Eliot Epstein is Chief Environmental Scientist for Tetra Tech, Inc. and an adjunct professor of public health at Boston University School of Public Health at the School of Medicine. He received his B.S. degree in Forestry from New York College of Forestry at Syracuse University, an M.S. degree in Agronomy from the University of Massachusetts, and a Ph.D. in soil physics from Purdue University. For 16 years he was a research leader for the U.S. Department of Agriculture’s Agricultural Research Service and an adjunct professor of soil physics at the University of Maine. His research there concentrated on soil erosion and runoff and soil water relations of plants., In 1972, Dr. Epstein transferred to the USDA ARS research center in Beltsville, Maryland, where he conducted research on the use of biosolids, and where, in 1975, he researched and developed the aerated static pile method (ASP). In 1980, he became president of E&A Environmental Consultants, Inc., a premier company in composting and beneficial use of organic materials. In that capacity, he was the principal-in-charge of numerous projects conducted by the staff located in Massachusetts, North Carolina, and Washington State., Dr. Epstein has more than 30 years of experience in biosolids composting, and has managed or directed more than 400 composting projects in the United States, Canada and Europe. He consulted on composting and biosolids management for the US EPA, World Bank and United Nations. In 2001, Dr. Epstein and his staff joined Tetra Tech, Inc., a leading company in water reuse, wastewater and beneficial use of organic residues.