Atlantic RBCA Guidance for Vapour Intrusion Assessments

Atlantic PIRI is pleased to release the final version of the Atlantic RBCA Guidance for Vapour Intrusion Assessments (December 2016). This document provides guidance on the assessment of vapour intrusion and is intended to supersede the User Guidance for Soil Vapour and Indoor Air Monitoring Assessments (Atlantic PIRI, 2006).

Thank you to all who provided commentary on the draft document during the Public Review Period. Revisions were made to the document because of this feedback, the most noticeable of which is the removal of chlorinated solvents.

Please refer to the Atlantic RBCA Guidance for Vapour Intrusion Assessments Implementation Procedure (December 2016) which outlines the implementation process for the new guidance.

The toxicological data for perchloroethylene (PCE, also known as tetrachloroethylene) and trichloroethylene (TCE) were based on toxicological reference values published by Health Canada in their 2010 guidance document. In their review comments, Health Canada noted they are in the process of updating their 2010 guidance document and has recommended that more recent toxicity reference values published by the US EPA be used for the assessment of sites contaminated with PCE and TCE.

Consequently, Atlantic PIRI has made the decision to remove all references to chlorinated solvents from the Guidance for Vapour Intrusion Assessments (December 2016) and accepts Health Canada’s recommendation that the more recent US EPA toxicity reference values be used for the assessment of sites contaminated with PCE and TCE. Please refer to Implementation Procedure and Technical Bulletin #2 for PCE and TCE (December 2016) for further details.

Provincial regulatory staff can be contacted regarding any questions on the new Guidance for Vapour Intrusion Assessments document or the changes related to the chlorinated solvents toxicological information.