EPA Issues Draft Final Vapor Intrusion Guidance; Open for Public Comment Until May 24

April 19, 2013
Michael C. Gross and Darryl D. Borrelli

On April 16, 2013, the United States Environmental Protection Agency (“EPA”) issued its Draft Final Guidance for Assessing and Mitigating the Vapor Intrusion Pathway From Subsurface Sources to Indoor Air (referred to hereafter as the “Final VI Guidance”).  The Final VI Guidance is EPA’s first substantial revision to its recommended framework for assessing vapor intrusion risks since 2002 and will substantially alter the process for entities undertaking the remediation of properties impacted by volatile and semi-volatile organic compounds (“VOCs and SVOCs”) under EPA oversight and is likely to affect state programs as well.  The Final VI Guidance is open for public comment until May 24, 2013. 

Vapor intrusion is the general term given to the migration of hazardous vapors from any underground contamination source (e.g. soil and/or groundwater) into indoor air.  Vapor intrusion has emerged as a significant public health concern as vapors can accumulate to the point of toxicity for building occupants in both residential and non-residential properties.  Vapor intrusion can also present an explosion risk in certain scenarios.  While all VOCs and SVOCs can trigger vapor intrusion concerns, the majority of properties that will result in a need to conduct a vapor intrusion investigation involve groundwater contaminated with perchloroethylene (“PERC”, a solvent commonly used as a dry cleaning fluid), trichloroethylene (“TCE”, a commonly used industrial degreasing solvent) or petroleum hydrocarbons such as benzene.  While the Final VI Guidance indicates that it is “generally applicable to petroleum hydrocarbons”, EPA also simultaneously released a second guidance document entitled “Guidance for Addressing Petroleum Vapor Intrusion at Leaking Underground Tank Sites.” 

The Final VI Guidance must be utilized at any property being evaluated by EPA under CERCLA, RCRA, or EPA’s brownfield program. However, EPA also “recommends consideration” of the Final VI Guidance in a wide range of instances, including cleanups at brownfield sites.  Significant new requirements include but are not limited to:

  • Consideration of vapor intrusion at sites undergoing a Superfund Five Year Review where EPA will now examine vapor intrusion in evaluating remedy effectiveness—even where vapor intrusion was not addressed as part of the original remedial action;
  • An expansion of EPA’s recommended approach to evaluating and mitigating vapor intrusion in nonresidential buildings (e.g. schools, libraries, hotels and hospitals);
  • New toxicity values for various constituents that will increase or decrease acceptable indoor air screening levels;
  • Use of a “multiple lines of evidence” approach in evaluating vapor intrusion risks which will likely result in a requirement for increased sampling of off-site properties;
  • Recommendations for pre-emptive mitigation and early action scenarios;
  • Requirements for operation and maintenance of vapor mitigation systems;
  • New flexibility related to indoor air sampling methodologies;
  • New community involvement requirements; and
  • New institutional control requirements.

Affected parties (e.g., current or former property owners or tenants, developers, municipalities, financial institutions, consultants and lawyers) will need to carefully consider how to apply the Final VI Guidance in the context of cleanups or environmental due diligence, especially at sites where it is unclear whether state or federal vapor intrusion assessment requirements will apply.  Since the Final VI Guidance has the potential to “reopen” previously closed contaminated sites for further investigation and response, parties to real estate transactions that may have relied on prior vapor intrusion assessment procedures should carefully consider the potential impacts of the Final VI Guidance.  Finally, borrowers involved with financing at properties impacted by VOCs should realize that vapor intrusion concerns are now at the forefront of environmental concerns in the lending community.

For additional information on the Final VI Guidance, please contact Michael C. Gross at 484-430-2321 or mgross@mankogold.com or Darryl Borrelli at 484-430-2302 or dborrelli@mankogold.com.  Michael served on the Vapor Intrusion Legal Task Group of ASTM International which was charged with crafting a uniform standard for assessing vapor intrusion risks in commercial real estate transactions.  On May 13, 2013, he is co-presenting a national webinar entitled "Vapor Intrusion - Legal Concerns, Risk Management, and Scientific Factors for Attorneys and their Clients" on behalf of the American Law Institute.