3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-09

PAGE 1 OF 24

Final Report

Analysis of PFOA, PFBS, PFHS, and PFOS in Aqueous Samples from 

3M Decatur, Alabama: Groundwater Treatment Plant GAC System –

October 2013

Laboratory Request Number: ISO13-07-09

Method Requirement: 3M Method ETS-8-044.1

Report Date – Date of Last Signature

Testing Laboratory

3M EHS&S 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. ISO13-07-09

PAGE 2 OF 24

3M Environmental Laboratory

3M Environmental Laboratory Technical Director: William K. Reagen, Ph.D.

3M Principal Analytical Investigator: Susan Wolf

Report Author: Chelsie Grochow

Analytical Report ISO13-07-09

3M Decatur Groundwater Treatment Plant System; October 2013 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 October 28, 2013. 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 ISO13-07-09. Analysis of the 

samples was completed as specified under 3M Environmental Laboratory General Project Outline 

(GPO) number GPO11-1006.

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 surrogates 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”. Select 

internal standards were used 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. ISO13-07-09

PAGE 3 OF 24

Table 1. Sample Results Summary

3M LIMS ID Sample Description

PFOA 

Concentration 

(ng/mL)

PFBS 

Concentration 

(ng/mL)

PFHS 

Concentration 

(ng/mL)

PFOS 

Concentration 

(ng/mL)

ISO13-07-09-001 DAL-GW-ACI; Sample 1880 1620 873 2080

ISO13-07-09-002 DAL-GW-ACI; Sample Dup 1870 1560 858 2120

Average 1880 (1) 1590 (1) 866 (1) 2100 (1)

%RPD Sample/Sample Dup 0.53 3.8 1.7 1.9

ISO13-07-09-004 DAL-GW-ACM2; Sample 0.164 803 0.289 0.407

ISO13-07-09-005 DAL-GW-ACM2; Sample Dup 0.152 825 0.273 0.973

Average 0.158 (2) 814 (1) 0.281 (2) 0.690 (2)

%RPD Sample/Sample Dup 7.6 2.7 5.7 82 (3)

ISO13-07-09-007 DAL-GW-ACE; Sample 0.261 0.460 0.198 0.0785

ISO13-07-09-008 DAL-GW-ACE; Sample Dup 0.200 0.297 0.161 <0.0232

Average 0.231 (2) 0.379 (2) 0.180 (2) 0.0785 (2)

%RPD Sample/Sample Dup 26 (3) 43 (3) 21 (3) NA

ISO13-07-09-010 DAL-GW-WW8R; Sample 2970 327 1350 4580

ISO13-07-09-011 DAL-GW-WW8R; Sample Dup 2680 296 1250 4230

Average 2830 (1) 312 (1) 1300 (1) 4410 (1)

%RPD Sample/Sample Dup 10 9.9 7.7 7.9

ISO13-07-09-013 DAL-GW-WW9R; Sample 2890 287 1290 4490

ISO13-07-09-014 DAL-GW-WW9R; Sample Dup 2740 285 1260 4260

Average 2820 (1) 286 (1) 1280 (1) 4380 (1)

%RPD Sample/Sample Dup 5.3 0.70 2.3 5.3

ISO13-07-09-019 DAL-GW-WW10R; Sample 2110 255 1010 3080

ISO13-07-09-020 DAL-GW-WW10R; Sample Dup 2190 272 1040 3230

Average 2150 (1) 264 (1) 1030 (1) 3160 (1)

%RPD Sample/Sample Dup 3.7 6.4 2.9 4.7

ISO13-07-09-022 DAL-GW-WW11R; Sample 1100 241 511 1690

ISO13-07-09-023 DAL-GW-WW11R; Sample Dup 1090 239 510 1650

Average 1100 (1) 240 (1) 511 (1) 1670 (1)

%RPD Sample/Sample Dup 0.91 0.83 0.20 2.4

NA = Not Applicable

(1) Reported results were prepared and analyzed by ETS-8-044.1 using external standard calibration. The analytical method 

uncertainties associated with the reported results are as follows: PFOA ±15%, PFBS ±16%, PFHS ±13%, and PFOS ±15%.

(2) Reported results were 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 ±16%, PFBS ±14%, PFHS ±19%, and PFOS ±14%.

(3) Sample/sample duplicate RPD did not meet acceptance criteria of ≤20%.
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REPORT NO. ISO13-07-09

PAGE 4 OF 24

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 October 28, 2013 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. Collected sample bottles were received by the laboratory at 

ambient conditions on October 31, 2013.

2.3 Sample Preparation

All samples were diluted with methanol and analyzed for all analytes. Samples diluted 1:10 were 

prepared by removing a 1 mL aliquot of the well mixed sample and adding 8.9 mL of methanol and 0.1 

mL of a surrogate spiking solution. 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. 

Prepared samples were analyzed by external standard calibration. 

The ACE and ACM2 sample sets and the Trip Blank sample were prepared and analyzed for all 

analytes by transferring an aliquot of the well mixed sample into an autovial. 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 sample bottles for ACE, ACM2, and Trip Blank were spiked with an 

internal standard mix at a nominal concentration of 1 ng/mL prior to being sent to the field for sample 

collection. 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.
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-09

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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 

procedures outlined in method ETS-12-010. 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 Kirk

Analysis Dates

11/19/13 – external standard calibration

11/20/13 – internal standard calibration 

Analytical Method ETS-8-044.1

Liquid Chromatograph Agilent 1260

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 5, 20, or 40 μL

Mass Spectrometer Applied Biosystems TripleQuad 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)

0 0.00 750 90.0 10.0

1 0.50 750 90.0 10.0

2 4.00 750 70.0 30.0

3 6.00 750 70.0 30.0

4 11.0 750 20.0 80.0

5 13.0 750 20.0 80.0

6 13.5 750 10.0 90.0

7 16.0 750 10.0 90.0

8 16.5 750 90.0 10.0

9 19.0 750 90.0 10.0
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-09

PAGE 6 OF 24

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 on 11/20/13.

3 Data Analysis

3.1 Calibration

External Standard Calibration Analysis on 11/19/13: 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 

eleven spiked standards ranging from 0.02 ng/mL to 50 ng/mL (nominal) were analyzed. The 

standards also contained the surrogates at concentrations ranging from 0.02 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 11/20/13: Samples were analyzed against a matrix-matched 

stable isotope internal standard calibration curve. Calibration standards were prepared by spiking 

known amounts of stock solutions into laboratory prepared reagent water. The calibration standards 

contained an internal standard mix at a nominal concentration of 1 ng/mL. A total of thirteen calibration 

standards ranging from 0.025 ng/mL to 25 ng/mL (nominal) were analyzed with the prepared samples. 

Of these thirteen calibration standards, eleven contained the surrogates at concentrations ranging from 

0.025 ng/mL to 10 ng/mL nominal. 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.
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-09

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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.

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 Calibration LOQ, ng/mL 

PFOA Internal standard 0.0240

PFBS Internal standard 0.0250

PFHS Internal standard 0.0400

PFOS Internal standard 0.0232

PFOA External standard 0.0192 (1)

PFBS External standard 0.0200 (1)

PFHS External standard 0.0200 (1)

PFOS External standard 0.0185 (1)

(1) The dilution factor was not applied to the LOQ.

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.

* 100%

Spike Concentration

Calculated Concentration LCSPercent Recovery =

* 100%

average LCS recovery

standard deviation LCS replicates LCS% RSD =
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REPORT NO. ISO13-07-09

PAGE 8 OF 24

Table 7. Lab Control Spike Results.

ETS-8-044.1

External Standard 

Calibration

Analyzed 11/19/13 PFOA (Linear + Branched) PFOA surrogate

Lab ID

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

LCS-131118-1 0.191 0.210 110 0.199 0.228 115

LCS-131118-2 0.191 0.209 109 0.199 0.223 112

LCS-131118-3 0.191 0.220 115 0.199 0.220 110

Average ± %RSD 111% ± 2.9% 112% ± 2.2%

LCS-131118-4 4.74 5.49 116 4.94 5.45 110

LCS-131118-5 4.74 5.41 114 4.94 5.21 105

LCS-131118-6 4.74 5.37 113 4.94 5.28 107

Average ± %RSD 114% ± 1.3% 107% ± 2.4%

LCS-131118-7 38.2 38.7 101

LCS-131118-8 38.2 39.8 104

LCS-131118-9 38.2 39.3 103

Average ± %RSD 103% ± 1.5%

ETS-8-044.1

External Standard 

Calibration

Analyzed 11/19/13 PFBS PFHS

Lab ID

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

LCS-131118-1 0.199 0.226 114 0.199 0.220 110

LCS-131118-2 0.199 0.223 112 0.199 0.217 109

LCS-131118-3 0.199 0.223 112 0.199 0.226 114

Average ± %RSD 113% ± 1.0% 111% ± 2.4%

LCS-131118-4 4.95 5.70 115 4.95 5.68 115

LCS-131118-5 4.95 5.54 112 4.95 5.64 114

LCS-131118-6 4.95 5.51 111 4.95 5.54 112

Average ± %RSD 113% ± 1.8% 114% ± 1.3%

LCS-131118-7 39.8 40.8 102 39.8 40.2 101

LCS-131118-8 39.8 41.8 105 39.8 41.3 104

LCS-131118-9 39.8 41.0 103 39.8 40.6 102

Average ± %RSD 103% ± 1.5% 102% ± 1.5%
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Table 7 continued. Lab Control Spike Results.

ETS-8-044.1

External Standard 

Calibration

Analyzed 11/19/13 PFOS (Linear + Branched) PFOS surrogate

Lab ID

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

LCS-131118-1 0.185 0.221 120 0.190 0.215 113

LCS-131118-2 0.185 0.209 113 0.190 0.206 108

LCS-131118-3 0.185 0.220 119 0.190 0.207 109

Average ± %RSD 117% ± 3.2% 110% ± 2.4%

LCS-131118-4 4.59 5.53 121 4.73 5.14 109

LCS-131118-5 4.59 5.41 118 4.73 5.02 106

LCS-131118-6 4.59 5.43 118 4.73 5.09 108

Average ± %RSD 119% ± 1.5% 108% ± 1.4% 

LCS-131118-7 36.9 39.0 106

LCS-131118-8 36.9 40.0 108

LCS-131118-9 36.9 39.1 106

Average ± %RSD 107% ± 1.1%

ETS-8-044.1

Internal Standard 

Calibration

Analyzed 11/20/13 PFOA (Linear + Branched) PFOA surrogate

Lab ID

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

LCS-131120-1 0.190 0.179 94.3 0.198 0.195 98.3

LCS-131120-2 0.190 0.167 87.7 0.198 0.200 101

LCS-131120-3 0.190 0.190 99.9 0.198 0.199 100

Average ± %RSD 94.0% ± 6.5% 99.8% ± 1.4%

LCS-131120-4 1.90 1.91 100 1.98 1.91 96.3

LCS-131120-5 1.90 1.95 103 1.98 1.95 98.4

LCS-131120-6 1.90 1.93 102 1.98 1.91 96.2

Average ± %RSD 102% ± 1.5% 97.0% ± 1.3%

LCS-131120-7 19.0 18.6 97.8

LCS-131120-8 19.0 18.6 98.1

LCS-131120-9 19.0 17.7 93.2

Average ± %RSD 96.4% ± 2.8%
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Table 7 continued. Lab Control Spike Results.

ETS-8-044.1

Internal Standard 

Calibration

Analyzed 11/20/13 PFBS PFHS

Lab ID

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

LCS-131120-1 0.198 0.185 93.3 0.198 0.198 99.9

LCS-131120-2 0.198 0.182 91.8 0.198 0.190 96.0

LCS-131120-3 0.198 0.204 103 0.198 0.204 103

Average ± %RSD 96.0% ± 6.3% 99.6% ± 3.5%

LCS-131120-4 1.98 2.14 108 1.98 2.19 111

LCS-131120-5 1.98 2.14 108 1.98 2.16 109

LCS-131120-6 1.98 2.10 106 1.98 2.15 109

Average ± %RSD 107% ± 1.1% 110% ± 1.0%

LCS-131120-7 19.9 19.5 98.2 19.9 19.1 96.1

LCS-131120-8 19.9 19.2 96.3 19.9 19.5 98.0

LCS-131120-9 19.9 18.4 92.5 19.9 19.4 97.3

Average ± %RSD 95.7% ± 3.0% 97.1% ± 0.99%

ETS-8-044.1

Internal Standard 

Calibration

Analyzed 11/20/13 PFOS (Linear + Branched) PFOS surrogate

Lab ID

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

LCS-131120-1 0.184 0.181 98.2 0.189 0.196 104

LCS-131120-2 0.184 0.175 95.0 0.189 0.189 100

LCS-131120-3 0.184 0.188 102 0.189 0.194 103

Average ± %RSD 98.4% ± 3.6% 102% ± 2.0%

LCS-131120-4 1.84 1.95 106 1.89 1.92 102

LCS-131120-5 1.84 1.97 107 1.89 1.94 103

LCS-131120-6 1.84 1.92 105 1.89 1.89 100

Average ± %RSD 106% ± 0.94% 102% ± 1.5% 

LCS-131120-7 18.4 18.6 101

LCS-131120-8 18.4 18.0 97.7

LCS-131120-9 18.4 17.8 96.9

Average ± %RSD 98.5% ± 2.2%
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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 7.44 ±15%

PFBS External Standard 7.96 ±16%

PFHS External Standard 6.60 ±13%

PFOS External Standard 7.66 ±15%

PFOA Internal Standard 7.76 ±16%

PFBS Internal Standard 6.98 ±14%

PFHS Internal Standard 9.46 ±19%

PFOS Internal Standard 7.07 ±14%

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. 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 spikes are presented in section 4 of this report. 

*100%

Spike Concentraton

(Sample Concentration of FMS Average Concentration:FieldSample & FieldSample Dup.) FMS Recovery − =

Table 9. Field Matrix Spike Concentrations.

Final Concentration (ng/mL)

Location Description PFOA PFBS PFHS PFOS

ACI Field Matrix Spike 2480 2500 2510 2500

ACM2 Field Matrix Spike 4.95 5.00 5.00 5.00

ACE Field Matrix Spike 4.95 5.00 5.00 5.00

WW8R, WW9R, 

WW10R, WW11R Field Matrix Spike 2480 2500 2510 2500

Trip Blank

Low Field Matrix Spike 4.95 5.00 5.00 5.00

High Field Matrix Spike 2480 2500 2510 2500
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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. Percent relative 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 meeting the method acceptance criteria of ±30%, demonstrate that the method is 

appropriate for the given matrix. 

All field matrix spike samples and surrogate recovery standards met method acceptance criteria except 

where noted below.

DAL-GW-ACM2; the FMS sample (5 ng/mL) was not appropriate for PFBS; however, the surrogate 

recovery standard 13C4-PFOS met method acceptance criteria. No additional QC samples were 

prepared. 
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Table 10. DAL GW ACI 131028 (1)

PFOA PFBS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-09-001 DAL-GW-ACI-0-131028 1880 NA 1620 NA

ISO13-07-09-002 DAL-GW-ACI-DB-131028 1870 NA 1560 NA

ISO13-07-09-003 DAL-GW-ACI-FMS-131028 4090 89.1 3740 86.0

Average Concentration (ng/mL) ± %RPD 1880 ng/mL ± 0.53% 1590 ng/mL ± 3.8%

PFHS PFOS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-09-001 DAL-GW-ACI-0-131028 873 NA 2080 NA

ISO13-07-09-002 DAL-GW-ACI-DB-131028 858 NA 2120 NA

ISO13-07-09-003 DAL-GW-ACI-FMS-131028 3270 95.8 4500 96.0

Average Concentration (ng/mL) ± %RPD 866 ng/mL ± 1.7% 2100 ng/mL ± 1.9% 

13C4-PFOA 13C4-PFOS

3M LIMS ID Description %Recovery %Recovery

ISO13-07-09-001 DAL-GW-ACI-0-131028 99.8 102

ISO13-07-09-002 DAL-GW-ACI-DB-131028 99.3 99.6

ISO13-07-09-003 DAL-GW-ACI-FMS-131028 96.1 103

Average Concentration (ng/mL) ± %RSD 98.4% ± 2.0% 102% ± 1.7%

NA = Not Applicable

(1) Samples were analyzed by external standard calibration. The surrogate recovery standards 13C4-PFOA and 13C4-PFOS were 

added to the samples during sample preparation.
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REPORT NO. ISO13-07-09

PAGE 14 OF 24

Table 11. DAL GW ACM2 131028

PFOA (1) PFBS (2)

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-09-004 DAL-GW-ACM2-0-131028 0.164 NA 803 NA

ISO13-07-09-005 DAL-GW-ACM2-DB-131028 0.152 NA 825 NA

ISO13-07-09-006 DAL-GW-ACM2-FMS-131028 5.07 99.2 860 NC

Average Concentration (ng/mL) ± %RPD 0.158 ng/mL ± 7.6% 814 ng/mL ± 2.7%

PFHS (1) PFOS (1)

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-09-004 DAL-GW-ACM2-0-131028 0.289 NA 0.407 NA

ISO13-07-09-005 DAL-GW-ACM2-DB-131028 0.273 NA 0.973 NA

ISO13-07-09-006 DAL-GW-ACM2-FMS-131028 5.34 101 5.89 104

Average Concentration (ng/mL) ± %RPD 0.281 ng/mL ± 5.7% 0.690 ng/mL ± 82% (3)

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

3M LIMS ID Description %Recovery %Recovery

ISO13-07-09-004 DAL-GW-ACM2-0-131028 101 110

ISO13-07-09-005 DAL-GW-ACM2-DB-131028 101 107

ISO13-07-09-006 DAL-GW-ACM2-FMS-131028 104 103

Average Concentration (ng/mL) ± %RSD 102% ± 1.7% 107% ± 3.3%

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.

(2) Samples were analyzed by external standard calibration. 

(3) Sample/sample duplicate RPD did not meet acceptance criteria of ≤20%.
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REPORT NO. ISO13-07-09

PAGE 15 OF 24

Table 12. DAL GW ACE 131028 (1)

PFOA PFBS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-09-007 DAL-GW-ACE-0-131028 0.261 NA 0.460 NA

ISO13-07-09-008 DAL-GW-ACE-DB-131028 0.200 NA 0.297 NA

ISO13-07-09-009 DAL-GW-ACE-FMS-131028 4.80 92.3 5.38 100

Average Concentration (ng/mL) ± %RPD 0.231 ng/mL ± 26% (2) 0.379 ng/mL ± 43% (2)

PFHS PFOS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-09-007 DAL-GW-ACE-0-131028 0.198 NA 0.0785 NA

ISO13-07-09-008 DAL-GW-ACE-DB-131028 0.161 NA <0.0232 NA

ISO13-07-09-009 DAL-GW-ACE-FMS-131028 5.37 104 5.35 105

Average Concentration (ng/mL) ± %RPD 0.180 ng/mL ± 21% (2) 0.0785 ng/mL

13C4-PFOA 13C4-PFOS

3M LIMS ID Description %Recovery %Recovery

ISO13-07-09-007 DAL-GW-ACE-0-131028 99.7 93.9

ISO13-07-09-008 DAL-GW-ACE-DB-131028 94.4 101

ISO13-07-09-009 DAL-GW-ACE-FMS-131028 101 107

Average Concentration (ng/mL) ± %RSD 98.4% ± 3.6% 101% ± 6.5%

NA = Not Applicable

(1) Samples were analyzed by internal standard calibration.

(2) Sample/sample duplicate RPD did not meet acceptance criteria of ≤20%.
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REPORT NO. ISO13-07-09

PAGE 16 OF 24

Table 13. DAL GW WW8R 131028 (1)

PFOA PFBS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-09-010 DAL-GW-WW8R-0-131028 2970 NA 327 NA

ISO13-07-09-011 DAL-GW-WW8R-DB-131028 2680 NA 296 NA

ISO13-07-09-012 DAL-GW-WW8R-FMS-131028 5450 106 2830 101

Average Concentration (ng/mL) ± %RPD 2830 ng/mL ± 10% 312 ng/mL ± 9.9%

PFHS PFOS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-09-010 DAL-GW-WW8R-0-131028 1350 NA 4580 NA

ISO13-07-09-011 DAL-GW-WW8R-DB-131028 1250 NA 4230 NA

ISO13-07-09-012 DAL-GW-WW8R-FMS-131028 3930 105 7340 117

Average Concentration (ng/mL) ± %RPD 1300 ng/mL ± 7.7% 4410 ng/mL ± 7.9%

13C4-PFOA 13C4-PFOS

3M LIMS ID Description %Recovery %Recovery

ISO13-07-09-010 DAL-GW-WW8R-0-131028 101 108

ISO13-07-09-011 DAL-GW-WW8R-DB-131028 99.8 108

ISO13-07-09-012 DAL-GW-WW8R-FMS-131028 100 102

Average Concentration (ng/mL) ± %RSD 100% ± 0.64% 106% ± 3.3%

NA = Not Applicable

(1) Samples were analyzed by external standard calibration. The surrogate recovery standards 13C4-PFOA and 13C4-PFOS were 

added to the samples during sample preparation.
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REPORT NO. ISO13-07-09

PAGE 17 OF 24

Table 14. DAL GW WW9R 131028 (1)

PFOA PFBS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-09-013 DAL-GW-WW9R-0-131028 2890 NA 287 NA

ISO13-07-09-014 DAL-GW-WW9R-DB-131028 2740 NA 285 NA

ISO13-07-09-015 DAL-GW-WW9R-FMS-131028 5420 105 2780 99.8

Average Concentration (ng/mL) ± %RPD 2820 ng/mL ± 5.3% 286 ng/mL ± 0.70%

PFHS PFOS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-09-013 DAL-GW-WW9R-0-131028 1290 NA 4490 NA

ISO13-07-09-014 DAL-GW-WW9R-DB-131028 1260 NA 4260 NA

ISO13-07-09-015 DAL-GW-WW9R-FMS-131028 3800 100 7090 108

Average Concentration (ng/mL) ± %RPD 1280 ng/mL ± 2.3% 4380 ng/mL ± 5.3%

13C4-PFOA 13C4-PFOS

3M LIMS ID Description %Recovery %Recovery

ISO13-07-09-013 DAL-GW-WW9R-0-131028 103 104

ISO13-07-09-014 DAL-GW-WW9R-DB-131028 99.4 106

ISO13-07-09-015 DAL-GW-WW9R-FMS-131028 103 97.6

Average Concentration (ng/mL) ± %RSD 102% ± 2.0% 103% ± 4.3%

NA = Not Applicable

(1) Samples were analyzed by external standard calibration. The surrogate recovery standards 13C4-PFOA and 13C4-PFOS were 

added to the samples during sample preparation.
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REPORT NO. ISO13-07-09

PAGE 18 OF 24

Table 15. DAL GW WW10R 131028 (1)

PFOA PFBS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-09-019 DAL-GW-WW10R-0-131028 2110 NA 255 NA

ISO13-07-09-020 DAL-GW-WW10R-DB-131028 2190 NA 272 NA

ISO13-07-09-021 DAL-GW-WW10R-FMS-131028 4520 95.6 2670 96.2

Average Concentration (ng/mL) ± %RPD 2150 ng/mL ± 3.7% 264 ng/mL ± 6.4%

PFHS PFOS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-09-019 DAL-GW-WW10R-0-131028 1010 NA 3080 NA

ISO13-07-09-020 DAL-GW-WW10R-DB-131028 1040 NA 3230 NA

ISO13-07-09-021 DAL-GW-WW10R-FMS-131028 3490 98.0 5710 102

Average Concentration (ng/mL) ± %RPD 1030 ng/mL ± 2.9% 3160 ng/mL ± 4.7%

13C4-PFOA 13C4-PFOS

3M LIMS ID Description %Recovery %Recovery

ISO13-07-09-019 DAL-GW-WW10R-0-131028 102 105

ISO13-07-09-020 DAL-GW-WW10R-DB-131028 102 104

ISO13-07-09-021 DAL-GW-WW10R-FMS-131028 97.6 102

Average Concentration (ng/mL) ± %RSD 101% ± 2.5% 104% ± 1.5%

NA = Not Applicable

(1) Samples were analyzed by external standard calibration. The surrogate recovery standards 13C4-PFOA and 13C4-PFOS were 

added to the samples during sample preparation.
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REPORT NO. ISO13-07-09

PAGE 19 OF 24

Table 16. DAL GW WW11R 131028 (1)

PFOA PFBS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-09-022 DAL-GW-WW11R-0-131028 1100 NA 241 NA

ISO13-07-09-023 DAL-GW-WW11R-DB-131028 1090 NA 239 NA

ISO13-07-09-024 DAL-GW-WW11R-FMS-131028 3380 91.9 2560 92.8

Average Concentration (ng/mL) ± %RPD 1100 ng/mL ± 0.91% 240 ng/mL ± 0.83%

PFHS PFOS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-09-022 DAL-GW-WW11R-0-131028 511 NA 1690 NA

ISO13-07-09-023 DAL-GW-WW11R-DB-131028 510 NA 1650 NA

ISO13-07-09-024 DAL-GW-WW11R-FMS-131028 2860 93.6 4160 99.6

Average Concentration (ng/mL) ± %RPD 511 ng/mL ± 0.20% 1670 ng/mL ± 2.4%

13C4-PFOA 13C4-PFOS

3M LIMS ID Description %Recovery %Recovery

ISO13-07-09-022 DAL-GW-WW11R-0-131028 95.6 103

ISO13-07-09-023 DAL-GW-WW11R-DB-131028 97.6 102

ISO13-07-09-024 DAL-GW-WW11R-FMS-131028 101 104

Average Concentration (ng/mL) ± %RSD 98.1% ± 2.8% 103% ± 0.97%

NA = Not Applicable

(1) Samples were analyzed by external standard calibration. The surrogate recovery standards 13C4-PFOA and 13C4-PFOS were 

added to the samples during sample preparation.
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REPORT NO. ISO13-07-09

PAGE 20 OF 24

Table 17. Trip Blank Results

PFOA PFBS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-09-016 DAL-GW-TRIP01-0-131028 <0.0240 (1) NA <0.250 (1) NA

ISO13-07-09-017 DAL-GW-TRIP01-LS-131028 5.23 (2) 106 5.18 (2) 104

ISO13-07-09-018 DAL-GW-TRIP01-HS-131028 2430 (2) 98.0 2390 (2) 95.6

PFHS PFOS

3M LIMS ID Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO13-07-09-016 DAL-GW-TRIP01-0-131028 <0.400 (1) NA <0.0232 (1) NA

ISO13-07-09-017 DAL-GW-TRIP01-LS-131028 5.05 (2) 101 5.27 (2) 105

ISO13-07-09-018 DAL-GW-TRIP01-HS-131028 2450 (2) 97.6 2620 (2) 105

13C4-PFOA 13C4-PFOS

3M LIMS ID Description %Recovery %Recovery

ISO13-07-09-016 DAL-GW-TRIP01-0-131028 111 (1) 111 (1)

ISO13-07-09-017 DAL-GW-TRIP01-LS-131028 107 (2) 110 (2)

ISO13-07-09-018 DAL-GW-TRIP01-HS-131028 107 (2) 106 (2)

NA = Not Applicable

(1) Samples were analyzed by internal standard calibration.

(2) Samples were analyzed by external standard calibration. The surrogate recovery standards 13C4-PFOA and 13C4-PFOS were 

added to the samples during sample preparation.

3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-09

PAGE 22 OF 24

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 12/14/2012 1/17/2013 2/13/2013 3/27/2013 4/29/2013 5/31/2013 6/27/2013 7/23/2013 9/30/2013 10/28/2013

PFOA 2580 1910 2300 2220 1480 1860 1480 1630 2320 1880

PFBS 723 588 830 1060 1360 1040 708 1230 356 1590

PFHS 1380 895 1580 1090 777 940 942 749 1400 866

PFOS 2810 1810 2940 2490 1670 2150 1590 1680 3240 2100

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

ACE 12/14/2012 1/17/2013 2/13/2013 3/27/2013 4/29/2013 5/31/2013 6/27/2013 7/23/2013 9/30/2013 10/28/2013

PFOA 0.102 <0.0240 0.124 0.0380 0.0422 0.0725 0.0717 0.0643 0.115 0.231

PFBS <0.0250 <0.0250 0.0360 <0.0250 0.392 24.8 111 1960 1950 0.379

PFHS 0.117 <0.0250 0.178 0.0477 0.057 0.105 0.118 0.0778 0.156 0.180

PFOS 0.0376 <0.0232 0.0329 <0.0232 <0.0232 <0.0232 <0.0232 0.0277 0.0452 0.0785
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-09

PAGE 23 OF 24

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 12/13/2012 1/17/2013 2/13/2013 3/27/2013 4/29/2013 5/31/2013 6/27/2013 7/23/2013 9/30/2013 10/28/2013

PFOA 3630 4350 3250 3640 3190 2760 2760 2640 2890 2830

PFBS 441 410 354 385 364 289 282 263 303 312

PFHS 1740 1930 1900 1760 1610 1330 1340 1260 1370 1300

PFOS 4920 5710 4850 5120 4830 4180 4110 3910 4100 4410

WW9R - Sample Results in ng/mL

WW9R 12/13/2012 1/17/2013 2/13/2013 3/27/2013 4/29/2013 5/31/2013 6/27/2013 7/23/2013 9/30/2013 10/28/2013

PFOA 3360 2710 2850 3330 2650 2660 2630 2410 2730 2820

PFBS 321 184 236 278 244 226 225 212 249 286

PFHS 1480 954 1400 1440 1200 1120 1140 1030 1220 1280

PFOS 4080 3690 4100 4660 4340 4210 4150 3670 4200 4380
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO13-07-09

PAGE 24 OF 24

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 9/30/2013 10/28/2013

PFOA 2070 2150

PFBS 247 264

PFHS 1030 1030

PFOS 2770 3160

WW11R - Sample Results in ng/mL

WW11R 9/30/2013 10/28/2013

PFOA 1720 1100

PFBS 299 240

PFHS 1000 511

PFOS 2200 1670