Basic Environmental Engineering is compartively a fascinating branch of Engineering. It deals with the concepts of chemistry applied to the different field of engineering. It deals mainly with the following major field namely-Water pollution, Air pollution, Differents, Soil waste management, Ecology etc. The main object of this book is to furnish important inormatons related to these fields. The book will be helpful for the engineering. The questions in this book have been complied from B.E. Exam. The authors are deeply indebted to a number in various engineering colleges of the state, mainly Dr. Radha Chaudhary (Geetanjali Institute), and Dr. R.K. Malkani (Aravali College), Dr. Ritu Vyas (Pacifi Institute) and Dr. Monika Sharma (Techno India NJR Institute) for their co-operation during the preparation of this manuscript. The authors express their thanks to their colleagues and friends, who wncouraged for writting such a book, which is helpful to engineering students. Any suggestion from teacher, students and reader are always welcome.