PA Brownfields Environmental Law : Pennsylvania Environmental Law & Brownfields Lawyer & Attorney : Fox Rothschild Law Firm : Philadelphia PA

This afternoon, April 16, 2013, USEPA's Office of Solid Waste and Emergency Response released for public input two draft vapor intrusion guidance documents: a general guidance for all compounds; and one focused on petroleum hydrocarbons released from underground storage tanks. The documents can be accessed at:  http://www.epa.gov/oswer/vaporintrusion. Public input must be submitted by May 24, 2013, at:  http://www.regulations.gov; docket number: EPA-HQ-RCRA-2002-0033-007.

As reported previously on this blog, our office was among those who formally petitioned USEPA, in December 2012, to release these documents for public comment on the basis that the leaked versions revealed an approach that has fundamentally changed from the last general USEPA draft from 2002.  We appreciate that OSWER has taken this important step, and we encourage all interested stakeholders to review these important documents and provide their input.  Please reach out to a member of our group if you would like to explore collaborating in this effort.

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As indicated in a recent post, ASTM International has developed a revision of the Phase I protocol, Standard Practice for Environmental Assessments: Phase I Environmental Site Assessment Process (“E 1527‑05”) that will be issued this year.

A topic being heatedly discussed, especially by consultants, is whether the revised E 1527 will require vapor intrusion evaluation or a vapor encroachment analysis under ASTM's E 2600-10, Standard Guide for Vapor Encroachment Screening on Property Involved in Real Estate Transactions.  The answer on both accounts is "no." 

A better question is whether the significant scientific and regulatory developments related to vapor migration and intrusion in many jurisdictions should already be informing professional judgments of environmental professionals performing Phase I environmental site assessments under the existing E 1527-05.  The answer to this question, in my view, is "yes."

Vapor intrusion evaluations are well beyond the level of information and analysis that takes place in a Phase I. Speculating about whether chemical vapors are entering buildings should not be part of a Phase I report. This is the reason that ASTM's E 2600-08, Standard Practice for Vapor Intrusion Assessment  (which used Phase I-type information to presume that vapor intrusion was occurring at a target property) needed to be thrown out. 

ASTM's replacement document, the E 2600-10 Standard Guide for Vapor Encroachment is purposefully not a Standard Practice.  The E 2600-10 Guide itself expressly states that it is not part of all appropriate inquiries or of the performance of a Phase I under E 1527-05.  I was a primary author of the Legal Appendix published with E 2600-10.  Why I was involved in the process, and yet don't recommend E 2600-10 to clients, is a separate topic that relates to strong resistance to withdrawing E 2600-08 without a replacement document, and, for example, the fact that search distances in E 2600-10 don't meet the requirements of E 1527-05.    

On the other hand, there is nothing in the existing E 1527-05 (or coming in the revision) that carves the presence of hazardous substances in vapor form out of the definition of a recognized environmental condition ("REC") (nor anything that carves vapors out of the scope of AAI or CERCLA jurisdiction). The growing understanding of how volatile chemicals move in the subsurface should inform environmental professionals' judgments about whether hazardous substances are likely present at a target property in making Phase I REC determinations; the developing science, regulations and guidance on vapor intrusion may need to be considered by the environmental professional when he or she determines whether the presence of a volatile chemical in the subsurface of the property can be considered de minimis. 

Having said all of this, when an environmental professional has determined that volatiles are likely present at the target property in the groundwater (or soil) above de minimis levels, that condition is the REC, and there is no justification or need for the environmental professional to speculate further about the vapor pathway in the Phase I report.  Evaluation of that pathway is beyond Phase I, as is complete delineation of the extent of any other REC.

To me, it seems that it should be a rare case where a consultant can, on Phase I type information, support a determination that a hazardous volatile is likely present in soil gas of the target above de minimis levels based solely on vapor movement (independent of groundwater movement) from an offsite release. In other words, the 'vapor only' REC is theoretically possible, but should be practically rare, and nothing in AAI or E 1527-05 justifies speculation or requires sampling.

Because there is and will continue to be confusion on this topic, it is important to make sure that you are on the same page with any consultant you hire for a Phase I, especially for brownfield properties.  Note especially that a consultant who inserts a statement disclaiming any consideration of vapors in the Phase I assessment may generate a Phase I report that does not satisfy all appropriate inquiries.

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In December 2012 we reported on some of the challenges created by the vapor intrusion pathway under the Act 2 brownfields program in Vapor Intrusion and Act 2 – Imperfect Together. This is an update. 

On January 29, 2013, the Department convened a meeting of the vapor intrusion subcommittee of the Cleanup Standards Scientific Advisory Board at the Rachel Carson Building in Harrisburg. We reviewed and discussed a proposal from the Department for how vapor intrusion could be managed under a Statewide Health Standard (“SHS”) clean-up and possible paths forward to update the existing guidance. The meeting included worthwhile discussion on number of aspects of this difficult subject. 

If nothing else, our discussions brought into sharp focus the biggest challenges the CSSAB and Department face in revising the vapor intrusion guidance:

1.         Soil gas samples. Given growing concern about the reliability of soil gas samples taken from outside the footprint of an existing building (see recent NJ 2013 VI Technical Guidance treatment of this issue, Section 3.3.2, Alternative Soil Gas Sampling), whether near-building and “exterior” soil vapor sampling can and should play a role in evaluation of the vapor intrusion pathway.

2.         Future development. Especially in light of the concern noted above about the reliability of exterior soil gas sampling, how to establish a SHS mechanism for vapor intrusion analysis for sites (and parts of sites) that do not yet contain buildings to prevent vapor intrusion analysis for future development from undermining the certainty of an Act 2 release of liability.

3.         Screening values for indoor air, ground water, soil gas, sub-slab soil gas and/or soil. 

-- On what basis to establish appropriate screening values for groundwater and subslab soil gas that are protective but not overly conservative? Is Johnson-Ettinger still the appropriate model to use?

-- How to make screening values established from modeling more relevant and useful for a wider range of sites where, e.g.,  soil types or depths to contaminant may differ from the model’s assumptions.

-- How to mitigate effects on existing releases of liability when revised screening values are established that likely will differ by orders of magnitude from the values in the 2004 guidance.

-- Whether meaningful screening values can be established for soil sample results, or whether any amount of volatiles in soil samples could justify further steps to evaluate the vapor pathway even in the SHS context.

-- Whether to use the existing DEP toxicity values or the IRIS values set by the United States Environmental Protection Agency in calculating screening values.

4.         Timing. The Department is anxious to move forward with guidance for SHS clean-ups. There was considerable sentiment within the subcommittee that the current 2004 guidance, in particular the screening values in that guidance, needed to be updated as soon as reasonably possible. However, one consideration is that USEPA has not issued a revision of its 2002 vapor intrusion guidance (initially targeted for November of 2012) and some interested parties, including our office, have submitted formal requests urging that USEPA issue its fundamentally rewritten guidance as a draft for public comment before issuance of a final document. 

The Department and the subcommittee will be working through each of the these issues as we move toward revised guidance in the coming year. The full CSSAB meetings for 2013  are set at the moment for April 11, 2013 and October 23, 2013. 

If you have questions, insights or concerns please let us know.  We will keep you posted here.

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Vapor intrusion, the migration of a volatile chemical from subsurface contamination into the indoor air of a building, was not viewed as a significant exposure pathway in 1995 when Act 2 was written into law. It is viewed as significant now. The emerging importance of this pathway poses unique challenges for DEP and responsible parties under Act 2. It also has the potential to undermine some of the predictability that Act 2 is designed to provide. Managing the risks related to vapor intrusion under Act 2 requires understanding the issues, including the steps that DEP has already taken to address them and the changes that are likely to come. We cover these issues briefly in this post.

Part of the challenge of vapor intrusion for DEP, and the regulated community, is structural -- vapor intrusion exposures are not considered in development of Statewide Health Medium Specific Concentrations (MSCs) for soil and groundwater under Act 2. Perhaps more in theory than practice, this means that achieving MSCs for a volatile contaminant below a building does not ensure that the contaminant is not present at unacceptable levels in the indoor air – the MSCs are not calculated to be protective for vapor migration to indoor air (though they may be protective for most substances in any event). More problematic is that the “point of compliance” for attainment of groundwater MSCs is the property boundary. This means that under the attainment criteria established in the Act 2 statute itself, high levels of a volatile chemical – a source for vapor intrusion to indoor air -- could be left in groundwater under an on-site building as long as the groundwater MSC is achieved at the property boundary.   

DEP has taken steps to address these issues. 

In January 2004, the DEP Clean Standards Science Advisory Board (CSSAB) issued Section IV.A.4 of the Technical Guidance Manual -- Pennsylvania Vapor Intrusion into Buildings from Groundwater and Soil under the Act 2 Statewide Health Standard (2004 SHS VI Guidance). This guidance states, “Indoor air quality (IAQ) from the vapor intrusion of contaminants into buildings from groundwater and soil is not assessed under the Statewide Health standard in the Act 2, Chapter 250 regulations.”   Though not itself a regulation, the guidance provides “additional screening requirements . . . to prevent unacceptable risk” from vapor intrusion in the context of Statewide health standard sign-offs. The guidance provides decision matrices to be followed under the Statewide health standard; includes MSCs for Indoor Air Quality; screening values that can be used to evaluate groundwater and soil data if site conditions match the underlying assumptions; and a framework for evaluating vapor intrusion risks.  DEP also developed valuable questions and answers on vapor intrusion in the Land Recycling Q and A Database (Category: Vapor Intrusion).  

In January 2011, DEP made the evaluation of vapor intrusion part of the law in promulgating a regulatory provision at Section 250.312 for Statewide Health Standard signoffs: “The final report must include, as appropriate, an assessment of the vapor intrusion pathway.”

In addition, in March 2011, DEP re-convened the CSSAB Vapor Intrusion Subcommittee, to support an update of the 2004 SHS VI Guidance. Preliminary work was done by the DEP and the subcommittee in 2011. After a hiatus, the next meeting of the subcommittee is scheduled for late January 2013. As a member of that subcommittee I will keep you posted as appropriate. At this point, I expect a guidance more focused on sub-slab and indoor air sampling -- consistent with recent New Jersey VI Guidance and the recently ‘leaked’ revision of the USEPA guidance, substantial revision to some of the screening values, and that includes discussion of proceeding directly to the installation of mitigation systems in lieu of extended investigation.  Mitigation systems can be relatively inexpensive and work well.  The downside is the environmental covenant that will be required if mitigation is to be relied on in a release of liability.    

One recommendation, if you plan to rely on an existing Act 2 release of liability for any site where volatile contaminants remain, seek out good advice on whether vapor intrusion has the potential to undermine the certainty you expect from the release of liability.

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