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Home My WebLink AboutDRC-2018-010997 - 0901a0688090ee97Energy Fuels Resources (USA) Inc. 225 Union Blvd. Suite 600 Lakewood, CO, US, 80228 303 974 2140 DR C —2-0(8-0i0997 www.energyfuels.com October 22, 2018 VIA PDF AND OVERNIGHT DELIVERY Scott Anderson, Director of Waste Management and Radiation Control State of Utah Department of Environmental Quality 195 North 1950 West P.O. Box 144880 Salt Lake City, UT 84114-4880 Div of Waste Management and Radiation Control OCT 2 5 2018 Re: State of Utah Stipulation and Consent Order ("SCO") Docket Number UGW-20-01 White Mesa Uranium Mill — Energy Fuels Resources (USA) Inc. ("EFRI") Plan and Time Schedule Pursuant to Part II.H.2 of the Groundwater Corrective Action Plan ("GCAP") included as Attachment 1 to the SCO Dear Mr. Anderson: Part II.H.1) of the GCAP states that "At any time EFR[I] submits a quarterly report that demonstrates an exceedance (second quarter of chloroform exceedance), EFR[I] will provide a written exceedance notice to the Director ("Exceedance Notice") for all wells that have demonstrated such an exceedance." EFRI provided notice to the Director that the concentrations of chloroform in TW4-40 exceeded the respective GCAL of 70 ug/L for two or more consecutive quarters by letter dated August 28, 2018. Part II.H.2) of the GCAP requires that "Within 60 days after the time of submittal of a quarterly report that demonstrates an exceedance as defined in Part II.G, EFR[I] will provide a plan and schedule for remedial actions to address and resolve the excursion, for Director approval." This is the plan and schedule required under Part II.H.2) of the GCAP for TW4-40 for the second quarter of 2018. If you should have any questions regarding this submittal please contact me at (303) 389-4134. Yours truly, ENERGY FUELS RESOURCES (USA) INC. Kathy Weinel Quality Assurance Manager cc: David Frydenlund, Terry Slade, Logan Shumway, Scott Bakken, Paul Goranson, Stewart Smith (HGC) WHITE MESA MILL State of Utah Stipulation and Consent Order Docket No. UGW-20-01 Plan and Time Schedule Under Part II.H.2 For Exceedances in TW4-40 in the Second Quarter of 2018 Energy Fuels Resources (USA) Inc. 225 Union Boulevard, Suite 600 Lakewood, CO 80228 October 22, 2018 1. INTRODUCTION Energy Fuels Resources (USA) Inc. ("EFRI") operates the White Mesa Uranium Mill (the "Mill"), located near Blanding Utah. EFRI performed second quarter 2018 chloroform monitoring during the period from April 1, to June 30, 2018 under the September 14, 2015 Groundwater Corrective Action Plan ("GCAP"), included as Attachment 1 to the executed Stipulation and Consent Order ("SCO"). Part II.H.1) of the GCAP states that "At any time EFR[I] submits a quarterly report that demonstrates an exceedance (second quarter of chloroform exceedance), EFR[I] will provide a written exceedance notice to the Director ("Exceedance Notice") for all wells that have demonstrated such an exceedance." EFRI provided notice to the Director that the concentrations of chloroform in TW4-40 exceeded the respective GCAL of 70 ug/L for two or more consecutive quarters by letter dated August 28, 2018. Part II.H.2) of the GCAP requires that "Within 60 days after the time of submittal of a quarterly report that demonstrates an exceedance as defined in Part MG, EFR[I] will provide a plan and schedule for remedial actions to address and resolve the excursion, for Director approval." This is the plan and schedule required under Part II.H.2) of the GCAP for TW4-40 for the second quarter of 2018. 2. WELLS SUBJECT TO THIS PLAN The following well is covered by this Plan: Table 1 Chloroform Results in TW4-40 Constituent Monitoring Event GCAL (ug/L) Results (ug/L) 248 131 Chloroform Q1 2018 Q2 2018 70.0 3. BACKGROUND The chloroform plume is currently entirely within the Mill property boundary and is bounded on all sides by wells having chloroform concentrations that are either non-detect or less than 70 tig/L (Figure 1). The plume is bounded to the north by TW4-25; to the west and southwest by MW-31, MW-32, TW4-23, and TW4-24; far to the southwest by MW-17; to the east by TW4-3, TW4-5, TW4-13, TW4-14, TW4-18, TW4-27, TW4-30, TW4-36 and TW4-38; to the south by TW4-34; far to the south by MW-40; and to the southeast by TW4-35. 1 Pumping from wells within and immediately adjacent to the chloroform plume as of the second quarter of 2018 (5.3 gpm) exceeds calculated 'background' flow through the plume (3.4 gpm) and is therefore considered adequate. In addition, because of continued reductions in saturated thicknesses and hydraulic gradients resulting from reduced wildlife pond recharge, 'background' flow through the plume is expected to continue to diminish, thereby reducing the pumping needed to control the plume. In Q3 2017 chloroform at TW4-26 exceeded the respective GCAL of 70 ug/L for two or more consecutive quarters. As a result, TW4-26 no longer bounded the chloroform plume to the south-southwest. MW-17 still bounds the plume to the far southwest (cross-gradient), and MW- 22 still bounds the plume far to the south (cross- to downgradient). MW-40, installed during Q1 2018, also bounds the plume far to the south. In response to the TW4-26 exceedance EFRI installed compliance monitoring well TW4-40, located approximately 200 feet south of TW4-26 as shown in Figure 1, which was positioned immediately cross-to downgradient of TW4-26. TW4-40 was installed in early Q1 2018 and was sampled in Q1 2018 and Q2 2018. As shown in Table 1, TW4-40 exceeded the respective GCAL of 70 ug/L for those two consecutive quarters. The southernmost portion of the chloroform plume is affected by decreasing water levels (since about the fourth quarter of 2013), and generally increasing concentrations (at TW4-26 and TW4- 29) which are consistent with reduced wildlife pond seepage, in particular, reduced seepage from the southern wildlife pond. As the groundwater mound associated with the southern pond decays, groundwater flow directions in the southern extremity of the plume are likely to become more southerly, and plume migration is likely to turn more to the south. An increasingly southerly direction of plume migration is consistent with generally increasing concentrations at TW4-26 since the third quarter of 2016 and the exceedance at TW4-40. Although chloroform concentrations at TW4-40 exceed 70 ug/L, concentrations have been decreasing since installation in Q1 2018, likely due to initiation of pumping at TW4-41 during Q2 2018. 4. PLAN AND TIME SCHEDULE This is a plan and schedule for actions to address and resolve the excursion noted in Table 1 above as required by the GCAP. Part II.H.2).i) of the GCAP states that the plan and schedule may include, but is not limited to the installation of one or more pumping wells in the vicinity of the well found in exceedance and installation of one or more replacement wells for the compliance well in exceedance. EFRI plans to address the exceedance through the installation of one well (TW4-42) and the conversion of TW4-40 to a pumping well. Figure 2 shows the locations of proposed small-diameter test borings, one of which will be overdrilled and completed as new chloroform compliance well TW4-42. As shown in Figure 2, the proposed test boring locations are spaced at approximately 200-foot intervals downgradient of TW4-40. The test boring installation order is indicated by the labels 1 through 3. Each test boring will be sampled for chloroform. The samples will be analyzed by a State of Utah certified laboratory on the most expedited schedule available. The closest test boring to TW4-40 that is <5 ug/L for chloroform will be completed as compliance well TW4-42. The remaining test borings will be abandoned in accordance with State of Utah Administrative Rules for Water Wells R655-4-14. 2 The rationale for the test boring installation order is to gather chloroform concentration information needed to complete the new compliance well as close as possible to the south while remaining outside of the plume area. 4.1. Experts Reports to be Prepared As required by Part II.H.4, EFRI will submit an as-built report within 60 days of well installation for the newly installed well proposed in this plan and time schedule. Boring logs for the well and test borings will be included in the as-built report. Assessment of the plume, hydraulic capture and effectiveness of the remediation strategy will be discussed in the quarterly chloroform reports submitted as required by the GCAP. 4.2. Time Schedule The installation of the proposed well and the completion of the as-built report will be completed in accordance with the required timeframes specified in the approved and executed GCAP. The proposed wells will be installed and operational within 90 days of director approval of this plan and time schedule and the as-built report will be completed within 60 days of well completion. 5. CONCLUSION The chloroform plume is currently entirely within the Mill property boundary and is bounded on all sides by wells having chloroform concentrations that are either non-detect or less than 70 tig/L. Data collected to date indicate that, except for the lack of a well bounding the plume immediately to the south of TW4-40, there are sufficient chloroform monitoring and pumping wells to effectively define, control, and monitor the plume. Chloroform pumping as of the second quarter of 2018 (5.3 gpm) exceeds calculated 'background' flow through the plume (3.4 gpm) and is therefore considered adequate. In addition, because of continued reductions in saturated thicknesses and hydraulic gradients resulting from reduced wildlife pond recharge, 'background' flow through the plume is expected to continue to diminish, thereby reducing the pumping needed to control the plume. As previously stated, within the southernmost portion of the plume, decreasing water levels (since about the fourth quarter of 2013), and generally increasing concentrations at TW4-26 and TW4-29 are consistent with reduced wildlife pond seepage, in particular, reduced seepage from the southern wildlife pond. As the groundwater mound associated with the southern pond decays, groundwater flow directions in the southern extremity of the plume are likely to become more southerly, and plume migration is likely to turn more to the south. An increasingly southerly direction of plume migration is consistent with generally increasing concentrations at TW4-26 and the exceedance at TW4-40. Proposed new compliance monitoring well TW4-42 will be located south of and immediately downgradient of TW4-40 as shown by the test boring locations in Figure 2. TW4-40 will be converted to a pumping well. Pumping at TW4-40 is expected to increase chloroform mass removal rates and to help prevent downgradient chloroform transport to the 3 south. As discussed above, small-diameter pilot holes are proposed to be drilled as shown in Figure 2 and sampled for chloroform to ensure that new compliance well TW4-42 is located outside of the plume. 4 FIGURES Tl-12 TWt4-19 abandoned o TWN-16 abandoned o TWN-17, NO 20 abandoitod • MW-01 1WN-10 abandoned o TWN-09 TWN-06 atmndo6ed, TWIV-13 abanc.ioned TWN-05 TWN-07 TWN-08 NS o TWN-18 TWN-02 TWN-04 I - TW4-250 TW4-21 MW-26,- ND 2‘..) • MW-29 TW4-28 T,W4-32 TW4-18 TW4-22 TW4-19 TW4-2E TW4-39 TW4-05 TW4-37 TW4-20 TW4-38 TW4-09 TW4-12 TW4-10 TW4-03 TW4-16 TW4-11 TW4-13 MW•-^1 TW4-02 TW4-07, •IIVV:(14 „ TW4-08 `;TW4-36 • MW-32 TW4-01 - Cell 4B MW-360 )0, , TW4-04 TW4-41 cTW4-14 TW4-40. TW4 TW4-27TW4-31 TW4-23 TW4-33 TW4-26 TW4-29 -RN "TW4-35 TW4-34 • MW-33 • MW-34 • MW-37 • MW-15 PIEZ:04 , • MW-17 PIEZ-05 MV1-3A MW-40 MV7-21 MW-39 • MW-20 MW-38 EXPLANATION NS = not sampled, ND = not detected; ND 20 = not detected in second quarter 'W4-40 '1EZ-3A NI) 'a) • MW-22 kriged chloroform isocon and label temporary perched monitoring well installed February, 2018 showing concentration in pg/L May, 2016 replacement of perched piezometer Piez-03 (not sampled) perched monitoring well H Ibc=le,l í UI U y, FIGURE 1 TW4-7 0 TWN-1 MW-32 PIEZ-1 r concentration in pg/L perched monitoring well showing concentration in pg/L temporary perched monitoring well showing concentration in pg/L temporary perched nitrate monitoring well (not sampled) perched piezometer (not sampled) NOTES: MW-4, MW-26, TW4-1, TW4-2, TW4-4, TW4-11, TW4-19, TW4-20, TW4-21, TW4-37, TW4-39 and TW4-41 are chloroform pumping wells; TW4-22, TW4-24, TW4-25 and TWN-2 are nitrate pumping wells IMW INN HYDRO GEO CHEM, INC. APPROVED KRIGED 3rd QUARTER, 2018 CHLOROFORM (pg/L) WHITE MESA SITE DATE REFERENCE H:/718000fTW42/Plan/Uchl0918.srf TVVN-01 O -- 551 5 TWN-04 ••••••• PIEZ-3A TW4-18\ 0 TW4-05 TW4-39, OTW4-38 TW4-10 TW4-03 TW4-12 -4‘4 TW4-09 O MW-31 05548 T 14 1000 feet EXPLANATION proposed pilot boring and installation sequence kriged 03 2018 chlorform plume boundary kriged water level contour o showing elevation in feet amsl 55 TW4-40 -4o- 5530 PIEZ-3A 5584 MW-25 • 5534 TW4-7 0 5540 PIEZ-04 5528 temporary perched monitoring well installed February, 2018 showing elevation in feet amsl May, 2016 replacement of perched piezometer Piez-03 showing elevation in feet amsl perched monitoring well showing elevation in feet amsl temporary perched monitoring well showing elevation in feet amsl perched piezometer showing elevation in feet amsl NOTES: MW-4, MW-26, TW4-1, TW4-2, TW4-4, TW4-11, TW4-19, TW4-20, TW4-21, TW4-37, TW4-39 and TW4-41 are chloroform pumping wells; TW4-22, TW4-24 TW4-25 and TWN-2 are nitrate pumping wells; TW4-1, TW4-2, TW4-11 and TW4-41 water levels are below the base of the Burro Canyon Formation PROPOSED PILOT BORINGS (ONE TO BE COMPLETED AS TW4-42) SHOWING KRIGED 3rd QUARTER, 2018 WATER LEVELS AND CHLOROFORM PLUME BOUNDARY DATE REFERENCE F11718000/tw42/Plan/TW42PropBorings.srf HYDRO GEO CHEM, INC. APPROVED FIGURE 2