Environment is essential for our survival and the survival of all the species present on Earth. Environmental engineering is the study and process of using the applications of engineering in preserving and protecting the human population and other species by saving the environment. It deals with preventing and minimizing the harmful effects that human activities have on the ecosystem. The topics included in this textbook offer deep insights about the methods and techniques used in this area. Also included herein is a detailed explanation of the various concepts and applications of environmental engineering. It is a complete source of knowledge on the present status of this important field.