The book Environmental engineering covers a wide range of topics-water, sanitation and drainage, solid and liquid waste treatment, energy, pollution control and environmental planning. the basis of environmental engineering is the sustainability which include the ecology, climate, geology, hydrology, and infrastructure services. One of the major challenges pertains to making the cities more sustainable by environmental planning, which have been explained in detail. Several examples, explained in a simple, flowing language and more than 200 drawings and visuals give a practical focus to the book.