DRC-2020-002185 - 0901a06880bd4ad1

DRC-2020-002185 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
GARY R. HERBERT Governor SPENCER J. COX
Lieutenant Governor
Department of
Environmental Quality
L. Scott Baird Executive Director DIVISION OF WASTE MANAGEMENT AND RADIATION CONTROL Ty L. Howard Director
February 5, 2020
Scott Clow, Environmental Programs Director
Ute Mountain Ute Tribe Environmental Programs Department P.O. Box 448 Towaoc, CO 81334-0448

RE: Response to Ute Mountain Ute Tribe Letter Dated January 8, 2020 Dear Mr. Clow:
This letter is in response to a letter from the Ute Mountain Ute Tribe (UMUT) dated January 8, 2020.
The UMUT Letter was received by the Division of Waste Management and Radiation Control (Division) on January 17, 2020 and addresses four topics regarding the Utah Groundwater Quality Discharge Permit for the Energy Fuels Resources (EFR) White Mesa Uranium Mill, Permit No. UGW370004 (Permit), including: 1. Adjusted Groundwater Compliance Limits (GWCL’s) for Total
Dissolved Solids (TDS), Sulfate, Selenium and Uranium in monitoring well MW-31: 2. Adjusted
GWCL for Fluoride in monitoring well MW-14: 3. Replacement monitoring well MW-24A: 4. Background groundwater chemistry, and: 5. Dissolved Oxygen (DO) readings reported in the EFR 3rd Quarter 2019 Groundwater Monitoring Report. These UMUT concerns are discussed below:
1. Groundwater Monitoring Well MW-31, Adjusted GWCL’s for TDS, Sulfate, Selenium and Uranium: The Division reviews the EFR monitoring constituent concentration data (submitted in Mill quarterly reports) in groundwater, and compares those measured concentrations against their corresponding Permit GWCLs. The GWCLs have been established with consideration of background monitoring
concentrations of metals and identified pre-existing data trends. The GWCLs are based on statistical analysis using all historical groundwater monitoring data for each well. If any of the concentrations exceed the GWCL then Energy Fuels Resources (USA) Inc. (“EFR”) is required to determine the source of the exceedances and eliminate or confirm Mill activities as the source. EFR submits “plan and schedules” and “source assessment reports” to the Division Director according to requirements of the
Permit for review and approval. (Over)

Copies of EFR source assessment reports and associated Division review memorandums and
correspondence can be found on the Division website at: “https://deq.utah.gov/waste-management-and-radiation-control/stipulated-consent-agreement-ugw13-03-white-mesa-uranium-mill-energy-fuels-resources-usa-inc.”. As the UMUT is aware, documents regarding EFR submission of the August 21, 2017 Source Assessment Report (SAR) for monitoring well MW-31 and Division Review
(Review Memorandum dated March 14, 2018 and Division Transmittal Letter to EFR dated
March 20, 2018) are posted on this web-page. GWCL’s for total dissolved solids, sulfate selenium and uranium were adjusted according to SAR findings and Division review findings that the rising concentration trends are not caused by Mill activities and are attributed to background concentrations in the perched aquifer. Based on findings the GWCL’s were modified per the Utah Administrative Code
(UAC) R317-6 for Class III groundwater.
2. Groundwater Monitoring Well MW-14, Adjusted GWCL for Fluoride: Documents are available on the Division website regarding the adjusted fluoride GWCL for monitoring well MW-14. The EFR Source Assessment Report was dated June 25, 2018 and the Division review
memo and transmittal letter were dated July 17, 2018 and July 25, 2018 respectively. The fluoride GWCL was adjusted according to SAR findings and Division review findings. Based on Division review of the background statistics, fluoride is showing a decreasing trend. Data was normally distributed based on the DWMRC post 2/2/2010 data set (point of inflection) and removal of a verified outlier. Per the currently approved statistical flow chart for the Mill, which is in conformance with
U.S. Environmental Protection Agency statistical guidance, the GWCL was set according to mean + 2 standard deviations. The EFR calculation of mean + 2 standard deviations based on the entire data set was 0.22 mg/L and is included in Appendix B-1 of the SAR. Although the EFR data set did not show normal or lognormal distribution, the EFR result was within the range of DWMRC calculations and therefore, the EFR result appeared to be protective and reflective of the fluoride data.

3. Replacement Monitoring Well MW-24A Per Division review of an EFR June 27, 2019 SAR including monitoring well MW-24 and regarding parameters at monitoring well MW-24 it was noted that recent increasing trends for certain parameters
has resulted in out-of-compliance status and warrants further investigation. Based on DWMRC review findings and a conference call discussion with EFR on September 3, 2019 it was decided that additional source assessment needs to be conducted for monitoring well MW-24. EFR mentioned during the call, that there is a potential that monitoring well construction could be the cause of the out of compliance parameters and that additional evaluation to determine if this is the cause could include the construction
of a nearby monitoring well and subsequent tandem sampling of the two wells to determine if well construction is an issue. Based on discussion this was determined to be a useful and reasonable evaluation of the non-compliance. Consideration is given that based on a review of indicator parameters and the comprehensive historical data record, the parameter trends and out-of compliance do not appear to be caused by a tailings wastewater source.

4. Background Groundwater Chemistry:
The second page of the Letter discusses issues regarding background groundwater quality and background concentrations of the perched Burro Canyon Aquifer. The evaluation of background groundwater concentration in monitoring wells screened in the perched aquifer has been previously
discussed and documented. Specifically, the following documents regarding UMUT background
groundwater quality have been recently provided to the UMUT regarding background groundwater quality issues: 1. A February 15, 2017 Division Letter to Scott Clow, UMUT in response to UMUT Letters to the
Division Director dated December 16, 2016 and January 20, 2017;
2. A May 10, 2017 Division Letter to Colin Larrick, UMUT in response to a UMUT Letter to the
Division Director dated April 11; 3. A September 23, 2015 Division Review Memorandum Regarding Technical Review of the UMUT contracted Geo-Logic Associates 2017 Report1, prepared by Tom Rushing, P.G. and provided to
the UMUT.
Per the Letter Page 2 the UMUT states that “we refer the Division to the Tribe’s repeated comments submitted over the course of two decades expressing its concerns about the Mill’s impact on groundwater and offering technical approaches.” As you are aware the Division spends a great deal of time and resources responding to the UMUT comments, as was recently undertaken during the Mill
Permit and Radioactive Materials License renewals. A thorough and detailed response to every comment issued by the UMUT is included in the Public Participation Summary and supporting documents regarding the renewal process. This was in addition to significant efforts to provide venues for a public hearing in Salt Lake City and a venue to receive oral comments from the public in Blanding.
In regard to the UMUT comments regarding updated isotopic studies and liner testing on page 2 of the Letter, this issue has been discussed per previous letters sent to the Division by the UMUT, and written comments regarding the Division position was provided to the UMUT per the Division letter responses (No.’s 1 and 2 above), please refer to these letters regarding the Division response.
Additionally, the second page of the Letter states that the Division should refer to a report prepared on behalf of the UMUT by Geo-Logic Associates in 2017. As you are aware, the Division has conducted a technical review of the Geo-Logic report and found that the report review of data and conclusions are not representative of concentrations which would be expected in the event of a tailings solution release. The Geo-Logic report does not consider relative mobility of contaminants, background concentrations of
metals, comparisons with GWCL’s, or rising trends. It is expected that in the case of metals, the same metals will be found in the shallow aquifer Burro Canyon Rock as are found in the ore used to produce the tailings, and therefore the same metals will be found in natural background concentrations as are found in the tailings solution. Geo-Logic has simply compared a biased assessment of background concentrations in the Burro Canyon Aquifer with average tailings solution concentrations. These

1 Geo-Logic Associates, August 2015, Data Review and Evaluation of Groundwater Monitoring White Mesa Uranium Mill,
Prepared for the Ute Mountain Ute Tribe

Division review findings have been discussed in multiple meetings between Division and UMUT and
have been provided to you multiple times in writing per the listed documents No.’s 1, 2 and 3 above. 5. EFR Field DO Readings:
As the UMUT is probably aware the requirement to include DO as a field monitoring parameter for
groundwater monitoring was recently included in the Permit (Part I.E.1.d.) and monitoring during the 3rd Quarter of 2019 was the first quarter that the requirement was implemented, and the 3rd Quarter Monitoring Report (Report) was the first to report DO readings. Per the Division review findings it was noted that several of the monitoring wells had DO readings greater than 100% and that in general all of
the monitoring well readings appeared higher in % DO than would be expected in the perched aquifer
groundwater. Based on this finding, the Division contacted EFR during finalization of the Report review (by conference call on December 11, 2019) and it was discussed with EFR and their environmental
consultant (Hydro Geo Chem) that oxygen was likely introduced into the samples due to the low
permeability and small saturated thickness of the perched aquifer combined with agitation during purging and sampling. Per discussion, it was agreed that additional evaluation would be conducted by EFR to determine potential effects of the sample oxygenation, and evaluation of alternate micro-purge/low-flow sample collection to evaluate the impact of DO in the groundwater samples. EFR will
submit a plan and time schedule for the evaluation, including a planned date for a final report
submission to the Division for review and approval, on or before April 9, 2020. This agreement was formalized by a Division confirmatory action letter sent to EFR and dated January 13, 2020. During discussion of this issue it was noted that per review of UMUT data for the WM_GMMW_E
monitoring well (collected 2011) dissolved oxygen was measured at 105.9%. It appears that the UMUT
has had the same issue in the past. The Division would be interested in the UMUT findings and actions regarding erroneous DO readings in the groundwater samples for their wells. It was noted that when the UMUT submitted the 2011 data there was no accompanying information regarding well data or sampling procedures (e.g. pump rates and purge procedures) or stabilization criteria (field parameter
stabilization) used by the UMUT.
If you have any questions regarding this letter, please call Tom Rushing at [phone]. Sincerely,
Ty L. Howard, Director Division of Waste Management and Radiation Control
TLH/TR/al c: Kirk Benge, Health Officer, San Juan Public Health Department
Rick Meyer, Environmental Health Director, San Juan Public Health Department Scott Hacking, P.E., DEQ District Engineer