After my blog post yesterday about ways to minimize or avoid acrylic paint residue down the drain, there were some differing opinions in the comments on whether rinsing tools used with acrylic paint in home drains is or isn’t a problem.
So, to try and get to the answer, I did some research online on disposing of acrylic paint down the drain. Poke around long enough and you’ll find opinions going every direction. It is a topic with very strong opinions on each side. The general consensus seems to be that sending a lot of acrylic paint down the drain is a bad idea, but that to clog your pipes, you would need to put a lot down there in a short period of time and that it would take a long time for it to build up if you only send down a very little at a time. Simple logic and knowledge of the way acrylic paint dries, would tell you though that if you were to say, dump a jar of liquid acrylic paint into your drain and walk away, you would be likely to get a clog. So it seems to be largely situational: how much paint, how long and in some cases, whether you use enough water to speed the paint out of your own pipes to go elsewhere.
There are people who say they’ve been rinsing acrylic paint down the drain for thirty years and never had a problem. I found a few who said they had done a lot of house painting and got a sudden clog and worried that it was caused by the paint, but didn’t come back to confirm that paint was the problem. I did find an article on eHow that talked about plumbing traps that are supposed to help with paint build up in drains. I guess the paint collects in the trap and you can then open up the trap and scrape it out. (Sounds like fun, huh?)
For those with septic systems like me, there is “A Homeowner’s Guide to Septic Systems” from the EPA that says not to put acrylic paint into your system because it can mess with the whole biology of how the septic system works. From what I’m reading, it is pretty clear that acrylic paint and septic systems are not a good mix.
Now if you are on public water and sewer, you might think that as long as you run the water long enough to clear the paint out of your own pipes, that there is no problem. But I have also read a few things that indicate that acrylic paint that makes its way to sewage treatment plants can cause problems there. I think the attitude of local sewer officials may vary on the subject, I suspect depending on how much of a problem they’ve found it to be at their own particular treatment plants. If you are on public water and sewer, you might want to check with the sewage disposal folks in your local area about what is OK (suggested / legal) to put down the drain in your area.
For those interested in getting rid of paint waste without putting it down the drain, check out the Waste Disposal page at the Golden Paints web site.
From everything I’m reading, it is generally considered OK to dispose of solid (dried out) acrylic paint in your regular trash disposal. (Check with your local waste management to confirm that they agree.) It is generally considered NOT OK to dispose of liquid acrylic paint in regular trash mostly because it can make a big mess for the collection folks, their trucks, etc. So if you have dried out bottles or jars of craft paint, you are probably fine throwing it out. If they are still liquid, either give them away to someone else to use or dry them out to a solid and then throw them out. Now, oil-based paints on the other hand, are considered hazardous and need to be disposed of through hazardous collection sites in your area.
This information may not definitively answer the question, but I hope that you at least find it interesting.
If you like birds, be sure to also check out VSN’s other blog, Birdseed & Binoculars.