Du Pont Barksdale and Chequamegon Projects Update July

Du. Pont Barksdale and Chequamegon Projects Update July 22, 2008 Du. Pont CRG July 22, 2008 Former Du. Pont Barksdale Works

Purpose of Meeting n Barksdale: n n n Provide a status update on site priorities and public commitments. Provide a summary of on-going 2008 site activities. Chequamegon-Nicolet National Forest: n Provide a status update on site investigation activities at the Cabin Lake and Clover sites. July 22, 2008 Former Du. Pont Barksdale Works 2

Former Du. Pont Barksdale Works Project Update July 22, 2008 Former Du. Pont Barksdale Works

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: ü ü ü 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. July 22, 2008 Former Du. Pont Barksdale Works 4

Project Priorities Other Commitments: n Continue to work with WDNR in the investigation/cleanup of siterelated impacts. n Continue to be available and communicate with neighbors. July 22, 2008 Former Du. Pont Barksdale Works 5

Summary of 2008 Barksdale Work July 22, 2008 Former Du. Pont Barksdale Works

Summary of 2008 Work Continue to fulfill water supply commitments Site Investigation n n Site clearing. Grid sampling of 200 locations. Biased sampling at 300 plus locations. Geophysical work to determine subsurface anomalies. Using explosive detection device (FIDO). July 22, 2008 Former Du. Pont Barksdale Works 7

map of 08 inv priorities. July 22, 2008 Former Du. Pont Barksdale Works 8

Summary of 2008 Work Recovery and Disposal of Residual Site Materials: n Removed approximately 800 pounds of DNT. n TNT recovery and disposal planned. Evaluation of Remedial Technologies: n Field scale bio-pilot being conducted. n Continued laboratory studies at GA Tech. n University of Waterloo DNX studies. Synthesis of DNX isomers: n Completed in early 2008. n Developing screening values. July 22, 2008 Former Du. Pont Barksdale Works 9

Alternative Water Supply Waterline Completed December 2005. Provides Municipal Drinking Water Access to: n 47 Homes n 8 Undeveloped Parcels Over 6 million gallons of water delivered through the pipeline since installation. July 22, 2008 Former Du. Pont Barksdale Works 10

Clearing Work Sites July 22, 2008 Former Du. Pont Barksdale Works 11

Residual Product Removal DNT Removal: n Discovered solid DNT below a floor slab during Bio Cell preparation at former Trivelene Sweating House. July 22, 2008 Former Du. Pont Barksdale Works 12

Screening with Geophysics (EM 61) July 22, 2008 Former Du. Pont Barksdale Works 13

FIDO Analysis Equipment July 22, 2008 Former Du. Pont Barksdale Works 14

Screening with Vacuum Cartridges MEVA SAMPLING PROCESS • Clear brush and ground cover. • Survey 1 -acre grid corners and stake 1/16 th 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. July 22, 2008 Former Du. Pont Barksdale Works 15

Sample MEVA results July 22, 2008 Former Du. Pont Barksdale Works 16

TNT Located by MEVA TNT found by FIDO visible only after tall grass & sheet metal hiding it was removed. July 22, 2008 Former Du. Pont Barksdale Works 17

Evaluation of Remedial Technologies July 22, 2008 Former Du. Pont Barksdale Works

Barksdale Field DNT Bio-Pilot 2008 July 22, 2008 Former Du. Pont Barksdale Works 19

2008 Bio-Pilot Work Overview n n Reduction of DNT via biodegradation observed by GA Tech in studies funded by Du. Pont. 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). n Work started in June 2008 at four locations. July 22, 2008 Former Du. Pont Barksdale Works 20

2008 Pilot Locations n n Lydol House (4 cells from 2007) Trivilene No. 1 Sweating House TNT No. 4 Bi/Tri House TNT No. 2 Wash House July 22, 2008 Former Du. Pont Barksdale Works 21

map of 08 inv priorities. SITES July 22, 2008 Former Du. Pont Barksdale Works 22

Trivilene #1 Sweating House Sweating Ho July 22, 2008 Former Du. Pont Barksdale Works

#1 Trivilene Sweating House Cell July 22, 2008 Former Du. Pont Barksdale Works 24

TNT #4 Bi-Tri House Bi. Tri Ho July 22, 2008 Former Du. Pont Barksdale Works

TNT #4 Bi-Tri House Cell July 22, 2008 Former Du. Pont Barksdale Works 26

TNT #2 Wash House divert SW Wash Ho Bi. Tri Ho Neut. Ho July 22, 2008 Former Du. Pont Barksdale Works

Barksdale Bio-Pilot June 2008 TNT 02 Wash House Cell Prior to first tilling July 22, 2008 Former Du. Pont Barksdale Works 28

# 2 Wash House Cell July 22, 2008 Former Du. Pont Barksdale Works 29

Typical debris removed by raking July 22, 2008 Former Du. Pont Barksdale Works 30

Lydol House Cells July 22, 2008 Former Du. Pont Barksdale Works 31

Tractor with Howard Rotovator 700 DUT July 22, 2008 Former Du. Pont Barksdale Works 32

Tilling No. 2 Wash House July 22, 2008 Former Du. Pont Barksdale Works 33

Pilot Status All locations tilled approximately once per month n Periodic sampling for n Nitramine and nitroaromatic organic compounds n p. H n Nitrogen, Phosphorus, and Potassium n n Adjust p. H in cells as necessary July 22, 2008 Former Du. Pont Barksdale Works 34

Barksdale Path Forward Continue to investigate high priority areas on-site: • Focus on high priority areas, including characterization and remediation. July 22, 2008 Former Du. Pont Barksdale Works 35

Map of priority areas of investigation. n Use map from April 2 n July 22, 2008 Former Du. Pont Barksdale Works 36

Barksdale Path Forward n n n Continue biodegradation studies. Continue to address DNX isomer and As/Pb issues. Continue public interaction and water supply commitments. July 22, 2008 Former Du. Pont Barksdale Works 37

Chequamegon-Nicolet National Forest Update July 22, 2008 Former Du. Pont Barksdale Works

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Chequamegon-Nicolet National Forest Project Summary: n n Du. Pont 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. July 22, 2008 Former Du. Pont Barksdale Works 40

Chequamegon-Nicolet National Forest Completed field portion of the Phase II Archaeological investigation in June 2008 n n 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. n 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. July 22, 2008 Former Du. Pont Barksdale Works 41

Chequamegon-Nicolet National Forest Path Forward: n n 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, Du. Pont 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. July 22, 2008 Former Du. Pont Barksdale Works 42

Questions or comments? July 22, 2008 Former Du. Pont Barksdale Works 43