Document vZJaa5kQddRmZLqOqjNoGgQ6

3M ENVIRONMENTAL LABORATORY REPORT NO. ISO14-07-05 Final Report Analysis of PFOA, PFBS, PFHS, and PFOS in Aqueous Samples from 3M Decatur, Alabama: Groundwater Treatment Plant GAC System May 2014 Laboratory Request Number: ISO14-07-05 Method Requirement: 3M Method ETS-8-044.1 Report Date - Date of Last Signature Testing Laboratory 3M EHS Operations 3M Environmental Laboratory Building 260-5N-17 Maplewood, MN 55144-1000 Requester Gary Hohenstein 3M Building 224-5W-03 Saint Paul, MN 55144-1000 Phone: (651) 737-3570 The testing reported herein meet the requirements of ANSI/ISO/IEC 17025:2005 "General Requirements for the Competence of Testing and Calibration Laboratories", in accordance with the A2LA Testing Certificate # 2052.01. Additionally, the laboratory's quality system has been audited and was determined to be in conformance with the EPA GLPs (40 CFR 792) by an independent A2LA assessment. PAGE 1 OF 25 3M ENVIRONMENTAL LABORATORY REPORT NO. ISO14-07-05 3M Environmental Laboratory 3M Environmental Laboratory Technical Director: William K. Reagen, Ph.D. 3M Principal Analytical Investigator: Susan Wolf Report Author: Susanna Emond Analytical Report ISO14-07-05 3M Decatur Groundwater Treatment Plant System; May 2014 Sampling Report Date: Date of Last Signature 1 Introduction/Summary The 3M Environmental Laboratory analyzed water samples from the groundwater treatment plant GAC system at the 3M Decatur, AL facility. Water samples were collected by Weston Solutions personnel on May 15, 2014. Samples were returned to the 3M Environmental Laboratory for analysis of Perfluorooctanoate (PFOA), Perfluorobutane sulfonate (PFBS), Perfluorohexane sulfonate (PFHS), Perfluorooctane sulfonate (PFOS) under laboratory project number ISO14-07-05. Analysis of the samples was completed as specified under 3M Environmental Laboratory General Project Outline number ISO14-07. The 3M Environmental Laboratory provided sample containers for seven sampling locations; ACI, ACM2, ACE, WW8R, WW9R, WW10R, and WW11R. The sample set consisted of a field sample, field sample duplicate and a field matrix spike. Each empty container was marked with a "fill to here" line that corresponded to a final volume of 200 mL. Containers reserved for field matrix spikes were fortified with an appropriate matrix spike solution containing all analytes prior to being sent to the field for sample collection. Sample bottles for sampling locations ACM2 and ACE, along with the Trip Blank sample and low spike, were fortified with internal standards and surrogate recovery standards prior to being sent to the field for sample collection. Samples were prepared and analyzed by method ETS-8-044.1 "Method of Analysis for the Determination of Perfluorinated Compounds in Water by LC/MS/MS; Direct Injection Analysis". Internal standards were used for select samples to aid in the data quality objectives. Table 1 summarizes the sample results using the analytical method identified above. All results for quality control samples prepared and analyzed with the samples will be reported and discussed elsewhere in this report. PAGE 2 OF 25 3M ENVIRONMENTAL LABORATORY REPORT NO. ISO14-07-05 Table 1. Sample Results Summary (1) 3M LIMS ID Sample Description PFOA Concentration (ng/mL) PFBS Concentration (ng/mL) PFHS Concentration (ng/mL) PFOS Concentration (ng/mL) ISO14-07-05-001 DAL-GW-ACI-0-140515 1910 1290 824 536 ISO14-07-05-002 DAL-GW-ACI-DB-140515 1670 1160 718 485 Average 1790 1230 771 511 %RPD Sample/Sample Dup 13 11 14 10 ISO14-07-05-004 DAL-GW-ACM2-0-140515 0.132 973 0.142 0.328 ISO14-07-05-005 DAL-GW-ACM2-DB-140515 0.130 1070 0.141 0.307 Average 0.131 (2) 1020 0.142 (2) 0.318 (2) %RPD Sample/Sample Dup 1.5 9.5 0.71 6.6 ISO14-07-05-007 DAL-GW-ACE-0-140515 0.104 205 0.0892 0.644 ISO14-07-05-008 DAL-GW-ACE-DB-140515 0.0940 199 0.0916 0.673 Average 0.0990 (2) 202 0.0904 (2) 0.659 (2) %RPD Sample/Sample Dup 10 3.0 2.7 4.4 ISO14-07-05-010 DAL-GW-WW8R-0-140515 2680 289 1150 4280 ISO14-07-05-011 DAL-GW-WW8R-DB-140515 2580 291 1160 4170 Average 2630 290 1160 4230 %RPD Sample/Sample Dup 3.8 0.69 0.87 2.6 ISO14-07-05-013 DAL-GW-WW9R-0-140515 2620 261 1110 4740 ISO14-07-05-014 DAL-GW-WW9R-DB-140515 2690 270 1160 4830 Average 2660 266 1140 4790 %RPD Sample/Sample Dup 2.6 3.4 4.4 1.9 ISO14-07-05-016 DAL-GW-WW10R-0-140515 1810 223 846 2760 ISO14-07-05-017 DAL-GW-WW10R-140515 1710 216 799 2590 Average 1760 220 823 2680 %RPD Sample/Sample Dup 5.7 3.2 5.7 6.4 ISO14-07-05-019 DAL-GW-WW11R-0-140515 1200 230 651 1610 ISO14-07-05-020 DAL-GW-WW11R-DB-140515 1290 244 646 1890 Average 1250 237 649 1750 %RPD Sample/Sample Dup 7.2 5.9 0.77 16 NR = Not reportable (1) Reported results from samples prepared and analyzed by ETS-8-044.1 using external standard calibration except where otherwise noted. The analytical method uncertainties associated with the reported results are as follows: PFOA 15%, PFBS 17%, PFHS 12%, and PFOS 13%. (2) Sample set prepared and analyzed by ETS-8-044.1 using internal standard calibration. The analytical method uncertainties associated with the reported results are as follows: PFOA 15%, PFHS 17%, and PFOS 16%. PAGE 3 OF 25 3M ENVIRONMENTAL LABORATORY REPORT NO. ISO14-07-05 2 Methods - Analytical and Preparatory 2.1 Methods Analysis was completed using 3M Environmental Laboratory Method ETS-8-044.1 "Method of Analysis for the Determination of Perfluorinated Compounds in Water by LC/MS/MS; Direct Injection Analysis". Table 2. Target Analytes Target Analytes Perfluorooctanoic Acid (C8 Acid) Perfluorobutanesulfonate (C4 Sulfonate ) Perfluorohexanesulfonate (C6 Sulfonate) Perfluorooctanesulfonate (C8 Sulfonate) Acronym PFOA PFBS PFHS PFOS Reference Material Structure Linear + Branched Linear Linear Linear + Branched 2.2 Sample Collection Samples were collected on May 15, 2014 in NalgeneTM (high-density polyethylene) bottles prepared at the 3M Environmental Laboratory. Prior to sample collection, bottles designated for field matrix spikes were spiked in the laboratory with a known volume of an appropriate matrix spiking solution containing PFOA, PFBS, PFHS, and PFOS. Sample bottles for sampling locations ACM2 and ACE, along with the Trip Blank sample and low spike, were fortified with a mixture of mass-labeled internal standards at a nominal concentration of 1 ng/mL and a mixture of surrogate recovery standards at a nominal concentration of 0.1 ng/mL prior to being sent to the field for sample collection. Collected sample bottles were received by the laboratory at ambient conditions on May 20, 2014. 2.3 Sample Preparation All samples were initially prepared by diluting with methanol (dilution factor of 100) and analyzing for all target analytes. The 1:100 dilutions were prepared by removing a 0.1 mL aliquot of the well mixed sample and adding 9.8 mL of methanol and 0.1 mL of a surrogate spiking solution (nominal concentration of 1 ng/mL). On-column dilution was utilized for select samples for dilution levels up to 200X. Prepared samples were analyzed by external standard calibration. The ACE and ACM2 sample sets and the Trip Blank sample and low spike were subsequently prepared by removing a 0.4 mL aliquot of the well mixed sample and diluting it with 0.4 mL of methanol (dilution factor of 2). Prepared samples were analyzed by internal standard calibration. During the preparation of the laboratory control samples for internal standard calibration, an aliquot of a separate internal standard spiking solution was added to the laboratory control samples (nominal concentration of 1 ng/mL). The laboratory control samples were analyzed in the same manner as the samples. 2.4 Analysis All samples and quality control samples were analyzed for four target analytes using high performance liquid chromatography/tandem mass spectrometry (HPLC/MS/MS). Pertinent instrument parameters, the liquid chromatography gradient program, and the specific mass transitions analyzed are described in the tables below. Due to the nature of the sample, the wide range of concentrations found in the sample, and the environmental occurrence of multiple isomers of the laboratory's analytes of interest, the software used for processing the analytical results is not able to consistently integrate the analytical peak, manual integration of the analytical peak is necessary. All manual integrations are performed following the PAGE 4 OF 25 3M ENVIRONMENTAL LABORATORY REPORT NO. ISO14-07-05 procedures outlined in SOP ETS-12-010.1 The consistency of the laboratory's integration is ensured through the training of laboratory personnel, the peer review process required for all manual integrations, the review of manual integrations by the QAU, and where necessary the review of manual integrations by laboratory management. Table 3. Instrument Parameters. Instrument Name Analysis Dates Analytical Method Liquid Chromatograph Guard column Analytical column Injection Volume Mass Spectrometer Ion Source Polarity Software ETS McCoy 5/22/14 and 5/28/14 - external standard calibration 6/4/14 - internal standard calibration ETS-8-044.1 Agilent 1290 Betasil C18 (4.6 mm X 100 mm), 5 u Betasil C18 (4.6 mm X 100 mm), 5 u 10 or 5 uL Applied Biosystems API 5500 Turbo Spray Negative Analyst 1.6.1 Table 4. Liquid Chromatography Gradient Program Step Number 0 1 2 3 4 5 6 7 8 9 Total Time (min) 0.0 0.50 4.00 6.00 11.00 13.00 13.50 16.00 16.50 19.00 Flow Rate (uL/min) Percent A (2 mM ammonium acetate) ETS-8-044.1 Analysis 750 750 750 750 750 750 750 750 750 750 90 90 70 70 20 20 10 10 90 90 Percent B (Methanol) 10 10 30 30 80 80 90 90 10 10 PAGE 5 OF 25 3M ENVIRONMENTAL LABORATORY REPORT NO. ISO14-07-05 Table 5. Mass Transitions. Analyte Mass Transition Q1/Q3 Internal Standard (1) Mass Transition Q1/Q3 413/369 PFOA 413/219 [1 3 C8 ]PFOA 421/376 413/169 PFBS 299/80 299/99 [1 8 O2 ]PFBS 303/84 PFHS 399/99 399/80 [13Cs]PFHS 402/80 499/99 PFOS 499/80 [1 3 C8 ]PFOS 507/80 499/130 [13C4]PFOA surrogate 417/372 [1 3 C8 ]PFOA 421/376 [13C4]PFOS surrogate 503/80 [1 3 C8 ]PFOS 507/80 Dwell time was 20 msec for each transition. The individual transitions were summed to produce a "total ion chromatogram" (TIC), which was used for quantitation. (1) Internal standards were used for the analysis 6/4/14. 3 Data Analysis 3.1 Calibration External Standard Calibration Analysis on 5/22/14 and 5/28/14: Samples were analyzed against an external standard calibration curve. Calibration standards were prepared by spiking known amounts of the stock solution containing the target analytes into 90:10 methanol: Milli-Q laboratory water. A total of nine spiked standards ranging from 0.1 ng/mL to 50 ng/mL (nominal) were analyzed. The standards also contained the surrogates at concentrations ranging from 0.1 ng/mL to 25 ng/mL nominal. A quadratic, 1/x weighted, calibration curve of the standard peak area counts was used to fit the data for each analyte. The data were not forced through zero during the fitting process. Calculating the standard concentrations using the peak area counts and the resultant calibration curve confirmed accuracy of each curve point. Internal Standard Calibration Analysis on 6/4/14: Samples were analyzed for all analytes against a matrix-matched stable isotope internal standard calibration curve. Calibration standards were prepared by spiking known amounts of stock solutions into 50 mL of 50:50 methanol:laboratory reagent water. The calibration standards contained an internal standard mix at a nominal concentration of 0.5 ng/mL. A total of thirteen calibration standards ranging from 0.0125 ng/mL to 50 ng/mL (nominal) were analyzed (0.0125 ng/mL to 10 ng/mL (nominal) for the SRSs). Low or high points may have been disabled to meet method criteria. A quadratic, 1/x weighted, calibration curve of the ratio of the standard peak area counts over the internal standard peak area counts was used to fit the data for each analyte. The data were not forced through zero during the fitting process. Calculating the standard concentrations using the peak area ratios and the resultant calibration curve confirmed accuracy of each curve point. For each calibration curve, the reference standards of PFOA and PFOS used to prepare the calibration standards consisted of both linear and branched isomers. Each curve point was quantitated using the overall calibration curve and reviewed for accuracy. Method calibration accuracy requirements of 10025% (10030% for the lowest curve point) were met for all analytes. The correlation coefficient r was greater than 0.995 for all analytes. PAGE 6 OF 25 3M ENVIRONMENTAL LABORATORY REPORT NO. ISO14-07-05 3.2 System Suitability A calibration standard was analyzed four times at the beginning of the analytical sequence to demonstrate overall system suitability. The acceptance criteria for system suitability samples is less than or equal to 5% relative standard deviation (RSD) for peak area/ratio and retention time criteria of less than or equal to 2% RSD. These criteria were met for all analytes with the exception of the peak area count RSD for PFBS (7.1%) and PFHS (6.6%) analyzed on 5/22/14. A method deviation is filed with the raw data. 3.3 Limit of Quantitation (LOQ) The LOQ as defined in method ETS-8-044.1 is the lowest non-zero calibration standard in the curve that meets linearity and accuracy requirements and for which the area counts are at least twice those of the appropriate blanks. The LOQs associated with the sample analysis are listed in Table 6. Table 6. LOQ LOQ, ng/mL LOQ, ng/mL LOQ, ng/mL LOQ, ng/mL Analyte 5/22/14 Analysis (1) 5/22/14 Analysis (2) 5/28/14 Analysis (3) 6/4/14 Analysis (4) PFOA 9.58 19.2 9.58 0.0240 PFBS 10.0 20.0 NA 0.0500 PFHS 10.0 20.0 NA 0.0500 PFOS 9.27 18.5 9.27 0.0232 NA = Not Applicable (1) The dilution factor of 100 was applied to the LOQ for the analysis of the Trip Blank HS sample for all analytes, and locations ACM2 and ACE for PFBS. (2) The dilution factor of 200 was applied to the LOQ for the analysis of locations ACI, WW8R, WW9R, WW10R, and WW11R. (3) The dilution factor of 100 was applied to the LOQ for the analysis of WW11R for PFOA and PFOS. (4) The dilution factor of 2 was applied to the LOQ for the analysis of the Trip Blank sample and low spike for all analytes, and locations ACM2 and ACE for PFOA, PFHS, and PFOS. 3.4 Continuing Calibration During the course of the analytical sequence, several continuing calibration verification samples (CCVs) were analyzed to confirm that the instrument response and the initial calibration curve were still in control. The method acceptance criteria of 100% 25% was met for all analytes. 3.5 Blanks Two types of blanks were prepared and analyzed with the samples: method blanks/solvent blanks and field/trip blanks. Each blank result was reviewed and used to evaluate method performance to determine the LOQ for each analyte. 3.6 Lab Control Spikes (LCSs) Low, mid, and high lab control spikes were prepared for the target analytes and analyzed in triplicate, while only low and high lab control spikes were prepared for the surrogates. LCSs were prepared by spiking known amounts of the analytes into either 10 mL of laboratory-prepared matrix matched water or 1 mL of Milli-Q water to produce the desired concentration. When applicable, the LCSs were then diluted with methanol in the same manner as the samples. Method ETS-8-044.1 states that the average recovery of LCSs at each spiking level be within 80%-120% with a RSD <20%. All LCS samples met method accuracy criteria. All LCSs were used in the determination of the analytical method uncertainty in section 3.7. The following calculations were used to generate data in Table 7. PAGE 7 OF 25 3M ENVIRONMENTAL LABORATORY REPORT NO. ISO14-07-05 Calculated Concentration * ____ _ LCS Percent Recovery -------------------------------------* 100% Spike Concentration LCS% RSD = standard deviation LCS replicates * 1QQ% average LCS recovery Table 7. Lab Control Spike Results. ETS-8-044.1 External Standard Calibration Analyzed 5/22/14 Lab ID Spiked Concentration (ng/mL) PFBS Calculated Concentration (ng/mL) LCS-140522-1 LCS-140522-2 LCS-140522-3 Average %RSD LCS-140522-4 LCS-140522-5 LCS-140522-6 Average %RSD LCS-140522-7 LCS-140522-8 LCS-140522-9 Average %RSD 1.00 0.830 1.00 0.856 1.00 0.916 86.7% 5.1% 10.0 11.1 10.0 8.97 10.0 9.51 98.6% 11% 39.8 40.2 39.8 40.9 39.8 42.8 104% 2.9% %Recovery Spiked Concentration (ng/mL) PFHS Calculated Concentration (ng/mL) 83.0 1.00 0.888 85.6 1.00 0.923 91.6 1.00 0.987 93.3% 5.4% 111 10.0 11.5 89.7 10.0 9.52 95.1 10.0 9.47 102% 11% 101 39.8 39.8 103 39.8 42.6 107 39.8 41.3 104% 3.4% %Recovery 88.8 92.3 98.7 115 95.2 94.7 100 107 104 ETS-8-044.1 External Standard Calibration Analyzed 5/22/14 Lab ID PFOA (Linear + Branched) Spiked Calculated Concentration Concentration (ng/mL) (ng/mL) %Recovery PFOS (Linear + Branched) Spiked Calculated Concentration Concentration (ng/mL) (ng/mL) %Recovery LCS-140522-1 LCS-140522-2 LCS-140522-3 Average %RSD LCS-140522-4 LCS-140522-5 LCS-140522-6 Average %RSD LCS-140522-7 LCS-140522-8 LCS-140522-9 Average %RSD 0.958 0.958 0.958 9.58 9.58 9.58 38.2 38.2 38.2 0.859 0.855 0.911 91.3% 3.5% 10.5 9.36 9.45 102% 6.7% 39.4 41.2 40.1 105% 2.4% 89.6 89.2 95.0 110 97.7 98.7 103 108 105 0.927 0.927 0.927 9.27 9.27 9.27 36.9 36.9 36.9 0.861 0.878 0.928 95.8% 3.9% 10.5 9.37 9.56 106% 6.6% 38.9 41.7 38.6 108% 4.3% 92.8 94.7 100 114 101 103 105 113 105 PAGE 8 OF 25 3M ENVIRONMENTAL LABORATORY REPORT NO. ISO14-07-05 Table 7 continued. Lab Control Spike Results. ETS-8-044.1 External Standard Calibration Analyzed 5/22/14 Lab ID 13C4-PFOA surrogate Spiked Calculated Concentration Concentration (ng/mL) (ng/mL) %Recovery 13C4-PFOS surrogate Spiked Calculated Concentration Concentration (ng/mL) (ng/mL) %Recovery LCS-140522-1 LCS-140522-2 LCS-140522-3 Average %RSD 0.998 0.998 0.998 0.887 0.879 0.956 90.9% 4.7% 88.9 88.1 95.8 0.956 0.956 0.956 0.882 0.887 0.942 94.5% 3.7% 92.2 92.8 98.6 LCS-140522-4 LCS-140522-5 LCS-140522-6 Average %RSD 9.98 9.89 9.98 8.72 9.98 9.10 92.6% 6.4% 99.1 87.4 91.2 9.56 10.0 9.56 8.87 9.56 8.98 97.3% 6.9% 105 92.8 94.0 ETS-8-044.1 External Standard Calibration Analyzed 5/28/14 Lab ID PFOA (Linear + Branched) Spiked Calculated Concentration Concentration (ng/mL) (ng/mL) %Recovery PFOS (Linear + Branched) Spiked Calculated Concentration Concentration (ng/mL) (ng/mL) %Recovery LCS-140528-1 LCS-140528-2 LCS-140528-3 Average %RSD LCS-140528-4 LCS-140528-5 LCS-140528-6 Average %RSD LCS-140528-7 LCS-140528-8 LCS-140528-9 Average %RSD 0.958 0.958 0.958 9.58 9.58 9.58 38.2 38.2 38.2 0.943 0.915 0.933 97.1% 1.6% 10.4 10.4 10.4 109% 0.53% 41.5 37.2 38.0 102% 6.1% 98.5 95.5 97.4 109 108 109 109 97.3 99.4 0.927 0.927 0.927 9.27 9.27 9.27 36.9 36.9 36.9 0.960 0.952 0.945 103% 0.97% 10.4 10.3 10.6 113% 1.0% 41.0 37.0 37.2 104% 5.8% 104 103 102 112 112 114 111 100 101 PAGE 9 OF 25 3M ENVIRONMENTAL LABORATORY REPORT NO. ISO14-07-05 Table 7 continued. Lab Control Spike Results. ETS-8-044.1 External Standard Calibration Analyzed 5/28/14 Lab ID 13C4-PFOA surrogate Spiked Calculated Concentration Concentration (ng/mL) (ng/mL) %Recovery 13C4-PFOS surrogate Spiked Calculated Concentration Concentration (ng/mL) (ng/mL) %Recovery LCS-140528-1 LCS-140528-2 LCS-140528-3 Average %RSD 0.998 0.998 0.998 0.964 0.955 0.961 96.2% 0.48% 96.6 95.7 96.3 0.956 0.956 0.956 0.947 0.952 0.948 99.3% 0.29% 99.1 99.6 99.1 LCS-140528-4 LCS-140528-5 LCS-140528-6 Average %RSD 9.98 9.83 9.98 10.2 9.98 10.2 101% 2.3% 98.5 102 103 9.56 9.62 9.56 9.83 9.56 10.4 104% 4.0% 101 103 109 ETS-8-044.1 Internal Standard Calibration Analyzed 6/4/14 Lab ID LCS-140604-1 LCS-140604-2 LCS-140604-3 Average %RSD LCS-140604-4 LCS-140604-5 LCS-140604-6 Average %RSD LCS-140604-7 LCS-140604-8 LCS-140604-9 Average %RSD Spiked Concentration (ng/mL) PFBS Calculated Concentration (ng/mL) 0.198 0.198 0.198 0.147 0.166 0.179 82.7% 9.9% 9.92 8.15 9.92 9.00 9.92 7.92 84.2% 6.8% 39.6 38.0 39.6 40.5 39.6 41.5 101% 4.5% %Recovery Spiked Concentration (ng/mL) PFHS Calculated Concentration (ng/mL) 74.0 0.198 0.205 83.8 0.198 0.200 90.3 0.198 0.205 103% 1.7% 82.2 9.92 10.1 90.7 9.92 10.5 79.8 9.92 9.45 101% 5.4% 96.0 39.6 46.5 102 39.6 47.6 105 39.6 47.1 119% 0.84% %Recovery 104 101 104 102 106 95.2 118 120 119 PAGE 10 OF 25 3M ENVIRONMENTAL LABORATORY REPORT NO. ISO14-07-05 Table 7 continued. Lab Control Spike Results. ETS-8-044.1 Internal Standard Calibration Analyzed 6/4/14 Lab ID LCS-140604-1 LCS-140604-2 LCS-140604-3 Average %RSD LCS-140604-4 LCS-140604-5 LCS-140604-6 Average %RSD LCS-140604-7 LCS-140604-8 LCS-140604-9 Average %RSD PFOA (Linear + Branched) Spiked Calculated Concentration Concentration (ng/mL) (ng/mL) %Recovery PFOS (Linear + Branched) Spiked Calculated Concentration Concentration (ng/mL) (ng/mL) %Recovery 0.190 0.190 0.190 0.178 0.180 0.187 95.6% 2.5% 93.6 94.9 98.2 0.184 0.184 0.184 0.209 0.197 0.203 110% 2.8% 113 107 111 9.50 8.23 9.50 9.03 9.50 8.82 91.5% 4.7% 86.7 95.1 92.8 9.20 9.07 9.20 9.81 9.20 9.87 104% 4.7% 98.6 107 107 38.0 42.3 38.0 42.7 38.0 42.2 111% 0.52% 111 112 111 36.7 43.2 36.7 43.5 36.7 44.0 119% 0.84% 118 119 120 ETS-8-044.1 Internal Standard Calibration Analyzed 6/4/14 Lab ID LCS-140604-1 LCS-140604-2 LCS-140604-3 Average %RSD LCS-140604-4 LCS-140604-5 LCS-140604-6 Average %RSD 13C4-PFOA surrogate Spiked Calculated Concentration Concentration (ng/mL) (ng/mL) %Recovery 13C4-PFOS surrogate Spiked Calculated Concentration Concentration (ng/mL) (ng/mL) %Recovery 0.198 0.198 0.198 0.181 0.183 0.195 94.0% 4.1% 91.3 92.3 98.5 0.189 0.189 0.189 0.193 0.201 0.197 104% 1.9% 102 106 104 1.98 1.65 1.98 1.59 1.98 1.76 84.2% 5.2% 83.4 80.2 88.9 1.90 1.68 1.90 1.77 1.90 1.85 92.9% 4.9% 88.2 93.1 97.3 PAGE 11 OF 25 3M ENVIRONMENTAL LABORATORY REPORT NO. ISO14-07-05 3.7 Analytical Method Uncertainty Analytical uncertainty is based on historical QC data that is control charted and used to evaluate method accuracy and precision. The method uncertainty is calculated following ETS-12-012.2. The standard deviation is calculated for the set of accuracy results (in %) obtained for the QC samples. The expanded uncertainty is calculated by multiplying the standard deviation by a factor of 2, which corresponds to a confidence level of 95%. Table 8. Analytical Method Uncertainty. Analyte PFOA PFBS PFHS PFOS PFOA PFBS PFHS PFOS Calibration Method External Standard External Standard External Standard External Standard Internal Standard Internal Standard Internal Standard Internal Standard Standard Deviation (%) 7.51 8.40 6.09 6.30 7.58 9.02 8.30 7.96 Method Uncertainty 15% 17% 12% 13% 15% 18% 17% 16% 3.8 Field Matrix Spikes (FMS) A field matrix spike was collected at each sampling point to verify that the analytical method is applicable to the collected matrix. Field matrix spikes are generated by adding a measured volume of field sample to a container spiked by the laboratory with the target analytes prior to shipping sample containers for sample collection. Table 9 lists the concentrations of the spikes used for this sampling round. Field matrix spike recoveries within method acceptance criteria of 10030% confirm that "unknown" components in the sample matrix do not significantly interfere with the extraction and analysis of the analytes of interest. The standards used for the preparation of the field matrix spiking solutions contained reference materials comprised of both linear and branched isomers for PFOA and PFOS. Field matrix spike recoveries and associated results for each sample set are presented in section 4 of this report. The following calculation was used to generate data in section 4. FMS Recovery - (Sample Concentration of FMS - Average Concentration: Field Sample & Field Sample Dup.) * 1 0 0 % Spike Concentraton PAGE 12 OF 25 3M ENVIRONMENTAL LABORATORY REPORT NO. ISO14-07-05 Table 9. Field Matrix Spike Concentrations. Location ACI ACM2, ACE WW8R, WW9R WW10R WW11R Trip Blank Description Field Matrix Spike Field Matrix Spike Field Matrix Spike Field Matrix Spike Field Matrix Spike Low Field Matrix Spike High Field Matrix Spike Firial Concentr.tion (ng/mL PFOA PFBS PFHS PFOS 1980 4.94 2470 1980 988 4.94 2470 1980 4.95 2480 1980 990 4.95 2480 1980 4.95 2480 1980 990 4.95 2480 1980 4.95 2480 1980 990 4.95 2480 In addition to target analyte field matrix spikes, sample bottles for locations ACM2 and ACE, along with the Trip Blank sample and low spike, contained stable isotope surrogate recovery standards 13C4PFOA and 13C4-PFOS, which were added at a nominal concentration of 0.1 ng/mL prior to sample collection. The 13C4-labeled PFOA was selected to represent PFOA. The 13C4-labeled PFOS was selected to represent the C4, C6, and C8 perfluorosulfonic acids. Surrogate recoveries within method acceptance criteria of 10030% confirm that "unknown" components in the sample matrix do not significantly interfere with the preparation and analysis of the analytes of interest. Surrogate spike recoveries are presented in section 4 of this report. The following calculation was used to generate data in section 4. Calculated Concentration,,.,.,.... SRS Recovery = ---------------------------------------- *100% Spike Concentration 4 Data Summary and Discussion The tables below summarize the sample results and field matrix spike recoveries for the seven locations as well as the Trip Blank. Each table provides the average concentration and the relative percent difference (%RPD) of the sample and sample duplicate. Results and average values are rounded to three significant figures. Relative percent difference (%RPD) values are rounded to two significant figures. Because of rounding, values may vary slightly from those listed in the raw data. Field matrix spikes and surrogate recoveries meeting the method acceptance criteria of 30%, demonstrate that the method is appropriate for the given matrix. All field samples met method acceptance criteria with the following exceptions: The FMS spike level at 5 ng/mL was not appropriate for PFBS for sampling locations ACM2 and ACE (Tables 11 and 12, respectively). However, the surrogate recovery standard 13C4-PFOS met method acceptance criteria and therefore, no additional QC samples were prepared. The recovery for PFOA-Surr for sample ISO14-07-05-016 (WW10R Sample, Table 15) was 67.1%. The average recovery for PFOA-Surr for the sample set was within acceptance criteria at 82.6%. In addition, the FMS sample met method acceptance criteria for all target analytes. Therefore no adjustment was made to the analytical method uncertainty. PAGE 13 OF 25 3M ENVIRONMENTAL LABORATORY REPORT NO. ISO14-07-05 Table 10. DAL GW ACI 140515 (1) 3M LIMS ID Sample Description ISO14-07-05-001 DAL-GW-ACI-0-140515 ISO14-07-05-002 DAL-GW-ACI-DB-140515 ISO14-07-05-003 DAL-GW-ACI-FMS-140515 Average Concentration (ng/mL) %RPD PFOA PFBS Concentration (ng/mL) %Recovery 1910 NA 1670 NA 3640 93.4 1790 ng/mL 13% Concentration (ng/mL) %Recovery 1290 NA 1160 NA 3220 101 1230 ng/mL 11% 3M LIMS ID Sample Description ISO14-07-05-001 DAL-GW-ACI-0-140515 ISO14-07-05-002 DAL-GW-ACI-DB-140515 ISO14-07-05-003 DAL-GW-ACI-FMS-140515 Average Concentration (ng/mL) %RPD PFHS PFOS Concentration (ng/mL) %Recovery 824 NA 718 NA 2600 92.4 771 ng/mL 14% Concentration (ng/mL) %Recovery 536 NA 485 NA 2390 94.9 511 ng/mL 10% 13C4-PFOA 13C4-PFOS 3M LIMS ID Sample Description ISO14-07-05-001 DAL-GW-ACI-0-140515 ISO14-07-05-002 DAL-GW-ACI-DB-140515 ISO14-07-05-003 DAL-GW-ACI-FMS-140515 Average Concentration (ng/mL) %RSD %Recovery 100 94.6 94.4 96.3% 3.3% %Recovery 119 105 106 110% 6.7% NA = Not Applicable (1) Samples were analyzed by external standard calibration on 5/22/14. The surrogate recovery standards 13C4-PFOA and 13C4- PFOS were added to the samples during sample preparation. PAGE 14 OF 25 3M ENVIRONMENTAL LABORATORY REPORT NO. ISO14-07-05 Table 11. DAL GW ACM2 140515 (1) 3M LIMS ID Sample Description ISO14-07-05-004 DAL-GW-ACM2-0-140515 ISO14-07-05-005 DAL-GW-ACM2-DB-140515 ISO14-07-05-006 DAL-GW-ACM2-FMS-140515 Average Concentration (ng/mL) %RPD 3M LIMS ID Sample Description ISO14-07-05-004 DAL-GW-ACM2-0-140515 ISO14-07-05-005 DAL-GW-ACM2-DB-140515 ISO14-07-05-006 DAL-GW-ACM2-FMS-140515 Average Concentration (ng/mL) %RPD PFOA PFBS (2) Concentration (ng/mL) %Recovery 0.132 NA 0.130 NA 4.42 86.8 0.131 ng/mL 1.5% Concentration (ng/mL) %Recovery 973 NA 1070 NA 1030 NC 1020 ng/mL 9.5% PFHS PFOS Concentration (ng/mL) %Recovery 0.142 NA 0.141 NA 5.16 101 0.142 ng/mL 0.71% Concentration (ng/mL) %Recovery 0.328 NA 0.307 NA 5.39 102 0.318 ng/mL 6.6% 13C4-PFOA 13C4-PFOS 13C4-PFOS (2) 3M LIMS ID Sample Description ISO14-07-05-004 DAL-GW-ACM2-0-140515 ISO14-07-05-005 DAL-GW-ACM2-DB-140515 ISO14-07-05-006 DAL-GW-ACM2-FMS-140515 Average Concentration (ng/mL) %RSD %Recovery 88.2 88.7 79.5 85.5% 6.1% %Recovery 101 91.2 93.2 95.1% 5.3% %Recovery 109 119 112 113% 4.7% NA = Not Applicable NC = Not Calculated; Spike level was less than 0.5x the endogenous sample concentration. (1) Samples were analyzed by internal standard calibration on 6/4/14 except where otherwise noted. (2) Samples were analyzed by external standard calibration on 5/22/14. The surrogate recovery standard 13C4-PFOS was added to the samples during sample preparation. PAGE 15 OF 25 3M ENVIRONMENTAL LABORATORY REPORT NO. ISO14-07-05 Table 12. DAL GW ACE 140515 (1) 3M LIMS ID Sample Description ISO14-07-05-007 DAL-GW-ACE-0-140515 ISO14-07-05-008 DAL-GW-ACE-DB-140515 ISO14-07-05-009 DAL-GW-ACE-FMS-140515 Average Concentration (ng/mL) %RPD 3M LIMS ID Sample Description ISO14-07-05-007 DAL-GW-ACE-0-140515 ISO14-07-05-008 DAL-GW-ACE-DB-140515 ISO14-07-05-009 DAL-GW-ACE-FMS-140515 Average Concentration (ng/mL) %RPD PFOA PFBS (2) Concentration (ng/mL) %Recovery 0.104 NA 0.0940 NA 4.46 88.3 0.0990 ng/mL 10% Concentration (ng/mL) %Recovery 205 NA 199 NA 197 NC 202 ng/mL 3.0% PFHS PFOS Concentration (ng/mL) %Recovery 0.0892 NA 0.0916 NA 5.15 102 0.0904 ng/mL 2.7% Concentration (ng/mL) %Recovery 0.645 NA 0.673 NA 5.35 94.8 0.659 ng/mL 4.4% 13C4-PFOA 13C4-PFOS 13C4-PFOS (2) 3M LIMS ID Sample Description ISO14-07-05-007 DAL-GW-ACE-0-140515 ISO14-07-05-008 DAL-GW-ACE-DB-140515 ISO14-07-05-009 DAL-GW-ACE-FMS-140515 Average Concentration (ng/mL) %RSD %Recovery 80.3 92.2 89.9 87.5% 7.2% %Recovery 108 101 93.5 101% 7.1% %Recovery 113 104 109 109% 3.9% NA = Not Applicable NC = Not Calculated; Spike level was less than 0.5x the endogenous sample concentration. (1) Samples were analyzed by internal standard calibration on 6/4/14 except where otherwise noted. (2) Samples were analyzed by external standard calibration on 5/22/14. The surrogate recovery standard 13C4-PFOS was added to the samples during sample preparation. PAGE 16 OF 25 3M ENVIRONMENTAL LABORATORY REPORT NO. ISO14-07-05 Table 13. DAL GW WW8R 140515 (1) 3M LIMS ID Sample Description ISO14-07-05-010 DAL-GW-WW8R-0-140515 ISO14-07-05-011 DAL-GW-WW8R-DB-140515 ISO14-07-05-012 DAL-GW-WW8R-FMS-140515 Average Concentration (ng/mL) %RPD 3M LIMS ID Sample Description ISO14-07-05-010 DAL-GW-WW8R-0-140515 ISO14-07-05-011 DAL-GW-WW8R-DB-140515 ISO14-07-05-012 DAL-GW-WW8R-FMS-140515 Average Concentration (ng/mL) %RPD PFOA PFBS Concentration (ng/mL) %Recovery 2680 NA 2580 NA 4450 73.7 2630 ng/mL 3.8% Concentration (ng/mL) %Recovery 289 NA 291 NA 2610 93.5 290 ng/mL 0.69% PFHS PFOS Concentration (ng/mL) %Recovery 1150 NA 1160 NA 3170 81.3 1160 ng/mL 0.87% Concentration (ng/mL) %Recovery 4280 NA 4170 NA 6150 77.6 4230 ng/mL 2.6% 13C4-PFOA 13C4-PFOS 3M LIMS ID Sample Description ISO14-07-05-010 DAL-GW-WW8R-0-140515 ISO14-07-05-011 DAL-GW-WW8R-DB-140515 ISO14-07-05-012 DAL-GW-WW8R-FMS-140515 Average Concentration (ng/mL) %RSD %Recovery 93.6 96.0 87.0 92.2% 5.1% %Recovery 107 110 95.2 104% 7.6% NA = Not Applicable (1) Samples were analyzed by external standard calibration on 5/22/14. The surrogate recovery standards 13C4-PFOA and 13C4- PFOS were added to the samples during sample preparation. PAGE 17 OF 25 3M ENVIRONMENTAL LABORATORY REPORT NO. ISO14-07-05 Table 14. DAL GW WW9R 140515 (1) 3M LIMS ID Sample Description ISO14-07-05-013 DAL-GW-WW9R-0-140515 ISO14-07-05-014 DAL-GW-WW9R-DB-140515 ISO14-07-05-015 DAL-GW-WW9R-FMS-140515 Average Concentration (ng/mL) %RPD 3M LIMS ID Sample Description ISO14-07-05-013 DAL-GW-WW9R-0-140515 ISO14-07-05-014 DAL-GW-WW9R-DB-140515 ISO14-07-05-015 DAL-GW-WW9R-FMS-140515 Average Concentration (ng/mL) %RPD PFOA PFBS Concentration (ng/mL) %Recovery 2620 NA 2690 NA 4800 86.8 2660 ng/mL 2.6% Concentration (ng/mL) %Recovery 261 NA 270 NA 2410 86.5 266 ng/mL 3.4% PFHS PFOS Concentration (ng/mL) %Recovery 1110 NA 1160 NA 3220 84.1 1140 ng/mL 4.4% Concentration (ng/mL) %Recovery 4740 NA 4830 NA 7020 90.1 4790 ng/mL 1.9% 13C4-PFOA 13C4-PFOS 3M LIMS ID Sample Description ISO14-07-05-013 DAL-GW-WW9R-0-140515 ISO14-07-05-014 DAL-GW-WW9R-DB-140515 ISO14-07-05-015 DAL-GW-WW9R-FMS-140515 Average Concentration (ng/mL) %RSD %Recovery 85.6 95.0 86.6 89.0% 5.8% %Recovery 96.7 103 94.1 98.0% 4.9% NA = Not Applicable (1) Samples were analyzed by external standard calibration on 5/22/14. The surrogate recovery standards 13C4-PFOA and 13C4- PFOS were added to the samples during sample preparation. PAGE 18 OF 25 3M ENVIRONMENTAL LABORATORY REPORT NO. ISO14-07-05 Table 15. DAL GW WW10R 140515 (1) 3M LIMS ID Sample Description ISO14-07-05-016 DAL-GW-WW10R-0-140515 ISO14-07-05-017 DAL-GW-WW10R-DB-140515 ISO14-07-05-018 DAL-GW-WW10R-FMS-140515 Average Concentration (ng/mL) %RPD 3M LIMS ID Sample Description ISO14-07-05-016 DAL-GW-WW10R-0-140515 ISO14-07-05-017 DAL-GW-WW10R-DB-140515 ISO14-07-05-018 DAL-GW-WW10R-FMS-140515 Average Concentration (ng/mL) %RPD PFOA PFBS Concentration (ng/mL) %Recovery 1810 NA 1710 NA 3570 91.4 1760 ng/mL 5.7% Concentration (ng/mL) %Recovery 223 NA 216 NA 2050 92.4 220 ng/mL 3.2% PFHS PFOS Concentration (ng/mL) %Recovery 846 NA 799 NA 2710 95.3 823 ng/mL 5.7% Concentration (ng/mL) %Recovery 2760 NA 2590 NA 4850 110 2680 ng/mL 6.4% 13C4-PFOA 13C4-PFOS 3M LIMS ID Sample Description ISO14-07-05-016 DAL-GW-WW10R-0-140515 ISO14-07-05-017 DAL-GW-WW10R-DB-140515 ISO14-07-05-018 DAL-GW-WW10R-FMS-140515 Average Concentration (ng/mL) %RSD %Recovery 67.1 (2) 89.2 91.4 82.6% 16% %Recovery 72.8 96.7 97.5 89.0% 16% NA = Not Applicable (1) Samples were analyzed by external standard calibration on 5/22/14. The surrogate recovery standards 13C4-PFOA and 13C4- PFOS were added to the samples during sample preparation. (2) Surrogate recovery standard did not meet acceptance criteria of 100% 30%. PAGE 19 OF 25 3M ENVIRONMENTAL LABORATORY REPORT NO. ISO14-07-05 Table 16. DAL GW WW11R 140515 (1) 3M LIMS ID Sample Description ISO14-07-05-019 DAL-GW-WW11R-0-140515 ISO14-07-05-020 DAL-GW-WW11R-DB-140515 ISO14-07-05-021 DAL-GW-WW11R-FMS-140515 Average Concentration (ng/mL) %RPD 3M LIMS ID Sample Description ISO14-07-05-019 DAL-GW-WW11 R-0-140515 ISO14-07-05-020 DAL-GW-WW11 R-DB-140515 ISO14-07-05-021 DAL-GW-WW11 R-FMS-140515 Average Concentration (ng/mL) %RPD PFOA PFBS Concentration (ng/mL) %Recovery 1200 NA 1290 NA 2040 80.5 1250 ng/mL 7.2% Concentration (ng/mL) %Recovery 230 NA 244 NA 1250 102 237 ng/mL 5.9% PFHS PFOS Concentration (ng/mL) %Recovery 651 NA 646 NA 1860 122 649 ng/mL 0.77% Concentration (ng/mL) %Recovery 1610 NA 1890 NA 2540 79.8 1750 ng/mL 16% 13C4-PFOA 5/22/14 13C4-PFOS 5/22/14 13C4-PFOA 5/28/14 13C4-PFOS 5/28/14 3M LIMS ID Sample Description ISO14-07-05-019 DAL-GW-WW11 R-0-140515 ISO14-07-05-020 DAL-GW-WW11 R-DB-140515 ISO14-07-05-021 DAL-GW-WW11 R-FMS-140515 Average Concentration (ng/mL) %RSD %Recovery 94.4 95.6 97.4 95.8% 1.6% %Recovery %Recovery 105 107 108 107% 1.6% 88.2 90.3 87.3 88.6% 1.7% %Recovery 88.8 86.0 85.8 86.9% 2.0% NA = Not Applicable (1) Samples were analyzed by external standard calibration 5/22/14 or 5/28/14. The surrogate recovery standards 13C4-PFOA and 13C4-PFOS were added to the samples during sample preparation. PAGE 20 OF 25 3M ENVIRONMENTAL LABORATORY REPORT NO. ISO14-07-05 Table 17. Trip Blank Results 3M LIMS ID ISO14-07-05-022 ISO14-07-05-023 ISO14-07-05-024 Sample Description DAL-GW-TRI P-0-140515 DAL-GW-TRIP-LS-140515 DAL-GW-TRI P-HS-140515 3M LIMS ID ISO14-07-05-022 ISO14-07-05-023 ISO14-07-05-024 Sample Description DAL-GW-TRI P-0-140515 DAL-GW-TRI P-LS-140515 DAL-GW-TRI P-HS-140515 PFOA PFBS Concentration (ng/mL) <0.0240 (1) 4.49 (1) 2270 (2) %Recovery NA 90.9 91.9 Concentration (ng/mL) <0.0500 (1) 4.06 (1) 2140 (2) %Recovery NA 82.0 86.3 PFHS PFOS Concentration (ng/mL) <0.0500 (1) 4.97 (1) 2230 (2) %Recovery NA 100 89.9 Concentration (ng/mL) <0.0232 (1) 4.87 (1) 2290 (2) %Recovery NA 98.4 92.3 13c 4-p f o a (1) 13c 4-p f o s (1) 13C4-PFOA (2) 13C4-PFOS (2) 3M LIMS ID ISO14-07-05-022 ISO14-07-05-023 ISO14-07-05-024 Sample Description DAL-GW-TRI P-0-140515 DAL-GW-TRI P-LS-140515 DAL-GW-TRI P-HS-140515 %Recovery 87.3 93.5 NA %Recovery 101 89.1 NA %Recovery 98.3 75.6 86.2 %Recovery 106 74.4 85.7 NA = Not Applicable (1) Samples were analyzed by internal standard calibration on 6/4/14. (2) Samples were analyzed by external standard calibration on 5/22/14. The surrogate recovery standards 13C4-PFOA and 13C4- PFOS were added to the samples during sample preparation PAGE 21 OF 25 3M ENVIRONMENTAL LABORATORY REPORT NO. ISO14-07-05 5 Conclusion Laboratory control spikes were used to determine the analytical method accuracy and precision for all analytes. The accuracy and precision were then used to estimate the method uncertainty for the results. Field matrix spike recoveries demonstrated that the analytical method was appropriate for the given sample matrix. Analysis was completed using 3M Environmental Laboratory Method ETS-8044.1 "Method of Analysis for the Determination of Perfluorinated Compounds in Water by LC/MS/MS; Direct Injection Analysis". Analytical results are reported in Table 1 and 10-17 of this report. 6 Data / Sample Retention All remaining sample and associated project data (hardcopy and electronic) will be archived according to 3M Environmental Laboratory standard operating procedures. 7 Attachments Attachment A: Analyte Trend Data for the Decatur Ground Water Treatment Plant (GWTP) GAC System. 8 Signatures Digitally signed by Susan T. W olf DN: c=US, st=MN, l=St. Paul, ou=3M Environmental Laboratory - authenticated by LRA, email=stw olf@ mm m .com , o=3M, cn=Susan T. W olf Reason: i have reviewed this document Date: 2014.06.26 10:53:13 -05`00' Susan T. Wolf, 3M Principal Analytical Investigator Digitally signed by William K. Reagen DN: c=US. st=MIN. l=St. Paul, ou=Laboratory Director. ou=3lvl Environmental Laboratory - authenticated by LRA. email=wkreagen@mmm.com. o=3M, cn=William K. Reagen Reason: I am approving this document Date: 2014.06.27 12:42:16 -05'00' William K. Reagen, Ph.D., 3M Environmental Laboratory Technical Director The 3M Environmental Laboratory's Quality Assurance Unit has audited the data and report for this project. Digitally signed by Matthew D. Naruko-Stewart DN: c=US. st=MN. l=St. Paul, ou=Quality Assurance Unit. ou=3M Environmental Laboratory - authenticated by LRA. email=mstewart2@mmm.com. o=3M. cn=Matthew D. NarukoStewart Reason: I agree to the terms defined by the placement of my signature on this document Date: 2014.06.26 13:31:16 -05'00' Quality Assurance Representative This test report shall not be reproduced except in full, without written approval of the 3M Environmental Laboratory. PAGE 22 OF 25 3M ENVIRONMENTAL LABORATORY REPORT NO. ISO14-07-05 Attachment A: Analyte Trend Data for select sampling points at the Decatur Ground Water Treatment Plant (GWTP) GAC System. ACI (Activated Carbon Influent) - Sample Results in ng/mL FC Charting for DAL_GWTP_ACI ACI PFOA PFBS PFHS PFOS 6/27/13 1480 708 942 1590 7/23/13 1630 1230 749 1680 9/30/13 2320 356 1400 3240 10/28/13 1880 1590 866 2100 11/18/13 2190 1100 1330 2240 12/13/13 1830 1350 695 1970 1/30/14 1580 202 845 2700 2/27/14 1870 1470 737 1800 3/31/14 2410 541 1110 3600 4/23/14 2080 1250 790 1480 5/15/14 1790 1230 771 511 No samples were collected in August 2013. ACE (Activated Carbon Effluent) - Sample Results in ng/mL FC Charting far DAL_GWTP_ACE ACE PFOA PFBS PFHS PFOS 6/27/13 0.0717 111 0.118 <0.0232 7/23/13 0.0641 1960 0.0778 0.0277 9/30/13 0.115 1950 0.156 0.0452 10/28/13 0.231 0.379 0.180 0.0785 11/18/13 0.478 0.592 0.366 0.0726 12/13/13 0.0798 0.0766 0.0648 0.0303 No samples were collected in August 2013. 1/30/14 0.490 0.257 0.219 0.209 2/27/14 0.138 0.0360 0.0706 0.0966 3/31/14 0.262 0.224 0.108 0.139 4/23/14 0.172 69.7 0.0812 0.0567 5/15/14 0.0990 202 0.0904 0.659 PAGE 23 OF 25 3M ENVIRONMENTAL LABORATORY REPORT NO. ISO14-07-05 Attachment A: Analyte Trend Data for select sampling points at the Decatur Ground Water Treatment Plant (GWTP) GAC System WW8R - Sample Results in ng/mL W W 8R PFOA PFBS PFHS PFOS 6/27/13 2760 282 1340 4110 7/23/13 2640 263 1260 3910 9/30/13 2890 303 1370 4100 10/28/13 2830 312 1300 4410 11/18/13 3040 362 1440 4750 12/13/13 2720 316 1270 4060 1/30/14 2660 326 1460 3990 2/27/14 2560 331 1370 4170 3/31/14 3290 357 1470 5790 4/23/14 2730 283 1180 3840 5/15/14 2630 290 1160 4230 No samples were collected in August 2013. WW9R - Sample Results in ng/mL PFO A------- --------PFO S------- --------- P FB S ------- --------- PFHS------- W W 9R PFOA PFBS PFHS PFOS 6/27/13 2630 225 1140 4150 7/23/13 2410 212 1030 3670 9/30/13 2730 249 1220 4200 10/28/13 2820 286 1280 4380 11/18/13 2950 305 1340 4540 12/13/13 2690 259 1170 4190 1/30/14 2900 317 1460 4800 No samples were collected in August 2013. 2/27/14 2630 270 1370 4660 3/31/14 3380 341 1550 5420 4/23/14 2820 257 1120 3820 5/15/14 2660 266 1140 4790 PAGE 24 OF 25 3M ENVIRONMENTAL LABORATORY REPORT NO. ISO14-07-05 Attachment A: Analyte Trend Data for select sampling points at the Decatur Ground Water Treatment Plant (GWTP) GAC System WW10R - Sample Results in ng/mL W W 10R PFOA PFBS PFHS PFOS 9/30/13 2070 247 1030 2770 10/28/13 2150 264 1030 3160 11/18/13 2400 303 1120 3890 12/13/13 1890 239 885 2920 1/30/14 1330 250 757 1570 2/27/14 1780 260 935 2860 3/31/14 2140 278 1030 3490 4/23/14 1850 243 885 2130 5/15/14 1760 220 823 2680 WW11R - Sample Results in ng/mL W W 11R PFOA PFBS PFHS PFOS 9/30/13 1720 299 1000 2200 10/28/13 1100 240 511 1670 11/18/13 1320 287 680 1850 12/13/13 1060 198 512 1570 1/30/14 814 168 362 1540 2/27/14 1300 262 696 2100 3/31/14 1190 254 549 1890 4/23/14 1120 212 527 1630 5/15/14 1250 237 649 1750 PAGE 25 OF 25