DuPont Barksdale and Chequamegon Projects Update

1. DuPont Barksdale and Chequamegon Projects Update July 22, 2008 DuPont CRG

2. 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

3. Former DuPont Barksdale Works Project Update

4. 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. Former DuPont Barksdale Works

5. 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. Former DuPont Barksdale Works

6. Summary of 2008 Barksdale Work

7. Summary of 2008 Work Continue to fulfill water supply commitments Site 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). Former DuPont Barksdale Works

8. map of 08 inv priorities. Former DuPont Barksdale Works

9. Summary of 2008 Work 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. Former DuPont Barksdale Works

10. 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. Former DuPont Barksdale Works

11. Clearing Work Sites Former DuPont Barksdale Works

12. Residual Product Removal DNT Removal: • Discovered solid DNT below a floor slab during Bio Cell preparation at former Trivelene Sweating House. Former DuPont Barksdale Works

13. Screening with Geophysics (EM61) Former DuPont Barksdale Works

14. FIDO Analysis Equipment Former DuPont Barksdale Works

15. 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. Former DuPont Barksdale Works

16. Sample MEVA results Former DuPont Barksdale Works

17. TNT Located by MEVA TNT found by FIDO visible only after tall grass & sheet metal hiding it was removed. Former DuPont Barksdale Works

18. Evaluation of Remedial Technologies

19. Barksdale Field DNT Bio-Pilot 2008 Former DuPont Barksdale Works

20. 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. Former DuPont Barksdale Works

21. 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 Former DuPont Barksdale Works

22. SITES map of 08 inv priorities. Former DuPont Barksdale Works

23. Sweating Ho Trivilene #1 Sweating House

24. #1 Trivilene Sweating House Cell Former DuPont Barksdale Works

25. BiTri Ho TNT #4 Bi-Tri House

26. TNT #4 Bi-Tri House Cell Former DuPont Barksdale Works

27. divert SW Wash Ho BiTri Ho Neut. Ho TNT #2 Wash House

28. Barksdale Bio-Pilot June 2008TNT02 Wash House CellPrior to first tilling Former DuPont Barksdale Works

29. # 2 Wash House Cell Former DuPont Barksdale Works

30. Typical debris removed by raking Former DuPont Barksdale Works

31. Lydol House Cells Former DuPont Barksdale Works

32. Tractor with Howard Rotovator 700 DUT Former DuPont Barksdale Works

33. Tilling No. 2 Wash House Former DuPont Barksdale Works

34. 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 Former DuPont Barksdale Works

35. Barksdale Path Forward Continue to investigate high priority areas on-site: • Focus on high priority areas, including characterization and remediation. Former DuPont Barksdale Works

36. Map of priority areas of investigation. • Use map from April 2 Former DuPont Barksdale Works

37. Barksdale Path Forward • Continue biodegradation studies. • Continue to address DNX isomer and As/Pb issues. • Continue public interaction and water supply commitments. Former DuPont Barksdale Works

38. Chequamegon-Nicolet National Forest Update

39. Former DuPont Barksdale Works

40. Chequamegon-Nicolet National Forest Project 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. Former DuPont Barksdale Works

41. Chequamegon-Nicolet National Forest Completed 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. Former DuPont Barksdale Works

42. Chequamegon-Nicolet National Forest Path 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. Former DuPont Barksdale Works

43. Questions or comments? Former DuPont Barksdale Works