Re: [Leica] Darkrooms and Septic Systems

["Michael D. Turner" <mike@lcl-imaging.com>]

Hi Leon-
I might also point out that ammonium thiosulfate is a very rich nutrient
for bacteria. As a former lab owner, I was constantly struggling with
biological activity in wash tanks immediately following fix tanks. So
post-silver recovery fixer might be a boost for your flora(any septic tank
experts out there to comment on that?).

Also, leave the hardener out of your fixer if you only use modern films
like Tmax whose emulsions are prehardened. It's unnecessary, and you
probably don't need boric acid in your septic tank.

- -Mike
At 09:17 PM 10/22/1998 EDT, LP6@aol.com, you wrote...
>
>Re:  Darkroom Silver and Acid Effluent into Septic Systems: (?)
>
>Joe Stephenson and Bill Franson have kindly informed me over the LUG that it
>is the used acid fixer that contains the silver and that this can be
retrieved
>with a Rotex Silver Recovery Kit.  So much for the metal!
>
>They also inform me that the enemy of the bacterial flora in the septic
system
>is acid primarily and that this can be neutralized by allowing the mixture of
>developer and stop bath to stand before discarding into the system.  
>
>Since sodium bicarbonate (backing soda) is often added to septic systems as a
>routine maintenance measure, I suppose extra bicarbonate might assure further
>acid dilution originating from my darkroom operations?  So much for the acid!
>
>Have I got my facts straight?  What have we left out?
>
>In conclusion, I'm surprised that LUGites haven't encountered this problem in
>greater numbers than the response to my septic quiery on the LUG suggests?
>Maybe its the more strict Massachusetts (near Nashua, NH) building codes vs.
>the more relaxed codes elsewhere?  Any other thoughts?
>
>Leon
>LP6@aol.com
>
>
>
Mike

"Sing whatever is well made..."
- -W. B. Yeats