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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Information IN Actions Information OUT
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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Information IN Actions Information OUT
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
Scoping Process Results
Scoping Process Issues
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Information IN Actions Information OUT
From Previous Step To Next Step
Scoping Process Results
Scoping Process Issues
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
2 - Approaches (cont.)
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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
2 - Approaches (cont.)
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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)
*Does not include layback area
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.
*Does not include layback area
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.
Interview Issues (cont.)
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Land Use: – Base commander believes land use is industrial
– EPA believes land use should be residential
Interview Issues (cont.)
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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
Demonstrate sitecompliance or needfor further cleanup
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
Demonstrate sitecompliance or needfor further cleanup
Schedule delays, Cost overruns, Lack of sufficient sample
data
Jack Nottingham,State Office of theEnvironment
Demonstrate sitecompliance or needfor further cleanup
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.
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.
Global Issues Meeting (cont.)
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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.
Global Issues Meeting (cont.)
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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.
Global Issues Meeting (cont.)
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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.
Global Issues Meeting (cont.)
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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.
Global Issues Meeting (cont.)
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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.
Global Issues Meeting (cont.)
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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
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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
Questions?