Jeffrey A. Johnson, Ph.D., CPG, LRS, is currently working as a geologist with NewFields. Having more than 25 years of professional experience in natural resource assessment, site characterization, remedial operations, and technical analyses, he’s worked on various projects throughout North America for major petroleum corporations, legal firms, manufacturing companies, and the U.S. Environmental Protection Agency. Johnson has worked on groundwater/surface water issues for more than 20 years. For the past 10 years, he has worked extensively in the characterization and remediation of LNAPL and DNAPL sites, and is actively working on NAPL impacts to sediments and characterizing the differences between groundwater and in situ NAPL emplacement. Johnson holds a Ph.D. in geology from the University of California, Berkeley.