This three-year REU Site program at the University of Colorado, Boulder is focused in the broad area of environmental engineering.  Over the ten-week summer program, nine or ten undergraduate students per year will conduct research on a broad range of topics in environmental engineering emphasizing multimedia approaches (water, air, soil) and long-term drivers of environmental systems such as energy, climate variability and hydrology. An interesting feature of this program is that, three or four of the students per summer will work for five weeks on research projects with affiliated programs in Puerto Rico.