former dupont barksdale works project update december 14, 2006 great lakes visitors center dupont...

Former DuPont Barksdale Works Project Update

December 14, 2006

Great Lakes Visitors Center

DuPont CRG

December 14, 2006 Former DuPont Barksdale Works 2

DuPont Company Representatives

Brad Nave – Project Director, DuPont Corporate Remediation Group

Jon Hammerberg – Senior Project Engineer, URS Corporation


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

Barksdale Project Priorities and Commitments ReviewBrad Nave


Project Priorities

Four Project Priorities:

1. Continue to provide drinking water that meets appropriate Wisconsin regulatory standards for all site-related compounds to residents with impacted wells

2. Develop plan for long-term drinking water supply and implement as appropriate

3. Evaluate for potential off-site surface water issues and take appropriate action

4. Identify priority source areas and take appropriate action


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


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


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

2006 Site InvestigationJon Hammerberg


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


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


2006 Site Investigation Map


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


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Northern Area Investigation Maps


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


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Southern Area Investigation Map


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


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2006 S Risk & Corridor


Insert maps/pictures of issues/findings.

Draft Northern Area Undeveloped Area

Investigation Results

1. Does not include biased samples

2. Results compared to site-specific recreational RCLS


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


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)


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Path ForwardBrad Nave


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

Chequamegon-Nicolet National Forest UpdateBrad Nave


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


2006 Cabin Lake Work

Insert mapCABINLAKE


2006 Clover Results

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•OPERATORSSTATION

NorthPad

SouthPad


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


Questions or comments?

former dupont barksdale works project update december 14, 2006 great lakes visitors center dupont...

Documents

acres site

site priorities

plant fenceoff site

siterelated compounds

undeveloped grounds

plant fencesouthern

related water supply

neighborsfulfill commitments