DuPont Barksdale and Chequamegon Projects Update

July 22, 2008

DuPont CRG

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Purpose of Meeting Barksdale:

Provide a status update on site priorities and public commitments.

Provide a summary of on-going 2008 site activities.

Chequamegon-Nicolet National Forest:

Provide a status update on site investigation activities at the Cabin Lake and Clover sites.

Former DuPont Barksdale Works Project Update

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Project Priorities

Current Priorities: Identify priority source areas and take appropriate action. Evaluate for potential off-site surface water issues and take

appropriate action.

Priorities Addressed: Continue to provide drinking water that meets appropriate

Wisconsin regulatory standards for all site-related compounds to residents with impacted wells.

Develop plan for long-term drinking water supply and implement as appropriate.

Fulfill commitments on Home Value Protection Plan.

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Project Priorities

Other Commitments: Continue to work with WDNR in the investigation/cleanup of site-

related impacts. Continue to be available and communicate with neighbors.

Summary of 2008 Barksdale Work

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Continue to fulfill water supply commitmentsSite Investigation

Site clearing. Grid sampling of 200 locations. Biased sampling at 300 plus locations. Geophysical work to determine subsurface anomalies. Using explosive detection device (FIDO).

Summary of 2008 Work

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map of 08 inv priorities.

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Recovery and Disposal of Residual Site Materials:

Removed approximately 800 pounds of DNT. TNT recovery and disposal planned.

Evaluation of Remedial Technologies: Field scale bio-pilot being conducted. Continued laboratory studies at GA Tech. University of Waterloo DNX studies.

Synthesis of DNX isomers: Completed in early 2008. Developing screening values.

Summary of 2008 Work

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Alternative Water Supply

Waterline Completed December 2005.Provides Municipal Drinking Water Access to:

47 Homes 8 Undeveloped Parcels

Over 6 million gallons of water delivered through the pipeline since installation.

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Clearing Work Sites

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Residual Product RemovalDNT Removal:

Discovered solid DNT below a floor slab during Bio Cell preparation at former Trivelene Sweating House.

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Screening with Geophysics (EM61)

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FIDO Analysis Equipment

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Screening with Vacuum Cartridges

MEVA SAMPLING PROCESS

• Clear brush and ground cover.

• Survey 1-acre grid corners and stake 1/16th acre sub-squares.

• Vacuum the surface of each sub-square and record conditions during collection.

• Return the cartridge to the testing office, incubate the cartridge and analyze with the FIDO detector.

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Sample MEVA results

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TNT Located by MEVA

TNT found by FIDO visible only after tall grass & sheet metal hiding it was removed.

Evaluation of Remedial Technologies

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Barksdale Field DNT Bio-Pilot 2008

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2008 Bio-Pilot Work

Overview Reduction of DNT via biodegradation observed

by GA Tech in studies funded by DuPont. Small field-scale pilot conducted in 2007 at

Barksdale.• 2007 results promising, pilot scaled up in 2008.• Pilot locations chosen based on manufacturing

history (predominately DNT). Work started in June 2008 at four locations.

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2008 Pilot Locations Lydol House (4 cells from 2007) Trivilene No. 1 Sweating House TNT No. 4 Bi/Tri House TNT No. 2 Wash House

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map of 08 inv priorities.

SITES

Sweating Ho

Trivilene #1 Sweating House

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#1 Trivilene Sweating House Cell

TNT #4 Bi-Tri House

BiTri Ho

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TNT #4 Bi-Tri House Cell

TNT #2 Wash House

Wash Ho

BiTri Ho

Neut. Ho

divert SW

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Barksdale Bio-Pilot June 2008TNT02 Wash House CellPrior to first tilling

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# 2 Wash House Cell

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Typical debris removed by raking

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Lydol House Cells

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Tractor with Howard Rotovator 700 DUT

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Tilling No. 2 Wash House

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Pilot Status All locations tilled approximately

once per month Periodic sampling for

Nitramine and nitroaromatic organic compounds

pH Nitrogen, Phosphorus, and Potassium

Adjust pH in cells as necessary

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Continue to investigate high priority areas on-site:• Focus on high priority areas, including

characterization and remediation.

Barksdale Path Forward

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Map of priority areas of investigation.

Use map from April 2

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Continue biodegradation studies. Continue to address DNX isomer and As/Pb

issues. Continue public interaction and water supply

commitments.

Barksdale Path Forward

Chequamegon-Nicolet National Forest Update

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Chequamegon-Nicolet National ForestProject Summary:

DuPont working in conjunction with the US Forest Service (USFS) to investigate two sites (Cabin Lake and Clover) in the Chequamegon-Nicolet National Forest.

Delineation of debris, via geophysical surveying, was the first investigation step:

• Delineation completed at Cabin Lake in late 2006, while debris delineation was completed at Clover in May 2007.

• Debris delineation report submitted to USFS on June 7, 2007.

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Chequamegon-Nicolet National ForestCompleted field portion of the Phase II Archaeological investigation in June 2008

Approximately 1,500 man hours of field work. Excavated 188 Shovel Test Pits (STPs) and 17 Test Units

(TUs).• Recovered artifacts that appear to be associated with past logging

activities.• Artifacts shipped to URS’ archaeology lab in Maryland for further

study and curation preparation. Report preparation underway.

• Expected submittal to agency before the end of the calendar year.• USFS and Wisconsin State Historical Preservation Office will

determine if the site is eligible for National Historic Register of Places.

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Chequamegon-Nicolet National ForestPath Forward:

Once the archaeological work is reported and a determination as to what extent, if any, the logging site will need to be addressed as part of planned environmental work at Cabin Lake, DuPont will submit the final work plan for environmental investigation of the Clover and Cabin Lake sites to USFS for review.

The environmental investigations at Clover and Cabin Lake are planned for 2009, pending USFS approval to proceed.

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Questions or comments?