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# DuPont Marshall Laboratory PFOA Sampling Results – December 2007 and January 2008

Date: July 2009 Project No.: 18985591.07003DuPont Marshall Laboratory PFOA Sampling Results – December 2007 and January 2008 Table of Contents

Marshall Labs PFOA Sampling Results_12-07 and 01-08.doc i
Wilmington, DE 

## Table of Contents

1.0 DuPont Marshall Laboratory PFOA Sampling Results – December 2007 and January 2008 ...............................................................................................................1

Tables

Table 1 Summary of PFOA Soil Analytical Results

Table 2 Summary of PFOA Groundw ater Analytical Results

Figure

Figure 1 PFOA Sample LocationsDuPont Marshall Laboratory PFOA Sampling Results – DuPont Marshall Laboratory PFOA Sampling Results – December 2007 and

December 2007 and January 2008 January 2008

Marshall Labs PFOA Sampling Results_12-07 and 01-08.doc 1
Wilmington, DE 

## 1.0 DuPont Marshall Laboratory PFOA Sampling Results – December 2007 and January 2008

In December 2007 and January 2008, DuPont comp leted site characteri zation activities at the DuPont Marshall Laboratory facility in Ph iladelphia, Pennsylvania. In conjunction with these activities, DuPont investigated th e subsurface soil and groundwater at the site for the presence of Perfluorooctanoic Acid (PFOA).

A total of six soil borings were advanced using a Geoprobe Macro-Core Soil Sampling system (1.5-inch ID) in the area of the fo rmer Teflon processing & handling area. The locations of the soil borings are shown on Figure 1. Soil was transferred from the sampling device to a Pyrex mixing bowl for ho mogenization. Soil samples were then transferred to sample collection bottles (s upplied by the laboratory ) using Pyrex spoons or trowels. The soil samples were shippe d to Test America of Denver, Colorado and analyzed for PFOA. The analytical results of the soil sampling ar e presented on Table 1.

A total of 9 temporary piezometers were in stalled to intersect the shallow groundwater system at various locations to determine groundw ater quality at the si te. The locations of the piezometers are shown on Figure 1. Each piezometer was installed using Geoprobe ®
Direct Push method. The piezometers were constructed using 1-inch diameter schedule 40 polyvinyl chloride (PVC) pipe and 10-slot (0.010-inch) screen, which was advanced into the saturated zone. The piezometers we re allowed to sit for at least 24 hours to naturally develop.

Groundwater samples were collected from the temporary piezometers using a peristaltic pump. Following sampling, the temporar y wells were properly abandoned and permanently sealed using cement-bentonite. The groundwater samples were shipped to Test America and analyzed for PFOA. The analytical results of the groundwater sampling are presented on Table 2.

## TablesTable 1DuPont Marshall LaboratorySummary of PFOA Soil Analytical ResultsTotal (T)/ Sample IDBS-8 (0-2') BS-8 (4-6') BS-9 (0-2') BS-10 (0-2') BS-10 (4-6') BS-10 (6-8') BS-11 (0-2') BS-11 (4-6') BS-12 (0-2') BS-13 (0-2')Analyte Units Diss. (D) Date1/9/08 1/9/08 1/9/08 1/9/08 1/9/08 1/9/08 1/9/08 1/9/08 12/28/07 12/28/07PFOA UG/KG T ND (0.79) NQ (0.68) NQ (0.60) NQ (0.63) ND (0.64) 5.1 ND (0.63) ND (0.65) ND (0.63) 4.4ND = Non detect at stated reporting limitNQ = Compound detected at a level between the limit of detection (LOD) and reporting limit (LOQ); result is not quantifiable.Table 2DuPont Marshall LaboratorySummary of PFOA Groundwater Analytical ResultsTotal (T)/ Sample IDA8 B4 BS-1 C13 C8 E4 G9 I10 J14Analyte Units Diss. (D) Date1/9/08 12/20/07 1/24/08 1/18/08 1/10/08 12/18/07 1/15/08 1/2/08 1/24/08PFOA UG/L T 0.31 0.042 0.28 0.37 0.28 0.012 NQ (0.0021) B ND (0.0021) 0.016ND = Non detect at stated reporting limitNQ = Compound detected at a level between the limit of detection (LOD) and reporting limit (LOQ); result is not quantifiable.

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