Quote Originally Posted by Gerald C Koch View Post
Kodak in one of its publications states that there is no adverse effect on septic systems from the amateur darkroom. The professional darkroom is another matter.

I'm afraid Kodak's publications no longer make this statement.

Darkroom Design for Amateur Photographers • AK-3 explicitly states the opposite: http://www.kodak.com/global/en/profe...bs/ak3/ak3.pdf

Environmental Guidelines for Amateur Photographers • J-300 is the best Kodak reference I can find on the subject: http://www.kodak.de/ek/uploadedFiles...er/J300ENG.pdf

That being said, I don't think the trace amounts the OP was asking about (in the rinse and wash solutions) are of concern.