Quote Originally Posted by DSLR View Post
I'm going to develop a roll of 120 tomorrow and have a few questions. When I'm doing the stop bath (with water) is it OK to let that little bit of developer (Hc110) go down the drain? Same with the fixer, after I pour the used stuff back in the bottle is it alright to let the little amount still on the film rinse down the drain? I'm going to pour the used developer into an empty water bottle and will discard the fixer properly as well. I have a septic tank so that's why I'm worried.
Septic systems work in part by the soil filtering the effluent so by the time it gets to the groundwater it is fit enough to drink. If this didn't happen, there would be contaminated groundwater everywhere. Think of all the things people pour down their drains--soaps, detergents, household cleaning chemicals, and who knows what else. So I doubt if you need to worry about any harm to the environment. To reiterate what has been said before on this site, the only problem might be silver or silver compounds interfering with bacterial action that breaks down solid wastes. But again the small amount a typical home darkroom worker uses would likely not pose a problem compared to a big lab. I have been pouring all my chemistry down the drain for years and when my tank has been pumped I have never been told of any problems, nor have I heard of any cases where it has happened.