These are some of the universities which have good program for post studies after Masters in Environmental Science:

United States:
Arizona State University
Washington State University
Arkansas State University
University of California, Santa Barbara
University of Idaho
Indiana University
University of Idaho
University of California, Berkeley
The University of Texas

Australia:
The University of New South Wales
Murdoch University
La Trobe University
Macquarie University
The University of Western Australia
University of Melbourne
University of Wollongong