Presentation of 2002 Barksdale Investigations and Path Forward June 25, 2002 Presented by: DuPont Corporate Remediation Group

Introduction Brad Nave

2002 Barksdale Investigations and Path Forward Presenters Brad Nave Introduction, Background, and General Project Overview Cary Pooler, P.G. 2001 Findings and Recommendations Jon Hammerberg, P.E. Historical Document Review Findings 2002 Recommendations and next steps June 25, 2002 2002 Barksdale Investigations and Path Forward

Today’s Public Meeting Reviews 2001 site investigation results Discusses actions taken since 2001 Shares current historical review results Discusses future project plans Provides an opportunity to ask questions June 25, 2002 2002 Barksdale Investigations and Path Forward

2002 Barksdale Investigations and Path Forward The DuPont Philosophy Conduct investigations that allow DuPont and the regulatory agency to make informed decisions and take appropriate steps to protect human health and the environment June 25, 2002 2002 Barksdale Investigations and Path Forward

Former Barksdale Works Location Wedal Road East Ondassagon Road Ondassagon Road Nolander Road State Hwy 13 Bjork Road Former Plant June 25, 2002 2002 Barksdale Investigations and Path Forward

Overall Project Objectives Provide drinking water that meets appropriate Wisconsin regulatory standards for all site-related compounds Develop plan for long-term drinking water supply and implement as appropriate Evaluate for potential off-site surface issues and take appropriate action Identify priority source areas and take appropriate action June 25, 2002 2002 Barksdale Investigations and Path Forward

2001 Findings and Recommendations Cary Pooler

2001 Investigation Findings Groundwater: Plumes identified in east-central and northeast areas Nitroaromatic/nitramine organics are the primary COPCs Three groundwater zones identified COPCs are limited to the shallow and intermediate zones Deep flow zone has potential as a drinking water supply Former Production Areas: Site-related constituents are present in the former production areas which could be exposed to erosion. Former Operation Area: A release is indicated near the Burning Ground which may have contributed to groundwater impact. Site-related constituents are present at the Burning Ground surface which could be exposed to erosion. June 25, 2002 2002 Barksdale Investigations and Path Forward

2002 Barksdale Investigations and Path Forward 2001 Recommendations Priority 1: Continue to operate and maintain drinking water treatment systems while evaluating alternative supplies: Install systems at residences with identified impacts Conduct regular maintenance and sampling Continue analytical sampling to confirm correct operation Continue to communicate results to WDNR June 25, 2002 2002 Barksdale Investigations and Path Forward

2001 Recommendations (continued) Priority 2: Continue to collect information to be used to plan for an alternative long-term drinking water supply: Obtain residential well construction details Confirm analytical results from the deep zone Install additional monitoring wells Conduct deep zone pumping tests June 25, 2002 2002 Barksdale Investigations and Path Forward

2001 Recommendations (continued) Priority 3: Identify off-site soil or sediment issues and address as appropriate: Implement erosion control measures as appropriate to prevent potential off-site migration of site-related constituents from production areas identified in 2001 Complete sediment sampling in on-site drainages as appropriate June 25, 2002 2002 Barksdale Investigations and Path Forward

2001 Recommendations (continued) Priority 4: Identify source areas and take appropriate action: Review the results of the surface water and sediment sampling and communicate to WDNR Continue detailed historical research into past operations Continue working with WDNR to plan future investigations for areas requiring further action June 25, 2002 2002 Barksdale Investigations and Path Forward

Historical Document Review Jon Hammerberg

Historical Documentation Review Purpose Provide a framework for management of information Prioritize screening and sampling efforts Goals Identify former uses of site areas Identify former uses of site buildings Identify potential chemicals and products present Identify former chemical routes of migration . June 25, 2002 2002 Barksdale Investigations and Path Forward

Historical Documentation Review: Process: Identify information sources Obtain copies of documents from sources Review documents obtained for relevance Cross reference documents to determine position on site Ground truth positions and conditions of buildings identified Obtain specific details on identified areas Ground-truth reports of employees and experts Revise site maps and repeat process as needed June 25, 2002 2002 Barksdale Investigations and Path Forward

Historical Documentation Review - Status Sources of documents were identified in summer 2001 Documents were requested from sources in fall 2001 Compiled documents through March 2002 Cross-referenced documents from March through May Ground truthed documents from May through June Several process areas remain to be ground truthed including the NG, Powder and Dynamite lines. A second round of ground truthing has been started this week. Employee interviews will begin in July. Additional ground truthing is planned to follow the interviews. June 25, 2002 2002 Barksdale Investigations and Path Forward

Historical Review - Preliminary Observations Production areas ground truthed to date are: TNT (Triton) production lines 1 through 10 TNX production lines 1 through 5 DNT (Trivelene and Lydol) production lines 1 through 3 Triton Refine Triton Finishing Powder Line (DNT pumps and screening houses only) Nitramex/Nitramon Primer Pack June 25, 2002 2002 Barksdale Investigations and Path Forward

Historical Review - Preliminary Observations (cont.) Support areas/buildings ground truthed to date are: OV Plant Power Plant and Laundry Lead Melting Pot Ammonium Nitrate Cystalizer Empty Barrel Store Magazines (16 built in WW-I, 7 kept in WW-II, 1 built post 1966) June 25, 2002 2002 Barksdale Investigations and Path Forward

Historical Review - Preliminary Observations (cont.) Operational period waste areas ground truthed are: Burning Ground Crushed Barrel Dump Reed Fields Decomissioning period waste areas identified are Decon Burn Area (on top of former reed fields) Demolition debris piles in production areas Former Power Plant Reservoir debris dump June 25, 2002 2002 Barksdale Investigations and Path Forward

Historical Review - Preliminary Observations (cont.) Bare spots found in 2001 correlate with nitration, neutralization and graining building foundations in the No. 2 and No. 4 TNT lines. Similar spots have since been found near neutralization and graining buildings in the other TNT lines or the equivalent buildings in the DNT lines. Acid area soil samples with detected nitramine compounds (Area 2 samples 3 and 4) were in an area near former waste acid recycling tanks. Bare spots were also found near the waste acid rail car loading areas at the production lines. Areas covered with cinders were observed in the acid plants, lead melt pot and shop/office areas. Bare spots were not observed to date in the TNX, Nitramex or Powder Line areas. June 25, 2002 2002 Barksdale Investigations and Path Forward

Historical Review - Preliminary Conclusions The foundations observed in the areas ground truthed to-date correspond very well to the buildings shown on the historic plans indicating that the plans provide reliable depictions of former site operations. The processes identified on the drawings agree with the site operational area designations shown in past reports indicating that past assumptions regarding historic operations remain valid. No process areas have been identified by the historic documents which would change our belief that there have not been releases from the site to land located to the northwest, west, or south. June 25, 2002 2002 Barksdale Investigations and Path Forward

Historical Documentation Review Next Steps: Integrate findings into the prioritized site investigation effort. Continue review of documents as they become available return June 25, 2002 2002 Barksdale Investigations and Path Forward

Questions and Comments?

2002 Barksdale Investigations and Path Forward General Information Contact DuPont: (715) 373-1127 Project website: http://www.dupont.com/barksdale Next meeting will be 3rd Quarter 2002 June 25, 2002 2002 Barksdale Investigations and Path Forward

Thanks for coming tonight