DuPont Barksdale and Chequamegon Projects Update December 12, 2007 DuPont CRG Great Lakes Visitors Center

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update7 Purpose of Meeting Barksdale: Provide an update on site priorities and public commitments. Provide a summary of site investigation work completed in Summarize next steps. Chequamegon-Nicolet National Forest: Provide an update on site investigation activities at the Cabin Lake and Clover sites.

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update8 DuPont Representatives Brad Nave – DuPont, Sr. Site Director Jon Hammerberg – URS Corporation, Sr. Project Engineer

Former DuPont Barksdale Works Project Update

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update10 Barksdale Project Priorities Current Priorities: Identify priority source areas and take appropriate action. Priorities Addressed: Evaluate for potential off-site surface water issues and take appropriate action. Sampling by DuPont and WDNR/EPA has identified no issues. 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. All previously affected wells are closed. No homes in affected area are using local groundwater. Washburn municipal water supply (completed in 2005) currently supplies homes in affected area.

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update11 Barksdale Project Priorities Other Commitments: Fulfill commitments on Home Value Protection Plan. Ended after construction of municipal water supply. Continue to work with WDNR. Continue to be available and communicate with neighbors.

Summary of 2007 Barksdale Work

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update13 Reported Investigation Results Prepared a Current Conditions Report that: Summarized all investigation data collected to date (~ ). Established priorities for future investigation work. Submitted in May Conducted extensive site investigation that: Identified over 560 acres as eligible for no further action in To date, over 1,400 of the former 1,800 acres of the site have been investigated and are eligible for no further action. Confirmed that the property formerly owned by DuPont outside of the site fence is unaffected and appropriate for continued residential and recreational use. Reaffirmed that there are no other affected potable drinking water wells in the vicinity of the site. Summary of 2007 Barksdale Work

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update14 Continued administrative efforts: Working with WDNR to request Case Closure of the five Use Areas that comprise 442 acres south of Boyd Creek. Continue to implement administrative controls in order to reduce the potential for human exposure to site- related compounds on-site. Continue to support municipal water supply. Pay Washburn for municipal water system meter fees, water usage, and maintenance. Address possible electrical grounding issues. Summary of 2007 Barksdale Work

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update15 Recovery and Disposal of Residual Site Materials. Evaluation of Remedial Technologies: Field scale bio-pilot conducted. Continued laboratory studies at GA Tech. Synthesis of DNX isomers: SWRI, Inc. Summary of 2007 Work

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update16 Site Divided in 61 Use Areas: Production Areas – 21 areas. Support Areas – 14 areas. Waste Areas – 9 areas. Historically Undeveloped Areas – 16 areas. Groundwater – treated as a single Use Area. Current Condition of Site: Primary use of property formerly owned by DuPont is recreational or residential. Residential property is limited to areas outside of fence that were either historically undeveloped or used for support purposes. Current Conditions Report Summary

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update17 Current Conditions Report Summary Priority Ranking of Use Areas: 33 Use Areas ranked High Priority for further investigation. 21 Use Areas ranked Low Priority for further investigation. 7 Use Areas ranked No Further Action. 5 in the Southern Area 2 north of Boyd Creek

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update18 Electrical Grounding DuPont is addressing possible electrical grounding issues with the municipal water supply pipeline: Some homes may have been grounded to plumbing as part of original home construction. This practice is outdated according to current electrical code. With connection to municipal supply, ground may have been interrupted. DuPont will have licensed electrical contractor check each home connected to municipal water system. If the home is improperly grounded due to DuPont’s work, grounding will be addressed.

2007 Site Investigation Work

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update20 Overview 2007 Site Investigation Activities: Geophysical surveying Soil sampling and trenching in former production areas Discrete soil sampling at biased locations Grid sampling generally in non-manufacturing areas FIDO Surveying

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update Investigation Priorities

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update22

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update23 Clearing Work Sites Cleared: Four miles of new trails. X-acres of sample sites.

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update24 Screening with Geophysics (EM61) Used to: Map metallic debris. Locate metallic pipe lines. Locate utility lines. Identify changes in soil conductivity.

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update25 Geophysics EM61 Results— PAI

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update26 Trench Investigation Used to: Verify geophysical detections. Locate & sample non-metallic pipes. Locate & sample foundations. Recover buried TNT. Profile process ditches.

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update27 Trench Sampling at Foundations

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update28 Trench Sampling at Foundations

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update29 Recovering TNT from Catch Box Total of 1,920 pounds of soil and TNT recovered and disposed in 2007 (contained 470 pounds of TNT ).

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update30 Profiling Product Residues in Ditch TNX

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update31 FIDO Analysis Equipment

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update32 Screening with Vacuum Cartridges Used to: Compare relative TNT/DNT strength between site areas. Locate visibly obscured TNT pieces in tall grass and in debris piles. Locate TNT impacted soil. Identify large buried TNT deposits. Screen excavated soil for live loading. Screen borehole samples to select sample depths.

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update33 TNT Located Using Cartridges and FIDO TNT found by FIDO visible only after tall grass & sheet metal hiding it was removed.

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update34 Drilling and Soil Sampling

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update35 Soil Samples

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update36 Removing Asbestos 250-lf of exposed pipe insulation was removed.

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update37 Waste Water Treatment and Disposal 2,500 gallons removed in 2007.

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update38 Debris and Scrap Metal Recovery

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update39 Debris and Scrap Metal Disposal Total of 50 cubic yards of scrap removed to date.

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update40 Off-site Monitoring Project Summary Per agreement with WDNR, wells to the south and southeast of site that are not connected to the municipal water supply are monitored biennially until In 2007, 33 wells were sampled. Second sampling event since installation of municipal water supply. Samples analyzed for nitroaromatic and nitramine organic compounds. All sample results continue to be non-detect. Results reaffirm that there are no other affected potable wells in the vicinity of the site and municipal water is not needed in this area. Next sampling event will be in 2009.

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update41 Off-Site Monitoring Results

2007 Administrative Efforts

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update43 Priority Rankings 2007

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update44 Proposed Priority Rankings—2008

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update45 Closure Request Request Submittal will Include: Historical Site Summary. Verification of Site Zoning. Analytical Summary of Soil/Sediment/Surface Water and Groundwater Data. Summary of Historical Groundwater Elevation Data. Maintenance Plan. GIS Registry Submittal.

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update46 Pending Closure Request Area South of Boyd Creek

Remedial Technology Evaluation

DNT Biodegradation Study

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update49 DNT Pilot - Background Purpose: To replicate GA Tech pilot at field scale. Location: Former Lydol House. Goals: Determine if DNT concentrations can be reduced in the field by applying key learnings from GA Tech 2006 Pilot. Evaluate if technology can get DNT concentrations below land use specific criteria.

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update50 Barksdale Field DNT Bio Pilot

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update51 Project Setup and Challenges Area divided into four 10’ x 20’ cells>: Cell 1 – control (initial tilling only). Cell 2 – monthly tilling only. Cell 3 – monthly tilling and pH adjustment. Cell 4 – monthly tilling and water addition. Sampling frequency: DNTs monthly. pH and field parameters biweekly. Challenges: Tilling clayey soil to a depth of 2 feet. Started with a slightly different soil matrix than was used in Georgia Tech pilot. Higher concentrations of DNX isomers and TNT. Lower intial concentrations of DNT Lower intial soil pH (<3.5 to 5 average).

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update52 Results and Conclusions Conclusions: 2,4 DNT and 2,6 DNT appear to be degradeable in the field. Pilot results suggest achieving land-use specific criteria is possible. Howard Rotovator is an effective tool for tilling soils to 2 feet. DNX isomers not readily degradeable.

Additional Target Analytes

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update54 DuPont will include up to 15 new compounds to routine nitroaromatic/nitramine organic laboratory analyses, assuming reliable laboratory standards can be obtained and successful analytical performance studies are conducted. The 15 compounds consist of four DNT and 11 DNX isomers. DNT isomers identified: 3,4-DNT 2,3-DNT 2,5-DNT 3,5-DNT Standards have been located for the 3,4- and 2,3-DNT isomers. DuPont is currently trying to obtain standards for the remaining two isomers. Eleven DNX isomers have been identified as potentially present. Five have been located and purchased, five more have been synthesized; one more to go. Additional Target Analytes

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update55 Continue to investigate high priority areas on-site: Near-term investigation focus will be high priority areas. Periodically characterize surface water and sediment in drainages located at the security fence line. Work with WDNR to administratively close the five Use Areas south of Boyd Creek. Continue to implement administrative controls in order to reduce the potential for human exposure to site-related compounds. Continue biodegradation studies. Scale-up in Continue to sample off site potable wells. Continue to address possible addition of new target analytes. Continue public interaction and water supply commitments. Barksdale Path Forward

Chequamegon-Nicolet National Forest Update

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update57

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update58 Chequamegon-Nicolet National Forest Project Summary: DuPont is working with the US Forest Service (USFS) to investigate two former metal cladding sites (Cabin Lake and Clover). Metallic debris delineation completed at Cabin Lake in late 2006, while debris delineation was completed at Clover in May Debris delineation report submitted to USFS on June 7, 2007.

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update59 Chequamegon-Nicolet National Forest In June 2007, DuPont and USFS representatives met to discuss debris delineation results and plan the next phase of investigation activity (soil sampling). During this meeting, USFS personnel informed DuPont that there are four potential cultural resource areas in the vicinity of the Cabin Lake and Clover sites and that DuPont must conduct an archaeological evaluation. DuPont and USFS conceptually agreed on the scope of soil sampling work: Sampling work will include biased soil sampling and trenching at both sites where the most concentrated metallic debris was identified. Sampling work will include sediment and surface water sampling from within Cabin Lake.

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update60 Chequamegon-Nicolet National Forest Since June 2007, DuPont and USFS representatives have: Determined which potential locations will be subject to archaeological study. One area at Cabin Lake (a former logging camp) will require further study. Remaining sites are outside of DuPont’s investigation area and are not subject to archaeological study. Completed a joint field reconnaissance in November 2007 of the archaeological areas. Conceptually agreed on the scope of archaeological work: Historical file review of location at Cabin Lake. Work plan development and approval. Completion of archaeological study.

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update61 Cabin Lake Geophysical Findings

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update62 Clover Geophysical Findings

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update63 Chequamegon-Nicolet National Forest Path Forward: DuPont is currently completing the historical file review and developing the archaeological work plan. Once archaeological field work is complete and reported (estimated summer 2008), DuPont will submit the final work plan for the environmental investigation to USFS for review and undertake the proposed work, pending appropriate archaeological permits from Wisconsin and USFS.

December 12, 2007 DuPont Barksdale and Chequamegon Projects Update64 Questions or comments?