1 of 99 The EPA 7-Step DQO Process Step 1 - State the Problem Presenter: Sebastian Tindall (60...

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The EPA 7-Step DQO Process

Step 1 - State the Problem

Presenter:Sebastian Tindall

(60 minutes)(15 minute Morning Break)

Day 2 DQO Training CourseModule 1

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Objective

Based on comprehensive Scoping, to be able to develop, for a specific project:

1. a list of contaminants of concern,

2. a conceptual site model (CSM),

3. a problem statement(s)

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Generic Flow Chart

Information IN Actions Information OUT

From Previous Step To Next Step

Information

OUT to

Next Step

Information IN

From Previous

StepActions

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Information

OUT to

Next Step

Information IN

From Previous

StepActions

Added information is presented in bubblesto explain how to implement an action orexplain items to consider.

Generic Flow Chart

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Examples

There are two types of examples found in this training– The general example

CS

– The case study that is used to show the flow of the logic. The same case study is used for each step. It is called “Heli-101 Pad” and has the icon in the upper right corner.

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Step Objective:

To clearly define the Problem so that the focus of the Project will be unambiguous

Step 1: State the Problem

Step 4: Specify Boundaries

Step 2: Identify Decisions

Step 3: Identify Inputs

Step 1: State the Problem

Step 5: Define Decision Rules

Step 6: Specify Error Tolerances

Step 7: Optimize Sample Design

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Step 1a - State the ProblemInformation IN Actions Information OUT

From Previous Step To Next StepIdentify the DQO Team and define each member’s roles and responsibilities

Continue activities

Identify the decision makers and define each member’s roles and responsibilities

Identify the Stakeholders and determine who will represent their interests

Planning Meeting

Identify available resources and relevant deadlines

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Continue activities



Planning Meeting

Identify available resources and relevant deadlines• The DQO Team is the technical group that

will develop the DQOs for the project• The number of members will be directly related to the size and complexity of the problem

Step 1a - State the Problem

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Continue activities



Planning Meeting


DQO Team may include:• Chemist• Hydrogeologist• Engineer• Safety Specialist• Statistician• Modeler• Quality Assurance (QA)/ Quality Control (QC) Specialist• Etc.


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Name Organization Area of Technical Expertise

Dr. Phil Meyer State University Technical Lead/Facilitator

Deborah Howard A.J. Consulting Regulatory Analysis

Pete Weiss A.J. Consulting Environmental Engineer

Samantha R. Rigley Detection Laboratories, Inc. Chemist

John Soilman A.J. Consulting Geologist

Rusty Rushman A.J. Consulting Risk Assessor

Susan Blackbird A.J. Consulting Statistician

Lt. Dan Mansel Army Corps of EngineersProject Manager

provide site history

DQO Team Members CS

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Continue activities



Planning Meeting


• Stipulate the anticipated budget, available personnel, and contractual vehicles to be used• Enumerate any deadlines for completion of the study and any intermediate deadlines that may need to be met


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Project Activities Budget Contractual Vehicle Milestone Dates

DQO summary report $15,000 Subcontract 1/1/02

Sampling and analysis plan $20,000 Subcontract 3/1/02

Sample analyses $45,000 Subcontract 6/30/02

Data quality assessment $8,000 Subcontract 7/21/02

Decision document $15,000 Subcontract 9/1/02

Available Resources and DeadlinesCS

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Budget and Milestones

As is the case in the example, budgets and schedules are often set without any systematic planning

It is preferred that the DQO Process be performed well before the budget and schedule are established

Budgets for implementing the DQO Process are a must

The results of the DQO Process can then be used to set the remaining project schedule and budget

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Continue activities



Planning Meeting


Decision makers are those that have authorityover the study and are representatives of:• Department of the Army• Environmental Protection Agency• State Regulatory Agency


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Name Organization Role and Responsibility

Col. Stanely Carter U.S. Army Base Commander

Dempsey Fitzgerald U.S. EPA Federal Regulator

Lt. Dan Mansel Army Corps of Engineers Project Manager

Jack Nottingham State Office of the Environment State Regulator

Decision Makers CS

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Continue activities



Planning Meeting


Decision Makers:• Seek, consider, and represent the concerns of the Stakeholders• Have the ultimate authority for making final decisions based

on the recommendations of the DQO Team


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Continue activities



Planning Meeting

Identify available resources and relevant deadlinesStakeholders are groups or individuals that will be impacted

by the decisions made as a result of the DQO Process.


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Name Organization Represented By

Citizens for a CleanerCommunity

Local Special Interest Group Tom Ahlgreen

Associated Native Americans Local Native American’s Group Gary Silverhawk

Sierra Club National Special Interest Group Jessica Gonzalez

Mayor/City Council Local Community Martin Larson

Stakeholders CS

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Scoping Process Results

Scoping Process Issues

Scoping Process Results:

• Collect site history, process knowledge,

• Summarize existing analytical data

• Specify areas to be investigated

• Summarize all recorded spills and releases

• Document applicable regulations

• Current housekeeping practices

• Current local environmental conditions

Administrative and logistical elements

Step 1b - State the Problem

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Remedial Action Soil Process Knowledge

Heli-101 flight pad used 1970-1995 Used to load, unload and maintain aircraft Used oils and fuels spilled and washed off

pad, draining to the surrounding soil 1980 used as staging area for transformer

and motor oils

CS

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1990s used as area to decon equipment from the Gulf War

Collection sump used to capture pad rinsate from Gulf War

Equipment was washed to remove depleted uranium

1995 trace uranium found on pad

CSRemedial Action Soil Process Knowledge (cont.)

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Summary of Existing Data All data collected from surface soil (0-6”) Summary of existing total petroleum hydrocarbon

(TPH) data See next table All TPHs were below regulatory limit of 100 mg/kg PCBs detected in 2 of 5 samples and were above state

limit of 1 mg/kg No other volatiles, semivolatiles, or metals (excluding

Pb, U) were detected above background The Base ground and surface water have not detected

contamination

CS

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RI/FS Data –Inorganics and TPH(surface soil samples)

CS

Sample IDLead

(mg/kg)Uranium(mg/kg)

TPH(mg/kg)

HELI-101-A 18 102 4.0HELI-101-B 27 96 3.0HELI-101-C 15 78 2.5HELI-101-D 10 86 2.0HELI-101-E1 12 112 0.03 UHELI-101-E2(duplicate of HELI-101-E1)

15 92 0.03 U

HELI-101-blk(Field Blank)

1.0 U 50 U 0.03 U

Sample Average* 16.7 92.8 2.3Standard Deviation 6.4 10.6 1.5Relative Standard Deviation 39% 11% 64%U = Not detectedJ = Estimated Concentration* Sample average includes duplicate sample (but not the blank)

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RI/FS Data –PCBs (surface soil samples)

CS

Sample IDAroclor

1016(mg/kg)

Aroclor1221

(mg/kg)

Aroclor1232

(mg/kg)

Aroclor1242

(mg/kg)

Aroclor1248

(mg/kg)

Aroclor1254

(mg/kg)

Aroclor1260

(mg/kg)HELI-101-A 0.03 U 0.03 U 0.03 U 0.03 U 0.03 U 0.05 J 0.03 U

HELI-101-B 0.03 U 0.03U

0.03 U 0.7 J 0.03 U 0.20 1.5

HELI-101-C 0.03 U 0.08 J 0.05 J 0.7 J 0.03 U 0.03 U 0.03 U

HELI-101-D 0.03 U 0.08 J 0.06 J 0.7 J 0.03 U 0.30 2.0

HELI-101-E1 0.03 U 0.17 0.09 J 0.9 J 0.03 U 0.20 0.75

HELI-101-E2(duplicate ofHELI-101-E1)

0.03 U 0.03 U 0.10 J 0.7 J 0.03 U 0.35 1.1

HELI-101-blk(Field Blank)

0.03 U 0.03 U 0.03 U 0.03 U 0.03 U 0.03 U 0.03 U

SampleAverage*

0.03 U 0.06 0.05 0.58 0.03 U 0.17 0.89

StandardDeviation

0 0.03 .03 0.31 0 0.13 0.88

RelativeStandardDeviation

0% 53% 54% 54% 0% 74% 99%

U = Not detectedJ = Estimated Concentration* Sample average includes duplicate sample (but not the blank)

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Areas to be InvestigatedCS

Plan View

Former PadLocation

RunoffZone

0 50 100 150 ft 0 15 30 46 m

BufferZone

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Summary of Spills and Releases*

Pad is ~75’ in diameter Add 50’ to include the Run-off area (d=125’) Buffer Zone is ~265’ in diameter, with Pad

centered within Area of Pad is 4,418 ft2

Area of Pad + Run-off Area = 12,272 ft2

Area of Buffer Zone is 42,884 ft2 (excluding Pad and Run-off area)

*Does not include layback area

CS

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Volume of Pad & Run-off zone, 0-6”, is 227 yd3

Volume of Buffer Zone, 0-6”, is 794 yd3 (excluding Pad and Run-off area)

Volume of Pad & Run-off zone, 6”-10’, is 4,318 yd3

Volume of Buffer Zone, 6”-10’, is 15,089 yd3 (excluding Pad area)


Summary of Spills andReleases* (cont.)

CS

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No releases recorded before 1977 (e.g., before adopting RCRA)

Drum inventories from 1980s were imprecise Reports from 1990s were sparse and not

declassified. One report did include uranium data from the sump at 450 mg/L.

Interviews indicate that predominant metals were Pb and U. U was depleted.

CS


Summary of Spills andReleases* (cont.)

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Current Conditions

Housekeeping practices– physically barricaded to prevent use

Site conditions and local environment– Pad is removed, land is barren without

vegetation– Avg. rainfall ~20 in./yr– Groundwater at ~50 ft below grade– Temperatures range 12 to 98°F– No endangered species– No cover or water collection system

CS

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Areas to be investigated:– exclude surface or groundwater– exclude biota (covered by overall base program)– include soil via direct exposure– include soil area/volume

Current Conditions (cont.) CS

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Scoping Issues

The degree and extent of soil contamination reported from the RI/FS is questionable

There are different opinions as to whether multiple constituents of interest exist and whether the constituents are present above regulated levels at the site

CS

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From Previous Step To Next StepConduct interviews with decision makers and Stakeholders to determine their:

•Objectives

•Requirements (applies to decision makers only)

•Concerns

Specify interview issues

Hold Global Issues Meeting to resolve scoping and interview issues



Continue activities

Any differences in interviewees’ objectives, requirements or concerns are listed as issues.

Step 1c - State the Problem

Note

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Interview Issues

Shipment of wastes from the base could impact the local community: Local authorities expressed a concern over the transport of hazardous materials from the Base. Of particular concern was the impact to community traffic flow and the potential for an accidental release.

CS

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Suitability/protectiveness of cleanup standards: Current State regulations regarding cleanup levels have been questioned by local stakeholders (special interest groups) as to their degree of protectiveness. Current special interest groups have argued that contamination, at any level, poses an unnecessary and unacceptable threat to human health and the environment. These special interest groups have asserted that the Base has a moral obligation to remove all detectable contamination in order to ensure that the surrounding community and wildlife is protected.

Interview Issues (cont.) CS

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Schedule delays, cost overruns, lack of sufficient sample data: The Base has expressed concerns over the involvement of special interests, particularly, those who would require that the Base perform potentially unneeded cleanup operations that are well beyond the scope and intent of the law. The Base has also expressed a concern that the operation be managed within the schedule and costs for which the project has been assigned. There is also a need to collect data that will be sufficient for its intended purpose; site closure/risk assessment input, or, designation of the waste for cleanup and disposal.

CSInterview Issues (cont.)

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Land Use: – Base commander believes land use is industrial

– EPA believes land use should be residential

CSInterview Issues (cont.)

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•Objectives


•Concerns





Continue activities

Global Issues Meeting:Resolve any outstanding scoping issues and/or interview issues with decision makers.


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CSExample Heli-101 Pad Objectives, Requirements, and Concerns

Responsible Party Objectives Requirements Concerns

John Ahlgreen,Citizens for aCleaner Community

Elimination ofenvironmental risk

Suitability/protectiveness ofcleanup standards.

Col. Stanely Carter,Base Commander

Demonstrate sitecompliance or needfor further cleanup

Comply with regulations.

Schedule delays, Cost overruns, Lack of sufficient sample

data

Dempsey Fitzgerald,U.S. EPA


Lower overall risk tohuman health and theenvironment.

Lack of sufficient sample data, orcollection of data not suited forrisk assessment.

Martin Larson,Mayor/City Council

Protection of theneighboringcommunity andcomply with localordinances.

Shipment of wastes from the basecould impact the localcommunity.

Lt. Dan Mansel,Army Corps ofEngineers


Schedule delays, Cost overruns, Lack of sufficient sample

data

Jack Nottingham,State Office of theEnvironment


Lower overall risk tohuman health and theenvironment.

Lack of sufficient sampledata, or collection of data notsuited for risk assessment.

Impacts to the localcommunity and stateinterests.

Gary Silverhawk,Associated NativeAmericans

Return of the land toits native state andclean up tobackground levels

Suitability/protectiveness ofcleanup standards.

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Global Issues Meeting Scoping Issue:

– The degree and extent of soil contamination reported from the RI/FS is questionable

Resolution:– Currently available historical information (existing data) was

collected with the intent to characterize the site for disposal according to RI/FS considerations. However, such characterization data are not sufficient to support a decision for site closure or a decision to conduct additional remedial action if deemed necessary.

CS

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Interview Issue: – Shipment of wastes from the Base could impact the local

community: Local authorities expressed a concern over the transport of hazardous materials from the Base. Of particular concern was the impact to community traffic flow and the potential for an accidental release.

Global Issues Meeting (cont.)CS

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Resolution: – The only quantities planned for off-site shipment are

small quantities of slightly contaminated soil and/or water that would be sent to an independent analytical laboratory. Large shipments of hazardous substances are not planned. All Department of Transportation regulations will be followed as applicable. Shipments will be timed for off-peak traffic hours. If a large-scale soil remediation project is spawned as a result of the sampling effort, waste shipments will be planned at that time, and in such a way as to minimize the impact to the community.

CS

Global Issues Meeting (cont.)

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Interview Issue:

– Suitability/protectiveness of cleanup standards: Current State cleanup standards are questioned by the interest groups. The concern is that the standards are not protective of the wild life and community.

Resolution:

– The State and Federal agencies have explained the risk assessment process to the interest groups. Compliance with these risk levels will be protective. The State has encouraged the special interest groups to take their concerns to the legislature. Based on more information related to the risk assessment process, the interest groups indicated that the approach was logical.

CS


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Interview Issue: – Schedule delays, cost overruns, lack of sufficient sample

data: The Base has expressed concerns over the involvement of special interests, particularly, those who would require that the Base perform potentially unneeded cleanup operations that are well beyond the scope and intent of the law. The Base has also expressed a concern that the operation be managed within the schedule and costs (presented later in this example) for which the project has been assigned. There is also a need to collect data that will be sufficient for its intended purpose; site closure/risk assessment input, or, designation of the waste for cleanup and disposal.

CS


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Resolution:

– The Base is relying on the DQO Process to determine the most cost-effective and technically defendable means for collection of samples. Furthermore, the Base will be using the DQO Process to document agreement of the sampling strategy with the regulators and local community as a means of reducing base liability. The SAP generated from the DQO effort will result in data collection sufficient for its intended purpose.

CS


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Interview Issue:

– Data will not be of sufficient quality for risk assessment: Regulators are concerned that previous data are not of the quality to support risk assessment.

Resolution:

– Regulators will be participants in the DQO Process which defines the data and quality requirements. In addition, they may take split samples at the same time sampling is performed.

CS


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Interview Issue:

– Conflicting land uses (industrial vs. residential): Regulators believe the land use is residential which decreases the allowable risk (10-6 as opposed to 10-5) and may result in allowing higher concentrations to remain in the soil. Base command believes the land use is industrial.

CS


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Resolution:

– For all government facilities a federal facility agreement (FFA) is signed between the EPA/State and the federal agency that owns the site (e.g., DOE or military). By law, this agreement indicates that the federal agency owning the site can designate the land use or agree to negotiate the land use. The FFA indicated that the military would designate the land use, thus, it will be industrial.

CS


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Global Issues Resolutions

Conceptual Site Model

Problem StatementEstimate COPC distributions

Provide rationale for COPC exclusions

Create final list of COPCs with rationale for inclusions

Specify release mechanisms

Identify fate and transport mechanisms

List potential receptors

Discuss decision drivers

Write CSM Summary Narrative

Identify COPCs

Step 1d - State the Problem

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Identify COPCs

Define the total list of COPCs :Identify:

• Source of contamination: Reactor fuel rods• Type of contamination from each source: Fission products• Specific COPCs Am-241, Co-60, Cs-137


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CSExample Heli-101 Pad -Total List of COPCs for Each Waste Stream

Waste Stream

Known orSuspected

Source(s) ofContamination(e.g., equipment

maintenance,storage)

Type ofContamination

(General)(e.g., petroproduct)

COPCs(Specific)

(e.g., Lead, PCBs)

Aircraft FuelingOperations

Leaded andUnleaded Fuel

TPHLead

AircraftMaintenanceOperations (OilChange)

Used Motor Oil TPHLead

Maintenance ofthe Aircraft

AircraftMaintenanceOperations (CoolantChange)

Used Coolant Ethylene Glycol

1,2,2-Trichlorotrifluoroethane (Freon 113)

Used Motor OilStorage

Used Motor Oil TPHLead

Staging Area forOils

Used TransformerOil Storage

Used TransformerOil

PCBs

Decontaminationof SpecialEquipment

Steam Spray runoff Heavy Metals Antimony, Arsenic, Beryllium, CadmiumCobalt, Copper , Iron, Thallium, TitaniumLead, Phosphorous , Selenium , TungstenUranium (total), Vanadium, Zinc,Zirconium

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Identify COPCs

Identify COPC Exclusions:• Develop rationale for the exclusion of any of the COPCs• Document the rationale for any exclusions

Example: - Isotope with short half-life- No health or ecological risk


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Identify COPCs

Consider the following questions:1. Was the compound/element ever used at the site?2. Does the compound react with water and thus no longer exist?3. For waste, does the pH of the matrix degrade the compound?4. Is the compound volatile and thus evaporate?


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COPC Exclusions CS

Waste Stream COPCs Rationale for Exclusion

Ethylene GlycolNot detected during RI/FS process. Eliminated fromfurther consideration in the RI/FS. Water soluble anddegrades in environment

Maintenance ofthe Aircraft

1,2,2-Trichlorotrifluoro-ethane(Freon 113)

This compound is highly volatile and is likely to haveevaporated at the surface before traveling through thesoil to groundwater. Compound not detected usingfield analytical method


No exclusions NA


Antimony, Arsenic, BerylliumCadmium, Cobalt, CopperThallium, Titanium,PhosphorousSelenium, Tungsten, Vanadium,Zinc, Zirconium

According to RI/FS data, these metals were not foundin quantities exceeding the site background, or werenot present above regulatory thresholds.

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Identify COPCs

Identify the Final List of COPCs


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Final List of COPCs CS

Waste Stream COPCs Rationale for Inclusion

Maintenance of theAircraft

TPH

Lead


TPH

Lead

PCBs


Lead

Uranium

Detected in quantities potentially posing increase health risks.

Lead attributable to one waste stream could not be distinguishedfrom lead attributable to other waste streams.Uranium has no ‘established risk information in the current stateregulations’, therefore special risk analysis is needed.Weapons contained depleted uranium, therefore no isotopicanalysis is needed.

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Identify COPCs

How the release occurred?Still occurring?Single large release?Small release over long time?Stack release of gases?Contaminated debris?


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Release Mechanisms How the COPCs arrived at the facility COPCs were typically washed from spills on the helicopter

pad and into the surrounding soil. Because all remaining structures have been removed during pad decommissioning, the only physical component in the CSM is environmental media (e.g., gravel, sand, and soil). The soil is suspected of being contaminated by spilled material that was washed from the pad at various times during the pad’s history. The physical components of the site include surface and subsurface soils and gravel within the known boundaries of the spill.

CS

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Identify COPCs

Begin to evaluate the fate & transport of COPCs

Begin to evaluate the distribution of COPCs


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Identify COPCs

Step 1d - State the ProblemUsed to make assumption on the distribution (lateral/vertical) of COPCs

Dependent on:• Types of COPCs expected• How they arrived• Amount of time since the release• Environmental conditions since the release• Effect of natural processes• Wind, weather, erosion, re-charge, etc.

Types of sampling media:• Soil• Concrete• Groundwater• Gravel• Etc.

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Fate and Transport How has fate and transport mechanisms affected

the COPCs

Unimpeded access is assumed for all sampling media. Because the site has been exposed to weather (precipitation) since the spill occurrences, some transport into the subsurface is likely to have occurred; therefore, to support clean site confirmation, the underlying soil is included within the boundaries of the site.

CS

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Identify COPCs

Examples of receptors are • Humans• Plants• Animals


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Receptors

Future land use– It is anticipated that the land must be released for

industrial use at some future time. Therefore, potential receptors include human workers as well as the surrounding biota (e.g., shrubbery).

CS

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Data for groundwater wells on the military base have not indicated contamination attributable to this site

This leads one to believe that there is no groundwater contamination, thus the groundwater ingestion pathway is not complete and does not require added investigation. Industrial workers will use sanitary water from the city.

Potential ReceptorsCS

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Original SoilSurface

Total VadoseZone Depth

Previous PadLocation

10 ft

CSPotential Receptors (cont.)

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Identify COPCs

Spatial and frequency distributions

This is key point for determining the number of samples


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Football Field

One-AcreFootball Field

30'0"

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Spatial Distribution - Football Field

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Probability Density Function

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Identify COPCs

Liquid spill Plume model (decreasing with distance)Burn pit Lateral and vertical heterogeneityTank sludge Lateral homogeneity/vertical heterogeneityFill What information is available about the fill?Concrete Drivers? Air; Water; Contact


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Spatial Surface Soil Sample Results

B (27, 96, 3, 1.5)

D (10, 86, 1, 2.0)

E2 (15, 92, 0.03, 11)E1 (12, 112, 0.03, 0.75)

C (15, 78, 2.5, 0.03)

A (18, 102, 4, 0.03)

Letter = sample point

Concentrations (Pb, U, TPH, Aroclor 1260)

CS

Plan View

Former PadLocation

RunoffZone

0 50 100 150 ft 0 15 30 46 m

BufferZone

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Distributions Presumed Spatial Distributions of the COPCs

– The pad was washed, and therefore the area where the edge of the pad once existed is likely to have higher concentrations than the area further away from the previous edge of the pad. It cannot be assumed that contamination decreases with depth from the surface. However, contamination is expected to decrease with depth; therefore, deeper soils are assigned a lower probability of being contaminated.

– The probability of contamination will be scaled within a range bounded by the arbitrary lateral and vertical boundary to be determined during sample optimization (Step 7). This is because the amount of data collected from the RI/FS is not sufficient to define the physical boundaries of the expected residual contamination. The previous RI/FS did not use the DQO Process.

CS

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Frequency DistributionConcentration,

pCi/g ColorNumber of Marbles

1 N/A 02 N/A 03 Clear 94 White 785 Green 2696 Red 3737 Yellow 2258 Blue 439 Black 3

10 N/A 0

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Frequency DistributionCS

Pb Concentration(mg/kg)

Frequency

0-7 07-14 2

14-21 221-28 128-35 0

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HistogramCS

0

1

2

3

Pb Concentration (mg/kg)

Fre

qu

en

cy

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Histogram (cont.)CS

0

1

2

3

4

U Concentration

Fre

qu

en

cy

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CSHistogram (cont.)

0

1

2

3

4

0 1.7 3.4 5.1 6.8

TPH Concentration

Fre

qu

en

cy

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CSHistogram (cont.)

0

1

2

3

Arochlor 1260

Fre

qu

en

cy

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Mo = Md = Mn

Normal

Mo Md Mn

Lognormal

M0 = modeMd = medianMn = mean

% of time when x < is high,(when n is small)

Distribution Curves

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Identify COPCs

Identify driver compounds (e.g., based on greatest risk or movement or half-life)Examine concentration range and compare to action limit(e.g., far below or above action limit, near action level)


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Identify COPCsOverall objectives of the project:

• Is the decision risk based?• Waste characterization based?• Regulatory restraints?• Future land uses?• Pilot study?• Remedial action?• Monitoring effort?• Characterization effort?• All potential data uses/users identified?


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Decision Drivers Future land use

– Effect of residual contamination on the ecosystem was not previously considered

– Direct long-term industrial land use was not considered in the past risk models

– All parties agreed to use industrial land use as the scenario

– If concentrations are below the levels based on industrial use, the remediation will be complete, otherwise added remediation will be needed

CS

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Identify COPCsUse information gathered from the scoping process,decision maker interviews and the Global Issues Meeting to develop a CSM

The CSM may be presented in the following forms:• Narrative statement• Graphical • Tabular


The CSM narrative summary states clearly the current understanding of the condition of the site

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CSM Narrative

The Heli-101 Pad and the surrounding soil (surface and underlying) extending laterally up to 95 ft in any direction from the perimeter of the pad and up to a depth of 10 ft constitutes the conceptual model for the contaminated site. It is graphically depicted in the plan view and section view in the following section. Surface soil is defined as soil up to a depth of 6 in. and underlying (subsurface) soil is defined as soil up to a further depth of 10 ft.

(Etc.………………………………………..)

CS

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Plan View

Section View

Former PadLocation

RunoffZone

0 50 100 150 ft0 15 30 46 m

Former PadLocation

RunoffZone

Grade Level

0 50 100 150 ft0 15 30 46 m

Vertical not to scale

BufferZone

CSM Spatial GraphicalCS

BufferZone

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Overview of the Receptor Pathway(CSM) Tabular

PrimarySources

PrimaryRelease

Mechanism

SecondarySources

SecondaryRelease

MechanismPathway

Oil andFuel

Residualfrom

Equipment

Spills

Cleaning

Soil

Dust

StormWaterRunoff

Wind

SurfaceWater &

Sediments

ReceptorHuman Biota

Exposure Route A

rea

Res

iden

tsS

i te

visi

tors

Terr

estr

ial

Aqu

atic

IngestionInhalation X X XDermal Contact

Ingestion X X XDermal Contact X X X

Ingestion X X X XInhalationDermal Contact X X X X

CS

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Identify COPCs

The goal of the DQO Process is to develop a sampling design that will confirm or reject the CSM.


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Problem Statements

The CSM is used to constrain the problem statement(s)

The Problem Statement(s) allows the planning to be focused on issues that must be resolved with data and makes the problem unambiguous

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Identify COPCs

A concise problem statement describes:• The problem as it is currently understood• The conditions that are causing the problem


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Problem Statement Format

General Format: In order to [support decisions for site

remediation/better understand the nature of the waste/establish a basis for materials management] data are required that define [the nature and extent of contamination/the constituents of concern/the source and characteristics of the materials].

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In order to confirm that the on-site in-situ GC/MS analysis can replace method 8260B results for use in final verification of closure, data regarding volatiles using both methods are needed.

In order to determine whether the concrete should be disposed at a TSCA incinerator, data regarding the PCBs in the concrete surface are needed.

Problem Statement Examples

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Process knowledge indicates that there would have been low plutonium concentrations in the wastes disposed through the tank and relatively few other radionuclides should be present. Limited sampling of the sludge indicates that plutonium is distributed within strata throughout the tank; however, this distribution is somewhat heterogeneous and ill-defined. Characterization data are required to evaluate the need for an early removal action and, as required, to determine the appropriate methods for (1) removal of the sludge from Tank Y, (2) stabilization and packaging of the waste, and (3) sludge disposal.

‘Typical’ Problem Statement Example

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In order to determine whether the residual soils at the site are contaminated, data regarding potential contaminants in the surface and underlying soils are needed.

Problem Statement CS

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Step 1 Summary Scoping is the most important activity Adequate resources (time, money, people) must be

provided for scoping Adequate resources must be provided for the DQO

Process Identify the decision makers’ objectives, requirements,

and concerns Performing interviews allows the facilitator to

understand each decision maker’s objectives and requirements

Resolving global issues allows technical staff to focus on providing defensible designs

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Global issues include land use and interpretation of regulations

Step 1 Summary (cont.)

Logic for inclusion and exclusion of COPCs must be documented

It is possible to greatly decrease the number of COPCs based on sound technical logic

Remember, if there is no receptor there is no risk CSM is based on scoping The DQO Process goal is to test the CSM CSM allows one to focus on problems that are

resolved by data/information

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Continue activities



Planning Meeting



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•Objectives


•Concerns





Step 1b - State the Problem



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Continue activities

Scoping Process Results:

• Collect site history, process knowledge,

• Summarize existing analytical data

• Specify areas to be investigated

• Summarize all recorded spills and releases

• Document applicable regulations

• Current housekeeping practices

• Current local environmental conditions

Administrative and logistical elements


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Identify COPCs


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End of Module 1

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1 of 99 The EPA 7-Step DQO Process Step 1 - State the Problem Presenter: Sebastian Tindall (60...

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