Darkroom Chemicals and Septic Systems

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Does anyone have any information on the "do's and don'ts" of disposing darkroom chemicals (black and white...dev, stop, fix, selenium, etc.) down a septic system? I recall reading about this somewhere before, but I can't seem to remember where. (Perhaps an old issue of View Camera?) I have a friend who is building a large darkroom capable of producing 30x40 inch archival fiber-base black and white prints, so chemical disposal is going to be a primary concern. Any comments? Thanks in advance. :)

-- Adam D. DeKraker (adam.dekraker@wmich.edu), July 29, 1999



I know there was a thread on this at photo.net. Worth a search there (http://photo.net/bboard/q-and-a-fetch-msg.tcl?msg_id=000DSx, http://photo.net/bboard/q-and-a-fetch-msg.tcl?msg_id=0003Zb). There is also some info I found at the Kodak website. The tricky one in the dev/stop/fix is the fix which has dissolved silver. A muncipal waste system is supposeed to treat and remove the silver, but with seeptic tanks, thats not an option. The most convenient option is perhaps to use a silver retrieval kit (I don't think they are too frightfully expensive). I've also heard that once you mix all three together, it makes a good fertilizer! Selenium is a heavy metal and we need to be responsible about how we discharge this into the environment. The best option is perhaps to work it to exhaustion. So wait till you have a set of prints to tone. To be on the safe side, run a few work prints through it at the end even after you've exhausted capacity. Please also bear in mind that this is based on the information I have looked for and come across. Please cross check everything. Hope this helps.


-- N Dhananjay (ndhanu@umich.edu), July 30, 1999.

Have you taken a look at Kodak's technical publication J-300, Environmental Guidelines for Amateur Photographers?

-- M Heal (kmheal@audiolab.uwaterloo.ca), July 30, 1999.

Hi, Just an addendum to the above comment about Selenium Toner. In trying to introduce as little of this hazardous material into the environment, I have developed my own "method" of use and disposal which greatly reduces waste. Common practice (the one espoused by Ansel Adams) is to mix the selenium toner with a hypo-clearing solution of some kind. This, however, requires that the bath be discarded when the hypo-clear is exhausted and/or too old (which is typically 24 hours!). Instead of this procedure, I transfer prints from the second fixing bath directly into a selenium toning bath mixed with water only, and from there into a normal hypo-clearing soution. This does add one step, but allows the selenium toner to be saved and reused for long periods of time. Therein lies the key to disposing of as little selenium as possible. I have found that by mixing a solution of Kodak Selenium Toner about 1:9 and replenishing it with undiluted toning solution from the bottle whenever toning times become too long, that I can use the same toning bath for months, possibly years, without discarding. The problem of fixer carry-over seems to solve itself in that a fine black precipitate forms (which I am guessing is formed from selenium attaching itself to the dissolved silver compounds in the carried-over fixer) which can easily be filtered out using coffee filters or the like whenever necessary and placed in a container for appropriate disposal later. I have one gallon of such solution that I have been using for significantly longer than one year without discarding and it seems to work just fine. I have toned literally hundreds of prints with it, replenishing "by feel" to achieve comfortable toning times by adding a few ounces of the concentrated stock solution whenever the toning times get too long. I archivally process all prints, and after toning and washing they pass all the standard tests for residual silver compounds and fixer. I am a little concerned that some compounds may be building up in the toning bath that might have an effect on the longevity of prints, but so far, I have observed no negative affects whatsoever. I only discard the solution when the sludging problem becomes too excessive, and then only after I have worked the solution to exhaustion, i .e. when toning times are really way to long for comfort. Then the solution goes into old plastic milk jugs to await the hazardous waste pickup which takes place only once a year in my neck of the woods. This is possibly a viable method for reducing selenium effluent from our typically low-volume (when compared with photo labs) darkrooms. Any reactions and thoughts from the LF community here?? Regards, ;^D)

-- Doremus Scudder (ScudderLandreth@compuserve.com), August 01, 1999.

Concerning septic tanks specifically, I've read that it is OK to dump any photographic chemistry down the drain as long as they are thoroughly oxygenated. To do this you put chemistry in open troughs, stir every now and then and leave for over 24 hours. Supposedly it is then septic-safe. According to the spec. sheets that you can get from any chemical manufacturers as required by the EPA, Indicator Stop Bath is the most toxic and the most injuious to human health, both through contact and from breathing. Can't say I've tried this method and I can't say I even want to because I have already dealt with a septic crash brought on by non-photographic factors, but this is what I have heard.

A man who delivered a Port-A-Potty to my property for use during a party told me that his company would install a tank for me that would collect all effluent from my darkroom and haul it. How much? No clue, we didn't get that far. But it wouldn't be real cheap because they treat it as toxic waste, as required. It also would never handle an archival wash. That's all I know. Septic is a problem for photographers.

-- Rob Tucher (rtphotodoc@juno.com), August 05, 1999.

I was planning a darkroom in my new house (on a septic system) until I read this. Are there any other solutions?

Information on Septic System Disposal

Kodak does not recommend the use of septic systems for disposal of photographic processing chemicals because the disposal of photographic processing solutions may affect the proper operations of the septic system. Septic tank systems are used for the disposal of domestic waste, primarily in areas where municipal sewers are unavailable. Therefore, they are engineered for that stated purpose, and operate with anaerobic (in the absence of oxygen) biological action to accomplish the treatment of discharged wastes.

Discharge from septic tank systems may adversely affect sources of underground drinking water. Regulations have been established by the federal Environmental Protection Agency (EPA) and many states to minimize that potential. Your U.S. EPA Regional or State Administrator of the Underground Injection Control (UIC) Program and/or local health department should be contacted to determine whether the discharge of photoprocessing effluents into your septic system is allowable. Due to increased enforcement on disposal to Class V injection wells which include septic tanks, thorough inquiry on the regional, state or local compliance requirements is advised.

Other disposal options for your photoprocessing waste include household hazardous waste collection facilities in your area, discharge to a nearby municipal wastewater treatment plant, or a licensed chemical hauler. Household hazardous waste collection facilities are options only if you generate less than 100 kilograms (220 pounds) of hazardous waste per calendar month.

Customers who use KODAK photographic chemicals can also arrange to have their wastes properly treated and disposed of by using the KODAK RELAY Program

-- Stewart Ethier (sethier@goez.net), May 11, 2002.

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