March 15, 2011

Anyone involved with the sale or purchase of property should be aware of the latest developments related to vapor intrusion. Regulators at the federal and state level are now looking at the potential for vapors to impact and, in some cases, enter into building structures. The concerns are related to findings at sites across the country that vapors are accumulating under building foundations and potentially entering structures through cracks in foundations or other structural elements.

Vapor concerns arise at sites that are near gas stations or dry cleaning operations where there have been releases of solvents, volatile organic compounds and petroleum products. Depending on soil types, groundwater conditions and other factors, vapor plumes may travel ahead of pockets of soil contamination or tainted groundwater plumes. Federal and state environmental agencies are often requiring testing and corrective measures to protect building occupants. Agency staff are now more frequently asking for tests of soil vapor at sites where there have been documented releases. If documented releases are in close proximity to building structures, additional testing underneath building slabs and, in some cases, of indoor air is being required.

The ramifications for parties involved with real estate – building owners, tenants, lenders, buyers, occupants – are significant.

  • Parties who are involved with the investigation of past and current releases now need to consider whether vapors may affect the subject or surrounding property.
  • Landlords and owners of structures near where a release has occurred may need to assess potential vapor impacts on their buildings and whether tenant notifications and protective measures may be required.
  • Buyers and lenders who are ordering Phase I Environmental Site Assessments should consider whether vapor impacts may be an issue of concern.  It may be prudent to consult with qualified legal counsel to assess the risk, the scope of the due diligence undertaking and whether follow up or corrective actions are required.
  • The American Society of Testing and Materials (ASTM) has reissued a Standard Guide for Vapor Encroachment Screening On property Involved in Real Estate Transactions, E2600-10, that provides protocols for vapor screening and establishes a standard of care. For information on the ASTM Standard Guide, please visit:
  • State standards vary depending on the jurisdiction and in certain cases the regulatory program that is involved in reviewing site specific conditions.
  • The EPA and state environmental authorities are reopening past cleanups and taking a new look at the potential for vapor intrusion which raises liability concerns.
  • In sites where new buildings are being constructed it may be possible to install vapor barriers and or vapor mitigation systems under the floors of the building during construction. The corrective measures required for existing structures may be more difficult to implement.
  • In some cases in Minnesota, the EPA is stepping in to address potential vapor concerns, holding public meetings, conducting vapor surveys in homes and installing vapor mitigation control including sub-slab depressurization systems. The EPA has announced it is reserving its rights to seek recovery of its costs from responsible parties.

What should a property owner do if vapor is identified as an issue of concern? How can a lender on a commercial transaction ensure that its risks due to vapor concerns are minimized? How do vapor concerns affect the purchase and sale of commercial, industrial or residential property? Can I proceed with a sale or should more work be done?

It is not possible to answer questions related to the potential impact of vapor intrusion in a general way. For that reason, as is stated in our disclaimer below, no visitor should rely on information contained in this website or blog. Anyone concerned about vapor intrusion should contact a qualified attorney and review the details of their specific situation.

On March 9, 2011, environmental law attorney Joseph Maternowski, Chair of Hessian & McKasy’s Environmental Law Attorney Practice Group, participated in a “Due Diligence at Dawn” seminar sponsored by Environmental Data Resources (EDR) on the topic of “Why Vapor Intrusion Matters: An Environmental Attorney’s Perspective” in Minneapolis, Minnesota. A copy of the materials from Mr. Maternowski’s presentation can be found at: (see article entitled: “Due Diligence at Dawn”).

Mr. Maternowski, an experienced environmental lawyer, is involved with all aspects of environmental due diligence and offers legal service packages to lenders, buyers and sellers of real estate and others for professional services. Mr. Maternowski provides innovative legal services including expedited legal review of Phase I Environmental Site Assessments and Lender Liability Assessments for his clients. For more information about these legal services packages, please go to:

The views contained within this entry and on this website are my own and do not constitute those of Hessian & McKasy, a Professional Association.


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