Integration of both science and engineering is called as environmental engineering. Principles of science & engineering helps in improving the natural environment which gives healthy life to human beings by giving pure water, air, and land and it also keep the area pollution free. Environmental engineering includes waste water management, air pollution control, waste disposal, public health issues etc. Environmental engineering involves science and engineering strategies to improve the nature in order to provide healthy and clean air, water, and land for the habitation of human beings and other organisms. It includes air pollution control, waste water management, waste disposal, recycling, industrial hygiene, radiation protection, and public health issues etc. It even studies the impact on the nature due to a proposed construction projects. Environmental engineers study the effect of the new technologies on the environment. To do so, they do various tests like, hazardous waste management study, to find the significance of some hazards on the environment, and they also develop certain strategies to avoid mishaps. It involves recent discoveries in the area of sustainability, environmental safety, recent developments in green chemistry, wastewater reuse, water supply and its treatment, air pollution and water pollution prevention, disposal of waste etc..