Former DuPont Barksdale Works Project Update

1. Former DuPont Barksdale Works Project Update December 14, 2006 Great Lakes Visitors Center DuPont CRG

2. DuPont Company Representatives • Brad Nave – Project Director, DuPont Corporate Remediation Group • Jon Hammerberg – Senior Project Engineer, URS Corporation Former DuPont Barksdale Works

3. Purpose of Meeting • Provide an update on site priorities and public commitments • Provide an update on work completed in 2006 and preliminary results • Discuss next steps Former DuPont Barksdale Works

4. Barksdale Project Priorities and Commitments ReviewBrad Nave

5. Project Priorities Four Project Priorities: • 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 • Evaluate for potential off-site surface water issues and take appropriate action • Identify priority source areas and take appropriate action Former DuPont Barksdale Works

6. Project Priorities Other Commitments: • Continue to work with WDNR in the investigation/cleanup of site impacts • Continue to be available and communicate with neighbors • Fulfill commitments on Home Value Protection Plan Former DuPont Barksdale Works

7. Alternative Water Supply • Alternative Water Supply • To date, DuPont has been billed $115.6M and paid over $114.3M in related water supply costs to Washburn • Managing invoices, supply, and maintenance with Washburn Former DuPont Barksdale Works

8. Home Value Protection Plan Home Value Protection Program has expired. • DuPont fulfilled all commitments and obligations • Last property (vacant lot) sold on June 23, 2006 Former DuPont Barksdale Works

9. 2006 Site InvestigationJon Hammerberg

10. 2006 Site Investigations • Purpose of investigations: • Evaluate suitability of selected site areas for recreational use • Continue characterizing former production areas • Prioritize areas for future activities Former DuPont Barksdale Works

11. 2006 Site Investigations • 800 samples from 4 geographic focus areas • Northern Production Area: (274 acres) site of former manufacturing and support operations • Northern Grid Area: (305 acres) lightly or undeveloped grounds inside the plant fence • Southern Area: (443 acres) product storage and undeveloped grounds inside the plant fence • Off Site Areas: (117 acres) residential and undeveloped grounds outside the plant fence Former DuPont Barksdale Works

12. 2006 Site Investigation Map Former DuPont Barksdale Works

13. Northern Area Investigation • Continued site characterization via • Trenching in former production areas • Discrete soil sampling at biased locations • Grid sampling generally in undeveloped areas • Geophysical survey of waste sites • Clearing (4.3 miles of new roads, 17 miles cleared) • Installation of 6 wells and interior groundwater sampling • Surface water and sediment sampling • Recovered and disposed TNT during investigation • ~2,000 pounds of TNT recovered to date • ~500 pounds recovered in 2006 • Evaluated perchlorate distribution in groundwater and soils Former DuPont Barksdale Works

14. Northern Area Investigation Maps • Insert. Former DuPont Barksdale Works

15. Southern Area Investigation • Continued site characterization • Supplemental sampling in areas where elevated concentrations of inorganic constituents were detected in 2005 • Discrete soil sampling at biased locations • Grid sampling Former DuPont Barksdale Works

16. Southern Area Investigation Map • Insert. Former DuPont Barksdale Works

17. 2006 Investigations Findings • Findings in undeveloped areas: • Large portions of the northern and southern undeveloped areas are acceptable for current recreational use • Approximately 438 of the 443 acres in the southern area are below site-specific recreational screening levels • Grid locations that exceed site-specific screening levels are principally confined to roadways and railroad beds • Arsenic responsible for most of the risk in the south • Area-wide cumulative risks within frequently used southern transportation corridors are in acceptable range for current use • Explosive compounds do not significantly contribute to overall risk in the southern area • Approximately 300 of the 305 acres within the northern gridded area appear to be acceptable for the current recreational use based on preliminary data evaluation Former DuPont Barksdale Works

18. 2006 S Risk & Corridor • Insert map Former DuPont Barksdale Works

19. Insert maps/pictures of issues/findings. • Does not include biased samples • Results compared to site-specific recreational RCLS Draft Northern Area Undeveloped Area Investigation Results Former DuPont Barksdale Works

20. 2006 Investigations Findings • Findings in production or waste areas • 18 of 21 areas on site have been investigated; the 3 yet to be evaluated potentially contain nitroglycerin and require different sampling procedures. • Products visible at the surface in 2/3rds of the areas evaluated and in the subsurface (> 2ft bgs) in half of the areas evaluated • Products are generally encountered along former process buildings and ditches; some located beneath building slabs • Product found in five buried waste and debris deposits (0.5 to four acres in size) located across the site • Potential asbestos containing material visible in 5 of the 18 areas evaluated Former DuPont Barksdale Works

21. Perchlorate • Concentrations in groundwater onsite range between non-detect (at 0.01) to 1,200 parts per billion • The majority of the boundary groundwater results were less than 1 ppb • Three exceptions are observed downgradient of former burning ground south of Barksdale Village and north of Boyd’s Creek. East of HWY 13 perchlorate was detected at 250 ppb in groundwater • Perchlorate was not detected in the two potable wells sampled on-site • Concentrations in soil (ranged from non-detect to 2.2 mg/Kg) are below the residential screening value (55 mg/Kg) Former DuPont Barksdale Works

22. Insert maps/pictures of issues/findings. Former DuPont Barksdale Works

23. Path ForwardBrad Nave

24. Near Term Path Forward • Complete Current Conditions Report • Continue investigation • Production areas • Follow-up in previously investigated areas • Characterization of areas previously not investigated • Three dynamite/ nitroglycerine areas • Continue to understand NX distribution and contribution to risk • Northern Undeveloped Areas • Continued investigation and risk screening as determined by output of 2006 data evaluation • Meet commitments regarding municipal water supply • Research at GA Tech and on-site • Share results with WDNR and community members Former DuPont Barksdale Works

25. Chequamegon-Nicolet National Forest UpdateBrad Nave

26. 2006 Chequamegon National Forest Work • National Forest Service contacted DuPont in April 2006 regarding two reported former detonation cladding sites • DuPont and the Forest Service developed a framework for future actions and the technical approach for a geophysical investigation at both sites • Field work begun in October to delineate the extent of metallic debris at the Clover and Cabin Lake sites • Delineation of debris completed at the Cabin Lake site • Debris delineation partially complete at the Clover site, work will resume in 2007 when weather allows Former DuPont Barksdale Works

27. Former DuPont Barksdale Works

28. CABINLAKE 2006 Cabin Lake Work • Insert map Former DuPont Barksdale Works

29. NorthPad SouthPad OPERATORSSTATION 2006 Clover Results • Insert map Former DuPont Barksdale Works

30. 2007 Chequamegon National Forest Work • Continue delineating metal at the Clover site • Report 2006 findings for both sites • Work with the Forest Service to develop and execute a soil sampling program at both sites Former DuPont Barksdale Works

31. Questions or comments? Former DuPont Barksdale Works