The New Definitions of Vapor Migration and Encroachment

August 05, 2016

Many states have provided guidance in addressing vapor for several years. The most recent revision to the ASTM 1527-Phase I Standards pushed vapor migration and vapor encroachment consideration to the forefront during the due diligence process. Formerly ASTM defined a Recognized Environmental Conditional (REC) as “any hazardous substances or petroleum products into structures on the property or into the ground, ground water or surface water of the property.”

The Revised Definition

In the revised definition, the specific references of ground and ground water are omitted and replaced with the terms releases to the environment, broadening the definition and medium considered. It is not within the scope of a Phase I ESA to evaluate the potential for vapor to be present inside a building as the result of a release (vapor intrusion). However, it is within the scope to identify the presence or likely presence of hazardous substances or petroleum products on the property due to a release. This is based on an understanding of the various pathways and how contamination is likely to migrate onto the property.

The goal is to evaluate if a property or parcel involved in a real estate transaction has been impacted with chemicals of concern (COC) that may migrate as vapor onto a property or into a building as a result of contaminated soil and/or groundwater on or near the property. During due diligence, if a vapor issue is identified, it is not necessarily a deal killer. However, popular mitigation options are available to minimize the risk of vapor intrusion. These include source remediation, elimination of the receptors, institutional/engineering controls, elimination or reduction of the exposure, or some combination of these options.

Environmental Site Assessments

Bock & Clark has a full staff available to perform Phase I (ASTM E1527-13) and Phase II (ASTM E1903) Environmental Site Assessments in conformance with American Society for Testing and Materials (ASTM) E 1527-13 and E1903 respectively, and the Environmental Protection Agency All Appropriate Inquiry.

Review our Sample Phase I ESA (PDF) and request a quote today.