Indoor Air Vapor Intrusion Database

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Indoor Air Vapor Intrusion Database
Robert S. Truesdale Environment, Health, and
Safety Division Research Triangle Park, North
Carolina
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IAVI Database Purpose

• Compile empirical observations collected from
  high-quality investigations across the nation to
  help ensure that draft VI screening criteria are
  not overly or under-protective
• Compare and contrast attenuation factors based on
  indoor air measurements paired with groundwater,
  soil gas, or subslab measurements
• Identify factors and conditions that
  significantly influence subsurface to indoor air
  vapor attenuation (including precluding factors)

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Design Requirements

• Strict controls on additions/changes/modifications
  
• Expandable and maintainable for the long-term
• Easy transfer to other database programs
• Efficient/effective data collection instrument(s)

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Design Requirements (cont.)

• Cost-effective data transfer to regulators and
  researchers
• Clear, effective data summaries
• Contain information to evaluate data quality,
  representativeness, and completeness
• Can contain all data needed to apply VI guidance
  at subject sites

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Design Process

• Dr. Helen Dawsons Region 8 VI database provided
  key data elements and base data
• 2-day meeting in Region 8 with EPA researchers,
  EPA regulators, State regulators to establish
  content, data quality objectives, preliminary
  specifications
• Analysis of EPA data standards for database
  design elements and structure (OSWER DED, STORET
  EDD, Region 2 MEDD)
• New elements and tables added for VI-specific
  data
• Draft database design reviewed by EPA/State team,
  selected experts
• Final IAVI database design

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IAVIdb Design
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IAVIdb Design (cont.)
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IAVIdb Design Key Tables
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Data Collection Instrument

• IAVIdb website (http//iavi.rti.org)
• Downloadable Microsoft Access database
• Data entry forms to capture key information
• Data provider
• Site conditions
• Building characteristics
• Attenuation factors
• Media concentrations (indoor air, ambient air,
  groundwater, soil gas)

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Pilot Database

• Initial data collection effort to test database
  design, data collection instrument, collect
  preliminary data
• Data transferred from existing Region 8 VI
  database
• Two-month collection effort 6 respondents, 7
  sites, and 42 buildings (21 residential, 8
  commercial, 13 other)

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Pilot Database (cont.)

• Site types 4 chlorinated solvent sites, 2
  petroleum sites, 1 landfill
• Attenuation factors groundwater (13), soil gas
  (15), and subslab (98)
• Data received in a variety of formats (forms,
  other electronic, hardcopy) manual entry
  required in many cases
• Most data received just prior to contract end,
  precluding significant data analysis

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Conclusions Pilot IAVI Database

• Database design is suitable for intended purpose
• Data entry forms designed for easy entry pilot
  comments and experience suggest further
  improvements
• Respondents are busy data collection needs to
  allow for form entries, electronic submittals,
  and hard copy submittals (as a last resort)

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Conclusions (cont.)

• Analysis is ongoing, but preliminary data
  received suggest that
• the current guidance appears protective
• certain petroleum compounds may attenuate to a
  greater degree than chlorinated hydrocarbons
• Indoor contaminant sources can confound indoor
  air results

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Preliminary Results(interpretation ongoing)
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Preliminary Results(interpretation ongoing)
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Next Steps

• Existing data
• confirm data with respondents
• document data quality information
• review data / select valid attenuation factors
• identify precluding factors
• summarize results
• Improve data entry forms (address expert
  comments, add user help features)
• Develop specifications for electronic data
  submittals

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Next Steps (cont.)

• Develop easy-to-use summary and more detailed
  data outputs for regulators, researchers, other
  stakeholders
• Solicit additional data from EPA regulators and
  researchers
• Consider ICR to expand data collection effort to
  other states and private parties

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For database, documentation, this presentation,
go to

• http//iavi.rti.org

Please Visit!