MICHAEL H. GERARDI holds an MS in biology from James Madison University and provides wastewater operator training and troubleshooting of municipal and industrial wastewater treatment plants in the United States, Canada, the Caribbean, and Europe. He has authored more than eighty technical articles. He is currently responsible for the development and presentation of wastewater biology courses at the Pennsylvania State University.

MEL C. ZIMMERMAN is professor and chair of the Biology Department at Lycoming College. He also directs the Clean Water Institute at Lycoming. He has been teaching courses in ecology, aquatic biology, and tropical marine biology for twenty-four years. His research and publications deal with stream ecology and restoration, wetland ecology, and wastewater biology.