Matthew Lahvis is a Principal Soil and Groundwater Engineer at Shell Global Solutions (US) Inc. in Houston, Texas, where he provides technical support on soil and groundwater issues related to oil and gas operations. Matt’s role is multidisciplinary, involving research on petroleum chemical fate and transport, development of risk-based, sustainable business practices, review of site-investigation and remedial strategies, external advocacy, and legal support. Matt has authored numerous research articles and a book chapter on vapor intrusion. His research on vapor intrusion was critical in helping underpin California’s Low-Threat Tank Closure Policy and USEPA’s and ITRC’s vapor intrusion guidance. More globally, Matt served as a technical advisor in the development of vapor intrusion guidance for China, the UK, Australia, and Canada. Over Matt’s career, he has earned two CEO HSSE and Social Performance Awards, an Executive VP Brilliant People and Responsible Partner Award, and a scientific achievement award by the US EPA Office of Underground Storage Tanks. Matt is a member of the American Petroleum Institute’s Soil and Groundwater Task Force and an Associate Editor for Groundwater Monitoring and Remediation journal. Prior to joining Shell, Matt worked for 11 years at the US Geological Survey - New Jersey District where he authored the open-source unsaturated-zone transport model R-UNSAT. Matt was also an Adjunct Professor at Drexel University where he received his PhD in Civil Engineering in 1993.