The 7-Step DQO Process

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DQO Training Course Day 3Module 18
The EPA 7-Step DQO Process
Step 1 Problem StatementDQO Case Study
Presenter Sebastian Tindall
45 minutes
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DQO Case Study
Heli-101 Flight Pad
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Step 1a - State the Problem
Information IN Actions
Information OUT From Previous Step
To Next Step
Identify the DQO Team and define each members
roles and responsibilities
Identify available resources and relevant
deadlines
Planning Meeting
Continue activities
Identify the decision makers and define each
members roles and responsibilities
Identify the Stakeholders and determine who will
represent their interests
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Step 1b - State the Problem
Information IN Actions
Information OUT From Previous Step
To Next Step

• 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
Continue activities
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Step 1c - State the Problem
Information IN Actions
Information OUT From Previous Step
To Next Step

• Conduct interviews with decision makers and
  Stakeholders to determine their
• Objectives
• Requirements (applies to decision makers only)
• Concerns

Scoping Process Results Scoping Process Issues
Specify interview issues
Scoping Process Results Scoping Process Issues
Hold Global Issues Meeting to resolve scoping and
interview issues
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Step 1d - State the Problem
Information IN Actions
Information OUT From Previous Step
To Next Step
Identify COPCs
Provide rationale for COPC exclusions
Create final list of COPCs with rationale for
inclusions
Scoping Process Results Scoping Process
Issues Global Issues Resolutions
Specify release mechanisms
Conceptual Site Model
Identify fate and transport mechanisms
List potential receptors
Problem Statement
Estimate COPC distributions
Discuss decision drivers
Write CSM Summary Narrative
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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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2 - Approaches (cont.)

• 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.

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2 - Approaches (cont.)

• 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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2 - Approaches (cont.)

• 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 butmore 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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DQO Team Members
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Available Resources and Deadlines
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Decision Makers
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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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Remedial Action Soil Process Knowledge (cont.)

• 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

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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)
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RI/FS Data PCBs (surface soil samples)
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Areas to be Investigated
Plan View
Former Pad Location
Buffer Zone
Runoff Zone
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Summary of Spills and Releases

• Pad is 75 in diameter
• Add 50 to include the Run-off zone (d125)
• 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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Summary of Spills andReleases (cont.)

• 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
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Summary of Spills andReleases (cont.)

• 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
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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 98F
• No endangered species
• No cover or water collection system

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Current Conditions (cont.)

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

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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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Interview Issues (cont.)

• 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.

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Interview Issues (cont.)

• 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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Interview Issues (cont.)

• Land Use
• Base commander believes land use is industrial
• EPA believes land use should be residential

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(No Transcript)
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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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Global Issues Meeting (cont.)

• 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.

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Global Issues Meeting (cont.)

• 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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Global Issues Meeting (cont.)

• 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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Global Issues Meeting (cont.)

• 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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Global Issues Meeting (cont.)

• 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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Global Issues Meeting (cont.)

• 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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Global Issues Meeting (cont.)

• 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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Global Issues Meeting (cont.)

• 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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(No Transcript)
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COPC Exclusions part 2
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Final List of COPCs
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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 pads
  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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Potential Receptors

• 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.

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Potential Receptors (cont.)
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Spatial Surface Soil Sample Results
A (18, 102, 4, 0.03)
B (27, 96, 3, 1.5)
Plan View
Former Pad Location
Buffer Zone
C (15, 78, 2.5, 0.03)
D (10, 86, 1, 2.0)
Runoff Zone
Letter sample point Concentrations (Pb, U, TPH,
Aroclor 1260)
E1 (12, 112, 0.03, 0.75)
E2 (15, 92, 0.03, 11)
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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
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Histogram
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Histogram (cont.)
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Histogram (cont.)
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Histogram (cont.)
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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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CSM Spatial Graphical
Plan View
Former Pad Location
Buffer Zone
Runoff Zone
Section View
Former Pad Location
Buffer Zone
Grade Level
Runoff Zone
60 of 101
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Overview of the Receptor Pathway(CSM) Tabular
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Problem Statement

• 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.

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End of Module 18

• Thank you
• Questions?