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Former DuPont Barksdale Works Project Update. June 07, 2006 Great Lakes Visitors Center DuPont CRG. DuPont Company Representatives. Brad Nave: Project Director – DuPont Corporate Remediation Group Cary Pooler: Project Manager – URS Corporation. Purpose of Meeting. Barksdale:
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Former DuPont Barksdale Works Project Update June 07, 2006 Great Lakes Visitors Center DuPont CRG
DuPont Company Representatives • Brad Nave: Project Director – DuPont Corporate Remediation Group • Cary Pooler: Project Manager – URS Corporation Former DuPont Barksdale Works
Purpose of Meeting • Barksdale: • 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. • Chequamegon-Nicolet National Forest: • Provide a status update on activities. Former DuPont Barksdale Works
Barksdale Project Priorities and Commitments ReviewBrad Nave
Project Priorities Four Project Priorities: • 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. • Evaluate for potential off-site surface water issues and take appropriate action. • Identify priority source areas and take appropriate action. Former DuPont Barksdale Works
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. Former DuPont Barksdale Works
Home Value Protection Plan Home Value Protection Program has expired. • Last municipal water connection was in June 2005. • Eligibility expired for the final group of residents in 4Q2006. • A single vacant lot is the only residential property currently in the program and sale of the property is pending. Former DuPont Barksdale Works
Work Completed in 2006 • Alternative Water Supply • Managing invoices, supply, and maintenance with Washburn. • To date, DuPont has paid $93,620.86 in related water supply costs to Washburn. • Well abandonment documentation sent to homeowners and WDNR. Former DuPont Barksdale Works
Work Completed in 2006 • Georgia Tech Bio-Pilot • DNT isomers not currently detected in aqueous phase. • System was operated for 5 months and a 90% reduction was observed. • Soil from system taken back to lab to further determine limits of degradation. Former DuPont Barksdale Works
Work Completed in 2006 • Site Investigation Work • 2006 Work plan submitted to WDNR in March. • Preliminary approval has been received from WDNR. Former DuPont Barksdale Works
2006 Site Investigation • 2006 Site Investigation • Investigation has two geographic focus areas: • Northern Area • Investigation multi-faceted. • Southern Area • Investigation focusing on surface soils. • Investigation to begin this month. • Estimated completion of field work is September 2006. • Reporting by the end of the year. Former DuPont Barksdale Works
Northern Area InvestigationPlanned Work • Determine distribution of site-related constituents. • Trenching. • Grid sampling in select aeas. • TNT recovery and disposal as part investigation efforts. • Debris identification and recovery. • Perchlorate distribution in groundwater. Former DuPont Barksdale Works
Insert maps/pictures of issues/findings. Former DuPont Barksdale Works
Insert maps/pictures of issues/findings. Former DuPont Barksdale Works
Southern Area InvestigationGrid Sizes Former DuPont Barksdale Works
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.) Former DuPont Barksdale Works
Southern Area InvestigationPreliminary Findings • 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. Former DuPont Barksdale Works
Insert maps/pictures of issues/findings. Former DuPont Barksdale Works
Southern Area InvestigationPlanned Work • Conduct additional sampling for the purposes of delineating specific areas along historic roadways and railways. Former DuPont Barksdale Works
Chequamegon National Forest • National Forest Service contacted DuPont in April 2006. • Requested DuPont work with Forest Service to develop a framework for future actions within the National Forest. • DuPont met with USDA-FS on June 7, 2006 to discuss path forward. • Future work will address both the Cabin Lake and Clover sites. Former DuPont Barksdale Works
Questions or comments? Former DuPont Barksdale Works
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. Former DuPont Barksdale Works
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. Former DuPont Barksdale Works
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. Former DuPont Barksdale Works
PerchlorateOverview • EPA has established a 24.5 ppb limit in drinking water for perchlorate. • Perchlorate inhibits iodide uptake. Former DuPont Barksdale Works