George Tchobanoglous is a professor emeritus of environmental engineering in the Department of Civil and Environmental Engineering at the University of California at Davis. He received a B.S. degree in civil engineering from the University of the Pacific, an M.S. degree in sanitary engineering from the University of California at Berkeley, and a Ph.D. in environmental engineering from Stanford University. His principal research interests are in the areas of wastewater treatment, wastewater filtration, UV disinfection, water reuse, wastewater management for small systems, and solid waste management. He has authored or co-authored over 500 technical publications including 22 textbooks and 8 reference works. His books are well known for successfully bridging the gap between academia and the day-to-day world of the engineer. He has given more than 500 technical presentations, both in the United States and abroad. He is a Past President of the Association of Environmental Engineers and Science Professors. Among his many honors, in 2003 he received the Clarke Prize from the National Water Research Institute. In 2004, he received the Distinguished Service Award for Research and Education in Integrated Waste Management from the Waste-To-Energy Research and Technology Council. In 2004, he was also inducted into the National Academy of Engineering. In 2005, he was awarded an honorary Doctor of Engineering from the Colorado School of Mines. In 2007, he received the Frederick George Pohland Medal awarded by AAEE and AEESP. In 2012 he received the Excellence in Engineering Education Award, AAEE and AEESP and was elected as a WEF Fellow. He is also a registered professional engineer.

H. David Stensel is a professor of civil and environmental engineering at the University of Washington, Seattle, WA. Prior to his academic positions, he spent 10 years in practice developing and applying industrial and municipal wastewater treatment processes. He received a B.S. degree in civil engineering from Union College, Schenectady, NY, and M.E. and Ph.D. degrees in environmental engineering from Cornell University. His principal research interests are in the areas of wastewater treatment, biological nutrient removal, sludge processing methods, biodegradation of hazardous substances, and stormwater treatment. He has authored or coauthored over 100 technical publications and a textbook on biological nutrient removal. He has received the ASCE Rudolf Hering Medal and twice received the Water Environment Federation Harrison Prescott Eddy Medal for his research contributions. He is a member of numerous professional societies, and has served as chair of the ASCE Environmental Engineering Division, treasurer of the American Association of Environmental Engineering Professors, and associate editor of the Water Environment Federation Research Journal. He is a registered professional engineer and a diplomate in the American Academy of Environmental Engineers.

Ryujiro Tsuchihashi is a senior process engineer with AECOM. He received his B.S. and M.S. in civil and environmental engineering from Kyoto University, Japan, and a Ph.D. in environmental engineering from the University of California, Davis. The areas of his expertise include wastewater/water reclamation process evaluation and design, evaluation and assessment of water reuse systems, biological nutrient removal, molecular technologies in the detection of pathogenic organisms in the aquatic environment, and evaluation of greenhouse gas emission reduction from wastewater treatment processes. He was a co-author of the textbook "Water Reuse: Issues, Technologies and Applications," a companion textbook to this textbook. He is leading the Technical Practice Network on water reuse, AECOM's internal technical network. Ryujiro Tsuchihashi has been an employee of AECOM for 10 years.

Frank Burton served as vice president and chief engineer of the western region of Metcalf & Eddy in Palo Alto, California for 30 years. He retired from Metcalf & Eddy in 1986 and has been in private practice in Los Altos, California, specializing in treatment technology evaluation, facilities design review, energy management, and value engineering. He received his B.S. in mechanical engineering from Lehigh University and an M.S. in civil engineering from the University of Michigan. He was co-author of the third and fourth editions of the Metcalf & Eddy textbook “Wastewater Engineering: Treatment and Reuse.” He has authored over 30 publications on water and wastewater treatment and energy management in water and wastewater applications. He is a registered civil engineer in California and is a life member of the American Society of Civil Engineers, American Water Works Association, and Water Environment Federation.

Mohammad Abu-Orf is AECOM’s North America biosolids practice leader and wastewater director. He received his B.S. in civil engineering from Birzeit University, West Bank, Palestine and received his M.S. and Ph.D. in civil and environmental engineering from the University of Delaware. He worked with Siemens Water Technology and Veolia Water as biosolids director of research and development. He is the main inventor on five patents and authored and co-authored more than 120 publications focusing on conditioning, dewatering, stabilization and energy recovery from biosolids. He was awarded first place for Ph.D. in the student paper competition by the Water Environment Federation for two consecutive years in 1993 and 1994. He coauthored manuals of practice and reports for the Water Environment Research Foundation. He served as an editor of the Specialty Group for Sludge Management of the International World Association for six years and served on the editorial board of the biosolids technical bulletin of the Water Environment Federation. Mohammad Abu-Orf has been an employee of AECOM for 6 years.

Gregory A. Bowden is a technical leader with AECOM. He received his B.S. in chemical engineering from Oklahoma State University and a Ph.D. in chemical engineering from the University of Texas at Austin. He worked for Hoechst Celanese (Celanese AG) for 10 years as a senior process engineer, supporting wastewater treatment facility operations at chemical production plants in North America. He also worked as a project manager in the US Filter/Veolia North American Technology Center. His areas of expertise include industrial wastewater treatment, biological and physical/chemical nutrient removal technologies and biological process modeling. Dr. Bowden is a member of the Water Environment Federation and has been an AECOM employee for 9 years.

William P. Pfrang is a Vice-President of AECOM and Technical Director of their Metro-New York Water Division. He began his professional career with Metcalf & Eddy, Inc. as a civil engineer in 1968. During his career, he has specialized municipal wastewater treatment plant design including master planning, alternative process assessments, conceptual, and detailed design. Globally, he has been the lead engineer for wastewater treatment projects in the United States, Southeast Asia, South America, and the Middle East. He received his B.S. and M.S. in civil engineering from Northeastern University. He is a registered professional engineer and a member of the American Academy of Environmental Engineers and the Water Environment Federation. William Pfrang has been an employee of AECOM for 39 years.