Atlantic RBCA Guidance for Vapour Intrusion Assessments

Atlantic RBCA Guidance for Vapour Intrusion Assessments

The Atlantic RBCA Guidance for Vapour Intrusion Assessments (December 2016, updated April 2019) supercedes the User Guidance for Soil Vapour and Indoor Air Monitoring Assessments (Atlantic PIRI, 2006).

The Guidance document originally released in Dec. 2016 (and updated April 2019) does not include specific reference to chlorinated solvents. This was based on Health Canada’s recommendation that the most recent toxicity reference values published by the US EPA be used for the assessment of sites contaminated with perchloroethylene (PCE, also known as tetrachloroethylene) and trichloroethylene (TCE). Please refer to Implementation Procedure and Technical Bulletin #2 for PCE and TCE (December 2016, updated April 2019) for further details.

In April 2019, the Guidance (and all accompanying documents) were updated to reflect revisions made to the calculations for the Residential/Agricultural Vapour Intrusion Screening Levels (VISLs) for Soil Vapour, following the discovery of a miscalculation in the tables. Also note that certain sub-slab and soil vapour VISLs have changed slightly due to rounding of values in the calculations. In addition, the Guidance was updated to include a biodegradation factor of 10 into the calculation of Residential/Agricultural and Commercial/Industrial VISLs for Soil Vapour.

If you have questions about the Atlantic RBCA Guidance for Vapour Intrusion Assessments (December 2016, updated April 2019) you may contact Atlantic PIRI or your provincial environmental regulator.