3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO14-07-03

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 –

March 2014

Laboratory Request Number: ISO14-07-03

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. ISO14-07-03

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: Susanna Emond

Analytical Report ISO14-07-03

3M Decatur Groundwater Treatment Plant System; March 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 March 31, 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 ISO14-07-03. Analysis of the 

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

(GPO) number GPO13-1289.

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. ISO14-07-03

PAGE 3 OF 24

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)

ISO14-07-03-001 DAL-GW-ACI-0 - 140331 2350 536 1090 3430

ISO14-07-03-002 DAL-GW-ACI-DB - 140331 2470 546 1120 3760

Average 2410 541 1110 3600

%RPD Sample/Sample Dup 5.0 1.8 2.7 9.2

ISO14-07-03-004 DAL-GW-ACM2-0 - 140331 2.15 3240 0.927 3.60

ISO14-07-03-005 DAL-GW-ACM2-DB - 140331 1.91 3230 0.808 3.28

Average 2.03 (2) 3240 0.868 (2) 3.44 (2)

%RPD Sample/Sample Dup 12 0.31 14 9.3

ISO14-07-03-007 DAL-GW-ACE-0 - 140331 0.257 0.224 0.105 0.131

ISO14-07-03-008 DAL-GW-ACE-DB - 140331 0.266 0.223 0.111 0.146

Average 0.262 (2) 0.224 (2) 0.108 (2) 0.139 (2)

%RPD Sample/Sample Dup 3.4 0.45 5.6 11

ISO14-07-03-010 DAL-GW-WW8R-0 - 140331 3330 344 1430 5980

ISO14-07-03-011 DAL-GW-WW8R-DB - 140331 3240 370 1510 5600

Average 3290 357 1470 5790

%RPD Sample/Sample Dup 2.7 7.3 5.4 6.6

ISO14-07-03-013 DAL-GW-WW9R-0 - 140331 3580 356 1630 4920

ISO14-07-03-014 DAL-GW-WW9R-DB - 140331 3180 325 1460 5920

Average 3380 341 1550 5420

%RPD Sample/Sample Dup 12 9.1 11 18

ISO14-07-03-016 DAL-GW-WW10R-0 - 140331 2110 278 1030 3760

ISO14-07-03-017 DAL-GW-WW10R - 140331 2170 277 1030 3210

Average 2140 278 1030 3490

%RPD Sample/Sample Dup 2.8 0.36 0.00 16

ISO14-07-03-019 DAL-GW-WW11R-0 - 140331 1190 257 544 1870

ISO14-07-03-020 DAL-GW-WW11R-DB - 140331 1180 250 554 1910

Average 1190 254 549 1890

%RPD Sample/Sample Dup 0.84 2.8 1.8 2.1

(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 ±14%, PFBS ±18%, PFHS ±10%, and PFOS ±8.0%.

(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 ±11%, PFBS ±21%, PFHS ±17%, and PFOS ±10%.
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO14-07-03

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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 March 31, 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 April 4, 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). 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 

procedures outlined in method ETS-12-010.1 The consistency of the laboratory’s integration is 
3M ENVIRONMENTAL LABORATORY

REPORT NO. ISO14-07-03

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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 DaVinci ETS McCoy

Analysis Dates

4/15/14 – external standard calibration

5/1/14 – internal standard calibration 4/30/14– external standard calibration

Analytical Method ETS-8-044.1 ETS-8-044.1

Liquid Chromatograph Agilent 1290 Agilent 1290

Guard column Prism RP (2.1 mm X 50 mm), 5 μ Betasil C18 (4.6 mm X 100 mm), 5 μ

Analytical column Betasil C18 (2.1 mm X 100 mm), 5 μ Betasil C18 (4.6 mm X 100 mm), 5 μ

Injection Volume 5 μL 10 or 5 μL

Mass Spectrometer Applied Biosystems API 6500 Applied Biosystems API 5500

Ion Source Turbo Spray Turbo Spray

Polarity Negative Negative

Software Analyst 1.6 Analyst 1.6.1

Table 4. Liquid Chromatography Gradient Program (1)

Step 

Number

Total Time 

(min)

Percent A

(2 mM ammonium acetate)

Percent B

(Methanol)

0 0.00 90.0 10.0

1 0.50 90.0 10.0

2 4.00 70.0 30.0

3 6.00 70.0 30.0

4 11.0 20.0 80.0

5 13.0 20.0 80.0

6 13.5 10.0 90.0

7 16.0 10.0 90.0

8 16.5 90.0 10.0

9 19.0 90.0 10.0

(1) The flow rate was 300 μL/min for ETS DaVinci analyses on 4/15/14 and 5/1/14, and 750 μL/min for McCoy analysis on 

4/30/14.
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REPORT NO. ISO14-07-03

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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 5/1/14.

3 Data Analysis

3.1 Calibration

External Standard Calibration Analysis on 4/15/14 and 4/30/14: 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 

ten spiked standards ranging from 0.1 ng/mL to 100 ng/mL (nominal) were analyzed. Of these ten 

calibration standards, eight 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 5/1/14: 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 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 

with the prepared samples. Of these thirteen calibration standards, ten contained the surrogates at 

concentrations ranging from 0.0125 ng/mL to 10 ng/mL (nominal). 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 13C4-PFOS analyzed on 4/15/14 (6.1%). A method deviation is included 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

4/15/14 and 4/30/14 Analysis (1)

LOQ, ng/mL

5/1/14 Analysis(2)

PFOA 9.58 0.0240

PFBS 10.0 0.0250

PFHS 10.0 0.0250

PFOS 9.27 0.0232

(1) The dilution factor of 100 was applied to the LOQ.

(2) The dilution factor of 2 was 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 with the following exception:

5/1/14 Analysis: The mid level LCSs for PFBS had an average recovery of 78.9%. A method deviation 

is included with the raw data.

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. ISO14-07-03

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Table 7. Lab Control Spike Results.

ETS-8-044.1

External Standard Calibration

Analyzed 4/15/14 PFBS PFHS

Lab ID

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

LCS-140408-1 1.00 1.12 112 1.00 1.10 110

LCS-140408-2 1.00 1.08 108 1.00 1.08 108

LCS-140408-3 1.00 1.06 106 1.00 1.07 107

Average ± %RSD 109% ± 2.8% 108% ± 1.4%

LCS-140408-4 10.0 10.8 108 10.0 10.8 108

LCS-140408-5 10.0 10.4 104 10.0 10.5 105

LCS-140408-6 10.0 10.3 103 10.0 10.4 104

Average ± %RSD 105% ± 2.5% 106% ± 2.0%

LCS-140408-7 79.4 83.6 105 79.4 83.5 105

LCS-140408-8 79.4 86.5 109 79.4 86.3 109

LCS-140408-9 79.4 84.6 107 79.4 83.5 105

Average ± %RSD 107% ± 1.9% 106% ± 2.2%

ETS-8-044.1

External Standard Calibration

Analyzed 4/15/14 PFOA (Linear + Branched) 13C4-PFOA surrogate

Lab ID

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

LCS-140408-1 0.958 1.09 114 0.998 1.10 110

LCS-140408-2 0.958 1.06 111 0.998 1.07 108

LCS-140408-3 0.958 1.07 111 0.998 1.10 110

Average ± %RSD 112% ± 1.5% 109% ± 1.1%

LCS-140408-4 9.58 10.3 107 9.98 11.1 111

LCS-140408-5 9.58 9.88 103 9.98 11.2 112

LCS-140408-6 9.58 10.3 107 9.98 11.7 118

Average ± %RSD 106% ± 2.2% 114% ± 3.3%

LCS-140408-7 76.0 84.8 112

LCS-140408-8 76.0 83.7 110

LCS-140408-9 76.0 84.4 111

Average ± %RSD 111% ± 0.90%

(1) LCS recovery did not meet acceptance criteria of 100 ± 20%.
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Table 7 continued. Lab Control Spike Results.

ETS-8-044.1

External Standard Calibration

Analyzed 4/15/14 PFOS (Linear + Branched) 13C4-PFOS surrogate

Lab ID

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

LCS-140408-1 0.927 1.02 110 0.956 1.03 108

LCS-140408-2 0.927 1.03 111 0.956 1.04 109

LCS-140408-3 0.927 1.04 112 0.956 1.02 106

Average ± %RSD 111% ± 0.90% 108% ± 1.4%

LCS-140408-4 9.27 9.87 106 9.56 10.7 112

LCS-140408-5 9.27 9.81 106 9.56 10.6 111

LCS-140408-6 9.27 10.1 109 9.56 10.6 111

Average ± %RSD 107% ± 1.6% 111% ± 0.52%

LCS-140408-7 73.6 78.7 107

LCS-140408-8 73.6 81.1 110

LCS-140408-9 73.6 81.4 111

Average ± %RSD 109% ± 1.9%

ETS-8-044.1

External Standard Calibration

Re-analysis 4/30/14 PFOS (Linear + Branched) 13C4-PFOS surrogate

Lab ID

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

LCS-140430-1 0.927 0.989 107 0.956 1.05 109

LCS-140430-2 0.927 0.981 106 0.956 1.06 111

LCS-140430-3 0.927 0.975 105 0.956 1.05 110

Average ± %RSD 106% ± 0.94% 110% ± 0.91%

LCS-140430-4 9.27 9.47 102 9.56 10.6 110

LCS-140430-5 9.27 10.0 108 9.56 11.0 115

LCS-140430-6 9.27 9.79 106 9.56 10.9 114

Average ± %RSD 105% ± 2.9% 113% ± 2.3%

LCS-140430-7 36.9 38.9 105

LCS-140430-8 36.9 40.2 109

LCS-140430-9 36.9 40.8 110

Average ± %RSD 108% ± 2.4%

(1) LCS recovery did not meet acceptance criteria of 100 ± 20%.
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Table 7 continued. Lab Control Spike Results.

ETS-8-044.1

Internal Standard Calibration

Analyzed 5/1/14 PFOA (Linear + Branched) 13C4-PFOA surrogate

Lab ID

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

LCS-140429-1 0.190 0.151 79.5 0.198 0.162 81.7

LCS-140429-2 0.190 0.154 81.2 0.198 0.190 96.2

LCS-140429-3 0.190 0.179 94.2 0.198 0.190 96.0

Average ± %RSD 85.0% ± 9.5% 91.3% ± 9.1%

LCS-140429-4 9.50 7.58 79.8 1.98 1.61 81.4

LCS-140429-5 9.50 8.47 89.1 1.98 1.81 91.3

LCS-140429-6 9.50 8.19 86.2 1.98 1.76 88.7

Average ± %RSD 85.0% ± 5.6% 87.1% ± 5.9%

LCS-140429-7 38.0 35.5 93.5

LCS-140429-8 38.0 33.8 88.9

LCS-140429-9 38.0 33.2 87.4

Average ± %RSD 89.9% ± 3.5%

ETS-8-044.1

Internal Standard Calibration

Analyzed 5/1/14 PFBS PFHS

Lab ID

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

LCS-140429-1 0.198 0.166 83.8 0.198 0.169 85.4

LCS-140429-2 0.198 0.181 91.6 0.198 0.190 95.9

LCS-140429-3 0.198 0.176 88.7 0.198 0.186 94.1

Average ± %RSD 88.0% ± 4.5% 91.8% ± 6.1%

LCS-140429-4 9.92 7.38 74.4 9.92 8.21 82.8

LCS-140429-5 9.92 7.95 80.2 9.92 8.54 86.1

LCS-140429-6 9.92 8.14 82.0 9.92 8.43 85.0

Average ± %RSD 78.9% ± 5.0% (1) 84.6% ± 2.0%

LCS-140429-7 39.6 33.3 84.0 39.6 36.1 91.3

LCS-140429-8 39.6 32.5 82.0 39.6 36.5 92.1

LCS-140429-9 39.6 29.7 75.1 39.6 36.1 91.3

Average ± %RSD 80.4% ± 5.8% 91.6% ± 0.50%

(1) LCS recovery did not meet acceptance criteria of 100 ± 20%.
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Table 7 continued. Lab Control Spike Results.

ETS-8-044.1

Internal Standard Calibration

Analyzed 5/1/14 PFOS (Linear + Branched) 13C4-PFOS surrogate

Lab ID

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

Spiked 

Concentration 

(ng/mL)

Calculated 

Concentration 

(ng/mL) %Recovery

LCS-140429-1 0.184 0.173 94.2 0.189 0.170 90.0

LCS-140429-2 0.184 0.153 82.9 0.189 0.164 86.9

LCS-140429-3 0.184 0.167 90.6 0.189 0.183 96.8

Average ± %RSD 89.2% ± 6.5% 91.2% ± 5.6%

LCS-140429-4 9.20 7.56 82.1 1.90 1.62 85.4

LCS-140429-5 9.20 8.11 88.2 1.90 1.75 92.0

LCS-140429-6 9.20 8.09 88.0 1.90 1.75 92.3

Average ± %RSD 86.1% ± 4.0% 89.9% ± 4.3% 

LCS-140429-7 36.7 32.4 88.3

LCS-140429-8 36.7 32.7 89.1

LCS-140429-9 36.7 34.0 92.6

Average ± %RSD 90.0% ± 2.5%

(1) LCS recovery did not meet acceptance criteria of 100 ± 20%.

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%. 

• The analytical method uncertainty as calculated by ETS-12-012.2 for PFBS by internal standard 

calibration was ± 11%. The recovery of the mid set of LCS analyzed on 5/1/14 was 78.9% for 

PFBS by internal standard calibration for the samples analyzed on this date. The analytical 

uncertainty was expanded to ± 21%. 

Table 8. Analytical Method Uncertainty.

Analyte Calibration Method Standard Deviation (%) Method Uncertainty

PFOA External Standard 7.04 ±14%

PFBS External Standard 9.03 ±18%

PFHS External Standard 5.05 ±10%

PFOS External Standard 4.02 ±8.0%

PFOA Internal Standard 5.38 ±11%

PFBS Internal Standard NA ±21%

PFHS Internal Standard 8.55 ±17%

PFOS Internal Standard 5.21 ±10%

NA = Not Applicable
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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 field matrix 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. 

*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 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, WW11R Field Matrix Spike 1980 1980 1980 1980

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 were 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. The surrogate spike 

recoveries are presented in section 4 of this report. 

*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 meeting the method acceptance criteria of ±30%, demonstrate that the method is 

appropriate for the given matrix. 
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For those analytes where the field matrix spike level was not appropriate as compared to the sample 

concentration, the surrogate recovery standards were used to assess method accuracy. For all 

sampling locations, surrogate recovery standards where applicable and field matrix spike recoveries 

met method acceptance criteria (where applicable).

Table 10. DAL GW ACI 140331 (1)

PFOA PFBS

3M LIMS ID Sample Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO14-07-03-001 DAL-GW-ACI-0 - 140331 2350 NA 536 NA

ISO14-07-03-002 DAL-GW-ACI-DB - 140331 2470 NA 546 NA

ISO14-07-03-003 DAL-GW-ACI-FMS - 140331 4680 115 2540 101

Average Concentration (ng/mL) ± %RPD 2140 ng/mL ± 5.0% 541 ng/mL ± 1.8%

PFHS PFOS

3M LIMS ID Sample Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO14-07-03-001 DAL-GW-ACI-0 - 140331 1090 NA 3430 NA

ISO14-07-03-002 DAL-GW-ACI-DB - 140331 1120 NA 3760 NA

ISO14-07-03-003 DAL-GW-ACI-FMS - 140331 3330 112 6110 127

Average Concentration (ng/mL) ± %RPD 1110 ng/mL ± 2.7% 3600 ng/mL ± 9.2% 

13C4-PFOA 13C4-PFOS

3M LIMS ID Sample Description %Recovery %Recovery

ISO14-07-03-001 DAL-GW-ACI-0 - 140331 104 101

ISO14-07-03-002 DAL-GW-ACI-DB - 140331 104 98.0

ISO14-07-03-003 DAL-GW-ACI-FMS - 140331 94.9 94.8

Average Concentration (ng/mL) ± %RSD 101% ± 5.3% 98.0% ± 3.4%

NA = Not Applicable

(1) Samples were analyzed by external standard calibration on 4/15/14. 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 140331

PFOA (1) PFBS (2)

3M LIMS ID Sample Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO14-07-03-004 DAL-GW-ACM2-0 - 140331 2.15 NA 3240 NA

ISO14-07-03-005 DAL-GW-ACM2-DB - 140331 1.91 NA 3230 NA

ISO14-07-03-006 DAL-GW-ACM2-FMS - 140331 7.02 101 3220 NC

Average Concentration (ng/mL) ± %RPD 2.03 ng/mL ± 12% 3240 ng/mL ± 0.31%

PFHS (1) PFOS (1)

3M LIMS ID Sample Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO14-07-03-004 DAL-GW-ACM2-0 - 140331 0.927 NA 3.60 NA

ISO14-07-03-005 DAL-GW-ACM2-DB - 140331 0.808 NA 3.28 NA

ISO14-07-03-006 DAL-GW-ACM2-FMS - 140331 5.67 97.0 8.27 97.6

Average Concentration (ng/mL) ± %RPD 0.868 ng/mL ± 14% 3.44 ng/mL ± 9.3%

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

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

ISO14-07-03-004 DAL-GW-ACM2-0 - 140331 101 97.4 107

ISO14-07-03-005 DAL-GW-ACM2-DB - 140331 103 92.1 108

ISO14-07-03-006 DAL-GW-ACM2-FMS - 140331 98.8 108 114

Average Concentration (ng/mL) ± %RSD 101% ± 2.1% 99.1% ± 8.1% 109% ± 3.6%

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 5/1/14.

(2) Samples were analyzed by external standard calibration on 4/15/14. The surrogate recovery standard 13C4-PFOS was added 

to the samples during sample preparation.
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Table 12. DAL GW ACE 140331 (1)

PFOA PFBS

3M LIMS ID Sample Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO14-07-03-007 DAL-GW-ACE-0 - 140331 0.257 NA 0.224 NA

ISO14-07-03-008 DAL-GW-ACE-DB - 140331 0.266 NA 0.223 NA

ISO14-07-03-009 DAL-GW-ACE-FMS - 140331 4.95 94.9 5.21 101

Average Concentration (ng/mL) ± %RPD 0.262 ng/mL ± 3.4% 0.224 ng/mL ± 0.45%

PFHS PFOS

3M LIMS ID Sample Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO14-07-03-007 DAL-GW-ACE-0 - 140331 0.105 NA 0.131 NA

ISO14-07-03-008 DAL-GW-ACE-DB - 140331 0.111 NA 0.146 NA

ISO14-07-03-009 DAL-GW-ACE-FMS - 140331 4.90 96.8 4.90 96.2

Average Concentration (ng/mL) ± %RPD 0.108 ng/mL ± 5.6% 0.139 ng/mL ± 11%

13C4-PFOA 13C4-PFOS

3M LIMS ID Sample Description %Recovery %Recovery

ISO14-07-03-007 DAL-GW-ACE-0 - 140331 98.3 91.2

ISO14-07-03-008 DAL-GW-ACE-DB - 140331 107 107

ISO14-07-03-009 DAL-GW-ACE-FMS - 140331 94.5 96.4

Average Concentration (ng/mL) ± %RSD 99.8% ± 6.2% 98.2% ± 8.1%

NA = Not Applicable

(1) Samples were analyzed by internal standard calibration on 5/1/14.
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Table 13. DAL GW WW8R 140331 (1)

PFOA PFBS

3M LIMS ID Sample Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO14-07-03-010 DAL-GW-WW8R-0 - 140331 3330 NA 344 NA

ISO14-07-03-011 DAL-GW-WW8R-DB - 140331 3240 NA 370 NA

ISO14-07-03-012 DAL-GW-WW8R-FMS - 140331 6200 118 3310 119

Average Concentration (ng/mL) ± %RPD 3290 ng/mL ± 2.7% 357 ng/mL ± 7.3%

PFHS PFOS

3M LIMS ID Sample Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO14-07-03-010 DAL-GW-WW8R-0 - 140331 1430 NA 5980 NA

ISO14-07-03-011 DAL-GW-WW8R-DB - 140331 1510 NA 5600 NA

ISO14-07-03-012 DAL-GW-WW8R-FMS - 140331 4420 119 8730 119

Average Concentration (ng/mL) ± %RPD 1470 ng/mL ± 5.4% 5790 ng/mL ± 6.6%

13C4-PFOA 13C4-PFOS

3M LIMS ID Sample Description %Recovery %Recovery

ISO14-07-03-010 DAL-GW-WW8R-0 - 140331 103 92.8

ISO14-07-03-011 DAL-GW-WW8R-DB - 140331 104 98.2

ISO14-07-03-012 DAL-GW-WW8R-FMS - 140331 91.4 90.2

Average Concentration (ng/mL) ± %RSD 99.6% ± 7.2% 93.7% ± 4.4%

NA = Not Applicable

(1) Samples were analyzed by external standard calibration on 4/15/14. 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 140331

PFOA (1) PFBS (1)

3M LIMS ID Sample Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO14-07-03-013 DAL-GW-WW9R-0 - 140331 3580 NA 356 NA

ISO14-07-03-014 DAL-GW-WW9R-DB - 140331 3180 NA 325 NA

ISO14-07-03-015 DAL-GW-WW9R-FMS - 140331 5850 100 3020 108

Average Concentration (ng/mL) ± %RPD 3380 ng/mL ± 12% 341 ng/mL ± 9.1%

PFHS (1) PFOS (2)

3M LIMS ID Sample Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO14-07-03-013 DAL-GW-WW9R-0 - 140331 1630 NA 4920 NA

ISO14-07-03-014 DAL-GW-WW9R-DB - 140331 1460 NA 5920 NA

ISO14-07-03-015 DAL-GW-WW9R-FMS - 140331 4130 104 7390 79.6

Average Concentration (ng/mL) ± %RPD 1550 ng/mL ± 11% 5420 ng/mL ± 18%

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

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

ISO14-07-03-013 DAL-GW-WW9R-0 - 140331 101 85.4 109

ISO14-07-03-014 DAL-GW-WW9R-DB - 140331 103 89.7 105

ISO14-07-03-015 DAL-GW-WW9R-FMS - 140331 90.2 88.6 106

Average Concentration (ng/mL) ± %RSD 98.2% ± 7.1% 87.9% ± 2.6% 107% ± 1.8%

NA = Not Applicable

(1) Samples were analyzed by external standard calibration on 4/15/14. The surrogate recovery standards 13C4-PFOA and 13C4-

PFOS were added to the samples during sample preparation.

(2) Samples were analyzed by external standard calibration on 4/30/14. The surrogate recovery standard 13C4-PFOS was added 

to the samples during sample preparation.
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Table 15. DAL GW WW10R 140331 (1)

PFOA PFBS

3M LIMS ID Sample Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO14-07-03-016 DAL-GW-WW10R-0 - 140331 2110 NA 278 NA

ISO14-07-03-017 DAL-GW-WW10R-DB - 140331 2170 NA 277 NA

ISO14-07-03-018 DAL-GW-WW10R-FMS - 140331 4070 97.7 2260 100

Average Concentration (ng/mL) ± %RPD 2140 ng/mL ± 2.8% 278 ng/mL ± 0.36%

PFHS PFOS

3M LIMS ID Sample Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO14-07-03-016 DAL-GW-WW10R-0 - 140331 1030 NA 3760 NA

ISO14-07-03-017 DAL-GW-WW10R-DB - 140331 1030 NA 3210 NA

ISO14-07-03-018 DAL-GW-WW10R-FMS - 140331 3030 101 5980 126

Average Concentration (ng/mL) ± %RPD 1030 ng/mL ± 0.0% 3490 ng/mL ± 16%

13C4-PFOA 13C4-PFOS

3M LIMS ID Sample Description %Recovery %Recovery

ISO14-07-03-016 DAL-GW-WW10R-0 - 140331 106 99.0

ISO14-07-03-017 DAL-GW-WW10R-DB - 140331 109 98.6

ISO14-07-03-018 DAL-GW-WW10R-FMS - 140331 94.0 91.5

Average Concentration (ng/mL) ± %RSD 103% ± 7.8% 96.4% ± 4.4%

NA = Not Applicable

(1) Samples were analyzed by external standard calibration on 4/15/14. The surrogate recovery standards 13C4-PFOA and 13C4-

PFOS were added to the samples during sample preparation.
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Table 16. DAL GW WW11R 140331

PFOA (1) PFBS (1)

3M LIMS ID Sample Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO14-07-03-019 DAL-GW-WW11R-0 - 140331 1190 NA 257 NA

ISO14-07-03-020 DAL-GW-WW11R-DB - 140331 1180 NA 250 NA

ISO14-07-03-021 DAL-GW-WW11R-FMS - 140331 3450 115 2350 106

Average Concentration (ng/mL) ± %RPD 1190 ng/mL ± 0.84% 254 ng/mL ± 2.8%

PFHS (1) PFOS (2)

3M LIMS ID Sample Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO14-07-03-019 DAL-GW-WW11R-0 - 140331 544 NA 1870 NA

ISO14-07-03-020 DAL-GW-WW11R-DB - 140331 554 NA 1910 NA

ISO14-07-03-021 DAL-GW-WW11R-FMS - 140331 2590 103 3850 99.0

Average Concentration (ng/mL) ± %RPD 549 ng/mL ± 1.8% 1890 ng/mL ± 2.1%

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

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

ISO14-07-03-019 DAL-GW-WW11R-0 - 140331 108 102 107

ISO14-07-03-020 DAL-GW-WW11R-DB - 140331 108 102 106

ISO14-07-03-021 DAL-GW-WW11R-FMS - 140331 98.7 98.2 101

Average Concentration (ng/mL) ± %RSD 105% ± 5.2% 101% ± 2.0% 104% ± 2.8%

NA = Not Applicable

(1) Samples were analyzed by external standard calibration on 4/15/14. The surrogate recovery standards 13C4-PFOA and 13C4-

PFOS were added to the samples during sample preparation.

(2) Samples were analyzed by external standard calibration on 4/30/14. The surrogate recovery standard 13C4-PFOS was 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

ISO14-07-03-022 DAL-GW-TRIP-0 - 140331 <0.0240 (1) NA <0.0250 (1) NA

ISO14-07-03-023 DAL-GW-TRIP-LS - 140331 4.89 (1) 99.0 4.74 (1) 95.8

ISO14-07-03-024 DAL-GW-TRIP-HS - 140331 2840 (2) 115 2490 (2) 101

PFHS PFOS

3M LIMS ID Sample Description

Concentration 

(ng/mL) %Recovery

Concentration 

(ng/mL) %Recovery

ISO14-07-03-022 DAL-GW-TRIP-0 - 140331 <0.0250 (1) NA <0.0232 (1) NA

ISO14-07-03-023 DAL-GW-TRIP-LS - 140331 4.61 (1) 93.1 4.90 (1) 92.9

ISO14-07-03-024 DAL-GW-TRIP-HS - 140331 2690 (2) 109 2910 (2) 118

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

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

ISO14-07-03-022 DAL-GW-TRIP-0 - 140331 98.9 106 101 94.7

ISO14-07-03-023 DAL-GW-TRIP-LS - 140331 106 95.4 103 98.5

ISO14-07-03-024 DAL-GW-TRIP-HS - 140331 NA NA 100 100

NA = Not Applicable

(1) Samples were analyzed by internal standard calibration on 5/1/14.

(2) Samples were analyzed by external standard calibration on 4/15/14. 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 4/29/13 5/31/13 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

PFOA 1480 1860 1480 1630 2320 1880 2190 1830 1580 1870 2410

PFBS 1360 1040 708 1230 356 1590 1100 1350 202 1470 541

PFHS 777 940 942 749 1400 866 1330 695 845 737 1110

PFOS 1670 2150 1590 1680 3240 2100 2240 1970 2700 1800 3600

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

ACE 4/29/13 5/31/13 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

PFOA 0.0422 0.0725 0.0717 0.0641 0.115 0.231 0.478 0.0798 0.490 0.138 0.262

PFBS 0.392 24.8 111 1960 1950 0.379 0.592 0.0766 0.257 0.0360 0.224

PFHS 0.0570 0.105 0.118 0.0778 0.156 0.180 0.366 0.0648 0.219 0.0706 0.108

PFOS <0.0232 <0.0232 <0.0232 0.0277 0.0452 0.0785 0.0726 0.0303 0.209 0.0966 0.139
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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 4/29/13 5/31/13 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

PFOA 3190 2760 2760 2640 2890 2830 3040 2720 2660 2560 3290

PFBS 364 289 282 263 303 312 362 316 326 331 357

PFHS 1610 1330 1340 1260 1370 1300 1440 1270 1460 1370 1470

PFOS 4830 4180 4110 3910 4100 4410 4750 4060 3990 4170 5790

WW9R - Sample Results in ng/mL

WW9R 4/29/13 5/31/13 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

PFOA 2650 2660 2630 2410 2730 2820 2950 2690 2900 2630 3380

PFBS 244 226 225 212 249 286 305 259 317 270 341

PFHS 1200 1120 1140 1030 1220 1280 1340 1170 1460 1370 1550

PFOS 4340 4210 4150 3670 4200 4380 4540 4190 4800 4660 5420
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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

PFOA 2070 2150 2400 1890 1330 1780 2140

PFBS 247 264 303 239 250 260 278

PFHS 1030 1030 1120 885 757 935 1030

PFOS 2770 3160 3890 2920 1570 2860 3490

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

PFOA 1720 1100 1320 1060 814 1300 1190

PFBS 299 240 287 198 168 262 254

PFHS 1000 511 680 512 362 696 549

PFOS 2200 1670 1850 1570 1540 2100 1890