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Home My WebLink AboutDRC-2012-001160 - 0901a068802b1554State of Utah GARY R HERBERT Governor GREG BELL Lxeutenant Governor Department of Environmental Quality Amanda Smith Executive Director DPVISION OF RADIATION CONTROL Rusty Lundberg Director ORC-2012-001160 February 13 2012 Mr David C Frydenlund Vice President Regulatory Affairs and Counsel Denison Mines (USA) Corp (DUSA) Independence Plaza Suite 950 1050 Seventeenth Street Denver CO 80265 RE White Mesa Mill Evaluation of Deep Water Supply Well WW 2 Utah Groundwater Discharge Permit No UGW370004 Part IH 3 Notice of Enforcement Discretion and Closeout Letter Dear Mr Frydenlund The Utah Division of Radiation Control (DRC) has completed its review of Denison Mines (USA) Corp (DUSA) submitted letter report White Mesa Mill Evaluation of Deep Supply Well WW 2 Utah Groundwater Discharge Permit No UGW370004 (Report) dated January 24 2012 The review was based on compliance with the Ground Water Quality Discharge Permit No UGW370004 (Permit) Part IH 3 Based on the information provided in the Report the DRC has concluded that the findings of the Report are inconclusive to prove that well WW 2 s well casing and annular seal have physical and hydraulic integrity to isolate the two aquifers because ofthe following 1) DR 1 was logged by drill cuttings and identified strata contacts below ground surface (bgs) at 100 feet which may only be accurate withm couple of feet and because these measurements are not associated with an elevation this adds to the confusion of where exactly the Brushy Basm contact IS located at DR 1 in relation to well WW 2 2) Because cement bond logs and/or temperature logs were not used by DUSA to identify the Brushy Basm Member/Burro Canyon Formation contact the drilling report for well WW 2 that shows the well was grouted from the ground surface to 100 feet bgs may be easily off by a few feet or more and 3) Possible elevations differences between DR 1 and well WW 2 locations Therefore using depth bgs to determine if well WW 2 is keyed into the Brushy Basin Member may be misinterpreted Because well WW 2 is a deep water supply well and the water in the well could be used for dnnking water the DRC met with Utah Division of Dnnking Water (DDW) to discuss well WW 2 DDW was familiar with well WW 2 at the Mill and told the DRC that DUSA is required to sample the well and submit the results to DDW DDW descnbed that if any of these constituents sampled exceed a maximum contaminant level (MCL) or if there is any detectable concentrations of volatile organic compounds (VOCs) observed DDW will enforce remedial action 195 North 1950 West Salt Lake City UT Mailing Address PO Box 144850 SaltLakeCity UT 84114 4850 Telephone (801)536 4250 Fax (801)533-4097 TDD (801)536 4414 d q I hg Pr ted on 100% e ycled pape Page 2 Enforcement Discretion Part IH 3(a) of the Permit required DUSA to perform one of the following investigation techniques well casing video logs cement bond logs and/or temperature logs to venfy that the casing and annular seal is intact and creates both a physical bamer and hydrauhc isolation between the shallow unconfined and the deep confined aquifers Although DUSA did perform an investigauon of well WW 2 they failed to perform any of the techniques listed in Part IH 3(a) of the Permit This is a violation of Part IH 3(a) of the Permit However the Executive Secretary believes that even though DUSA failed to perform any of the investigation techniques required in Part IH 3(a) of the Permit the deep aquifer found in well WW 2 is protected and enforcement discretion is appropnate in this matter for the following reasons • Well WW 2 is located upgradient of the tailings cells and the Chloroform and Nitrate plumes therefore it is unlikely groundwater in this well has been affected or will be affected by these potential sources • Well WW 2 currently provides the Mill with water for eye wash stauons and showers is pumped several times a day and yields about 160 gallons per minute The deeper confined aquifer is protected due to the artesian condiUons in the confined aquifer and the repeated removal of water from well WW 2 This acuve pumping will deliver any potenUal contarmnants back to the ground surface for use in the Mill operations • Well WW 2 is regulated by the DDW DUSA is required to sample the well and submit the results to DDW The DDW has assured the DRC that if any samples exceed a MCL for any constituent or if there is any detectable concentrations of VOCs observed the DDW will enforce remedial action Thank you for your cooperation in this matter If you have any questions or comments regarding this letter please contact Dean Henderson at (801) 536 0046 This letter constitutes a closeout of Part IH 3 of the Permit which will be removed from the Permit in a future Permit Modification UTAH WATER QUALITY BOARD Rusty Lundberg Co Executive Secretary RL/DH CC Ken Bousfield DDW