Mark Lyverse is a senior staff hydrogeologist with Chevron’s Energy Technology Company. He is a member of the Site Assessment and Remediation Team in San Ramon , California and is a subject matter expert in LNAPL. Since 1990, he has provided technical advice both domestically and internationally to project managers and consultants in the areas of developing site strategies, site characterization, assessment, and remediation. His experience prior to Chevron includes 10 years with the U.S.G.S and 2 years in private consulting. Mark has been a member of the American Petroleum Institute’s soil and groundwater technical group since 2002 and was industry co-chair the former RTDF LNAPL group from 2001-2005. In that role he made technical presentations to over hundreds of attendees from various regulatory and stakeholder groups. In addition, he routinely provides technical transfer workshops and seminars to project managers engaged in site assessment and remediation activities at numerous Chevron sites. His current research interests include a collaboration with Colorado State University (CSU) investigating LNAPL stability/ mobility/ recoverability, natural source zone (LNAPL) depletion, and developing innovative techniques to better understand and manage petroleum sheens. He is a co-inventor on three patents with CSU related to these topics. Mark earned a bachelor of science degree in forestry from Utah State in Logan in 1977 and a master’s degree in Water Resources (specialization in hydrology) from the University of Wyoming in Laramie in 1981.