Warren Viessman, Jr. is Professor Emeritus with the Department of Environmental Engineering Sciences, College of Engineering University of Florida. He served as Associate Dean for Academic Programs from 1990 to 2003, and prior to that was Chairman of the Department of Environmental Engineering Sciences. Dr. Viessman is senior author of widely used textbooks on water supply and pollution control, hydrology, and water management. He has served on numerous national, regional and state committees and commissions, and is recognized for his outstanding contributions to water resources and environmental policy making and analysis at state and national levels. His many national awards attest to his efforts in these fields. He is an Honorary Member of the American Society of Civil Engineers and a registered professional engineer. Mark L Hammer is Professor Emeritus of civil engineering and is an author of environmental engineering publications in the United States and Saudi Arabia. During his long tenure as a professor at the University of Nebraska-Lincoln, Dr. Hammer also served as the Director of the Environmental Protection Agency Grant in Water Quality Control. He has taught at the King Fahd University of Petroleum & Minerals and King Abdul Aziz University, Saudi Arabia, where he conducted environmental engineering research in addition to his teaching responsibilities. He is a member of the American Water Works Association and the Water Environment Federation.