Might be somewhat of a weird combination for a double major, but what schools are notable for their Arabic and engineering (specifically biomedical or environmental) programs?
Ohio State
University of Oklahoma
http://www.ou.edu/cis/sponsored_programs/arabic_flagship_program.html
http://www.ou.edu/coe/cees/undergrad_programs/env_engineering.html
American University of Beirut. 
My son will be attending the school in the fall, but not in engineering. My dad, a UT-Austin professor, had several of the AUB engineering faculty as his students.