Mr. Roberts-
I have a darkroom, a septic system, and a private well, and live above a river... Needless to say I don't want to damage any of those things.
After reading and reading, I decided I was O.K. as long as no fixer goes in the drain, no toner, and developer and stop are mixed together to neutralize them beforehand.
From what I've been able to gather, heavy metals are the largest threat to the biology in your septic tank and the groundwater around your home. Fixer is loaded with silver and selenium toner contains selenium, so they're the largest threat. I take my fixer to a one hour joint that is gracious enough to have it recycled for me, at no cost(!) I save my toner and take it to local household waste pickups. This is not free, of course.
The next threat is PH imbalance. Neutralizing the developer and stop together roughly eliminate this threat to your septic tank. If this doesn't seem like a complete enough solution to you, some printers mix these chemicals together, then allow them to dry and oxidize outdoors. The dried waste is then taken to a landfill.
I also limit myself to two printing sessions per month to minimize my impact.
Unfortunately, really good information on the subject is hard to find. There have been endless discussions on Pnet and APUG about it. I suggest you read everything you can find and decide for yourself.
If you learn something the rest of us should be aware of please post!
