Lutes, C., J. Lowe and L. Lund “Vapor Intrusion (VI) Guidance in an Age of Federalism” Presented at Air and Waste Management Association’s 111th Annual Conference and Exposition; June 25 – 28, 2018 Hartford, CT

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Paper # 418058
Vapor Intrusion (VI) Guidance in an Age of
Federalism
Air and Waste Management Association’s 111th Annual Conference and Exposition
June 25 – 28, 2018
Hartford, CT
CH2M is now Jacobs
Chris Lutes, Jacobs, Raleigh, NC
John Lowe, Jacobs, Spokane, WA
Loren Lund, Jacobs, Shelley, ID

2. Agenda
• Management of vapor intrusion (VI) is an example of “federalism”, where it’s
defined as a central government and states sharing authority.
• EPA’s final VI guidance published in 2015 encourages states to develop their
own guidelines.
• There are upsides and downsides with state guidelines
‾ Downsides: lack of consistency between states that create difficulties with risk
communication and risk management.
‾ Upsides: States can become the “laboratories of democracy” to explore different
investigation and management approaches.
• Examples of regulatory diversity – toxicity and more
• Practical aspects of working in this diverse environment

3. Levels of Guidance
• Federal EPA
• EPA regional (ten regions)
• State
• Local
‾ CA urban fire department was the
“lead agency” on a dry cleaner site;
‾ San Diego County has its own VI
guidance
‾ Mountain View CA imposes VI
mitigation requirements in permitting
Federalism in speed limits graphic from
http://web.ics.purdue.edu/~mclauchl/F01/Pol101/Fed01.html

4. California (early 2018) – Example of Multiple
Layers of Authority over VI
EPA (Region 9)
Cal-EPA
OEHHA
RWQCBsDTSC
San Diego County
CA toxicity values
RSLs TCE Rapid Action
guidance
Federal
State
Local City of Mountain View
Levels of Authority

5. EPA 2015 “Final VI Guide” Wasn’t the Last Word:
• Region IV: Nov 2017 “Draft: Superfund Division’s Risk
Management Approach for Indoor Air Vapor Intrusion Data” – tiered
approach with flow charts
• Region V: Sept 2017 Memo: “Data Management and Communication at
Residential Properties”
• Region VII Nov 2016 Memo: Covers TCE action level; risk communication
• National: January 2017 Addition of a Subsurface Intrusion Component to
the Hazard Ranking System

6. EPA 2015 Final VI Guide Defined Some Principles for
States to Use in Developing Guidelines
“EPA recommends that state agencies…. ensure they incorporate features such as:
• Using multiple lines of evidence to support pathway-incomplete determinations and
“no-further-action” decisions;
• Collecting multiple rounds of indoor air sampling to characterize exposure levels in
indoor air in existing buildings;
• Focusing lab analyses ….on vapor-forming chemicals known or suspected to be
released to the subsurface environment;…;
• Assessing human health risk posed by less-than-chronic exposure durations; and
• Considering reasonably expected future conditions, as well as current conditions,
when making risk management decisions”
(EPA 2015)
“In Essentials Unity, In Non-Essentials Liberty, In All Things Charity”
Marco Antonio de Dominis (d. 1624).

7. Concept of “Cooperative Federalism”
• EPA 2018-2022 Strategic plan “Goal 2 – Cooperative Federalism:
Rebalance the power between Washington and the states to create
tangible environmental results for the American people. “
• Environmental Council of the States (ECOS) Cooperative Federalism
2.0. Key points:
‾ “the workgroup has secured an agency commitment to consult first with states
on forthcoming proposed revisions to U.S. EPA Superfund-related groundwater
policies”
‾ Emphasis on state access to EPA ORD information/products especially
regarding toxicity values for contaminants of emerging concern.

8. Graphic reprinted from Fairfax County Public Schools: http://onlinecampus.fcps.edu/media2/Social_Studies/GOVT/Topic04/TAIF.htm

9. Vapor Intrusion Concerns Have Expanded Beyond
Early Adopter States (CA, CO, NY, NJ, MA)
Huffington Post 3/22/13
Midtown Raleigh News 2/28/14
http://www.myfoxtampabay.com 12/6/13
The Post-Standard 11/10/09
Law and the Environment 3/14/13
WYFF4.com 8/22/14
Tampa Bay Times
9/18/08
Billings Gazette 1/24/13
Science Daily 6/26/12
Washington Times, 9/27/14

10. VI Guidelines Have Now Been Developed in 39 States
• Certain aspects of EPA’s VI guidelines appear nearly uniformly in state guidelines – tiered
approaches; multiple lines of evidence.
• Substantial diversity in many other aspects: attenuation factors, screening levels,
numbers of samples/events for indoor air sampling
Reprinted with
Permission from :
Eklund et al., 2018

11. State Guidance Documents Difficult to Follow Because
States Structure them in Different Ways
• CA – by subject: VI/Indoor Air Guidance, Soil Gas Investigation Guide,
Screening Levels Users Guide, Low Threat Closure Policy, Mitigation
Advisory
• NC: by program: Inactive Hazardous Sites Branch, Division of Waste
Management,, “Individual cleanup programs in DWM may have additional
requirements for VI investigations; therefore, the appropriate regulatory
cleanup program should always be consulted before performing a VI
investigation.”
• MI – VI guidance document, separate documents for TCE and 1,4-
dioxane, recommendations for Interim Action Screening Levels, Cleanup
Criteria Tables; separate document of footnotes for tables!
• NY: Evolutionary: VI Guidance from 2006 but Soil Cleanup Guidance in
2010, TCE fact sheet in 2015, Updated Decision Matrices in 2017

12. Downside: Growing Awareness that the Variability from
State-to-State Screening Levels Might Pose Problems
• This issue is less-acknowledged in VI practice, but the same issue has been
noted with poly- and perfluorinated alkyl substances (PFAS) in drinking
water
‾ “These differences among states demonstrate the difficulty in calculating health risk
goals and determining risk reductions without federal standards, and are creating public
confusion about what levels of PFAS are safe in drinking water.”
‾ "Without this unified message and information, we're concerned that several sets of
different risk numbers will be communicated from each agency, which will cause
confusion, delay, or worse, no action at all.“
• January 12, 2018 letter to EPA and the Centers for Disease Control (CDC) from the
Association of Safe Drinking Water Administrators (ASDWA) encouraging more Federal
engagement with states in developing limits for PFAS in drinking water.

13. Unlike PFAS in Drinking Water, No Calls (Yet) for a
Leadership Summit on VI

14. TCE Rapid Action is One of the Best Examples of the
Variability in VI Guidance
• Prompt (days to weeks) response action may also be warranted where
short-term exposures may pose unacceptable risk ... (noncancer hazard >1
based on fetal heart toxicity) – EPA, 2015
• All of the agency numbers are derived from the same toxicity value – EPA’s
Reference Concentration (RfC) of 2 µg/m3 derived using a developmental
toxicity (fetal cardiac malformation) endpoint.
• Key factors in rapid action guidance include: concentration value, hazard
quotient, exposure period, and action required if exposures are higher than
the concentration value – these factors are modified in one form or another
by different agencies.

15. Example Continued
• EPA Region 7 and the state of Michigan concluded in 2016 that a single one-
day exposure to TCE can produce developmental toxic effects, based on a
conservative interpretation of EPA guidance.
‾ Uses EPA’s RfC for assessing and managing acute exposures.
‾ Not a use that had been foreseen by the developers of the RfC.
• In contrast, the state of Indiana has issued guidance that formally rejects the
use of developmental toxic effects in deriving a TCE rapid action level.

16. Using EPA Region 9 Guidance as a Benchmark for Comparison
Agency uses approach that is consistent with EPA Region 9
Agency uses approach that diverges from EPA Region 9
Variations in Residential Action Rapid Levels for TCE
The "Standard"
Agency
EPA R9,
DTSC,
SFRWQCB
EPA R7 EPA R10 CTDPH NHDES NJDEP MADEP
Concentration 2 ug/m3
2.1 ug/m3
5 ug/m3
6 ug/m3
2.1 ug/m3
Hazard Quotient HQ = 1 HQ = 1 (?)
No HQ = 1
value
Exposure Period 24 hours 21 days
Action
"Accelerated"
action
"Immediate"
action
Not
specified
Relocate
occupants
"Accelerated"
action
Concentration 6 ug/m3
4 ug/m3
20 ug/m3
6.3 ug/m3
20 ug/m3
Hazard Quotient HQ = 3
No HQ = 3
value
No HQ = 3
value
No HQ = 3
value
HQ = 2 HQ = 10 HQ = 10
Exposure Period 24 hours
Action
Immediate
("Urgent")
action
Relocate
occupants
Accelerated
action
Relocate
occupants
Within a few
days
("Urgent")
"Immediate"
action
Variations
OEPA

17. Upsides: States as the “Laboratories of Democracy”
A state may, if its citizens choose,
serve as a laboratory; and try novel
social and economic experiments
without risk to the rest of the
country.
- U.S. Supreme Court Justice Louis Brandeis, New
State Ice Co. v Liebmann (1932)
Brandeis portrait http://npg.si.edu/media/87T0002A_1.jpg

18. Massachusetts Guidance – Provides a Range of Defined
Outcomes
• Temporary Solution: considered a waypoint in remediation, not an end state.
‾ Substantial Hazards eliminated
‾ Nature and extent of contamination has been characterized
‾ Groundwater and soil vapor plumes are controlled
‾ Response action is under way, and active O&M (including VI mitigation) is ongoing
• Permanent Solution:
‾ Health risks reduced to No Significant Risk (NSR) levels
‾ Substantial Hazards eliminated
‾ Appropriate Activity Use Limitations (AULs) selected
‾ Concentrations in soil and groundwater reduced below Upper Concentration Limits.
‾ O&M is limited to operation of an Active or a Passive Exposure Pathway Mitigation
Measure.

19. Pennsylvania Guidance – More Clearly Defined Offramps
from VI Assessment
Source: PADEP. 2017. 2017 Vapor Intrusion Guidance FAQs.

20. California Guidance – Being Updated in 2018
• Example of harmonizing multiple state agencies
• Gradual rollout with initially stringent guidance to force standardized data
collection;
• Publish those data on agency web sites (Envirostor – DTSC; Geotracker –
RWQCBs); use data to derive CA-specific attenuation factors and update in
a few years
• Will continue to require HVAC-off sampling – not common in other
jurisdictions, but driven by local climatic conditions
• Requiring three ambient samples per indoor sampling day – not common
elsewhere

21. Best Practices in an Era of “VI Federalism”
• Be prepared for the regulatory fragmentation:
develop some familiarity with guidelines across
multiple states and EPA Regions based on your
organizations geographic footprint.
• Regulatory and issue tracking i.e. DoD’s Emerging
Contaminants Directorate “scan-watch-act” process
• Staff projects with a combination of state specific
expertise and national expertise to put state
expectations in a larger technical context
• Communicate frequently with regulators to
understand any evolving regulatory requirements
and their technical perspective regarding lines of
evidence and level of project urgency
Image from
https://libguides.stthomas.edu/compliance

22. Best Practices in an Era of “VI Federalism”
• Share the lessons-learned across state agencies; promote
the use of new diagnostic tools (controlled building
depressurization/real-time monitoring; surrogates, indicators
and tracers in indoor air).
‾ Some states have more limited resources for training or staying
current with the state-of-the-science.
• Regardless of the variation between agency guidelines,
there is a fairly consistent response if TCE rapid action is
triggered.
‾ Plan for rapid action - agree upon rapid action levels and responses
‾ Employ building diagnostic tools to rapidly identify potential
pathways
‾ Pre-position vendors, equipment and supplies to implement
mitigation measures
‾ Initiate and maintain effective risk communication
Image from
https://libguides.stthomas.edu/compliance

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Thank you!
Chris Lutes
Christopher.Lutes@ch2m.com