Dr. Stephen Geiger is an environmental scientist working for ERM in Washington, DC. He has more than 25 years of experience in site characterization and remediation through the assessment of bioavailability of metals and organics in soils and sediments, the statistical analysis of environmental data, innovative applications of environmental chemistry, and human health and ecological risk assessment. He has conducted research on the bioavailability of PAHs in sediments and soils, as well as phytoremediation for PAH-contaminated soils and CN-contaminated groundwater. Stephen earned a bachelorís degree in biology at Gettysburg College in Gettysburg, Pennsylvania in 1975. After college he worked in Honduras from 1976 to 1978 as a Peace Corps Volunteer on a soil management program. He then earned a masterís degree in soil science from Rutgers University in New Brunswick, New Jersey in 1983, and a doctoral degree in soil chemistry from Texas A&M University in College Station, Texas in 1986. From 1987 to 1992 he worked in Niger, West Africa, conducting research on soil-plant nutrient relationships.