Septic system water filter

I am starting to design a darkroom in a spare bedroom. The home has a septic system. I was looking to design a chemical filtration system that would remove the chemicals from the water that is going to the septic system. I am going to print traditional silver prints along with alternative processed prints. Is there a system or components that you can buy that is already setup for this situation? Any advise or comments would sure be appreciated. Thanks in advance.

Steven

I wouldn't see how any filter would work. Filters filter particulates. The chemistry is in solution. Besides, the standard developers and fixers are for the large part biodegradeable. And stop bath is about the same as vinegar. I have a septic tank too. I wouldn't worry, unless you're going into production or commercial.

Hi,

If you really want to clean your water, there is still some very small reverse osmosis system. But pay attention that you will still have a concentrate of waste that you will have to do something with.

If I only have a small or occasional amount of used, non-fixer chemicals, I just flush them. If I'm working in the darkroom a lot or in the days I did color I collect used chemicals in 5 gallon buckets and take them to the local wastewater plant where they let me dump it in the untreated ponds free of charge. A small amount is not going to hurt your septic. The problem comes in determining when a small amount becomes a big amount. I like to err on the side of caution. If I'm producing gallons of used chemical waste per week, I take it to the plant. If its just a few liters, I flush. What you also want to watch is your water usage, because overuse will flush solids into your field and you'll be buying a new septic system. My wash water goes directly outside so I don't worry about that.

Unless you plan to process an extremely high volume of film and prints, you should have no problem with your waste water and it will not affect on your septic tank. You just need to treat your system regularly with yeast packets to keep the tank working, which you should do anyhow. Most photographic chemicals tend to neutralize each other and there is not enough silver or other byproducts to cause any problem with ordinary home use.

Get a copy of Kodak publication J-300, "Environmental Guidelines for Amateur Photographers". You will find the answers that you are looking for.

jk0592 said:

Get a copy of Kodak publication J-300, "Environmental Guidelines for Amateur Photographers". You will find the answers that you are looking for.

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Wow! What quick responses to my post this morning. Thank you all so much for your input. I just joined this forum this morning and I can already see that there are some great people here. I just noticed that members can post some of their images. I will try and get a few uploaded soon. It is always great to see what people are shooting. Thanks again.

jk0592 said:

Get a copy of Kodak publication J-300, "Environmental Guidelines for Amateur Photographers".

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For convenience, here's the link...

Environmental Guidelines for Amateur Photographers
Publication #J-300, Eastman Kodak Company, 1999

Ken

I had the same problem and so built the drain from the darkroom to a soakaway. You don't want to put chemicals into your septic tank.

I've had the luck to enjoy a career in scientific research and analytical chemistry before taking up photography full time. One of my challenges was teaching chemists at the local water supply and sewerage department about photographic chemicals in the effluent they had to treat. The "no fixer down the drain" anxiety comes up about a hundred times a year and has been doing so for at least half a century.

The following does not apply to industrial scale photo materials manufacturing or a major processing lab, only households connected to a sewer line or a proper septic system:

Developers are mild reducing agents that oxidise rapidly to inert components. The BOD (Biological Oxygen Demand) challenge offered by a home darkroom is much smaller than the BOD from a dishwasher, in-sink garbage disposal unit, or a toilet.

Stop bath is a very mild acid that has no measurable effects on highly buffered systems like septic tanks or sewerage treatment plants.

In moderate quantities (ounces, not tons) silver tetrathionate and similar compounds which characterise used fixer don't harm sewerage treatment systems or septic systems. The silver very quickly gets converted to silver sulphide in the presence of the free sulphide ion (smells like rotten eggs!). Silver sulphide is geologically stable and biologically inert and has one of the lowest solubility products known in chemistry. The stability and inertness of silver sulphide is the key to the remarkable archival properties of sepia toned photographs.

Do your own calculations. Just estimate your yearly use of silver from your photographic materials consumption, allow 1 milligram per square inch, and divide this by your yearly water consumption from the water meter. I bet it's in the parts per billion range where no conceivable biological effect can be credibly imagined.

In my professional career I have inspected home septic systems that have been "ruined" by people doing photographic processing. In every case it has been the fault of extravagant archival washing at the end of the processing sequence. Sending maybe two or three hundred extra litres of water a day into a system for days on end dilutes the activated sludge and slows the biological reactions that process and neutralise the usual septic stream. The extra water can also overwhelm the soakage pit or trench that lies at the end of the septic system and deliver a squelchy smelly mess.

The world being what it is many local effluent standards are written by lawyers and/or accountants who don't know a dot of chemistry but know about culpability and lawsuits. Even Kodak publication J-300 which is the de facto last word on "fixer down the drain" is more about avoiding potential disputes and less about the niceties of chemistry. If you choose check with local authorities, ask their permission for what you intend to do, and they say no, I guess you have to comply.

Maris said:

Even Kodak publication J-300 which is the de facto last word on "fixer down the drain" is more about avoiding potential disputes and less about the niceties of chemistry.

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That's my take as well, based on personal experience. I simply posted the link for reference.

I have had a small, but nicely equipped, home darkroom in the same location now for 24 years. It's on a septic system originally installed in 1978. Using standard black-and-white processing chemicals that all eventually go down the drain, I have never had a single issue in almost a quarter-century of light hobbyist-level usage.

I do suppose YMMV, but mine never has.

Ken

Additives like yeast will do no harm but are entirely unnecessary for a healthy septic system.

Even if the used fixer becomes harmless once dumped, its irresponsible to dump non-renewable, recoverable resources such as silver down the drain. Much better to recover the silver or donate used fixer to a photo lab who will recover it.

Wayne said:

Even if the used fixer becomes harmless once dumped, its irresponsible to dump non-renewable, recoverable resources such as silver down the drain. Much better to recover the silver or donate used fixer to a photo lab who will recover it.

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Where do you think the silver came from in the first place?

Ken

The silver came from mines, like the one they are trying to build in my backyard to bring more out of the ground. Why, do you think it came from septic field deposits, and that those are some sort of mineable resource? You seem to be implying that wasting silver is just a natural process, and that's a pretty thin tightrope to walk.

Tom1956 said:

I wouldn't see how any filter would work. Filters filter particulates. The chemistry is in solution. Besides, the standard developers and fixers are for the large part biodegradeable. And stop bath is about the same as vinegar. I have a septic tank too. I wouldn't worry, unless you're going into production or commercial.

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Typically selective means that not (only) work mechanically but chemically as ion-exchangers and activated carbon are called filters too.

jk0592 said:

Get a copy of Kodak publication J-300, "Environmental Guidelines for Amateur Photographers". You will find the answers that you are looking for.

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this publication is 20+ years old
kodak has recanted on their stance and says in a newer publication
not to dump any fix &c down the drain.

it is best to lrern what is and is not allowed where you live
so you don't foul your waste system.
if you are interested in removing the Ag from your fix feel free to contact me
i Will be happy to help you with an affordable recoverysystem.

have fun
john

Wayne said:

The silver came from mines, like the one they are trying to build in my backyard to bring more out of the ground. Why, do you think it came from septic field deposits, and that those are some sort of mineable resource? You seem to be implying that wasting silver is just a natural process, and that's a pretty thin tightrope to walk.

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Saying that silver, or any other mineral resource, came from a mine is akin to saying that steaks come from grocery stores. They do, but only in the most superficial and misleading sense.

Your silver was not created by the mine. It was likely created hundreds of thousands of years or more before modern humans even existed, possibly as part of a hydrothermal depositional sequence of related elements and compounds. Depending on your local geology this could have occurred as super-heated, mineral-laden fluids rose up under natural pressure through cracks in the earth caused by tectonic activity. As those fluids cooled they precipitated out into various mineral suites within those cracks, which we call veins, some of which included silver and/or silver compounds. Gold is often also part of that particular sequence.

It's possible that the silver in your backyard has been there since before mankind ever evolved as a viable species. Mining is the process by which that element is concentrated to a useful level for our needs and purposes. Once our purpose is served, that silver will be returned to the earth's structure from whence it originally came, to again lie quietly while awaiting its future fate.

The concept of waste is a human economic one. It's not a natural process. Waste is the economic process whereby the cost to concentrate (mine) a resource exceeds the value derived from the subsequent use of that concentrate to generate value. If you pay $100 to concentrate an ounce of silver, but can subsequently only generate $50 in value from use of that concentrated silver, you have "wasted" $50 of your original value. That may be an important distinction to you, but it's not a distinction at all to Nature.

But the silver atoms themselves are unaffected. Whether they exist in their originally precipitated deposit in the earth, or are hanging on your wall as a photographic print, or have been re-deposited back into the earth in your leech field as harmless silver sulfide, or were more likely pumped from your septic tank and transported and re-deposited back into the earth somewhere else, makes little difference. They have not been lost. They have not been wasted. They have not been transmuted into another element. They still exist, and could again be recovered from leech fields if the future economics to do so made sense.

Ken

That took a whole lot of words to state the extremely obvious Ken. Silver comes from the earth, not mines or jewelry stores, how true. I think I remember something about that in my undergraduate work in geology.

You keyed in on the wrong word, you should have paid more attention to "irresponsible" instead of "waste". A lot of fuel, energy and most likely pollution and its cleanup paid by taxpayers (if cleaned up at all) went into taking that silver out of the ground and processing it, and manufacturing products and moving them to market. Dumping it back into/onto the ground where it has nearly zero chance of ever becoming economically feasible to mine it is irresponsible, just like throwing your tin, aluminum and plastic in the back yard is irresponsible. You have a very narrow and producer-centric view of the economics involved-we all pay the cost.

Wayne said:

That took a whole lot of words to state the extremely obvious...

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Sometimes that's necessary for those who may be missing the extremely obvious...

If you have any background at all in the Geological Sciences then you should already understand the effect that scale has on the oft-repeated hysteria that to dump a liter of used fixer into a septic tank once every two or three months is tantamount to creating a new Superfund site. A geologist understands scale. Both in regard to volume, and especially in regard to time. Applying arguments of scale to such claims goes with the territory. Or should.

If your point is rather to assert an economic argument that wasting money is bad after the initial outlay to concentrate the resource, we all know that. But that's not a resource argument. It's an economic one. And a very, very good economic one. Everyone should be using John's silver magnets. But not to save the earth from silver down the drain. Do it to save yourself the money down the drain.

As far as the silver itself goes, you can recover silver from your fixer until the cows come home, but at some point the cycle will terminate. One of your as yet unborn great-great-grandchildren will be cleaning out their attic, look at your old silver photo, not remember anything about it or you, and toss it. Where it will then be picked up by the disposal company, put on a truck or train, transported to an approved landfill, and... be returned to the earth from whence it came.

And there is nothing you can do about that. You're going to live 50-100 years. The earth has been around for 4,540,000,000 years. Google-up The Pale Blue Dot. We are for all practical purposes a closed system, whether you want to acknowledge that or not.

Given all of this, here's a question for you...

What exactly, at the most fundamental level, is the crime against Nature in removing silver from one hole in your backyard (a mine), then depositing it into another hole in your backyard (a septic tank)?

Ken