Vapor Intrusion Regulation in Texas

Vapor Intrusion Vapor Intrusion Regulation in the Regulation in the TexasTexas

Scott D. DeatheragePartner, Gardere Wynnne SewellDallas, [email protected]

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Texas Regulation of Vapor Intrusion Is Texas Regulation of Vapor Intrusion Is a Somewhat Ambiguous Approacha Somewhat Ambiguous Approach

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 (TCEQ).

The US Environmental Protection Agency has put pressure on the TCEQ to further develop and implement vapor intrusion regulations or guidance.

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To What To What ExtentExtent Does the TCEQ Does the TCEQ Regulate Indoor Air Emissions?Regulate 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; and Petroleum storage tank (PST) releases may be addressed

differently from Texas Risk Reduction Rules—TCEQ internal guidance regarding vapor intrusion generally, and PST corrective action guidance generally

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To What Extent Does the TCEQ To What Extent Does the TCEQ Regulate Indoor Air Emissions?Regulate Indoor Air Emissions? TCEQ, Health Effects Review of Soil and Air Samples at Vista

Chemical Site – Leander ISD Elementary School No. 19, Travis County Samples Collected February-April 2007 (April 1, 2007), at 3.

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.

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To What Extent Does the TCEQ To What Extent Does the TCEQ Regulate Indoor Air Emissions?Regulate Indoor Air Emissions? TCEQ, Remediation Division, Institutional Controls under

TRRP, RG-366/TRRP-16 (Revised May 2010), at 8, 18. 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. See §350.111(b)(6).

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To What Extent Does the TCEQ To What Extent Does the TCEQ Regulate Indoor Air Emissions?Regulate Indoor Air Emissions?

EPA Region 6 has been attempting to convince 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.

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What Regulations Apply in Texas What Regulations Apply in Texas to Vapor Intrusion?to Vapor 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.

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What Regulations Apply in Texas What Regulations Apply in Texas to Vapor Intrusion?to Vapor Intrusion?

Certain parties commenting on the proposed TRRP Rule asked that the agency clarify that indoor air is not regulated under TRRP.

In the response in the final rule preamble, 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. 30 Tex. Admin. Code § 350.51(b).

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Do the Notification Requirements for Do the Notification Requirements for Human Exposure Include Indoor Air Human Exposure Include Indoor Air

Exposure?Exposure? TRRP Rule requires notice to parties

exposed to chemicals of concern. 30 Tex. Admin. Code § 350.55(e).

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.

TCEQ, Remediation Provision, Notification Requirements, RG-366/TRRP-17 (Revised March 2009).

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Would the PCL for Indoor Air Be the Would the PCL for Indoor Air Be the Risk Based Exposure Level or an Risk Based Exposure Level or an Occupational Level?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) for TCE, 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.

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Does the RBEL or Worker Exposure Does the RBEL or Worker Exposure Level Apply to the Notice Level Apply to the Notice

Requirements?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

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Does the RBEL or Worker Does the RBEL or Worker Exposure Level Apply to the Exposure Level Apply to the Notice Requirements?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. 30 Tex. Admin. Code § 350.55(e)(2); see also 24

Tex. Reg. 7323, 7611.

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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 believe that the foundation is sufficiently impermeable to prevent permeation of vapors through the foundation.

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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)

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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

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Practical Questions for Parties Practical Questions for Parties Dealing with a Potential Vapor Dealing with a Potential Vapor Issue in TexasIssue in Texas 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?

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Transactional Concerns in TexasTransactional Concerns in Texas

Will OSHA/ACGIH levels be acceptable to a buyer? Or a Lender? Or a Tenant, or its employees or customers? With Municipal Setting Designations being available in

certain Texas cities, that allow significantly higher concentrations of constituents to remain in groundwater, 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?

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Transactions in GeneralTransactions in General

What provisions should be revised or added to purchase and sale agreements or loan documents?

Due diligence—when is the right time to evaluate vapor risk?

Should sampling, sub slab or indoor air, be conducted? Risks?

What might the mitigation steps be? Should those be implemented without sampling? What are the relative costs?

If new development planned, what construction design steps may be appropriate?

Should additional soil or groundwater treatment be considered?

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Scott D. DeatheragePartnerGardere Wynne SewellDallas, Texas [email protected]

Energy and environmental lawyer with experience in compliance auditing, environmental corporate governance, enforcement actions and litigation, permitting, environmental and climate change disclosures under SEC and voluntary programs. Areas of experience include air emissions, wastewater, welands, solid and hazardous waste, contaminated soil and groundwater, and health and safety.

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Vapor Intrusion Regulation in Texas