MDEQ Vapor Intrusion Guidelines and the New VIAP Calculator

The Michigan Department of Environmental Quality (MDEQ) has established guidelines for Vapor Intrusion (VI). Vapor intrusion is an exposure pathway resulting from the migration of volatile chemicals from the subsurface into overlying buildings with human receptors. According to the MDEQ, a source, migration path, and a human receptor must all be present for the VI pathway to be considered a risk. Vapors can be generated from sources that include contaminated groundwater and soil, NAPL, or buried waste.

The MDEQ is currently finalizing updates to Michigan Part 201 (Cleanup Criteria Requirements for Response Activity) for VI action screening levels, which are expected to be finalized in 2018.  In August 2017, the MDEQ released interim action screening levels for volatilization to indoor air. The finalized VI updates are expected to include revised screening levels and generic cleanup criteria for the vapor intrusion pathway. The MDEQ is also planning to provide a volatilization to indoor air pathway (VIAP) calculator for developing facility-specific screening levels based on site conditions. The MDEQ will be hosting a webinar to provide interested parties with an opportunity to learn more about the VIAP calculator. 

Merit Laboratories performs laboratory testing to support vapor intrusion projects.  Analytical testing performed by Merit includes the analysis of Volatile Organic Compounds (VOCs) by EPA Method TO-15. Merit is NELAP-accredited for the analysis of VOCs by TO-15.  The laboratory maintains a large stock of sample collection media to support VI projects, including bottle vacs, Silonite™ ceramic coated canisters, flow controllers and helium shrouds.  Please contact Merit to learn more about how we can support your vapor intrusion project testing needs.