An Overview ofAn Overview of Environmental Environmental InvestigationsInvestigations

January 22, 2002

Presented by:DuPont Corporate Remediation Group

Today’s meeting...Today’s meeting...

Provide an overview of the basic Provide an overview of the basic objectives, strategy, and techniques objectives, strategy, and techniques for conducting an environmental for conducting an environmental investigation.investigation.

DuPont’s PhilosophyDuPont’s Philosophy

Conduct investigations that allow Conduct investigations that allow DuPont and the regulatory agency DuPont and the regulatory agency to make informed decisions and to make informed decisions and take appropriate steps to take appropriate steps to protect protect human health and the environment.human health and the environment.

Environmental Environmental Investigations Investigations

• Usually an iterative approach.Usually an iterative approach.

• Vary in complexity.Vary in complexity.

• Address multiple needs.Address multiple needs.– Human and ecological exposure via Human and ecological exposure via

• Groundwater.Groundwater.

• Soil and/or sediment.Soil and/or sediment.

• Surface water.Surface water.

• Air.Air.

Basic Environmental Basic Environmental Investigation StepsInvestigation Steps

• Research historical land use, Research historical land use, specifically detailed operations, specifically detailed operations, spills, etc.spills, etc.

• Develop analytical program.Develop analytical program.– Identify chemicals of concern (COCs) Identify chemicals of concern (COCs)

and appropriate analytical methods. and appropriate analytical methods.

Basic Environmental Basic Environmental Investigation Steps, Investigation Steps, continuedcontinued

• Identify appropriate investigation Identify appropriate investigation techniques. techniques.

• Develop work plan.Develop work plan.

• Agency interaction.Agency interaction.

• Perform vendor selection and Perform vendor selection and contracting.contracting.

Basic Environmental Basic Environmental Investigation Steps, Investigation Steps, continuedcontinued

• Mobilize and set-up field operations.Mobilize and set-up field operations.

• Sample potentially impacted media Sample potentially impacted media (air, soil, sediment, groundwater, (air, soil, sediment, groundwater, and surface water).and surface water).

• Review analytical data for usability.Review analytical data for usability.

• Perform hydrogeologic review.Perform hydrogeologic review.

Basic Environmental Basic Environmental Investigation Steps, Investigation Steps, continuedcontinued• Evaluate media-specific characteristics.Evaluate media-specific characteristics.

– Types of COCs present. Types of COCs present.

– Concentration(s) of COCs at exposure Concentration(s) of COCs at exposure points.points.

• Evaluate results against realistic Evaluate results against realistic exposure scenarios for humans and exposure scenarios for humans and environmental receptors.environmental receptors.

Basic Environmental Basic Environmental Investigation Steps, Investigation Steps, continuedcontinued

• Evaluate if corrective measures are Evaluate if corrective measures are warranted based on available data.warranted based on available data.– Fix may be temporary.Fix may be temporary.

• Report findings and recommend next Report findings and recommend next steps.steps.

• Agency interaction and repeat steps for Agency interaction and repeat steps for next phase of investigation, as next phase of investigation, as necessary.necessary.

Evaluating Historical Land Evaluating Historical Land UseUse

• Aerial photography.Aerial photography.

• Engineering prints.Engineering prints.– Construction and operation details.Construction and operation details.

– Raw materials.Raw materials.

• Personnel interviews.Personnel interviews.

• Public files.Public files.

Historical ResearchHistorical ResearchAugust 23, 1995August 23, 1995

Historical Research Historical Research March 20, 1947March 20, 1947

Historical Research Historical Research April 1, 1947April 1, 1947

Historical Research Historical Research November 30, 1951November 30, 1951

Historical Research Historical Research November 25, 1968November 25, 1968

March 20, March 20, 19471947

April 1, 1947April 1, 1947

November 30, November 30, 19511951

November 25, November 25, 19681968

Historical Research Historical Research August 23, 1995August 23, 1995

Analytical Program Analytical Program DevelopmentDevelopment• Generate potential COC list and Generate potential COC list and

select analytical methods.select analytical methods.• Identify acceptable analytical Identify acceptable analytical

laboratory or laboratories.laboratory or laboratories.

• Develop Quality Assurance Project Plan Develop Quality Assurance Project Plan (QAPP).(QAPP).

• Consider time-sensitive samples in Consider time-sensitive samples in schedule.schedule.

• Shipping issues and lab waste disposal.Shipping issues and lab waste disposal.

Identify Investigation Identify Investigation TechniquesTechniques• Consider nature of COCs.Consider nature of COCs.

– Corrosive, ignitable, flammable, float, Corrosive, ignitable, flammable, float, sink, sorb to soil, bioaccumulative, sink, sorb to soil, bioaccumulative, toxicity, etc. toxicity, etc. • Consider COCs and sample device Consider COCs and sample device

interaction.interaction.

• Consider site conditions (access, Consider site conditions (access, underground obstructions, power lines, underground obstructions, power lines, and other hazards).and other hazards).

• Consider worker health and safety (PPE).Consider worker health and safety (PPE).

Work PlanWork Plan

• Summary guidance document for all Summary guidance document for all work proposed.work proposed.

• Specifies all procedures, techniques Specifies all procedures, techniques and protocols to be employed during and protocols to be employed during investigation.investigation.– Uses historical research, interviews with Uses historical research, interviews with

former workers, etc. as guidance.former workers, etc. as guidance.

• References QAPP.References QAPP.

Agency InteractionAgency Interaction

• WDNR provides oversight and WDNR provides oversight and recommendations.recommendations.– Integral part of site assessment.Integral part of site assessment.

– Work plan may be revised based on Work plan may be revised based on WDNR input.WDNR input.

ContractingContracting

• DuPont contracts with all vendors to DuPont contracts with all vendors to ensure project work is performed ensure project work is performed according to the work plan.according to the work plan.

Mobilization and SamplingMobilization and Sampling

• Set-up is integral to a successful Set-up is integral to a successful field program.field program.– Need offices, communications, etc. Need offices, communications, etc.

– Access issues resolved (clearing, off-Access issues resolved (clearing, off-road vehicles, etc.).road vehicles, etc.).

• Field work can range from days to years.Field work can range from days to years.– Depends on objectives.Depends on objectives.

– Unforeseen circumstances/conditions.Unforeseen circumstances/conditions.

– Weather.Weather.

Field WorkField Work

Specialized Specialized EquipmentEquipment

Seven Pieces of Drilling Seven Pieces of Drilling Equipment Used in 2001Equipment Used in 2001

Track Mounted Auger DrillingTrack Mounted Auger Drilling

ATV Core DrillingATV Core Drilling

Rotosonic DrillingRotosonic Drilling

Reverse Circulation Air Reverse Circulation Air Rotary DrillingRotary Drilling

Advancing Reverse Advancing Reverse Circulation CasingCirculation Casing

Mud Rotary DrillingMud Rotary Drilling

Geophysical LoggingGeophysical Logging

Groundwater SamplingGroundwater Sampling

Robotic ExcavationRobotic Excavation

Transportation of wastes to off Transportation of wastes to off site disposalsite disposal

Containment and Temporary Containment and Temporary Storage of Drill CuttingsStorage of Drill Cuttings

Well Well SamplingSampling

Field Field DelaysDelays

Analytical Data ReviewAnalytical Data Review

• Analytical data is the cornerstone of Analytical data is the cornerstone of the investigation.the investigation.

• Prelim. results typically provided within 30 to Prelim. results typically provided within 30 to 60 days from receipt by lab.60 days from receipt by lab.– Based on lab capacity, complexity of analyses, etc.Based on lab capacity, complexity of analyses, etc.

– Third-party review.Third-party review.

– Final results.Final results.

– Project team review can take months. Project team review can take months.

Hydrogeologic ReviewHydrogeologic Review

• Geologic conditions.Geologic conditions.

• Groundwater flow, gradient, and direction.Groundwater flow, gradient, and direction.

• Extent of contamination in aquifer (vertical Extent of contamination in aquifer (vertical and horizontal).and horizontal).

• Volume of contaminated groundwater.Volume of contaminated groundwater.

• Mass of contaminants in aquifer.Mass of contaminants in aquifer.

Hydrogeologic Review, Hydrogeologic Review, continuedcontinued• Volume of contaminated soil.Volume of contaminated soil.

• Mass of contaminants in vadose zone Mass of contaminants in vadose zone (soil).(soil).

• Fate and transport.Fate and transport.– Nature of compounds.Nature of compounds.

– Nature of site.Nature of site.

Exposure EvaluationExposure Evaluation

• Identify exposure pathways and Identify exposure pathways and scenarios.scenarios.– Type(s) of potential receptors at locations.Type(s) of potential receptors at locations.

– Frequency, duration, etc.Frequency, duration, etc.

• Compare to calculated or agency Compare to calculated or agency published health-based guidance.published health-based guidance.– Conforms to agency guidance.Conforms to agency guidance.

– Identifies potential issues.Identifies potential issues.

Corrective MeasuresCorrective Measures

• Evaluate exposure pathways that need Evaluate exposure pathways that need elimination.elimination.– Consider if remedy is to be interim or final.Consider if remedy is to be interim or final.

– Consider type of exposure.Consider type of exposure.

– Consider size of the exposure area and Consider size of the exposure area and nature of COCs.nature of COCs.

– Reference mass, volume calculations made Reference mass, volume calculations made earlier. earlier.

– Evaluate technologies.Evaluate technologies.

Reporting and WDNR Reporting and WDNR ReviewReview• Report memorializes Report memorializes

efforts and publicly efforts and publicly communicates results.communicates results.– Can be very large Can be very large

(months to prepare and (months to prepare and review).review).

– Serves as basis for next Serves as basis for next phase.phase.

Reporting and Agency Reporting and Agency ReviewReview• WDNR review integral.WDNR review integral.

• Next phase designed and process Next phase designed and process repeated.repeated.

Summary of StepsSummary of Steps• Research historical land use.Research historical land use.

• Develop/refine analytical program.Develop/refine analytical program.

• Identify appropriate investigation Identify appropriate investigation techniques. techniques.

• Develop work plan.Develop work plan.

• Agency interaction.Agency interaction.

• Perform vendor selection and Perform vendor selection and contracting.contracting.

• Mobilize and set-up field operations.Mobilize and set-up field operations.

• Sample potentially impacted media. Sample potentially impacted media.

• Review analytical data for usability.Review analytical data for usability.

• Hydrogeologic review.Hydrogeologic review.

• Evaluate media-specific Evaluate media-specific characteristics.characteristics.

• Evaluate results against realistic Evaluate results against realistic exposure scenarios for humans and exposure scenarios for humans and environmental receptors.environmental receptors.

• Evaluate if corrective measures are Evaluate if corrective measures are warranted.warranted.

• Report findings and recommend next Report findings and recommend next steps.steps.

• Agency interaction and repeat steps Agency interaction and repeat steps for next phase of investigation, as for next phase of investigation, as necessary.necessary.

Questions?Questions?

Next MeetingNext Meeting

Date:Date:

Time:Time:

Place:Place:

Subject:Subject:

March 26, 2002March 26, 2002

7:00 p.m.7:00 p.m.

Northern Great Lakes Northern Great Lakes Visitors CenterVisitors Center

Results of the Phase I Results of the Phase I InvestigationInvestigation