This presentation describes the current status of vapor intrusion regulation in Texas under existng rules and guidance documents, and points out the ambiguity and case-by-case nature of vapor intrustion regualtion in the State at this time.

1. Vapor Intrusion RegulationVapor Intrusion Regulation
in Texasin Texas
Scott D. Deatherage
Dallas, Texas
scottddeatherage@gmail.com
214-356-0979

2. California Regulation of Vapor Intrusion asCalifornia Regulation of Vapor Intrusion as
Example of More Defined ApproachExample of More Defined Approach
 In 2007, AB 422 amended the California Health and Safety Code to require that
risk assessments performed under the jurisdiction of the DTSC include the
development of reasonable maximum estimates of exposure to volatile organic
compounds (VOCs) that may enter the indoor air of current or future structures
on the site. It also adds a section to the California Water Code that gives the
Water Board the authority to require a risk assessment for a brownfield site,
which must also address the potential for vapor intrusion.
 Risk assessments performed under the jurisdiction of either the DTSC or the
Water Board must be conservatively conducted to:
 address chronic, low level exposures and the cumulative impact of all volatile
chemicals;
 address the risks to sensitive identifiable population subgroups, such as infants,
children and pregnant women; and
 require that all maximum exposure scenarios include not only the current use of the
property, but also the reasonably foreseeable future use of the prop erty (e.g., current
commercial or industrial use, but foreseeable residential use in the future). If a property
owner does not want to cleanup the site to allow for future residential use, then the
agency may require a deed restriction prohibiting future residential use without further
assessment or cleanup.

3. California Guidance DocumentCalifornia Guidance Document
 Department of Toxic Substances Control, California
Environmental Protection Agency, Guidance for the
Evaluation and Mitigation of Subsurface Vapor Intrusion
to Indoor Air (Vapor Intrusion Guidance) (Oct. 2011)
 Provides a stepwise and sometimes iterative process
for the investigation of vapor intrusion and describes
procedures for screening and site-specific evaluation
of potential risks associated with this exposure
pathway.
 Indoor air concentrations estimated from soil gas or
groundwater concentrations by fate and transport
models for vapor intrusion and/or measured indoor air
concentrations are used in the assessment.
 Models for estimating indoor air concentrations include
default attenuation factors for vapor migration from
soil gas or groundwater to indoor air, and default and
site-specific inputs to the U.S. EPA version of the
Johnson and Ettinger vapor intrusion model.

4. California Guidance DocumentCalifornia Guidance Document
 Eleven Step Process
 Step 1, Identifying Spills and Releases
 Step 2, Site Characterization
 Step 3, Evaluate Whether the Exposure Pathway is
Complete
 Step 4, Evaluation of Acute Hazard in Existing
Building
 Step 5, If no acute hazards exist, then the evaluating
party should proceed to a Preliminary Screening
Evaluation
 Step 6, If Step 5 reveals a potentially significant
human health risk, the evaluating party should perform
an Additional Site Characterization

5. California Guidance DocumentCalifornia Guidance Document
 Step 7, This step is closely related to Step 6 and
simply describes the manner in which the data
collected in Step 6 should be analyzed.
 Step 8, Building Survey and Work Plan
Development
 Step 9, Indoor Air Sampling
 Step 10, Evaluation of Indoor Air Sampling
Results and Response Actions
 Step 11, Mitigate Indoor Air Exposure, Monitoring,
and Implementation of Engineering Controls

6. EPA Region 9 Approach for TCE
 Region 9 has adopted a short-term exposure guideline for TCE that
assumes there is a teratogenic impact from TCE.
 The EPA Memo sets short-term exposure levels based on a Hazard
Quotient, or HQ, calculated from toxicological conclusions
developed from the 2011 IRIS Review, including an additional
margin of safety.
 The short term exposure guidelines require “prompt” (i.e., within
weeks) responses to concentrations as low as 2 µg/m3 of TCE in
residences and 7 µg/m3 of TCE in commercial buildings for a 10-
hour shift.
 The short-term exposure guidelines require “urgent” responses,
including the possibility of evacuation, to concentrations as low 6
µg/m 3 in residences and 21 µg/m3 in commercial buildings for a
ten hour shift.

7. Texas Regulation of Vapor Intrusion as anTexas Regulation of Vapor Intrusion as an
Example of More Ambiguous Approach toExample of More Ambiguous Approach to
RegulationRegulation
 Regulation of vapor intrusion and indoor air
under environmental programs has been
ambiguous and case-by-case.
 Not addressed regularly in environmental
remediation by the Texas Commission on
Environmental Quality.
 The US Environmental Protection Agency
has put pressure on the TCEQ to further
develop and implement vapor intrusion
regulations.

8. To WhatTo What ExtentExtent Does the TCEQ RegulateDoes the TCEQ Regulate
Indoor Air Emissions?Indoor Air Emissions?
 Various statements by the TCEQ and the
lack of an actual specific policy and guidance
documents to direct parties to address vapor
intrusion have left a level of uncertainty with
the regulated community as to
 the extent to which the TCEQ expects vapor
intrusion to be investigated and addressed, or
 whether a typical site investigation would need to
consider vapor intrusion at all

9. To What Extent Does the TCEQ RegulateTo What Extent Does the TCEQ Regulate
Indoor Air Emissions?Indoor Air Emissions?
 The TCEQ does not typically evaluate indoor air, and the
TRRP rule is not written to specifically address this
exposure scenario; however, since Weston collected
indoor air data, the TS elected to evaluate it. Detected
constituents in indoor air were evaluated by comparing
results to TRRP risk based exposure levels (RBELs) for
residential inhalation (AirRBELInh). The inhalation
RBELs are conservative health-based values which are
protective of long-term or chronic inhalation over 30
years of exposure for 350 days per year, based on adult
and child exposure scenarios. RBELs are not available
for every chemical detected, so the TRRP guidance was
followed to calculate RBELs for those chemicals where
information was readily available to do so.

10. To What Extent Does the TCEQ RegulateTo What Extent Does the TCEQ Regulate
Indoor Air Emissions?Indoor Air Emissions?
 As another example, if the undeveloped affected property contains
COCs that are a common concern for potential indoor vapor
intrusion, then indoor vapor intrusion could become a complete
exposure pathway at the affected property if building development
occurs in the future.
 If the indoor vapor intrusion exposure pathway is a reasonably
anticipated to be completed exposure pathway, then unless the
affected property is determined to be in compliance with indoor
vapor intrusion soil and groundwater PCLs, an IC [institutional
control] is required. For a deed notice indicate that either future
building development should be designed to preclude indoor vapor
intrusion from the underlying soil or groundwater, or provide notice
that the affected property should be re-evaluated for potential indoor
vapor intrusion before developing buildings. For a restrictive
covenant, prohibit future building development unless buildings are
designed to preclude indoor vapor intrusion from the underlying soil
or groundwater, or prohibit building development until a
demonstration is approved by the TCEQ that the affected property is
protective against indoor vapor intrusion.

11. To What Extent Does the TCEQ RegulateTo What Extent Does the TCEQ Regulate
Indoor Air Emissions?Indoor Air Emissions?
 EPA Region 6 historically pressured the TCEQ to
develop a more robust vapor intrusion program
through more definitive rules and guidance as to
how to identify, regulate, and remedy vapor
intrusion.
 Region 6 has even reviewed TCEQ files for closed
sites, particularly those where a Municipal Setting
Designation Certificate has been issued.
 The TCEQ has indicated at times that only outdoor
air (rather than indoor air) is typically addressed
under the Texas Risk Reduction Rules (TRRP).
 Much of the regulated community has this
perception as well.

12. What Regulations Apply in Texas to VaporWhat Regulations Apply in Texas to Vapor
Intrusion?Intrusion?
 The Texas Risk Reduction Rules (TRRP)
apply in the case of evaluating remediation
levels or soil and groundwater in Texas, other
than releases of constituents from petroleum
storage tanks.
 We will focus on non-Petroleum Storage
Tank (PST) rules initially, and then discuss
the PST regulations.

13. What Regulations Apply in Texas to VaporWhat Regulations Apply in Texas to Vapor
Intrusion?Intrusion?
 Certain parties commenting on the proposed
TRRP Rule asked that the agency clarify that
indoor air is not regulated under TRRP.
 The Agency stated that it reserved the ability
to regulate indoor air COCs migrating from
other media such as soil and groundwater.
 The TRRP Rules state that the Agency may
require testing of indoor and outdoor air.

14. Do the Notification Requirements for HumanDo the Notification Requirements for Human
Exposure Include Indoor Air Exposure?Exposure Include Indoor Air Exposure?
 TRRP Rule requires notice to parties
exposed to chemicals of concern
 A TCEQ guidance document states that
notice is required where the following occurs:
 Exposure to vapors in excess of the Tier 1 human
health PCL in the basement of a building
overlying shallow groundwater containing a COC.

15. Would the PCL for Indoor Air Be the Risk BasedWould the PCL for Indoor Air Be the Risk Based
Exposure Level or an Occupational Level?Exposure Level or an Occupational Level?
 The Protective Concentration Limit (PCL) for Air
could would be based on an environmental agency
calculation or a worker protection calculation, either
 the Risk Based Exposure Level (RBEL), or
 for occupational exposures, the Occupational Safety and
Health Administration (OSHA) or American Conference of
Governmental Industrial Hygienists (ACGIH) levels,
whichever is lower
 The TRRP Rules allow concentrations for worker
exposure to be substituted for the RBEL.

16. Does the RBEL or Worker Exposure LevelDoes the RBEL or Worker Exposure Level
Apply to the Notice RequirementsApply to the Notice Requirements??
 The notification guidance document and applicable
regulation state that the PCLs that would require
notice include those for inhalation.
 The TRRP requires notice when Tier 1 PCLs are
exceeded.
 Tier 1 PCLs are the most conservative, and are
often used as a screening level for delineation of
COCs in environmental media.
 The Tier 2 and Tier 3 PCLs are determined using
more site-specific data.
 For Air, the Tier 1 PCL equals the risk based
exposure level for the relevant COC

17. Does the RBEL or Worker ExposureDoes the RBEL or Worker Exposure
Level Apply to the Notice Requirements?Level Apply to the Notice Requirements?
 The TCEQ does provide in the TRRP Rule
that the applicable Tier 2 or Tier 3 PCL as
appropriately derived for the property or site,
may be stated in the notice to show the
relevant standard, such as the occupational
standard, is not being exceeded.

18. Vapor Intrusion and PST ProgramVapor Intrusion and PST Program
 RG-36, Risk-Based Corrective Action for Leaking Petroleum Storage Tank
Sites (PDF), is being updated and is currently unavailable. Once the updates
are complete, the document will be made available for download.
 Clarifications and Amendments for Implementation of RG-36, Risk-Based
Corrective Action for Leaking Storage Tank Sites
 Customized Texas RBCA software contains a model for the evaluation of
volatile emissions from groundwater to indoor air.
 “the default building parameter assumptions are likely over conservative
for many buildings.”
 “the target groundwater concentrations derived to be protective of this
pathway may in many instances be the driver for the site unnecessarily.”
 “When qualitatively this is a pathway of concern and the target
concentrations for this pathway are exceeded, field verification of vapor
concentrations may be the logical next step.”
 “This pathway may be more appropriate for evaluation when there is a
history of reported vapors, or when high concentrations are in close
proximity to building foundations and there is reason to be believe that
the foundation is sufficiently impermeable to prevent permeation of
vapors through the foundation.”

19. Vapor Intrusion and PST ProgramVapor Intrusion and PST Program
 Point of Exposure Evaluation for Indoor Air
Risk
 Footprint of the building in question must be
evaluated.
 1994 RG-36 Guidance stated
 For occupational exposure, OSHA PELs as
targets
 For residential levels, all federal and state
regulations apply, and the project manager should
consult with Texas Department of Health (now the
Texas Department of State Health Services)

20. Vapor Intrusion and PST ProgramVapor Intrusion and PST Program
 1994 RG-36 Guidance stated
 Target air concentrations only reviewed when
 concern of a potential vapor hazard, or
 known or suspected indoor air exposure to contaminants
 RG-36 under review and it is not clear how
vapor intrusion or indoor air issues will be
addressed differently, if at all

21. Recent Positions Taken by the TCEQ
Regarding Vapor Intrusion
 Reviewing Vapor Intrusion Risk in Most
Remediation Sites
 Voluntary Cleanup Program Reviewing Vapor
Intrusion
 Approach to Chlorinated Solvents, Largely
Trichloroethylene (TCE)
 Greater review if groundwater concentrations are
high

22. Case Study: Existing Building with
Acceptable Subslab Vapors
 Testing had been conducted below the
slab, but not in the building itself
 The TCEQ sought deed restriction that
would require approval of any changes to
the heating and air conditioning (HVAC) of
building

23. Case Study: Existing Building with
Acceptable Subslab Vapors
 Questioned EPA’s ability and expertise in
reviewing HVAC systems
 Refused approach as property could not
be sold with a requirement to seek TCEQ
approval to work on HVAC

24. Case Study: Site to Be Redeveloped
 Property under contract
 High TCE concentrations in soil and
groundwater
 Building to be demolished
 TCEQ stated that an engineering control
would be required for new construction
 Vapor barrier was suggested as a
requirement in a deed restriction

25. Case Study: Site to Be Redeveloped
 We asked for a general statement that a
vapor barrier be required in a deed restriction
 TCEQ stated that it would have to approve
any deed restriction and any vapor barrier
 To avoid concerns of buyer, we argued that
the restriction state a vapor barrier meeting
industry standards be required without further
TCEQ approval
 Agency insisted on approval, but admitted it
did not have expertise in vapor barriers

26. Case Study: Vapors in Building—
Worker Exposure Levels Allowed
 Existing Office Building
 Historic TCE in groundwater at high
concentrations around and under building
 Tight limestone, little diffusion
 Client decided to test for indoor vapors
 Detected, but only in winter
 Tried to reduce by sealing floors, carbon
filtering of air, more outdoor air

27. Case Study: Vapors in Building—
Worker Exposure Levels Allowed
 Despite all actions, still vapors in building
 However, below AGCIH levels
 Client followed rules to provide notice under
Tier 1 PCL
 Obtained approval from TCEQ for Tier 2 PCL
for TCE

28. Case Study: Vapors in Building—
Worker Exposure Levels Allowed
 Obtained approval for ACGIH levels
 Prepared health and safety plan
 Because of worker expressed concern, and
other concerns, company decided to move
workers to another building until vapor issue
resolved

29. Case Study: Vapors in Building—Worker
Exposure Levels Allowed, or Not?
 Existing Manufacturing Building
 Historic TCE in groundwater at high
concentrations around and under building
 Tight limestone, little diffusion
 Client decided to test for indoor vapors
 Detected, but only in winter
 Tried to reduce by sealing floors, carbon
filtering of air, more outdoor air

30. Case Study: Vapors in Building—Worker
Exposure Levels Allowed, or Not?
 TCEQ sent letter requesting indoor air testing
 Despite all actions, still vapors in building
 However, below AGCIH levels
 Client followed rules to provide notice under
Tier 1 PCL
 Obtained approval from TCEQ for Tier 2 PCL
for TCE


31. Case Study: Vapors in Building—Worker
Exposure Levels Allowed, or Not?
 Obtained approval for ACGIH levels
 Prepared health and safety plan
 However, the TCEQ sent a letter that greatly
surprised us, and called into question the
TCEQ’s approach to vapor intrusion
generally and TCE specifically

32. Case Study: Vapors in Building—Worker
Exposure Levels Allowed, or Not?
 TCEQ letter stated that company was in
compliance with applicable regulations
 Met notification requirements for Tier 1 PCL for
TCE
 Health and Safety Plan was submitted
 ACGIH level would be the exposure level for
commercial/industrial workers
 This would be the Tier 2/Tier 3 PCLs

33. Case Study: Vapors in Building—Worker
Exposure Levels Allowed, or Not?
 The letter, however, raised issues beyond the
applicable regulations
 The TCEQ decided to “recommend” other actions
beyond the regulations
 Recommended that actions be taken to address
“short-term” exposure to TCE
 Recommended that “precautionary” notification be
given to workers
 “Pregnant women (and those who may become
pregnant) are the main concern

34. Case Study: Vapors in Building—Worker
Exposure Levels Allowed, or Not?
 The letter, however, raised issues beyond the
applicable regulations
 The first eight weeks of pregnancy are of primary
concern
 “It is important for workers t be made aware of this
potential risk as well as suggesting ways for
pregnant women (and those who may become
pregnant) to immediately mitigate potential
exposure, such as limiting time the the affected
areas.”

35. Case Study: Vapors in Building—Worker
Exposure Levels Allowed, or Not?
 The letter, however, raised issues beyond the
applicable regulations
 Recommended that the Health and Safety Plan
be revised to reflect actions to address short-term
exposure, and to revise sampling methodology
and frequency of sampling to address this
concern

36. Case Study: Vapors in Building—Worker
Exposure Levels Allowed, or Not?
 The TCEQ approach is similar to EPA
Region 9 approach
 Similar to approach taken by California
 Apparently, EPA is encouraging states to
take this approach
 But it is beyond regulatory requiremnts, but
puts company that might not follow it in a
difficult position
 “Damned if you do, damned if you don’t”
situation

37. Practical Questions for Parties DealingPractical Questions for Parties Dealing
with a Potential Vapor Issuewith a Potential Vapor Issue
 Should the switch to an occupational level be
pursued?
 If the TCEQ does not require soil vapor or indoor air
sampling, should it be tested?
 Should employees be left in area exceeding a
RBEL?
 How should the vapor issues be discussed with
employees?
 How do you address off-site issues?
Commercial/Industrial? Residential?

38. Transactional Concerns
 Will OSHA/ACGIH levels be acceptable to a
buyer?
 Lender?
 With Municipal Setting Designations being
available in certain Texas cities, will vapor
issues become more of an issue?
 What will be the future outcome of TCEQ and
EPA discussions and TCEQ development of
vapor intrusion guidance?

39. Transactional Examples
 Shopping Center with PCE contamination
 Seller only willing to agree to address to worker
exposure levels
 Query whether that would be acceptable to buyer
or lender base on current TCEQ position
 Building next door to gas stations
 Buyer wanted to delay sale until potential vapor
from gasoline resolved
 Would not accept testing and passing benzene
PCLs for air in building or subslab

40. Conclusions
 TCEQ positions in some ways as strict or
stricter than other states
 Using “recommendations” to attempt to
pressure companies to do more than
regulations require
 TCE science of impact on women based on
single rat study; arguably questionable
science
 EPA approach to get states to follow this
approach may not be appropriate