I imported the french pg files encoded in utf8 however the webwork read them in iso88591
Can I modify webwork to read the files in utf8?
Probably yes, if you have access to the command line and the mysql database. (Back things up first!) and then change the character set being used in the tables.
If you are using webwork 2.15 or later (perhaps 2.14 as well) then you should have modified the database at that time to be utf8mb4 (mysql's version of full unicode, 4 byte character encoding ) compatible. The documentation on webwork site about this is still rather spotty, but there is lots of information within mysql documentation. We're still catching up on the uniform internationalization of webwork -- its a new feature and I hope that it takes off.