I ended up calling my local EPA field office regarding the disposal of photographic chemicals. First of all, he was not impressed with my idea of boiling down the chemicals... surprise, surprise
) Mainly, mixing up chemicals and then bringing up to very high concentrations.
Anyhoo... we then talked about how to dispose of the chemicals, his first suggestion was to take them all to the local recycling "days" where I could dispose of them. Since I was planning on doing this anyhow, I was in agreement. But then I asked about what chemicals I could safely pour down the drain. No surprise he said photo-flo and stop bath if well diluted. Fixer was next and was a definite no-no since I have a septic system. As has been stated here many times, silver will kill the bacteria in the tank. Even if I did the steel wool treatment, which he said was quite effective, it was still no-go.
Finally we talked about the developer. He had a concern dumping this down the drain, but it was not the chemical per se. This he said biodegraded quickly and would not be seen in the water supply (aqua-firs). He was concerned that there was silver in the developer, a by-product of the development process. He said that he has a long-standing debate with his neighbor, an avid photographer, on this matter. He admitted that his neighbor has been dumping the developer down the drain for years and has not had a problem.
To be a bit more scientific on this, I said that I would look into the cost of getting the silver tested in my developer. If reasonable, I will assemble two samples. One will be 500ml of XTOL 1+1 after developing a roll of 120 film (Plus-X in my case). Second sample will be Dektol after a week's worth of prints. After I get the results we can then calculate the concentration of silver in the tank, Assume 5 rolls/week (2.5L XTOL 1+1) and 1/2 gal Dektol / week and account for my getting the tank pumped every 3 years and get a maximum silver concentration. He can then find out what the effect will be. I suspect the silver concentration in the developer will be quite low and this would be a non-issue, but would be interesting to see for peace of mind. Anyone have any idea what the PPM of silver in the developer would be after developing a roll of film?
Regards,
Jim