# 3

GLP10-01-01 Interim Report 21: Analysis for PFOA in Decatur, AL Soils

Collected from Well Location 610 in August, 2011



## Study Title 3M Environmental Laboratory Analytical Protocol GLP 10-01-01: Analysis of Perfluorooctanoic Acid (PFOA) in Groundwater, Soil and Sediment for t he 3M Decatur Phase 3 Site-Related Monitoring Program


## Data Requirement EPA TSCA Good Laboratory Practice Standards 40 CFR Part 792



## Study Director Jaisimha Kesari P.E., DEE Weston Solutions, Inc. 1400 Weston Way West Chester, PA 19380 

### Phone: 610-701-3761 

## Principal Analytical Investigator

Cleston C. Lange, Ph.D. 3M Environmental Laboratory 

## Interim Report Completion Date

Upon Signing 

## Performing Laboratory 3M Environmental Health and Safety Operations

Environmental Laboratory 3M Center, Bldg 260-05-N-17 St. Paul, MN 55144 

## Project Identification GLP10-01-01-21
Total Number of Pages

19Study: GLP10-01-01, Interim Report 21 Analysis for PFOA in Decatur, AL Soils Collected fr om Well Location 610

Page 2 of 19 This page has been reserved for specific country re quirements.study : GLP10-01-01 , Interi m Repor t 2 1 Analysi s fo r PFO A i n Decatur , A L Soil s Collecte d fro m Wel l Locatio n 61 0



## jGL P COMPLIANC E ST^|EMEN T

Repor t Title : GLP10-01-0 1 Interi m Repor t 21 : Analysi s fo r PFO A i n Decatur , A L Soil s Collecte d fro m Wel l Locatio n 61 0 i n Augus t 2011

. 3 M Environmenta l Laborator y Analytica l Protoco l GLP10

- 01-01 : Analysi s o f Perfluorooctanoi c Aci d (PFOA ) i n Groundwater , Soi l an d Sedimen t fo r th e 3 M Decatu r Phas e 3 Site-Relate d Monitorin g Program

.

Thi s analytica l phas e wa s conducte d i n complianc e wit h Toxi c Substance s Contro l Ac t (TSCA ) Good Laborator y Practic e (GLP ) Standards , 4 0 CF R 792 , wit h th e exception s liste d below :

Exception s t o GL P compliance :

• Test , contro l an d referenc e substance s wer e no t al l characterize d unde r GLPs

.

• Sample s environmenta l samples , ther e wa s n o dosin g an d n o specifi c tes t substanc e fo r thi s study

.

Gar y Hohenstein , Sponso r Representativ e Dat e

Jaisimh a Kesari , P.E. , DEE , Stud y Directo r

Pag e 3 o f 1 9Study : GLP10-01-01 , Interi m Repor t 2 1 Analysi s fo r PFO A i n Decatur , A L Soil s Collecte d fro m Wel l Locatio n 61 0



## iQuALiT Y ASSURANC E STATEMEN T

Repor t Title : GLP10-01-0 1 Interi m Repor t 21 : Analysi s fo r PFO A i n Decatur , A L Soil s Collecte d fro m Wel l Locatio n 61 0 i n Augus t 2011

. 3 M Environmenta l Laborator y Analytica l Protoco l GLP10-01-01 : Analysi s o f Perfluorooctanoi c Aci d (PFOA ) i n Groundwater , Soi l an d Sedimen t fo r th e 3 M Decatu r Phas e 3 Site-Relate d Monitorin g Program

.

Thi s interi m stud y repor t an d th e accompanyin g dat a wer e audite d b y th e 3 M Environmenta l Laborator y Qualit y Assuranc e Uni t (QAU) , a s indicate d below

. Th e finding s wer e reporte d t o th e principa l investigato r (P.I.) , laborator y managemen t an d stud y director

.

stud y Inspectio n Date s Phas e Dat e Reporte d t o stud y Inspectio n Date s Phas e P.I

. Stud y Directo r •Managemen t Stud y Directo r

Nov

. 14-15,201 1 Interi m Repor t an d Dat a 11/25/201 1 1/13/201 2 1/13/201 2



# A A

. f-'/ ^
QA U Representativ e Dat e

Pag e 4 o f 1 9Study: GLP10-01-01, Interim Report 21 Analysis for PFOA in Decatur, AL Soils Collected fr om Well Location 610

Page 5 of 19 

## T ABLE OF 

## C ONTENTS
GLP Compliance Statement ..........................

................................................... ......................................... 3 Quality Assurance Statement .......................

................................................... .......................................... 4

Table of Contents .................................

................................................... ................................................... 5

List of Tables ....................................

................................................... ................................................... ..... 6

1 Study Information .................................

................................................... ............................................ 7

2 Summary ...........................................

................................................... ............................................... 8

3 Introduction ......................................

................................................... ................................................. 9

4 Test, Control and Reference Substances ............

................................................... ........................... 9

5 Test System .......................................

................................................... ............................................. 10

6 Method Summary ....................................

................................................... ....................................... 10

6.1 Methods ...........................................

................................................... .................................. 10

6.2 Sample Receipt ....................................

................................................... ............................. 10

6.3 Sample Preparation ................................

................................................... ........................... 10

6.4 Percent Soil Moisture Determination ...............

................................................... ................. 11

6.5 LC/MS/MS Analysis .................................

................................................... .......................... 11

7 Analytical Results ................................

................................................... ........................................... 13

7.1 Calibration .......................................

................................................... ................................... 13

7.2 Limits of Quantitation (LOQs) .....................

................................................... ...................... 14

7.3 Continuing Calibration ............................

................................................... ........................... 14

7.4 Blanks ............................................

................................................... ..................................... 14

7.5 Laboratory Control Spikes (LCSs) ..................

................................................... .................. 14

7.6 Laboratory Matrix Spikes (LMSs) ...................

................................................... .................. 15

7.7 Percent Moisture Determinations ...................

................................................... .................. 16

7.8 Individual Sample Results .........................

................................................... ........................ 16Study: GLP10-01-01, Interim Report 21 Analysis for PFOA in Decatur, AL Soils Collected fr om Well Location 610

Page 6 of 19 8 Conclusion ........................................

................................................... .............................................. 17

9 Data/Sample Retention .............................

................................................... ..................................... 17

10 List of Attachments ...............................

................................................... .......................................... 17

11 Signatures ........................................

................................................... ............................................... 18


## L IST OF 

## T

ABLES
Table 1. PFOA Results for Decatur, AL Soils from W ell Location 610, August 2011 ..................... ...... 8 Table 2. LMS Recovery for Decatur, AL Soils from W ell Location 610, August 2011 ..................... ...... 8

Table 3. Control and Reference Substances ........

................................................... ................................ 9

Table 4. Instrument Information ..................

................................................... ......................................... 12 Table 5. Gradient Liquid Chromatography Conditions (ETS-8-053)....................................... .............. 12

Table 6. Mass Transitions ........................

................................................... ............................................ 12 Table 7. PFOA Calibration Summary (Calibrated with linear PFOA) ..................................... .............. 13

Table 8. LCS Results .............................

................................................... .............................................. 15
Table 10. Percent Moistures for Decatur, AL Soils from Well Location 610, August 2011 ............... .. 16
Table 11. Individual PFOA Results for Decatur, AL Soils from Well Location 610, August 2011 ....... 1 6Study: GLP10-01-01, Interim Report 21 Analysis for PFOA in Decatur, AL Soils Collected fr om Well Location 610

Page 7 of 19 

### 1 Study Information

Sponsor 3M Company
Sponsor Representative Gary A. Hohenstein Environmental Manager Special Projects, EHS Operations Bldg 224-5W-03 St. Paul, MN 55144 Phone: (651) 737-3570 gahohenstein@mmm.com
Study Director Jaisimha Kesari, P.E., DEE Weston Solutions, Inc. 1400 Weston Way West Chester, PA 19380

Study Analytical Testing Facility 3M EHS Operations Environmental Laboratory Building 260-5N-17 St. Paul, MN 55144
Study Personnel (3M Environmental Laboratory) Cleston C. Lange, Ph.D., Principal Analytical Inves tigator William K. Reagen, Ph.D., Laboratory Manager Patrick Kenney, Laboratory Technician (Pace Analyti cal, Professional Services) Marlene Heying, Laboratory Technician (Pace Analyti cal, Professional Services)
Study Dates Study Initiation: March 08, 2010 Interim Analytical Initiation: September 12, 2011 Interim Analytical Completion: October 19, 2011 Interim Report Completion: Upon final Signatures

Location of Archives All original raw data and analytical reports have b een archived at the 3M Environmental Laboratory according to 40 CFR Part 792. The test substance and analytical reference standard reserve samples are archived at the 3M Env ironmental Laboratory according to 40 CFR Part 79Study: GLP10-01-01, Interim Report 21 Analysis for PFOA in Decatur, AL Soils Collected fr om Well Location 610

Page 8 of 19 

### 2 Summary

This interim report provides the PFOA concentration results for the four soils collected in August 201 1 at well location 610 near the 3M facility at Decatur, AL. One travel blank (trip blank), containing approximately 16 grams of control soil in a sample bottle, accompanied the sample bottles to and from the site and was also analyzed. Samples were logged in to the laboratory information management system (LIMS) under project GLP10-01-01-21. Four aliquots of each soil were removed from each sample bottle and accurately weighed. The third and fourth repli cates of each sample were fortified with nominal 5. 00 and 50.0 ng of PFOA as a low and high laboratory ma trix spiked (LMS), respectively. A single LMS for the trip blank was fortified with nominal 1.00 ng of PF OA. Sample were extracted and analyzed per method ETS-8-053 which employs analysis by liquid chromato graphy with triple quadrapole mass spectrometric detection (LC/MS/MS). The LMS results provided a m easure of PFOA recovery from individual samples. The relative percent difference (RPD) of the duplic ate sample results was used to assess the analytica l precision of the sample results. The percent moist ure of each soil was also determined as part of the study. The PFOA concentrations and RPDs are summar ized in Table 1 . The PFOA fortification levels and recoveries of PFOA from the LMS samples are sum marized in Table 2

.

Table 1. PFOA Results for Decatur, AL Soils from W ell Location 610

**3M LIMS ID Sample ID Avg. PFOA Concentration**  **(ng/g; dry weight) Relative Percent**  **Difference** GLP10-01-01-21-001 DAL-SB-610S-0-0000 4.57 10%
GLP10-01-01-21-002 DAL-SB-610S-0-0010 10.3 7.0%
GLP10-01-01-21-003 DAL-SB-610S-0-0040 6.21 2.9% GLP10-01-01-21-004 DAL-SB-610S-0-0150 BLQ N/A GLP10-01-01-21-005 TRIP BLANK-1 BLQ N/A BLQ; The integrated peak area response for PFOA in the sample was below the PFOA peak area response fo r the lowest standard that was used to construct the calibration curve (< nominal 0.200 ng/g). Data Accuracy determined from LMS results was withi n 100+ 29%, and RPD (precision) determined for analytical duplicates was < 15%. N/A; not applicable The analytical method uncertainty determined from L CSs was + 13%; determined at the 95% CI.

Table 2. LMS Recovery for Decatur, AL Soils from W ell Location 610

**3M LIMS ID Sample ID PFOA Spike**  **Concentration (ng/g; dry**  **weight) PFOA Recovery** 

**(Data Accuracy)**

GLP10-01-01-21-001 Low DAL-SB-610S-0-0000 Lab Matri x Spike Low 6.07 103% GLP10-01-01-21-001 High DAL-SB-610S-0-0000 Lab Matr ix Spike High 58.9 102% GLP10-01-01-21-002 Low DAL-SB-610S-0-0010 Lab Matri x Spike Low 5.60 98.7% GLP10-01-01-21-002 High DAL-SB-610S-0-0010 Lab Matr ix Spike High 57.2 112% GLP10-01-01-21-003 Low DAL-SB-610S-0-0040 Lab Matri x Spike Low 5.05 129% GLP10-01-01-21-003 High DAL-SB-610S-0-0040 Lab Matr ix Spike High 52.4 111% GLP10-01-01-21-004 Low DAL-SB-610S-0-0150 Lab Matri x Spike Low 4.90 94.8% [a] GLP10-01-01-21-004 High DAL-SB-610S-0-0150 Lab Matr ix Spike High 49.5 114% [a] GLP10-01-01-21-005 LMS Trip Blank-1 Lab Matrix Spik e Low 1.01 102% [a] [a] Samples with an endogenous PFOA level of BLQ we re treated as a concentration of zero to calculate recovery.Study: GLP10-01-01, Interim Report 21 Analysis for PFOA in Decatur, AL Soils Collected fr om Well Location 610

Page 9 of 19 

### 3 Introduction

The soil analyses reported herein were conducted as part of the Phase 3 Environmental Monitoring and Assessment Program for the 3M facility located in Decatur, Alabama. The objective of the overall program is to gain information regarding co ncentrations of perfluorooctanoate (PFOA) in various environmental media such as groundwater, so ils and sediments that are associated with and near the Decatur facility. Reported herein are the results from analysis of soils from near well location 610, located near the 3M facility in Decat ur, AL. The samples were collected by Weston Solutions, Inc. personnel in August 2011 and shippe d to the 3M Environmental Laboratory for quantitative analysis of PFOA. One soil travel bla nk (trip blank) was also analyzed. This report describes the sample shipment, receipt, extraction and quantitative LC/MS/MS analysis procedures conducted for determination of PFOA in t he soils for project GLP10-01-01-21. Additionally, included in this report are the asses sment of the analytical precision and accuracy for the reported PFOA concentration results, the recove ry results for a stable isotope labeled surrogate ( 13 C 4 -PFOA ) that was added to each soil aliquot prior to extr action, and the determined percent moisture content of each soil.



### 4 Test, Control and Reference Substances

This study does not have a test substance in the cl assic sense of a GLP study because this study was purely analytical in nature. The reference and control substances are listed in Table 3

.

Table 3. Control and Reference Substances

Test Substance PFOA (linear

isomer), free acid Technical PFOA (linear + branched isomers), ammonium salt 13 C 4 -PFOA 13 C 8 -PFOA

Use Calibration & LMSs LCSs Surrogate Internal Stan dard Source Oakwood 3M Wellington Labs Wellington Labs Expiration Date 9/29/2012 2/27/2017 10/22/2012 10/2 2/2012 Storage Conditions Frozen Frozen Frozen Frozen

Chemical Lot 3440 332 MPFOA1009 M8PFOA0408 TCR Number TCR07-0041 1/1 TCR-123 TCR09-0075 2/9 TC R09-0067 5/9 Physical Description Powder White Powder Methanol Solution [a] Methanol Solution [a] Purity 99.5% 95% >98% 97.9% [a] Stable isotope labeled materials are typically provided as methanolic solutions by the vendor (sou rce) and are treated as 100% pure; the vendor’s reported methano l stock concentration is used for calculating conce ntrations of diluted standards made from them.Study: GLP10-01-01, Interim Report 21 Analysis for PFOA in Decatur, AL Soils Collected fr om Well Location 610

Page 10 of 19 

### 5 Test System

There was not a test system for this study in the c lassic sense of a GLP study. This study was conducted for analysis of off-site soils collected near well location 610, near the 3M facility in Decatur, AL. Samples for this study are “real worl d” environmental samples. 

### 6 Method Summary

6.1 Methods

Soil extractions and quantitative LC/MS/MS analysis were performed following validated method ETS-8-053.0. The analysis conducted for reporting results was performed on October 5, 2011 as analytical run s111005a.



### 6.2 Sample Receipt

On August 23, 2011 four (4) empty 250-mL HDPE Nalg eneTM sample bottles, and one travel blank (trip blank) containing approximately 16 gram s of a control soil TCR-842, were sent from the 3M Environmental Laboratory to Weston Solutions, In c. field personnel for collection of soils from well location 610. Following the soil sample col lections by Weston Solutions, Inc. personnel, 4 soil-filled sample bottles and the trip blank were sent to the laboratory for analysis. The samples were received with sample chains of custody numbers 16926 on September 12, 2011. A discrepancy between the date of bottle order sent t o Decatur (8/23/2011) and the listed date of collection of the soils (8/19/2011) indicated sampl es were collected prior to receiving the bottles and trip blank. Charles Young of Weston, Inc. wh o oversaw the soil collections at Decatur was notified and indicated that the trip blank likely d id not accompany the samples during collection in Decatur since other bottles apparently were used th an those sent on 8/23/2011. However, the trip blank did accompany the samples when shipped back t o 3M. A protocol deviation regarding this was written and is maintained in the study folder f or project GLP10-01-01-21. Any impact on the study sample results for the soils collected under GLP10-01-01-21 was regarded as minimal. Soil samples from Decatur, AL are regulated and wer e appropriately shipped in accordance with USDA/APHIS soil permit number P330-09-00125. Sample nomenclature follows the form DAL-SB-610x-xx -xxxx where the first string defines the Decatur Alabama (DAL) project area, the second string defin es the sample media (i.e., SB= soil boring), the th ird string defines the specific well identity (well 610 ). The fourth string defines the sample type (0 = primary sample, DB = field duplicate, RB = equipment rinsea te blank). The fifth string indicates the sampling depth range (0040 indicates 4.0 ft to 4.5 ft interv al soil sample).



### 6.3 Sample Preparation

Sample preparation was conducted as a single batch on October 4-5, 2011. Each soil extraction involved removal of a 1 cubic centimeter (1 cc; 1 mL) soil aliquot (typically ~ 1 gram) from each sample bottle using a fixed volume 1 cc s poon, transferring it to a 15 mL conical centrifuge tube, followed by accurate weight determination of the aliquot on a 5-place balance. Then, nominal 3. 0 ng of internal standard (IS; nominal 3.0 ng) was ad ded to each soil aliquot. Then the soil aliquot wa s extracted by addition of 8 mL of a 4:1 acetonitrile :water solution followed by sonication for 1 to 2 h ours and then centrifugation to remove solids. The supe rnatant from each was then transferred to an autovi alStudy: GLP10-01-01, Interim Report 21 Analysis for PFOA in Decatur, AL Soils Collected fr om Well Location 610

Page 11 of 19 for analysis. An accurately measured volume of eac h supernatant was analyzed by LC/MS/MS. For a few samples, the 1cc aliquot resulted in only ~0.65 gram of soil, therefore, extra soil was used in those extractions in order to be closer to 1 gram o f sample. In those few instances the inclusion of extra sample ensured adequate sensitivity for target ana lytes was achieved for the final extract. During preparation, each sample received nominal 3. 0 ng of a stable isotope labeled surrogate recovery standard (SRS) as 13 C 4 -PFOA. Although not included as part of the data accuracy assessment for this study, SRS recovery determinations were included as part of an ongoing method validation aspect for SRS behavior in environmental soil samples for pote ntial future applications. The SRS was quantified from a SRS calibration curve constructed from analy sis of calibration standards prepared from the SRS in calibration standards. The SRS recovery was det ermined based on the calculated concentration of SRS from the analysis and recovery of SRS from each sample is included in Table 10 , but was not used for evaluation of data accuracy for this study and is otherwise excluded from the discussions in the report. Each analytical sample was prepared in duplicate fo r analysis of PFOA in the soil sample. Additional ly, a third and fourth replicate was weighed out and us ed to prepare a low- LMS and high-LMS, fortified with nominal 5.0 ng and 50.0 ng of PFOA (linear iso mer), respectively. LMS results were used for determination of data accuracy. RPD of duplicate s amples results was used for determination of data precision. Calibration standards were prepared by spiking know n quantities of PFOA (linear isomer) into 1-cubic centimeter (1 cc, 1 mL) aliquots of 3M Environmenta l Laboratory control soil TCR-842. The nominal mass of 1 cc of control soil TCR-842 is 1.0 gram (d ry). The nominal calibration standard range prepar ed and analyzed was 0.200 ng/g to 500 ng/g. Laboratory control spike (LCS) samples were prepare d with each sample preparation batch; prepared at three levels (nominal 3.00 ng/g, 30.0 ng/g and 300 ng/g) and each level in triplicate. The LCSs were prepared using control soil TCR-842, same as calibr ation standards, and were fortified with technical PFOA (linear + branched isomer). The LCS results were used to estimate the analytical method uncertainty.



### 6.4 Percent Soil Moisture Determination

The percent moisture of soils was used to calculate the dry weight of the wet soils weighed during sample preparations for PFOA analysis, and was dete rmined by gravimetric analysis. Dry weights were determined for separate weighings than the weighing s used for PFOA extraction and analysis procedures. To determine the percent moisture, dup licate aliquots of each soil sample were removed and the accurate “wet” weight determined for each. All aliquots were dried at > 100°C until no further mass loss occurred from water evaporation, at which time the accurate dried weights were determined. The difference in mass, attributed to water evapora tion, was used to calculate the percent moisture of the original soil. The averaged percent moisture r esult for each was then used to calculate the soil PFOA concentration on a dry weight basis, and is re ported for each soil in Table 9

. 

### 6.5 LC/MS/MS Analysis

The LC/MS/MS analysis was performed on October 5, 2 011 as analytical run S111005a and was performed by as described in method ETS-8-053.0 The relative percent difference (RPD) of the duplic ate sample results was used as a measure of the analytical precision. The determined recovery of fortified PFOA from the LMS samples was used as a measure of sample-specific analytical acc uracy. Recovery of the surrogate ( 13 C 4 -PFOA) is included within this report in Table 10 as an indirect measure of analytical data accuracy , and is not considered in the accuracy assessment for this study and is only included as part of an ongoing method validation aspect in which surrogate r ecovery behavior is being evaluated in “real world” environmental samples for possible future ap plications.Study: GLP10-01-01, Interim Report 21 Analysis for PFOA in Decatur, AL Soils Collected fr om Well Location 610

Page 12 of 19 Details of the specific instrument parameters, the liquid chromatography gradient program, and the specific mass transitions analyzed are detailed in the raw data, and are briefly described below in Table 4 , Table 5 and Table 6

.

Table 4. Instrument Information

Instrument Name ETS-Stan Analytical Method ID ETS-8-053.0 Liquid Chromatograph Agilent 1100 with Binary Pump Guard column Pre-Autosampler; Prism RP (2.1 x 50 mm, 5 μ ) Extraction column Oasis HLB (3 x 20 mm, 25 μ ); 30°C Analytical column Betasil C18 (2.1 x 100 mm, 5 μ ) Injection Volume 25 μ L Mass Spectrometer API 4000 Ion Source TurboIon Spray Polarity Negative Software Analyst 1.4.2

Table 5. Gradient Liquid Chromatography Conditions (ETS-8-053)

Step Number Total Time

[min] Flow Rate

[mL/min] Percent A

[2 mm Aqueous Ammonium Acetate] Percent B [ Acetonitrile]

1 0.0 0.400 97.0 3.0 2 3.0 0.400 97.0 3.0 3 3.5 0.400 70.0 30.0 4 17.0 0.400 40.0 60.0 5 17.5 0.400 10.0 90.0 6 19.5 0.400 10.0 90.0 7 20.0 0.400 97.0 3.0 8 23.0 0.400 97.0 3.0

Table 6. Mass Transitions

Analyte Mass Transitions Monitored PFOA 413>169, 413>219, 413>369

13 C 4 -PFOA (Surrogate) 417>169, 417>219, 417>372

13 C 8 -PFOA (IS) 421>172, 421>223, 421>376 Note: Multiple mass transitions are summed to give the instrument response for that analyte.Study: GLP10-01-01, Interim Report 21 Analysis for PFOA in Decatur, AL Soils Collected fr om Well Location 610

Page 13 of 19 

### 7 Analytical Results

All results are rounded to three significant figure s according to EPA rounding rules. Because of rounding, values may vary slightly from those found in the raw data. All results were calculated from accurate values in the raw data. Laboratory matri x spikes (LMS) meeting the method acceptance criteria of 100 ± 30%, demonstrate that the method was appropriate. The 5.00 ng spiked concentrations for the low LMS were the most adequa te with respect to the endogenous PFOA measured in the samples.



### 7.1 Calibration

Calibration standards were prepared by spiking vary ing known quantities of PFOA (linear isomer) and surrogate, and a fixed quantity of internal standar d, into separate 1-cubic centimeter (1 cc, 1 mL) aliquots of 3M Environmental Laboratory matrix soil TCR-842 (nominal 1.0 gram per mL). A total of eleven (11) soil matrix calibration standards rangi ng from nominal PFOA concentration 0.200 ng/g to 20 0 ng/g were prepared for the definitive analysis. Following the analysis of calibration standards, th e nominal concentration of each standard was plotted versus the measured analyte peak area/IS peak area response ratio. A quadratic equation with 1/x weighting was used to fit the calibration response data. Calibration curves were not forced through z ero. Calculating the determined standard concentration using the resultant calibration curve and comparing to the known concentration confirmed accuracy of each curve point within 100 ± 30% (+ 35% at the LLOQ). The correlation coefficient (r) was greater than 0.999, and coefficient of determinatio n (r 2 ) was greater than 0.990. Calibration results for PFOA are summarized in Table 7

. Because soil weights vary significantly for a 1 cc (1 mL) soil sample, depending on soil type and mois ture content, the instrument response was calibrated for the known concentrations of PFOA based on the mass quantity of PFOA added to each 1 cc soil calib ration standard prior to extraction ( e.g. calibrated in this study for a range of 0.200 ng/g to 200 ng/g PF OA). Because a 1cc aliquot of control soil TCR-842 weighs approximately 1.0 gram (dry weight) and has less than 5% moisture content, the nominal concentration range of the calibration was essentia lly 0.200 ng/g to 200 ng/g. However, because the sample soils vary in moisture content and soil comp osition and density, 1 cc aliquots of field soil sa mples typically weigh more than 1.0 gram. Therefore, the final measured results from the analysis were adjusted for the accurate determined dry weight of the 1 cc sample aliquot that was extracted.

Table 7. PFOA Calibration Summary (Calibrated with linear PFOA)

Analytical Run PFOA (ng) [a]

r

STD 1 STD 2 STD

3 STD

4 STD 5 STD 6 STD 7 STD 8 STD 9 STD 10 STD 11 STD 12

Actual Conc. 0.200 0.500 0.749 0.999 2.50 5.00 9.99 25.0 50.0 99.9 200 500 N/A

S111005a 0.185 0.505 0.722 1.01 2.52 5.08 10.5 25.7 50.8 96. 2 202 500 0.9999
Recovery (%) 92.5 101 96.3 101 101 102 105 103 102 96.2 101 100 N/A N/A; not applicable [a] PFOA concentrations are nominal ng/g (dry wt.) and based on a nominal mass of1.0 gram (dry wt.) fo r each 1 cubic centimeter (1 mL) of control soil used to prepare each calibration stand ard.Study: GLP10-01-01, Interim Report 21 Analysis for PFOA in Decatur, AL Soils Collected fr om Well Location 610

Page 14 of 19 

### 7.2 Limits of Quantitation (LOQs)

The lower limit of quantitation (LLOQ) was the low est non-zero calibration standard in the curve that met linearity and accuracy requirements (100 + 35%) and for which the area counts were at least 2 X that of the average response determined from the method bla nks. The LLOQ for this study was nominal concentration 0.200 ng/g, and was the lowest prepar ed calibration standard. All sample analyte responses less than the response of the 0.200 ng/g calibration standard were reported as BLQ (below the limits of quantitation). The upper limit of qu antitation (ULOQ) was nominal concentration 200 ng/ g.


### 7.3 Continuing Calibration

During the course of each analysis, continuing cali bration verifications (CCVs) was performed by regul ar injection of a mid-level calibration standard after approximately every 15 samples in the analytical r un. The back calculated concentration results were used to confirm that the instrument response and the initial calibration curve were still in control. A ll CCVs flanking reported data met the method crite ria of 100% ± 30% accuracy.



### 7.4 Blanks

Three types of blanks were analyzed during this ana lysis: method blanks were prepared with blank matrix soil TCR-842 and were spiked with IS and sur rogate; travel blanks (trip blanks) prepared from aliquots of soil TCR-842 contained in sealed bottle s that accompanied the bottle order to Decatur, and sample shipment back to 3M Environmental Laboratory ; and solvent blanks containing extraction solvent. The different blanks results were reviewe d to evaluate potential contamination during shipme nt and sampling, to evaluate method performance parame ters such as injector carry over and also to establish the LLOQ and the performance of the blank s were considered in the reporting of all results.



### 7.5 Laboratory Control Spikes (LCSs)

Laboratory control spikes were prepared by spiking known quantities of PFOA (linear + branched isomers) into 1 cc aliquots of soil TCR-842, fortif ied with nominal 3.0 ng, 30 ng and 300 ng PFOA (lin ear + branched isomer). The linear + branched isomer q uantitation using a linear PFOA calibration curve provided a measure of accuracy in quantifying the s um of potential linear + branched PFOA isomers that are commonly associated with environmental samples. Each LCS level was prepared in triplicate. The averaged results of the LCS analyses are shown in Table 8 and calculated analytical method uncertainty is shown in Table 9. The method acceptance criteria of 100 ± 30% was m et for all LCSs. The LCS recoveries were calculated using the following equa tion:



### 100% * ion Concentrat Spike LCS)

of ion Concentrat d (Determine Recovery LCS =Study: GLP10-01-01, Interim Report 21 Analysis for PFOA in Decatur, AL Soils Collected fr om Well Location 610

Page 15 of 19 Table 8. LCS Results

Sample ID PFOA Recovery 3.00 ng LCS 30.0 ng LCS 300 ng LCS
LCSs (S111005a) 91.0% 86.0% 86.3% 84.7% 92.3% 88.3% 93.0% 90.3% 107% Average Recovery 

### 89.6% 89.6% 93.9% Std Dev. 

### 4.4% 3.2% 11% RSD 

### 4.9% 3.6% 12% LCS concentrations were 3.00 ng, 30.0 ng and 300 ng of PFOA (linear + branched isomers) added to each nominal 1 gram of control soil used to prepare the LCSs (1 cc of soil TCR-842 equal to nominal 1.0 gram; dry weight).

Table 9. Analytical Method Uncertainty Determinati on 

### Sample ID PFOA Recovery (%) 3 ng LCS in TCR-842, replicate 1 91.0% 3 ng LCS in TCR-842, replicate 2 84.7% 3 ng LCS in TCR-842, replicate 3 93.0% 30 ng LCS in TCR-842, replicate 1 86.0% 30 ng LCS in TCR-842, replicate 2 92.3% 30 ng LCS in TCR-842, replicate 3 90.3% 300 ng LCS in TCR-842, replicate 1 86.3% 300 ng LCS in TCR-842, replicate 2 88.3% 300 ng LCS in TCR-842, replicate 3 107% Average 91.0% Standard Deviation 6.7% RSD 7.3% Analytical Method Uncertainty (2 x Std. Dev.); 95% CI 13%


### 7.6 Laboratory Matrix Spikes (LMSs)

Laboratory matrix spikes (LMSs) were generated by s piking a known quantity of PFOA (linear) to an aliquot of each soil sample and then preparing the sample the same as regular non-spiked samples. For this study, two LMSs were prepared for each fie ld sample, fortified with 5.00 ng and 50.0 ng of PF OA as a low LMS and high LMS, respectively. One LMS w as prepared for the trip blank an fortified with nominal 1.00 ng PFOA The LMS recoveries for PFOA f rom samples are shown in Table 2 and ranged from 94.8% to 129%. The method acceptance criter ia of 100 ± 30% was met for all LMSs. The PFOA recovery calculations for LMS samples used the foll owing equation:



### 100% * ion Concentrat Spike Sample) Field of ion Concentrat Determined LMS of ion Concentrat d (Determine Recovery LMS −

=Study: GLP10-01-01, Interim Report 21 Analysis for PFOA in Decatur, AL Soils Collected fr om Well Location 610

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### 7.7 Percent Moisture Determinations

The percent moisture was determined in duplicate fo r each soil sample. For each replicate, a sample aliquot is accurately weighed to determine the “wet ” weight. Then the aliquot is dried at > 100°C unt il no further loss in mass occurs (due to water evaporati on), and then the dry weight is accurately determin ed. The average percent moisture and RPD of the duplica te determinations for each is reported in Table 10

. The percent moisture was calculated by the followin g equation:



### 100% * Mass Wet Soil Original Mass)

Soil Dried Mass Wet Soil (Original Moisture Percent −

=

Table 10. Percent Moistures for Decatur, AL Soils from Well Location 610

LIMS ID Sample ID Average Percent Moisture (w/w) [a] Relative Percent Difference [a]

GLP10-01-01-21-001 DAL-SB-610S-0-0000 13.0% 2.1% GLP10-01-01-21-002 DAL-SB-610S-0-0010 9.46% 0.53% GLP10-01-01-21-003 DAL-SB-610S-0-0040 12.8% 14% GLP10-01-01-21-004 DAL-SB-610S-0-0150 19.4% 0.32% GLP10-01-01-21-005 TRIP BLANK-1 1.97% 16% [a] Percent moisture determined for duplicate samp les of soil taken from each sample bottle



### 7.8 Individual Sample Results

. The individual sample concentration results are shown in Table 11. Table 11. Individual PFOA Results for Decatur, AL Soils from Well Location 610

Sample Description Surrogate ( 13 C 4 -PFOA) Recovery [a] LMS Spike

Concentratio n (ng/g; dry weight) Measured

PFOA Concentration (ng/g; dry weight) LMS

Recovery (Data Accuracy) [b] Average PFOA

Concentration (ng/g; dry wt.) and RPD (Data Precision) GLP10-01-01-21-001 119% N/A 4.80 N/A 4.57 GLP10-01-01-21-001 Dup 123% 4.33 GLP10-01-01-21-001 Low LMS 108% 6.07 10.8 103% 10% GLP10-01-01-21-001 High LMS 108% 58.9 64.5 102% GLP10-01-01-21-002 116% N/A 10.6 N/A 10.3 GLP10-01-01-21-002 Dup 109% 9.91 GLP10-01-01-21-002 Low LMS 108% 5.60 15.8 98.7% 7.0% GLP10-01-01-21-002 High LMS 113% 57.2 74.2 112% GLP10-01-01-21-003 124% N/A 6.11 N/A 6.21 GLP10-01-01-21-003 Dup 109% 6.30 GLP10-01-01-21-003 Low LMS 118% 5.05 12.7 129% 2.9% GLP10-01-01-21-003 High LMS 104% 52.4 64.1 111% GLP10-01-01-21-004 123% N/A BLQ N/A BLQStudy: GLP10-01-01, Interim Report 21 Analysis for PFOA in Decatur, AL Soils Collected fr om Well Location 610

Page 17 of 19 Table 11. Individual PFOA Results for Decatur, AL Soils from Well Location 610

Sample Description Surrogate ( 13 C 4 -PFOA) Recovery [a] LMS Spike

Concentratio n (ng/g; dry weight) Measured

PFOA Concentration (ng/g; dry weight) LMS

Recovery (Data Accuracy) [b] Average PFOA

Concentration (ng/g; dry wt.) and RPD (Data Precision) GLP10-01-01-21-004 Dup 109% BLQ GLP10-01-01-21-004 Low LMS 111% 4.90 4.64 94.8% [c] N/A GLP10-01-01-21-004 High LMS 114% 49.5 56.2 114% [c]
GLP10-01-01-21-005 118% N/A BLQ N/A BLQ GLP10-01-01-21-005 Dup 117% BLQ
GLP10-01-01-21-005 LMS 115% 1.01 1.03 102% [c] N/A N/A; not applicable [a] Surrogate recovery determined for samples forti fied with 3.0 ng of 13 C 4 -PFOA and quantified from a 13 C 4 -PFOA calibration curve, but otherwise not used for data accuracy assessment s for the study. [b] LMSs prepared using PFOA (linear isomer). [c] Values below the LLOQ (BLQ) were treated as a c oncentration of zero for LMS recovery calculations



### 8 Conclusion

Analysis of the Decatur, AL soils collected from ne ar well location 610 was successfully completed following 3M Environmental Laboratory method ETS-8- 053.0 and conducted as 3M study GLP10-01- 01-21. The average PFOA concentration results for the soil samples are summarized in Table 1 and associated LMS recoveries are summarized in Table 2 . The PFOA results for each individual sample replicate are provided in Table 10

. All sample results were reported with acceptable LM S recoveries within 100 + 30%, and all gave acceptable RPDs of less than 50% for duplicate dete rmined results. The travel blank that accompanied the sample bottles shipments was below the low limit of quantitation (BLQ, less than nominal 0.200 ng/g) , indicating there was not any contamination of samples during sample shipment, storage and preparation for analysis.



### 9 Data/Sample Retention

All soil samples and associated project data (hardc opy and electronic) will be archived as project GLP 10- 01-01-21according to 3M Environmental Laboratory st andard operating procedures.



### 10 List of Attachments

Attachment A: Preparation Forms, Raw Data and Chromatogramsstudy : GLP10-01-01 , Interi m Repor t 2 1 Analysi s fo r PFO A i n Decatur , A L Soil s Collecte d fro m Wel l Locatio n 61 0



## i1 1 Signature s

Repor t Approval : 

# '•A:i

Clesto n C

. Lange , Ph.D. , Principa l Analytica l Investigato r Dat e

Willia m K

. Reagen , Ph.D. , 3 M Environmenta l Laborator y Managemen t Dat e



# f2

- Gar y A

. Hoheristein , Sdbnso r Representativ e Dat e

Ddt e Jaisimh a Kesari , Stud y Directo r

Pag e 1 8 o f 1 9Study: GLP10-01-01, Interim Report 21 Analysis for PFOA in Decatur, AL Soils Collected fr om Well Location 610

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## Attachment A Preparation Forms, Raw Data and Chromatograms