Kodak has the facts at http://www.kodak.com/global/en/corp/.../pdfs/j300.pdf

There was a time Kodak was sloppy with waste disposal (the site of the 1 Choke Cherry Road Kodachrome processing plant is now a Superfund site), but they are clean now, and are very responsible about providing accurate information.

The only thing that isn't biodegradable is the silver in the fixer and bleach. Since silver is a cumulative toxin like mercury, you want to divert it. Use steel wool to extract the silver before disposing of fixer or bleach. This is so easy it's silly not to do it, even if you're not required to do it.

Alternately, bring the fixer and bleach to any 1-hour lab that properly does silver recovery. (I'd suspect that almost all do.) If they have half a brain, they will accept it gratefully, since they will recover and SELL the silver. You would be giving them something for nothing.