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Home My WebLink AboutDRC-2014-004678 - 0901a06880477ffeDepartment of Environmental Quality Amanda Smith Executive Director State of Utah DIVISION OF RADIATION CONTROL Rusty Lundberg Director GARY R. HERBERT Governor DRC 2014-004678 SPENCER J. COX Lieutenant Governor MEMORANDUM TO: File 7AA THROUGH Phil Goble, Compliance Section Manager pf.6, FROM: Tom Rushing, P.G. DATE: July 14, 2014 SUBJECT: Energy Fuels Resources (USA) Inc., Background Groundwater Quality Report for Monitoring Wells MW-35, MW-36, and MW-3 7 This is to summarize the Utah Division of Radiation Control ("DRC") review of the Energy Fuels Resources (USA) Inc. May 1, 2014 "Background Groundwater Quality Report for Monitoring Wells MW-35, MW-36, and MW-3 7 White Mesa Uranium Milt ("Background Report"). The Report was prepared to comply with Utah Ground Water Discharge Permit No. UGW370004 ("Permit") Part I.H.5. Part I.H.5 of the Permit states, "Background Groundwater Quality Report for Well MW-35 and New Monitoring Wells - within 30 calendar days of Director approval of the new monitoring well As-built Report required by Part I.H.4. above, the Permittee shall commence a quarterly groundwater sampling program that will comply with the following Permit requirements: a. Routine groundwater compliance monitoring requirements of Part I.E. I b. Well monitoring procedure requirements of Part I. E. 5. c. After completion of eight consecutive quarters of groundwater sampling and analysis of well MW-35 and the new wells required by Part I.H. 4. the Permittee shall submit a Background Report for Director approval that will include: I. Data preparation and statistical analysis of groundwater quality data, including, but not limited to, evaluation of data characteristics and internal data consistency, treatment of non-detectable values, and statistical methods used. These statistics shall be calculated using the Decision Tree/Flowchart used for the previous Background Reports that were conditionally approved by the DRC on August 24, 2007. Summary: 195 North 1950 West • Salt Lake City, UT Mailing Address: P.O. Box 144850 • Salt Lake City, UT 84114-4850 Telephone (801) 536-4250 • Fax (801) 533-4097 • T.D.D. (801) 536-4414 www.deq.utah.gov Printed on 100% recycled paper EFR MW-35, MW-36 and MW-37 Background Report DRC Review Memo Page 2 2. Shallow aquifer average linear groundwater velocity calculated for the new wells based on well specific hydraulic conductivity, hydraulic gradient, and effective aquifer porosity, d. If after review of the report, and the Director determines that additional information is required, the Permittee shall provide all requested information, resolve all issues identified, and resubmit the report for Director review and approval within a timeframe approved by the Director. After approval of this report, the Director will re-open the Permit and establish an appropriate monitoring frequency in accordance with the criteria found in Part I.E. 1(b) or (c), and establish Groundwater Compliance Limits in Table 2 for well MW-35 and each of the new wells.'''' Based on review of the Background Report, DRC staff recommends that Groundwater Compliance Limits and Monitoring Frequencies be included in the Permit as discussed below. Ground Water Velocity Calculations: The groundwater monitoring network for the White Mesa Uranium Mill is screened in the Burro Canyon Formation. Per past studies and reviews the Burro Canyon Formation is highly variable in conglomeratic deposition (fluvial), shows spatial variability in groundwater hydraulic and geochemical parameters. The monitoring parameters are therefore set on an intrawell basis with background concentrations of individual parameters being evaluated separately for each monitoring well. Permeability of the Burro Canyon Formation is generally low. No significant joints or fractures within the formation have been documented in past studies and monitoring well installations. Any observed joints or fractures were noted to have been cemented (calcific) with no open space or impacts on hydraulic conductivity estimates. Per the EFR June 6, 2014 Hydrogeology Report for the White Mesa Uranium Mill and a 1994 report prepared by Titan Environmental titled Hydrogeological Evaluation of White Mesa Uranium Mill, "hydraulic conductivity of the Burro Canyon Formation ranges from 1.9 * 10'7 to 1.6 * 10'3 cm/s, with a geometric mean of 1.01 * 10'5 cm/s, based on the results of 12 pumping/recovery tests performed in monitoring wells and 30 packer tests performed in borings prior to 1994. As discussed in Section 2, subsequent testing of wells by HGC yields a hydraulic conductivity range of approximately 2 * 10'8 to 0.01 cm/s." It was noted in the EFR June 6, 2014 Report that hydraulic conductivities and groundwater pore velocities in the south-southwest portion of the facility (location of monitoring wells MW-35, MW-36 and MW-37) are lower than compared with other areas of the facility. The May 1, 2014 Report Section 3.5 Hydraulic Properties summarizes activities to calculate groundwater velocity at monitoring wells MW-35, MW-36 and MW-37. The EFR calculations are based on the geometric mean of "well-specific estimates of hydraulic conductivities, hydraulic gradient, and effective porosity." The May 1, 2014 Report, Table 11, lists hydraulic parameters and notes that the data is taken from a report prepared by Hydro Geo Chem. (2010, 2011). EFR MW-35, MW-36 and MW-37 Background Report DRC Review Memo Page 3 Table 1: Aquifer Parameters Calculated for Monitoring Wells MW-35, MW-36, and MW-37 Well, MW-35 MW-36 MW-37 Hydraulic : Conductivity K (cm/s) • 3.48E-04 4.51 E-04 1.28E-06 Porosity 0.18 0.18 0.18 Hydraulic Gradient 0.004 0.005 0.008 Average Linear Groundwater > Velocity (ft/yr) 8 13 0.6 Per review of the relevant well installation and hydraulic testing reports prepared by Hydro Geo Chem., listed below, it appears that the groundwater velocities were based on estimations of hydraulic conductivity and specific storage calculated with the use of the Kansas Geological Survey ("KGS") Model, and field slug testing measurements (falling head) at each monitoring well. Per review of the slug test results tables for each of the applicable monitoring wells, it appears that the measured values correspond to the values submitted with the background monitoring report. 1. Hydro Geo Chem. Inc., October 11, 2010, Installation and Hydraulic Testing of Perched Monitoring Wells MW-33, W-34 and MW-35 at the White Mesa Uranium Mill near Blanding, Utah 2. Hydro Geo Chem. Inc., June 28, 2011, Installation and Hydraulic Testing of Perched Monitoring Wells MW-36 and MW-37 at the White Mesa Uranium Mill near Blanding, Utah Per review of the Hydro Geo Chem. Inc. reports, it appears that data were collected and analyzed according to appropriate slug test methods, however, per limitations of slug testing methods it is noted that the calculated linear groundwater velocities are considered estimates only. Per review of the drill logs and well completion diagrams for monitoring wells MW-35, MW-36, and MW-37, the following information was noted: Table 2: Well Completion Data Well No. Screen Interval (ft.) Static Water Level § (ft-) • ' •"" ^ Brushy Basin Formation Contact Depth (ft.) MW-35 83.6 to 123.6 110.5 123.6 MW-36 79.9 to 119.9 109.6 119.9 MW-37 80.2 to 120.2 110.6 120.2 Well constructions and formation descriptions, and screened depths for the three monitoring wells are almost the same. Per criteria listed in the Permit Part I.E., groundwater samples are to be collected at the following frequencies; Semi-annual (2 times/year) where groundwater velocity is less than 10 feet/year, and, EFR MW-35, MW-36 and MW-37 Background Report DRC Review Memo Page 4 • Quarterly (4 times/year) where groundwater velocity is equal to or greater than 10 feet/year. Based on the calculated groundwater pore velocities discussed above, the required monitoring frequencies for monitoring wells MW-35, MW-36, and MW-37 are listed on table 3 below. Table 3: Monitoring Frequency Monitoring Well No. Monitoring Frequency MW-35 Semi-Annual MW-36 Quarterly MW-37 Semi-Annual Class of Groundwater GW-35, GW-36, GW-37: Per DRC review of the average TDS concentrations for monitoring wells MW-35, MW-36 and MW-37, based on all data submitted for the applicable well, the groundwater class protection level for the three study wells was Class III (total dissolved solids greater than 3,000 mg/L and less than 10,000 mg/L. Table 4: Ground Water Class (UAC R317-6-3) at Monitoring Wells MW-35, MW-36, and MW-37 Well No. Number of Samples TDS Concentration Average Groundwater Class Protection Level -l (UAC R317-6-4) MW-35 12 3,855 mg/L Class III MW-36 10 4,462 mg/L Class III MW-37 10 3,885 mg/L Class III Utah Administrative Code (UAC) R-317-6-4.6 concerning setting of protection levels based on fractions of the ground water quality standards for Class III Groundwater are summarized on table 5 below: Table 5 - Fraction of GWQS Method Class III Protection Levels Groundwater Class TDS Limit Groundwater Protection Levels Undetectable Contaminant (greatest of) Detectable Contaminant (greatest of) ; III 1.25 * BG 0.5 * GWQS MDL 1.5 * BG Mean + 2a 0.5 * GWQS Per above and Section 3.3 of the Report revised groundwater compliance limit were calculated and are presented in Table 10 of the Report. The proposed GWCL's are summarized on the tables below. Note that several of the listed Ground Water Quality Standards ("GWQS") were included in the Permit as "ad hoc" standards based on literature values (U.S. Environmental Protection Agency Drinking Water Maximum Contaminant Levels and Risk Based Concentrations). Most of the proposed GWCL's were calculated based on fractions of the GWQS's (Ground Water Class EFR MW-35, MW-36 and MW-37 Background Report DRC Review Memo Page 5 Basis) as listed on the table below. In cases where the GWCL's were calculated by alternative methods, according to the Director Approved Statistical Process Flow Chart (Intera, 2007), the calculation tables were reviewed and crosschecked. Additionally, the statistical flow chart was expanded to include a process for monitoring wells and parameters which show an upward concentration trend (Figure 3 ofthe Report). Per discussion below, the proposed "modified approach" was reviewed by DRC for individual cases where applied by EFR and in all cases was found to be unwarranted as included on Table 6 below. Table 6 - Monitoring Wells Subject to EFR Proposed Modified Statistical Methods Monitoring Well umber ^Parameter. : Modified Method f&djl§: DRC Comments * MW-35 Gross Alpha Highest Historic Value ("HHV") + 2a MW-35 Slight Increasing Trend- not appropriate MW-35 Total Dissolved Solids HHV + 2a Reset according to Utah Rules 1.25 x Background MW-35 Selenium HHV + 2a MW-35 Slight Increasing Trend appropriate not MW-36 Gross Alpha Fractional Fractional approach in conformance with the Utah Rules MW-36 Total Dissolved Solids Mean+4a Reset according to Utah Rules 1.25 x Background MW-37 Selenium Fractional Fractional approach in conformance with the Utah Rules MW-37 Sulfate Mean+4a MW-37 Slight Increasing - not appropriate The proposed GWCL's were adjusted by DRC and are included on the tables below in a separate column. Table 7 - Proposed GWCL's for Monitoring Well MW-35 and DRC Adjustments Monitoring Well MW-35 Parameter Proposed GWCL GWQS Method DRC Adjustment Ammonia 0.14 mg/L 25 mg/L Mean + 2a Nitrate/Nitrite 5 mg/L 10 mg/L Fractional Arsenic 25 ug/L 50 ug/L Fractional EFR MW-35, MW-36 and MW-37 Background Report DRC Review Memo Page 6 Monitoring Well MW-35 Parameter Proposed GWCL GWQS Method DRC Adjustment Beryllium 2 ug/L 4 ug/L Fractional Cadmium 2.5 ug/L. 5 ug/L Fractional Chromium 50 ug/L 100 ug/L Fractional Cobalt 365 ug/L 730 ug/L Fractional Copper 650 ug/L 1,300 ug/L Fractional Iron 330.08 ug/L 11,000 ug/L Mean + 2a Lead 7.5 ug/L 15 Mg/L Fractional Manganese 290.68 ug/L 800 ug/L Mean + 2a Mercury 2 pg/L Fractional Molybdenum 20 pg/L 40 pg/L Fractional Nickel 5 pg/L 10 pg/L Fractional Selenium 33.73 pg/L 50 pg/L Modified HHV+2a Fraction GWQS = 25 pg/L Silver 50 pg/L 100 pg/L Fractional Thallium Ug/L 2 pg/L Fractional Tin 8,500 pg/L 17,000 pg/L Fractional Uranium 26.76 pg/L 30 pg/L Mean + 2a Vanadium 30 pg/L 60 pg/L Fractional Zinc 2,500 pg/L 5,000 ug/L Fractional Gross Alpha 12.21 pCi/L 15pCi/L Modified HHV +2a Fraction GWQS = 7.5 pCi/L Acetone 350 pg/L 700 pg/L Fractional Benzene 2.5 pg/L 5 pg/L Fractional Methyl Ethyl Ketone 2,000 pg/L 4,000 pg/L Fractional Carbon Tetrachloride 2.5 pg/L 5 pg/L Fractional Chloroform 35 pg/L 70 pg/L Fractional Chloromethane 15 pg/L 30 pg/L Fractional Methylene Chloride 2.5 pg/L 5 pg/L Fractional Naphthalene 50 pg/L 100 pg/L Fractional Tetrahydrofuran 23 pg/L 46 pg/L Fractional Toluene 500 pg/L 1,000 pg/L Fractional Xylenes, Total 5,000 pg/L 10,000 pg/L Fractional Chloride 69.12 mg/L Mean + 2a Fluoride 0.42 mg/L 4 mg/L Mean + 2a Field pH 6.15 mg/L Mean + 2a Sulfate 2,400 mg/L HHV EFR MW-35, MW-36 and MW-37 Background Report DRC Review Memo Page 7 Monitoring Well MW-35 Parameter Proposed GWCL GWQS Method DRC Adjustment i TDS 5,123.55 mg/L HHV + 2a 1.25 xBckgnd = 4821.88 mg/L Table 8 - Proposed GWCL's for Monitoring Well MW-36 and DRC Adjustments Monitoring Well MW-36 Parameter Proposed GWCL GWQS Method ;;%DRCti Adjustment Ammonia 12.5 mg/L 25 mg/L Fractional Nitrate/Nitrite 5 mg/L 10 mg/L Fractional Arsenic 25 pg/L 50 pg/L Fractional Beryllium 2 pg/L 4 pg/L Fractional Cadmium 2.5 pg/L 5 ug/L Fractional Chromium 50 pg/L 100 pg/L Fractional Cobalt 365 pg/L 730 pg/L Fractional Copper 650 pg/L 1,300 pg/L Fractional Iron 5,500 pg/L 11,000 pg/L Fractional Lead 7.5 pg/L 15 pg/L Fractional Manganese 400 pg/L 800 pg/L Fractional Mercury 2 pg/L Fractional Molybdenum 20 pg/L 40 pg/L Fractional Nickel 50 pg/L 100 pg/L Fractional Selenium 307.42 pg/L 50 pg/L 100 pg/L Mean + 2a Silver 50 pg/L 2 pg/L 17,000 pg/L Fractional Thallium 1.35 pg/L Mean + 2a Tin 8,500 pg/L Fractional Uranium 26.42 pg/L 30 pg/L Mean + 2a Vanadium 30 pg/L 60 pg/L Fractional Zinc 2,500 pg/L 5,000 pg/L Fractional Gross Alpha 7.50 pCi/L 15pCi/L Mean + 2a Acetone 350 ug/L 700 pg/L Fractional Benzene 2.5 pg/L 5 pg/L Fractional Methyl Ethyl Ketone 2,000 pg/L 4,000 pg/L Fractional Carbon Tetrachloride 2.5 pg/L 5 pg/L Fractional Chloroform 35 pg/L 70 pg/L Fractional Chloromethane 15 pg/L 30 pg/L Fractional Methylene Chloride 2.5 pg/L 5 pg/L Fractional Naphthalene 50 ug/L 100 pg/L Fractional EFR MW-35, MW-36 and MW-37 Background Report DRC Review Memo Page 8 Monitoring Well MW-36 Parameter Proposed GWCL GWQS Method* DRC Adjustment Tetrahydrofuran 23 pg/L 46 pg/L Fractional Toluene 500 pg/L 1,000 pg/L Fractional Xylenes, Total 5,000 pg/L 10,000 pg/L Fractional Chloride 73 mg/L HHV Fluoride 0.35 mg/L 4 mg/L Mean + 2a Field pH 6.49 mg/L Mean + 2a Sulfate 3,146.21 mg/L Mean + 2a TDS 4,860.50 mg/L Mean + 4a 1.25xBckgnd 5470 mg/L Table 9 - Proposed GWCL's for Monitoring Well MW-37 and DRC Adjustments Monitoring Well MW-37 . . Parameter i Proposed GWCL GWQS Method DRC Adjustment Ammonia 12.5 mg/L 25 mg/L Fractional Nitrate/Nitrite 2.22 mg/L 10 mg/L Mean + 2a Arsenic 25 pg/L 50 pg/L Fractional Beryllium 2 pg/L 4 pg/L Fractional Cadmium 2.5 pg/L 5 Pg/L Fractional Chromium 50 pg/L 100 pg/L Fractional Cobalt 365 ug/L 730 pg/L Fractional Copper 650 pg/L 1,300 pg/L Fractional Iron 5,500 ug/L 11,000 pg/L Fractional Lead 7.5 pg/L 15 pg/L Fractional Manganese 400 pg/L 800 pg/L Fractional Mercury Ug/L 2 ug/L Fractional Molybdenum 20 pg/L 40 pg/L Fractional Nickel 50 ug/L 100 pg/L Fractional Selenium 25 pg/L 50 pg/L Fractional Silver 50 pg/L 100 pg/L Fractional Thallium 1 Ug/L 2 pg/L Fractional Tin 8,500 pg/L 17,000 pg/L Fractional Uranium 18.08 pg/L 30 pg/L Mean + 2a Vanadium 30 pg/L 60 pg/L Fractional Zinc 41.25 pg/L 5,000 pg/L Mean + 2a Gross Alpha 4.20 pCi/L 15pCi/L Mean + 2a Acetone 350 pg/L 700 pg/L Fractional Benzene 2.5 pg/L 5 ug/L Fractional Methyl Ethyl Ketone 2,000 pg/L 4,000 pg/L Fractional EFR MW-35, MW-36 and MW-37 Background Report DRC Review Memo Page 9 Monitoring Well MW-37 Parameter Proposed GWCL GWQS Method Adjustment Carbon Tetrachloride 2.5 pg/L 5 pg/L Fractional Chloroform 35 pg/L 70 pg/L Fractional Chloromethane 15 ug/L 30 pg/L Fractional Methylene Chloride 2.5 pg/L 5 pg/L Fractional Naphthalene 50 pg/L 100 pg/L Fractional Tetrahydrofuran 23 pg/L 46 pg/L Fractional Toluene 500 pg/L 1,000 ug/L Fractional Xylenes, Total 5,000 pg/L 10,000 pg/L Fractional Chloride 57.3 mg/L Mean + 2a Fluoride 0.31 mg/L 4 mg/L Mean + 2a Field pH 6.61 mg/L Mean + 2a Sulfate 3,311.97 mg/L Modified Mean + 4a Mean + 2a = 2927.65 mg/L TDS 4,126.63 mg/L Mean + 2a 1.25xBckgnd 4866.25 mg/L Conclusions: Based on review as discussed above, it is recommended that Groundwater Compliance Limits for groundwater monitoring wells MW-35, MW-36 and MW-37 and monitoring frequencies be included in the permit as listed in tables 7, 8, and 9 above, with the listed DRC adjustments. References Hydro Geo Chem, Inc., October 11, 2010, Installation and Hydraulic Testing of Perched Monitoring Wells MW-33, MW-34, and MW-35 at the White Mesa Uranium Mill near Blanding, Utah. Hydro Geo Chem Inc., June 28, 2011, Installation and Hydraulic Testing of Perched Monitoring Wells MW-36 and MW-37 at the White Mesa Uranium Mill Near Blanding, Utah. Hydro Geo Chem, Inc., July 10, 2012, Site Hydrology and Estimation of Groundwater Travel Times in the Perched Zone, White Mesa Uranium Mill Site Near Blanding, Utah, Prepared for Denison Mines (USA) Corp. by Hydro Geo Chem Inc., July 10, 2012. 4 INTERA Incorporated, October 2007, Revised Background Groundwater Quality Report: Existing Wells for Denison Mines (USA) Corp. 's White Mesa Mill Site, San Juan County, Utah. EFR MW-35, MW-36 and MW-37 Background Report DRC Review Memo Page 10 5 INTERA Incorporated, May 1, 2014, Background Groundwater Quality Report for Monitoring Wells MW-35, MW-36, and MW-37 White Mesa Uranium Mill. 6 United States Environmental Protection Agency, March 2009, Statistical Analysis of Groundwater Monitoring Data at RCRA Facilities, Unified Guidance, EPA 530/R-09-007, Office of Resource Conservation and Recovery, Program Implementation and Information Division. 7 Utah Division of Radiation Control, December 1, 2004, Statement of Basis for Ground Water Discharge Permit No. UGW450005, White Mesa Uranium Mill