Dr. K. Chekiri and J. Bolin presentation at the 2012 Michigan Safety Conference. Understanding vapor intrusion

1. What EH&S Managers Need to Know
About Vapor Intrusion
By
Khaled Chekiri, Ph.D., P.E. and Jeffrey A. Bolin, M.S., CHMM
Dragun Corporation - April 18, 2011

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3.  Regulatory concerns
 Property transaction concerns
 Legal liability
 Health concerns
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4. USEPA VI Path
November 2002: EPA Draft VI Guidance
(not applicable to petroleum)
March 2011: EPA solicited (more) comments
September 2011: Petroleum guidance
February 2012: Technical updates
November 2012: Final VI Guidance (expected)
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5. 2004 – 7 States (Including Michigan)
2010 – 32 States
2012 – 32 +
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6. Re-openers?
What do you mean it’s not closed?
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7.  Anywhere there is “potential” from a previous
release.
 Notable VI sites include
 Love Canal in Niagara Falls, NY - 70's
 Hillside school in Needham, MA - 80's
 Redfield site in Denver, CO. - 90's
 Bishop St. site in Cambridge, ON. - 00's
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8.  Buying/Selling Property
 Merger/Acquisition
 Confusion = Delays = $$$
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9.  All Appropriate Inquiries (AAI)
 ASTM 1527-05
 Vapor Encroachment Condition (VEC)
 ASTM 2600-10
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10.  Where is your site relative
to a known plume?
 …or just within an AOC?
 Non-petroleum hydrocarbon
 1/3 mile (1,760 feet)
 Petroleum hydrocarbon
 1/10 mile (528 feet)
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11.  AAI Continuing Obligations
 Michigan Due Care
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12.  Employee Exposure?
 What is an “okay” exposure?
 ACGIH, PEL,
 Something Else?
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13.  Diffusion
~ slow vs. advection
 Fick’s Law:
Movement of molecules from
a high concentration to a low
concentration
Mass Movement (Flux) = D dC/dx
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14. α= Cindoor air
Csoil vapor
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15.  Safety
 Economics
 Social
 Time constraints
 Defensible results
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16.  Critical thinking
 Conceptual site model
 Multiple lines of evidence
 Other considerations
 Sampling methods
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17.  Does it make sense?
 Data validation
 Screening levels
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18.  Geology
 Water table
 Contaminant
 Underground utilities
 Sensitive receptors
 Existing and potential future buildings
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19.  Indoor air
 Soil vapor (deep and shallow)
 Groundwater
 Background concentrations (ambient air)
 Building construction
 Soil stratigraphy
 Chemicals (presence, ratios)
 Temporal patterns (heating and cooling)
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20.  Access agreements
 Regulator involved?
 Risk communication
 Potential litigation
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21.  Background sources
 Sample custody
 Temporal variability
 Multiple home visits
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22. Passive Active
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23. Sub-slab probes Soil vapor points
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26.  Source remediation
 Mitigation
 Institutional controls
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27.  Sebawaing, MI
 Port Huron, MI
 Salina, KS
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28. Soil Vapor Points
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29.  Properly assessing VI is complicated; it requires
well thought-out strategy and execution – as with
all data GIGO.
 VI may or may not be part of environmental due
diligence or other environmental assessments – it
should be on your checklist to ask if it has been
evaluated.
 Don’t rush to remediate or mitigate based on VI
data; do the data make sense?
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30.  Contact Information:
 Khaled Chekiri, Ph.D., PE
 (kchekiri@dragun.com)
 Jeffrey A. Bolin, M.S., CHMM
 (jbolin@dragun.com)
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