former dupont barksdale works project update

Former DuPont Barksdale Works Project Update

June 06, 2006Great Lakes Visitors Center

DuPont CRG

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DuPont Company Representatives

Brad Nave: Project Director – DuPont Corporate Remediation Group

Cary Pooler: Project Manager – URS Corporation

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Purpose of Meeting

Reaffirm site priorities and public commitments.

Provide an update on work completed since the December 2005 public meeting.

Provide an overview for planned work for 2006.

Project Priorities and Commitments ReviewBrad Nave

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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.

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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.

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Other Commitments

Home Value Protection Plan – Home Value Protection Program has expired.

Last municipal water connection was in June 2005.

Availability of the program was the last calendar day of August 2005 for most residents.

A single vacant lot is the only residential property currently in the program and is for sale.

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Work Completed in 2006

Alternative Water Supply– Managing invoices with Washburn– Well abandonment documentation sent to

homeowners and WDNR Georgia Tech Bio-Pilot

– Insert bullet updates Site Investigation Work

– 2006 Work plan submitted to WDNR in March. Preliminary approval has been received from WDNR.

Planned 2006 Site InvestigationCary Pooler

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Site InvestigationWork Planned for 2006

Work planned for 2006:– Historical building/process review– Groundwater investigation– Waste area identification– Debris location/recovery– Discrete soil sampling– Excavation of soil adjacent to select former

process and support buildings and select process ditches

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Northern Area InvestigationIssues Identified

Learnings to date include:– Two separate plumes of site-related constituents

in groundwater.– Over 280 historical buildings across site.– 13 waste management areas identified to date.

Two former burning grounds. Remaining areas include empty containers,

building rubble and other debris.– TNT present at surface and at depth at select

building foundations and ditches.

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Northern Area InvestigationIssues Identified

Learnings to date (continued):– Percentage level concentrations of DNT isomers

at select locations across the site.– Bare areas distributed across former

manufacturing areas.– Bare areas in former acid production areas.– Potential asbestos containing material (PACM).– Debris includes empty drums, process vessels,

and a variety of other metallic and non-metallic wastes.

– Perchlorate preliminarily identified in groundwater.

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PerchlorateOverview

Perchlorate is both a naturally occurring and manmade anion consisting of chlorine bonded to four oxygen atoms (ClO4

-).

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PerchlorateOverview

Why are we looking for perchlorate at Barksdale?– A historical document identified in February of

2005 indicated that the former Barksdale plant manager was corresponding with a chemist in Chile about staffing.

– This letter may indicate a that sodium nitrate from Chile was used for as a raw material for nitric acid production at Barksdale.

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PerchlorateOverview

At this time, most naturally occurring sources of perchlorate appear to be geographically limited to arid environments. High natural perchlorate concentrations are found in Chilean caliche and some potash ores.– Sodium nitrate is leached from Chilean caliche to

make fertilizers, among other products. Chilean nitrate derived fertilizers were the

primary fertilizers used in the United States until the 1960s.

– Sodium nitrate (“soda nitre” or “Chilean saltpeter”) was formerly an important raw material for the production of nitric acid in the United States and elsewhere.

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PerchlorateOverview

Preliminary results:– Preliminary laboratory results indicate that

concentrations in groundwater surrounding the former nitric acid production area range between 0.033 to 150 parts per billion (ppb).

– Perchlorate was not detected in the two potable wells sampled on-site.

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PerchlorateOverview

EPA has established a 24.5 ppb limit in drinking water for perchlorate.– Perchlorate inhibits iodide uptake.

Next steps:– Sample additional wells on-site in Spring 2006.

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Northern Area InvestigationHistorical Buildings/Ditches

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Northern Area InvestigationWork Completed to Date

Trenching Investigation– Investigation of subsurface residual product

distribution and identification of former subsurface pit and drain locations.

– Phase I – Identify typical conditions Used remote controlled excavator Focus on soil adjacent to former process

buildings.

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Northern Area InvestigationWork Completed to Date

Trenching Investigation(continued):– Phase II –

Used shielded conventional excavator. Focus on process ditches & buildings similar to

those from Phase I. Used bulk (mechanized) excavation to

determine location and expose deposits Used forensic (hand dug) excavation to

determine detail of deposition of solid deposits.

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Northern Area InvestigationWork Completed to Date

Phase I excavation (at Finishing Plant)

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Northern Area InvestigationWork Completed to Date

Phase II excavation (at Refine ditch)

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Northern Area InvestigationHistorical Buildings/Ditches

TNT

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Northern Area InvestigationWork Completed to Date

More excavation photos showing TNT.TNT Layer

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Northern Area InvestigationWork Completed to Date

More excavation photos showing TNT.

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Northern Area InvestigationWork Completed to Date

More excavation photos showing TNT.

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TNT Removal Process

Collect & size pieces by hand Weigh, wet, and pack in antistatic bags Courier ship bags to St.Louis for incineration

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Northern Area InvestigationWork Completed to Date

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Northern Area InvestigationPictures of Waste AreasWest Boyd Rail Fill

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Northern Area InvestigationPictures of Waste AreasWest Boyd Rail Fill

Slab Crossing Debris

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Northern Area InvestigationPictures of Waste AreasWest Boyd Rail Fill

Nitramon Area Container

Dump

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Northern Area InvestigationPictures of Waste AreasCrushed Drum Dump

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Northern Area InvestigationWork Completed to Date

Typical surficial debris recovered.

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Northern Area InvestigationWork Completed to Date

Bare area photos.

Bare Area

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Northern Area InvestigationPath Forward

Continue to determine distribution of site-related constituents.

– Four month field effort planned for 2006.– Explore feasibility of alternative investigation techniques.

Continue TNT recovery and disposal as part investigation efforts.

Continue debris identification and recovery. Continue to understand perchlorate distribution in

groundwater. Consider grid sampling in select areas. Continue pilot test work at GA Tech

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Site-related Research Work

Continuing Georgia Institute of Technology research on destruction of DNT and TNT.

– Study being conducted by Dr. Joe Hughes (Professor and Chair of the Civil Engineering Dept. at Ga. Tech) and Dr. Jim Spain.

– Study initiated in early 2004 and is ongoing.– A portion of their research on TNT destruction was published in the

peer reviewed journal Environmental Science and Technology this year.

– Scaled-up DNT bioremediation project to address DNT contaminated soils is in progress at the Georgia Tech facility.

Soils used in the system are from the Barksdale site. System will run until all DNT degraded or other suitable

endpoint is reached Final results should be available by the end of 2006. Updates will be provided in future public meetings.

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Proposed Barksdale Soil Biodegradation Pilot Proposed pilot project is a simple set up with low operation and

maintenance requirements.

Water, pH adjustment &

Nutrients (phosphate,

magnesium, calcium, iron)

DNT Biodegradation ReactorSite Soils

Contaminated w/ DNT (source of bacteria and DNT)

Gravel for Drainage

1 DNT 2 NO2

-

Methanol +NO2

-

N2 + CO2 + H2O

Methanol (wood alcohol)

Denitrification Reactor to Remove Nitrite

(bacteria from soils)

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Southern Area InvestigationScope of Work

Worked with WDNR to develop a work plan to investigate southern area.– Focus of work was to:

Determine nature and extent of site-related constituents in surface soil.

Determine if current recreational use is appropriate.

– Work plan approved by WDNR. Site sampling was very comprehensive,

encompassing both grid-based and biased sampling at 640 locations (416 analyzed) over 400+ acres.

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Southern Area Investigation Scope

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Southern Area InvestigationPreliminary Findings

With the exception of one occurrence of benzo(a)pyrene at the residential screening level, arsenic and lead are the only constituents that exceed residential or recreational screening levels.

The extent of contamination is generally limited to soils along historic roadways in the central portion of the parcel. (The one exception being at select samples in the northeastern corner of the parcel.)

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The nature and distribution of contamination is consistent with our understanding of historic site operations and our experience at other munitions manufacturing sites.

Arsenic and lead concentrations are well correlated, especially in samples that exceed their respective screening criteria. Hence, selected remediation of elevated levels of one constituent would also address the other.

Southern Area InvestigationPreliminary Findings

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The levels of lead and arsenic observed do not represent an acute health risk, and as such, use of this area for an additional season of occasional recreational activities would not be expected to result in unacceptable exposures.

A waste disposal area (1970s berm) was identified. Waste materials primarily consist of building rubble.

Southern Area InvestigationPreliminary Findings

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Southern Area InvestigationGrid Sizes

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Northern Area InvestigationIssues Identified

Insert maps/pictures of issues/findings.

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Southern Area InvestigationIssues Identified

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Southern Area Investigation1970s Berm

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Southern Area Investigation1970s Berm

1970s Berm

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Southern Area InvestigationSuggested Path Forward

Conduct additional sampling (Spring, 2006) for the purposes of delineating specific areas along historic roadways and railways.

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Summary of Presentation

Priorities remain unchanged. Progress made in northern and southern

sections of property in 2005.– Over 400 pounds of TNT recovered and destroyed

in northern section in 2005, and several former process areas were investigated. Four months of field work are planned in 2006.

– Groundwater investigation resulted in detections of perchlorate. Additional samples to follow 2Q06.

– 640 locations sampled in southern section of the site (over 400 acres). Additional investigation of several areas is planned for 2006.

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Questions or comments?