2. Overview
What is Vapor Intrusion (VI)?
Why Should I Care?
Causes of VI
Identifying and Investigating the problem
Fixing the problem
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3. What is Vapor Intrusion?
NJDEP: … migration of volatile chemicals from the
subsurface into overlaying buildings through
subsurface soils or preferential pathways.
USEPA: … migration of hazardous vapors from any
subsurface vapor source, such as contaminated soil
or ground water, through the soil into an overlying
building or structure.
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4. Key Terms in the VI world
• Vapor
• VIG or VITG – Vapor Intrusion Guidance/
Vapor Intrusion Technical Guidance
• SSSG –Sub-slab Soil Gas
• IA – Indoor Air
• IEC – Immediate Environmental Concern
• OMM – Operations Maintenance and
Monitoring
• Res v Non-Res
• LSRP – Licensed Site Remediation
Professional
• RAL – Rapid Action Level
• Capillary fringe
• Vadose zone
• Attenuation factor
• Ambient Air
• Critical distance
• LTM – Long Term Monitoring
• VC – Vapor Concern
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Enough with the Acronyms!!

5. Why Should I Care?
• The VI “Pathway”
– Health impacts of contaminants
• Regulatory and Legal
Implications
– Buying property
– Developing land
– Deed Notices & CEAs
– Legacy concerns
• Getting ahead of a Problem
– Prevention
– Mitigation
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6. The Vapor Intrusion Pathway
Key Concepts:
1. Contaminant Source
2. Contaminant Migration
3. Contaminant Exposure (Contaminants are
Entering the Building )
Collectively, these 3 concepts complete the
VI Pathway - Without any 1 feature, Vapor
Intrusion cannot exist. Other breathing hazards
can still exist.
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7. A Picture Tells a Thousand Words
Source : NJDEP Vapor Intrusion Technical Guidance (2013)
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8. 8
Source : USEPA OSWER Technical Guidance (2015)

9. Is There a Problem?
DUE DILIGENCE!
In NJ, this usually means a Phase I/Preliminary
Assessment Report.
A proper DD assessment will include diligent inquiry into
subject and surrounding property conditions that could
cause VI.
Remember: Due Diligence is only as good as the party
conducting the assessment!
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10. How is VI Investigated?
Source
(Typically in ground water, but can be
soil)
Migration
(Frequently Sub-Slab Soil Gas)
Building
(Indoor Air)
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11. Sampling Ground Water
• Only concerned with the top 6 feet of water column
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12. Sample Sub-Slab Soil Gas
• Samples generally collected over ~10 minute period,
although time may vary
• Major Concerns: “Short circuiting” of soil gas with
indoor air
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13. Sample Indoor Air
• Samples usually collected over a 24-hour period
• Sample at breathing height
• Major Concern: Background Sources
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14. Background Sources
Background Sources can cause false positives and
costly, unnecessary mitigation.
Accounting for background sources:
1. Additional Outdoor Air Sample – “Ambient”
2. Detailed Chemical Inventory and Building Survey
3. Knowledge of building history (D.D.)
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15. Building/Chemical Inventory
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16. Background Sources
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Source : NJDEP Vapor Intrusion Technical Guidance (2013)

17. Data Interpretation
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Source : NJDEP Vapor Intrusion Technical Guidance (2013)
Suggests
Background
Suggests
VI

18. Multiple Lines of Evidence
• NJDEP is pushing investigators to provide
“Multiple Lines of Evidence” supporting the
conclusion that VI is (or is not) an issue at a
property.
• Additional lines of evidence could include
• Soil Characteristics
•Building Conditions
•Contaminant Ratios in Soil Gas vs. Indoor Air…
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19. Time is of the Essence - Regulatory Impacts
• VI must be investigated 150 days
from identification of a potential VI
issue.
• If an Immediate Environmental
Concern is identified, interim
mitigation is required to commence
within 14 days of identification of an
issue (i.e. receipt of sample results).
• Other regulatory timeframes may also
apply
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20. VI Identified… What next?
Mitigation is required
NJDEP considers
Active Sub-Slab Depressurization Systems
(SSDS) as the best method of VI mitigation.
So, what is an Active SSDS?
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21. Active SSDS
• A SSDS depressurizes the sub-slab and prevents the
migration of impacted soil gas into the structure.
• Very similar to a Radon Mitigation System, but with more
diagnostic checks and regulatory requirements
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22. Active SSDS
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23. Active SSDS
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Warehouse in New Jersey:
• 7-Sump/1-Blower System
• Mitigation area of approximately 30,000 sq. ft.

24. Active SSDS
Proper SSDS Design is dependent on:
•Building Use
•Construction Type
•Soil Permeability
Each building requires a tailored
approach
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25. Alternate Mitigation Approaches –
Long Term Monitoring
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Long Term Monitoring can be appropriate and cost
effective when soil gas is elevated, but indoor air clean. It is
particularly cost effective if there are near term plans for
site redevelopment.

26. Alternate Mitigation Approaches –
Passive SSDS
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• Similar to an Active SSDS, but there are no
powered fans.
•Passive SSDS can usually be converted to Active if
needed.
• Particularly cost effective in new construction
where there is an identified potential for VI and
construction can include the installation of a sub-
slab venting layer.

27. Alternate Mitigation Approaches –
Passive SSDS
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NJDEP guidance references the Cupolex system
as one such venting layer, however there are
many such products

28. Alternate Mitigation Approaches
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There are other mitigation techniques as well:
• Building Pressurization
• Soil Vapor Extraction systems
• Aerated floor systems
• Spray on Barriers (in conjunction w/ other approaches)
• Sub-Surface Pressurization
• Restriction of building access
Mitigation approach should be tailored to the building on a
case by case basis.

29. Case Study: Ironbound, Newark
• Ronson Metals Corp. manufactured lighters in
Newark from 1950s to 1989
• Environmental investigation had been ongoing, but
abruptly ceased in the mid-1990s
• Ground water was not properly investigated, fell
through the cracks
•In 2003, the property was redeveloped with
residential homes
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30. Case Study: Ironbound, Newark
Source:http://www.nj.com/essex/index.ssf/2014/04/newark_homes_not_so_sweet_with_toxic_vapors_seeping_inside.html
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31. Case Study: Ironbound, Newark
Source: http://www.nj.com/essex/index.ssf/2014/04/newark_homes_not_so_sweet_with_toxic_vapors_seeping_inside.html
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32. Case Study: Ironbound, Newark
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Currently site is identified in NJDEP Mapping Software as Deed Restricted, but
known ground water contamination is not mapped as investigation is ongoing.
Source: NJDEP GeoWeb

33. Case Study: Ironbound, Newark
As of December 2015:
• 59 residences have been sampled for potential
VI issues.
• 28 Active Sub-Slab Depressurization Systems
have been installed.
• The investigation of ground water and
potential VI issues is ongoing.
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34. Case Study: Ironbound Newark
Lessons:
• VI impacts can be “missed” – especially in older
cases
• Regardless of blame, litigation can be costly
• Proper Due Diligence is the Key to Assessing Risk
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35. In Conclusion
• VI is a necessary consideration for building in NJ, residential or commercial
• Assessment of VI potential is an important step in calculating
purchase/development risk - Professional due diligence by is critical
• There are regulatory and legal ramifications to be aware of
• If a risk exists, there are solutions – pre and post construction
• VI can be a hurdle - it does not have be a deal breaker
Finally, VI is not the sole aspect of a site that can affect indoor air quality, as
demonstrated by the now famous Kiddie Kollege case…
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36. Case Study - Kiddie Kollege
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37. Questions?
Christina M. Faust
Project Manager, Whitman
732-390-5858
cfaust@whitmanco.com
or
Michael Adams
Project Scientist, Whitman
732-390-5858
madams@whitmanco.com
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