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Home My WebLink AboutDRC-2015-003145 - 0901a06880541ab5,0 « - State of Utah GARY R. HERBERT Governor SPENCER J. COX Lieutenant Governor Department of Environmental Quality Alan Matheson Acting Executive Director DIVISION OF RADIATION CONTROL Rusty Lundberg Director DRC-2015-003145 MEMORANDUM TO: FROM: DATE: SUBJECT: C r Phil Goble Dean Henderson June 29, 2015 Review of the 2nd, 3rd and 4th Quarter 2014 Chloroform Monitoring Reports 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 13, 2014, 2nd Quarter 2014 Chloroform Monitoring Report ("2nd Report"); November 11, 2014, 3rd Quarter 2014 Chloroform Monitoring Report ("3rd Report"); and the February 25, 2014, 4th Quarter 2014 Chloroform Monitoring Report ("4th Report") for the Chloroform Contamination Investigation. For the review of this report the following regulatory enforcement documents were used: • EFR issued Ground Water Quality Discharge Permit No. UGW370004 ("Permit") on March 8, 2005; last revised on June 8, 2013. • 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. Monitor wells TW4-35 and TW4-36 were sampled for the first time in 3rd quarter 2014 monitoring event (see Table 1 below): MW-4 MW-26 MW-32 TW4-1 TW4-2 TW4-3 TW4-7 TW4-8 TW4-9 TW4-10 TW4-11 TW4-12 TW4-18 TW4-19 TW4-20 TW4-21 TW4-22 TW4-23 TW4-27 TW4-28 TW4-29 TW4-30 TW4-31 TW4-32 195 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 TW4-4 TW4-5 TW4-6 TW4-13 TW4-14 TW4-16 TW4-24 TW4-25 TW4-26 TW4-33 TW4-34 TW4-35 TW4-36 In each quarter the 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, TW4-23, TW4-28 (in 2nd and 3rd quarters), and TW4-32. 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, TW4-28 (in 4th quarter) TW4-29, TW4-30, TW4-31, TW4-33, TW4-34, TW4-35 and TW36. 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 + Nitrite as Nitrogen. Use of analytical methods is consistent with the requirements of the QAP requirements. 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 QAQC 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 Page 3 and/or sample dilution. In all cases the reported value for the analyte was higher than the increased detection limit. Sample Duplicates In the 2nd quarter monitoring event two duplicate samples were collected. Monitor well TW4-12 and its duplicate sample TW4-65 and TW4-16 and its duplicate sample TW4-70. All analytical results for the two sample/duplicate pairs were within the 20% acceptance limits (as required in the QAP), with the exception of nitrate in TW4-12 (see Table 2 below). The reported nitrate concentration for TW4-12 and TW4-65 was 17 mg/l and 13.8 mg/l respectively resulting in a calculated RPD of 20.1 %. EFR noted this exceedance and responded: "The corrective actions that were taken in accordance with the QAP procedure are as follows' the QA Manager contacted the Analytical Laboratory and requested a review of the raw data to assure that there were no transcription errors and the data were accurately reported. The laboratory noted that the data were accurate and reported correctly. Reanalysis was not completed as the samples were beyond the holding time. " Based on EFR response in this circumstance it is recommended that there be no enforcement action but use the higher nitrate concentration result for TW4-12 (17 mg/l) for compliance purposes. In the 3rd quarter monitoring event three duplicate samples were collected. Monitor well TW4-28 and its duplicate sample TW4-65, monitor well TW4-8 and its duplicate sample TW4-70, and monitor well TW4-6 and its duplicate sample TW4-75. All analytical results for the three sample/duplicate pairs were within the 20% acceptance limits (as required in the QAP), with the exception of chloroform in TW4-28 and nitrate in TW4-8, (see Table 2 below). The reported chloroform concentration for TW4-28 and TW4-65 was <1.0 \xg/\ and 3.2 ug/l respectively (RPD > 20%). The reported nitrate concentration result for TW4-8 and TW4-70 was 0.6 mg/l and 1.9 mg/l respectively (RPD 104%). EFR noted these exceedances and responded: "...duplicate results outside of acceptance limits was implemented during the quarter for the results in duplicate pairs TW4-8/TW4-70 and TW4-6/TW4-75. The corrective action that were taken in accordance with the QAP procedure are as follows: the QA Manager contacted the Analytical Laboratory and requested a review of the raw data to assure that there were no transcription errors and the data were accurately reported. The laboratory noted that the data were accurate and reported correctly. Reanalysis was not completed as the samples were beyond the holding time. " Based on EFR response in these circumstances it is recommended that there be no enforcement action but use the higher chloroform concentration for TW4-28 (3.2 ug/l) and use the higher nitrate concentration for TW4-70 (1.9mg/l) for compliance purposes. In the 4th quarter monitoring event two duplicate samples were collected. Monitor well TW4-12 and its duplicate sample TW4-65 and monitor well TW4-5 and its duplicate sample TW4-70. All duplicate samples analytical results for the 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 ofthe Permit: Page 4 • The quarterly groundwater compliance monitoring wells. • Existing monitoring well MW-4 and all ofthe 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 and TWN-2. 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 in 2nd quarter 2014 is 9.9 lbs., 3rd quarter 2014 is 10.3 lbs. and 4th quarter 2014 14.7 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 ug/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 Page 5 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 up to the 4th quarter 2014 monitoring event appeared to show that the chloroform contaminate plume and associated contaminants, carbon tetrachloride, chloromethane, and methylene chloride is bound by up gradient, cross gradient, and down gradient wells that have a chloroform concentration of <70 ug/L (GWQS = 70 |ig/L) Monitor Wells Exceeding Chloroform Concentrations GWQS of 70ug/L Ten monitor wells: TW4-1, TW4-2, TW4-6, TW4-7, TW4-8, TW4-9, TW4-10, TW4-16, TW4- 21.TW4-29, and TW4-33. For the first time in several quarterly monitoring events wells TW4-6. TW4-9 and TW4-16 exceeded the chloroform GWQS. For TW4-6 chloroform concentrations in the 3rd and 4th quarter 2014 monitoring events increased to above the chloroform GWQS with results of 260 and 723 ug/L respectively for the first time since the 4th quarter 2010. There are wells down gradient of TW4-6 with concentrations below the chloroform GWQS. However, if chloroform concentrations continue to be above the GWQS TW4-6 may be a candidate for a pumping well in the future. For TW4-9 chloroform concentrations in the 2nd, 3rd and 4th 2014 quarterly events increased to 6.9, 47, and to above the GWQS of 101 ug/L respectively. Prior chloroform concentrations starting with the 1 st quarter 2005 monitoring event were mostly <1.0 ug/L. Since use of the northern wildlife ponds ceased in March 2012 the reduction in recharge and decay of the associated groundwater mound may have changed flow directions. This change in groundwater flow directions may be the cause for increase in chloroform concentrations. Because TW4-9 is located upper end of the chloroform plume no actions recommended at this time. For TW4-16 chloroform concentrations in the 3rd and 4th quarter 2014 monitoring events increased to above the chloroform GWQS with results of 371 and 387 ug/L respectively for the first time since the 3rd quarter 2005. As stated above for TW4-9, the decay of the associated groundwater mound below the northern wildlife ponds may have changed flow directions. This change in groundwater flow directions may be the cause for increase in chloroform concentrations. MW-31 and MW-32 are down gradient with chloroform concentrations at <1.0 ug/L. No actions are recommended at this time. Page 6 Monitor Wells with Chloroform Concentrations between 1 ug/L and 70pg/L Four monitor wells: TW4-5, TW4-18, TW4-26, and TW4-28 chloroform concentrations of <70ug/L. Pumping Wells Chloroform Concentrations Pumping wells MW-4, MW-26, TW4-4, TW4-19, TW4-20, and TW4-22 exceed chloroform concentrations of 70ug/L. Pumping well TW4-24 had a chloroform concentration of 25.8 ug/L and TW4-25 had non-detectable chloroform concentrations (<1.0 ug/L). Monitor Wells Below the Laboratory Chloroform Detection Limit (<1.0 ug/L) The following monitor wells are below the laboratory detection limit for chloroform (<1.0 ug/L): MW-32, TW4-3, TW4-12, TW4-13, TW4-14, TW4-23, TW4-27, TW4-30, TW4-31, TW4-32, TW4-34, TW4-35 and TW4-36. 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, TW4-26. TW4-27 continue to exceed the GWQS (10 mg/L) and have wells downgradient to with nitrate concentrations <10 mg/L. At this time, no further action, other than continued quarterly sampling, is recommend. 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 of the 2nd, 3rd and 4th Quarter 2014 Chloroform Monitoring Reports for the chloroform contamination investigation. Table 2 Summary of QA/QC Samples 2nd Quarter 2014 Parameter GWQS Duplicate of TW4-12 TW4-12 TW4-65 RPD Duplicate of TW4-16 TW4-16 TW4-70 RPD Nitrate + Nitrite (as N) Chloride Chloroform Carbon tetrachloride Chloromethane Methylene Chloride 10 mg/L none 70 ug/L 5 ug/L 30 ug/L 5ug/L 17 40.2 13.9 40.8 20.1 •1.5 4.94 80.7 4.59 67.2 <1.0 <1.0 <1.0 <1.0 <l.0 <1.0 <1.0 <1.0 nc nc nc nc <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 7.3 18.3 nc nc nc nc nc = not calculated Summary of QA/QC Samples 3rd Quarter 2014 Parameter GWQS Duplicate of TW4-28 TW4-28 TW4-65 RPD Duplicate of TW4-8 TW4-8 TW4-70 RPD Duplicate of TW4-8 TW4-6 TW4-75 RPD Nitrate + Nitrite (as N)^ Chloride Chloroform Carbon tetrachloride Chloromethane Methylene Chloride 10 mg/L none 70ug/L 5 ug/L 30 ug/L 5jjg/L 14.2 50 <1.0 <1.0 <1.0 <1.0 14.5 51 3.2 -2.1 -2.0 -104.8 0.6 47 107 1.9 47 104 <1.0 <1.0 <l.0 nc nc nc <I.O <1.0 <1.0 <1.0 <1.0 <1.0 -104.0 0.0 2.8 nc nc nc na na <1.0 <1.0 <l.0 260 na na <1.0 <1.0 <1.0 nc nc 340 -26.7 nc nc nc nc na not calculated ; not analyzed Summary of QA/QC Samples 4th Quarter 2014 Parameter Nitrate + Nitrite (as N) Chloride Chloroform Carbon tetrachloride Chloromethane Methylene Chloride GWQS 10 mg/L none 70ug/L_ 5 ug/L 30 ug/L^ 5 ug/L Duplicate of TW4-12 TW4-12 ^6.1 50.2 <1.0 <1.0 <1.0 <!.() TW4-65 15.2 49.7 <1.0 <1.0 <1.6 <1.0 RPD 5.8 1.0 nc nc nc nc Duplicate of TW4-5 TW4-5 8.31 45.1 <1.0 <l.0 <1.0 <1.0 TW4-70 8.64 44.5 <1.0 <L0 <1.0 <1.0 RPD -3.9 1.3 nc nc nc nc nc = not calculated Tabel 3 Chloroform Mass Removal Calculations DUSA White Mesa Mill, Bland, Utah 2nd Quarter 2014 Well ID MW-4 MW-26 TW4-4 TW4-19 TW4-20 TW4-22 TW4-24 TW4-25 Ave Chloroform (ug/L) Chloroform (g/L) Chloroform (Ibs/L) Chloroform (lbs/gal) Total gallons pumped 1st qtr 2014 lbs of chloroform removed Gallons of chloroform removed 1,390 1 39E-03 3 07E-06 1 16E-05 71,935 0.8 0 07 1,960 1 96E-03 4 33E-06 1 64E-05 23,758 0.4 0 03 1,220 1 22E-03 2 70E-06 1.02E-05 60,235 0.6 0 05 810 8 10E-04 1 79E-06 6 77E-06 297,660 2.0 0 16 22,100 2 21E-02 4.88E-05 1.85E-04 18,462 3.4 0 28 12,400 1 24E-02 2 74E-05 1.04E-04 24,194 2.5 0 20 62.7 6 27E-05 1 39E-07 5 24E-07 216,984 0.1 0 009 0 0 00E+00 0 00E+00 0.00E+00 124,830 0.0 0 00 total lbs of chloroform removed 9.9 total gallons of chloroform removed 0 80 3rd Quarter 2014 Well ID MW-4 MW-26 TW4-4 TW4-19 TW4-20 TW4-22 TW4-24 TW4-25 Ave Chloroform (ug/L) Chloroform (g/L) Chloroform (Ibs/L) Chloroform (lbs/gal) Total gallons pumped 1st qtr 2014 lbs of chloroform removed Gallons of chloroform removed 1,490 1.49E-03 3 29E-06 1 25E-05 74,788 0.9 0 08 2,120 2 12E-03 4.68E-06 1.77E-05 24,062 0.4 0 03 1,320 1 32E-03 2 92E-06 1.10E-05 69,229 0.8 0 06 1410 1.41E-03 3 12E-06 1 18E-05 309,742 3.7 0 30 12,400 1 24E-02 2.74E-05 1 04E-04 17,238 1.8 0.15 12,400 1 24E-02 2 74E-05 1 04E-04 24,611 2.6 0 21 76 3 7 63E-05 1 69E-07 6.38E-07 213,653 0.1 0 011 0 00E+00 O.OOE+00 0 00E+00 119,664 0.0 0 00 total lbs of chloroform removed 10.3 total gallons of chloroform removed 0 83 4th Quarter 2014 Well ID MW-4 MW-26 TW4^l TW4-19 TW4-20 TW4-22 TW4-24 TW4-25 Ave Chloroform (ug/L) Chloroform (g/L) Chloroform (Ibs/L) Chloroform (lbs/gal) Total gallons pumped 1st qtr 2014 lbs of chloroform removed Gallons of chloroform removed 1,390 1 39E-03 3 07E-06 1 16E-05 71,935 0.8 0 07 1,960 1 96E-03 4.33E-06 1 64E-05 23,758 0.4 0 03 1,220 1 22E-03 2 70E-06 1 02E-05 60,235 0.6 0 05 4,310 4 31E-03 9 52E-06 3 60E-05 198,331 7.1 0 58 23,300 2 33E-02 5.15E-05 1 95E-04 16,342 3.2 0 26 12,400 1.24E-02 2.74E-05 1 04E-04 24,194 2.5 0 20 25 8 2 58E-05 5 70E-08 2.16E-07 178,469 0.04 0 003 0.00E+00 0 00E+00 0 OOE+00 124,830 0.0 0 00 total lbs of chloroform removed 14.7 total gallons of chloroform removed 1 20 TABLE 1 (1 of 27) Historic Summary Of Monitoring Parameters Up To The 4th Quarter 2014 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (5 M9/L) Chloride No GWQS (mg/L) Chloroform (70 Mfl/L) Chloromethane (30 ug/L) Methylene Chloride (5 M9/L) Nitrate, Nitrate + Nitrite (10 mg/L) MW-4 (chlorc pumping well) 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 1st Qtr 2/28/67 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/68 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/14/09 1st Qtr 2/17/10 2nd Qtr 6/14/10 3rd Qtr 8/6/10 4th Qtr 10/15/10 1st Qtr 2/23/11 2nd Qtr 6/1/11 3rd Qtr 8/17/11 4th Qtr 11/16/11 NA NA <10 <50 <50 <50 <50 NA NA NA 53 2,900 3,170 3,500 3,000 2.1 49 49 48 50 3,100 3,000 2,820 2,830 NA NA <10 <50 <50 <50 <50 NA NA <10 <50 1.4 1.6 1.8 1.9 1.7 47 45 47 45 1.7 1.8 1.8 1.7 42 42 35 45 2,300 2,000 2,600 2,300 2.400 2,500 1,800 2,100 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1.5 1.3 1.4 1.6 1.2 1.2 1.5 1.4 37 34 43 44 2,200 1,800 2,000 1,800 1.5 1.4 1.1 1.3 45 41 38 41 40 35 41 40 1,600 2,100 1,900 1,500 <1.0 <1.0 <1.0 <1.0 <T.o" <1.0 <1.0 <1.0 1,700 1,700 1,700 1,600 <1.0 <1.0 <1.0 <1.0 <50 <50 <50 <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 <i.6 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 6.3 7.1 7.0 7.0 6.6 6.0 1.2 6.4 6.3 7.0 6.2 6.2 5.8 6.1 6.4 5.9 5.7 5.2 5.3 5.8 4.0 5.1 4.8 4.9 46 4.9 4.9 5.1 4.8 4.9 5.0 4.8 4.8 4.2 4.9 5.3 4.7 4.1 3.7 5.1 1st Qtr 1/23/12 2nd Qtr 6/6/12 3rd Qtr 9/4/12 4th Qtr 10/4/12 1 1.2 1.5 1 41 39 41 41 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 3rd Qtr 9/3/13 4th Qtr 10/29/13 1st Qtr 1/27/14 2nd Qtr 5/19/14 3rd Qtr 8/11 /14 4th Qtr 10/21/14 <1.0 1.48 1.31 1.13 5.58 37.8 44 41.4 40.1 1,670 1,490 1,520 1,410 <1.0 <1.0 <1.0 <1.0 4.15 5.21 7.6 38.5 39.9 41 41.5 1,390 1,390 1,490 1,440 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <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 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/05 4th Qtr 11/8/05 Tst'Qtr 2/28707 NA NA <10 <so <50 <S0 <50 NA NA NA 55 3,700 3,740 3,800 3,000 NA NA <10 <50 2.4 53 54 54 54 60 3,700 3,300 3,190 3,370 <50 <50 <50 <1.0 NA NA <10 <50 <50 <50 <50 <1.0 <T6 7.1 7.8 6.9 6.7 5.8 7.3 1.2 7.1 7.1 1.9 2,500 <1.0 Well abandonded NA = not analyzed Shaded indicates concentrations exceeding GWQS. Bold and italics indicates the MDL exceeded the GWQS. TABLE 1 (2 of 27) Historic Summary Of Monitoring Parameters Up To The 4th Quarter 2014 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (5 ug/L) No Chloride GWQS (mg/L) Chloroform (70 ug/L) Chloromethane (30 ug/L) Methylene Chloride (5 HB"-) Nitrate, Nitrate + Nitrite (10 mg/L) MW-26 (former TW4-15) Chloroform pumping well 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 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 11/18/08 1st Qtr 3/4/69 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/14/09 1st Qtr 2/17/10 2nd Qtr 6/14/10 3rd Qtr 8/16/10 4th Qtr 10/15/10 1st Qtr 2/23/11 2nd Qtr 5/31/11 3rd Qtr 8/17/11 4th Qtr 11/16/11 (1)12/5/11 1st Qtr 2/7/12 2nd Qtr 6/6/12 3rd Qtr 9/4/12 4th Qtr 10/4/12 1st Qtr 2/11/13 2nd Qtr 6/5/13 3rd Qtr 9/3/13 4th Qtr 10/29/13 1st Qtr 1/27/14 2nd Qtr 5/19/14 3rd Qtr 8/11 /14 4th Qtr 10/21/14 NA NA <5.0 <50 <50 <50 <50 <1.0 <1.0 <1.0 <1.0 <1.0 <T6 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 <1.0 <T6 <1.0 <1.0 <1.0 <1.0 <1.0 NA <1.0 <To <1.0 <1 <1 <1 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA NA NA NA 12 55 310 442 960 1,000 52 52 65 54 56 49 57 57 1,100 830 2,170 282 570 300 1,400 2,000 NA NA 5.4 <50 <50 <50 <50 <1.0 <T6 <1.0 <1.0 <1.0 49 57 44 64 NA 49 48 46 60 57 40 49 65 930 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 <1.0 730 1,600 2,200 970 <1.0 <1.0 <1.0 <1.0 57 88 58 69 NA 98 73 73 68 450 1,800 720 NA 1,800 81.9 77.9 60.5 72.3 2,400 3,000 3,100 1,200 2,120 4,030 2,940 1,410 <1.0 <1.0 <1.0 NA <1.0 <1.6 <1.0 <1 <1 <1 <1.0 <1.0 <1 59.4 53.4 59 60.1 1,400 1,960 2,120 2,090 <1.0 <1.0 8.7 <1.0 NA NA <5.0 <50 <50 <50 <50 NA <1.0 2.6 5.5 13 36 14 40 53 24 100 NA 51 12 30 40 19 21 6.5 3.6 1.3 7.2 NA 2.9 16 21 31 4 9.34 52.4 33.2 4.03 13.8 15.4 26 23.2 0.3 0.2 0.2 0.3 6.2 0.2 1.4 0.3 6.6 0.4 1 0.6 6.1 0.6 0.2 0.1 0.4 0.2 0.1 2.3 6.2 6.8 0.6 0.7 6.5 0.4 0.9 2.0 NA 1.7 2.5 2.6 1.8 2.3 2.1 1.2 1.4 6.5 0.9 0.7 0.9 (1) VOCs were resampled because laboratory missed holding t NA = not analyzed Shaded indicates concentrations exceeding GWQS. Bold and italics indicates the MDL exceeded the GWQS. TABLE 1 (3 of 27) Historic Summary Of Monitoring Parameters Up To The 4th Quarter 2014 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (5 ug/L) No Chloride GWQS (mg/L) Chloroform (7Q ug/n Chloromethane (30 ug/L) Methylene Chloride (5 ug/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 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/16/09 1st Qtr 2/17/10 2nd Qtr 6/14/10 3rd Qtr 8/16/10 4th Qtr 10/15/10 1st Qtr 2/23/11 2nd Qtr 5/25/11 3rd Qtr 8/16/11 4th Qtr 11/16/11 <1) 12/7/11 1st Qtr 1/18/12 2nd Qtr 6/22/12 3rd Qtr 9/5/12 4th Qtr 10/10/12 1st Qtr 2/11/13 2nd Qtr 6/18/13 3rd Qtr 9/3/13 4th Qtr 10/29/13 1st Qtr 1/29/14 2nd Qtr 5/23/14 3rd Qtr 8/26 /14 4th Qtr 10/29/14 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 <1 0 <1 0 <1 0 <1 0 <1 0 <1 0 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 NA NA NA NA 33 32 30 32 31 32 32 31 32 31 29 30 26 30 31 33 35 38 32 28 24 40 31 33 32 21 32 33 35 34 3 34 9 33 35 7 34 39 7 34 349 <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 <1 0 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 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 <1 0 <1 0 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 32 35 1 8 1 5 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 <1 0 <1 0 <1 0 <1 0 <1 0 <1 0 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 <0 1 <0 1 <0 1 <0 1 <0 1 <0 1 <1 0 < 1 <1 0 <1 0 <1 0 <1 0 < 1 <1 0 <1 0 <0 05 < 1 <0 1 <0 1 <0 1 <0 1 <0 1 <0 1 <0 1 <0 1 <0 1 <0 1 <0 1 NA <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) VOCs were resampled because laboratory missed holding t NA = not analyzed Shaded indicates concentrations exceeding GWQS TABLE 1 (4 of 27) Historic Summary Of Monitoring Parameters Up To The 4th Quarter 2014 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (5 M9/L) Chloride No GWQS (mg/L) Chloroform (70 ug/L) Chloromethane (30 Mg/L) Methylene Chloride (5 Mg/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-1 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 TstQtr2728767 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 1st Qtr 3/11/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/29/09 1st Qtr 3/3/10 2nd Qtr 6/14/10 3rd Qtr 8/18/10 4th Qtr 10/15/10 NA NA <10 <50 <50 <50 <50 <1.0 <1.0 <i76' <1.0 NA NA NA 1.4 ......... 1.4 1.3 1.3 1.3 1.1 1.3 1.3 1.1 1 1.2 1 52 2,700 3,080 2,900 2,400 49 48 51 47 2,700 2,200 2,840 2,260 47 45 43 43 39 39 35 41 1,900 1,900 2,300 2,000 2,000 1,900 1,700 1,700 NA NA <10 <50 <50 <50 <50 <1.0 <7.o <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 37 37 36 41 1,700 1,500 1,700 1,400 35 40 35 40 1,300 1,600 1,600 1,500 <1.0 <1.0 <1.0 <1.0 <1 6 <1.0 <1.0 <1.0 NA NA <10 <50 <50 <50 <50 <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 9.1 10.6 9.8 9.7 9.4 9.6 9.2 8.9 9 8.4 7.8 7.6 8.68 8.15 9.3 7.5 6.9 7.3 6.8 7.1 6.8 6.7 6.6 1st Qtr 2/24/11 2nd Qtr 6/1/11 3rd Qtr 8/18/11 4th Qtr 11/29/11 1st Qtr 1/24/12 2nd Qtr 6/14/12 3rd Qtr 9/28/12 4th Qtr 10/4/12 1st Qtr 2/13/13 2nd Qtr 6/19/13 3rd Qtr 9/3/13 4th Qtr 11/14/13 1st Qtr 2/5/14 2nd Qtr 5/23/14 3rd Qtr 8/27/14 4th Qtr 10/29/14 <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 3.66 5.47 4.77 41 35 36 40 1,300 1,200 1,300 1,500 38 42 39 40 1,300 1,000 1,000 1,100 37.6 39.1 37.6 36.5 38.9 37.4 38 38.7 1,320 1,100 1,150 1,280 1,090 1,020 845 1,140 <1.0 <1.0 <1.0 <1.0 <T.o <1.0 <1.0 <1.0 <i.6 <1.0 <1.0 <1.0 <T.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 <1.0 1.4 <1.0 <1.0 <1.0 <1.0 6.6 6.6 6.8 6.6 6.8 7.1 5.0 6.5 7.6 6.9 7.1 7.1 7.7 6.9 4.8 6.3 NA = not analyzed Shaded indicates concentrations exceeding GWQS. Bold and italics indicates the MDL exceeded the GWQS. TABLE 1 (5 of 27) Historic Summary Of Monitoring Parameters Up To The 4th Quarter 2014 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (5 ug/L) Chloride No GWQS (mg/L) Chloroform (70 H9/L) Chloromethane (30 ug/L) Methylene Chloride (5 ug/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 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 11/18/08 1st Qtr 3/11/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/29/09 1st Qtr 3/3/10 2nd Qtr 6/14/10 3rd Qtr 8/18/10 4th Qtr 10/15/10 1st Qtr 2/24/11 2nd Qtr 6/2/11 3rd Qtr 8/17/11 4th Qtr 11/29/11 NA NA <10 <50 <50 <50 <50 NA NA NA NA 2.3 1.8 2.5 2.2 2.1 2.3 2.2 2.4 2.4 NA 2.2 2 2 2 2 2.6 2.5 2.1 2.4 2.2 1.6 2.8 56 56 56 54 55 3,700 3,750 3,900 3,500 3.800 3,200 4,120 3,420 NA NA <10 <50 <50 <50 <50 <1.0 54 50 49 51 48 46 42 47 2,300 3,000 340 (?) 3,200 NA 3,300 3,100 2,800 3,200 <1.0 <1.0 <1.0 <1.0 <T6 <1.0 <1.0 NA <2.0 46 44 43 46 3,100 2,800 3,000 1,600 <1.0 <1.0 <1.0 <1.0 42 43 43 41 2,600 3,300 3,300 3,000 46 42 48 49 3,100 3,000 2,400 3,900 <1.0 <1.0 <1.0 <1.0 <T6 <1.0 <1.0 <1.0 NA NA <10 <50 <50 <50 <50 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA 7.7 8.6 8.0 7.8 7.5 7.1 7.4 7.6 7.3 7.8 7.3 6.9 6.9 7.4 7.1 8.0 6.5 6.4 6.6 6.4 6.8 8.7 6.6 6.5 7.6 6.8 6.0 7.0 7_.1 7.7 4.0 7.6 ........ 7.5 9.3 8.4 7.9 9.1 6.2 8.5 1st Qtr 1/24/12 2nd Qtr 6/14/12 3rd Qtr 9/28/12 4th Qtr 10/4/12 1st Qtr 2/13/13 2nd Qtr 6/19/13 3rd Qtr 9/3/13 4th Qtr 11/14/13 1st Qtr 2/6/14 2nd Qtr 5/23/14 3rd Qtr 8/27/14 4th Qtr 10/30/14 2 2.1 1.8 2 5.17 2.65 2.41 3.15 7.1 6.05 1.4 2.6 49 52 76 49 46 46.9 44.9 43.9 2,500 2,500 2,900 3,100 3.586 3,110 3,480 3,740 <1.0 <1.0 <1.0 <1.0 45.9 45.4 45 45.5 3,180 2,930 3,170 3,580 <1.0 2 <1.0 <1.0 <7.o" <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 3.6 <1.0 <1.0 <1.0 <1.0 NA = not analyzed Shaded indicates concentrations exceeding GWQS. Bold and italics indicates the MDL exceeded the GWQS. TABLE 1 (6 of 27) Historic Summary Of Monitoring Parameters Up To The 4th Quarter 2014 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (5 Mfl/L) Chloride No GWQS (mg/L) Chloroform (70 ug/L) Chloromethane (30 ug/L) Methylene Chloride (5 ug/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-3 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 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/29/09 1st Qtr 2/23/10 2nd Qtr 6/14/10 3rd Qtr 8/10/10 4th Qtr 10/15/10 1st Qtr 2/15/11 2nd Qtr 5/25/11 3rd Qtr 8/16/11 4th Qtr 11/14/11 1st Qtr 1/17/12 2nd Qtr 5/31/12 3rd Qtr 8/29/12 4th Qtr 10/3/12 1st Qtr 2/7/13 2nd Qtr 6/29/13 3rd Qtr 9/3/13 4th Qtr 11/6/13 1st Qtr 1/22/14 2nd Qtr 5/21/14 3rd Qtr 8/13/14 4th Qtr 10/23/14 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 <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 NA NA NA 26 26 26 26 23 22 23 24 27 21 19 19 22 21 20 21 22 23 24 22 26 23 23 23 23 21 24 25 25 23 7 23 8 25 24 1 24 9 24 4 26 26 7 <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 <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 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 <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 64 2 3 1 6 22 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 <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 35 37 35 33 33 71 29 1 5 3 1 33 3 1 28 2" 8 29 27 26 25 29 28 26 28 30 3 1 33 35 37 40 44 7 1 44 49 48 5 1 58 49 59 67 60 53 6 1 NA = not analyzed Shaded indicates concentrations exceeding GWQS TABLE 1 (7 of 27) Historic Summary Of Monitoring Parameters Up To The 4th Quarter 2014 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (5 ug/L) Chloride No GWQS (mg/L) Chloroform (70 ug/L) Chloromethane (30 pg/L) Methylene Chloride (5 ug/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-4 (chlorc pumping well) 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 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 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 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/29/09 1st Qtr 2/17/10 2nd Qtr 6/14/10 3rd Qtr 8/10/10 4th Qtr 10/15/10 istQtr2723/il 2nd Qtr 6/1/11 3rd Qtr 8/17/11 4th Qtr 11/16/11 1st Qtr 1/23/12 2nd Qtr 6/6/12 3rd Qtr 9/4/12 4th Qtr 10/3/12 1st Qtr 2/11/13 2nd Qtr 6/29/13 3rd Qtr 9/3/13 4th Qtr 10/3/13 1st Qtr 1/27/14 2nd Qtr 5/19/14 3rd Qtr 8/11/14 4th Qtr 10/21/14 NA NA <10 <50 <50 <50 <50 NA <2.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA NA NA 1.7 1.5 1.7 1.5 1.5 1.6 1.5 1.4 NA 1.2 1.2 1.1 1.1 1 1.2 1.3 1.3 1.4 1.2 1.2 1 1.2 5.3 3.88 4.94 4.94 54 3,100 2,400 3,200 2,800 51 48 50 49 2,900 2,600 2,850 2,670 NA NA <10 <50 <50 <50 <50 <1.0 49 47 45 47 43 42 39 44 NA 37 34 39 41 2,200 2,400 2,700 2,500 2.800 2,500 2,200 2,500 2,200 1,800 2,000 950 <1.0 <1.0 <1.0 <1.0 48 35 36 38 1,700 1,700 2,100 1,700 41 35 40 39 1,800 1,700 1,500 1,500 38 43 39 38 1,200 1,500 1,600 1,400 <1.0 <1.0 <1.0 NA <2.0 <T.6 <1.0 <1.0 <1.0 <76 <1.0 <1.0 <1.0 <7.6 <1.0 <1.0 <1.0 <Tx> <1.0 <1.0 <1.0 39 39.6 38.8 43.9 1,460 1,330 1,380 1,360 37.4 47.5 40 40 1,260 1,220 1,320 1,130 <1.0 <1.0 <1.0 <1.0 <i'.o" <1.0 <1.0 NA NA <10 <50 <50 <50 <50 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <2.0 <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 7.1 <1.0 <1.0 <1.0 <1.0 NA 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 10.8 8.8 10.1 10.2 8.2 8.4 7.6 6.6 7.6 7.3 7.1 7.0 7.0 6.6 7.0 7.1 7.1 7.1 7.0 7.4 6.3 7.2 7.8 7.3 5.9 5.3 7.0 NA = not analyzed Shaded indicates concentrations exceeding GWQS Bold and italics indicates the MDL exceeded the GWQS. TABLE 1 (8 of 27) Historic Summary Of Monitoring Parameters Up To The 4th Quarter 2014 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (5 Mfl/L) No Chloride GWQS (mg/L) Chloroform (70 ug/L) Chloromethane (30 Mfl/L) Methylene Chloride (5 Mfl/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-5 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 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/29/09 1st Qtr 2/25/10 2nd Qtr 6/14/10 3rd Qtr 8/11/10 4th Qtr 10/15/10 NA NA <2.5 <2.5 <2.5 <2.5 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.6 <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 NA <1.0 1st Qtr 1/18/12 2nd Qtr 6/6/12 3rd Qtr 9/11/12 4th Qtr 10/3/12 1st Qtr 2/13/13 2nd Qtr 6/13/13 3rd Qtr 9/5/13 4th Qtr 11/13/13 1st Qtr 1/30/14 2nd Qtr 5/22/14 3rd Qtr 8/14/14 4th Qtr 11/13/13 <1.0 <1.0 <1.0 <1.0 <1.6 <1.0 <1.0 <1.0 <i.o <1.0 <1.0 <1.0 NA NA NA NA 56 120 113 82 63 NA NA 52 51 54 55 66 51 53.7 47.1 <1.0 <1.0 57 45 38 39 35 26 9.2 9.4 36 37 34 37 34 37 48 41 11 9.3 11 10 <1.0 <1.0 <1.0 <1.0 <1.6 <1.0 <1.0 <1.0 12 13 12 8.5 <1.0 <1.0 <1.0 <1.0 43 28 38 41 <1.0 <1.0 <1.0 <1.0 34 35 37 30 NA 10 9 10 7.9 <1.0 <1.0 <1.0 NA <1.0 22 39 37 38 7.6 8.4 12 34.3 36.5 39.1 41.1 10.8 11.2 11.6 14.4 <1.0 <1.0 <1.0 <1.0 <T.6 <1.0 <1.0 <1.0 40.5 51.4 44 45.1 12.5 13.4 12.0 14.6 <1.0 <1.0 <1.0 <1.0 5.8 2.5 NA NA <2.5 <2.5 3.1 3.1 <2.5 <2.5 <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 NA <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1 6 <1.0 <1.0 <1.0 NA 4.9 3.7 6.0 6.0 6.0 5.9 6.7 2.9 7.8 7.0 7.7 8.2 74 8.7 7.9 9.3 ........ 7.5 8.3 7.5 6.8 7.1 7.0 7.2 ........ 7.2 7.5 6.0 5.8 8.0 8.1 7.7 8.2 10.7 7.8 7.8 9.2 7.8 7.2 8.3 (1) VOCs were resampled because laboratory missed holding NA = not analyzed Shaded indicates concentrations exceeding GWQS. time. TABLE 1 (9 of 27) Historic Summary Of Monitoring Parameters Up To The 4th Quarter 2014 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (5 Mfl/L) No Chloride GWQS (mg/L) Chloroform (70 Mg/L) Chloromethane (30 ug/L) Methylene Chloride (5 Mfl/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 1st Qtr 3/9/66 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 1st Qtr 3/11/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/29/09 1st Qtr 2/25/10 2nd Qtr 6/14/10 3rd Qtr 8/11/10 4th Qtr 10/15/10 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 <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 NA <1.0 <1.0 NA NA NA NA <1.0 32 31 30 37 65 2.5 10 17 31 19 11 42.8 NA NA 2.8 1.3 NA NA <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 32 38 36 35 33 35 35 33 35 37 37 41 46 11 18 18 <1.0 <1.0 <1.0 <1.0 52 24 39 37 <1.0 <1.0 <1.0 <1.0 81 120 280 250 45 33 31 41 1000 590 630 420 40 42 39 36 33 NA 47 9.6 16 21 50 <1.0 <1.0 <1.0 <1.0 <7.6 <1.0 <1.0 <1.0 <T6 <1.0 <1.0 NA <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <i"6 <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 NA <1.0 <1.0 0.2 0.4 0.8 0.9 1.2 1.0 0.6 1.4 1.8 0.6 0.7 0.8 1.1 0.9 1.1 1.0 2.2 2.7 5.0 6.1 1.8 2.5 3.9 4.3 0.7 0.3 0.3 0.8 NA 0.8 6.7 0.2 0.1 0.2 6.2 0.2 0.2 1.5 6.2 0.3 4.2 6.9 1st Qtr 1/18/12 2nd Qtr 6/13/12 3rd Qtr 9/11/12 4th Qtr 10/3/12 1st Qtr 2/13/13 2nd Qtr 6/13/13 3rd Qtr 9/5/13 4th Qtr 11/13/13 <1.0 <1.0 <1.0 <1.0 <T6 <1.0 <1.0 <1.0 1st Qtr 1/29/14 2nd Qtr 5/22/14 3rd Qtr 8/14/14 <3)3rd Qtr 9/24/14 4th Qtr 10/29/14 <1.0 <1.0 <1.0 <1.0 <1.0 38 40 41 404 37.9 40.6 40.2 ........... 37 40 NA 41.1 38 4.7 6.9 9 <1.0 <1.0 <1.0 <1.0 6.89 4.86 5.93 5.51 5.7 5.7 202 260 723 <1.0 <1.0 <1.0 <1.0 <7.6 <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 NA (1) VOCs were resampled because laboratory missed holding (2) Results of the TW4-70 the duplicate sample for TW4-6. (3) Reanalyzed for VOCs only. NA = not analyzed Shaded indicates concentrations exceeding GWQS. time. TABLE 1 (10 of 27) Historic Summary Of Monitoring Parameters Up To The 3rd Quarter 2014 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (5 ug/L) Chloride No GWQS (mg/L) Chloroform (70 ug/L) Chloromethane (30 ug/L) Methylene Chloride (5 ug/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-7 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 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 Tst Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 11/18/08 1st Qtr 3/11/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/29/09 1st Qtr 3/3/10 2nd Qtr 6/14/10 3rd Qtr 8/11/10 4th Qtr 10/15/10 NA NA <10 <50 <50 <50 <50 NA <2.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA NA NA 1.5 1.1 1.5 1.4 1.2 1.3 1.3 1.4 NA 1.2 1 52 3,100 2,700 3,100 2,500 48 47 51 49 47 45 44 45 43 43 35 40 NA 35 37 37 37 1,900 2,200 2,140 2,160 1.830 2,600 2,300 1,900 2,200 1,800 1,600 2,500 1,800 1,400 1,500 1,300 NA NA <10 <50 <50 <50 <50 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <2.0 35 31 36 38 1,200 1,100 1,500 1,100 <1.0 <1.0 <1.0 <1.0 <i76 <1.0 <1.0 <1.0 NA NA <10 <50 <50 <50 <50 <1.0 <1.0 <1.0 <1.0 <1.0 .......... <1.0 <1.0 NA <2.0 .......... <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA 5.2 5.4 5.2 5.3 1 4.5 4.7 4.6 6 5.1 4.7 4.7 4.2 4.8 4.16 4.01 3.7 3.8 4.1 4.2 3.8 3.9 3.9 4 1st Qtr 2/23/11 2nd Qtr 6/1/11 3rd Qtr 8/18/11 4th Qtr 11/29/11 1st Qtr 1/19/12 2nd Qtr 6/14/12 3rd Qtr 9/13/12 4th Qtr 10/4/12 1st Qtr 2/13/13 2nd Qtr 6/18/13 3rd Qtr 9/12/13 4th Qtr 11/14/13 1st Qtr 2/5/14 2nd Qtr 5/22/14 3rd Qtr 8/27/14 |4th Qtr 10/30/14 <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 45 35 37 37 37 41 40 41 1,300 1,200 1,200 1,000 <1.0 <1.0 <1.0 <1.0 1,000 790 870 940 <1.0 <1.0 <1.0 <1.0 37.7 39.3 36.4 37.2 940 953 1,040 1,050 5.41 4.78 38.2 37.7 39 40.2 946 847 857 926 <1.0 <1.0 <1.0 <1.0 <T6" <1.0 1.5 <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 3.6 4.0 4.1 3.8 39 4.0 3.8 3.8 3.5 4.0 4.2 4.1 4.2 4.2 2.9 3.7 NA = not analyzed Shaded indicates concentrations exceeding GWQS. Bold and italics indicates the MDL exceeded the GWQS. TABLE 1 (11 of 27) Historic Summary Of Monitoring Parameters Up To The 4th Quarter 2014 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (5 ug/L) Chloride No GWQS (mg/L) Chloroform (70 ug/L) Chloromethane (30 M9/L) Methylene Chloride (5 M9/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 NA NA NA 41 <1.0 <1.0 10 1.1 NA NA <1.0 1.7 NA NA NA <1.0 <0.1 <1.0 <1.0 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 39 37 39 40 1.3 1.8 2.1 1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <.1 0.3 0.1 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/17/09 1st Qtr 2/24/10 2nd Qtr 6/14/10 3rd Qtr 8/18/10 4th Qtr 10/15/10 <1.0 <1.0 <1.0 <1.0 <T6 <1.0 <1.0 <1.0 <i.o <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 2/16/11 2nd Qtr 5/25/11 3rd Qtr 8/16/11 4th Qtr 11/16/11 (1)12/7/11 1st Qtr 1/18/12 2nd Qtr 5/13/12 3rd Qtr 8/29/12 4th Qtr 10/3/12 1st Qtr 2/7/13 2nd Qtr 5/30/13 3rd Qtr 9/5/13 4th Qtr 11/7/13 <1.0 <1.0 <1.0 <1.0 <1 6 <1.0 <1.0 <1.0 <i.6" <1.0 <1.0 <1.0 39 42 42 43 46 45 39 44 42 44 44 51 2.5 2.5 1.5 3.5 <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 57 42 45 46 <1.0 <1.0 <1.0 <1.0 52 45 46 45 NA <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <7.6 <1.0 <1.0 <1.0 45 44 48 47 46.6 45.5 47.5 46.1 <1.0 <1.0 <1.0 <1.0 <1.6 <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 <T.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 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <0.05 <0.05 <0.1 <0.1 <0.1 <0.1 <6.i <0.1 <0.1 <0.1 NA <0.1 <0.1 <0.1 0.7 0.2 0.5 0.1 0.1 0.1 0.1 0.2 0.3 0.2 0.1 0.4 0.1 1st Qtr 1/23/14 (2)2/6/2014 2nd Qtr 5/22/14 3rd Qtr 8/27/14 Duplicate TW4-70 4th Qtr 10/29/14 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 48.5 46.5 53 47 47 46.7 63.8 100.0 122.0 107 104 191 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 0.2 0.2 0.5 0.6 1.9 0.9 (1) VOCs were resampled because laboratory missed holding time. (2) Resampled to verify chloroform concentration that was collected on 1/23/14. NA = not analyzed Shaded indicates concentrations exceeding GWQS. TABLE 1 (12 of 27) Historic Summary Of Monitoring Parameters Up To The 4th Quarter 2014 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (5 M9/L) Chloride No GWQS (mg/L) Chloroform (70 ug/L) Chloromethane (30 pg/L) Methylene Chloride (5 Mg/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-9 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 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/17/09 1st Qtr 2/23/10 2nd Qtr 6/14/10 3rd Qtr 8/13/10 4th Qtr 10/15/10 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 <1.0 <1.0 <1.0 NA NA NA 3.8 1.2 42 <1.0 <1.0 NA NA <1.0 2.9 NA NA <1.0 <1.0 38 39 41 44 <1.0 <1.0 <1.0 19 2.6 2.7 <1.0 <1.0 44 42 38 40 <1.0 21 9.5 8.7 35 35 28 58 1.3 1 <1.0 <1.0 30 30 30 37 47 33 40 34 <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 <io' <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 <1.0 1.3 1.3 1.3 1.3 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, 1.3 3.4 4 2.3 1st Qtr 2/17/11 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 NA <1.0 1st Qtr 1/18/12 2nd Qtr 5/31/12 3rd Qtr 8/30/12 4th Qtr 10/3/12 1st Qtr 2/7/13 2nd Qtr 5/30/13 3rd Qtr 9/5/13 4th Qtr 11/7/13 <1.0 <1.0 <1.0 <1.0 <i.b <1.0 <1.0 <1.0 1st Qtr 1/29/14 2nd Qtr 5/22/14 3rd Qtr 8/14/14 4th Qtr 10/29/14 <1.0 <1.0 <1.0 <1.0 NA 41 38 21 38 <1.0 <1.0 <1.0 NA <1.0 <1.0 <1.0 <1.0 NA <1.0 28 23 22 21 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 20.6 21.4 22.7 23.6 22 24 27 25 <1.0 <1.0 <1.0 <1.0 <i.b 6.9 47 101 <1.0 <1.0 <1.0 <1.0 <T.o" <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <1.0 <1.0 <1.0 <1.0 <1.0 <i.b <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 2.3 4.0 3.9 3.8 4.5 4.5 4.0 4.9 4.4 3.4 2.7 4.3 (1) VOCs were resampled because laboratory missed holding time. NA = not analyzed Shaded indicates concentrations exceeding GWQS. TABLE 1 (13 of 27) Historic Summary Of Monitoring Parameters Up To The 4th Quarter 2014 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (5 ug/L) No Chloride GWQS (mg/L) Chloroform (70 ug/L) Chloromethane (30 ug/L) Methylene Chloride (5 ug/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 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 11/18/08 1st Qtr 3/11/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/22/09 1st Qtr 3/3/10 2nd Qtr 6/14/10 3rd Qtr 8/12/10 4th Qtr 10/15/10 1st Qtr 2/23/11 2nd Qtr 6/14/11 3rd Qtr 8/17/11 4th Qtr 11/16/11 1st "Qtr" 1/19/12 2nd Qtr 6/14/11 3rd Qtr 9/12/12 4th Qtr 10/3/12 1st Qtr 2/13/13 2nd Qtr 6/13/13 3rd Qtr 9/12/13 4th Qtr 11/14/13 1st Qtr 1/29/14 2nd Qtr 5/23/14 3rd Qtr 8/27/14 4th Qtr 10/30/14 NA NA <2.5 <2.5 <5.0 <5.0 <5.0 <1.0 <T6 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <i"6" <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 NA NA NA NA 5.16 52 140 62 110 300 50 54 61 58 190 300 504 452 NA NA <2.5 <50 <5.0 <5.0 6.2 NA NA <2.5 <2.5 1.6 <5.0 <5.0 <5.0 <1.0 2 54 59 59 55 58 51 61 500 350 660 470 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA 620 720 660 1,200 <1.0 <1.0 <1.0 NA <2.0 64 62 51 51 1,100 1,200 910 300 48 42 38 52 460 220 100 1,100 32 42 41 45 620 280 180 110 40 46 44 45 76 79 130 140 <1.0 <1.0 <1.0 <1.0 ............. <1.0 <1.0 <1.0 <i"6 <1.0 <1.0 <1.0 <i"6" <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <2.0 <T.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 <1.0 <1.0 49.1 51.5 67.9 70.9 154 486 1,126 1,380 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 73 77.3 74 75.2 1,260 1,110 1,060 1,220 <1.0 <1.0 <1.0 1.5 <1.0 <1.0 <1.0 <1.0 NA 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 11.6 9.8 8.1 3.8 5.0 1.6 0.8 11.0 9.0 3.3 1.9 1.1 0.9 0.8 1.0 1.6 1.2 5.6 13.0 16.0 16.8 13.9 9.8 13.2 NA = not analyzed Shaded indicates concentrations exceeding GWQS. TABLE 1 (14 of 27) Historic Summary Of Monitoring Parameters Up To The 4th Quarter 2014 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (5 ug/L) Chloride No GWQS (mg/L) Chloroform (70 ug/L) Chloromethane (30 Mg/L) Methylene Chloride (5 ug/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-11 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 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 11/18/08 1st Qtr 3/11/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/29/09 NA NA <10 <100 <50 <50 <50 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 <1.0 NA NA NA 1.7 1.3 1.6 1.7 1.6 NA 58 56 56 55 55 4,400 3,590 4,400 4,400 4,400 4,300 4,080 3,660 NA NA <10 <100 <50 <50 <50 NA NA <10 <100 <50 <50 <50 2.7 54 53 53 53 63 46 42 47 NA 49 44 49 46 3,600 3,800 4,500 4,400 340 640 900 1,000 1 ,000 980 1,000 860 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <2.0 ............ <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 <1.0 1.3 1.6 1.2 NA 8.7 10.3 9.4 9.4 9.2 10.0 10.0 10.0 10.1 10.6 10.2 9.8 7.7 7.3 7.9 9.5 7.3 6.8 7.0 6.6 1st Qtr 3/3/10 2nd Qtr 6/14/10 3rd Qtr 8/12/10 4th Qtr 10/15/10 TstQtr27237il 2nd Qtr 6/1/11 3rd Qtr 8/17/11 4th Qtr 11/16/11 1st Qtr 1/24/12 2nd Qtr 6/13/12 3rd Qtr 9/13/12 4th Qtr 10/3/12 1st Qtr 2/13/13 2nd Qtr 6/18/13 3rd Qtr 9/12/13 4th Qtr 11/13/13 1st Qtr 2/5/14 2nd Qtr 5/23/14 3rd Qtr 8/27/14 4th Qtr 10/29/14 <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 42 40 43 49 820 820 800 720 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 46 49 48 46 43 52 49 50 1,000 930 820 1500 610 660 740 730 3.23 47.3 49.3 46.6 46.7 867 788 865 874 5.19 48.5 51.6 48 56.4 785 751 719 803 <1.0 <1.0 <1.0 <1.0 ............ <1.0 <1.0 <1.0 <TF <1.0 <1.0 <1.0 <1 6 <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 1.2 <1.0 <1.0 <1.0 <1.0 6.8 6.9 6.7 6.4 ....... 7.3 7.1 7.1 ........ 6.7 3.0 7.0 ...... 7.4 7.1 8.0 8.5 6.9 5.4 7.3 NA = not analyzed Bold and italics indicates the MDL exceeded the GWQS. Bold and italics indicates the MDL exceeded the GWQS. TABLE 1 (15 of 27) Historic Summary Of Monitoring Parameters Up To The 4th Quarter 2014 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (5 ug/L) Chloride No GWQS (mg/L) Chloroform (70 ug/L) Chloromethane (30 M9/L) Methylene Chloride (5 Mfl/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 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 NA NA <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA NA NA 19 19 16 16 16 <1.0 <1.0 <1.0 <1.0 <1 6 <1.0 <1.0 <1.0 NA NA 5.8 1.0 NA NA <1.0 <1.0 2.6 1.4 1.4 <1.0 16 18 29 16 <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 1.4 1.6 1.5 1.4 1.3 1.4 1.4 1.4 1.5 1.5 1.4 1.4 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 1st Qtr 3/11/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/16/09 1st Qtr 2/23/10 2nd Qtr 6/14/10 3rd Qtr 8/10/10 4th Qtr 10/15/10 1st Qtr 2/15/11 2nd Qtr 5/25/11 3rd Qtr 8/16/11 4th Qtr 11/15/11 1st Qtr 1/17/12 2nd Qtr 5/31/12 3rd Qtr 8/29/12 4th Qtr 10/3/12 1st Qtr 2/13/13 2nd Qtr 5/29/13 3rd Qtr 8/29/13 4th Qtr 11/6/13 1st Qtr 1/22/14 2nd Qtr 5/21/14 3rd Qtr 8/27/14 4th Qtr 10/23/14 <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 <1.0 16 19 18 22 ....... 22 22 23 <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 22 29 35 31 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 31 32 31 30 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 28 34 39 39 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 36.7 38.6 41.7 41.4 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 41.6 40.2 47 50.2 <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 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 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 18.4 17.0 13.0 16.1 NA = not analyzed Shaded indicates concentrations exceeding GWQS. TABLE 1 (16 of 27) Historic Summary Of Monitoring Parameters Up To The 4th Quarter 2014 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (5 U9/L) Chloride No GWQS (mg/L) Chloroform (70 M9/L) Chloromethane (30 ug/L) Methylene Chloride (5 M9/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-13 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 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/16/09 1st Qtr 2/24/10 2nd Qtr 6/14/10 3rd Qtr 8/10/10 4th Qtr 10/15/10 1st Qtr 2/15/11 2nd Qtr 5/25/11 3rd Qtr 8/16/11 4th Qtr 11/15/11 1st Qtr 1/17/12 2nd Qtr 5/31/12 3rd Qtr 8/29/12 4th Qtr 10/3/12 1st Qtr 2/13/13 2nd Qtr 5/29/13 3rd Qtr 8/29/13 4th Qtr 11/6/13 1st Qtr 1/22/14 2nd Qtr 5/21/14 3rd Qtr 8/13/14 4th Qtr 10/23/14 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 <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 NA NA NA 69 67 66 65 33 59 59 58 58 54 58 50 58 58 57 63 60 53 53 55 55 60 56 60 54 55' 59 60 60 59 3 56 63 5 58 5 63.1 56.1 62 66 1 <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 <1 0 <1 0 <1 0 <1 0 <1 0 <1 0 <1 0 <1 0 <1 <1 <1 <1 <1 <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 <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 3 1 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 <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 42 43 46 4.3 42 49 43 08 4_0 46 44 4 1 38 42 43 46 3" 7 1 2 47 4 1 43 52 56 58 55 64 52 59 55 60 62 59 6" 3 68 72 65 7~1 60 48 63 NA = not analyzed Shaded indicates concentrations exceeding GWQS TABLE 1 (17 of 27) Historic Summary Of Monitoring Parameters Up To The 4th Quarter 2014 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (5 ug/L) Chloride No GWQS (mg/L) Chloroform (70 ug/L) Chloromethane (3Q ug/L) Methylene Chloride (5 ug/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 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/16/09 1st Qtr 3/3/10 2nd Qtr 6/14/10 3rd Qtr 8/10/10 4th Qtr 10/15/10 1st Qtr 2/15/11 2nd Qtr 6/14/11 3rd Qtr 8/16/11 4th Qtr 11/15/11 1st Qtr 1/17/12 2nd Qtr 6/14/11 3rd Qtr 8/29/12 4th Qtr 10/3/12 1st Qtr 2/7/13 2nd Qtr 5/29/13 3rd Qtr 8/29/13 4th Qtr 11/6/13 1st Qtr 1/22/14 2nd Qtr 5/21/14 3rd Qtr 8/13/14 4th Qtr 10/23/14 NS NS NS NS NS NS NS <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 <1 0 <1 0 <1 0 <1 0 <1 0 <1 0 <1 0 NS NS NS NS NS NS NS 37 38 38 36 38 57 35 34 40 35 36 38 34 33 49 35 29 25 24 33 15 20 35 37 37 35 2 38 6 37 6 36 5 35 5 32 5 38 38 9 NS NS NS NS NS NS NS NS <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 <1 0 <1 0 <1 0 <1 0 <1 0 <1 0 NS NS NS NS NS NS NS <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 <1 0 <1 0 <1 0 <1 0 <1 0 <1 0 <1 0 NS NS NS NS NS NS NS <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 <1 0 <1 0 <1 0 <1 0 <1 0 <1 0 <1 0 NS NS NS NS NS NS NS 24 23 1 4 1 1 08 0_4 1 6 1 38 0 76 1 6 1 4 1 5 1 4 25 29 28 29 1 8 1 4 26 1 7 1 9 33 39 39 4" 6 44 45 48 59 49 4 1 52 NS = not sampled Shaded indicates concentrations exceeding GWQS TABLE 1 (18 of 27) Historic Summary Of Monitoring Parameters Up To The 4th Quarter 2014 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (5 ug/L) No Chloride GWQS (mg/L) Chloroform (70 ug/L) Chloromethane (30 ug/L) Methylene Chloride (s ug/U Nitrate, Nitrate + Nitrite (10 mg/L) TW4-16 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 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/17/09 1st Qtr 2/24/10 2nd Qtr 6/14/10 3rd Qtr 8/24/10 4th Qtr 10/15/10 NA NA <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <Td <1.0 <1.0 <1.0 <L6 <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 NA <1.0 1st Qtr 1/18/12 2nd Qtr 5/26/11 3rd Qtr 8/30/12 4th Qtr 10/3/12 TsFotr 2/7/13 2nd Qtr 5/30/13 3rd Qtr 9/5/13 4th Qtr 11/7/13 <1.0 <1.0 <1.0 <1.0 NA NA NA NA 64 240 212 85 14 NA NA NA NA 60 55 60 62 39 13 5.2 13.6 3.2 2.6 i.i 2.4 <1.0 <1.0 79 75 65 69 52 58 71 89 <1.0 8.7 2.6 7.1 1.4 ii 10 3.9 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 73 76 79 76 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 77 64 72 71 <1.0 2.1 4.3 3 <1.0 <1.0 <1.0 <1.0 86 81 63 38 15 16 9.2 NA <1.0 <1.0 <1.0 <1.0 NA <1.0 48 53 59 59 <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 NA <1.0 <1.0 <1.0 43 5.9 <0.1 <0.1 <0.1 21 8.9 2.7 9.2 6.6 1.8 5.1 1 26 14 6.6 1.4 1.7 <0.1 <0.1 <0.1 1.4 3 1.9 2.7 5.6 12.3 9.9 5.4 4.4 <0.1 1.5 10.5 9.8 9.6 8.9 8.8 5.2 4.2 4.7 4.6 3.3 7 5 1.7 0.4 0.1 <1.0 <1.0 <1.0 <1.0 1st Qtr 1/29/14 2nd Qtr 5/22/14 3rd Qtr 8/14/14 (2)3rd Qtr 9/24/14 4th Qtr 10/29/14 <1.0 <1.0 <1.0 <1.0 <1.0 58.1 49.8 54.4 56.6 <1.0 <1.0 <1.0 66.8 80.7 80 NA 92.1 13.4 6.93 14.6 229 371 387 <1.0 <1.0 <1.0 <1.0 <iTo <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 4.21 <0.1 <0.1 <0.1 1.4 3.2 4.9 5.1 NA 8.4 (1) VOCs were resampled because laboratory missed holding (2) VOCs were resampled NA = not analyzed Shaded indicates concentrations exceeding GWQS. time. TABLE 1(19 of 27) Historic Summary Of Monitoring Parameters Up To The 4th Quarter 2014 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (5 ug/L) Chloride No GWQS (mg/L) Chloroform (70 ug/L) Chloromethane (30 ug/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 1st Qtr 3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/22/09 1st Qtr 2/24/10 2nd Qtr 6/14/10 3rd Qtr 8/12/10 4th Qtr 10/15/10 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 <7.6 <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 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 <r.o <1.0 <1.0 NA <1.0 1st Qtr 2/13/13 2nd Qtr 6/13/13 3rd Qtr 9/5/13 4th Qtr 11/13/13 <1.0 <1.0 <1.0 <1.0 <i'6 <1.0 <1.0 <1.0 1st Qtr 1/30/14 2nd Qtr 5/22/14 3rd Qtr 8/14/14 4th Qtr 10/28/14 <1.0 <1.0 <1.0 <1.0 NA NA NA 41 38 29.8 39 14 NA NA 36 35 35 34 30 28 32 27 12 12 10.8 12.5 9.2 8 8.9 7.4 <1.0 <1.0 <i.6 <1.0 <1.0 <1.0 23 23 26 30 6.4 5.7 8 9.4 29 30 26 30 11 16 13 8.2 <1.0 <1.0 <1.0 <1.0 <i.6 <1.0 <1.0 <1.0 41 35 37 50 69 29 29 30 52 36 23 23 NA NA 18 30 26 27 39 26 29 28 25 24 38 30 <1.0 <1.0 <1.0 <1.0 < 176 <1.0 <1.0 NA <1.0 <1.0 <1.0 <1.0 <1.0 2.8 1.1 1.6 2.7 23.1 22.9 36.2 37.1 38.9 47 49 40.8 34.9 37.9 41 44.3 6.93 6.93 32.8 33 <1.0 <1.0 <1.0 <1.0 <i.o <1.0 <1.0 <1.0 NA NA <1.0 <1.0 <T6 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <i.b <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <i.b <1.0 <1.0 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 NA 14.1 12.9 13.3 7.3 5.9 4.7 6.1 5.7 5.1 4.9 5.0 4.4 0.7 4.6 4.9 5.2 5.2 6.2 5.9 5.4 5.1 9.0 9.0 10.0 10.6 9.0 4.6 6.3 4.4 6.6 6.6 6.0 5.6 8.9 12.1 14.2 ........... 12.2 9.8 11.1 (1) VOCs were resampled because laboratory missed holding time. NA = not analyzed Shaded indicates concentrations exceeding GWQS. TABLE 1 (20 of 27) Historic Summary Of Monitoring Parameters Up To The 4th Quarter 2014 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (5 M9/L) Chloride No GWQS (mg/L) Chloroform (70 M9/L) Chloromethane (3Q van.) Methylene Chloride (5 pg/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-19 chioi pumping well 1st Qtr 3/16/05 2nd Qtr 5/25/05 3rd Qtr 8/31/05 4th Qtr 12/7/05 Tst Qtr'3/9/06 2nd Qtr 6/14/06 3rd Qtr 7/20/06 4th Qtr 11/8/06 NA NA <5.0 <50 NA NA NA 81 <50 <50 <50 86 116 1.6 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/68 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 Did not sample 1.3 1.9 1.9 <1.0 2.9 8.6 12 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/22/09 1.2 1.2 15 16 1st Qtr 2/17/10 2nd Qtr 6/14/10 3rd Qtr 8/16/10 4th Qtr 10/15/10 1.3 4.2 4.9 1.3 1st Qtr 2/17/11 2nd Qtr 6/7/11 3rd Qtr 8/17/11 4th Qtr 11/17/11 (1) 12/5/11 17 8.3 2.1 5.4 1st Qtr 1/23/12 2nd Qtr 6/6/12 3rd Qtr 9/4/12 4th Qtr 10/3/12 1.5 1.1 3.5 4 1st Qtr 2/13/13 2nd Qtr 6/5/13 3rd Qtr 9/3/13 4th Qtr 10/29/13 5.15 5.15 20.7 6.42 123 134 2,200 1,200 1,400 2,800 1.200 1,100 1,120 1,050 NA NA <5.0 <50 NA NA <5.0 <50 <50 <50 <50 2.6 133 129 132 131 128 113 124 127 132 43 124 144 132 142 146 135 148 148 148 138 149 149 150 164 148 179 134 1,200 1,100 1,100 1,800 1,000 3,600 4,200 1.100 990 6,600 4,700 940 1,800 2,000 1,200 3,400 4,000 970 2,200 650 460 950 1500 4,210 2,070 8,100 942 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <f.6 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <T6 <1.0 <1.0 <1.0 <7.6 <1.0 <1.0 <1.0 <T6 <1.0 <1.0 <1.0 <50 <50 <50 <1.0 <i".'6"' <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 5.3 5.7 4.6 4 5.2 4.3 4.6 4 4.1 4 2.2 2.8 35.2 47.8 3.2 2.4 <0.1 26.7 2 4.4 5.9 2.7 17.0 12.0 3.0 5.0 0.6 2.4 2.5 4.1 8.0 3.0 17.6 4.7 1st Qtr 1/27/14 2nd Qtr 5/19/14 3rd Qtr 8/11/14 4th Qtr 10/21/14 4.05 5.51 1.9 4.8 134 152 140 130 586 810 1,410 4,310 <1.0 <1.0 8.3 <1.0 <1.0 <1.0 <1.0 <1.0 1.6 1.3 1.6 4.7 (1) VOCs were resampled because laboratory missed holding time. NA = not analyzed Bold and italics indicates the MDL exceeded the GWQS. Shaded indicates concentrations exceeding GWQS. TABLE 1 (21 of 27) Historic Summary Of Monitoring Parameters Up To The 4th Quarter 2014 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (5 ug/l) Chloride No GWQS (mg/L) Chloroform (7Q ug/L) Chloromethane (30 ug/L) Methylene Chloride (5 ug/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-20 cnjoi pumping well 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 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/14/09 1st Qtr 2/17/10 2nd Qtr 6/14/10 3rd Qtr 8/16/10 4th Qtr 10/15/10 1st Qtr 2/23/11 2nd Qtr 6/1/10 3rd Qtr 8/17/11 4th Qtr 11/16/11 1st Qtr 1/23/12 2nd Qtr 6/6/12 3rd Qtr 9/4/12 4th Qtr 10/3/12 1st Qtr 2/11/13 2nd Qtr 6/5/13 3rd Qtr 9/3/13 4th Qtr 10/29/13 1st Qtr 1/27/14 2nd Qtr 5/19/14 3rd Qtr 8/11/14 4th Qtr 10/21/14 NA <10 <250 <50d <500 <1000 NA 7.1 3.1 2.2 3.5 6.8 9 13 15 5.7 4.9 8.4 14 2.7 11 12 20 27 10 7.3 7.2 10 33 26 22 19.6 32.5 25.7 17.3 18.4 22.1 14.1 18.5 NA NA Monitor well was not installed 131 120 235 134 124 124 112 117 170 132 191 156 168 164 164 153 187 179 200 196 203 220 177 207 186 207 262 289 302 252 250 260 272 254 269 299 292 39,000 3,800 19,000 9,200 61,000 5,300 11,000 4,400 1,800 5,200 9,000 13,000 30,000 21,000 NA 8,200 6,800 13,000 15,000 3,500 18,000 15,000 24,000 31,000 8,100 3,800 7,900 "Hood 36,000 13,000 19,000 18,500 26,300 26,800 15,700 17,800 22,100 12,400 23,300 NA <10 <250 <500 <500 <1000 1.9 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 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 <To <1.0 <1.0 <1.0 <T.o <1.0 <1.0 <1.0 <T.d 4.04 2.31 55.2 NA <10 <250 <566 <500 <1000 <1.0 NA <1.0 <1.0 <1.0 2.2 1.1 1.8 1.9 1.5 1.2 3.7 5.2 4.2 4.4 3.0 3.2 3.7 2.2 5.5 19.0 2.1 3.1 2.5 1.3 1.21 1.3 2.14 1.37 2.04 3.98 2.2 2.38 10.10 2.90 1.80 3.80 9.40 2.90 3.50 4.20 2.30 2.10 5.60 0.90 8.00 4.44 5.51 5.10 2.90 3.30 5.30 2.00 5.60 5.30 4.60 4.40 4.80 6.50 4.20 7.90 11.00 10.80 11.00 9.07 9.80 8.65 9.64 7.56 5.95 4.30 7.67 (1) VOCs were resampled because laboratory missed holding time. NA = not analyzed Bold and italics indicates the MDL exceeded the GWQS. Shaded indicates concentrations exceeding GWQS. TABLE 1 (22 of 27) Historic Summary Of Monitoring Parameters Up To The 4th Quarter 2014 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (5 MQ/L) Chloride No GWQS (mg/L) Chloroform (70 Mg/L) Chloromethane (30 ug/L) Methylene Chloride (5 ug/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-21 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 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 11/18/08 1st Qtr 3/11/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/22/09 1st Qtr 2/25/10 2nd Qtr 614/10 3rd Qtr 8/13/10 4th Qtr 10/15/10 NA <5.0 <1.0 <2.5 <2.5 <2.5 <1.0 <1.0 NA <1.0 <1.0 <1.0 <1.0 "<T.o~ <1.0 1st Qtr 2/22/11 2nd Qtr 6/28/11 3rd Qtr 8/17/11 4th Qtr 11/16/11 <1) 12/7/1 1st Qtr 1/19/12 2nd Qtr 6/13/12 3rd Qtr 9/13/12 4th Qtr 10/4/12 1st Qtr 2/13/13 2nd Qtr 6/18/13 3rd Qtr 9/13/13 4th Qtr 11/13/13 <1.0 1st Qtr 2/5/14 2nd Qtr 5/22/14 3rd Qtr 8/27/14 4th Qtr 10/29/14 <1,0 1.04 1.8 5.8 7 1.7 1.6 9.2 1.2 1.2 4.8 6.3 6.7 6.4 5.4 6 7 5.25 3.49 2.13 6.23 4.73 NA NA NA Monitor well was not installed 353 347 318 357 296 306 327 300 288 331 271 244 284 279 291 281 256 228 266 278 210 303 290 287 287 228 285 142 270 221 243 207 206 200 243 230 252 192 78 86 120 120 108 139 160 300 140 120 NA 390 180 120 170 180 200 200 160 170 210 390 200 230 290 460 390 420 400 410 390 282 328 244 204 220 240 204 229 NA <5.0 <1.0 <2 5 <2.5 <2.5 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 <1.0 <T6" <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 <Txf <1.0 <1.0 <1.0 NA <5.0 <1.0 <2.5 <2.5 <2.5 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <2.0 <i .0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 2.04 2.04 NA 14.6 10.1 9.6 8.5 10.2 8.9 8.7 8.7 8.6 8.6 8.3 14.3 8.8 7.57 8.0 8.3 8.1 9.2 8.4 8.4 12.0 14.0 7.0 9.0 12.0 14.0 13.0 15.0 11.0 13.0 14.0 11.8 13.8 10.3 9.0 114 11.5 7.1 10.0 (1) VOCs were resampled because laboratory missed holding time. NA = not analyzed Shaded indicates concentrations exceeding GWQS. TABLE 1 (23 of 27) Historic Summary Of Monitoring Parameters Up To The 4th Quarter 2014 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (5 MH/L) Chloride No GWQS (mg/L) Chloroform (70 M9/L) Chloromethane (30 ug/L) Methylene Chloride (5 pg/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-22 nitrate pumping well 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 1st Qtr 2/28/07 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 11/18/08 1st Qtr 3/11/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/29/09 1st Qtr 3/3/16 2nd Qtr 6/14/10 3rd Qtr 8/24/10 4th Qtr 10/15/10 NA <5.0 <5.0 <io <w <10 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <2.0 <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 NA <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 1st Qtr 2/11/13 2nd Qtr 6/5/13 3rd Qtr 9/3/13 4th Qtr 10/29/13 1st Qtr 1/27/14 2nd Qtr 5/19/14 3rd Qtr 8/11/14 4th Qtr 10/29/14 1.3 1.2 3.24 3.35 3.25 8.09 6.06 6.65 1.9 3.32 NA NA NA Monitor well was not installed 253 236 221 221 236 347 273 259 238 519 271 524 539 177 177 391 175 427 134 130 134 114 138 120 174 NA 36 35 130 130 586 487 501 598 614 540 596 340 290 320 390 280 864 350 440 740 530 440 NA 1,400 1,200 6,300 630 390 730 2,300 380 2,200 540 340 340 NA 1,300 210 450 400 200 120 121 330 10,600 12,500 9,640 13,300 12,100 12,400 12,400 12,400 NA <5.0 <5.0 <10 <10 <10 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <1.0 <T.o <1.0 <1.0 <1.0 <iT6 <1.0 <1.0 <1.0 1.6 <1.0 <1.0 40 1.61 NA <5.0 <5.0 <10 <10 <10 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 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 2.83 NA NA 18.2 15.7 15.1 15.3 14.3 14.5 15.9 20.9 19.3 19.3 18.8 20.7 20.6 40.3 17.8 36.8 19.0 15.0 16.0 18.0 17.0 15.0 19.0 14.0 12.8 7.0 14.0 58.0 50.2 29.7 45.2 54.6 47.2 41.5 54.9 (1) VOCs were resampled because laboratory missed holding time. NA = not analyzed Shaded indicates concentrations exceeding GWQS. Bold and italics indicates the MDL exceeded the GWQS. TABLE 1 (24 of 27) Historic Summary Of Monitoring Parameters Up To The 4th Quarter 2014 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (5 ug/L) No Chloride GWQS (mg/L) Chloroform (70 ug/L) Chloromethane (3Q ug/U Methylene Chloride (5 ug/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-23 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 11/18/08 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/16/09 1st Qtr 2/24/10 2nd Qtr 6/14/10 3rd Qtr 8/24/10 4th Qtr 10/15/10 1st Qtr 2/16/11 2nd Qtr 6/14/11 3rd Qtr 8/16/11 4th Qtr 11/15/11 1st Qtr 1/17/12 2nd Qtr 5/31/12 3rd Qtr 8/29/12 4th Qtr 10/3/12 1st Qtr 2/7/13 2nd Qtr 5/30/13 3rd Qtr 9/5/13 4th Qtr 11/7/13 1st Qtr 1/23/14 2nd Qtr 5/19/14 3rd Qtr 8/13/14 4th Qtr 10/28/14 <1 0 <1 0 <1 0 <1 0 <1 0 <1 0 NA <2 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 NA 47 46 43 41 41 35 51 41 43 43 37 45 40 40 34 44' 44 41 43 40 44 46 45 43 6 44 7 48 43 44 6 42 3 46 46 8 <1 0 <1 0 <1 0 <1 0 <1 0 <1 0 NA <2 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 <1 0 <1 0 <1 0 <1 0 <1 0 NA <2 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 <1 0 <1 0 <1 0 <1 0 <1 0 NA <2 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 05 <0 05 NA <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 NA = not analyzed Shaded indicates concentrations exceeding GWQS TABLE 1 (25 of 27) Historic Summary Of Monitoring Parameters Up To The 4th Quarter 2014 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (5 ug/L) Chloride No GWQS (mg/L) Chloroform (70 ug/L) Chloromethane (30 ug/L) Methylene Chloride (5 ug/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-24 nitrate pumping well 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 1st Qtr 3/28/08 2nd Qtr 6/25/08 3rd Qtr 9/10/08 4th Qtr 10/15/08 11/18/08 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/16/09 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 <1.0 <1.0 NA <2.0 .......... <1.0 <1.0 <1.0 1st Qtr 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 .......... <1.0 <1.0 NA <1.0 1st Qtr 1/16/12 2nd Qtr 6/6/12 3rd Qtr 8/30/12 4th Qtr 10/3/12 1st Qtr 2/11/13 2nd Qtr 6/5/13 3rd Qtr 8/30/13 4th Qtr 10/29/13 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1st Qtr 1/27/14 2nd Qtr 5/19/14 3rd Qtr 8/11/14 4th Qtr 10/21/14 NA NA 1.18 <1.0 <1.0 <10 770 791 692 2.6 2.2 1.5 <1.0 <1.0 <1.0 740 834 1180 1130 NA <2.0 1010 759 618 1080 896 639 587 522 .......... 1110 967 608 NA 373 355 489 405 <1.0 <1.0 <1.0 1260 916 998 1030 809 1020 1150 1050 1.5 1.4 2.9 <1.0 <1.0 <1.0 NA <2.0 1.4 1.5 1.4 1.2 <1.0 <1.0 <1.0 <1.0 1.3 1.7 1.8 1.4 <1.0 <1.0 <1.0 <1.0 1.8 1.1 1.7 1.2 <1.0 <1.0 <1.0 NA <1.0 <1.0 <1.0 <1.0 <1.0 1 17.4 21.8 32.5 <1.0 <1.0 <1.0 <1.0 78.5 62.7 76.3 25.8 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <i.O <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 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 NA NA 26.1 29 24.7 24.4 45.3 38.4 44.8 30.5 30.4 30.7 28.3 33.1 30 31 31 31 35 34 35 37 I 38 35.9 23.7 33 35 31.6 35.0 31.5 35.7 (1) VOCs were resampled because laboratory missed holding time. NA = not analyzed Shaded indicates concentrations exceeding GWQS. TABLE 1 (26 of 27) Historic Summary Of Monitoring Parameters Up To The 4th Quarter 2014 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (5 PPA) Chloride No GWQS (mg/L) Chloroform (70 M9/L) Chloromethane (30 pg/L) Methylene Chloride (5 Mfl/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-25 nitrate pumping well 2nd Qtr 6/27/07 3rd Qtr 8/15/07 4th Qtr 10/10/07 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 1st Qtr 3/4/09 2nd Qtr 6/23/09 3rd Qtr 9/14/09 4th Qtr 12/14/09 1st Qtr 2/23/10 2nd Qtr 6/14/10 3rd Qtr 8/10/10 4th Qtr 10/15/10 1st Qtr 2/16/11 2nd Qtr 5/25/11 3rd Qtr 8/16/11 4th Qtr 11/15/11 1st Qtr 1/16/12 2nd Qtr 5/31/12 3rd Qtr 9/4/12 4th Qtr 10/3/12 1st Qtr 2/11/13 2nd Qtr 6/5/13 3rd Qtr 9/4/13 4th Qtr 10/31/13 1st Qtr 1/27/14 2nd Qtr 5/19/14 3rd Qtr 8/11/14 4th Qtr 10/21/14 <1.0 <1.0 <1.0 ............. <1.0 <1.0 NA <2.0 <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 <i 6 <1.0 <1.0 <1.0 NA 395 382 358 <1.0 <1.0 2.2 <1.0 <1.0 <1.0 374 344 333 366 <1.0 <1.0 <1.0 NA <2.0 <1.0 <1.0 <1.0 NA <2.0 332 328 328 371 296 306 250 312 <1.0 <1.0 <1.6 <1.0 ........... <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <L0" <1.0 <1.0 <1.0 315 321 276 294 1.8 <1.0 <1.0 <1.0 304 287 334 338 190 136 119 88.6 <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 85.7 51.1 67 58.1 <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 NA <2.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <i.6 <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 NA 17.1 29 17 18.7 22.1 18.8 21.3 15.3 15.3 3.3 14.2 14.4 16 14 15 15 16 16 16 16 16 17 17 9.04 5.24 6 6 2.2 1.2 1.6 1 (1) VOCs were resampled because laboratory missed holding time. NA = not analyzed Shaded indicates concentrations exceeding GWQS. TABLE 1 (27 of 27) Historic Summary Of Monitoring Parameters Up To The 4th Quarter 2014 Chloroform Contamination Investigation DUSA White Mesa Mill Well Sampling Event Parameter GWQS Carbon Tetrachloride (5 Mfl/L) Chloride No GWQS (mg/L) Chloroform (70 pg/L) Chloromethane (30 ug/L) Methylene Chloride (5 ug/L) Nitrate, Nitrate + Nitrite (10 mg/L) TW4-26 2nd Qtr 6/14/10 3rd Qtr 8/24/10 4th Qtr 10/15/10 1st Qtr 2/16/11 2nd Qtr 5/26/11 3rd Qtr 8/17/11 4th Qtr 11/16/11 (D 12/7/11 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <1.0 1st Qtr 1/18/12 2nd Qtr 6/6/12 3rd Qtr 9/11/12 4th Qtr 10/3/12 1st Qtr 2/7/13 2nd Qtr 6/13/13 3rd Qtr 9/5/13 4th Qtr 11/7/13 1st Qtr 1/29/14 2nd Qtr 5/21/14 3rd Qtr 8/11/14 4th Qtr 10/28/14 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <T.O <1.0 <1.0 <1.0 33 17 22 13 5.2 5.4 <1.0 <1.0 <1.0 30 15 19 26 NA NA 2 2.9 2.8 5.2 17 19 19 19 7 4.1 4.9 4.9 16.6 14.5 17.6 15.9 4.9 2.12 2.81 3.37 16.9 15.4 15 14.6 1.43 4.23 1.3 2.45 <1.0 <1.0 <1.0 NA <1.0 <7.6 <1.0 <1.0 <1.0 <76 <1.0 <1.0 <1.0 <7.b"" <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA <1.0 <i.b <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 NA 7.9 9.0 9.6 10.0 10.0 11.0 10.0 11.0 12.0 9.0 12.0 12.5 13.6 11.7 15.9 14.2 12.5 10.8 12-31 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 1st Qtr 2/7/13 2nd Qtr 6/13/13 3rd Qtr 8/30/13 4th Qtr 11/6/13 <1.0 <1.0 <1.0 <1.0 1st Qtr 1/23/14 2nd Qtr 5/21/14 3rd Qtr 8/13/14 4th Qtr 10/28/14 <1.0 <1.0 <1.0 <1.0 11 17 21 18 18.8 20.3 19 21.8 31.8 20.6 23 24.4 <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 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 24.0 41.0 37.0 36.0 31.2 29.4 27.2 29.8 m 27.0 28.2 TW4-28 2nd Qtr 6/19/13 3rd Qtr 8/29/13 4th Qtr 11/6/13 <1.0 <1.0 <1.0 1st Qtr 1/22/14 2nd Qtr 5/21/14 3rd Qtr 8/13/14 4th Qtr 10/23/14 DS TW4-65 <1.0 <1.0 <1.0 <1.0 <1.0 44.6 45.3 45.3 47.8 45.7 50 52.1 51 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 3.2 <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 14.9 17.3 16.2 16.9 16.5 14.2 16.5 14.5 TW4-29 2nd Qtr 6/19/13 2nd Qtr 7/11/13 3rd Qtr 9/26/13 4th Qtr 11/13/13 <1.0 <1.0 <1.0 <1.0 44.8 37.7 41.4 42.5 242 262 246 260 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 4.6 3.5 4.2 4.1 4.6 3.5 3.4 3.6 1st Qtr 2/5/14 2nd Qtr 5/22/14 3rd Qtr 8/27/14 4th Qtr 10/29/14 <1.0 <1.0 <1.0 <1.0 14.9 38.2 41 41 258 262 242 290 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 TW4-30 2nd Qtr 6/19/13 3rd Qtr 9/26/13 4th Qtr 11/13/13 <1.0 <1.0 <1.0 1st Qtr 1/23/14 2nd Qtr 5/22/14 3rd Qtr 8/13/14 4th Qtr 10/23/14 <1.0 <1.0 <1.0 <1.0 36 36.3 35.9 36.9 31.9 38 37.1 <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 1.2 ........ 1.4 1.5 1.8 TW4-31 2nd Qtr 6/19/13 3rd Qtr 9/5/13 4th Qtr 11/7/13 <1.0 <1.0 <1.0 28.4 29.4 28 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1.3 1.1 1.3 1st Qtr 1/23/14 2nd Qtr 5/21/14 3rd Qtr 8/13/14 4th Qtr 10/28/14 <1.0 <1.0 <1.0 <1.0 28.5 26.3 30 37.1 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 1.3 1.2 1.1 1.8 TW4-32 4th Qtr 11/14/13 1st Qtr 1/22/14 2nd Qtr 5/21/14 3rd Qtr 8/13/14 4th Qtr 10/23/14 <1.0 <1 0 <1.0 <1.0 <1.0 52.1 54.5 54.9 64 62.6 <1.0 <i 6 <1.0 <1.0 <1.0 <1.0 ........... <1.0 <1.0 <1.0 <1.0 .......... <1.0 <1.0 <1.0 4.3 5.1 5.6 4.2 2.1 TW4-33 4th Qtr 11/14/13 1st Qtr 1/30/14 2nd Qtr 5/22/14 3rd Qtr 8/27/14 4th Qtr 10/29/14 <1.0 <1.0 <1.0 <1.0 <1.0 47.2 43.5 46.8 43 44.2 126 124 121 104 124 <1.0 .......... <1.0 <1.0 <1.0 <1.0 .......... <1.0 <1.0 <1.0 1.8 2.6 1.6 1.5 2.2 TW4-34 4th Qtr 11/14/13 1st Qtr 1/23/14 2nd Qtr 5/22/14 3rd Qtr 8/13/14 4th Qtr 10/29/14 <1.0 <1.0 <1.0 <1.0 <1.0 19.2 20.4 17.9 18 17.8 <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 1.6 1.9 1.7 1.1 1.2 TW4-35 3rd Qtr 8/27/14 4th Qtr 10/28/14 <1.0 <1.0 34 34.1 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 0.2 0.35 TW4-36 3rd Qtr 8/27/14 4th Qtr 10/23/14 <1.0 <1.0 65 67.3 <1.0 <1.0 <1.0 <1.0 <1.0 <1.0 <0.1 <0.1 DS = Duplicate Sample Shaded indicates concentrations exceeding GWQS. (1) VOCs were resampled because laboratory missed holding time.