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Home My WebLink AboutDRC-2013-003136 - 0901a068803bc5c9State of Utah GARY R. HERBERT Governor GREG BELL Lieutenant Governor Department of Environmental Quality Amanda Smith Executive Director DIVISION OF RADIATION CONTROL Rusty Lundberg Director "DRC-2013-003136" MEMORANDUM TO: FROM: DATE: SUBJECT: fib 70 (} Phil Goble Dean Henderson September 12,2013 Review of the 2nd Quarter 2013 Chloroform Monitoring Report for the Chloroform Contamination Investigation, Energy Fuels Resources (USA) Inc. ("EFR") White Mesa Uranium Mill, near Blanding, Utah The Utah Division of Radiation Control ("DRC") has reviewed the August 26, 2013, 2nd Quarter 2013 Chloroform Monitoring Report ("Report") for the Chloroform Contamination Investigation. For the review of this report the following regulatory enforcement documents were used: • EFR was issued Ground Water Quality Discharge Permit No. UGW3 70004 ("Permit") on March 8, 2005; last revised on August 24, 2012. • The EFR Quality Assurance Plan ("QAP") June 7, 2012 (Revision. 7.2) REVIEW Monitor Well Sampling The following monitor wells were sampled as required in the QAP (see Table 1 below): TW4-1, TW4-2, TW4-3, TW4-4, TW4-5, TW4-6, TW4-7, TW4-8, TW4-9, TW4-10, TW4-11, TW4-12, TW4-13, TW4-14, TW4-16, TW4-18, TW4-19, TW4-20, TW4-21, TW4-22, TW4-23, TW4-24, TW4-25, MW-4, MW-26 (formerly TW4-15), MW-32 (formerly TW4-17), TW4-26, TW4-27, TW4-28, TW4-29, TW4-30,and TW4-31. The following monitoring wells were purged using the three approved QAP well purging strategies and meet QAP requirements for each strategy: 1. Purging two casing volumes with stable field parameters for specific conductivity, turbidity, pH, redox potential, and water temperature (within 10% RPD): Wells: MW-32, TW4-1, TW4-5, TW4-8, TW4-9, TW4-11, TW4-12, TW4-16, TW4-18, TW4- 21, and TW4-23. 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 Page 2 2. Purging a well to dryness and stability of field parameters for pH, specific conductivity, and water temperature only after recovery: Wells: TW4-2, TW4-3, TW4-6, TW4-7, TW4-10, TW4-13, TW4-14, TW4-26, TW4-27, TW4-29, TW4-30, and tw4-31. 3. Pumping Wells: MW-4, MW-26, TW4-4, TW4-19, TW4-20, TW4-22, TW4-24, and TW4-25. The water samples for the above wells were analyzed for the following constituents as required in the QAP: Chloroform, Chloromethane, Carbon tetrachloride, Methylene chloride, Chloride and Nitrate plus Nitrite as Nitrogen. Use of analytical methods is consistent with the requirements of the QAP requirements. QAQC Holding Times The method holding times for each parameter for samples collected at each monitor well were received and analyzed within the required holding times in the QAP. Receipt Temperature All samples were received within the required QAP temperature limit of 6° C. Detection Limits All analytes were measured and reported to the required reporting limits. However, several sets of sample results had the reporting limit raised for at least one analyte due to matrix interference and/or sample dilution. In all cases the reported value for the analyte was higher than the increased detection limit. Sample Duplicates Three duplicate samples were collected. Well TW4-16 and its duplicate sample TW4-65, TW4-26 and its duplicate sample TW4-70, and TW4-29 (resample) and its duplicate sample TW4-65 (Note: duplicate sample for TW4-16 and TW4-29 are both identified as TW4-65) All analytical results for the three sample/duplicate pairs were within the 20% acceptance limits as required in the QAP (see Table 2 below). Groundwater Head Monitoring Depth to groundwater was measured in the following wells and/or piezometers, as required in Part I.E.3 of the Permit: • The quarterly groundwater compliance monitoring wells. • Existing monitoring well MW-4 and all of the temporary chloroform investigation wells. • Piezometers P-l, P-2, P-3, P-4 and P-5. • MW-20 and MW-22. • Nitrate monitoring wells. • The DR piezometers which were installed during the Southwest Hydrologic Investigation. In addition, weekly and monthly depth to groundwater measurements were taken in MW-4, MW-26, TW4- 4, TW4-19, TW4-20, TW4-22, TW4-24, and TW4-25. Page 3 Mass Removed Chloroform removal was first estimated from the first quarter 2007. Since that estimation the mass removed by each pumping well for each quarter has been calculated. Estimated reported mass removed 2nd quarter 2013 is 13.5 lbs. Table 3 below verifies this estimate. Reporting The Report included the following information as required in the QAP: a) Introduction b) Sampling and Monitoring Plan -Description of monitor wells -Description of sampling methodology, equipment and decontamination procedures -Identify all quality assurance samples, e.g. trip blanks, equipment blanks, duplicate samples c) Data Interpretation -Interpretation of groundwater levels, gradients, and flow directions. Interpretations will include a discussion on: 1) A current site groundwater contour map, 2) hydrographs to show groundwater elevation in each monitor well over time, 3) depth to groundwater measured and groundwater elevation from each monitor well summarized in a data table, that includes historic groundwater level data for each well, and 4) an evaluation of the effectiveness of hydraulic capture of all contaminants of concern. -Interpretation of all analytical results for each well, including a discussion on: 1) a current chloroform isoconcentration map with one of the isoconcentration lines showing the 70 (ig/L boundary, 2) graphs showing chloroform concentration trends in each well through time and, 3) analytical results for each well summarized in a data table, that includes historic analytical results for each well. -Calculate chloroform mass removed by pumping wells. Calculations would include: 1) total historic chloroform mass removed, 2) total historic chloroform mass removed for each pumping well, 3) total chloroform mass removed for the quarter and, 4) total chloroform mass removed from each pumping well for the quarter. d) Conclusions and Recommendations e) Electronic copy of all laboratory results for Chloroform Investigation monitoring conducted during the quarter. f) Copies of DUSA field records, laboratory reports and chain of custody forms. Evaluation of the Chloroform Contaminate Plume and Its Associated Contaminants Bounding Chloroform Plume Groundwater monitoring data for the 2nd quarter 2013 monitoring event appeared to show that the chloroform contaminate plume and associated contaminants, carbon tetrachloride, chloromethane, and Page 4 methylene chloride is bound in all directions by wells that have a chloroform concentration of <70 [ig/L (GWQS = 70 jiig/L) with the exception of TW4-29 that has a chloroform concentration of 262 ng/L. TW4-29 is approximately 200 feet south of well TW4-27 that apparently bound the chloroform plume to the south with non-detectable chloroform concentrations (<1.0 ng/L). On July 29, 2013 EFR submitted a letter with proposed actions that include the installation of two new monitor wells in the vicinity of TW4- 29 to investigate the chloroform plume migration. On August 2, 2013 DRC sent EFR a conditionaly approval letter on their proposed actions. Monitor Wells Exceeding Chloroform Concentrations of 70|ug/L Seven monitor wells: TW4-1, TW4-2, TW4-7, TW4-10, TW4-11, TW4-21, and TW4-29 exceed chloroform concentrations of 70|ug/L. All but TW4-10, TW4-21, and TW4-29 show decreasing trends. Monitor Wells with Chloroform Concentrations Between 1 fig/L and 70ug/L Four monitor wells: TW4-5, TW4-6, TW4-18, and TW4-26 chloroform concentrations of <70jiig/L. TW4- 18, appears to have a increasing trend. Pumping Wells Chloroform Concentrations Pumping wells MW-4, MW-26, TW4-4, TW4-19, TW4-20, and TW4-22 exceed chloroform concentrations of 70ng/L. Pumping well TW4-24 had a historic high chloroform concentration of 17.4 Ug/L and TW4-25 have non-detectable chloroform concentrations (<1.0 u.g/L). Monitor Wells Below the Laboratory Chloroform Detection Limit (<1.0 fXg/L) The following monitor wells are below laboratory detection limit for chloroform (<1.0 fig/L): MW-32, TW4-3, TW4-8, TW4-9, TW4-12, TW4-13, TW4-14, TW4-16, TW4-23, TW4-27, TW4-28, TW4-30, TW4-31 (see Table 1 below). Nitrate. Nitrate + Nitrite ("nitrate") Concentrations Monitor wells TW4-21, TW4-22, TW4-24, and TW4-25 all exceed the nitrate GWQS of 10 mg/l. All of these nitrate exceedances for these wells appear to be a result of the nitrate contaminant plume up-gradient of the chloroform contaminant plume. This nitrate contaminant plume is being addressed under the Nitrate Corrective Action Plan, approved on December 12, 2012. Nitrate concentrations in TW4-12 and TW4-27 continue to exceed the GWQS (10 mg/L). EFR is currently preparing a contamination investigation report that will be submitted to DRC. Conclusions on Compliance with the Permit and QAP Per the DRC review it appears that the Report complies with Permit and QAP. Therefore a letter will be drafted for the Director Signature, notifying EFR of the review and closing-out ofthe 2nd Quarter 2013 Chloroform Monitoring Report for the chloroform contamination investigation. Page 5 References Energy Fuels Resources (USA) Inc., June 7, 2012 White Mesa Uranium Mill, Ground Water Monitoring Quality Assurance Plan (Revision 7.2). Energy Fuels Resources (USA) Inc., February 18, 2013 White Mesa Uranium Mill Chloroform Monitoring Report 1st Quarter 2013 (October through December 2012). Energy Fuels Resources (USA) Inc., February 6, 2013, 14-day Notification for Installation of Four Additional Monitoring Wells. Energy Fuels Resources (USA) Inc., July 29, 2013, Letter, Subject: Utah Groundwater Discharge Permit ("GWDP") UGW3 70004 Follow-up and response to February 14, 2013 Confirmatory Action Letter State of Utah Division of Water Quality Department of Environmental Quality, August 24, 2012, Ground Water Discharge Permit for Denison Mines (USA) Corp. at the White Mesa Mill Facility Near Blanding, Utah. State of Utah Division of Water Quality Department of Environmental Quality, August 23, 1999, White Mesa Uranium Mill: Notice of Violation and Groundwater Corrective Action Order, Docket No UGW-20-01. State of Utah Division of Water Quality Department of Environmental Quality, January 2009, Stipulated Consent Agreement, UDEQ Docket No. UGW-09-03. Utah Division of Radiation, February 14, 2013, Nitrate Contamination Investigation. Nitrate Concentrations Exceeding the Groundwater Quality Standard in Monitor Wells TW4-12 and TW4-27. Confirmatory Action Letter. Utah Division of Radiation, August 2, 2013, Letter, Subject: Nitrate Contamination Investigation at Monitor Wells TW4-12 and TW4-28. Chloroform Contamination Investigation at Monitor Well TW4-29. Conditional Approval. Page 6 TABLE 1 Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2013 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (5ug/L) Chloride (mg/L) No GWQS Chloroform (70 pg/L) Chloromethane (30 pg/L) Methylene Chloride (S pg/L) Nitrate, Nitrate + Nitrite (10 mg/L) MW-4 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <10 <50 53 2,900 3,170 3,500 3,000 NA NA <10 <50 NA NA <10 <50 lstQtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 <50 <50 <50 3,100 3,000 2,820 2,830 <50 <50 <50 <50 <50 <50 <1.0 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 2,300 2,000 2,600 2,300 <1.0 <1.0 <1.0 <1.0 :1.0 :1.0 :1.0 =1.0 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 2,400 2,500 1,800 2,100 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/14/09 2,200 1,800 2,000 1,800 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 lstQtr 2/17/10 2nd Qtr 6/14/10 3rd Qtr 8/6/10 4th Qtr 10/15/10 1,600 2,100 1,900 1,500 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/23/11 2nd Qtr 6/1/11 3rd Qtr 8/17/11 4th Qtr 11/16/11 1,700 1,700 1,700 1,600 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 1/23/12 2nd Qtr 6/6/12 3rd Qtr 9/4/12 4th Qtr 10/4/12 1,500 1,400 1,500 1,300 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/11/13 2nd Qtr 6/5/13 1.48 1.31 37.8 44 1,670 1,490 <1.0 <1.0 <1.0 <1.0 MW-4A(TW4-A) 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <10 <50 3,700 3,740 3,800 3,000 NA NA <10 <50 NA NA <10 <50 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/05 4th Qtr 11/8/05 <50 <50 <50 2.4 3,700 3,300 3,190 3,370 <50 <50 <50 <1.0 <50 <SO <50 <1.0 <i".o" 1st Qtr 2/28/07 2,500 <1.0 Well abandonded MW-26 (former TW4-15) 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <5.0 <50 55 310 442 960 1,000 NA NA 5.4 <50 NA NA <5.0 <50 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 <S0 <50 <50 <1.0 1,100 830 2,170 282 <so <so <50 <1.0 <50 <50 <50 lstQtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 :1.0 :1 6 :1.0 :1.0 570 300 1,400 2,000 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 4th Qtr 11/18/09 <1.0 <1.0 <1.0 NA <2.0 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/14/09 <1.0 <1.0 <1.0 <1.0 930 1,300 630 1,700 '950 410 850 1,100 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 <1.0 40 53 24 100 51 12 30 40 19 lstQtr 2/17/10 2nd Qtr 6/14/10 3rd Qtr 8/16/10 4th Qtr 10/15/10 d.O <1.0 <1.0 730 1,600 2,200 970 :1.0 :1.0 :1.0 = 1.0 <1.0 1st Qtr 2/23/11 2nd Qtr 5/31/11 3rd Qtr 8/17/11 4th Qtr 11/16/11 (1)12/5/11 <1.0 <1.0 <1.0 <1.0 57 450 1,800 720 1,800 "2,400 3,000 3,100 1,200 :1.0 :1.0 :1.0 <1.0 „.....„... <1.0 <1 <1 2.9 ....... 21 31 4 9.34 52.4 1st Qtr 2/7/12 2nd Qtr 6/6/12 3rd Qtr 9/4/12 4th Qtr 10/4/12 <1.0 <1.0 <1 <1 1st Qtr 2/11/13 <1 2nd Qtr 6/5/13 <1.0 81.9 77.9 2,120 4,030 <1 <1.0 (1) VOCs were resampled because laboratory missed holding I NA = not analyzed NS = not sampled Shaded indicates concentrations exceeding GWQS. Bold and red = highest concentration since montioring started. Bold and blue = lowest concentration since montioring started. Bold and italics indicates the MDL exceeded the GWQS. 1st Qtr = January - March 2nd Qtr = April - June 3rd Qtr = July - September 4th Qtr = October - December TABLE 1 Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2013 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (S H9/L) Chloride (mg/L) No GWQS Chloroform (70 pg/L) Chloromethane (30 pg/L) Methylene Chloride (5 pg/L) Nitrate, Nitrate + Nitrite (10 mg/L) MW-32 (former TW4-17) 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <1.0 <1.0 33 1.0 <1.0 <1.0 <1.0 NA NA 1.0 <1.0 <0.1 0.1 <0.1 <0.1 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 10 1.0 <1.0 1.0 <1.0 1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <0.1 <0.1 <1.0 <.1 lstQtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1.0 <1.0 1.0 <1.0 <1.0 <1.0 <1.0 1.0 1.0 1.0 <1.0 <1.0 :1.0 :1.0 :1.0 :1.0 <1.0 <1.0 1.0 <1.0 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 <1.0 <1.0 1.0 1.0 <1.0 1.0 1.0 <1.0 1.0 1.0 <1.0 <1.0 <1.0 1.0 1.0 <1.0 <1 <1.0 <1.0 <0.05 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/16/09 <1.0 <1.0 <1.0 <1.0 10 1.0 ........ <1.0 <1.0 1.0 <1.0 <1.0 :1.0 :i.O <1.0 <1.0 <.1 <0.1 <0.1 <0.1 lstQtr 2/17/10 2nd Qtr 6/14/10 3rd Qtr 8/16/10 4th Qtr 10/15/10 1.0 1.0 <1.0 1.0 1.0 <1.0 <1.0 1.0 <1.0 1.0 1.0 <1.0 1.0 1.0 <1.0 <1.0 <0.1 0.1 <0.1 <0.1 1st Qtr 2/23/11 2nd Qtr 5/25/11 3rd Qtr 8/16/11 4th Qtr 11/16/11 (,) 12/7/11 1.0 1.0 <1.0 :1.0 1st Qtr 1/18/12 2nd Qtr 6/22/12 3rd Qtr 9/5/12 4th Qtr 10/10/12 1.0 <1.0 1.0 1.0 1.0 <1.0 <1.0 :1.0 <1.0 <1.0 1.0 <1.0 <1.0 1.0 <1.0 <1.0 <1.0 1.0 <1.0 ......... 1.0 <1.0 <1.0 1.0 „„_.. <1.0 1.0 1.0 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 <0.1 1st Qtr 2/11/13 2nd Qtr 6/18/13 <1.0 <1.0 34.3 34.9 <1.0 1.0 1.0 <1.0 <1.0 1.0 <0.1 <0.1 TW4-1 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <10 <so 2,700 3,080 2,900 2,400 NA NA <10 <50 NA NA <10 <50 9.1 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 <so <so 2,700 2,200 2,840 2,260 <50 <50 <50 1.0 <so <50 <50 <1.0 9.2 8.9 9 8.4 7 7 8 68 3.15 9.3 "7.5 6.9 7.3 6.8 Ti 6.8 6.7 6.6 "6.6 6.6 6.8 66 "68 7.1 5.0 65 To 6.9 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1,900 1,900 2,300 2,000 1.0 1.0 <1.0 <1.0 <1.0 1.0 1.0 i.o 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 2,000 1,900 1,700 1,700 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/11/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/29/09 :1.0 :1.0 1,700 1,500 1,700 1,400 <1.0 <1.0 <1.0 <1.0 :1.0 ••i.o H.o :1.0 1st Qtr 3/3/10 2nd Qtr 6/14/10 3rd Qtr 8/18/10 4th Qtr 10/15/10 <1.0 1,300 1,600 1,600 1,500 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/24/11 2nd Qtr 6/1/11 3rd Qtr 8/18/11 4th Qtr 11/29/11 <1.0 <1.0 <1.0 <1.0 1,300 1,200 1,300 1,500 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 1/24/12 2nd Qtr 6/14/12 3rd Qtr 9/28/12 4th Qtr 10/4/12 <1.0 <1.0 <1.0 <1.0 1,300 1,000 1,000 1,100 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/13/13 2nd Qtr 6/19/13 |<1.0 3.66 37.6 39.1 1,320 1,100 =1.0 :1.0 <1.0 <1.0 (1) VOCs were resampled because laboratory missed holding I NA = not analyzed NS = not sampled Shaded indicates concentrations exceeding GWQS. Bold and red = highist concentration since montioring started. Bold and blue = lowest concentration since montioring started. Bold and italics indicates the MDL exceeded the GWQS. 1 st Qtr = January - March 2nd Qtr = April - June 3rd Qtr = July - September 4th Qtr = October - December TABLE 1 Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2013 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride (5 pg/L) Chloride (mg/L) No GWQS Parameter GWQS Chloroform (70 pg/L) Chloromethane (30 pg/L) Methylene Chloride (S pg/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-2 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <10 <50 3,700 3,750 3,900 3,500 NA NA 10 <50 NA NA <10 <50 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 <50 <50 <50 3,800 3,200 4,120 3,420 <50 <50 <50 1.0 <50 <50 <50 <1.0 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 2,300 3,000 340 (?) 3,200 :1.0 :1.0 :1.0 :1.b 1.0 <1.0 1.0 1.0 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 4th Qtr 11/18/09 3,300 3,100 2,800 3,200 "'37i00 2,800 3,000 1,600 1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 NA <2.0 NA 1st Qtr 3/11/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/29/09 <1.0 1.0 1.0 1.0 <1.0 <1.0 :1.0 :1.0 1st Qtr 3/3/10 2nd Qtr 6/14/10 3rd Qtr 8/18/10 4th Qtr 10/15/10 2,600 3,300 3,300 3,000 <1.0 1.0 1.0 1.0 <1.0 <1.0 <1.0 <1.0 lstQtr 2/24/11 2nd Qtr 6/2/11 3rd Qtr 8/17/11 4th Qtr 11/29/11 3,100 3,000 2,400 3,900 :1.0 :1.0 :1.0 :1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 1/24/12 2nd Qtr 6/14/12 3rd Qtr 9/28/12 4th Qtr 10/4/12 2,500 2,500 2,900 3,100 1.0 <1.0 1.0 1.0 <1.0 <1.0 <1.0 <1.0 lstQtr 2/13/13 2nd Qtr 6/19/13 5.17 2.65 46 46.9 3,580 3,110 :1.0 :1.0 <1.0 <1.0 TW4-3 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA NA <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 .„„...„... <1.0 <1.0 <1.0 <i.o <1.0 <1.0 <1.0 <1.0 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 10 :1 6 :1.0 :1.0 <1.0 <1.0 <1.0 <1.0 = 1.0 .......... :1.0 :i.O =1.0 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 <1.0 <1.0 <1.0 <1.0 :1.0 :1.0 :1.d :1.0 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <10 <1.0 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/29/09 =1.0 :1.0 <1.0 <1.0 <1.0 <1.0 .......... <1.0 <1.0 <1.0 <1.0 <1.0 lstQtr 2/23/10 2nd Qtr 6/14/10 3rd Qtr 8/10/10 4th Qtr 10/15/10 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <i.o <1.0 1st Qtr 2/15/11 2nd Qtr 5/25/11 3rd Qtr 8/16/11 4th Qtr 11/14/11 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 1/17/12 2nd Qtr 5/31/12 3rd Qtr 8/29/12 4th Qtr 10/3/12 <1.0 <1.0 <1.0 <1.0 :1.0 :1.0 :1.0 =1.0 :1.0 :1.0 :i.O =1.0 lstQtr 2/7/13 2nd Qtr 6/29/13 :1.0 :1.0 23.7 23.8 <1.0 <1.0 :1.0 :1.0 NA = not analyzed NS = not sampled Shaded indicates concentrations exceeding GWQS. Bold and red = highist concentration since montioring started. Bold and blue = lowest concentration since montioring started. Bold and italics indicates the MDL exceeded the GWQS. 1 st Qtr = January - March 2nd Qtr = April - June 3rd Qtr = July - September 4th Qtr = October - December TABLE 1 Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2013 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (S pg/L) Chloride (mg/L) No GWQS Chloroform (70 pg/L) Chloromethane (30 pg/L) Methylene Chloride (5 pg/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-4 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <10 <50 3,100 2,400 3,200 2,800 NA NA <10 <50 NA NA <10 <50 10.0 11.3 9.9 10.2 9.5 8.6 9.7 10.1 9.0 9.4 9.5 9.5 9.2 108 88 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 <50 <50 <50 2,900 2,600 2,850 2,670 <50 <50 <50 <1.0 <50 <50 <50 <1.0 lstQtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 2,200 2,400 2,700 2,500 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 4th Qtr 11/18/09 NA <2.0 2,800 2,500 2,200 2,500 '2"200 1,800 2,000 950 <1.0 <1.0 <1.0 NA <2.0 <1.0 <i.o <1.0 NA <2.0 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/29/09 :1.0 :1.0 :1.0 :1.0 = 1.0 sib :1.0 :1.0 10.2 8.2 8.4 7.6 6.6 7.6 7.3 7.1 7.0 7.0 6.6 7.0 fi 7.1 7.1 7.0 7.4 6.3 1st Qtr 2/17/10 2nd Qtr 6/14/10 3rd Qtr 8/10/10 4th Qtr 10/15/10 1,700 1,700 2,100 1,700 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/23/11 2nd Qtr 6/1/11 3rd Qtr 8/17/11 4th Qtr 11/16/11 <1.0 1,800 1,700 1,500 1,500 <1.0 <1.0 <1.0 <1.0 <1.0 <i.o <1.0 <1.0 1st Qtr 1/23/12 2nd Qtr 6/6/12 3rd Qtr 9/4/12 4th Qtr 10/3/12 <1.0 <1.0 1.2 1 1,200 1,500 1,600 1,400 <1.0 <1.0 <1.0 <1.0 <1.0 <i 6 <1.0 <1.0 1st Qtr 2/11/13 2nd Qtr 6/29/13 1 <1.0 39 39.6 1,460 1,330 :1.0 :1.0 <1.0 <1.0 TW4-5 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <2.5 <2.5 120 113 82 63 NA NA <2.5 <2.5 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 <2.5 <2.5 <1.0 <1.0 66 51 53.7 47.1 <1.0 <1.0 <2.5 <2.5 <1.0 <1.0 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 :1.0 :1.0 :1.0 :1.0 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 :1.0 :1.0 :1.0 :1.0 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/29/09 :1.0 :1.0 :1.0 :1.0 <1.0 <1.0 <i".'6" <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/25/10 2nd Qtr 6/14/10 3rd Qtr 8/11/10 4th Qtr 10/15/10 <1.0 <1.0 <1.0 <1.0 :1.0 =1.0 :1.0 :1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/22/11 2nd Qtr 5/26/11 3rd Qtr 8/7/11 4th Qtr 11/16/11 (1) 12/7/11 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 ........... <1.0 <i.O <1.0 <1.0 <1.0 <1.0 <1.0 _.. <1.0 <1.0 <1.0 1st Qtr 1/18/12 2nd Qtr 6/6/12 3rd Qtr 9/11/12 4th Qtr 10/3/12 <1.0 <1.0 <1.0 <1.0 5.8 8.0 8.1 7.7 8.2 10.7 lstQtr 2/13/13 2nd Qtr 6/13/13 =1.0 :1.0 34.3 36.5 10.8 11.2 :1.0 H.O <1.0 <1.0 (1) VOCs were resampled because laboratory missed holding I NA = not analyzed NS = not sampled Bold and red = highist concentration since montioring started. Bold and blue = lowest concentration since montioring started. Shaded indicates concentrations exceeding GWQS. Bold and italics indicates the MDL exceeded the GWQS. 1 st Qtr = January - March 2nd Qtr = April - June 3rd Qtr = July - September 4th Qtr = October - December TABLE 1 Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2013 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (5 pg/L) Chloride (mg/L) No GWQS (70 pg/L) Chloromethane (30 pg/L) Methylene Chloride (S pg/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-6 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA 1.0 <1.0 NA NA 1.0 <1.0 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 <1.0 <1.0 1.0 10 31 19 11 42.8 1.0 <1.0 10 1.0 1.0 <1.0 <1.0 1.0 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 :1.0 :1.6 :1.0 :1.0 1.0 <1.0 <1.0 1.0 1.0 1.0 <10 <1.0 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 10 1.0 1.0 <1.0 10 10 10 <1.0 1.0 <1.0 1.0 <1.0 1st Qtr 3/11/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/29/09 <1.0 1.0 :1.0 :10 81 120 280 250 <1.0 <1.0 ........ 10 <1.0 1.0 :1.0 :1 6 1st Qtr 2/25/10 2nd Qtr 6/14/10 3rd Qtr 8/11/10 4th Qtr 10/15/10 10 10 <1.0 <10 1000 590 630 420 :1.0 :1.0 :1.0 :1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/23/11 2nd Qtr 5/26/11 3rd Qtr 8/17/11 4th Qtr 11/16/11 <1) 12/7/11 <2) 11/16/11 <1.0 1.0 1.0 1.0 <1.0 :1.0 :1.0 :1.0 :1.0 :1.0 <1.0 1.0 10 1.0 <1.0 1st Qtr 1/18/12 2nd Qtr 6/13/12 3rd Qtr 9/11/12 4th Qtr 10/3/12 <1.0 <1.0 <1.0 <1.0 <1.0 1.0 10 1.0 10 <1.0 1.0 1.0 1st Qtr 2/13/13 2nd Qtr 6/13/13 :1.0 :1.0 40.4 37.9 6.89 4.86 <1.0 <1.0 :10 :10 TW4-7 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <10 <50 3,100 2,700 3,100 2,500 NA NA <10 <50 NA NA <10 <50 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 <50 <50 <50 1,900 2,200 2,140 2,160 <50 <SO <50 <1.0 <so <50 <50 <1.0 lstQtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1,830 2,600 2,300 1,900 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <10 <1.0 5.1 4.7 4.7 4.2 4.8 4.16 4.01 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 4th Qtr 11/18/09 NA <2.0 2,200 1,800 1,600 2,500 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 NA <2.0 1st Qtr 3/11/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/29/09 <1.0 <1.0 1,800 1,400 1,500 1,300 <1.0 <1.0 .......... <1.0 :10 =1.0 <10 <1.0 lstQtr 3/3/10 2nd Qtr 6/14/10 3rd Qtr 8/11/10 4th Qtr 10/15/10 <1.0 <1.0 1 <1.0 1,200 1,100 1,500 1,100 :1.0 :1.0 :1.0 :1.0 =1.0 :1.0 d.O =1.0 1st Qtr 2/23/11 2nd Qtr 6/1/11 3rd Qtr 8/18/11 4th Qtr 11/29/11 <10 <1.0 <1.0 <1.0 1,300 1,200 1,200 1,000 <1.0 <1.0 <1.0 <1.0 <1.0 <10 <1 0 <1.0 1st Qtr 1/19/12 2nd Qtr 6/14/12 3rd Qtr 9/13/12 4th Qtr 10/4/12 <1.0 <1.0 <10 <1.0 1,000 790 870 940 <1.0 <1.0 <1.0 <1.0 :10 :1.0 :1.0 :10 1stQtr2/13/13 <1.0 2ndQtr6/18/13 <1.0 37.7 39.3 940 953 <1.0 <1.0 :1.0 :1.0 (1) VOCs were resampled because laboratory missed holding 1 (2) Results of the TW4-70 the duplicate sample for TW4-6. NA = not analyzed NS = not sampled Shaded indicates concentrations exceeding GWQS. Bold and red = highest concentration since montioring started. Bold and blue = lowest concentration since montioring started. Bold and italics indicates the MDL exceeded the GWQS. 1 st Qtr = January - March 2nd Qtr = April - June 3rd Qtr = July - September 4th Qtr = October - December TABLE 1 Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2013 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride (5 pg/L) Parameter GWQS Chloride (mg/L) No GWQS (70 pg/L) Chloromethane (30 pg/L) Methylene Chloride (5 pg/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-8 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <1 0 <1 0 1.7 :1.0 NA NA NA <1.0 ........... <1.0 <1.0 <1.0 .„„...„... <1.0 <1.0 <1.0 ........... <1.0 <1.0 <i.o ........... <i.o <i.o <1.0 <To <i.o <1.0 <0 1 <1.0 <1.0 <1.0 <1 0.2 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 :1.0 d.O 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <10 d.o 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 d.O <1.0 <1 0 <10 <1.0 <1.0 <i.0 <1.0 d.O d.6 d.O d.O <1.0 <0.05 <0.05 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/17/09 <1.0 <1.0 <i'.o" <1.0 <1.0 <1 0 <To" <1 0 <1.0 <1.0 ......... <1.0 <0.1 <0 1 <0.1 <0.1 .......... 1st Qtr 2/24/10 2nd Qtr 6/14/10 3rd Qtr 8/18/10 4th Qtr 10/15/10 <1.0 <1.0 <i.0 <1.0 <1.0 <i.o <1.0 <1.0 <1.0 <1.0 <1.0 d.o <1.0 .......... <1.0 <1.0 <1.0 <0.1 <0.1 0.1 ........ lstQtr 2/16/11 2nd Qtr 5/25/11 3rd Qtr 8/16/11 4th Qtr 11/16/11 <1 '12/7/11 <1.0 <1.0 <1 0 :1.0 <1.0 <1.0 <1 0 <1.0 <1.0 <1.0 <1.0 .......... <1.0 <1.0 <i.o 1st Qtr 1/18/12 2nd Qtr 5/13/12 3rd Qtr 8/29/12 4th Qtr 10/3/12 <1.0 <1.0 <1 0 <1^0 d.O d.O d 0 d 0 <1.0 <1 0 <1 0 <1 0 03 02 0.1 <0 1 0.4 <0.1 1st Qtr 2/7/13 2nd Qtr 5/30/13 d.O d.O 46.6 45.5 d.O d.O <1.0 <1.0 d.O d.O TW4-9 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <1^0 <1.0 d.O d.O NA NA <1.0 <1.0 .......... <i.o <1.0 <1 o .......... <1.0 <1.0 <1.0 ,„„„.„.„ <1 0 <1.0 <1 0 ,„.„..„„. <1.0 <1.0 <1.0 ........... <1.0 <1.0 <1 0 .......... <1 0 <i.o <1.0 1.3 1.3 1.3 i.3 1.5 1.5 0.9 0.7 0.6 1.3 1.8 2 2 1 2.3 2.79 1.99 2.5 2.3 2.5 1.7 1.4 1.5 1.2 1.8 i".3 3.4 4 2.3 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 d.O <1.0 <1 0 <1.0 d.O d.O <1.0 <1.0 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 ........... <1.0 <1.0 <1.0 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 d.O d.O d.O d.O d.O d.O 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/17/09 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/23/10 2nd Qtr 6/14/10 3rd Qtr 8/13/10 4th Qtr 10/15/10 <1.0 <1.0 <1 0 <i 6 <1 o <1.0 <1 0 <1.0 <1.0 <1 0 -d.O •d.o 1st Qtr 2/17/11 2nd Qtr 5/25/11 <1.0 <1 0 d.O d.O <1.0 <1.0 <1.0 <1.0 ........... 3rd Qtr 8/16/11 4th Qtr 11/16/11 fjj 12/7/11 1st Qtr 1/18/12 2nd Qtr 5/31/12 3rd Qtr 8/30/12 4th Qtr 10/3/12 d.O d.O d.o d.O d.O d.O d.O d.O d.O <1.0 <1.0 <1.0 <1.0 .......... <1.0 <1.0 .......... <1.0 1st Qtr 2/7/13 2nd Qtr 5/30/13 <1.0 <1.0 20.6 21.4 <1.0 <1.0 (1) VOCs were resampled because laboratory missed holding time. NA = not analyzed NS = not sampled Shaded indicates concentrations exceeding GWQS. Bold and red = highest concentration since montioring started. Bold and blue = lowest concentration since montioring started. Bold and italics indicates the MDL exceeded the GWQS. 1 st Qtr = January - March 2nd Qtr = April - June 3rd Qtr = July - September 4th Qtr = October - December TABLE 1 Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2013 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride (5 pg/L) Chloride (mg/L) No GWQS Parameter GWQS (70 pg/L) Chloromethane (30 pg/L) Methylene Chloride (5 pg/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-10 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA 2.5 25 140 62.4 110 300 <2.5 <5.0" <5.0 <5.0 NA NA <2.5 <2.5 1.6 0.8 1.1 3.3 2.4 3.5 6.8 5.7 7.3 5.1 7.3 6.7 7.3 9.9 9.23 10.5 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 5.0 <5.0 <5.0 1.0 190 300 504 452 <5.0 5.0 <5.0 1.0 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1.0 1.0 1.0 <1.0 500 350 660 470 <1.0 <1.0 1.0 1.0 1.0 <1.0 1.0 1.0 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 4th Qtr 11/18/09 1.0 <1.0 <1.0 NA <2.0 620 720 660 1,200 ...... 1,200 910 300 1.0 <1.0 <1.0 NA <2.0 1.0 1.0 <1.0 NA <2.0 1st Qtr 3/11/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/22/09 <1.0 1.0 1.0 <1.0 1.0 1.0 <i.b 1.0 :1.0 :1.0 <1.0 1.0 11.6 9.8 8.1 3.8 5.0 1 0.8 11.0 90 3.3 1.9 1.1 0.9 0.8 1.0 1.6 1.2 5.6 1st Qtr 3/3/10 2nd Qtr 6/14/10 3rd Qtr 8/12/10 4th Qtr 10/15/10 :1.0 :1.0 :1.0 :1.0 460 220 100 1100 <1.0 1.0 1.0 1.0 :1.0 :1.0 :1.0 :1.0 1st Qtr 2/23/11 2nd Qtr 6/14/11 3rd Qtr 8/17/11 4th Qtr 11/16/11 1.0 1.0 <1.0 <1.0 620 280 180 110 1.0 <1.0 <1.0 <1.0 :1.0 :i.O :1.0 :1.0 1st Qtr 1/19/12 2nd Qtr 6/14/11 3rd Qtr 9/12/12 4th Qtr 10/3/12 <1.0 1.0 1.0 1.0 76 79 130 140 1.0 <1.0 1.0 1.0 <1.0 <1.0 <1.0 <1.0 lstQtr 2/13/13 2nd Qtr 6/13/13 :1.0 :1.0 49.1 51.5 154 486 :1.0 :1.0 :1.0 :1.0 TW4-11 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <10 <100 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 <50 <S0 <50 4,400 3,590 4,400 4,400 NA NA <10 <100 NA NA <10 <100 4,400 4,300 4,080 3,660 <50 <50 <50 <50 <50 <SO 8.7 3 9.4 9.4 .._ 10.0 10.0 10.0 io."i 10.6 10.2 9.8 "Ti 7.3 7.9 9.5 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 3,600 3,800 4,500 4,400 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 4th Qtr 11/18/09 <1.0 <1.0 <1.0 NA <2.0 340 640 900 1,000 1,000 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 NA <2.0 1st Qtr 3/11/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/29/09 <1.0 <1.0 <1.0 <1.0 =1.0 :1.0 A C :1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/3/10 2nd Qtr 6/14/10 3rd Qtr 8/12/10 4th Qtr 10/15/10 <1.0 <1.0 <1.0 <1.0 820 820 800 720 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/23/11 2nd Qtr 6/1/11 3rd Qtr 8/17/11 4th Qtr 11/16/11 <1.0 <1.0 <1.0 <1.0 1,000 930 820 1500 =1.0 =1.6 =1.0 =1.0 :1.0 :i.O :1.0 =1.0 1st Qtr 1/24/12 2nd Qtr 6/13/12 3rd Qtr 9/13/12 4th Qtr 10/3/12 <1.0 <1.0 <1.0 <1.0 610 660 740 730 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 lstQtr 2/13/13 2nd Qtr6/18/13 |<1.0 3.23 47.3 49.3 867 788 =1.0 :1.0 A.O :1.0 (1) VOCs were resampled because laboratory missed holding I NA = not analyzed NS = not sampled Shaded indicates concentrations exceeding GWQS. Bold and red = highest concentration since montioring started. Bold and blue = lowest concentration since montioring started. Bold and italics indicates the MDL exceeded the GWQS. 1st Qtr = January - March 2nd Qtr = April - June 3rd Qtr = July - September 4th Qtr = October - December TABLE 1 Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2013 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride (S pg/L) Chloride (mg/L) No GWQS Parameter GWQS Chloroform (70 pg/L) Chloromethane (30 pg/L) Methylene Chloride (5 pg/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-12 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA NA <1.0 <1.0 .„.„..„... <1.0 <1.0 <1.0 .„„.„... <1.0 <1.0 <1.0 .„_ <1.0 <1.0 <1.0 .......... <1.0 <i.0 <1.0 ,„_.. <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 .„„„.„.„ <1.0 <1.0 <1.0 <1.0 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <i".o" <1.0 <1.0 <1.0 1.3 1.4 1.4 1.4 1.5 1.5 1.4 1.4 1.6 2.7 2.7 2.5 2.4 3.8 5.1 3.6 4^0 11.0 9.0 8.0 6.5' 7.0 6.8 8.0 ""7.7 10.0 13.0 13.0 .....„..„. 14.2 lstQtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/11/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/16/09 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <iTd" <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/23/10 2nd Qtr 6/14/10 3rd Qtr 8/10/10 4th Qtr 10/15/10 <1.0 <1 0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/15/11 2nd Qtr 5/25/11 3rd Qtr 8/16/11 4th Qtr 11/15/11 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 1/17/12 2nd Qtr 5/31/12 3rd Qtr 8/29/12 4th Qtr 10/3/12 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 lstQtr 2/13/13 2nd Qtr 5/29/13 <1.0 <1.0 36.7 38.6 <1.0 <1.0 <1.0 <1.0 TW4-13 lstQtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA NA <1.0 <1.0 ........... <1.0 <1.0 <1.0 .„„...„... <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 .„.„..„... <i.o ._. <1.0 <1.0 <1.0 <i"o" <1.0 <1.0 <1.0 .„„...„... <1.0 <1.0 <1.0 .„„...„... <1.0 lstQtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 :1.0 :1.0 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/16/09 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 .......... <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/24/10 2nd Qtr 6/14/10 3rd Qtr 8/10/10 4th Qtr 10/15/10 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/15/11 2nd Qtr 5/25/11 3rd Qtr 8/16/11 4th Qtr 11/15/11 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 1/17/12 2nd Qtr 5/31/12 3rd Qtr 8/29/12 4th Qtr 10/3/12 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/13/13 <1.0 2nd Qtr 5/29/13 <1.0 59.3 56 <1.0 <1.0 <1.0 <1.0 NA = not analyzed NS = not sampled Shaded indicates concentrations exceeding GWQS. Bold and italics indicates the MDL exceeded the GWQS. 1 st Qtr = January - March 2nd Qtr = April - June 3rd Qtr = July - September 4th Qtr = October - December TABLE 1 Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2013 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride (S P9/L) Chloride (mg/L) No GWQS Parameter GWQS Chloroform (70 pg/L) Chloromethane (30 pg/L) Methylene Chloride (5 pg/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-14 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 NS NS NS <1.0 NS NS NS <1.0 NS NS NS <1.0 lstQtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 <1.0 <1.0 <1.0 <1.0 :1.0 H.O H.O = 1.0 :1.0 :1.0 H.b =1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 0.4 1.6 1.38 0.76 i'i 1.4 1.5 1.4 2.5 2.9 2.8 2.9 18 1.4 2.6 1.7 i'.9 3.3 3.9 3.9 ""46 4.4 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/16/09 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 ........... <1.0 :1.0 = 1.0 <1.0 <1.0 :1.0 H.0 <1.0 <1.0 1st Qtr 3/3/10 2nd Qtr 6/14/10 3rd Qtr 8/10/10 4th Qtr 10/15/10 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 :1.0 :1.0 :10 H.O <1.0 <1.0 <1.0 <1.0 1st Qtr 2/15/11 2nd Qtr 6/14/11 3rd Qtr 8/16/11 4th Qtr 11/15/11 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <i.o <1.0 = 1.0 H-.O :1.0 H.O 1st Qtr 1/17/12 2nd Qtr 6/14/11 3rd Qtr 8/29/12 4th Qtr 10/3/12 = 1.0 =1.0 H.b =1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 lstQtr 2/7/13 2nd Qtr 5/29/13 <1.0 <1.0 35.2 38.6 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 TW4-16 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <1.0 <1.0 240 212 85 14 6.6 <0.1 <0.1 <0.1 1.4 3 1.9 2.7 5.6 .....„„„. 9.9 5.4 4.4 "<6."i 1.5 10.5 9.8 9.6 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 <1.0 <1.0 <1.0 <1.0 lstQtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 :1.0 :1.0 :1.0 H.O 39 13 5.2 13.6 =1.0 =1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/17/09 <1.0 <1.0 = 1.0 :1.0 <1.0 <1.0 .......... <1.0 :1.0 :1.0 <1.0 <1.0 :1.0 :1.0 :1.0 :1.0 1st Qtr 2/24/10 2nd Qtr 6/14/10 3rd Qtr 8/24/10 4th Qtr 10/15/10 <1.0 <1.0 <1.0 <1.0 :1.0 :1.0 :1.0 :1.0 :1.0 <1.0 <1.0 <1.0 <1.0 lstQtr 2/22/11 2nd Qtr 5/26/11 3rd Qtr 8/17/11 4th Qtr 11/16/11 <1) 12/7/11 <1.0 <1.0 <1.0 <1.0 :1.0 :i.O :1.0 <1.0 <1.0 <1.0 <1.0 <1.0 .......... <1.0 <1.0 <1.0 1st Qtr 1/18/12 2nd Qtr 5/26/11 3rd Qtr 8/30/12 4th Qtr 10/3/12 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 .......... 0.1 <0.1 <0.1 <0.1 ......... <0.1 1stQtr2/7/13 <1.0 2nd Qtr 5/30/13 <1.0 58.1 49.8 =1.0 =1.0 =1.0 :1.0 (1) VOCs were resampled because laboratory missed holding 1 NA = not analyzed NS = not sampled Bold and red = highest concentration since montioring started. Bold and blue = lowest concentration since montioring started. Shaded indicates concentrations exceeding GWQS. Bold and italics indicates the MDL exceeded the GWQS. 1st Qtr = January - March 2nd Qtr = April - June 3rd Qtr = July - September 4th Qtr = October - December TABLE 1 Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2013 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride (5 pg/L) Chloride (mg/L) No GWQS Parameter GWQS Chloroform (70 pg/L) Chloromethane (30 pg/L) Methylene Chloride (5 pg/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-18 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <1.0 <1.0 38 29.8 39 14 NA NA <1.0 <1.0 14.1 12.9 13.3 7.Z 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 <1.0 <1.0 <1.0 <1.0 12 12 10.8 12.5 8 8.9 7.4 <1.0 <1.0 :1.0 H.O AO A.O 5.9 4.7 6.1 5.7 5.'i 4.9 5.0 4.4 0.7 4.6 4.9 5.2 5.2 6.2 5.9 5.4 5."l 9.0 9.0 10.0 io.o 9.0 4.6 6.3 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/22/09 :1.0 = 1.0 :1.0 H.O <1.0 <1.0 .......... <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/24/10 2nd Qtr 6/14/10 3rd Qtr 8/12/10 4th Qtr 10/15/10 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/22/11 2nd Qtr 5/26/11 3rd Qtr 8/17/11 4th Qtr 11/16/11 (1) 12/7/11 <1.0 <1.0 <1.0 =1.0 :1.0 =1.0 <1.0 .......... <1.0 <1.0 <1.0 <1.0 <1.0 <1 0 A.O ......... A.O A.O A.O 1st Qtr 1/18/12 2nd Qtr 6/13/12 3rd Qtr 9/11/12 4th Qtr 10/3/12 :1.0 H.CI :1.0 Ho lstQtr 2/13/13 2nd Qtr 6/13/13 :1.0 H6 23.1 22.9 34.9 37.9 =1.0 :1.0 :1.0 = 1.0 TW4-19 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA NA <5.0 <50 2,200 1,200 1,400 2,800 NA NA <5.0 <50 NA NA <5.0 <50 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 <50 <50 <50 123 134 1,200 1,100 1,120 1,050 1,200 <50 <50 <S0 <50 <50 <50 <1.0 ........... :1.0 :1.0 lstQtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 Did not sample 129 132 1,100 1,100 :1.0 :1.0 :1.0 4.1 4 .......... 2.8 35.2 47.8 3.2 2.4 <0.1 26.7 2 4.4 5.9 2.7 .......... 12.0 3.0 5.0 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 <1.0 8.6 12 131 128 113 124 1,800 1,000 3,600 4,200 1,100 6,600 4,700 <1.0 <1.0 <1.0 <1.0 =1.0 A.O A.O AO 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/22/09 127 132 43 124 <1.0 <1.0 .......... <1.0 <1.0 <1.0 :1.0 :1.0 lstQtr 2/17/10 2nd Qtr 6/14/10 3rd Qtr 8/16/10 4th Qtr 10/15/10 144 132 142 146 940 1,800 2,000 1,200 <1.0 <1.0 <1.0 <1.0 =1.0 :1.0 A.O AO lstQtr 2/17/11 2nd Qtr 6/7/11 3rd Qtr 8/17/11 4th Qtr 11/17/11 <1) 12/5/11 135 148 148 148 3,400 4,000 970 2,200 '650 460 950 1500 <1.0 <1.0 <1.0 =1.0 =1.0 =1.0 <1.0 .......... <1.0 <1.0 <1.0 =1.0 ........ A.O A.O A.O 1st Qtr 1/23/12 2nd Qtr 6/6/12 3rd Qtr 9/4/12 4th Qtr 10/3/12 138 149 149 150 1st Qtr 2/13/13 5.15 2nd Qtr 6/5/13 5.15 164 148 4,210 2,070 <1.0 <1.0 =1.0 =1.0 (1) VOCs were resampled because laboratory missed holding I NA = not analyzed NS = not sampled Bold and fed = highest concentration since montioring started. Bold and blue = lowest concentration since montioring started. Shaded indicates concentrations exceeding GWQS. Bold and italics indicates the MDL exceeded the GWQS. 1st Qtr = January - March 2nd Qtr = April - June 3rd Qtr = July - September 4th Qtr = October - December TABLE 1 Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2013 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (5 pg/L) Chloride (mg/L) No GWQS Chloroform (70 pg/L) Chloromethane (30 pg/L) Methylene Chloride (5 pg/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-20 lstQtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA <10 <250 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 <500 <500 <1000 131 120 235 134 124 39,000 3,800 19,000 9,200 61,000 5,300 11,000 NA <10 <250 was not installed NA <10 <250 <500 <500 <1000 <500 <500 <1000 2.9 1.8 3.8 9.4 2.9 3.5 4.2 2.3 2.1 5.6 0.9 8.0 4.4 5.5 5 i 2.9 3.3 5.3 2.0 5.6 5.3 4.6 4.4 4.8 6.5 4.2 7.9 11.0 10.8 11.0 9."i 9.8 lstQtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 124 112 117 170 4,400 1,800 5,200 9,000 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 132 191 156 168 13,000 30,000 21,000 <1.0 <1.0 <1.0 NA 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/14/09 164 164 153 187 8,200 6,800 13,000 15,000 :1.0 d.O •1 0 =1.0 1st Qtr 2/17/10 2nd Qtr 6/14/10 3rd Qtr 8/16/10 4th Qtr 10/15/10 179 200 196 203 3,500 18,000 15,000 24,000 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/23/11 2nd Qtr 6/1/10 3rd Qtr 8/17/11 4th Qtr 11/16/11 220 177 207 186 31,000 8,100 3,800 7,900 :1.0 d.O d.O =1.0 19.0 2.1 3.1 2.5 1st Qtr 1/23/12 2nd Qtr 6/6/12 3rd Qtr 9/4/12 4th Qtr 10/3/12 207 262 289 302 11,000 36,000 13,000 19,000 <1.0 <1.0 <1.0 <1.0 =1.0 =1.0 =1.0 1st Qtr 2/11/13 2nd Qtr 6/5/13 19.6 32.5 252 250 18,500 26,300 d.O d.O 1.21 1.3 TW4-21 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA <5.0 1.0 353 192 78 86 NA <5.0 <1.0 I was not installed NA :5.0 d.O 14.6 10.1 9.6 8.5 10.2 8.7 8J1 8.6 8.6 8.3 .....„..„. 8.8 7.57 8.0 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 2.5 2.5 <2.5 347 318 357 296 120 120 108 139 1*60 300 140 120 "390 180 120 170 "i'80 200 200 160 "170 210 390 200 "230 290 460 390 '420 400 410 390 "'282 328 <2.5 <2.5 <2.5 <1.0 ........... <1.0 <1.0 <1.0 <1.0 <1.0 NA <2.0 <1.0 ........... <1.0 <T6" <1.0 <1.0 <1.0 <i6" <1.0 <1.0 <1.0 _.. <1.0 <1.0 <1.0 ........... <1.0 <2.5 <2.5 <2.5 <1.0 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 <1.0 <1.0 306 327 300 288 <1.0 <1.0 <1.0 <1.0 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 4th Qtr 11/18/09 331 271 244 284 <1.0 <1.0 <1.0 NA <2.0 lstQtr 3/11/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/22/09 d.O d.O d.O d.O 279 291 281 256 <1.0 <1.0 d.O d.O 8.3 8.1 9.2 8.4 '""§"4 12.0 14.0 7.0 "T.Q 12.0 14.0 13.0 1st Qtr 2/25/10 2nd Qtr 614/10 3rd Qtr 8/13/10 4th Qtr 10/15/10 d.o d.o 228 266 278 210 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/22/11 2nd Qtr 6/28/11 3rd Qtr 8/17/11 4th Qtr 11/16/11 m 12/7/11 303 290 287 287 <1.0 <1.0 <1.0 <1.0 1st Qtr 1/19/12 2nd Qtr 6/13/12 3rd Qtr 9/13/12 4th Qtr 10/4/12 228 285 142 270 d.O d.O d.O d.o 15.0 11.0 13.0 14.0 ......„.„. 13.8 lstQtr 2/13/13 2nd Qtr 6/18/13 5.25 3.49 221 243 <1.0 <1.0 (1) VOCs were resampled because laboratory missed holding I NA = not analyzed NS = not sampled Bold and red = highest concentration since montioring started. Bold and blue = lowest concentration since montioring started. Shaded indicates concentrations exceeding GWQS. Bold and italics indicates the MDL exceeded the GWQS. 1 st Qtr = January - March 2nd Qtr = April - June 3rd Qtr = July - September 4th Qtr = October - December TABLE 1 Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2013 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (5 pg/L) Chloride (mg/L) No GWQS Chloroform (70 pg/L) Chloromethane (30 pg/L) Methylene Chloride (5 pg/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-22 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 NA <5.0 <50 253 Monitor well was not installed NA 340 290 320 NA 5.0 <5.0 <5.0 <5.0 18.2 15.7 15.1 .......... 14.3 14.5 15.9 ......... 19.3 19.3 18.8 .......... 41.9 38.7 36.3 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 <10 <10 <10 <1.0 236 221 221 236 390 280 <10 <10 <10 <10 <10 <10 <1.0 ........ <1.0 <1.0 <1.0 „..„.„„. <1.0 <1.0 <2.0 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 :1.0 :1.0 H.O H 6 347 273 259 238 440 740 530 440 <1.0 1.0 1.0 1.0 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 4th Qtr 11/18/09 :1.0 Ho NA <2.0 519 271 524 539 1,400 1,200 6,300 630 1.0 1.0 1.0 NA <2.0 1st Qtr 3/11/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/29/09 <1.0 <1.0 <1.0 <1.0 177 177 391 175 390 730 2,300 380 1.0 1.0 <1.0 1.0 =1.0 =1.0 :1.0 = 1.0 20.7 20.6 40.3 17.8 ......... 19.0 15.0 16.0 ' 18.0 17.0 15.0 19.0 1st Qtr 3/3/10 2nd Qtr 6/14/10 3rd Qtr 8/24/10 4th Qtr 10/15/10 <1.0 <1.0 <1.0 <1.0 427 134 130 134 2,200 540 340 340 :1.0 :1.0 =1.0 :1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/22/11 2nd Qtr 6/1/11 3rd Qtr 8/17/11 4th Qtr 11/16/11 (1> 12/7/11 <1.0 <1.0 <1.0 114 138 120 174 1,300 210 450 400 :1.0 :1.0 d.O d.O ........ H d :10 :1.0 <1.0 <1.0 <1.0 <1.0 ......... <1.0 <1 0 <1.0 1st Qtr 1/19/12 2nd Qtr 6/13/12 3rd Qtr 9/12/12 4th Qtr 10/4/12 <1.0 <1.0 <1.0 <1.0 200 120 121 330 14.0 12.8 7.0 14.0 ......... 50.2 lstQtr 2/11/13 2nd Qtr 6/5/13 3.24 3.35 130 596 10,600 12,500 <1.0 <1.0 d.O d.O TW4-23 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 d.o d.O d.O <1.0 <1.0 <1.0 <0.1 <0.1 <0.1 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 4th Qtr 11/18/09 <1.0 <1.0 <1.0 NA <2.0 NA <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 NA <2.0 <0.1 <0.1 <0.05 <0.05 NA 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/16/09 <1.0 <1.0 <1.0 <1.0 d.O d.o d 0 d.O <1.0 <1.0 d.O d.O <1.0 <1.0 <1.0 <1.0 <0.1 <0.1 <0.1 <0.1 1st Qtr 2/24/10 2nd Qtr 6/14/10 3rd Qtr 8/24/10 4th Qtr 10/15/10 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <0.1 <0.1 <0.1 <0.1 1st Qtr 2/16/11 2nd Qtr 6/14/11 3rd Qtr 8/16/11 4th Qtr 11/15/11 <1.0 <1 0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 d.O d.O d.O d.O d.O d.O d.O d.O <0.1 <0.1 <0.1 <0.1 1st Qtr 1/17/12 2nd Qtr 5/31/12 3rd Qtr 8/29/12 4th Qtr 10/3/12 <1.0 <1.0 <1.0 <1.0 d.o d.o d.O d.o d.O d.O d.O d.O ......... d.O <1.0 <1.0 <1.0 <1.0 <0.1 <0.1 <0.1 <0.1 1st Qtr 2/7/13 <1.0 2nd Qtr 5/30/13 <1.0 43.6 <1.0 44.7 d.O d.O <0.1 6.1 (1) VOCs were resampled because laboratory missed holding time. NA = not analyzed NS = not sampled Bold and red = highest concentration since montioring started. Bold and blue = lowest concentration since montioring started. Shaded indicates concentrations exceeding GWQS. Bold and italics indicates the MDL exceeded the GWQS. 1st Qtr = January - March 2nd Qtr = April - June 3rd Qtr = July - September 4th Qtr = October - December TABLE 1 Historic Summary Of Monitoring Parameters Up To The 2nd Quarter 2013 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Carbon Tetrachloride (5 pg/L) Chloride (mg/L) No GWQS Parameter GWQS Chloroform (70 pg/L) Chloromethane (30 pg/L) Methylene Chloride (5 pg/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-24 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 <1.0 <1.0 <1.0 770 791 692 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 26.1 29 24.7 "24.4 45.3 38.4 44.8 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 4th Qtr 11/18/09 <1.0 <1.0 <1.0 NA <2 0 740 834 1180 1130 NA <2.0 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 NA <2.0 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/16/09 <1.0 <1.0 <1.0 <1.0 1010 759 618 1080 <1.0 <1.0 ........... <1.0 <1.0 <1.0 <1.0 <1.0 30.5 30.4 30.7 28.3 .......... 30 31 31 '31 35 34 1st Qtr 2/25/10 2nd Qtr 6/14/10 3rd Qtr 8/24/10 4th Qtr 10/15/10 <1.0 <1.0 <1.0 <1.0 639 587 522 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 lstQtr 2/17/11 2nd Qtr 5/26/11 3rd Qtr 8/17/11 4th Qtr 11/16/11 <1) 12/7/11 1.0 <1.0 <1.0 <1.0 1st Qtr 1/16/12 2nd Qtr 6/6/12 3rd Qtr 8/30/12 4th Qtr 10/3/12 <1.0 <1.0 <1.0 <1.0 1100 1110 967 608 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 373 355 489 405 <1.0 <1.0 <1.0 1 i" 17.4 <1.0 ........... <1.0 <1.0 <1.0 <1.0 .„„.„„. <1.0 <1.0 <1.0 1st Qtr 2/11/13 2nd Qtr 6/5/13 <1.0 <1.0 1260 916 <1.0 <1.0 <1.0 <1.0 TW4-25 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 <1.0 <1.0 <1.0 395 382 358 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 17.1 29 17 18.7 22.1 88 lstQtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 4th Qtr 11/18/09 <1.0 <1.0 <1.0 NA <2.0 374 344 333 366 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 NA <2.0 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/14/09 :1.0 :1.0 <1.0 <1.0 332 328 328 371 <1.0 <1 0 .......... <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 15.3 15.3 3.3 14.2 .......... 16 14 15 15 16 16 16 16 16 17 17 9 5 1st Qtr 2/23/10 2nd Qtr 6/14/10 3rd Qtr 8/10/10 4th Qtr 10/15/10 <1.0 <1.0 <1.0 <1.0 296 306 250 312 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 lstQtr 2/16/11 2nd Qtr 5/25/11 3rd Qtr 8/16/11 4th Qtr 11/15/11 <1.0 <1.0 <1.0 <1.0 315 321 276 294 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 1/16/12 2nd Qtr 5/31/12 3rd Qtr 9/4/12 4th Qtr 10/3/12 <1.0 <1.0 <1.0 <1.0 304 287 334 338 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/11/13 2nd Qtr 6/5/13 <1.0 <1.0 190 136 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 TW4-26 2nd Qtr 6/14/10 3rd Qtr 8/24/10 4th Qtr 10/15/10 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 lstQtr 2/16/11 2nd Qtr 5/26/11 3rd Qtr 8/17/11 4th Qtr 11/16/11 (1) 12/7/11 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 .......... <1.0 <1.0 <1.0 1st Qtr 1/18/12 2nd Qtr 6/6/12 3rd Qtr 9/11/12 4th Qtr 10/3/12 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/7/13 2nd Qtr 6/13/13 <1.0 <1.0 16.6 14.5 4.9 2.12 <1.0 <1.0 <1.0 <1.0 TW4-27 1st Qtr 1/18/12 2nd Qtr 6/13/12 3rd Qtr 9/4/12 4th Qtr 10/3/12 <1.0 <1.0 <1.0 <1.0 <1.0 <1 0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/7/13 2nd Qtr 6/13/13 <1.0 <1.0 18.8 <1.0 20.3 <1.0 <1.0 <1.0 <1.0 <1.0 TW4-28 2nd Qtr 6/19/13 |<1.0 TW4-29 2nd Qtr 6/19/13 2nd Qtr 7/11/13 <1.0 <1.0 44 8 242 37.7 262 <1.0 <1.0 <1.0 <1.0 TW4-30 2nd Qtr 6/19/13 36|<1.0 |<1.0 TW4-31 2nd Qtr 6/19/13 <1.0 28.4|<1.0 |<1.0 M.3 NA = not analyzed NS = not sampled Shaded indicates concentrations exceeding GWQS. Bold and italics indicates the MDL exceeded the GWQS. 1 st Qtr = January - March 2nd Qtr = April - June 3rd Qtr = July - September 4th Qtr = October - December Table 2 Summary of QA/QC Samples 2nd Quarter 2013 Parameter GWQS Dup TW4-16 icate of MW-16 TW4-65 RPD Dup TW4-26 icate of TW4-26 TW4-70 RPD Nitrate + Nitrite (as N) 10 mg/L <0.1 O.I nc 13.6 13.1 3.7 Chloride none 49.8 51.4 -3.2 14.5 15 -3.4 Chloroform 70 ug/L <1.0 <1.0 nc 2.12 2.28 -7.3 Carbon tetrachloride 5 pg/L <1.0 <1.0 nc <1.0 <1.0 nc Chloromethane 30 pg/L <1.0 <1.0 nc <1.0 <1.0 nc Methylene Chloride 5 pg/L 4.21 4.12 2.2 <1.0 <1.0 nc Parameter GWQS Dup TW4-29 icate of TW4-29 TW4-65 RPD Nitrate + Nitrite (as N) 10 mg/L 3.52 3.41 3.2 Chloride none 37.7 42.2 -11.3 Chloroform 70 pg/L 262 261 0.4 Carbon tetrachloride 5 pg/L <1.0 <1.0 nc Chloromethane 30 pg/L <1.0 <1.0 nc Methylene Chloride 5 pg/L <1.0 <1.0 NC nc = not calculated Tabel 3 Chloroform Mass Removal Calculations DUSA White Mesa Mill, Bland, Utah 2nd Quarter 2013 DRC Mass Removal Calculations Well ID MW4 MW-26 TW4-4 TW4-19 TW4-20 TW4-22 TW4-24 Ave. Chloroform (ug/L) Chloroform (g/L) Chloroform (Ibs/L) Chloroform (lbs/gal) Total gallons pumped 4th qtr 2012 lbs of chloroform removed Gallons of chloroform removed 1,490 T.49E-03 3.29E-06 1.25E-05 4,030 71,187 0.89 0.07 4.03E-03 8.90E-06 3.37E-05 25,343 0.85 0.07 1,330 1.33E-03 2.94E-06 1.11 E-05 65,603 0.73 0.06 2,070 2.07E-03 4.57E-06 T.73E-05 226,224 3.92 0.32 26,300 2.63E-02 5.81 E-05 2.20E-04 20,252 4.45 0.36 12,500 1.25E-02 2.76E-05 17 1.74E-05 —— 1.05E-04 25,523 2.67 0.22 1.46E-07 187,509 0.027285 0.002220 total lbs of chloroform removed 13.54 total gallons of chloroform removed 1.10