Prof. Francis J. Hopcroft recently retired from teaching civil and environmental engineering after 23 years in the classroom and about 40years of consulting in the field. He is the author of six environmental engineering and hazardous waste management books, the coauthor of 22 such books, and a contributor to a dozen or more professional manuals of practice. He was registered as a Professional Engineer in all six New England states and as a Licensed Site Professional in the Commonwealth of Massachusetts. Before starting his teaching career, he spent 25 years in professional practice as a consultant, an EPA regulator, and as the President of several consulting firms doing site assessment for the presence of hazardous materials. He continued his consulting work while teaching to maintain currency in his field and to bring current concepts into the classroom. Dr. Abigail Charest is an Associate Professor and Dean of the School of Management at Wentworth Institute of Technology (WIT) in Boston, Massachusetts. She is currently the Blittersdorf Endowed Professor and utilizes the professorship to address topics of sustainability in the curriculum. She is an avid researcher, experimenter, and innovator in the laboratory. She is focused on the biological nature of environmental work and developed the biological experiments in this book, among others. She has also been the lead faculty member in the redevelopment of a graduate program in civil engineering at Wentworth. She earned her doctorate from the Worcester Polytechnic Institute, and prior to entering into academia, she worked in the field of environmental consulting in the New England area. During this time, she received her Professional Engineering license in the Commonwealth of Massachusetts.