Environmental engineers use the principles of engineering, soil science, biology, and chemistry to develop solutions to environmental problems. They are involved in efforts to improve recycling, waste disposal, public health, and control of water and air pollution. Environmental engineers work in a variety of settings because of the nature of the tasks they do. When they are working with other engineers and urban and regional planners, environmental engineers are likely to be in offices. When they are carrying out solutions through construction projects, they are likely to be at construction sites.