 (Class III) Nitrate + Nitrite (as N) (mg/L) 5 1/14/2020 17.5 2/4/2020 18 0 3/10/2020 19.2 4/6/2020 18.8 5/5/2020 20.1 6/2/2020 18.7 7/7/2020 19.2 8/10/2020 21.6 9/1/2020 18.4 Sulfate (mg/L) 993 1120 1150 1080 1130 1080 1130 1150 1100 1110 TDS (mg/L) 2132 2220 2240 2380 2400 2330 2440 2400 2580 2650 Uran um (ug/L) 15 14.8 NA NA 15.5 NA NA 18.1 19.7 18.5 Chloride (mg/L) 143 381 370 368 376 361 377 370 368 367 MW-36 (Class III) Sulfate (mg/L) 3146.21 1/ t 4/2020 2660 2/5/2020 2540 3/10/2020 2890 4/9/2020 2660 5/5/2020 2480 6/2/2020 2770 7/6/2020 2610 NS NA NS NA Required Semi-Annual Sampling Wells MW-12 (Class III) Uranium (ug/L) 23.5 1/16/2020 21.9 NS NA NS NA 4/9/2020 23.7 NS NA NS NA 7/8/2020 25.6 NS NA NS NA Selenium (ug/L) 19 NA 41.2 40.1 MW-24 (Class III) Beryllium (ug/L) 2 /22/2020 2.07 NS NA NS NA 4/22/2020 2.95 NS NA NS NA 7/10/2020 2.59 NS NA NS NA Cadm um (ug/L) 6 43 7.30 NA NA 8.46 NA NA 8.43 NA NA Fluoride (mg/L) 0 47 0.805 NA NA 0.732 NA NA 1.08 NA NA Nickel (mg/L) 50 68 NA NA 72.6 NA NA 76.7 NA NA Manganese (ug/L) 7507 7010 NA NA 7750 NA NA 8010 NA NA Thallium (ug/L) 2.01 1.92 NA NA 2.81 NA NA 3.07 NA NA Sulfate (mg/L) 2903 2960 NA NA 2870 NA NA 2920 NA NA Field pH (S.U.) 5 0 8 5 6.01 NA NA 5.60 NA NA 5.70 NA NA MW-27 (Class IR) Nitrate + Nitrite (as N) (mg/L) 5.6 1/16/2020 6.18 NS NA NS NA 4/8/2020 6.43 NS NA NS NA 7/8/2020 6.62 NS NA NS NA MW-28 (Class III) Chloride (mg/L) l 05 1/16/2020 151 NS NA NS NA 4/15/2020 129 NS NA NS NA 7/8/2020 140 NS NA NS NA Selenium (ug/L) 1 13.4 NA NA 10.2 NA NA 15.5 NA NA Nitrate + Nitrite (as N) (mg/L) 5 NA NA NA 2.6 NA NA 4.58 NA NA Gross Alpha (pCi/L) 2.42 1.79 NA NA 1.69 NA NA 1.60 NA NA Uranium (ug/L) 4.9 7.56 NA NA 5.91 NA NA 11,80 NA NA MW-32 (Class III) Chloride (mg/L) 35.39 1/14/2020 38.0 NS NA NS NA 4/7/2020 36.4 NS NA NS NA 7/6/2020 33.0 NS NA NS NA MW 35 (Class 11) Nitrogen, Ammonia as N 0.1 1/16/2020 0 0919 NS NA NS NA 4/9/2020 0.0772 NS NA NS NA 7/6/2020 0.108 NS NA NS NA Notes: NS= Not Required and Not Sampled NA= Not Applicable Exceedances are shown in yellow Pursuant to the DWMRC letter ofJuly 28, 2020, these constituents will no longer be monitored on an accelerated schedule. These constituents will be dropped from this report after this quarter.