Septic Tank and Developing Chemicals?

picker77 · Mar 10, 2009

Here's an off the wall question I've not seen anywhere: Will common darkroom chemicals hurt the happy little microbes that do the unseen dirty work in my septic tank? Not everybody that does home developing lives in town...

Photo Engineer · Mar 10, 2009

There are several threads on this subject here on APUG.

PE

trexx · Mar 10, 2009

Fixer is the only concern, as used fixer will contain the excess silver. Search the threads here for gory details.

picker77 · Mar 10, 2009

Thanks, I should have realized no developing subject, however obtuse, has remained unaddressed on APUG! Ha. I'll do some looking.

bsdunek · Mar 10, 2009

Just for the record - neither my Dad or I have had any trouble with septic tanks and B&W photo chemicals. Really, the amount you would put down the drain in a home darkroom compared to all the water and waste, is really tiny. If you had a commercial operation, that might be a different story.

Christopher Walrath · Mar 10, 2009

To each his own on this one, I guess. I don't have septic. However, I have always heard absolutely not. However there are those exceptions to any rule.

removed account4 · Mar 10, 2009

usually towns and cities have a household waste collection day
so you can dispose of your spent fixer ...

ntenny · Mar 10, 2009

I wish I knew more about the toxicity of developing agents generally. I don't want to knock out the septic tank, of course, but in addition I'd like to avoid turning the leach field into a Superfund site...

Keeping silver out of the tank (and the environment generally) seems to be a no-brainer, but what about developing chemicals? Metol and hydroquinone have lurid toxicity warnings, and in what may be excessive caution I take anything involving those to the hazmat dump, along with used fixer---but phenidone is used in such small quantities that I suspect it's probably OK. (I think the safety of vitamin C and instant coffee goes without saying.)

But it's hard to get a sense of perspective about this stuff. People talk about photo chemicals as if they were made of live anthrax and plutonium, but that has a lot to do with reasonable caution about direct contact over the long term.

It's worth remembering that discarded developing agents are going to oxidise---the important questions are (1) what are they going to oxidise into?, and (2) what's going to get reduced for them to do it?, neither of which is directly connected to the hazardosity of the original chemicals. But I don't have anything like the chemistry chops to figure out the answers.

-NT

picker77 · Mar 10, 2009

I guess the concentration and frequency would have at least something to do with it. I suppose i put anywhere from 50 to 100+ gallons of water into a 500 gallon septic tank daily, and I'd be dumping a few ounces of diluted photo chemicals once every week or two. Hard to figure out if it's something I should worry about. I could take it to the landfill, and it would be soaked into the earth further from my house and closer to somebody else's house, but don't know if that even makes sense for the volume I'd do. All I know for sure is I hope the EPA doesn't get interested in photography--God only knows how many exams and licenses we'd have to buy and renew.

resummerfield · Mar 10, 2009

bsdunek said:
Just for the record - neither my Dad or I have had any trouble with septic tanks and B&W photo chemicals. Really, the amount you would put down the drain in a home darkroom compared to all the water and waste, is really tiny. If you had a commercial operation, that might be a different story.

That's my experience, too. In almost 20 years of flushing several gallons weekly, I've never had a problem.

CBG · Mar 10, 2009

ntenny said:
I wish I knew more about the toxicity of developing agents generally. I don't want to knock out the septic tank, of course, but in addition I'd like to avoid turning the leach field into a Superfund site...

Should you want a sane view, "The Darkroom Cookbook" by Steve Anchell, has a balanced view of the relative hazards of the various substances one deals with. Should you want the hysterical version, out on the net, you can find any cockamamie idiocy you want.

ntenny said:
but what about developing chemicals? Metol and hydroquinone have lurid toxicity warnings, and in what may be excessive caution I take anything involving those to the hazmat dump, along with used fixer---but phenidone is used in such small quantities that I suspect it's probably OK. (I think the safety of vitamin C and instant coffee goes without saying.)

See above.

ntenny said:
But it's hard to get a sense of perspective about this stuff. People talk about photo chemicals as if they were made of live anthrax and plutonium, but that has a lot to do with reasonable caution about direct contact over the long term.

Everyone Panic!!!

DWThomas · Mar 10, 2009

Having seen household cleaning chemicals bleach color out of a laminate countertop or erode the enamel off a bathtub, I suspect most photo chemicals don't represent much of a threat to a septic tank when discarded in home darkroom quantities and dilutions. Purely by an accident of pipe routing, my darkroom wastewater goes to a "French drain" separate from the septic system, so I can't actually verify my speculation.

DaveT

Aurum · Mar 10, 2009

Compared to what you flush daily that is your own *personal* pollution production, a couple of films worth of dilute chems is not something to worry about.

IMHO

ntenny · Mar 10, 2009

Aurum said:
Compared to what you flush daily that is your own *personal* pollution production, a couple of films worth of dilute chems is not something to worry about.

But the whole point of septic systems is that they're populated with bacteria that live to biodegrade your personal pollution production. I'm not sure the microbe has yet evolved that specialises in digesting metol.

I did learn recently that ammonium thiosulfate is actually a fairly common ingredient in fertiliser, which would suggest that *unspent* rapid fixers aren't actually a particularly scary pollutant. I don't know if they acquire anything worrisome other than silver in the course of being used, though.

I figure, given that my town has free hazmat disposal and I'm supposed to take used batteries there occasionally anyway, I might as well err on the side of caution and give them any chemicals about which I have doubts.

-NT

removed account4 · Mar 10, 2009

when i lived near boston the storm drains used to have
stencils of fish on them and the label that read " goes to the cove "
or something like that to remind people that they are not alone here ...
and not to use the storm drains as their own personal "flush-away/ waste hauler"
every once in a while i would see a guy from the local machine shop pouring
glow in the dark green liquids down the storm drain in front of his shop, knowing
full well where his nasty fluids were going to end up.

i am always amazed at how most people here refuse to take responsibility for their use of photochemicals ...
it is always someone else's responsibility to do the right thing, or boy the Ewaste or
my household waste is so much worse than my darkroom waste ...

not much different than the guy at the machine shop i suppose ...

jgcull · Mar 10, 2009

>>>To each his own on this one, I guess. I don't have septic. However, I have always heard absolutely not.<<<

Absolutely not, what?

>>>Will common darkroom chemicals hurt the happy little microbes<<<

Absolutely not hurt the happy little microbes, or absolutely don't let chemicals into the septic?

WarEaglemtn · Mar 10, 2009

Eastman Kodak has a number of studies on this and have said normal darkroom chemistry won't harm a septic system in amounts most home darkrooms put out. Silver recovery for the fixer is a normal procedure. Then mix the developers with the fixer which usually neutralizes both the acid and basic solutions.

Selenium toner is a different animal. If you mix it with fixer you dump it and hope. Very dilute solutions may not do anything. I mix the selenium separate and after use I put it into a container with an open top, mesh screen over it, and let it evaporate outside(summer) or a basement room(winter) and later toss the container in the hazardous waste disposal container set up once a year in our nearby town. Same thing with the potassium cyanide and the nasty sensitizer for carbon printing. Just don't want stuff this bad in my septic even if it is 'safe'.

Check with Eastman Kodak as they still have the publications with information that should answer your questions to your satisfaction.

Septic Tank and Developing Chemicals?

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