Role of environmental engineers for the betterment of environment

I have just passed out 12th class and I would like to know the role of environmental engineers for the betterment of environment?

Role of environmental engineers are very vast in terms of conducting studies on different aspects like hazardous waste management in which they try to evaluate the significance of different kinds of hazards in water. The different roles of environmental engineers are as follows:

1. Studying different aspects of waste management and making a report
2. Evaluating different hazardous materials in environment and making strategies to treat and contain it.
3. Designing municipal water supply so the waste can be managed at one place systematically.
4. Researching on the environmental impact of the construction projects and the waste that gets accumulated at different areas, cities.
5. Designing and studying the waste treatment system and making it more efficient to help environment fight the hazardous elements present in the waste.
6. Studying techniques to minimize the effect of acid rain, global warming, ozone depletion and other factors caused by pollution and excessive emission of waste.
7. Studying different automobiles emissions and devising ways to prevent it.
8. Creating regulations by collaborating with technicians, engineers and specialists on different environmental issues.