3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO14-07-05

PAGE 1 OF 25

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.
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO14-07-05

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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.

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.
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO14-07-05

PAGE 3 OF 25

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%.
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO14-07-05

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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 Acronym

Reference 

Material Structure

Perfluorooctanoic Acid (C8 Acid) PFOA Linear + Branched

Perfluorobutanesulfonate (C4 Sulfonate ) PFBS Linear

Perfluorohexanesulfonate (C6 Sulfonate) PFHS Linear

Perfluorooctanesulfonate (C8 Sulfonate) PFOS 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 
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO14-07-05

PAGE 5 OF 25

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 ETS McCoy

Analysis Dates

5/22/14 and 5/28/14 – external standard calibration

6/4/14 – internal standard calibration

Analytical Method ETS-8-044.1

Liquid Chromatograph Agilent 1290

Guard column Betasil C18 (4.6 mm X 100 mm), 5 μ

Analytical column Betasil C18 (4.6 mm X 100 mm), 5 μ

Injection Volume 10 or 5 μL

Mass Spectrometer Applied Biosystems API 5500

Ion Source Turbo Spray

Polarity Negative

Software Analyst 1.6.1

Table 4. Liquid Chromatography Gradient Program 

Step 

Number

Total Time 

(min) Flow Rate (μL/min)

Percent A

(2 mM ammonium acetate)

Percent B

(Methanol)

ETS-8-044.1 Analysis

0 0.0 750 90 10

1 0.50 750 90 10

2 4.00 750 70 30

3 6.00 750 70 30

4 11.00 750 20 80

5 13.00 750 20 80

6 13.50 750 10 90

7 16.00 750 10 90

8 16.50 750 90 10

9 19.00 750 90 10
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO14-07-05

PAGE 6 OF 25

Table 5. Mass Transitions.

Analyte

Mass Transition

Q1/Q3 Internal Standard (1) Mass Transition

Q1/Q3

PFOA

413/369

[

13 413/219 C8]PFOA 421/376

413/169

PFBS

299/80

[

18

O2]PFBS 303/84

299/99

PFHS

399/99

[

13C3]PFHS 402/80

399/80

PFOS

499/99

[

13 499/80 C8]PFOS 507/80

499/130

[

13C4]PFOA surrogate 417/372 [13C8]PFOA 421/376

[

13C4]PFOS surrogate 503/80 [13C8]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 

100±25% (100±30% for the lowest curve point) were met for all analytes. The correlation coefficient r 

was greater than 0.995 for all analytes.
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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

Analyte

LOQ, ng/mL

5/22/14 Analysis (1)

LOQ, ng/mL

5/22/14 Analysis (2)

LOQ, ng/mL

5/28/14 Analysis (3)

LOQ, ng/mL

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.
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REPORT NO. ISO14-07-05

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* 100%

Spike Concentration

Calculated Concentration LCSPercent Recovery =

* 100%

average LCS recovery

standard deviation LCS replicates LCS% RSD =

Table 7. Lab Control Spike Results.

ETS-8-044.1

External Standard Calibration

Analyzed 5/22/14 PFBS PFHS

Lab ID

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

LCS-140522-1 1.00 0.830 83.0 1.00 0.888 88.8

LCS-140522-2 1.00 0.856 85.6 1.00 0.923 92.3

LCS-140522-3 1.00 0.916 91.6 1.00 0.987 98.7

Average ± %RSD 86.7% ± 5.1% 93.3% ± 5.4%

LCS-140522-4 10.0 11.1 111 10.0 11.5 115

LCS-140522-5 10.0 8.97 89.7 10.0 9.52 95.2

LCS-140522-6 10.0 9.51 95.1 10.0 9.47 94.7

Average ± %RSD 98.6% ± 11% 102% ± 11%

LCS-140522-7 39.8 40.2 101 39.8 39.8 100

LCS-140522-8 39.8 40.9 103 39.8 42.6 107

LCS-140522-9 39.8 42.8 107 39.8 41.3 104

Average ± %RSD 104% ± 2.9% 104% ± 3.4%

ETS-8-044.1

External Standard Calibration

Analyzed 5/22/14 PFOA (Linear + Branched) PFOS (Linear + Branched)

Lab ID

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

LCS-140522-1 0.958 0.859 89.6 0.927 0.861 92.8

LCS-140522-2 0.958 0.855 89.2 0.927 0.878 94.7

LCS-140522-3 0.958 0.911 95.0 0.927 0.928 100

Average ± %RSD 91.3% ± 3.5% 95.8% ± 3.9%

LCS-140522-4 9.58 10.5 110 9.27 10.5 114

LCS-140522-5 9.58 9.36 97.7 9.27 9.37 101

LCS-140522-6 9.58 9.45 98.7 9.27 9.56 103

Average ± %RSD 102% ± 6.7% 106% ± 6.6%

LCS-140522-7 38.2 39.4 103 36.9 38.9 105

LCS-140522-8 38.2 41.2 108 36.9 41.7 113

LCS-140522-9 38.2 40.1 105 36.9 38.6 105

Average ± %RSD 105% ± 2.4% 108% ± 4.3%
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Table 7 continued. Lab Control Spike Results.

ETS-8-044.1

External Standard Calibration

Analyzed 5/22/14 13C4-PFOA surrogate 13C4-PFOS surrogate

Lab ID

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

LCS-140522-1 0.998 0.887 88.9 0.956 0.882 92.2

LCS-140522-2 0.998 0.879 88.1 0.956 0.887 92.8

LCS-140522-3 0.998 0.956 95.8 0.956 0.942 98.6

Average ± %RSD 90.9% ± 4.7% 94.5% ± 3.7%

LCS-140522-4 9.98 9.89 99.1 9.56 10.0 105

LCS-140522-5 9.98 8.72 87.4 9.56 8.87 92.8

LCS-140522-6 9.98 9.10 91.2 9.56 8.98 94.0

Average ± %RSD 92.6% ± 6.4% 97.3% ± 6.9%

ETS-8-044.1

External Standard Calibration

Analyzed 5/28/14 PFOA (Linear + Branched) PFOS (Linear + Branched)

Lab ID

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

LCS-140528-1 0.958 0.943 98.5 0.927 0.960 104

LCS-140528-2 0.958 0.915 95.5 0.927 0.952 103

LCS-140528-3 0.958 0.933 97.4 0.927 0.945 102

Average ± %RSD 97.1% ± 1.6% 103% ± 0.97%

LCS-140528-4 9.58 10.4 109 9.27 10.4 112

LCS-140528-5 9.58 10.4 108 9.27 10.3 112

LCS-140528-6 9.58 10.4 109 9.27 10.6 114

Average ± %RSD 109% ± 0.53% 113% ± 1.0%

LCS-140528-7 38.2 41.5 109 36.9 41.0 111

LCS-140528-8 38.2 37.2 97.3 36.9 37.0 100

LCS-140528-9 38.2 38.0 99.4 36.9 37.2 101

Average ± %RSD 102% ± 6.1% 104% ± 5.8%
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Table 7 continued. Lab Control Spike Results.

ETS-8-044.1

External Standard Calibration

Analyzed 5/28/14 13C4-PFOA surrogate 13C4-PFOS surrogate

Lab ID

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

LCS-140528-1 0.998 0.964 96.6 0.956 0.947 99.1

LCS-140528-2 0.998 0.955 95.7 0.956 0.952 99.6

LCS-140528-3 0.998 0.961 96.3 0.956 0.948 99.1

Average ± %RSD 96.2% ± 0.48% 99.3% ± 0.29%

LCS-140528-4 9.98 9.83 98.5 9.56 9.62 101

LCS-140528-5 9.98 10.2 102 9.56 9.83 103

LCS-140528-6 9.98 10.2 103 9.56 10.4 109

Average ± %RSD 101% ± 2.3% 104% ± 4.0%

ETS-8-044.1

Internal Standard Calibration

Analyzed 6/4/14 PFBS PFHS

Lab ID

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

LCS-140604-1 0.198 0.147 74.0 0.198 0.205 104

LCS-140604-2 0.198 0.166 83.8 0.198 0.200 101

LCS-140604-3 0.198 0.179 90.3 0.198 0.205 104

Average ± %RSD 82.7% ± 9.9% 103% ± 1.7%

LCS-140604-4 9.92 8.15 82.2 9.92 10.1 102

LCS-140604-5 9.92 9.00 90.7 9.92 10.5 106

LCS-140604-6 9.92 7.92 79.8 9.92 9.45 95.2

Average ± %RSD 84.2% ± 6.8% 101% ± 5.4%

LCS-140604-7 39.6 38.0 96.0 39.6 46.5 118

LCS-140604-8 39.6 40.5 102 39.6 47.6 120

LCS-140604-9 39.6 41.5 105 39.6 47.1 119

Average ± %RSD 101% ± 4.5% 119% ± 0.84%
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Table 7 continued. Lab Control Spike Results.

ETS-8-044.1

Internal Standard Calibration

Analyzed 6/4/14 PFOA (Linear + Branched) PFOS (Linear + Branched)

Lab ID

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

LCS-140604-1 0.190 0.178 93.6 0.184 0.209 113

LCS-140604-2 0.190 0.180 94.9 0.184 0.197 107

LCS-140604-3 0.190 0.187 98.2 0.184 0.203 111

Average ± %RSD 95.6% ± 2.5% 110% ± 2.8%

LCS-140604-4 9.50 8.23 86.7 9.20 9.07 98.6

LCS-140604-5 9.50 9.03 95.1 9.20 9.81 107

LCS-140604-6 9.50 8.82 92.8 9.20 9.87 107

Average ± %RSD 91.5% ± 4.7% 104% ± 4.7%

LCS-140604-7 38.0 42.3 111 36.7 43.2 118

LCS-140604-8 38.0 42.7 112 36.7 43.5 119

LCS-140604-9 38.0 42.2 111 36.7 44.0 120

Average ± %RSD 111% ± 0.52% 119% ± 0.84%

ETS-8-044.1

Internal Standard Calibration

Analyzed 6/4/14 13C4-PFOA surrogate 13C4-PFOS surrogate

Lab ID

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

LCS-140604-1 0.198 0.181 91.3 0.189 0.193 102

LCS-140604-2 0.198 0.183 92.3 0.189 0.201 106

LCS-140604-3 0.198 0.195 98.5 0.189 0.197 104

Average ± %RSD 94.0% ± 4.1% 104% ± 1.9%

LCS-140604-4 1.98 1.65 83.4 1.90 1.68 88.2

LCS-140604-5 1.98 1.59 80.2 1.90 1.77 93.1

LCS-140604-6 1.98 1.76 88.9 1.90 1.85 97.3

Average ± %RSD 84.2% ± 5.2% 92.9% ± 4.9%
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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 Calibration Method Standard Deviation (%) Method Uncertainty

PFOA External Standard 7.51 ±15%

PFBS External Standard 8.40 ±17%

PFHS External Standard 6.09 ±12%

PFOS External Standard 6.30 ±13%

PFOA Internal Standard 7.58 ±15%

PFBS Internal Standard 9.02 ±18%

PFHS Internal Standard 8.30 ±17%

PFOS Internal Standard 7.96 ±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 100±30% 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.

*100%

Spike Concentraton

(Sample Concentration of FMS Average Concentration:FieldSample & FieldSample Dup.) FMS Recovery − =
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Table 9. Field Matrix Spike Concentrations.

Final Concentration (ng/mL)

Location Description PFOA PFBS PFHS PFOS

ACI Field Matrix Spike 1980 1980 1980 1980

ACM2, ACE Field Matrix Spike 4.94 4.95 4.95 4.95

WW8R, WW9R Field Matrix Spike 2470 2480 2480 2480

WW10R Field Matrix Spike 1980 1980 1980 1980

WW11R Field Matrix Spike 988 990 990 990

Trip Blank

Low Field Matrix Spike 4.94 4.95 4.95 4.95

High Field Matrix Spike 2470 2480 2480 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 13C4-

PFOA 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 100±30% 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.

*100%

Spike Concentration

Calculated Concentration SRS Recovery =

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. 
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Table 10. DAL GW ACI 140515 (1)

PFOA PFBS

3M LIMS ID Sample Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO14-07-05-001 DAL-GW-ACI-0-140515 1910 NA 1290 NA

ISO14-07-05-002 DAL-GW-ACI-DB-140515 1670 NA 1160 NA

ISO14-07-05-003 DAL-GW-ACI-FMS-140515 3640 93.4 3220 101

Average Concentration (ng/mL) ± %RPD 1790 ng/mL ± 13% 1230 ng/mL ± 11%

PFHS PFOS

3M LIMS ID Sample Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO14-07-05-001 DAL-GW-ACI-0-140515 824 NA 536 NA

ISO14-07-05-002 DAL-GW-ACI-DB-140515 718 NA 485 NA

ISO14-07-05-003 DAL-GW-ACI-FMS-140515 2600 92.4 2390 94.9

Average Concentration (ng/mL) ± %RPD 771 ng/mL ± 14% 511 ng/mL ± 10% 

13C4-PFOA 13C4-PFOS

3M LIMS ID Sample Description %Recovery %Recovery

ISO14-07-05-001 DAL-GW-ACI-0-140515 100 119

ISO14-07-05-002 DAL-GW-ACI-DB-140515 94.6 105

ISO14-07-05-003 DAL-GW-ACI-FMS-140515 94.4 106

Average Concentration (ng/mL) ± %RSD 96.3% ± 3.3% 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.
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Table 11. DAL GW ACM2 140515 (1)

PFOA PFBS (2)

3M LIMS ID Sample Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO14-07-05-004 DAL-GW-ACM2-0-140515 0.132 NA 973 NA

ISO14-07-05-005 DAL-GW-ACM2-DB-140515 0.130 NA 1070 NA

ISO14-07-05-006 DAL-GW-ACM2-FMS-140515 4.42 86.8 1030 NC

Average Concentration (ng/mL) ± %RPD 0.131 ng/mL ± 1.5% 1020 ng/mL ± 9.5%

PFHS PFOS

3M LIMS ID Sample Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO14-07-05-004 DAL-GW-ACM2-0-140515 0.142 NA 0.328 NA

ISO14-07-05-005 DAL-GW-ACM2-DB-140515 0.141 NA 0.307 NA

ISO14-07-05-006 DAL-GW-ACM2-FMS-140515 5.16 101 5.39 102

Average Concentration (ng/mL) ± %RPD 0.142 ng/mL ± 0.71% 0.318 ng/mL ± 6.6%

13C4-PFOA 13C4-PFOS 13C4-PFOS (2)

3M LIMS ID Sample Description %Recovery %Recovery %Recovery

ISO14-07-05-004 DAL-GW-ACM2-0-140515 88.2 101 109

ISO14-07-05-005 DAL-GW-ACM2-DB-140515 88.7 91.2 119

ISO14-07-05-006 DAL-GW-ACM2-FMS-140515 79.5 93.2 112

Average Concentration (ng/mL) ± %RSD 85.5% ± 6.1% 95.1% ± 5.3% 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.
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Table 12. DAL GW ACE 140515 (1)

PFOA PFBS(2)

3M LIMS ID Sample Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO14-07-05-007 DAL-GW-ACE-0-140515 0.104 NA 205 NA

ISO14-07-05-008 DAL-GW-ACE-DB-140515 0.0940 NA 199 NA

ISO14-07-05-009 DAL-GW-ACE-FMS-140515 4.46 88.3 197 NC

Average Concentration (ng/mL) ± %RPD 0.0990 ng/mL ± 10% 202 ng/mL ± 3.0%

PFHS PFOS

3M LIMS ID Sample Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO14-07-05-007 DAL-GW-ACE-0-140515 0.0892 NA 0.645 NA

ISO14-07-05-008 DAL-GW-ACE-DB-140515 0.0916 NA 0.673 NA

ISO14-07-05-009 DAL-GW-ACE-FMS-140515 5.15 102 5.35 94.8

Average Concentration (ng/mL) ± %RPD 0.0904 ng/mL ± 2.7% 0.659 ng/mL ± 4.4%

13C4-PFOA 13C4-PFOS 13C4-PFOS (2)

3M LIMS ID Sample Description %Recovery %Recovery %Recovery

ISO14-07-05-007 DAL-GW-ACE-0-140515 80.3 108 113

ISO14-07-05-008 DAL-GW-ACE-DB-140515 92.2 101 104

ISO14-07-05-009 DAL-GW-ACE-FMS-140515 89.9 93.5 109

Average Concentration (ng/mL) ± %RSD 87.5% ± 7.2% 101% ± 7.1% 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.
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Table 13. DAL GW WW8R 140515 (1)

PFOA PFBS

3M LIMS ID Sample Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO14-07-05-010 DAL-GW-WW8R-0-140515 2680 NA 289 NA

ISO14-07-05-011 DAL-GW-WW8R-DB-140515 2580 NA 291 NA

ISO14-07-05-012 DAL-GW-WW8R-FMS-140515 4450 73.7 2610 93.5

Average Concentration (ng/mL) ± %RPD 2630 ng/mL ± 3.8% 290 ng/mL ± 0.69%

PFHS PFOS

3M LIMS ID Sample Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO14-07-05-010 DAL-GW-WW8R-0-140515 1150 NA 4280 NA

ISO14-07-05-011 DAL-GW-WW8R-DB-140515 1160 NA 4170 NA

ISO14-07-05-012 DAL-GW-WW8R-FMS-140515 3170 81.3 6150 77.6

Average Concentration (ng/mL) ± %RPD 1160 ng/mL ± 0.87% 4230 ng/mL ± 2.6%

13C4-PFOA 13C4-PFOS

3M LIMS ID Sample Description %Recovery %Recovery

ISO14-07-05-010 DAL-GW-WW8R-0-140515 93.6 107

ISO14-07-05-011 DAL-GW-WW8R-DB-140515 96.0 110

ISO14-07-05-012 DAL-GW-WW8R-FMS-140515 87.0 95.2

Average Concentration (ng/mL) ± %RSD 92.2% ± 5.1% 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.
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Table 14. DAL GW WW9R 140515 (1)

PFOA PFBS

3M LIMS ID Sample Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO14-07-05-013 DAL-GW-WW9R-0-140515 2620 NA 261 NA

ISO14-07-05-014 DAL-GW-WW9R-DB-140515 2690 NA 270 NA

ISO14-07-05-015 DAL-GW-WW9R-FMS-140515 4800 86.8 2410 86.5

Average Concentration (ng/mL) ± %RPD 2660 ng/mL ± 2.6% 266 ng/mL ± 3.4%

PFHS PFOS

3M LIMS ID Sample Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO14-07-05-013 DAL-GW-WW9R-0-140515 1110 NA 4740 NA

ISO14-07-05-014 DAL-GW-WW9R-DB-140515 1160 NA 4830 NA

ISO14-07-05-015 DAL-GW-WW9R-FMS-140515 3220 84.1 7020 90.1

Average Concentration (ng/mL) ± %RPD 1140 ng/mL ± 4.4% 4790 ng/mL ± 1.9%

13C4-PFOA 13C4-PFOS

3M LIMS ID Sample Description %Recovery %Recovery

ISO14-07-05-013 DAL-GW-WW9R-0-140515 85.6 96.7

ISO14-07-05-014 DAL-GW-WW9R-DB-140515 95.0 103

ISO14-07-05-015 DAL-GW-WW9R-FMS-140515 86.6 94.1

Average Concentration (ng/mL) ± %RSD 89.0% ± 5.8% 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.
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Table 15. DAL GW WW10R 140515 (1)

PFOA PFBS

3M LIMS ID Sample Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO14-07-05-016 DAL-GW-WW10R-0-140515 1810 NA 223 NA

ISO14-07-05-017 DAL-GW-WW10R-DB-140515 1710 NA 216 NA

ISO14-07-05-018 DAL-GW-WW10R-FMS-140515 3570 91.4 2050 92.4

Average Concentration (ng/mL) ± %RPD 1760 ng/mL ± 5.7% 220 ng/mL ± 3.2%

PFHS PFOS

3M LIMS ID Sample Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO14-07-05-016 DAL-GW-WW10R-0-140515 846 NA 2760 NA

ISO14-07-05-017 DAL-GW-WW10R-DB-140515 799 NA 2590 NA

ISO14-07-05-018 DAL-GW-WW10R-FMS-140515 2710 95.3 4850 110

Average Concentration (ng/mL) ± %RPD 823 ng/mL ± 5.7% 2680 ng/mL ± 6.4%

13C4-PFOA 13C4-PFOS

3M LIMS ID Sample Description %Recovery %Recovery

ISO14-07-05-016 DAL-GW-WW10R-0-140515 67.1 (2) 72.8

ISO14-07-05-017 DAL-GW-WW10R-DB-140515 89.2 96.7

ISO14-07-05-018 DAL-GW-WW10R-FMS-140515 91.4 97.5

Average Concentration (ng/mL) ± %RSD 82.6% ± 16% 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%.
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Table 16. DAL GW WW11R 140515 (1)

PFOA PFBS

3M LIMS ID Sample Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO14-07-05-019 DAL-GW-WW11R-0-140515 1200 NA 230 NA

ISO14-07-05-020 DAL-GW-WW11R-DB-140515 1290 NA 244 NA

ISO14-07-05-021 DAL-GW-WW11R-FMS-140515 2040 80.5 1250 102

Average Concentration (ng/mL) ± %RPD 1250 ng/mL 7.2% 237 ng/mL ± 5.9%

PFHS PFOS

3M LIMS ID Sample Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO14-07-05-019 DAL-GW-WW11R-0-140515 651 NA 1610 NA

ISO14-07-05-020 DAL-GW-WW11R-DB-140515 646 NA 1890 NA

ISO14-07-05-021 DAL-GW-WW11R-FMS-140515 1860 122 2540 79.8

Average Concentration (ng/mL) ± %RPD 649 ng/mL ± 0.77% 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 %Recovery %Recovery %Recovery %Recovery

ISO14-07-05-019 DAL-GW-WW11R-0-140515 94.4 105 88.2 88.8

ISO14-07-05-020 DAL-GW-WW11R-DB-140515 95.6 107 90.3 86.0

ISO14-07-05-021 DAL-GW-WW11R-FMS-140515 97.4 108 87.3 85.8

Average Concentration (ng/mL) ± %RSD 95.8% ± 1.6% 107% ± 1.6% 88.6% ± 1.7% 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.
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Table 17. Trip Blank Results

PFOA PFBS

3M LIMS ID Sample Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO14-07-05-022 DAL-GW-TRIP-0-140515 <0.0240 (1) NA <0.0500 (1) NA

ISO14-07-05-023 DAL-GW-TRIP-LS-140515 4.49 (1) 90.9 4.06 (1) 82.0

ISO14-07-05-024 DAL-GW-TRIP-HS-140515 2270 (2) 91.9 2140 (2) 86.3

PFHS PFOS

3M LIMS ID Sample Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO14-07-05-022 DAL-GW-TRIP-0-140515 <0.0500 (1) NA <0.0232 (1) NA

ISO14-07-05-023 DAL-GW-TRIP-LS-140515 4.97 (1) 100 4.87 (1) 98.4

ISO14-07-05-024 DAL-GW-TRIP-HS-140515 2230 (2) 89.9 2290 (2) 92.3

13C4-PFOA (1) 13C4-PFOS (1) 13C4-PFOA (2) 13C4-PFOS (2)

3M LIMS ID Sample Description %Recovery %Recovery %Recovery %Recovery

ISO14-07-05-022 DAL-GW-TRIP-0-140515 87.3 101 98.3 106

ISO14-07-05-023 DAL-GW-TRIP-LS-140515 93.5 89.1 75.6 74.4

ISO14-07-05-024 DAL-GW-TRIP-HS-140515 NA NA 86.2 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
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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-8-

044.1 “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

Susan T. Wolf, 3M Principal Analytical Investigator

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.

Quality Assurance Representative 

This test report shall not be reproduced except in full, without written approval of the 3M Environmental 

Laboratory.
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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

ACI 6/27/13 7/23/13 9/30/13 10/28/13 11/18/13 12/13/13 1/30/14 2/27/14 3/31/14 4/23/14 5/15/14

PFOA 1480 1630 2320 1880 2190 1830 1580 1870 2410 2080 1790

PFBS 708 1230 356 1590 1100 1350 202 1470 541 1250 1230

PFHS 942 749 1400 866 1330 695 845 737 1110 790 771

PFOS 1590 1680 3240 2100 2240 1970 2700 1800 3600 1480 511

No samples were collected in August 2013.

ACE (Activated Carbon Effluent) - Sample Results in ng/mL

ACE 6/27/13 7/23/13 9/30/13 10/28/13 11/18/13 12/13/13 1/30/14 2/27/14 3/31/14 4/23/14 5/15/14

PFOA 0.0717 0.0641 0.115 0.231 0.478 0.0798 0.490 0.138 0.262 0.172 0.0990

PFBS 111 1960 1950 0.379 0.592 0.0766 0.257 0.0360 0.224 69.7 202

PFHS 0.118 0.0778 0.156 0.180 0.366 0.0648 0.219 0.0706 0.108 0.0812 0.0904

PFOS <0.0232 0.0277 0.0452 0.0785 0.0726 0.0303 0.209 0.0966 0.139 0.0567 0.659

No samples were collected in August 2013.
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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

WW8R 6/27/13 7/23/13 9/30/13 10/28/13 11/18/13 12/13/13 1/30/14 2/27/14 3/31/14 4/23/14 5/15/14

PFOA 2760 2640 2890 2830 3040 2720 2660 2560 3290 2730 2630

PFBS 282 263 303 312 362 316 326 331 357 283 290

PFHS 1340 1260 1370 1300 1440 1270 1460 1370 1470 1180 1160

PFOS 4110 3910 4100 4410 4750 4060 3990 4170 5790 3840 4230

No samples were collected in August 2013.

WW9R - Sample Results in ng/mL

WW9R 6/27/13 7/23/13 9/30/13 10/28/13 11/18/13 12/13/13 1/30/14 2/27/14 3/31/14 4/23/14 5/15/14

PFOA 2630 2410 2730 2820 2950 2690 2900 2630 3380 2820 2660

PFBS 225 212 249 286 305 259 317 270 341 257 266

PFHS 1140 1030 1220 1280 1340 1170 1460 1370 1550 1120 1140

PFOS 4150 3670 4200 4380 4540 4190 4800 4660 5420 3820 4790

No samples were collected in August 2013.
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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

WW10R 9/30/13 10/28/13 11/18/13 12/13/13 1/30/14 2/27/14 3/31/14 4/23/14 5/15/14

PFOA 2070 2150 2400 1890 1330 1780 2140 1850 1760

PFBS 247 264 303 239 250 260 278 243 220

PFHS 1030 1030 1120 885 757 935 1030 885 823

PFOS 2770 3160 3890 2920 1570 2860 3490 2130 2680

WW11R - Sample Results in ng/mL

WW11R 9/30/13 10/28/13 11/18/13 12/13/13 1/30/14 2/27/14 3/31/14 4/23/14 5/15/14

PFOA 1720 1100 1320 1060 814 1300 1190 1120 1250

PFBS 299 240 287 198 168 262 254 212 237

PFHS 1000 511 680 512 362 696 549 527 649

PFOS 2200 1670 1850 1570 1540 2100 1890 1630 1750