Todd McAlary is the Practice Leader for Vapor Intrusion at GeoSyntec Consultants, Inc.. Todd conducted his first assessment of subsurface vapor intrusion to indoor air beginning in 1992, and has been the Technical Director of one of the world's largest studies of subsurface vapor intrusion since 1997. He has since conducted screening level assessments, peer reviews or site-specific assessments of vapor intrusion at several dozen sites across North America and internationally. He was invited by the U.S. EPA to participate in the development of the RCRA Supplemental EI Guidance on vapor intrusion, and was one of the three primary co-authors. He was the only non-regulator on the Steering Committee for the U.S. EPA Seminar on Indoor Air Vapor Intrusion, helped produce the CD version of the seminar, was a panel member for three workshops at the AEHS conferences aimed at addressing comments on the 2002 Draft OSWER Vapor Intrusion Guidance, and is a member of the expert panel charged with producing the 2006 revision. He has conducted leading applied research in this emerging field, and has presented at over 20 conferences on the topic, as well as short courses at Battelle and AWMA conferences and webinars with EICE. He was the primary author for the Electric Power Research Institute's (EPRI's) Vapor Intrusion Reference Handbook, and a contributing author or editor to vapor intrusion guidance documents prepared by Atlantic Provinces Partnership for RBCA Implementation (PIRI), Health Canada, the New Jersey DEP, and the Interstate Technical and Regulatory Council (ITRC) Vapor Intrusion team, for which he received an award in 2006 for his participation. Todd earned a bachelor's degree in geological engineering in 1986 and a master's degree in hydrogeology in 1989, both from the University of Waterloo in in Waterloo, Ontario, Canada . His master's research project involved the determination of vapor diffusion coefficients in variably saturated sand columns. Todd is a licensed professional engineer in his home province of Ontario and is a licensed geologist in North Carolina .