Geosyntec Consultants Inc.
Helen Dawson:Helen is a recognized leader in vapor intrusion. She was the primary author of the U.S. EPA's Office of Solid Waste Emergency Response (OSWER) Draft Guidance for Evaluating the Vapor Intrusion to Indoor Air Pathway from Groundwater and Soils in 2002. She also was the primary investigator and author on two key technical documents that support vapor intrusion assessment: one on background indoor air concentrations in residences and another on the subsurface-to-indoor air attenuation at vapor intrusion sites. She continues to advance the state of the practice though specialized presentations for clients, invited talks at national conferences, and participation in expert panels advising regulatory agencies.Beyond vapor intrusion, Helen's practice spans a wide range of technical disciplines including groundwater characterization, and contaminant fate and transport modeling related to the spread of dense non-aqueous phase liquids, chlorinated solvents, and metals in the environment.