I would like a list of paid summer internships in France for
upperclass, undergraduate environmental or chemical engineering
students, preferably in Paris.  I need a list of internships for
companies that require little or no prior knowledge of French,
although it would be great if the internship offered classes in
French. I would like the list to include a balance between
environmental engineering internships and chemical engineering
internships.  If possible, I would like information on an internship
that involves environmental computer modeling.  The duration of the
internships needs to be from the end of May or early June until the
end of August.

Try these websites:

http://aipt.org/subpages/iaeste_us/index.php
http://www.internabroad.com/listingsp3.cfm/listing/16296

also do a Google search:
France internships engineering

Good luck