Mike Simpson asks:
I have a question about what you feel is the hazardous effect, if any, of disposing watercolor waste water onto the ground or plants, etc.?
Mike,
I guess the best answer I can give you is to bring along a big container to dump the wastewater in and then dump out the water responsibly when you get back home or back to your hotel.
I guess the best answer I can give you is to bring along a big container to dump the wastewater in and then dump out the water responsibly when you get back home or back to your hotel.
Although some pigments such as titanium white are relatively inert in watercolor our gouache, it's hard to know what hazardous materials might be in an actual jar of wastewater. If you use cadmiums or cobalts, etc., there are going to be some toxins in the mix.
Some pigments can also stain a sidewalk, stone, or a ground surface, and that's not good. And appearances matter. Even if you know what you're dumping is innocuous, it may not look like that to someone walking by, or someone organizing the event. One artist in a group who accidentally drops their palette or dumps their wastewater in a sensitive location can wreck it for every other painter who comes later.
Some pigments can also stain a sidewalk, stone, or a ground surface, and that's not good. And appearances matter. Even if you know what you're dumping is innocuous, it may not look like that to someone walking by, or someone organizing the event. One artist in a group who accidentally drops their palette or dumps their wastewater in a sensitive location can wreck it for every other painter who comes later.
Also, some institutions such as colleges have to follow very strict OSHA rules. They get in major trouble unless every artist follows very strict clean-up practices, which involves designated buckets for wastewater. All this is even more important for oil painters who deal with solvents. So it's a good idea to ask around to find out what's OK.
Please be sure to read the comments, which has some expert insights about what happens to toxins after they enter the waste stream.
------
A few months ago, I asked around at my local municipal orgs about this very question, and got a variety of answers on this. One group thought it was fine to dump watercolor "rinsate" (marvelous word) down the drain. The sewage folks were less happy with that idea, and suggested that one 1) let the old water sit for the pigment particles to settle out; 2) pour off the mostly clean water; and 3) bind the remaining, pigment-heavy water with something you can send to the landfill. Non-clumping cat litter, drywall joint mix, or concrete were all options for the binding. Basically, you want something that won't leach.
ReplyDeleteI should add to my previous reply — no one was completely certain about the question. Oil paints and solvents have regulations one can refer to. Water media, apparently, do not.
ReplyDeleteWm, what a great, complete, answer. ^^^^
ReplyDeleteFortunately were we live (Montreal) we have a recycling/disposal center. Like a very clean city dump with everything organised by material. Train car for metal, wood, plastic, etc.
I collect the sediment, by pouring off the solvent for reuse. When the sediment jar get's full I can take the whole jar to our eco-center and leave it the paints and solvents collection area for 'safe disposal'. I'm assuming the authorities do the right thing with it :) ~m
I don't oil paint that much, and I don't use a lot of solvent (only for cleanup, not for painting), so it can take years to fill a waste jar.
Wm and Marc, thanks for explaining the procedures you use. Honestly I was a little unsure what's the proper way to deal with the stuff when you get home, but what you both say makes sense.
ReplyDeleteThe world is a funny place. Earth was always the medium by which certain metals were recycled into their component parts and turned into soil. Earthworms and other microorganisms did this work. The ocean, and our waterways were never meant to be the 'filters" or "cleansers" of harmful materials. The earth itself was meant to be the filter. It is the biofilter. Water was the carrier that moved materials around, but there is nothing in water that does the conversion job. Water is the universal solvent. The earth's soil is the cleanser and converter.
ReplyDeleteIn fact, earthworms are effective at taking heavy metals like Cadmium and Zinc and pooping out the ready-to-compost parts, while retaining the dangerous parts. I am not a scientist, and I read an article about the role earthworms have to play many years ago - cannot find it now. But this article kinda talks about this process: http://www.mining.com/remediating-heavy-metals-using-a-worm-compost/ and there is an excellent book called "Teaming with Microbes" that goes into more detail.
None of this offers a practical solution for that beautiful word Wm used, "rinsate." In a crowded, chemical world, it is a difficult problem.
Although I do artwork and play guitar professionally (I get paid)... my day job is a chemist... I worked a year at a waste treatment center and for many years ran waste water quality control analysis... bottom line: I try to avoid the heavy metals as they don't go away... however, most of the water treatment is carried out by bacteria digesting organic wastes... so... although I like Cad red... I don't much use it opt for the synthetic organic analogs such as Azo dyes... which bacteria can chew to pieces (there won't be that much CO2)... also Indian Yellow breaks down and leaves behind Magnesium which is already in water...
ReplyDeleteThanks Arturo and Susan for sharing your expertise about what happens with toxins after they enter the waste stream.
ReplyDeleteOver on Facebook, Mary Mulvihill says: "I don't send anything down the drain. For watercolor and acrylic wastewater I have a five gallon bucket that came with a lid. I keep it outdoors where I allow the water to evaporate. The sediment settles on the bottom. So far, there are several inches of sediment at the bottom. It's five gallons because on a long painting day I can empty my rinsing containers many times. Someday, I'll snap the lid on it, label the contents and turn it in at a toxic disposal event. I do the same with solvent from oil painting except I use a jar with a lid. I pour the clean solvent off after the paint sediment has settled to the bottom. When the sediment has reached a level that makes the jar "too small" to use, I screw the lid on, label it and take it to a toxic disposal event. I've explained to the workers at the event what I have, they have been fine with it and told me the jar will go into large drums of paint residue that they then know how to dispose of." Thanks, Mary!
ReplyDeleteI'm surprised no one recycles their waste pigments into gray paint! Seems especially easy to do with watercolor waste.
ReplyDeleteI can't believe I never thought of this!
DeleteWith oils I've been using the same water filter jug, with the top half filled with sand, to dispose of my turpentine. The 'filtered' turps I get out of the bottom is slightly yellowed but fine for cleaning brushes and can be used over and over again. I buy in new clean turps for mixing with medium, but with this method I've never had to dispose of any turps at all - that's no advice for water mediums, but it's how I solved my worries about the volume of turps I was using and how to dispose of it.
ReplyDeleteI pour watercolor, gouache, acrylic water through a paper coffee filter. Any fine mesh will also do a decent job: paint strainers from paint and home improvement stores, even the foot from women's nylons as well as other fabrics. The simpler it is to do the more likely artists are to do it.
ReplyDeleteThere's an artist on YouTube, John Muir Laws, a naturalist who paints outdoors. He uses a cut off cotton sock tube on his wrist to wipe off the watercolor from his waterbrush. This way, there's no spill on the earth.
ReplyDeleteThanks for your suggestions, and for those of the various respondents. An additional suggestion for oil paints: There is a brand called Silicoil, which consists of an aluminum coil in a widemouth jar of silicon-based "solvent" that, as one strokes a brush across the coil, causes the paint and turpentine, etc., to slide off the brush and wind up in the bottom of the jar. Gradually it fills the jar, at which point you pour off the liquid, scrape the guck out for hazardous waste disposal, and presumably add some fresh liquid. I've used it, and it works well for me.
ReplyDeleteThis comment has been removed by the author.
ReplyDelete