Hans W. Meinardus is a senior hydrogeologist with INTERA, Inc. in Austin, Texas. He has a BS and an MS in Geology from Texas A&M University, with a specialization in Hydrogeology under Dr. Pat Domenico. He has worked with INTERA (formerly Duke Engineering and Services from 1997-2001) since graduation in 1991. For the past eight years he has specialized in NAPL source zone characterization, remediation, and remediation performance assessment, and has been involved in the development and deployment of innovative NAPL characterization and remediation technologies. Mr. Meinardus has been the INTERA project manager at Hill Air Force Base in Utah since 1995 where he was responsible for conducting Partitioning Interwell Tracer Tests (PITTs) (including the first full-scale implementation in 1998-99), three successful surfactant-flood remediation demonstrations (1996-7), and three full-scale surfactant floods (1999-2002). Mr. Meinardus was responsible for quantitatively delineating the volume and extent of the DNAPL source at Hill AFB's Operable Unit 2, and also assisted in the design and implementation of a cometabolic bioventing demonstration. He is currently involved in a post-surfactant flood bioremediation study at OU2, and is managing several other efforts to characterize contaminated sites, assess remedial options using numerical simulation studies, and to remediate NAPL source zones. His numerical ground-water flow and transport modeling experience includes developing, using, and managing three-dimensional single-phase and multi-phase numerical models for use in site investigation and in the design and evaluation of remedies at various facilities contaminated with NAPLs, lead, and arsenic. He has been an instructor for numerous DNAPL site characterization and remediation short courses, including ESTCP workshops. In addition, he has co-authored several peer-reviewed papers and presented on various NAPL topics at numerous conferences. Mr. Meinardus currently serves on the DNAPL team of the Interstate Technology Regulatory Council (ITRC).