I think enviro-engineering is really a great area to work, but actually I am not familiar with any school having that specific focus.
I assume you are an undergraduate, so I would suggest that you take as many courses in engineering and environmental sciences (and math) as possible, and develop your own enviro-engineering curriculum. Later in graduate school you can continue along the same path, or go to a school that is strong in atmospheric, oceanic, hydrological and geological sciences, and also strong in hydrological engineering. It is my experience at the University of Maryland, which is an example of such school, that students will be encouraged to do multidisciplinary studies. For example we have several joint students between our Atmospheric and Oceanic Science Department and Chemistry, with a number of Ph. D.'s in atmospheric and oceanic chemistry. Similarly we have a number of Applied Math students that did their theses in atmospheric sciences. I am affiliated with ESSIC, the Earth System Science Interdisciplinary Center, and with the School of Engineering, as well as our Atmospheric and Oceanic Science Department.
Let me know if this answers your most interesting question!