Loading...
HomeMy WebLinkAboutDRC-2017-001854 - 0901a068806cd4e7Energy Fuels Resources (USA) Inc. 225 Union Blvd. Suite 600 Lakewood, CO, US, 80228 303 974 2140 www.energyfuels.com March 10,2017 Div of Waste Management and Radiation Control Sent VIA E-MAIL AND EXPRESS 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 Tpc-zon-ooie&t Re: Transmittal of Plan and Time Schedule under Utah Ground Water Discharge Permit UGW370004 Part LG.4 (c) White Mesa Mill (the “Mill”) Dear Mr. Anderson: This letter transmits Energy Fuels Resources (USA) Inc.’s (“EFRFs”) Plan and Time Schedule pursuant to State of Utah Groundwater Discharge Permit UGW370004 (the “Permit”) Part I.G.4(c) for MW-31 for the fourth quarter of 2016. Part I.G.2 of the Permit provides that out-of-compliance (“OOC”) status exists when the concentration of a pollutant in two consecutive samples from a compliance monitoring point exceeds a groundwater compliance limit (“GWCL”). While consecutive exceedance have been noted in MW-31 and other wells at the site, a plan and time schedule have not been required or appropriate in light of other actions currently being undertaken by EFRI or in light of other reports submitted by EFRI. This Plan covers uranium in MW-31 that was identified as being in violation of Part I.G.2 of the Permit, in the Fourth Quarter 2016 Exceedance Notice, dated February 10, 2017. In addition, this Plan and the associated SAR will address the additional constituents of sulfate, selenium and total dissolved solids (“TDS”). These exceedances were addressed in previous SARs, but have exceeded the recalculated GWCLs specified in those SARs due to statistically significant trends noted in these previous studies. Please contact me if you have any questions or require any further information. Yours very truly, Energy Fuels Resources (USA) Inc. Kathy Weinel Quality Assurance Manager cc: Mark Chalmers David Turk Scott Bakken David Frydenlund WHITE MESA MILL State of Utah Ground Water Discharge Permit UGW370004 Plan and Time Schedule Under Part I.G.4 (c) For Exceedances in MW-31 in the Fourth Quarter of 2016 Energy Fuels Resources (USA) Inc. 225 Union Boulevard, Suite 600 Lakewood, CO 80228 March 10, 2017 1. INTRODUCTION Energy Fuels Resources (USA) Inc. (“EFRI”) operates the White Mesa Uranium Mill (the “Mill”), located near Blanding Utah, under State of Utah Ground Water Discharge Permit UGW370004 (the “Permit”). This is the plan and time schedule (the “Plan”) required under Part I.G.4(c) of the Permit relating to violations of Part LG.2 of the Permit for the MW-31 for the fourth quarter of 2016. Part I.G.2 of the Permit provides that out-of-compliance status exists when the concentration of a pollutant in two consecutive samples from a compliance monitoring point exceeds a groundwater compliance limit (“GWCL”) in Table 2 of the Permit. While consecutive exceedance have been noted in MW-31 and other wells at the site, a plan and time schedule and Source Assessment Report (“SAR”) have not been required or appropriate in light of other actions currently being undertaken by EFRI or in light of other reports submitted by EFRI, and as determined by Division of Waste Management and Radiation Control (“DWMRC”) Staff. Specifically, consecutive exceedances which occurred in previous reporting periods are discussed in the SARs submitted to DWMRC October 10, 2012, May 8, 2013, August 30, 2013, December 17, 2013, January 13, 2014, March 19, 2014, December 9, 2015, June 24, 2016 and the Plan and Time Schedule submitted December 4, 2014. Additionally, pH was addressed in reports dated November 9, 2012 and December 7, 2012. A description of the other actions and reports which have affected the requirement to submit a plan and time schedule are as follows: 1. Nitrate + nitrite and chloride in monitoring wells at the site have been the subject of ongoing investigations at the Mill. Based on the results of the previous investigations, EFRI and the Director acknowledge that it has not been possible to date to determine the source(s), cause(s), attribution, magnitudes of contribution, and proportion(s) of the local nitrate + nitrite and chloride in groundwater. EFRI submitted a Corrective Action Plan (“CAP”) in February 2012 for nitrate + nitrite and chloride in groundwater. The CAP was approved on December 12, 2012 and the activities associated with the CAP are on­ going. Based on information provided by DWMRC in teleconferences on April 27, and May 2, 2011, due to the ongoing activities and actions, the 30-day plan and schedule for assessment is not required for nitrate + nitrite and chloride exceedances at this time. 2. As discussed in previous quarterly groundwater sampling reports, the background levels and GWCFs for pH were established based on eight or more quarters of laboratory data, which are historically higher than field data. EFRFs letter to the Director dated January 31, 2011 proposed the recalculation of the GWCFs for field pH. Following the statistical evaluation of pH data by EFRTs geochemical consultant, ENTERA, Inc., EFRI compared the Mill’s groundwater pH data from Q2 2011 and noted that all of the June 2011 groundwater results, and many of the other results from Q2 2011, were already outside the revised GWCFs that were to be proposed in the June 30, 2011 letter. Pursuant to teleconferences with DWMRC on December 5, and December 19, 2011, EFRI submitted a Work Plan and Schedule on January 20, 2012 and a revised plan based on DWMRC comments on April 13, 2012. Based on the approved Work Plan and Time Schedule, EFRI and DWMRC entered into a Stipulated Consent Agreement (“SCA”) dated July 12, 2012. The SCA required the completion of the pH Report and the Pyrite Investigation and associated report. The pH Report and Pyrite Investigation Report were submitted November 9, 2012 and December 7, 2012 respectively. By letter dated April 25, 2013, DWMRC accepted the conclusions that the out-of-compliance results for pH are due to background effects within the aquifer matrix and are not caused by Mill activities. DWMRC also approved the recalculation of the GWCLs. As a result, the 30-day plan and schedule for assessment is not required for field pH exceedances. 3. A Plan and Time Schedule will not be prepared for monitoring wells with two successive exceedances in Q3 2014 if successive exceedances were reported in a previous quarter and were included in the Source Assessment Reports (“SARs”), submitted October 10, 2012, May 8, 2013, August 30, 2013, December 17, 2013, January 13, 2014, and March 19, 2014. A Plan and Time Schedule will not be submitted for those constituents covered by the previously mentioned SARs, because the conclusions and actions delineated in those reports were either accepted by DWMRC as documented in DWMRC correspondence dated April 25, 2013, July 23, 2013, September 17, 2013 January 7, 2014, March 10, 2014, and June 5, 2014 respectively. Chloroform and methylene chloride are the subject of the ongoing chloroform pumping program and are covered by State of Utah Notice of Violation (“NOV”) and Groundwater Corrective Action Order (“CAO”) State of Utah Department of Environmental Quality (“UDEQ”) Docket No. UGW-20-01. As a result, the 30-day plan and schedule for assessment of chloroform and methylene chloride exceedances is not required. The Permit was originally issued in March 2005, at which time GWCLs were set on an interim basis, based on fractions of State Ground Water Quality Standards or the equivalent, without reference to natural background at the Mill site. The Permit also required that EFRI prepare a background groundwater quality report to evaluate all historic data for the purposes of establishing background groundwater quality at the site and developing GWCLs under the Permit. As required by then Part I.H.3 of the Permit, EFRI submitted the following to the Director of the State of Utah Division of Radiation Control (the “Director”): • A Revised Background Groundwater Quality Report: Existing Wells For Denison Mines (USA) Corp.’s Mill Site, San Juan County, Utah, October 2007, prepared by INTERA, Inc. (the “Existing Wells Background Report”); • A Revised Addendum: — Evaluation of Available Pre-Operational and Regional Background Data, Background Groundwater Quality Report: Existing Wells For Denison Mines (USA) Corp.’s Mill Site, San Juan County, Utah, November 16, 2007, prepared by INTERA, Inc. (the “Regional Background Report”); and • A Revised Addendum: — Background Groundwater Quality Report: New Wells For Denison Mines (USA) Corp. ’s Mill Site, San Juan County, Utah, April 30, 2008, prepared by INTERA, Inc. (the “New Wells Background Report, and together with the Existing Wells Background Report and the Regional Background Report, the “Background Reports”). Based on a review of the Background Reports and other information and analyses the Director re-opened the Permit and modified the GWCLs to be equal to the mean concentration of background for each constituent on an intrawell basis plus two standard deviations or the equivalent. The modified GWCLs became effective on January 20, 2010. Part I.G.4 c) of the GWDP states, with respect to exceedances of GWCLs, “that the Permittee shall prepare and submit within 30 calendar days to the Executive Secretary a plan and a time schedule for assessment of the sources, extent and potential dispersion of the contamination, and an evaluation of potential remedial action to restore and maintain groundwater quality to insure that Permit limits will not be exceeded at the compliance monitoring point and that DMT or BAT will be reestablished.” Pursuant to this requirement, EFRI has submitted twelve Plans and Time Schedules and nine associated SARs to address previous dual exceedances (as required in light of other actions currently being undertaken by EFRI and as determined by DWMRC Staff and stated in teleconferences with EFRI on April 27 and May 2, 2011). This Plan covers uranium in MW-31 that was identified as being in violation of Part LG.2 of the Permit, in the Fourth Quarter 2016 Exceedance Notice, dated February 10, 2017. In addition, this Plan and the associated SAR will address the additional constituents of sulfate and selenium. These exceedances were addressed in previous SARs, but have exceeded the recalculated GWCLs specified in those SARs due to statistically significant trends noted in these previous studies. 2. CONSTITUENTS AND WELLS SUBJECT TO THIS PLAN The following constituents are covered by this Plan: Table 1 Constituent and Well Subject to this Plan Constituent POC Well Current GWCL Previously Recalculated GWCL Q4 2016 Results Selenium (ug/L) MW-31 71 86.81 88.2, 89.0, 87.1 Sulfate (mg/L) MW-31 532 697.6 720, 752, 748 Uranium MW-31 9.1 Not Applicable 9.56, 10.3 It should be noted that the fourth Quarter 2016 Exceedance Notice identifies a number of wells, with consecutive exceedances of other constituents. None of those constituents are included in this Plan, for the reasons stated in Section 1 above and in the Q4 2106 Exceedance Notice. This Plan and the associated SAR are being submitted to DWMRC by EFRI to address exceedances in MW-31 for uranium and for additional constituents which were addressed in previous SARs, but have exceeded the recalculated GWCLs specified in those previous SARs due to statistically significant trends noted in previous studies. Nitrate + Nitrite and Chloride concentrations in MW-31 are associated with the Nitrate/Chloride plume, and are currently covered by the December 12, 2012 Stipulation and Consent Order. With respect to pH, EFRI and DWMRC entered into a Stipulated Consent Agreement (“SCA,,) dated July 12, 2012. The SC A required the completion of the pH Report and the Pyrite Investigation and associated report. The pH Report and Pyrite Investigation Report were submitted November 9, 2012 and December 7, 2012 respectively. By letter dated April 25, 2013, DWMRC accepted the conclusions that the out-of-compliance results and site-wide decrease in pH are due to background effects within the aquifer matrix and are not caused by Mill activities. The site-wide decrease in pH due to background effects within the aquifer matrix has continued. 3. CATEGORIES FOR ANALYSIS Previously EFRI has categorized wells and constituents in several categories as follows: • Constituents Potentially Impacted by Decreasing pH Trends Across the Site • Newly Installed Wells with Interim GWCLs • Constituents in Wells with Previously Identified Rising Trends • Pumping Wells • Other Constituents Uranium and selenium in MW-31 fall within the first category: Constituents Potentially Impacted by Decreasing pH Trends Across the Site. Sulfate falls within the last category: Other Constituents. It is important to note that selenium and sulfate also fall within the third category: Constituents in Wells with Previously Identified Rising Trends. Assessment of these constituents in MW-31 will follow the process noted below with additional considerations to address the previously identified rising trend. 3.1. Constituents Potentially Impacted by Decreasing pH Trends Across the Site EFRI has observed a decreasing trend in pH in a number of monitoring wells across the Mill site. See the discussions in the SAR dated October 10, 2012, the pH Report dated November 9, 2012 and the Pyrite Investigation Report dated December 7, 2012. The pH Report specifically noted that wells MW-03A, MW-11, MW-12, MW-14, MW-15, MW-17, MW-18, MW-22, MW-24, MW-25, MW-30, MW-32, and MW-37 showed significantly decreasing trends in pH. Since the publication of the pH Report dated November 9, 2012 and the Pyrite Investigation Report dated December 7, 2012, pH in MW-31 now shows a significantly decreasing trend. Review of the pH time plots included in the pH Report indicates a decreasing trend in pH in most wells across the site. By letter dated April 25, 2013, DWMRC accepted the conclusions that the decreasing trends for pH are due to background effects within the aquifer matrix and are not caused by Mill activities. The mobility in groundwater of uranium and selenium is sensitive to decreases in pH. In addition, selenium also falls within the Constituents in Wells with Previously Identified Rising Trends category. 3.2. Other Constituents As previously noted sulfate falls within the third category and the fifth category. Assessment of sulfate in MW-31 will follow the process previously used for constituents classified under the “other” category. The location of MW-31 is important when determining potential sources of contamination. MW-31 was included in the October 2012 SAR for exceedances in for exceedances in TDS and sulfate and the December 2015 SAR for exceedances in sulfate, selenium, field pH, and TDS. The previous SARs concluded that the increasing chloride, and sulfate concentrations were due to the proximity of that well to the nitrate/chloride plume. MW-31 is located at the margin of the nitrate/chloride plume. The nitrate/chloride plume has been the subject of many studies that are described in detail in the following reports: • Nitrate Contamination Investigation Report • Quarterly Nitrate Reports 2009-2015 The nitrate/chloride plume is currently being addressed by the ongoing activities under the DWMRC-approved CAP. 4. PLAN 4.1. General This Plan is a plan and time schedule for assessment of the sources, extent and potential dispersion of the contamination, and an evaluation of potential remedial action to restore and maintain groundwater quality to ensure that Permit limits will not be exceeded at the compliance monitoring point and that, to the extent applicable, discharge minimization technology and best available technology will be reestablished. Given the recent analyses in the Background Reports, SARs, pH Report, and Pyrite Report and other recent information relating to the Chloroform and Nitrate/Chloride investigations at the site, EFRI believes that all of the exceedances are likely due to background influences (including a natural decreasing trend in pH across the site, changing water levels in some wells and other factors), disruption of the aquifer by pumping, and/or the geochemical influences of the existing chloroform and nitrate/chloride plumes. Therefore, the first step in the analysis will be to perform an assessment of the potential sources for each exceedance to determine whether the exceedance is due to background influences or Mill activities. If an exceedance is determined to be due to background influences then it will not be necessary to perform any further evaluations on the extent and potential dispersion of the contamination or to perform an evaluation of potential remedial actions. Monitoring will continue, and where appropriate revised GWCLs will be proposed to reflect changes in background conditions at the site. However, if any of the exceedances are determined to be caused by Mill activities, then EFRI will proceed to the next step and will consider the extent and potential dispersion of the contamination, and will perform an evaluation of potential remedial actions to restore and maintain groundwater quality to ensure that Permit limits will not be exceeded at the compliance monitoring point. This two-step approach is necessary, because, in light of the varied background conditions at the site and previously identified background trends, it can’t be assumed that consecutive exceedances of a constituent in a well represents contamination that has been introduced to the groundwater. It is first necessary to establish whether or not the exceedances represent background influences. 4.2. Constituents Potentially Impacted by Decreasing pH Trends Across the Site As mentioned above, EFRI has observed a decreasing trend in pH in a number of monitoring wells across the Mill site. The mobility of uranium and selenium in groundwater is sensitive to decreases in pH. The primary focus of the source assessment for selenium and uranium in MW-31 will be two­ fold. First, EFRI will determine whether or not there is any new information that would suggest that the previous analyses conducted in the New Wells Background Report, the SAR, or the pH Report have changed since the date of that Report. This analysis will include the following: (i) A geochemical analysis that will evaluate the behavior of the constituents in MW-31 to determine if there are any changes in the behavior of indicator constituents, such as chloride, sulfate, fluoride and uranium since the date of the Existing Wells Background Report, the SARs, and the pH Report, that may suggest a change in the behavior of that well since the date of that Report; (ii) If necessary, a mass balance analysis that will evaluate the observed concentrations in light of the concentrations in Mill tailings and the presence or absence of any mounding at the location of the well in question; and Second, a pH analysis will be performed for uranium and selenium that will: (iii) Review the behavior of pH in the well to determine if there has been a significant decrease in pH in the well; and (iv) Analyze the expected impact from any such decrease in pH on the concentration of selenium, based on currently available information. The foregoing analyses (both steps) will be included in the Source Assessment Report. If no significant changes are identified that would suggest that the previous analysis conducted in the New Wells Background Report, the SAR and the pH Report, has changed other than what would be expected from decreasing trends in pH, then EFRI will propose changes to the GWCL for uranium and selenium in MW-31 to better reflect background concentrations at the site. If significant changes are identified that cannot be attributed to changes in pH or other natural phenomena, then EFRI will propose to the Director further analysis that may be required in order to identify the source and the extent and potential dispersion of the contamination, as well as potential remedial actions. 4.3. Other Constituents The primary focus of the source assessment for these constituents will again be to determine whether or not there is any new information that would suggest that the previous analysis conducted in the New Wells Background Report, SARs, pH Report and Pyrite Report has changed since the date of those Reports. This analysis will include the following for each constituent listed in Table 4: (i) A geochemical analysis that will evaluate the behavior of all of the constituents in the well in question to determine if there are any changes in the behavior of indicator constituents, such as chloride, sulfate, fluoride and uranium since the date of the Existing Wells Background Report and the SARs that may suggest a change in the behavior of that well since the date of those Reports; (ii) A mass balance analysis that will evaluate the observed concentrations in light of the concentrations in Mill tailings and the presence or absence of any mounding at the location of the well in question; (iii) An analysis of the extent, if any, to which the constituents may be influenced by geochemical changes caused by migrating nitrate and/or chloride or chloroform from the existing plumes; and (iv) An analysis of the extent, if any, to which the constituents may be influenced by changes in other constituents in ground water that have resulted from changes in pH or any other natural phenomenon. The foregoing analysis will be included in the Source Assessment Report. If no significant changes are identified that would suggest that the previous analysis conducted in the Background Reports for the constituents in question has changed, then EFRI will propose changes to the GWCLs for those wells to better reflect background concentrations at the site. If significant changes are identified that are attributable to geochemical changes caused by either the nitrate/chloride plume or the chloroform plume, then the constituents should be considered in connection with the applicable plume, and the associated CAP. If significant changes are identified that cannot be attributed to one of the existing plumes, or other background influences, then EFRI will propose to the Executive Secretary further analysis that may be required in order to identify the source and the extent and potential dispersion of the contamination, as well as potential remedial actions. 4.4. Expert Reports to be Prepared The results of the statistical analysis and, if appropriate, recalculation of the GWCL will be compiled as a SAR that will be submitted to DWMRC within 90 days of the approval of this plan. The SAR will detail the results of all of the analyses to be performed and the conclusions to be drawn from such analyses, including any proposed revisions to existing GWCLs. Specifically, the SAR will follow the format of the previously submitted SARs and will include discussions, results and conclusions of the analysis and appendices containing the following: A geochemical analysis of MW-31 Comparison of calculated and measured TDS for samples with complete major ions Charge balance calculations Descriptive statistics Box plots to identify extreme outliers Histograms and Shapiro Wilk test for normality Regression or Mann Kendall trend analysis Proposed Revised GWCLs for MW-31 A geochemical analysis of Indicator Parameters in MW-31 Descriptive Statistics Box plots to identify extreme outliers Histograms and Shapiro Wilk test for normality Regression and/or Mann Kendall trend analysis A pH analysis in MW-31 Descriptive Statistics Box plots to identify extreme outliers Histograms and Shapiro Wilk test for normality Regression and/or Mann Kendall trend analysis 5. TIME SCHEDULE The SAR will be submitted to the Director within 90 days after approval of this Plan. The SAR contemplated by this submission, may be combined with any subsequent SARs resulting from other Plans and Schedules for other out of compliance constituents, as necessary. 6. CONCLUSION Given the varied background groundwater quality at the site it cannot be assumed that consecutive exceedances of a constituent in a monitoring well means that contamination has been introduced to groundwater in that well. The location of MW-31 is important when determining potential sources of contamination. MW-31 was included in the October 2012 SAR for exceedances in IDS and sulfate and the December 2015 SAR for exceedances in sulfate, selenium, field pH, and TDS. The previous SARs concluded that the concentrations of many constituents in MW-31 were due to or affected by the proximity of that well to the nitrate/chloride plume and to a statistically significant decreasing pH. MW-31 is located at the margin of the nitrate/chloride plume. The nitrate/chloride plume has been the subject of many studies that are described in detail in separate reports.