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ASTM Publishes Revised Standard for Conducting Vapor Encroachment Screening


On June 14, 2010, ASTM International published the Standard for Vapor Encroachment Screening of Property Involved in Real Estate Transactions, ASTM E2600-10 (the “2010 VES Standard”). The 2010 VES Standard replaces the Standard Practice for the Assessment of Vapor Intrusion into Structures on Property Involved in Real Estate Transactions, E2600-08 published in March 2008. The 2010 VES Standard provides a standardized process for conducting evaluations regarding the potential for vapors to adversely impact property involved in real estate transactions.

The purpose of the 2010 VES Standard is to identify Vapor Encroachment Conditions (“VEC”) that may migrate onto a property due to the presence of contaminated soils and/or groundwater on or in the vicinity of the property. The standard defines the term “vapor encroachment condition” as the presence or likely presence of constituent of concern vapors in the sub-surface of a property that are caused by the release of vapors from contaminated soil or groundwater. The 2010 VES Standard sets out a two-tiered screening process designed to identify the presence of VECs. The first tier is designed to address the existence of known or suspected contaminated properties within a study area and results in a conclusion that a VEC exists, likely exists, cannot be ruled out or can be ruled out. The second tier of the screening process is designed to address VECs that cannot be ruled out based on the information obtained during the first tier analysis. The second tier investigation involves a more refined screening process under which numeric screening criteria are applied to existing or newly acquired soil, soil gas, and/or groundwater analytical results to evaluate whether or not a VEC is present at a subject property.

It should be noted that the 2010 VEC Standard does not alter or replace the ASTM Phase I Environmental Site Assessment (“ESA”) standard, E1527-05, that is designed to satisfy All Appropriate Inquiry (“AAI”) under the Comprehensive Environmental Response, Compensation and Liability Act (“CERCLA”) and the associated AAI regulations, 40 CFR § 312.11. Satisfaction of AAI requirements is a prerequisite for a purchaser of real estate to qualify for certain exceptions to liability set forth under CERCLA. However, the 2010 VEC Standard provides a methodology under which an environmental professional performing a Phase I ESA can determine whether vapors from hazardous substances and petroleum products are on or migrating to a subject property and satisfies the criteria to be identified as a recognized environmental condition during the performance of a Phase I ESA. If a VEC is identified at a property that is the subject of a Phase I ESA, the environmental professional would be required to determine whether the VEC constituted a REC.

The 2010 VES Standard is available at

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