1. An Overview of Environmental Investigations January 22, 2002 Presented by: DuPont Corporate Remediation Group

2. Today’s meeting... Provide an overview of the basic objectives, strategy, and techniques for conducting an environmental investigation.

3. DuPont’s 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.

4. Environmental Investigations Usually an iterative approach.Usually an iterative approach. Vary in complexity.Vary in complexity. Address multiple needs.Address multiple needs. –Human and ecological exposure via Groundwater.Groundwater. Soil and/or sediment.Soil and/or sediment. Surface water.Surface water. Air.Air.

5. Basic Environmental Investigation Steps Research historical land use, specifically detailed operations, spills, etc.Research historical land use, specifically detailed operations, spills, etc. Develop analytical program.Develop analytical program. –Identify chemicals of concern (COCs) and appropriate analytical methods.

6. Basic Environmental Investigation Steps, continued Identify appropriate investigation techniques.Identify appropriate investigation techniques. Develop work plan.Develop work plan. Agency interaction.Agency interaction. Perform vendor selection and contracting.Perform vendor selection and contracting.

7. Basic Environmental Investigation Steps, continued Mobilize and set-up field operations.Mobilize and set-up field operations. Sample potentially impacted media (air, soil, sediment, groundwater, and surface water).Sample potentially impacted media (air, soil, sediment, groundwater, and surface water). Review analytical data for usability.Review analytical data for usability. Perform hydrogeologic review.Perform hydrogeologic review.

8. Basic Environmental Investigation Steps, continued Evaluate media-specific characteristics.Evaluate media-specific characteristics. –Types of COCs present. –Concentration(s) of COCs at exposure points. Evaluate results against realistic exposure scenarios for humans and environmental receptors.Evaluate results against realistic exposure scenarios for humans and environmental receptors.

9. Basic Environmental Investigation Steps, continued Evaluate if corrective measures are warranted based on available data.Evaluate if corrective measures are warranted based on available data. –Fix may be temporary. Report findings and recommend next steps.Report findings and recommend next steps. Agency interaction and repeat steps for next phase of investigation, as necessary.Agency interaction and repeat steps for next phase of investigation, as necessary.

10. Evaluating Historical Land Use Aerial photography.Aerial photography. Engineering prints.Engineering prints. –Construction and operation details. –Raw materials. Personnel interviews.Personnel interviews. Public files.Public files.

11. Historical Research August 23, 1995

12. Historical Research March 20, 1947

13. Historical Research April 1, 1947

14. Historical Research November 30, 1951

15. Historical Research November 25, 1968

16. March 20, 1947 April 1, 1947 November 30, 1951 November 25, 1968

17. Historical Research August 23, 1995

18. Analytical Program Development Generate potential COC list and select analytical methods.Generate potential COC list and select analytical methods. Identify acceptable analytical laboratory or laboratories.Identify acceptable analytical laboratory or laboratories. Develop Quality Assurance Project Plan (QAPP).Develop Quality Assurance Project Plan (QAPP). Consider time-sensitive samples in schedule.Consider time-sensitive samples in schedule. Shipping issues and lab waste disposal.Shipping issues and lab waste disposal.

19. Identify Investigation Techniques Consider nature of COCs.Consider nature of COCs. –Corrosive, ignitable, flammable, float, sink, sorb to soil, bioaccumulative, toxicity, etc. Consider COCs and sample device interaction.Consider COCs and sample device interaction. Consider site conditions (access, underground obstructions, power lines, and other hazards).Consider site conditions (access, underground obstructions, power lines, and other hazards). Consider worker health and safety (PPE).Consider worker health and safety (PPE).

20. Work Plan Summary guidance document for all work proposed.Summary guidance document for all work proposed. Specifies all procedures, techniques and protocols to be employed during investigation.Specifies all procedures, techniques and protocols to be employed during investigation. –Uses historical research, interviews with former workers, etc. as guidance. References QAPP.References QAPP.

21. Agency Interaction WDNR provides oversight and recommendations.WDNR provides oversight and recommendations. –Integral part of site assessment. –Work plan may be revised based on WDNR input.

22. Contracting DuPont contracts with all vendors to ensure project work is performed according to the work plan.DuPont contracts with all vendors to ensure project work is performed according to the work plan.

23. Mobilization and Sampling Set-up is integral to a successful field program.Set-up is integral to a successful field program. –Need offices, communications, etc. –Access issues resolved (clearing, off-road vehicles, etc.). Field work can range from days to years.Field work can range from days to years. –Depends on objectives. –Unforeseen circumstances/conditions. –Weather.

24. Field Work

25. Specialized Equipment

26. Seven Pieces of Drilling Equipment Used in 2001

27. Track Mounted Auger Drilling

28. ATV Core Drilling

29. Rotosonic Drilling

30. Reverse Circulation Air Rotary Drilling

31. Advancing Reverse Circulation Casing

32. Mud Rotary Drilling

33. Geophysical Logging

34. Groundwater Sampling

35. Robotic Excavation

36. Transportation of wastes to off site disposal

37. Containment and Temporary Storage of Drill Cuttings

38. Well Sampling

39. Field Delays

40. Analytical Data Review Analytical data is the cornerstone of the investigation.Analytical data is the cornerstone of the investigation. Prelim. results typically provided within 30 to 60 days from receipt by lab.Prelim. results typically provided within 30 to 60 days from receipt by lab. –Based on lab capacity, complexity of analyses, etc. –Third-party review. –Final results. –Project team review can take months.

41. Hydrogeologic Review Geologic conditions.Geologic conditions. Groundwater flow, gradient, and direction.Groundwater flow, gradient, and direction. Extent of contamination in aquifer (vertical and horizontal).Extent of contamination in aquifer (vertical and horizontal). Volume of contaminated groundwater.Volume of contaminated groundwater. Mass of contaminants in aquifer.Mass of contaminants in aquifer.

42. Hydrogeologic Review, continued Volume of contaminated soil.Volume of contaminated soil. Mass of contaminants in vadose zone (soil).Mass of contaminants in vadose zone (soil). Fate and transport.Fate and transport. –Nature of compounds. –Nature of site.

43. Exposure Evaluation Identify exposure pathways and scenarios.Identify exposure pathways and scenarios. –Type(s) of potential receptors at locations. –Frequency, duration, etc. Compare to calculated or agency published health-based guidance.Compare to calculated or agency published health-based guidance. –Conforms to agency guidance. –Identifies potential issues.

44. Corrective Measures Evaluate exposure pathways that need elimination.Evaluate exposure pathways that need elimination. –Consider if remedy is to be interim or final. –Consider type of exposure. –Consider size of the exposure area and nature of COCs. –Reference mass, volume calculations made earlier. –Evaluate technologies.

45. Reporting and WDNR Review Report memorializes efforts and publicly communicates results.Report memorializes efforts and publicly communicates results. –Can be very large (months to prepare and review). –Serves as basis for next phase.

46. Reporting and Agency Review WDNR review integral.WDNR review integral. Next phase designed and process repeated.Next phase designed and process repeated.

47. Summary of Steps Research historical land use.Research historical land use. Develop/refine analytical program.Develop/refine analytical program. Identify appropriate investigation techniques.Identify appropriate investigation techniques. Develop work plan.Develop work plan. Agency interaction.Agency interaction. Perform vendor selection and contracting.Perform vendor selection and contracting. Mobilize and set-up field operations.Mobilize and set-up field operations. Sample potentially impacted media.Sample potentially impacted media. Review analytical data for usability.Review analytical data for usability. Hydrogeologic review.Hydrogeologic review. Evaluate media-specific characteristics.Evaluate media-specific characteristics. Evaluate results against realistic exposure scenarios for humans and environmental receptors.Evaluate results against realistic exposure scenarios for humans and environmental receptors. Evaluate if corrective measures are warranted.Evaluate if corrective measures are warranted. Report findings and recommend next steps.Report findings and recommend next steps. Agency interaction and repeat steps for next phase of investigation, as necessary.Agency interaction and repeat steps for next phase of investigation, as necessary.

48. Questions?

49. Next Meeting Date:Time:Place:Subject: March 26, 2002 7:00 p.m. Northern Great Lakes Visitors Center Results of the Phase I Investigation