Environmental Due Diligence & Risk Management

Preparing for my webinar on "Addressing Vapor Intrusion during a Property Transaction," I ran across an ASTM article that gave a great basic snapshot of the four tiers involved in conducting a vapor intrusion assessment. I have copied an exerpt below, but you can find more information at www.astm.org.

Anthony J. Buonicore, chair of ASTM Task Group E50.02.06 on Vapor Intrusion, says E2600 defines good commercial and customary practice for conducting a vapor intrusion assessment on a property parcel involved in real estate transactions. “The specific intent was to establish a methodology to determine whether or not there is a reasonable probability that vapor intrusion could present an environmental risk and liability,” says Buonicore. For commercial real estate transactions, Buonicore notes that the vapor intrusion investigation, as defined by E2600, could be used independently of, or as a supplement to, E1527, Practice for Environmental Site Assessments: Phase I Environmental Site Assessment Process.

The evaluation process, as described in E2600, consists of four tiers. The first two screening tiers are used to assess the potential for a vapor intrusion issue to exist, so that properties with a low risk can be screened out quickly and inexpensively. The third tier provides for more site-specific and comprehensive investigation if the potential for vapor intrusion cannot reasonably be eliminated at the Tier 1/Tier 2 levels, while Tier 4 addresses mitigation alternatives.

According to Buonicore, because timeliness may be more important than investigation or mitigation costs during real estate transactions, an E2600 user does not need to proceed sequentially through the tiers in the standard. “In most cases, however, it is expected that it would be more cost effective and sufficient time would be available in the real estate transaction to conduct at a minimum a Tier 1 screening evaluation and, if necessary, a Tier 2 screening evaluation before proceeding to a more costly and time-consuming Tier 3 investigation or to Tier 4 mitigation,” says Buonicore. He also notes that the process described in E2600 is designed to complement existing federal and state vapor intrusion policies or guidance.

Look for future posts detailing what is involved with each tier level!