November 5, 2018

« All News

Todd McAlary to Present on New Tools for Vapor Intrusion Mitigation Design to the Michigan Association of Environmental Professionals

Todd McAlary, Ph.D., P.Eng., P.G. (Toronto) will present "New Tools for Vapor Intrusion Mitigation Design" at the Michigan Association of Environmental Professionals (MAEP) Professional Development Meeting at the Block Brewing Company in Howell, Michigan from 5:30 p.m. - 9:00 p.m. on November 7, 2018.

Geosyntec's Wayne Amber, Ph.D., (Michigan) sits on the Board of Directors and will also be attending the event along with Rob Ferree, C.P.G., (Michigan) and Bryan VanDuinen, P.E. (Michigan). Geosyntec is the sole sponsor for the event.

Todd is a Senior Principal Engineer based in Toronto with more than 30 years of international consulting experience focused on the evaluation of contaminant fate and transport in soil and groundwater.

The Michigan Association of Environmental Professionals was founded in 1978. They host professional development meetings and publish newsletters throughout the year to bring relevant content to their membership; they host annual golf outings to raise funds for our Environmental Education Grant program; and they award grant funding to local schools, universities, community organizations, and other non-profits to encourage and inspire the next generation of environmental professionals.

Summary of ESTCP Research Project ER2013-22

Mitigation systems for radon and volatile organic compound (VOC) vapor intrusion to indoor air (VI) are usually designed to impose a measurable vacuum beneath the floor slab of a building through gas extraction from below the floor and the primary monitoring parameter is the static vacuum imposed by the system. This approach has some limitations associated with spatial variability in the vacuum field, temporal variability in the ambient cross-slab pressure gradient and building-specific conditions (bulk average permeability of the floor slab and material below the floor). Several new lines of evidence have been developed through a 5-year research program sponsored by the U.S. Department of Defense, through the ESTCP program. The analysis includes monitoring of transient vacuum response to turning the extraction fans on and off, helium tracer testing and mass emission monitoring combined with a mathematical model of fluid flow in a two-layer system (Hantush and Jacob, 1955). The incremental cost to include the additional lines of evidence is small and the savings generally increase as the size of the building increases, so net savings are to be expected for medium or large buildings. Case studies from three buildings of different sizes will be included to demonstrate the application of the new lines of evidence.

More Information

Learn more about the event:
Learn more about registration:
For consultation regarding subsurface contaminant vapors, contact Todd McAlary at This email address is being protected from spambots. You need JavaScript enabled to view it.
Learn more about Todd at: