DRC-2021-008242 - 0901a06880eb8f71

DRC-2021-008242 195 North 1950 West • Salt Lake City, UT Mailing Address: P.O. Box 144880 • Salt Lake City, UT 84114-4880
Telephone [phone] • Fax [phone] • T.D.D. [phone]
www.deq.utah.gov
Printed on 100% recycled paper
State of Utah
SPENCER J. COX Governor DEIDRE HENDERSON Lieutenant Governor
Department of Environmental Quality
Kimberly D. Shelley Executive Director
DIVISION OF WASTE MANAGEMENT AND RADIATION CONTROL Douglas J. Hansen Director June 16, 2021
Kathy Weinel, Quality Assurance Manager
Energy Fuels Resources (USA) Inc.
225 Union Blvd. Suite 600 Lakewood, CO 80228 RE: Energy Fuels Resources (USA) Inc., Revised March 4, 2021, Background Report for Monitoring Wells MW-38, MW-39, and MW-40 White Mesa Uranium Mill (Mill):
Utah Groundwater Discharge Permit No. UGW370004 (Permit) Dear Ms. Weinel:
The Division of Waste Management and Radiation Control (“DWMRC”) has reviewed the Energy Fuels
Resources (USA) Inc. (“EFRI”) June 7, 2021Transmittal of Errata Pages for the Background Report for
MW-38, MW-39, and MW-40 (“Errata Pages”), which updates the EFRI June 4, 2021 document titled Background Groundwater Quality Report for Monitoring Wells MW-38, MW-39, and MW-40, White Mesa Uranium Mill (“Report”). Specifically, the Errata Pages and the revised Report provide updated proposed GWCLs for: 1) pH in MW-38, 2) pH and manganese in MW-39, and 3) pH and gross alpha in
MW-40. This letter is to update the ground water compliance limit (GWCL) tables in the previous DWMRC letter dated May 21, 2021, which summarized the DWMRC Review of the Report and included tables of
DWMRC approved GWCLs for monitoring wells MW-38, MW-39, and MW-40. The tables have been
updated per the Errata Pages and per a May 26, 2021 conference call between the DWMRC and EFRI. The updated GWCLs are included in bold in the revised tables. Note that in accordance with the May 21, 2021, DWMRC letter, decisions regarding whether MW-38, MW-39, and MW-40 will be included in the Permit as compliance monitoring wells or general monitoring wells will be made at the time of Permit modification. GWCLs will be formalized in the Permit at that time after posting the draft
modified Permit and statement of basis in following with public notice and participation requirements. (Over)
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Monitoring Well MW-38
Parameter Proposed GWCL GWQS Method DWMRC
Adjustment
Ammonia 12.5 mg/L 25 mg/L Fractional
Nitrate/Nitrite 16.04 mg/L 10 mg/L Mean + 2α
Arsenic 25 µg/L 50 µg/L Fractional
Beryllium 2 µg/L 4 µg/L Fractional
Cadmium 2.5 µg/L 5 µg/L Fractional
Chromium 50 µg/L 100 µg/L Fractional
Cobalt 365 µg/L 730 µg/L Fractional
Copper 650 µg/L 1,300 µg/L Fractional Iron 5500 µg/L 11,000 µg/L Fractional
Lead 7.5 µg/L 15 µg/L Fractional
Manganese 400 µg/L 800 µg/L Fractional
Mercury 1.39 µg/L 2 µg/L Poisson Prediction Limit
Molybdenum 20 µg/L 40 µg/L Fractional
Nickel 16.25 µg/L 10 µg/L Poisson Prediction Limit
Selenium 178.74 µg/L 50 µg/L Mean + 2α
Silver 50 µg/L 100 µg/L Fractional
Thallium 1.39 µg/L 2 µg/L Poisson Prediction Limit
Tin 8,500 µg/L 17,000 µg/L Fractional
Uranium 7.16 µg/L 30 µg/L Mean + 2α
Vanadium 30 µg/L 60 µg/L Fractional
Zinc 2,500 µg/L 5,000 µg/L Fractional
Gross Alpha 7.5 pCi/L 15 pCi/L Fractional
Acetone 350 µg/L 700 µg/L Fractional
Benzene 2.5 µg/L 5 µg/L Fractional
Methyl Ethyl Ketone 2,000 µg/L 4,000 µg/L Fractional
Carbon
Tetrachloride
2.5 µg/L 5 µg/L Fractional
Chloroform 35 µg/L 70 µg/L Fractional
Chloromethane 15 µg/L 30 µg/L Fractional Methylene Chloride 2.5 µg/L 5 µg/L Fractional
Naphthalene 50 µg/L 100 µg/L Fractional
Tetrahydrofuran 23 µg/L 46 µg/L Fractional
Toluene 500 µg/L 1,000 µg/L Fractional Xylenes, Total 5,000 µg/L 10,000 µg/L Fractional
Chloride 48.7 mg/L Mean + 2α
Fluoride 0.98 mg/L 4 mg/L Mean + 2α
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Monitoring Well MW-38
Parameter Proposed GWCL GWQS Method DWMRC Adjustment
Field pH 6.68 S.U. 6.5 – 8.5 S.U. Mean - 2α 6.5 – 8.5 S.U GWQS Sulfate 3126.75 mg/L HHV**
TDS 5008.75 mg/L 1.25 X Mean (1.25 X BG*)
*BG = Background **HHV= Highest Historical Value
Monitoring Well MW-39
Parameter Proposed GWCL GWQS Method DWMRC Adjustment
Ammonia 0.33 mg/L 25 mg/L Mean + 2α
Nitrate/Nitrite 5 mg/L 10 mg/L Fractional
Arsenic 25 µg/L 50 µg/L Fractional
Beryllium 5.97 µg/L 4 µg/L Mean + 2α Cadmium 3.01 µg/L 5 µg/L Mean + 2α
Chromium 50 µg/L 100 µg/L Fractional
Cobalt 79.17 µg/L 730 µg/L Mean + 2α
Copper 35.55 µg/L 1,300 µg/L Mean + 2α
Iron 15506.23 µg/L 11,000 µg/L Mean + 2α
Lead 7.5 µg/L 15 µg/L Fractional
Manganese 2444.22 µg/L 800 µg/L Mean + 2α Mercury 1.39 µg/L 2 µg/L Poisson Prediction Limit
Molybdenum 20 µg/L 40 µg/L Fractional
Nickel 39.25 µg/L 100 µg/L Mean + 2α
Selenium 25 µg/L 50 µg/L Mean + 2α Silver 50 µg/L 100 µg/L Fractional
Thallium 3.82 µg/L 2 µg/L Mean + 2α
Tin 8,500 µg/L 17,000 µg/L Fractional
Uranium 13.95 µg/L 30 µg/L Mean + 2α
Vanadium 30 µg/L 60 µg/L Fractional
Zinc 259 µg/L 5,000 µg/L Mean + 2α
Gross Alpha 5.47 pCi/L 15 pCi/L Mean + 2α Acetone 350 µg/L 700 µg/L Fractional
Benzene 2.5 µg/L 5 µg/L Fractional
Methyl Ethyl
Ketone
2,000 µg/L 4,000 µg/L Fractional
Carbon Tetrachloride 2.5 µg/L 5 µg/L Fractional
Chloroform 35 µg/L 70 µg/L Fractional
Chloromethane 15 µg/L 30 µg/L Fractional
Methylene
Chloride
2.5 µg/L 5 µg/L Fractional
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Monitoring Well MW-39
Parameter Proposed GWCL GWQS Method DWMRC Adjustment
Naphthalene 50 µg/L 100 µg/L Fractional
Tetrahydrofuran 23 µg/L 46 µg/L Fractional
Toluene 500 µg/L 1,000 µg/L Fractional
Xylenes, Total 5,000 µg/L 10,000 µg/L Fractional Chloride 43.68 mg/L Mean + 2α
Fluoride 0.82 mg/L 4 mg/L Mean + 2α
Field pH 3.83 S.U. 6.5 – 8.5 S.U. Mean - 2α 3.83 – 8.5 S.U. Sulfate 3522.07 mg/L Mean + 2α
TDS 4,713.48 mg/L Mean + 4α 1.25 X BG = 5270 mg/L

Monitoring Well MW-40
Parameter Proposed GWCL GWQS Method DWMRC Adjustment
Ammonia 12.5 mg/L 25 mg/L Fractional
Nitrate/Nitrite 3.41 mg/L 10 mg/L Mean + 2α
Arsenic 25 µg/L 50 µg/L Fractional
Beryllium 2 µg/L 4 µg/L Fractional
Cadmium 2.5 µg/L 5 µg/L Fractional
Chromium 50 µg/L 100 µg/L Fractional
Cobalt 365 µg/L 730 µg/L Fractional
Copper 650 µg/L 1,300 µg/L Fractional
Iron 5,500 µg/L 11,000 µg/L Fractional
Lead 7.5 µg/L 15 µg/L Fractional Manganese 400 µg/L 800 µg/L Fractional
Mercury 1.39 µg/L 2 µg/L Poisson Prediction Limit
Molybdenum 20 µg/L 40 µg/L Fractional
Nickel 50 µg/L 100 µg/L Fractional
Selenium 240.75 µg/L 50 µg/L 1.5 X Mean (1.5 X BG)
Silver 50 µg/L 100 µg/L Fractional
Thallium 1 µg/L 2 µg/L Fractional
Tin 8,500 µg/L 17,000 µg/L Fractional
Uranium 28.92 µg/L 30 µg/L Mean + 2α
Vanadium 30 µg/L 60 µg/L Fractional
Zinc 2500 µg/L 5,000 µg/L Fractional
Gross Alpha 2.20 pCi/L 15 pCi/L Mean + 2α Acetone 350 µg/L 700 µg/L Fractional
Benzene 2.5 µg/L 5 µg/L Fractional
Methyl Ethyl
Ketone
2,000 µg/L 4,000 µg/L Fractional
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Monitoring Well MW-40
Parameter Proposed GWCL GWQS Method DWMRC Adjustment
Carbon Tetrachloride 2.5 µg/L 5 µg/L Fractional
Chloroform 35 µg/L 70 µg/L Fractional
Chloromethane 15 µg/L 30 µg/L Fractional
Methylene
Chloride
2.5 µg/L 5 µg/L Fractional
Naphthalene 50 µg/L 100 µg/L Fractional
Tetrahydrofuran 23 µg/L 46 µg/L Fractional
Toluene 500 µg/L 1,000 µg/L Fractional
Xylenes, Total 5,000 µg/L 10,000 µg/L Fractional
Chloride 49.20 mg/L Mean + 2α Fluoride 0.86 mg/L 4 mg/L Mean + 2α
Field pH 6.27 S.U. 6.5 – 8.5 S.U. Mean - 2α 6..27 – 8.5 S.U.
Sulfate 2680.35 mg/L Mean + 2α
TDS 3848.65 mg/L Mean + 2α 1.25 x BG = 4337.5 mg/L
If you have any questions, please call Tom Rushing at [phone].
Sincerely,

Phil Goble, Uranium Mills and Radioactive Materials Section Manager Division of Waste Management and Radiation Control
PRG/TR/as c: Mike Moulton, Interim Health Officer, San Juan County Public Health Department Ronnie Nieves, Environmental Health Director, San Juan County Public Health Department
Russell Seeley, UDEQ District Engineer