1 of 63 The EPA 7-Step DQO Process Step 1 – Problem Statement DQO Case Study Presenter: Sebastian...

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The EPA 7-Step DQO Process

Step 1 – Problem StatementDQO Case Study

Presenter: Sebastian Tindall

45 minutes

DQO Training CourseDay 3

Module 18

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DQO Case Study

Heli-101 Flight Pad

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Information 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

Step 1a - State the Problem

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From Previous Step To Next Step

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

Step 1b - State the Problem

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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

Scoping Process Results

Scoping Process Issues

Step 1c - State the Problem



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From Previous Step To Next Step



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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2 Approaches Approach 1: Traditional lab methods Approach 2: Field analytical methods with

final confirmation via lab methods– Select onsite methods that focuses on driver

COPCs (e.g., risk drivers, transport drivers, etc.)

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2 Approaches

Approach 1

Use predominantly fixed traditional laboratory analyses and specify the method specific details at the beginning of the DQO Process and do not change measurement objectives as more information is obtained

This approach will contain serious flaws.

Note: Students are expected to point out these flaws as the class progresses.

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Approach 2

Allow more field decisions to meet the measurement objectives and allow the objectives to be refined in the field using dynamic work plans (Managing Uncertainty approach)

This approach will attempt to overcome the serious flaws shown in Approach 1.

2 - Approaches (cont.)

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Approach 2 - Dynamic Work Plans – Real-time, decision making in the field allows

for a seamless flow of site activities resulting in fewer mobilizations

– Requires more flexible contracting approach– Requires experienced, well-trained field team

(e.g., geologists, chemists and statisticians) either in the field or able to receive and process electronic data in real-time


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Approach 2 – Allows collection of more data in real-time– Allows real-time decisions to be made– Must have flexible but established decision

trees approved by decision makers ahead of time

– Need general statements of measurement quality that will be interpreted by field team

– May be more costly due to higher level of expertise required but…more defensible

– Overcomes the Classical Statistical Burdens


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Objective

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

1. a list of Contaminants of Potential Concern,

2. a conceptual site model (CSM),

3. a problem statement(s)

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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

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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

Sampling & 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 Deadlines

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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

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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

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Remedial Action Soil Process Knowledge

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

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

motor oils

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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

Remedial 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

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

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)

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 InvestigatedPlan 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 zone (d=125’) Buffer zone is ~265’ in diameter, with Pad

centered within Area of Pad is 4,418 ft2

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

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

*Does not include layback area

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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 zone)

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

Volume of Buffer zone, 6”-10’, is 15,089 yd3 (excluding Pad and Run-off zone)


Summary of Spills andReleases* (cont.)

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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.


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

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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.)

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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

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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.

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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.)

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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.


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Land Use: – Base commander believes land use is industrial

– EPA believes land use should be residential


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Example 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.

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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.)

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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.


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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.


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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.


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Resolution:

– The Base is relying on the DQO Process to determine the most cost-effective and technically defensible means for collection of samples. The DQO Process will specify the decision makers’ tolerable limits on decision errors, which are used for limiting uncertainty in the data and therefore reduce the chance of unnecessary cleanup. 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.


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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.


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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.


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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.


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Example 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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COPC Exclusions; part 2

Waste Stream COPCs Rationale for Exclusion

Ethylene Glycol Not detected during RI/FS process. Eliminated from further consideration in the RI/FS. Water soluble and degrades in environment.

Maintenance of the Aircraft

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

This compound is highly volatile and is likely to have evaporated at the surface before traveling through the soil to groundwater. Compound not detected using field analytical method.

Staging Area for Oils

No exclusions NA

Decontamination of Special Equipment

Antimony, Arsenic, Beryllium Cadmium, Cobalt, Copper Thallium, Titanium, Phosphorous Selenium, Tungsten, Vanadium, Zinc, Zirconium

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

These metals do not adsorb to gravels and sands found at this site and data from GW does not show these metals.

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Final List of COPCs

Waste Stream COPCs Rationale for Inclusion

Maintenance of theAircraft

TPH

Lead

Staging Area forOils

TPH

Lead

PCBs

Decontaminationof SpecialEquipment

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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Release Mechanisms How the COPCs arrived at the site

Motor pool type supplies and products were transported to the site to aid in maintenance operations. Transformers containing PCBs were stored at the site. COPCs were typically washed from spills on the helicopter pad and into the surrounding soil.

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Fate and Transport How has fate and transport mechanisms affected

the COPCs

The soil is suspected of being contaminated by spilled material that leaked or 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. 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.

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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).

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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 Receptors

50 of 63Groundwater

Original SoilSurface

Total VadoseZone Depth

Previous PadLocation

10 ft

Potential Receptors (cont.)

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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)

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.

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Frequency Distribution

Pb Concentration(mg/kg)

Frequency

0-7 07-14 2

14-21 221-28 128-35 0

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Histogram

0

1

2

3

Pb Concentration (mg/kg)

Fre

qu

en

cy

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Histogram (cont.)

0

1

2

3

4

U Concentration

Fre

qu

en

cy

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Histogram (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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Histogram (cont.)

0

1

2

3

Arochlor 1260

Fre

qu

en

cy

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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

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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.………………………………………..)

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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 Graphical

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

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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

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End of Module 18

Thank you

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