When you apply to enroll in the Environmental Engineering program, your application will also automatically be considered for teaching assistantship and research assistantships.
However, the process is extremely competitive, and applying to or being admitted to the program does not guarantee support.
You should contact professors in your specialization area directly for research assistantship availability.
Unless exceptionally well qualified, you will be considered for financial support only after you have demonstrated superior performance in academic work during your first year in residence.